WorldWideScience

Sample records for fundamental radiation effect

  1. Fundamental radiation effects studies in the fusion materials program

    International Nuclear Information System (INIS)

    Doran, D.G.

    1982-01-01

    Fundamental radiation effects studies in the US Fusion Materials Program generally fall under the aegis of the Damage Analysis and Fundamental Studies (DAFS) Program. In a narrow sense, the problem addressed by the DAFS program is the prediction of radiation effects in fusion devices using data obtained in non-representative environments. From the onset, the program has had near-term and long-term components. The premise for the latter is that there will be large economic penalties for uncertainties in predictive capability. Fusion devices are expected to be large and complex and unanticipated maintenance will be costly. It is important that predictions are based on a maximum of understanding and a minimum of empiricism. Gaining this understanding is the thrust of the long-term component. (orig.)

  2. Physics fundamentals and biological effects of synchrotron radiation therapy

    International Nuclear Information System (INIS)

    Prezado, Y.

    2010-01-01

    The main goal of radiation therapy is to deposit a curative dose in the tumor without exceeding the tolerances in the nearby healthy tissues. For some radioresistant tumors, like gliomas, requiring high doses for complete sterilization, the major obstacle for curative treatment with ionizing radiation remains the limited tolerance of the surrounding healthy tissue. This limitation is particularly severe for brain tumors and, especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restricted. One possible solution is the development of new radiation therapy techniques exploiting radically different irradiation modes and modifying, in this way, the biological equivalent doses. This is the case of synchrotron radiation therapy (SRT). In this work the three new radiation therapy techniques under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France) will be described, namely: synchrotron stereotactic radiation therapy (SSRT), microbeam radiation therapy (MRT) and minibeam radiation therapy. The promising results in the treatment of the high grade brain tumors obtained in preclinical studies have paved the way to the clinical trials. The first patients are expected in the fall of 2010. (Author).

  3. Fundamental radiation effect on polymers energy transfer from radiation to polymer

    International Nuclear Information System (INIS)

    Seguchi, T.

    2007-01-01

    Polymer modification as cross-link, chain scission, and graft-polymerization by radiation is initiated by the quantum energy transferred from radiation to polymers. The active species for chemical reactions are produced through ionization or activation of polymer molecules for any radiation source. The energy transfer occurs mainly by ionic interaction between radiation and polymer molecule, and the contribution from the collision interaction is miner. The radiation of electromagnetic wave as X-ray or γ-ray generates the energetic electron which induces ionic interaction with polymer molecule. The energy loss profile along the penetration to polymer material is much different among the radiation sources of EB, γ-ray, and ion beams in the macroscopic mechanism. In this article, the behavior of single event, that is, the event induced by one electron, γ-ray, ion, and neutron is described by the macroscopic mechanism and by the microscopic mechanism. (authors)

  4. Fundamental remote sensing science research program. Part 1: Scene radiation and atmospheric effects characterization project

    Science.gov (United States)

    Murphy, R. E.; Deering, D. W.

    1984-01-01

    Brief articles summarizing the status of research in the scene radiation and atmospheric effect characterization (SRAEC) project are presented. Research conducted within the SRAEC program is focused on the development of empirical characterizations and mathematical process models which relate the electromagnetic energy reflected or emitted from a scene to the biophysical parameters of interest.

  5. Radiation chemistry in Taiwan, fundamental and applied

    International Nuclear Information System (INIS)

    Wang, U.P.

    1980-01-01

    Both fundamental and applied research works on radiation chemistry in Taiwan have been described from the view point of economic development of new radiation chemical industry by applying unique chemical reactions on radiation processing. Seven items on the basic and applied research works and the status of recent industrial development of radiation chemistry have been consequently selected to be delineated as the major contents along this line in this paper. (author)

  6. Radiation protection. Scientific fundamentals, legal regulations, practical applications. Compendium

    International Nuclear Information System (INIS)

    Buchert, Guido; Gay, Juergen; Kirchner, Gerald; Michel, Rolf; Niggemann, Guenter; Schumann, Joerg; Wust, Peter; Jaehnert, Susanne; Strilek, Ralf; Martini, Ekkehard

    2011-06-01

    The compendium on radiation protection, scientific fundamentals, legal regulations and practical applications includes contributions to the following issues: (1) Effects and risk of ionizing radiation: fundamentals on effects and risk of ionizing radiation, news in radiation biology, advantages and disadvantages of screening investigations; (2) trends and legal regulations concerning radiation protection: development of European and national radiation protection laws, new regulations concerning X-rays, culture and ethics of radiation protection; (3) dosimetry and radiation measuring techniques: personal scanning using GHz radiation, new ''dose characteristics'' in practice, measuring techniques for the nuclear danger prevention and emergency hazard control; (4) radiation exposure in medicine: radiation exposure of modern medical techniques, heavy ion radiotherapy, deterministic and stochastic risks of the high-conformal photon radiotherapy, STEMO project - mobile CT for apoplectic stroke patients; (5) radiation exposure in technology: legal control of high-level radioactive sources, technical and public safety using enclosed radioactive sources for materials testing, radiation exposure in aviation, radon in Bavaria, NPP Fukushima-Daiichi - a status report; (6) radiation exposure in nuclear engineering: The Chernobyl accident - historical experiences or sustaining problem? European standards for radioactive waste disposal, radioactive material disposal in Germany risk assessment of ionizing and non-ionizing radiation (7) Case studies.

  7. Fundamentals of pracical radiation protection. 4. upd. ed.

    International Nuclear Information System (INIS)

    Vogt, H.G.

    2007-01-01

    Humans have no means of sensing high-energy radiation from radioactive materials and other radiation sources. Health effects may occur after a delay of several days to several years, until it is too late to take protective measures. This book does not focus on the medical aspect but on the prevention of radiation damage by appropriate preventive and technical measures. It is based on scientific investigations of radiation effects and long years of experience with radiation sources. For a better understanding, fundamental concepts of radiation physics and biology are explained, followed by chapters on radiation metering, protective measures and legal regulations. Only radiation sources with a radiation energy below about 100 MeV are considered. (orig.)

  8. Fundamental matters on radiation risk communication

    International Nuclear Information System (INIS)

    Shinohara, Kunihiko; Nagai, Hiroyuki; Yonezawa, Rika; Ohuchi, Hiroko; Chikamoto, Kazuhiko; Taniguchi, Kazufumi; Morimoto, Eriko

    2009-01-01

    In the field of atomic energy and radiation utilization, radiation risk is considered as one of the social uneasy factors. About the perception of risks, there is a gap between experts and general public (non-experts). It is said that the general public tends to be going to judge risk from intuitive fear and a visible concrete instance whereas the experts judge it scientifically. A company, an administration or experts should disclose relating information about the risks and communicate interactively with the stakeholders to find the way to solve the problem with thinking together. This process is called 'risk communication'. The role of the expert is important on enforcement of risk communication. They should be required to explain the information on the risks with plain words to help stakeholders understand the risks properly. The Japan Health Physics Society (JHPS) is the largest academic society for radiation protection professionals in Japan, and one of its missions is supposed to convey accurate and trustworthy information about the radiation risk to the general public. The expert group on risk communication of ionizing radiation of the JHPS has worked for the purpose of summarizing the fundamental matters on radiation risk communication. 'Lecture on risk communication for the members of the JHPS.' which has been up on the JHPS web-site, and the symposium of 'For better understanding of radiation risk.' are a part of the activities. The expert group proposes that the JHPS should enlighten the members continuously for being interested in and practicing risk communication of radiation. (author)

  9. Radiation modification of polymers: fundamentals and applications

    International Nuclear Information System (INIS)

    Clough, R.L.

    2003-01-01

    When polymers were first exposed to ionizing radiation some 50 years ago, the resultant changes were found to be complex and relatively non-selective. Most importantly, irradiation was seen to give a mix of bond forming and bond breaking processes, and different polymer types were classified into two groups according to which process predominated. For polymers in the 'crosslinking' category, large industrial applications emerged within the first two decades of the initiation of this field, including heat shrink products, high performance wire insulation and tire manufacturing. There has been continuing work toward development of a wide range of new applications based on polymers and radiation, and this field remains quite active today. One approach to finding new commercial processes has been to take advantage of a variety of different radiation-induced phenomena (for example, uses for chain scission have emerged for enhancing the processing properties of various bulk polymers, for recycling of rubber, and for microlithography and LIGA). Another approach has taken advantage of progress in the science of radiation chemistry, by employing our increasing knowledge to enhance and/or reduce competing processes through the use of additives, the design of specialized resins, controlling gaseous atmospheres, varying processing conditions such as temperature, post-irradiation treatments, etc. This presentation will survey some of the exciting developments in polymer radiation processing, and will point out some of the underlying phenomena that are being manipulated to further their success. We will finish by describing progress on fundamental isotope-labeling studies of one longstanding mechanistic complexity, oxidation chemistry, which is critical in many radiation processing applications, such as retarding post-irradiation degradation problems, enhancing chain scission where desired, altering surface polarity, and providing a useful pretreatment in grafting schemes

  10. Areas of research in radiation chemistry fundamental to radiation biology

    International Nuclear Information System (INIS)

    Powers, E.L.

    1980-01-01

    Among all the environmental hazards to which man is exposed, ionizing radiation is the most thoroughly investigated and the most responsibly monitored and controlled. Nevertheless, because of the importance of radiation in modern society from both the hazard as well as the utilitarian standpoints, much more information concerning the biological effects induced and their modification and reversal is required. Together with radiation physics, an understanding of radiation chemistry is necessary for full appreciation of biological effects of high and low energy radiations, and for the development of prophylactic, therapeutic and potentiating methods and techniques in biological organisms. The necessity of understanding the chemistry of any system, biological or not, that is to be manipulated and controlled, is so obvious as to make trivial a statement to that effect. If any natural phenomenon is to be put to our use, surely the elements of it must be studied and appreciated fully. In the preliminary statements of the various panels of this general group, the need for additional information on the basic radiation chemistry concerned in radiation-induced biological effects pervades throughout

  11. The fundamentals of the radiation thermal technology for cement production

    International Nuclear Information System (INIS)

    Abramson, I.G.; Kapralova, R.M.; Nikiforov, Yu.V.; Egorov, G.B.; Vaisman, A.F.

    1995-01-01

    The fundamentals of principally new radiation thermal way of cement production are presented. The peculiarities of qualities and structure of clinker obtained by this way are given. The technical economic advantages of the new technology are shown

  12. IAEA fundamental standards for protection against radiation

    International Nuclear Information System (INIS)

    1981-01-01

    The Governor's Counsel of the IAEA has just approved the revision of existing norms, previously prepared in cooperation with the ILO, WHO and OECD. The revised norms represent a great advance in the efforts to reduce risks for which there is no threshold value. A further initiative of the IAEA is the program of radiation protection standards for nuclear power stations. They form the first international instructions for a normalised basis of safety in nuclear power stations. The need for exchange of information was emphasised at the International Conference in Stockholm in 1980. The existing safety norms were considered adequate at the time. The IAEA activities in the field of standards, advice and technical help, exchange of information and training and emergency planning are also mentioned. (Auth.)

  13. Radiobiology: radiotherapy and radiation protection, fundamental bases

    International Nuclear Information System (INIS)

    Tubiana, M.

    2008-01-01

    The radiobiology constitutes one of the most successful tools of the research in biology. It has for twenty years, as all the biology, strangely progressed with the increase of the knowledge in molecular biology and the new techniques of the genome exploration. It allows to dissect the living matter, to analyze the repair mechanisms of the damage in the molecular, cellular and tissular scale, to understand the transformation of a normal cell in cancer cell as well as the system of defence, multiple and powerful, against the carcinogenesis to mammals, notably to man. The radiobiology is the base on which the radiotherapy was built and perfected, now this one contributes largely to the cure of half of the cancers. With the increase of the number of the long-term cures, the indication of the second cancers provoked by the ionizing radiations and the cytotoxic largely increased: to reduce their frequency is an imperative, the radiobiology has to help to make it. (N.C.)

  14. Fundamentals of Coherent Synchrotron Radiation in Storage Rings

    International Nuclear Information System (INIS)

    Sannibale, F.; Byrd, J.M.; Loftsdottir, A.; Martin, M.C.; Venturini, M.

    2004-01-01

    We present the fundamental concepts for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The analysis includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use these concepts to optimize the performance of a source for CSR emission

  15. Radiative sky cooling: fundamental physics, materials, structures, and applications

    Science.gov (United States)

    Sun, Xingshu; Sun, Yubo; Zhou, Zhiguang; Alam, Muhammad Ashraful; Bermel, Peter

    2017-07-01

    Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

  16. Radiative sky cooling: fundamental physics, materials, structures, and applications

    Directory of Open Access Journals (Sweden)

    Sun Xingshu

    2017-07-01

    Full Text Available Radiative sky cooling reduces the temperature of a system by promoting heat exchange with the sky; its key advantage is that no input energy is required. We will review the origins of radiative sky cooling from ancient times to the modern day, and illustrate how the fundamental physics of radiative cooling calls for a combination of properties that may not occur in bulk materials. A detailed comparison with recent modeling and experiments on nanophotonic structures will then illustrate the advantages of this recently emerging approach. Potential applications of these radiative cooling materials to a variety of temperature-sensitive optoelectronic devices, such as photovoltaics, thermophotovoltaics, rectennas, and infrared detectors, will then be discussed. This review will conclude by forecasting the prospects for the field as a whole in both terrestrial and space-based systems.

  17. Fundamentals - state of the art of radiation techniques

    International Nuclear Information System (INIS)

    Wogman, N.A.

    1982-01-01

    In minerals exploration and extraction, nuclear techniques have several advantages. The techniques are elementally specific and their exploration range varies from a few millimeters in average rock formations to more than a meter. Because of the heterogeneous disposition of minerals and difficult environments in which measurements are required (in boreholes, on conveyor belts, in bunkers), interrogating techniques are required which exhibit both elemental specificity and range. It is for these fundamental reasons that nuclear techniques are the only possible techniques which satisfy all requirements. A variety of techniques have been developed and used. These are based on energy dispersive x-ray fluorescence (EDXRF), measurement of natural gamma-ray radiation, gamma-ray attenuation and scattering, and on neutron interactions. This paper discusses the fundamentals of these four techniques and their applications. A table is also provided listing some existing selected applications of nuclear techniques in mineral exploration, mining and processing

  18. Nonlinear generation of the fundamental radiation in plasmas

    International Nuclear Information System (INIS)

    Chian, A.C.L.; Rizzato, F.B.

    1993-01-01

    Nonlinear generation of coherent electromagnetic radiation by intense Langmuir waves in the vicinity of the fundamental plasma frequency f p is of current interest in space and laboratory plasmas. In a pioneer work, Lashmore-Davies demonstrated that an efficient process for converting intense Langmuir waves into f p electromagnetic radiation can be achieved by two counterstreaming Langmuir pump waves through an electromagnetic oscillating two-stream instability. Recently Chian and Alves, Akimoto and Rizzato and Chian extended the formalism of Lashmore-Davies in order to include mixed processes with induced modes which are purely electrostatic or electromagnetic. In this paper we extend our previous analysis, in order to study the nonlinear interaction involving travelling electromagnetic pumps, low-frequency density fluctuations and high-frequency f p modes which can be electrostatic-electromagnetic hybrids. (author) 5 refs., 2 figs

  19. Fundamental Technology Development for Radiation Damage in Nuclear Materials

    International Nuclear Information System (INIS)

    Kwon, Sang Chul; Kwon, J. H.; Kim, E. S. and others

    2005-04-01

    This project was performed to achieve technologies for the evaluation of radiation effects at materials irradiated at HANARO and nuclear power plants, to establish measurement equipment and software for the analysis of radiation defects and to set up facilities for the measurements of radiation damage with non-destructive methods. Major targets were 1) establishment of hot laboratories and remote handling facilities/ technologies for the radioactive material tests, 2) irradiation test for the simulation of nuclear power plant environment and measurement/calculation of physical radiation damage, 3) evaluation and analysis of nano-scale radiation damage, 4) evaluation of radiation embrittlement with ultrasonic resonance spectrum measurement and electromagnetic measurement and 5) basic research of radiation embrittlement and radiation damage mechanism. Through the performance of 3 years, preliminary basics were established for the application research to evaluation of irradiated materials of present nuclear power plants and GEN-IV systems. Particularly the results of SANS, PAS and TEM analyses were the first output in Korea. And computer simulations of radiation damage were tried for the first time in Korea. The technologies will be developed for the design of GEN-IV material

  20. Biophysical radiation effects

    International Nuclear Information System (INIS)

    Fidorra, J.

    1982-07-01

    The biological effectiveness of ionizing radiation is based upon the absorption of energy in molecular structures of a cell. Because of the quantum nature of radiation large fluctuations of energy concentration in subcellulare regions has to be considered. In addition both the spatial distribution of a sensitive molecular target and cellulare repair processes has to be taken into consideration for an assessment of radiation action. In radiation protection the difference between the quality factor and the Relative Biological Effectiveness has a fundamental meaning and will be discussed in more detail. The present report includes a short review on some relevant models on radiation action and a short discussion on effects of low dose irradiation. (orig.) [de

  1. Fundamentals of radiation materials science metals and alloys

    CERN Document Server

    Was, Gary S

    2017-01-01

    The revised second edition of this established text offers readers a significantly expanded introduction to the effects of radiation on metals and alloys. It describes the various processes that occur when energetic particles strike a solid, inducing changes to the physical and mechanical properties of the material. Specifically it covers particle interaction with the metals and alloys used in nuclear reactor cores and hence subject to intense radiation fields. It describes the basics of particle-atom interaction for a range of particle types, the amount and spatial extent of the resulting radiation damage, the physical effects of irradiation and the changes in mechanical behavior of irradiated metals and alloys. Updated throughout, some major enhancements for the new edition include improved treatment of low- and intermediate-energy elastic collisions and stopping power, expanded sections on molecular dynamics and kinetic Monte Carlo methodologies describing collision cascade evolution, new treatment of t...

  2. Fundamental radiation effects in αAg-Zn alloys: Zener relaxation, study of the mobility of point defects and the evolution of their populations in a particle flux

    International Nuclear Information System (INIS)

    Halbwachs, Michel.

    1977-01-01

    After a recall on the physical effects of radiations, a model used to describe the defect populations produced in a fast particle flux is presented. The experimental devices used and the measurements carried out on a solid solution of αAg-Zn are described. The results obtained in an electron flux are compared with the forecastings of the theoretical models. The mobility and the apparent recombination radius of vacancies and autointerstitials, the absorption efficiency of dislocations in regard to point defects and the participation of autointerstitials to short-range order are studied. A similar study carried out under neutron irradiation is reported. The influence of neutron doses and temperature on atomic mobility is investigated. An experiment carried out under gamma photon irradiation enables a comparison to be made between the creation of defects by gamma photons and electrons [fr

  3. Fundamentals of health physics for the radiation-protection officer

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, B.L.; Traub, R.J.; Gilchrist, R.L.; Mann, J.C.; Munson, L.H.; Carbaugh, E.H.; Baer, J.L.

    1983-03-01

    The contents of this book on health physics include chapters on properties of radioactive materials, radiation instrumentation, radiation protection programs, radiation survey programs, internal exposure, external exposure, decontamination, selection and design of radiation facilities, transportation of radioactive materials, radioactive waste management, radiation accidents and emergency preparedness, training, record keeping, quality assurance, and appraisal of radiation protection programs. (ACR)

  4. Fundamentals of health physics for the radiation-protection officer

    International Nuclear Information System (INIS)

    Murphy, B.L.; Traub, R.J.; Gilchrist, R.L.; Mann, J.C.; Munson, L.H.; Carbaugh, E.H.; Baer, J.L.

    1983-03-01

    The contents of this book on health physics include chapters on properties of radioactive materials, radiation instrumentation, radiation protection programs, radiation survey programs, internal exposure, external exposure, decontamination, selection and design of radiation facilities, transportation of radioactive materials, radioactive waste management, radiation accidents and emergency preparedness, training, record keeping, quality assurance, and appraisal of radiation protection programs

  5. Reference neutron radiations. Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2000-01-01

    ISO 8529 consists of the following parts, under the general title Reference neutron radiations: Part 1: Characteristics and methods of production; Part 2: Calibration fundamentals of radiation protection devices related to the basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of response as a function of energy and angle of incidence. This Part 2. of ISO 8529 takes as its starting point the neutron sources described in ISO 8529-1. It specifies the procedures to be used for realizing the calibration conditions of radiation protection devices in neutron fields produced by these calibration sources, with particular emphasis on the corrections for extraneous effects (e.g., the neutrons scattered from the walls of the calibration room). In this part of ISO 8529, particular emphasis is placed on calibrations using radionuclide sources (clauses 4 to 6) due to their widespread application, with less details given on the use of accelerator and reactor sources (8.2 and 8.3). This part of ISO 8529 then leads to ISO 8529-3 which gives conversion coefficients and the general rules and procedures for calibration

  6. Some practical applications of fundamental standards in radiation protection

    International Nuclear Information System (INIS)

    Duhamel, Francis; Lavie, Jean-Marie

    1964-05-01

    After some general considerations on the recommendations made by the International Commission on Radiological Protection (ICRP) regarding standards of internal or external exposure of organs or tissues to different types of radiations, and a recall of the main problems raised by acute radio-exposures (dose assessment in case of accident, assessment of the dose due to an emergency intervention in case of accident, classification of radio-elements), this report describes how ICRP recommendations have been implemented by the CEA, and tries to relate the problem of acute radio-exposures to the problem of chronic radio-exposures. This study is limited to the case of workers and to internal contamination by inhalation, but can be easily extended to other groups or other contamination types. The authors thus recall some fundamental data and definitions regarding values recommended by the ICRP for chronic radio-exposure and for acute exposure (acceptable exposure, accidental exposure, concerted exposure, units), present and comment how standards are practically applied for dose calculation and assessment. Formulas allow a quick assessment of radiological consequences of an acute radio-exposure, or vice-versa [fr

  7. Radiation effects

    International Nuclear Information System (INIS)

    Collings, E.W.

    1986-01-01

    An important cause of deterioration in superconducting magnets intended for high-energy physics and fusion-reactor applications is radiation damage. The present chapter deals chiefly with the effects of electron, proton, gamma and neutron irradiation on the properties of stabilized Ti-Nb-base composite superconductors. The authors examine the particle-accelerator environment, electron irradiation of Ti-Nb superconductor, proton irradiation of Ti-Nb superconductor and its stabilizer, and deuteron irradiation of Ti-Nb superconductor. A section discussing the fusion reactor environment in general is presented, and the two principal classes of fusion reactor based on the magnetic-confinement concept, namely the tokamak and the mirrormachine are examined. Also discussed is neutron irradiation of Cu/TiNb composite superconductors and critical current density of neutronirradiated Ti-Nb. Finally, radiation damage to stabilizer and insulating materials is described

  8. Radiation degradation of poly(olefin sulphone)s - Fundamental research to practical applications

    International Nuclear Information System (INIS)

    Bowden, M.J.; O'Donnell, J.H.

    1985-01-01

    The degradation of poly(olefin sulphone)s by high energy radiation, particularly by γ-rays and electron beams, provides an example of the application of fundamental science to high technology industry. Scientific interest in the radiation degradation of these polymers was first aroused by the discovery that they underwent highly specific bond scission in the backbone chain as the primary result of absorption of high energy radiation and in fact they were the first polymers in which such an effect had been demonstrated. This conclusion was initially based mainly on evidence from electron spin resonance spectroscopy and was subsequently verified by studies of molecular weight changes. These studies showed that the poly(olefin sulphone)s not only degraded by main chain scission but were also among the most radiation-sensitive polymers known. The extremely high sensitivity of poly(olefin sulphone)s to radiation-induced main-chain scission has found application in the field of microelectronics. Electron beam writing on poly(olefin sulphone) films is used to produce lithographic masks for the manufacture of integrated circuits on silicon wafers. Poly(1-butene sulphone) (PBS) is currently used in the production of a substantial proportion of the masks for the industry. The fundamental aspects of the radiation degradation of poly(olefin sulphone)s and the practical applications to high technology are reviewed. (author)

  9. Radiation protection. Scientific fundamentals, legal regulations, practical applications. Compendium; Strahlenschutz. Wissenschaftliche Grundlagen, Rechtliche Regelungen, Praktische Anwendungen. Kompendium

    Energy Technology Data Exchange (ETDEWEB)

    Buchert, Guido; Gay, Juergen; Kirchner, Gerald; Michel, Rolf; Niggemann, Guenter; Schumann, Joerg; Wust, Peter; Jaehnert, Susanne; Strilek, Ralf; Martini, Ekkehard (eds.)

    2011-06-15

    The compendium on radiation protection, scientific fundamentals, legal regulations and practical applications includes contributions to the following issues: (1) Effects and risk of ionizing radiation: fundamentals on effects and risk of ionizing radiation, news in radiation biology, advantages and disadvantages of screening investigations; (2) trends and legal regulations concerning radiation protection: development of European and national radiation protection laws, new regulations concerning X-rays, culture and ethics of radiation protection; (3) dosimetry and radiation measuring techniques: personal scanning using GHz radiation, new ''dose characteristics'' in practice, measuring techniques for the nuclear danger prevention and emergency hazard control; (4) radiation exposure in medicine: radiation exposure of modern medical techniques, heavy ion radiotherapy, deterministic and stochastic risks of the high-conformal photon radiotherapy, STEMO project - mobile CT for apoplectic stroke patients; (5) radiation exposure in technology: legal control of high-level radioactive sources, technical and public safety using enclosed radioactive sources for materials testing, radiation exposure in aviation, radon in Bavaria, NPP Fukushima-Daiichi - a status report; (6) radiation exposure in nuclear engineering: The Chernobyl accident - historical experiences or sustaining problem? European standards for radioactive waste disposal, radioactive material disposal in Germany risk assessment of ionizing and non-ionizing radiation (7) Case studies.

  10. Adaptive radiation versus 'radiation' and 'explosive diversification': why conceptual distinctions are fundamental to understanding evolution.

    Science.gov (United States)

    Givnish, Thomas J

    2015-07-01

    Adaptive radiation is the rise of a diversity of ecological roles and role-specific adaptations within a lineage. Recently, some researchers have begun to use 'adaptive radiation' or 'radiation' as synonymous with 'explosive species diversification'. This essay aims to clarify distinctions between these concepts, and the related ideas of geographic speciation, sexual selection, key innovations, key landscapes and ecological keys. Several examples are given to demonstrate that adaptive radiation and explosive diversification are not the same phenomenon, and that focusing on explosive diversification and the analysis of phylogenetic topology ignores much of the rich biology associated with adaptive radiation, and risks generating confusion about the nature of the evolutionary forces driving species diversification. Some 'radiations' involve bursts of geographic speciation or sexual selection, rather than adaptive diversification; some adaptive radiations have little or no effect on speciation, or even a negative effect. Many classic examples of 'adaptive radiation' appear to involve effects driven partly by geographic speciation, species' dispersal abilities, and the nature of extrinsic dispersal barriers; partly by sexual selection; and partly by adaptive radiation in the classical sense, including the origin of traits and invasion of adaptive zones that result in decreased diversification rates but add to overall diversity. © 2015 The Author. New Phytologist © 2015 New Phytologist Trust.

  11. Limiting value definition in radiation protection physics, legislation and toxicology. Fundamentals, contrasts, perspectives

    International Nuclear Information System (INIS)

    Smeddinck, Ulrich; Koenig, Claudia

    2016-01-01

    The volume is the documentation of an ENTRIA workshop discussion on limiting value definition in radiation protection including the following contributions: Introduction in radiation protection -fundamentals concepts of limiting values, heterogeneity; evaluation standards for dose in radiation protection in the context of final repository search; definition of limiting values in toxicology; public participation to limiting value definition - a perspective for the radiation protection regulation; actual developments in radiation protection.

  12. Polymers and electromagnetic radiation fundamentals and practical applications

    CERN Document Server

    Schnabel, Wolfram

    2014-01-01

    This first book to cover the interaction of polymers with radiation from the entire electromagnetic spectrum adopts a multidisciplinary approach to bridge polymer chemistry and physics, photochemistry, photophysics and materials science. The text is equally unique in its scope, devoting equal amounts of attention to the three aspects of synthesis, characterization, and applications. The first part deals with the interaction of polymers with non-ionizing radiation in the frequency-range from sub-terahertz via infrared radiation to visible and ultraviolet light, while the second covers interaction with ionizing radiation from the extreme ultraviolet to X-ray photons. The result is a systematic overview of how both types of radiation can be used for different polymerization approaches, spectroscopy methods and lithography techniques. Authored by a world-renowned researcher and teacher with over 40 years of experience in the field, this is a highly practical and authoritative guide.

  13. Radiation protection in nuclear medicine: fundamentals and methods

    International Nuclear Information System (INIS)

    Kaul, A.; Roedler, H.D.; Freie Univ. Berlin

    1976-01-01

    Consequences for the protection of patients, protection of persons, and protection of the public are derived from the recommendations of the ICRP and the legal requirements for the handling of unsealed radioactive substances in diagnostics and therapy according to the First Radiation Protection Ordinance and its amended version, as well as from the 'guidelines for radiation protection when using radioactive substances in medicine'. (orig./LN) [de

  14. Some fundamental considerations of the equation of radiative transfer

    International Nuclear Information System (INIS)

    Kuriyan, J.G.; Sudarshan, E.C.G.

    1978-10-01

    The radiation transfer of the vector electromagnetic field was first formulated by Chandrasekhar while deriving the polarization characteristics of a sunlit sky. There are two subtle problems underlying this treatment. The first concerns the crucial identification of a Stokes parameter with the specific intensity of radiation. While both depend on position in 3-D space, the latter has, intrinsic to it, an additional angular dependence defining the flow of the radiation field. How can this inadequacy be remedied without damaging the results obtained heretofore from Chandrasekhar's formalism. The second problem arises from the fact that the radiative transfer equation describes the transport of an incoherent radiation field through space. This, however, seems to contradict the results of the Van Cittert-Zernike-Wolf theorem which implies that an incoherent field develops coherence as it passes through free space implying, of course, that the radiative transfer equation must involve not incoherent but partially coherent fields. The vector transfer equation of the direct beam (Beer's law) is derived from first principles. The analysis of this equation provides a satisfactory resolution of these two problems. The result also shows that the Beer's law will have to be modified to a matrix law to accommodate systems that are not spherically symmetric. 13 references

  15. Radiation mutagenesis in development of genetic fundamentals of cotton selection

    International Nuclear Information System (INIS)

    Musaev, D.A.; Almatov, A.S.

    1987-01-01

    Some results of investigations on preparation and genetic analysis of mutants in inbreeding lines of genetic collections of cotton plants, as well as problems on mutant application in practical selection are covered. The results show that the scientific authenticity and efficiency of fundamental and applied investigations in the field of experimental mutagenesis of cotton plants,being a facultative self-polinator, depend on keeping necessary methodical requirements. Application of inbreeding lines of genetic collection with marker features as the initial material, isolation of plants usinng self-polination of flowers on all stages of investigation are related to these requirements. Several methodical recommendations on genetic-selective investigations are developed

  16. Notes on radiation effects on materials

    International Nuclear Information System (INIS)

    Anno, J.N.

    1984-01-01

    The effects of radiation from nuclear reactions on various classes of materials are examined in an introductory textbook for students of nuclear engineering. Topics discussed include the units and general scale of radiation damage, fundamental interactions of neutrons and gamma rays with materials, transient radiation effects on electrical components, radiation effects on organic materials and on steels, nuclear fission effects, surface effects of nuclear radiations, radiation effects on biological material, and neutron and gamma-ray dosimetry. Graphs, diagrams, tables of numerical data, and problems for each chapter are provided. 122 references

  17. Tabulation of Fundamental Assembly Heat and Radiation Source Files

    International Nuclear Information System (INIS)

    T. deBues; J.C. Ryman

    2006-01-01

    The purpose of this calculation is to tabulate a set of computer files for use as input to the WPLOAD thermal loading software. These files contain details regarding heat and radiation from pressurized water reactor (PWR) assemblies and boiling water reactor (BWR) assemblies. The scope of this calculation is limited to rearranging and reducing the existing file information into a more streamlined set of tables for use as input to WPLOAD. The electronic source term files used as input to this calculation were generated from the output files of the SAS2H/ORIGIN-S sequence of the SCALE Version 4.3 modular code system, as documented in References 2.1.1 and 2.1.2, and are included in Attachment II

  18. Radiation effects at ISABELLE

    International Nuclear Information System (INIS)

    Sanger, P.A.; Danby, G.T.

    1975-01-01

    Shielding, radiation damage, and radiation heating at the planned ISABELLE storage rings were considered. Radiation shielding studies were reviewed and were found to be adequate for present day dosage limits. Radiation damage could be encountered in some extreme cases, but is not expected to limit the performance of the superconducting magnets. Experiments to study the effect of radiation heating on actual magnets are recommended

  19. Fundamental safety principles. Safety fundamentals

    International Nuclear Information System (INIS)

    2006-01-01

    This publication states the fundamental safety objective and ten associated safety principles, and briefly describes their intent and purpose. The fundamental safety objective - to protect people and the environment from harmful effects of ionizing radiation - applies to all circumstances that give rise to radiation risks. The safety principles are applicable, as relevant, throughout the entire lifetime of all facilities and activities - existing and new - utilized for peaceful purposes, and to protective actions to reduce existing radiation risks. They provide the basis for requirements and measures for the protection of people and the environment against radiation risks and for the safety of facilities and activities that give rise to radiation risks, including, in particular, nuclear installations and uses of radiation and radioactive sources, the transport of radioactive material and the management of radioactive waste

  20. Fundamental safety principles. Safety fundamentals

    International Nuclear Information System (INIS)

    2007-01-01

    This publication states the fundamental safety objective and ten associated safety principles, and briefly describes their intent and purpose. The fundamental safety objective - to protect people and the environment from harmful effects of ionizing radiation - applies to all circumstances that give rise to radiation risks. The safety principles are applicable, as relevant, throughout the entire lifetime of all facilities and activities - existing and new - utilized for peaceful purposes, and to protective actions to reduce existing radiation risks. They provide the basis for requirements and measures for the protection of people and the environment against radiation risks and for the safety of facilities and activities that give rise to radiation risks, including, in particular, nuclear installations and uses of radiation and radioactive sources, the transport of radioactive material and the management of radioactive waste

  1. Effective and fundamental quantum fields at criticality

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, Michael

    2010-10-28

    We employ Wetterich's approach to functional renormalization as a suitable method to investigate universal phenomena in non-perturbative quantum field theories both qualitatively and quantitatively. Therefore we derive and investigate flow equations for a class of chiral Yukawa models with and without gauge bosons and reveal fixed-point mechanisms. In four dimensions chiral Yukawa systems serve as toy models for the standard model Higgs sector and show signatures of asymptotically safe fixed points by a balancing of bosonic and fermionic contributions. In the approximations investigated this renders the theory fundamental and solves the triviality problem. Further, we obtain predictions for the Higgs mass and even for the top mass of our toy model. In three dimensions we compute the critical exponents which define new universality classes and provide benchmark values for systems of strongly correlated chiral fermions. In a Yukawa system of non-relativistic two-component fermions a fixed point dominates the renormalization flow giving rise to universality in the BCS-BEC crossover. We push the functional renormalization method to a quantitative level and we compute the critical temperature and the single-particle gap with a considerable precision for the whole crossover. Finally, we provide further evidence for the asymptotic safety scenario in quantum gravity by confirming the existence of an ultraviolet fixed point under inclusion of a curvature-ghost coupling. (orig.)

