WorldWideScience

Sample records for natural background ionising

  1. Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

    International Nuclear Information System (INIS)

    Little, Mark P; Wakeford, Richard; Kendall, Gerald M

    2009-01-01

    The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

  2. Evaluation of Background Ionising Radiation Levels in Benue State ...

    African Journals Online (AJOL)

    Evaluation of Background Ionising Radiation Levels in Benue State University Teaching Hospital Makurdi North Central Nigeria. H Mohammad, J T Iortile, J E Ekediwe, L Alumuku, E A Okon, D M Chia, E Ejeh, F U Ugbo ...

  3. The natural radiation background

    International Nuclear Information System (INIS)

    Duggleby, J.C.

    1982-01-01

    The components of the natural background radiation and their variations are described. Cosmic radiation is a major contributor to the external dose to the human body whilst naturally-occurring radionuclides of primordial and cosmogenic origin contribute to both the external and internal doses, with the primordial radionuclides being the major contributor in both cases. Man has continually modified the radiation dose to which he has been subjected. The two traditional methods of measuring background radiation, ionisation chamber measurements and scintillation counting, are looked at and the prospect of using thermoluminescent dosimetry is considered

  4. Proceedings. Protection of the natural environment. International symposium on ionising radiation

    International Nuclear Information System (INIS)

    Amiro, B.; Johansson, Gunnar; Larsson, Carl-Magnus; Luening, M.

    1996-01-01

    The symposium was organised jointly by the Swedish Radiation Protection Institute and the Atomic Energy Control Board of Canada. The programme was organised around six major topics: Biological effects of ionising radiation; Ecological effects of ionising radiation; Behaviour and transport of radionuclides in the natural environment; Criteria for environmental protection; Assessment methodology; and Social and economic aspects. All 86 contributions (excluding the opening addresses) have been separately indexed

  5. Estimating COCOM Natural Background Dormancy

    Science.gov (United States)

    2015-04-01

    ER D C/ CR RE L TR -1 5- 7 Phase IV Army Camouflage Development Effort Estimating COCOM Natural Background Dormancy Co ld R eg io ns...ERDC/CRREL TR-15-7 April 2015 Estimating COCOM Natural Background Dormancy Alexis L. Coplin and Charles C. Ryerson Cold Regions Research and...phenological stage, controls color and tex- ture of natural vegetation as it cycles through greenup, verdancy, senes- cence, and dormancy . For the Army

  6. Teaching about Natural Background Radiation

    Science.gov (United States)

    Al-Azmi, Darwish; Karunakara, N.; Mustapha, Amidu O.

    2013-01-01

    Ambient gamma dose rates in air were measured at different locations (indoors and outdoors) to demonstrate the ubiquitous nature of natural background radiation in the environment and to show that levels vary from one location to another, depending on the underlying geology. The effect of a lead shield on a gamma radiation field was also…

  7. 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)

  8. Measurement of natural background radiation intensity on a train.

    Science.gov (United States)

    Chen, Yen-Fu; Lin, Jeng-Wei; Sheu, Rong-Jiun; Lin, Uei-Tyng; Jiang, Shiang-Huei

    2011-03-01

    This work aims to measure different components of natural background radiation on a train. A radiation measurement system consisting of four types of radiation detectors, namely, a Berkeley Lab cosmic-ray detector, moderated (3)He detector, high-pressure ionisation chamber and NaI(Tl) spectrometer, associated with a global positioning system unit was established for this purpose. For the commissioning of the system, a test measurement on a train along the railway around the northern Taiwan coast from Hsinchu to Hualien with a distance of ∼ 275 km was carried out. No significant variation of the intensities of the different components of natural background radiation was observed, except when the train went underground or in the tunnels. The average external dose rate received by the crew of the train was estimated to be 62 nSv h(-1).

  9. Measurement of natural background radiation intensity on a train

    International Nuclear Information System (INIS)

    Chen, Y. F.; Lin, J. W.; Sheu, R. J.; Lin, U. T.; Jiang, S. H.

    2011-01-01

    This work aims to measure different components of natural background radiation on a train. A radiation measurement system consisting of four types of radiation detectors, namely, a Berkeley Lab cosmic-ray detector, moderated 3He detector, high pressure ionisation chamber and NaI(Tl) spectrometer, associated with a global positioning system unit was established for this purpose. For the commissioning of the system, a test measurement on a train along the railway around the northern Taiwan coast from Hsinchu to Hualien with a distance of ∼275 km was carried out. No significant variation of the intensities of the different components of natural background radiation was observed, except when the train went underground or in the tunnels. The average external dose rate received by the crew of the train was estimated to be 62 nSv h -1 . (authors)

  10. Ambient Background Particulate Compositiion Outdoor Natural Background: Interferents/Clutter

    Science.gov (United States)

    2011-08-01

    current generation of point and standoff BW detectors. Data were extracted from 2 long- term environmental background studies, which provide the rationale...cause False Alarms by these non specific biodctectors. The response of biodetection technologies to the naturally occurring bioaerosol interferents...day, and can be affected by regional and local sources. Regional sources and most local emission sources generally become dispersed and mixed

  11. Controllable forms of natural background radiation

    International Nuclear Information System (INIS)

    1988-03-01

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

  12. 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)

  13. Speech recognition in natural background noise.

    Directory of Open Access Journals (Sweden)

    Julien Meyer

    Full Text Available In the real world, human speech recognition nearly always involves listening in background noise. The impact of such noise on speech signals and on intelligibility performance increases with the separation of the listener from the speaker. The present behavioral experiment provides an overview of the effects of such acoustic disturbances on speech perception in conditions approaching ecologically valid contexts. We analysed the intelligibility loss in spoken word lists with increasing listener-to-speaker distance in a typical low-level natural background noise. The noise was combined with the simple spherical amplitude attenuation due to distance, basically changing the signal-to-noise ratio (SNR. Therefore, our study draws attention to some of the most basic environmental constraints that have pervaded spoken communication throughout human history. We evaluated the ability of native French participants to recognize French monosyllabic words (spoken at 65.3 dB(A, reference at 1 meter at distances between 11 to 33 meters, which corresponded to the SNRs most revealing of the progressive effect of the selected natural noise (-8.8 dB to -18.4 dB. Our results showed that in such conditions, identity of vowels is mostly preserved, with the striking peculiarity of the absence of confusion in vowels. The results also confirmed the functional role of consonants during lexical identification. The extensive analysis of recognition scores, confusion patterns and associated acoustic cues revealed that sonorant, sibilant and burst properties were the most important parameters influencing phoneme recognition. . Altogether these analyses allowed us to extract a resistance scale from consonant recognition scores. We also identified specific perceptual consonant confusion groups depending of the place in the words (onset vs. coda. Finally our data suggested that listeners may access some acoustic cues of the CV transition, opening interesting perspectives for

  14. Ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The law covering ionising radiations in Belgium is summarised under the headings: the outline law of 19 March 1958; the General Regulation for the protection of the population and workers against the danger of ionising radiation (introduction; application; the control of classified establishments; organisation of general protection; importation, transit and distribution of radioactive substances; transport of radioactive substances; nuclear propulsion; ionising radiation in human or veterinary medicine; prohibitions and authorisations; exceptional measures; monitoring of the national territory and of the population as a whole; the approval of experts, organisations and doctors; monitoring; the public company for the management of radioactive waste and fissile materials); the law of 4 August 1955 concerning state security in the field of nuclear energy; civil responsibility; the Interministerial Commission on Nuclear Safety and State Security in the Nuclear Field; the non-proliferation of nuclear arms. (U.K.)

  15. 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

  16. Natural background radiation and population dose in China

    Energy Technology Data Exchange (ETDEWEB)

    Guangzhi, C. (Ministry of Public Health, Beijing, BJ (China)); Ziqiang, P.; Zhenyum, H.; Yin, Y.; Mingqiang, G.

    On the basis of analyzing the data for the natural background radiation level in China, the typical values for indoor and outdoor terrestrial gamma radiation and effective dose equivalents from radon and thoron daughters are recommended. The annual effective dose equivalent from natural radiation to the inhabitant is estimated to be 2.3 mSv, in which 0.54 mSv is from terrestrial gamma radiation and about 0,8 mSv is from radon and its short-lived daughters. 55 Refs.

  17. 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.

  18. 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.

  19. 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

  20. The nature of luminous Lyα emitters at z ˜ 2-3: maximal dust-poor starbursts and highly ionising AGN

    Science.gov (United States)

    Sobral, David; Matthee, Jorryt; Darvish, Behnam; Smail, Ian; Best, Philip N.; Alegre, Lara; Röttgering, Huub; Mobasher, Bahram; Stroe, Ana Paulino-Afonso Andra; Oteo, Iván

    2018-03-01

    Deep narrow-band surveys have revealed a large population of faint Lyα emitters (LAEs) in the distant Universe, but relatively little is known about the most luminous sources (L_Lyα {≳} 10^{42.7} erg s-1; L_Lyα {≳} L^*_{Lyα }). Here we present the spectroscopic follow-up of 21 luminous LAEs at z ˜ 2 - 3 found with panoramic narrow-band surveys over five independent extragalactic fields (≈4 × 106 Mpc3 surveyed at z ˜ 2.2 and z ˜ 3.1). We use WHT/ISIS, Keck/DEIMOS and VLT/X-SHOOTER to study these sources using high ionisation UV lines. Luminous LAEs at z ˜ 2-3 have blue UV slopes (β =-2.0^{+0.3}_{-0.1}), high Lyα escape fractions (50^{+20}_{-15}%) and span five orders of magnitude in UV luminosity (M_{UV}≈ -19 to -24). Many (70%) show at least one high ionisation rest-frame UV line such as CIV, NV, CIII], HEII or OIII], typically blue-shifted by ≈100 - 200 km s-1 relative to Lyα. Their Lyα profiles reveal a wide variety of shapes, including significant blue-shifted components and widths from 200 to 4000 km s-1. Overall, 60 ± 11 % appear to be AGN dominated, and at L_{Lyα }>10^{43.3} erg s-1 and/or M_{UV}starbursts. Our results show that luminous LAEs at z ˜ 2-3 are a diverse population and that 2 × L^*_{Lyα } and 2 × M_UV^* mark a sharp transition in the nature of LAEs, from star formation dominated to AGN dominated.

  1. Is natural background or radiation from nuclear power plants leukemogenic?

    International Nuclear Information System (INIS)

    Cronkite, E.P.

    1989-01-01

    The objective in this review is to provide some facts about normal hemopoietic cell proliferation relevant to leukemogenesis, physical, chemical, and biological facts about radiation effects with the hope that each person will be able to decide for themselves whether background radiation or emissions from nuclear power plants and facilities significantly add to the spontaneous leukemia incidence. 23 refs., 1 tab

  2. Impact assessment of ionising radiation in wildlife

    International Nuclear Information System (INIS)

    2001-01-01

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on ionising radiation impact to wildlife, upon which a robust assessment approach may be developed. The methodology will provide an interim approach, whilst awaiting the outcome of the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET) due to end in October 2003. The aims of the report were: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; to outline and review relevant European Directives which have impacted on the requirements to assess the impact to wildlife from ionising radiation in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach with which to assess the 'scale of risk' to wildlife from the effects of ionising radiation, with spreadsheets to support the methodology. The report describes the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on those ecosystems most likely to be impacted by the authorised discharges of radioactivity within the UK. As there is no international consensus on the approach to be taken to assess the impact of ionising radiation on wildlife, some countries have adopted their own legislation. The report evaluates these regulatory frameworks and describe the current UK position

  3. Genetic damage from low-level and natural background radiation

    International Nuclear Information System (INIS)

    Oftedal, P.

    1988-01-01

    Relevant predictions that have been made of possible low level biological effects on man are reviewed, and the estimate of genetic damage is discussed. It is concluded that in spite of a number of attempts, no clear-cut case of effects in human populations of radiation at natural levels has been demonstrated. The stability of genetic material is dynamic, with damage, repair and selection running as continuous processes. Genetic materials are well protected and are conservative in the extreme, not least because evolution by genetic adaptation is an expensive process: Substitution of one allele A 1 by another A 2 means the death of the whole A 1 population

  4. Trichloromethyl compounds - natural background concentrations and fates within and

    DEFF Research Database (Denmark)

    Albers, Christian Nyrop; Hansen, Poul Erik; Jacobsen, Ole Stig

    2010-01-01

    occurrence and cycling of organic compounds with a trichloromethyl moiety in common. The study areas are temperate coniferous forests. Trichloromethyl compounds can be found in all compartments of the forests (groundwater, soil, vegetation and throughfall), but not all compounds in all compartments....... Other positive relations occur, which in combination with chlorination experiments performed in the laboratory, point to the fact that all the trichloromethyl compounds may be formed concurrently in the soil, and their subsequent fates then differ due to different physical, chemical and biological....... Based on this and previous studies, a conceptual model for the natural cycling of trichloromethyl compounds in forests is proposed...

  5. Impact assessment of ionising radiation on wildlife

    International Nuclear Information System (INIS)

    Copplestone, D.; Bielby, S.; Jones, S.

    2001-01-01

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on the impacts of ionising radiation on wildlife, upon which a robust assessment approach may be developed. This approach will also feed into the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET), due to complete in October 2003. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The aims of the report are: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; an outline and review of the relevant European and national legislation which has impacts on the requirements for assessments of the impact of ionising radiation on wildlife in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach to assess the impacts to wildlife from ionising radiation from authorised discharges in England and Wales, with spreadsheets to support the methodology. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those

  6. Corrigendum to “Sorption/desorption of non-hydrophobic and ionisable pharmaceutical and personal care products from reclaimed water onto/from a natural sediment” Sci Total Environ 472 (2014) 273–281

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Hernández, Virtudes, E-mail: virtudes.martinez@imdea.org [IMDEA Agua, Madrid Institute for Advanced Studies in Water, Parque Científico Tecnológico de la Universidad de Alcalá, 28805 Alcalá de Henares, Madrid (Spain); Meffe, Raffaella; Herrera, Sonia [IMDEA Agua, Madrid Institute for Advanced Studies in Water, Parque Científico Tecnológico de la Universidad de Alcalá, 28805 Alcalá de Henares, Madrid (Spain); Arranz, Elena [University of Alcalá, Geography and Geology Department, 28871 Alcalá de Henares, Madrid (Spain); Bustamante, Irene de [IMDEA Agua, Madrid Institute for Advanced Studies in Water, Parque Científico Tecnológico de la Universidad de Alcalá, 28805 Alcalá de Henares, Madrid (Spain); University of Alcalá, Geography and Geology Department, 28871 Alcalá de Henares, Madrid (Spain)

    2015-02-01

    In the present work, the sorption of pharmaceutical and personal care products (PPCPs) (acetaminophen, atenolol, carbamazepine, caffeine, naproxen and sulphamethoxazole) onto the natural organic matter (NOM) and the inorganic surfaces of a natural sandy loam sediment was quantified separately. The quantification was based on the PPCP charge, their degree of ionisation, their octanol-water partitioning coefficient (K{sub OW}) and the sediment organic carbon fraction (ƒ{sub OC}). PPCP desorption from the sediment was examined under conditions of infiltrating water containing a high concentration of inorganic ions (mimicking infiltrating reclaimed water), and a low concentration (and smaller diversity) of inorganic ions (mimicking rainwater infiltration). Batch tests were performed using a sediment/water ratio of 1:4 and a PPCP initial concentration ranging from 1 to 100 μg L{sup −1}. The results showed the type and degree of PPCP ionisation to strongly influence the sorption of these compounds onto the sediment. The sorption of cationic species onto the sediment was higher than that of anionic species and mostly reversible; the sorption of neutral species was negligible with the exception of caffeine. The anionic species sorbed less onto the sediment, but also desorbed less easily. Most of the compounds showed a sorption that was highly influenced by interaction with mineral surfaces. The presence of inorganic ions had no impact on the desorption of the PPCPs from the sediment. According to the calculated percentages of removal, the mobility followed the order: carbamazepine > acetaminophen > naproxen > atenolol > sulphamethoxazole > caffeine.

  7. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer.

    Science.gov (United States)

    McColl, Neil; Auvinen, Anssi; Kesminiene, Ausrele; Espina, Carolina; Erdmann, Friederike; de Vries, Esther; Greinert, Rüdiger; Harrison, John; Schüz, Joachim

    2015-12-01

    Ionising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other epidemiological studies of groups that have been exposed to radiation from medical, occupational or environmental sources; experimental animal studies; and studies of cellular responses to radiation. Considering exposure to environmental ionising radiation, inhalation of naturally occurring radon is the major source of radiation in the population - in doses orders of magnitude higher than those from nuclear power production or nuclear fallout. Indoor exposure to radon and its decay products is an important cause of lung cancer; radon may cause approximately one in ten lung cancers in Europe. Exposures to radon in buildings can be reduced via a three-step process of identifying those with potentially elevated radon levels, measuring radon levels, and reducing exposure by installation of remediation systems. In the 4th Edition of the European Code against Cancer it is therefore recommended to: "Find out if you are exposed to radiation from naturally high radon levels in your home. Take action to reduce high radon levels". Non-ionising types of radiation (those with insufficient energy to ionise molecules) - including extremely low-frequency electric and magnetic fields as well as radiofrequency electromagnetic fields - are not an established cause of cancer and are therefore not addressed in the recommendations to reduce cancer risk. Copyright © 2015 International Agency for Research on Cancer. Published by Elsevier Ltd. All rights reserved.

  8. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.

    1981-01-01

    The mutagenic effects of ionising radiation on germ cells with resulting genetic abnormalities in subsequent generations, are considered. Having examined a simple model to explain the interaction of ionising radiation with genetic material and discussed its limitations, the methods whereby mutations are transmitted are discussed. Methods of estimating genetic risks and the results of such studies are examined. (U.K.)

  9. On the role of natural radiation background in the initial development of plants

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Vagabova, M.Eh.; Primak-Mirolyubov, V.N.

    1977-01-01

    To obtain data on plant development under strictly controlled decreased natural radiation conditions, the experiment with radish seeds was conducted in a special chamber having a decreased natural radiation background. It has been shown that the development of seedlings in the course of the first 4-5 days in significantly delayed, and it normalizes when radiation sources, imitating the natural radiation background, are placed inside the chamber

  10. Comparison of selection methods to deduce natural background levels for groundwater units

    NARCIS (Netherlands)

    Griffioen, J.; Passier, H.F.; Klein, J.

    2008-01-01

    Establishment of natural background levels (NBL) for groundwater is commonly performed to serve as reference when assessing the contamination status of groundwater units. We compare various selection methods to establish NBLs using groundwater quality data forfour hydrogeologically different areas

  11. Use of ionising radiation

    International Nuclear Information System (INIS)

    1988-11-01

    The Committee has inquired into and reported on the use of ionising radiation for commercial sterilisation, disinfestation, food preservation and other purposes with particular reference to human health and safety; environmental impacts, and adequacy of assessment and regulatory procedures. While food irradiation is apparently commercially successful overseas the application to Australia seems extremely limited - it would be used primarily for disinfestation of insect pests and perhaps to reduce levels of harmful bacteria in a limited range of foods. For other applications there are effective and more economic alternatives. The report reviews other studies of food irradiation and the policies and practices governing its use in other countries. The safety of irradiated food, the radiological safety issues and the regulations which would be required in Australia are dealt with in detail. The Committee recommends, inter alia, that the Australian Government should not approve the irradiation of food in Australia until such time as a routine commercial method of detection has been developed and that the import of caesium 137 for use as an irradiation source in commercial irradiation facilities be prohibited

  12. 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.

  13. The natural petroleum hydrocarbon background in subtidal sediments of Prince William Sound, Alaska

    International Nuclear Information System (INIS)

    Page, D.S.; Boehm, P.D.; Douglas, G.S.; Bence, A.E.

    1993-01-01

    A natural regional petroleum hydrocarbon background has been identified in the subtidal sediments of Prince William Sound. This hydrocarbon background, which is readily distinguished from Exxon Valdez spill oil by advanced hydrocarbon fingerprinting methods, is derived from petroleum seeps in the eastern Gulf of Alaska. The Alaska Coastal Current carries fine-grained sediments and associated hydrocarbons into the Sound where they are deposited. This activity has been ongoing for the past 160 years and probably for many thousands of years. Results of a stratified random study (SRS) of nearshore subtidal sediments conducted in 1990 and a fixed site study conducted in 1989, 1990, and 1991 show that this background is significant even in shallow water (3--30 m) and that it is a general phenomenon of the Sound. Polycyclic aromatic hydrocarbon (PAH) mixing model calculations show that, where present in nearshore subtidal sediments, residues of Exxon Valdez spill oil form a small increment on the natural background. The recognition of pre-existing natural and anthropogenic hydrocarbon backgrounds in a spill area is a fundamentally important component of natural resource damage assessment

  14. Natural background gamma-ray spectrum. List of gamma-rays ordered in energy from natural radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Ichimiya, Tsutomu [Japan Radioisotope Association, Tokyo (Japan); Narita, Tsutomu; Kitao, Kensuke

    1998-03-01

    A quick index to {gamma}-rays and X-rays from natural radionuclides is presented. In the list, {gamma}-rays are arranged in order of increasing energy. The list also contains {gamma}-rays from radioactive nuclides produced in a germanium detector and its surrounding materials by interaction with cosmic neutrons, as well as direct {gamma}-rays from interaction with the neutrons. Artificial radioactive nuclides emitting {gamma}-rays with same or near energy value as that of the natural {gamma}-rays and X-rays are also listed. In appendix, {gamma}-ray spectra from a rock, uranium ore, thorium, monazite and uraninite and also background spectra obtained with germanium detectors placed in iron or lead shield have been given. The list is designed for use in {gamma}-ray spectroscopy under the conditions of highly natural background, such as in-situ environmental radiation monitoring or low-level activity measurements, with a germanium detector. (author)

  15. Estimation of natural radiation background level and population dose in China

    International Nuclear Information System (INIS)

    Pan Ziqiang

    1992-01-01

    The authors describe in general the natural radiation background level in China, and based on available data present an estimated annual effective dose equivalent of the population to natural radiation that is some 2.3 mSv, of which about 0.54 mSv is from original γ radiation and about 0.8 mSv from radon and its short-lived daughters

  16. Food ionisation. Realities and perspectives

    International Nuclear Information System (INIS)

    Bonnet, G.

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  17. Geochemistry, biota and natural background levels in an arsenic naturally contaminated volcanic aquifer

    Science.gov (United States)

    Preziosi, Elisabetta; Amalfitano, Stefano; Di Lorenzo, Tiziana; Parrone, Daniele; Rossi, David; Ghergo, Stefano; Lungarini, Silvia; Zoppini, Anna Maria

    2015-04-01

    The tight links between chemical and ecological status are largely acknowledged as for surface water bodies, while aquifers are still considered as hidden groundwater reservoirs, rather than ecosystems to be preserved. Geochemical and biological interactions play a key role in all subterranean processes, including the dynamics of the fate of anthropogenic contaminants. Studies on groundwater dependent ecosystems (GDE) were mainly focused on karst aquifers so far, but an increased awareness on the importance of water-rock interactions and methodological improvements in microbial ecology are rapidly increasing the level of characterization of groundwater ecosystems in various hydrogeological contexts. Similarly, knowledge about groundwater biodiversity is still limited, especially if porous habitats are concerned. Yet, groundwater and GDEs are populated by a diverse and highly adapted biota, dominated by crustaceans, which provide important ecosystem services and act as biological indicators of chemical and quantitative impact on groundwater resources. In a previous research (Amalfitano et al. 2014), we reported that the microbial community heterogeneity may reflect the lithological and hydrogeological complexity within volcanic and alluvial facies transition in a groundwater body. The quantitative tracking of the microbial community structure allowed disentangling the natural biogeochemical processes evolving within the aquifer flow path. The analyses of groundwater crustaceans assemblages may contribute to shed more light upon the state and dynamics of such ecosystems. In the present research, a comprehensive study of a water table aquifer flowing through a quaternary volcanic district is being performed, including the geochemical (inorganic) composition, the microbial composition, and the analysis of crustacean assemblages . Groundwater samples are periodically collected from private wells and springs under a low anthropic impact. The key issues within the

  18. Natural radioactivity in the Dutch outdoor environment. The explanation of uncomprehended variations in the background

    International Nuclear Information System (INIS)

    Blaauboer, R.O.; Smetsers, R.C.G.M.

    1996-01-01

    In the Netherlands and many other countries research in the field of natural radioactivity is focused on the prevention of radon in the indoor environment. However, also the occurrence of natural radioactivity in the outdoor environment is an interesting subject to be studied. The natural background radiation in the outdoor environment, in particular its variations, hinders the verification of radiation level standards, caused by human activities. An analysis of the data of the Dutch National Monitoring Network for Radioactivity (LMR) provided more insight into those variations. This article is a summary of the authors' thesis on the subject. 5 figs., 8 refs

  19. Geographically determined dependencies in the value of the constant natural radiation gamma-background

    International Nuclear Information System (INIS)

    Miloslavov, V.

    2001-01-01

    The problem of the assessment of the influence of natural gamma background changes on the population is discussed. It is considered that the populations in different geographic regions have adapted by evolution mechanisms to the respective unchanged (without human activities) radiation background. The background limits for each area form the 'radiation comfortable zone' which varies very much for the different geographic areas. Leaving the 'comfortable zone' leads to a triggering of adaptive mechanisms in the population including the natural selection in order to reach an equilibrium. Thus, the radiation impact exceeding the 'comfortable zone' is expected to cause harm for a part of the population which is preliminarily burden or uncapable to adapt. From this point of view the increased morbidity due to radiation factor in those cases remains hidden. As a conclusion it is pointed out that the proposed increase of the annual dose for the population might result with harmful consequences for the whole human population

  20. Estimation of effective dose to public from external exposure to natural background radiation in saudi arabia

    International Nuclear Information System (INIS)

    Khalid, A. A.

    2003-01-01

    The effective dose values in sixteen cities in Saudi Arabia due to external exposure to natural radiation were evaluated. These doses are based on natural background components including external exposure to terrestrial radiation and cosmic rays. The importance of evaluating the effective dose to the public due to external exposure to natural background radiation lies in its epidemiological and dosimetric importance and in forming a basis for the assessment of the level of radioactive contamination or pollution in the environment in the future. The exposure to terrestrial radiation was measured using thermoluminescent dosimeters (TLD). The exposure from cosmic radiation was determined using empirical correlation. The values evaluated for the total annual effective dose in all cities were within the world average values. The highest total annual effective dose measured in Al-Khamis city was 802 μSv/y, as compared to 305 μSv/y in Dammam city, which was considered the lowest value

  1. Working safely with ionising radiation

    International Nuclear Information System (INIS)

    McDowell, D.J.

    1990-01-01

    A small leaflet provides information on working safely with ionizing radiation. Topics covered include the types of radiation, radiological units, external radiation, contamination and internal radiation, methods of protection form radiation, radiation monitors, protective clothing for contamination, personal dosemeters, radiation dose limits for classified workers and finally the Ionising Radiations Regulations 1985. (UK)

  2. Dose limits for ionising radiation

    International Nuclear Information System (INIS)

    Gifford, D.

    1989-01-01

    Dose limits for exposure to ionising radiation are assessed to see if they give sufficient protection both for the occupationally exposed and for the general public. It is concluded that current limits give a level of safety that satisfies the necessary criteria in the light of present knowledge and further reductions would be unlikely to improve standards of safety. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-09-15

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

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

    International Nuclear Information System (INIS)

    Kudyasheva, Alevtina G.; Shishkina, Ludmila N.; Shevchenko, Oksana G.; Bashlykova, Ludmila A.; Zagorskaya, Nadezhda G.

    2007-01-01

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

  5. Nature of association between rural background and practice location: A comparison of general practitioners and specialists

    Directory of Open Access Journals (Sweden)

    Humphreys John S

    2011-03-01

    Full Text Available Abstract Background Rural and remote areas are characterised by a shortage of medical practitioners. Rural background has been shown to be a significant factor associated with medical graduates' intentions and decisions to practise within a rural area, though most studies have only used simple definitions of rural background and not previously looked at specialists. This paper aims to investigate in detail the nature of the association between rural background and practice location of Australian general practitioners (GPs and specialists Methods Data for 3156 GPs and 2425 specialists were obtained from the Medicine in Australia: Balancing Employment and Life (MABEL study. Data on the number of childhood years resident in a rural location and population size of their rural childhood location were matched against current practice location. Logistic regression modelling was used to calculate adjusted associations between doctors in rural practice and rural background, sex and age. Results GPs with at least 6 years of their childhood spent in a rural area were significantly more likely than those with 0-5 years in a rural area to be practising in a rural location (OR 2.28, 95% CI 1.69-3.08, whilst only specialists with at least 11 years rural background were significantly more likely to be practising in a rural location (OR 2.27, 95% CI 1.77-2.91. However, for doctors with a rural background, the size of the community that they grew up in was not significantly associated with the size of the community in which they currently practise. Both female GPs and female specialists are similarly much less likely to be practising in a rural location compared with males (GPs: OR 0.53, 95% CI 0.45-0.62. Conclusions This study elucidates the association between rural background and rural practice for both GPs and specialists. It follows that increased take-up of rural practice by new graduates requires an increased selection of students with strong rural

  6. Contribution from natural and man-made background radiations to Indian population

    International Nuclear Information System (INIS)

    Ramachandran, T.V.; Eappen, K.P.; Shaikh, A.N.; Mayya, Y.S.; Puranik, V.D.

    2005-01-01

    Living organisms are exposed to ionizing radiation existed naturally. Sources of ionizing radiation are cosmic ray, which comes from outer space, terrestrial radionuclides which occurs in the earth's crust, in building materials and in air, water and food and in human body itself. The annual effective dose at sea level from cosmic rays is 240 μSv. It can also vary as a result of human activities and practices. Component of the sources of exposures to Indian population has been assessed based on the data generated. Total contribution to the natural sources to the Indian population works out to be 2.3 mSv/y as against the global value of 2.4 mSv/y. Estimated contribution to the background radiation from actual practices such as mining of heavy metals (U and Th), coal fired power plants, mining of phosphate rocks and its use as fertilizers, production of natural gas, production of gas mantles and luminescent dial and air travel works out be 1.24 x 10 -3 mSv/y. Nuclear weapon tests contributes about 0.008 mSv/y and the exposure due to nuclear power production contributes about 5.0 x 10 -5 mSv/y to the background radiation. Brief review and comparison of the dose rates arising from natural and man-made sources to the Indian population is given. (author)

  7. Natural background radioactivity of the earth's surface -- essential information for environmental impact studies

    International Nuclear Information System (INIS)

    Tauchid, M.; Grasty, R.L.

    2002-01-01

    An environmental impact study is basically a study of change. This change is compared to the preexisting conditions that are usually perceived to be the original one or the 'pristine' stage. Unfortunately reliable information on the 'so called' pristine stage is far from adequate. One of the essential parts of this information is a good knowledge of the earth's chemical make up, or its geochemistry. Presently available data on the geochemistry of the earth's surface, including those related to radioactive elements, are incomplete and inconsistent. The main reason why a number of regulations are judged to be too strict and disproportional to the risks that might be caused by some human activities, is the lack of reliable information on the natural global geochemical background on which environmental regulations should be based. The main objective of this paper is to present a view on the need for complete baseline information on the earth's surface environment and in particular its geochemical character. It is only through the availability of complete information, including reliable baseline information on the natural radioactivity, that an appropriate study on the potential effect of the various naturally occurring elements on human health be carried out. Presented here are a number of examples where the natural radioactivity of an entire country has been mapped, or is in progress. Also described are the ways these undertakings were accomplished. There is a general misconception that elevated radioactivity can be found only around uranium mines, nuclear power reactors and similar nuclear installations. As can be seen from some of these maps, the natural background radioactivity of the earth's surface closely reflects the underlying geological formations and their alteration products. In reality, properly regulated and managed facilities, the levels of radioactivity associated with many of these facilities are generally quite low relative to those associated with

  8. Advisory group on ionising radiation

    International Nuclear Information System (INIS)

    Harrison, J.R.

    1996-01-01

    The Advisory Group on Ionising Radiation has a busy and challenging work programme. Its reports will be published in the Documents of the NRPB series. These may advise further research or could form the basis of formal NRPB advice. Covering the full spectrum of radiation issues at work, in public health and clinical medicine, and the environment, it should enhance the radiation advice available to NRPB. (author)

  9. Cancer occurrence in the high natural background radiation area of Kerala coast

    International Nuclear Information System (INIS)

    Krishnan Nair, M.; Sreedevi Amma, N.; Ramachandran, T.P.; Varghese Cherian; Jayalakshmy, P.; Mani, K.S.; Boban, T.G.; Jayadevan, S.; Gangadharan, P.

    1994-01-01

    In order to assess the health effects if any, in populations living in high background radiation areas, the Department of Atomic Energy has sanctioned a 5-year project to establish a Registry covering Karunagappally taluk. The study proposes to cover a population of about 1,00,000 persons living in high background radiation areas where the radiation levels range anywhere between 10 and 825 μR/h inside the houses; for comparison the study proposes to cover another 3,00,000 persons living in nearby normal areas where the natural radiation levels range between 6 and 200 μ R/h. The data collected so far in the first 2.5 years are presented in this paper which covers a population of about 1,10,000 persons living in three villages. No attempt is made to interpret the data at this preliminary stage. (author). 7 tabs

  10. Natural and man-made environmental background radiation exposure levels: a review

    International Nuclear Information System (INIS)

    Puranik, V.D.; Ramachandran, T.V.

    2005-01-01

    All living organisms are continuously exposed to ionizing radiation, which always existed naturally. Important sources are cosmic rays which comes from outer space and from the surface of the sun, terrestrial radionuclides which occurs in the earth's crust, in building materials and in air, water and foods and in the human body itself. Some of the exposures are fairly constant and uniform for all individuals everywhere, for example, the dose from ingestion of potassium-40 in food. Other exposures vary depending on location. Cosmic rays, for example are, more intense at higher altitudes, and the concentrations of uranium and thorium in soils are elevated in localized areas. Exposures can also vary as a result of human activities and practices. In particular, the building materials of houses and the design and ventilation systems strongly influences the indoor levels of the radioactive gas radon and its decay products, which contributes significantly to doses through inhalation. Component of the sources of exposures to Indian population has been assessed based on the data generated. Total estimated contribution to the natural sources to the Indian population works out to 2.3 mSv/y as against the global value of 2.4 mSv/y. Estimated modified source which includes mining of heavy metals, coal fired power plants, mining of phosphate rocks and its use as fertilizers, production of natural gas, production of gas mantles and luminescent dial and air travel contribution to the background radiation to the Indian population works out to be 1.2 x 10 -3 mSv/y; while atmospheric weapon tests contributes about 0.045 mSv/y, medical exposure contributes about 0.048 mSv/y and exposure due to nuclear power production contributes about 5.0 x 10 -5 mSv/y to the background radiation. Brief review and comparison of the dose rates arising from natural and other man made sources to the Indian population is given. (author)

  11. European Code against Cancer 4th Edition: Ionising and non-ionising radiation and cancer

    NARCIS (Netherlands)

    N. McColl (Neil); A. Auvinen (Anssi); A. Kesminiene (Ausrele); C. Espina (Carolina); F. Erdmann (Friederike); E. de Vries (Esther); R. Greinert (Rüdiger); J. Harrison (John); J. Schüz (Joachim)

    2015-01-01

    textabstractIonising radiation can transfer sufficient energy to ionise molecules, and this can lead to chemical changes, including DNA damage in cells. Key evidence for the carcinogenicity of ionising radiation comes from: follow-up studies of the survivors of the atomic bombings in Japan; other

  12. Nature of the low-energy, γ-like background for the Cherenkov Telescope Array

    Science.gov (United States)

    Sitarek, Julian; Sobczyńska, Dorota; Szanecki, Michał; Adamczyk, Katarzyna; Cumani, Paolo; Moralejo, Abelardo

    2018-01-01

    The upcoming Cherenkov Telescope Array (CTA) project is expected to provide unprecedented sensitivity in the low-energy ( ≲ 100 GeV) range for Cherenkov telescopes. Most of the remaining background in this energy range results from misidentified hadron showers. In order to fully exploit the potential of the telescope systems it is worthwhile to look for ways to further improve the available analysis methods for γ/hadron separation. We study the composition of the background for the planned CTA-North array by identifying events composed mostly of a single electromagnetic subcascade or double subcascade from a π0 (or another neutral meson) decay. We apply the standard simulation chain and state-of-the-art analysis chain of CTA to evaluate the potential of the standard analysis to reject such events. Simulations show a dominant role of such single subcascade background for CTA up to energies ∼ 70 GeV. We show that a natural way of rejection of such events stems from a shifted location of the shower maximum, and that the standard stereo reconstruction method used by CTA already exploits most of expected separation.

  13. Diseases induced by ionising radiation

    International Nuclear Information System (INIS)

    1984-11-01

    An interim report is presented by the Industrial Injuries Advisory Council in accordance with Section 141 of the Social Security Act 1975 on the question whether the terms of prescription for occupational diseases induced by ionising radiation should be amended to cover a wider range of conditions. A lack of persuasive statistical data has prevented reliable estimates of health risks of radiation workers in the UK to be made. However the report gives details of the progress made so far and the difficulties encountered. (U.K.)

  14. Trichloromethyl compounds--natural background concentrations and fates within and below coniferous forests.

    Science.gov (United States)

    Albers, Christian Nyrop; Hansen, Poul Erik; Jacobsen, Ole Stig

    2010-11-15

    Pollution with organochlorines has received major attention due to various environmental effects, but it is now increasingly recognized, that they also take part in biogeochemical cycles and that natural background concentrations exist for several chlorinated compounds. We here report the natural occurrence and cycling of organic compounds with a trichloromethyl moiety in common. The study areas are temperate coniferous forests. Trichloromethyl compounds can be found in all compartments of the forests (groundwater, soil, vegetation and throughfall), but not all compounds in all compartments. The atmospheric input of trichloromethyl compounds is found to be minor, with significant contributions for trichloroacetic acid (TCAA), only. In top soil, where the formation of the compounds is expected to occur, there is a clear positive relationship between chloroform and trichloroacetyl containing compounds. Other positive relations occur, which in combination with chlorination experiments performed in the laboratory, point to the fact that all the trichloromethyl compounds may be formed concurrently in the soil, and their subsequent fates then differ due to different physical, chemical and biological properties. TCAA cannot be detected in soil and groundwater, but sorption and mineralization experiments performed in the laboratory in combination with analyses of vegetation, show that TCAA is probably formed in the top soil and then partly taken up by the vegetation and partly mineralized in the soil. Based on this and previous studies, a conceptual model for the natural cycling of trichloromethyl compounds in forests is proposed. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Food preservation by ionising radiation

    International Nuclear Information System (INIS)

    Andrade, M. E.

    1996-01-01

    The process of food preservation by ionising radiation is an alternative, or a complement, to the traditional methods of heating, refrigerating, freezing or using chemical additives. The study and development of this technique has started on the beginning of the fifties but it is based on the radiation killing effect on micro-organisms discovered by the end of last century. Foodstuffs are treated in appropriate plants: isotopic facilities (gamma radiation) and accelerated electron beams produced by machines called accelerators. The FAO and WHO in close cooperation with the IAEA have played an important role on the development of the process and on the increment of the industrial application of food irradiation. Over the world there are about 37 countries trading foods treated by ionising radiation. However, governments have been slow to clear the utilization of this process. The main reason of this attitude is in general due to the fact that the advantages of the technique are not clearly understood. Therefore, the dissemination of the information could on one hand clarify who has to take decisions and on the other hand support the choice of those foods by the consumers. This is the unique way to dynamize the application of this process

  16. Beam Cooling with ionisation losses

    CERN Document Server

    Rubbia, Carlo; Kadi, Y; Vlachoudis, V

    2006-01-01

    A novel type of particle "cooling", called Ionization Cooling, is applicable to slow (v of the order of 0.1c) ions stored in a small ring. The many traversals through a thin foil enhance the nuclear reaction probability, in a steady configuration in which ionisation losses are recovered at each turn by a RF-cavity. For a uniform target "foil" the longitudinal momentum spread diverges exponentially since faster (slower) particles ionise less (more) than the average. In order to "cool" also longitudinally, a chromaticity has to be introduced with a wedge shaped "foil". Multiple scattering and straggling are then "cooled" in all three dimensions, with a method similar to the one of synchrotron cooling, but valid for low energy ions. Particles then stably circulate in the beam indefinitely, until they undergo for instance nuclear processes in the thin target foil. This new method is under consideration for the nuclear production of a few MeV/A ion beams. Simple reactions, for instance Li 7 + D Li 8 + p, are more ...

  17. Mode shape and natural frequency identification for seismic analysis from background vibration

    International Nuclear Information System (INIS)

    Bhan, S.; Wozniak, Z.

    1986-10-01

    Background vibration in a CANDU plant can be used to determine the dynamic characteristics of major items of equipment, such as calandria, the fuelling machines and the primary heat transport pumps. These dynamic characteristics can then be used to verify the seismic response of the equipment which, at present, is based on theoretical models only. The feasibility and basic theory of this new approach (which uses accelerations measured at several points on a structure and does not require knowledge of the source of excitation) was established in Phase I of the study. This report is based on Phase II in which the methods of analysis developed in Phase I were improved and verified experimentally. A Fast Fourier Transform (FFT) algorithm was incorporated and an interactive curve fitting technique was developed to obtain the dynamic characteristics in the form of natural frequencies, mode shapes and damping ratios. The method is now available for use at a CANDU plant

  18. Relation between cancer incidence or mortality and external natural background radiation in Japan

    International Nuclear Information System (INIS)

    Ujeno, Y.

    1983-01-01

    Analysis was performed on the relationships between the organ dose-equivalent rate due to natural background radiation (mSv/a) and three parameters of cancer risk: the age-adjusted cancer incidence (patients x 10 5 persons x a -1 ) in 13 large areas, the standardized mortality ratio of cancers in 46 large areas, and the cancer mortality in the population aged more than 40 years old (cancer deaths x 10 5 persons x a -1 ) in 649 small areas. The age-adjusted liver cancer incidence in males fitted the exponential model significantly (p<0.01) and the relationship of stomach cancer mortality of aged males in small areas fitted the linear model significantly (p<0.05). No relationship was observed with regard to female cancer in either case. The relationships between the three parameters and various other cancers of both sexes were not statistically significant. (author)

  19. Nature and characteristics of temperature background effect for interactive respiration process.

    Science.gov (United States)

    Gong, Guangcai; Deng, Xiaorui

    2017-08-17

    Indoor air quality (IAQ) is much more crucial to human health than its atmospheric air quality counterpart. Improving indoor air environment requires investigating how different indoor air stability affects airflow trajectory. By presenting both manikin experiment and Computational Fluid Dynamics (CFD) simulation, we find that temperature background effect, i.e., indoor air stability, which is a measure of the nature or attribute of the capacity to keep the original or initial inertia force or inertia transmission state instead of turbulence diffusion or transmission restraining state, i.e., a kind of inertia stability, rather than a turbulence diffusion characteristic stability, is markedly affecting the interactive respiration process. So we define and derive a new parameter called G c number as a criterion to judge air stability. Furthermore, we find the phenomenon of inertia conjugation. Air stability and inertia conjugation, which named together as temperature background effect, work together on interactive respiration process. This work gives us a re-orientation of temperature difference agents and thus improves human being's living environment.

  20. 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)

  1. Medical exposure to ionising radiation and the risk of brain tumours

    DEFF Research Database (Denmark)

    Blettner, Maria; Schlehofer, Brigitte; Samkange-Zeeb, Florence

    2007-01-01

    BACKGROUND: The role of exposure to low doses of ionising radiation in the aetiology of brain tumours has yet to be clarified. The objective of this study was to investigate the association between medically or occupationally related exposure to ionising radiation and brain tumours. METHODS: We...... used self-reported medical and occupational data collected during the German part of a multinational case-control study on mobile phone use and the risk of brain tumours (Interphone study) for the analyses. RESULTS: For any exposure to medical ionising radiation we found odds ratios (ORs) of 0.63 (95...... regions. CONCLUSION: We did not find any significant increased risk of brain tumours for exposure to medical ionising radiation....

  2. Estimation of thyroid gland state of voles natural populations from increased radioactive background territories

    Energy Technology Data Exchange (ETDEWEB)

    Raskosha, O.; Ermakova, O.; Kaneva, A. [Institute of Biology of Komi Scientific Center, Ural Division of Russian Academy of Science (Russian Federation)

    2014-07-01

    Investigation of effects caused in biological objects by chronic low-intensity radiation in their natural habitats is one of the most important problems of modern radioecology. The aim of our work - complex estimation of state of thyroid gland of voles inhabiting increased radioactive background territories. We investigated tundra voles (Microtus oeconomus Pall.) that were sampled at different stages of population cycle from the experimental and the control sites in the Uhta region of the Komi Republic, Russia. Experimental site contamination resulted from commercial extraction od radium between the 1930's and 1950's. Irradiation exposure dose at the site was 50-2000 mR/h (at the control site 10-15 mR/h). Complex estimation of thyroid was made by histological, morpho-metrical, radioimmunological and cytogenetic methods. Results showed high sensitivity of thyroid gland of tundra voles from chronically irradiated natural populations. We found reliable changes in morphological features of thyroid, in the level of thyroidal hormones and increased frequency of cells with micro-nucleuses in animals sampled from the experimental site as compared with the control ones. It was also showed, that chronic exposure of ionizing irradiation at the same range of absorbed doses can cause different effects in animals depending on sex, age and the stage of population cycle. This confirms the need of including these biological factors to analysis of low doses effects in the natural populations during radioecological studies. Investigations were supported by RFBR grants No. 13-04-01750? and No. 13-04-90351-RBUa. Document available in abstract form only. (authors)

  3. Epidemiological studies on disturbances of human fetal development in areas with various doses of natural background radiation. I. Relationship between incidences of Down's syndrome or visible malformation and gonad dose equivalent rate of natural background radiation

    International Nuclear Information System (INIS)

    Ujeno, Y.

    1985-01-01

    The relationship between environmental radiation to the gonads and incidences of Down's syndrome and visible malformation was analyzed using Kendall's rank correlation method. The subjects, studied during a 3-yr period (1979-1981), were inhabitants of 46 prefectures in Japan that had various dose rates of natural background ionizing radiation. Results showed that the natural background very low-dose radiation rate was not a predominant factor responsible for inducing Down's syndrome or other visible malformations

  4. A novel natural environment background model for Monte Carlo simulation and its application in the simulation of anticoincidence measurement

    International Nuclear Information System (INIS)

    Li, Sangang; Wang, Lei; Cheng, Yi; Tuo, Xianguo; Liu, Mingzhe; Yao, Fuliang; Leng, Fengqing; Cheng, Yuanyuan; Cai, Ting; Zhou, Yan

    2016-01-01

    This study proposes a novel natural environment background model by modeling brief environment conditions. It uses Geant4 program to simulate decays of 238 U, 232 Th, and 40 K in soil and obtains compositions of different-energy gamma rays in the natural environment background. The simulated gamma spectrum of the natural environment background agrees well with the experimental spectrum, particularly above 250 keV. The model is used in the simulation of anticoincidence measurement, indicating that the natural environment background can be decreased by approximately 88%, and the Compton attenuation factor is 2.22. The simulation of anticoincidence measurement can improve the minimum detectable activity (MDA) of the detection system. - Highlights: • This study proposes a novel natural environment background model by simulating decays of 238 U, 232 Th, and 40 K in soil. • The simulated gamma spectrum of the natural environment background agrees well with the experimental spectrum, particularly above 250 keV. • The proposed environment background model is applied to study the properties of anticoincidence detector.

  5. A novel natural environment background model for Monte Carlo simulation and its application in the simulation of anticoincidence measurement.

    Science.gov (United States)

    Li, Sangang; Wang, Lei; Cheng, Yi; Tuo, Xianguo; Liu, Mingzhe; Yao, Fuliang; Leng, Fengqing; Cheng, Yuanyuan; Cai, Ting; Zhou, Yan

    2016-02-01

    This study proposes a novel natural environment background model by modeling brief environment conditions. It uses Geant4 program to simulate decays of (238)U, (232)Th, and (40)K in soil and obtains compositions of different-energy gamma rays in the natural environment background. The simulated gamma spectrum of the natural environment background agrees well with the experimental spectrum, particularly above 250 keV. The model is used in the simulation of anticoincidence measurement, indicating that the natural environment background can be decreased by approximately 88%, and the Compton attenuation factor is 2.22. The simulation of anticoincidence measurement can improve the minimum detectable activity (MDA) of the detection system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. 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

  7. Hydrogeochemical characterization and Natural Background Levels in urbanized areas: Milan Metropolitan area (Northern Italy)

    Science.gov (United States)

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

    2017-04-01

    Although aquifers in densely populated and industrialized areas are extremely valuable and sensitive to contamination, an estimate of the groundwater quality status relative to baseline conditions is lacking for many of them. This paper provides a hydrogeochemical characterization of the groundwater in the Milan metropolitan area, one of the most densely populated areas in Europe. First, a conceptual model of the study area based on the analysis of the spatial distribution of natural chemical species and indicator contaminants is presented. The hydrochemical facies of the study area depend on the lithology of catchments drained by the main contributing rivers and on the aquifer settings. The anthropogenic influence on the groundwater quality of superficial aquifers is studied by means of probability plots, concentration versus depth plots and spatial-temporal plots for nitrate, sulfate and chloride. These allow differentiation of contaminated superficial aquifers from deep confined aquifers with baseline water quality. Natural Background Levels (NBL) of selected species (Cl, Na, NH4, SO4, NO3, As, Fe, Mn and Zn) are estimated by means of the pre-selection (PS) and the component separation (CS) statistical approaches. The NBLs depend on hydrogeological settings of the study area; sodium, chloride, sulfate and zinc NBL values never exceed the environmental water quality standards. NBL values of ammonium, iron, arsenic and manganese exceed the environmental water quality standards in the anaerobic portion of the aquifers. On the basis of observations, a set of criteria and precautions are suggested for adoption with both PS and CS methods in the aquifer characterization of highly urbanized areas.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

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

    International Nuclear Information System (INIS)

    Rochedo, Elaine R.R.; Salles, Krause C.S.; Prado, Nadya M.C.

    2013-01-01

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

  10. Naturally occurring 32 Si and low-background silicon dark matter detectors

    Energy Technology Data Exchange (ETDEWEB)

    Orrell, John L.; Arnquist, Isaac J.; Bliss, Mary; Bunker, Raymond; Finch, Zachary S.

    2018-05-01

    The naturally occurring radioisotope Si-32 represents a potentially limiting background in future dark matter direct-detection experiments. We investigate sources of Si-32 and the vectors by which it comes to reside in silicon crystals used for fabrication of radiation detectors. We infer that the Si-32 concentration in commercial single-crystal silicon is likely variable, dependent upon the specific geologic and hydrologic history of the source (or sources) of silicon “ore” and the details of the silicon-refinement process. The silicon production industry is large, highly segmented by refining step, and multifaceted in terms of final product type, from which we conclude that production of Si-32-mitigated crystals requires both targeted silicon material selection and a dedicated refinement-through-crystal-production process. We review options for source material selection, including quartz from an underground source and silicon isotopically reduced in Si-32. To quantitatively evaluate the Si-32 content in silicon metal and precursor materials, we propose analytic methods employing chemical processing and radiometric measurements. Ultimately, it appears feasible to produce silicon-based detectors with low levels of Si-32, though significant assay method development is required to validate this claim and thereby enable a quality assurance program during an actual controlled silicon-detector production cycle.

  11. Grounding a natural background level for fluoride in a potentially contaminated crystalline aquifer in south India.

    Science.gov (United States)

    Sajil Kumar, P J

    2017-12-01

    Fluoride contamination is one of the most alarming issues for those countries that depend on groundwater drinking water supply. A careful examination of the hydrogeochemical conditions and routine monitoring of fluoride level are therefore quintessential. Estimation of natural background level (NBL) of fluoride becomes significant information for assessing the current and future contamination episodes. Vellore District in Tamil Nadu is a hard rock terrain known for its F-rich groundwater. In this study, we attempted to form a benchmark for fluoride using hydrochemical pre-selection (based on TDS and NO 3 ) and cumulative probability plots (CPP). Principle components analysis is (PCA) applied to evaluate the corresponding factor grouping of the total of 68 samples, which is later mapped using geostatistical tool in ArcGIS. From the CPP, we derived the NBL of F as 0.75 mg/L. This value is compared with the observed concentration in each sample and they were spatially plotted based on the NBL. Resultant plot suggests that W-NW part of the study area has exceeded and E-EW regions are below the NBL of F. Spatial variation of the factor scores also supported this observation. Grounding an NBL and extending it to other parts of the potential contaminated aquifers are highly recommended for better understanding and management of the water supply systems.

  12. Natural indoor gamma background in an urban environment of Southern Poland

    International Nuclear Information System (INIS)

    Koperski, J.

    1984-01-01

    A regional survey of indoor exposure to natural gamma background from terrestrial sources was performed in the urban environment of six administrative provinces of Southern Poland. 1351 dwelling houses at 144 localities were monitored using of LiF:Mg,Ti thermoluminescence dosemeters. The dose rates observed indoors were between 32 and 185 nGy.h -1 and were strongly dependent on the types of building materials used in the dwellings monitored. The highest mean provincial values were found in slag and fly-ash dwellings (77-123 nGy.h -1 ), while in wooden dwellings these values were the lowest (42-51 nGy.h -1 ). Intermediate values occurred in clay brick dwellings (57-102 nGy.h -1 ), in dwellings of mixed, wooden-brick construction (60-79 nGy,h -1 ) and in dwellings made of gravel-sand prefabricates (52-68 nGy.h -1 ). The calculated mean annual per capita effective dose equivalent rates ranged between 0.2 mSv.y -1 , for the inhabitants of wooden houses, and 0.6 mSv.y -1 for those living in houses made of coal by-product prefabricates. (author)

  13. Measurement of the 36Cl deposition flux in central Japan: natural background levels and seasonal variability.

    Science.gov (United States)

    Tosaki, Yuki; Tase, Norio; Sasa, Kimikazu; Takahashi, Tsutomu; Nagashima, Yasuo

    2012-04-01

    Essential parameters for the applications of (36)Cl as a tracer in groundwater studies include the initial (36)Cl/Cl ratio, at the time of recharge, and/or the natural background deposition flux of (36)Cl in the recharge area. To facilitate the hydrological use of (36)Cl in central Japan, this study aimed to obtain a precise estimate of the long-term average local (36)Cl flux and to characterize its seasonal variability. The (36)Cl in precipitation was continuously monitored in Tsukuba, central Japan over a period of >5 years. The (36)Cl flux showed a clear seasonal variation with an annual peak during the spring, which was attributed to the seasonal variability of tropopause height. The long-term average (36)Cl flux (32±2atoms m(-2)s(-1)), estimated from the measured data, was consistent with the prediction from the (36)Cl latitudinal fallout model scaled using the global mean production rate of 20atoms m(-2)s(-1). The initial (36)Cl/Cl ratio was estimated to be (41±6)×10(-15), which is similar to that of pre-bomb groundwater in the Tsukuba Upland. An observation period covering an 11-year solar cycle would yield more accurate estimates of the values, given the increased (36)Cl flux during the solar minimum. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

    Science.gov (United States)

    Jafery, Khawarizmi Mohd; Embong, Zaidi; Khee, Yee See; Haimi Dahlan, Samsul; Tajudin, Saiful Azhar Ahmad; Ahmad, Salawati; Kudnie Sahari, Siti; Maxwell, Omeje

    2018-01-01

    The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong-Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka-Tavy, Harimau Tampoi, Kulai-Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ± 26.28 μR hr-1 and 7 ± 0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern

  15. The biological effects of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Higson, D.J.

    2016-01-01

    Scenarios for exposure to ionising radiation range from natural background radiation (chronic) to the explosions of atomic bombs (acute), with some medical, industrial and research exposures lying between these extremes. Biological responses to radiation that predominate at high doses incurred at high dose rates are different from those that predominate at low doses and low dose rates. Single doses from bomb explosions ranged up to many thousand mGy. Acute doses greater than about 1000 mGy cause acute radiation syndrome (ARS). Below this threshold, radiation has a variety of potential latent health effects: Change to the incidence of cancer is the most usual subject of attention but change to longevity may be the best overall measure because decreased incidences of non-cancer mortality have been observed to coincide with increased incidence of cancer mortality. Acute doses greater than 500 mGy cause increased risks of cancer and decreased life expectancy. For doses less than 100 mGy, beneficial overall health effects ('radiation hormesis') have been observed. At the other end of the spectrum, chronic exposure to natural radiation has occurred throughout evolution and is necessary for the normal life and health of current species. Dose rates greater than the present global average of about 2 mGy per year have either no discernible health effect or beneficial health effects up to several hundred mGy per year. It is clearly not credible that a single health effects model -- such as the linear no-threshold (LNT) model of risk estimation -- could fit all latent health effects. A more realistic model is suggested.