  2. Effective and fundamental quantum fields at criticality

    International Nuclear Information System (INIS)

    Scherer, Michael

    2010-01-01

    We employ Wetterich's approach to functional renormalization as a suitable method to investigate universal phenomena in non-perturbative quantum field theories both qualitatively and quantitatively. Therefore we derive and investigate flow equations for a class of chiral Yukawa models with and without gauge bosons and reveal fixed-point mechanisms. In four dimensions chiral Yukawa systems serve as toy models for the standard model Higgs sector and show signatures of asymptotically safe fixed points by a balancing of bosonic and fermionic contributions. In the approximations investigated this renders the theory fundamental and solves the triviality problem. Further, we obtain predictions for the Higgs mass and even for the top mass of our toy model. In three dimensions we compute the critical exponents which define new universality classes and provide benchmark values for systems of strongly correlated chiral fermions. In a Yukawa system of non-relativistic two-component fermions a fixed point dominates the renormalization flow giving rise to universality in the BCS-BEC crossover. We push the functional renormalization method to a quantitative level and we compute the critical temperature and the single-particle gap with a considerable precision for the whole crossover. Finally, we provide further evidence for the asymptotic safety scenario in quantum gravity by confirming the existence of an ultraviolet fixed point under inclusion of a curvature-ghost coupling. (orig.)

  3. Radiation effects and radiation risks

    International Nuclear Information System (INIS)

    Lengfelder, E.; Forst, D.; Feist, H.; Pratzel, H.

    1988-01-01

    The book presents the facts and the principles of assessment and evaluation of biological radiation effects in general and also with particular reference to the reactor accident of Chernobyl, reviewing the consequences and the environmental situation on the basis of current national and international literature, including research work by the authors. The material compiled in this book is intended especially for physicians, but will also prove useful for persons working in the public health services, in administration, or other services taking care of people. The authors tried to find an easily comprehensible way of presenting and explaining the very complex processes and mechanisms of biological radiation effects and carcinogenesis, displaying the physical primary processes and the mechanisms of the molecular radiation effects up to the effects of low-level radiation, and present results of comparative epidemiologic studies. This section has been given considerable space, in proportion to its significance. It also contains literature references for further reading, offering more insight and knowledge of aspects of special subject fields. The authors also present less known results and data and discuss them against the background of well-known research results and approaches. Apart from the purpose of presenting comprehensive information, the authors intend to give an impact for further thinking about the problems, and helpful tools for independent decisions and action on the basis of improved insight and assessment, and in this context particularly point to the problems induced by the Chernobyl reactor accident. (orig./MG) With 8 maps in appendix [de

  4. Latent Fundamentals Arbitrage with a Mixed Effects Factor Model

    Directory of Open Access Journals (Sweden)

    Andrei Salem Gonçalves

    2012-09-01

    Full Text Available We propose a single-factor mixed effects panel data model to create an arbitrage portfolio that identifies differences in firm-level latent fundamentals. Furthermore, we show that even though the characteristics that affect returns are unknown variables, it is possible to identify the strength of the combination of these latent fundamentals for each stock by following a simple approach using historical data. As a result, a trading strategy that bought the stocks with the best fundamentals (strong fundamentals portfolio and sold the stocks with the worst ones (weak fundamentals portfolio realized significant risk-adjusted returns in the U.S. market for the period between July 1986 and June 2008. To ensure robustness, we performed sub period and seasonal analyses and adjusted for trading costs and we found further empirical evidence that using a simple investment rule, that identified these latent fundamentals from the structure of past returns, can lead to profit.

  5. Fundamental rights reflected by the legislation regarding radiation and nuclear power

    International Nuclear Information System (INIS)

    Han, Eun Ok; Lee, Jae Seong; Cho, Hong Jea

    2016-01-01

    Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. 15-29By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights

  6. Fundamental rights reflected by the legislation regarding radiation and nuclear power

    Energy Technology Data Exchange (ETDEWEB)

    Han, Eun Ok [Korea Academy of Nuclear Safety, Seoul (Korea, Republic of); Lee, Jae Seong [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Cho, Hong Jea [Korea National Defense University, Goyang (Korea, Republic of)

    2016-05-15

    Despite the visible growth in radiation usage and nuclear power development, the analysis of their relationship with fundamental rights, a subject of public concern regarding issues including the right to health, environmental rights, safety rights, the right to know, the right to development, and the right to life, is currently non-existent. 15-29By examining various fundamental rights in the context of positive laws regarding radiation and nuclear power in an idealistic perspective that guarantees the maximum degree of rights, this paper aims to propose legislative supplements that will lead to improvements in quality of life. In the South Korean Constitution, radiation and nuclear power is a subject incorporating several rights, including at least 12 clauses that are directly related to fundamental rights; these constitutional rights are manifested in the various clauses of the 14 positive laws regarding radiation and nuclear power. The question on the relative importance of each fundamental right as reflected in these positive laws- whether the right to life should be prioritized or considered equal in weight to the right to health, environmental rights, the right to know, and safety rights- requires careful deliberation and is difficult to humanly resolve in the short term. Making policy that expands the usage of radiation and nuclear power while simultaneously preventing their associated risks is an important task for the Republic of Korea, and a proper value judgment is necessary to find a balance in its associated rights.

  7. Effects of radiation on erythropoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Harriss, E B

    1971-04-01

    Since the pioneer work of Heineke (1903; 1905) many workers have studied the effect of radiation on haemopoiesis. Their work has been reviewed by Bloom (1948), by Jacobson (1954) and more recently by Bond et al. (1965). The subject continues to stimulate much interest but is now more concerned with the effects of radiation on the multipotential stem cell pool than on radiation damage to the erythropoietic cells themselves. Death from haemopoietic failure following an LD{sub 50/30} dose of radiation is probably not attributable to failure of erythropoiesis; while damage to the erythropoietic system certainly plays a part in the syndrome, it is not a major factor contributing to the death of the animal. Although the severity and time course of the response vary with the species studied, the general effects of radiation on erythropoiesis are similar in all mammalian bone marrow studied to date. Likewise, though the severity of the reaction varies somewhat with the energy of the radiation and has been used to compare the relative biological effectiveness of different types of radiation (Sinclair et al., 1962; Sztanyik, 1967), the response is different only in degree and not in its fundamental pattern. The initial syndrome of depression and recovery will therefore be described largely by reference to work performed on the response of the rat to single acute exposures of either whole-body or partial-body irradiation with conventional X-rays.

  8. Context Effects in Western Herbal Medicine: Fundamental to Effectiveness?

    Science.gov (United States)

    Snow, James

    2016-01-01

    Western herbal medicine (WHM) is a complex healthcare system that uses traditional plant-based medicines in patient care. Typical preparations are individualized polyherbal formulae that, unlike herbal pills, retain the odor and taste of whole herbs. Qualitative studies in WHM show patient-practitioner relationships to be collaborative. Health narratives are co-constructed, leading to assessments, and treatments with personal significance for participants. It is hypothesized that the distinct characteristics of traditional herbal preparations and patient-herbalist interactions, in conjunction with the WHM physical healthcare environment, evoke context (placebo) effects that are fundamental to the overall effectiveness of herbal treatment. These context effects may need to be minimized to demonstrate pharmacological efficacy of herbal formulae in randomized, placebo-controlled trials, optimized to demonstrate effectiveness of WHM in pragmatic trials, and consciously harnessed to enhance outcomes in clinical practice. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Space radiation effects

    International Nuclear Information System (INIS)

    Li Shiqing; Yan Heping

    1995-01-01

    The authors briefly discusses the radiation environment in near-earth space and it's influences on material, and electronic devices using in space airship, also, the research developments in space radiation effects are introduced

  10. Radiation effects in space

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1986-01-01

    The paper discusses the radiation environment in space that astronauts are likely to be exposed to. Emphasis is on proton and HZE particle effects. Recommendations for radiation protection guidelines are presented

  11. Radiation protection: Scientific fundamentals, legal regulations, practical applications. Compendium. 8. ed.

    International Nuclear Information System (INIS)

    Buchert, G.; Czarwinski, R.; Martini, E.; Ruehle, H.; Wust, P.

    2003-01-01

    In 2003, radiation effects and radiation risks were again a central issue, with new biokinetic and dosimetric models. Preliminary experience with new legal regulations on radiation protection was a central issue. Dosimetry and radiation protection metrology were gone into, as was radiation exposure in medicine, engineering, and the environment. New diagnostic methods in medicine were presented, and radiation exposures resulting from some of these techniques were analyzed. Industrial applications of ionising radiation and technical radiography were presented. Nuclear engineering was covered as well, e.g. how to maintain the current know-how after the agreed nuclear phase-out, the transport of spent fuel elements, and the safety of nuclear power stations in eastern Europe. As in the years before, detection limits in radiation measurement, calculations of radiation exposure, incidents in nuclear facilities, and radiation exposure assessment after safety-relevant incidents were among the issues discussed. (orig.)

  12. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed [pt

  13. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  14. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  15. Introduction and fundamentals: Lecture No. 2. Course on advances in radiation, International School of Radiation Damage and Protection, Erice, Italy, September 1979

    International Nuclear Information System (INIS)

    Thomas, R.H.

    1979-09-01

    This lecture discusses advances in the fundamental sciences which underlie that science variously called health physics or radiation. Some of the underlying assumptions of radiation protection are discussed, and some developments in the radiological sciences since 1975 described

  16. Radiation Therapy Side Effects

    Science.gov (United States)

    Radiation therapy has side effects because it not only kills or slows the growth of cancer cells, it can also affect nearby healthy cells. Many people who get radiation therapy experience fatigue. Other side effects depend on the part of the body that is being treated. Learn more about possible side effects.

  17. Radiation effects on polyaniline

    International Nuclear Information System (INIS)

    Oki, Yuichi; Kondo, Kenjiro; Suzuki, Takenori; Numajiri, Masaharu; Miura, Taichi; Doi, Shuji; Ohnishi, Toshihiro.

    1992-01-01

    Effects of γ-irradiation on electrical conductivity of polyaniline were investigated. A drastic increase of the conductivity due to radiation-induced doping was observed in combined systems of polyaniline films and halogen-containing polymers. This effect can be applied to measure an integrated radiation dose. (author)

  18. Radiation effects in space

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1987-07-01

    As more people spend more time in space, and the return to the moon and exploratory missions are considered, the risks require continuing examination. The effects of microgravity and radiation are two potential risks in space. These risks increase with increasing mission duration. This document considers the risk of radiation effects in space workers and explorers. 17 refs., 1 fig., 4 tabs

  19. 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

  20. Radiation effects and radioprotectors

    Energy Technology Data Exchange (ETDEWEB)

    Purohit, R.K., E-mail: dr_rajendra_purohit@yahoo.co.in [Radiation Biology Laboratory, Department of Zoology, Govt. Dungar College, Bikaner (India); Bugalia, Saroj [Department of Zoology, S.K. Kalyan College, Sikar (India); Dakshene, Monika [Department of Chemistry, Govt. College, Kota (India)

    2012-07-01

    Radiation exposure causes damage to biological systems and these damages are mediated by the generation of free radicals and reactive oxygen species targeting vital cellular components such as DNA and membranes. DNA repair systems and the endogenous cellular biochemical defense mechanisms against reactive oxygen species and antioxidants enzymes like reduced Glutathione (GSH), Superoxide dismutase, Glutathione peroxidase catalase etc. fail upon exposures to higher as well as chronic radiation doses leading to alterations in cell functions, cell death or mutations. Radioprotectors prevent these alterations and protect cells and tissues from the deleterious effects of radiations. Radioprotectors are of great importance due to their possible and potential application during planned radiation exposures such as radiotherapy, diagnostic scanning, clean up operations in nuclear accidents, space expeditions etc. and Unplanned radiations exposures such as accidents in nuclear industry, nuclear terrorism, natural background radiation etc. Many of the available synthetic radioprotectors are toxic to mammalian system at doses required to be effective as radioprotector. Increasing uses of ionizing radiation have drawn the attention of many radiobiologists towards their undesired side effects produced in various tissues and for modifying them to facilitate the beneficial uses of radiation. Modification of radiation response is obtained by means of chemical substances that can significantly decrease the magnitude of response when present in a biological system during irradiation. Radioprotectors are chemicals that modify a cell's response to radiation. Radioprotectors are drugs that protect normal (non cancerous) cells from the damage caused by radiation therapy. These agents promote the repair of normal cells that are exposed to radiation. Various chemicals, like Cysteamine, MPG , WR-2721 have been tested for the protection against harmful effects of radiation. These radio

  1. Radiation effects and radioprotectors

    International Nuclear Information System (INIS)

    Purohit, R.K.; Bugalia, Saroj; Dakshene, Monika

    2012-01-01

    Radiation exposure causes damage to biological systems and these damages are mediated by the generation of free radicals and reactive oxygen species targeting vital cellular components such as DNA and membranes. DNA repair systems and the endogenous cellular biochemical defense mechanisms against reactive oxygen species and antioxidants enzymes like reduced Glutathione (GSH), Superoxide dismutase, Glutathione peroxidase catalase etc. fail upon exposures to higher as well as chronic radiation doses leading to alterations in cell functions, cell death or mutations. Radioprotectors prevent these alterations and protect cells and tissues from the deleterious effects of radiations. Radioprotectors are of great importance due to their possible and potential application during planned radiation exposures such as radiotherapy, diagnostic scanning, clean up operations in nuclear accidents, space expeditions etc. and Unplanned radiations exposures such as accidents in nuclear industry, nuclear terrorism, natural background radiation etc. Many of the available synthetic radioprotectors are toxic to mammalian system at doses required to be effective as radioprotector. Increasing uses of ionizing radiation have drawn the attention of many radiobiologists towards their undesired side effects produced in various tissues and for modifying them to facilitate the beneficial uses of radiation. Modification of radiation response is obtained by means of chemical substances that can significantly decrease the magnitude of response when present in a biological system during irradiation. Radioprotectors are chemicals that modify a cell's response to radiation. Radioprotectors are drugs that protect normal (non cancerous) cells from the damage caused by radiation therapy. These agents promote the repair of normal cells that are exposed to radiation. Various chemicals, like Cysteamine, MPG , WR-2721 have been tested for the protection against harmful effects of radiation. These radio

  2. Man and radiation effects

    International Nuclear Information System (INIS)

    Rausch, L.

    1982-01-01

    The book describes the effects of ionizing radiation on man in a simple, popular, detailed and generally valid manner and gives a comprehensive picture of the concepts, elements, principles of function, and perspectives of medical radiobiology. Radiobiology in general is explained, and its application in research on the causes of radiolesions and radiation diseases as well as a radiotherapy and radiation protection is discussed in popular form. (orig./MG) [de

  3. Biological radiation effects

    International Nuclear Information System (INIS)

    Kiefer, J.

    1989-01-01

    The book covers all aspects of biological radiation effects. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are discussed, taking into account modern developments and techniques. The effects on the human organism are reviewed, both from the point of view of applications in medicine as well as with regard to radiation hazards (teratogenic, gonadal and carcinogenic effects)

  4. Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Phillpot, Simon; Tulenko, James

    2011-09-08

    The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

  5. Fundamental Processes of Coupled Radiation Damage and Mechanical Behavior in Nuclear Fuel Materials for High Temperature Reactors

    International Nuclear Information System (INIS)

    Phillpot, Simon; Tulenko, James

    2011-01-01

    The objective of this work has been to elucidate the relationship among microstructure, radiation damage and mechanical properties for nuclear fuel materials. As representative nuclear materials, we have taken an hcp metal (Mg as a generic metal, and Ti alloys for fast reactors) and UO2 (representing fuel). The degradation of the thermo-mechanical behavior of nuclear fuels under irradiation, both the fissionable material itself and its cladding, is a longstanding issue of critical importance to the nuclear industry. There are experimental indications that nanocrystalline metals and ceramics may be more resistant to radiation damage than their coarse-grained counterparts. The objective of this project look at the effect of microstructure on radiation damage and mechanical behavior in these materials. The approach to be taken was state-of-the-art, large-scale atomic-level simulation. This systematic simulation program of the effects of irradiation on the structure and mechanical properties of polycrystalline Ti and UO2 identified radiation damage mechanisms. Moreover, it will provided important insights into behavior that can be expected in nanocrystalline microstructures and, by extension, nanocomposites. The fundamental insights from this work can be expected to help in the design microstructures that are less susceptible to radiation damage and thermomechanical degradation.

  6. Radiation effects in gases

    International Nuclear Information System (INIS)

    Leonhardt, J.W.

    1985-01-01

    Problems in the studies of radiation effects in gases are discussed. By means of ionization- excitation- and electron-capture yields various applications are characterized: ionization detectors, X-ray detectors, radionuclide battery, and radiation-induced chemical gas-phase reactions. Some new results of basic research in respect to the SO 2 oxidation are discussed. (author)

  7. Effects of ionizing radiations

    International Nuclear Information System (INIS)

    Gaussens, G.

    1984-08-01

    After recalling radiation-matter interaction, influence on radiation effects of chemical composition, structure, irradiation atmosphere, dose rate, temperature of organic materials and evolution of electrical, mechanical and physical properties are reviewed. Then behaviour under irradiation of main organic materials: elastomers, thermoplastics, thermosetting plastics, oils and paints are examined. 68 refs [fr

  8. Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

    International Nuclear Information System (INIS)

    2004-01-01

    ISO 6980 consists of the following parts, under the general title Nuclear energy - Reference beta-particle radiation: Part 1: Method of production; Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field; Part 3: Calibration of area and personal dosimeters and determination of their response as a function of energy and angle of incidence. This part 2 of ISO 6980 specifies methods for the measurement of the directional absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0.066 to 3.54 MeV (maximum energy). Radiation energies outside this range are beyond the scope of this standard. While measurements in a reference geometry (depth of 0.07 mm at perpendicular incidence in a tissue-equivalent slab phantom) with a reference class extrapolation chamber are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. The ambient dose equivalent, H*(10) as used for area monitoring of strongly penetrating radiation, is not an appropriate quantity for any beta radiation, even for that penetrating a 10 mm thick layer of ICRU tissue (i.e. E max > 2 MeV). If adequate protection is provided at 0.07 mm, only rarely will one be concerned with other depths, for example 3 mm. This document is geared towards organizations wishing to establish reference-class dosimetry capabilities for beta particles, and serves as a guide to the performance of dosimetry with the reference class extrapolation chamber for beta-particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties

  9. Nuclear knowledge management: a very fundament of a national radiation protection infrastructure

    International Nuclear Information System (INIS)

    Jovanovic, Slobodan

    2008-01-01

    Full text: Knowledge is fundament of any progress, and so is the case with nuclear knowledge (NK) for radiation protection. However, this axiomatic and notorious fact is sometimes interpreted/understood in a sense that knowledge is there for granted. If persistent, this dangerously wrong attitude may silently lead to prevailing of ignorance vs. knowledge/ competence and to RP degradation in much respect, with far reaching consequences. Having behind many decades of experience with research, development and utilization of radiation sources for various purposes (including both electric power generation and non-power applications) and with renewed expectations from nuclear sector in solving global energy crisis in front, nuclear knowledge management (NKM) is getting a growing attention lately. This comes due to accentuation, in many counties, of issues with NK creation, dissemination, transfer, preservation and maintenance, or its proper verification/ employing, positioning versus other knowledge, even valorization and public acceptance. Therein, RP is among the areas much sensitive and depending on the effects mentioned. RP infrastructure in a country comprising regulatory elements (institutional and legal framework), technical support organizations (service providers), educational institutions (universities, training centers), RP associations, source manufacturers, traders and users themselves is, as a matter of fact, a complex system of multidisciplinary nature. Physicists, chemists, biologists, environmentalists, medical physicists and practitioners, engineers, managers, lawyers, technicians have their place within the system. It is a common denominator for them all to need a particular NK pertinent to their duties. This very knowledge cannot be missed. Also, it cannot be improvised or substituted by some other knowledge from their respective specialties, neither by that of other people with different backgrounds, who might come in replacement. Unfortunately, it

  10. Neutrons and synchrotron radiation in engineering materials science from fundamentals to applications

    CERN Document Server

    Schreyer, Andreas; Clemens, Helmut; Mayer, Svea

    2017-01-01

    Retaining its proven concept, the second edition of this ready reference specifically addresses the need of materials engineers for reliable, detailed information on modern material characterization methods. As such, it provides a systematic overview of the increasingly important field of characterization of engineering materials with the help of neutrons and synchrotron radiation. The first part introduces readers to the fundamentals of structure-property relationships in materials and the radiation sources suitable for materials characterization. The second part then focuses on such characterization techniques as diffraction and scattering methods, as well as direct imaging and tomography. The third part presents new and emerging methods of materials characterization in the field of 3D characterization techniques like three-dimensional X-ray diffraction microscopy. The fourth and final part is a collection of examples that demonstrate the application of the methods introduced in the first parts to probl...

  11. The fundamental parameter method applied to X-ray fluorescence analysis with synchrotron radiation

    Science.gov (United States)

    Pantenburg, F. J.; Beier, T.; Hennrich, F.; Mommsen, H.

    1992-05-01

    Quantitative X-ray fluorescence analysis applying the fundamental parameter method is usually restricted to monochromatic excitation sources. It is shown here, that such analyses can be performed as well with a white synchrotron radiation spectrum. To determine absolute elemental concentration values it is necessary to know the spectral distribution of this spectrum. A newly designed and tested experimental setup, which uses the synchrotron radiation emitted from electrons in a bending magnet of ELSA (electron stretcher accelerator of the university of Bonn) is presented. The determination of the exciting spectrum, described by the given electron beam parameters, is limited due to uncertainties in the vertical electron beam size and divergence. We describe a method which allows us to determine the relative and absolute spectral distributions needed for accurate analysis. First test measurements of different alloys and standards of known composition demonstrate that it is possible to determine exact concentration values in bulk and trace element analysis.

  12. Fundaments for creation of national radiation protection standard for nuclear gauges

    International Nuclear Information System (INIS)

    Ferreira, Luiz Cavalcante

    2016-01-01

    The present work It aims to provide fundaments for the creation of a national standard of practice, safety and responsible use of nuclear gauges in accordance with the recommendations already existing national and international. The work deals with the protection against ionizing radiation, an outline of a proposal for a standard that discriminates in its articles and paragraphs, the basic principles of a proposal for a standard that discriminates in its articles and paragraphs, the basic principles of safety and security, and some pointes that are also relevant such as the responsibilities of those involved in acquisition and nuclear gauge operation, storage, maintenance, testing and emergency situations. The result is to provide a means to limit the dose of operators and people from the public and maintain these limits within the recommended by CNEN, reducing exposure do ionizing radiation, and having greater control in operating the equipment. (author)

  13. Neutrons and synchrotron radiation in engineering materials science. From fundamentals to applications. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Staron, Peter [Helmholtz-Zentrum Geesthacht, Zentrum fuer Material- und Kuestenforschung GmbH, Geesthacht (Germany). Inst. of Materials Research; Schreyer, Andreas [European Spallation Source ERIC, Lund (Sweden); Clemens, Helmut; Mayer, Svea (eds.) [Montanuniv. Leoben (Austria). Dept. of Physical Metallurgy and Materials Testing

    2017-07-01

    This book provides a systematic overview of the increasingly important field of characterization of engineering materials with the help of neutrons and synchrotron radiation. The first part introduces readers to the fundamentals of structure-property relationships in materials and the radiation sources suitable for materials characterization. The second part then focuses on such characterization techniques as diffraction and scattering methods, as well as direct imaging and tomography. The third part presents new and emerging methods of materials characterization in the field of 3D characterization techniques like three-dimensional X-ray diffraction microscopy. The fourth and final part is a collection of examples that demonstrate the application of the methods introduced in the first parts to problems in materials science.

  14. Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

    International Nuclear Information System (INIS)

    Schultz, E.

    1985-01-01

    Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

  15. Dosimetry of ionizing radiation. Fundamentals and applications. Dosimetrie ionisierender Strahlen. Grundlagen und Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Reich, H [ed.

    1990-01-01

    In the first chapter of the book, a brief description is given of the historical development of dosimetry, of its objectives and special role within the context of general physical metrology, followed by detailed explanations of the physical fundamentals of this science: the sources and fields of radiation, interactions between radiation and matter as well as radiation detectors. The terminology and units of measurement used in dosimetry are explained in a separate chapter. Chapters 7 and 8, which outline the various theoretical and experimental methods of dose determination, are the most essential contributions to this volume. Chapter 9 deals with the ways in which dosimetry is used in special cases in radiotherapy as well as in the measurement of very small or very large doses. Chapter 10 gives a survey of recently introduced units of measurements and methods to calculate the body dose with reference to the particular type of exposure used. Appendix A contains tables of measuring units, physical constants and measuring techniques along with at-a-glance information on the legal regulations concerning the calibration of dosimeters. Appendix B gives practical guidance on the handling of hardware-related inaccuracies of measurement in dose determination procedures and appendix C embraces 22 pages of tables showing data on radiation physics. (orig./HP) With 150 figs., 50 tabs. in the text, and annex with tables.

  16. Radiation effects on materials in high-radiation environments

    International Nuclear Information System (INIS)

    Weber, W.J.; Mansur, L.K.; Clinard, F.W. Jr.; Parkin, D.M.

    1991-01-01

    A workshop on Radiation Effects on Materials in High-Radiation Environments was held in Salt Lake City, Utah (USA) from August 13 to 15, 1990 under the auspices of the Division of Materials Sciences, Office of Basic Energy Sciences, US Department of Energy. The workshop focused on ceramics, alloys, and intermetallics and covered research needs and capabilities, recent experimental data, theory, and computer simulations. It was concluded that there is clearly a continuing scientific and technological need for fundamental knowledge on the underlying causes of radiation-induced property changes in materials. Furthermore, the success of many current and emerging nuclear-related technologies critically depend on renewed support for basic radiation-effects research, irradiation facilities, and training of scientists. The highlights of the workshop are reviewed and specific recommendations are made regarding research needs. (orig.)

  17. Radiation. Doses, effect, risk

    International Nuclear Information System (INIS)

    Vapirev, E.; Todorov, P.

    1994-12-01

    This book outlines in a popular form the topic of ionizing radiation impacts on living organisms. It contains data gathered by ICRP for a period of 35 years. The essential dosimetry terms and units are presented. Natural and artificial sources of ionizing radiation are described. Possible biological radiation effects and diseases as a consequence of external and internal irradiation at normal and accidental conditions are considered. An assessment of genetic risk for human populations is presented and the concept of 'acceptable risk' is discussed

  18. Introduction and fundamentals

    International Nuclear Information System (INIS)

    Thomas, R.H.

    1980-01-01

    This introduction discusses advances in the fundamental sciences which underlie the applied science of health physics and radiation protection. Risk assessments in nuclear medicine are made by defining the conditions of exposure, identification of adverse effects, relating exposure with effect, and estimation of the overall risk for ionizing radiations

  19. Handbook of radiation effects

    International Nuclear Information System (INIS)

    Holmes-Siedle, A.; Adams, L.

    1993-01-01

    This handbook is intended to serve as a tool for designers of equipment and scientific instruments in cases where they are required to ensure the survival of the equipment in radiation environments. High-technology materials, especially semiconductors and optics, tend to degrade on exposure to radiation in many different ways. Intense high-energy radiation environments are found in nuclear reactors and accelerators, machines for radiation therapy, industrial sterilization, and space. Some engineers have to build equipment which will survive a nuclear explosion from a hostile source. Proper handling of a disaster with radioactive materials requires equipment which depends utterly on semiconductor microelectronics and imaging devices. Thus the technology of radiation-tolerant electronics is an instrument for good social spheres as diverse as disaster planning and the exploration of Mars. In order to design equipment for intense environments like those described above, then degradation from high-energy irradiation must be seen as a basic design parameter. The aim of this handbook is to assist the engineer or student in that thought; to make it possible to write intelligent specifications; to offer some understanding of the complex variety of effects which occur when high-technology components encounter high-energy radiation; and to go thoroughly into the balance of choices of how to alleviate the effects and hence achieve the design aims of the project. Separate abstracts were prepared for 15 chapters of this book

  20. Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Jatau, B.D.; Garba, N.N.; Yusuf, A.M.; Yamusa, Y. A.; Musa, Y.

    2013-01-01

    In earlier studies, researchers aimed a single particle at the nucleus of the cell where DNA is located. Eighty percent of the cells shot through the nucleus survived. This contradicts the belief that if radiation slams through the nucleus, the cell will die. But the bad news is that the surviving cells contained mutations. Cells have a great capacity to repair DNA, but they cannot do it perfectly. The damage left behind in these studies from a single particle of alpha radiation doubled the damage that is already there. This proved, beyond a shadow of doubt, those there biological effects occur as a result of exposure to radiation, Radiation is harmful to living tissue because of its ionizing power in matter. This ionization can damage living cells directly, by breaking the chemical bonds of important biological molecules (particularly DNA), or indirectly, by creating chemical radicals from water molecules in the cells, which can then attack the biological molecules chemically. At some extent these molecules are repaired by natural biological processes, however, the effectiveness of this repair depends on the extent of the damage. The interaction of ionizing with the human body, arising either from external sources outside the body or from internal contamination of the body by radioactive materials, leads to the biological effects which may later show up as a clinical symptoms. Basically, this formed the baseline of this research to serve as a yardstick for creating awareness about radiation and its resulting effects.

  1. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  2. Radiation-induced segregation: A microchemical gauge to quantify fundamental defect parameters

    International Nuclear Information System (INIS)

    Simonen, E.P.; Bruemmer, S.M.

    1994-12-01

    Defect Kinetic are evaluated for austenitic stainless alloys by comparing model predictions to measured responses for radiation-induced grain boundary segregation. Heavy-ions, neutrons and proton irradiations having substantial statistical bases are examined. The combined modeling and measurement approach is shown to be useful for quantifying fundamental defect parameters. The mechanism evaluation indicates vacancy, migration energies of 1.15 eV or less and a vacancy formation energy at grain boundaries of 1.5 eV. Damage efficiencies of about 0.03 were established for heavy-ions and for light-water reactor neutrons. Inferred proton damage efficiencies were about 0.15. Segregation measured in an advanced gas-cooled reactor component was much greater than expected using the above parameters

  3. Radiation effects on living systems

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1980-10-01

    This bibliography includes papers and reports by Atomic Energy of Canada Limited scientists concerning radiation effects on living systems. It is divided into three sections: Radiobiology, Radiation Biochemistry and Radiation Chemistry. (auth)

  4. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Heribanova, A.

    1995-01-01

    The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

  5. Bystander effects of radiation

    International Nuclear Information System (INIS)

    Umar, Neethu Fathima; Daniel, Nittu

    2013-01-01

    The Radiation-Induced Bystander Effect is the phenomenon in which unirradiated cells show irradiated effects due to the signals received from nearby irradiated cells. Evidence suggests that targeted cytoplasmic irradiation results in mutation in the nucleus of the hit cells. Cells that are not directly hit by an alpha particle, but are in the vicinity of one that is hit, also contribute to the genotoxic response of the cell population. When cells are irradiated, and the medium is transferred to unirradiated cells, these unirradiated cells show bystander responses when assayed for clonogenic survival and oncogenic transformation. The demonstration of a bystander effect in human tissues and, more recently, in whole organisms have clear implication of the potential relevance of the non-targeted response to human health. This effect may also contribute to the final biological consequences of exposure to low doses of radiation. The radiation-induced bystander effect represents a paradigm shift in our understanding of the radiobiological effects of ionizing radiation, in that extranuclear and extracellular events may also contribute to the final biological consequences of exposure to low doses of radiation. Multiple pathways are involved in the bystander phenomenon, and different cell types respond differently to bystander signalling. Using cDNA microarrays, a number of cellular signalling genes, including cyclooxygenase-2 (CQX-2), have been shown to be casually linked to the bystander phenomenon. The observation that inhibition of the phosphorylation of extracellular signal-related kinase (ERK) suppressed the bystander response further confirmed the important role of the mitogen-activated protein kinase (MAPK) signalling cascade in the bystander process. The cells deficient in mitochondrial DNA showed a significantly reduced response to bystander signalling, suggesting a functional role of mitochondria in the signalling process. (author)

  6. Radiation effects on superconductivity

    International Nuclear Information System (INIS)

    Brown, B.S.

    1975-01-01

    The effect of radiation on the superconducting transition temperature (T/sub c/), upper critical field (H/sub c2/), and volume-pinning-force density (F/sub p/) were discussed for the three kinds of superconducting material (elements, alloys, and compounds). 11 figures, 3 tables, 86 references

  7. Genetic effects of radiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    1977-01-01

    Many of the most important findings concerning the genetic effects of radiation have been obtained in the Biology Division of Oak Ridge National Laboratory. The paper focuses on some of the major discoveries made in the Biology Division and on a new method of research that assesses damage to the skeletons of mice whose fathers were irradiated. The results discussed have considerable influence upon estimates of genetic risk in humans from radiation, and an attempt is made to put the estimated amount of genetic damage caused by projected nuclear power development into its proper perspective

  8. Fundamentals of radiological protection

    International Nuclear Information System (INIS)

    Wells, J.; Mill, A.J.; Charles, M.W.

    1978-05-01

    The basic processes of living cells which are relevant to an understanding of the interaction of ionizing radiation with man are described. Particular reference is made to cell death, cancer induction and genetic effects. This is the second of a series of reports which present the fundamentals necessary for an understanding of the bases of regulatory criteria such as those recommended by the International Commision on Radiological Protection (ICRP). Others consider basic radiation physics and the biological effects of ionizing radiation. (author)

  9. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1981-05-01

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  10. Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    1979-01-01

    The last day of March 1978 marked the completion of the first 3 years of operation of the Radiation Effects Research Foundation in Hiroshima and Nagasaki. RERF was established on 1 April 1975 as successor to the Atomic Bomb Casualty Commission which had been in continuous operation since 1947. This record of the first 3 years of operation consists of selected reports and other documents prepared in the course of conducting the business of RERF and includes a brief history, a late radiation effects that might be conducted at RERF. The wisdom and thought given to the research program and its operation by the Scientific Council and the Board of Directors is reflected in the minutes of their meetings which are included in the Appendix. (Mori, K.)