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

    Directory of Open Access Journals (Sweden)

    Sanjay Premi

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

  17. Airborne laser-spark for ambient desorption/ionisation.

    Science.gov (United States)

    Bierstedt, Andreas; Riedel, Jens

    A novel direct sampling ionisation scheme for ambient mass spectrometry is presented. Desorption and ionisation are achieved by a quasi-continuous laser induced plasma in air. Since there are no solid or liquid electrodes involved the ion source does not suffer from chemical interferences or fatigue originating from erosive burning or from electrode consumption. The overall plasma maintains electro-neutrality, minimising charge effects and accompanying long term drift of the charged particles trajectories. In the airborne plasma approach the ambient air not only serves as the plasma medium but at the same time also slows down the nascent ions via collisional cooling. Ionisation of the analyte molecules does not occur in the plasma itself but is induced by interaction with nascent ionic fragments, electrons and/or far ultraviolet photons in the plasma vicinity. At each individual air-spark an audible shockwave is formed, providing new reactive species, which expands concentrically and, thus, prevents direct contact of the analyte with the hot region inside the plasma itself. As a consequence the interaction volume between plasma and analyte does not exceed the threshold temperature for thermal dissociation or fragmentation. Experimentally this indirect ionisation scheme is demonstrated to be widely unspecific to the chemical nature of the analyte and to hardly result in any fragmentation of the studied molecules. A vast ensemble of different test analytes including polar and non-polar hydrocarbons, sugars, low mass active ingredients of pharmaceuticals as well as natural biomolecules in food samples directly out of their complex matrices could be shown to yield easily accessible yet meaningful spectra. Since the plasma medium is humid air, the chemical reaction mechanism of the ionisation is likely to be similar to other ambient ionisation techniques. Wir stellen hier eine neue Ionisationsmethode für die Umgebungsionisation (ambient ionisation) vor. Sowohl die

  18. 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

  19. Ionising radiation safety training in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Jenks, G.J.; O'Donovan, E.J.B.; Wood, W.B.

    1998-01-01

    Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation. However, most are designated as radiation protection officers as a secondary duty. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A Training Course, responding to these requirements, has been developed to emphasize, basic radiation theory and protection, operation of radiation monitors available in the ADO, an understanding of the Ionising Radiation Safety Manual, day-to-day radiation safety in units and establishments, and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved successful, both for the students and the ADO generally. To seek national accreditation of the course through the Australian National Training Authority, as a first step, competency standards have been proposed. (authors)

  20. A Discussion about Ionising and Non-Ionising Radiation and the Critical Issue of Mobile Phones

    Science.gov (United States)

    Kontomaris, Stylianos-Vasileios; Malamou, Anna

    2018-01-01

    Electromagnetic radiation is one of the most important issues affecting peoples' lives today. The misunderstanding of students and the general population of the effects of electromagnetic radiation is a problem which must be eliminated. Thus, a discussion about ionising and non-ionising radiation focusing on the crucial issue of radiation emitted…

  1. On the Nature of the Microwave Background at the Lagrange 2 Point. Part II

    Directory of Open Access Journals (Sweden)

    Borissova L.

    2007-10-01

    Full Text Available In this work the mathematical methods of General Relativity are used to answer the following questions: if a microwave background originates from the Earth, what would be its density and associated dipole measured at the altitude of a U2 aeroplane (25 km, the COBE satellite (900 km, and the 2nd Lagrange point (1.5 million km, the position of the WMAP and PLANCK satellites? The first problem is solved via Einstein’s equations for the electromagnetic field of the Earth. The second problem is solved using the geodesic equations for light-like particles (photons which are mediators for electromagnetic radiation. We have determined that a microwave background that originates at the Earth (the Earth microwave background decreases with altitude so that the density of the energy of such a background at the altitude of the COBE orbit (900 km is 0.68 times less than that at the altitude of a U2 aeroplane. The density of the energy of the background at the L2 point is only ~1E-7 of the value detected by a U2 aeroplane or at the COBE orbit. The dipole anisotropy of the Earth microwave background, due to the rapid motion of the Earth relative to the source of another field which isn’t connected to the Earth but is located in depths of the cosmos, doesn’t depend on altitute from the surface of the Earth. Such a dipole will be the same irrespective of the position at which measurements are taken.

  2. Comparison of segmentation algorithms for cow contour extraction from natural barn background in side view images

    NARCIS (Netherlands)

    Hertem, van T.; Alchanatis, V.; Antler, A.; Maltz, E.; Halachmi, I.; Schlageter Tello, A.A.; Lokhorst, C.; Viazzi, S.; Romanini, C.E.B.; Pluk, A.; Bahr, C.; Berckmans, D.

    2013-01-01

    Computer vision techniques are a means to extract individual animal information such as weight, activity and calving time in intensive farming. Automatic detection requires adequate image pre-processing such as segmentation to precisely distinguish the animal from its background. For some analyses

  3. Wave operators for atomic photo-ionisation

    International Nuclear Information System (INIS)

    Muller, H.G.; Tip, A.

    1983-01-01

    The time development of a system consisting of an atom in an external electromagnetic field with fixed propagation direction is studied (vector potential A(x,t)=A(x 3 -ct)). It is shown that the Moeller wave-operators, relevant for photo-ionisation, exist, provided the components Asub(σ)(u) of A decay as |u|sup(-1-epsilon), epsilon>O, for large argument u. Since A(x,t) is not necessarily spatially homogeneous, the above results can serve as a starting point for an investigation of field-gradient effects on photo-ionisation processes. (author)

  4. The Pedagogy of Science Teachers from Non-Natural Science Backgrounds

    Science.gov (United States)

    Woods, Shaneka

    2017-01-01

    This is a descriptive, exploratory, qualitative, collective case study that explores the pedagogical practices of science teachers who do not hold natural science degrees. The intent of this study is to support the creation of alternative pathways for recruiting and retaining high-quality secondary science teachers in K-12 education. The…

  5. Natural Covariant Planck Scale Cutoffs and the Cosmic Microwave Background Spectrum

    Science.gov (United States)

    Chatwin-Davies, Aidan; Kempf, Achim; Martin, Robert T. W.

    2017-07-01

    We calculate the impact of quantum gravity-motivated ultraviolet cutoffs on inflationary predictions for the cosmic microwave background spectrum. We model the ultraviolet cutoffs fully covariantly to avoid possible artifacts of covariance breaking. Imposing these covariant cutoffs results in the production of small, characteristically k -dependent oscillations in the spectrum. The size of the effect scales linearly with the ratio of the Planck to Hubble lengths during inflation. Consequently, the relative size of the effect could be as large as one part in 1 05; i.e., eventual observability may not be ruled out.

  6. The nature of the background in transmission (e,2e) experiments

    International Nuclear Information System (INIS)

    Vos, M.; Storer, P.; Kheifets, A.S.; McCarthy, I.E.; Weigold, E.

    1995-08-01

    The authors present (e,2e) data of a graphitic carbon film over a large energy range (from 0 to 330 eV binding energy). This range contains both the valence band and the C 1s core level. Below the valence band there is always intensity, due to inelastic scattering effects. The momentum characteristics of this background are discussed. Finally, the intensity-ratio of the valence band features and the core level are compared with the theoretically calculated one. 9 refs., 4 figs

  7. Authenticity perceptions of nature based-attractions, such as Preiksetolen, Norway, by people with different backgrounds

    OpenAIRE

    Ivanova, Aleksandra

    2017-01-01

    Master's thesis in International hotel and tourism management This explorative case study is about Preikestolen, one of the most iconic attraction in Norway. Recently, it has an increasing number in visitation and provides relatively easy hiking, due its’ route developments, engaging “mass” or individual tourists with different levels of experience. Nature-based tourism satisfies the needs of contemporary tourists, providing a variety of visual and physical experiences, such as recreation,...

  8. Investigation of natural radiation background and assessment of its population dose in China

    International Nuclear Information System (INIS)

    1989-01-01

    This paper presents the nationwide survey in 1984-1988 of environmental external radiation by integrating measurements, and the assessment of population doses from obtained data. Thermoluminescent dosimeters (TLD) model ETLD-80 with CaSO 4 : Dy were used. The survey was conducted in two different scales. In general survey, TLDs were distributed in whole area of every investigated provinces; and in local survey, one city and one village within each province were selected and investigated for the purpose of comparison of the natural radiation levels between the rural and urban areas. A marked characteristics was noted that the level of natural environmental radiation in south China seems to be higher than that in north China. It may be attributed to the geological difference in both parts. The annual individual average and collective effective dose equivalents to population of China from natural environmental radiation were estimated to be 780 μSv and 8.1 x 10 5 man. Sv, based on the model recommended by UNSCEAR 1988 Report

  9. Biological Effects of Ionising Radiation and Countermeasures (Les effets biologiques des rayonnements ionisants et leurs contre-mesures)

    Science.gov (United States)

    2018-01-01

    blood of pet dogs living in areas highly contaminated by organochlorine pesticides [10]. Aim: • To evaluate the effectiveness of using military...REPORT TR-HFM-222 Biological Effects of Ionising Radiation and Countermeasures (Les effets biologiques des rayonnements ionisants et leurs contre...REPORT TR-HFM-222 Biological Effects of Ionising Radiation and Countermeasures (Les effets biologiques des rayonnements ionisants et leurs contre

  10. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    In this work we have studied aerosol formation at ultra-low ionisation levels, using the existing deep underground science facility at Boulby mine, UK. At 1100 m depth, with a corresponding factor 106 reduction in cosmic ray muon flux, the Boulby facility is an ideal place to study the role of ions...

  11. Statistical methods for determination of background levels for naturally occuring radionuclides in soil at a RCRA facility

    International Nuclear Information System (INIS)

    Guha, S.; Taylor, J.H.

    1996-01-01

    It is critical that summary statistics on background data, or background levels, be computed based on standardized and defensible statistical methods because background levels are frequently used in subsequent analyses and comparisons performed by separate analysts over time. The final background for naturally occurring radionuclide concentrations in soil at a RCRA facility, and the associated statistical methods used to estimate these concentrations, are presented. The primary objective is to describe, via a case study, the statistical methods used to estimate 95% upper tolerance limits (UTL) on radionuclide background soil data sets. A 95% UTL on background samples can be used as a screening level concentration in the absence of definitive soil cleanup criteria for naturally occurring radionuclides. The statistical methods are based exclusively on EPA guidance. This paper includes an introduction, a discussion of the analytical results for the radionuclides and a detailed description of the statistical analyses leading to the determination of 95% UTLs. Soil concentrations reported are based on validated data. Data sets are categorized as surficial soil; samples collected at depths from zero to one-half foot; and deep soil, samples collected from 3 to 5 feet. These data sets were tested for statistical outliers and underlying distributions were determined by using the chi-squared test for goodness-of-fit. UTLs for the data sets were then computed based on the percentage of non-detects and the appropriate best-fit distribution (lognormal, normal, or non-parametric). For data sets containing greater than approximately 50% nondetects, nonparametric UTLs were computed

  12. Geological background of the estimation of natural stresses in soil body

    Directory of Open Access Journals (Sweden)

    Chernyshev Sergey Nikolaevich

    2015-01-01

    Full Text Available Initial and boundary conditions are always given for solving the problem of calculating the interaction of tunnels and other underground structures with soil and rocks. The same conditions are set for calculating the surface buildings. These initial data for calculation are divided into three groups: 1 the geometrical shape of the layers of rocks (geological structure; 2 the parameters of the strength and compressibility of rocks; 3 compressive stresses in the array. These data all over the world are set with engineering surveys. In engineering surveys there are good methods of determining the source of the data 1 and 2. But there is no available methodology for determining the natural stress state. Therefore, compressive and tensile stresses are usually determined by mathematical modeling. The calculation of the compressive stresses is done on the basis of the following hypotheses: compressive stresses are created by the weight of rocks; they go down in proportion to the density of rocks; the main normal stress is has a vertical direction; normal stress in horizontal direction is smaller. The value of the horizontal stress is was calculated using Poisson’s ratio. This hypothesis of the nineteenth century was used another 50 years ago, when it was not known exactly about the movement of the continents and when compressive stresses in the earth’s crust have not yet been measured. Today a universal application of this hypothesis is not correct. Now the application of this hypothesis in many cases is not correct. In this research paper an attempt is made to specify the area, in which the above hypothesis can be used. This is done on the basis of current scientific evidence. Abroad this way of calculating tunnels and other underground structures and bases of buildings should be done taking into account the real field of natural stresses. The geological characteristics of the location of the axes of stresses in soil body are based on the study of

  13. 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

  14. The Nature of the Unresolved Extragalactic Cosmic Soft X-Ray Background

    Science.gov (United States)

    Cappelluti, N.; Ranalli, P.; Roncarelli, M.; Arevalo, P.; Zamorani, G.; Comastri, A.; Gilli, R.; Rovilos, E.; Vignali, C.; Allevato, V.; hide

    2013-01-01

    In this paper we investigate the power spectrum of the unresolved 0.5-2 keV cosmic X-ray background (CXB) with deep Chandra 4-Msec (Ms) observations in the Chandra Deep Field South (CDFS). We measured a signal that, on scales >30 arcsec, is significantly higher than the shot noise and is increasing with angular scale. We interpreted this signal as the joint contribution of clustered undetected sources like active galactic nuclei (AGN), galaxies and the intergalactic medium (IGM). The power of unresolved cosmic source fluctuations accounts for approximately 12 per cent of the 0.5-2 keV extragalactic CXB. Overall, our modelling predicts that approximately 20 per cent of the unresolved CXB flux is produced by low-luminosity AGN, approximately 25 per cent by galaxies and approximately 55 per cent by the IGM. We do not find any direct evidence of the so-called 'warm hot intergalactic medium' (i.e. matter with 10(exp 5) less than T less than 10(exp 7) K and density contrast delta less than 1000), but we estimated that it could produce about 1/7 of the unresolved CXB. We placed an upper limit on the space density of postulated X-ray-emitting early black holes at z greater than 7.5 and compared it with supermassive black hole evolution models.

  15. Doubling potential of fibroblasts from different species after ionising radiation

    International Nuclear Information System (INIS)

    Macieira-Coelho, A.; Diatloff, C.; Malaise, E.

    1976-01-01

    It is stated that whereas chicken fibroblasts invariably die after a certain number of doublings in vitro, and this fact is never altered by chemical or physical agents, mouse fibroblasts invariably acquire spontaneously an infinite growth potential. In the human species fibroblasts never acquire spontaneously the capacity to divide for ever, although they can become permanent cell lines after treatment with certain viruses. This behaviour of fibroblasts in vitro has been attributed to different nutritional requirements. Experiments are described with human and mouse fibroblasts in which it was found that the response to ionising radiation matches the relative tendencies of the fibroblasts to yield permanent cell lines. Irradiation was commenced during the phase of active proliferation. Human fibroblast cultures irradiated with 100 R stopped dividing earlier than the controls, whereas cultures irradiated with 200, 300 and 500 R had the same lifespan as the control cultures. Cultures irradiated with 400 R showed the longest survival. With mouse fibroblasts the growth curves of the irradiated cells were of the same type as in the controls, but recovery occurred earlier. The results indicated that ionising radiation accelerates a natural phenomenon; in cells with a limited growth potential (chicken) it shortens the lifespan, whereas in cells that can acquire an unlimited growth potential (mouse) it accelerates acquisition of this potential; human fibroblasts showed an intermediate response, since ionising radiation neither established the cultures as with mouse cells nor reduced the number of cells produced as with chicken fibroblasts. Possible explanations for the different behaviour of the species are offered. (U.K.)

  16. Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.

    NARCIS (Netherlands)

    Have, ten R.; Rietjens, I.M.C.M.; Hartmans, S.; Swarts, H.J.; Field, J.A.

    1998-01-01

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was

  17. Cosmic microwave background polarization as a probe of the anomalous nature of the cold spot

    Science.gov (United States)

    Vielva, P.; Martínez-González, E.; Cruz, M.; Barreiro, R. B.; Tucci, M.

    2011-01-01

    One of the most interesting explanations for the non-Gaussian cold spot detected in the Wilkinson Microwave Anisotropy Probe (WMAP) data by Vielva et al. is that it arises from the interaction of the cosmic microwave background radiation with a cosmic texture. In this case, a lack of polarization is expected in the region of the spot, as compared to the typical values associated to large fluctuations of a Gaussian and isotropic random field. In addition, other physical processes related to a non-linear evolution of the gravitational field could lead to a similar scenario. However, some of these alternative scenarios (e.g. a large void in the large-scale structure) have been shown to be very unlikely. In this work we characterize the polarization properties of the cold spot under both hypotheses: a large Gaussian fluctuation and an anomalous feature generated, for instance, by a cosmic texture. We also propose a methodology to distinguish between them, and we discuss its discrimination power as a function of the instrumental noise level. In particular, we address the cases of current experiments, like WMAP and Planck, and others in development as the Q, U and I Joint Tenerife Experiment (QUIJOTE). We find that for an ideal experiment with a high-polarization sensitivity, the Gaussian hypothesis could be rejected at a significance level better than 0.8 per cent. While WMAP is far from providing useful information in this respect, we find that Planck will be able to reach a significance level of around 7 per cent; in addition, we show that the ground-based experiment QUIJOTE could provide a significance level of around 1 per cent, close to the ideal case. If these results are combined with the significance level found for the cold spot in temperature, the capability of QUIJOTE and Planck to reject the alternative hypothesis becomes 0.025 and 0.124 per cent, respectively.

  18. Patterns of population differentiation and natural selection on the celiac disease background risk network.

    Directory of Open Access Journals (Sweden)

    Aaron Sams

    Full Text Available Celiac disease is a common small intestinal inflammatory condition induced by wheat gluten and related proteins from rye and barley. Left untreated, the clinical presentation of CD can include failure to thrive, malnutrition, and distension in juveniles. The disease can additionally lead to vitamin deficiencies, anemia, and osteoporosis. Therefore, CD potentially negatively affected fitness in past populations utilizing wheat, barley, and rye. Previous analyses of CD risk variants have uncovered evidence for positive selection on some of these loci. These studies also suggest the possibility that risk for common autoimmune conditions such as CD may be the result of positive selection on immune related loci in the genome to fight infection. Under this evolutionary scenario, disease phenotypes may be a trade-off from positive selection on immunity. If this hypothesis is generally true, we can expect to find a signal of natural selection when we survey across the network of loci known to influence CD risk. This study examines the non-HLA autosomal network of gene loci associated with CD risk in Europe. We reject the null hypothesis of neutrality on this network of CD risk loci. Additionally, we can localize evidence of selection in time and space by adding information from the genome of the Tyrolean Iceman. While we can show significant differentiation between continental regions across the CD network, the pattern of evidence is not consistent with primarily recent (Holocene selection across this network in Europe. Further localization of ancient selection on this network may illuminate the ecological pressures acting on the immune system during this critically interesting phase of our evolution.

  19. Cellular and molecular effects of natural background radiation on human population in Kerala coast, India: from chromosome ends to transcriptome

    International Nuclear Information System (INIS)

    Das, Birajalaxmi; Jain, Vinay; Saini, Divyalakshmi; Ghosh, Anu; Seshadri, M.; Sandhya Kiran, P.

    2010-01-01

    Venous blood samples of 32 male volunteers (age group 35-45 years) from different background dose groups. Factors like life style, smoking, drinking alcohol, chewing, previous exposure to radiation and medical history etc. were properly recorded. Microarray analysis was performed using Affymetrix FlGU133 plus 2.0 chip and the expression level of 54,675 genes were obtained for each sample. In order to assess the effect of chronic natural background radiation we have categorized our samples into four groups. To derive genes that are differentially regulated between these four groups, 'Exposed group versus Control' was set up and the linear model was fitted to each gene using the expression data on samples. A fold change threshold of 1.3, 1.5 and 2.0 and an adjusted p-value threshold of 0.05 was set in the study. Analysis was done using 'limma' library of R and Genowiz

  20. 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.

  1. Antioxidant Protection in Blood against Ionising Radiation

    International Nuclear Information System (INIS)

    Bognar, G.; Meszaros, G.; Koteles, G. J.

    2001-01-01

    Full text: The quantities of the antioxidants in the human blood are important indicators of health status. The routine determinations of activities/capacities of antioxidant compounds would be of great importance in assessing individual sensitivities against oxidative effects. We have investigated the sensitivities of those antioxidant elements against various doses of ionising radiation tested by the RANDOX assays. Our results show dose-dependent decreases of antioxidant activities caused by the different doses. The total antioxidant status value linearly decreased up to 1 Gy, but further increase of dose (2 Gy) did not influence the respective values although the test system still indicated their presence. It means that the human blood retains 60-70% of its total antioxidant capacity. Radiation induced alterations of the antioxidant enzymes: glutathione peroxidase and superoxide dismutase have been also investigated. The activities of glutathione peroxidase and superoxide dismutase decreased linearly upon the effects of various doses of ionising radiation till 1 Gy. Between 1 and 2 Gy only further mild decreases could be detected. In this case the human blood retained 40-60% of these two antioxidant enzymes. These observations suggest either the limited response of antioxidant system against ionising radiation, or the existence of protection system of various reactabilities. (author)

  2. Protection of the environment from ionising radiation: ethical issues

    International Nuclear Information System (INIS)

    Oughton, Deborah

    2003-01-01

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to environmental protection are discussed: First, the question of valuing the environment and implications for the definition of harm and monetary valuation of environmental goods; second, difficulties with scientific uncertainty and applications of the precautionary principle; and third, issues concerned with the distribution of risk and its relevance fo participation in decision-making. In summary, the paper argues that there are strong ethical grounds to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors

  3. Protection of the environment from ionising radiation: ethical issues.

    Science.gov (United States)

    Oughton, Deborah

    2003-01-01

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to environmental protection are discussed: First, the question of valuing the environment and implications for the definition of harm and monetary valuation of environmental goods; second, difficulties with scientific uncertainty and applications of the precautionary principle; and third, issues concerned with the distribution of risk and its relevance for participation in decision-making. In summary, the paper argues that there are strong ethical grounds to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors. Copyright 2002 Elsevier Science Ltd.

  4. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Q-balls with ATLAS. A dedicated trigger was developed and deployed for proton-proton collisions at a centre of mass energy of 8 TeV. It uses the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The high threshold (HT) readout capability of the TRT is used to distinguish HIPs from other background processes. The trigger requires significantly lower energy depositions in the electromagnetic calorimeters and is thereby capable of probing a larger range of HIP masses and charges. A description of the algorithm for this newly developed trigger is presented, along with a comparitive study of its performance during the 2012 data-taking period with respect to previous efforts.

  5. Effects of reduced natural background radiation on Drosophila melanogaster growth and development as revealed by the FLYINGLOW program.

    Science.gov (United States)

    Morciano, Patrizia; Iorio, Roberto; Iovino, Daniela; Cipressa, Francesca; Esposito, Giuseppe; Porrazzo, Antonella; Satta, Luigi; Alesse, Edoardo; Tabocchini, Maria Antonella; Cenci, Giovanni

    2018-01-01

    Natural background radiation of Earth and cosmic rays played a relevant role during the evolution of living organisms. However, how chronic low doses of radiation can affect biological processes is still unclear. Previous data have indicated that cells grown at the Gran Sasso Underground Laboratory (LNGS, L'Aquila) of National Institute of Nuclear Physics (INFN) of Italy, where the dose rate of cosmic rays and neutrons is significantly reduced with respect to the external environment, elicited an impaired response against endogenous damage as compared to cells grown outside LNGS. This suggests that environmental radiation contributes to the development of defense mechanisms at cellular level. To further understand how environmental radiation affects metabolism of living organisms, we have recently launched the FLYINGLOW program that aims at exploiting Drosophila melanogaster as a model for evaluating the effects of low doses/dose rates of radiation at the organismal level. Here, we will present a comparative data set on lifespan, motility and fertility from different Drosophila strains grown in parallel at LNGS and in a reference laboratory at the University of L'Aquila. Our data suggest the reduced radiation environment can influence Drosophila development and, depending on the genetic background, may affect viability for several generations even when flies are moved back to normal background radiation. As flies are considered a valuable model for human biology, our results might shed some light on understanding the effect of low dose radiation also in humans. © 2017 Wiley Periodicals, Inc.

  6. Natural background values for heavy metals in the sediments of a contaminated Northern Adriatic lagoon environment: a geochemical perspective

    Directory of Open Access Journals (Sweden)

    Covelli S.

    2013-04-01

    Full Text Available Major and trace elements were determined in 14 sediment cores collected from the Marano and Grado Lagoon (northern Adriatic sea. The lagoon is contaminated by several harmful priority substances, heavy metals included, and it has also been declared a “polluted site of national interest” (SIN mainly due to high Hg concentrations in sediments. Based on a normalization procedure involving predicted linear relationships for “metal vs Al” obtained from the core subsamples, background values for each metal were evaluated on a regional scale and according to the grain-size variability. Compared to Environmental Quality Standards reported in the Italian laws and regulations, the estimated background ranges show that bottom sediments are naturally “enriched” in some metals, such as Cr, Ni and Cd especially in sediments with a high percentage of the fine component. A correct evaluation on sediment quality status should be made on the basis of regional background values for each metal, taking into account local geochemical characteristics, i.e. mineralogical composition and grain-size variability of sediments.

  7. Study and optimization of the ionisation channel in the Edelweiss dark matter direct detection experiment

    International Nuclear Information System (INIS)

    Censier, B.

    2006-02-01

    The EDELWEISS experiment is aiming at the detection of Weakly Interactive Massive Particles (WIMPs), today's most favoured candidates for solving the dark matter issue. Background ionising particles are identified thanks to the simultaneous measurement of heat and ionisation in the detectors. The main limitation to this method is coming from the ionisation measurement, charge collection being less efficient in some part of the detectors known as 'dead' areas. The specificity of the measurement is due to the use of very low temperatures and low collection fields. This thesis is dedicated to the study of carrier trapping. It involves time-resolved charge measurements as well as a simulation code adapted to the specific physical conditions. We first present results concerning charge trapping at the free surfaces of the detectors. Our method allows to build a surface-charge in a controlled manner by irradiation with a strong radioactive source. This charge is then characterised with a weaker source which acts as a probe. In a second part of the work, bulk-trapping characteristics are deduced from charge collection efficiency measurements, and by an original method based on event localisation in the detector. The results show that a large proportion of the doping impurities are ionised, as indicated independently by the study of degradation by space-charge build-up. In this last part, near-electrodes areas are found to contain large densities of charged trapping centres, in connection with dead-layer effects. (author)

  8. Food ionisation. Realities and perspectives; L'ionisation alimentaire. Realites et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  9. Detection of WIMPs in the Edelweiss experiment. Study of the radioactive background noise and measurements with bolometers; Recherche des wimp's du halo galactique dans l'experience edelweiss: etude du bas bruit radioactif et mesures a l'aide de bolometres a double detection ionisation/chaleur

    Energy Technology Data Exchange (ETDEWEB)

    Miramonti, L. [CEA/Saclay, Dept. d' Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l' Instrumentation Associee (DAPNIA), 91 - Gif-sur-Yvette (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-11-01

    This thesis is dedicated to the detection of black matter in the form of WIMPs (weakly interacting massive particle). The characteristics of the interaction of WIMPs with matter are recalled. The very low number of expected events (<1 event/day.Kg) implies a radioactive background noise as weak as possible, furthermore the exponential decrease of the interacting rate with increasing energy calls for detectors with very low thresholds. Bolometers present advantages in WIMPs detection: i) very good resolution and very low thresholds, ii) very broad range of materials that can be used as absorber, the only requirements are: a crystal structure, to be a diamagnetic isolator and to have a convenient Debye temperature, iii) the possibility of detecting ionizing or non-ionizing particles, iv) the possibility of identifying the incident particle by measuring both temperature and another parameter such as ionization or scintillation, and v) the possibility of localizing the interaction inside the absorber by detecting ballistic phonons. The problematic of radioactive background noise is presented and the answers to the different sources (cosmic radiation,natural and artificial radioactivity) generating the background noise are examined. The materials used in the building of the detector and cryostat must be carefully chosen, they should be as little radioactive as possible. The test benches used to select materials for the Edelweiss experiment are described. The first measurements concerning the detectors Ge-4 and Ge-7 are presented. (A.C.)

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

    International Nuclear Information System (INIS)

    Arunachalam, Kantha Deivi; Subhasini, K.

    2015-06-01

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

  11. Health effects of ionising radiation

    International Nuclear Information System (INIS)

    Mohammadi, S.

    2000-01-01

    Human and animal studies have shown an increased incidence of cancer and malformation due to radioactive materials and external radiation. The biological effects of radiation on tissues are the occurrence of morphological and functional changes in the body. The critical parts of the body are those tissues or organs which when irradiated, are likely to influence the health of the individual or its offspring. The probability of these changes depends on the radiation dose. There are two main types of damage due to radiation dose. Radiation Sickness with well-defined symptoms like cancer and inherited disorders which can appear after several years. A second type of damage, namely Acute Radiation Sickness results after exposure of the whole or parts of the body to high doses of radiation greater than 1 Gy. There are safety standards for the amount of dose equivalent that is taken as acceptable. The International Commission on Radiological Protection (ICRP) has given norms in which natural and medical causes were not included. These are given as recommended values (1966) and proposed values (2000), both in mSv/yr: population at large: 1.7 and 0.4; members of the public: 5 and 2; and radiologic workers: 50 and 20, respectively. Taking into account the increased number of reactor accidents, the question is how safe is our safety standards? Even when one is able to connect a quantitative risk with a radiation dose, there are three fundamental principles which we should obey in dealing with risks from radiation. These are: (1) Avoid any risk. (2) The risk should be related to the possible benefit. (3) Any dose below the politically agreed limits is acceptable

  12. Proceedings of the 8. International symposium on the natural radiation environment (NRE-VIII). Book of abstracts

    International Nuclear Information System (INIS)

    2007-01-01

    Theoretical and experimental papers are presented in these proceedings covering the following subjects: cosmic radiation, solar activity and cosmogenic radionuclides - natural radiation from space, high background areas - life in naturally elevated radiation areas, radon and thoron - indoors and outdoors, other terrestrial natural radionuclides - natural radioactivity, NORM/TENORM, including depleted uranium - technologically enhanced natural radioactivity, dosimetry and health risk assessment biological effects of natural radioactivity , exposures of biota to natural radioactivity, metrology, modelling and epidemiology, BSS and legal issues - regulating natural radioactivity, RDD (dirty bombs and terrorism - terrorism and natural radioactive material, non-ionising radiation (NIR) an the NRE 11), geochronology plus natural radioactivity and the theory of time

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

    International Nuclear Information System (INIS)

    Ngo Van Thanh

    2008-01-01

    The author had studied the natural radiation background in 68 districts belong 40 provinces and cities of Vietnam from 2002 to 2005. The estimated results clearly show that the average external irradiation dose levels and the average annual external radiation equivalent dose affected on the human body are 0.181± 0.0189 μSv/h and 1599 ± 171.8 μSv/year respectively, both are in normal limit; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Buon Ma Thuot city (DakLak province), Phuoc Son district (Quang Nam province), Tan An district (Long An province). The radon concentration in the human being and the average annual internal inhalation irradiation equivalent dose affected on the human beings are 26.9 ± 15.89 Bq/m 3 and 392.88 ± 231.99 μSv/year respectively; the maximums are in Nha Trang city (Khanh Hoa province), Bac Binh district (Binh Phuoc province); the minimums are in Vung Tau city (Ba Ria- Vung Tau province), Tan An district (Long An province), Rach Gia district (Kien Giang province). The terrestrial radionuclide concentrations in the cereals, foodstuffs (rice, meat, vegetables), water, earth and the average annual internal irradiation equivalent dose are 829.2 ± 38.06 Bq/kg and 229.3 ± 67.70 μSv/year respectively; the highest levels are in Phong Tho district (Lai Chau province), Dien Bien city; the lowest levels are in Dong Xoai district (Binh Phuoc province), Tan An district (Long An province). The average total annual natural radiation background effective equivalent dose level affected on the human body is 2206.9 ± 529.30 μSv/year; the highest levels are in Lai Chau district (Lai Chau province); the lowest levels are in Tan An district (Long An province). The 14 maps of Natural Radiation Background in several localized regions belong 40 provinces and cities of Viet Nam had been set up. These results can reserve for serviceman and public health in the both wartime and peacetime. (author)

  14. Hydrochemical trends for public supply well fields in The Netherlands (1898-2008), natural backgrounds and upscaling to groundwater bodies

    Science.gov (United States)

    Mendizabal, Igor; Baggelaar, Paul K.; Stuyfzand, Pieter J.

    2012-07-01

    SummaryStatistical trend analysis is applied to a 110 years long groundwater quality time series from the national network of public supply well fields (PSWFs) in The Netherlands. Such a groundwater quality monitoring network should be available in many countries, so that approaches and experiences presented here could be of interest world wide. Trendless concentration data series measured in the early years, which should bear the least anthropogenic influences, are selected to quantify the regional natural background concentration levels (NBLs) of groundwater resources at the depth of abstraction. Trends in the period 1960-2005, which contained a more homogeneous data set, are normalized to drinking water standards, mapped in planar view and cross sections, and used to identify the responsible hydrochemical processes. Seven representative trend bundles are defined by aggregation of trends for individual chemical parameters. Trend reversals due to either environmental sanitation measures or well field adaptation measures are identified by comparing significant trends obtained for two different periods within the time series. Natural background levels (NBLs) for individual PSWFs are upscaled to the national groundwater body level (as reported to EU), by aggregating them according to a PSWF typology based on a Hydrochemical System Analysis. This aggregation method groups together PSWFs that deliver waters of the same origin and similar hydrogeochemical environment. PSWFs delivering old groundwaters with a very stable quality are clearly differentiated from PSWFs pumping highly vulnerable aquifers characterized by strongly deteriorating water quality trends. Results are presented on national maps of The Netherlands with NBLs and water quality trends for selected major constituents. A normalized concentration change index (NCC) is defined and mapped to relate the quality difference between a recent survey (in 2008) and calculated NBLs, to the EU drinking water

  15. Ionising energy treatment of fresh fruit

    International Nuclear Information System (INIS)

    Rigney, C.J.

    1985-01-01

    The main purposes of the ionising energy treatment of fresh fruit are: the extension of shelf life of the commodity due to a direct physiological effect on the particular product; the extension of shelf life of the commodity due to a reduction in the development of moulds and rots which would normally render the product worthless; and the killing of insect pests of quarantine significance, to allow for normal marketing of fresh fruit without the risk of introducing insect pests to previously pest-free areas

  16. Transition dynamics in two-photon ionisation

    Science.gov (United States)

    Vacher, Morgane; Gaillac, Romain; Maquet, Alfred; Taïeb, Richard; Caillat, Jérémie

    2017-11-01

    We review various aspects of photoemission dynamics in the case of two-photon ionisation. We first recall the definition of a transition phase specific to two-photon transitions. Numerical experiments on model atoms are used to show how the group delay associated with the transition phase is actually representative of the early dynamics of the detected photoelectron wave packets. Then we address the question of measuring these transition delays using a standard interferometric technique of experimental attosecond physics, so-called rabbit. Finally, we outline different reinterpretations of rabbit giving access to the more fundamental scattering dynamics affecting any photoemission processes.

  17. Contribution to the study and use of ionisation chambers for nuclear reactor control (1965)

    International Nuclear Information System (INIS)

    Duchene, J.

    1961-02-01

    At the moment ionisation chambers are the detectors which are best suited to the task of nuclear reactor control by neutronic measurements. We have thought it wise to state some generalities concerning reactor dynamics, the various neutron detection methods, the working of ionisation chambers and the measurement methods used. Our contribution to reactor control techniques consists on the one hand in an attempt to make a synthesis of the factors influencing the operation of ionisation chambers, the study of these factors, and on the other hand in the development of ionisation chambers of the fission and boron types, making it possible to follow the working of a reactor from the moment it starts up until maximum power is attained. In the field of fission chambers, we have in particular improved the technique for depositing uranium oxide on aluminium and have perfected the electrolytic deposition process on other metals: stainless steel, copper, molybdenum, nickel, tantalum, titanium, kovar, tungsten and beryllium. We have developed several types of fission chambers used during the start-up of reactors: one type of medium performance now in use in French piles one high-sensitivity type one high-temperature type which has operated up to 600 deg. C. As far as boron chambers are concerned, we have studied the perturbations caused to the measurement by the exposure of the chamber to high neutron flux and to a very strong γ radiation. This exposure brings about a modification of the properties of the constituent materials and causes a background noise in the chamber which can seriously handicap the neutron measurements. We have shown that the compensation technique makes it possible to limit this noise and to thereby increase the range of measurement of conventional ionisation chambers intended for power measurements. Finally, we have built two types of compensation chambers used in the French reactors and have begun the study of a third type of high sensitivity for high

  18. The analysis on the extreme water shortage event in Hangzhou in 1247 AD and its natural and social backgrounds

    Science.gov (United States)

    Liu, Haolong

    2017-04-01

    Yangtze River Delta locating in the north subtropics of China, is famous for numerous rivers and lakes. Because of East Asian monsoon rainfall, flood is always the most primary disaster in this area during the past 2000 years. However, there were also several extreme water shortage events in the history. Example in Hangzhou in 1247 AD was such a typical year in the area. In the paper, the severity of this extreme event and the closely tied spatiotemporal variation of drought in Yangtze River Delta was quantitatively analyzed on the basis of documentary records during Southern Song Dynasty. Furtherly, its natural and social backgrounds was discussed. The result s are summarized as follows: 1) Wells, canals and West Lake of Hangzhou dried up in 1247 AD. The water level of canals was about 1.32-2.64 m lower than that in the normal year. The reduction of storage capacity in West Lake was 21 million stere or so. 2) The droughts in Yangtze River Delta was moderate on the whole, but that in the west of Zhejiang Province was severe. The drought in Hangzhou lasted from the 2nd lunar month to the end of this year. 3) The water shortage event was closely related to the quick going north and farther northern location of summer rain belt. The descending sea-level weakening the tide in Qiantang River, can also reduce the supply of water resources. 4) The quick growth of urban population, excessive aquaculture, and ineffective government supervision played an important social role in the process of this event. In the all, this extreme water shortage event was the result of both natural and social factors. This research is very helpful for the futuristic water resource forecast in Yangtze River Delta, and it also affords us lessons on the risk management and heritage conservation that merit attention. Key Words: Hangzhou, 1247 AD, water shortage, canal, West Lake, natural factors, social factors

  19. Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: Study protocol

    NARCIS (Netherlands)

    M. Gallastegi (Mara); M. Guxens Junyent (Mònica); A. Jiménez-Zabala (Ana); I. Calvente (Irene); M. Fernández (Marta); L. Birks (Laura); B. Struchen (Benjamin); M. Vrijheid (Martine); M. Estarlich (Marisa); M.F. Fernandez (Mariana); M. Torrent (Maties); F. Ballester (Ferran); J.J. Aurrekoetxea (Juan José); J. Ibarluzea (Jesús); D. Guerra (David); J. González (Julián); M. Röösli (Martin); L. Santa-Marina (Loreto)

    2016-01-01

    textabstractBackground: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol

  20. An approach in determining the baseline data on the natural background radioactivity of Batanes province, its implications to national security

    International Nuclear Information System (INIS)

    Reyes, Rolando Y.

    2005-01-01

    Since the dropping of the first atomic bombs in Hiroshima and Nagasaki on August 1945, the world has lived under the shadow of nuclear threat. This was heightened by the Chernobyl nuclear accident in 1986 and magnified by the September 11, 2001 terrorist attack of the World Trade Center in the USA. While the threat is global, nuclear security is a national responsibility. The Philippine government is presently formulating the Philippine Nuclear Security Plan (PNSP) to address nuclear security and terrorism. It is in this light that this research study was undertaken whose product can be used as input in the PNSP, particularly in the emergency preparedness and response strategy of the plan. The purpose of the study is to pilot a baseline study on the natural background radioactivity of Batan Island, Batanes province, and develop a scheme for replicating the Batan baseline study in other selected sites in the Philippines. Establishing a baseline data on the natural background radioactivity of the country is a proactive stand of trying to be prepared for any untoward nuclear event that can pose harm of the nation, people and environment. The baseline data will provide an important point of reference in assessing increases of radiation caused by serious nuclear and/or radiological incident, either accidentally or intentionally that may occur within and outside the national territory. A modified ground gamma ray spectrometric survey technique with the use of a portable gamma ray spectrometer and global positioning system was used in determining the distribution and abundance of the naturally occurring radioelements potassium (K), uranium (U), thorium (Th) and total natural radiation (TNR) of Batan Island. Prior to the field survey, a thorough calibration of the portable gamma ray instrument was instituted that converted the measured gamma-ray count data into ground concentrations of K, U and Th. This allowed the systematic measurement of 73 sampling/data stations for

  1. Monitoring the effectiveness of the natural anticoagulant sulodexide in pregnant women with autoimmune hyperthyroidism on the background of hyperhomocysteinemia

    Directory of Open Access Journals (Sweden)

    A.Yu. Scherbakov

    2017-04-01

    Full Text Available According to modern concepts, the occurrence of complications in utero-placental pool during pregnancy is a common cause of primary placental insufficiency, severe forms of late gestosis, recurrent miscarriage. It is obvious that the study of the nature of violations in the hemostatic system during pregnancy and the development of methods for timely correction will be the prevention of many obstetric diseases. Among the factors that affect hemostasis, thyroid hormones occupy a special place, they are able to influence not only the functional activity of platelets, but also adjust the intensity of the plasma and tissue fibrinolysis. Oppression of fibrinolytic activity is one of the pathogenetic factors of thrombosis development. The aim – to study the efficacy of natural anticoagulant sulodexide in pregnant women with autoimmune hyperthyroidism on the background of hyperhomocysteinemia. Materials and methods. The study involved 34 pregnant women with autoimmune hyperthyroidism complicated by hyperhomocysteinemia. A control group comprised 29 somatically healthy pregnant women. General clinical examination was carried out, the main indicators of all the links of the hemostatic system and the level of homocysteine were determined. Results. We determined that the main group of pregnant is characterized with chronometric and structural hypercoagulation, which manifests itself in the form of subclinical syndrome of disseminated intravascular coagulation, leading to complications of pregnancy, childbirth and the pathological condition of the fetus. Addition of anticoagulant sulodexide to the standard treatment led to the significant change in indices of all the components of hemostasis in pregnant women of the main group, in particular normalization of the total capacity of the coagulation and fibrinolytic systems. Decrease in activity of intravascular coagulation and platelet aggregation, the level of homocysteine was marked. Clinical indicators of

  2. 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

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

    International Nuclear Information System (INIS)

    Linsalata, Paul; Morse, Robert; Ford, Helen; Eisenbud, Merril; Franca, E.P.; de Castro, M.B.; Lobao, Nazyo; Sachett, Ivanor; Carlos, Marcia

    1991-01-01

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

  4. Natural radioactivity content in groundwater of Mt. Etna’s eastern flank and gamma background of surrounding rocks.

    Directory of Open Access Journals (Sweden)

    Beata Kozłowska

    2016-02-01

    Full Text Available Waters of Mt. Etna are the main source of drinking water for the local population and are also distributed in municipal supply systems to neighbouring areas. Radioactivity in underground waters and surrounding rocks from the eastern flank of Mt.Etnawas investigated on the basis of 9 water and 8 rocks samples from 12 localities altogether. Three samples were from water drainage galleries and six from water wells. All water intakes are used for consumption. Activity concentration of uranium isotopes 234,238U, radium isotopes 226,228Ra and radon 222Rn were determined with the use different nuclear spectrometry techniques. The determination of uranium isotopes was carried out with the use of alpha spectrometry. The measurements of radium and radon activity concentration in water were performed with the use of a liquid scintillation technique. Additionally, rocks surrounding the intakes were examined with gamma spectrometry. All water samples showed uranium concentration above Minimum Detectable Activity (MDA, with the highest total uranium (234U + 238U activity concentration equal to 149.2±6 mBq/L. Conversely, all samples showed radium isotopes activity concentrations below MDA. Radon activity concentration was within the range from 2.91±0.36 to 21.21±1.10 Bq/L, hence these waters can be classified as low – radon waters. Gamma natural background of the rocks surrounding the water sampling sites was found on the same levels as other volcanic rocks of Italy.

  5. Medical effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Coggle, J.E.

    1990-01-01

    Ionising radiation is genotoxic and causes biological effects via a chain of events involving DNA strand breaks and 'multiply damaged sites' as critical lesions that lead to cell death. The acute health effects of radiation after doses of a few gray, are due to such cell death and consequent disturbance of cell population kinetics. Because of cellular repair and repopulation there is generally a threshold dose of about 1-2 Gy below which such severe effects are not inducible. However, more subtle, sub-lethal mutational DNA damage in somatic cells of the body and the germ cells of the ovary and testis cause the two major low dose health risks -cancer induction and genetic (heritable) effects. This paper discusses some of the epidemiological and experimental evidence regarding radiation genetic effects, carcinogenesis and CNS teratogenesis. It concludes that current risk estimates imply that about 3% of all cancers; 1% of genetic disorders and between 0% and 0.3% of severe mental subnormality in the UK is attributable to the ubiquitous background radiation. The health risks associated with the medical uses of radiation are smaller, whilst the nuclear industry causes perhaps 1% of the health detriment attributable to background doses. (author)

  6. Background radiation

    International Nuclear Information System (INIS)

    Arnott, D.

    1985-01-01

    The effects of background radiation, whether natural or caused by man's activities, are discussed. The known biological effects of radiation in causing cancers or genetic mutations are explained. The statement that there is a threshold below which there is no risk is examined critically. (U.K.)

  7. Does human activity impact the natural antibiotic resistance background? Abundance of antibiotic resistance genes in 21 Swiss lakes.

    Science.gov (United States)

    Czekalski, Nadine; Sigdel, Radhika; Birtel, Julia; Matthews, Blake; Bürgmann, Helmut

    2015-08-01

    Antibiotic resistance genes (ARGs) are emerging environmental contaminants, known to be continuously discharged into the aquatic environment via human and animal waste. Freshwater aquatic environments represent potential reservoirs for ARG and potentially allow sewage-derived ARG to persist and spread in the environment. This may create increased opportunities for an eventual contact with, and gene transfer to, human and animal pathogens via the food chain or drinking water. However, assessment of this risk requires a better understanding of the level and variability of the natural resistance background and the extent of the human impact. We have analyzed water samples from 21 Swiss lakes, taken at sampling points that were not under the direct influence of local contamination sources and analyzed the relative abundance of ARG using quantitative real-time PCR. Copy numbers of genes mediating resistance to three different broad-spectrum antibiotic classes (sulfonamides: sul1, sul2, tetracyclines: tet(B), tet(M), tet(W) and fluoroquinolones: qnrA) were normalized to copy numbers of bacterial 16S rRNA genes. We used multiple linear regression to assess if ARG abundance is related to human activities in the catchment, microbial community composition and the eutrophication status of the lakes. Sul genes were detected in all sampled lakes, whereas only four lakes contained quantifiable numbers of tet genes, and qnrA remained below detection in all lakes. Our data indicate higher abundance of sul1 in lakes with increasing number and capacity of wastewater treatment plants (WWTPs) in the catchment. sul2 abundance was rather related to long water residence times and eutrophication status. Our study demonstrates the potential of freshwater lakes to preserve antibiotic resistance genes, and provides a reference for ARG abundance from lake systems with low human impact as a baseline for assessing ARG contamination in lake water. Copyright © 2015 Elsevier Ltd. All rights

  8. Disposal regulations and techniques applicable to devices using ionising radiation

    International Nuclear Information System (INIS)

    Vidal, J.P.

    1998-01-01

    L'office de Protection contre les rayonnement ionisants, being a government body under the supervision of Ministry of Health and Labour, among other different missions controls the compliance of radiation protection laws with the aim to guarantee the safe operation of equipment using ionising radiation sources. These regulations concerning competence of personnel, especially in the field of medicine or application of ionising radiation on humans, are restricted only to medical doctors (or dentists in their domain) by technical constraints dealing with design of equipment and its exploitation. At the same time regulations define conditions of permanent control in order to verify compliance of radiation protection laws

  9. Innershell ionisation at small impactparameters in proton-atom collisions

    International Nuclear Information System (INIS)

    Duinker, W.

    1981-01-01

    This thesis concentrates on innershell ionisation in proton-atom collisions. An experiment on K-shell ionisation of argon is described, performed in a gasfilled collision chamber under single collision conditions. Further experiments with carbon and aluminium were performed, the K-shell vacancy production in the collision of protons with these atoms being detected through the measurement of Auger-electrons. A spectrometer with a large solid angle was specially constructed for this and its performance is described. K-shell ionisation accompanying nuclear (p,γ) reactions has also been measured using 26 Mg and 27 Al. (Auth./C.F.)

  10. Ionisation of highly excited atoms by electric fields

    International Nuclear Information System (INIS)

    Leopold, J.G.; Percival, I.C.

    1979-01-01

    The Monte-Carlo classical trajectory method is used to obtain the probability for microwave ionisation of atoms in states n = approximately 66 in agreement with the experiments of Bayfield and Koch (Phys. Rev. Lett.; 33: 258 (1974)). In addition the method displays the time evolution of excitation and ionisation processes and shows that the latter may proceed through a great variety of intermediate excitation processes. The mechanism is discussed. An expression for the probability of ionisation at a certain time is given in terms of the probability of orbits which lie in invariant tori. Quantal effects are not significant for comparison with the Bayfield-Koch experiment, but they are discussed in connection with implications of the results for multiphoton laser ionisation of low n states. (author)

  11. Radiative transfer calculations of the diffuse ionised gas in disc galaxies with cosmic ray feedback.

    Science.gov (United States)

    Vandenbroucke, Bert; Wood, Kenneth; Girichidis, Philipp; Hill, Alex; Peters, Thomas

    2018-03-01

    The large vertical scale heights of the diffuse ionised gas (DIG) in disc galaxies are challenging to model, as hydrodynamical models including only thermal feedback seem to be unable to support gas at these heights. In this paper, we use a three dimensional Monte Carlo radiation transfer code to post-process disc simulations of the Simulating the Life-Cycle of Molecular Clouds (SILCC) project that include feedback by cosmic rays. We show that the more extended discs in simulations including cosmic ray feedback naturally lead to larger scale heights for the DIG which are more in line with observed scale heights. We also show that including a fiducial cosmic ray heating term in our model can help to increase the temperature as a function of disc scale height, but fails to reproduce observed DIG nitrogen and sulphur forbidden line intensities. We show that, to reproduce these line emissions, we require a heating mechanism that affects gas over a larger density range than is achieved by cosmic ray heating, which can be achieved by fine tuning the total luminosity of ionising sources to get an apropriate ionising spectrum as a function of scale height. This result sheds a new light on the relation between forbidden line emissions and temperature profiles for realistic DIG gas distributions.

  12. Order and disorder in weakly ionised plasmas

    International Nuclear Information System (INIS)

    Dutt, T.L.; Dhar, P.K.

    1977-01-01

    The observation of some unusual radial structures in discharges in pure He and Ar in a magnetic field is reported. The structures depended on the angle between the discharge tube axis and the magnetic field direction, and support the previously proposed idea that gaseous plasma energised under certain conditions can have regions in which the electrons have an ordered spatial distribution. The weakly ionised high frequency electrodeless discharges were energised at powers between 500 W and 1 kW, coupled to the discharge from an amplifier by a 143 cm quarter-wavelength twin transmission line, connected to two copper bands, 14 cm apart, placed closely around the outside of the discharge tube. The discharge was maintained continuously between the bands in a position centrally between a pair of Helmholtz coils in a horizontal uniform magnetic field. Optical flats sealed to each end of the hard glass tubes made it possible to view the discharges axially. The tubes were 70 cm long and of internal radius 1.84 cm. A pattern of luminous and non-luminous plasma regions was observed, arranged in coaxial symmetry, the complexity of the pattern depending on the magnitude of the magnetic field. Patterns for He are shown and discussed, and comparisons are made with the patterns for Ar. Significant evidence was obtained for the presence of order in the non-luminous regions. It is thought that stationary states are formed under certain conditions, and conditions for their formation are discussed. (U.K.)

  13. Study and optimization of the ionisation channel in the Edelweiss dark matter direct detection experiment; Etude et optimisation de la voie ionisation dans l'experience Edelweiss de detection directe de la matiere noire

    Energy Technology Data Exchange (ETDEWEB)

    Censier, B

    2006-02-15

    The EDELWEISS experiment is aiming at the detection of Weakly Interactive Massive Particles (WIMPs), today's most favoured candidates for solving the dark matter issue. Background ionising particles are identified thanks to the simultaneous measurement of heat and ionisation in the detectors. The main limitation to this method is coming from the ionisation measurement, charge collection being less efficient in some part of the detectors known as 'dead' areas. The specificity of the measurement is due to the use of very low temperatures and low collection fields. This thesis is dedicated to the study of carrier trapping. It involves time-resolved charge measurements as well as a simulation code adapted to the specific physical conditions. We first present results concerning charge trapping at the free surfaces of the detectors. Our method allows to build a surface-charge in a controlled manner by irradiation with a strong radioactive source. This charge is then characterised with a weaker source which acts as a probe. In a second part of the work, bulk-trapping characteristics are deduced from charge collection efficiency measurements, and by an original method based on event localisation in the detector. The results show that a large proportion of the doping impurities are ionised, as indicated independently by the study of degradation by space-charge build-up. In this last part, near-electrodes areas are found to contain large densities of charged trapping centres, in connection with dead-layer effects. (author)

  14. Ionisation and dissociation of water induced by swift multicharged ions

    International Nuclear Information System (INIS)

    Legendre, S.

    2006-02-01

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni 25+ ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO 2 radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H 2 O 2+ makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

  15. Teachers' Knowledge and Views on the Use of Learners' Socio-Cultural Background in Teaching Natural Sciences in Grade 9 Township Classes

    Science.gov (United States)

    Mavuru, Lydia; Ramnarain, Umesh

    2017-01-01

    This article explores teachers' knowledge and views on the role of learners' socio-cultural background when teaching Natural Sciences to Grade 9 learners at three South African township schools. Within a socio-cultural framework, the research investigated how teachers accommodate learners' cultural norms and values, religion and beliefs,…

  16. Investigation On Natural Background Radioactivity At TanLong, Lagi, BinhThuan Residential Area On Ilmenite Deposit Location

    International Nuclear Information System (INIS)

    Pham Thi Kim Loan; Tran Van Luyen; Thai Khac Dinh

    2008-01-01

    An Ilmenite deposit zone located at TanLong, Lagi, Binh Thuan province. After the year of 2000, a new village of population has set up at this place. To estimate the effect on the human health of radioactivity accompanying with the deposit, the sand samples were collected and natural radioactive analyzed at center for nuclear techniques. The average year doses D annual , hazard radiation exposed index H ex and Radium equivalence Ra eq were calculated based on the natural radioactivities. The results show that these factors are overcome the international average as well as southern Vietnam values. (author)

  17. The influence of the nature of background anions on the buffer capacity of glycine-containing electrolytes for nickel electroplating

    Science.gov (United States)

    Dolgikh, O. V.; Zuen, Vu Tkhi; Sotskaya, N. V.

    2009-06-01

    The buffer properties of acetate, sulfate, and chloride glycine-containing electrolytes for nickel electroplating were studied. Various forms of the amino acid and background anions were shown to act in solution as two buffer systems related by competitive complex formation. The buffer capacity of a solution was then the result of the joint action of these systems. The contribution of each of them was determined by its absolute concentration in solution on the one hand and changes in this concentration caused by the addition of H+ or OH- ions on the other.

  18. Probable participation of some elements from the natural background radiation in the etiopathogenesis of metropathia haemorrhagica climacterica

    International Nuclear Information System (INIS)

    Bakyrdzhiev, D.; Manolov, P.; Dandalov, P.

    1976-01-01

    The analysis of the discovered and treated for eleven years 91 years 912 women with climacteric metrorrhagia from 68 towns with a population of 130 000 showed a percentage which was two to ten times greater concentration in one of the towns. The clinic, paraclinic and histology, as well as social, environmental, nutritional, sexual and other factors which were examined, did not clarify this fact. The authors directed their attention to the natural radioactivity. The concentration of radium 226 and potassium 40 were determined by the standard methods (IAAE-1966) using an apparatus for low concentrations in the samples of blood and urine of the patients as well as in water, soil and plant material from three regions with equal number of population but various ratio of the patients (10:6:4for metrorrhagia climacterica and 10:6:4 for myoma uteri). In the most contaminated region especially in the plant material (e.g. biological indicator) the level of natural radioactivity was almost two times higher at the upper limit of the natural radioactive amount. It could not be excluded that under certain circumstances (absolute estrogemy, young quickly transforming cells of the endometrium, etc.) within these limiits the examined radioactive elements could stimulate proliferative processes and to catalize enzymatic systems, participating in the etiopathogenesis of climacteric metrorrhagia. (author)

  19. Calculated ionisation potentials to determine the oxidation of vanillin precursors by lignin peroxidase.

    OpenAIRE

    Have, ten, R.; Rietjens, I.M.C.M.; Hartmans, S.; Swarts, H.J.; Field, J.A.

    1998-01-01

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugeno...

  20. 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)

  1. Natural radionuclides in environmental media: a review of natural levels of radioactivity and background radiation levels and an assessment of factors affecting these levels

    International Nuclear Information System (INIS)

    Bradley, E.J.

    1993-01-01

    A review of the literature has been carried out to assemble the information available on the levels of naturally-occurring radionuclides in environmental media in the UK. Some data from other countries are included for comparison. The data are compiled on the basis of geographical origin into five main sectors: air; waters; vegetation; soils, rocks and sediments; and foodstuffs. A summary table is provided for each main section. (author)

  2. 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

  3. Diagnostic medical exposures. Advice on exposure to ionising radiation during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, C.; Shrimpton, J.; Bury, R

    1998-07-01

    The main objective of NRPB advice concerning in utero exposures to ionising radiations is 'to prevent unnecessary exposure of the fetus when medical diagnostic procedures involving ionising radiations are indicated during pregnancy'. In addition, advice is meant to help to avoid unnecessary concern or action if an exposure does occur. NRPB issued ASP8 (Exposure to ionising radiation of pregnant women: advice on the diagnostic exposure of women who are, or who may be, pregnant) in 1985. This advice suggested that there would be no risks to the concepts following irradiation during the first 10 days of the menstrual cycle and that subsequent risks in the remainder of the first 4 week period would be likely to be so small that no special limitation on exposure was required - sometimes known as 'the 28-day rule'. In 1993, NRPB published further advice to replace ASP8 in the Documents of the NRPB series, in Volume 4, No 4 - henceforth referred to as Doc NRPB 4(4){sup 2} - which drew upon data published since 1985. The more recent data suggest that risks in the interval between 10 days and the date at which the next menstrual period is due, although still small for most diagnostic procedures, may be significant for higher dose procedures. Consequently, it is considered there is a need to operate a modified policy for such higher dose procedures. This pocket publication has been produced to present in a concise and user-friendly format the basis of the most recent NRPB advice and to provide a guide for the implementation of that advice in the everyday practice of diagnostic radiology. The opportunity has also been taken to provide the most up to date data on doses in the UK. This publication is split into three parts: an introduction to the terms used in the document, a practical guide to implementation of the advice, and the scientific background to the advice.

  4. Diagnostic medical exposures. Advice on exposure to ionising radiation during pregnancy

    International Nuclear Information System (INIS)

    Sharp, C.; Shrimpton, J.; Bury, R.

    1998-01-01

    The main objective of NRPB advice concerning in utero exposures to ionising radiations is 'to prevent unnecessary exposure of the fetus when medical diagnostic procedures involving ionising radiations are indicated during pregnancy'. In addition, advice is meant to help to avoid unnecessary concern or action if an exposure does occur. NRPB issued ASP8 (Exposure to ionising radiation of pregnant women: advice on the diagnostic exposure of women who are, or who may be, pregnant) in 1985. This advice suggested that there would be no risks to the concepts following irradiation during the first 10 days of the menstrual cycle and that subsequent risks in the remainder of the first 4 week period would be likely to be so small that no special limitation on exposure was required - sometimes known as 'the 28-day rule'. In 1993, NRPB published further advice to replace ASP8 in the Documents of the NRPB series, in Volume 4, No 4 - henceforth referred to as Doc NRPB 4(4) 2 - which drew upon data published since 1985. The more recent data suggest that risks in the interval between 10 days and the date at which the next menstrual period is due, although still small for most diagnostic procedures, may be significant for higher dose procedures. Consequently, it is considered there is a need to operate a modified policy for such higher dose procedures. This pocket publication has been produced to present in a concise and user-friendly format the basis of the most recent NRPB advice and to provide a guide for the implementation of that advice in the everyday practice of diagnostic radiology. The opportunity has also been taken to provide the most up to date data on doses in the UK. This publication is split into three parts: an introduction to the terms used in the document, a practical guide to implementation of the advice, and the scientific background to the advice

  5. Connecting stars and ionised gas with integral-field spectroscopy

    NARCIS (Netherlands)

    McDermid, Richard M.; Emsellem, Eric; Shapiro, Kristen L.; Bacon, Roland; Bureau, Martin; Cappellari, Michele; Davies, Roger L.; de Zeeuw, Tim; Falcon-Barroso, Jesus; Krajnovic, Davor; Kuntschner, Harald; Peletier, Reynier F.; Sarzi, Marc; van de Ven, Glenn

    Using integral-field spectroscopy, the SAURON survey has shown that early-type galaxies, once thought to be essentially devoid of gas, commonly show ionised gas emission. This emission is found with a rich variety of distributions and kinematics, ranging from very uniform disks or rings, and

  6. Cost considerations for an ionising energy treatment facility

    International Nuclear Information System (INIS)

    Culpitt, R.A.

    1985-01-01

    Variables influencing the cost of food irradiation can be included under three broad headings: the physical characteristics of products to be treated; the operational characteristics of the plant to be used; costs of establishment and operation of an ionising energy treatment

  7. The case against protecting the environment from ionising radiation

    International Nuclear Information System (INIS)

    Smith, J.T.

    2004-01-01

    The objective of this paper is to present the (rarely heard) argument in favour of retention of the present system of radiation protection of the environment. There has been a recent trend in the radioecological and radiation protection community towards greater regulation of the effects of ionising radiations on biota. In particular, the often quoted International Commission on Radiation Protection (ICRP) hypothesis that: If humans are protected from the effects of ionising radiation, then flora and fauna are also adequately protected has been criticised as being too anthropocentric and not adequate for protection of the environment. In this paper I will challenge this view, arguing firstly that this statement is almost always quoted out of its proper context, and secondly that the ICRP hypothesis does adequately protect the environment from the effects of ionising radiations. In view of the relatively insignificant effect of regulated releases of ionising radiation on the environment, the economic cost of further regulation will not result in a significant environmental benefit. Whilst empirical research to test the ICRP hypothesis should continue, until there is clear evidence against it, this simple and cost-effective approach should be retained. This would benefit the environment by directing scarce resources to more urgent environmental problems. (author)

  8. EFFECTS OF NATURAL ORIFICE SECRETIONS IN PERITONEAL CAVITY IN THE BACKGROUND OF NATURAL ORIFICE TRANSLUMINAL ENDOSCOPIC SURGERY (NOTES AN EXPERIMENTAL STUDY IN ANIMALS

    Directory of Open Access Journals (Sweden)

    Devendra

    2015-03-01

    Full Text Available Natural Orifice Transluminal Endoscopic Surgery (NOTES is a new form of minimally invasive surgery which eliminates traditional skin incisions by accessing internal body cavities through natural orifices. In our experimental animal study, we compared the incidences intraperitoneal abscess formation , culture swab of peritoneal cavity positive for organism, intraperitoneal adhesion formation and mean adhesion score before and after lavaging the portal of entry of albino rat , i.e. transgastric and transvaginal. On vaginal route as a portal of entry into peritoneal cavity , on the 7th day , 66% rats developed abscesses , 88% rats had culture swab positive and 88% rats developed intraperitoneal adhesion (grade - 2 before any cleansing of vaginal cavity with antiseptic solution . Now after lavage with povidone iodine solution, only 11% developed abscesses , 22% were peritoneal swab culture positive and 33% had interbowel and parietal adhesion of (grade 0 - 1. On 21 st day , the complication observed was adhesion formation in pre lavage group of 66% incidence and 16% after vaginal lavage. The incidence of complications were reduced significantly after lavage with antiseptic solution as shown by p values (p<0.01 for abscess formation, p< 0.01 for culture positivity and p< 0.01 for adhesions formation. Also the mean adhesion scoring was significantly reduced (p <0.02 after vaginal lavage on the 7 th day. Gastric route as the portal of entry into the peritoneal cavity, again the same variables were compared on the 7th and the 21st day , but wash was given with antibiotic solution (Cefazolin. On the 7th day , 44% had abscesses, 77% were culture positive and 66% had adhesions (Grade 1 - 2 before gastric lavage with antibiotic solution . After wash of stomach, 11% were culture positive and 44% developed adhesions (Grade 0 - 1. Here, abscess formation (p<0.02 and mean adhesion scoring (p<0.05 were significantly reduced after stomach wash. On the 21st day

  9. Dissipative instabilities in a partially ionised prominence plasma slab. II. The effect of compressibility

    Science.gov (United States)

    Mather, J. F.; Ballai, I.; Erdélyi, R.

    2018-02-01

    This study deals with the dissipative instability that appears in a compressible partially ionised plasma slab embedded in a uniform magnetic field, modelling the state of the plasma in solar prominences. In the partially ionised plasma, the dominant dissipative effect is the Cowling resistivity. The regions outside the slab (modelling the solar corona) are fully ionised, and the dominant mechanism of dissipation is viscosity. Analytical solutions to the extended magnetohydrodynamic (MHD) equations are found inside and outside of the slab and solutions are matched at the boundaries of the slab. The dispersion relation is derived and solutions are found analytically in the slender slab limit, while the conditions necessary for the appearance of the instability is investigated numerically for the entire parameter space. Our study is focussed on the effect of the compressibility on the generation and evolution of instabilities. We find that compressibility reduces the threshold of the equilibrium flow, where waves can be unstable, to a level that is comparable to the internal cusp speed, which is of the same order of flow speeds that are currently observed in solar prominences. Our study addresses only the slow waves, as these are the most likely perturbations to become unstable, however the time-scales of the instability are found to be rather large ranging from 105-107 s. It is determined that the instability threshold is further influenced by the concentration of neutrals and the strength of the viscosity of the corona. Interestingly, these two latter aspects have opposite effects. Our numerical analysis shows that the interplay between the equilibrium flow, neutrals and dispersion can change considerably the nature of waves. Despite employing a simple model, our study confirms the necessity of consideration of neutrals when discussing the stability of prominences under solar conditions.

  10. COMPARISON OF NATURAL BACKGROUND DOSE RATES FOR RESIDENTS OF THE AMARGOSA VALLEY, NV, TO THOSE IN LEADVILLE, CO, AND THE STATES OF COLORADO AND NEVADA

    International Nuclear Information System (INIS)

    D. Moeller and L. C. Sun

    2006-01-01

    In the latter half of 2005, the U.S. Environmental Protection Agency (USEPA) published a Proposed Rule (40 CFR Part 197) for establishing a dose rate standard for limiting radionuclide releases from the proposed Yucca Mountain high-level radioactive waste repository during the time period from 10 4 to 10 6 years after closure. The proposed standard was based on the difference in the estimated total dose rate from natural background in the Amargosa Valley and the ''average annual background radiation'' for the State of Colorado. As defined by the USEPA, ''natural background radiation consists of external exposures from cosmic and terrestrial sources, and internal exposures from indoor exposures to naturally-occurring radon''. On the basis of its assessments, the USEPA estimated that the difference in the dose rate in the two identified areas was 3.5 mSv y -1 . The purpose of this review was to provide an independent evaluation and review of this estimate. One of the first observations was that, because site-specific dose rate measurements for the Amargosa Valley ''were not available'', the dose rates for various sources of natural background in that area, used by the USEPA in its assessment, were based on modifications of the average values for the State of Nevada. A second observation was that the conversion factor applied in estimating the dose rates due to exposures to indoor radon and its decay products was a factor of 2 higher than the currently accepted value. Further review revealed that site-specific data for many natural background sources in the Amargosa Valley were available. One particularly important observation was that about 91% of the residents of that area live in mobile homes which, due to their construction and design, have indoor radon concentrations comparable to, or less than, those outdoors. For that reason, alone, the USEPA estimate of the average dose rate for residents of the Amargosa Valley, due to indoor radon, was not valid. For purposes

  11. SU-F-T-166: On the Nature of the Background Visible Light Observed in Fiber Optic Dosimetry of Proton Beams

    Energy Technology Data Exchange (ETDEWEB)

    Darafsheh, A; Kassaee, A; Finlay, J [University of Pennsylvania, Philadelphia, PA (United States); Taleei, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: The nature of the background visible light observed during fiber optic dosimetry of proton beams, whether it is due to Cherenkov radiation or not, has been debated in the literature recently. In this work, experimentally and by means of Monte Carlo simulations, we shed light on this problem and investigated the nature of the background visible light observed in fiber optics irradiated with proton beams. Methods: A bare silica fiber optics was embedded in tissue-mimicking phantoms and irradiated with clinical proton beams with energies of 100–225 MeV at Roberts Proton Therapy Center. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze in detail the emission spectrum of the fiber tip across the visible range of 400–700 nm. Monte Carlo simulation was performed by using FLUKA Monte Carlo code to simulate Cherenkov light and ionizing radiation dose deposition in the fiber. Results: The experimental spectra of the irradiated silica fiber shows two distinct peaks at 450 and 650 nm, whose spectral shape is different from that of Cherenkov radiation. We believe that the nature of these peaks are connected to the point defects of silica including oxygen-deficiency center (ODC) and non-bridging oxygen hole center (NBOHC). Monte Carlo simulations confirmed the experimental observations that Cherenkov radiation cannot be solely responsible for such a signal. Conclusion: We showed that Cherenkov radiation is not the dominant visible signal observed in bare fiber optics irradiated with proton beams. We observed two distinct peaks at 450 and 650 nm whose nature is connected with the point defects of silica fiber including oxygen-deficiency center and non-bridging oxygen hole center.

  12. 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.

  13. Of the necessity of knowledge of the natural pedo-geochemical background content in the evaluation of the contamination of soils by trace elements.

    Science.gov (United States)

    Baize, D; Sterckeman, T

    2001-01-08

    In order to evaluate the contamination of the Dornach (Switzerland) site within the framework of the CEEM-Soil project, each participating team was allowed to take a maximum of 15 samples. The French team's sampling was organized in such a way as to answer the following questions: (i) what is the natural concentration of the soils at this site (local pedo-geochemical background content)?; (ii) what are the levels of Cd, Cu, Pb and Zn contamination of the soil?; (iii) what is the depth reached by the surface contamination that is derived from atmospheric fallout?; (iv) how is the contamination spread along the longest axis of the area under study? The relationships between total Fe and the trace metals have allowed local variations in the natural pedo-geochemical background content to be detected and thus permitted the anthropogenic contamination to be estimated. There would appear to be a low level of Pb contamination over all the site investigated (an increase of the order of 5-10 mg kg(-1) on the background level), limited to the surface humus-bearing layers. There is also a significant contamination by Cu over all of the site (an increase of the order of 30-40 mg kg(-1)). This contamination has remained in the surface horizons (0-20 cm). Very high Zn and Cd concentrations have been found in the four surface (0-4 cm) and deep horizons (15-70 cm) taken under the forest and very much lower values in the samples taken from cultivated soils. The most likely explanation is an unequal inheritance between the upper part of the site (wooded with thinner very clayey soils) and the lower cultivated part of the site (with thicker less clayey soils developed in a loamy material). For various reasons, it seems unlikely that a contamination of the wooded part should be so much higher than the cultivated part due to the interception of atmospheric dust by the trees. The local pedo-geochemical background Cd and Zn content of the upper wooded part proved to be clearly higher than

  14. Effects of chronic low level natural background radiation on the induction and rejoining of DNA strand breaks in human Go lymphocytes

    International Nuclear Information System (INIS)

    Vivek Kumar, P.R.; Cheriyan, V.D.; Seshadri, M.

    2010-01-01

    Thirty three inhabitants of the coastal areas of Kerala, from Chavara-Neendakara belt in Karunagappally taluk, were selected, as the population living here receives high level natural background radiation primarily due to the presence of thorium ( 232 Th) in the monazite containing beach sand. Eighteen individuals from a nearby normal background radiation area were included as control in this study. Participants in both groups were male, non- smokers and with comparable age (P=0.96, Student's t-test). Blood samples were collected with informed consent. Lymphocytes from these individuals were subjected to alkaline single cell gel electrophoresis (comet) assay to estimate DNA strand breaks. A challenge assay procedure is followed, in which lymphocytes from these individuals were exposed to 2Gy or 4Gy of 60 Co gamma radiation at a dose-rate of 1.4Gy/minute (Low dose irradiator 2000, BRIT, India) on ice and were investigated immediately (induction) or assayed after short durations (7, 14 and 30 minutes), that allowed repair of DNA damage (rejoining). In addition, comet assay coupled with endonuclease III (ENDO III) was used to assess oxidized pyrimidine bases. Results were expressed as 'DNA strand breaks per million base pairs' (SB/10 6 bp) calculated with the mean of 'percentage of DNA in comet tail' (%T) obtained from each sample, using a calibration curve. In this study data from the two groups were compared by the non-parametric Mann-Whitney U-test, otherwise indicated. This pilot study suggest a possible adaptive process in individuals exposed to chronic low level natural background radiation, indicated by an increase in repair of DNA strand breaks. Results might also suggest an elevated level of reactive oxygen species (ROS) scavenging mechanism in HBRA subjects compared to the controls. However, our findings need to be validated in a larger study population

  15. Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material

    International Nuclear Information System (INIS)

    Hernandez, C.; Fernandez, M.; Quejido, A. L.

    2006-01-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound esposure time. Due to the complex matrix of this fly ash material, a two-steps purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs

  16. Isotope dilution-thermal ionisation mass spectrometric analysis for tin in a fly ash material

    International Nuclear Information System (INIS)

    Hernandez, Carolina; Fernandez, Marta; Quejido, Alberto J.; Sanchez, Dolores M.; Morante, Ramon; Martin, Raul

    2006-01-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solution has been prepared from 112 Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4.5 M HCl during 25 min ultrasound exposure time. Due to the complex matrix of this fly ash material, a two-step purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10.11 ± 0.55 and 10.50 ± 0.64 μmol g -1 ) are comparable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference materials certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of samples

  17. Measurement of the total ionisation intensity near the ground and separation of the various components

    International Nuclear Information System (INIS)

    Grevet, Ph.

    1965-06-01

    The aim of this work is to measure the total amount of ion-pairs produced in the air per unit time and unit volume. It is possible, furthermore, by using continuous recording to study the variations in the ionisation due to α, β and γ radiation at a height of one metre. The apparatus which has been developed consists of two chambers of 120 litres: one, hermetically sealed detects the γ component, the other with a circulation of the ambient air detects the α and γ; it is thus possible by difference to evaluate the α component. The chambers and the associated electronic equipment have been designed for continuous operation in the open air. Another chamber without walls can be used for measuring directly the total ionisation intensity and from this an approximate calculation may be made of the β component. A series of recordings has been made near Saclay where the natural radio-activity level is moderate, and in regions of low and high activity (near the sea and in the CEA's mining divisions). It has thus been possible to show the variation in the γ component as a function of the geographic position of the measurement (from 3.7 to 6.3 l/cm 3 .s), the very large variations of the α component at a given place with changing meteorological conditions (from 1.5 to 45 l/cm 3 .s at Saclay for example) an the far smaller variations in the β component. (author) [fr

  18. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment

    International Nuclear Information System (INIS)

    Di Stefano, Ph.

    1998-01-01

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author)

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

    Directory of Open Access Journals (Sweden)

    Sajad Borzoueisileh

    2013-01-01

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

  20. Population exposure to ionising radiation in India

    International Nuclear Information System (INIS)

    Narayanan, K.K.; Krishnan, D.; Subba Ramu, M.C.

    1991-01-01

    Estimates of exposure from various radiation sources to Indian population are given. The per caput dose from all the identifiable sources, both natural and man-made is estimated to be 2490 μSv per year to the present population of India. 97.9% of this dose is contributed by natural sources which include cosmic and terrestrial radiations, 1.93% by medical sources used for diagnostic and treatment purpose, 0.3% by exposures due to activities related nuclear fuel cycle, nuclear tests and nuclear accidents, and 0.07% by miscellaneous sources such as industrial applications, consumer products, research activities, air travel etc. The monograph is written for the use of the common man. (M.G.B.). 25 refs., 7 tabs., 7 figs

  1. The Effects of Ionising Radiation on MEMS Silicon Strain Gauges: Preliminary Background and Methodology

    Science.gov (United States)

    2006-09-01

    stamping tool. That is, the droplet is formed on the tip of the dispenser while in contact with the dogbone, and the tip is then withdrawn vertically...to be a capillary action due to the silicon- aluminium contact. This flow occurs even with the AE-15 cured at room temperatures and below, rather than

  2. Ionising radiation and the developing human brain

    International Nuclear Information System (INIS)

    Schull, W.J.

    1991-01-01

    This article reviews the effects of radiation exposure of the developing human brain. Much of the evidence has come from the prenatally exposed in Hiroshima and Nagasaki. The effects on development age, mental retardation, head size, neuromuscular performance, intelligence tests, school performance and the occurrence of convulsions are discussed. Other topics covered include the biological nature of the damage to the brain, risk estimates in human and problems in radiation protection. (UK)

  3. 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

  4. Experimental data on low energy electron impact ionisation of W

    Science.gov (United States)

    Schlummer, T.; Ertmer, S.; Brezinsek, S.; Eksaeva, A.; Pospieszczyk, A.; Borodin, D.; Kirschner, A.; Kreter, A.; Linsmeier, Ch; Sergienko, G.; Unterberg, B.

    2017-12-01

    We present experimental data on the rate coefficient for electron impact ionisation of W atoms at electron temperatures between 5 and 10 eV. Our results undercut different theoretical data sets based on the Born approximation and the distorted wave approximation, respectively, by more than a factor of 3. Better agreement in absolute values is found with a more recent work by Goswami et al. The present data match well with earlier measurements by Steinbrink obtained with a different method.

  5. Medical use of ionising radiation - challenges for the third millennium

    International Nuclear Information System (INIS)

    Leitz, W.

    2003-01-01

    From the very beginning after its discovery ionising radiation has been in beneficial use for health care. But even the drawbacks showed up very early: only a few months after Roentgens discovery reports were published on patients who got severe skin damage after fluoroscopy with x-rays. This finding of the adverse effects was soon turned into something positive: ionising radiation could be used for treatment of cancer. In 1928 radiologists took the initiative to the foundation of what later became the International Commission on Radiological Protection, ICRP. Medical use of ionising radiation is giving by far the largest contribution to the radiation burden of the global population from artificial sources, on average 0,3 mSv per year and inhabitant, excluding doses from radiation treatment. In the Nordic countries this dose is approximately 0,7 mSv. This isn't a problem by itself. The total benefit is exceeding the total radiation risk with large margins. But the margins could even be larger. Methods for examinations and treatments have often a potential for improvements, meaning that the medical effect can be obtained with a lower dose to the patient. In certain circumstances the examination does not contribute to the further treatment of the patient or to her/his well-being and is then regarded as not justified. The huge challenge we are facing depends among other things on the extreme fast technical development which enables exposures of a magnitude that we haven't seen before and applications we only could dream about. There is a risk that the motto 'do what is possible to do' is followed instead of 'do what the individual patient needs'. This presentation addresses the possibilities, but also the dangers that medical use of ionising radiation in medical care is facing in the new millennium, or at least in its first years. (orig.)

  6. Exposures to natural radiation in Switzerland

    International Nuclear Information System (INIS)

    Murith, Ch.; Gurtner, A.

    1999-01-01

    The exposure of human beings to ionising radiation from natural sources is a continuing and inescapable feature of life on earth. There are two main sources that contribute to this exposure: high-energy cosmic-ray particles incident to the earth's atmosphere and radioactive nuclides that originated in the earth's crust and are present everywhere in the environment, including human body itself. Both external and internal exposures to humans arise from these sources. Exposures to natural radiation sources in Switzerland and some of their variations are here summarised and the resulting effective doses are compared to those from man-made sources exposures. It results that the natural background exposures are more significant for the population than most exposures to man-made sources. (authors)

  7. Complex systems of biological interest stability under ionising radiations

    International Nuclear Information System (INIS)

    Maclot, Sylvain

    2014-01-01

    This PhD work presents the study of stability of molecular systems of biological interest in the gas phase after interaction with ionising radiations. The use of ionising radiation can probe the physical chemistry of complex systems at the molecular scale and thus consider their intrinsic properties. Beyond the fundamental aspect, this work is part of the overall understanding of radiation effects on living organisms and in particular the use of ionizing radiation in radiotherapy. Specifically, this study focused on the use of low-energy multiply charged ions (tens of keV) provided by the GANIL (Caen), which includes most of the experiments presented. In addition, experiments using VUV photons were also conducted at synchrotron ELETTRA (Trieste, Italy). The bio-molecular systems studied are amino acids and nucleic acid constituents. Using an experimental crossed beams device allows interaction between biomolecules and ionising radiation leads mainly to the ionization and fragmentation of the system. The study of its relaxation dynamics is by time-of-flight mass spectrometry coupled to a coincidences measurements method. It is shown that an approach combining experiment and theory allows a detailed study of the fragmentation dynamics of complex systems. The results indicate that fragmentation is generally governed by the Coulomb repulsion but the intramolecular rearrangements involve specific relaxation mechanisms. (author) [fr

  8. Impact ionisation measurement and modelling of long wavelength avalanche photodiodes

    CERN Document Server

    Ng, J S

    2003-01-01

    Impact ionisation coefficients are measured in In sub 0 sub . sub 5 sub 3 Ga sub 0 sub . sub 4 sub 7 As and excess noise characteristics are measured in sub-micron ln sub 0 sub . sub 5 sub 2 Al sub 0 sub . sub 4 sub 8 As. Photomultiplication measurements performed on a series of In sub 0 sub . sub 5 sub 3 Ga sub 0 sub . sub 4 sub 7 As p-i-n diodes are reported. Taking careful account of factors which could give rise to erroneous results at low fields, ln sub 0 sub . sub 5 sub 3 Ga sub 0 sub . sub 4 sub 7 As ionisation coefficients are deduced at room temperature as a function of electric field. The results confirm the low field ionisation behaviour of alpha and the conventional field dependence of beta. Excess avalanche noise factors of In sub 0 sub . sub 5 sub 2 Al sub 0 sub . sub 4 sub 8 As p-i-n diodes, with i-region thicknesses ranging from 1.0 mu m to 0.1 mu m, are reported. The results indicate effective beta/alpha values lying between 0.15 and 0.23, comparable with or lower than the values reported in ...

  9. 'Natural background' soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

    Science.gov (United States)

    Doerr, S.H.; Woods, S.W.; Martin, D.A.; Casimiro, M.

    2009-01-01

    Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle (??sl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is

  10. Molecular mechanisms of plant response to ionising radiation. Exploration of the glucosinolate role in the anti-oxidative response

    International Nuclear Information System (INIS)

    Gicquel, M.

    2012-01-01

    Terrestrial organisms are exposed to low doses of ionising radiation from natural or anthropogenic sources. The major effects of the radiations are due to DNA deterioration and water radiolysis which generates an oxidative stress by free radical production. Plants constitute good models to study the effects of ionising radiations and the search of antioxidant molecules because of their important secondary metabolism. Thus this thesis, funded by the Brittany region, characterized the physiological and molecular response of the model plant Arabidopsis thaliana to low (10 Gy) and moderate (40 Gy) doses of ionising radiation, and was therefore interested in glucosinolates, characteristic compounds of the Brassicaceae family. The global proteomic and transcriptomic studies carried out on this model revealed (1) a common response for both doses dealing with the activation of DNA repair mechanisms, cell cycle regulation and protection of cellular structures; (2) an adjustment of the energetic metabolism and an activation of secondary compounds biosynthesis (i.e. glucosinolates and flavonoids) after the 10 Gy dose; (3) an induction of enzymatic control of ROS, the regulation of cellular components recycling and of programmed cell death after the 40 Gy dose. The potential anti-oxidative role of glucosinolates was then explored. The in vitro anti-oxidative power of some glucosinolates and their derivative products were demonstrated. Their modulating effects against irradiation-induced damages were then tested in vivo by simple experimental approaches. The importance of the glucosinolate level to give a positive or negative effect was demonstrated. (author)

  11. Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background" values (past 8000 years).

    Science.gov (United States)

    Givelet, Nicolas; Roos-Barraclough, Fiona; Shotyk, William

    2003-12-01

    Peat cores from three bogs in southern Ontario provide a complete, quantitative record of net rates of atmospheric Hg accumulation since pre-industrial times. For comparison with modern values, a peat core extending back 8000 years was used to quantify the natural variations in Hg fluxes for this region, and their dependence on climatic change and land use history. The net mercury accumulation rates were separated into "natural" and "excess" components by comparing the Hg/Br ratios of modern samples with the long-term, pre-anthropogenic average Hg/Br. The average background mercury accumulation rate during the pre-anthropogenic period (from 5700 years BC to 1470 AD) was 1.4 +/- 1.0 microg m(-2) per year (n = 197). The beginning of Hg contamination from anthropogenic sources dates from AD 1475 at the Luther Bog, corresponding to biomass burning for agricultural activities by Native North Americans. During the late 17th and 18th centuries, deposition of anthropogenic Hg was at least equal to that of Hg from natural sources. Anthropogenic inputs of Hg to the bogs have dominated continuously since the beginning of the 19th century. The maximum Hg accumulation rates decrease in the order Sifton Bog, in the City of London, Ontario (141 microg Hg m(-2) per year), Luther Bog in an agricultural region (89 microg Hg m(-2) per year), and Spruce Bog which is in a comparatively remote, forested region (54 microg Hg m(-2) per year). Accurate age dating of recent peat samples using the bomb pulse curve of 14C shows that the maximum rate of atmospheric Hg accumulation occurred during AD 1956 and 1959 at all sites. In these (modern) samples, the Hg concentration profiles resemble those of Pb, an element which is known to be immobile in peat bogs. The correlation between these two metals, together with sulfur, suggests that the predominant anthropogenic source of Hg (and Pb) was coal burning. While Hg accumulation rates have gone into strong decline since the late 1950's, Hg

  12. Radioprotective Effects of Sulfur-containing Mineral Water of Ramsar Hot Spring with High Natural Background Radiation on Mouse Bone Marrow Cells.

    Science.gov (United States)

    Heidari, A H; Shabestani Monfared, A; Mozdarani, H; Mahmoudzadeh, A; Razzaghdoust, A

    2017-12-01

    We intend to study the inhibitory effect of sulfur compound in Ramsar hot spring mineral on tumor-genesis ability of high natural background radiation. The radioprotective effect of sulfur compounds was previously shown on radiation-induced chromosomal aberration, micronuclei in mouse bone marrow cells and human peripheral lymphocyte. Ramsar is known for having the highest level of natural background radiation on Earth. This study was performed to show the radioprotective effect of sulfur-containing Ramsar mineral water on mouse bone marrow cells. Mice were fed three types of water (drinking water, Ramsar radioactive water containing sulfur and Ramsar radioactive water whose sulfur was removed). Ten days after feeding, mice were irradiated by gamma rays (0, 2 and 4 Gy). 48 and 72 hours after irradiating, mice were killed and femurs were removed. Frequency of micronuclei was determined in bone marrow erythrocytes. A significant reduction was shown in the rate of micronuclei polychromatic erythrocyte in sulfur-containing hot spring water compared to sulfur-free water in hot spring mineral water. Gamma irradiation induced significant increases in micronuclei polychromatic erythrocyte (MNPCE) and decreases in polychromatic erythrocyte/polychromatic erythrocyte + normochromatic erythrocyte ratio (PCEs/PCEs+NCEs) (P spring water compared to sulfur-free hot spring mineral water. Also, apparently there was a significant difference between drinking water and sulfur-containing hot spring water in micronuclei polychromatic erythrocyte and polychromatic erythrocyte/polychromatic erythrocyte+ normochromatic erythrocyte ratio. The results indicate that sulfur-containing mineral water could result in a significant reduction in radiation-induced micronuclei representing the radioprotective effect of sulfur compounds.

  13. 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

  14. The ionising radiations: a daily reality Las radiaciones ionizantes: una realidad cotidiana

    Directory of Open Access Journals (Sweden)

    Eduardo Gallego Díaz

    2010-12-01

    Full Text Available This paper introduce the nature of the radioactive substances and of the ionising radiation, the effects that they cause on the matter and the available media for their detection and measure, as well as the sources of natural radiation, to which the human being are exposed. Next, in the more detailed part of this paper, it is described the wide range of ionising radiations uses in: medicine, agriculture, earth sciences, biology and in some other scientific fields, that allow to pose its impact in the perspective of facing the ones from natural sources. The article concludes that for avoiding damages it is necessary proper protection against the radioactive substances, but avoiding limitation their beneficial uses in the various ranges described. For finishing this paper, the basic principles of radiation protection are described, due to they are the its principal aim.Este trabajo introduce la naturaleza de las sustancias radiactivas y de la radiación ionizante, los efectos que causa sobre la materia y los medios disponibles para su detección y medida, así como las fuentes de radiación naturales a las que los seres humanos estamos expuestos. Seguidamente, en el apartado más amplio del trabajo, se describen las múltiples aplicaciones de las radiaciones ionizantes en la medicina, la agricultura, la industria, las ciencias de la tierra, la biología y otras ramas, lo que permite poder poner su impacto en perspectiva frente al de las fuentes naturales. La tesis final del artículo es que para evitar sufrir daños resulta necesario protegerse adecuadamente de los efectos nocivos de la radiación y las sustancias radiactivas, pero sin limitar innecesariamente su utilización beneficiosa en los numerosos ámbitos descritos. Ese es el objetivo fundamental de la protección radiológica, cuyos principios básicos se presentan para terminar.

  15. On ionising radiation and breast cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Anders

    1999-05-01

    of cell killing is obvious at higher doses (5-10 Gy) leading to a flattening or downward curvature. Fractionation of dose does not seem to modify risk. Protracted exposures may carry lower risks than fractionated or acute exposures. Women with benign breast diseases are more sensitive compared to women with normal breasts. Age-at-exposure is a strong modifier of excess additive risk. For excess relative risk with adjustment for attained age, only the BBD-cohort shows strong dependence on age-at-exposure. Even if risk decreases with age-at-exposure, ages over 40 years at exposure carry increased risk. EAR models provides simpler description of excess risks over populations with different background rates. In EAR-models modification-terms are needed to describe the increasing excess risk by attained age. Radiogenic breast cancers occur at the same ages as non-radiogenic breast cancers occur. Time from exposure to occurrence is inversely related to age-at-exposure. The excess absolute risk pattern by attained age is similar to background rates pattern. Breast cancer risks are raised throughout life. In the BBD study cancer risks in other organs than the breast was studied as well. Results indicated that scattered doses from breast irradiation may increase the risk of cancer from other sites but the small number of cases in different locations precludes strong interpretation. Mammographic mass screening radiation risk is not, under careful consideration of dose, a crucial factor for the endorsement of a mammographic screening program of women from 40 years of age 125 refs, 12 figs, 16 tabs

  16. Semiclassical calculation of ionisation rate for Rydberg helium atoms in an electric field

    International Nuclear Information System (INIS)

    Wang De-Hua

    2011-01-01

    The ionisation of Rydberg helium atoms in an electric field above the classical ionisation threshold has been examined using the semiclassical method, with particular emphasis on discussing the influence of the core scattering on the escape dynamics of electrons. The results show that the Rydberg helium atoms ionise by emitting a train of electron pulses. Unlike the case of the ionisation of Rydberg hydrogen atom in parallel electric and magnetic fields, where the pulses of the electron are caused by the external magnetic field, the pulse trains for Rydberg helium atoms are created through core scattering. Each peak in the ionisation rate corresponds to the contribution of one core-scattered combination trajectory. This fact further illustrates that the ionic core scattering leads to the chaotic property of the Rydberg helium atom in external fields. Our studies provide a simple explanation for the escape dynamics in the ionisation of nonhydrogenic atoms in external fields. (atomic and molecular physics)

  17. Recent trends in utilising ionising radiations for nondestructive evaluation of materials (Preprint No. SP-3)

    International Nuclear Information System (INIS)

    Raj, Baldev; Venkatraman, B.

    1988-02-01

    The various NDT techniques based on the use of ionising radiations can be broadly classified into radiography, radiation gaging techniques and analytical techniques. This paper highlights the state of art of these techniques along with their applications. While an effort has been made to cover the major techniques based on ionising radiations, many techniques utilising ionising radiations as xeroradiography, laminography, ionography etc, have not been dealt with due to their restricted applications. (author). 23 refs., 4 figs

  18. Calculated ionisation potentials determine the oxidation of vanillin precursors by lignin peroxidase.

    Science.gov (United States)

    ten Have, R; Rietjens, I M; Hartmans, S; Swarts, H J; Field, J A

    1998-07-03

    In view of the biocatalytic production of vanillin, this research focused on the lignin peroxidase (LiP) catalysed oxidation of naturally occurring phenolic derivatives: O-methyl ethers, O-acetyl esters, and O-glucosyl ethers. The ionisation potential (IP) of a series of model compounds was calculated and compared to their experimental conversion by LiP, defining a relative IP threshold of approximately 9.0 eV. Based on this threshold value only the O-acetyl esters and glucosides of isoeugenol and coniferyl alcohol would be potential LiP substrates. Both O-acetyl esters were tested and were shown to be converted to O-acetyl vanillin in molar yields of 51.8 and 2.3%, respectively.

  19. Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

    2010-03-01

    Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

  20. Fitness of equipment used for medical exposures to ionising radiation

    International Nuclear Information System (INIS)

    1998-01-01

    The advice in this guidance note is aimed at employers in control of equipment used for medical exposures to ionising radiation and ancillary equipment. This includes NHS trusts, health authorities or boards, private hospitals, clinics, surgeries, medical X-ray facilities in industry, dentists and chiropractors. The guidance should also be useful to radiation protection advisers appointed by such employers. The guidance provides advice on the requirements of regulation 33 of the Ionising Radiations Regulations 1985 (IRR85). In particular, it covers: (a) the selection, installation, maintenance, calibration and replacement of equipment to ensure that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person to the extent that this is compatible with the intended diagnostic or therapeutic purpose; (b) recommended procedures for the definitive calibration of radiotherapy treatment; and (c) the need to investigate incidents involving a malfunction or defect in any 'radiation equipment' which result in medical exposures much greater than intended and to notify the Health and Safety Executive (HSE). 'Medical exposure' is defined in IRR85 as exposure of a person to ionising radiation for the purpose of his or her medical or dental examination or treatment which is conducted under the direction of a suitably qualified person and includes any such examination or treatment conducted for the purposes of research. For convenience, people undergoing medical exposure will be referred to as 'patients' in this guidance. Nothing in this publication is intended to indicate whether or not patients should be informed of any incident resulting from malfunction or defect in equipment used for medical exposure and the possible consequences of that exposure. As stated above, this guidance concerns medical exposures much greater than intended and although exposures much lower than intended can also have serious consequences, the incident would not

  1. Use of ionising radiation for food processing applications

    International Nuclear Information System (INIS)

    Ninjoor, V.

    1989-01-01

    Food irradiation is a recently developed technique used to sterilize and preserve food. Food products are exposed to ionising radiations such as X-rays, gamma rays or high energy electrons which destroy food borne pathogens and parasites and inhibit sprouting. Shelf life of food is extended. The following aspects of radiation processing of food are discussed in the monograph: radiation sources, choice of dose for specific results, safety and nutritional quality of radiation processed food, international status of acceptance of food irradiation, and cost. (M.G.B.). 6 tabs

  2. Ionising radiation and cancer risk: software for risk estimation

    International Nuclear Information System (INIS)

    Siiskonen, T.

    2008-04-01

    Many authors, e.g. the BEIR (Committee on the Biological Effects of Ionizing Radiations) VII committee, have developed models for the risk of cancer resulting from an exposure to ionising radiation. This report describes a software, based on the BEIR VII risk models, which is used for the risk estimation. The risk models, calculation methods and the usage of the software are presented. Finally, illustrative examples are given. The software is developed in Radiation Dosimetry Laboratory of Radiation and Nuclear Safety Authority (STUK). (orig.)

  3. Ionisation constants of inorganic acids and bases in aqueous solution

    CERN Document Server

    Perrin, D D

    2013-01-01

    Ionisation Constants of Inorganic Acids and Bases in Aqueous Solution, Second Edition provides a compilation of tables that summarize relevant data recorded in the literature up to the end of 1980 for the ionization constants of inorganic acids and bases in aqueous solution. This book includes references to acidity functions for strong acids and bases, as well as details about the formation of polynuclear species. This text then explains the details of each column of the tables, wherein column 1 gives the name of the substance and the negative logarithm of the ionization constant and column 2

  4. Thermal ionisation mass spectrometry (TIMS): what, how and why?

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2002-01-01

    Thermal ionisation mass spectrometry (TIMS) is one of the oldest mass spectrometric techniques, which has been used for determining the isotopic composition and concentration of different elements using isotope dilution. In spite of the introduction of many other inorganic mass spectrometric techniques like spark source mass spectrometry (SSMS), glow discharge mass spectrometry (GDMS), inductively coupled plasma-mass spectrometry (ICP-MS), secondary ion mass spectrometry (SIMS), the TIMS technique plays the role of a definitive analytical methodology and still occupies a unique position in terms of its capabilities with respect to precision and accuracy as well as sensitivity

  5. Background Material

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Hyytiäinen, Kari; Saraiva, Sofia

    This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders.......This document serves as a background material to the BONUS Pilot Scenario Workshop, which aims to develop harmonised regional storylines of socio-ecological futures in the Baltic Sea region in a collaborative effort together with other BONUS projects and stakeholders....

  6. 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

  7. Documentation of Occupational Accidents and Diseases caused by Ionising Radiation

    International Nuclear Information System (INIS)

    Fehringer, F.; Seitz, G.

    2004-01-01

    . One of the major goals of the institutions for statutory accident insurance is the prevention of occupational diseases. To perform a successful prevention work it is necessary not only to count the number of accidents or diseases in the various working fields but to look for details of the conditions of work and the human response to those conditions. The institutions for statutory accident insurance have engaged the institution for statutory accident insurance in the precision engineering and electrical industry to carry out documentation, in form of a data bank, for all cases of occupational diseases which could be caused by ionising radiation. Those are not only the cases which are accepted as occupational disease but also the cases where a suspicion of an occupational disease is announced but finally rejected. At the moment about 1700 cases are included in the data bank. For preserving the anonymity information to name and residence are deleted. Various data to one single case are linked by a case-specific key-number. Information to occupation and field of working, to details of a possible exposure to ionising radiation like kind of radiation, time and duration of radiation, exposure of the whole body or of parts of the body and whole body or organ doses are collected. Additional information refers to medical aspects like diagnosis and date of diagnosis. (Author)

  8. Electron impact ionisation cross sections of iron oxides

    Science.gov (United States)

    Huber, Stefan E.; Mauracher, Andreas; Sukuba, Ivan; Urban, Jan; Maihom, Thana; Probst, Michael

    2017-12-01

    We report electron impact ionisation cross sections (EICSs) of iron oxide molecules, FexOx and FexOx+1 with x = 1, 2, 3, from the ionisation threshold to 10 keV, obtained with the Deutsch-Märk (DM) and binary-encounter-Bethe (BEB) methods. The maxima of the EICSs range from 3.10 to 9 . 96 × 10-16 cm2 located at 59-72 eV and 5.06 to 14.32 × 10-16 cm2 located at 85-108 eV for the DM and BEB approaches, respectively. The orbital and kinetic energies required for the BEB method are obtained by employing effective core potentials for the inner core electrons in the quantum chemical calculations. The BEB cross sections are 1.4-1.7 times larger than the DM cross sections which can be related to the decreasing population of the Fe 4s orbitals upon addition of oxygen atoms, together with the different methodological foundations of the two methods. Both the DM and BEB cross sections can be fitted excellently to a simple analytical expression used in modelling and simulation codes employed in the framework of nuclear fusion research. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-80308-2.

  9. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

    Mohankumar, M.N.; Jeevanram, R.K.

    1995-01-01

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

  10. Investigation of damage mechanism by ionising radiation on biomolecules

    International Nuclear Information System (INIS)

    Lau How Mooi

    1996-01-01

    Occupational radiation hazard is a very controversial subject. Effects from high radiation doses are well known from past experiences. However, hazard from low doses is still a subject that is hotly debated upon until now. The occupational dosimetry used now is based on a macroscopic scale. Lately, microdosimetry is fast gaining recognition as a more superior way of measuring hazard. More importantly, scientists are researching the basic damage mechanism that leads to biological effects by ionising radiation. In this report, a simulation study of the basic damage mechanism is discussed . This simulation is based upon Monte Carlo calculations and using polyuridylic acid (Poly-U) as the DNA model This simulation tries to relate the physics and chemistry of interactions of ionising radiation with biomolecules. The computer codes used in this simulation, OREC and RADLYS were created by Hamm et al. (1983) in Oak Ridge National Laboratory. The biological endpoints in this simulation are the strand break and base release of the DNA, which is the precursor of all biological effects. These results are compared with model studies that had been done experimentally to check the validity of this simulation. The G-values of strand break and base release from this simulation were -2.35 and 2.75 and compared well with results from irradiation experiments by von Sonntag (I 98 7) from Max Plank's Institute, Germany

  11. The ecological relevance of current approaches for environmental protection from exposure to ionising radiation

    International Nuclear Information System (INIS)

    Copplestone, David; Howard, Brenda J.; Brechignac, Francois

    2004-01-01

    This paper discusses the current approaches to environmental protection from ionising radiation from an ecological perspective, highlighting the need to understand fully what we are trying to protect. Ecologically relevant endpoints for environmental protection are discussed along with the need to integrate protection from ionising radiation with the approaches adopted for non-radioactive contaminants. A possible integrated assessment approach is outlined

  12. Chemically modified carbon nanotubes as material enhanced laser desorption ionisation (MELDI) material in protein profiling

    International Nuclear Information System (INIS)

    Najam-ul-Haq, M.; Rainer, M.; Schwarzenauer, T.; Huck, C.W.; Bonn, G.K.

    2006-01-01

    Biomarkers play a potential role in the early detection and diagnosis of a disease. Our aim is to derivatize carbon nanotubes for exploration of the differences in human body fluids e.g. serum, through matrix assisted laser desorption ionisation/time of flight mass spectrometry (MALDI/TOF-MS) that can be related to disease and subsequently to be employed in the biomarker discovery process. This application we termed as the material enhanced laser desorption ionisation (MELDI). The versatility of this technology is meant to increase the amount of information from biological samples on the protein level, which will have a major impact to serve the cause of diagnostic markers. Serum peptides and proteins are immobilized on derivatized carbon nanotubes, which function as binding material. Protein-loaded suspension is placed on a stainless steel target or buckypaper on aluminum target for direct analysis with MALDI-MS. The elution method to wash the bound proteins from carbon nanotubes was employed to compare with the direct analysis procedure. Elution is carried out by MALDI matrix solution to get them out of the entangled nanotubes, which are difficult to desorb by laser due to the complex nanotube structures. The advantage of these optimized methods compared to the conventional screening methods is the improved sensitivity, selectivity and the short analysis time without prior albumin and immunoglobulin depletion. The comparison of similarly modified diamond and carbon nanotubes exhibit differences in their nature to bind the proteins out of serum due to the differences in their physical characteristics. Infrared (IR) spectroscopy provided hint for the presence of tertiary amine peak at the crucial chemical step of iminodiacetic acid addition to acid chloride functionality on carbon nanotubes. Atomic absorption spectroscopy (AAS) was utilized to quantitatively measure the copper capacity of these derivatized carbon nanotubes which is a direct measure of capacity of

  13. Exceedance probability map: a tool helping the definition of arsenic Natural Background Level (NBL) within the Drainage Basin to the Venice Lagoon (NE Italy)

    Science.gov (United States)

    Dalla Libera, Nico; Fabbri, Paolo; Mason, Leonardo; Piccinini, Leonardo; Pola, Marco

    2017-04-01

    Arsenic groundwater contamination affects worldwide shallower groundwater bodies. Starting from the actual knowledges around arsenic origin into groundwater, we know that the major part of dissolved arsenic is naturally occurring through the dissolution of As-bearing minerals and ores. Several studies on the shallow aquifers of both the regional Venetian Plain (NE Italy) and the local Drainage Basin to the Venice Lagoon (DBVL) show local high arsenic concentration related to peculiar geochemical conditions, which drive arsenic mobilization. The uncertainty of arsenic spatial distribution makes difficult both the evaluation of the processes involved in arsenic mobilization and the stakeholders' decision about environmental management. Considering the latter aspect, the present study treats the problem of the Natural Background Level (NBL) definition as the threshold discriminating the natural contamination from the anthropogenic pollution. Actually, the UE's Directive 2006/118/EC suggests the procedures and criteria to set up the water quality standards guaranteeing a healthy status and reversing any contamination trends. In addition, the UE's BRIDGE project proposes some criteria, based on the 90th percentile of the contaminant's concentrations dataset, to estimate the NBL. Nevertheless, these methods provides just a statistical NBL for the whole area without considering the spatial variation of the contaminant's concentration. In this sense, we would reinforce the NBL concept using a geostatistical approach, which is able to give some detailed information about the distribution of arsenic concentrations and unveiling zones with high concentrations referred to the Italian drinking water standard (IDWS = 10 µg/liter). Once obtained the spatial information about arsenic distribution, we can apply the 90th percentile methods to estimate some Local NBL referring to every zones with arsenic higher than IDWS. The indicator kriging method was considered because it

  14. Determination of exposure rates from natural background radiation in Khartoum using LiF:Mg,Cu,P (GR-200) and CaSo4: Mn TLD chips

    International Nuclear Information System (INIS)

    Suliman, I.I.; Khangi, F.A.; Shaddad, I.A.; Suliman, I.A.; El Amin, O.I.

    2002-01-01

    The exposure rates from natural background radiation - including terrestrial gamma radiation and the ionizing component of cosmic rays - were measured for the first time in the city of khartoum using two types of TLD materials: LiF:Mg,Cu,P (GR-200) and CaSo 4 :Mn TLD chips. Measurements were performed at two sites simultaneously, one site was selected on land in the vicinity of the Sudan Atomic Energy Commission, for the purposes of the measurement of the total exposure rate outdoors, while the other site was located on a buoy anchored in the Blue Nile, and was selected to measure the exposure rate due to the ionizing component of cosmic rays. The investigations were conducted for periods of between 5 and 28 days. Calibration was performed on a selected number of dosimeters to determine the exposure rates at each site. The exposure rates from the ionizing component of cosmic rays in Khartoum were found to be respectively 33 nGy.h -1 and 30 nGy.h -1 , in the measurements performed within the scope of this work using GR-200 and CaSo 4 :Mn dosimeters, while the total values for exposure on land were found to be 45 nGy.h -1 and 42 nGy.h -1 respectively. These values compare reasonably well with other national averages reported in the UNSCEAR publication. The comparison of the results for the two dosimetric materials demonstrates both the sensitivity and suitability of GR-200 for the purposes of environmental monitoring (orig.)

  15. Contribution to the study and use of ionisation chambers for nuclear reactor control (1965); Contribution a l'etude et a l'utilisation des chambres d'ionisation pour le controle des reacteurs nucleaires (1965)

    Energy Technology Data Exchange (ETDEWEB)

    Duchene, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-02-15

    At the moment ionisation chambers are the detectors which are best suited to the task of nuclear reactor control by neutronic measurements. We have thought it wise to state some generalities concerning reactor dynamics, the various neutron detection methods, the working of ionisation chambers and the measurement methods used. Our contribution to reactor control techniques consists on the one hand in an attempt to make a synthesis of the factors influencing the operation of ionisation chambers, the study of these factors, and on the other hand in the development of ionisation chambers of the fission and boron types, making it possible to follow the working of a reactor from the moment it starts up until maximum power is attained. In the field of fission chambers, we have in particular improved the technique for depositing uranium oxide on aluminium and have perfected the electrolytic deposition process on other metals: stainless steel, copper, molybdenum, nickel, tantalum, titanium, kovar, tungsten and beryllium. We have developed several types of fission chambers used during the start-up of reactors: one type of medium performance now in use in French piles one high-sensitivity type one high-temperature type which has operated up to 600 deg. C. As far as boron chambers are concerned, we have studied the perturbations caused to the measurement by the exposure of the chamber to high neutron flux and to a very strong {gamma} radiation. This exposure brings about a modification of the properties of the constituent materials and causes a background noise in the chamber which can seriously handicap the neutron measurements. We have shown that the compensation technique makes it possible to limit this noise and to thereby increase the range of measurement of conventional ionisation chambers intended for power measurements. Finally, we have built two types of compensation chambers used in the French reactors and have begun the study of a third type of high sensitivity for

  16. 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

  17. RF System for the MICE Demonstration of Ionisation Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Ronald, K.; et al.

    2017-04-01

    Muon accelerators offer an attractive option for a range of future particle physics experiments. They can enable high energy (TeV+) high energy lepton colliders whilst mitigating the difficulty of synchrotron losses, and can provide intense beams of neutrinos for fundamental physics experiments investigating the physics of flavor. The method of production of muon beams results in high beam emittance which must be reduced for efficient acceleration. Conventional emittance control schemes take too long, given the very short (2.2 microsecond) rest lifetime of the muon. Ionisation cooling offers a much faster approach to reducing particle emittance, and the international MICE collaboration aims to demonstrate this technique for the first time. This paper will present the MICE RF system and its role in the context of the overall experiment.

  18. Studies of Non-Targeted Effects of Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  19. Ionisation of L subshells of heavy atoms by deuteron collision

    International Nuclear Information System (INIS)

    Sokhi, R.S.; Crumpton, D.; Trautmann, D.

    1989-01-01

    L i subshell ionisation cross sections for 1.2-3.0 MeV deuteron impact on thin targets of W, Au, Pb and Bi have been measured experimentally. Measurements were made with the Birmingham University's 3MV Dynamitron accelerator and the cross sections were deduced from the emitted L X-rays. These cross sections and their ratios have been compared graphically with the ECPSSR and RHSCA models. The ECPSSR model underestimates the measured L 2 subshell cross sections but shows very good agreement with the L 3 subshell values. The RHSCA theory in general exhibits good agreement with the measured cross sections for the L 1 and L 2 subshells but overestimates the L 3 cross sections by up to 60%. (orig.)

  20. Studies of Non-Targeted Effects of Ionising Radiation

    International Nuclear Information System (INIS)

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae

    2006-01-01

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  1. Fitness of equipment used for medical exposure to ionising radiation

    International Nuclear Information System (INIS)

    1992-01-01

    The purpose of this note is to provide guidance to those who have duties under the Health and Safety at Work Act and other relevant legislation. It gives guidance on the practical application of legislation, concerning radiotherapy equipment. Two particular issues arise out of the requirements of Regulation 33 of the Ionising Radiations Regulations 1985 (IRR85) in relation to equipment which is used for medical exposures. These are the requirement to select, install and maintain this type of equipment in such a way that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person where this is compatible with the intended clinical purpose, including the need to ensure that equipment used for radiotherapy is properly calibrated, and the requirement to notify the Health and Safety Executive (HSE) when an incident occurs involving a malfunction or defect in any 'radiation equipment' which gives rise to a medical exposure that is much greater than intended. (author)

  2. First Results from the LEIR Ionisation Profile Monitors

    CERN Document Server

    Bal, C; Sautier, R; Tranquille, G

    2008-01-01

    The role of the Low Energy Ion Ring, LEIR, is to transform long pulses of lead ions from the Linac 3 to short dense bunches for transfer to the LHC. This is accomplished by the accumulation of up to 4 Linac pulses by electron cooling. In order to non-destructively monitor the cooling performance and determine the accumulated beam characteristics, two prototype ionisation profile monitors have been built and were tested during the LEIR commissioning runs with O4+ and Pb54+ ions in 2006. In this paper we present the results obtained with the prototype monitors, the problems encountered and describe the modifications made for the final design. The modified monitors have been installed on the LEIR machine and are waiting for the next ion run planned in August.