  11. Radiation Bystander Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Shokohzaman Soleymanifard

    2009-06-01

    Full Text Available Introduction: Radiation Induced Bystander Effect (RIBE which cause radiation effects in non-irradiated cells, has challenged the principle according to which radiation traversal through the nucleus of a cell is necessary for producing biological responses. What is the mechanism of this phenomenon? To have a better understanding of this rather ambiguous concept substantial number of original and reviewed article were carefully examined. Results: Irradiated cells release molecules which can propagate in cell environment and/or transmit through gap junction intercellular communication. These molecules can reach to non-irradiated cells and transmit bystander signals. In many investigations, it has been confirmed that these molecules are growth factors, cytokines, nitric oxide and free radicals like reactive oxygen species (ROS. Transmission of by stander signal to neighboring cells persuades them to produce secondary growth factors which in their turn cause further cell injuries. Some investigators suggest, organelles other than nucleus (mitochondria and cell membrane are the origin of these signals.  There is another opinion which suggests double strand breaks (DSB are not directly generated in bystander cells, rather they are due to smaller damage like single strand breaks which accumulate and end up to DSB. Although bystander mechanisms have not been exactly known, it can be confirmed that multiple mechanisms and various pathways are responsible for this effect. Cell type, radiation type, experimental conditions and end points identify the dominant mechanism. Conclusion: Molecules and pathways which are responsible for RIBE, also cause systemic responses to other non-irradiation stresses. So RIBE is a kind of systemic stress or innate immune responses, which are performed by cell microenvironment. Irradiated cells and their signals are components of microenvironment for creating bystander effects.

  12. Radiation effects in metals

    International Nuclear Information System (INIS)

    Leteurtre Jean.

    1978-01-01

    The current understanding of radiation damage in metals is reviewed, simplifying the actual complexity of the effects by considering some aspects separately. The production of point defects in metals, the primary damage state are first studied. The second part of the lecture is devoted to the evolution of this primary damage state as a function of temperature and dose: the steady state concentration of point defects, the nucleation of secondary defects and their growth are successively considered

  13. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Gray, W.M.; Watson, E.R.

    1977-01-01

    In five previous papers, the concept of Cumulative Radiation Effect (CRE) has been presented as a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Simple nomographic and tabular methods for the solution of practical problems in radiotherapy are now described. An essential feature of solving a CRE problem is firstly to present it in a concise and readily appreciated form, and, to do this, nomenclature has been introduced to describe schedules and regimes as compactly as possible. Simple algebraic equations have been derived to describe the CRE achieved by multi-schedule regimes. In these equations, the equivalence conditions existing at the junctions between schedules are not explicit and the equations are based on the CREs of the constituent schedules assessed individually without reference to their context in the regime as a whole. This independent evaluation of CREs for each schedule has resulted in a considerable simplification in the calculation of complex problems. The calculations are further simplified by the use of suitable tables and nomograms, so that the mathematics involved is reduced to simple arithmetical operations which require at the most the use of a slide rule but can be done by hand. The order of procedure in the presentation and calculation of CRE problems can be summarised in an evaluation procedure sheet. The resulting simple methods for solving practical problems of any complexity on the CRE-system are demonstrated by a number of examples. (author)

  14. Radiation effects on microelectronics

    International Nuclear Information System (INIS)

    Gover, J.E.

    1987-01-01

    Applications of radiation-hardened microelectronics in nuclear power systems include (a) light water reactor (LWR) containment building, postaccident instrumentation that can operate through the beta and gamma radiation released in a design basis loss-of-coolant accident; (b) advanced LWR instrumentation and control systems employing distributed digital integrated circuit (IC) technology to achieve a high degree of artificial intelligence and thereby reduce the probability of operator error under accident conditions; (c) instrumentation, command, control and communication systems for space nuclear power applications that must operate during the neutron and gamma-ray core leakage environments as well as the background electron, proton, and heavy charged particle environments of space; and (d) robotics systems designed for the described functions. Advanced microelectronics offer advantages in cost and reliability over alternative approaches to instrumentation and control. No semiconductor technology is hard to all classes of radiation effects phenomena. As the effects have become better understood, however, significant progress has been made in hardening IC technology. Application of hardened microelectronics to nuclear power systems has lagged military applications because of the limited market potential of hardened instruments and numerous institutional impediments

  15. Radiation effect on implanted pacemakers

    International Nuclear Information System (INIS)

    Pourhamidi, A.H.

    1983-01-01

    It was previously thought that diagnostic or therapeutic ionizing radiation did not have an adverse effect on the function of cardiac pacemakers. Recently, however, some authors have reported damaging effect of therapeutic radiation on cardiac pulse generators. An analysis of a recently-extracted pacemaker documented the effect of radiation on the pacemaker pulse generator

  16. Radiation effects on polyethylenes

    International Nuclear Information System (INIS)

    Suzuki, T.; Oki, Y.; Numajiri, M.; Miura, T.; Kondo, K.; Tanabe, Y.; Ishiyama, M.; Ito, Y.

    1992-01-01

    Radiation effects on four kinds of polyethylenes were studied from the viewpoints of mechanical properties, free radicals and free volumes. The samples were irradiated using a cobalt 60 gamma source to give doses up to 3MGy. The degradation of mechanical strength due to gamma-irradiation was evaluated by the elongation at break and its tensile strength. Radiation induced free radicals were measured by ESR. Free volumes observed by the o-Ps component of the positron annihilation spectrum are normally the large ones located in the amorphous regions and after irradiation these are created in crystalline regions, too. The sizes and the relative numbers of free volumes were evaluated by lifetimes and intensities of a long-lived component of positronium, respectively. Using these data, the properties of polyethylenes before and after irradiation are discussed. (author)

  17. Biological effects of ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The paper reports the proceedings of a conference organised jointly by Friends of the Earth (U.K.) and Greenpeace (International). The aim of the conference was to discuss the effects of low level radiation, particularly on man, within the terms of dose/risk relationships. The topics discussed included: sources of radiation, radiation discharges from nuclear establishments, predictive modelling of radiation hazards, radiation effects at Hiroshima, low dose effects and ICRP dose limits, variation in sensitivity to radiation, and the link between childhood cancer and nuclear power. (U.K.)

  18. Radiological fundamentals for decision making on public radiation protection measures in case of accident caused radionuclide release

    International Nuclear Information System (INIS)

    Genkel, Simone

    2009-01-01

    Following the accepted revised version of the recommendations concerning in the frame of emergency management by the German SSK (radiation protection commission) the radiological fundamentals dating from 1990 were revised. The corrections of the dose benchmarks for children and juveniles for the case of iodine tablets intake that were included, in the chapter on radiation protection for the field and rescue personnel of fire brigade and police the new regulations of the radiation protection ordinance were added. The volume includes two parts: Guidelines for emergency planning in the environment of nuclear facilities; guideline on public information in nuclear emergency situations.

  19. Effect of sample matrix on the fundamental properties of the inductively coupled plasma

    International Nuclear Information System (INIS)

    Lehn, Scott A.; Warner, Kelly A.; Huang Mao; Hieftje, Gary M.

    2003-01-01

    In the inductively coupled plasma (ICP), the emission intensities of atomic and ionic spectral lines are controlled by fundamental parameters such as electron temperature, electron number density, gas-kinetic temperature, analyte atom and ion number densities, and others. Accordingly, the effect of a sample matrix on the analyte emission intensity in an ICP might be attributable to changes in these fundamental parameters caused by the matrix elements. In the present study, a plasma imaging instrument that combines Thomson scattering, Rayleigh scattering, laser-induced fluorescence and computed tomography has been employed to measure the above-mentioned parameters in the presence and absence of matrix elements. The data thus obtained were all collected on a spatially resolved basis and without the need for Abel inversion. Calcium, strontium and barium served as analytes, while lithium, copper and zinc were introduced as matrix elements. Comparing the data with and without the matrix elements allows us to determine the extent to which each fundamental parameter changes in the presence of a matrix element, and to better understand the nature of the matrix effects that occur in the ICP. As has been seen in previous studies with different matrix elements, ion emission and ion number densities follow opposite trends when matrix interferents are introduced into the plasma: ion emission is enhanced by the presence of matrix interferents while ion concentrations are lowered. These changes are consistent with a shift from collisional deactivation to radiative decay of excited-state analyte species

  20. effects of flexural rigidity of reinforcement bars on the fundamental ...

    African Journals Online (AJOL)

    NIJOTECH

    Nigerian Journal of Technology, Vol. 28, No. 2, September, 2009 ... forth between the concrete surface and the ... number of layers on the fundamental frequency of vibration ... isotropic and an orthotropic flat plate models for predicting simple ...

  1. Biological radiation effects

    International Nuclear Information System (INIS)

    Koggl, D.; Dedenkov, A.N.

    1986-01-01

    All nowadays problems of radio biology are considered: types of ionizing radiations, their interaction with material; damage of molecular structures and their reparation; reaction of cells and their recovery from radiation damage; reaction of the whole organism and its separate systems. Particular attention is given to the problems of radiation carcinogenesis and radiation hazard for man

  2. Cumulative radiation effect

    International Nuclear Information System (INIS)

    Kirk, J.; Cain, O.; Gray, W.M.

    1977-01-01

    Cumulative Radiation Effect (CRE) represents a scale of accumulative sub-tolerance radiation damage, with a unique value of the CRE describing a specific level of radiation effect. Computer calculations have been used to simplify the evaluation of problems associated with the applications of the CRE-system in radiotherapy. In a general appraisal of the applications of computers to the CRE-system, the various problems encountered in clinical radiotherapy have been categorised into those involving the evaluation of a CRE at a point in tissue and those involving the calculation of CRE distributions. As a general guide, the computer techniques adopted at the Glasgow Institute of Radiotherapeutics for the solution of CRE problems are presented, and consist basically of a package of three interactive programs for point CRE calculations and a Fortran program which calculates CRE distributions for iso-effect treatment planning. Many examples are given to demonstrate the applications of these programs, and special emphasis has been laid on the problem of treating a point in tissue with different doses per fraction on alternate treatment days. The wide range of possible clinical applications of the CRE-system has been outlined and described under the categories of routine clinical applications, retrospective and prospective surveys of patient treatment, and experimental and theoretical research. Some of these applications such as the results of surveys and studies of time optimisation of treatment schedules could have far-reaching consequences and lead to significant improvements in treatment and cure rates with the minimum damage to normal tissue. (author)

  3. Effects of background radiation

    International Nuclear Information System (INIS)

    Knox, E.G.; Stewart, A.M.; Gilman, E.A.; Kneale, G.W.

    1987-01-01

    The primary objective of this investigation is to measure the relationship between exposure to different levels of background gamma radiation in different parts of the country, and different Relative Risks for leukaemias and cancers in children. The investigation is linked to an earlier analysis of the effects of prenatal medical x-rays upon leukaemia and cancer risk; the prior hypothesis on which the background-study was based, is derived from the earlier results. In a third analysis, the authors attempted to measure varying potency of medical x-rays delivered at different stages of gestation and the results supply a link between the other two estimates. (author)

  4. Radiation effects on vasoproliferation

    International Nuclear Information System (INIS)

    Yamaura, Hirotsugu; Matsuzawa, Taiju

    1975-01-01

    The authors quantitatively examined radiation effects on vascular proliferarion, using the rat transparent chamber technique to observe the living microcirculation. We studied the process of vasoproliferation and revascularization from the surrounding pre-existing vessels into the surgically avascularized area in the chamber, by measuring the vascular lenght photographically. A hyper-vascularized zone, about 0.5 mm in with, was formed on the vascularizing frontier, the significance of which is so far not known. When the chambers were irradiated with various doses of 60 Co γ-rays, a dose dependent inhibition of vasoproliferation was observed. (auth.)

  5. Radiation effects on vasoproliferation

    Energy Technology Data Exchange (ETDEWEB)

    Yamaura, H; Matsuzawa, T [Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis, Leprosy and Cancer

    1975-06-01

    The authors quantitatively examined radiation effects on vascular proliferarion, using the rat transparent chamber technique to observe the living microcirculation. We studied the process of vasoproliferation and revascularization from the surrounding pre-existing vessels into the surgically avascularized area in the chamber, by measuring the vascular lenght photographically. A hyper-vascularized zone, about 0.5 mm in with, was formed on the vascularizing frontier, the significance of which is so far not known. When the chambers were irradiated with various doses of /sup 60/Co ..gamma..-rays, a dose dependent inhibition of vasoproliferation was observed.

  6. Biological radiation effects

    International Nuclear Information System (INIS)

    Sejourne, Michele.

    1977-01-01

    This work examines ionizing radiations: what they are, where they come from, their actions and consequences, finally the norms and preventive measures necessary to avoid serious contamination, whether the individual or the population in general is involved. Man has always been exposed to natural irradiation, but owing to the growing use of ionizing radiations both in medicine and in industry, not to mention nuclear tests and their use as an argument of dissuasion, the irradiation of human beings is increasing daily. Radioactive contamination does remain latent, apart from acute cases, but this is where the danger lies since the consequences may not appear until long after the irradiation. Of all biological effects due to the action of radioelements the genetic risk is one of the most important, affecting the entire population and especially the generations to come. The risk of cancer and leukemia induction plays a substantial part also since a large number of people may be concerned, depending on the mode of contamination involved. All these long-term dangers do not of course exclude the various general or local effects to which the individual alone may be exposed and which sometimes constitute a threat to life. As a result the use of ionizing radiations must be limited and should only be involved if no other process can serve instead. The regulations governing radioelements must be stringent and their application strictly supervised for the better protection of man. This protection must be not only individual but also collective since pollution exists in air, water and land passes to plants and animals and finally reaches the last link in the food chain, man [fr

  7. Radiation effects and radiation risks. 2. ed.

    International Nuclear Information System (INIS)

    Lengfelder, E.; Forst, D.; Feist, H.; Pratzel, H.G.

    1990-01-01

    The book presents the facts and the principles of assessment and evaluation of biological radiation effects in general and also with particular reference to the reactor accident of Chernobyl, reviewing the consequences and the environmental situation on the basis of current national and international literature, including research work by the authors. The material compiled in this book is intended especially for physicians, but will also prove useful for persons working in the public health services, in administration, or other services taking care of people. The authors tried to find an easily comprehensible way of presenting and explaining the very complex processes and mechanisms of biological radiation effects and carcinogenesis, displaying the physical primary processes and the mechanisms of the molecular radiation effects up to the effects of low-level radiation, and present results of comparative epidemiologic studies. This section has been given considerable space, in proportion to its significance. It also contains literature references for further reading, offering more insight and knowledge of aspects of special subject fields. The authors also present less known results and data and discuss them against the background of well-known research results and approaches. Apart from the purpose of presenting comprehensive information, the authors intend to give an impact for further thinking about the problems, and helpful tools for independent decisions and action on the basis of improved insight and assessment, and in this context particularly point to the problems induced by the Chernobyl reactor accident. (orig.) With 10 maps in appendix [de

  8. Effects of radiation

    International Nuclear Information System (INIS)

    Masse, R.

    2006-01-01

    The medical consequences of a whole-body irradiation come from the destruction of cells and inflammatory reactions it provokes. The most sensitive organs are the tissues that actively split. The embryo is particularly sensitive, from 200 mSv for the effects on the brain development. The reproduction functions are reached for man from 2000 mSv, the ovary sensitivity is less, the oocytes do not split after the fetus life. For adult the bone marrow outrage leads to the disappearing of blood cells (4000 mSv). The doses from 6000 to 10000 mSv lead the failure of the digestive system and lung. for the upper doses every tissue is reached, particularly by the effects on cells of blood vessels. Important brain dysfunctions appear beyond 10000 mSv. As regards the delayed effects of overexposures the epidemiology brings to light sanitary consequences of the exposure of the population to the ionizing radiations and requires that all the possible factors associated for that purpose are considered. About hereditary effects, it appears that moderate acute radiation exposures of even a relatively large human population must have little impact, in spite of the rate of spontaneous congenital deformations is of the order of 6 %. For the induction of cancers, it is not observed excess for doses lower than 200 mSv for adults and 100 mSv for children (the populations studied are survival people of hiroshima and Nagasaki, patients treated by irradiation, uranium miners, children exposed to radioactive iodine after Chernobylsk accident). To simplify an expression of the risk has been fixed to 5% of induced cancer by Sv for population and 4% by Sv for workers, the different being explained by the demography and the sensitivity of the youngest age groups. As regards the low doses of radiations, a bundle of convergent epidemiological observations notices the absence of effects of the low doses rates. Biological mechanisms, notably of repair are approached, then certain accidents (Goiania

  9. Radiation effects on living systems

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1984-04-01

    This bibliography includes papers and reports by Atomic Energy of Canada Limited scientists concerning radiation effects on living systems. It is divided into three sections: Radiobiology, Radiation Biochemistry and Radiation Chemistry. It is intended that the bibliography will be updated regularly

  10. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1977-03-01

    A summary is given of studies on radiation effects in light-emitting diodes, laser diodes, detectors, optical isolators and optical fibers. It is shown that the study of radiation damage in these devices can provide valuable information concerning the nature of the devices themselves, as well as methods of hardening these devices for applications in radiation environments

  11. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1991-12-01

    Ionizing radiation effects on the gem cells, which can result in genetic abnormalities, are described. The basic mechanisms of radiation interactions with chromosomes, or specifically DNA, which can result in radiation induced mutation are discussed. Methods of estimating genetic risks, and some values for quantitative risk estimates are given. (U.K.). 13 refs., 2 figs., 1 tab

  12. Biological effects of particle radiation

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1988-01-01

    Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

  13. Biology of ionizing radiation effects

    International Nuclear Information System (INIS)

    Ferradini, C.; Pucheault, J.

    1983-01-01

    The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr

  14. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

    The hazards of radiations to man are briefly covered in this paper. The natural background sources of radiations are stated and their resulting doses are compared to those received voluntarily by man. The basis of how radiations cause biological damage is given and the resulting somatic effects are shown for varying magnitude of dose. Risk estimates are given for cancer induction and genetic effects are briefly discussed. Finally four case studies of radiation damage to humans are examined exemplifying the symptoms of large doses of radiations [af

  15. Radiation effects on lymphocytes

    International Nuclear Information System (INIS)

    Roser, B.

    1976-01-01

    This review of the ontogeny of lymphocyte populations concentrates on sites of production, rates of production, and the factors governing the differentiation and longevity of the various lymphocyte pools. The physiology of the lymphocyte pools is described with particular emphasis on recirculation from blood to lymph through lymphoid tissues. The separate routes of recirculation of both thymus-derived and nonthymus-derived lymphocytes and the possible anatomical sites and mechanisms of lymphocyte cooperation are discussed. Radiation effects on lymphocyte populations are divided into two sections. First, the effects of whole-body irradiation on the total lymphocyte pools are discussed including the differential effects of irradiation on T lymphocytes, B lymphocytes, lymphoblasts, and plasma cells. The differential sensitivity of various types of immune response is correlated, where possible, with the differential sensitivity of the lymphocyte types involved. Second, experimental attempts to selectively deplete discrete subpopulations of the total lymphocyte pools, e.g., recirculating cells, are briefly discussed with particular emphasis on studies on the effects of the localization of radionuclides in lymphoid tissue

  16. TH-A-16A-01: Image Quality for the Radiation Oncology Physicist: Review of the Fundamentals and Implementation

    International Nuclear Information System (INIS)

    Seibert, J; Imbergamo, P

    2014-01-01

    The expansion and integration of diagnostic imaging technologies such as On Board Imaging (OBI) and Cone Beam Computed Tomography (CBCT) into radiation oncology has required radiation oncology physicists to be responsible for and become familiar with assessing image quality. Unfortunately many radiation oncology physicists have had little or no training or experience in measuring and assessing image quality. Many physicists have turned to automated QA analysis software without having a fundamental understanding of image quality measures. This session will review the basic image quality measures of imaging technologies used in the radiation oncology clinic, such as low contrast resolution, high contrast resolution, uniformity, noise, and contrast scale, and how to measure and assess them in a meaningful way. Additionally a discussion of the implementation of an image quality assurance program in compliance with Task Group recommendations will be presented along with the advantages and disadvantages of automated analysis methods. Learning Objectives: Review and understanding of the fundamentals of image quality. Review and understanding of the basic image quality measures of imaging modalities used in the radiation oncology clinic. Understand how to implement an image quality assurance program and to assess basic image quality measures in a meaningful way

  17. Fundamental radiation effects studies in the fusion-materials program

    International Nuclear Information System (INIS)

    Doran, D.G.

    1981-10-01

    Some examples of progress being made in DAFS studies are given. The primary parameters in which most damage models are expressed are total displacements per atom (dpa), total helium concentration (appm), and the helium-to-dpa ratio. The concentrations of other transmutation products than helium have assumed significance in certain cases as will be seen below. The number of dpa is generally taken proportional to the damage energy, the total energy deposited in a material, corrected for the fraction dissipated in electronic excitation and ionization

  18. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Experiments with small animals, tissue cultures, and inanimate materials help with understanding the effects of ionizing radiation that occur at the molecular level and cause the gross effects observed in man. Topics covered in this chapter include the following: Radiolysis of Water; Radiolysis of Organic Compounds; Radiolysis in Cells; Radiation Exposure and Dose Units; Dose Response Curves; Radiation Effects in Animals; Factors Affecting Health Risks. 8 refs., 3 figs., 5 tabs

  19. Effect of a Nitrogen Impurity on the Fundamental Raman Band of Diamond Single Crystals

    Science.gov (United States)

    Gusakov, G. A.; Samtsov, M. P.; Voropay, E. S.

    2018-05-01

    The effect of nitrogen defects in natural and synthetic diamond single crystals on the position and half-width of the fundamental Raman band was investigated. Samples containing the main types of nitrogen lattice defects at impurity contents of 1-1500 ppm were studied. The parameters of the Stokes and anti-Stokes components in Raman spectra of crystals situated in a cell with distilled water to minimize the influence of heating by the exciting laser radiation were analyzed to determine the effect of a nitrogen impurity in the diamond crystal lattice. It was shown that an increase of impurity atoms in the crystals in the studied concentration range resulted in broadening of the Raman band from 1.61 to 2.85 cm-1 and shifting of the maximum to lower frequency from 1332.65 to 1332.3 cm-1. The observed effect was directly proportional to the impurity concentration and depended on the form of the impurity incorporated into the diamond lattice. It was found that the changes in the position and half-width of the fundamental Raman band for diamond were consistent with the magnitude of crystal lattice distortions due to the presence of impurity defects and obeyed the Gruneisen law.

  20. Effects of radiation on man

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1981-01-01

    The available evidence on the effects of radiation on man and the predictions that have been made of possible low level effects are reviewed. Data from United Nations Scientific Committee of the Effects of Atomic Radiation (UNSCEAR) and the committee on the Biological Effects of Ionising Radiation (BEIR) is used to illustrate the acute, delayed and hereditary effects of high dose levels. The effects of low dose levels are discussed on the assumption that both somatic and hereditary effects can be predicted on the basis of linear extrapolation from high dose effects. (U.K.)

  1. Fundamental properties of flotation frothers and their effect on flotation

    Energy Technology Data Exchange (ETDEWEB)

    Melo, F.; Laskowski, J.S. [University of British Columbia, Vancouver, BC (Canada). Dept. of Mining Engineering

    2006-05-15

    Froth flotation process requires the use of frothers. These important flotation agents are commonly characterized as either 'selective' or 'powerful' and are chosen following general guidelines and verification by laboratory and/or pilot plant tests. Fundamental properties of the flotation frothers have been extensively studied over the last few years. These studies have led to the development of standardised procedures to characterise frothers in terms of their ability to reduce bubble size and to increase foam stability. In this research project, the performance of five frothers in flotation of coal is evaluated and related to the fundamental properties of these agents. Since the recovery of water in the concentrate is closely related to the non-selective transport of solid particles by entrainment, the tested frothers are also assessed in terms of their ability to promote the transport of water towards the froth collection zone, both in absence and in presence of solids.

  2. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    Pathak, B.

    1989-12-01

    Ionizing radiation is energy that travels through space as electromagnetic waves or a stream of fast moving particles. In the workplace, the sources of ionizing radiation are radioactive substances, nuclear power plants, x-ray machines and nuclear devices used in medicine, research and industry. Commonly encountered types of radiation are alpha particles, beta particles and gamma rays. Alpha particles have very little penetrating power and pose a risk only when the radioactive substance is deposited inside the body. Beta particles are more penetrating than alpha particles and can penetrate the outer body tissues causing damage to the skin and the eyes. Gamma rays are highly penetrating and can cause radiation damage to the whole body. The probability of radiation-induced disease depends on the accumulated amount of radiation dose. The main health effects of ionizing radiation are cancers in exposed persons and genetic disorders in the children, grandchildren and subsequent generations of the exposed parents. The fetus is highly sensitive to radiation-induced abnormalities. At high doses, radiation can cause cataracts in the eyes. There is no firm evidence that ionizing radiation causes premature aging. Radiation-induced sterility is highly unlikely for occupational doses. The data on the combined effect of ionizing radiation and other cancer-causing physical and chemical agents are inconclusive

  3. Chemical effects of radiation

    International Nuclear Information System (INIS)

    Philips, G.O.

    1986-01-01

    Ionizing radiations initiate chemical changes in materials because of the high energy of their quanta. In water, highly reactive free radicals are produced which can initiate secondary changes of solutes, and in chemical of biological molecules in contact with the water. Free radicals can also be directly produced in irradiated medical products. Their fate can be identified and the molecular basis of radiation inactivation clarified. Methods have now been developed to protect and minimise such radiation damage. (author)

  4. Diffusion effects in undulator radiation

    Directory of Open Access Journals (Sweden)

    Ilya Agapov

    2014-11-01

    Full Text Available Quantum diffusion effects in undulator radiation in semiclassical approximation are considered. Short-term effects on the electron beam motion are discussed and it is shown that approaches based on diffusion approximation with drift-diffusion coefficients derived from undulator or bending magnet radiation spectrum, and on Poisson statistics with radiation spectrum defined by the local beding field, all lead to similar results in terms of electron energy spread for cases of practical interest. An analytical estimate of the influence of quantum diffusion on the undulator radiation spectrum is derived.

  5. Radiation effect on polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Deng Pengyang; Zhong Xiaoguang; Sun Jiazhen

    1999-01-01

    Polytetrafluoroethylene (PTFE) has always been regarded as a typical kind of radiation degradation polymer. But, in fact, PTFE can be induced crosslinking by γ-ray or electron beam at some special conditions (free oxygen and a narrow temperature region at 335 +- 5 degree C). Compared with radiation degradiation PTFE, cosslinking PTFE owns a lot of new properties. Some articles concerning with these have been published, which will be systematically reviewed in this

  6. Nonlinear generation of the fundamental radiation of interplanetary type III radio bursts

    International Nuclear Information System (INIS)

    Chian, A.C.L.; Alves, M.V.

    1988-01-01

    A new generation mechanism of interplanetary type III radio bursts at the fundamental electron plasma frequency is discussed. It is shown that the electromagnetic oscillating two-stream instability, driven by two oppositely propagating Langmuir waves, can account for the experimental observations. In particular, the major difficulties encountered by the previously considered electromagnetic decay instability are removed. 19 references

  7. Radiation effects on cell membranes

    International Nuclear Information System (INIS)

    Koeteles, G.J.

    1982-01-01

    Experimental data are presented concerning the effects of relatively low doses of x radiation and low concentration of tritiated water (HTO) on various receptor functions - concanavalin A, cationized ferritin, poliovirus of plasma membranes of animal and human cells which point to early and temporary disturbances of the composite structures and functions of membranes. References are given to the manifold influence of radiation-induced membrane phenomenon on the development and regeneration of radiation injuries. (author)

  8. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    Barnes, C.E.; Wiczer, J.J.

    1984-05-01

    Purpose of this report is to provide not only a summary of radiation damage studies at Sandia National Laboratories, but also of those in the literature on the components of optoelectronic systems: light emitting diodes (LEDs), laser diodes, photodetectors, optical fibers, and optical isolators. This review of radiation damage in optoelectronic components is structured according to device type. In each section, a brief discussion of those device properties relevant to radiation effects is given

  9. Reference radiation fields - Simulated workplace neutron fields - Part 2: Calibration fundamentals related to the basic quantities

    International Nuclear Information System (INIS)

    2008-01-01

    ISO 8529-1, ISO 8529-2 and ISO 8529-3, deal with the production, characterization and use of neutron fields for the calibration of personal dosimeters and area survey meters. These International Standards describe reference radiations with neutron energy spectra that are well defined and well suited for use in the calibration laboratory. However, the neutron spectra commonly encountered in routine radiation protection situations are, in many cases, quite different from those produced by the sources specified in the International Standards. Since personal neutron dosimeters, and to a lesser extent survey meters, are generally quite energy dependent in their dose equivalent response, it might not be possible to achieve an appropriate calibration for a device that is used in a workplace where the neutron energy spectrum and angular distribution differ significantly from those of the reference radiation used for calibration. ISO 8529-1 describes four radionuclide based neutron reference radiations in detail. This part of ISO 12789 includes the specification of neutron reference radiations that were developed to closely resemble radiation that is encountered in practice

  10. Effects of radiation; Effets des radiations

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    The medical consequences of a whole-body irradiation come from the destruction of cells and inflammatory reactions it provokes. The most sensitive organs are the tissues that actively split. The embryo is particularly sensitive, from 200 mSv for the effects on the brain development. The reproduction functions are reached for man from 2000 mSv, the ovary sensitivity is less, the oocytes do not split after the fetus life. For adult the bone marrow outrage leads to the disappearing of blood cells (4000 mSv). The doses from 6000 to 10000 mSv lead the failure of the digestive system and lung. for the upper doses every tissue is reached, particularly by the effects on cells of blood vessels. Important brain dysfunctions appear beyond 10000 mSv. As regards the delayed effects of overexposures the epidemiology brings to light sanitary consequences of the exposure of the population to the ionizing radiations and requires that all the possible factors associated for that purpose are considered. About hereditary effects, it appears that moderate acute radiation exposures of even a relatively large human population must have little impact, in spite of the rate of spontaneous congenital deformations is of the order of 6 %. For the induction of cancers, it is not observed excess for doses lower than 200 mSv for adults and 100 mSv for children (the populations studied are survival people of hiroshima and Nagasaki, patients treated by irradiation, uranium miners, children exposed to radioactive iodine after Chernobylsk accident). To simplify an expression of the risk has been fixed to 5% of induced cancer by Sv for population and 4% by Sv for workers, the different being explained by the demography and the sensitivity of the youngest age groups. As regards the low doses of radiations, a bundle of convergent epidemiological observations notices the absence of effects of the low doses rates. Biological mechanisms, notably of repair are approached, then certain accidents (Goiania

  11. Effects of radiation; Effets des radiations

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    The medical consequences of a whole-body irradiation come from the destruction of cells and inflammatory reactions it provokes. The most sensitive organs are the tissues that actively split. The embryo is particularly sensitive, from 200 mSv for the effects on the brain development. The reproduction functions are reached for man from 2000 mSv, the ovary sensitivity is less, the oocytes do not split after the fetus life. For adult the bone marrow outrage leads to the disappearing of blood cells (4000 mSv). The doses from 6000 to 10000 mSv lead the failure of the digestive system and lung. for the upper doses every tissue is reached, particularly by the effects on cells of blood vessels. Important brain dysfunctions appear beyond 10000 mSv. As regards the delayed effects of overexposures the epidemiology brings to light sanitary consequences of the exposure of the population to the ionizing radiations and requires that all the possible factors associated for that purpose are considered. About hereditary effects, it appears that moderate acute radiation exposures of even a relatively large human population must have little impact, in spite of the rate of spontaneous congenital deformations is of the order of 6 %. For the induction of cancers, it is not observed excess for doses lower than 200 mSv for adults and 100 mSv for children (the populations studied are survival people of hiroshima and Nagasaki, patients treated by irradiation, uranium miners, children exposed to radioactive iodine after Chernobylsk accident). To simplify an expression of the risk has been fixed to 5% of induced cancer by Sv for population and 4% by Sv for workers, the different being explained by the demography and the sensitivity of the youngest age groups. As regards the low doses of radiations, a bundle of convergent epidemiological observations notices the absence of effects of the low doses rates. Biological mechanisms, notably of repair are approached, then certain accidents (Goiania

  12. Ionizing radiations: effects and sources

    International Nuclear Information System (INIS)

    Vignes, S.; Nenot, J.C.

    1978-01-01

    Having first mentioned the effects of ionizing radiations in cancerogenisis, pre-natal, and genetic fields, the authors present the different sources of radiations and estimate their respective contributions to the total irradiation dose. Their paper makes reference to the main elements of a report issued by the United Nations Scientific Committee in 1977 [fr

  13. 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.)

  14. Epigenetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    EI-Naggar, A.M.

    2007-01-01

    Data generated during the last three decades provide evidence of Epigenetic Effects that ave-induced by ionizing radiation, particularly those of high LET values, and low level dose exposures. Epigenesist is defined as the stepwise process by which genetic information, as modified by environmental influences, is translated into the substance and behavior of cells, tissues, organism.The epigenetic effects cited in the literature are essentially classified into fine types depending on the type and nature of the effect induced.The most accepted postulation, for the occurrence of these epigenetic effects, is a radiation induced bio electric disturbances in the environment of the non-irradiated cellular volume. This will trigger signals that will induce effects in the unirradiated cells.The epigenetic effects referenced in the literature up to date are five types; namely, Genomic Instability, Bystander. Effects, Clastogenic Plasma Factors,, Abscopal Effects, and Tran generational Effects.The demonstration of Epigenetic Effects associated with exposure to ionizing radiation indicates the need to re- examine the concept of radiation dose and target size. Also an improved understanding of qualifiring and quantifying radiation risk estimates may be attained. Also, a more logical means to understand the underlying mechanisms of radiation induced carcinogenic transformation of cells

  15. Legal problems in the concretisation of the fundamental requirements on radiation protection. 2. paper

    International Nuclear Information System (INIS)

    Schattke, H.

    1980-01-01

    In contrast to justice administered by the Higher Administrative Court of Lueneburg, the author is of the opinion that the individual third party complaing within the framework of the rule to minimize radiation exposure laid down in the Radiation Protection Ordinance cannot refer to risks the population might be exposed to. This is the imperative consequence of the legal system which protects the individual. The fact that - contrary to the position held by the Higher Administrative Court of Lueneburg - Sections 45 and 46 of the Radiation Protection Ordinance include emissions caused by accidents is demonstrated by giving a word-for-word, systematical and teleological interpretation, using painstaking methods. The same goes for the importance of accident doses planned in Sect. 28 of the Radiation Protection Ordinance. To the extent to which it examines the import the basis of authorization would have for a radioecological ordinance, this contribution helps to understand the principles that govern radiation protection and the importance they have for licensing procedures under the Atomic Energy Law in general. (HP) [de

  16. Radiation hazards and biological effects of ionising radiation on man

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2004-01-01

    The contents of this chapter are follows - Mechanism of damage: direct action of radiation, indirect action of radiation. Classification of effects: somatic effect, induction of cancer, factors, affecting somatic effects, genetic effect, inherited abnormalities, induced effects, early effects, late effects, deterministic effect, stochastic effect. Effect of specific group: development abnormality, childhood Cancer, fertile women, risk and uncertainty, comparison of risk

  17. A REVIEW OF THE FUNDAMENTAL PRINCIPLES OF RADIATION PROTECTION WHEN APPLIED TO THE PATIENT IN DIAGNOSTIC RADIOLOGY.

    Science.gov (United States)

    Moores, B Michael

    2017-06-01

    A review of the role and relevance of the principles of radiation protection of the patient in diagnostic radiology as specified by ICRP has been undertaken when diagnostic risks arising from an examination are taken into account. The increase in population doses arising from diagnostic radiology over the past 20 years has been due to the widespread application of higher dose CT examinations that provide significantly more clinical information. Consequently, diagnostic risks as well as radiation risks need to be considered within the patient radiation protection framework. Justification and optimisation are discussed and the limitations imposed on patient protection by employing only a radiation risk framework is highlighted. The example of radiation protection of the patient in breast screening programmes employing mammography is used to highlight the importance of defined diagnostic outcomes in any effective radiation protection strategy. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. A review of the fundamental principles of radiation protection when applied to the patient in diagnostic radiology

    International Nuclear Information System (INIS)

    Moores, B. Michael

    2017-01-01

    A review of the role and relevance of the principles of radiation protection of the patient in diagnostic radiology as specified by ICRP has been undertaken when diagnostic risks arising from an examination are taken into account. The increase in population doses arising from diagnostic radiology over the past 20 years has been due to the widespread application of higher dose CT examinations that provide significantly more clinical information. Consequently, diagnostic risks as well as radiation risks need to be considered within the patient radiation protection framework. Justification and optimisation are discussed and the limitations imposed on patient protection by employing only a radiation risk framework is highlighted. The example of radiation protection of the patient in breast screening programmes employing mammography is used to highlight the importance of defined diagnostic outcomes in any effective radiation protection strategy. (author)

  19. A survey of theoretical fundamentals to radiative drying of sprays and of falling clouds

    International Nuclear Information System (INIS)

    Sandu, C.; Spiess, W.E.L.; Wolf, W.; Rasenescu, I.

    1976-01-01

    The present paper attempts to prepare a general description of the physical phenomena of the radiative drying of sprays and of falling clouds as an engineering application. Such an attempt remains unique in the frame work of special literature. The authors insist especially upon those aspects, which are going to be superposed over the classical, known aspects of the spray drying process, i.e.: a) the radiation extinction of the dense clouds, and b) the dynamic behaviour of the dense clouds under the influence of radiation. However, the authors believe that a lot of new studies and efforts are necessary to illuminate the whole feature of the process in a more applicable model. (orig.) [de

  20. Fundamentals of risk/benefit analysis in radiation uses in preventive medicine

    International Nuclear Information System (INIS)

    Stieve, F.E.

    1977-01-01

    The term 'risk' stems from the insurance branch. It serves to estimate the probability of making statements about future events on the basis of events which have taken place. Risk estimations are increasingly being made in medicine, especially for determining the advantages and dangers brought to the population by preventive measures. The international radiation protection commission has, for some time, been expressing the dangers of ionising radiation in terms of risk and using these terms as basis for the dose limit values it determined for the professional and general population. This paper deals with possibilities of determining risks in preventive medicine. For doing this, acceptable risk values must be determined and risks resulting from diseases, esp. from those which were not recognized in time, must be compared with those resulting from the application of ionising radiation. (orig.) [de

  1. Fundamental study of the radiation monitoring system based on evaluation of DNA lesions

    International Nuclear Information System (INIS)

    Shimizu, K.; Matuo, Y.; Izumi, Y.; Ikeda, T.

    2011-01-01

    The biological dosemeter that measures biological responses to ionising radiation is useful for radiation protection. This paper presents the development and characterisation of a gamma ray irradiation dosimetry system based on real-time PCR (polymerase chain reaction) methodology. Real-time PCR is used to amplify and simultaneously quantify a targeted DNA molecule. If there are no limitations due to limiting substrates or reagents, at each extension step, the amount of DNA target is doubled, leading to exponential (geometric) amplification of the specific DNA fragment. The essential point of this assay is that DNA lesions caused by ionising radiation block DNA synthesis by DNA polymerase, resulting in a decrease in the amplification of a damaged DNA template compared with that of non-damaged DNA templates. (authors)

  2. Radiation and radiation effects; Strahlung und Strahlenwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Neumaier, S. [Physikalisch-Technische Bundesanstalt, Berlin (Germany). Arbeitsgruppe Strahlenschutz; Janssen, H. [Physikalisch-Technische Bundesanstalt, Berlin (Germany). Abt. Ionisierende Strahlung

    2006-12-15

    The average dose incurred by the German population is about 4 millisievert p.a., about half of which results from natural radiation sources. The second half is caused nearly completely by medical applications. Only a very small fraction of the annual dose results from technical applications. This special issue of PTB focuses on the measuring problems relating to natural radiation sources and technical applications of ionizing radiation. The current contribution also outlines some important aspects of radiation exposure from medical applications. (orig.)

  3. Radiation Chemistry and Physical Chemistry of Chitosan and Other Polysaccharides. Fundamental Studies and Practical Applications

    International Nuclear Information System (INIS)

    Rosiak, Janusz M.; Czechowska-Biskup, Renata; Rokita, Bożena; Olejnik, Alicja K.

    2010-01-01

    This report summarizes the second year of activities performed at the Institute of Applied Radiation Chemistry (IARC) within the framework of the CRP project. It consists of two parts. Part I is a brief account of the activities related to design, tests, sample procurement and characterization and formulation of “Protocol for determination of intrinsic viscosity of chitosan” designed to be the basis of the interlaboratory study on viscometric determination of chitosan molecular weight as well as on radiation degradation of chitosan in controlled conditions. Part II contains the text of the Protocol, and is given in the Annex. (author)

  4. Legal problems in the concretisation of the fundamental requirements on radiation protection. 1. paper

    International Nuclear Information System (INIS)

    Bartholdy, V.

    1980-01-01

    The author deals with questions of radioecological regulations based on Sect. 45 p. 2 of the Radiation Protection Ordinance, emphasizing its significance for the transparency of decision-making processes under the Atomic Energy Law - which is not only a legally relevant aspect in the interest of debunking the discussion on nuclear energy utilization, but also under constitutional criteria of legal clarity. (HP) [de

  5. Radiation effects on structural materials

    International Nuclear Information System (INIS)

    Ghoniem, N.M.

    1991-01-01

    This report discusses the following topics on the effect radiation has on thermonuclear reactor materials: Atomic Displacements; Microstructure Evolution; Materials Engineering, Mechanics, and Design; Research on Low-Activation Steels; and Research Motivated by Grant Support

  6. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  7. Effects after prenatal radiation exposures

    International Nuclear Information System (INIS)

    Streffer, C.

    2001-01-01

    The mammalian organism is highly radiosensitive during all prenatal developmental periods. For most effects a dose relationship with a threshold is observed. These threshold doses are generally above the exposures from medical diagnostic procedures. The quality and extent of radiation effects are very much dependent on the developmental stage during which an exposure takes place and on the radiation dose. An exposure during the preimplantation period will cause lethality. Malformations are usually induced after exposures during the major organogenesis. Growth retardation is also possible during the late organogenesis and foetal periods. The lower limits of threshold doses for these effects are in the range of 100 mGy. A radiation exposure during the early foetal period can lead to severe mental retardation and impairment of intelligence. There are very serious effects with radiation doses above 0.3 Gy. Carcinogenesis can apparently occur after radiation exposures during the total prenatal development period. The radiation risk factor up to now has not been clear, but it seems that it is in the range of risk factors for cancer that are observed after exposures during childhood. For radiation doses that are used in radiological diagnostics the risk is zero or very low. A termination of pregnancy after doses below 100 mGy should not be considered. (author)

  8. Aerosol effects in radiation transfer

    International Nuclear Information System (INIS)

    Binenko, V.I.; Harshvardhan, H.

    1993-01-01

    The radiative properties and effects of aerosols are assessed for the following aerosol sources: relatively clean background aerosol, dust storms and dust outbreaks, anthropogenic pollution, and polluted cloud layers. Studies show it is the submicron aerosol fraction that plays a dominant radiative role in the atmosphere. The radiative effect of the aerosol depends not only on its loading but also on the underlying surface albedo and on solar zenith angle. It is only with highly reflecting surfaces such as Arctic ice that aerosols have a warming effect. Radiometric, microphysical, mineral composition, and refractive index measurements are presented for dust and in particular for the Saharan aerosol layer (SAL). Short-wave radiative heating of the atmosphere is caused by the SAL and is due mainly to absorption. However, the SAL does not contribute significantly to the long-wave thermal radiation budget. Field program studies of the radiative effects of aerosols are described. Anthropogenic aerosols deplete the incoming solar radiation. A case field study for a regional Ukrainian center is discussed. The urban aerosol causes a cooling of metropolitan centers, compared with outlying areas, during the day, which is followed by a warming trend at night. In another study, an increase in turbidity by a factor of 3 due to increased industrialization for Mexico City is noted, together with a drop in atmospheric transmission by 10% over a 50-year period. Numerous studies are cited that demonstrate that anthropogenic aerosols affect both the microphysical and radiative properties of clouds, which in turn affect regional climate. Particles acting as cloud nuclei are considered to have the greatest indirect effect on cloud absorptivity of short-wave radiation. Satellite observations show that low-level stratus clouds contaminated by ship exhaust at sea lead to an increase in cloud albedo

  9. Increasing Teacher Effectiveness. Fundamentals of Educational Planning, 39.

    Science.gov (United States)

    Anderson, Lorin W.

    Research on increasing teacher effectiveness is presented in this book. Chapter 1 outlines a framework for investigating and understanding teacher effectiveness, with attention to the following components: teacher and student characteristics; curriculum; classroom environment and management; teaching; and learning. Chapter 2 describes the two…

  10. RADIATION EFFECTS IN NUCLEAR WASTE MATERIALS

    International Nuclear Information System (INIS)

    Weber, William J.

    2000-01-01

    The objective of this research was to develop fundamental understanding and predictive models of radiation effects in glasses and ceramics at the atomic, microscopic, and macroscopic levels, as well as an understanding of the effects of these radiation-induced solid-state changes on dissolution kinetics (i.e., radionuclide release). The research performed during the duration of this project has addressed many of the scientific issues identified in the reports of two DOE panels [1,2], particularly those related to radiation effects on the structure of glasses and ceramics. The research approach taken by this project integrated experimental studies and computer simulations to develop comprehensive fundamental understanding and capabilities for predictive modeling of radiation effects and dissolution kinetics in both glasses and ceramics designed for the stabilization and immobilization of high-level tank waste (HLW), plutonium residues and scraps, surplus weapons plutonium, other actinides, and other highly radioactive waste streams. Such fundamental understanding is necessary in the development of predictive models because all experimental irradiation studies on nuclear waste materials are ''accelerated tests'' that add a great deal of uncertainty to predicted behavior because the damage rates are orders of magnitude higher than the actual damage rates expected in nuclear waste materials. Degradation and dissolution processes will change with damage rate and temperature. Only a fundamental understanding of the kinetics of all the physical and chemical processes induced or affected by radiation will lead to truly predictive models of long-term behavior and performance for nuclear waste materials. Predictive models of performance of nuclear waste materials must be scientifically based and address both radiation effects on structure (i.e., solid-state effects) and the effects of these solid-state structural changes on dissolution kinetics. The ultimate goal of this

  11. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    Loken, M.K.

    1983-01-01

    It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

  12. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  13. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.

    1997-01-01

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed

  14. Effects of radiation-counselling convergence education on radiation awareness

    Energy Technology Data Exchange (ETDEWEB)

    Seoung, Youl Hun [Dept. of Radiological Science, College of Health Science, Cheongju University, Cheongju (Korea, Republic of)

    2017-06-15

    The purpose of study was to analysis on the effects of radiation-counselling convergence education on radiation awareness. The survey objects were students of radiation-counselling convergence education from 12th May to 22th June in 2016. The questionnaires were education satisfactions and radiation awareness (risk, benefit, control) by Likert-type 5 scales. The analysis results revealed that education satisfactions of men students showed a significant higher female students and correlation coefficient of education satisfactions were the best high in the benefit and control of radiation. Finally radiation-counselling convergence education had a significant effect on radiation benefit. This convergence education influenced positive recognition on radiation benefit and it was indicated that radiation-counselors could treat clients on the basis of radiation benefit.

  15. Effects of radiation-counselling convergence education on radiation awareness

    International Nuclear Information System (INIS)

    Seoung, Youl Hun

    2017-01-01

    The purpose of study was to analysis on the effects of radiation-counselling convergence education on radiation awareness. The survey objects were students of radiation-counselling convergence education from 12th May to 22th June in 2016. The questionnaires were education satisfactions and radiation awareness (risk, benefit, control) by Likert-type 5 scales. The analysis results revealed that education satisfactions of men students showed a significant higher female students and correlation coefficient of education satisfactions were the best high in the benefit and control of radiation. Finally radiation-counselling convergence education had a significant effect on radiation benefit. This convergence education influenced positive recognition on radiation benefit and it was indicated that radiation-counselors could treat clients on the basis of radiation benefit

  16. Radiation, chemicals and combined effects

    International Nuclear Information System (INIS)

    Sinclair, W.K.

    1991-01-01

    A brief background has been provided on current carcinogenic risks from ionizing radiation and their magnitude in background circumstances. The magnitude of the risks from possibly carcinogenic chemicals at background levels in air, water and food are surprisingly similar. The exception is, perhaps, for the single source of radon which, while variable, on the average stands out above all other sources. Some basic principles concerning the interaction of combined radiation and chemicals and some practical examples where the two interact synergistically to enhance radiation effects has also been provided. Areas for human research in the future are discussed. (Author)

  17. Fundamental characterization of alternate fuel effects in continuous combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Blazowski, W.S.; Edelman, R.B.; Harsha, P.T.

    1978-09-11

    The overall objective of this contract is to assist in the development of fuel-flexible combustion systems for gas turbines as well as Rankine and Stirling cycle engines. The primary emphasis of the program is on liquid hydrocarbons produced from non-petroleum resouces. Fuel-flexible combustion systems will provide for more rapid transition of these alternate fuels into important future energy utilization centers (especially utility power generation with the combined cycle gas turbine). The specific technical objectives of the program are to develop an improved understanding of relationships between alternate fuel properties and continuous combustion system effects, and to provide analytical modeling/correlation capabilities to be used as design aids for development of fuel-tolerant combustion systems. Efforts this past year have been to evaluate experimental procedures for studying alternate fuel combustion effects and to determine current analytical capabilities for prediction of these effects. Jet Stirred Combustor studies during this period have produced new insights into soot formation in strongly backmixed systems and have provided much information for comparison with analytical predictions. The analytical effort included new applications of quasi-global modeling techniques as well as comparison of prediction with the experimental results generated.

  18. Electronic effects and fundamental physics studied in molecular interfaces.

    Science.gov (United States)

    Pope, Thomas; Du, Shixuan; Gao, Hong-Jun; Hofer, Werner A

    2018-05-29

    Scanning probe instruments in conjunction with a very low temperature environment have revolutionized the ability of building, functionalizing, and analysing two dimensional interfaces in the last twenty years. In addition, the availability of fast, reliable, and increasingly sophisticated methods to simulate the structure and dynamics of these interfaces allow us to capture even very small effects at the atomic and molecular level. In this review we shall focus largely on metal surfaces and organic molecular compounds and show that building systems from the bottom up and controlling the physical properties of such systems is no longer within the realm of the desirable, but has become day to day reality in our best laboratories.

  19. Measuring space radiation shielding effectiveness

    OpenAIRE

    Bahadori Amir; Semones Edward; Ewert Michael; Broyan James; Walker Steven

    2017-01-01

    Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles ...

  20. Radiation effects in optical components

    International Nuclear Information System (INIS)

    Friebele, E.J.

    1987-01-01

    This report discusses components of high performance optical devices may be exposed to high energy radiation environments during their lifetime. The effect of these adverse environments depends upon a large number of parameters associated with the radiation (nature, energy, dose, dose rate, etc.) or the system (temperature, optical performance requirements, optical wavelength, optical power, path length, etc.), as well as the intrinsic susceptibility of the optical component itself to degradation

  1. Environmental dosimetry and radiation effects

    International Nuclear Information System (INIS)

    Woodhead, D.S.

    1997-01-01

    Specific assessment of the potential effects on wild organisms of increased radiation exposure arising from the authorized disposal of radioactive wastes to the environment requires two interrelated sets of information. First, an estimate is required of the incremental radiation exposure; and second, dose rate-response relationships are necessary to predict the potential impact of the estimated incremental exposure. Each of these aspects will be discussed in detail. (author)

  2. Radiation effects at the SSC

    Energy Technology Data Exchange (ETDEWEB)

    Gilchriese, M.G.D. [ed.] [Superconducting Super Collider Lab., Dallas, TX (United States)

    1988-06-01

    This report contains a preliminary study of the effects of the radiation levels expected at the SSC on potential detector components and a subset of materials to be used in the SSC accelerators. The report does not contain a discussion of radiation damage to electronics components that may be used at the SSC. We have investigated many of the effects of radiation on silicon detectors, on wire chambers, on scintillating materials and the associated readout, on optical fibers for data transmission and on structural or other materials to be used in detector or accelerator components. In the SSC accelerator complex, in particular the storage rings, radiation damage will not present significant problems different than those now faced by existing high energy accelerators. We find that the effects of radiation damage on SSC detector components will be significant at the design luminosity of the ssc and will limit, or determine, many of the options for different detector components. In this regard the reader should keep in mind that, in the absence of a specific detector design, it is not possible to form definitive conclusions regarding the viability of the detector components. Since the radiation levels in experiments at the SSC will depend on the geometry and composition of the apparatus, simple yes /no generalizations about the feasibility of a detector component are not possible.

  3. The Effect of Communications Medium on the Fundamental Frequency of Speech.

    Science.gov (United States)

    Noll, A. Michael

    1978-01-01

    Describes the results of preliminary experiments to investigate the effects of communications medium (face-to-face and two-way closed circuit television) on the fundamental frequency of speakers in a dyadic communications situation. (JMF)

  4. Harmful effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Anon.

    1989-01-01

    Tanning for cosmetic purposes by sunbathing or by using artificial tanning devices is widespread. The hazards associated with exposure to ultraviolet radiation are of concern to the medical profession. Depending on the amount and form of the radiation, as well as on the skin type of the individual exposed, ultraviolet radiation causes erythema, sunburn, photodamage (photoaging), photocarcinogenesis, damage to the eyes, alteration of the immune system of the skin, and chemical hypersensitivity. Skin cancers most commonly produced by ultraviolet radiation are basal and squamous cell carcinomas. There also is much circumstantial evidence that the increase in the incidence of cutaneous malignant melanoma during the past half century is related to increased sun exposure, but this has not been proved. Effective and cosmetically acceptable sunscreen preparations have been developed that can do much to prevent or reduce most harmful effects to ultraviolet radiation if they are applied properly and consistently. Other safety measures include (1) minimizing exposure to ultraviolet radiation, (2) being aware of reflective surfaces while in the sun, (3) wearing protective clothing, (4) avoiding use of artificial tanning devices, and (5) protecting infants and children

  5. Biological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Hotz, G.

    1975-01-01

    After a brief survey about the main radiobiological effects caused by ionizing radiation, human symptoms after irradiation and incorporation are shown. The special radiotoxic effect of radionuclides which are chemically associated with metabolism-specific elements such as calcium and potassium is shown and methods of treatment are indicated. (ORU) [de

  6. Radiation Effects in Carbon Nanoelectronics

    Directory of Open Access Journals (Sweden)

    Cory D. Cress

    2012-07-01

    Full Text Available We experimentally investigate the effects of Co-60 irradiation on the electrical properties of single-walled carbon nanotube and graphene field-effect transistors. We observe significant differences in the radiation response of devices depending on their irradiation environment, and confirm that, under controlled conditions, standard dielectric hardening approaches are applicable to carbon nanoelectronics devices.

  7. Radiation Effects in Nuclear Waste Materials

    International Nuclear Information System (INIS)

    Weber, William J.

    2005-01-01

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials

  8. Radiation Effects in Nuclear Waste Materials

    International Nuclear Information System (INIS)

    Weber, William J.; Wang, Lumin; Hess, Nancy J.; Icenhower, Jonathan P.; Thevuthasan, Suntharampillai

    2003-01-01

    The objective of this project is to develop a fundamental understanding of radiation effects in glasses and ceramics, as well as the influence of solid-state radiation effects on aqueous dissolution kinetics, which may impact the performance of nuclear waste forms and stabilized nuclear materials. This work provides the underpinning science to develop improved glass and ceramic waste forms for the immobilization and disposition of high-level tank waste, excess plutonium, plutonium residues and scrap, other actinides, and other nuclear waste streams. Furthermore, this work is developing develop predictive models for the performance of nuclear waste forms and stabilized nuclear materials. Thus, the research performed under this project has significant implications for the immobilization of High-Level Waste (HLW) and Nuclear Materials, two mission areas within the Office of Environmental Management (EM). With regard to the HLW mission, this research will lead to improved understanding of radiation-induced degradation mechanisms and their effects on dissolution kinetics, as well as development of predictive models for waste form performance. In the Nuclear Materials mission, this research will lead to improvements in the understanding of radiation effects on the chemical and structural properties of materials for the stabilization and long-term storage of plutonium, highly-enriched uranium, and other actinides. The research uses plutonium incorporation, ion-beam irradiation, and electron-beam irradiation to simulate the effects of alpha decay and beta decay on relevant glasses and ceramics. The research under this project has the potential to result in improved glass and ceramic materials for the stabilization and immobilization of high-level tank waste, plutonium residues and scraps, surplus weapons plutonium, highly-enriched uranium, other actinides, and other radioactive materials

  9. Kinetic theory of radiation effects

    International Nuclear Information System (INIS)

    Mansur, L.K.

    1987-01-01

    To help achieve the quantitative and mechanistic understanding of these processes, the kinetic theory of radiation effects has been developed in the DOE basic energy sciences radiation effects and fusion reactor materials programs, as well as in corresponding efforts in other countries. This discipline grapples with a very wide range of phenomena and draws on numerous sub-fields of theory such as defect physics, diffusion, elasticity, chemical reaction rates, phase transformations and thermodynamics. The theory is cast in a mathematical framework of continuum dynamics. Issues particularly relevant to the present inquiry can be viewed from the standpoints of applications of the theory and areas requiring further progress

  10. The biological effectiveness of heavy ion radiations in the environment

    International Nuclear Information System (INIS)

    Craven, P.A.

    1996-03-01

    Although heavy ions are rarely encountered in the majority of terrestrial environments, the exposure of humans to this fascinating class of ionizing radiation is becoming more frequent. Long-duration spaceflight, new radiotherapeutic procedures and enhanced levels of radon, and other naturally-occurring alpha particle emitters, have all increased concern and stimulated interest recently within the radiological protection and radiobiological communities. Significant data concerning the long-term effects of low levels of heavy ions on mammalian systems are correspondingly scarce, leading to increased emphasis on modelling all aspects of the radiation-organism interaction. Contemporary radiation protection procedures reflect the need for a more fundamental understanding of the mechanisms responsible for the biological actions of such radiations. Major deficiencies exist in the current recommendations for assessment of relative effectiveness, the enhanced severity of the biological consequences instigated by heavy ions, over conventional sparsely ionizing radiations. In an attempt to remedy some of the inadequate concepts and assumptions presently employed and, simultaneously, to gain insight into the fundamental mechanisms behind the notion of radiation quality, a series of algorithms have been developed and executed as computer code, to evaluate the biological effectiveness of heavy ion radiation ''tracks'' according to a number of criteria. These include consideration of the spatial characteristics of physical energy deposition in idealised cellular structures (finite particle range, radial extension of tracks via δ-ray emission) and the likelihood of induction and mis-repair of severe molecular lesions (double-strand breaks, multiply-damaged sites). (author)

  11. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

    1959-04-15

    To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

  12. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1982-12-01

    The subject is discussed under the headings: introduction; ionising radiation (alpha and beta particles, gamma- and X-radiation, neutrons, half-life, sources of radiation); biological effects; risk estimates (somatic) (early effects, delayed effects); risk estimates (hereditary); control of radiation; risk estimates (accidents). (U.K.)

  13. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    Radford, E.P.

    1980-01-01

    This presentation is restricted to the health effects of low doses of ionizing radiation. In general, these cumulative exposures are well below 100 rem, or about 50 times background or less. The two effects of interest in this dose range are genetic mutations and cancer production. The genetic effects will not be discussed in detail. The chief reason for the rise in risk estimates for cancer is the longer follow-up of exposed populations

  14. Fundamentals of multi-element analysis with electron and beta radiation. 3

    International Nuclear Information System (INIS)

    Thuemmel, H.W.

    1977-01-01

    Mass attenuation coefficients obtained from calculations with the empirical formula μsub(Σ) = Σ psub(i).μsub(i) have been compared with the theoretical Schmidt formula (1906), in which the effective mass attenuation coefficient μsub(th) of a mixture of substances is the product of a true effective mass attenuation coefficient μ 0 and an effective by-pass coefficient U. Numerical results obtained from many substances of strongly varying composition show that for mixtures of components with atomic numbers Zsub(i) differing not too much from each other (contents psub(i), mass attenuation coefficients μsub(i) μ(Zsub(i)) μsub(Σ) is an approximation of μsub(th). This limitation is the less important, the less the curvature of the dependence of the mass attenuation coefficients of all elements on the atomic number (author)

  15. Stimulating effects of ionizing radiation

    International Nuclear Information System (INIS)

    Jaworowski, Z.

    1995-01-01

    The influence of low doses on human organism is not definite known up to now. The worldwide discussion on this topic has been presented. A lot of analysed statistical data proved that the stimulating effect of low doses of ionizing radiation really exists and can have a beneficial influence on human health. 43 refs, 4 figs, 6 tabs

  16. Radiation effects on video imagers

    International Nuclear Information System (INIS)

    Yates, G.J.; Bujnosek, J.J.; Jaramillo, S.A.; Walton, R.B.; Martinez, T.M.; Black, J.P.

    1985-01-01

    Radiation sensitivity of several photoconductive, photoemissive, and solid state silicon-based video imagers was measured by analyzing stored photocharge induced by irradiation with continuous and pulsed sources of high energy photons and neutrons. Transient effects as functions of absorbed dose, dose rate, fluences, and ionizing particle energy are presented

  17. Biopositive Effects of Ionizing Radiation?

    International Nuclear Information System (INIS)

    Broda, E.

    1972-01-01

    This paper was written for a talk given by E. Broda in Vienna for an event organised by the chemical physical society, the Austrian biochemical society and the Austrian biophysical society in December 1972. In this paper Broda analyses the question of biopositive effects of ionizing radiation. (nowak)

  18. Biophysical fundamentals and considerations on variation of radiation quality in radiotherapy

    International Nuclear Information System (INIS)

    Abel, H.

    1975-01-01

    Considering the primarily critical structures of the cell, the dependence of DNA damage on LET is shown. For clarification of the repair of DNA damages phylogenetic tree analyses and biochemical investigations of repair mechanisms are considered useful. The relationship between oxygen effect and RBE in tumors is demonstrated

  19. Modification of radiation effects

    International Nuclear Information System (INIS)

    Lindenbaum, A.

    1975-01-01

    Results are reported from studies on the tissue distribution of 239 Pu and 241 Am in mice and beagle dogs and the effectiveness of various therapeutic treatments for decorporation. In dogs injected with monomeric Pu the value of a regimen of early and prolonged treatment with DTPA (diethylenetriaminepentaacetic acid) for minimizing the Pu burden in the soft tissues and skeleton was demonstrated. These results have immediate implication for DTPA treatment in man. New studies in mice verified the action of pyran copolymer antiviral agents in enhancing the effectiveness of DTPA for removal of polymeric Pu from the liver. Recent application of autoradiographic procedures for quantitatively comparing short- and long-term localization of monomeric and polymeric 239 Pu in dog liver showed that there is no net translocation of monomeric Pu within the liver between 6 and 90 days following injection. One of the molecular studies presently underway aims at synthesis of a variety of DTPA esters. The diethyl ester has already been prepared and tested for toxicity in mice. These compounds are designed to bring DTPA into contact with plutonium deposits unavailable to the action of ionic DTPA. (U.S.)

  20. Radiation effects on eye components

    Science.gov (United States)

    Durchschlag, H.; Fochler, C.; Abraham, K.; Kulawik, B.

    1999-08-01

    The most important water-soluble components of the vertebrate eye (lens proteins, aqueous humor, vitreous, hyaluronic acid, ascorbic acid) have been investigated in aqueous solution, after preceding X- or UV-irradiation. Spectroscopic, chromatographic, electrophoretic, hydrodynamic and analytic techniques have been applied, to monitor several radiation damages such as destruction of aromatic and sulfur-containing amino acids, aggregation, crosslinking, dissociation, fragmentation, and partial unfolding. Various substances were found which were able to protect eye components effectively against radiation, some of them being also of medical relevance.

  1. Low-level radiation effects: a fact book

    International Nuclear Information System (INIS)

    Brill, A.B.; Adelstein, S.J.; Saenger, E.L.; Webster, E.W.

    1982-01-01

    Low Level Raidation Effects: A Fact Book, prepared by the Society of Nuclear Medicine Subcommittee on the Risks of Low-Level Ionizing Radiation, attempts to examine the health effects of small doses of radiation. For immediate questions, this work provides a well-organized brief summary of recent radiologic data from refereed scientific literature and from the publications of advisory groups such as the National Council of Radiation Protection and Measurement (NCRP), the International Commission on Radiological Protection (ICRP), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the National Academy of Sciences (NAS). Since it consists almost entirely of tables and graphs from the above-mentioned sources along with summary paragraphs, the Fact Book is very useful in the preparation of lectures. The book is divided into seven sections. Chapter One, Glossary, Units and Conversion Factors, is useful because nearly all data given in the rest of the book is in conventional units and should be converted to SI units for future technical audiences. Chapter 2, Radiobiology, covers the fundamental principles of the field. Chapter 3, Radiation Doses, can be used to help an audience appreciate the relative magnitudes of radiation exposures they may read about or encounter. Chapter 4, Late Somatic Effects of Low Doses of Ionizing Radiation, gives data concerning cancer induction and embryonic effects, and Chapter 5 provides data on genetic effects Chapter 6, Risks, Statistical Facts and Public Perception can be used to compare the risks of radiation exposure with more commonly encountered risks

  2. Radiation Effects in Paediatric radiography

    International Nuclear Information System (INIS)

    Mutwasi, O.

    2006-01-01

    Diagnostic imaging has evolved from single technique to a field which we have a choice from many modalities. Some without radiation. Radiation producing modalities include plain films (low dose), Fluoroscopy (mid range dose), Computed tomography (high dose). Radiography dose can significantly be influenced in plain radiography by varying speed of screens, cassette construction and type of radiography. E.g. digital or computed. In computed or digital radiography we are no longer able to tell h igh dose b y the quality of images. The final image is by great extend a product of post processing algorithms. It's for this reasons that the basic understanding of the sensitivity and specifying of various types of examinations and of specifically radiation effects is mandatory for a paediatric imager

  3. Measuring space radiation shielding effectiveness

    Directory of Open Access Journals (Sweden)

    Bahadori Amir

    2017-01-01

    Full Text Available Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

  4. Measuring space radiation shielding effectiveness

    Science.gov (United States)

    Bahadori, Amir; Semones, Edward; Ewert, Michael; Broyan, James; Walker, Steven

    2017-09-01

    Passive radiation shielding is one strategy to mitigate the problem of space radiation exposure. While space vehicles are constructed largely of aluminum, polyethylene has been demonstrated to have superior shielding characteristics for both galactic cosmic rays and solar particle events due to the high hydrogen content. A method to calculate the shielding effectiveness of a material relative to reference material from Bragg peak measurements performed using energetic heavy charged particles is described. Using accelerated alpha particles at the National Aeronautics and Space Administration Space Radiation Laboratory at Brookhaven National Laboratory, the method is applied to sample tiles from the Heat Melt Compactor, which were created by melting material from a simulated astronaut waste stream, consisting of materials such as trash and unconsumed food. The shielding effectiveness calculated from measurements of the Heat Melt Compactor sample tiles is about 10% less than the shielding effectiveness of polyethylene. Shielding material produced from the astronaut waste stream in the form of Heat Melt Compactor tiles is therefore found to be an attractive solution for protection against space radiation.

  5. Biological radiation effects

    International Nuclear Information System (INIS)

    Russo, A.

    2000-01-01

    Everyone is exposed to a complex mix of electromagnetic fields (EMF) of different frequencies that permeate our environment. Exposures to these EMF are increasing significantly as technology advances unabated and new applications are found. Technological progress in the broadest sense of the word has always been associated with various hazards and risks, both perceived and real. The industrial, commercial and household application on EMF is no exception. Throughout the world, the general public is concerned that exposure to EMF from such sources as high voltage power lines, broadcasting networks, mobile telephones and their base stations could lead to adverse health consequences, especially in children. As a result, the construction of new power lines and broadcasting and mobile telephone network has met with considerable opposition in many countries. Public exposure to EMF is regulated by a variety of voluntary and legal limits, together with various national safety standards. Guidelines are designed to avoid all identified hazards, from short and long term exposure, recommended limits. The aim of this paper is to report the summary of the actual scientific knowledge about the potential health effects and hazards due to man made EMF and the new tendencies of the social and political choices [it

  6. Fundamentals of multi-element analysis with electron and beta radiation. 4

    International Nuclear Information System (INIS)

    Thuemmel, H.W.; Koerner, G.; Apel, K.

    1977-01-01

    Mass attenuation coefficients of liquid hydrocarbons and their oxygen, nitrogen and halogen derivates have been measured and compared with the values obtained according to the various calculation instructions (see pt.3). Using the most complete formula according to Schmidt the values obtained are systematically too low (up to 5 per cent), even with best parameter values. Only about half the values deviate by less than 3 per cent. Though the maximum deviations of 5 per cent are beyond the experimental errors (<= +-1 per cent) and the errors introduced by adaption of the general function to the mass attenuation coefficients of elementary absorbers (<= +-2.5 per cent), certain systematic deviation patterns (< 2.5 per cent) can be observed only for individual homologous series (alkanes, benzene derivatives), which may be caused by bonding effects or by remaining shortcomings of the model. The simple formula μsub(Σ) = Σpsub(i)μsub(i) provides effective mass attenuation coefficients, the error of which is up to 10 per cent. (author)

  7. Radiation effects in bulk and nanostructured silicon

    Energy Technology Data Exchange (ETDEWEB)

    Holmstrom, E.