  3. Fitness of equipment used for medical exposure to ionising radiation

    International Nuclear Information System (INIS)

    1992-01-01

    This document provides advice on two particular issues arising out of the requirements of Regulation 33 of the Ionising Radiations Regulations 1985 (IRR85) in relation to equipment which is used for medical exposures. These issues are: (a) the requirement to select, install and maintain this type of equipment in such a way that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person to the extent that this is compatible with the intended clinical purpose, including the need to ensure that equipment used for radiotherapy is properly calibrated; and (b) the requirement to notify the Health and Safety Executive (HSE) when an incident occurs involving a malfunction or defect in any 'radiation equipment' which gives rise to a medical exposure that is much greater then intended. (author)

  4. Environmental protection from ionising contaminants in the Arctic

    International Nuclear Information System (INIS)

    Brown, J.; Stensrud, H.; Strand, P.; Jaworska, A.

    2003-01-01

    The traditional ICRP doctrine concerning environmental protection, in essence expressing that the dose limits in place for man ensure that flora and fauna are protected from the effects of ionising radiation, has been recently criticised. In its place, a system for the radiological protection of the environment has been promoted to include agreed quantities and units, selected reference organisms, reference dose models and tables of effects for reference organisms. The EC project 'Environmental Protection for Ionising Contaminants in the Arctic 'EPIC' adopts a practical perspective in developing a protection framework for the Arctic environment. The objectives of the project were:(1) collate the information about environmental transfer of selected radionuclides (2) identify reference Arctic biota; (3) model the uptake of radionuclides; (4) develop a reference set of dose models (5) compile data of dose-effects relationships for reference biota, and (6) integrate assessment of environmental impact from radionuclides with those for other contaminants. In the selection of reference organisms, several key criteria have been identified: ecological niche, radiosensitivity, radioecological sensitivity, distribution and amenability to further research. The application of these criteria has allowed an informed selection of suitable Arctic reference organisms to be made. Field studies were performed in the area of residual radioactive contamination in the Republic of Sakha, Yakutia. Biological material and soils were sampled, notes on plant morphology in elevated dose area were made, and seeds from high dose rate areas were sampled and tested for germination rate. A database on dose-effects relationships has been constructed. The database is subdivided into radiation effects on terrestrial and aquatic organisms. The database will help to establish dose-effect relationships for different end points. At present, effort has been concentrated on populating the database; In

  5. Airborne hydrogen cyanide measurements using a chemical ionisation mass spectrometer for the plume identification of biomass burning forest fires

    Directory of Open Access Journals (Sweden)

    M. Le Breton

    2013-09-01

    Full Text Available A chemical ionisation mass spectrometer (CIMS was developed for measuring hydrogen cyanide (HCN from biomass burning events in Canada using I− reagent ions on board the FAAM BAe-146 research aircraft during the BORTAS campaign in 2011. The ionisation scheme enabled highly sensitive measurements at 1 Hz frequency through biomass burning plumes in the troposphere. A strong correlation between the HCN, carbon monoxide (CO and acetonitrile (CH3CN was observed, indicating the potential of HCN as a biomass burning (BB marker. A plume was defined as being 6 standard deviations above background for the flights. This method was compared with a number of alternative plume-defining techniques employing CO and CH3CN measurements. The 6-sigma technique produced the highest R2 values for correlations with CO. A normalised excess mixing ratio (NEMR of 3.68 ± 0.149 pptv ppbv−1 was calculated, which is within the range quoted in previous research (Hornbrook et al., 2011. The global tropospheric model STOCHEM-CRI incorporated both the observed ratio and extreme ratios derived from other studies to generate global emission totals of HCN via biomass burning. Using the ratio derived from this work, the emission total for HCN from BB was 0.92 Tg (N yr−1.

  6. Making ionising radiation a real experience for high school science students

    International Nuclear Information System (INIS)

    Whitlock, J.; Lang, P.; De La Matter, D.; Hinman, P.; White, B.

    2009-01-01

    The Canadian public has little understanding of ionising radiation due in part to its treatment in popular media. In principle, students learn about ionising radiation in their school science classes. Developments in science curricula are providing more education opportunities for this subject. The Canadian Nuclear Society's program for introducing real, personal experience with ionising radiation in the classroom is starting to make a difference. The demand is expected to exceed the resources of the CNS and the program is being developed to facilitate external support. This paper summarizes the need, the history of this program development, and the path forward. (author)

  7. A search for non-baryonic dark matter using an ionisation bolometer in the edelweiss experiment; Recherche de matiere sombre non-baryonique au moyen d`un bolometre a ionisation dans le cadre de l`experience edelweiss

    Energy Technology Data Exchange (ETDEWEB)

    Di Stefano, Ph. [CEA Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee]|[Paris-11 Univ., 91 - Orsay (France)

    1998-09-24

    The EDELWEISS experiment is an underground direct-detection search for hypothetical supersymmetric WIMPs that might solve the problem of dark matter. We have employed a cryogenic 70 g germanium ionisation bolometer, in which a WIMP would scatter elastically off a nucleus, creating both a heat and an ionisation signal. To offset the various electronic noises present in our necessarily small signals, we have s applied an optimal filtering technique in the frequency domain. This allows us to reach resolutions of 1.2 keV FWHM at 122 keV on north channels. It also provides good separation right down to low energies between the expected signal of nuclear recoils, and the photonic background of electron recoils which ionize more for a given energy. Calibration data show that we are able to reject 99.7 % of this background, while keeping 95% of the signal. However, our 1.17 kg.days of data searching for WIMPs show a third population encroaching on the expected signal. This is probably due to low energy photons or electrons interacting in the outer layers of the crystal, where charges are incompletely collected. Nevertheless, by trading off half of the conserved signal, we still manage to reject 98.5 % of the background. Thus the raw rate of 40 evts/d/kg/keV yields a conservative 90 % upper limit on the signal of 0.6 evts/d/kg/keV. This represents nearly a three orders of magnitude improvement for EDELWEISS, and puts the predicted supersymmetric phase space within two orders of magnitude. (author) 196 refs.

  8. Task 23 - background report on subsurface environmental issues relating to natural gas sweetening and dehydration operations. Topical report, February 1, 1994--February 28, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, J.A.

    1998-12-31

    This report describes information pertaining to environmental issues, toxicity, environmental transport, and fate of alkanolamines and glycols associated with natural gas sweetening and dehydration operations. Waste management associated with the operations is also discussed.

  9. Impact of chronic, low-level ionising radiation exposure on terrestrial invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Hingston, J.; Wood, M.D.; Copplestone, D.; Zinger, I. [Liverpool Univ., School of Biological Sciences, Merseyside (United Kingdom)

    2004-07-01

    There is a need to confirm that the environment is being adequately protected from the mixture of contaminants released into it. In the field of environmental radioactivity, tools have been developed to assess the impacts of ionising radiation on wildlife. The scientific data upon which these assessments are based is, however, lacking. New documentation has been produced by the UK Environment Agency to provide guidelines on structuring experiments (using environmentally relevant doses) and select suitable non-human species and endpoints for study. It is anticipated that this documentation will be used to direct future experiments in this field. This paper presents the results of the first of these experiments. Numbers of the earthworm Eisenia fetida and the wood louse Porcellio scaber were segregated and constantly exposed to one of six radiation doses (background, 0.1, 0.4, 1.5, 4.0 and 8.0 mGyh{sup -1}) for a total of 16 and 14 weeks respectively. The endpoints of mortality, number of viable offspring and average weight of an individual were recorded and the results of this study will be discussed here. (author)

  10. Eddy covariance flux measurements of ammonia by high temperature chemical ionisation mass spectrometry

    Directory of Open Access Journals (Sweden)

    J. Sintermann

    2011-03-01

    Full Text Available A system for fast ammonia (NH3 measurements with chemical ionisation mass spectrometry (CIMS based on a commercial Proton Transfer Reaction-Mass Spectrometer (PTR-MS is presented. It uses electron transfer reaction as ionisation pathway and features a drift tube of polyetheretherketone (PEEK and silica-coated steel. Heating the instrumental inlet and the drift tube to 180 °C enabled an effective time resolution of ~1 s and made it possible to apply the instrument for eddy covariance (EC measurements. EC fluxes of NH3 were measured over two agricultural fields in Oensingen, Switzerland, following fertilisations with cattle slurry. Air was aspirated close to a sonic anemometer at a flow of 100 STP L min−1 and was directed through a 23 m long 1/2" PFA tube heated to 150 °C to an air-conditioned trailer where the gas was sub-sampled from the large bypass stream. This setup minimised damping of fast NH3 concentration changes between the sampling point and the actual measurement. High-frequency attenuation loss of the NH3 fluxes of 20 to 40% was quantified and corrected for using an empirical ogive method. The instrumental NH3 background signal showed a minor interference with H2O which was characterised in the laboratory. The resulting correction of the NH3 flux after slurry spreading was less than 1‰. The flux detection limit of the EC system was about 5 ng m−2 s−1 while the accuracy of individual flux measurements was estimated 16% for the high-flux regime during these experiments. The NH3 emissions after broad spreading of the slurry showed an initial maximum of 150 μg m−2 s−1 with a fast decline in the following hours.

  11. The potential use of ionising energy treatment in Queensland's horticultural industries

    International Nuclear Information System (INIS)

    Heather, N.W.; Sheehy, P.T.; Muirhead, I.F.; Brown, B.I.; Hassall, R.N.

    1985-01-01

    The potential application of ionising energy treatment technology in Queensland falls into three categories: insect disinfestation, disease control and quality improvement. The technology fulfils the requirements of a disinfestation treatment against Queensland fruit fly and other pests of quarantine importance in respect to efficacy, absence of phytotoxicity, absence of residues and, on technical considerations would be an ideal replacement for the fumigant EDB. The report examines the purposes of ionising energy treatment, economic and marketing aspects and research needs

  12. Medical effects and risks of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Mettler, Fred A

    2012-01-01

    Effects and risk from exposure to ionising radiation depend upon the absorbed dose, dose rate, quality of radiation, specifics of the tissue irradiated and other factors such as the age of the individual. Effects may be apparent almost immediately or may take decades to be manifest. Cancer is the most important stochastic effect at absorbed doses of less than 1 Gy. The risk of cancer induction varies widely across different tissues; however, the risk of fatal radiation-induced cancer for a general population following chronic exposure is about 5% Sv −1 . Quantification of cancer risk at doses of less than 0.1 Gy remains problematic. Hereditary risks from irradiation that might result in effects to offspring of humans appear to be much lower and any such potential risks can only be estimated from animal models. At high doses (over 1 Gy) cell killing and modification causes deterministic effects such as skin burns, and bone marrow depression, in which case immunosuppression becomes a critical issue. Acute whole body penetrating gamma irradiation at doses in excess of 2 Gy results in varying degrees of acute radiation sickness and doses over 10 Gy are usually lethal as a result of combined organ injury. (note)

  13. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

    International Nuclear Information System (INIS)

    Petitfils, A.

    2007-09-01

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  14. Dosimetry of ionising radiation in modern radiation oncology

    Science.gov (United States)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  15. Nonlinear shock structure in a weakly ionised magnetoplasma

    Directory of Open Access Journals (Sweden)

    C. B. Dwivedi

    1994-12-01

    Full Text Available The formation of a neutral induced weak nonlinear shock structure in a weakly ionised magnetoplasma has been analytically investigated. Using the reductive perturbation method, basic dynamical equations of a three-component (electron, ion and neutral plasma have been reduced to a well-known Burger equation which can support a weak shock solution. Its stationary and initial value solutions have been derived to describe the characteristics of the weak shock profile. Asymptotic behaviour of the Burger solution results in a saw-tooth structure which has a practical implication to predict the nonlinear steepened structure of the nighttime irregularity in the lower portion of the Earth's ionosphere. Accordingly, it is suggested that the observation of saw-tooth shape of nighttime irregularity at 92 km could be attributed to the nonlinear saturation of the NILF mode instability as proposed by Dwivedi and Das in 1992. However, exact experimental verification of this suggestion requires more data on nighttime irregularity in the mesosphere and lower thermosphere (80-95 km for a wide range of scale sizes extending up to about 1 km and above.

  16. Martian sub-surface ionising radiation: biosignatures and geology

    Directory of Open Access Journals (Sweden)

    J. M. Ward

    2007-07-01

    Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

    We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

  17. Education and training issues in individual monitoring of ionising radiation

    International Nuclear Information System (INIS)

    Dimitriou, P.; Kamenopoulou, V.

    2011-01-01

    The present article deals with the education and training (E and T) issues of individual monitoring (IM) of ionising radiation, based on the requirements provided by the Basic Safety Standards EURATOM Directive and the European Commission Technical Recommendations for IM of external radiation. The structure and the objectives of E and T programmes addressed to the staff of dosimetry services, in order to allow the recognition and ensure the continuity of expertise are discussed. The necessity for the establishment of a national strategy for building competence in IM through information, education, training and retraining programmes, addressed to the individually monitored personnel is underlined. The train the trainers' concept is recognised as being an important tool for optimising resources and transferring the skills necessary for building competence. The conditions under which an efficient train the trainers' approach can be established are discussed. Examples of curricula concerning the key persons involved in the provision of E and T in occupational radiation protection are also given. (authors)

  18. The application of ionising radiation in industrial wastewater treatment technology

    International Nuclear Information System (INIS)

    Kos, L.; Perkowski, J.; Ledakowicz, S.

    2003-01-01

    An attempt was made to apply radiation techniques in the treatment of industrial wastewater from a dairy, brewery and sugar factory. For degradation of pollutants present in the wastewater, the following methods were used: irradiation, irradiation combined with aeration, ozonation, and combined irradiation and ozonation. For all three types of wastewater, the best method among these listed above appeared to be the method of irradiation combined with ozonation. Most degradable was the wastewater produced in sugar factories, and the least biodegradable appeared to be dairy wastewater. Depending on the dose of ozone and radiation, a maximum 60% reduction of COD was obtained. No effect of the wastewater aeration on its degradation by radiation was found. Changes in the content of mineral compounds were observed in none of the cases. The process of biological treatment of wastewater was carried out in a low-loaded, wetted bed. Pretreatment of the wastewater had no significant effect on the improvement of the biological step operation. Some effect was observed only in the case of the wastewater coming from a sugar factory. For medium concentrated wastewater from food industry, it is not economically justified to apply the pretreatment with the use of ionising radiation. (orig.)

  19. Occupational Exposure to Ionising Radiation in Greece (1994-1998)

    International Nuclear Information System (INIS)

    Kamenopoulou, V.; Drikos, G.; Dimitriou, P.

    2000-01-01

    This study was scheduled in order to analyse the individual annual dose information on classified workers in Greece, monitored and assessed by the central dosimetry service at the Greek Atomic Energy Commission for the years 1994-98. This service provides film badges to about 7500 workers all over the country on a monthly basis. Dose summaries were recorded and processed by the Dose Registry Information System, the database of which has been totally renewed since 1994. The statistical analysis provided refers to and deals with the mean annual dose, the collective dose, the distribution of the dose over the different specialities and the number of workers that have exceeded any of the established dose levels. Results concerning the annual dose summaries demonstrate a decrease in the collective and the mean individual dose to workers in the year 1995 and a slight but steady year-by-year increase thereafter during the period under consideration. This increasing tendency is discussed along with the increase in the ionising radiation applications, especially those in the medical sector, the change of the positioning of the film badge and the quality control measures provided by Greek law for radiation laboratories. (author)

  20. International conference on individual monitoring of ionising radiation

    International Nuclear Information System (INIS)

    Vanhavere, Filip

    2016-01-01

    This special issue of the journal Radiation Protection Dosimetry is dedicated to the Proceedings of the International Conference on Individual Monitoring of Ionising Radiation (IM2015), which is the fifth of a series of conferences dealing with individual monitoring. This conference series is initiated by EURADOS, the European Radiation Dosimetry Group, and is organised every 5 years. In 2015, the conference was jointly organised by the Belgian Nuclear Research Centre (SCK.CEN), AV Controlatom, and the Vrije Universiteit Brussel. It brought together scientists from regulatory authorities, individual monitoring services (IMS), research bodies, European networks and companies, for the purpose of facilitating the dissemination of knowledge, exchanging experiences and promoting new ideas in the field of individual monitoring. After the conference, 124 papers were submitted for publication in these peer-reviewed proceedings. From these, 103 were finally accepted for publication. The help of the numerous referees and the guest editors is very much appreciated. These proceedings provide a full image of the IM2015 conference. The high-level publications will be useful to improve the state of individual monitoring all over the world and aim to inspire many scientists to continue their work on a better monitoring of radiologically exposed workers

  1. The Ionising Radiations Advisory Committee Open Meeting 10 October 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    Full text: The Ionising Radiations Advisory Committee (IRAC) held its first open meeting on 10 October 2001 in response to a request from the Health and Safety Commission (HSC) that all its advisory committees should follow the Commission's example and hold such meetings. Some of the other advisory committees have already held open meetings and others are planning to do so shortly. The aim of the meeting was to enable members of the public to meet IRAC members and to find out more about the Committee - how it worked and the type of issues it dealt with. The first two sessions were devoted to short presentations describing IRAC's work and influences, now and in the future, on radiation protection generally. The third session was a discussion forum. The agenda for the meeting and the presentations are posted on the web at: www.hse.gov.uk/foi/iracopen.htm. Each session of presentations was followed by questions of clarification and the third session of the meeting comprised an open forum. Many of the questions raised were not directly relevant to IRAC but, nevertheless, members provided brief responses and referred questions on to others as appropriate. One question had been notified in advance, asking whether members of IRAC agreed that it is now (regrettably) reasonably foreseeable that a loss of containment of radioactive material may occur at a nuclear facility as a result of impact by an aeroplane or by other hostile acts, and that this should be made clear in published guidance on REPPIR. This question was not within IRAC's remit. The Chairman of the Nuclear Safety Advisory Committee offered to take the question to the Committee's next meeting. Issues discussed included: Concerns that exposure to ionising radiation at low levels is more dangerous than is currently reflected in risk estimates. The European Parliament has adopted a resolution calling on the main international bodies, including the International Commission on Radiological

  2. Impact ionisation mass spectrometry of polypyrrole-coated pyrrhotite microparticles

    Science.gov (United States)

    Hillier, Jon K.; Sternovsky, Zoltan; Armes, Steven P.; Fielding, Lee A.; Postberg, Frank; Bugiel, Sebastian; Drake, Keith; Srama, Ralf; Kearsley, Anton T.; Trieloff, Mario

    2014-07-01

    Cation and anion impact ionization mass spectra of polypyrrole-coated pyrrhotite cosmic dust analogue particles are analysed over a range of cosmically relevant impact speeds. Spectra with mass resolutions of 150-300 were generated by hypervelocity impacts of charged particles, accelerated to up to 37 km s-1 in a Van de Graaff electrostatic accelerator, onto a silver target plate in the Large Area Mass Analyzer (LAMA) spectrometer. Ions clearly indicative of the polypyrrole overlayer are identified at masses of 93, 105, 117, 128 and 141 u. Organic species, predominantly derived from the thin (20 nm) polypyrrole layer on the surface of the particles, dominate the anion spectra even at high (>20 km s-1) impact velocities and contribute significantly to the cation spectra at velocities lower than this. Atomic species from the pyrrhotite core (Fe and S) are visible in all spectra at impact velocities above 6 km s-1 for 56Fe+, 9 km s-1 for 32S+ and 16 km s-1 for 32S- ions. Species from the pyrrhotite core are also frequently visible in cation spectra at impact speeds at which surface ionisation is believed to dominate (Silver was confirmed as an excellent choice for the target plate of an impact ionization mass spectrometer, as it provided a unique isotope signature for many target-projectile cluster peaks at masses above 107-109 u. The affinity of Ag towards a dominant organic fragment ion (CN-) derived from fragmentation of the polypyrrole component led to molecular cluster formation. This resulted in an enhanced sensitivity to a particular particle component, which may be of great use when investigating astrobiologically relevant chemicals, such as amino acids.

  3. Calculation of Photo-Ionisation Cross Sections and Radiative Recombination Rate Coefficients for CO and CO+ Molecules

    International Nuclear Information System (INIS)

    Dhouioui Raja; Teulet Philippe; Cressault Yann; Ghalila Hassen; Riahi Riadh; Jaidane Nejm Eddine; Ben Lakhdar Zohra

    2014-01-01

    A method based upon the weighted total cross section (WTCS) theory is proposed to calculate the photo-ionisation cross sections and the radiative recombination rate coefficients between the fundamental level of CO and the main electronic states of its corresponding ion. Total photo-ionisation cross sections and radiative recombination rate coefficients are determined from the calculation of elementary vibrational photo-ionisation cross sections. Transitions between CO + (X, A and B) and CO(X) are considered. Total photo-ionisation cross sections and recombination coefficients are computed in the temperature interval 500–15000 K. (low temperature plasma)

  4. γH2AX expression as adaptive response of lymphocyte cells in resident of Takandeang village area with high background natural radiation

    International Nuclear Information System (INIS)

    Iin Kurnia; Teja Kisnanto; Yanti Lusiyanti

    2016-01-01

    Resident that living in high natural radiation has the potential for DNA damage due to exposure to radiation as a part of radiation adaptive response. It has also potentially initiation of genome instability that can cause cancer cell. DNA damage which can be observed with the γH2AX as biomarkers of DNA double strand break. This study aims to determine the expression γH2AX as the adaptive response of lymphocyte of populations living in areas with high natural radiation after being irradiated with challenge dose of 2 Gy. Blood samples from 12 residents were irradiated with 2 Gy and then the detection and counting of γH2AX foci were performed before and after irradiation at 50 lymphocyte cells. From the results study it was found a significant increase in the number of γH2AX foci in lymphocytes after receiving irradiation (p = 0.004). There were no significant differences in the number of γH2AX foci by age and gender either prior to or after irradiation. From this data we can conclude that 2 Gy irradiation directly causes DNA damage as in vitro adaptive response that observed by expression of γH2AX foci. (author)

  5. natural

    Directory of Open Access Journals (Sweden)

    Elías Gómez Macías

    2006-01-01

    Full Text Available Partiendo de óxido de magnesio comercial se preparó una suspensión acuosa, la cual se secó y calcinó para conferirle estabilidad térmica. El material, tanto fresco como usado, se caracterizó mediante DRX, área superficial BET y SEM-EPMA. El catalizador mostró una matriz de MgO tipo periclasa con CaO en la superficie. Las pruebas de actividad catalítica se efectuaron en lecho fijo empacado con partículas obtenidas mediante prensado, trituración y clasificación del material. El flujo de reactivos consistió en mezclas gas natural-aire por debajo del límite inferior de inflamabilidad. Para diferentes flujos y temperaturas de entrada de la mezcla reactiva, se midieron las concentraciones de CH4, CO2 y CO en los gases de combustión con un analizador de gases tipo infrarrojo no dispersivo (NDIR. Para alcanzar conversión total de metano se requirió aumentar la temperatura de entrada al lecho a medida que se incrementó el flujo de gases reaccionantes. Los resultados obtenidos permiten desarrollar un sistema de combustión catalítica de bajo costo con un material térmicamente estable, que promueva la alta eficiencia en la combustión de gas natural y elimine los problemas de estabilidad, seguridad y de impacto ambiental negativo inherentes a los procesos de combustión térmica convencional.

  6. Evaluation of host rocks and background lithologies as secondary contributors to the uranium and rare-earth element source-term at the Needle's Eye natural analogue site

    International Nuclear Information System (INIS)

    Hyslop, E.K.

    1993-01-01

    HMIP has a research programme investigating some naturally radioactive sites in the UK as geochemical analogues of radionuclide migration. The objective is to test thermodynamic database and computer codes used for modelling radionuclide migration under environmental conditions. This report describes a study of the distributions of uranium (U) and the rare-earth elements (REE) in the vicinity of pitchblende veins outcropping in the cliff at Needle's Eye on the Solway Coats, SW Scotland. This report improves the information available on the secondary source-terms of U and REE. The minerals in the country rocks are thought to be supplying only minor amounts of these elements to the groundwaters flowing into the Merse silts within the detailed study area close to the mineralisation in the cliff. The pitchblende veins are the principal source-term for U migrating into the Merse silts at the foot of the cliff. (author)

  7. 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.

  8. Rapid, Long-term Monitoring of CO2 Concentration and δ13CO2 at CCUS Sites Allows Discrimination of Leakage Patterns from Natural Background Values

    Science.gov (United States)

    Galfond, B.; Riemer, D. D.; Swart, P. K.

    2014-12-01

    In order for Carbon Capture Utilization and Storage (CCUS) to gain wide acceptance as a method for mitigating atmospheric CO2 concentrations, schemes must be devised to ensure that potential leakage is detected. New regulations from the US Environmental Protection Agency require monitoring and accounting for Class VI injection wells, which will remain a barrier to wide scale CCUS deployment until effective and efficient monitoring techniques have been developed and proven. Monitoring near-surface CO2 at injection sites to ensure safety and operational success requires high temporal resolution CO2 concentration and carbon isotopic (δ13C) measurements. The only technologies currently capable of this rapid measurement of δ13C are optical techniques such as Cavity Ringdown Spectroscopy (CRDS). We have developed a comprehensive remote monitoring approach using CRDS and a custom manifold system to obtain accurate rapid measurements from a large sample area over an extended study period. Our modified Picarro G1101-i CRDS allows for automated rapid and continuous field measurement of δ13CO2 and concentrations of relevant gas species. At our field site, where preparations have been underway for Enhanced Oil Recovery (EOR) operations, we have been able to measure biogenic effects on a diurnal scale, as well as variation due to precipitation and seasonality. Taking these background trends into account, our statistical treatment of real data has been used to improve signal-to-noise ratios by an order of magnitude over published models. Our system has proven field readiness for the monitoring of sites with even modest CO2 fluxes.

  9. 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.

  10. The biological effects of ionising radiation on Crustaceans: A review

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Neil; Lerebours, Adélaïde [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom); Smith, Jim T. [School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, Hampshire PO1 3QL (United Kingdom); Ford, Alex T., E-mail: alex.ford@port.ac.uk [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom)

    2015-10-15

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  11. Single-stage accelerator mass spectrometer radiocarbon-interference identification and positive-ionisation characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom); Freeman, S.P.H.T.; Xu, S.; Dougans, A. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, East Kilbride G75 0QF (United Kingdom)

    2013-01-15

    A single-stage accelerator mass spectrometer (SSAMS) is a good alternative to conventional spectrometers based on tandem electrostatic acceleration for radiocarbon measurement and permits experimentation with both negative and positive carbon ions. However, such {sup 14}C AMS of either polarity ions is limited by an interference. In the case of anion acceleration we have newly determined this to be summed {sup 13}C and {sup 16}O by improvising an additional Wien filter on our SSAMS deck. Also, {sup 14}C AMS might be improved by removing its dependency on negative-ionisation in a sputter ion source. This requires negative-ionisation of sample atoms elsewhere to suppress the {sup 14}N interference, which we accomplish by transmitting initially positive ions through a thin membrane. The ionisation dependence on ion-energy is found to be consistent with previous experimentation with vapours and thicker foils.

  12. Issues related to radiation protection in the medical application of ionising radiation

    International Nuclear Information System (INIS)

    Bhatt, B.C.; Tripathi, U.B.; Sharma, S.D.

    2002-01-01

    The medical application of ionising radiation is by far the largest contributor (about 95%) to human exposures from manmade sources of radiation. Diagnostic radiology, radiotherapy, nuclear medicine and interventional radiology procedures are common sources of the medical exposures. In addition to medical exposures, exposures also result from other radiation related occupational activities. This paper endeavours to summarise the relevant findings, conclusions and recommendations of UNSCEAR Report 2000 and the two recent IAEA international conferences, namely, (1) International Conference on the Radiological Protection of Patients in Diagnostic and Interventional Radiology, Nuclear Medicine and Radiotherapy, Malaga, Spain, 2001, and (2) International Conference on Occupational Radiological Protection: Protecting Workers against exposure to ionising radiation, Geneva, Switzerland, 2002, with reference to medical applications of ionising radiation

  13. Natural hazards in the Great Caucasus range on the background of climate change - risk maps for the Kazbegi and Mleta areas (Georgia)

    Science.gov (United States)

    Keller, Tatjana; Gaprindashvili, George; Gobejishvili, Ramin; Keggenhoff, Ina; Elizbarashvili, Mariam; Kalandadze, Besik; Lomidze, Nino; King, Lorenz

    2013-04-01

    features of the subsurface materials, and possibly by lowering the movement persistence up to a critical level in the aeration zone. Kazbegi and Mleta belong to an extremely complex mountainous area of Georgia according to its geology and the scale and frequency of natural disaster processes. Since the year 2000, the activation of these processes results in increased damage for population, farm lands and engineering facilities that can be observed almost every year. The occurrence intervals are becoming significantly shorter. As a result, more populated areas, engineering facilities and industrial objects have to be included in the risk zones.

  14. The significance of a new correspondence principle for electromagnetic interaction in strong optical field ionisation

    International Nuclear Information System (INIS)

    Boreham, B. W.; Hora, H.

    1997-01-01

    We have recently developed a correspondence principle for electromagnetic interaction. When applied to laser interactions with electrons this correspondence principle identifies a critical laser intensity I*. This critical intensity is a transition intensity separating classical mechanical and quantum mechanical interaction regimes. In this paper we discuss the further application of I* to the interaction of bound electrons in atoms. By comparing I* with the ionisation threshold intensities as calculated from a cycle-averaged simple-atom model we conclude that I* can be usefully interpreted as a lower bound to the classical regime in studies of ionisation of gas atoms by intense laser beams

  15. Ionisation of hydrogen-like atoms by a multiphoton absorption process

    International Nuclear Information System (INIS)

    Gontier, Y.; Trahin, M.

    1967-01-01

    The general expression for the amplitude of the probability of ionisation by a multiphoton absorption process is derived. Its non-relativistic limit is taken and the bipolar approximation is used for calculating the ionisation cross-section of hydrogen-like atoms. This latter involves the summation over intermediate virtual states by means of: a) a recursion relationship concerning angular functions, b) a particular technique which when applied to radial functions makes it possible to solve a system of inhomogeneous first-order differential equations. (authors) [fr

  16. Human-Nature Interaction in the Eastern Pamirs of Tajikistan - Ecosystem services against the background of pasture use and energy consumption

    Science.gov (United States)

    Vanselow, K. A.; Samimi, C.; Kraudzun, T.; Kreutzmann, H.

    2012-04-01

    -Dombois & Ellenberg 1974). Forage quality of the most important fodder plants was analyzed according to van Soest (1994). By combining the results the availability of metabolizable energy throughout the study area was estimated. Spatiotemporal variations of pasture use were mapped by repeatedly visiting all pasture camps from 2007 until 2009 and 280 pastoralist were interviewed. Furthermore, the development of usage rights, and the size and ownership of the herds since the Soviet era were assessed through archive work and topic-specific expert interviews. It could be shown that the mono-seasonal pasture utilization on the state farms contrasts with a distinct multi-seasonal present-day use. Consequently, pastures close to villages are permanently used, particularly in winter, and are heavily overgrazed. In contrast, grazing pressure on summer pastures is much less. However, also several distant summer pastures show high livestock numbers, which indicates that they are not underused, as it is often argued. Furthermore, it could be demonstrated that the actual degradation of dwarf shrub vegetation is not yet as severe as stated in reports and literature. These results can help to advise stakeholders (e.g. local administration, herders, NGOs) about sustainable management of the natural resources.

  17. Serum ionised calcium and cardiovascular disease in 45-years old men and women followed for 18 years

    DEFF Research Database (Denmark)

    Ogard, Christina Gerlach; Petersen, Janne; Jørgensen, Torben

    2006-01-01

    ) and a broader definition of CVD. Persons with ionised serum calcium in the highest quintile were compared with persons in the lower four quintiles. Results: In a univariate analysis persons with ionised serum calcium in the highest quintile had increased risk of IHD (p=0.001) and CVD (p=0.02) compared...

  18. Comparative evaluation of different approaches to environmental protection against ionising radiation in view of practicability and consistency

    International Nuclear Information System (INIS)

    Steiner, M.; Hornung, L.; Mundigl, S.; Kirchner, G.

    2006-01-01

    International organisations, including ICRP, IAEA and UNSCEAR, and the international scientific community are currently engaged in work on the protection of non-human species against ionising radiation as a complement to the existing framework centred on humans. The basic ideas and conceptual approaches developed during the last decade substantially agree with each other. The EC funded FASSET project (Framework for Assessment of Environmental Impact) summarizes and reviews the current knowledge of radiation effects on biota, provides basic dosimetric models for fauna and flora and suggests an assessment framework. Protection of the environment against ionising radiation, on the one hand, aims to close a conceptual gap in radiation protection. Therefore, current frameworks for environmental protection conceptually follow radiation protection of man. On the other hand, preservation of natural resources, habitats and the biological diversity are common objectives of environmental protection against radioactive as well as chemical pollutants, suggesting an integrated approach based on the fundamental ideas of conventional environmental protection. In essence, a conceptual framework encompassing protection of man as well as of fauna and flora against chemical and radioactive pollutants would be highly desirable in view of coherence, consistency and transparency. Such an umbrella concept communicates the positive message that similar issues are treated in a conceptually similar manner, thus facilitating scientific justification and public communication and increasing acceptance. This paper discusses different concepts and approaches to radiation protection of man, radiation protection of non-human biota and environmental protection against chemical pollutants, identifies common principles and differences, addresses conflicting requirements and evaluates the feasibility and limitations of such an encompassing framework. (authors)

  19. Comparative evaluation of different approaches to environmental protection against ionising radiation in view of practicability and consistency

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, M.; Hornung, L.; Mundigl, S.; Kirchner, G. [Federal Office for Radiation Protection, Salzgitter, (Germany)

    2006-07-01

    International organisations, including ICRP, IAEA and UNSCEAR, and the international scientific community are currently engaged in work on the protection of non-human species against ionising radiation as a complement to the existing framework centred on humans. The basic ideas and conceptual approaches developed during the last decade substantially agree with each other. The EC funded FASSET project (Framework for Assessment of Environmental Impact) summarizes and reviews the current knowledge of radiation effects on biota, provides basic dosimetric models for fauna and flora and suggests an assessment framework. Protection of the environment against ionising radiation, on the one hand, aims to close a conceptual gap in radiation protection. Therefore, current frameworks for environmental protection conceptually follow radiation protection of man. On the other hand, preservation of natural resources, habitats and the biological diversity are common objectives of environmental protection against radioactive as well as chemical pollutants, suggesting an integrated approach based on the fundamental ideas of conventional environmental protection. In essence, a conceptual framework encompassing protection of man as well as of fauna and flora against chemical and radioactive pollutants would be highly desirable in view of coherence, consistency and transparency. Such an umbrella concept communicates the positive message that similar issues are treated in a conceptually similar manner, thus facilitating scientific justification and public communication and increasing acceptance. This paper discusses different concepts and approaches to radiation protection of man, radiation protection of non-human biota and environmental protection against chemical pollutants, identifies common principles and differences, addresses conflicting requirements and evaluates the feasibility and limitations of such an encompassing framework. (authors)

  20. Measurement of the total ionisation intensity near the ground and separation of the various components; Mesure de l'intensite totale d'ionisation au voisinage du sol et separation de ses differentes composantes

    Energy Technology Data Exchange (ETDEWEB)

    Grevet, Ph. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-06-01

    The aim of this work is to measure the total amount of ion-pairs produced in the air per unit time and unit volume. It is possible, furthermore, by using continuous recording to study the variations in the ionisation due to {alpha}, {beta} and {gamma} radiation at a height of one metre. The apparatus which has been developed consists of two chambers of 120 litres: one, hermetically sealed detects the {gamma} component, the other with a circulation of the ambient air detects the {alpha} and {gamma}; it is thus possible by difference to evaluate the {alpha} component. The chambers and the associated electronic equipment have been designed for continuous operation in the open air. Another chamber without walls can be used for measuring directly the total ionisation intensity and from this an approximate calculation may be made of the {beta} component. A series of recordings has been made near Saclay where the natural radio-activity level is moderate, and in regions of low and high activity (near the sea and in the CEA's mining divisions). It has thus been possible to show the variation in the {gamma} component as a function of the geographic position of the measurement (from 3.7 to 6.3 l/cm{sup 3}.s), the very large variations of the {alpha} component at a given place with changing meteorological conditions (from 1.5 to 45 l/cm{sup 3}.s at Saclay for example) an the far smaller variations in the {beta} component. (author) [French] Le but de ce travail est de mesurer la quantite totale de paires d'ions produite dans l'air par unite de temps et de volume. Des enregistrements continus permettent, de plus, d'etudier les variations a 1 m du sol de cette ionisation due aux rayonnements {alpha}, {beta} et {gamma}. L'appareillage mis au point est forme de deux chambres de 120 litres: l'une hermetiquement fermee detecte la composante {gamma}; l'autre avec circulation de l'air ambiant detecte {alpha} + {gamma} ce qui permet d

  1. Nonthermal cosmic neutrino background

    Science.gov (United States)

    Chen, Mu-Chun; Ratz, Michael; Trautner, Andreas

    2015-12-01

    We point out that, for Dirac neutrinos, in addition to the standard thermal cosmic neutrino background (C ν B ), there could also exist a nonthermal neutrino background with comparable number density. As the right-handed components are essentially decoupled from the thermal bath of standard model particles, relic neutrinos with a nonthermal distribution may exist until today. The relic density of the nonthermal (nt) background can be constrained by the usual observational bounds on the effective number of massless degrees of freedom Neff and can be as large as nν nt≲0.5 nγ. In particular, Neff can be larger than 3.046 in the absence of any exotic states. Nonthermal relic neutrinos constitute an irreducible contribution to the detection of the C ν B and, hence, may be discovered by future experiments such as PTOLEMY. We also present a scenario of chaotic inflation in which a nonthermal background can naturally be generated by inflationary preheating. The nonthermal relic neutrinos, thus, may constitute a novel window into the very early Universe.

  2. The ionising radiation (medical exposure) regulations - IR (ME) R, Malta

    International Nuclear Information System (INIS)

    Desai, R.; Brejza, P.; Cremona, J.

    2004-01-01

    Full text: The regulations in Malta at present are in draft stage. These regulations partially implement European Council Directive 97/43/Euratom. This Directive lays down the basic measurements for the health and protection of individuals against dangers of ionising radiation in relation to medical exposure. The regulations impose duties on persons administering radiations, to protect people from unnecessary exposure whether as part of their own medical diagnosis, treatment or as part of occupational health worker for health screening, medico-legal procedures, voluntary participation in research etc. These regulations also apply to individuals who help other individuals undergoing medical exposure. Main provisions 1. Regulation 2 contains the definitions of 28 terms used in these regulations. 2. Regulation 3.1 and 3.2 sets out the medical exposures to which the regulations apply. 3. Regulation 4 requires approval of medical exposures due to medical research, from radiation protection board of Malta. 4. Regulation 5 prohibits new procedures involving medical exposure unless it has been justified in advance. 5. Regulation 6 provides conditions justifying medical exposures. It prohibits any medical exposure from being carried out which has not been justified and authorized and sets out matters to be taken into account for justification. 6. Regulation 7 requires that practitioner justifies the exposure, shall pay special attention towards (a) exposure from medical research procedures where there is no direct health benefit to the individual undergoing exposure, (b) exposures for medico-legal purposes; (c) exposures to pregnant or possible pregnant women and (d) exposures to breast-feeding women. 7. Regulation 8.1 to 8.3 prohibit any medical exposure from being carried out which has not been justified and sets out matters to be taken for justification 8. Regulation 8.4 prohibits an exposure if it cannot be justified. 9. Regulation 9 requires the employer to provide a

  3. Natural and man-made hexavalent chromium, Cr(VI), in groundwater near a mapped plume, Hinkley, California—study progress as of May 2017, and a summative-scale approach to estimate background Cr(VI) concentrations

    Science.gov (United States)

    Izbicki, John A.; Groover, Krishangi D.

    2018-03-22

    This report describes (1) work done between January 2015 and May 2017 as part of the U.S. Geological Survey (USGS) hexavalent chromium, Cr(VI), background study and (2) the summative-scale approach to be used to estimate the extent of anthropogenic (man-made) Cr(VI) and background Cr(VI) concentrations near the Pacific Gas and Electric Company (PG&E) natural gas compressor station in Hinkley, California. Most of the field work for the study was completed by May 2017. The summative-scale approach and calculation of Cr(VI) background were not well-defined at the time the USGS proposal for the background Cr(VI) study was prepared but have since been refined as a result of data collected as part of this study. The proposed summative scale consists of multiple items, formulated as questions to be answered at each sampled well. Questions that compose the summative scale were developed to address geologic, hydrologic, and geochemical constraints on Cr(VI) within the study area. Each question requires a binary (yes or no) answer. A score of 1 will be assigned for an answer that represents data consistent with anthropogenic Cr(VI); a score of –1 will be assigned for an answer that represents data inconsistent with anthropogenic Cr(VI). The areal extent of anthropogenic Cr(VI) estimated from the summative-scale analyses will be compared with the areal extent of anthropogenic Cr(VI) estimated on the basis of numerical groundwater flow model results, along with particle-tracking analyses. On the basis of these combined results, background Cr(VI) values will be estimated for “Mojave-type” deposits, and other deposits, in different parts of the study area outside the summative-scale mapped extent of anthropogenic Cr(VI).

  4. Chapter 8. Ionisation radiation and human organism. Radioactivity of human tissues

    International Nuclear Information System (INIS)

    Toelgyessy, J.; Harangozo, M.

    2000-01-01

    This is a chapter of textbook of radioecology for university students. In this chapter authors deal with ionisation radiation and human organism as well as with radioactivity of human tissues. Chapter consists of next parts: (1) Radiation stress of human organism; (2) Radioactivity of human tissues and the factors influencing radioactive contamination; (3) Possibilities of decreasing of radiation stress

  5. Bioaerosol detection by aerosol TOF-mass spectrometry: Application of matrix assisted laser desorption/ionisation

    NARCIS (Netherlands)

    Wuijckhuijse, A.L. van; Stowers, M.A.; Kientz, Ch.E.; Marijnissen, J.C.M.; Scarlett, B.

    2000-01-01

    In previous publications the use of an aerosol time of flight mass spectrometer was reported for the on-line measurements of aerosols (Weiss 1997, Kievit 1995). The apparatus is capable of measuring the size as well as the chemical composition, by the use of Laser Desorption/Ionisation (LDI), of an

  6. For discussion: obtaining consent for ionising radiation: has the time come?

    International Nuclear Information System (INIS)

    Mendelson, Richard M.

    2010-01-01

    Full text: The aim of this paper is to promote debate on the issues surrounding the provision of information to, and the obtaining of valid consent from patients exposed to ionising radiation (IR) from diagnostic and interventional imaging procedures, This is especially pertinent in view of recent interest in the risks of IR expressed in the medical and lay press.

  7. Examining Pre-Service Teachers' Use of Atomic Models in Explaining Subsequent Ionisation Energy Values

    Science.gov (United States)

    Wheeldon, Ruth

    2012-01-01

    Chemistry students' explanations of ionisation energy phenomena often involve a number of non-scientific or inappropriate ideas being used to form causality arguments. Research has attributed this to many science teachers using these ideas themselves (Tan and Taber, in "J Chem Educ" 86(5):623-629, 2009). This research extends this work by…

  8. International responsability of state by the deleterius effects of ionising radiation

    International Nuclear Information System (INIS)

    Faria, N.M. de.

    1988-01-01

    International Responsability of State, considering the deleterius effects of ionising radiation on the human being, property, territory and environment which are under other jurisdiction, is focused. Conventional rules, costumary rules, the evolution of ''opinion juris'' as well as the decisions of tribunals related to the subject are analysed. (author) [pt

  9. Destruction of Raman biosignatures by ionising radiation and the implications for life detection on Mars.

    Science.gov (United States)

    Dartnell, Lewis R; Page, Kristian; Jorge-Villar, Susana E; Wright, Gary; Munshi, Tasnim; Scowen, Ian J; Ward, John M; Edwards, Howell G M

    2012-04-01

    Raman spectroscopy has proven to be a very effective approach for the detection of microorganisms colonising hostile environments on Earth. The ExoMars rover, due for launch in 2018, will carry a Raman laser spectrometer to analyse samples of the martian subsurface collected by the probe's 2-m drill in a search for similar biosignatures. The martian surface is unprotected from the flux of cosmic rays, an ionising radiation field that will degrade organic molecules and so diminish and distort the detectable Raman signature of potential martian microbial life. This study employs Raman spectroscopy to analyse samples of two model organisms, the cyanobacterium Synechocystis sp. PCC 6803 and the extremely radiation resistant polyextremophile Deinococcus radiodurans, that have been exposed to increasing doses of ionising radiation. The three most prominent peaks in the Raman spectra are from cellular carotenoids: deinoxanthin in D. radiodurans and β-carotene in Synechocystis. The degradative effect of ionising radiation is clearly seen, with significant diminishment of carotenoid spectral peak heights after 15 kGy and complete erasure of Raman biosignatures by 150 kGy of ionising radiation. The Raman signal of carotenoid in D. radiodurans diminishes more rapidly than that of Synechocystis, believed to be due to deinoxanthin acting as a superior scavenger of radiolytically produced reactive oxygen species, and so being destroyed more quickly than the less efficient antioxidant β-carotene. This study highlights the necessity for further experimental work on the manner and rate of degradation of Raman biosignatures by ionising radiation, as this is of prime importance for the successful detection of microbial life in the martian near subsurface.

  10. Quantification of complex DNA damage by ionising radiation. An experimental and theoretical approach

    International Nuclear Information System (INIS)

    Fulford, J.

    2000-05-01

    Ionising radiation potentially produces a broad spectrum of damage in DNA including single and double strand breaks (ssb and dsb) and base damages. It has been hypothesised that sites of complex damage within cellular DNA have particular biological significance due to an associated decreased efficiency in repair. The aim of this study is to gain further understanding of the formation of complex DNA damage. Irradiations of plasmid DNA illustrate that an increase in ionising density of the radiation results in a decrease in ssb yields/Gy but an increase in dsb per ssb, indicative of an increase in the number of complex damage sites per simple isolated damage site. As the mechanism for damage formation shifts from purely indirect at low scavenging capacities to a significant proportion of direct at higher scavenging capacities the proportion of complex damage increases. Comparisons with the yields of ssb and dsb simulated by Monte-Carlo calculations for Al K USX and α-particles also indicate this correspondence. The ionisation density of low energy, secondary electrons produced by photons was assessed experimentally from the dependence of the yield of OH radicals escaping intra-track recombination on photon energy. As energy decreases the OH radical yield initially decreases reflecting an increased ionisation density. However, with further decrease in photon energy the yield of OH radicals increases in line with theoretical calculations. Base damage yields were determined for low and high ionising density radiation over a range of scavenging capacities. As scavenging capacity increases the base damage: ssb ratios increases implying a contribution from electrons to base damage. It is proposed that base damage contributes to DNA damage complexity. Complex damage analysis reveals that at cell mimetic scavenging capacities, 23% and 72% of ssb have an additional spatially close damage site following γ-ray and α-particle irradiation respectively. (author)

  11. The natural background to the quality of groundwater: implications for the implementation of the Framework Water Directive in Europe; El fondo natural de la calidad del agua subterranea: implicaciones para la aplicacion de la Directiva Marco del Agua en Europa

    Energy Technology Data Exchange (ETDEWEB)

    Manzano, M.; Custodio, E.; Nieto, P.

    2003-07-01

    The most recent water legislation issued world-wide require to establish a scientifically based definition for groundwater baseline quality, which is simple to use and nimble for politicians and managers. Derived from the European projects Baseline, groundwater baseline has been defined as the range of concentrations of a given element, species or chemical substance present is solution, being derived from natural geological, biogical, or atmospheric sources. The terms of this definition conforms the methodology to use to accomplish European water laws requirements: 1) to establish groundwater baseline for the European water bodies within next years: 2) to study hydrochemical trends and to distinguish baseline trends from pollution trends; 3) to inquiry the causes of pollution trends, set up restoration programs and monitor their success by determining the start of chemical trends reversals. The methodology used in the European project BaSeLiNe to answer these questions and the main methodological and conceptual conclusions are used to illustrate the need for an accurate determination of groundwater baseline. (Author) 4 refs.

  12. A self-calibrating ionisation chamber for the precise intensity calibration of high-energy heavy-ion beam monitors

    International Nuclear Information System (INIS)

    Junghans, A.

    1996-01-01

    The intensity of a 136 Xe(600 A MeV) beam has been determined by simultaneously measuring the particle rate and the corresponding ionisation current with an ionisation chamber. The ionisation current of this self-calibrating device was compared at higher intensities with the current of a secondary-electron monitor and a calibration of the secondary-electron current was achieved with a precision of 2%. This method can be applied to all high-energy heavy-ion beams. (orig.)

  13. gammaH2AX foci form preferentially in euchromatin after ionising-radiation.

    Directory of Open Access Journals (Sweden)

    Ian G Cowell

    Full Text Available BACKGROUND: The histone variant histone H2A.X comprises up to 25% of the H2A complement in mammalian cells. It is rapidly phosphorylated following exposure of cells to double-strand break (DSB inducing agents such as ionising radiation. Within minutes of DSB generation, H2AX molecules are phosphorylated in large chromatin domains flanking DNA double-strand breaks (DSBs; these domains can be observed by immunofluorescence microscopy and are termed gammaH2AX foci. H2AX phosphorylation is believed to have a role mounting an efficient cellular response to DNA damage. Theoretical considerations suggest an essentially random chromosomal distribution of X-ray induced DSBs, and experimental evidence does not consistently indicate otherwise. However, we observed an apparently uneven distribution of gammaH2AX foci following X-irradiation with regions of the nucleus devoid of foci. METHODOLOGY/PRINCIPLE FINDINGS: Using immunofluorescence microscopy, we show that focal phosphorylation of histone H2AX occurs preferentially in euchromatic regions of the genome following X-irradiation. H2AX phosphorylation has also been demonstrated previously to occur at stalled replication forks induced by UV radiation or exposure to agents such as hydroxyurea. In this study, treatment of S-phase cells with hydroxyurea lead to efficient H2AX phosphorylation in both euchromatin and heterochromatin at times when these chromatin compartments were undergoing replication. This suggests a block to H2AX phosphorylation in heterochromatin that is at least partially relieved by ongoing DNA replication. CONCLUSIONS/SIGNIFICANCE: We discuss a number of possible mechanisms that could account for the observed pattern of H2AX phosphorylation. Since gammaH2AX is regarded as forming a platform for the recruitment or retention of other DNA repair and signaling molecules, these findings imply that the processing of DSBs in heterochromatin differs from that in euchromatic regions. The

  14. 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

  15. Comparison of external doses between radio-contaminated areas and areas with high natural terrestrial background using the individual dosimeter "D-shuttle" 75 months after the Fukushima Daiichi nuclear power plant accident.

    Science.gov (United States)

    Tsubokura, Masaharu; Nomura, Shuhei; Yoshida, Izumi; Sawano, Toyoaki; Miyazaki, Makoto; Tomita, Satoru; Oikawa, Tomoyoshi; Watanabe, Masami

    2017-12-13

    After the Fukushima Daiichi nuclear power plant accident, the air dose gradually decreases every year due to the physical decay of radioactive materials and environmental changes as well as countermeasures. However, there is little information on personal behavioral patterns and individual dose from external exposure among the inhabitants around the nuclear power plant. To evaluate the dose from external exposure in Minamisoma city and compare the differences with outside of Fukushima, we started the external dose assessment project in cooperation with city officials in Minamisoma as well as other three cities in Japan, where the natural terrestrial background radiation level is relatively high. In these four cities, external dose was measured using the D-shuttle for 2 weeks, and the places of activity of participants were recorded every hour to compare and evaluate the dose from external exposure and to clarify whether there is a difference in the exposure dose by behavior. The annual doses from external exposure for 100 participants from four municipalities ranged from 0.566 to 1.295 with a mean value of 0.784 mSv/year, which was sufficiently low for health effects. The external doses in Minamisoma city were comparable to those in municipalities with a relatively high natural radiation background in Japan. The time spent at home and in the workplace accounted for most of the time of the participants, and this also contributed to majority of the total dose from external exposure. The amount of exposure at times other than home and workplace was very small regardless of the indoor or outdoor location in the city or outside. Continuous dosimetry and countermeasures at home and workplace are important for individuals who present high values, for future dose reduction and radiation protection. . © 2017 IOP Publishing Ltd.

  16. European Communities (Foodstuffs treated with ionising radiation) Regulations, 2000. Statutory Instrument S.I. No. 297 of 2000

    International Nuclear Information System (INIS)

    2000-01-01

    These Regulations give effect to Directive 1999/2/EC (the framework Directive) of the European Parliament and of the Council of 22 February 1999 on the approximation of the laws of the Member States concerning foods and food ingredients treated with ionising radiation and Directive 1999/3/EC (the implementing Directive) of the European Parliament and of the Council of 22 February 1999 on the establishment of a Community list of foods and food ingredients treated with ionising radiation. The effect of these Regulations is to lay down the general provisions for the treatment of foodstuffs with ionising radiation. Provisions concerning the approval and control of irradiation facilities and rules on labelling are also included. A positive list of foodstuffs authorised for treatment with ionising radiation and their maximum radiation doses are defined in the implementing Directive. These Regulations should be read together with the two Directives (author)

  17. How do air ions reflect variations in ionising radiation in the lower atmosphere in a boreal forest?

    Directory of Open Access Journals (Sweden)

    X. Chen

    2016-11-01

    Full Text Available Most of the ion production in the atmosphere is attributed to ionising radiation. In the lower atmosphere, ionising radiation consists mainly of the decay emissions of radon and its progeny, gamma radiation of the terrestrial origin as well as photons and elementary particles of cosmic radiation. These types of radiation produce ion pairs via the ionisation of nitrogen and oxygen as well as trace species in the atmosphere, the rate of which is defined as the ionising capacity. Larger air ions are produced out of the initial charge carriers by processes such as clustering or attachment to pre-existing aerosol particles. This study aimed (1 to identify the key factors responsible for the variability in ionising radiation and in the observed air ion concentrations, (2 to reveal the linkage between them and (3 to provide an in-depth analysis into the effects of ionising radiation on air ion formation, based on measurement data collected during 2003–2006 from a boreal forest site in southern Finland. In general, gamma radiation dominated the ion production in the lower atmosphere. Variations in the ionising capacity came from mixing layer dynamics, soil type and moisture content, meteorological conditions, long-distance transportation, snow cover attenuation and precipitation. Slightly similar diurnal patterns to variations in the ionising capacity were observed in air ion concentrations of the cluster size (0.8–1.7 nm in mobility diameters. However, features observed in the 0.8–1 nm ion concentration were in good connection to variations of the ionising capacity. Further, by carefully constraining perturbing variables, a strong dependency of the cluster ion concentration on the ionising capacity was identified, proving the functionality of ionising radiation in air ion production in the lower atmosphere. This relationship, however, was only clearly observed on new particle formation (NPF days, possibly indicating that charges after

  18. Levels of naturally occurring gamma radiation measured in British homes and their prediction in particular residences

    Energy Technology Data Exchange (ETDEWEB)

    Kendall, G.M. [University of Oxford, Cancer Epidemiology Unit, Oxford (United Kingdom); Wakeford, R. [University of Manchester, Centre for Occupational and Environmental Health, Institute of Population Health, Manchester (United Kingdom); Athanson, M. [University of Oxford, Bodleian Library, Oxford (United Kingdom); Vincent, T.J. [University of Oxford, Childhood Cancer Research Group, Oxford (United Kingdom); Carter, E.J. [University of Worcester, Earth Heritage Trust, Geological Records Centre, Henwick Grove, Worcester (United Kingdom); McColl, N.P. [Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Chilton, Didcot, Oxon (United Kingdom); Little, M.P. [National Cancer Institute, DHHS, NIH, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, Bethesda, MD (United States)

    2016-03-15

    Gamma radiation from natural sources (including directly ionising cosmic rays) is an important component of background radiation. In the present paper, indoor measurements of naturally occurring gamma rays that were undertaken as part of the UK Childhood Cancer Study are summarised, and it is shown that these are broadly compatible with an earlier UK National Survey. The distribution of indoor gamma-ray dose rates in Great Britain is approximately normal with mean 96 nGy/h and standard deviation 23 nGy/h. Directly ionising cosmic rays contribute about one-third of the total. The expanded dataset allows a more detailed description than previously of indoor gamma-ray exposures and in particular their geographical variation. Various strategies for predicting indoor natural background gamma-ray dose rates were explored. In the first of these, a geostatistical model was fitted, which assumes an underlying geologically determined spatial variation, superimposed on which is a Gaussian stochastic process with Matern correlation structure that models the observed tendency of dose rates in neighbouring houses to correlate. In the second approach, a number of dose-rate interpolation measures were first derived, based on averages over geologically or administratively defined areas or using distance-weighted averages of measurements at nearest-neighbour points. Linear regression was then used to derive an optimal linear combination of these interpolation measures. The predictive performances of the two models were compared via cross-validation, using a randomly selected 70 % of the data to fit the models and the remaining 30 % to test them. The mean square error (MSE) of the linear-regression model was lower than that of the Gaussian-Matern model (MSE 378 and 411, respectively). The predictive performance of the two candidate models was also evaluated via simulation; the OLS model performs significantly better than the Gaussian-Matern model. (orig.)