    2012-07-01

    Understanding radiation effects in silicon (Si) is of great technological importance. The material, being the basis of modern semiconductor electronics and photonics, is subjected to radiation already at the processing stage, and in many applications throughout the lifetime of the manufactured component. Despite decades of research, many fundamental questions on the subject are still not satisfactorily answered, and new ones arise constantly as device fabrication shifts towards the nanoscale. In this study, methods of computational physics are harnessed to tackle basic questions on the radiation response of bulk and nanostructured Si systems, as well as to explain atomic-scale phenomena underlying existing experimental results. Empirical potentials and quantum mechanical models are coupled with molecular dynamics simulations to model the response of Si to irradiation and to characterize the created crystal damage. The threshold displacement energy, i.e., the smallest recoil energy required to create a lattice defect, is determined in Si bulk and nanowires, in the latter system also as a function of mechanical strain. It is found that commonly used values for this quantity are drastically underestimated. Strain on the nanowire causes the threshold energy to drop, with an effect on defect production that is significantly higher than in an another nanostructure with similar dimensions, the carbon nanotube. Simulating ion irradiation of Si nanowires reveals that the large surface area to volume ratio of the nanostructure causes up to a three-fold enhancement in defect production as compared to bulk Si. Amorphous defect clusters created by energetic neutron bombardment are predicted, on the basis of their electronic structure and abundance, to cause a deleterious phenomenon called type inversion in Si strip detectors in high-energy physics experiments. The thinning of Si lamellae using a focused ion beam is studied in conjunction with experiment to unravel the cause for

  8. Genomic instability and radiation effects

    International Nuclear Information System (INIS)

    Christian Streffer

    2007-01-01

    Complete text of publication follows. Cancer, genetic mutations and developmental abnormalities are apparently associated with an increased genomic instability. Such phenomena have been frequently shown in human cancer cells in vitro and in situ. It is also well-known that individuals with a genetic predisposition for cancer proneness, such as ataxia telangiectesia, Fanconi anaemia etc. demonstrate a general high genomic instability e.g. in peripheral lymphocytes before a cancer has developed. Analogous data have been found in mice which develop a specific congenital malformation which has a genetic background. Under these aspects it is of high interest that ionising radiation can increase the genomic instability of mammalian cells after exposures in vitro an in vivo. This phenomenon is expressed 20 to 40 cell cycles after the exposure e.g. by de novo chromosomal aberrations. Such effects have been observed with high and low LET radiation, high LET radiation is more efficient. With low LET radiation a good dose response is observed in the dose range 0.2 to 2.0 Gy, Recently it has been reported that senescence and genomic instability was induced in human fibroblasts after 1 mGy carbon ions (1 in 18 cells are hit), apparently bystander effects also occurred under these conditions. The instability has been shown with DNA damage, chromosomal aberrations, gene mutation and cell death. It is also transferred to the next generation of mice with respect to gene mutations, chromosomal aberrations and congenital malformations. Several mechanisms have been discussed. The involvement of telomeres has gained interest. Genomic instability seems to be induced by a general lesion to the whole genome. The transmission of one chromosome from an irradiated cell to an non-irradiated cell leads to genomic instability in the untreated cells. Genomic instability increases mutation rates in the affected cells in general. As radiation late effects (cancer, gene mutations and congenital

  9. Thermal effects in radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1985-01-01

    The balance of ionizing radiation energy incident on an object being processed is discussed in terms of energy losses, influencing the amount really absorbed. To obtain the amount of heat produced, the absorbed energy is corrected for the change in internal energy of the system and for the heat effect of secondary reactions developing after the initiation. The temperature of a processed object results from the heat evolved and from the specific heat of the material comprising the object. The csub(p) of most materials is usually much lower than that of aqueous systems and therefore temperatures after irradiation are higher. The role of low specific heat in radiation processing at cryogenic conditions is stressed. Adiabatic conditions of accelerator irradiation are contrasted with the steady state thermal conditions prevailing in large gamma sources. Among specific questions discussed in the last part of the paper are: intermediate and final temperature of composite materials, measurement of real thermal effects in situ, neutralization of undesired warming experienced during radiation processing, processing at temperatures other than ambient and administration of very high doses of radiation. (author)

  10. Radiation effects in silicate glasses

    International Nuclear Information System (INIS)

    Bibler, N.E.; Howitt, D.G.

    1988-01-01

    The study of radiation effects in complex silicate glasses has received renewed attention because of their use in special applications such as high level nuclear waste immobilization and fiber optics. Radiation changes the properties of these glasses by altering their electronic and atomic configurations. These alterations or defects may cause dilatations or microscopic phase changes along with absorption centers that limit the optical application of the glasses. Atomic displacements induced in the already disordered structure of the glasses may affect their use where heavy irradiating particles such as alpha particles, alpha recoils, fission fragments, or accelerated ions are present. Large changes (up to 1%) in density may result. In some cases the radiation damage may be severe enough to affect the durability of the glass in aqueous solutions. In the paper, the authors review the literature concerning radiation effects on density, durability, stored energy, microstructure and optical properties of silicate glasses. Both simple glasses and complex glasses used for immobilization of nuclear waste are considered

  11. Thermal effects in radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1984-01-01

    The balance of ionizing radiation energy incident on an object being processed is discussed in terms of energy losses, influencing the amount really absorbed. To obtain the amount of heat produced, the absorbed energy is corrected for the change in internal energy of the system and for the heat effect of secondary reactions developing after the initiation. The temperature of a processed object results from the heat evolved and from the specific heat of the material comprising the object. The specific heat of most materials is usually much lower than that of aqueous systems and therefore temperatures after irradiation are higher. The role of low specific heat in radiation processing at cryogenic conditions is stressed. Adiabatic conditions of accelerator irradiation are contrasted with the steady state thermal conditions prevailing in large gamma sources. Among specific questions discussed in the last part of the paper are: intermediate and final temperature of composite materials, measurement of real thermal effects in situ, neutralization of undesired warming experienced during radiation processing, processing at temperatures other than ambient and administration of very high doses of radiation

  12. Health effects of radiation and the implications for radiation safety

    International Nuclear Information System (INIS)

    Gonzalez, A.J.; Anderer, J.

    1991-01-01

    In this Paper two elements of a multiphase analysis of radiation exposures in the living environment - the human health effects of ionizing radiation and the implications for radiation safety policy and practices - are presented. Part 1 draws together the current state of scientific knowledge and insight about the human health effects of radiation, describing these in terms of known cause-related deterministic effects and of the estimated incidence of stochastic effects as defined by biostatistics and biological models. The 1988 UNSCEAR report provides an authoritative basis for such an examination. Part 2 explores some of the major implications that the state-of-the-art of radiation biology has - or should have - for radiation safety policy and practices. (author)

  13. Current research in Canada on biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1980-05-01

    A survey of current research in Canada on the biological effects of ionizing radiation has been compiled. The list of projects has been classified according to structure (organizational state of the test system) as well as according to the type of effects. Using several assumptions, ballpark estimates of expenditures on these activities have been made. Agencies funding these research activities have been tabulated and the break-down of research in government laboratories and in academic institutions has been designated. Wherever possible, comparisons have been made outlining differences or similarities that exist between the United States and Canada concerning biological radiation research. It has been concluded that relevant research in this area in Canada is inadequate. Wherever possible, strengths and weaknesses in radiation biology programs have been indicated. The most promising course for Canada to follow is to support adequately fundamental studies of the biological effects of radiation. (auth)

  14. Fundamental ecology is fundamental.

    Science.gov (United States)

    Courchamp, Franck; Dunne, Jennifer A; Le Maho, Yvon; May, Robert M; Thébaud, Christophe; Hochberg, Michael E

    2015-01-01

    The primary reasons for conducting fundamental research are satisfying curiosity, acquiring knowledge, and achieving understanding. Here we develop why we believe it is essential to promote basic ecological research, despite increased impetus for ecologists to conduct and present their research in the light of potential applications. This includes the understanding of our environment, for intellectual, economical, social, and political reasons, and as a major source of innovation. We contend that we should focus less on short-term, objective-driven research and more on creativity and exploratory analyses, quantitatively estimate the benefits of fundamental research for society, and better explain the nature and importance of fundamental ecology to students, politicians, decision makers, and the general public. Our perspective and underlying arguments should also apply to evolutionary biology and to many of the other biological and physical sciences. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Fundamentals of radiological protection

    International Nuclear Information System (INIS)

    Charles, M.W.; Wells, J.; Mill, A.J.

    1978-04-01

    A brief review is presented of the early and late effects of ionising radiation on man, with particular emphasis on those aspects of importance in radiological protection. The terminology and dose response curves, are explained. Early effects on cells, tissues and whole organs are discussed. Late somatic effects considered include cancer and life-span shortening. Genetic effects are examined. The review is the third of a series of reports which present the fundamentals necessary for an understanding of the basis of regulatory criteria, such as those of the ICRP. (u.K.)

  16. Research on radiation effect and radiation protection at JAEA

    International Nuclear Information System (INIS)

    Saito, Kimiaki

    2007-01-01

    Researches on radiation effect and radiation protection at JAEA have been carried out in different sections. In recent years, the organizations were rearranged to attain better research circumstances, and new research programs started. At present, radiation effect studies focus on radiation effect mechanisms at atomic, molecular and cellular levels including simulation studies, and protection studies focus on dosimetry for conditions difficult to cover with currently used methods and data as well as the related basic studies. The outlines of the whole studies and also some descriptions on selected subjects will be given in this paper. (author)

  17. Effective Exchange Rates in Central and Eastern European Countries: Cyclicality and Relationship with Macroeconomic Fundamentals

    Directory of Open Access Journals (Sweden)

    Stavárek Daniel

    2015-06-01

    Full Text Available This paper examines the evolution of effective exchange rates in nine Central and Eastern European countries in terms of development trends, volatility and cyclicality. Consequently, it provides direct empirical evidence on the nature of the relationship between effective exchange rates and selected macroeconomic fundamentals, addressing a key precondition of numerous exchange rate determination models and theories that attempt to explain the role of exchange rates in the economy. The results suggest that flexible exchange rate arrangements are reflected in both nominal and real effective exchange rates having higher volatility and variability. Furthermore, the results provide mixed evidence in terms of intensity, direction and cyclicality, but show a weak correlation between exchange rates and fundamentals. Sufficiently high coefficients are found only for money supply. Consequently, using fundamentals for the determination of exchange rates and using the exchange rate to explain economic development may be of limited use for the countries analyzed.

  18. Evidence of Dopant Type-Inversion and Other Radiation Damage Effects of the CDF Silicon Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Ballarin, Roberto [Univ. of the Basque Country, Leioa (Spain)

    2010-06-01

    The aim of this document is to study the effect of radiation damage on the silicon sensors. The reflection of the effect of radiation can be observed in two fundamental parameters of the detector: the bias current and the bias voltage. The leakage current directly affects the noise, while the bias voltage is required to collect the maximum signal deposited by the charged particle.

  19. Health effects of radiation damage

    International Nuclear Information System (INIS)

    Gasimova, K; Azizova, F; Mehdieva, K.

    2012-01-01

    Full text : A summary of the nature of radiactive contamination would be incomplete without some mention of the human health effects relatied to radioactivity and radioactive materials. Several excellent reviews at the variety of levels of detail have been written and should be consulted by the reader. Internal exposures of alpha and beta particles are important for ingested and inhaled radionuclides. Dosimetry models are used to estimate the dose from internally deposited radioactive particles. As mentioned above weighting parameters that take into account the radiation type, the biological half-life and the tissue or organ at risk are used to convert the physically absorbed dose in units of gray (or red) to the biologically significant committed equivalent dose and effective dose, measured in units of Sv (or rem). There is considerable controversy over the shape of the dose-response curve at the chronic low dose levels important for enviromental contamination. Proposed models include linear models, non-linear models and threshold models. Because risks at low dose must be extrapolated from available date at high doses, the shape of the dose-response curve has important implications for the environmental regulations used to protect the general public. The health effect of radiation damage depends on a combination of events of on the cellular, tissue and systemic levels. These lead to mutations and cellular of the irradiated parent cell. The dose level at which significant damage occurs depends on the cell type. Cells that reproduce rapidily, such as those found in bone marrow or the gastrointestinal tract, will be more sensitive to radiation than those that are longer lived, such as striated muscle or nerve cells. The effects of high radiation doses on an organ depends on the various cell types it contains

  20. Genetic and somatic effects of ionizing radiation

    International Nuclear Information System (INIS)

    1986-01-01

    This is the ninth substantive report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) to the General Assembly. This report contains reviews on three special topics in the field of biological effects of ionizing radiation that are among those presently under consideration by the Committee: genetic effects of radiation, dose-response relationships for radiation-induced cancer and biological effects of pre-natal irradiation

  1. Modification of radiation sensitivity: the oxygen effect

    International Nuclear Information System (INIS)

    Quintiliani, M.

    1979-01-01

    Four fundamental aspects of the oxygen effect in radiobiology are reviewed, with emphasis on single cell systems: (1) Radiosensitivity in relation to oxygen concentration. In many biological systems, this relationship is remarkably well represented by the well-known Howard-Flanders/Alper formula. Often, however, the degree of uncertainty associated with the estimation of the value of K in the formula is fairly high. Recent data on V79-753B cells indicate a biphasic influence of oxygen concentration on radiosensitivity that cannot be described in terms of the Howard-Flanders/Alper model. (2) The oxygen effect in relation to survival level. The influence of very low oxygen concentrations on the shoulder of the survival curves of irradiated cells is still controversial. Also, the oxygen dependence of repair processes for sublethal and potentially lethal damage need to be better defined. (3) Time-scale of the oxygen effect. All the experimental data obtained with the use of fast techniques indicate that the time scale of the oxygen effect is consistent with that of free radical reactions. This appears to be compatible with the hypothesis that oxygen acts by fixation of a radiation-induced reversible damage. The existence of two types of damage with different rates of decay is suggested, both in bacterial and mammalian cells. (4) Molecular mechanisms of the oxygen effect. In spite of the very large literature on this subject, the identification of the detailed molecular mechanisms of the oxygen effect must still be considered goals for future research

  2. Fundamental Movement Skills and Children with Attention-Deficit Hyperactivity Disorder: Peer Comparisons and Stimulant Effects

    Science.gov (United States)

    Harvey, William J.; Reid, Greg; Grizenko, Natalie; Mbekou, Valentin; Ter-Stepanian, Marina; Joober, Ridha

    2007-01-01

    The purpose of this study was to compare the fundamental movement skills of 22 children with attention-deficit hyperactivity disorder (ADHD), from 6 to 12 years of age, to gender- and age-matched peers without ADHD and assess the effects of stimulant medication on the movement skill performance of the children with ADHD. Repeated measures analyses…

  3. pH Effects in Foods: Development, Validation and Calibration of a Fundamental Model

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Biekman, E.S.A.; Greiner, R.; Seyhan, F.; Barringer, S.A.

    2001-01-01

    The effects of pH observed in the activity of a number of enzymes from different origins and the degradation of green colour in blanched vegetables, was modelled based on fundamental kinetic principles by considering hydrogen ions as an integral part of the reaction mechanism. Parameters were

  4. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  5. Radiation effects on microelectronics in space

    International Nuclear Information System (INIS)

    Srour, J.R.; McGarrity, J.M.

    1988-01-01

    The basic mechanisms of space radiation effects on microelectronics are reviewed in this paper. Topics discussed include the effects of displacement damage and ionizing radiation on devices and circuits, single event phenomena, dose enhancement, radiation effects on optoelectronic devices and passive components, hardening approaches, and simulation of the space radiation environment. A summary is presented of damage mechanisms that can cause temporary or permanent failure of devices and circuits operating in space

  6. Effect of radiation in radiotherapy

    International Nuclear Information System (INIS)

    Hirata, Hideki; Fujibuchi, Toshio; Saito, Tsutomu

    2013-01-01

    The title subject is easily explained for the deterministic effect, secondary cancer formation and case reports of accidental exposure at radiotherapy. For the deterministic effect, the dose-effect relationship is sigmoidal in normal and cancer tissues, and the more separated are their curves, the more favorable is the radiotherapy. TD 5/5 is the tolerable dose to yield <5% of irreversible radiation injury to the normal tissue within 5 years after the therapy and is generally dose-limiting. The curves are of various shapes depending on the tissue composition that its functional subunit (FSU) is parallel like lobules of the liver, or in series like neuron. Symptoms appear complicated on these factors. Recent development of CT-based therapeutic planning has made it possible to analyze the partial tissue volume to be irradiated and its absorbed dose by the relationship (dose volume histogram, DVH) between the electron density vs CT value regardless to anatomy. The normal tissue complication probability is a model composed from the physical DVH and biological factors of FSU composition and cellular radiation susceptibility, and is a measure of the irreversible late effect manifested in normal tissues. Epidemiology has shown the increased risk of secondary cancer formation by radiotherapy. Children are highly susceptible to this, and in adults undergoing the therapy of a certain cancer, it is known that the risk of radiation carcinogenesis is increased in the particular tissue. There are presented such case reports of accidental excessive exposure at radiotherapy as caused by an inappropriate use of detector, partial loss of data in a therapeutic planning device, reading of reversed MRI image, and too much repeated use of the old-type electric portal imaging device. (T.T.)

  7. Radiation Effects in Nuclear Ceramics

    Directory of Open Access Journals (Sweden)

    L. Thomé

    2012-01-01

    Full Text Available Due to outstanding physicochemical properties, ceramics are key engineering materials in many industrial domains. The evaluation of the damage created in ceramics employed in radiative media is a challenging problem for electronic, space, and nuclear industries. In this latter field, ceramics can be used as immobilization forms for radioactive wastes, inert fuel matrices for actinide transmutation, cladding materials for gas-cooled fission reactors, and structural components for fusion reactors. Information on the radiation stability of nuclear materials may be obtained by simulating the different types of interactions involved during the slowing down of energetic particles with ion beams delivered by various types of accelerators. This paper presents a review of the radiation effects occurring in nuclear ceramics, with an emphasis on recent results concerning the damage accumulation processes. Energetic ions in the KeV-GeV range are used to explore the nuclear collision (at low energy and electronic excitation (at high energy regimes. The recovery by electronic excitation of the damage created by ballistic collisions (SHIBIEC process is also addressed.

  8. Radiation effects on cell membranes

    International Nuclear Information System (INIS)

    Koeteles, G.J.

    1982-01-01

    The recent developments in the field of membrane biology of eukaryotic cells result in revival of relevant radiobiological studies. The spatial relations and chemical nature of membrane components provide rather sensitive targets. Experimental data are presented concerning the effects of relatively low doses of X-irradiation and low concentration of tritiated water (HTO) on various receptor functions - concanavalin A, cationized ferritin, poliovirus - of plasma membranes of animal and human cells which point to early and temporary disturbances of the composite structures and functions of membranes. References are given to the multifold roles of radiationinduced membrane phenomena on the development and regeneration of radiation injuries. (orig.)

  9. Radiation effects on cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Koeteles, G.J.

    1982-11-01

    The recent developments in the field of membrane biology of eukaryotic cells result in revival of relevant radiobiological studies. The spatial relations and chemical nature of membrane components provide rather sensitive targets. Experimental data are presented concerning the effects of relatively low doses of X-irradiation and low concentration of tritiated water (HTO) on various receptor functions - concanavalin A, cationized ferritin, poliovirus - of plasma membranes of animal and human cells which point to early and temporary disturbances of the composite structures and functions of membranes. References are given to the multifold roles of radiationinduced membrane phenomena on the development and regeneration of radiation injuries.

  10. Effect of radiation on food

    Energy Technology Data Exchange (ETDEWEB)

    Sofyan, R [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1983-07-01

    Research reports on the effect on radiation on food are reviewed. Irradiation processing inhibits the sprouting of vegetables, delays ripening, reduces the number of microorganisms that spoil food, controls patrogenic organisms and parasites found in food, disinfests food of insects, and disinfects spices of microbes. So far there has been no evidence that food irradiaton introduces nutritional or microbiological problems. The FAO/WHO/IAEA expert committee on the wholesomeness of irradiated food recommend the acceptability from a toxicological stand-point of any food commodity irradiated up to an overall average dose of 10 kilograys.

  11. Effect of radiation on food

    International Nuclear Information System (INIS)

    Sofyan, Rochestri

    1983-01-01

    Research reports on the effect on radiation on food are reviewed. Irradiation processing inhibits the sprouting of vegetables, delays ripening, reduces the number of microorganisms that spoil food, controls patrogenic organisms and parasites found in food, disinfests food of insects, and disinfects spices of microbes. So far there has been no evidence that food irradiaton introduces nutritional or microbiological problems. The FAO/WHO/IAEA expert committee on the wholesomeness of irradiated food recommend the acceptability from a toxicological stand-point of any food commodity irradiated up to an overall average dose of 10 kilograys. (RUW)

  12. Effects of radiation upon gastrointestinal motility

    Institute of Scientific and Technical Information of China (English)

    Mary F Otterson

    2007-01-01

    Whether due to therapeutic or belligerent exposure, the gastrointestinal effects of irradiation produce symptoms dreaded by a majority of the population. Nausea, vomiting, diarrhea and abdominal cramping are hallmarks of the prodromal phase of radiation sickness, occurring hours to days following radiation exposure. The prodromal phase is distinct from acute radiation sickness in that the absorptive, secretory and anatomic changes associated with radiation damage are not easily identifiable. It is during this phase of radiation sickness that gastrointestinal motility significantly changes. In addition, there is evidence that motor activity of the gut contributes to some of the acute and chronic effects of radiation.

  13. The Brookhaven Radiation Effects Facility

    Energy Technology Data Exchange (ETDEWEB)

    Grand, P.; Snead, C.L.; Ward, T.

    1988-01-01

    The Neutral Particle Beam (NPB) Radiation Effects Facility (REF), funded by the Strategic Defense Initiative Office (SDIO) through the Defense Nuclear Agency (DNA) and the Air Force Weapons Laboratory (AFWL), has been constructed at Brookhaven National Laboratory (BNL). Operation started in October 1986. The facility is capable of delivering pulsed H{sup -}, H{sup o}, and H{sup +} beams of 100 to 200 MeV energy up to 30 mA peak current. Pulses can be adjusted from 5 {mu}s to 500 {mu}s length at a repetition rate of 5 pps. The beam spot on target is adjustable from 3 to 100 cm diameter (2 {sigma}) resulting in a maximum dose of about 10 MRads (Si) per pulse (small beam spot). Experimental use of the REF is being primarily supported by the SDI lethality (LTH-4) program. The program has addressed ionization effects in electronics, both dose rate and total dose dependence, radiation-sensitive components, and dE/dx effects in energetic materials including propellants and high explosives (HE). This paper describes the facility, its capabilities and potential, and the experiments that have been carried out to date or are being planned. 2 refs., 10 figs.

  14. The Brookhaven Radiation Effects Facility

    International Nuclear Information System (INIS)

    Grand, P.; Snead, C.L.; Ward, T.

    1988-01-01

    The Neutral Particle Beam (NPB) Radiation Effects Facility (REF), funded by the Strategic Defense Initiative Office (SDIO) through the Defense Nuclear Agency (DNA) and the Air Force Weapons Laboratory (AFWL), has been constructed at Brookhaven National Laboratory (BNL). Operation started in October 1986. The facility is capable of delivering pulsed H - , H/sup o/, and H + beams of 100 to 200 MeV energy up to 30 mA peak current. Pulses can be adjusted from 5 μs to 500 μs length at a repetition rate of 5 pps. The beam spot on target is adjustable from 3 to 100 cm diameter (2 σ) resulting in a maximum dose of about 10 MRads (Si) per pulse (small beam spot). Experimental use of the REF is being primarily supported by the SDI lethality (LTH-4) program. The program has addressed ionization effects in electronics, both dose rate and total dose dependence, radiation-sensitive components, and dE/dx effects in energetic materials including propellants and high explosives (HE). This paper describes the facility, its capabilities and potential, and the experiments that have been carried out to date or are being planned. 2 refs., 10 figs

  15. Effects of radiation on DNA

    International Nuclear Information System (INIS)

    Braddock, M.

    1985-07-01

    The hydroxyl radical (OH radical) is the most damaging radical produced by the effect of ionizing radiation in water. The rate of reaction of the OH radical with purified, native and isodisperse DNA has been determined as compared with calf thymus DNA. This has been achieved by direct observation of the rate of formation of the DNA-OH radical adduct, and by competition with SCN - . Results obtained from direct observation are consistent with calculations which have been performed using the encounter frequency model of Braams and Ebert. However, results obtained for OH radical with DNA derived from competition plots suggest a rate constant somewhat lower than that obtained from direct observation. The relative merits of both techniques are discussed. In order to study the effect of energy deposited directly in the DNA, dry films of purified plasmid DNA have been irradiated in a system where the indirect effects of radical interaction have been minimized. The present results indicate that with different molecular lengths of plasmid DNA, non-random breakage may occur, and that additional damage may be brought about at sites of previously existing damage. Differences in the sensitivity of plasmid DNA molecules of varying lengths to radiation induced double strand breaks have been demonstrated. (author)

  16. Biological effects of ionizing radiations. Radiological accident from Goiania, GO, Brazil

    International Nuclear Information System (INIS)

    Okuno, Emico

    2013-01-01

    This article presents the fundaments of radiation physics, the natural and artificial sources, biological effects, radiation protection. We also examine the sequence of events that resulted in Goiania accident with a source of caesium-137 from abandoned radiotherapy equipment and its terrible consequences. (author)

  17. Effects of ionizing radiation on vitamins

    International Nuclear Information System (INIS)

    Thayer, D.W.; Fox, J.B. Jr.; Lakritz, L.

    1991-01-01

    Vitamins are known to be sensitive to the effects of ionizing radiation. Since most foods contain a large proportion of water, the most probable reaction of the ionizing radiation would be with water; and as vitamins are present in very small amounts compared with other substances in the food they will be affected indirectly by the radiation. This chapter discusses the effect of ionizing radiation on water soluble vitamins and fat soluble vitamins. (author)

  18. Radiation effects of high and low doses

    International Nuclear Information System (INIS)

    El-Naggar, A.M.

    1998-01-01

    The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

  19. Medical response to effects of ionising radiation

    International Nuclear Information System (INIS)

    Crosbie, W.A.; Gittus, J.H.

    1989-01-01

    The proceedings of a conference on 'Medical Response to Effects of Ionising Radiation' in 1989 in the form of nineteen papers published as a book. Topics discussed include radiation accidents at nuclear facilities, the medical management of radiation casualties, the responsibilities, plans and resources for coping with a nuclear accident and finally the long term effects of radiation, including leukaemia epidemiology studies. All papers were selected and indexed separately. (UK)

  20. Radiation effects in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Begay, F.; Rosen, L.; Petersen, D.F.; Mason, C.; Travis, B. [Los Alamos National Lab., NM (United States); Yazzie, A. [Navajo Nation, Window Rock, AZ (United States). Dept. of History; Isaac, M.C.P.; Seaborg, G.T. [Lawrence Berkeley National Lab., CA (United States); Leavitt, C.P. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Physics and Astronomy

    1999-04-01

    Although the Navajo possess substantial resource wealth-coal, gas, uranium, water-this potential wealth has been translated into limited permanent economic or political power. In fact, wealth or potential for wealth has often made the Navajo the victims of more powerful interests greedy for the assets under limited Navajo control. The primary focus for this education workshop on the radiation effects in the environment is to provide a forum where scientists from the nuclear science and technology community can share their knowledge toward the advancement and diffusion of nuclear science and technology issues for the Navajo public. The scientists will make an attempt to consider the following basic questions; what is science; what is mathematics; what is nuclear radiation? Seven papers are included in this report: Navajo view of radiation; Nuclear energy, national security and international stability; ABC`s of nuclear science; Nuclear medicine: 100 years in the making; Radon in the environment; Bicarbonate leaching of uranium; and Computational methods for subsurface flow and transport. The proceedings of this workshop will be used as a valuable reference materials in future workshops and K-14 classrooms in Navajo communities that need to improve basic understanding of nuclear science and technology issues. Results of the Begay-Stevens research has revealed the existence of strange and mysterious concepts in the Navajo Language of nature. With these research results Begay and Stevens prepared a lecture entitled The Physics of Laser Fusion in the Navajo language. This lecture has been delivered in numerous Navajo schools, and in universities and colleges in the US, Canada, and Alaska.

  1. Effects of ionizing radiation on life

    International Nuclear Information System (INIS)

    Rausch, L.

    1982-01-01

    Radiobiology in the last years was able to find detailed explanations for the effects of ionizing radiation on living organisms. But it is still impossible to make exact statements concerning the damages by radiation. Even now, science has to content itself with probability data. Moreover no typical damages of ionizing radiation can be identified. Therefore, the risks of ionizing radiation can only be determined by comparison with the spontaneous rate of cancerous or genetic defects. The article describes the interaction of high-energy radiation with the molecules of the organism and their consequences for radiation protection. (orig.)

  2. γ radiation effects on Collembola

    International Nuclear Information System (INIS)

    Loring, S.J.

    1985-01-01

    Pitfall traps were used to collect surface-active Collembola at intervals of 10-100 m from a γ radiation source on Long Island, N.Y., during the summer of 1968. Thirty-two species of Collembola were collected along the radiation transect. Community diversities were similar at all intervals except 10 m. Collembola appeared resistant to γ radiation; only chronic, very high γ radiation exposure seriously affected population levels and community diversity of surface Collembola

  3. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

    Electromagnetic radiation and microwave exist mankind's environment widely. People realize they disserve authors' health when authors make use of them. Electromagnetic radiation is one of the major physic factors which injure people's health. A review of the biologic mechanism about electromagnetic radiation and microwave, their harmful effects to human body, problems in authors' research and the prospect

  4. Study of biological effect of radiation

    International Nuclear Information System (INIS)

    Li Guisheng

    1992-01-01

    The some progress on the study of biological effect for protract exposure to low dose rate radiation is reported, and it is indicated that the potential risk of this exposure for the human health and the importance of the routine monitoring of radiation dose for various nuclear installations. The potential exposure to the low dose rate radiation would attract people's extra attention

  5. Molecular and cellular effects of radiations

    International Nuclear Information System (INIS)

    Peak, M.J.; Peak, J.G.; Ito, A.; Roth, R.M.

    1985-01-01

    This program is concerned with the basic nature of the biological effects of mutagenic and carcinogenic environmental radiations, including those solar ultraviolet and visible radiations responsible for the most common form of human cancer: cancer of the skin. Concentrating on the damages to DNA caused by these radiations, the program attempts to delineate the basic mechanisms whereby such damage may occur. 14 refs

  6. Radiation effects on biochemical systems

    International Nuclear Information System (INIS)

    Seddon, G.M.

    2000-04-01

    Xanthine oxidase catalyses the oxidative hydroxylation of hypoxanthine, xanthine and a wide range of carbonyl compounds. The enzyme exists as an oxidase and a dehydrogenase; both catalyze the oxidation of the same substrates. Steady state radiolysis and pulse radiolysis were used to generate oxidative and reductive free radicals. Their effects on the enzymatic activity of xanthine oxidase were determined. Initially inactivation studies were carried out to evaluate the extent to which radiolysis in aqueous solution affects the enzyme activity. Values of D 37 and G inactivation were calculated following irradiation in the presence of free radical scavengers and in the presence of catalase and superoxide dismutase. The kinetic constants Vmax and Km were also determined following radiolysis. The effect of ionising radiation on the iron content of xanthine oxidase was measured using atomic absorption spectrometry. Native gel electrophoresis and iso-electric focussing were performed in an attempt to demonstrate changes in the overall structure of the enzyme. The binding of xanthine oxidase to heparin was carried out by measuring, (1) the displacement of methylene blue (MB + ) from a heparin-MB + complex, (2) affinity chromatography and, (3) pulse radiolysis. The effect of irradiation on the binding process was investigated using techniques (1) and (2). Finally the radiation-induced conversion of xanthine oxidase to dehydrogenase was established. The results indicate that xanthine oxidase is inactivated greatest in the presence of air and irradiation causes Vmax to he reduced and Km to increase. The iron content of irradiated xanthine oxidase is unaffected. Electrophoresis shows the enzyme becomes fragmented and the isoelectric points of the fragments vary over a wide range of pH. Binding of xanthine oxidase to heparin as measured by displacement of MB + from a heparin-MB + complex suggests that irradiation increases the affinity of the enzyme for the polyanion, whereas

  7. The effects of radiation on man

    International Nuclear Information System (INIS)

    Saunders, P.

    1981-01-01

    Available evidence on the effects of high levels of radiation on man and the predictions which have been made on possible low level effects, by extrapolation of the high level data, are summarised. The factors which influence the biological effects of radiation are examined and acute, delayed, somatic and hereditary effects as reported in the literature, are discussed. (U.K.)

  8. JUDICIAL PROTECTION EFFECTIVENESS AND THE FUNDAMENTAL RIGHT TO PROOF IN THE NEW BRAZILIAN CIVIL PROCEDURE RULES

    Directory of Open Access Journals (Sweden)

    Luis Alberto Reichelt

    2017-05-01

    Full Text Available The present study aims to reflect about the effectiveness of the fundamental right of proof considering the Civil Procedure Rules, taking as a measure the ideas of truth discovery through the process and of the rational persuasion. In this sense, it is examined the testimonial evidence with the introduction of the possibility of cross-examination and also the expert witness in the context of the procedural negotiation.

  9. Empirical Investigation of the Effects of the Fundamentals on the Exchange Rate

    OpenAIRE

    Castro, Juan R.

    2005-01-01

    This paper examines, by using several econometric techniques, the effects of foreign reserves and other fundamental variables on the exchange rate using the target zone theory, This paper uses monthly data for Chile from January 1979 to November 1997 The data used consists of foreign reserves, credit from the Central Bank, domestic reserves, imports, exports, claims on government, GDP, foreign liabilities, domestic and foreign interest rate. We find that the interest differential does not hav...

  10. DOE fundamentals handbook: Chemistry

    International Nuclear Information System (INIS)

    1993-01-01

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. This volume contains the following modules: reactor water chemistry (effects of radiation on water chemistry, chemistry parameters), principles of water treatment (purpose; treatment processes [ion exchange]; dissolved gases, suspended solids, and pH control; water purity), and hazards of chemicals and gases (corrosives [acids, alkalies], toxic compounds, compressed gases, flammable/combustible liquids)

  11. Long term effects of radiation in man

    International Nuclear Information System (INIS)

    Tso Chih Ping; Idris Besar

    1984-01-01

    An overview of the long term effects of radiation in man is presented, categorizing into somatic effects, genetic effects and teratogenic effects, and including an indication of the problems that arise in their determination. (author)

  12. Environmental radiation effects. A need to question old paradigms and to enhance collaboration between radiation biologists and radiation ecologists

    International Nuclear Information System (INIS)

    Hinton, T.G.; Whicker, F.W.

    2003-01-01

    The radiological sciences are a real enigma- the maturity and depth of understanding concerning human dosimetry contrasts sharply with our shallow understanding about radiological effects to biota. The richness of the radiological sciences is apparent by looking at the refinements made to the fundamental unit used in human dosimetry. The radiological sciences have developed to where probabilistic risk factors can now be applied that predict specific deleterious effects to humans per unit dose. And yet, these same radiological sciences that have made such advances in human dosimetry, are primitive when effects to biota are concerned. There are no specialized units, no agreed upon weighting factors, no factors that account for distributions within an organism's body, and certainly no risk factors. There are no internationally agreed upon criteria or policies that explicitly address protection of the environment from ionizing radiation. There is not even agreement as to what endpoint should be measured to quantify an environmental effect. The bold aspect of the ICRP framework is the inclusion of sub-lethal effects (reduced reproductive success, scorable DNA damage) as endpoints. A major research consortium funded by the European Union, is also recommending that cytogenetic damage be used as an effect endpoint. The inclusion of sub-lethal endpoints begs for a linkage between molecular effects and those observed in individuals and populations. To do so, will require a strengthening of what has traditionally been separated disciplines of radiation biology and radiation ecology. The impacts of phenomena studied in the petri dishes of radiation biologists (such as genomic instability, adaptive response, and bystander effects) need to be explored and correlated to effects observed in whole organisms and populations, in collaboration with radiation ecologists. (M. Suetake)

  13. Non controlled effect of ionizing radiations : involvement for radiation protection

    International Nuclear Information System (INIS)

    Little, J. B.

    2005-01-01

    It is widely accepted that damage to DNA is the critical event on irradiated cells, and that double strand breaks are the primary DNA lesions responsible for the biological effects of ionizing radiation. This has lead to the long standing paradigm that these effects, be they cytotoxicity, mutagenesis or malignant transformation, occur in irradiated cells as a consequences of the DNA damage they incur. Evidence has been accumulating over the past decade, however, to indicate that radiation may induce effects that ar not targeted to the irradiated cells itself. Two non-targeted effects will be described in this review. The first, radiation-induced genomic instability, is a phenomenon whereby signals are transmitted to the progeny of the irradiated cell over many generations, leading to the occurrence of genetic effects such as mutations and chromosomal aberrations arising in the distant descendants of the irradiated cell. Second, the bystander effect, is a phenomenon whereby irradiated cells transmit damage signals to non-irradiated cells in a mixed population, leading to genetic effects arising in these bystander cells that received no radiation exposure. the model system described in this review involves dense monolayer cultures exposed to very low fluences of alpha particles. The potential implications of these two phenomena for the analysis of the risk to the human population of exposure to low levels of ionising radiation is discussed. (Author) 111 refs

  14. Graphene Field Effect Transistor for Radiation Detection

    Science.gov (United States)

    Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

    2016-01-01

    The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

  15. Comparison of the dose-effect relationship for UV radiation and ionizing radiation

    International Nuclear Information System (INIS)

    Leenhouts, H.P.; Sijsma, M.J.; Chadwick, K.H.

    1990-06-01

    Ionizing radiation and ultraviolet radiation (UV) are both physical agents with mutagenic and carcinogenic properties. However, there are some basic differences in the fundamental mechanism of their interaction with biological material that may have consequences for risk assessment. In this paper the dose-effect relationships for gamma radiation and UV at cellular level will be used to demonstrate the different radio-biological effectiveness of both agents. The results will be discussed in the framework of a biophysical model, based on the assumption that DNA doublestranded lesions are crucial for the cytotoxic action. After exposure to ionizing radiation, the lesions are fixed immediately following irradiation, but after UV exposure the lethal lesions are recognized only in the next DNA synthesis phase. The combination of this concept with the mechanism of lesion induction and the possibility of repair, leads to different dose and time relationships for the radiation effects of both agents. The possible consequences for risk assessment at low levels will be discussed. (author). 9 refs.; 5 figs

  16. Process and kinetics of the fundamental radiation-electrochemical reactions in the primary coolant loop of nuclear reactors

    International Nuclear Information System (INIS)

    Kozomara-Maic, S.

    1987-06-01

    In spite of the rather broad title of this report, its major part is devoted to the corrosion problems at the RA reactor, i.e. causes and consequences of the reactor shutdown in 1979 and 1982. Some problems of reactor chemistry are pointed out because they are significant for future reactor operation. The final conclusion of this report is that corrosion processes in the primary coolant circuit of the nuclear reactor are specific and that radiation effects cannot be excluded when processes and reaction kinetics are investigated. Knowledge about the kinetics of all the chemical reactions occurring in the primary coolant loop are of crucial significance for safe and economical reactor operation [sr

  17. Calculation And Design Of A New Configuration For Radiation Shielding At Neutron Beam No.3 For Fundamental And Applied Researches

    International Nuclear Information System (INIS)

    Vuong Huu Tan; Tran Tuan Anh; Nguyen Kien Cuong; Nguyen Canh Hai; Nguyen Xuan Hai; Pham Ngoc Son; Ho Huu Thang

    2011-01-01

    The tangential horizontal channel of No. 3 of the Dalat Research Reactor has been opened and used during the 1990s. The utilizations of the thermal neutron beam at this channel were the Neutron Radiography and the Prompt Gamma Neutron Activation Analysis method (PGNAA). At present, the neutron beam used for nuclear structure data researches based on the Summing of Amplitude Coincident Pulses system (SACP). Beside, several related research equipments have been set up and operated for the research purposes. A renovation of the neutron channel, therefore, will play an important role in safe and effective utilizations of the neutron beam in fields of nuclear physic training and researches. A new configuration for radiation shielding has been simulated by MCNP code. The calculated results of dose rates for neutron and gamma at working positions are in range of dose rate limit. (author)

  18. Radiation-induced polymerization and radiation effect on polymers

    International Nuclear Information System (INIS)

    Seguchi, Tadao

    1977-12-01

    The processes of radiation-induced polymerization of monomers and also radiation effects on polymers have been studied by instrumental analyses of electron spin resonance (ESR), nuclear magnetic resonance (NMR) and electron microscopy. In radiation-induced polymerization, graft-copolymerization and absorbed state polymerization were taken up. For graft-copolymerization, monomers such as methylmethacrylate and butadiene were made to react with irradiated polyethylene, and behaviors of the initiating radicals and propagating radicals were followed under the reaction by ESR. For absorbed state polymerization, acrylonitrile/zeolite and methylmethacrylate/zeolite were chosen. Absorbed monomers were irradiated at 77 0 K and polymerized at room temperature. Active species and the concentrations were measured by ESR and the yields of polymer were observed by NMR. In radiation effect on polymers, polyvinylfluoride, polyvinylidenfluoride and polytetrafluoroethylene were taken up. Active species trapped in the polymer matrixes were identified and decay and reactivity of the species were also studied. On the basis of information from the electron microscopy and x-ray analysis, radiation effects on these polymers are described. In polytetrafluoroethylene produced by radiation polymerization, the relation between morphology and polymerization conditions and also the process of crystallization during polymerization were studied. (auth.)

  19. Untargeted effects of ionizing radiation: Implications for radiation pathology

    International Nuclear Information System (INIS)

    Wright, Eric G; Coates, Philip J

    2006-01-01

    The dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation, characteristically associated with the consequences of energy deposition in the cell nucleus, arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that have received damaging signals produced by irradiated cells (radiation-induced bystander effects) or that are the descendants of irradiated cells (radiation-induced genomic instability). Radiation-induced genomic instability is characterized by a number of delayed adverse responses including chromosomal abnormalities, gene mutations and cell death. Similar effects, as well as responses that may be regarded as protective, have been attributed to bystander mechanisms. Whilst the majority of studies to date have used in vitro systems, some adverse non-targeted effects have been demonstrated in vivo. However, at least for haemopoietic tissues, radiation-induced genomic instability in vivo may not necessarily be a reflection of genomically unstable cells. Rather the damage may reflect responses to ongoing production of damaging signals; i.e. bystander responses, but not in the sense used to describe the rapidly induced effects resulting from direct interaction of irradiated and non-irradiated cells. The findings are consistent with a delayed and long-lived tissue reaction to radiation injury characteristic of an inflammatory response with the potential for persisting bystander-mediated damage. An important implication of the findings is that contrary to conventional radiobiological dogma and interpretation of epidemiologically-based risk estimates, ionizing radiation may contribute to malignancy and particularly childhood leukaemia by promoting initiated cells rather than being the initiating agent. Untargeted mechanisms may also contribute to other pathological consequences

  20. Effect of a 6-Week Active Play Intervention on Fundamental Movement Skill Competence of Preschool Children.

    Science.gov (United States)

    Foulkes, J D; Knowles, Z; Fairclough, S J; Stratton, G; O'Dwyer, M; Ridgers, N D; Foweather, L

    2017-04-01

    This study examined the effectiveness of an active play intervention on fundamental movement skills of 3- to 5-year-old children from deprived communities. In a cluster randomized controlled trial design, six preschools received a resource pack and a 6-week local authority program involving staff training with help implementing 60-minute weekly sessions and postprogram support. Six comparison preschools received a resource pack only. Twelve skills were assessed at baseline, postintervention, and at a 6-month follow-up using the Children's Activity and Movement in Preschool Study Motor Skills Protocol. One hundred and sixty-two children (Mean age = 4.64 ± 0.58 years; 53.1% boys) were included in the final analyses. There were no significant differences between groups for total fundamental movement skill, object-control skill or locomotor skill scores, indicating a need for program modification to facilitate greater skill improvements.

  1. A-bomb radiation effects digest

    International Nuclear Information System (INIS)

    Shigematsu, Itsuzo; Akiyama, Mitoshi; Sasaki, Hideo; Ito, Chikako; Kamada, Nanao.

    1993-01-01

    This publication is the digest of the book 'Genbaku Hoshasen no Jintai Eikyo (Effects of A-bomb Radiation on the Human Body)' (365p.), published in Japanese by Hiroshima International Council for Medical Care of the Radiation-Exposed. Following a brief description on the damage of the atomic bomb, the subjects of malignant tumors, endocrine and metabolic deseases, ocular lesions, dermatologic effects, prenatal exposure, chromosoal aberrations, mutations, sensitivity to radiation, immune function, genetic effects and other effects of radiation are summarized. (J.P.N.)

  2. Determination of the detection limit and decision threshold for ionizing radiation measurements. Part 2: Fundamentals and application to counting measurements with the influence of sample treatment

    International Nuclear Information System (INIS)

    2000-01-01

    This part of ISO 11929 addresses the field of ionizing radiation measurements in which events (in particular pulses) on samples are counted after treating them (e.g. aliquotation, solution, enrichment, separation). It considers, besides the random character of radioactive decay and of pulse counting, all other influences arising from sample treatment, (e.g. weighing, enrichment, calibration or the instability of the test setup). ISO 11929 consists of the following parts, under the general title Determination of the detection limit and decision threshold for ionizing radiation measurements: Part 1: Fundamentals and application to counting measurements without the influence of sample treatment; Part 2: Fundamentals and application to counting measurements with the influence of sample treatment; Part 3: Fundamentals and application to counting measurements by high resolution gamma spectrometry, without the influence of sample treatment; Part 4: Fundamentals and application to measurements by use of linear scale analogue ratemeters, without the influence of sample treatment. This part of ISO 11929 was prepared in parallel with other International Standards prepared by WG 2 (now WG 17): ISO 11932:1996, Activity measurements of solid materials considered for recycling, re-use or disposal as non radioactive waste, and ISO 11929-1, ISO 11929-3 and ISO 11929-4 and is, consequently, complementary to these documents

  3. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

    Kaul, Alexander; Burkart, Werner; Grosche, Bernd; Jung, Thomas; Martignoni, Klaus; Stephan, Guenther

    1997-01-01

    This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

  4. Fundamental length

    International Nuclear Information System (INIS)

    Pradhan, T.

    1975-01-01

    The concept of fundamental length was first put forward by Heisenberg from purely dimensional reasons. From a study of the observed masses of the elementary particles known at that time, it is sumrised that this length should be of the order of magnitude 1 approximately 10 -13 cm. It was Heisenberg's belief that introduction of such a fundamental length would eliminate the divergence difficulties from relativistic quantum field theory by cutting off the high energy regions of the 'proper fields'. Since the divergence difficulties arise primarily due to infinite number of degrees of freedom, one simple remedy would be the introduction of a principle that limits these degrees of freedom by removing the effectiveness of the waves with a frequency exceeding a certain limit without destroying the relativistic invariance of the theory. The principle can be stated as follows: It is in principle impossible to invent an experiment of any kind that will permit a distintion between the positions of two particles at rest, the distance between which is below a certain limit. A more elegant way of introducing fundamental length into quantum theory is through commutation relations between two position operators. In quantum field theory such as quantum electrodynamics, it can be introduced through the commutation relation between two interpolating photon fields (vector potentials). (K.B.)

  5. Radiation hazards and their effects

    International Nuclear Information System (INIS)

    Lunu, Shyam; Kumar, Hemant; Joshi, Pankaj Kumar; Songara, Venkteshwer

    2012-01-01

    Radiation can be classified into ionizing radiation and non-ionizing radiation, based on whether it is capable of ionizing atoms and breaking chemical bonds. Ultraviolet and higher frequency such as X-rays, gamma rays are ionizing. These pose their own special hazards. Non ionizing radiation is associated with two major potential hazards. i.e. electrical and biological. Additionally includes electric current caused by radiation can generate sparks and create a fire or explosive hazards. Strong radiation can induce current capable of delivering an electric shock. Extremely high power electromagnetic radiation can cause electric currents strong enough to create sparks when an induced voltage exceeds the breakdown voltage of surrounding mediums. A 2009 study at the University of Basal in Switzerland found that intermitted exposure of human cells to a 50 Hz electromagnetic field at a flux density of 10 Gy induced a slight but significant increase of DNA fragmentation in the comet assay. Mobile phones radiation and health concerns have been raised, especially following the enormous increase in the use of wireless mobile telephony throughout the world. Mobile phones use electromagnetic radiation in the microwaves range and some believes this may be harmful to human health. (author)

  6. Fundamental study of ash formation and deposition: Effect of reducing stoichiometry

    Energy Technology Data Exchange (ETDEWEB)

    Helble, J.J.; Bool, L.E.; Kang, S.G. [and others

    1995-11-01

    This project is designed to examine the effects of combustion stoichiometry on the fundamental aspects of ash formation and ash deposit initiation. Emphasis is being placed on reducing stoichiometries associated with low-NOx combustion, although a range of oxidant/fuel ratios are being considered. Previous work has demonstrated that ash formation depends strongly upon coal mineralogy, including mineral type, size, amount, and the presence of organically associated inorganic species. Combustion temperature and the oxidation state of iron also play a significant role. As these latter items will vary with changes in stoichiometry, research to determine the net effect on deposition is required.

  7. Some characteristics and effects of natural radiation

    International Nuclear Information System (INIS)

    Mc Laughlin, J.P.

    2015-01-01

    Since life first appeared on the Earth, it has, in all its subsequent evolved forms including human, been exposed to natural radiation in the environment both from terrestrial and extra-terrestrial sources. Being an environmental mutagen, ionising natural radiation may have played a role of some significance in the evolution of early life forms on Earth. It has been estimated by United Nations Scientific Committee on the Effects of Atomic Radiation that at the present time, exposure to natural radiation globally results in an annual average individual effective dose of about 2.4 mSv. This represents about 80 % of the total dose from all sources. The three most important components of natural radiation exposure are cosmic radiation, terrestrial radioactivity and indoor radon. Each of these components exhibits both geographical and temporal variabilities with indoor radon exposure being the most variable and also the largest contributor to dose for most people. In this account, an overview is given of the characteristics of the main components of the natural radiation environment and some of their effects on humans. In the case of cosmic radiation, these range from radiation doses to aircrew and astronauts to the controversial topic of its possible effect on climate change. In the case of terrestrial natural radiation, accounts are given of a number of human exposure scenarios. (author)

  8. Radiation effects in ice: New results

    International Nuclear Information System (INIS)

    Baragiola, R.A.; Fama, M.; Loeffler, M.J.; Raut, U.; Shi, J.

    2008-01-01

    Studies of radiation effects in ice are motivated by intrinsic interest and by applications in astronomy. Here we report on new and recent results on radiation effects induced by energetic ions in ice: amorphization of crystalline ice, compaction of microporous amorphous ice, electrostatic charging and dielectric breakdown and correlated structural/chemical changes in the irradiation of water-ammonia ices

  9. Radiation effects of ion beams on polymers

    International Nuclear Information System (INIS)

    Tagawa, Seiichi

    1993-01-01

    Recent progress in the radiation effects of ion beams on polymers are reviewed briefly. Our recent work on the radiation effects of ion beams on polystyrene thin films on silicon wafers and time resolved emission studies on polymers are described. (orig.)

  10. Radiation protection in the age of accountability - measuring our effectiveness

    International Nuclear Information System (INIS)

    Hutchinson, D.E.

    1993-01-01

    Effectiveness and accountability were catch-words of the 1980s for public and private enterprises. This mood has persisted into the current decade and radiation protection authorities have not escaped the organisational microscope. But whereas simple models and measures of effectiveness can be applied to most private companies and government agencies, organisations in the regulatory and preventative health areas cannot be assessed by the same criteria. These organisations are fundamentally different because their primary objective is one of minimisation. This paper looks at options for measuring and reporting the effectiveness of radiation protection organisations. Some performance indicators are proposed and evaluated. The intention is not, however, to present a 'solution' to this apparently vexing problem. Indeed, the answer may be that there is none. 11 refs., 4 figs

  11. The Exclusion of Persons Trans Labour Market and Non Effectiveness of the Fundamental Right to Work

    Directory of Open Access Journals (Sweden)

    Neumalyna Lacerda Alves Dantas Marinho

    2016-10-01

    Full Text Available This article aims to study the exclusion of trans people in the labor market and the resulting non-effectiveness of the fundamental right to work. The work in contemporary society presents itself not only as a means of survival, it is also and not least, a means of social inclusion and promoter of the development process and human dignity. These people are invisible and the margins of society imposing heteronormative behavior. Thus, it was used in this study a bibliographic and documentary research made from literature review of the authoritative literature on the subject.

  12. Radiobiologic effects at low radiation levels

    International Nuclear Information System (INIS)

    Casarett, G.W.

    1975-01-01

    Data are reviewed on the effects of low radiation doses on mammals. Data from the 1972 report on the Biological Effects of Ionizing Radiation issued by the Advisory Committee of the National Academy of Sciences and National Research Council are discussed. It was concluded that there are certain radiosensitive systems in which low doses of radiation may cause degenerative effects, including gametogenic epithelium, lens of the eye, and developing embryos. Despite extensive investigation of genetic effects, including chromosomal effects, neither the amount of change that will be caused by very low levels of irradiation nor the degree of associated detriment is known

  13. Deciphering free-radical code of radiation effects

    International Nuclear Information System (INIS)

    Volovyk, S.; Bazyka, D.; Loganovsky, K.; Bebeshko, V.

    2007-01-01

    Complete text of publication follows. Objective: Ionizing radiation is fundamental environmental factor for life origin and evolution. Free radicals, primordial 'sea' for life conceiving and existence, induced by cosmic and terrestrial background radiation, are evolutionally archetypal, ubiquitous, and omnipotent in physiological- pathophysiological dichotomy. Classical free-radical paradigm in radiation biology and medicine, focused in essence on oxidative damage, needs new conceptualization and generalization. Methods: Suggested novel insights into free radicals dual immanent nature and functions in organism systems are based on original concepts of radicals dynamic charge transfer (CT) - redox ambivalence (interactional nucleo-, electro-, and ambiphilicity spectrum); pertinent chemical reactivity and selectivity delocalization model; physiological functional ambivalence and complementarity, and dynamic free-radical homeostasis. Results: Subtle perturbations in radicals CT spatiotemporal homeodynamics, in responsive signaling / controlling networks, concomitant alterations in genes expression, transcription, and apoptosis, redox control of mitochondrial ET chain, telomere/telomerase balance, DNA CT, circadian clock, hemispheric biochemical dominance/accentuation, including alteration of nitric oxide-superoxide complementarity, membranes permeability, neurotransmission pattern, synaptic circuitry, etc under radiation exposure have more fundamental impact on organism systems (especially CNS and CVS) deterioration than simple radicals inflicted oxidative (nitrosative) damage of cellular constituents. Conclusions: This novel conceptualization of free-radical paradigm constitutes new dimension in deciphering molecular mechanisms of radiation effects on subtle borderline norm-pathology and continuity-discontinuity dichotomy in organisms systems disorders - CT(redox)omics, which involves investigation of CT, redox, and spin states of free radicals, DNA bases

  14. Physics of intense, high energy radiation effects.

    Energy Technology Data Exchange (ETDEWEB)

    Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

    2011-02-01

    This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic

  15. Physics of intense, high energy radiation effects

    International Nuclear Information System (INIS)

    Hjalmarson, Harold Paul; Hartman, E. Frederick; Magyar, Rudolph J.; Crozier, Paul Stewart

    2011-01-01

    This document summarizes the work done in our three-year LDRD project titled 'Physics of Intense, High Energy Radiation Effects.' This LDRD is focused on electrical effects of ionizing radiation at high dose-rates. One major thrust throughout the project has been the radiation-induced conductivity (RIC) produced by the ionizing radiation. Another important consideration has been the electrical effect of dose-enhanced radiation. This transient effect can produce an electromagnetic pulse (EMP). The unifying theme of the project has been the dielectric function. This quantity contains much of the physics covered in this project. For example, the work on transient electrical effects in radiation-induced conductivity (RIC) has been a key focus for the work on the EMP effects. This physics in contained in the dielectric function, which can also be expressed as a conductivity. The transient defects created during a radiation event are also contained, in principle. The energy loss lead the hot electrons and holes is given by the stopping power of ionizing radiation. This information is given by the inverse dielectric function. Finally, the short time atomistic phenomena caused by ionizing radiation can also be considered to be contained within the dielectric function. During the LDRD, meetings about the work were held every week. These discussions involved theorists, experimentalists and engineers. These discussions branched out into the work done in other projects. For example, the work on EMP effects had influence on another project focused on such phenomena in gases. Furthermore, the physics of radiation detectors and radiation dosimeters was often discussed, and these discussions had impact on related projects. Some LDRD-related documents are now stored on a sharepoint site (https://sharepoint.sandia.gov/sites/LDRD-REMS/default.aspx). In the remainder of this document the work is described in catergories but there is much overlap between the atomistic calculations, the

  16. Radiation Effects on Polymers - XI

    DEFF Research Database (Denmark)

    Ghanem, N. A.; El-Awady, N. I.; Singer, Klaus Albert Julius

    1979-01-01

    With the aim of improving properties of cellulose acetate membranes for reverse osmosis desalination, grafting was performed using high energy electrons. In this paper, the grafting parameters (radiation dose and method, monomer concentration, solvents, chain transfer agent and redox system...

  17. Radiation effects in polycarbonate capacitors

    Directory of Open Access Journals (Sweden)

    Vujisić Miloš

    2009-01-01

    Full Text Available The aim of this paper is to examine the influence of neutron and gamma irradiation on the dissipation factor and capacitance of capacitors with polycarbonate dielectrics. The operation of capacitors subject to extreme conditions, such as the presence of ionizing radiation fields, is of special concern in military industry and space technology. Results obtained show that the exposure to a mixed neutron and gamma radiation field causes a decrease of capacitance, while the loss tangent remains unchanged.

  18. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  19. Genetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Myers, D.K.; Childs, J.D.

    1980-01-01

    The genetic material in living organisms is susceptible to damage from a wide variety of causes including radiation exposure. Most of this damage is repaired by the organism; the residual damage and damage which is not correctly repaired can lead to genetic changes such as mutations. In lower organisms, most offspring carry an unaltered copy of the genetic information that was present in the parental organism, most of the genetic changes which do occur are not caused by natural background radiation, and the increase in frequency of genetic changes after irradiation at low-dose rates is directly proportional to total radiation dose. The same principles appear to be valid in mammals and other higher organisms. About 105 out of every 1000 humans born suffer from some genetic or partly-genetic condition requiring medical attention at some time. It has been estimated that approximately 1 person in every 2000 born carry a deleterious genetic mutation that was caused by the continued exposure of many generations of our ancestors to natural background radiation. On the same basis, it is predicted that the incidence of genetic diseases would be increased to 106 per 1000 in the children and grandchildren of radiation workers who were exposed to 1 rem per year commencing at age 18. However, there was no detectable change in the health and fitness of mice whose male ancestors were repeatedly exposed to high radiation doses up to 900 rem per generation. (auth)

  20. Modification of genetic effects of gamma radiation by laser radiation

    International Nuclear Information System (INIS)

    Khotyljova, L.V.; Khokhlova, S.A.; Khokhlov, I.V.

    1988-01-01

    Full text: Mutants obtained by means of ionizing radiation and chemical mutagens often show low viability and productivity that makes their use in plant breeding difficult. Methods reducing the destructive mutagen action on important functions of plant organism and increasing quality and practical value of induced mutants would be interesting. We believe that one method for increasing efficiency of experimental mutagenesis in plants is the application of laser radiation as a modificator of genetic effects of ionizing radiation and chemical mutagens. Combined exposure of wheat seedlings to a gamma radiation dose of 2 kR and to laser radiation with the wave length of 632.8 nm (power density - 20 mVt/cm 2 , exposure - 30 min.) resulted in reducing the chromosomal aberration percentage from 30.5% in the gamma version to 16.3% in the combined treatment version. A radiosensibilizing effect was observed at additional exposure of gamma irradiated wheat seeds to laser light with the wave length of 441.6 nm where chromosomal aberration percentage increased from 22% in the gamma-irradiation version to 31% in the combined treatment version. By laser radiation it is also possible to normalize mitotic cell activity suppressed by gamma irradiation. Additional seedling irradiation with the light of helium-neon laser (632.8 nm) resulted in recovery of mitotic cell activity from 21% to 62% and increasing the average content of DNA per nucleus by 10%. The influence of only laser radiation on plant variability was also studied and it was shown that irradiation of wheat seeds and seedlings with pulsed and continuous laser light of visible spectrum resulted in phenotypically altered forms in M 2 . Their frequencies was dependent upon power density, dose and radiation wave length. Number of altered forms increased in going from long-wave to short-wave spectrum region. In comparing efficiency of different laser types of pulsed and continuous exposure (dose - 180 J/cm 2 ) 2% of altered

  1. Radiation effects on light sources and detectors

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1985-01-01

    The rapidly expanding field of optoelectronics includes a wide variety of both military and non-military applications in which the systems must meet radiation exposure requirements. Herein, we review the work on radiation effects on sources and detectors for such optoelectronic systems. For sources the principal problem is permanent damage-induced light output degradation, while for detectors it is ionizing radiation-induced photocurrents

  2. Bystander Effects of Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Little, John B. [Harvard T.H. Chan School of Public Health, Boston, MA (United States). Dept. of Genetics and Complex Diseases

    2017-01-17

    The objectives of this grant renewal are to provide administrative support and travel funds to allow the continued participation of the principal investigator (Dr. John B. Little) as an advisor to research initiated by several research fellows from his laboratory. The actual research will be carried out under the direction of Dr. Hatsumi Nagasawa with the collaboration of Dr. Joel Bedford at the Colorado State University, and by Drs. Edouard Azzam and Sonia de Toledo at the University of Medicine and Dentistry of New Jersey. Dr. Little will advise on the planning of experiments and development of experimental protocols, the analysis of data, and the preparation of manuscripts for publication. The Specific Aims for several of the planned experiments include: 1) to extend studies of the role of recombinational repair in the bystander effect by examining other genes in this pathway and cell lines deficient in excision repair; 2) to continue studies to determine the nature of the damage signal transmitted to bystander cells including the expression of several connexins in the bystander response, and the extent to which the enhanced oxidative metabolism observed in bystander cells may relate to the nature of the transmitted bystander signal; 3) to utilize a genome-wide approach to examine the genetic basis for the hypersensitivity to ionization we have observed in unaffected parents of patients with hereditary retinoblastoma, as well as from a group of apparently normal individuals that show similar radiosensitivity; 4) to complete studies concerning the induction of high frequencies of cells with massive chromosome damage in clonal derivatives of p53 and p21 knockout mouse cell lines; in particular to examine the role of telomere changes in this phenomenon. Overall, the results of these studies should enhance our understanding of the risk of low-dose exposures to ionizing radiation, including human populations to residential radon as well as occupational exposures.

  3. Bystander Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Little, John B.

    2017-01-01

    The objectives of this grant renewal are to provide administrative support and travel funds to allow the continued participation of the principal investigator (Dr. John B. Little) as an advisor to research initiated by several research fellows from his laboratory. The actual research will be carried out under the direction of Dr. Hatsumi Nagasawa with the collaboration of Dr. Joel Bedford at the Colorado State University, and by Drs. Edouard Azzam and Sonia de Toledo at the University of Medicine and Dentistry of New Jersey. Dr. Little will advise on the planning of experiments and development of experimental protocols, the analysis of data, and the preparation of manuscripts for publication. The Specific Aims for several of the planned experiments include: 1) to extend studies of the role of recombinational repair in the bystander effect by examining other genes in this pathway and cell lines deficient in excision repair; 2) to continue studies to determine the nature of the damage signal transmitted to bystander cells including the expression of several connexins in the bystander response, and the extent to which the enhanced oxidative metabolism observed in bystander cells may relate to the nature of the transmitted bystander signal; 3) to utilize a genome-wide approach to examine the genetic basis for the hypersensitivity to ionization we have observed in unaffected parents of patients with hereditary retinoblastoma, as well as from a group of apparently normal individuals that show similar radiosensitivity; 4) to complete studies concerning the induction of high frequencies of cells with massive chromosome damage in clonal derivatives of p53 and p21 knockout mouse cell lines; in particular to examine the role of telomere changes in this phenomenon. Overall, the results of these studies should enhance our understanding of the risk of low-dose exposures to ionizing radiation, including human populations to residential radon as well as occupational exposures.

  4. Chernobyl health effects: radiation or stress?

    International Nuclear Information System (INIS)

    Grinkhal', G.

    1996-01-01

    Consideration is given to results of wide-scale examination of human population, subjected to the effect of radiation in result of Chernobyl accident. The examined contingents consisted of liquidators, evacuated from 30-km zone, people still living in contamination territories, children of irradiated parents and children, who received large radiation doses. High levels of respiratory system diseases, digestive system diseases, cardiovascular diseases and nervous system diseases were revealed for these people. It was revealed that stress, socio-economic and chemical factors played sufficient role in disease incidence. It is shown that fair of radiation may damage more, than radiation itself

  5. Late effects of radiation: host factors

    International Nuclear Information System (INIS)

    Fry, R.J.M.; Storer, J.B.

    1983-01-01

    The paper discusses the influence of host factors on radiation late effects and in particular cancer. Radiation induces cellular changes that result in initiated cells with a potential to become cancers. The expression of the initiated cells as tumors is influenced, if not determined, by both tissue and systemic factors that are sex-, age-, and species-dependent

  6. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    Clerc, H.

    1991-03-01

    In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

  7. Radiation effects on Fischer-Tropsch syntheses

    International Nuclear Information System (INIS)

    Hatada, M.; Matsuda, K.

    1977-01-01

    Radiation effects on Fischer-Tropsch synthesis has been examined using high dose rate electron beams and Fe-Cu-diatomaceous earth catalyst. Yields of saturated hydrocarbons were found to increase by irradiation, but the yields of these compounds were decreased by raising reaction temperature without irradiation, suggesting the presence of radiation chemical process in catalytic reactions. (author)

  8. Radiation effects in charge coupled devices

    International Nuclear Information System (INIS)

    Williams, R.A.; Nelson, R.D.

    1975-01-01

    Charge coupled devices (CCD s) exhibit a number of advantages (low cost, low power, high bit density) in their several applications (serial memories, imagers, digital filters); however, fairly elementary theoretical considerations indicate that they will be very vulnerable to permanent radiation damage, by both neutrons and ionizing radiation, and to transient upset by pulsed ionizing radiation. Although studies of permanent ionizing-radiation damage in CCD's have been reported, little information has been published concerning their overall nuclear radiation vulnerability. This paper presents a fairly comprehensive experimental study of radiation effects in a 256-cell surface-channel, CCD shift-register. A limited amount of similar work is also presented for a 128-cell surface-channel device and a 130 cell peristaltic CCD shift register. The radiation effects phenomena discussed herein, include transient-ionizing-radiation responses, permanent ionizing- radiation damage to transfer efficiency, charge-carrying capacity and input transfer gate bias, and neutron damage to storage time--determined from dark current and charge-up time measurements

  9. Poloidal field effects on fundamental minority ion cyclotron resonance heating in a tokamak plasma

    International Nuclear Information System (INIS)

    Jun, S. C.; Imre, Kaya; Stevens, D. C.; Weitzner, Harold; Chang, C. S.

    2000-01-01

    Minority ion fundamental cyclotron resonance is studied in a large tokamak in which the geometrical optics approximation applies off resonance and the minority average speed is less than the wave phase speeds. Poloidal equilibrium magnetic field effects are included, which lead to nontrivially nonlocal integrodifferential equations for the wave fields. Exact reciprocity relation is given as well as explicit analytic solutions for the transmission coefficients for both the high and low field side incidences. Numerical solutions are needed only for the high field side incident reflection coefficient. Numerical schemes are described and numerical results are presented together with a reliable error bound. Typically, energy absorption increases with poloidal field. The energy absorption increases with minority density at low values of minority density. However, it decreases at high minority density. Poloidal field effects weaken the dependence of energy absorption on the toroidal wave number. (c) 2000 American Institute of Physics

  10. The fundamental attribution error in detecting deception: the boy-who-cried-wolf effect.

    Science.gov (United States)

    O'Sullivan, Maureen

    2003-10-01

    Most people are unable to detect accurately when others are lying. Many explanations for this inability have been suggested but the cognitive heuristics involved in lie detection have received little attention. The present study offers evidence from two experiments, based on two different groups of observers, judging two different kinds of lies, presented in two different testing situations, that the fundamental attribution error significantly undermines the ability to detect honesty and deception accurately. Trait judgments of trustworthiness were highly correlated with state judgments of truthfulness, leading, as predicted, to positive correlations with honest detection accuracy and negative correlations with deception detection accuracy. More accurate lie detectors were significantly more likely than less accurate lie detectors to separate state and trait judgments of honesty. The effect of other biases, such as the halo effect and the truthfulness bias, also are examined. Implications for future research and practice are discussed.

  11. Coherence effects in radiative scattering

    International Nuclear Information System (INIS)

    Knoll, J.; Lenk, R.