  19. Performance evaluation of synthetic diamond to realize ionisation chamber for radiotherapy application

    International Nuclear Information System (INIS)

    Guerrero Waryn, M.J.

    2005-09-01

    This work focuses on the optimisation of synthetic CVD diamond quality to realize ionisation chambers for radiotherapy. Diamonds samples have been synthesized and characterized using thermally stimulated measurement. These measurements showed the presence of trapping levels due to crystalline defects or impurities in material. The study of the response of these samples under irradiation has showed a correlation between the charged state of traps (priming and overshoot phenomena) and the response of the detector (stabilization of the signal). To remove the overshoot phenomenon which prevents from reproducible measurements, we used a specific operating set up controlling the device temperature. This technique enables to neutralize these instable phenomena and to use CVD diamond for ionisation chamber fabrication. (author)

  20. Exploring the Powerful Ionised Wind in the Seyfert Galaxy PG1211+143

    Science.gov (United States)

    Pounds, Ken

    2013-10-01

    Highly-ionised high-speed winds in AGN (UFOs) were first detected with XMM-Newton a decade ago, and are now established as a key factor in the study of SMBH accretion, and in the growth and metal enrichment of their host galaxies. However, information on the ionisation and dynamical structure, and the ultimate fate of UFOs remains very limited. We request a 600ks extended XMM-Newton study of the prototype UFO PG1211+143 in AO-13, to obtain high quality EPIC and RGS spectra, to map the flow structure and variability, while seeking evidence for the anticipated interaction with the ISM and possible conversion of the energetic wind to a momentum-driven flow.

  1. An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

    CERN Document Server

    Fessler, P; Eberle, H; Raad-Iseli, C D; Hilt, B; Huss, D; Krummenacher, F; Lutz, Jean Robert; Prevot, G; Renouprez, Albert Jean; Sigward, M H; Schwaller, B; Voltolini, C

    1999-01-01

    Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). ...

  2. The effect of highly ionising particles on the CMS silicon strip tracker

    CERN Document Server

    Adam, W; Bergauer, T; Bouhali, O; Clerbaux, B; De Langhe, E; De Lentdecker, G; De Wolf, E; Friedl, M; Frühwirth, R; Hrubec, Josef; Krammer, Manfred; Pernicka, Manfred; Tasevsky, M; Waltenberger, W

    2005-01-01

    Inelastic nuclear collisions of hadrons incident on silicon sensors can generate secondary highly ionising particles (HIPs) and deposit as much energy within the sensor bulk as several hundred minimum ionising particles. The large signals generated by these 'HIP events' can momentarily saturate the APV25 front-end readout chip for the silicon strip tracker (SST) sub-detector of the compact muon solenoid (CMS) experiment, resulting in deadtime in the detector readout system. This paper presents studies of this phenomenon through simulation, laboratory measurements and dedicated beam tests. A proposed change to a front-end component to reduce the APV25 sensitivity to HIP events is also examined. The results are used to infer the expected effect on the performance of the CMS SST at the future large hadron collider. The induced inefficiencies are at the percent level and will have a negligible effect on the physics performance of the SST.

  3. Experimental techniques for studying bystander effects in vitro by high and low-LET ionising radiation.

    Science.gov (United States)

    Hill, M A; Stevens, D L; Kadhim, M; Blake-James, M; Mill, A J; Goodhead, D T

    2006-01-01

    Ionising radiation can induce responses within non-exposed neighbouring (bystander) cells which potentially have important implications on the estimates of risk from low dose or low dose rate exposures of ionising radiations. A range of strategies have been developed for investigating bystander effects in vitro for both high-LET alpha particles or low-LET ultrasoft X rays using either partial shielding (grids, half-shields and slits) or by using a co-culture system where two physically separated populations of cells can be cultured together, allowing one population of cells to be irradiated while the second population remains unirradiated. The techniques described provide a useful tool to study bystander effects and complement microbeam studies. Studies using these systems show significant increases in the unirradiated bystander cells for various end points including the induction of chromosomal instability in haemopoetic stem cells and transformation in CGL1 cells.

  4. Tools to discover anionic and nonionic polyfluorinated alkyl surfactants by liquid chromatography electrospray ionisation mass spectrometry

    DEFF Research Database (Denmark)

    Trier, Xenia; Granby, Kit; Christensen, Jan H.

    2011-01-01

    A tiered approach is proposed for the discovery of unknown anionic and nonionic polyfluorinated alkyl surfactants (PFASs) by reversed phase ultra high performance liquid chromatography (UHPLC) – negative electrospray ionisation – quadrupole time of flight mass spectrometry (UHPLC–ESI−–QTOF–MS). T......A tiered approach is proposed for the discovery of unknown anionic and nonionic polyfluorinated alkyl surfactants (PFASs) by reversed phase ultra high performance liquid chromatography (UHPLC) – negative electrospray ionisation – quadrupole time of flight mass spectrometry (UHPLC...... such as [M−H+solvent]− and [(M−H)(M−H+Na)n]− were used to confirm the identity of the precursor ions. In relation to quantification of PFASs, we discuss how their surfactancy influence the ESI processes, challenge their handling in solution and choices of precursor-to-product ions for MSMS of e...

  5. Bucked Coils lattice: a novel ionisation cooling lattice for the Neutrino Factory

    International Nuclear Information System (INIS)

    Alekou, A; Pasternak, J

    2012-01-01

    A successful muon ionisation cooling channel for the Neutrino Factory and Muon Collider, requires simultaneously a strong focusing and a large mean RF gradient. To date, all candidate design lattices achieved these requirements with a large magnetic field in the RF cavities, which can potentially limit the achievable gradient leading to RF breakdown. This paper presents the Bucked Coils lattice, designed to reduce the magnetic field at the RF cavities while achieving a satisfactory cooling effect and muon transmission. The Bucked Coils managed to achieve significantly reduced magnetic field components at the RF position, while also achieving a comparable transmission to the FSIIA lattice, the current reference ionisation cooling lattice of the Neutrino Factory. A detailed comparison with respect to the magnetic field reduction, cooling dynamics and transmission is given. A preliminary feasibility study taking into account the hoop stress of the coils and their superconducting operation is also presented.

  6. Indigenous instruments for medical applications of ionising radiations and their performance

    International Nuclear Information System (INIS)

    Gangadharan, P.

    1980-01-01

    The Division of Radiological Protection of the Bhabha Atomic Research Centre, Bombay, has developed and fabricated electronic instruments, such as various types of dosimeters, monitors and electronic circuits required in radiotherapy, nuclear medicine and radiation protection monitoring of ionising radiations. They are grouped according to the purpose in charts. Their basic operating principles, circuits adopted for radiation measurement, and brief specifications such as range of measurements, accuracy, power supply, uses etc. are given. The design features of dosimetric instruments, which determine its reliability are shown in a chart. The vulnerable components such as ionisation chambers, amplifiers etc. require special attention during their design as they are affected by environmental conditions. Remedial measures to improve upon the overall system reliability are also given. (M.G.B.)

  7. The Coulomb deflection effect on the L3-subshell alignment in low-velocity proton impact ionisation

    International Nuclear Information System (INIS)

    Palinkas, J.; Schlenk, B.; Valek, A.

    1981-01-01

    The alignment parameter of the L 3 subshell of gold has been determined by measuring the angular distribution of the Lsub(l)/Lsub(γ) intensity ratio following proton impact ionisation in the 0.25-0.60 MeV energy range. The experimental results make it clear that the minimum of the alignment parameter at low energies found earlier for He + impact also exists in the case of proton impact ionisation. (author)

  8. K-shell ionisation cross sections for W, Au and U by low velocity protons

    International Nuclear Information System (INIS)

    Castro Faria, N.V. de; Freire Junior, F.L.; Montenegro, E.C.; Pinho, A.G. de; Silveira, E.F. da.

    1984-01-01

    Proton-induced K-shell ionisation cross section for W, Au and U by low velocity protons were obtained from thick target measurements. For the first time the lowest incident energy reached a value less than 10 times the binding energy of the K-shell electron (less than 9 times in the case of Au). Possible errors are thoroughly examined and a comparison with other available experimental results and theoretical values is presented and discussed. (Author) [pt

  9. Decontamination of hospital wastes by the combined action of ionising radiation and heat - the thermorad process

    International Nuclear Information System (INIS)

    Icre, P.; Rocquigny, H. de

    1995-01-01

    The Thermorad process is used for decontaminating hospital wastes at the hospital as they are collected from the different departments. The process utilises the combined microbiological effects of ionising radiation (5 kGy) and dry heat (60 o C). The treatment unit, which is compact and of small size, contains a cobalt 60 source of under 100,000 curies and has an annual treatment capacity of 5000 m 3 . (author)

  10. The effect of the 1985 Ionising Radiations Regulations on a service inspection company

    International Nuclear Information System (INIS)

    Outhwaite, D.

    1988-01-01

    The paper concerns the significant changes and requirements resulting from the 1985 Ionising Radiations Regulations, and examines their effect on the administration and operations of a service inspection company engaging in Industrial Radiography. The major innovations introduced by the 1985 Regulations are discussed under three topic headings: 1) local rules and radiation protection personnel, 2) controlled and supervised areas, and 3) hazard assessments and contingency plans. (U.K.)

  11. An isotopic analysis of ionising radiation as a source of sulphuric acid

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  12. An isotope view on ionising radiation as a source of sulphuric acid

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  13. Use of ionising radiation in the teaching of physics and chemistry

    International Nuclear Information System (INIS)

    2000-01-01

    The guide lays down the safety requirements for the use of radiation in school education, as well as the principles regulating the use of radiation sources without the safety licence referred to in section 16 of the Finnish Radiation Act (592/1991). The guide covers the use of radiation sources emitting ionising radiation in elementary schools and high schools, as well as the use of radiation in the teaching of physics and chemistry in vocational training institutions and corresponding educational institutions

  14. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    Energy Technology Data Exchange (ETDEWEB)

    Etard, Cecile; Aubert, Bernard [Institut de Radioprotection et de Surete Nucleaire, Medical Expertise Unit, Fontenay-aux-Roses (France); Mezzarobba, Myriam [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Institut de Radioprotection et de Surete Nucleaire, IRSN/PRP-HOM/SRBE/LEPID, Laboratoire d' Epidemiologie, Fontenay-aux-Roses (France)

    2014-12-15

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  15. International Atomic Energy Agency Regional Workshop on Commercialisation of ionising energy treatment of food: proceedings

    International Nuclear Information System (INIS)

    Wills, P.; Toner, B.

    1985-01-01

    The global need to ensure adequate food supplies places a demand on new technologies and techniques to improve yields and preservation of food by eliminating or reducing bacterial degradation and infestation of raw or processed foods. The use of ionising radiation in food processing also has potential to alleviate certain food-borne diseases which cause serious threats to the health of people in many countries

  16. Radon in drinking water: Comparison and evaluation of two ionisation chamber activity measurement methods.

    Science.gov (United States)

    Wiedner, H; Lotter, K; Karner, P; Friedmann, H; Maringer, F J

    2018-04-01

    In this study the radon activity concentration of water samples from the so called "Thermenlinie" are measured using two different techniques: currents measured with an ionisation chamber setup developed by H. Friedmann are compared with results obtained using a commercially available AlphaGUARD. A fit to compensate for measurements made in non-equilibrium state is applied and the detection limit is estimated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    International Nuclear Information System (INIS)

    Etard, Cecile; Aubert, Bernard; Mezzarobba, Myriam; Bernier, Marie-Odile

    2014-01-01

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  18. The philosophy and assumptions underlying exposure limits for ionising radiation, inorganic lead, asbestos and noise

    International Nuclear Information System (INIS)

    Akber, R.

    1996-01-01

    Full text: A review of the literature relating to exposure to, and exposure limits for, ionising radiation, inorganic lead, asbestos and noise was undertaken. The four hazards were chosen because they were insidious and ubiquitous, were potential hazards in both occupational and environmental settings and had early and late effects depending on dose and dose rate. For all four hazards, the effect of the hazard was enhanced by other exposures such as smoking or organic solvents. In the cases of inorganic lead and noise, there were documented health effects which affected a significant percentage of the exposed populations at or below the [effective] exposure limits. This was not the case for ionising radiation and asbestos. None of the exposure limits considered exposure to multiple mutagens/carcinogens in the calculation of risk. Ionising radiation was the only one of the hazards to have a model of all likely exposures, occupational, environmental and medical, as the basis for the exposure limits. The other three considered occupational exposure in isolation from environmental exposure. Inorganic lead and noise had economic considerations underlying the exposure limits and the exposure limits for asbestos were based on the current limit of detection. All four hazards had many variables associated with exposure, including idiosyncratic factors, that made modelling the risk very complex. The scientific idea of a time weighted average based on an eight hour day, and forty hour week on which the exposure limits for lead, asbestos and noise were based was underpinned by neither empirical evidence or scientific hypothesis. The methodology of the ACGIH in the setting of limits later brought into law, may have been unduly influenced by the industries most closely affected by those limits. Measuring exposure over part of an eight hour day and extrapolating to model exposure over the longer term is not the most effective way to model exposure. The statistical techniques used

  19. Determination of the ionisation potential of certain hydrocarbons in the liquid phase

    International Nuclear Information System (INIS)

    Casanovas, J.; Grob, R.; Brunet, G.; Sabattier, R.; Guelfucci, J.P.; Blanc, D.

    1978-01-01

    The first results obtained are presented on the determination of the ionisation potential of four alkanes (n-hexane, n-pentane, cyclopentane and trimethyl-2,2,4 pentane) in the liquid phase. In the gaseous phase, the ionisation potential values of these hydrocarbons are respectively 10.18 eV for n-hexane, 10.35 eV for n-pentane, 10.53 eV for cyclopentane and 9.86 eV for trimethyl-2,2,4 pentane. Consequently rare gas resonance lamps (krypton and Xenon) were made, sealed and excited by an ultra-high frequency wave, which emit photons in the energy field concerned, i.e. from 8.5 eV to 11eV. The energy of the photons emitted by these lamps is respectively 8.44 eV (100%) and 9.57 eV (2%) for xenon and 10.03 eV (100%) and 10.64 eV (5%) for krypton. From the extent of the induced ionisation currents and particularly the value of the ratio of the currents induced by the photons of the krypton and xenon lamps, a minimum value of the ionisation potential drop can be deduced compared with the gas phase of 0.61 eV for n-hexane, 0.78 eV for n-pentane, 0.96 eV for cyclopentane and a maximum value of 1.42 eV for trimethyl-2,2,4 pentane [fr

  20. Absolute 3PO triple differential cross sections for electron-helium Wannier threshold ionisation

    International Nuclear Information System (INIS)

    Carruthers, D.R.J.; Crothers, D.S.F.

    1992-01-01

    The uniform semiclassical approximation of Crothers is employed to find a final-state 3 P O wave function for threshold electron impact ionisation of helium. The Kohn variational principle is applied perturbatively to evaluate the scattering amplitude and hence the absolute 3 P O contribution to the triple differential cross sections. These plus the previous absolute singlet results of Crothers are compared favourably with the relative experimental results of Selles et al. (orig.)

  1. Ionisation and dissociation of water induced by swift multicharged ions; Etude de l'ionisation et de la dissociation d'H{sub 2}O induites par collision avec des ions multicharges rapides

    Energy Technology Data Exchange (ETDEWEB)

    Legendre, S

    2006-02-15

    Ionization and dissociation of water molecules and water clusters induced by 11.7 MeV/A Ni{sup 25+} ions were carried out by imaging techniques. Branching ratios, ionisation cross sections and Kinetic Energy Released distributions have been measured together with fragmentation dynamics studies. Multiple ionization represents approximately 30% of the ionizing events. Double ionization produces in significant way atomic oxygen, considered as a possible precursor of the large production of HO{sub 2} radical in liquid water radiolysis by ions of high Linear Energy Transfer. We evidence a strong selectivity of bond breakage in the case of ion-induced HOD fragmentation. Once the molecule doubly ionized, the breakage of the O-H bond is found 6.5 times more probable than that of the O-D bond. A semi-classical calculation simulating the fragmentation dynamics on the potential energy surface of the ground-state of di-cation H{sub 2}O{sup 2+} makes possible to as well reproduce the preferential nature of the breakage of the O-H bond as the position and the shift of the kinetic energy distributions. First results concerning interaction with water clusters are also reported. Measurements in coincidence are carried out giving access to correlation, with the distributions in energy and angle of the emitted fragments. Mass spectrum points fast intra-cluster proton transfer, leading to the emission of protonated clusters. (author)

  2. Histamine protects bone marrow against cellular damage induced by ionising radiation.

    Science.gov (United States)

    Medina, Vanina A; Croci, Máximo; Carabajal, Eliana; Bergoc, Rosa M; Rivera, Elena S

    2010-04-01

    Based on our previous data on the histamine radioprotective effect on small intestine, in the present work we aimed to determine whether histamine is able to protect bone marrow cells against ionising radiation damage. 56 mice and 40 rats were divided into four groups. Histamine and histamine-irradiated groups received a daily subcutaneous histamine injection (0.1 mg/kg) starting 24 h before irradiation. Irradiated groups received a single dose on whole-body using Cesium-137 source and were sacrificed three days after irradiation. We evaluated the number of medullar components, bone marrow trophism, oedema, vascular damage, and other histological characteristics and also proliferation markers by immunohistochemistry. Histamine treatment substantially reduced the grade of aplasia, the oedema and vascular damage induced by ionising radiation on bone marrow of mice and rats. Additionally, histamine preserved medullar components increasing the number of megakaryocytes (14.0 +/- 1.0 vs. 7.3 +/- 1.0 in mice; and 9.9 +/- 1.3 vs. 4.1 +/- 1.0 in rats, P effect was associated with an increased proliferation rate of bone marrow cells. Histamine reduces ionising radiation toxicity on bone marrow cells being a suitable candidate for use as radioprotector, especially for patients undergoing radiotherapy who are at the risk of bone marrow or small intestine damage.

  3. Evaluation of chromosomal aberrations in radiologists and medical radiographers chronically exposed to ionising radiation

    International Nuclear Information System (INIS)

    Kasuba, V.; Rozgaj, R.; Jazbec, A.

    2005-01-01

    Chromosomal aberrations are fairly reliable indicators of damage induced by ionising radiation. This study included 180 radiologists and medical radiographers (technicians) and 90 controls who were not occupationally exposed to ionising radiation. All exposed subjects were routinely monitored with film badge, and none was exposed to a radiation dose exceeding the limit for occupational exposure recommended by the International Commission on Radiological Protection (ICRP). Two hundred metaphases for each person were scored. The frequencies of acentric fragments, dicentrics, ring chromosomes and chromosomal exchanges were determined and compared to those obtained in the control group. Chromosome aberrations were analysed using Poisson regression for profession, age, sex, smoking and years of exposure. Age, smoking, diagnostic exposure to X-rays and occupation were found to correlate with the occurrence of acentric fragments. The influence of exposure duration on the frequency of acentric fragments was greater in medical radiographers than in radiologists. Smoking and sex were found to correlate with the occurrence of dicentric chromosomes, which were more common in men than in women. As chromosome aberrations exceeded the expected level with respect to the absorbed dose, our findings confirm the importance of chromosome analysis as a part of regular medical check-up of subjects occupationally exposed to ionising radiation.(author)

  4. Relativistic reflection from accretion disc ionised due to illumination from on-axis compact corona

    Science.gov (United States)

    Dovciak, M.; Guainazzi, M.; Svoboda, J.

    2014-07-01

    We re-visit the relativistic (light bending) reflection scenario of AGN spectra in the lamp-post geometry. We compute the ionisation of the disc consistently with the amount of illumination from the on-axis compact corona. In this model the ionisation pattern of the disc is dependent on the distance from the centre according to astrophysically-motivated assumptions. We investigate the complementarity of different model parameters like: a) the intrinsic primary flux and the height of the corona, both affecting the normalization of the observed primary power-law; b) the height of the corona and the black hole spin, both affecting the amount of radiation emitted from the innermost regions of the disc; and c) the intrinsic primary flux, the height of the corona and the density of the disc, the three parameters that affect the ionisation state of the disc. We examine how these complementarities manifest themselves when fitting X-ray broadband spectra of the Seyfert 1 Galaxy MCG-6-30-15.

  5. A detailed study of the pulse height deficit effect in gas ionisation detectors

    International Nuclear Information System (INIS)

    Weijers, T.D.M.; Timmers, H.; Ophel, T.R.; Elliman, R.G.

    2000-01-01

    Full text: Gas ionisation detectors were originally developed for nuclear physics applications but have more recently also found use in nuclear techniques of analysis such as accelerator mass spectrometry (AMS) and ion beam analysis (IBA). They are ideal for heavy ion detection primarily because they do not suffer from radiation damage. It is well known that the pulse height versus energy relation for gas ionization detectors is non-linear. Previous studies have established that this is due to a pulse height deficit effect, which increases with both the atomic number and energy of the detected ion, and is of the order of 5 - 8MeV for typical fission fragment energies and masses. Published data does not, however, provide accurate estimates of the size of this effect for the wide range of ion species and energies applicable to materials analysis applications such as heavy ion elastic recoil detection (HIERDA), nor does it provide complete understanding of the factors which contribute to the effect. This presentation reports on a detailed study of the pulse height deficit effect, undertaken at the ANU 14UD pelletron accelerator facility using a propane-filled gas ionisation detector. Results will be presented quantifying the size of the pulse height deficit for a variety of ion species and energies. Furthermore, it will be demonstrated that a significant residual pulse height deficit remains after accounting for energy loss in the detector window, and non-ionising energy loss processes in the detector gas

  6. Evaluation of cytogenetic damage in nuclear medicine personnel occupationally exposed to low-level ionising radiation

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.; Poropat, M.

    2005-01-01

    Despite intensive research over the last few decades, there still remains considerable uncertainty as to the genetic impact of ionising radiation on human populations, particularly at low levels. The aim of this study was to provide data on genetic hazards associated with occupational exposure to low doses of ionising radiation in nuclear medicine departments. The assessment of DNA damage in peripheral blood lymphocytes of medical staff was performed using the chromosome aberration (CA) test. Exposed subjects showed significantly higher frequencies of CA than controls. There were significant inter-individual differences in DNA damage within the exposed population, indicating differences in genome sensitivity. Age and gender were not confounding factors, while smoking enhanced the levels of DNA damage only in control subjects. The present study suggests that chronic exposure to low doses of ionising radiation in nuclear medicine departments causes genotoxic damage. Therefore, to avoid potential genotoxic effects, the exposed medical personnel should minimise radiation exposure wherever possible. Our results also point to the significance of biological indicators providing information about the actual risk to the radiation exposed individuals.(author)

  7. Health protection of persons occupationally exposed to ionising radiation in Croatia

    International Nuclear Information System (INIS)

    Zavalic, M.

    2005-01-01

    The aim of this study was to investigate the health condition of workers occupationally exposed to ionising radiation. The results for 1406 workers exposed to ionising radiations, who were regularly examined in 2004, were analysed using Statistica 5.0. The analysis included workers' case histories, frequency of illnesses and causes of temporary or permanent work disability. Of 1406 workers, 16 (1.13%) were found permanently disabled; in 11 the cause of disability was lens opacity, in 2 persistent trombocitophenia, and in 2 malignant tumour. Twenty-four workers were temporarily disabled, of whom 5 due to pregnancy. Thrombocytopenia was found in 12 men and only one woman. Anaemia was found in 4 women; dicentric chromosomes were the cause of temporary disability in one person, and tuberculosis in one person. Medical examinations of Croatian workers confirm low occupational exposure to ionising radiation. With this type of radiation, the established lens impairments could not be characterised as occupational. The two malignant tumours however were recognised as occupational diseases.(author)

  8. The health detriment associated with low doses of ionising radiation

    International Nuclear Information System (INIS)

    Smith, H.

    1991-01-01

    Some of the problems and uncertainties in using available data to derive risk estimates are discussed in relation to low dose irradiation. Topics considered are:- dose and dose response relationships for stochastic effects following low doses of low LET radiation, estimates of probability of human radiation-induced cancer at low doses, proposed estimates of probability of fatal cancer for low dose, low dose rate, low-LET radiation, natural incidence of severe hereditary diseases, estimates of probability of radiation-induced severe hereditary diseases at low doses, deterministic effects resulting from low dose prenatal exposure, cancer induction including leukemia following human in utero irradiation, mental retardation, and total health detriment. (UK)

  9. 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.

  10. 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

  11. Environmental ionising radiation study: Assessment of the public exposure to the environmental gamma and X rays, and to radon in Antananarivo city

    International Nuclear Information System (INIS)

    Raoelina Andriambololona; Ravelomanantsoa, S.D; Rabesiranana, N.

    2001-01-01

    Radioactivity is one of the indicators of the environmental state because humankind is continuously exposed to ionising radiations. Knowledge of the various components of this natural radioactivity becomes a necessity. As Antananarivo is the most populated city of Madagascar, its environmental radioactivity and radiation dose were assessed with the aim of establishing a database for radioactivity levels. The present work is entitled 'Assessment of the Public Exposure to the Environmental Gamma and X-rays, and to Radon in Antananarivo City'. This paper is the synthesis of several works carried out within the frame of a research project that lasted three years (April 1998-April 2001), consisting of more than a hundred in-situ measurements campaigns and laboratory sample analyses. Ionising radiations were measured through gamma and X ray global counting. Environmental material radioactivity was characterized by in-situ and laboratory gamma spectrometry. Alpha, gamma and X ray dosimetric measurements were done indoor and outdoor, in daytime and at night. The results obtained were the basis for three scientific communications at the Madagascar National Academy of Arts, Letters and Sciences. The first is entitled 'The Cesium-137 Artificial Radioisotope Pollution in Antananarivo City' (June 1998), the second 'the Atmospheric Radon in Antananarivo City '(May 1999), and the third 'Kerma in Air and Counting Rate of the Environmental Gamma and X Rays in Antananarivo City' (December 2000). From this work, the environmental gamma and X ray , and radon contribution to natural radiation doses were obtained. We have found that the population of Antananarivo is exposed to an annual average effective dose of 5.3 mSv.y -1 , which is two times higher than the world quoted value.

  12. Synthetic diamond devices for radiotherapy applications: Thermoluminescent dosimeter and ionisation chamber

    International Nuclear Information System (INIS)

    Descamps, C.; Tromson, D.; Mer, C.; Nesladek, M.; Bergonzo, P.

    2006-01-01

    In radiotherapy field, the major usage of dosimeters is in the measurement of the dose received by the patient during radiotherapy (in-vivo measurements) and in beam calibration and uniformity checks. Diamond exhibits several interesting characteristics that make it a good candidate for radiation detection. It is indeed soft-tissue equivalent (Z=6 compared to Z=7.42 for human tissue), mechanically robust and relatively insensitive to radiation damage, chemically stable and non toxic. Moreover, the recent availability of synthetic samples, grown under controlled conditions using the chemical vapour deposition (C.V.D.) technique, allowed decreasing the high cost and the long delivery time of diamond devices. Diamond can be use for off-line dosimetry as thermoluminescent dosimeters or for on-line dosimetry as ionisation chamber [2,3]. These both applications are reported here. For this study, samples were grown in the laboratory and devices were then tested under X-ray irradiations and in clinical environment under medical cobalt source. The work described in this paper was performed in the framework of the European Integrated Project M.A.E.S.T.R.O., Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology, (6. FP) which is granted by the European Commission.The first results of this study clearly show that C.V.D. diamond detectors are suitable for dosimetry in radiotherapy applications. Moreover, for both T.L. dosimeters and ionisation chambers applications, and even though the sensitivity is subsequently reduced, nitrogen incorporation in films seems to significantly improve the dosimetric characteristics of the devices. Therefore, the optimisation of the material quality appears as a very important issue in order to increase the dosimetric characteristics of devices and more particularly, for use as thermoluminescent dosimeters, other impurities (Nickel, Phosphorus) will be tested. For ionisation chamber applications, experiments with

  13. A micro-gap, air-filled ionisation chamber as a detector for criticality accident dosimetry

    International Nuclear Information System (INIS)

    Murawski, I.; Zielczynski, M.; Gryzinski, M.A.; Golnik, N.

    2014-01-01

    A micro-gap air-filled ionisation chamber was designed for criticality dosimetry. The special feature of the chamber is its very small gap between electrodes of only 0.3 mm. This prevents ion recombination at high dose rates and minimises the influence of gas on secondary particles spectrum. The electrodes are made of polypropylene because of higher content of hydrogen in this material, when compared with soft tissue. The difference between neutron and gamma sensitivity in such chamber becomes practically negligible. The chamber's envelope contains two specially connected capacitors, one for polarising the electrodes and the other for collecting the ionisation charge. Air-filled ionisation chamber with very small gap is a simple dosemeter, which fulfills the most desired properties of criticality accident dosemeters. Short ion collection time is achieved by combination of small gap and relatively high polarising voltage. For the same reason, parasitic recombination of ions in the chamber is negligibly small even at high dose rates. The difference between neutron and gamma sensitivity is small for tissue-equivalent chamber and is expected to become practically negligible when the chamber electrodes are made of polypropylene. Additional capacitor provides a broad measuring range from ∼0.1 Gy up to ∼25 Gy; however, leakage of electrical charge from polarising capacitor has to be observed and taken into account. Periodical re-charging of the device is necessary. Obviously, final test of the device in conditions simulating criticality accident is needed and will be performed as soon as available. (authors)

  14. Transcription-based model for the induction of chromosomal exchange events by ionising radiation

    International Nuclear Information System (INIS)

    Radford, I.A.

    2003-01-01

    The mechanistic basis for chromosomal aberration formation, following exposure of mammalian cells to ionising radiation, has long been debated. Although chromosomal aberrations are probably initiated by DNA double-strand breaks (DSB), little is understood about the mechanisms that generate and modulate DNA rearrangement. Based on results from our laboratory and data from the literature, a novel model of chromosomal aberration formation has been suggested (Radford 2002). The basic postulates of this model are that: (1) DSB, primarily those involving multiple individual damage sites (i.e. complex DSB), are the critical initiating lesion; (2) only those DSB occurring in transcription units that are associated with transcription 'factories' (complexes containing multiple transcription units) induce chromosomal exchange events; (3) such DSB are brought into contact with a DNA topoisomerase I molecule through RNA polymerase II catalysed transcription and give rise to trapped DNA-topo I cleavage complexes; and (4) trapped complexes interact with another topo I molecule on a temporarily inactive transcription unit at the same transcription factory leading to DNA cleavage and subsequent strand exchange between the cleavage complexes. We have developed a method using inverse PCR that allows the detection and sequencing of putative ionising radiation-induced DNA rearrangements involving different regions of the human genome (Forrester and Radford 1998). The sequences detected by inverse PCR can provide a test of the prediction of the transcription-based model that ionising radiation-induced DNA rearrangements occur between sequences in active transcription units. Accordingly, reverse transcriptase PCR was used to determine if sequences involved in rearrangements were transcribed in the test cells. Consistent with the transcription-based model, nearly all of the sequences examined gave a positive result to reverse transcriptase PCR (Forrester and Radford unpublished)

  15. The potential use of diamond coated tungsten tips as a field ionisation source

    Energy Technology Data Exchange (ETDEWEB)

    Brown, A.; Prawer, S.; Legge, G.J.F.; Kostidis, L.I. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1996-12-31

    Tungsten tips are convenient for use in a high brightness gaseous phase field ionisation source. However, the lifetime of these tips is not adequate for practical use. The authors are investigating whether coating tungsten tips with diamond using Chemical Vapor Deposition (CVD) will improve the practicality of using these tips by an improvement in longevity of the source and/or an improvement in brightness due to the effects of the property of negative electron affinity which has been observed on CVD diamond. 1 ref.

  16. Characterisation of the Muon Beams for the Muon Ionisation Cooling Experiment

    CERN Document Server

    Adams, D.; Alekou, A.; Apollonio, M.; Asfandiyarov, R.; Back, J.; Barber, G.; Barclay, P.; de Bari, A.; Bayes, R.; Bayliss, V.; Bertoni, R.; Blackmore, V.J.; Blondel, A.; Blot, S.; Bogomilov, M.; Bonesini, M.; Booth, C.N.; Bowring, D.; Boyd, S.; Bradshaw, T.W.; Bravar, U.; Bross, A.D.; Capponi, M.; Carlisle, T.; Cecchet, G.; Charnley, G.; Cobb, J.H.; Colling, D.; Collomb, N.; Coney, L.; Cooke, P.; Courthold, M.; Cremaldi, L.M.; DeMello, A.; Dick, A.; Dobbs, A.; Dornan, P.; Fayer, S.; Filthaut, F.; Fish, A.; Fitzpatrick, T.; Fletcher, R.; Forrest, D.; Francis, V.; Freemire, B.; Fry, L.; Gallagher, A.; Gamet, R.; Gourlay, S.; Grant, A.; Graulich, J.S.; Griffiths, S.; Hanlet, P.; Hansen, O.M.; Hanson, G.G.; Harrison, P.; Hart, T.L.; Hartnett, T.; Hayler, T.; Heidt, C.; Hills, M.; Hodgson, P.; Iaciofano, A.; Ishimoto, S.; Kafka, G.; Kaplan, D.M.; Karadzhov, Y.; Kim, Y.K.; Kolev, D.; Kuno, Y.; Kyberd, P.; Lau, W.; Leaver, J.; Leonova, M.; Li, D.; Lintern, A.; Littlefield, M.; Long, K.; Lucchini, G.; Luo, T.; Macwaters, C.; Martlew, B.; Martyniak, J.; Middleton, S.; Moretti, A.; Moss, A.; Muir, A.; Mullacrane, I.; Nebrensky, J.J.; Neuffer, D.; Nichols, A.; Nicholson, R.; Nugent, J.C.; Onel, Y.; Orestano, D.; Overton, E.; Owens, P.; Palladino, V.; Palmer, R.B.; Pasternak, J.; Pastore, F.; Pidcott, C.; Popovic, M.; Preece, R.; Prestemon, S.; Rajaram, D.; Ramberger, S.; Rayner, M.A.; Ricciardi, S.; Richards, A.; Roberts, T.J.; Robinson, M.; Rogers, C.; Ronald, K.; Rubinov, P.; Rucinski, R.; Rusinov, I.; Sakamoto, H.; Sanders, D.A.; Santos, E.; Savidge, T.; Smith, P.J.; Snopok, P.; Soler, F.J.P.; Stanley, T.; Summers, D.J.; Takahashi, M.; Tarrant, J.; Taylor, I.; Tortora, L.; Torun, Y.; Tsenov, R.; Tunnell, C.D.; Vankova, G.; Verguilov, V.; Virostek, S.; Vretenar, M.; Walaron, K.; Watson, S.; White, C.; Whyte, C.G.; Wilson, A.; Wisting, H.; Zisman, M.

    2013-01-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.5--2.3 \\pi mm-rad horizontally and 0.6--1.0 \\pi mm-rad vertically, a horizontal dispersion of 90--190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE.

  17. Semiempirical confrontations between theory and experiment in highly ionised complex atoms

    International Nuclear Information System (INIS)

    Curtis, L.J.

    1989-01-01

    Highly ionised complex atoms, which have many electrons stripped away but many electrons still remaining, are presently a subject of vigorous experimental study. The high precision experimentally attainable for these systems suggests their use in the investigation of higher order theoretical processes, and the specification of these interactions is essential to the development of reliable predictive methods. It is shown that parametric reductions which combine ab initio theoretical calculations with experimental observations can yield predictions of much higher precision than could be obtained from either source separately. These formulations also reveal subtle regularities in the measured data that are not exhibited by the corresponding computations, which suggest possible calculational improvements. (orig.)

  18. Determining Parameters of Photodiodes which are Characteristics from Ionisation Chambers Following IEC 731-1982 Standards

    International Nuclear Information System (INIS)

    Barbosa, R.A.; Lopes, R.T.; Tauhata, L.; Poledna, R.

    1999-01-01

    A dosemeter is presented with a photodiode base, characterised as a field class instrument. The performance of three photodiode models, a commercially available (Siemens) and two others (Hamamatsu), were compared with the performance of the ionisation chamber, using the limits established in the IEC 731 Standard as requirement. The long-term stability and the energy dependence tests have shown results outside the limits but, in special situations such as X ray beam monitoring, these deficiencies have no influence on the dosemeter performance. The rotation test results have shown the possibility of using a photodiode to determine the field uniformity. (author)

  19. A front-end ASIC for ionising radiation monitoring with femto-amp capabilities

    International Nuclear Information System (INIS)

    Voulgari, E.; Noy, M.; Anghinolfi, F.; Perrin, D.; Krummenacher, F.; Kayal, M.

    2016-01-01

    An ultra-low leakage current Application Specific Integrated Circuit (ASIC) called Utopia (Ultralow Picoammeter) has been designed and fabricated in AMS 0.35 μm CMOS, in order to be used as the front-end for ionising radiation monitoring at CERN. It is based on the topology of a Current to Frequency Converter (CFC) through charge balancing and demonstrates a wide dynamic range of 8.5 decades without range changing. Due to a design aimed at minimising input leakage currents, input currents as low as 01 fA can be measured

  20. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.; Barclay, P.; Bayliss, V.; Bradshaw, T.W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Watson, S.; Wilson, A. [Harwell Oxford, STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); Adey, D.; Back, J.; Boyd, S.; Harrison, P.; Pidcott, C.; Taylor, I. [University of Warwick, Department of Physics, Coventry (United Kingdom); Alekou, A.; Apollonio, M.; Barber, G.; Colling, D.; Dobbs, A.; Dornan, P.; Fayer, S.; Fish, A.; Hunt, C.; Leaver, J.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Richards, A.; Santos, E.; Savidge, T.; Takahashi, M. [Imperial College London, Department of Physics, Blackett Laboratory, London (United Kingdom); Asfandiyarov, R.; Blondel, A.; Graulich, J.S.; Karadzhov, Y.; Verguilov, V.; Wisting, H. [Universite de Geneve, DPNC, Section de Physique, Geneva (Switzerland); De Bari, A.; Cecchet, G. [Sezione INFN Pavia (Italy); Dipartimento di Fisica Nucleare e Teorica, Pavia (Italy); Bayes, R.; Forrest, D.; Nugent, J.C.; Soler, F.J.P.; Walaron, K. [The University of Glasgow, School of Physics and Astronomy, Glasgow (United Kingdom); Bertoni, R.; Bonesini, M.; Lucchini, G. [Sezione INFN Milano Bicocca (Italy); Dipartimento di Fisica G. Occhialini, Milano (Italy); Blackmore, V.J.; Carlisle, T.; Cobb, J.H.; Lau, W.; Rayner, M.A.; Tunnell, C.D. [University of Oxford, Department of Physics, Oxford (United Kingdom); Blot, S.; Kim, Y.K. [University of Chicago, Enrico Fermi Institute, Chicago, IL (United States); Bogomilov, M.; Kolev, D.; Rusinov, I.; Tsenov, R.; Vankova, G. [St. Kliment Ohridski University of Sofia, Department of Atomic Physics, Sofia (Bulgaria); Booth, C.N.; Hodgson, P.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P.J. [University of Sheffield, Department of Physics and Astronomy, Sheffield (United Kingdom); Bowring, D.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.P.; Zisman, M.S. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Bravar, U. [University of New Hampshire, Durham, NH (United States); Bross, A.D.; Fitzpatrick, T.; Leonova, M.; Moretti, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; Rucinski, R. [Fermilab, Batavia, IL (United States); Capponi, M.; Iaciofano, A.; Orestano, D.; Pastore, F.; Tortora, L. [Sezione INFN Roma Tre e Dipartimento di Fisica, Roma (Italy); Charnley, G.; Collomb, N.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Owens, P.; White, C. [STFC Daresbury Laboratory, Cheshire (United Kingdom); Coney, L.; Fletcher, R.; Hanson, G.G.; Heidt, C. [University of California, Riverside, CA (United States); Cooke, P.; Gamet, R. [University of Liverpool, Department of Physics, Liverpool (United Kingdom); Cremaldi, L.M.; Hart, T.L.; Luo, T.; Sanders, D.A.; Summers, D.J. [University of Mississippi, Oxford, MS (United States); Dick, A.J.; Ronald, K.; Whyte, C.G. [University of Strathclyde, Department of Physics, Glasgow (United Kingdom); Filthaut, F. [NIKHEF, Amsterdam (Netherlands); Freemire, B.; Hanlet, P.; Kafka, G.; Kaplan, D.M.; Rajaram, D.; Snopok, P.; Torun, Y. [Illinois Institute of Technology, Chicago, IL (United States); Hansen, O.M.; Ramberger, S.; Vretenar, M. [CERN, Geneva (Switzerland); Ishimoto, S. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki (Japan); Kuno, Y.; Sakamoto, H. [Osaka University, Graduate School of Science, Department of Physics, Toyonaka, Osaka (Japan); Kyberd, P.; Littlefield, M.; Nebrensky, J.J. [Brunel University, Uxbridge (United Kingdom); Onel, Y. [University of Iowa, Department of Physics and Astronomy, Iowa City, IA (United States); Palladino, V. [Universita Federico II, Sezione INFN Napoli (Italy); Dipartimento di Fisica, Napoli (Italy); Palmer, R.B. [Brookhaven National Laboratory, Upton, NY (US); Roberts, T.J. [Muons, Inc., Batavia, IL (US); Collaboration: The MICE Collaboration

    2013-10-15

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2-2.3 {pi} mm-rad horizontally and 0.6-1.0 {pi} mm-rad vertically, a horizontal dispersion of 90-190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE. (orig.)

  1. Characterisation of the muon beams for the Muon Ionisation Cooling Experiment

    International Nuclear Information System (INIS)

    Adams, D.; Barclay, P.; Bayliss, V.; Bradshaw, T.W.; Courthold, M.; Francis, V.; Fry, L.; Hayler, T.; Hills, M.; Lintern, A.; Macwaters, C.; Nichols, A.; Preece, R.; Ricciardi, S.; Rogers, C.; Stanley, T.; Tarrant, J.; Watson, S.; Wilson, A.; Adey, D.; Back, J.; Boyd, S.; Harrison, P.; Pidcott, C.; Taylor, I.; Alekou, A.; Apollonio, M.; Barber, G.; Colling, D.; Dobbs, A.; Dornan, P.; Fayer, S.; Fish, A.; Hunt, C.; Leaver, J.; Long, K.; Martyniak, J.; Middleton, S.; Pasternak, J.; Richards, A.; Santos, E.; Savidge, T.; Takahashi, M.; Asfandiyarov, R.; Blondel, A.; Graulich, J.S.; Karadzhov, Y.; Verguilov, V.; Wisting, H.; De Bari, A.; Cecchet, G.; Bayes, R.; Forrest, D.; Nugent, J.C.; Soler, F.J.P.; Walaron, K.; Bertoni, R.; Bonesini, M.; Lucchini, G.; Blackmore, V.J.; Carlisle, T.; Cobb, J.H.; Lau, W.; Rayner, M.A.; Tunnell, C.D.; Blot, S.; Kim, Y.K.; Bogomilov, M.; Kolev, D.; Rusinov, I.; Tsenov, R.; Vankova, G.; Booth, C.N.; Hodgson, P.; Nicholson, R.; Overton, E.; Robinson, M.; Smith, P.J.; Bowring, D.; DeMello, A.; Gourlay, S.; Li, D.; Prestemon, S.; Virostek, S.P.; Zisman, M.S.; Bravar, U.; Bross, A.D.; Fitzpatrick, T.; Leonova, M.; Moretti, A.; Neuffer, D.; Popovic, M.; Rubinov, P.; Rucinski, R.; Capponi, M.; Iaciofano, A.; Orestano, D.; Pastore, F.; Tortora, L.; Charnley, G.; Collomb, N.; Gallagher, A.; Grant, A.; Griffiths, S.; Hartnett, T.; Martlew, B.; Moss, A.; Muir, A.; Mullacrane, I.; Owens, P.; White, C.; Coney, L.; Fletcher, R.; Hanson, G.G.; Heidt, C.; Cooke, P.; Gamet, R.; Cremaldi, L.M.; Hart, T.L.; Luo, T.; Sanders, D.A.; Summers, D.J.; Dick, A.J.; Ronald, K.; Whyte, C.G.; Filthaut, F.; Freemire, B.; Hanlet, P.; Kafka, G.; Kaplan, D.M.; Rajaram, D.; Snopok, P.; Torun, Y.; Hansen, O.M.; Ramberger, S.; Vretenar, M.; Ishimoto, S.; Kuno, Y.; Sakamoto, H.; Kyberd, P.; Littlefield, M.; Nebrensky, J.J.; Onel, Y.; Palladino, V.; Palmer, R.B.; Roberts, T.J.

    2013-01-01

    A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2-2.3 π mm-rad horizontally and 0.6-1.0 π mm-rad vertically, a horizontal dispersion of 90-190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE. (orig.)

  2. The fragmentation mechanism of five-membered lactones by electrospray ionisation tandem mass spectrometry

    Science.gov (United States)

    Crotti, Antônio E. M.; Fonseca, Tatiana; Hong, Hui; Staunton, James; Galembeck, Sérgio E.; Lopes, Norberto P.; Gates, Paul J.

    2004-04-01

    A series of five-membered lactones (both saturated and unsaturated) and a lactam were analysed by electrospray ionisation tandem (ESI-MS/MS) and sequential mass spectrometry (ESI-MSn). It was observed that the main fragment ions were derived from neutral losses of CO and/or H2O (NH3 for the lactam). The fragmentation pathways followed are rationalised in terms of the resulting carbocation stability and the energy of the possible fragment ions, calculated by the CBS-Q composite method.

  3. X-ray spectroscopy of highly ionised atoms of Ti through Zn in a dense plasma

    International Nuclear Information System (INIS)

    Morita, Shiguro; Fujita, Junji

    1985-01-01

    X-ray spectra for several elements have been observed from a high-temperature plasma produced in a vacuum spark using a curved-crystal spectrometer. The transition wavelengths of the He-like resonance lines for Ti through Zn are determined for the first time under careful experimental treatments. The result is compared with theoretical predictions. The transition wavelengths of the Fe He-like resonance series lines up to 1s6p-1s 2 and the Kβ transition energies of Ti partially M-shell-ionised ions (Ti VI-XIII) are also determined. As a result, several satelite lines are found. (orig.)

  4. Non-targeted effects of ionising radiation—Implications for low dose risk

    DEFF Research Database (Denmark)

    Kadhim, Munira; Salomaa, Sisko; Wright, Eric

    2013-01-01

    Non-DNA targeted effects of ionising radiation, which include genomic instability, and a variety of bystander effects including abscopal effects and bystander mediated adaptive response, have raised concerns about the magnitude of low-dose radiation risk. Genomic instability, bystander effects an......) Integrated Project funded by the European Union. Here we critically examine the evidence for non-targeted effects, discuss apparently contradictory results and consider implications for low-dose radiation health effects. © 2012 Elsevier B.V. All rights reserved....

  5. Selektive Ionisation von Wasserstoffbrücken-gebundenen Clustern und Molekülen

    OpenAIRE

    Braun, Julian

    2007-01-01

    Im ersten Teil der Dissertation werden diverse Typen von Wasserstoff-Brücken, wie die O-H···O, die N-H···O und die N-H···Pi Brücke in isolierten Heterodimeren aus Indol, Phenol und Naphthol mit Wasser und Benzol, untersucht. Mit Mass Analyzed Threshold Ionization (MATI), einer kombinierten Technik aus Flugzeit-Massenspektrometrie und resonanter Mehr-Photonen-Ionisation (REMPI) im gekühlten Überschall-Molekularstrahl, gelang die Aufzeichnung von kationischen Spektren dieser Systeme und damit u...

  6. Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol

    Directory of Open Access Journals (Sweden)

    Mara Gallastegi

    2016-02-01

    Full Text Available Abstract Background Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood Project, a prospective cohort study. Methods/Design Indirect (proximity to emission sources, questionnaires on sources use and geospatial propagation models and direct methods (spot and fixed longer-term measurements and personal measurements were conducted in order to assess exposure levels of study participants aged between 7 and 18 years old. The methodology used varies depending on the frequency of the EMF-NIR and the environment (homes, schools and parks. Questionnaires assessed the use of sources contributing both to Extremely Low Frequency (ELF and Radiofrequency (RF exposure levels. Geospatial propagation models (NISMap are implemented and validated for environmental outdoor sources of RFs using spot measurements. Spot and fixed longer-term ELF and RF measurements were done in the environments where children spend most of the time. Moreover, personal measurements were taken in order to assess individual exposure to RF. The exposure data are used to explore their relationships with proximity and/or use of EMF-NIR sources. Discussion Characterisation of the EMF-NIR exposure by this combination of methods is intended to overcome problems encountered in other research. The assessment of exposure of INMA cohort children and adolescents living in different regions of Spain to the full frequency range of EMF-NIR extends the characterisation of environmental exposures in this cohort. Together with other data obtained in the project, on socioeconomic and family characteristics and development of the children

  7. Emissions and doses from sources of ionising radiation in the Netherlands: radiation policy monitoring

    International Nuclear Information System (INIS)

    Eleveld, H.; Pruppers, M.

    2002-01-01

    In 1997 the Ministry of Housing, Spatial Planning and the Environment requested RIVM to develop an information system for policy monitoring. One of the motives was that the European Union requires that the competent authorities of each member state ensure that dose estimates due to practices involving exposure to ionising radiation are made as realistic as possible for the population as a whole and for reference groups in all places where such groups may occur. Emissions of radionuclides and radiation to the environment can be classified as follows: (1) emissions to the atmosphere, (2) emissions to the aquatic system and (3) emission of external radiation from radioactive materials and equipment that produces ionising radiation. Released radioactivity is dispersed via exposure pathways, such as the atmosphere, deposition on the ground and farmland products, drinking water, fish products, etc. This leads to radiation doses due to inhalation, ingestion and exposure to external radiation. To assess the possible radiation doses different kinds of models are applied, varying from simple multiplications with dispersion coefficients, transfer coefficients and dose conversion coefficients to complex dispersion models. In this paper an overview is given of the human-induced radiation doses in the Netherlands. Also, trends in and the effect of policy on the radiation dose of members of the public are investigated. This paper is based on an RIVM report published recently. A geographical distribution of radiation risks due to routine releases for a typical year in the Netherlands was published earlier

  8. Modelling the propagation of effects of chronic exposure to ionising radiation from individuals to populations

    Energy Technology Data Exchange (ETDEWEB)

    Alonzo, F. [Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex (France); Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)], E-mail: frederic.alonzo@irsn.fr; Hertel-Aas, T. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Gilek, M. [School of Life Sciences, Soedertoern University College, 14189 Huddinge (Sweden); Gilbin, R. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Oughton, D.H. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Garnier-Laplace, J. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)

    2008-09-15

    This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h{sup -1}). Population extinction was predicted at 43 mGy h{sup -1}. In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h{sup -1}), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.

  9. Closing of Coster-Kronig transitions in multiply ionised gold atoms

    International Nuclear Information System (INIS)

    Banas, D.; Braziewicz, J.; Czarnota, M.; Fijal, I.; Jaskola, M.; Korman, A.; Kretschmer, W.; Pajek, M.; Semaniak, J.

    2003-01-01

    The paper discusses the effect of closing of L- and M-shell Coster-Kronig (CK) transitions in multiply ionised Au atoms, for which the selected CK transitions become energetically forbidden. This effect plays an important role when the Coster-Kronig energy for single-hole configuration is relatively low, being comparable with a change of the electronic binding energies in multiply ionised atom. We show, by using a simplified model, that for gold the effect of closing of CK transitions occurs for strong L 1 -L 3 M 4,5 transition for the L 1 -subshell as well as the M 3 -M 5 N 6,7 and M 4 -M 5 O 3,4 CK transitions for the M 3 - and M 4 -subshell, respectively. We demonstrate that the discussed effect of closing CK transitions substantially changes the X-ray fluorescence and Coster-Kronig yields and thus has to be considered in interpretation of X-rays excited by heavy ion impact

  10. Correlation of the ionisation response at selected points of IC sensitive regions with SEE sensitivity parameters under pulsed laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gordienko, A V; Mavritskii, O B; Egorov, A N; Pechenkin, A A; Savchenkov, D V [National Research Nuclear University ' ' MEPhI' ' (Russian Federation)

    2014-12-31

    The statistics of the ionisation response amplitude measured at selected points and their surroundings within sensitive regions of integrated circuits (ICs) under focused femtosecond laser irradiation is obtained for samples chosen from large batches of two types of ICs. A correlation between these data and the results of full-chip scanning is found for each type. The criteria for express validation of IC single-event effect (SEE) hardness based on ionisation response measurements at selected points are discussed. (laser applications and other topics in quantum electronics)

  11. On magnetospheric electron impact ionisation and dynamics in Titan's ram-side and polar ionosphere – a Cassini case study

    Directory of Open Access Journals (Sweden)

    G. R. Lewis

    2007-11-01

    Full Text Available We present data from the sixth Cassini flyby of Titan (T5, showing that the magnetosphere of Saturn strongly interacts with the moon's ionosphere and exo-ionosphere. A simple electron ionisation model provides a reasonable agreement with the altitude structure of the ionosphere. Furthermore, we suggest that the dense and cold exo-ionosphere (from the exobase at 1430 km and outward to several Titan radii from the surface can be explained by magnetospheric forcing and other transport processes whereas exospheric ionisation by impacting low energy electrons seems to play a minor role.

  12. Simulations of the muon-induced neutron background of the EDELWEISS-II experiment for Dark Matter search

    International Nuclear Information System (INIS)

    Horn, O.M.

    2007-01-01

    In modern astroparticle physics and cosmology, the nature of Dark Matter is one of the central problems. Particle Dark Matter in form of WIMPs is favoured among many proposed candidates. The EDELWEISS direct Dark Matter search uses Germanium bolometers to detect these particles by nuclear recoils. Here, the use of two signal channels on an event-by-event basis, namely the heat and ionisation signal, enables the detectors to discriminate between electron and nuclear recoils. This technique leaves neutrons in the underground laboratory as the main background for the experiment. Besides (α,n) reactions of natural radioactivity, neutrons are produced in electromagnetic and hadronic showers induced by cosmic ray muons in the surrounding rock and shielding material of the Germanium crystals. To reach high sensitivities, the EDELWEISS-II experiment, as well as other direct Dark Matter searches, has to efficiently suppress this neutron background. The present work is devoted to study the muon-induced neutron flux in the underground laboratory LSM and the interaction rate within the Germanium crystals by using the Monte Carlo simulation toolkit Geant4. To ensure reliable results, the implemented physics in the toolkit regarding neutron production is tested in a benchmark geometry and results are compared to experimental data and other simulation codes. Also, the specific energy and angular distribution of the muon flux in the underground laboratory as a consequence of the asymmetric mountain overburden is implemented. A good agreement of the simulated muon flux is shown in a comparison to preliminary experimental data obtained with the EDELWEISS-II muon veto system. Furthermore, within a detailed geometry of the experimental setup, the muon-induced background rate of nuclear recoils in the bolometers is simulated. Coincidences of recoil events in the Germanium with an energy deposit of the muoninduced shower in the plastic scintillators of the veto system are studied to

  13. Simulations of the muon-induced neutron background of the EDELWEISS-II experiment for Dark Matter search

    Energy Technology Data Exchange (ETDEWEB)

    Horn, O.M.