    1993-03-01

    The bremsstrahl-production of photons in dense matter is reinvestigated using the example of an exactly solvable quantum mechanical model in one space dimension. Coherence phenomena between successive radiative scatterings among the constituents lead to a modification of the production cross section in the medium relative to the incoherent quasi-free prescription used in kinetic models. Analytic expressions for the correction factor have been derived comparing the quantum rates with the corresponding incoherent quasi-free rates. The result has implications for the kinetic description of all kinds of radiative processes in nucleus-nucleus collisions, both on the level of hadron and parton dynamics. (orig.)

  12. Refractive index of ternary and quaternary compound semiconductors below the fundamental absorption edge: Linear and nonlinear effects

    International Nuclear Information System (INIS)

    Jensen, B.; Torabi, A.

    1985-01-01

    The index of refraction n is calculated as a function of frequency and mole fraction x for the following compounds: Hg/sub l-x/Cd/sub x/Te, Al/sub x/Ga/sub l-x/As, and In/sub l-x/Ga/sub x/As/sub y/P/sub l-y/ lattice matched to InP. Lattice matching of In/sub l-x/Ga/sub x/As/sub y/P/sub l-y/ to InP requires that x = 0.466 y. The theoretical result for the refractive index is obtained from a quantum mechanical calculation of the dielectric constant of a compound semiconductor. It is given in terms of the basic material parameters of band gap energy, effective electron mass m/sub n/, effective heavy hole mass m/sub rho/, spin orbit splitting energy, lattice constant, and carrier concentration n/sub e/ or rho for n-type or rho-type materials, respectively. If these quantities are known as functions of mole fraction x, there are no adjustable parameters involved. A negative change in the refractive index near the fundamental absorption edge is predicted on passing radiation through a crystal if the change in carrier concentration of the initially unoccupied conduction band is assumed proportional to internal intensity I. Comparison of theory with experimental data is given

  13. Physics of radiation effects in crystals

    CERN Document Server

    Johnson, RA

    1986-01-01

    ``Physics of Radiation Effects in Crystals'' is presented in two parts. The first part covers the general background and theory of radiation effects in crystals, including the theory describing the generation of crystal lattice defects by radiation, the kinetic approach to the study of the disposition of these defects and the effects of the diffusion of these defects on alloy compositions and phases. Specific problems of current interest are treated in the second part and include anisotropic dimensional changes in x-uranium, zirconium and graphite, acceleration of thermal creep in reactor ma

  14. Effects of radiation on scintillating fiber performance

    International Nuclear Information System (INIS)

    Bauer, M.L.; Cohn, H.; Efremenko, Yu.; Gordeev, A.; Kamyshkov, Yu.; Onopienko, D.; Savin, S.; Shmakov, K.; Tarkovsky, E.; Young, K.G.; Carey, R.; Rothman, M.; Sulak, L.; Worstell, W.; Parr, H.

    1992-01-01

    Continued rapid improvements in formulations for scintillating fibers require the ability to parameterize and predict effects of radiation on detector performance. Experimental techniques necessary to obtain needed information and calculational procedures used in performing predications for hadron scintillating fiber calorimetry in the Superconducting Supercollider environment are described. The experimental techniques involve control of the testing environment, consideration of dose rate effects, and other factors. These calculations involve the behavior of particle showers in the detector, expected levels of radiation, and parameterization of the radiation effects. A summary of significant work is also presented

  15. Effects of radiation on scintillating fiber performance

    International Nuclear Information System (INIS)

    Young, K.G.; Bauer, M.L.; Cohn, H.; Efremenko, Yu.; Gordeev, A.; Kamyshkov, Yu.; Onopienko, D.; Savin, S.; Shmakov, K.; Tarkovsky, E.; Carey, R.; Rothman, M.; Sulak, L.; Worstell, W.; Paar, H.

    1993-01-01

    Continued rapid improvements in formulations for scintillating fibers require the ability to parameterize and predict effects of radiation on detector performance. Experimental techniques necessary to obtain desired information and calculational procedures used in performing predictions for hadron scintillating fiber calorimetry in the Superconducting Supercollider environment are described. The experimental techniques involve control of the testing environment, consideration of dose rate effects, and other factors. The calculations involve the behavior of particle showers in the detector, expected levels of radiation, and parameterization of the radiation effects. A summary of significant work is also presented

  16. Effects of Parkinson's Disease on Fundamental Frequency Variability in Running Speech.

    Science.gov (United States)

    Bowen, Leah K; Hands, Gabrielle L; Pradhan, Sujata; Stepp, Cara E

    2013-09-01

    In Parkinson's Disease (PD), qualitative speech changes such as decreased variation in pitch and loudness are common, but quantitative vocal changes are not well documented. The variability of fundamental frequency (F0) in 32 individuals (23 male) with PD both ON and OFF levodopa medication was compared with 32 age-matched healthy controls (23 male). Participants read a single paragraph and estimates of fundamental frequency (F0) variability were determined for the entire reading passage as well as for the first and last sentences of the passage separately. F0 variability was significantly increased in controls relative to both PD groups and PD patients showed significantly higher F0 variability while ON medication relative to OFF. No significant effect of group was seen in the change in F0 variability from the beginning to the end of the reading passage. Female speakers were found to have higher F0 variability than males. F0 variability was both significantly reduced in PD relative to controls and significantly increased in patients with PD during use of dopaminergic medications. F0 variability changes over the course of reading a paragraph may not be indicative of PD but rather dependent on non-disease factors such as the linguistic characteristics of the text.

  17. Effects of Parkinson’s Disease on Fundamental Frequency Variability in Running Speech

    Science.gov (United States)

    Bowen, Leah K.; Hands, Gabrielle L.; Pradhan, Sujata; Stepp, Cara E.

    2013-01-01

    In Parkinson’s Disease (PD), qualitative speech changes such as decreased variation in pitch and loudness are common, but quantitative vocal changes are not well documented. The variability of fundamental frequency (F0) in 32 individuals (23 male) with PD both ON and OFF levodopa medication was compared with 32 age-matched healthy controls (23 male). Participants read a single paragraph and estimates of fundamental frequency (F0) variability were determined for the entire reading passage as well as for the first and last sentences of the passage separately. F0 variability was significantly increased in controls relative to both PD groups and PD patients showed significantly higher F0 variability while ON medication relative to OFF. No significant effect of group was seen in the change in F0 variability from the beginning to the end of the reading passage. Female speakers were found to have higher F0 variability than males. F0 variability was both significantly reduced in PD relative to controls and significantly increased in patients with PD during use of dopaminergic medications. F0 variability changes over the course of reading a paragraph may not be indicative of PD but rather dependent on non-disease factors such as the linguistic characteristics of the text. PMID:25838754

  18. Characteristics of natural background external radiation and effective dose equivalent

    International Nuclear Information System (INIS)

    Fujimoto, Kenzo

    1989-01-01

    The two sources of natural radiation - cosmic rays and primordial radionuclides - are described. The factors affecting radiation doses received from natural radiation and the calculation of effective dose equivalent due to natural radiation are discussed. 10 figs., 3 tabs

  19. Overview of radiation effects research in photonics

    Science.gov (United States)

    Webb, Robert C.; Cohn, Lewis M.; Taylor, Edward W.; Greenwell, Roger A.

    1995-05-01

    A brief overview of ongoing radiation effects research in photonics is presented focusing on integrated optic and acousto-optic components. A short summary of radiation-induced effects in electro-optic modulators, detector arrays, and other photonic technologies is presented along with extensive references. The coordinated radiation effects studies among researchers within the Tri-Service Organizations and international experimental teams are beginning to demonstrate consistent measurements of radiation-induced effects in photonic components and confirming earlier reported data. This paper will present an overview of these coordinated investigations and focus on key research being conducted with the AFMC Phillips Laboratory, Naval Research Laboratory, Defence Nuclear Agency, NATO Nuclear Effects Task Group, and the Tri-Service Photonics Coordinating Committee.

  20. Effects of small radiation doses

    International Nuclear Information System (INIS)

    Fuchs, G.

    1986-01-01

    The term 'small radiation dosis' means doses of about (1 rem), fractions of one rem as well as doses of a few rem. Doses like these are encountered in various practical fields, e.g. in X-ray diagnosis, in the environment and in radiation protection rules. The knowledge about small doses is derived from the same two forces, on which the radiobiology of human beings nearly is based: interpretation of the Hiroshima and Nagasaki data, as well as the experience from radiotherapy. Careful interpretation of Hiroshima dates do not provide any evidence that small doses can induce cancer, fetal malformations or genetic damage. Yet in radiotherapy of various diseases, e.g. inflammations, doses of about 1 Gy (100 rad) do no harm to the patients. According to a widespread hypothesis even very small doses may induce some types of radiation damage ('no threshold'). Nevertheless an alternative view is justified. At present no decision can be made between these two alternatives, but the usefullness of radiology is definitely better established than any damage calculated by theories or extrapolations. Based on experience any exaggerated fear of radiations can be met. (author)

  1. Effect of radiation processing on meat tenderisation

    International Nuclear Information System (INIS)

    Kanatt, Sweetie R.; Chawla, S.P.; Sharma, Arun

    2015-01-01

    The effect of radiation processing (0, 2.5, 5 and 10 kGy) on the tenderness of three types of popularly consumed meat in India namely chicken, lamb and buffalo was investigated. In irradiated meat samples dose dependant reduction in water holding capacity, cooking yield and shear force was observed. Reduction in shear force upon radiation processing was more pronounced in buffalo meat. Protein and collagen solubility as well as TCA soluble protein content increased on irradiation. Radiation processing of meat samples resulted in some change in colour of meat. Results suggested that irradiation leads to dose dependant tenderization of meat. Radiation processing of meat at a dose of 2.5 kGy improved its texture and had acceptable odour. - Highlights: • Effect of radiation processing on tenderness of three meat systems was evaluated. • Dose dependant reduction in shear force seen in buffalo meat. • Collagen solubility increased with irradiation

  2. Effects of gamma radiation in tomato seeds

    Energy Technology Data Exchange (ETDEWEB)

    Wiendl, Toni A.; Wiendl, Fritz W.; Franco, Suely S.H.; Franco, Jose G.; Althur, Valter, E-mail: tawiendl@hotmail.com, E-mail: gilmita@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

  3. Radiation effect on rocket engine performance

    Science.gov (United States)

    Chiu, Huei-Huang; Kross, K. W.; Krebsbach, A. N.

    1990-01-01

    Critical problem areas involving the effect of radiation on the combustion of bipropellants are addressed by formulating a universal scaling law in combination with a radiation-enhanced vaporization combustion model. Numerical algorithms are developed and data pertaining to the Variable Thrust Engine (VTE) and the Space Shuttle Main Engine (SSME) are used to conduct parametric sensitivity studies to predict the principal intercoupling effects of radiation. The analysis reveals that low-enthalpy engines, such as the VTE, are vulnerable to a substantial performance setback due to radiative loss, whereas the performance of high-enthalpy engines such as the SSME are hardly affected over a broad range of engine operation. Combustion enhancement by radiative heating of the propellant has a significant impact on propellants with high absorptivity.

  4. Effects of gamma radiation in tomato seeds

    International Nuclear Information System (INIS)

    Wiendl, Toni A.; Wiendl, Fritz W.; Franco, Suely S.H.; Franco, Jose G.; Althur, Valter; Arthur, Paula B.

    2013-01-01

    Tomato dry seeds of the hybrid 'Gladiador' F1 were exposed to low doses of gamma radiation from Co-60 source at 0,509 kGy tax rate in order to study stimulation effects of radiation on germination and plant growth. Eight treatments radiation doses were applied as follows: 0 (control); 2,5; 5,0; 7,5; 10,0; 12,5; 15,0; 20,0 Gy. Seed germination as well as green fruits number, harvested fruit number, fruit weight and total production were assessed to identify occurrence of stimulation. Tomato seeds and plants were handled as for usual tomato production in Brazil. Low doses of gamma radiation treatment in the seeds stimulate germination and substantially increase fruit number and total production up to 86% at 10 Gy dose. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production thus, showing hormetic effects. (author)

  5. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    Girdhani, S.; Hlatky, L.; Sachs, R.

    2015-01-01

    Proton radiation provides significant dosimetric advantages when compared with gamma radiation due to its superior energy deposition characteristics. Although the physical aspects of proton radiobiology are well understood, biological and clinical endpoints are understudied. The current practice to assume the relative biological effectiveness of low linear energy transfer (LET) protons to be a generic value of about 1.1 relative to photons likely obscures important unrecognised differentials in biological response between these radiation qualities. A deeper understanding of the biological properties induced by proton radiation would have both radiobiological and clinical impact. This article briefly points to some of the literature pertinent to the effects of protons on tissue-level processes that modify disease progression, such as angiogenesis, cell invasion and cancer metastasis. Recent findings hint that proton radiation may, in addition to offering improved radio-therapeutic targeting, be a means to provide a new dimension for increasing therapeutic benefits for patients by manipulating these tissue-level processes. (authors)

  6. The effects of ionizing radiation on man

    International Nuclear Information System (INIS)

    Watson, G.M.

    1975-08-01

    This paper describes the major effects of ionizing radiation on man and the relationship between such effects and radiation dose, with the conclusion that standards of radiological safety must be based on the carcinogenetic and mutagenic properties of ionizing radiation. Man is exposed to radiation from natural sources and from man-made sources. Exposure from the latter should be regulated but, since there is little observational or experimental evidence for predicting the effects of the very small doses likely to be required for adequate standards of safety, it is necessary to infer them from what is seen at high doses. Because the formal relationship between dose and effect is not fully understood, simplifying assumptions are necessary to estimate the effects of low doses. Two such assumptions are conventionally used; that there is a linear relationship between dose and effect at all levels of dose, and that the rate at which a dose of radiation is given does not alter the magnitude of the effect. These assumptions are thought to be conservative, that is they will not lead to an underestimation of the effects of small radiation doses although they may give an over-estimate. (author)

  7. Fundaments for creation of national radiation protection standard for nuclear gauges; Fundamentos para implantacao de norma nacional de protecao radiologica para medidores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Luiz Cavalcante

    2016-11-01

    The present work It aims to provide fundaments for the creation of a national standard of practice, safety and responsible use of nuclear gauges in accordance with the recommendations already existing national and international. The work deals with the protection against ionizing radiation, an outline of a proposal for a standard that discriminates in its articles and paragraphs, the basic principles of a proposal for a standard that discriminates in its articles and paragraphs, the basic principles of safety and security, and some pointes that are also relevant such as the responsibilities of those involved in acquisition and nuclear gauge operation, storage, maintenance, testing and emergency situations. The result is to provide a means to limit the dose of operators and people from the public and maintain these limits within the recommended by CNEN, reducing exposure do ionizing radiation, and having greater control in operating the equipment. (author)

  8. Fast Neutron Radiation Effects on Bacillus Subtili

    International Nuclear Information System (INIS)

    Chen Xiaoming; Zhang Jianguo; Chu Shijin; Ren Zhenglong; Zheng Chun; Yang Chengde; Tan Bisheng

    2009-01-01

    To examine the sterilizing effect and mechanism of neutron radiation, Bacillus subtilis var. niger. strain (ATCC 9372) spores were irradiated with the fast neutron from the Chinese fast burst reactor II(CFBR-II). The plate-count results indicated that the D 10 value was 384.6 Gy with a neutron radiation dose rate of 7.4 Gy/min. The rudimental catalase activity of the spores declined obviously with the increase in the radiation dose. Meanwhile, under the scanning electron microscope, no visible influence of the neutron radiation on the spore configuration was detected even if the dose was increased to 4 kGy. The content and distribution of DNA double-strand breaks induced by neutron radiation at different doses were measured and quantified by pulsed-field gel electrophoresis (PFGE). Further analysis of the DNA release percentage (PR), the DNA breakage level (L), and the average molecular weight, indicated that DNA fragments were obviously distributed around the 5 kb regions at different radiation doses, which suggests that some points in the DNA molecule were sensitive to neutron radiation. Both PR and L varied regularly to some extent with the increase in radiation dose. Thus neutron radiation has a high sterilization power, and can induce falling enzyme activity and DNA breakage in Bacillus subtilis spores

  9. Radiative effects of global MODIS cloud regimes

    Science.gov (United States)

    Oreopoulos, Lazaros; Cho, Nayeong; Lee, Dongmin; Kato, Seiji

    2018-01-01

    We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations. PMID:29619289

  10. Radiative Effects of Global MODIS Cloud Regimes

    Science.gov (United States)

    Oraiopoulos, Lazaros; Cho, Nayeong; Lee, Dong Min; Kato, Seiji

    2016-01-01

    We update previously published MODIS global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 dataset. We implement a slightly different derivation method, investigate the composition of the regimes, and then proceed to examine several aspects of CR radiative appearance with the aid of various radiative flux datasets. Our results clearly show the CRs are radiatively distinct in terms of shortwave, longwave and their combined (total) cloud radiative effect. We show that we can clearly distinguish regimes based on whether they radiatively cool or warm the atmosphere, and thanks to radiative heating profiles to discern the vertical distribution of cooling and warming. Terra and Aqua comparisons provide information about the degree to which morning and afternoon occurrences of regimes affect the symmetry of CR radiative contribution. We examine how the radiative discrepancies among multiple irradiance datasets suffering from imperfect spatiotemporal matching depend on CR, and whether they are therefore related to the complexity of cloud structure, its interpretation by different observational systems, and its subsequent representation in radiative transfer calculations.

  11. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    Gates, M.T.

    1993-01-01

    The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

  12. The Effects of Ionizing Radiation on Mammalian Cells.

    Science.gov (United States)

    Biaglow, John E.

    1981-01-01

    Discusses the effects of radiation on dividing cells and factors influencing these effects; also briefly reviews the radical mechanism for radiation damage. Emphasizes the importance of oxygen in radiation effects. (CS)

  13. The moderating effects of contact with lesbian and gay friends on the relationships among religious fundamentalism, sexism, and sexual prejudice.

    Science.gov (United States)

    Cunningham, George B; Melton, E Nicole

    2013-01-01

    The purpose of this study was to examine the degree to which contact with lesbian and gay friends moderated the effects of religious fundamentalism and sexism on sexual prejudice. The authors gathered data from 269 heterosexual adults living in Texas. Results indicate that the effects of religious fundamentalism on sexual prejudice were reduced when contact was high. However, the positive association between modern sexism and sexual prejudice was not moderated by contact. The authors discuss theoretical and practical implications.

  14. Internal friction, microstructure, and radiation effects

    International Nuclear Information System (INIS)

    Wechsler, M.S.; Sommer, W.F.; Davidson, D.R.

    1984-01-01

    A brief review is given of internal friction relaxation peaks and background internal friction. The microstructural origin of the internal friction is discussed. Particular emphasis is placed on radiation effects

  15. Effects of solar radiation on glass

    Science.gov (United States)

    Tucker, Dennis S.; Kinser, Donald L.

    1991-01-01

    The effects of solar radiation of selected glasses are reported. Optical property degradation is studied using UV-Vis spectrophotometry. Strength changes are measured using a concentric ring bend test. Direct fracture toughness measurements using an indentation test are planned.

  16. Decomposition of radiational effects of model feedbacks

    International Nuclear Information System (INIS)

    Ellsaesser, H.W.; MacCracken, M.C.; Potter, G.L.; Mitchell, C.S.

    1981-08-01

    Three separate doubled CO 2 experiments with the statistical dynamic model are used to illustrate efforts to study the climate dynamics, feedbacks, and interrelationships of meteorological parameters by decomposing and isolating their individual effects on radiation transport

  17. Sterilizing radiation effects on selected polymers

    International Nuclear Information System (INIS)

    Skiens, W.E.

    1979-03-01

    The mechanism of radiation effects and their industrial applications are discussed for the following classes of polymers: thermoplastics, thermosets, elastomers, films and fibers, and adhesives/coatings/potting compounds. 35 references, 3 tables

  18. Radiobiology: Biologic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Held, K.D.

    1987-01-01

    The biologic effects after exposure to ionizing radiation, such as cell death or tissue injury, result from a chain of complex physical, chemical, metabolic, and histologic events. The time scale of these radiation actions spans many orders of magnitude. The physical absorption of ionizing radiation occurs in about 10 -18 s, while late carcinogenic and genetic effects are expressed years or even generations later. Collectively, these effects form the science of radiobiology. Many of the concepts discussed in this chapter have been developed through the study of effects generated in tissues by external radiation sources, but they apply generally and often specifically to internally distributed radiopharmaceuticals which form the central topic of this book

  19. Genetic effects of ionizing radiations in Eucaryocytes

    International Nuclear Information System (INIS)

    Jullien, Pierre

    1976-01-01

    The litterature on the genetic effects of ionizing radiations is reviewed, especially as concerns specific loci or chromosome mutations. Extrapolation from one species to another is considered as well as extra-nuclear mutations [fr

  20. The effect of ionizing radiation on cyanophyta

    International Nuclear Information System (INIS)

    Kondrat'eva, N.V.; Shevchenko, T.F.; Golubkova, M.G.

    1989-01-01

    Publication data on the effect of ionizing radiation on cyanophyta are generalized. The conclusion about the presence of premises for forming cyanophyta radiobiology as special direction of procaryotic algae investigation is made

  1. [Effects of radiation exposure on human body].

    Science.gov (United States)

    Kamiya, Kenji; Sasatani, Megumi

    2012-03-01

    There are two types of radiation health effect; acute disorder and late on-set disorder. Acute disorder is a deterministic effect that the symptoms appear by exposure above a threshold. Tissues and cells that compose the human body have different radiation sensitivity respectively, and the symptoms appear in order, from highly radiosensitive tissues. The clinical symptoms of acute disorder begin with a decrease in lymphocytes, and then the symptoms appear such as alopecia, skin erythema, hematopoietic damage, gastrointestinal damage, central nervous system damage with increasing radiation dose. Regarding the late on-set disorder, a predominant health effect is the cancer among the symptoms of such as cancer, non-cancer disease and genetic effect. Cancer and genetic effect are recognized as stochastic effects without the threshold. When radiation dose is equal to or more than 100 mSv, it is observed that the cancer risk by radiation exposure increases linearly with an increase in dose. On the other hand, the risk of developing cancer through low-dose radiation exposure, less 100 mSv, has not yet been clarified scientifically. Although uncertainty still remains regarding low level risk estimation, ICRP propound LNT model and conduct radiation protection in accordance with LNT model in the low-dose and low-dose rate radiation from a position of radiation protection. Meanwhile, the mechanism of radiation damage has been gradually clarified. The initial event of radiation-induced diseases is thought to be the damage to genome such as radiation-induced DNA double-strand breaks. Recently, it is clarified that our cells could recognize genome damage and induce the diverse cell response to maintain genome integrity. This phenomenon is called DNA damage response which induces the cell cycle arrest, DNA repair, apoptosis, cell senescence and so on. These responses act in the direction to maintain genome integrity against genome damage, however, the death of large number of

  2. Fundamentals of risk management understanding, evaluating and implementing effective risk management

    CERN Document Server

    Hopkin, Paul

    2012-01-01

    Now more than ever, organizations must plan, response and recognize all forms of risks that they face. "Fundamentals of Risk Management", now in its second edition, provides a comprehensive introduction to the subject of commercial and business risk for anyone studying for a career in risk as well as a broad range of risk professionals. It examines the key components of risk management and its application with examples to demonstrate its benefit to organisations in the public and private sector. The second edition has been completely updated to take into account the greater influence of ISO 3100, the emergence of Governance Risk and Compliance (GRC) and the wide use of the bowtie method to illustrate risk management. In addition, there is now a chapter on the skills and competencies required by an effective risk manager.

  3. Bank Stock Returns in Responding the Contribution of Fundamental and Macroeconomic Effects

    Directory of Open Access Journals (Sweden)

    Ridwan Nurazi

    2016-06-01

    Full Text Available This study attempts to examine the effect of financial fundamentals information using CAMELS ratios and macroeconomics variables surrogated by interest rate, exchange rate, and inflation rate toward stock return. By employing panel data analysis (Pooled Least Squared Model, the results reveal that several financial ratios perform a bit contrary to the theory, in which the ratio of CAR shows positive sign but insignificantly contributes to stock returns. Also, the ratio of NPL does not affect the return. In fact, ROE and LDR positively and significantly contribute toward banks’ stock return. Meanwhile, NIM and BOPO show negative signs. The other macroeconomic variables, interest rate (IR, exchange rate (ER and inflation rate (INF are consistent with the a priori expectation, in which those variables negatively and significantly contribute to stock return of 16 banks, for the observation period from 2002 to 2011 in the Indonesian banking sector.

  4. Effects of radiations on ornamental fish

    International Nuclear Information System (INIS)

    Anita; Kalyankar, Amol D.; Ohlyan, Sunita; Gupta, R.K.

    2012-01-01

    Radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiations: ionizing and non-ionizing. Ultraviolet, X-rays, and gamma rays are some examples of radiation. 'Ornamental fish' is designed for aquatic hobbyists and the aquatic industry for several purposes. UV light has two primary uses in fish culture: Controlling green water and disinfecting the water supply. Many proponents of UV disinfection sometimes overlook the additional benefits relating to ornamental fish; those being that cleaner water reduces the stress on the fish by not having to fight off diseases, thus enhancing its immune system and leading to faster growth and more brilliant colors. Ultraviolet sterilizers are often used in aquaria to help control unwanted microorganisms in the water. UV radiation also ensures that exposed pathogens cannot reproduce, thus decreasing the likelihood of a disease outbreak in an aquarium. Despite of these benefits, the ill-effects of radiations cannot be ruled out. Ultraviolet Radiation-induced DNA Damage is seen in the skin of the Platyfish Xiphophorus. Higher radiation doses may cause the gastrointestinal syndrome that leads to defects of the intestinal mucosa barrier with successive contamination of musculature. Exposure to UV radiation can kill the fish and induce sublethal effects in embryos, larvae and adults. The change in skin includes irregularity of skin surface, epidermal oedema, necrosis etc. Irradiation may badly influence the textural attributes of fish muscle. (author)

  5. Effect of ionizing radiations on connective tissue

    International Nuclear Information System (INIS)

    Altman, K.I.; Gerber, G.B.

    1980-01-01

    The effects of ionizing radiations on connective tissue in lung, heart, vasculature, kidney, skin, and skeletal tissues are reviewed. Special emphasis is given to the effect of ionizing radiations on vasculo-connective tissue and fibrotic changes following radiation-induced injury to organs and tissues. In order to put the subject matter in proper prospective, the general biochemistry, physiology, and pathology of connective tissue is reviewed briefly together with the participation of connective tissue in disease. The review closes with an assessment of future problems and an enumeration and discussion of important, as yet unanswered questions

  6. Radiation abuse and its effects

    Energy Technology Data Exchange (ETDEWEB)

    Halm, A

    1976-06-01

    This paper delves into overuse practiced in diagnostic radiography. The conventional attitudes to low-dose irradiation are critically examined, as is the MPD related to individual radiosensitivity. Concern is expressed that a sizeable proportion of radiologists ignore important aspects of the Code of Practice and this attitude is readily emulated in the hospital setting. The author advocates education within the medical profession and the community on the risks involved in radiation abuse and the benefits derived from justified exposures to x rays.

  7. Radiation Effects in M and NEMS

    Science.gov (United States)

    2016-03-31

    electrical basis of operation of M&NEM structures? In particular, cumulative damage by non - ionizing energy loss can, in principle, alter the... Radiation Effects in M&NEMS Michael Alles, Kirill Bolotin, Alex Zettl, Brian Homeijer, Jim Davidson, Ronald Schrimpf, Robert Reed, Dan Fleetwood...understanding radiation effects on the relevant properties of the constituent materials and structures, particularly advanced 2D materials, and the

  8. Modifiers of radiation effects in the eye

    Science.gov (United States)

    Kleiman, Norman J.; Stewart, Fiona A.; Hall, Eric J.

    2017-11-01

    World events, including the threat of radiological terrorism and the fear of nuclear accidents, have highlighted an urgent need to develop medical countermeasures to prevent or reduce radiation injury. Similarly, plans for manned spaceflight to a near-Earth asteroid or journey to Mars raise serious concerns about long-term effects of space radiation on human health and the availability of suitable therapeutic interventions. At the same time, the need to protect normal tissue from the deleterious effects of radiotherapy has driven considerable research into the design of effective radioprotectors. For more than 70 years, animal models of radiation cataract have been utilized to test the short and long-term efficacy of various radiation countermeasures. While some compounds, most notably the Walter Reed (WR) class of radioprotectors, have reported limited effectiveness when given before exposure to low-LET radiation, the human toxicity of these molecules at effective doses limits their usefulness. Furthermore, while there has been considerable testing of eye responses to X- and gamma irradiation, there is limited information about using such models to limit the injurious effects of heavy ions and neutrons on eye tissue. A new class of radioprotector molecules, including the sulfhydryl compound PrC-210, are reported to be effective at much lower doses and with far less side effects. Their ability to modify ocular radiation damage has not yet been examined. The ability to non-invasively measure sensitive, radiation-induced ocular changes over long periods of time makes eye models an attractive option to test the radioprotective and radiation mitigating abilities of new novel compounds.

  9. Radiation effects on eye components

    International Nuclear Information System (INIS)

    Durchschlag, H.; Fochler, C.; Abraham, K.; Kulawik, B.

    1998-01-01

    The radiation damage (X-ray, UV light) of the most important components of the vertebrate eye (crystallins and other proteins, hyaluronic acid, vitreous, aqueous humour, ascorbic acid) has been investigated by various methods of physical chemistry. UV absorption and fluorescence spectroscopy as well as circular dichroism unveiled changes of the chromophores/fluorophores of the constituent biopolymers and low-molecular components, together with alterations of helix content and the occurrence of aggregation. Size-exclusion chromatography, analytical ultracentrifugation, densimetry, viscometry and light scattering experiments monitored changes of the global structure of proteins and polysaccharides involved. Electrophoreses allowed conclusions on fragmentation, unfolding and crosslinking. Analytical methods provided information regarding the integrity of groups of special concern (SH, SS) and revealed the existence of stable noxious species (H 2 O 2 ). By means of various measures and additives, manifold modifications of the impact of both ionizing and nonionizing radiation may be achieved. Caused by differences in the primary reactions, eye polymers are protected efficaciously by typical OH radical scavengers against X-irradiation, whereas compounds which exhibit absorption behavior in the UV range turn out to act as potent protectives ('chemical filters') against UV light. A few substances, such as ascorbate, are able to provide protection against both sorts of radiation and are even able to exhibit a slight chemical repair of already damaged particles. The results obtained are of importance for understanding pathological alterations of the eye (loss of transparency, cataractogenesis) and for developing new strategies for protection and repair of eye components. (author)

  10. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

    1999-01-01

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  11. Perturbed effects at radiation physics

    International Nuclear Information System (INIS)

    Külahcı, Fatih; Şen, Zekâi

    2013-01-01

    Perturbation methodology is applied in order to assess the linear attenuation coefficient, mass attenuation coefficient and cross-section behavior with random components in the basic variables such as the radiation amounts frequently used in the radiation physics and chemistry. Additionally, layer attenuation coefficient (LAC) and perturbed LAC (PLAC) are proposed for different contact materials. Perturbation methodology provides opportunity to obtain results with random deviations from the average behavior of each variable that enters the whole mathematical expression. The basic photon intensity variation expression as the inverse exponential power law (as Beer–Lambert's law) is adopted for perturbation method exposition. Perturbed results are presented not only in terms of the mean but additionally the standard deviation and the correlation coefficients. Such perturbation expressions provide one to assess small random variability in basic variables. - Highlights: • Perturbation methodology is applied to Radiation Physics. • Layer attenuation coefficient (LAC) and perturbed LAC are proposed for contact materials. • Perturbed linear attenuation coefficient is proposed. • Perturbed mass attenuation coefficient (PMAC) is proposed. • Perturbed cross-section is proposed

  12. Model study of radiation effects on the gastrointestinal cell system

    International Nuclear Information System (INIS)

    Kicherer, G.

    1983-03-01

    Since it is now possible to calculate the radiation fields used for medicinal purposes by means of radiation transport programs it was started to determine with mathematical models of radioeffects not only the physical effects or irradiation, but also the resulting biological radioresponses. This supplementary biologic information is not only of large general importance, but particularly valuable for the medicinal application of the biologically highly effective neutron radiation. With support by the Institute for Medicinal Radiophysics and Radiobiology of Essen University Hospital, and of two biomathematical working groups of Ulm University and Cologne University Hospital, who are experienced in the field of establishing mathematical models of the hematogenic cellular system, we developed out of experimental fundamental findings a cellkinetic, kybernetic model of the intestinal mucosa, which is highly sensitive to radiation. With this newly established model we succeeded for the first time in simulating comprehensively and quantitatively the time-dependent acute radioresponse of such a radiosensitive cellular system. For the first time we successfully used the computer simulation languages DARE-P and GASP, which are principally employed for solving problems in automatic control technology, and set up a radioresponse model. (orig.) [de

  13. Coordinating the effects of multiple variables: a skill fundamental to scientific thinking.

    Science.gov (United States)

    Kuhn, Deanna; Pease, Maria; Wirkala, Clarice

    2009-07-01

    The skill of predicting outcomes based on simultaneous effects of multiple factors was examined. Over five sessions, 91 sixth graders engaged this task either individually or in pairs and either preceded or followed by six sessions on the more widely studied inquiry task that requires designing and interpreting experiments to identify individual effects. Final assessment, while indicating a high level of mastery on the inquiry task, showed progress but continuing conceptual challenges on the multivariable prediction task having to do with understanding of variables, variable levels, and consistency of a variable's operation across occasions. Task order had a significant but limited effect, and social collaboration conferred only a temporary benefit that disappeared in a final individual assessment. In a follow-up study, the lack of effect of social collaboration was confirmed, as was that of feedback on incorrect answers. Although fundamental to science, the concept that variables operate jointly and, under equivalent conditions, consistently across occasions is one that children appear to acquire only gradually and, therefore, one that cannot be assumed to be in place.

  14. Effective dose: a radiation protection quantity

    CERN Document Server

    Menzel, H G

    2012-01-01

    Modern radiation protection is based on the principles of justification, limitation, and optimisation. Assessment of radiation risks for individuals or groups of individuals is, however, not a primary objective of radiological protection. The implementation of the principles of limitation and optimisation requires an appropriate quantification of radiation exposure. The International Commission on Radiological Protection (ICRP) has introduced effective dose as the principal radiological protection quantity to be used for setting and controlling dose limits for stochastic effects in the regulatory context, and for the practical implementation of the optimisation principle. Effective dose is the tissue weighted sum of radiation weighted organ and tissue doses of a reference person from exposure to external irradiations and internal emitters. The specific normalised values of tissue weighting factors are defined by ICRP for individual tissues, and used as an approximate age- and sex-averaged representation of th...

  15. Non-targeted effects of ionising radiation

    International Nuclear Information System (INIS)

    Belyakov, O.V.

    2008-01-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects and genomic instability. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm would cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (LNT) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (orig.)

  16. Biological effects of high-energy radiation

    International Nuclear Information System (INIS)

    Curtis, S.B.