    2007-12-21

    In modern astroparticle physics and cosmology, the nature of Dark Matter is one of the central problems. Particle Dark Matter in form of WIMPs is favoured among many proposed candidates. The EDELWEISS direct Dark Matter search uses Germanium bolometers to detect these particles by nuclear recoils. Here, the use of two signal channels on an event-by-event basis, namely the heat and ionisation signal, enables the detectors to discriminate between electron and nuclear recoils. This technique leaves neutrons in the underground laboratory as the main background for the experiment. Besides ({alpha},n) reactions of natural radioactivity, neutrons are produced in electromagnetic and hadronic showers induced by cosmic ray muons in the surrounding rock and shielding material of the Germanium crystals. To reach high sensitivities, the EDELWEISS-II experiment, as well as other direct Dark Matter searches, has to efficiently suppress this neutron background. The present work is devoted to study the muon-induced neutron flux in the underground laboratory LSM and the interaction rate within the Germanium crystals by using the Monte Carlo simulation toolkit Geant4. To ensure reliable results, the implemented physics in the toolkit regarding neutron production is tested in a benchmark geometry and results are compared to experimental data and other simulation codes. Also, the specific energy and angular distribution of the muon flux in the underground laboratory as a consequence of the asymmetric mountain overburden is implemented. A good agreement of the simulated muon flux is shown in a comparison to preliminary experimental data obtained with the EDELWEISS-II muon veto system. Furthermore, within a detailed geometry of the experimental setup, the muon-induced background rate of nuclear recoils in the bolometers is simulated. Coincidences of recoil events in the Germanium with an energy deposit of the muoninduced shower in the plastic scintillators of the veto system are studied

  14. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry; Proprietes thermoluminescentes du diamant CVD: applications a la dosimetrie des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Petitfils, A

    2007-09-15

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  15. Zambia Country Background Report

    DEFF Research Database (Denmark)

    Hampwaye, Godfrey; Jeppesen, Søren; Kragelund, Peter

    This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change).......This paper provides background data and general information for the Zambia studies focusing on local food processing sub­‐sector; and the local suppliers to the mines as part of the SAFIC project (Successful African Firms and Institutional Change)....

  16. Multidisciplinary approach to assess the sensitivity of dwarf tomato plants to low-LET ionising radiation

    Science.gov (United States)

    De Micco, Veronica; De Pascale, Stefania; Aronne, Giovanna; Paradiso, Roberta; Vitaglione, Paola; Turano, Mimmo; Arena, Carmen

    Ionising radiation, acting alone or in interaction with microgravity and other environmental constraints, may affect plant at molecular, morpho-structural and physiological level. The intensity of the plant’s response depends on the properties of radiation and on the features of the plant itself. Indeed, different species are characterised by different susceptibility to radiation which may change during the life course. The aim of this research was to study the radiosensitivity to low-LET ionising radiation of plants of dwarf tomato (Solanum lycopersicum L. ‘Microtom’) at two phenological phases (vegetative and reproductive), within the purpose of analysing plants for consideration as candidates for Bioregenerative Life Support Systems (BLSS) in Space. To pursue this objective, plants of the cultivar Microtom were irradiated with different doses of X-rays either at the stage of the second true leaf (VP - vegetative phase) or when at least one flower was blossomed (RP - reproductive phase). Plant’s response to ionising radiation was assessed through a multidisciplinary approach combining genetic analyses, ecophysiological measurements, morpho-anatomical characterisation of leaves and fruits, nutritional analyses of fruits. Growth, molecular and morpho-functional traits were measured during plant development up to fruiting in both VP and RP plant groups, and compared with non-irradiated control plants. Plant growth was monitored weekly recording parameters such as plant height, number of leaves, leaf area, flowering and fruiting rate. Potential DNA alterations were explored through Random Amplified Polymorphic DNA (RAPD) technique. The efficiency of the photosynthetic apparatus was evaluated by determining photosynthetic pigment composition, photochemistry and leaf gas exchanges. Leaf and fruit structure were analysed through light and epi-fluorescence microscopy. Leaf anatomical traits related to photosynthetic efficiency, and to structural radioprotection

  17. Background radiation map of Thailand

    International Nuclear Information System (INIS)

    Angsuwathana, P.; Chotikanatis, P.

    1997-01-01

    The radioelement concentration in the natural environment as well as the radiation exposure to man in day-to-day life is now the most interesting topic. The natural radiation is frequently referred as a standard for comparing additional sources of man-made radiation such as atomic weapon fallout, nuclear power generation, radioactive waste disposal, etc. The Department of Mineral Resources commenced a five-year project of nationwide airborne geophysical survey by awarding to Kenting Earth Sciences International Limited in 1984. The original purpose of survey was to support mineral exploration and geological mapping. Subsequently, the data quantity has been proved to be suitable for natural radiation information. In 1993 the Department of Mineral Resources, with the assistance of IAEA, published a Background Radiation Map of Thailand at the scale of 1:1,000,000 from the existing airborne radiometric digital data. The production of Background Radiation Map of Thailand is the result of data compilation and correction procedure developed over the Canadian Shield. This end product will be used as a base map in environmental application not only for Thailand but also Southeast Asia region. (author)

  18. Time-dependent hydrogen ionisation in 3D simulations of the solar chromosphere. Methods and first results

    NARCIS (Netherlands)

    Leenaarts, J.; Wedemeyer-Bohm, S.

    2006-01-01

    Context. The hydrogen ionisation degree deviates substantially from statistical equilibrium under the conditions of the solar chromosphere. A realistic description of this atmospheric layer thus must account for time-dependent non-equilibrium effects. Aims. Advancing the realism of numerical

  19. Testing of the effect of the entry beam tube windows of the silicon detectors of the ionisation radiation

    International Nuclear Information System (INIS)

    Kopestansky, J.; Tykva, R.; Stanek, S.

    1995-01-01

    This paper deals with testing of the entry beam tube windows of the silicon detectors of the ionisation radiation with surface barrier.The influence of the parameters of basic material and modified technologic preparation on the size and homogeneity of the windows was tested

  20. Thermally and optically stimulated luminescence of AlN-Y2O3 ceramics after ionising irradiation

    DEFF Research Database (Denmark)

    Trinkler, L.; Bos, A.J.J.; Winkelman, A.J.M.

    1999-01-01

    Thermally (TL) and optically stimulated luminescence (OSL) were studied in AlN-Y2O3 ceramics after irradiation with ionising radiation. The extremely high TL sensitivity (approximately 60 times the sensitivity of LiF:Mg,Tl (TLD-100)) makes AlN-Y2O3 ceramics attractive as a TLD material. However...

  1. Desorption electrospray ionisation mass spectrometry: A rapid screening tool for veterinary drug preparations and forensic samples from hormone crime investigations

    NARCIS (Netherlands)

    Nielen, M.W.F.; Hooijerink, H.; Claassen, F.C.; Engelen, M.C.; Beek, van T.A.

    2009-01-01

    Hormone and veterinary drug screening and forensics can benefit from the recent developments in desorption electrospray ionisation (DESI) mass spectrometry (MS). In this work the feasibility of DESI application has been studied. Using a linear ion trap or quadrupole time-of-flight (TOF) MS

  2. The ionisation loss of relativistic charged particles in thin gas samples and its use for particle identification. I

    International Nuclear Information System (INIS)

    Cobb, J.H.; Allison, W.W.M.; Bunch, J.N.

    1976-01-01

    A brief review shows a significant discrepancy between available data and theoretical predictions on the ionisation loss of charged particles in thin gas-filled proportional counters. The discrepancy related both to the increase of the most probable loss at relativistic velocities (relativistic rise) and to the spectrum of such losses at a given velocity (the Landau distribution). The origin of this relativistic rise is discussed in simple terms and related to the phenomena of transition radiation and Cherenkov radiation. It is shown that the failure of the prediction is due to the small number of ionising collisions in a gas. This problem is overcome by using a Monte Carlo method rather than a continuous integral over the spectrum of single collision processes. A specific mode of the atomic form factors is used with a modified Born approximation to yield the differential cross sections needed for the calculation. The new predictions give improved agreement with experiment and are used to investigate the problem of identifying particles of known momenta in the relativistic region. It is shown that by measuring the ionisation loss of each particle several hundred times over 5m or more, kaon, pion and proton separation with good confidence level may be achieved. Many gases are considered and a comparison is made. The results are also compared with the velocity resolution achievable by measuring primary ionisation. (Auth.)

  3. Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry

    NARCIS (Netherlands)

    Bobeldijk, I.; Boonzaaijer, G.; Spies-Faber, E.J.; Vaes, W.H.J.

    2005-01-01

    Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual

  4. Workshop on 'Dosimetric Issues in the Medical use of Ionising Radiation'.

    Science.gov (United States)

    Bottollier-Depois, Jean-François; Vanhavere, Filip

    2008-01-01

    A joint workshop was initiated by EURADOS based on the work programme of the working group 'Radiation protection dosimetry of medical staff'. The workshop was held within the framework of the regular EURADOS Annual Meeting series, of which the 2008 event was held in Paris (AM2008). The topic 'Dosimetric Issues in the Medical Use of Ionising Radiation' is very broad, and is covered by the different European projects of FP6 and FP7. This topic is also a major part of the current activities of the French Society of Medical Physic (SFPM). By promoting this joint initiative, AM2008 was an opportunity for the wider scientific community with interests in this area to meet and follow the progress in the different fields. This report introduces the themes addressed during the workshop, from which most of the papers presented in this volume are included.

  5. Revisiting Bragg's X-ray microscope: scatter based optical transient grating detection of pulsed ionising radiation.

    Science.gov (United States)

    Fullagar, Wilfred K; Paganin, David M; Hall, Chris J

    2011-06-01

    Transient optical gratings for detecting ultrafast signals are routine for temporally resolved photochemical investigations. Many processes can contribute to the formation of such gratings; we indicate use of optically scattering centres that can be formed with highly variable latencies in different materials and devices using ionising radiation. Coherent light scattered by these centres can form the short-wavelength-to-optical-wavelength, incoherent-to-coherent basis of a Bragg X-ray microscope, with inherent scope for optical phasing. Depending on the dynamics of the medium chosen, the way is open to both ultrafast pulsed and integrating measurements. For experiments employing brief pulses, we discuss high-dynamic-range short-wavelength diffraction measurements with real-time optical reconstructions. Applications to optical real-time X-ray phase-retrieval are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Chemical profile of mango (Mangifera indica L.) using electrospray ionisation mass spectrometry (ESI-MS).

    Science.gov (United States)

    Oliveira, Bruno G; Costa, Helber B; Ventura, José A; Kondratyuk, Tamara P; Barroso, Maria E S; Correia, Radigya M; Pimentel, Elisângela F; Pinto, Fernanda E; Endringer, Denise C; Romão, Wanderson

    2016-08-01

    Mangifera indica L., mango fruit, is consumed as a dietary supplement with purported health benefits; it is widely used in the food industry. Herein, the chemical profile of the Ubá mango at four distinct maturation stages was evaluated during the process of growth and maturity using negative-ion mode electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry (ESI(-)FT-ICR MS) and physicochemical characterisation analysis (total titratable acidity (TA), total soluble solids (TSS), TSS/TA ratio, and total polyphenolic content). Primary (organic acids and sugars) and secondary metabolites (polyphenolic compounds) were mostly identified in the third maturation stage, thus indicating the best stage for harvesting and consuming the fruit. In addition, the potential cancer chemoprevention of the secondary metabolites (phenolic extracts obtained from mango samples) was evaluated using the induction of quinone reductase activity, concluding that fruit polyphenols have the potential for cancer chemoprevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Lactobacilli and ionising radiation: an example of the application to meat and meat products

    International Nuclear Information System (INIS)

    Holzapfel, W.H.

    1992-01-01

    Ionising radiation provides a practical pasteurisation method for the terminal treatment of refrigerated vacuum-packaged meat products with the aim of shelf life extension. However, the relatively high radiation resistance (γ-D 10 = 0.70-1.2 kGy) of typical meat Lactobacilli, especially Lb. sake, selectively favours their total domination after treatments with 5 kGy. Typical meat strains show higher resistance (in term of γ-D 10 values the decimal reduction value due to irradiation) in the log (exponential) than in the stationary phase. This phenomenon was observed both in semi-synthetic broth and in meat, and may be explained in terms of a DNA repair mechanism operative during the exponential phase. Packaging under different gas atmospheres resulted in increased resistance to radiation in presence of N 2 , whilst the highest death rate was observed in presence of CO 2 . (orig.) [de

  8. Molecular alterations in thyroid tumors induced after exposure to ionising radiation in infancy

    International Nuclear Information System (INIS)

    Bounacer, A.; Wicker, R.; Sarasin, A.; Suarez, H.G.; Schlumberger, M.; Caillou, B.

    1997-01-01

    We investigated the presence of molecular lesions in the ras, gsp and ret genes, in epithelial thyroid tumors developed in patients who had received ionising radiation therapy in infancy for benign or malignant conditions. Our data showed: a similar frequency of ras and gsp activating mutations in radiation-associated and 'spontaneous' tumors. However, while the mutations are only transversions in the radiation-associated tumors, they are transversions as well as transitions in the 'spontaneous' ones and a mutation in codon 691 giving rise to a polymorphism in the ret gene, and frequently associated to a C-cell hyperplasia in radiation-associated tumors. The frequency of this mutation was significantly higher (60%) in these tumors, than in normal controls (21%) or 'spontaneous' epithelial thyroid tumors (23%). (author)

  9. Draft guidance notes for the protection of persons exposed to ionising radiations in research and teaching

    International Nuclear Information System (INIS)

    1983-01-01

    These guidance notes have been prepared for those who use ionising radiation in a wide range of research work and teaching, such as that under the control of universities, polytechnics, Government Departments or research organisations and for those who work in industrial research laboratories. Ancillary activities, such as the testing and calibration of equipment and the storage and disposal of radioactive materials, are also covered by these notes so far as they are carried out on the same premises. The guidance notes indicate procedures for the protection of all persons who may be exposed as a result of these practices, i.e. all employed persons, apprentices and students, and members of the public. (author)

  10. Measurements of the electron impact ionisation cross sections of He, C, O and N atoms

    International Nuclear Information System (INIS)

    Brook, E.; Harrison, M.F.A.; Smith, A.C.H.

    1978-01-01

    Absolute measurements are reported of the electron impact ionisation cross sections of ground-state atoms of helium, carbon, nitrogen and oxygen for electron energies ranging from 7 to 1000 eV. The method used was that of crossed beams in which fast beams of atoms are produced by change capture of 2 to 4 keV ions in a gas target. The data for helium atoms above 100 eV are in excellent agreement (+-5%) with the absolute data of Rapp and Englander-Golden (J. Chem.Phys.; 43:1464 (1965)) who used a static gas target technique. However, the present data are smaller in magnitude at lower energies. Data for oxygen and nitrogen atoms are in adequate agreement with data from earlier crossed-beams experiments that employed thermal-energy atom beams. Comparisons are made with the various published theoretical cross sections. (author)

  11. Guidance notes for the protection of persons against ionising radiations arising from medical and dental use

    International Nuclear Information System (INIS)

    1988-01-01

    Guidance notes have been prepared by the NRPB, the Health Departments and the Health and Safety Executive for the protection of all persons against ionising radiations arising from medical and dental use. The guidance notes are a guide to good radiation protection practice consistent with regulatory requirements. The areas covered include medical and dental radiology, diagnostic X-ray equipment for medical and dental radiography, beam therapy and remotely controlled after-loading, brachytherapy, diagnostic and therapeutic uses of unsealed radioactive substances, diagnostic uses of sealed or other solid radioactive sources, patients leaving hospital after administration of radioactive substances, precautions after death of a patient whom radioactive substances have been administered, storage and movement of radioactive substances, disposal of radioactive waste and contingency planning and emergency procedures. (U.K.)

  12. Applying the ionising radiation regulations to radon in the UK workplace

    International Nuclear Information System (INIS)

    Denman, A. R.

    2008-01-01

    As a response to the identification of a health risk from workplace radon in the UK, the Ionising Radiations Regulations include the protection of workers from excessive levels of radon. Employers are required to make risk assessments, and the interpretation of the Health and Safety Executive is that the regulations apply to workplace premises in locations already designated as Radon Affected Areas for domestic purposes, with the difference that in workplaces, it is the maximum winter radon concentration rather than the annual average which is the parameter of interest. This paper discusses the rationale behind the current regulatory environment, outlines the role and duties of Accredited Radiation Protection Advisers and summarises the strategies necessary to conform to the regulations. (authors)

  13. Electrifying atmospheres charging, ionisation and lightning in the solar system and beyond

    CERN Document Server

    Aplin, Karen L

    2013-01-01

    Electrical processes take place in all planetary atmospheres. There is evidence for lightning on Venus, Jupiter, Saturn, Uranus and Neptune, it is possible on Mars and Titan, and cosmic rays ionise every atmosphere, leading to charged droplets and particles. Controversy surrounds the role of atmospheric electricity in physical climate processes on Earth; here, a comparative approach is employed to review the role of electrification in the atmospheres of other planets and their moons. This book reviews the theory, and, where available, measurements, of planetary atmospheric electricity, taken to include ion production and ion-aerosol interactions. The conditions necessary for a global atmospheric electric circuit similar to Earth’s, and the likelihood of meeting these conditions in other planetary atmospheres, are briefly discussed. Atmospheric electrification is more important at planets receiving little solar radiation, increasing the relative significance of electrical forces. Nucleation onto atmospheric ...

  14. Integrated cross sections for the ionisation of atomic hydrogen by electron impact

    International Nuclear Information System (INIS)

    Konovalov, D.A.; McCarthy, I.E.

    1992-05-01

    Distorted-wave Born approximation (DWBA) calculations are reported for singly-differential and total cross sections for the electron impact ionisation for atomic hydrogen at 25, 40, 60, 100, 150 and 250 eV. The theory is compared with available experiments. At all the energies except 25 eV the theory predicts a lower singly-differential cross section for the low-energy side of the secondary-electron energies (<5 eV), compared to the only available absolute measurements of Shyn (1992). The DWBA calculation is in good agreement with the experiment at 25 eV but only if e-e post-collision interaction is included in the theory in some way. 23 refs., 2 figs

  15. Time-dependent hydrogen ionisation in 3D simulations of the solar chromosphere. Methods and first results

    Science.gov (United States)

    Leenaarts, J.; Wedemeyer-Böhm, S.

    2006-12-01

    Context: .The hydrogen ionisation degree deviates substantially from statistical equilibrium under the conditions of the solar chromosphere. A realistic description of this atmospheric layer thus must account for time-dependent non-equilibrium effects. Aims: .Advancing the realism of numerical simulations of the solar chromosphere by improved numerical treatment of the relevant physics will provide more realistic models that are essential for interpretation of existing and future observations. Methods: .An approximate method for solving the rate equations for the hydrogen populations was extended and implemented in the three-dimensional radiation (magneto-)hydrodynamics code CO^5BOLD. The method is based on a model atom with six energy levels and fixed radiative rates. It has been tested extensively in one-dimensional simulations. The extended method has been used to create a three-dimensional model that extends from the upper convection zone to the chromosphere. Results: .The ionisation degree of hydrogen in our time-dependent simulation is comparable to the corresponding equilibrium value up to 500 km above optical depth unity. Above this height, the non-equilibrium ionisation degree is fairly constant over time and space, and tends to be at a value set by hot propagating shock waves. The hydrogen level populations and electron density are much more constant than the corresponding values for statistical equilibrium, too. In contrast, the equilibrium ionisation degree varies by more than 20 orders of magnitude between hot, shocked regions and cool, non-shocked regions. Conclusions: .The simulation shows for the first time in 3D that the chromospheric hydrogen ionisation degree and electron density cannot be calculated in equilibrium. Our simulation can provide realistic values of those quantities for detailed radiative transfer computations.

  16. EPR spectroscopy for the detection of foods treated with ionising radiation

    International Nuclear Information System (INIS)

    Stachowicz, W.; Burlinska, G.; Michalik, J.; Dziedzic-Goclawska, A.; Ostrowski, K.

    1996-01-01

    The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

  17. Gene expression following ionising radiation: identification of biomarkers for dose estimation and prediction of individual response.

    Science.gov (United States)

    Kabacik, Sylwia; Mackay, Alan; Tamber, Narinder; Manning, Grainne; Finnon, Paul; Paillier, Francois; Ashworth, Alan; Bouffler, Simon; Badie, Christophe

    2011-02-01

    To establish a panel of highly radiation responsive genes suitable for biological dosimetry and to explore inter-individual variation in response to ionising radiation exposure. Analysis of gene expression in response to radiation was carried out using three independent techniques (Microarray, Multiplex Quantitative Real-Time Polymerase Chain Reaction (MQRT- PCR) and nCounter® Analysis System) in human dividing lymphocytes in culture and peripheral blood leukocytes exposed ex vivo from the same donors. Variations in transcriptional response to exposure to ionising radiation analysed by microarray allowed the identification of genes which can be measured accurately using MQRT PCR and another technique allowing direct count of mRNA copies. We have identified genes which are consistently up-regulated following exposure to 2 or 4 Gy of X-rays at different time points, for all individuals in blood and cultured lymphocytes. Down-regulated genes including cyclins, centromeric and mitotic checkpoint genes, particularly those associated with chromosome instability and cancer could be detected in dividing lymphocytes only. The data provide evidence that there are a number of genes which seem suitable for biological dosimetry using peripheral blood, including sestrin 1 (SESN1), growth arrest and DNA damage inducible 45 alpha (GADD45A), cyclin-dependent kinase inhibitor 1A (CDKN1A), cyclin G1 (CCNG1), ferredoxin reductase (FDXR), p53 up-regulated mediator of apoptosis (BBC3) and Mdm2 p53 binding protein homolog (MDM2). These biomarkers could potentially be used for triage after large-scale radiological incidents and for monitoring radiation exposure during radiotherapy.

  18. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation; Etude de quelques syntheses de colorants thianziniques et indaminiques amorcees par les rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Balestic, S. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-03-15

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [French] Dans le but de trouver des reactions radiochimiques susceptibles d'une application industrielle pour valoriser les dechets radioactifs provenant des reacteurs nucleaires, il a ete entrepris une etude systematique de la synthese radiochimique des colorants thiazimiques tels que le Bleu de Methylene et le Violet de Lauth dont les premiers essais ont ete effectues par Loiseleur en 1954. La premiere partie de l'etude a porte sur l'identification et le dosage des colorants formes

  19. The Cosmic Background Explorer

    Science.gov (United States)

    Gulkis, Samuel; Lubin, Philip M.; Meyer, Stephan S.; Silverberg, Robert F.

    1990-01-01

    The Cosmic Background Explorer (CBE), NASA's cosmological satellite which will observe a radiative relic of the big bang, is discussed. The major questions connected to the big bang theory which may be clarified using the CBE are reviewed. The satellite instruments and experiments are described, including the Differential Microwave Radiometer, which measures the difference between microwave radiation emitted from two points on the sky, the Far-Infrared Absolute Spectrophotometer, which compares the spectrum of radiation from the sky at wavelengths from 100 microns to one cm with that from an internal blackbody, and the Diffuse Infrared Background Experiment, which searches for the radiation from the earliest generation of stars.

  20. Cosmic Tachyon Background Radiation

    CERN Document Server

    Tomaschitz, R

    1999-01-01

    The equilibrium statistical mechanics of a background radiation of superluminal particles is investigated, based on a vectorial wave equation for tachyons of the Proca type. The partition function, the spectral energy density, and the various thermodynamic variables of an ideal Bose gas of tachyons in an open Robertson-Walker cosmology are derived. The negative mass square in the wave equation changes the frequency scaling in the Rayleigh-Jeans law, and there are also significant changes in the low temperature regime as compared to the microwave background, in particular in the caloric and thermal equations of state.

  1. The Cosmic Microwave Background

    Directory of Open Access Journals (Sweden)

    Jones Aled

    1998-01-01

    Full Text Available We present a brief review of current theory and observations of the cosmic microwave background (CMB. New predictions for cosmological defect theories and an overview of the inflationary theory are discussed. Recent results from various observations of the anisotropies of the microwave background are described and a summary of the proposed experiments is presented. A new analysis technique based on Bayesian statistics that can be used to reconstruct the underlying sky fluctuations is summarised. Current CMB data is used to set some preliminary constraints on the values of fundamental cosmological parameters $Omega$ and $H_circ$ using the maximum likelihood technique. In addition, secondary anisotropies due to the Sunyaev-Zel'dovich effect are described.

  2. Sri Lanka; Background Papers

    OpenAIRE

    International Monetary Fund

    1995-01-01

    This Background Paper on Sri Lanka provides information on the economic developments during 1992–95. Developments in the domestic and external sectors are discussed. The deficiencies of the official consumer price index that resulted in a substantial understatement of inflation performance in 1994 and alternative estimates of underlying inflation are described. The structural rigidities in the labor market that perpetuate high unemployment and limit job growth are also described. The paper al...

  3. The cosmic infrared background experiment

    Science.gov (United States)

    Bock, James; Battle, John; Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hea; Matsumoto, Toshio; Matsuura, Shuji; Pak, Soojong; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Watabe, Toyoki

    2006-03-01

    The extragalactic background, based on absolute measurements reported by DIRBE and IRTS at 1.2 and 2.2 μm, exceeds the brightness derived from galaxy counts by up to a factor 5. Furthermore, both DIRBE and the IRTS report fluctuations in the near-infrared sky brightness that appear to have an extra-galactic origin, but are larger than expected from local ( z = 1-3) galaxies. These observations have led to speculation that a new class of high-mass stars or mini-quasars may dominate primordial star formation at high-redshift ( z ˜ 10-20), which, in order to explain the excess in the near-infrared background, must be highly luminous but produce a limited amount of metals and X-ray photons. Regardless of the nature of the sources, if a significant component of the near-infrared background comes from first-light galaxies, theoretical models generically predict a prominent near-infrared spectral feature from the redshifted Lyman cutoff, and a distinctive fluctuation power spectrum. We are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The cameras will search for spatial fluctuations in the background on angular scales from 7″ to 2°, where a first-light galaxy signature is expected to peak, over a range of angular scales poorly covered by previous experiments. CIBER will determine if the fluctuations reported by the IRTS arise from first-light galaxies or have a local origin. In a short rocket flight CIBER has sensitivity to probe fluctuations 100× fainter than IRTS/DIRBE, with sufficient resolution to remove local-galaxy correlations. By jointly observing regions of the sky studied by Spitzer and ASTRO-F, CIBER will build a multi-color view of the near

  4. Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material; Analisis de Estano en una Ceniza de Combustion mediante Espectrometria de Masas de Ionizacion Termica con Dilucion Isotopica

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, C.; Fernandez, M.; Quejido, A. L.

    2006-07-01

    Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound exposure time. Due to the complex matrix of this fly ash material, a two-step purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs.

  5. Veterinary applications of ionising radiation HERCA Task Force on Veterinary Applications. Main results of the Questionnaire 'National regulatory requirements with regard to veterinary medical applications of ionising radiation' and conclusions of the TF

    International Nuclear Information System (INIS)

    Van Bladel, Lodewijk; Berlamont, Jolien; Michalczak, Herbert; Balogh, Lajos; Peremans, Kathelijne

    2013-11-01

    In the fall of 2012, the subject of radiation protection in veterinary medicine was raised during the meeting of the HERCA Board. Issues with regard to this subject had been brought to the attention of HERCA by the European College of Veterinary Diagnostic Imaging (ECVDI). In October 2012, the Board decided to charge a small Task Force (TF) to further explore the issues in this field. This TF drew up a questionnaire which looked at the general radiation protection regulatory requirements in veterinary medicine applications of ionizing radiation. The results of this study showed large differences in the requirements applicable in the HERCA member countries. The TF also noticed the increasing use of more complex imaging procedures and of different radio-therapeutic modalities, which may imply greater risks of exposure of humans to ionising radiation. These results were presented during the HERCA Board meeting in Berlin, Germany and on which the Board decided to establish a Working Group on veterinary applications of ionising radiations (WG Vet). The main results of the Questionnaire 'National regulatory requirements with regard to veterinary medicine applications of ionising radiation' is attached in Appendix

  6. Family Background and Entrepreneurship

    DEFF Research Database (Denmark)

    Lindquist, Matthew J.; Sol, Joeri; Van Praag, Mirjam

    Vast amounts of money are currently being spent on policies aimed at promoting entrepreneurship. The success of such policies, however, rests in part on the assumption that individuals are not ‘born entrepreneurs’. In this paper, we assess the importance of family background and neighborhood...... effects as determinants of entrepreneurship. We start by estimating sibling correlations in entrepreneurship. We find that between 20 and 50 percent of the variance in different entrepreneurial outcomes is explained by factors that siblings share. The average is 28 percent. Allowing for differential...... entrepreneurship does play a large role, as do shared genes....

  7. Background and introduction

    DEFF Research Database (Denmark)

    Jensen, Per Anker; van der Voordt, Theo; Coenen, Christian

    2012-01-01

    in scope between FM and CREM is that CREM has its focus on real estate as physical and economical assets utilized by an organisation, while FM has a wider service focus. The difference in scope between FM and CREM on one side and B2B marketing on the other is that FM and CREM are related to organisations...... background information to understand the following chapters in this book. Research limitations: The chapter is mainly based on the experience and knowledge of the editors. It does not include original research but provides an introductory overview of the book. Originality/value: This chapter takes a look...

  8. Malaysia; Background Paper

    OpenAIRE

    International Monetary Fund

    1996-01-01

    This Background Paper on Malaysia examines developments and trends in the labor market since the mid-1980s. The paper describes the changes in the employment structure and the labor force. It reviews wages and productivity trends and their effects on unit labor cost. The paper highlights that Malaysia’s rapid growth, sustained since 1987, has had a major impact on the labor market. The paper outlines the major policy measures to address the labor constraints. It also analyzes Malaysia’s recen...

  9. C3: The Compositional Construction of Content: A New, More Effective and Efficient Way to Marshal Inferences from Background Knowledge that will Enable More Natural and Effective Communication with Automomous Systems

    Science.gov (United States)

    2014-01-06

    Headquarters Services , Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202...that it is stopped, so we coerce the motion of the SUV in 72 to a ‘stopped state.’ (Compare secret service agents dismounting from the presidential...Nature, 522–523. Matsuki, K., Chow, T., Hare, M., Elman , J., Scheepers, C., & McRae, K. (2011). Event-based plausibility immediately influences on-line

  10. Non-targeted effects of ionising radiation (note). A new European integrated project, 2006-2010

    International Nuclear Information System (INIS)

    Salomaa, S.; Wright, E.G.; Hildebrandt, G.; Kadhim, M.; Little, M.P.; Prise, K.M.; Belyakov, O.V.

    2007-01-01

    Complete text of publication follows. The general objectives of the NOTE project are: (1) to investigate the mechanisms of nontargeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to investigate if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to investigate if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) to investigate individual susceptibility and other factors modifying non-targeted responses; (5) to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects. The NOTE brings together 19 major European and Canadian groups involved in the discovery, characterisation and mechanistic investigation of non-targeted effects of ionising radiation in cellular, tissue and animal models. The NOTE research activities are organised in six work packages. Four work packages (WPs 2-5) are problem-oriented, focussing on major questions relevant for the scientific basis of the system of radiation protection: WP2 Mechanisms of non-targeted effects, WP3 Non-cancer diseases, WP4 Factors modifying non-targeted responses, WP5 Modelling of non-targeted effects. The integration activities provided by WP6 strengthen the collaboration by supporting the access to infrastructures, mobility and training. WP7 provides dissemination and exploitation activities in the form of workshops and a public website. Managerial activities (WP1) ensure the organisation and structures for decision making, monitoring of progress, knowledge management and efficient flow of information and financing. Coordinator of the NOTE project is Prof

  11. Occupational radiation injuries from ionising rays recorded in the Federal Republic of Germany during the period between 1953 and 1979

    International Nuclear Information System (INIS)

    Soffke, R.

    1986-01-01

    An evaluation of 218 occupational diseases, which were reported between 1953 and 1979 and officially recognised as being caused by ionising rays, showed these to be made up chiefly by skin disorders (61%, equally distributed over acute and chronic forms), even though considerable percentage shares were also calculated for haematological ailments (15%) and bronchial carcinomas developed by uranium miners. There was a total of 42 deaths, 32 of which were ascribed to uranium mining and 10 to haematological diseases. In all, the annual rate of occupational diseases attributed to ionising rays shows a tendency to decline, even though the number of individuals exposed to radiation is increasing. The incidence of radiation injuries was calculated to be in the order of 0.01% for persons at risk of occupational radiation exposure. (orig./EDB) [de

  12. A cascade method of training for the revised CEGB Radiological Safety Rules and the Ionising Radiations Regulations 1985

    International Nuclear Information System (INIS)

    Jackson, J.R.; John, P.G.L.

    1986-01-01

    In order to achieve compliance with the Ionising Radiations Regulations 1985 the CEGB has introduced a revised set of Radiological Safety Rule. These Rules are for implementation at all sites under the Board's control where ionising radiations are used. It was a requirement that the new Safety Rules be brought into operation on a common date and to a consistent standard of performance throughout the industry; this necessitated a considerable training programme to familiarise and inform some 8,000 staff working at a large number of locations. The training week of identified groups of staff varied widely, according to their different levels of authority and responsibility. The paper sets out the means by which the chosen cascade method of training was selected and developed, and gives details of the modular package of training material which was produced. It also relates how the management objectives were met within the constraints of an uncompromising time schedule. (author)

  13. The 1sσ molecular orbital ionisation in asymmetric ion-atom collisions by direct Coulomb interaction

    International Nuclear Information System (INIS)

    Montenegro, E.C.; Sigaud, G.M.

    1984-11-01

    The adiabatic perturbation theory is applied to the ionisation of the 1sσ molecular orbital (MO) and extended to less adiabatic collisions by imposing an asymptotic matching with the semi-classical approximation. The transient molecular state wavefunction is modelled using the concept of an 'effective' charge for the colliding system. Through this procedure, the transition amplitudes are evaluated simulating both the relaxation of the passive electrons and the modification of the active electron wave-function, as well as their connection with the motion of the centre of charge during the collision. The direct Coulomb ionisation of the 1sσ MO is calculated for projectiles following hyperbolic paths, in terms of this 'effective' charge, using the current-vector formalism. Comparison is made with a large amount of experimental data showing good agreement. (Author) [pt

  14. Influence of Low-Dose Ionising Radiation on the Occurrence of Chromosomal Aberrations in Horse Lymphocytes after In vitro Irradiation

    International Nuclear Information System (INIS)

    Rukavina, D.; Hasanbasic, D.; Haveric, A.; Haveric, S.; Ajanovic, A.; Katica, A.

    2008-01-01

    It is well known that ionising radiation affect the chromosomal aberrations that have been used as a reliable criteria in biological dosimetry. Many studies confirm that the increase of radiation doses is related to the increase of mutation number and that even low doses could induce the mutations. Thus in this study we analysed the influence of low-dose ionising radiation to the occurrence of chromosomal aberrations in lymphocytes of peripheral blood of 12 horses after in vitro X-irradiation. To gain metaphase plates the method of cultivation periphery blood lymphocytes was employed. The observed aberrations were recorded and classified according to the International System of Cytogenetic Nomenclature (ISCN). The results showed that the percentage of chromosomal aberrations in irradiated blood (0.1 Gy and 0.2 Gy) was higher relative to the controlled samples of nonirradiated blood.(author)

  15. Northern pipelines : backgrounder

    International Nuclear Information System (INIS)

    2002-04-01

    Most analysts agree that demand for natural gas in North America will continue to grow. Favourable market conditions created by rising demand and declining production have sparked renewed interest in northern natural gas development. The 2002 Annual Energy Outlook forecasted U.S. consumption to increase at an annual average rate of 2 per cent from 22.8 trillion cubic feet to 33.8 TCF by 2020, mostly due to rapid growth in demand for electric power generation. Natural gas prices are also expected to increase at an annual average rate of 1.6 per cent, reaching $3.26 per thousand cubic feet in 2020. There are currently 3 proposals for pipelines to move northern gas to US markets. They include a stand-alone Mackenzie Delta Project, the Alaska Highway Pipeline Project, and an offshore route that would combine Alaskan and Canadian gas in a pipeline across the floor of the Beaufort Sea. Current market conditions and demand suggest that the projects are not mutually exclusive, but complimentary. The factors that differentiate northern pipeline proposals are reserves, preparedness for market, costs, engineering, and environmental differences. Canada has affirmed its role to provide the regulatory and fiscal certainty needed by industry to make investment decisions. The Government of the Yukon does not believe that the Alaska Highway Project will shut in Mackenzie Delta gas, but will instead pave the way for development of a new northern natural gas industry. The Alaska Highway Pipeline Project will bring significant benefits for the Yukon, the Northwest Territories and the rest of Canada. Unresolved land claims are one of the challenges that has to be addressed for both Yukon and the Northwest Territories, as the proposed Alaska Highway Pipeline will travel through traditional territories of several Yukon first Nations. 1 tab., 4 figs

  16. Statutory Instruments No 144 of 1994. European Communities (Protection of outside workers from ionising radiation) Regulations, 1994

    International Nuclear Information System (INIS)

    1994-04-01

    These Regulations implement Council Directive 90/641 EURATOM of 4 December, 1990 on the operational protection of outside workers exposed to the risk of ionising radiation during their activities in controlled areas. The Regulations provide for the radiation protection of workers liable to receive an exposure of high radiation levels while working away from their employers' premises. The Regulations also apply to workers who come from, or who go to work in, another Member State of the European Community

  17. Treating meats with ionising radiations. An EPR approach to the reconstruction of the administered dose and its reliability

    Energy Technology Data Exchange (ETDEWEB)

    Alberti, Angelo, E-mail: aalberti@isof.cnr.i [ISOF-CNR, Area della Ricerca, Via P. Gobetti 101, I-40129 Bologna (Italy); Chiaravalle, Eugenio [Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia 20, I-71100 Foggia (Italy); Corda, Ugo; Fuochi, Piergiorgio; Macciantelli, Dante [ISOF-CNR, Area della Ricerca, Via P. Gobetti 101, I-40129 Bologna (Italy); Mangiacotti, Michele; Marchesani, Giuliana [Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia 20, I-71100 Foggia (Italy); Plescia, Elena [ISOF-CNR, Area della Ricerca, Via P. Gobetti 101, I-40129 Bologna (Italy)

    2011-01-15

    Treatment of food with ionising radiations in order to increase its shelf-life is largely employed in many countries. Because of restrictions issued by different governments on the use of this technique, in addition to the identification of irradiated foodstuffs, it may be important to determine the radiation dose administered to the foodstuffs. An EPR based protocol to reconstruct the administered dose from samples of irradiated meats (rabbit, pork and duck) within an uncertainty of {+-}25% is reported.

  18. A value-critical assessment of the policy construction of hazard and risk for the safe use of ionising radiation

    International Nuclear Information System (INIS)

    Wallace, A.B.

    1993-01-01

    This paper presents a critique of the concept of ionising radiation safety policy from value perspectives that differ from those of the rationalist scientific. It attempts to present a social interpretation of the constitution of the present methods of policy composition that are primarily based on a conservative, orthodox, scientific paradigm. A modification of this process is then offered to integrate social discourse into the policy construction without compromising the value of the scientific input. 6 refs

  19. Ionising energy treatment for fresh horticultural produce -mandarins and other produce, Trials 1 and 2, May-July 1987

    International Nuclear Information System (INIS)

    McLauchlan, R.L.; Brown, B.I.; Mitchell, G.E.; Aston, J.W.; Wood, A.F.; Isaacs, A.R.; Williams, S.M.; Nottingham, S.M.; Wilson, P.R.; Juffs, H.S.; Johnson, G.I.; Heather, N.W.; Giles, J.E.; Wills, P.A.

    1988-01-01

    Two trials are described on the effect of ionising energy treatment, or irradiation, on the quality, shelf-life and composition of fresh produce, mainly at doses consistent with disinfestation treatment for quarantine purposes. Trial 1, carried out in May 1987, deals with replicated treatments of Imperial mandarins and preliminary observation treatments on a range of other produce. Trial 2 deals with replicated treatments of Ellendale mandarins and preliminary observation treatments on other produce

  20. Temporal naturalism

    Science.gov (United States)

    Smolin, Lee

    2015-11-01

    Two people may claim both to be naturalists, but have divergent conceptions of basic elements of the natural world which lead them to mean different things when they talk about laws of nature, or states, or the role of mathematics in physics. These disagreements do not much affect the ordinary practice of science which is about small subsystems of the universe, described or explained against a background, idealized to be fixed. But these issues become crucial when we consider including the whole universe within our system, for then there is no fixed background to reference observables to. I argue here that the key issue responsible for divergent versions of naturalism and divergent approaches to cosmology is the conception of time. One version, which I call temporal naturalism, holds that time, in the sense of the succession of present moments, is real, and that laws of nature evolve in that time. This is contrasted with timeless naturalism, which holds that laws are immutable and the present moment and its passage are illusions. I argue that temporal naturalism is empirically more adequate than the alternatives, because it offers testable explanations for puzzles its rivals cannot address, and is likely a better basis for solving major puzzles that presently face cosmology and physics. This essay also addresses the problem of qualia and experience within naturalism and argues that only temporal naturalism can make a place for qualia as intrinsic qualities of matter.

  1. Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

    International Nuclear Information System (INIS)

    Vincke, H.; Forkel-Wirth, D.; Perrin, D.; Theis, C.

    2005-01-01

    CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c -1 . Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

  2. FREQUENCY OF CHROMOSOMAL ABERRATIONS AND MICRONUCLEI IN HORSE LYMPHOCYTES FOLLOWING IN VITRO EXPOSURE TO LOW DOSE IONISING RADIATION

    Directory of Open Access Journals (Sweden)

    Dunja Rukavina

    2012-07-01

    Full Text Available Ionising radiation is known to cause chromosomal instability, which is observed as increased frequency of chromosomal aberration and micronuclei. These are listed as reliable criteria in biological dosimetry. Numerous experiments conducted on both animal and plant models demonstrated that increase in radiation dosage is followed by increased mutation frequency, and that mutations occur even at the lowest exposure. We used horse blood in vitro irradiated by low doses of ionizing radiation. Cultivation of peripheral blood lymphocytes and micronucleus test were used as biomarkers of genetic damage. The observed aberrations were recorded and classified in accordance with the International System of Cytogenetic Nomenclature. Micronuclei were identified on the basis of criteria proposed by Fenech et al. (8. Analysis of chromosomal aberration showed increased frequency of aberrations in blood cultures exposed to 0,1 Gy and 0,2 Gy compared to the controls. Microscopic analysis of chromosomal damage in in vitro micronucleus test revealed that the applied radiation dose induced micronuclei while no binucleated cells with micronuclei were found in lymphocytes that were not irradiated. In this paper we analysed the influence of low dose ionising radiation on frequency of chromosomal aberration and micronuclei in horse lymphocytes following in vitro exposure to X-rays (0,1 Gy and 0,2 Gy. Key words: chromosomal aberrations, micronuclei, ionising radiation, horse lymphocytes

  3. Pump cavitation background noise

    International Nuclear Information System (INIS)

    Cha, Y.S.

    1976-01-01

    Cavitation is defined as the growth and collapse of cavities associated with the change in pressure in contrast to the case of boiling where change in temperature is the dominating factor. It is commonly accepted that cavitation inception occurs when the minimum pressure in a system reaches the vapor pressure corresponding to the local temperatures of the liquid. The foregoing statement is, in fact, another way of defining incipient boiling which is usually defined as the condition where the temperature reaches the saturation temperature corresponding to the system pressure. Therefore, there is no difference between cavitation and boiling since both are associated with the growth and collapse of bubbles in a liquid. Cavitation noise may not be avoidable for an LMFBR primary pump under normal operating conditions, and will be present as background during boiling detection by acoustic methods

  4. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    International Nuclear Information System (INIS)

    Fehringer, F.; Seitz, G.; Hammer, G.P.; Blettner, M.

    2006-01-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  5. Effect of ionizing radiation on cardiovascular system; Les effets des rayonnements ionisants sur le systeme cardiovasculaire

    Energy Technology Data Exchange (ETDEWEB)

    Milliat, F.; Benderitter, M.; Gaugler, M.H. [Institut de radioprotection et de surete nucleaire, DRPH, SRBE, Laboratoire de radiopathologie et de therapies experimentales (LRTE), Fontenay-aux-Roses (France)

    2011-07-01

    Radiotherapy treatment for cancer of the chest, mediastinal area or the neck area is associated with increased risk of cardiovascular disease. With the increasing number of cancer patients and the increased treatment efficiency, the number of cancer survivors is increasing exponentially. The cancer survivors live longer and their long-term follow-up must be considered. The cardiovascular toxicity is mainly associated with the treatment of breast cancer, Hodgkin's lymphoma and head and neck cancer. Radiation-induced cardiovascular effects are insidious and chronic. Their occurrence is linked to numerous factors including the age of the patient at the beginning of the radiotherapy schedule, the number of years following radiotherapy, the doses (and volume) to the heart and the large vessels (coronary and carotid arteries), and the association with the traditional cardiovascular risk factors. Pathophysiological mechanisms remain unclear and, even if similarities with age-related atherosclerosis were established, the specificities of the radiation-induced atherosclerosis for high doses remain to be discovered. For low/moderate doses of ionising radiation, recent epidemiological studies provide evidence of increased risk of cardiovascular pathologies. A better knowledge of the mechanisms associated with the radiation-induced cardiovascular pathologies and the more precise identification of the populations at risk in the future should allow a more effective care of these patients with cardiovascular risk. (authors)

  6. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    Energy Technology Data Exchange (ETDEWEB)

    Camats, Nuria [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Ruiz-Herrera, Aurora [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, Juan Jose [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Acien, Maribel [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Paya, Pilar [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Giulotto, Elena [Dipartimento di Genetica e Microbiologia Adriano Buzzati Traverso, Universita degli Studi di Pavia, 27100 Pavia (Italy); Egozcue, Josep [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Francisca [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Montserrat [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain) and Departament de Biologia Cellular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)]. E-mail: Montserrat.Garcia.Caldes@uab.es

    2006-03-20

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs.

  7. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation

    International Nuclear Information System (INIS)

    Balestic, S.

    1961-03-01

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author) [fr

  8. The combined effects of diabetes and ionising radiation on the rat retina: an ultrastructural study

    International Nuclear Information System (INIS)

    Stitt, A.W.; Anderson, H.R.; Gardiner, T.A.; Archer, D.B.; McIntyre, Irene

    1994-01-01

    The combined effect of STZ-diabetes and ionising radiation on the rat retina was investigated. Wistar rats, which had been diabetic for 6 months, were irradiated with a single dose of x-rays (1500 cGy) and the ultrastructural effects evaluated at 4-10 mths post-irradiation. At 4 months post-irradiation, the outer nuclear layer of the retina was greatly reduced in thickness and the photoreceptor outer segments were disorganised and reduced in length. By 6 months post-irradiation, the photoreceptor cells were virtually absent, bringing the external limiting membrane into close apposition to the RPE. At 10 months post-irradiation, the RPE was atrophic and degenerative with retinal glial cells coming into contact with Bruch's membrane. This study has described a progressive inner retinal ischemia, with cytoid bodies, capillary non-perfusion and general atrophy of the inner retina intensifying markedly with increasing post-irradiation time. The results suggest that irradiated STZ-diabetic rats may provide a useful model of outer retinal neovascularisation and progressive inner retina ischemia. (author)

  9. Law on protection against ionising radiation and nuclear safety in Slovenia

    International Nuclear Information System (INIS)

    Breznik, B.; Krizman, M.; Skrk, D.; Tavzes, R.

    2003-01-01

    The existing legislation related to nuclear and radiation safety in Slovenia was introduced in 80's. The necessity for the new law is based on the new radiation safety standards (ICRP 60) and the intention of Slovenia to harmonize the legislation with the European Union. The harmonization means adoption of the basic safety standards and other relevant directives and regulations of Euratom. The nuclear safety section of this law is based on the legally binding international conventions ratified by Slovenia. The general approach is similar to that of some members of Nuclear Energy Agency (OECD). The guidelines of the law were set by the Ministry of the Environment and Spatial Planning, Nuclear Safety Administration, and Ministry of Health. The expert group of the Ministry of Environment and Spatial Planning and the Ministry of Health together with the representatives of the users of the ionising sources and representatives of the nuclear sector, prepared the draft of the subject law. The emphasis in this paper is given to main topics and solutions related to the control of the occupationally exposed workers, radiation safety, licensing, nuclear and waste safety, and radiation protection of people and patients. (authors)

  10. Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

    International Nuclear Information System (INIS)

    Ryu, Tae Ho; Kim, Jin Kyu; An, Kwang-Guk

    2014-01-01

    This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl 2 ) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl 2 (0-160 mg kg -1 ) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl 2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl 2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

  11. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    International Nuclear Information System (INIS)

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  12. On the divergences in assessment of environmental impacts from ionising radiation following the Fukushima accident.

    Science.gov (United States)

    Strand, P; Sundell-Bergman, S; Brown, J E; Dowdall, M

    2017-04-01

    The accident at the Fukushima-Daiichi Nuclear Power Station on March 11, 2011, led to significant contamination of the surrounding terrestrial and marine environments. Whilst impacts on human health remain the primary concern in the aftermath of such an accident, recent years have seen a significant body of work conducted on the assessment of the accident's impacts on both the terrestrial and marine environment. Such assessments have been undertaken at various levels of biological organisation, for different species, using different methodologies and coming, in many cases, to divergent conclusions as to the effects of the accident on the environment. This article provides an overview of the work conducted in relation to the environmental impacts of the Fukushima accident, critically comparing and contrasting methodologies and results with a view towards finding reasons for discrepancies, should they indeed exist. Based on the outcomes of studies conducted to date, it would appear that in order to avoid the fractured and disparate conclusions drawn in the aftermath of previous accidents, radioactive contaminants and their effects can no longer simply be viewed in isolation with respect to the ecosystems these effects may impact. A combination of laboratory based and field studies with a focus on ecosystem functioning and effects could offer the best opportunities for coherence in the interpretation of the results of studies into the environmental impacts of ionising radiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    International Nuclear Information System (INIS)

    Camats, Nuria; Ruiz-Herrera, Aurora; Parrilla, Juan Jose; Acien, Maribel; Paya, Pilar; Giulotto, Elena; Egozcue, Josep; Garcia, Francisca; Garcia, Montserrat

    2006-01-01

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs

  14. Gene expression analysis after low dose ionising radiation exposure of the developing organism

    International Nuclear Information System (INIS)

    Abderrafi Benotmane, M.

    2007-01-01

    Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two main stages of development are of interest; 1) the gastrula stage at which ionizing radiation can induce several malformations. 2) the organogenesis. During brain development, epidemiological studies of the atomic bomb survivors of Hiroshima/Nagasaki showed increased risk of mental retardation in children of women exposed between weeks 8-15 of pregnancy or at a lower extend between weeks 15 to 25

  15. Detection of the effects of low dose ionising irradiation on epidermal function

    Energy Technology Data Exchange (ETDEWEB)

    Barton, S.P.; Black, D.R.; Gaskell, S.A.; Marks, R. (Welsh National School of Medicine, Cardiff (UK)); Sathyanarayana, J.R.; Paterson, I. (Velindre Hospital, Whitchurch, Cardiff (UK))

    1985-01-01

    A non-invasive technique for the detection of small doses of X irradiation to the skin would be important for improvements in radiation protection. In this investigation we have studied the effects of doses of X rays of less than 2.0 Gy (sub-erythemal) on human skin in order to select such a technique. Our results indicate that a dose of X rays between 0.5 and 1.0 Gy was sufficient to depress significantly epidermal cell production in the basal layer. Accompanying this change in epidermal cell production after 1.0 Gy exposure, there was a reduction in the rate of desquamation of corneocytes. In the stratum granulosum, changes in ''non-specific esterase'' activity (a marker of lysosomal enzyme release) were also observed. Thus at three stages of the keratinisation process, functional alterations had occurred within three days of exposure to an X ray dose of 1.0 Gy. For this reason it seems likely that the various changes were at least partially independent of each other and that the stratum corneum may serve as a biological dosimeter for the detection of exposure to low doses of ionising radiation.

  16. Analysis of e-e angular correlations in near-threshold electron impact ionisation of helium

    International Nuclear Information System (INIS)

    Selles, P.; Huetz, A.; Mazeau, J.

    1987-01-01

    Using a coincidence technique in a coplanar geometry, triple differential cross sections (TDCS) for electron impact ionisation of helium are measured in the 0.5-2 eV energy range above threshold. As a few states (O <= L <= 2) of the two outgoing electrons are obviously involved in the process, their respective intensities appear as unknown parameters in the theoretical TDCS as deduced in the frame of the Wannier theory. The authors show that almost all these parameters can be determined through normalisation to the measured TDCS in two specific geometries: in the first one the two electrons are kept in opposite directions while in the second one they remain symmetrical with respect to the incident beam. A comparison with the complete set of data is then performed. The measured TDCS are in agreement with the Wannier theory for the lowest energies (0.5 and 1 eV). At 2 eV the overall agreement becomes poorer, although some predictions of the Wannier theory still apply. Finally specific measurements at 8 eV clearly show from consideration of symmetry that the Wannier theory no longer applies at this energy. (author)

  17. A gas ionisation Direct-STIM detector for MeV ion microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Norarat, Rattanaporn, E-mail: rattanaporn@rmutl.ac.th [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Faculty of Science and Agriculture, Rajamangala University of Technology Lanna, Chiang Rai, 57120 Chiang Rai (Thailand); Department of Physics, University of Jyväskylä, P.O. Box 35, Jyväskylä FI-40014 (Finland); Guibert, Edouard; Jeanneret, Patrick; Dellea, Mario; Jenni, Josef [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland); Roux, Adrien; Stoppini, Luc [Tissue Engineering Laboratory, Campus Biotech, Chemin des Mines 9, Geneva (Switzerland); Whitlow, Harry J. [University of Applied Sciences (HES-SO), Haute Ecole Arc Ingénierie, Eplatures-Gris 17, CH-2300 La Chaux-de-Fonds (Switzerland)

    2015-04-01

    Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Müller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors (e.g. proton induced fluorescence). Here we report the performance for imaging ReNcells VM with μm resolution where energy resolutions of <24 keV fwhm could be achieved for 1 MeV protons using isobutane gas.

  18. Optical polarization: background and camouflage

    Science.gov (United States)

    Škerlind, Christina; Hallberg, Tomas; Eriksson, Johan; Kariis, Hans; Bergström, David

    2017-10-01

    Polarimetric imaging sensors in the electro-optical region, already military and commercially available in both the visual and infrared, show enhanced capabilities for advanced target detection and recognition. The capabilities arise due to the ability to discriminate between man-made and natural background surfaces using the polarization information of light. In the development of materials for signature management in the visible and infrared wavelength regions, different criteria need to be met to fulfil the requirements for a good camouflage against modern sensors. In conventional camouflage design, the aimed design of the surface properties of an object is to spectrally match or adapt it to a background and thereby minimizing the contrast given by a specific threat sensor. Examples will be shown from measurements of some relevant materials and how they in different ways affect the polarimetric signature. Dimensioning properties relevant in an optical camouflage from a polarimetric perspective, such as degree of polarization, the viewing or incident angle, and amount of diffuse reflection, mainly in the infrared region, will be discussed.

  19. Background Suppression Effects on Signal Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Burr, Tom [Los Alamos National Laboratory

    2008-01-01

    Gamma detectors at border crossings are intended to detect illicit nuclear material. One performance challenge involves the fact that vehicles suppress the natural background, thus potentially reducing detection probability for threat items. Methods to adjust for background suppression have been considered in related but different settings. Here, methods to adjust for background suppression are tested in the context of signal estimation. Adjustment methods include several clustering options. We find that for the small-to-moderate suppression magnitudes exhibited in the analyzed data, suppression adjustment is only moderatel helpful in locating the signal peak, and in estimating its width or magnitude.

  20. Low background infrared (LBIR) facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Low background infrared (LBIR) facility was originally designed to calibrate user supplied blackbody sources and to characterize low-background IR detectors and...

  1. 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

  2. Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers

    Science.gov (United States)

    Butts, Samantha F.; Sammel, Mary D.; Greer, Christine; Rebbeck, Timothy R.; Boorman, David W.; Freeman, Ellen W.

    2016-01-01

    Objective This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers. Methods Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B. Results Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4–3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31–69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03–2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54–5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21–98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry. Conclusions Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging. PMID:24448104

  3. Cigarettes, genetic background, and menopausal timing: the presence of single nucleotide polymorphisms in cytochrome P450 genes is associated with increased risk of natural menopause in European-American smokers.

    Science.gov (United States)

    Butts, Samantha F; Sammel, Mary D; Greer, Christine; Rebbeck, Timothy R; Boorman, David W; Freeman, Ellen W

    2014-07-01

    This study aims to evaluate associations between variations in genes involved in the metabolism of environmental chemicals and steroid hormones and risk of menopause in smokers. Survival analysis was performed on 410 eligible participants from the Penn Ovarian Aging study (ongoing for 14 years), a cohort study of late-reproductive-age women. Single nucleotide polymorphisms at the following loci were studied: COMT Val158Met, CYP1B1*4 Asn452Ser, CYP1B1*3 Leu432Val, and CYP3A4*1B. Significant interactions between smoking and single nucleotide polymorphisms were observed in European-American carriers of CYP3A4*1B and CYP1B1*3, supporting a greater risk of menopause entry compared with those not carrying these alleles. Among CYP1B1*3 carriers, smokers had a greater risk of menopause entry than nonsmokers (adjusted hazard ratio [HR], 2.26; 95% CI, 1.4-3.67; median time to menopause, 10.42 and 11.07 y, respectively). No association between smoking and menopause was identified in CYP1B1 wild types. Among CYP3A4*1B carriers, smokers were at greater risk for menopause entry than nonsmokers (adjusted HR, 15.1; 95% CI, 3.31-69.2; median time to menopause, 11.36 and 13.91 y, respectively). Risk of menopause entry in CYP3A4 wild types who smoked was far lower (adjusted HR, 1.59; 95% CI, 1.03-2.44). Heavily smoking CYP1B1*3 carriers (adjusted HR, 3.0; 95% CI, 1.54-5.84; median time to menopause, 10.41 y) and heavily smoking CYP3A4*1B carriers (adjusted HR, 17.79; 95% CI, 3.21-98.65; median time to menopause, 5.09 y) had the greatest risk of menopause entry. Our finding that the risk of menopause entry in European-American smokers varies depending on genetic background represents a novel gene-environment interaction in reproductive aging.

  4. Climate change. Scientific background and process

    Energy Technology Data Exchange (ETDEWEB)

    Alfsen, Knut H.; Fuglestvedt, Jan; Seip, Hans Martin; Skodvin, Tora

    1999-07-01

    The paper describes briefly the natural and man-made forces behind climate change and outlines climate variations in the past. It also discusses the future impact of anthropogenic emission of greenhouse gases, and the background, organisation and functioning of the Intergovernmental Panel on Climate Change (IPCC)

  5. Risk of cancer after low doses of ionising radiation: retrospective cohort study in 15 countries

    Science.gov (United States)

    Cardis, E; Vrijheid, M; Blettner, M; Gilbert, E; Hakama, M; Hill, C; Howe, G; Kaldor, J; Muirhead, C R; Schubauer-Berigan, M; Yoshimura, T; Bermann, F; Cowper, G; Fix, J; Hacker, C; Heinmiller, B; Marshall, M; Thierry-Chef, I; Utterback, D; Ahn, Y-O; Amoros, E; Ashmore, P; Auvinen, A; Bae, J-M; Solano, J Bernar; Biau, A; Combalot, E; Deboodt, P; Sacristan, A Diez; Eklof, M; Engels, H; Engholm, G; Gulis, G; Habib, R; Holan, K; Hyvonen, H; Kerekes, A; Kurtinaitis, J; Malker, H; Martuzzi, M; Mastauskas, A; Monnet, A; Moser, M; Pearce, M S; Richardson, D B; Rodriguez-Artalejo, F; Rogel, A; Tardy, H; Telle-Lamberton, M; Turai, I; Usel, M; Veress, K

    2005-01-01

    Objectives To provide direct estimates of risk of cancer after protracted low doses of ionising radiation and to strengthen the scientific basis of radiation protection standards for environmental, occupational, and medical diagnostic exposures. Design Multinational retrospective cohort study of cancer mortality. Setting Cohorts of workers in the nuclear industry in 15 countries. Participants 407 391 workers individually monitored for external radiation with a total follow-up of 5.2 million person years. Main outcome measurements Estimates of excess relative risks per sievert (Sv) of radiation dose for mortality from cancers other than leukaemia and from leukaemia excluding chronic lymphocytic leukaemia, the main causes of death considered by radiation protection authorities. Results The excess relative risk for cancers other than leukaemia was 0.97 per Sv, 95% confidence interval 0.14 to 1.97. Analyses of causes of death related or unrelated to smoking indicate that, although confounding by smoking may be present, it is unlikely to explain all of this increased risk. The excess relative risk for leukaemia excluding chronic lymphocytic leukaemia was 1.93 per Sv (< 0 to 8.47). On the basis of these estimates, 1-2% of deaths from cancer among workers in this cohort may be attributable to radiation. Conclusions These estimates, from the largest study of nuclear workers ever conducted, are higher than, but statistically compatible with, the risk estimates used for current radiation protection standards. The results suggest that there is a small excess risk of cancer, even at the low doses and dose rates typically received by nuclear workers in this study. PMID:15987704

  6. Protein oxidative damage and redox imbalance induced by ionising radiation in CHO cells.

    Science.gov (United States)

    Pietraforte, Donatella; Paulicelli, Eleonora; Patrono, Clarice; Gambardella, Lucrezia; Scorza, Giuseppe; Testa, Antonella; Fattibene, Paola

    2018-03-16

    Reactive oxygen species (ROS) are important mediators of the cytotoxicity induced by the direct reaction of ionising radiation (IR) with all critical cellular components, such as proteins, lipids, and nucleic acids. The derived oxidative damage may propagate in exposed tissues in a dose- and spatiotemporal dependent manner to other cell compartments, affecting intracellular signalling, and cell fate. To understand how cell damage is induced, we studied the oxidative events occurring immediately after cell irradiation by analysing the fate of IR-derived ROS, the intracellular oxidative damage, and the modification of redox environment accumulating in Chinese hamster ovary (CHO) within 1 h after cell irradiation (dose range 0-10 Gy). By using the immuno-spin trapping technique (IST), spectrophotometric methods, and electron paramagnetic resonance (EPR) spectroscopy, we showed that IR-derived ROS (i) induced an IST-detectable, antioxidant-inhibitable one-electron oxidation of specific intracellular proteins; (ii) altered the glutathione (GSH) content (which was found to increase below 2 Gy, and decrease at higher doses, leading to a redox imbalance); (iii) decreased glutathione peroxidase and glutaredoxin activity; (iv) modified neither glutathione reductase nor thioredoxin reductase activity; (v) were detected by spin trapping technique, but adduct intensity decreased due to cell competition for ROS; and (vi) induced no EPR-detectable radicals assignable to oxidised cellular components. In conclusion, our results showed that IR generated an early high oxidising potential (protein radical intermediates, redox imbalance, modified redox enzyme activity) in irradiated cells potentially able to propagate the damage and induce oxidative modification of secondary targets.

  7. Accurate simulation of ionisation chamber response with the Monte Carlo code PENELOPE

    International Nuclear Information System (INIS)

    Sempau, Josep; Andreo, Pedro

    2011-01-01

    Ionisation chambers (IC) are routinely used in hospitals for the dosimetry of the photon and electron beams used for radiotherapy treatments. The determination of absorbed dose to water from the absorbed dose to the air filling the cavity requires the introduction of stopping power ratios and perturbation factors, which account for the disturbance caused by the presence of the chamber. Although this may seem a problem readily amenable to Monte Carlo simulation, the fact is that the accurate determination of IC response has been, for various decades, one of the most important challenges of the simulation of electromagnetic showers. The main difficulty stems from the use of condensed history techniques for electron and positron transport. This approach, which involves grouping a large number of interactions into a single artificial event, is known to produce the so-called interface effects when particles travel across surfaces separating different media. These effects can be sizeable when the electron step length is not negligible compared to the size of the region being crossed, as it is the case with the cavity of an IC. The artefact, which becomes apparent when the chamber response shows a marked dependence on the adopted step size, can be palliated with the use of sophisticated electron transport algorithms. These topics are discussed in the context of the transport model implemented in the PENELOPE code. The degree of violation of the Fano theorem for a simple, planar geometry, is used as a measure of the stability of the algorithm with respect to variations of the electron step length, thus assessing the 'quality' of its condensed history scheme. It is shown that, with a suitable choice of transport parameters, PENELOPE simulates IC response with an accuracy of the order of 0.1%.

  8. Bi-Abundance Ionisation Structure of the Wolf-Rayet Planetary Nebula PB 8

    Science.gov (United States)

    Danehkar, A.

    2018-01-01

    The planetary nebula PB 8 around a [WN/WC]-hybrid central star is one of planetary nebulae with moderate abundance discrepancy factors (ADFs 2-3), which could be an indication of a tiny fraction of metal-rich inclusions embedded in the nebula (bi-abundance). In this work, we have constructed photoionisation models to reproduce the optical and infrared observations of the planetary nebula PB 8 using a non-LTE stellar model atmosphere ionising source. A chemically homogeneous model initially used cannot predict the optical recombination lines. However, a bi-abundance model provides a better fit to most of the observed optical recombination lines from N and O ions. The metal-rich inclusions in the bi-abundance model occupy 5.6% of the total volume of the nebula, and are roughly 1.7 times cooler and denser than the mean values of the surrounding nebula. The N/H and O/H abundance ratios in the metal-rich inclusions are 1.0 and 1.7 dex larger than the diffuse warm nebula, respectively. To reproduce the Spitzer spectral energy distribution of PB 8, dust grains with a dust-to-gas ratio of 0.01 (by mass) were also included. It is found that the presence of metal-rich inclusions can explain the heavy element optical recombination lines, while a dual-dust chemistry with different grain species and discrete grain sizes likely produces the infrared continuum of this planetary nebula. This study demonstrates that the bi-abundance hypothesis, which was examined in a few planetary nebulae with large abundance discrepancies (ADFs > 10), could also be applied to those typical planetary nebulae with moderate abundance discrepancies.

  9. Interactions between carbo-platin, cisplatin and ionising radiation in an human ovarian cancer cell line

    International Nuclear Information System (INIS)

    Scalliet, P.

    1999-01-01

    Cisplatin (CDDP) and radiotherapy are frequently used concomitantly in the treatment of various malignant conditions. Because of its toxicity, cisplatin tends to be replaced by carbo-platin (CBDCA) in several indications. Available data regarding the combined effects of cisplatin and carbo-platin with ionising radiation are contradictory. Various concentrations of cisplatin and carbo-platin and various timing of association with radiation have been tested in vitro in a human ovarian cancer cell line. The parental cell line (AOvC-0) and a cisplatin-resistant stable sub-line (AOvC-CDDP/O) (De Pooter et al., Cn Res, 1991) were exposed to carbo-platin (2.5, 5 and 10 M) and to CDDP (1, 2.5 and 5 M), 16 h and 4 h before and 4 h and 16 h after irradiation, respectively. Cell survival was evaluated by a classical clonogenic assay. Exposure of AOvC-0 to 5M CBDCA and of AOvC-CDDDP/O to 10 M CBDCA, before or shortly after radiation exposure, increased cell lethality in a clear supra-additive way, with the highest DEF in the shoulder region of the survival curve and at radiation doses relevant to clinical radiotherapy. In the sensitive cell line, 5 M carbo-platin resulted in an additional lethality equivalent to 4.5 Gy; in the resistant cells, 10M carbo-platin was equivalent to 3.6 Gy. Replacing carbo-platin by cisplatin in an identical set-up demonstrated exclusively simple additivity (DEF = 1). These data suggest that carbo-platin and cisplatin delivered at equi-toxic doses interact with radiation a different way and that, in the present set-up, only carbo-platin enhanced the effects of radiation. Carbo-platin might consequently be a better candidate than cisplatin in some concomitant combinations with radiotherapy. (authors)

  10. Physical interaction of ionising radiations with the intracellular macromolecular target DNA and its biological consequences

    International Nuclear Information System (INIS)

    Geard, C.R.; Loucas, B.D.

    1995-01-01

    Chromosomal DNA breaks were evaluated in normal human fibroblasts after irradiation of non-cycling G1 phase cells with 90 keV·μm -1 α particles and 250 kV p X rays. Yields were measured using the premature chromosome condensation technique in interphase cells, straight after and 24 h after irradiation, and by mitotic scoring of terminal deletions following cellular release at 24 h and progression through the cell cycle. Yields were related to the frequencies of energy deposition events per cell nucleus estimated microdosimetrically for X rays and by relating fluence to nuclear cross-sectional areas for the α particles. Linear relationships were found for both radiations and at all three times post-irradiation. Initial break yields of 1.3 x 10 o and 1.6 x 10 -2 per energy deposition event for α particles and X rays respectively, changed to residual yields (24 h) of 4.0 x 10 -1 and 1.3 x 10 -3 , and for terminal deletions at mitosis to 6.0 x 10 -3 and 4.0 x 10 -5 per energy deposition event. That is, one 90 keV·μm -1 α particle is about 100 times more biologically effective than an electron track from 250 kV p X rays and greater than 99% of initially induced chromosomal DNA breaks are repaired/misrepaired before the next mitosis. Misrepair will involve illegitimate interactions and combinations of pairs of lesions, entities which pre-dominate at mitosis, while a failure to repair/misrepair resulting in relic DNA double strand breaks is likely to be of minimal consequence. Lesion interaction, proximity dependent, and largely irrespective of LET dependent lesion severity will then be the principal basis for the unwanted biological sequelae from ionising radiations. (Author)

  11. The Design of Diagnostic Medical Facilities where Ionising Radiation is used

    International Nuclear Information System (INIS)

    Malone, J.; O'Reilly, G.; O'Connor, U.; Gallagher, A.; Sheahan, N.; Fennell, S.

    2009-06-01

    The original Code of Practice on The Design of Diagnostic Medical Facilities Using Ionising Radiation was first published by the Nuclear Energy Board in 1988. In the intervening years the 'Blue Book' as it became known has served the medical community well as the sector has expanded and modernised and the late Dr Noel Nowlan, then Chief Executive of the Nuclear Energy Board, deserves much credit for initiating this pioneering contribution to radiation safety in Ireland. There have been significant developments since its publication in terms of the underlying radiation protection legislation, regulatory practice as well as developments in new technologies that have given rise to the need for a revision of the Code. This revised Code is based on a comprehensive draft document produced by the Haughton Institute under contract to the RPII and was finalised following extensive consultations with the relevant stakeholders. The revised Code includes a brief review of the current legislative framework and its specific impact on the management of building projects (Chapters 1 and 2), a presentation of the main types of radiological (Chapter 3) and nuclear medicine (Chapter 4) facilities, a treatment of the technical aspects of shielding calculations (Chapter 5) and a discussion of the practical aspects of implementing shielding solutions in a building context (Chapter 6). The primary purpose of the Code is to assist in the design of diagnostic facilities to the highest radiation protection standards in order to ensure the safety of workers and members of the public and the delivery of a safe service to patients. Diagnostic radiology is a dynamic environment and the Code is intended to be used in consultation with the current literature, an experienced Radiation Protection Advisor and a multidisciplinary project team

  12. Recombination in liquid filled ionisation chambers with multiple charge carrier species: Theoretical and numerical results

    International Nuclear Information System (INIS)

    Aguiar, P.; González-Castaño, D.M.; Gómez, F.; Pardo-Montero, J.

    2014-01-01

    Liquid-filled ionisation chambers (LICs) are used in radiotherapy for dosimetry and quality assurance. Volume recombination can be quite important in LICs for moderate dose rates, causing non-linearities in the dose rate response of these detectors, and needs to be corrected for. This effect is usually described with Greening and Boag models for continuous and pulsed radiation respectively. Such models assume that the charge is carried by two different species, positive and negative ions, each of those species with a given mobility. However, LICs operating in non-ultrapure mode can contain different types of electronegative impurities with different mobilities, thus increasing the number of different charge carriers. If this is the case, Greening and Boag models can be no longer valid and need to be reformulated. In this work we present a theoretical and numerical study of volume recombination in parallel-plate LICs with multiple charge carrier species, extending Boag and Greening models. Results from a recent publication that reported three different mobilities in an isooctane-filled LIC have been used to study the effect of extra carrier species on recombination. We have found that in pulsed beams the inclusion of extra mobilities does not affect volume recombination much, a behaviour that was expected because Boag formula for charge collection efficiency does not depend on the mobilities of the charge carriers if the Debye relationship between mobilities and recombination constant holds. This is not the case in continuous radiation, where the presence of extra charge carrier species significantly affects the amount of volume recombination. - Highlights: • Analytical extension of Greening and Boag theories to multiple charge carriers. • Detailed numerical study of process of volume recombination in LICs. • Recombination in pulsed beams is independent of number and mobilities of carriers. • Multiple charge carriers have a significant effect in continuous

  13. Online molecular characterisation of organic aerosols in an atmospheric chamber using extractive electrospray ionisation mass spectrometry

    Science.gov (United States)

    Gallimore, Peter J.; Giorio, Chiara; Mahon, Brendan M.; Kalberer, Markus

    2017-12-01

    The oxidation of biogenic volatile organic compounds (VOCs) represents a substantial source of secondary organic aerosol (SOA) in the atmosphere. In this study, we present online measurements of the molecular constituents formed in the gas and aerosol phases during α-pinene oxidation in the Cambridge Atmospheric Simulation Chamber (CASC). We focus on characterising the performance of extractive electrospray ionisation (EESI) mass spectrometry (MS) for particle analysis. A number of new aspects of EESI-MS performance are considered here. We show that relative quantification of organic analytes can be achieved in mixed organic-inorganic particles. A comprehensive assignment of mass spectra for α-pinene derived SOA in both positive and negative ion modes is obtained using an ultra-high-resolution mass spectrometer. We compare these online spectra to conventional offline ESI-MS spectra and find good agreement in terms of the compounds identified, without the need for complex sample work-up procedures. Under our experimental conditions, EESI-MS signals arise only from particle-phase analytes. High-time-resolution (7 min) EESI-MS spectra are compared with simulations from the near-explicit Master Chemical Mechanism (MCM) for a range of reaction conditions. We show that MS peak abundances scale with modelled concentrations for condensable products (pinonic acid, pinic acid, OH-pinonic acid). Relative quantification is achieved throughout SOA formation as the composition, size and mass (5-2400 µg m-3) of particles is evolving. This work provides a robust demonstration of the advantages of EESI-MS for chamber studies over offline ESI-MS (time resolution, relative quantification) and over hard online techniques (molecular information).

  14. The electrical charging of inactive aerosols in high ionised atmosphere, the electrical charging of artificial beta radioactive aerosols; Le processus de charge electrique: des aerosols non radioactifs en milieu fortement ionise, des aerosols radioactifs artificiels emetteurs beta

    Energy Technology Data Exchange (ETDEWEB)

    Gensdarmes, F

    2000-07-01

    The electrical properties of aerosols greatly influence their transport and deposition in a containment. In a bipolar ionic atmosphere, a neutral electric charge on aerosols is commonly assumed. However, many studies report a different charge distribution in some situations, like highly ionised atmosphere or in the case of radioactive aerosols. Such situations could arise from a hypothetical accident in a nuclear power plant. Within the framework of safety studies which are carried out at IPSN, our aims were the study of electrical properties of aerosols in highly ionised atmosphere, and the study of artificial radioactive aerosols, in order to suggest experimental validation of available theories. For this purpose, we designed an experimental device that allows us to measure non-radioactive aerosol charge distribution under high gamma irradiation, up to 10{sup 4} Gy/h. With our experimental device we also studied the properties of small ions in the medium. Our results show a variation of the charge distribution in highly ionised atmosphere. The charge increases with the dose of gamma ray. We have related this variation with the one of the small ions in the gases, according to theoretical prediction. However, the model overestimates slightly our experimental results. In the case of the radioactive aerosols, we have designed an original experimental device, which allows us to study the charge distribution of a {sup 137}Cs aerosol. Our results show that the electric charging of such aerosols is strongly dependent on evolution parameters in a containment. So, our results underline a great enhancement of self-charging of particles which are sampled in a confined medium. Our results are qualitatively in agreement with the theoretical model; nevertheless the latter underestimates appreciably the self-charging, owing to the fact that wall effects are not taken into account. (author)

  15. Executive Summary - Historical background

    International Nuclear Information System (INIS)

    2005-01-01

    matter physics experiments at the High Flux Reactor of The Laue Langevin Institute and the ISIS spallation source at Rutherford-Appleton. Recently, we very actively entered the ICARUS neutrino collaboration and were invited to the PIERRE AUGER collaboration which will search for the highest energies in the Universe. Having close ties with CERN we are very actively engaged in CROSS-GRID, a large computer network project. To better understand the historical background of the INP development, it is necessary to add a few comments on financing of science in Poland. During the 70's and the 80's, research was financed through the so-called Central Research Projects for Science and Technical Development. The advantage of this system was that state-allocated research funds were divided only by a few representatives of the scientific community, which allowed realistic allocation of money to a small number of projects. After 1989 we were able to purchase commercially available equipment, which led to the closure of our large and very experienced electronic workshop. We also considerably reduced our well equipped mechanical shop. During the 90's the reduced state financing of science was accompanied by a newly established Committee of Scientific Research which led to the creation of a system of small research projects. This precluded the development of more ambitious research projects and led to the dispersion of equipment among many smaller laboratories and universities. A large research establishment, such as our Institute, could not develop properly under such conditions. In all, between 1989 and 2004 we reduced our personnel from about 800 to 470 and our infrastructure became seriously undercapitalised. However, with energetic search for research funds, from European rather than national research programs, we hope to improve and modernize our laboratories and their infrastructure in the coming years

  16. Estimating radiological background using imaging spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-13

    Optical imaging spectroscopy is investigated as a method to estimate radiological background by spectral identification of soils, sediments, rocks, minerals and building materials derived from natural materials and assigning tabulated radiological emission values to these materials. Radiological airborne surveys are undertaken by local, state and federal agencies to identify the presence of radiological materials out of regulatory compliance. Detection performance in such surveys is determined by (among other factors) the uncertainty in the radiation background; increased knowledge of the expected radiation background will improve the ability to detect low-activity radiological materials. Radiological background due to naturally occurring radiological materials (NORM) can be estimated by reference to previous survey results, use of global 40K, 238U, and 232Th (KUT) values, reference to existing USGS radiation background maps, or by a moving average of the data as it is acquired. Each of these methods has its drawbacks: previous survey results may not include recent changes, the global average provides only a zero-order estimate, the USGS background radiation map resolutions are coarse and are accurate only to 1 km – 25 km sampling intervals depending on locale, and a moving average may essentially low pass filter the data to obscure small changes in radiation counts. Imaging spectroscopy from airborne or spaceborne platforms can offer higher resolution identification of materials and background, as well as provide imaging context information. AVIRIS hyperspectral image data is analyzed using commercial exploitation software to determine the usefulness of imaging spectroscopy to identify qualitative radiological background emissions when compared to airborne radiological survey data.

  17. Valence one-electron and shake-up ionisation bands of polycyclic aromatic hydrocarbons. IV. The dibenzanthracene species

    International Nuclear Information System (INIS)

    Deleuze, Michael S.

    2006-01-01

    A comprehensive study of the He (I) ultra-violet photoelectron spectra of the 1.2,3.4; 1.2,5.6 and 1.2,7.8 isomers of dibenzanthracene up to the double ionisation threshold at ∼18 eV is presented with the aid of one-particle Green's Function calculations performed using the outer-valence Green's Function (OVGF) approach and the third-order algebraic diagrammatic construction [ADC(3)] scheme, along with basis sets of improving quality. Suited extrapolations of the ADC(3) results for the one-electron energies characterising the π-band system (ε b < 10 eV) to Dunning's correlation consistent basis set of triple zeta quality (cc-pVTZ) enable theoretical insights into HeI measurements which approach chemical accuracy (1 kcal/mol or 43.4 meV). In contrast, a confrontation of simulated spectral envelopes with high-resolution He I photoelectron spectra indicates that polycyclic aromatic molecules with sterically overcrowded bay regions are more susceptible to undergo vibronic coupling complications at the σ-ionisation onset. OVGF/cc-pVDZ or OVGF/cc-pVTZ pole strengths smaller than 0.85 systematically corroborate a breakdown of the orbital (or one-electron) picture of ionisation at the ADC(3)/6-31G levels. The extent of shake-up bands is correspondingly related to topological, structural and magnetic criteria of aromaticity. Comparison is made with calculations of the lowest doublet-doublet excitation energies of the related radical cations, by means of time-dependent density functional theory (TDDFT)

  18. Lightning-driven inner radiation belt energy deposition into the atmosphere: implications for ionisation-levels and neutral chemistry

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2007-08-01

    Full Text Available Lightning-generated whistlers lead to coupling between the troposphere, the Van Allen radiation belts and the lower-ionosphere through Whistler-induced electron precipitation (WEP. Lightning produced whistlers interact with cyclotron resonant radiation belt electrons, leading to pitch-angle scattering into the bounce loss cone and precipitation into the atmosphere. Here we consider the relative significance of WEP to the lower ionosphere and atmosphere by contrasting WEP produced ionisation rate changes with those from Galactic Cosmic Radiation (GCR and solar photoionisation. During the day, WEP is never a significant source of ionisation in the lower ionosphere for any location or altitude. At nighttime, GCR is more significant than WEP at altitudes <68 km for all locations, above which WEP starts to dominate in North America and Central Europe. Between 75 and 80 km altitude WEP becomes more significant than GCR for the majority of spatial locations at which WEP deposits energy. The size of the regions in which WEP is the most important nighttime ionisation source peaks at ~80 km, depending on the relative contributions of WEP and nighttime solar Lyman-α. We also used the Sodankylä Ion Chemistry (SIC model to consider the atmospheric consequences of WEP, focusing on a case-study period. Previous studies have also shown that energetic particle precipitation can lead to large-scale changes in the chemical makeup of the neutral atmosphere by enhancing minor chemical species that play a key role in the ozone balance of the middle atmosphere. However, SIC modelling indicates that the neutral atmospheric changes driven by WEP are insignificant due to the short timescale of the WEP bursts. Overall we find that WEP is a significant energy input into some parts of the lower ionosphere, depending on the latitude/longitude and altitude, but does not play a significant role in the neutral chemistry of the mesosphere.

  19. Valence one-electron and shake-up ionisation bands of polycyclic aromatic hydrocarbons. IV. The dibenzanthracene species

    Energy Technology Data Exchange (ETDEWEB)

    Deleuze, Michael S. [Theoretische Chemie, Departement SBG, Universiteit Hasselt, Agoralaan, Gebouw D, B-3590 Diepenbeek (Belgium)], E-mail: michael.deleuze@uhasselt.be

    2006-10-26

    A comprehensive study of the He (I) ultra-violet photoelectron spectra of the 1.2,3.4; 1.2,5.6 and 1.2,7.8 isomers of dibenzanthracene up to the double ionisation threshold at {approx}18 eV is presented with the aid of one-particle Green's Function calculations performed using the outer-valence Green's Function (OVGF) approach and the third-order algebraic diagrammatic construction [ADC(3)] scheme, along with basis sets of improving quality. Suited extrapolations of the ADC(3) results for the one-electron energies characterising the {pi}-band system ({epsilon} {sub b} < 10 eV) to Dunning's correlation consistent basis set of triple zeta quality (cc-pVTZ) enable theoretical insights into HeI measurements which approach chemical accuracy (1 kcal/mol or 43.4 meV). In contrast, a confrontation of simulated spectral envelopes with high-resolution He I photoelectron spectra indicates that polycyclic aromatic molecules with sterically overcrowded bay regions are more susceptible to undergo vibronic coupling complications at the {sigma}-ionisation onset. OVGF/cc-pVDZ or OVGF/cc-pVTZ pole strengths smaller than 0.85 systematically corroborate a breakdown of the orbital (or one-electron) picture of ionisation at the ADC(3)/6-31G levels. The extent of shake-up bands is correspondingly related to topological, structural and magnetic criteria of aromaticity. Comparison is made with calculations of the lowest doublet-doublet excitation energies of the related radical cations, by means of time-dependent density functional theory (TDDFT)

  20. String pair production in non homogeneous backgrounds

    International Nuclear Information System (INIS)

    Bolognesi, S.; Rabinovici, E.; Tallarita, G.

    2016-01-01

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  1. String pair production in non homogeneous backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Bolognesi, S. [Department of Physics “E. Fermi” University of Pisa, and INFN - Sezione di Pisa,Largo Pontecorvo, 3, Ed. C, 56127 Pisa (Italy); Rabinovici, E. [Racah Institute of Physics, The Hebrew University of Jerusalem,91904 Jerusalem (Israel); Tallarita, G. [Departamento de Ciencias, Facultad de Artes Liberales,Universidad Adolfo Ibáñez, Santiago 7941169 (Chile)

    2016-04-28

    We consider string pair production in non homogeneous electric backgrounds. We study several particular configurations which can be addressed with the Euclidean world-sheet instanton technique, the analogue of the world-line instanton for particles. In the first case the string is suspended between two D-branes in flat space-time, in the second case the string lives in AdS and terminates on one D-brane (this realizes the holographic Schwinger effect). In some regions of parameter space the result is well approximated by the known analytical formulas, either the particle pair production in non-homogeneous background or the string pair production in homogeneous background. In other cases we see effects which are intrinsically stringy and related to the non-homogeneity of the background. The pair production is enhanced already for particles in time dependent electric field backgrounds. The string nature enhances this even further. For spacial varying electrical background fields the string pair production is less suppressed than the rate of particle pair production. We discuss in some detail how the critical field is affected by the non-homogeneity, for both time and space dependent electric field backgrouds. We also comment on what could be an interesting new prediction for the small field limit. The third case we consider is pair production in holographic confining backgrounds with homogeneous and non-homogeneous fields.

  2. Concerning background from calorimeter ports

    International Nuclear Information System (INIS)

    Digiacomo, N.J.

    1985-01-01

    Any detector system viewing a port or slit in a calorimeter wall will see, in addition to the primary particles of interest, a background of charged and neutral particles and photons generated by scattering from the port walls and by leakage from incompletely contained primary particle showers in the calorimeter near the port. The signal to noise ratio attainable outside the port is a complex function of the primary source spectrum, the calorimeter and port design and, of course, the nature and acceptance of the detector system that views the port. Rather than making general statements about the overall suitability (or lack thereof) of calorimeter ports, we offer here a specific example based on the external spectrometer and slit of the NA34 experiment. This combination of slit and spectrometer is designed for fixed-target work, so that the primary particle momentum spectrum contains higher momentum particles than expected in a heavy ion colliding beam environment. The results are, nevertheless, quite relevant for the collider case

  3. IBM-PC based data acquisition system for a laser enhanced ionisation spectrometer using a low cost GPIB card

    International Nuclear Information System (INIS)

    Sampath Kumar, R.; Ravindranath, S.V.G.

    1992-01-01

    An IBM-PC based data acquisition system has been developed for the existing laser enhanced ionisation spectrometer in the Division. Here the boxcar averager (type SR 250) which integrates the spectrometer output is interfaced to an IBM-PC, converted into a GPIB controller with the help of a locally available GPIB card, (Dynalog Micro Systems make PCL 848) through the GPIB port of the computer interface module (SR 245). The menu driven software developed in BASIC, triggers the scan in the dye laser through its control port, collects data from the spectrometer, plots, displays and stores it on the hard disc for further use. (author). 6 refs., 18 figs., 2 appendixes

  4. A TIME-OF-FLIGHT MASS SPECTROMETER FOR SIMS AND FIELD IONISED NEUTRAL ANALYSIS USING A PULSED LMIS

    OpenAIRE

    Waugh, A.; Kingham, D.; Richardson, C.; Goff, M.

    1987-01-01

    A new surface analysis instrument has been developed using an energy-compensated time-of-flight mass spectrometer. Samples are ionised for analysis either by microfocussed laser irradiation or by sputtering with a microfocussed (< 0.25 µm) mass-filtered beam of Ga+ ions from a liquid metal ion source. A framestore-based data system allows the simultaneous capture o f both SIMS mass spectra and mass-resolved ion images. Data are presented illustrating both SIMS and Laser Microprobe performance...

  5. LA SPECTROSCOPIE DE MASSE PAR IONISATION CHIMIQUE AVEC LA DIETHYLAMINE COMME GAZ REACTANT DES IRIDOIDES GLUCOSIDIQUES DE TYPE C-9

    Directory of Open Access Journals (Sweden)

    H SAADI

    2000-12-01

    Full Text Available Ce travail s’intéresse à l’étude de la spectrométrie de masse par ionisation chimique de quelques composés des iridoïdes glucosidiques de type C-9 extraits des plantes de l’espèce Euplantago en utilisant la diéthylamine comme gaz réactant. Nous avons appliqué la même technique que précédemment à deux d’entre eux se trouvant en abondance dans ce type de plantes, après leur acétylation.

  6. LA SPECTROSCOPIE DE MASSE PAR IONISATION CHIMIQUE AVEC LA DIETHYLAMINE COMME GAZ REACTANT DES IRIDOIDES GLUCOSIDIQUES DE TYPE C-9

    OpenAIRE

    H SAADI; Dj ZEGHOUGH; S.S POPOV

    2000-01-01

    Ce travail s’intéresse à l’étude de la spectrométrie de masse par ionisation chimique de quelques composés des iridoïdes glucosidiques de type C-9 extraits des plantes de l’espèce Euplantago en utilisant la diéthylamine comme gaz réactant. Nous avons appliqué la même technique que précédemment à deux d’entre eux se trouvant en abondance dans ce type de plantes, après leur acétylation.

  7. The ENEA calibration service for ionising radiations; Il centro di taratura per le radiazioni ionizzanti di Bologna. Parte 1: Fotoni

    Energy Technology Data Exchange (ETDEWEB)

    Monteventi, F.; Sermenghi, I. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1999-07-01

    The report describes all the facilities available at the the service of the ENEA Calibration Service for Ionising Radiations at Bologna (Italy). It gives a detailed description of all equipment qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters. [Italian] Il presente lavoro descrive i servizi e le attivita' del Centro di Taratura dell'ENEA di Bologna, in particolare delle attrezzature qualificate per la metrologia fotonica, dei campioni di misura e delle procedure adottate per la taratura degli strumenti e dei dosimetri.

  8. The report of the French Academy of Science: 'Problems associated with the effects of low doses of ionising radiation'

    International Nuclear Information System (INIS)

    Tubiana, M.

    1998-01-01

    In 1995 the French Academy of Science published a report on 'Problems associated with low doses of ionising radiation'. This report aroused interest among French-speaking scientists and a translation in English was published a year later. The report pointed out that an important issue in radioprotection was not whether to accept or reject the linear no-threshold model but rather to test its validity. The aim of this review is to analyse the report and its recommendations, and to briefly indicate the progress which has been made and the questions which remain open. Three areas of the report are covered in this review: DNA repair, carcinogenesis and epidemiological data. (author)

  9. Chemotaxonomy of bacteria by comprehensive GC and GC-MS in electron impact and chemical ionisation mode.

    Science.gov (United States)

    David, Frank; Tienpont, Bart; Sandra, Pat

    2008-10-01

    The analysis of the cellular lipidic fraction of bacteria is described. After hydrolysis and methylation, the fatty acid methyl esters (FAMEs) are determined by 1-D GC using the Sherlock MIDI bacteria identification system, by comprehensive GC (GC x GC) and by GC-MS in electron impact (EI) and positive chemical ionisation (PCI) mode. With GC x GC, the enhanced selectivity and group type separation provides a more complete elucidation of the fatty acids in microorganisms. GC-EI-MS and GC-PCI-MS were helpful for confirmation. The bacteria selected in this study are Brevundimonas diminuta, Chryseobacterium gleum and Stenotrophomonas maltophilia.

  10. Double spike methodology for uranium determination by thermal ionisation mass spectrometry: separation and purification of 234U

    International Nuclear Information System (INIS)

    Shah, P.M.; Saxena, M.K.; Sanjai Kumar; Aggarwal, S.K.; Jain, H.C.

    1995-01-01

    With an objective to prepare double spike of 233 U+ 234 U for determination of uranium concentration by Isotopic Dilution Thermal Ionisation Mass Spectrometry (ID-TIMS), 234 U was separated and purified from aged 238 Pu sample (15 years old) using several ion exchange and solvent extraction procedures. Final product containing 95% and 5% alpha activities of 234 and 238 Pu, respectively, which translates into 99.998 atom% of 234 U and 0.002 atom% of 238 Pu was found suitable for double spike. (author). 1 ref

  11. Mapping the gravitational wave background

    OpenAIRE

    Cornish, Neil J.

    2001-01-01

    The gravitational wave sky is expected to have isolated bright sources superimposed on a diffuse gravitational wave background. The background radiation has two components: a confusion limited background from unresolved astrophysical sources; and a cosmological component formed during the birth of the universe. A map of the gravitational wave background can be made by sweeping a gravitational wave detector across the sky. The detector output is a complicated convolution of the sky luminosity ...

  12. 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...

  13. WE-G-BRA-06: Calibrating an Ionisation Chamber: Gaining Experience Using a Dosimetry 'flight Simulator'.

    Science.gov (United States)

    Beavis, A; Saunderson, J; Ward, J

    2012-06-01

    Recently there has been great interest in the use of simulation training, with the view to enhance safety within radiotherapy practice. We have developed a Virtual Environment for Radiotherapy Training (VERT) which facilitates this, including the simulation of a number of 'Physics practices'. One such process is the calibration of an ionisation chamber for use in Linac photon beams. The VERT system was used to provide a life sized 3D virtual environment within which we were able to simulate the calibration of a departmental chamber for 6MV and 15 MV beams following the UK 1990 Code of Practice. The characteristics of the beams are fixed parameters in the simulation, whereas default (Absorbed dose to water) correction factors of the chambers are configurable thereby dictating their response in the virtual x-ray beam. When the simulation is started, a random, realistic temperature and pressure is assigned to the bunker. Measurement and chamber positional errors are assigned to the chambers. A virtual water phantom was placed on the Linac couch and irradiated through the side using a 10 × 10 field. With a chamber at the appropriate depths and irradiated iso-centrically, the Quality Indices (QI) of the beams were obtained. The two chambers were 'inter-compared', allowing the departmental chamber calibration factor to be calculated from that of the reference chamber. For the virtual 6/15 MV beams, the QI were found to be 0.668/ 0.761 and the inter-comparison ratios 0.4408/ 0.4402 respectively. The departmental chamber calibration factors were calculated; applying these and appropriate environmental corrections allowed the output of the Linac to be confirmed. We have shown how a virtual training environment can be used to demonstrate practical processes and reinforce learning. The UK CoP was used here, however any relevant protocol could be demonstrated. Two of the authors (Beavis and Ward) are Founders of Vertual Ltd, a spin-out company created to commercialise the

  14. Derivation of hazardous doses for amphibians acutely exposed to ionising radiation

    International Nuclear Information System (INIS)

    Fuma, Shoichi; Watanabe, Yoshito; Kawaguchi, Isao; Takata, Toshitaro; Kubota, Yoshihisa; Ban-nai, Tadaaki; Yoshida, Satoshi

    2012-01-01

    Derivation of effect benchmark values for each taxonomic group, which has been difficult due to lack of experimental effects data, is required for more adequate protection of the environment from ionising radiation. Estimation of effects doses from nuclear DNA mass and subsequent species sensitivity distribution (SSD) analysis were proposed as a method for such a derivation in acute irradiation situations for assumed nuclear accident scenarios. As a case study, 5% hazardous doses (HD 5 s), at which only 5% of species are acutely affected at 50% or higher lethality, were estimated on a global scale. After nuclear DNA mass data were obtained from a database, 50% lethal doses (LD 50 s) for 4.8 and 36% of the global Anura and Caudata species, respectively, were estimated by correlative equations between nuclear DNA mass and LD 50 s. Differences between estimated and experimental LD 50 s were within a factor of three. The HD 5 s obtained by the SSD analysis of these estimated LD 50 s data were 5.0 and 3.1 Gy for Anura and Caudata, respectively. This approach was also applied to the derivation of regional HD 5 s. The respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan. This HD 5 value for the Japanese Anura was significantly higher than the global value, while Caudata had no significant difference in global and Japanese HD 5 s. These results suggest that this approach is also useful for derivation of regional benchmark values, some of which are likely different from the global values. - Highlights: ► A possible method was proposed for derivation of an effect benchmark value for each taxonomic group. ► 50% lethal doses were estimated from nuclear DNA mass in amphibian species. ► 5% hazardous doses (HD 5 s) were estimated by species sensitivity distribution. ► Respective HD 5 s were 5.0 and 3.1 Gy for Anura and Caudata globally. ► Respective HD 5 s were 6.5 and 3.2 Gy for Anura and Caudata inhabiting Japan.

  15. Proposal for a Graded Authorisation Model for the Use of Ionising Radiation in Ireland

    International Nuclear Information System (INIS)

    2012-10-01

    The Radiological Protection Institute of Ireland RPII intends to refocus, streamline and modernise its regulation of the use of ionising radiation in Ireland. This report provides detailed proposals for establishing a graded approach to authorisation in which regulators will be able to focus on higher risk practices by simplifying requirements placed on those of lower risk, without compromising the safety or security of the Irish population. These proposals build on RPII strategic analyses that seek to navigate a course between the competing pressures of public sector reform and the rapid technological changes in medical and nuclear arenas, which challenge the licensing and advisory functions of RPII. A graded approach to authorisation provides the potential for a sustainable basis for future regulation in Ireland. Such an approach would be in line with the forthcoming EURATOM Basic Safety Standards and with general current regulatory trends, which are moving away from one-size-fits-all approaches towards more adaptive, interactive and transparent regulation. In seeking this reform, the RPII also aims to fully utilize the benefits of the internet and electronic communications and to improve the transparency of its processes. These proposals have been developed using a robust, comprehensive project methodology involving a root and branch analysis of current and potential future approaches to authorisation. A series of facilitated workshops were held, punctuated by intensive periods of focused co-enquiry, involving all members of the RPII Regulatory Service. This approach made the fullest use of the decades of expertise and knowledge of these staff. It also provided the platform for developing a common vision of a graded approach to authorisation; for agreeing the criteria for differentiating between levels of authorisation; for collecting the necessary evidence for decision-making and for identifying the implications of these decisions. The graded approach presented

  16. Investigation of cellular signalling responses to non-ionising radiation in melanocytes by microarray analysis

    International Nuclear Information System (INIS)

    Boyle, G.M.; Pedley, J.; Martyn, A.C.; Fraser, L.M.; Banducci, K.J.; Parsons, P.G.; Breit, S.N.

    2003-01-01

    Melanoma is a highly aggressive cancer resulting from the abnormal proliferation and spread of specialised pigment cells in the skin, known as melanocytes. Extensive epidemiological and molecular evidence suggests that a major risk factor for melanoma formation is exposure to non-ionising radiation in the form of solar ultra-violet (UV) light. However, the exact role of solar UV in the development of melanoma is unclear. To elucidate the molecular events that occur in melanocytes following solar UV exposure and determine how they lead to melanoma development, cDNA microarray analysis was used to analyse the gene expression profile of normal melanocytes, melanocytes exposed to simulated solar UV and melanoma cells. The development of cDNA microarray technology has allowed gene expression profiling at the mRNA level to be conducted for many thousands of genes simultaneously by hybridising an array of known sequences with labelled cDNA reverse transcribed form the sample RNA. Gene expression analysis was performed for over 13,000 genes. More than 500 genes were identified as differentially expressed in melanocytes following a single UV exposure, although overall there was a general suppression of transcription. Genes that were up-regulated included oncogenes and cytoskeletal genes; in contrast, genes encoding protein tyrosine kinases and apoptosis effectors were down-regulated. Many of the genes identified as being differentially expressed represent novel UV-regulated targets. Repeated exposure to solar UV resulted in the elevation in expression of a novel member of the transforming growth factor-b (TGF-b) superfamily, the Macrophage Inhibitory Cytokine-1 (MIC-1). Our results have shown that MIC-1 is up-regulated by solar UV in melanocytes, and is highly expressed (>3 fold) in a number of metastatic melanoma cell lines (31/61) in comparison to primary melanocytes. Furthermore functional, dimerised MIC-1 was found to be secreted by melanocytes, and secreted levels were

  17. Radiation gamma-background at Kurtovo resort

    International Nuclear Information System (INIS)

    Miloslavov, V.

    2000-01-01

    This report presents the difference between the measured values of the radiation gamma-background at Kurtovo resort (located at Rila National Park). The measurements are comparative and are carried out together with the Institute for Nuclear Research (Sofia) and various equipment from the National Center of Radiobiology and Radiation Protection (Sofia). Obtained results are compared according to the precessing method. The advantages of the method for real-time computer precessing of the flowing experimental data on the values of the natural gamma-background are underlined, including the use for early detection of dose increase, due to technological dose implements

  18. Hanford Site background: Part 1, Soil background for nonradioactive analytes. Revision 1, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Indian Academy of Sciences (India)

    tribpo

    10I 7 cm 2 and 101 9 cm 2 for (i) spectral shape as given by HM96 for a redshift of. 2.5, (ii) galactic spectra as taken from Bruzal (1983) and (iii) a combination of .... Note that all the absorption systems are sufficiently far away from the respective .... galaxy fail to yield a result as the column density ratios of Si and Fe can not.

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

    Indian Academy of Sciences (India)

    tribpo

    Taking the AGN flux to be that given by HM96 for z = 2.5, and additional flux from the galaxies, the observed column density ratios can not be explained and a minimum flux of. 9.4 ×10. 5 from the AGN is required, needing a total of -2.9 > log > —3.1, giving 1.6 ×10. 6<. G <2.3 ×10. 8 . Note that the Al II to Al ΙΠ ratio can not,.

  1. Leaf Anatomy and Photochemical Behaviour of Solanum lycopersicum L. Plants from Seeds Irradiated with Low-LET Ionising Radiation

    Directory of Open Access Journals (Sweden)

    V. De Micco

    2014-01-01

    Full Text Available Plants can be exposed to ionising radiation not only in Space but also on Earth, due to specific technological applications or after nuclear disasters. The response of plants to ionising radiation depends on radiation quality/quantity and/or plant characteristics. In this paper, we analyse some growth traits, leaf anatomy, and ecophysiological features of plants of Solanum lycopersicum L. “Microtom” grown from seeds irradiated with increasing doses of X-rays (0.3, 10, 20, 50, and 100 Gy. Both juvenile and compound leaves from plants developed from irradiated and control seeds were analysed through light and epifluorescence microscopy. Digital image analysis allowed quantifying anatomical parameters to detect the occurrence of signs of structural damage. Fluorescence parameters and total photosynthetic pigment content were analysed to evaluate the functioning of the photosynthetic machinery. Radiation did not affect percentage and rate of seed germination. Plants from irradiated seeds accomplished the crop cycle and showed a more compact habitus. Dose-depended tendencies of variations occurred in phenolic content, while other leaf anatomical parameters did not show distinct trends after irradiation. The sporadic perturbations of leaf structure, observed during the vegetative phase, after high levels of radiation were not so severe as to induce any significant alterations in photosynthetic efficiency.

  2. Modelling the tongue-of-ionisation using CTIP with SuperDARN electric potential input: verification by radiotomography

    Directory of Open Access Journals (Sweden)

    S. E. Pryse

    2009-03-01

    Full Text Available Electric potential patterns obtained by the SuperDARN radar network are used as input to the Coupled Thermosphere-Ionosphere-Plasmasphere model, in an attempt to improve the modelling of the spatial distribution of the ionospheric plasma at high latitudes. Two case studies are considered, one under conditions of stable IMF Bz negative and the other under stable IMF Bz positive. The modelled plasma distributions are compared with sets of well-established tomographic reconstructions, which have been interpreted previously in multi-instrument studies. For IMF Bz negative both the model and observations show a tongue-of-ionisation on the nightside, with good agreement between the electron density and location of the tongue. Under Bz positive, the SuperDARN input allows the model to reproduce a spatial plasma distribution akin to that observed. In this case plasma, unable to penetrate the polar cap boundary into the polar cap, is drawn by the convective flow in a tongue-of-ionisation around the periphery of the polar cap.

  3. Modelling the tongue-of-ionisation using CTIP with SuperDARN electric potential input: verification by radiotomography

    Directory of Open Access Journals (Sweden)

    S. E. Pryse

    2009-03-01

    Full Text Available Electric potential patterns obtained by the SuperDARN radar network are used as input to the Coupled Thermosphere-Ionosphere-Plasmasphere model, in an attempt to improve the modelling of the spatial distribution of the ionospheric plasma at high latitudes. Two case studies are considered, one under conditions of stable IMF Bz negative and the other under stable IMF Bz positive. The modelled plasma distributions are compared with sets of well-established tomographic reconstructions, which have been interpreted previously in multi-instrument studies. For IMF Bz negative both the model and observations show a tongue-of-ionisation on the nightside, with good agreement between the electron density and location of the tongue. Under Bz positive, the SuperDARN input allows the model to reproduce a spatial plasma distribution akin to that observed. In this case plasma, unable to penetrate the polar cap boundary into the polar cap, is drawn by the convective flow in a tongue-of-ionisation around the periphery of the polar cap.

  4. Radio-oxidation of an EPDM elastomer under weak or strong ionising radiations: measurement and modelling of dioxygen consumption

    International Nuclear Information System (INIS)

    Dely, N.

    2005-10-01

    Usually, the irradiation of polymers under ionising radiations occurs in air that is in the presence of oxygen. This leads to a radio oxidation process and to oxygen consumption. Our material is an EPDM elastomer (ethylene propylene 1,4 hexadiene) used as insulator in control-command cables in nuclear plants (Pressurised Water Reactor). A specific device has been conceived and built up during this PhD work for measuring very small oxygen consumptions with an accuracy of around 10%. Ionising radiations used are electrons at 1 MeV and carbon ions at 11 MeV per nucleon. Under both electron and ion irradiations, the influence of oxygen pressure on oxygen consumption has been studied in a very large range: between 1 and 200 mbar. In both cases, the yield of oxygen consumption is constant in-between 200 and 5 mbar. Then, at lower pressures, it decreases appreciably. On the other hand, the oxygen consumption during ion irradiation is four times smaller than during electron irradiation. This emphasizes the role of the heterogeneity of the energy deposition at a nano-metric scale. The adjustment of the experimental results obtained during electron irradiation with the general homogeneous steady-state kinetic model has allowed extracting all the values of the kinetic parameters for the chosen mechanism of radio oxidation. The knowledge of these numbers will allow us to face our results obtained during ion irradiation with a heterogeneous kinetic model under development. (author)

  5. Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

    Science.gov (United States)

    Demeter, S; Applegate, K E; Perez, M

    2016-06-01

    The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations. © The International Society for Prosthetics and Orthotics.

  6. Solvent Separating Secondary Metabolites Directly from Biosynthetic Tissue for Surface-Assisted Laser Desorption Ionisation Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    David Rudd

    2015-03-01

    Full Text Available Marine bioactive metabolites are often heterogeneously expressed in tissues both spatially and over time. Therefore, traditional solvent extraction methods benefit from an understanding of the in situ sites of biosynthesis and storage to deal with heterogeneity and maximize yield. Recently, surface-assisted mass spectrometry (MS methods namely nanostructure-assisted laser desorption ionisation (NALDI and desorption ionisation on porous silicon (DIOS surfaces have been developed to enable the direct detection of low molecular weight metabolites. Since direct tissue NALDI-MS or DIOS-MS produce complex spectra due to the wide variety of other metabolites and fragments present in the low mass range, we report here the use of “on surface” solvent separation directly from mollusc tissue onto nanostructured surfaces for MS analysis, as a mechanism for simplifying data annotation and detecting possible artefacts from compound delocalization during the preparative steps. Water, ethanol, chloroform and hexane selectively extracted a range of choline esters, brominated indoles and lipids from Dicathais orbita hypobranchial tissue imprints. These compounds could be quantified on the nanostructured surfaces by comparison to standard curves generated from the pure compounds. Surface-assisted MS could have broad utility for detecting a broad range of secondary metabolites in complex marine tissue samples.

  7. Assessing the surroundings for effects of ionising radiation on the granting of permits, DOVIS A. Emissions to air and water

    CERN Document Server

    Blaauboer, R O

    2002-01-01

    In the Netherlands, as in most other countries, one generally needs a permit to produce (including the manufacture, processing, control and storage), to apply or to dispose of radioactive materials, or to use equipment that produces ionising radiation. This permit must be in accordance with the Nuclear Energy Act. Limits that are set for radioactive material can be found in the Decree on radiation protection ('Besluit stralings-bescherming') which has been in force since March 1, 2002. Along with the application for a permit, calculation results have to be submitted on the radiation dose that members of the public receive as a consequence of (possible) emissions of radioactive material (into the atmosphere or surface water) or as a consequence of external irradiation. Fairly rough estimates, based on simple rules, will often be satisfactory. These rules can be found in an annex of a Ministerial Order on the assessment of consequences of ionising radiation (mr-AGIS). However, in some cases this will not be ade...

  8. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    Corey Piccioni

    Saharan Africa at US$4 billion per year for grains alone (World Bank, 2010). Considerable scope exists for research to find effecve ways to reduce food losses while increasing returns through product quality control, market segmentaon,.

  9. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Center for Mountain Ecosystem Studies, Kunming Institute of Botany of the Chinese Academy of Sciences, China: $1,526,000 to inform effective water governance in the Asian highlands of China, Nepal, and Pakistan. • Ashoka Trust for Research in Ecology and the Environment (ATREE), India: $1,499,300 for research on ...

  10. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    particularly in urban areas and emerging hunger hotspots. Migration caused by the ... Deltas: Deltas in Africa and South Asia are some of the world's most vulnerable coastal areas because of a critical combination ... rise and land subsidence persist, 5.4 million people in Africa and Asia might be displaced by 2050:. 93% live.

  11. Backgrounder

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    inequalities, and poverty based on rigorous data collection and analysis. ... at how poor urban planning may be contributing to forced evictions and mass relocations, which in turn can lead to violence in the form of ... communities with similar conditions of social exclusion experience different levels of violence. The study will.

  12. BACKGROUNDER

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC CRDI

    Through this initiative, four consortia will conduct research in three “hot spots” – regions where demographic trends, socio-economic development pathways, and strong climate signals put large numbers of people and their livelihoods at risk: semi-arid regions, deltas, and Himalayan river basins. The initiative brings ...

  13. Study on the influence of the B4C layer thickness on the neutron flux and energy distribution shape in multi-electrode ionisation chamber.

    Science.gov (United States)

    Tymińska, K; Maciak, M; Ośko, J; Tulik, P; Zielczyński, M; Gryziński, M A

    2014-10-01

    A model of a multi-electrode ionisation chamber, with polypropylene electrodes coated with a thin layer of B4C was created within Monte Carlo N-Particle Transport Code (MCNPX) and Fluktuierende Kaskade (FLUKA) codes. The influence of the layer thickness on neutron absorption in B4C and on the neutron spectra in the consecutive intra-electrode gas volumes has been studied using the MCNPX and FLUKA codes. The results will be used for designing the new type of the ionisation chamber. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. Background Rejection in the ARA Experiment

    Directory of Open Access Journals (Sweden)

    Pfendner Carl

    2017-01-01

    Full Text Available The Askaryan Radio Array (ARA is a radio frequency observatory under construction at the South Pole that is searching for ultrahigh energy neutrinos via the Askaryan effect. Thermal fluctuations currently dominate the trigger-level background for the observatory and anthropogenic sources also introduce a significant source of noise. By taking advantage of the observatory’s regular geometry and the expected coincident nature of the RF signals arriving from neutrino-induced events, this background can be filtered efficiently. This contribution will discuss techniques developed for the ARA analyses to reject these thermal signals, to reject anthropogenic backgrounds, and to search for neutrino-induced particle showers in the Antarctic ice. The results of a search for neutrinos from GRBs using the prototype station using some of these techniques will be presented.

  15. Socialcultural background of formation of classical metaphysics

    OpenAIRE

    I. Z. Derzhko

    2014-01-01

    The classical model of philosophy has shaped ideas about its nature and aims that were laid in ancient metaphysics, but have been substantially amended by civilizational change. Socialcultural background of philosophy became trends that began to emerge in late medieval culture has particularly flourished there during modern times. Sphere of existence is important for the development of any spiritual phenomenon. For metaphysics it is the idea of humanity, acting as a kind of cultural protest a...

  16. Background subtraction theory and practice

    CERN Document Server

    Elgammal, Ahmed

    2014-01-01

    Background subtraction is a widely used concept for detection of moving objects in videos. In the last two decades there has been a lot of development in designing algorithms for background subtraction, as well as wide use of these algorithms in various important applications, such as visual surveillance, sports video analysis, motion capture, etc. Various statistical approaches have been proposed to model scene backgrounds. The concept of background subtraction also has been extended to detect objects from videos captured from moving cameras. This book reviews the concept and practice of back

  17. 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.

  18. Field studies on long term ecosystem consequences of ionising radiation and chemical pollutants (EANOR Project)

    Energy Technology Data Exchange (ETDEWEB)

    Oughton, D. [Centre for Environmental Radioactivity - CERAD (Norway); Evseeva, T. [Institute of Biology RAS (Russian Federation); Erenturk, S. [Istanbul Technical University (Turkey)

    2014-07-01

    -barcoding, invertebrate DNA barcoding, DNA methylation, and other molecular endpoints is ongoing, together with studies of possible adaptation of plants, invertebrates and microorganisms. Preliminary results show significant differences in diversity for many species between contaminated and reference sites. However, more research is needed to draw conclusions about the cause of such observations. Nevertheless, by combining a through site characterisation and exposure assessment with a variety of ecologically relevant biomarker and endpoint measurements, the data produced should be a valuable contribution to international activities looking at the impacts of chronic exposure of ionising radiation on non-human species. Project participants: Elena Belykh, Anna Kaneva, Boris Kondratenok, Alla Kolesnikova, Alexey Kurdin, Tatinana Majstrenko, Taskayeva Anastasia Oleshya Vakhrusheva, Illa Velegzhaninov, Vladimir Zainullin (IoB, Komi Republic, Russia); S. Haciyakupoglu (Istanbul Technical University, Turkey); Rahime Oral, Sabriye Yusan, Filiz Gur Filiz (Ege University, Turkey); Murat Belivermis, Onder Kilic (Istanbul University, Turkey); Fatma Kocbas (Celal Bayar University, Turkey); Mustafa Akiner, (Rize University, Turkey); Claire Coutris, Erik Joner (Bioforsk, Norway); Turid Hertel-Aas, Emmanuel Lapied, Yevgeniya Tomkiv, Brit Salbu, Lindis Skipperud (Centre for Environmental Radioactivity, UMB, Norway). Document available in abstract form only. (authors)

  19. Application of stable isotopes (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4,} δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}) to determine natural background and contamination sources in the Guadalhorce River Basin (southern Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Urresti-Estala, Begoña, E-mail: b.urresti@uma.es [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain); Vadillo-Pérez, Iñaki; Jiménez-Gavilán, Pablo [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain); Soler, Albert [Grup de Mineralogia Aplicada i Medi Ambient, Fac. Geologia, Universitat de Barcelona, Barcelona (Spain); Sánchez-García, Damián; Carrasco-Cantos, Francisco [Universidad de Málaga, Facultad de Ciencias, Grupo de Geodinámica Externa, Campus de Teatinos s/n, 29071 Málaga (Spain)

    2015-02-15

    The integrated use of isotopes (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4,} δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}), taking into account existing hydrogeological knowledge of the study area (mainly hydrochemical), was applied in the Guadalhorce River Basin (southern Spain) to characterise SO{sub 4}{sup 2−} and NO{sub 3}{sup −} sources, and to quantify natural background levels (NBLs) in groundwater bodies. According to Water Framework Directive 2000/60/EC and, more recently, Groundwater Directive 2006/118/EC, it is important to determine NBLs, as their correct assessment is the first, essential step to characterising groundwater bodies, establishing threshold values, assessing chemical status and identifying trends in pollutant concentrations. In many cases, NBLs are high for some parameters and types of groundwater, making it difficult to distinguish clearly between factors of natural or human origin. The main advantages of using stable isotopes in a complex area like the Guadalhorce River Basin that exhibits widely varying hydrogeological and hydrochemical conditions and longstanding anthropogenic influences (mainly agriculture, but also many others) is accurate determination of pollution sources and precise quantification of NBLs. Since chemical analyses only provides the concentration of pollutants in water and not the source, three isotopic sampling campaigns for sulphates (δ{sup 34}S-SO{sub 4}, δ{sup 18}O-SO{sub 4}) were carried out, in 2006, 2007 and 2012, and another one was conducted for nitrates (δ{sup 15}N-NO{sub 3}, δ{sup 18}O-NO{sub 3}), in 2009, in groundwater bodies in order to trace the origins of each pollutant. The present study identified different pollution sources of dissolved NO{sub 3}{sup −} in groundwater using an isotopic composition and quantified the percentage of natural (lithology, chemical and biological processes) and anthropogenic (fertilisers, manure and sewage) SO{sub 4}{sup 2−} and matched a concentration

  20. 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)

  1. Gene expression profiling of PBL in response to ionising radiation and modeled microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — BACKGROUND: Ionizing radiation (IR) can be extremely harmful for human cells since an improper DNA-damage response (DDR) to IR can contribute to carcinogenesis...

  2. Identification of miRNAs involved in cell response to ionising radiation and modeled microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — BACKGROUND: Ionizing radiation (IR) can be extremely harmful for human cells since an improper DNA-damage response (DDR) to IR can contribute to carcinogenesis...

  3. Children of ethnic minority backgrounds

    DEFF Research Database (Denmark)

    Johansen, Stine Liv

    2010-01-01

    Children of ethnic minority background balance their everyday life between a cultural background rooted in their ethnic origin and a daily life in day care, schools and with peers that is founded in a majority culture. This means, among other things, that they often will have access to different ...

  4. DNA damaging by ionising radiations. Influence of the structure and of the environment; Degradation de l'ADN par les rayonnements ionisants. Influence de la structure et de l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Spotheim-Maurizot, M. [Institut National de la Sante et de la Recherche Medicale (INSERM), 45 - Orleans (France); Begusova, M. [Institut de Physique Nucleaire de Prague, Dept. de Dosimetrie des Radiations (Czech Republic); Charlier, M. [Centre National de la Recherche Scientifique (CNRS), Centre de Biophysique Moleculaire, 45 - Orleans-la-Source (France)

    2003-12-01

    DNA damaging by ionising radiations. Influence of the structure and of the environment. DNA which bears the genetic information of the cell is the critical target for radiolytic attack. In the nucleus, DNA is not a straight and naked double helix in B-form. The sequence of the bases, the topological stress, the interactions with other partners (proteins) induce structures different from the canonical B-form. The effects of radiations occur through the attack by radicals issued from water radiolysis. The most reactive one is the oxidative hydroxyl radical. The radiolytic process is a chemical process in which both reactivity and accessibility of reactive sites, and consequently the structure of DNA, are involved. We have developed a simulation code to calculate the hydroxyl radical attack of different DNA structures. This procedure uses structural data obtained by either NMR, crystallography or molecular modelling, and accurately fits the experimental results. (author)

  5. The Spatial Distribution of Alkaloids in Psychotria prunifolia (Kunth) Steyerm and Palicourea coriacea (Cham.) K. Schum Leaves Analysed by Desorption Electrospray Ionisation Mass Spectrometry Imaging

    DEFF Research Database (Denmark)

    Kato, Lucilia; Moraes, Aline Pereira; de Oliveira, Cecília Maria Alves

    2018-01-01

    INTRODUCTION: Species of the genera Psychotria and Palicourea are sources of indole alkaloids, however, the distribution of alkaloids within the plants is not known. Analysing the spatial distribution using desorption electrospray ionisation mass spectrometry imaging (DESI-MSI) has become attract...

  6. The Swedish radiation protection institute's regulations on general obligations in medical and dental practices using ionising radiation; issued on April 28, 2000

    International Nuclear Information System (INIS)

    2000-04-01

    These regulations are applicable to medical and dental practices with ionising radiation used for medical exposures. The regulations are also applicable to exposures of persons who knowingly and willingly, other than as part of their occupation, support and comfort patients undergoing medical exposure

  7. Dégradation de lŽADN par les rayonnements ionisants. Influence de la structure et de lŽenvironnement

    Czech Academy of Sciences Publication Activity Database

    Maurizot, M.; Běgusová, Marie

    11-12 (2003), s. 97-102 ISSN 0151-9093 R&D Projects: GA AV ČR IAA1048103 Institutional research plan: CEZ:AV0Z1048901 Keywords : DNA * ionising radiations * hydroxyl radical Subject RIV: BO - Biophysics Impact factor: 0.112, year: 2003

  8. The Swedish radiation protection institute's regulations on general obligations in medical and dental practices using ionising radiation; issued on April 28, 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-01

    These regulations are applicable to medical and dental practices with ionising radiation used for medical exposures. The regulations are also applicable to exposures of persons who knowingly and willingly, other than as part of their occupation, support and comfort patients undergoing medical exposure.

  9. Isotopic analysis of neodymium in a granite rock sample in presence of samarium and cerium by thermal ionisation mass spectrometry (TIMS)

    International Nuclear Information System (INIS)

    Rao, Radhika M.; Ramakumar, K.L.; Aggarwal, S.K.; Jain, H.C.

    1996-01-01

    Present investigations are directed towards looking into the possibility adopting a standardised procedure for measuring isotopic composition of Nd in a granite sample in presence of Sm and Ce employing a thermal ionisation mass spectrometry (TIMS) instrument with a variable multi-collection detector system

  10. Characterisation of chemical components for identifying historical Chinese textile dyes by ultra high performance liquid chromatography – photodiode array – electrospray ionisation mass spectrometer

    NARCIS (Netherlands)

    Han, J.; Wanrooij, J.; van Bommel, M.; Quye, A.

    2017-01-01

    This research makes the first attempt to apply Ultra High Performance Liquid Chromatography (UHPLC) coupled to both Photodiode Array detection (PDA) and Electrospray Ionisation Mass Spectrometer (ESI–MS) to the chemical characterisation of common textile dyes in ancient China. Three different

  11. Ion suppression in the determination of clenbuterol in urine by solid-phase extraction atmospheric pressure chemical ionisation ion-trap mass spectrometry

    NARCIS (Netherlands)

    van Hout, M.W.J.; Niederlander, H.A G; de Zeeuw, R.A.; de Jong, G.J.

    2003-01-01

    Ion suppression effects were observed during the determination of clenbuterol in urine with solid-phase extraction/multiple-stage ion-trap mass spectrometry (SPE/MS3), despite the use of atmospheric pressure chemical ionisation. During SPE, a polymeric stationary phase (polydivinylbenzene) was

  12. The Cosmic Infrared Background Experiment

    OpenAIRE

    Bock, James; Battle, John; Cooray, Asantha; Kawada, Mitsunobu; Keating, Brian; Lange, Andrew; Lee, Dae-Hea; Matsumoto, Toshio; Matsuura, Shuji; Pak, Soojong; Renbarger, Tom; Sullivan, Ian; Tsumura, Kohji; Wada, Takehiko; Watabe, Toyoki

    2005-01-01

    We are developing a rocket-borne instrument (the Cosmic Infrared Background ExpeRiment, or CIBER) to search for signatures of primordial galaxy formation in the cosmic near-infrared extra-galactic background. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The cameras will search for spatial fluctuations in the background on angular scales from 7 arcseconds to 2 degrees over a range of angular sca...

  13. Matrix-assisted laser desorption/ionisation mass spectrometry imaging and its development for plant protein imaging

    Directory of Open Access Journals (Sweden)

    Millar A Harvey

    2011-07-01

    Full Text Available Abstract Matrix-Assisted Laser Desorption/Ionisation (MALDI mass spectrometry imaging (MSI uses the power of high mass resolution time of flight (ToF mass spectrometry coupled to the raster of lasers shots across the cut surface of tissues to provide new insights into the spatial distribution of biomolecules within biological tissues. The history of this technique in animals and plants is considered and the potential for analysis of proteins by this technique in plants is discussed. Protein biomarker identification from MALDI-MSI is a challenge and a number of different approaches to address this bottleneck are discussed. The technical considerations needed for MALDI-MSI are reviewed and these are presented alongside examples from our own work and a protocol for MALDI-MSI of proteins in plant samples.

  14. The detection of piroxicam, tenoxicam and their metabolites in equine urine by electrospray ionisation ion trap mass spectrometry.

    Science.gov (United States)

    McKinney, Andrew R; Suann, Craig J; Stenhouse, Allen M

    2004-01-01

    An investigation has been conducted into the metabolism and urinary excretion of orally administered piroxicam and tenoxicam in the horse. The major component detected in urine after the administration of piroxicam was 5'-hydroxypiroxicam, which was detectable up to 24 h post-administration. Unchanged piroxicam was present only as a minor component. In contrast, unchanged tenoxicam was the major component observed after the administration of tenoxicam, being detectable for 72 h post-administration, while 5'-hydroxytenoxicam was a minor component. Phase II beta-glucuronide conjugation in each case was found to be negligible. The ion trap mass spectral characteristics of piroxicam, tenoxicam, 5'-hydroxypiroxicam and 5'-hydroxytenoxicam under electrospray ionisation conditions were examined in some detail. Copyright 2004 John Wiley & Sons, Ltd.

  15. Fourth IRMF comparison of calibrations of portable gamma-ray dose- rate monitors 2001-2002 Ionising radiation

    CERN Document Server

    Lewis, V E

    2002-01-01

    The Ionising Radiations Metrology Forum (IRMF) organised a fourth comparison of calibrations of gamma-ray dose-rate monitors in which fifteen establishments in the UK participated. The exercise involved the circulation of three gamma-ray monitors for calibration in the fields produced using sup 1 sup 3 sup 7 Cs, sup 2 sup 4 sup 1 Am and sup 6 sup 0 Co. The instruments used were an Electra with MC 20 probe, a Mini-Instruments Mini-rad 1000 and a Siemens electronic personal dosemeter Mk 2 (EPD). The responses relative to 'true' dose equivalent rate were calculated by the individual participants and submitted to the for analysis along with details of the facilities and fields employed. Details of the estimated uncertainties were also reported. The results are compared and demonstrate generally satisfactory agreement between the participating establishments. However, the participants' treatment of uncertainties needs improvement and demonstrates a need for guidance in this area.

  16. Method for determining the irradiation dose deposited in a scintillator by ionising radiation and associated device - WO 2013060745 A1

    International Nuclear Information System (INIS)

    2013-01-01

    The invention relates to a method for determining an irradiation dose deposited in a scintillator (5) by ionising radiation, said method comprising the steps of: irradiating the scintillator (5) for a pre-determined time; detecting an instant at which the scintillator (5) is excited, using a first photodetector (11); subsequently, detecting an instant at which a scintillation photon is received, using a second photodetector (14) operating in single photon counting mode; identifying each sequence formed by the detection of an excitation instant by the first photodetector (11) and the detection of a reception instant by the second photodetector (14) at a coincidence event; counting the number of coincidence events; and obtaining the irradiation dose deposited during the irradiation time as a function of the number of coincidence events counted and a pre-determined proportionality factor. (authors)

  17. Microscopical examination: the impact of different ionising radiation doses over protective clothing used in the operating theatre

    International Nuclear Information System (INIS)

    Abreu, M.J.; Cabec Silva, M.E.; Schacher, L.; Adolphe, D.

    2004-01-01

    The goals to be pursued by this paper are to highlight the effect of different ionising radiation methods, considered low temperature sterilisation, over protective clothing (surgical gowns) used in the operating theatre through microscopical examination. In order to investigate the influence of the radiation on the properties of nonwoven-based surgical gowns, two types of radiation (gamma and electron beam radiation) were considered in this study. The scanning electron microscope (SEM) is widely used in studies of polymers, although for this kind of nonwoven based structures, that goes through sterilisation treatments it isn't commonly used. So, this paper also intends to relate the results of the evaluation of comfort and barrier properties after irradiated at several doses in a range from 0 to 160 kGy. (orig.)

  18. An overview of the ERICA Integrated Approach to the assessment and management of environmental risks from ionising contaminants

    International Nuclear Information System (INIS)

    Larsson, Carl-Magnus

    2008-01-01

    The ERICA project (environmental risks from ionising contaminants: assessment and management, EC contract no. FI6R-CT-2004-508847) concluded with the publication of two main outputs: the ERICA Integrated Approach to the assessment and management of environmental risks from ionising radiation, of which also introduces the user to the second main output, the ERICA Tool, which is a software programme with supporting databases, that together with its associated help will guide users through the assessment process. More than 60 European scientists contributed to the ERICA Integrated Approach. In addition, a large number of experts, policy makers, and decision-makers in different areas have contributed views on the ERICA Integrated Approach and its associated Tool from the user's perspective, through participation in the End-Users Group set up under the ERICA project. Databases on transfer, dose conversion coefficients and radiation effects on biota have been developed specifically for the purpose of the Integrated Approach, and incorporated into, or interacting with, the Tool. Species sensitivity distributions of biological effects data have been performed and did not reveal, for chronic exposure, any statistical grounds for separation between terrestrial, marine and freshwater ecosystems in terms of species sensitivity to radiation; on the basis of such analysis a universal screening dose rate criterion of 10 μGy h -1 incremental dose rate is suggested for exiting the assessment procedure while being confident that environmental risks are negligible. This criterion is used for the two first tiers (conservative assessment with limited data requirement and various possibilities of incorporating user-defined parameter values, including the screening dose rate criterion) of the assessment methodology. Exposure situations of concern are carried through a third tier, making use of all relevant databases and with a number of issues and options listed to support and guide

  19. Berkeley Low Background Counting Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Sensitive low background assay detectors and sample analysis are available for non-destructive direct gamma-ray assay of samples. Neutron activation analysis is also...

  20. Botanical Dietary Supplements: Background Information

    Science.gov (United States)

    ... Office of Dietary Supplements Health Professional Other Resources Botanical Dietary Supplements Background Information Have a question? Ask ... on botanical dietary supplements? Disclaimer What is a botanical? A botanical is a plant or plant part ...

  1. Cosmic microwave background, where next?

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Ground-based, balloon-borne and space-based experiments will observe the Cosmic Microwave Background in greater details to address open questions about the origin and the evolution of the Universe. In particular, detailed observations the polarization pattern of the Cosmic Microwave Background radiation have the potential to directly probe physics at the GUT scale and illuminate aspects of the physics of the very early Universe.

  2. Measurement of small ion beams by thermal ionisation mass spectrometry using new 1013 Ohm resistors

    International Nuclear Information System (INIS)

    Koornneef, J.M.; Bouman, C.; Schwieters, J.B.; Davies, G.R.

    2014-01-01

    Highlights: • First data are presented using 10 13 Ohm resistors connected to Faraday collectors. • 5 prototype 10 13 Ohm resistors were installed in a TRITON-Plus TIMS. • Performance was tested by measuring Sr and Nd isotope ratios on  13 Ohm resistors perform better than ion counting and 10 11 Ohm resistors. • Fourth decimal variability can be resolved for Nd isotope ratios on 10 pg samples. - Abstract: We tested 5 newly manufactured – prototype – 10 13 Ohm resistors in the feedback loop of Faraday cup amplifiers to measure small ion beams by Thermal Ionisation Mass Spectrometry (TIMS). The high Ohmic resistors installed in the TRITON Plus at the VU University Amsterdam theoretically have 10 times lower noise levels relative to the default 10 11 Ohm resistors. To investigate the precision and accuracy of analyses using these new amplifiers we measured Sr and Nd isotopes of reference standards at a range of ion currents (3.2 × 10 −16 to 1 × 10 −12 A, corresponding to intensities of 32 μV to 100 mV on a default 10 11 Ohm amplifier) and on small amounts of material (100 and 10 pg). Internal precision and external reproducibility for Sr and Nd isotope ratios are both better when collected on 10 13 compared 10 12 Ohm resistors and to the default 10 11 Ohm resistors. At an 87 Sr ion current of 3 × 10 −14 A (3 mV on a 10 11 Ohm amplifier) the internal precision (2 SE) of 87 Sr/ 86 Sr is 5 times better for 10 13 Ohm resistors compared to 10 11 Ohm resistors. The external reproducibility (2 SD) at this beam intensity is 9 times better. Multiple 100 and 10 pg Sr standards, ran to exhaustion, yielded low 87 Sr/ 86 Sr compared to the long term average (e.g. 10 pg average = 0.710083 ± 164 (n = 11) instead of 0.710244 ± 12, n = 73). The average off-set for 10 pg standards can be explained by a loading blank contribution of 1.3 pg. In contrast, Nd data on 100 pg and 10 pg samples are accurate suggesting that Nd loading blanks do not compromise the

  3. Natural gas; Gas Natural

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Carlos A.; Moraes, Claudia C.D. [Eletricidade de Sao Paulo S.A. (ELETROPAULO), Sao Paulo, SP (Brazil); Fonseca, Carlos H.F. [Centrais Eletricas de Santa Catarina S.A., Florianopolis, SC (Brazil); Silva, Clecio Fabricio da; Alves, Ricardo P. [Companhia Paranaense de Energia (COPEL), Curitiba, PR (Brazil); Sposito, Edivaldo Soares; Hulle, Lutero [Espirito Santo Centrais Eletricas S.A. (ESCELSA), Vitoria, ES (Brazil); S. Martins, Icaro da [Centrais Eletricas do Norte do Brasil S.A. (ELETRONORTE), Belem, PA (Brazil); Vilhena, Joao Luiz S. de [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil); Fagundes, Zaluar Aquino [Companhia Estadual de Energia Eletrica do Estado do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    1996-12-31

    An increase in the consumption of natural gas in Brazil is an expected fact in what concerns energetic planning. This work presents the existing situation in what concerns natural gas utilization in the main world economies, as well as an analysis of the participation of this fuel among the energy final consumption per sources. The Brazilian consumption of natural gas is also analysed as well as the international agreement between Brazil and Bolivia for natural gas commercialization. Some legal, institutional and political aspects related to natural gas commercialization are also discussed. Finally, several benefits to be brought by the utilization of natural gas are presented 10 refs., 3 tabs.

  4. Application of stable isotopes (δ³⁴S-SO₄, δ¹⁸O-SO₄, δ¹⁵N-NO ₃, δ¹⁸O-NO ₃) to determine natural background and contamination sources in the Guadalhorce River Basin (southern Spain).

    Science.gov (United States)

    Urresti-Estala, Begoña; Vadillo-Pérez, Iñaki; Jiménez-Gavilán, Pablo; Soler, Albert; Sánchez-García, Damián; Carrasco-Cantos, Francisco

    2015-02-15

    The integrated use of isotopes (δ(34)S-SO4, δ(18)O-SO4, δ(15)N-NO3, δ(18)O-NO3), taking into account existing hydrogeological knowledge of the study area (mainly hydrochemical), was applied in the Guadalhorce River Basin (southern Spain) to characterise SO4(2-) and NO3(-) sources, and to quantify natural background levels (NBLs) in groundwater bodies. According to Water Framework Directive 2000/60/EC and, more recently, Groundwater Directive 2006/118/EC, it is important to determine NBLs, as their correct assessment is the first, essential step to characterising groundwater bodies, establishing threshold values, assessing chemical status and identifying trends in pollutant concentrations. In many cases, NBLs are high for some parameters and types of groundwater, making it difficult to distinguish clearly between factors of natural or human origin. The main advantages of using stable isotopes in a complex area like the Guadalhorce River Basin that exhibits widely varying hydrogeological and hydrochemical conditions and longstanding anthropogenic influences (mainly agriculture, but also many others) is accurate determination of pollution sources and precise quantification of NBLs. Since chemical analyses only provides the concentration of pollutants in water and not the source, three isotopic sampling campaigns for sulphates (δ(34)S-SO4, δ(18)O-SO4) were carried out, in 2006, 2007 and 2012, and another one was conducted for nitrates (δ(15)N-NO3, δ(18)O-NO3), in 2009, in groundwater bodies in order to trace the origins of each pollutant. The present study identified different pollution sources of dissolved NO3(-) in groundwater using an isotopic composition and quantified the percentage of natural (lithology, chemical and biological processes) and anthropogenic (fertilisers, manure and sewage) SO4(2-) and matched a concentration associated with the percentage in order to determine the NBLs in the basin. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Sensitive monitoring of monoterpene metabolites in human urine using two-step derivatisation and positive chemical ionisation-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Lukas [Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Schillerstrasse 25/29, 91054 Erlangen (Germany); Belov, Vladimir N. [Max Planck Institute for Biophysical Chemistry, Facility for Synthetic Chemistry, Am Fassberg 11, 37077 Göttingen (Germany); Göen, Thomas, E-mail: Thomas.Goeen@ipasum.med.uni-erlangen.de [Institute and Outpatient Clinic of Occupational, Social and Environmental Medicine, University of Erlangen-Nuremberg, Schillerstrasse 25/29, 91054 Erlangen (Germany)

    2013-09-02

    Highlights: •Sensitive monitoring of 10 metabolites of (R)-limonene, α-pinene, and Δ{sup 3}-carene in human urine samples. •Fast and simple sample preparation and derivatisation procedure using two-step silylation for unreactive tertiary hydroxyl groups. •Synthesis of reference substances and isotopically labelled internal standards of (R)-limonene, α-pinene, and Δ{sup 3}-carene metabolites. •Study on (R)-limonene, α-pinene, and Δ{sup 3}-carene metabolite background exposure of 36 occupationally unexposed volunteers. -- Abstract: A gas chromatographic–positive chemical ionisation-tandem mass spectrometric (GC–PCI-MS/MS) method for the simultaneous determination of 10 oxidative metabolites of the monoterpenoid hydrocarbons α-pinene, (R)-limonene, and Δ{sup 3}-carene ((+)-3-carene) in human urine was developed and tested for the monoterpene biomonitoring of the general population (n = 36). The method involves enzymatic cleavage of the glucuronides followed by solid-supported liquid–liquid extraction and derivatisation using a two-step reaction with N,O-bis(trimethylsilyl)-trifluoroacetamide and N-(trimethylsilyl)imidazole. The method proved to be both sensitive and reliable with detection limits ranging from 0.1 to 0.3 μg L{sup −1}. In contrast to the frequent and distinct quantities of (1S,2S,4R)-limonene-1,2-diol, the (1R,2R,4R)-stereoisomer could not be detected. The expected metabolite of (+)-3-carene, 3-caren-10-ol was not detected in any of the samples. All other metabolites were detected in almost all urine samples. The procedure enables for the first time the analysis of trace levels of a broad spectrum of mono- and bicyclic monoterpenoid metabolites (alcohols, diols, and carboxylic acids) in human urine. This analytical procedure is a powerful tool for population studies as well as for the discovery of human metabolism and toxicokinetics of monoterpenes.

  6. Neutron background estimates in GESA

    Directory of Open Access Journals (Sweden)

    Fernandes A.C.

    2014-01-01

    Full Text Available The SIMPLE project looks for nuclear recoil events generated by rare dark matter scattering interactions. Nuclear recoils are also produced by more prevalent cosmogenic neutron interactions. While the rock overburden shields against (μ,n neutrons to below 10−8 cm−2 s−1, it itself contributes via radio-impurities. Additional shielding of these is similar, both suppressing and contributing neutrons. We report on the Monte Carlo (MCNP estimation of the on-detector neutron backgrounds for the SIMPLE experiment located in the GESA facility of the Laboratoire Souterrain à Bas Bruit, and its use in defining additional shielding for measurements which have led to a reduction in the extrinsic neutron background to ∼ 5 × 10−3 evts/kgd. The calculated event rate induced by the neutron background is ∼ 0,3 evts/kgd, with a dominant contribution from the detector container.

  7. A definition of background independence

    International Nuclear Information System (INIS)

    Gryb, Sean

    2010-01-01

    We propose a definition for background (in)/dependence in dynamical theories of the evolution of configurations that have a continuous symmetry and test this definition on particle models and on gravity. Our definition draws from Barbour's best matching framework developed for the purpose of implementing spatial and temporal relationalism. Among other interesting theories, general relativity can be derived within this framework in novel ways. We study the detailed canonical structure of a wide range of best matching theories and show that their actions must have a local gauge symmetry. When gauge theory is derived in this way, we obtain at the same time a conceptual framework for distinguishing between background-dependent and -independent theories. Gauge invariant observables satisfying Kuchar's criterion are identified and, in simple cases, explicitly computed. We propose a procedure for inserting a global background time into temporally relational theories. Interestingly, using this procedure in general relativity leads to unimodular gravity.

  8. Classification of protein binders in artist's paints by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry: an evaluation of principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA).

    Science.gov (United States)

    Fremout, Wim; Kuckova, Stepanka; Crhova, Michaela; Sanyova, Jana; Saverwyns, Steven; Hynek, Radovan; Kodicek, Milan; Vandenabeele, Peter; Moens, Luc

    2011-06-15

    Proteomics techniques are increasingly applied for the identification of protein binders in historical paints. The complex nature of paint samples, with different kinds of pigments mixed into, and degradation by long term exposure to light, humidity and temperature variations, requires solid analysis and interpretation methods. In this study matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectra of tryptic-digested paint replicas are subjected to principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) in order to distinguish proteinaceous binders based on animal glues, egg white, egg yolk and milk casein from each other. The most meaningful peptide peaks for a given protein class will be determined, and if possible, annotated with their corresponding amino acid sequence. The methodology was subsequently applied on egg temperas, as well as on animal glues from different species. In the latter small differences in the MALDI-TOF mass spectra can allow the determination of a mammal or sturgeon origin of the glue. Finally, paint samples from the 16(th) century altarpiece of St Margaret of Antioch (Mlynica, Slovakia) were analysed. Several expected peaks are either present in lower abundance or completely missing in these natural aged paints, due to degradation of the paints. In spite of this mammalian glue was identified in the St Margaret samples. Copyright © 2011 John Wiley & Sons, Ltd.

  9. Generative electronic background music system

    International Nuclear Information System (INIS)

    Mazurowski, Lukasz

    2015-01-01

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions

  10. Generative electronic background music system

    Energy Technology Data Exchange (ETDEWEB)

    Mazurowski, Lukasz [Faculty of Computer Science, West Pomeranian University of Technology in Szczecin, Zolnierska Street 49, Szczecin, PL (Poland)

    2015-03-10

    In this short paper-extended abstract the new approach to generation of electronic background music has been presented. The Generative Electronic Background Music System (GEBMS) has been located between other related approaches within the musical algorithm positioning framework proposed by Woller et al. The music composition process is performed by a number of mini-models parameterized by further described properties. The mini-models generate fragments of musical patterns used in output composition. Musical pattern and output generation are controlled by container for the mini-models - a host-model. General mechanism has been presented including the example of the synthesized output compositions.

  11. Modeling background radiation in Southern Nevada.

    Science.gov (United States)

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

    2017-05-01

    Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project is to develop a method to predict the radiologic exposure rate of the geologic materials by creating a high resolution background model. The intention is for this method to be used in an emergency response scenario where the background radiation environment is unknown. Two study areas in Southern Nevada have been modeled using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low resolution aerial surveys from the National Uranium Resource Evaluation (NURE) Survey. Using these data, geospatial areas that are homogenous in terms of K, U, and Th, referred to as background radiation units, are defined and the gamma ray exposure rate is predicted. The prediction is compared to data collected via detailed aerial survey by the Department of Energy's Remote Sensing Lab - Nellis, allowing for the refinement of the technique. By using geologic units to define radiation background units of exposed bedrock and ASTER visualizations to subdivide and define radiation background units within alluvium, successful models have been produced for Government Wash, north of Lake Mead, and for the western shore of Lake Mohave, east of Searchlight, NV. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Low Background Micromegas in CAST

    DEFF Research Database (Denmark)

    Garza, J G; Aune, S.; Aznar, F.

    2014-01-01

    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 Micr......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/cm2/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/cm2/s, showing good prospects for the application of this technology in IAXO...

  13. Educational Choice. A Background Paper.

    Science.gov (United States)

    Quality Education for Minorities Network, Washington, DC.

    This paper addresses school choice, one proposal to address parental involvement concerns, focusing on historical background, definitions, rationale for advocating choice, implementation strategies, and implications for minorities and low-income families. In the past, transfer payment programs such as tuition tax credits and vouchers were…

  14. Family Background and Educational Choices

    DEFF Research Database (Denmark)

    McIntosh, James; D. Munk, Martin

    enrollments, especially for females. Not only did the educational opportunities for individuals with disadvantaged backgrounds improve absolutely, but their relative position also improved. A similarly dramatic increase in attendance at university for the period 1985-2005 was found for these cohorts when...

  15. The Cosmic Infrared Background Experiment

    Science.gov (United States)

    Bock, James; Battle, J.; Cooray, A.; Hristov, V.; Kawada, M.; Keating, B.; Lee, D.; Matsumoto, T.; Matsuura, S.; Nam, U.; Renbarger, T.; Sullivan, I.; Tsumura, K.; Wada, T.; Zemcov, M.

    2009-01-01

    We are developing the Cosmic Infrared Background ExpeRiment (CIBER) to search for signatures of first-light galaxy emission in the extragalactic background. The first generation of stars produce characteristic signatures in the near-infrared extragalactic background, including a redshifted Ly-cutoff feature and a characteristic fluctuation power spectrum, that may be detectable with a specialized instrument. CIBER consists of two wide-field cameras to measure the fluctuation power spectrum, and a low-resolution and a narrow-band spectrometer to measure the absolute background. The cameras will search for fluctuations on angular scales from 7 arcseconds to 2 degrees, where the first-light galaxy spatial power spectrum peaks. The cameras have the necessary combination of sensitivity, wide field of view, spatial resolution, and multiple bands to make a definitive measurement. CIBER will determine if the fluctuations reported by Spitzer arise from first-light galaxies. The cameras observe in a single wide field of view, eliminating systematic errors associated with mosaicing. Two bands are chosen to maximize the first-light signal contrast, at 1.6 um near the expected spectral maximum, and at 1.0 um; the combination is a powerful discriminant against fluctuations arising from local sources. We will observe regions of the sky surveyed by Spitzer and Akari. The low-resolution spectrometer will search for the redshifted Lyman cutoff feature in the 0.7 - 1.8 um spectral region. The narrow-band spectrometer will measure the absolute Zodiacal brightness using the scattered 854.2 nm Ca II Fraunhofer line. The spectrometers will test if reports of a diffuse extragalactic background in the 1 - 2 um band continues into the optical, or is caused by an under estimation of the Zodiacal foreground. We report performance of the assembled and tested instrument as we prepare for a first sounding rocket flight in early 2009. CIBER is funded by the NASA/APRA sub-orbital program.

  16. Stufenweise Ionisation positiv geladener Kohlenstoffund Stickstoffionen durch Elektronenstoss ($C^{2+} \\to C^{3+} \\to C^{4+} \\to C^{5+} \\to C^{6+}$ und $N^{3+} \\to N^{4+} \\to N^{5+} \\to N^{6+} \\to N^{7+}$)

    CERN Document Server

    Donets, E D; Donets, E D no 1; Ilyushchenko, V I no 1

    1975-01-01

    Stufenweise Ionisation positiv geladener Kohlenstoffund Stickstoffionen durch Elektronenstoss ($C^{2+} \\to C^{3+} \\to C^{4+} \\to C^{5+} \\to C^{6+}$ und $N^{3+} \\to N^{4+} \\to N^{5+} \\to N^{6+} \\to N^{7+}$)

  17. Exposure to background radiation in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Lab., Melbourne, VIC (Australia)

    1997-12-31

    The average effective dose received by the Australian population is estimated to be {approx}1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m{sup -3} in Queensland to 16 Bq m{sup -3} in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year. 9 refs., 2 tabs., 4 figs.

  18. Exposure to background radiation in Australia

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1997-01-01

    The average effective dose received by the Australian population is estimated to be ∼1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m -3 in Queensland to 16 Bq m -3 in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year

  19. Electrochemical separation and isotopic determination of thallium at the nanogram level by surface ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Arden, J.W.

    1983-01-01

    A rapid low-blank procedure is described for the co-separation of thallium and lead by sequential cathodic and anodic electrodeposition from natural samples, especially complex natural silicates, for subsequent mass spectrometry. A micro anion-exchange procedure is also described for the separation of thallium and lead. Ion currents of 10 - 10 A can be obtained from 1 ng of thallium. The isotopic composition of 1 ng of thallium can be measured on a Faraday detector with a precision of 0.05-0.1%. The total procedural blank is 3 pg. By using stable isotope dilution, 0.2 ng of thallium can be measured with a precision of 0.6% with only a 2% blank correction. This allows the accurate determination of thallium in natural samples down to concentration levels of about 50 pg g - 1 . The detection limit is 50 fg. This procedure has been applied to meteorites and terrestrial rocks. The stable isotope dilution technique is suitable for geochemical, environmental and toxicological studies requiring a highly sensitive, accurate and precise method for the determination of thallium. (Auth.)

  20. Identification of Wheat Varieties Using Matrix-assisted Laser Desorption/Ionisation Time-of-flight Mass Spectrometry and an Artificial Neural network

    DEFF Research Database (Denmark)

    Bloch, Helle Aagaard; Kesmir, Can; Petersen, Marianne Kjerstine

    1999-01-01

    A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness of this no......A novel tool for variety identification of wheat (Triticum aestivum L,) has been developed: an artificial neural network (ANN) is used to classify the gliadin fraction analysed by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS). The robustness...... of this novel method with respect to various experimental parameters has been tested, The results can be summarised: (i) With this approach 97% of the wheat varieties can be classified correctly with a corresponding correlation coefficient of 1.0, (ii) The method is fast since the time of extracting gliadins...

  1. Analysis of triacetone triperoxide complexes with alkali metal ions by electrospray and extractive electrospray ionisation combined with ion mobility spectrometry and mass spectrometry.

    Science.gov (United States)

    Hill, Alex R; Edgar, Mark; Chatzigeorgiou, Maria; Reynolds, James C; Kelly, Paul F; Creaser, Colin S

    2015-01-01

    The complexation of triacetone triperoxide (TATP) with a range of alkali metals has been studied by electrospray ionisation-mass spectrometry yield [M+Cat](+) ions for all of the alkali metals. The formation of [2TATP+Li+LiX](+) (X = Br, Cl) sandwich complexes was also observed. Collision cross- sections for the lithium-containing complexes of TATP were measured by travelling wave ion mobility spectrometry mass spectrometry, and compared well with computationally determined structures. Extractive electrospray ionisation (EESI) using a lithium doped electrospray is demonstrated for the detection of TATP vapours desorbed from a metal surface. The limit of detection for EESI was shown to be 20 ng using the [TATP+Li](+) ion.

  2. The risk of low doses of ionising radiation and the linear no threshold relationship debate; La controverse sur les effets des faibles doses de rayonnements ionisants et la relation lineaire sans seuil

    Energy Technology Data Exchange (ETDEWEB)

    Tubiana, M. [Centre Antoine Beclere, Faculte de Medecine, 75 - Paris (France); Masse, R. [11 rue du Haras, Residence Le Boqueteau, Acacias 2, 91 - Saint-Michel-sur-Orge (France); Vathaire, F. de [Institut Gustave Roussy, INSERM U 605., 94 - Villejuif (France); Averbeck, D. [Institut Curie, Section de Recherche, Lab. Raymond Latarjet, UMR2027 du CNRS, Centre Universitaire d' Orsay, 91 - Orsay (France); Aurengo, A. [Hopital Pitie-Salpetriere, Service Medecine Nucleaire, 75 - Paris (France)

    2007-04-15

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  3. Backgrounds and characteristics of arsonists.

    Science.gov (United States)

    Labree, Wim; Nijman, Henk; van Marle, Hjalmar; Rassin, Eric

    2010-01-01

    The aim of this study was to gain more insight in the backgrounds and characteristics of arsonists. For this, the psychiatric, psychological, personal, and criminal backgrounds of all arsonists (n=25), sentenced to forced treatment in the maximum security forensic hospital "De Kijvelanden", were compared to the characteristics of a control group of patients (n=50), incarcerated at the same institution for other severe crimes. Apart from DSM-IV Axis I and Axis II disorders, family backgrounds, level of education, treatment history, intelligence (WAIS scores), and PCL-R scores were included in the comparisons. Furthermore, the apparent motives for the arson offences were explored. It was found that arsonists had more often received psychiatric treatment, prior to committing their index offence, and had a history of severe alcohol abuse more often in comparison to the controls. The arsonists turned out to be less likely to suffer from a major psychotic disorder. Both groups did not differ significantly on the other variables, among which the PCL-R total scores and factor scores. Exploratory analyses however, did suggest that arsonists may differentiate from non-arsonists on three items of the PCL-R, namely impulsivity (higher scores), superficial charm (lower scores), and juvenile delinquency (lower scores). Although the number of arsonists with a major psychotic disorder was relatively low (28%), delusional thinking of some form was judged to play a role in causing arson crimes in about half of the cases (52%).

  4. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Generation of current pulses during polarisation of air ionised by ultraviolet laser radiation

    Science.gov (United States)

    Antipov, A. A.; Losev, Leonid L.; Soskov, V. I.

    1994-10-01

    Current pulses were generated in the course of the polarisation of air ionised by ultraviolet radiation. The dependence of the current pulse duration on the air pressure had a maximum. The amplitude of the pulses depended quadratically on the intensity of the laser radiation with the wavelength of 266 nm; the amplitude increased when the pressure was reduced in the range 10-760 Torr.

  5. Visualisation of abscisic acid and 12-oxo-phytodienoic acid in immature Phaseolus vulgaris L. seeds using desorption electrospray ionisation-imaging mass spectrometry

    OpenAIRE

    Enomoto, Hirofumi; Sensu, Takuya; Sato, Kei; Sato, Futoshi; Paxton, Thanai; Yumoto, Emi; Miyamoto, Koji; Asahina, Masashi; Yokota, Takao; Yamane, Hisakazu

    2017-01-01

    The plant hormone abscisic acid (ABA) and the jasmonic acid related-compound 12-oxo-phytodienoic acid (OPDA) play crucial roles in seed development, dormancy, and germination. However, a lack of suitable techniques for visualising plant hormones has restricted the investigation of their biological mechanisms. In the present study, desorption electrospray ionisation-imaging mass spectrometry (DESI-IMS), a powerful tool for visualising metabolites in biological tissues, was used to visualise AB...

  6. Risks of low dose ionising radiation exposures Riesgos derivados de la exposición a dosis bajas de radiación ionizante

    Directory of Open Access Journals (Sweden)

    Almudena Real Gallego

    2010-12-01

    Full Text Available Although ionising radiation has been shown to have several beneficial applications for humans, it can also produce detrimental effects in humans and the environment. To adequately protect man and environment from the potential harmful effects of ionising radiation, is essential to know in detail the biological effects produced by it, its characteristics and the various factors that influence these effects. That is the objective of this article, describe the current status of knowledge about biological effects induced by ionising radiation, with special emphasis on those effects occurring after low dose exposures.La radiación ionizante ha mostrado tener diversas aplicaciones beneficiosas para el hombre, pero también puede dañar la salud de las personas y el medio ambiente. Para proteger adecuadamente al hombre de los posibles efectos nocivos de la radiación ionizante es imprescindible conocer en detalle los efectos biológicos producidos por esta, sus características y los distintos factores que influyen en dichos efectos. Ese es el objetivo de este artículo: describir el estado actual del conocimiento sobre los efectos biológicos que puede producir la radiación ionizante, con especial énfasis en aquellos efectos que se producen tras la exposición a dosis bajas.

  7. 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...

  8. Biological background of dermal substitutes

    NARCIS (Netherlands)

    van der Veen, V. C.; van der Wal, M.B.; van Leeuwen, M.C.; Ulrich, M.; Middelkoop, E.

    2010-01-01

    Dermal substitutes are of major importance in treating full thickness skin defects, both in acute and chronic wounds. In this review we will outline specific requirements of three classes of dermal substitutes:-natural biological materials, with a more or less intact extracellular matrix

  9. CARIAA Background Studies Biophysical Impacts

    International Development Research Centre (IDRC) Digital Library (Canada)

    Garrett Kilroy

    CONTEXT. Increasing pressures on Semi-arid areas of. Africa and parts of Central and South Asia. (Google Earth and Milly et al 2005, Nature). Bangladesh Delta Inundation with 2m sea rise. (Mark Mulligan, 2009, KCL and Google Earth). River basins of Himalayas. (Immerzeel et al., Science 2010). Africa. Drought. Indicator.

  10. Characterisation of a proposed internet synthesis of N,N-dimethyltryptamine using liquid chromatography/electrospray ionisation tandem mass spectrometry.

    Science.gov (United States)

    Martins, Cláudia P B; Freeman, Sally; Alder, John F; Brandt, Simon D

    2009-08-14

    The psychoactive properties of N,N-dimethyltryptamine (DMT) are known to induce altered states of consciousness in humans. These properties attract great interest from clinical, neuroscientific, clandestine and forensic communities. The Breath of Hope Synthesis was reported on an internet website as a convenient two-step methodology for the preparation of DMT. The analytical characterisation of the first stage was the subject of previous publications by the authors and involved the thermal decarboxylation of tryptophan and the formation of tryptamine. The present study reports on the characterisation of the second step of this procedure which was based on the methylation of tryptamine. This employed methyl iodide and benzyltriethylammonium chloride/sodium hydroxide as a phase transfer catalyst. The reaction product was characterised by liquid chromatography/electrospray ionisation tandem mass spectrometry and orthogonal acceleration time-of-flight mass spectrometry. Quantitative evaluation was carried out in positive multiple reaction monitoring mode (MRM), which included synthesis of the identified reaction products. MRM screening of the product did not lead to the detection of DMT. Instead, 11.1% tryptamine starting material, 21.0% N,N,N-trimethyltryptammonium iodide (TMT) and 47.4% 1-N-methyl-TMT were detected. A 0.5% trace of the monomethylated N-methyltryptamine was also detected. This study demonstrated the impact on product purity of doubtful synthetic methodologies discussed on the internet.

  11. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    International Nuclear Information System (INIS)

    Palmans, H.; Verhaegen, F.

    1995-01-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire's multiple scattering theory and Vavilov's energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program's accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented

  12. Rapid evaporative ionisation mass spectrometry and chemometrics for high-throughput screening of growth promoters in meat producing animals.

    Science.gov (United States)

    Guitton, Yann; Dervilly-Pinel, Gaud; Jandova, Renata; Stead, Sara; Takats, Zoltan; Le Bizec, Bruno

    2018-01-17

    In a proof of concept perspective, Rapid Evaporative Ionisation Mass Spectrometry (REIMS) was explored for the direct analysis of meat samples from β-agonist treated livestock. In this context, the combination of REIMS with untargeted metabolomics was investigated to identify carcasses from treated animals on the basis of a modification of indirect metabolites profile. The REIMS analysis generated specific lipid profiles which enabled the differentiation of meat samples collected from pigs treated with ractopamine via their feeding regime. Furthermore, the strategy was found successful when tested on different muscle types (loin, shoulder and thigh), which further expands its applicability. Classification performances were greater than 95% accurate which fully answers requirements of a screening strategy. This research indicates that REIMS implemented in an untargeted-metabolomics workflow can be considered as a high-throughput and accurate strategy for real-time meat classification in relation to ractopamine (and wider β-agonists) treatment in pig production. This approach may subsequently be implemented as a rapid screening test, at the slaughterhouse or at border inspection points, to detect such practice.

  13. Matrix-Assisted Laser Desorption/Ionisation Mass Spectrometry Imaging in the Study of Gastric Cancer: A Mini Review

    Directory of Open Access Journals (Sweden)

    Andrew Smith

    2017-12-01

    Full Text Available Gastric cancer (GC is one of the leading causes of cancer-related deaths worldwide and the disease outcome commonly depends upon the tumour stage at the time of diagnosis. However, this cancer can often be asymptomatic during the early stages and remain undetected until the later stages of tumour development, having a significant impact on patient prognosis. However, our comprehension of the mechanisms underlying the development of gastric malignancies is still lacking. For these reasons, the search for new diagnostic and prognostic markers for gastric cancer is an ongoing pursuit. Modern mass spectrometry imaging (MSI techniques, in particular matrix-assisted laser desorption/ionisation (MALDI, have emerged as a plausible tool in clinical pathology as a whole. More specifically, MALDI-MSI is being increasingly employed in the study of gastric cancer and has already elucidated some important disease checkpoints that may help us to better understand the molecular mechanisms underpinning this aggressive cancer. Here we report the state of the art of MALDI-MSI approaches, ranging from sample preparation to statistical analysis, and provide a complete review of the key findings that have been reported in the literature thus far.

  14. Evaluation of ion chamber dependent correction factors for ionisation chamber dosimetry in proton beams using a Monte Carlo method

    Energy Technology Data Exchange (ETDEWEB)

    Palmans, H. [Ghent Univ. (Belgium). Dept. of Biomedical Physics; Verhaegen, F.

    1995-12-01

    In the last decade, several clinical proton beam therapy facilities have been developed. To satisfy the demand for uniformity in clinical (routine) proton beam dosimetry two dosimetry protocols (ECHED and AAPM) have been published. Both protocols neglect the influence of ion chamber dependent parameters on dose determination in proton beams because of the scatter properties of these beams, although the problem has not been studied thoroughly yet. A comparison between water calorimetry and ionisation chamber dosimetry showed a discrepancy of 2.6% between the former method and ionometry following the ECHED protocol. Possibly, a small part of this difference can be attributed to chamber dependent correction factors. Indications for this possibility are found in ionometry measurements. To allow the simulation of complex geometries with different media necessary for the study of those corrections, an existing proton Monte Carlo code (PTRAN, Berger) has been modified. The original code, that applies Mollire`s multiple scattering theory and Vavilov`s energy straggling theory, calculates depth dose profiles, energy distributions and radial distributions for pencil beams in water. Comparisons with measurements and calculations reported in the literature are done to test the program`s accuracy. Preliminary results of the influence of chamber design and chamber materials on dose to water determination are presented.

  15. Electron energy distribution in a weakly ionized plasma; Distribution des energies electroniques dans un plasma faiblement ionise

    Energy Technology Data Exchange (ETDEWEB)

    Cesari, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-03-15

    The aim of this work is to determine from both the theoretical and experimental points of view the type of distribution function for the electronic energies existing in a positive-column type cold laboratory plasma having an ionization rate of between 10{sup -6} and 10{sup -7}. The theoretical analysis, based on the imperfect Lorentz model and taking into account inelastic collisions is developed from the Boltzmann equation. The experimental method which we have employed for making an electrostatic analysis of the electronic energies makes use of a Langmuir probe used in conjunction with a transistorized electronic device. A comparison between the experimental and theoretical results yields information concerning the mechanisms governing electronic energy transfer on a microscopic scale. (author) [French] Le but de cette etude est de determiner d un double point de vue theorique et experimental le type de fonction de distribution des energies electroniques existant dans un plasma froid de laboratoire, du type colonne positive, dont le taux d ionisation est compris entre 10{sup -6} et 10{sup -7}. L'analyse theorique, basee sur le modele de Lorentz imparfait et tenant compte des collisions inelastiques est developpee a partir de l equation de Boltzmann. La methode experimentale d analyse electrostatique des energies electroniques que nous avons utilisee, met en jeu une sonde de Langmuir associee a un dispositif electronique a transistors. La comparaison des resultats experimentaux et theoriques nous fournit une connaissance des mechanismes qui regissent le transfert de l energie electronique a l echelle microscopique. (auteur)

  16. Analysis of oilfield produced waters and production chemicals by electrospray ionisation multi-stage mass spectrometry (ESI-MSn).

    Science.gov (United States)

    McCormack, P; Jones, P; Hetheridge, M J; Rowland, S J

    2001-10-01

    Large quantities of diverse polar organic chemicals are routinely discharged from oil production platforms in so-called produced waters. The environmental fate of many of these is unknown since few methods exist for their characterisation. Preliminary investigations into the use of multistage electrospray ionisation ion trap mass spectrometry (ESI-MSn) show its potential for the identification and quantification of compounds in specialty oilfield chemicals (corrosion inhibitors, scale inhibitors, biocides and demulsifiers) and produced waters. Multiple stage mass spectrometry (MSn) with both positive and negative ion detection allows high specificity detection and characterisation of a wide range of polar and charged molecules. For example, linear alkylbenzenesulfonates (LAS), alkyldimethylbenzylammonium compounds, 2-alkyl-1-ethylamine-2-imidazolines, 2-alkyl-1-[N-ethylalkylamide]-2-imidazolines and a di-[alkyldimethylammonium-ethyl]ether were all identified and characterised in commercial formulations and/or North Sea oilfield produced waters. The technique should allow the marine environmental effects and fates of some of these polar compounds to be studied.

  17. Mutation to ouabain-resistance in Chinese hamster cells: induction by ethyl methanesulphonate and lack of induction by ionising radiation

    International Nuclear Information System (INIS)

    Thacker, J.; Stephens, M.A.; Stretch, A.

    1978-01-01

    The spontaneous frequency of mutants resistant to growth inhibition by ouabian (OUAsup(R) mutants) was found to be about 5.10 -5 per viable cell in uncloned cultures of Chinese hamster V79-4 cells. In freshly-isolated clones or cultures started from a few cells this frequency was initially reduced to about 1.10 -6 in 1 mM ouabain. No increase in the frequency of OUAsup(R) mutants was found in cultures treated with γ-rays despite exploration of such variables as radiation dose, ouabain concentration, post-treatment interval before selection, cell density in selective medium, and clonal state of the cells at the time of adding ouabain (in situ vs. respreading method). A similar negative result was found for accelerated helium ions, for which the mutagenic effectiveness per unit dose has been shown to be about 10 times higher than γ-rays for the induction of thioguanine-resistant mutants in these cells. Recent evidence is reviewed in support of the suggestion that ionising radiation is unable to induce OUAsup(R) mutants because of the severity of the genetic damage it causes. (Auth.)

  18. For the development of therapy with ionising radiation in tooth, mouth and jaw medicine. An historical summary

    International Nuclear Information System (INIS)

    Halbleib, T.

    1983-01-01

    Based on the corresponding literature study, the development of therapy with ionising radiation, especially in the areas of tooth, mouth and jaw medicine, is reported from the discovery of X-rays up till the present. First from 1915 on did the X-ray antiphlogistic irradiation with in importance, from 1925 to about 1940 it played a domineering role, after the war was hardly still in use and since 1970 is considered in the stomatological sector obsolete. In comparison, already in 1905 there were individual successes in tumor therapy using X radiation. After many failures and competition with the method of radium therapy in the following years, a new upswing in X-radiation came starting in around 1930 with the introduction of the Chaoul contact therapy. The high point of this development is the introduction of supervolt therapy starting around 1965. It is the result of comprehensive research in the area of radiation physics. As a result of further developed techniques there were soon combined and competing procedures available, whose results, however, have not been adequately compared and documented. From 1970 on electronic data processing has primarily taken over individual irradiation planning (cobalt 60 and electron irradiation), predictions about clinically relevant therapy successes are not present at this time. (TRV) [de

  19. Role of the resistivity of insulating field emitters on the energy of field-ionised and field-evaporated atoms

    International Nuclear Information System (INIS)

    Arnoldi, L.; Silaeva, E.P.; Vurpillot, F.; Deconihout, B.; Cadel, E.; Blum, I.; Vella, A.

    2015-01-01

    In order to improve the accuracy of laser atom probe analyses, it is important to understand all the physical processes induced by the combination of the high electrical field and the femtosecond laser beam during field evaporation. New information can be accessed from the energy of evaporated surface atoms or field-ionised atoms of an imaging gas. In order to study the ions energy, we combine La-APT and FIM analyses in a new experimental setup equipped with electrostatic lenses. We report measurements for semiconductors and oxides and we study the influence of the illumination conditions (laser power and wavelength), the evaporation rate, the sample geometry and the tip preparation processes. The results are discussed taking into account the resistive properties of non-metallic samples and the photo-stimulated conductivity. This work clarifies the role of the laser and DC field in the energy deficit of field evaporated ions. - Highlights: • Energy from field emitted ion was studied. • Ion energy is influence by ohmic effect in atom probe and Field Ion Microscopy. • Ion energy deficit can be reduce by laser illumination and cancelled metallisation. • Tip electrical resistance is strongly dependant of the tip preparation.

  20. Overview of programmes for the assessment of risks to the environment from ionising radiation and hazardous chemicals

    International Nuclear Information System (INIS)

    Jones, C; Gilek, M

    2004-01-01

    Within the FASSET project, a review of existing programmes for the assessment of environmental risks from radioactive or hazardous substances was carried out in order to identify appropriate aspects that could be incorporated into the FASSET framework. The review revealed a number of different approaches, arising from the need to balance the information value of the assessment against the availability of data and the need to keep the assessment manageable. Most of the existing assessment programmes fit into a three-phase approach to environmental risk assessment: problem formulation, assessment and risk characterisation. However, the emphasis on particular assessment phases varies between programmes. The main differences between the different programmes are: the degree of specificity to a particular site, the level of detail of the assessment, the point at which a comparison is made between a criterion intended to represent 'what is acceptable' and a measured or predicted quantity, the choice of end-point for the assessment and the relationship between measurement end-points and assessment end-points. The existing assessment programmes are based on a similar general structure, which is suitable for use as a basis for the FASSET framework. However, certain aspects of the assessment of exposure and effects of ionising contaminants, e.g. dosimetry, require further development before incorporation into such a framework