    1976-01-01

    The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

  17. Radiation Effects on the Flow and Heat Transfer over a Moving Plate in a Parallel Stream

    International Nuclear Information System (INIS)

    Ishak, Anuar

    2009-01-01

    Effects of thermal radiation on the steady laminar boundary layer flow over a moving plate in a moving fluid is investigated. Under certain conditions, the present problem reduces to the classical Blasius and Sakiadis problems. It is found that dual solutions exist when the plate and the fluid move in the opposite directions. Moreover, the existence of thermal radiation is to reduce the heat transfer rate at the surface. (fundamental areas of phenomenology (including applications))

  18. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    Boas, J.F.; Solomon, S.B.

    1990-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risk to health from exposure to low levels of radiation. This risk effects can be at least qualitatively understood by considering the effects of radiation on cell DNA. Whilst exposure to high levels of radiation results in a number of identifiable effects, exposure to low levels of radiation may result in effects which only manifest themselves after many years. Risk estimates for low levels of radiation have been derived on the basis of a number of assumptions. In the case of uranium mine workers a major hazard arises from the inhalation of radon daughters. Whilst the correlation between radon daughter exposure and lung cancer incidence is well established, the numerical value of the risk factor is the subject of controversy. ICRP 50 gives a value of 10 cases per 10 6 person-years at risk per WLM (range 5-15 x 10 -6 PYR -1 WLM -1 ). The effect of smoking on lung cancer incidence rates amongst miners is also controversial. Nevertheless, smoking by miners should be discouraged

  19. Radiation abuse and its effects

    International Nuclear Information System (INIS)

    Halm, A.

    1976-01-01

    This paper delves into overuse practiced in diagnostic radiography. The conventional attitudes to low-dose irradiation are critically examined, as is the MPD related to individual radiosensitivity. Concern is expressed that a sizeable proportion of radiologists ignore important aspects of the Code of Practice and this attitude is readily emulated in the hospital setting. The author advocates education within the medical profession and the community on the risks involved in radiation abuse and the benefits derived from justified exposures to x rays. (author)

  20. Nonlinear generation of the fundamental radiation in plasmas: the influence of induced ion-acoustic and Langmuir waves

    International Nuclear Information System (INIS)

    Rizzato, F.B.

    1992-01-01

    A nonlinear emission mechanism of electromagnetic waves at the fundamental plasma frequency has been examined. This mechanism is based on the electromagnetic oscillating two-stream instability driven by two oppositely propagating Langmuir waves. The excitation of the electromagnetic oscillating two-stream instability is due to nonlinear wave-wave coupling involving Langmuir waves, low-frequency density waves and electromagnetic waves. The Chian and Alves model is improved using the generalized Zakharov equations. Attention is directed toward the influence of induced low-frequency and Langmuir waves on the properties of the electromagnetic oscillating two-stream instability. Presumably, the properties derived in the present context may be relevant to both space and laboratory plasmas. (author)

  1. Biological effects of ionizing radiations. Radiological accident from Goiania, GO, Brazil; Efeitos biologicos das radiacoes ionizantes. Acidente radiologico de Goiania

    Energy Technology Data Exchange (ETDEWEB)

    Okuno, Emico, E-mail: emico.okuno@if.usp.br [Instituto de Fisica da Universidade de Sao Paulo (IF-USP), SP (Brazil)

    2013-01-15

    This article presents the fundaments of radiation physics, the natural and artificial sources, biological effects, radiation protection. We also examine the sequence of events that resulted in Goiania accident with a source of caesium-137 from abandoned radiotherapy equipment and its terrible consequences. (author)

  2. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Durand, J.L.

    2000-01-01

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 ± 1) Gy was measured for LD50 with Dose Rate of (0.44 ± 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 ± 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses

  3. Radiation effects on ion exchange materials

    International Nuclear Information System (INIS)

    Gangwer, T.E.; Goldstein, M.; Pillay, K.K.S.

    1977-11-01

    An extensive literature review and data compilation has been completed on the radiation-damage of ion exchange resins. The primary goal of the study has been to review the available literature on ion exchange materials used in, as well as those with potential for use in, the nuclear fuel and waste reprocessing areas. The physical and chemical properties of ion exchangers are reviewed. Experimental parameters useful in characterizing the effects of radiation on synthetic ion exchange resins are identified or defined. In compiling the diverse types of data, an effort was made to present the experimental data or experimentally based parameters in a format that would be useful for inter-comparing radiation effects on resins. When subject to radiation there are various general trends or qualitative effects displayed by the different types of resins. These radiation-trends and effects have been formulated into qualitative statements. The present day level of understanding of the behavior of resins under ionizing radiation is too limited to justify quantitative predictive modeling. The limitations and deficiencies of the literature are discussed and the experimentation needed to achieve quantitative modeling are outlined. 14 figs., 108 references

  4. Radiation effects on ion exchange materials

    Energy Technology Data Exchange (ETDEWEB)

    Gangwer, T.E.; Goldstein, M.; Pillay, K.K.S.

    1977-11-01

    An extensive literature review and data compilation has been completed on the radiation-damage of ion exchange resins. The primary goal of the study has been to review the available literature on ion exchange materials used in, as well as those with potential for use in, the nuclear fuel and waste reprocessing areas. The physical and chemical properties of ion exchangers are reviewed. Experimental parameters useful in characterizing the effects of radiation on synthetic ion exchange resins are identified or defined. In compiling the diverse types of data, an effort was made to present the experimental data or experimentally based parameters in a format that would be useful for inter-comparing radiation effects on resins. When subject to radiation there are various general trends or qualitative effects displayed by the different types of resins. These radiation-trends and effects have been formulated into qualitative statements. The present day level of understanding of the behavior of resins under ionizing radiation is too limited to justify quantitative predictive modeling. The limitations and deficiencies of the literature are discussed and the experimentation needed to achieve quantitative modeling are outlined. 14 figs., 108 references.

  5. Radiation effects on optical data transmission systems

    International Nuclear Information System (INIS)

    Leskovar, B.

    1989-01-01

    The state of the art of optical transmitters, low loss fiber waveguides and receivers in both steady state and pulsed radiation environments is reviewed and summarized. Emphasis is placed on the effects of irradiation on the performance of light emitting and laser diodes, optical fiber waveguides and photodiodes. The influence of radiation-induced attenuation of optical fibers due to total dose, dose rate, time after irradiation, temperature, radiation history, photobleaching, OH and impurity content, dopant type and concentration is described. The performance of candidate components of the transmission system intended for deployment in the Superconducting Super Collider Detector and primary beam tunnel nuclear environment is discussed

  6. Radiation effects on the integrity of paper

    International Nuclear Information System (INIS)

    Otero D'Almeida, Maria Luiza; Medeiros Barbosa, Patricia de Souza; Boaratti, Marcelo Fernando Guerra; Borrely, Sueli Ivone

    2009-01-01

    Books and documents attacked by fungi and insects have already been treated by radiation for disinfestations purposes. However, there is still need to investigate the influence of radiation on the cellulose paper structure. The aim of this research was to study the effects of radiation on paper properties, especially those related to strength and appearance. Paper sheets for this study were prepared in the laboratory, using bleached eucalyptus pulp as raw material. No additives were used to concentrate the attention only on the effects of irradiation on the pure cellulose matrix. The samples were irradiated at IPEN's 60 Co Gammacell irradiator with six radiation doses, from 3 to 15 kGy at the dose rate 0.817 Gy/s. The properties of paper sheets were tested after irradiation and compared with unirradiated samples according to ISO methods. No significant changes were detected in paper samples irradiated up to 15 kGy.

  7. Effect of gamma radiation on Campylobacter jejuni

    International Nuclear Information System (INIS)

    Lambert, J.D.; Maxcy, R.B.

    1984-01-01

    Radiation resistance of Campylobacter jejuni in broth, ground beef, and ground turkey meat was determined using dose levels from 0-200 Krad at -30 +/- 10 0 C, at 0-5 0 C, and at 30 +/- 10 0 C. Irradiation at -30 0 C increased radiation resistance of cultures in ground meats; broth cultures were not greatly influenced by temperature. The effect of culture age on radiation resistance was also evaluated using cells in various physiological phases. Age did not have a pronounced effect on radiation resistance. The largest D 10 value for C. jejuni was 32 Krad, which was less than D 10 values commonly reported for salmonellae. 20 references, 4 figures

  8. Radiation effects on DNA methylation in mice

    International Nuclear Information System (INIS)

    Komura, J.; Kurishita, A.; Miyamura, Y.; Ono, T.; Tawa, R.; Sakurai, H.

    1992-01-01

    Effects of ionizing radiation on DNA methylation in liver, brain and spleen were examined by high performance liquid chromatography (HPLC). The total methylated cytosine level in the genome was reduced within 8 hours after 3.8 Gy of irradiation in liver of adult mice. But no appreciable effect was observed in brain and spleen. When mice were irradiated at newborn, liver DNA revealed no change in methylated cytosine level. Even though slight effects of radiation were detected in he methylation of the c-myc and c-fos genes, they were only temporary and no long-term effects were observed. These data suggest that the effect of radiation on DNA methylation in vivo is not prevailing a DNA damage, but rather influenced much through biological parameters. (author)

  9. Evidence for beneficial low level radiation effects and radiation hormesis

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

    Low doses in the mGy range cause a dual effect on cellular DNA. One effect concerns a relatively low probability of DNA damage per energy deposition event and it increases proportional with dose, with possible bystander effects operating. This damage at background radiation exposure is orders of magnitudes lower than that from endogenous sources, such as ROS. The other effect at comparable doses brings an easily obeservable adaptive protection against DNA damage from any, mainly endogenous sources, depending on cell type, species, and metabolism. Protective responses express adaptive responses to metabolic perturbations and also mimic oxygen stress responses. Adaptive protection operates in terms of DNA damage prevention and repair, and of immune stimulation. It develops with a delay of hours, may last for days to months, and increasingly disappears at doses beyond about 100 to 200 mGy. Radiation-induced apoptosis and terminal cell differentiation occurs also at higher doses and adds to protection by reducing genomic instability and the number of mutated cells in tissues. At low doses, damage reduction by adaptive protection against damage from endogenous sources predictably outweighs radiogenic damage induction. The analysis of the consequences of the particular low-dose scenario shows that the linear-no-threshold (LNT) hypothesis for cancer risk is scientifically unfounded and appears to be invalid in favor of a threshold or hormesis. This is consistent with data both from animal studies and human epidemiological observations on low-dose induced cancer. The LNT hypothesis should be abandoned and be replaced by a hypothesis that is scientifically justified. The appropriate model should include terms for both linear and non-linear response probabilities. Maintaining the LNT-hypothesis as basis for radiation protection causes unressonable fear and expenses. (author)

  10. The radiation effects on the living cell

    International Nuclear Information System (INIS)

    Sage, E.; Dutrillaux, B.; Soussi, Th.; Boiteux, S.; Lopez, B.; Feunteun, J.

    1999-06-01

    This publication is a presentation of particular points discussed during the colloquium of the 15-18 june 1999, for which scientific researches are performed at the CEA/CNRS. They deal with the radiobiology, for the radiation effects on living matter; with the DNA, for the knowledge and repair mechanisms on cells submitted to ionizing radiations; with the exposition to UV in correlation with neoplasms; with the P53 gene which is a tumour suppressor. (A.L.B.)

  11. Genetic effects of radiation. Annex I

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex is aimed at an updating of the 1977 UNSCEAR report, which presented a detailed review of the genetic effects of ionizing radiation, especially those parts that require significant revisions in the light of new data. There is an extensive bibliography with over 1000 references. Particular emphasis is given to those data that are relevant to the evaluation of genetic radiation hazards in man.

  12. Particle penetration and radiation effects

    CERN Document Server

    Sigmund, Peter

    This book, which has evolved from the author’s lectures at the University of Copenhagen and the University of Southern Denmark, draws on his experience as an active researcher in the interaction of charged particles with matter over more than forty years. The emphasis is on the theoretical description of fundamental phenomena, and much attention has been given to classic topics such as: Rutherford scattering; the theory of particle stopping as developed by Bohr, Bethe, Bloch and Lindhard; the statistical description of energy loss as developed by Bohr, Bothe, Williams and Landau; and numerous more recent developments. An attempt has been made to provide at least one complete derivation of a theoretical description for all central aspects. The presentation is intended to respect the ideas of the original authors, but much effort has been invested in establishing a unified and appealing notation consistent with present-day standards. It is intended that this volume will satisfy a long-standing need for a text...

  13. Biological effect of radiation on human

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae [and others

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved.

  14. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved

  15. Effects of Fundamental Movement Skills Training on Children With Developmental Coordination Disorder.

    Science.gov (United States)

    Yu, Jie; Sit, Cindy H; Burnett, Angus; Capio, Catherine M; Ha, Amy S; Huang, Wendy Y

    2016-04-01

    The purpose of this study was to examine the effects of fundamental movement skills (FMS) training on FMS proficiency, self-perceived physical competence (SPC), physical activity (PA), and sleep disturbance in children with developmental coordination disorder (DCD) compared with children with typical development (TD). A total of 84 children were allocated into either experimental group (DCD[exp], TD[exp]) who received 6 weeks of FMS training or control groups (DCD[con], TD[con]). FMS were assessed using the Test of Gross Motor Development-2, whereas PA was monitored using accelerometers. SPC and sleep disturbance were evaluated using questionnaires. Results showed that the DCD[exp] group had significantly higher scores in FMS and SPC compared with the DCD[con] group at posttest. The DCD[exp] group scored lower in sleep disturbance at follow-up when compared with posttest. It is suggested that short-term FMS training is effective in improving FMS and SPC and reducing sleep disturbances for children with DCD.

  16. The effect of a physical activity intervention on preschoolers' fundamental motor skills - A cluster RCT.

    Science.gov (United States)

    Wasenius, Niko S; Grattan, Kimberly P; Harvey, Alysha L J; Naylor, Patti-Jean; Goldfield, Gary S; Adamo, Kristi B

    2018-07-01

    To assess the effect of a physical activity intervention delivered in the childcare centres (CC), with or without a parent-driven home physical activity component, on children's fundamental motor skills (FMS). Six-month 3-arm cluster randomized controlled trial. Preschoolers were recruited from 18 licensed CC. CC were randomly assigned to a typical curriculum comparison group (COM), childcare intervention alone (CC), or childcare intervention with parental component (CC+HOME). FMS was measured with the Test of Gross Motor Development-2. Linear mixed models were performed at the level of the individual while accounting for clustering. Raw locomotor skills score increased significantly in the CC group (mean difference=2.5 units, 95% Confidence Intervals, CI, 1.0-4.1, p0.05) between group differences were observed in the raw object control skills, sum of raw scores, or gross motor quotient. No significant sex differences were found in any of the measured outcomes. A physical activity intervention delivered in childcare with or without parents' involvement was effective in increasing locomotor skills in preschoolers. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  17. Radiation effects in corundum monocrystal

    International Nuclear Information System (INIS)

    Soulayman, S.; Attiah, J.; Molhem, A. G.

    2007-01-01

    It is found by this work that the irradiation of corundum monocrystals by energetic particles creates stable lattice defects, as a result of the atomic displacements to the sublattice. We have identified the colour centers (F and F + ) and more complex ones line [Al i + F]. This finding is in an agreement with the experimental results, available in the literature. We have also investigated the mechanism of occurrence of, so called 'radiation memory' in corundum monocrystals. This phenomenon reflects the fact that, after irradiation and annealing at high temperature and irradiation again by the quanta of x-rays, the absorption line 302 nm (4.1 eV) in the spectrum of optical absorption is restored in the range 200-650 nm. A comparison of our results with the results of other researchers in carried out. (author)

  18. Additive effects of ultraviolet radiation

    International Nuclear Information System (INIS)

    Cullen, A.P.

    1980-01-01

    A xenon-mercury high pressure lamp and a double monochromator were used to produce ultraviolet (uv) radiation at 295 nm. Pigmented rabbit eyes were irradiated and evaluated by slitlamp biomicroscopy. Corneal threshold (Hc) was 0.05 J.cm-2 and lens threshold (hL) was 0.75 J.cm-2. Other eyes were irradiated with 2 Hc and evaluated from 4 to 24 h at 4 h intervals. Corneal damage was only greater than that expected from a single Hc exposure if the separation between the two Hc exposures did not exceed 8 h. The most repeatable and reliable corneal response to these levels of uv was the development of corneal epithelial granules

  19. Size effect in radiation damage

    International Nuclear Information System (INIS)

    Brumovsky, M.

    1979-01-01

    Radiation embrittlement of nuclear reactor pressure vessel steels is mostly measured using small standard specimens in dynamic bend tests. Their dimensions are much smaller than those of the reactor. The increase in the critical temperature (transition temperature from the brittle-to-ductile fracture) is normally measured using standard Charpy-V type specimens or small CT-type specimens. This increase is then used as the main parameter for the pressure vessel safety evaluation. The philosophy of experiments is discussed used for the nonirradiated and irradiated pressure vessel steels. A comparison of the increase in the transition temperature measured in different types of specimens using various testing methods (static and dynamic bend tests with notch or crack) is also made. The results of this comparison and another study showed a relatively good agreement. (author)

  20. Radiation Effects on Spacecraft Structural Materials

    International Nuclear Information System (INIS)

    Wang, Jy-An J.; Ellis, Ronald J.; Hunter, Hamilton T.; Singleterry, Robert C. Jr.

    2002-01-01

    Research is being conducted to develop an integrated technology for the prediction of aging behavior for space structural materials during service. This research will utilize state-of-the-art radiation experimental apparatus and analysis, updated codes and databases, and integrated mechanical and radiation testing techniques to investigate the suitability of numerous current and potential spacecraft structural materials. Also included are the effects on structural materials in surface modules and planetary landing craft, with or without fission power supplies. Spacecraft structural materials would also be in hostile radiation environments on the surface of the moon and planets without appreciable atmospheres and moons around planets with large intense magnetic and radiation fields (such as the Jovian moons). The effects of extreme temperature cycles in such locations compounds the effects of radiation on structural materials. This paper describes the integrated methodology in detail and shows that it will provide a significant technological advance for designing advanced spacecraft. This methodology will also allow for the development of advanced spacecraft materials through the understanding of the underlying mechanisms of material degradation in the space radiation environment. Thus, this technology holds a promise for revolutionary advances in material damage prediction and protection of space structural components as, for example, in the development of guidelines for managing surveillance programs regarding the integrity of spacecraft components, and the safety of the aging spacecraft. (authors)

  1. Medical exposure and the effects of radiation

    International Nuclear Information System (INIS)

    Okuyama, Chio

    2011-01-01

    Radiation gives cracks to genes. The influence is divided into deterministic effect with a threshold value, and the stochastic effect (tumor and genetic effect) which increases according to the exposure amount. Although we are put to various non-artificial radiations, which we cannot be avoided, on the earth, the contamination by artificial radiation can be defended. Artificial radioactive exposure includes medical exposure and non-medical exposure for example by nuclear power plant. As to medical examinations using radiation, the inquiry about the radiation exposure is increasing after the occurrence of the first nuclear power plant disaster of Fukushima. While concern about non-medical radioactive exposure increases, the uneasiness to medical irradiation is also increasing. The dose limit by artificial radioactive exposure other than medical exposure is set up in order to prevent the influence on the health. While the dose limit of the public exposure is set to the lower value than the total dose of non-artificial exposure concerning of a safety margin for all people, the dose limit of medical exposure is not defined, since it is thought that medical irradiation has a benefit for those who receive irradiation. Making an effort to decrease the radiation dose in performing the best medical treatment is the responsibility with which we are burdened. (author)

  2. Radiation effects concerns at a spallation source

    International Nuclear Information System (INIS)

    Sommer, W.F.

    1990-01-01

    Materials used at spallation neutron sources are exposed to energetic particle and photon radiation. Mechanical and physical properties of these materials are altered; radiation damage on the atomic scale leads to radiation effects on the macroscopic scale. Most notable among mechanical-property radiation effects in metals and metal alloys are changes in tensile strength and ductility, changes in rupture strength, dimensional stability and volumetric swelling, and dimensional changes due to stress-induced creep. Physical properties such as electrical resistivity also are altered. The fission-reactor community has accumulated a good deal of data on material radiation effects. However, when the incident particle energy exceeds 50 MeV or so, a new form of radiation damage ensues; spallation reactions lead to more energetic atom recoils and the subsequent temporal and spatial distribution of point defects is much different from that due to a fission-reactor environment. In addition, spallation reactions cause atomic transmutations with these new atoms representing an impurity in the metal. The higher-energy case is of interest at spallation sources; limited detailed data exist for material performance in this environment. 35 refs., 13 figs., 1 tab

  3. Topological magnetoelectric effects in microwave far-field radiation

    Energy Technology Data Exchange (ETDEWEB)

    Berezin, M.; Kamenetskii, E. O.; Shavit, R. [Microwave Magnetic Laboratory, Department of Electrical and Computer Engineering, Ben Gurion University of the Negev, Beer Sheva (Israel)

    2016-07-21

    Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of the free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.

  4. Radiation effects in LDD MOS devices

    International Nuclear Information System (INIS)

    Woodruff, R.L.; Adams, J.R.

    1987-01-01

    The purpose of this work is to investigate the response of lightly doped drain (LDD) n-channel transistors to ionizing radiation. Transistors were fabricated with conventional (non-LDD) and lightly doped drain (LDD) structures using both standard (non-hardened) and radiation hardened gate oxides. Characterization of the transistors began with a correlation of the total-dose effects due to 10 keV x-rays with Co-60 gamma rays. The authors find that for the gate oxides and transistor structures investigated in this work, 10 keV x-rays produce more fixed-charge guild-up in the gate oxide, and more interface charge than do Co-60 gamma rays. They determined that the radiation response of LDD transistors is similar to that of conventional (non-LDD) transistors. In addition, both standard and radiation-hardened transistors subjected to hot carrier stress before irradiation show a similar radiation response. After exposure to 1.0 x 10 6 rads(Si), non-hardened transistors show increased susceptibility to hot-carrier graduation, while the radiation-hardened transistors exhibit similar hot-carrier degradation to non-irradiated devices. The authors have demonstrated a fully-integrated radiation hardened process tht is solid to 1.0 x 10 6 rads(Si), and shows promise for achieving 1.0 x 10 7 rad(Si) total-dose capability

  5. Fundamentals of gas counters

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1994-01-01

    The operation of gas counters used for detecting radiation is explained in terms of the four fundamental physical processes which govern their operation. These are 1) conversion of neutral radiation into charged particles, 2) ionization of the host gas by a fast charge particle 3) transport of the gas ions to the electrodes and 4) amplification of the electrons in a region of enhanced electric field. Practical implications of these are illustrated. (UK)

  6. Fundamentals of radiological protection

    International Nuclear Information System (INIS)

    Mill, A.J.; Charles, M.W.; Wells, J.

    1978-04-01

    A review is presented of basic radiation physics with particular relevance to radiological protection. The processes leading to the production and absorption of ionising radiation are outlined, and the important dosimetric quantities and their units of measurements. The review is the first of a series of reports presenting the fundamentals necessary for an understanding of the basis of regulatory criteria such as those recommended by the ICRP. (author)

  7. Solar Radiation effect on the bituminous binder

    International Nuclear Information System (INIS)

    Tadeo Rico, A.; Torres Perez, A.

    2010-01-01

    Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

  8. Significance of radiation-induced bystander effects in radiation therapy

    International Nuclear Information System (INIS)

    Suzuki, Masao

    2014-01-01

    Since 1994, a Phase I/II clinical study and radiotherapy have carried out using carbon-ion beams produced with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences. Now we constructed the new treatment facility for the advanced carbon-ion therapy at HIMAC applying a 3D fast spot scanning system with pencil beams. In the field of fundamental biological studies for high-LET heavy ions, there are some reports regarding bystander effects after exposure to alpha particles derived from 238 Pu or He-ion microbeams. However, only limited sets of studies have examined bystander effects after exposure to different ion species heavier than helium, such as carbon ions. We have been investigating bystander cellular responses in both normal human and human tumor cells irradiated with the HIMAC carbon ions. Bystander cell-killing effect was observed in the cells harboring wild-type P53 gene, but not in the P53-mutated cells. Moreover, observed bystander effect was suppressed by treating with a specific inhibitor of gap-junction mediated cell-cell communication. There is clear evidence that the carbon-ion irradiation enables the enhanced cell killing in cells with wild-type P53 gene via gap-junction mediated bystander effect. (author)

  9. Effects of radiation on aquatic organisms

    International Nuclear Information System (INIS)

    Kaur, Harbhajan; Lata, Poonam; Sharma, Ankush

    2012-01-01

    With the onset of nuclear age, nuclear fuel cycle products, nuclear medicine techniques, disposal of radio active wastes on land or in water, fall out of testing nuclear weapons has contributed large amount of radio nuclides to the water bodies. Radio nuclides can imbalance aquatic ecosystem resulting in danger to natural life. The biological effects of radiation on aquatic life are mortality, pathophysiological, reproductive, developmental and genetic changes. A broad review of the results obtained about the aquatic organisms related to different phyla indicates that the lower or less developed or more primitive organisms are more resistant than the higher or more advanced, developed and complex organisms to ionizing radiation. The algae, protozoa are more resistant than the insects, crustaceans, molluscs and fishes. The changes in sensitivity between different stages of development have also been noted. A review of the results of exposing salmonoid gametes, eggs, fingerlings and adults to X-rays supports the concepts that radio sensitivity decreases with age. This paper presents a selective review on effects of radiation and radio nuclides on the aquatic life. It include uses and sources of radiation, effective quantity of radiation, lethal and sub lethal effect, effects on survival, growth, reproduction, behaviour, metabolism, carcinogenicity and mutagenicity. (author)

  10. Principles and techniques of radiation hardening. Volume 2. Transient radiation effects in electronics (TREE)

    International Nuclear Information System (INIS)

    Rudie, N.J.

    1976-01-01

    The three-volume book is intended to serve as a review of the effects of thermonuclear explosion induced radiation (x-rays, gamma rays, and beta particles) and the resulting electromagnetic pulse (EMP). Volume 2 deals with the following topics: radiation effects on quartz crystals, tantalum capacitors, bipolar semiconductor devices and integrated circuits, field effect transistors, and miscellaneous electronic devices; hardening electronic systems to photon and neutron radiation; nuclear radiation source and/or effects simulation techniques; and radiation dosimetry

  11. The physics of radiation protection

    International Nuclear Information System (INIS)

    Doerschel, B.; Schuricht, V.; Steuer, J.

    1996-01-01

    The book is aimed at both practising specialists and scientists wishing to learn about the fundamental science of radiation protection. The first part of the book, 'Physical Fundamentals of Radiation Protection', presents a concise description of radiation sources and radiation fields, interaction of radiation with matter, radiation effects and radiation damage, basic concept of radiation protection, radiation exposure of man, radiation protection measuring techniques and physical fundamentals for limiting radiation exposure. The second part, 'Calculational Exercises for Radiation Protection' is intended to supplement the first part by carrying out relevant calculations, amending and adding special aspects and to give guidance in solving practical problems. The book is written for scientists as well as for students and staff working in nuclear facilities, hospitals and institutions responsible for radiation and environmental protection. (UK)

  12. Health effects of low level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Sadao [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1998-12-31

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted `Radiation Hormesis` on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm `is it true or not?` After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey`s claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  13. Health effects of low level radiation

    International Nuclear Information System (INIS)

    Hattori, Sadao

    1998-01-01

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted 'Radiation Hormesis' on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm 'is it true or not?' After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey's claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  14. Radiation effects on bovine taste bud membranes

    International Nuclear Information System (INIS)

    Shatzman, A.R.; Mossman, K.L.

    1982-01-01

    In order to investigate the mechanisms of radiation-induced taste loss, the effects of radiation on preparations of enriched bovine taste bud membranes were studied. Taste buds containing circumvallate papilae, and surrounding control epithelial tissues devoid of taste buds, were obtained from steers and given radiation doses of 0-7000 cGy (rad). Tissue fractions were isolated into membrane-enriched and heterogeneous components using differential and sucrose gradient centrifugation of tissue homogenates. The yield of membranes, as measured by protein content in the buoyant membrane-enriched fractions, was reduced in quantity with increasing radiation dose. The relation between radiation dose and membrane quantity in membrane-enriched fractions could be fit by a simple exponential model with taste bud-derived membranes twice as radiosensitive as membranes from control epithelial tissue. Binding of sucrose, sodium, and acetate and fluoride stimulation of adenylate cyclase were nearly identical in both irradiated and nonirradiated intact membranes. Radiation had no effect on fractions of heterogeneous components. While it is not clear what changes are occurring in enriched taste cell membranes, damage to membranes may play an important role in the taste loss observed in patients following radiotherapy

  15. Effects of ionizing radiation on bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Suhadi, F [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1976-10-01

    The differences of radiosensitivities among bacteria in addition to the dependence upon the species or strains also depends on the environmental condition during irradiation (temperature, medium, the presence of protective or sensitizing agents, the gas phase or atmosphere, and water activity, or degree of hydration) and on the effects of the environmental condition before and after irradiation treatment (temperature of incubation, age of culture and growth medium). In general, spores are more resistant to radiation than vegetatic bacteria, with the exception that a few cocci are the most radiation resistant bacteria (Micrococcus and Streptococcus). The application of ionizing radiation in the fields of microbiology supports the radiation sterilization of medical and pharmaceutical products. In addition, microbiological aspects of food preservation, especially radurization, radicidation, and immunization studies by using irradiated microorganisms, are also important.

  16. Electromagnetic and radiation environments: effects on pacemakers

    International Nuclear Information System (INIS)

    Mouton, J.; Trochet, R.; Vicrey, J.; Sauvage, M.; Chauvenet, B.; Ostrovski, A.; Leroy, E.; Haug, R.; Dodinot, B.; Joffre, F.

    1999-01-01

    Nowadays, medical care development allows many people to share the benefits of implanted pacemakers (PM). PM can be perturbed and even fall in complete breakdowns in an electromagnetic and radiation environment. A stimuli-dependent patient can thus be seriously in danger. This article presents the effect of ionizing radiation from either a cobalt-60 source or from a linear accelerator (Saturne 43) on 12 pacemakers. It seems that technological progress make electronic circuits more sensitive to the cumulated dose of radiation. This survey shows that pacemakers have great difficulties to sustain ionizing radiation doses that are commonly delivered to patients during therapies. Usually perturbed functioning appears suddenly and means a strong shift of stimuli that might lead to heart failure

  17. Effect of radiation processing on meat tenderisation

    Science.gov (United States)

    Kanatt, Sweetie R.; Chawla, S. P.; Sharma, Arun

    2015-06-01

    The effect of radiation processing (0, 2.5, 5 and 10 kGy) on the tenderness of three types of popularly consumed meat in India namely chicken, lamb and buffalo was investigated. In irradiated meat samples dose dependant reduction in water holding capacity, cooking yield and shear force was observed. Reduction in shear force upon radiation processing was more pronounced in buffalo meat. Protein and collagen solubility as well as TCA soluble protein content increased on irradiation. Radiation processing of meat samples resulted in some change in colour of meat. Results suggested that irradiation leads to dose dependant tenderization of meat. Radiation processing of meat at a dose of 2.5 kGy improved its texture and had acceptable odour.

  18. The toxic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Draghita Payet, A.C.

    2006-06-01

    The sources of radiations to which the human body is subjected are of natural or artificial origin and the irradiation of the human body can take place either by internal or external way. The ionizing radiations act at several levels of the human body, the main thing being the molecule of DNA. The ionizing radiations have no specificity, the effects on the human body can be: somatic, genetic or hereditary, teratogen. In the case of a human being irradiation, we proceed to the diagnosis and to the treatment of the irradiated person, however, to decrease the incidence of injuries we use the radiation protection. The treatment if necessary will be established according to the irradiation type. (N.C.)

  19. Effects of radiation on the skin

    International Nuclear Information System (INIS)

    Hopewell, J.W.

    1985-01-01

    The effects of X-irradiation on pig skin are described, comparing and contrasting the effects seen in human and rodent skin. It is concluded that, anatomically, pig skin is the best animal model for human skin. The applications of the 'pig skin model' to investigations of the problems of radiation therapy and radiological protection of human skin are discussed. (U.K.)

  20. Radiation dose effects, hardening of electronic components

    International Nuclear Information System (INIS)

    Dupont-Nivet, E.

    1991-01-01

    This course reviews the mechanism of interaction between ionizing radiation and a silicon oxide type dielectric, in particular the effect of electron-hole pairs creation in the material. Then effects of cumulated dose on electronic components and especially in MOS technology are examined. Finally methods hardening of these components are exposed. 93 refs

  1. Numerical analysis of effects of transglottal pressure change on fundamental frequency of phonation.

    Science.gov (United States)

    Deguchi, Shinji; Matsuzaki, Yuji; Ikeda, Tadashige

    2007-02-01

    In humans, a decrease in transglottal pressure (Pt) causes an increase in the fundamental frequency of phonation (F0) only at a specific voice pitch within the modal register, the mechanism of which remains unclear. In the present study, numerical analyses were performed to investigate the mechanism of the voice pitch-dependent positive change of F0 due to Pt decrease. The airflow and the airway, including the vocal folds, were modeled in terms of mechanics of fluid and structure. Simulations of phonation using the numerical model indicated that Pt affects both the average position and the average amplitude magnitude of vocal fold self-excited oscillation in a non-monotonous manner. This effect results in voice pitch-dependent responses of F0 to Pt decreases, including the positive response of F0 as actually observed in humans. The findings of the present study highlight the importance of considering self-excited oscillation of the vocal folds in elucidation of the phonation mechanism.

  2. Black holes and fundamental fields: Hair, kicks, and a gravitational Magnus effect

    Science.gov (United States)

    Okawa, Hirotada; Cardoso, Vitor

    2014-11-01

    Scalar fields pervade theoretical physics and are a fundamental ingredient to solve the dark matter problem, to realize the Peccei-Quinn mechanism in QCD or the string-axiverse scenario. They are also a useful proxy for more complex matter interactions, such as accretion disks or matter in extreme conditions. Here, we study the collision between scalar "clouds" and rotating black holes. For the first time we are able to compare analytic estimates and strong field, nonlinear numerical calculations for this problem. As the black hole pierces through the cloud it accretes according to the Bondi-Hoyle prediction, but is deflected through a purely kinematic gravitational "anti-Magnus" effect, which we predict to be present also during the interaction of black holes with accretion disks. After the interaction is over, we find large recoil velocities in the transverse direction. The end-state of the process belongs to the vacuum Kerr family if the scalar is massless, but can be a hairy black hole when the scalar is massive.

  3. Effects of fundamentals acquisition and strategy switch on stock price dynamics

    Science.gov (United States)

    Wu, Songtao; He, Jianmin; Li, Shouwei

    2018-02-01

    An agent-based artificial stock market is developed to simulate trading behavior of investors. In the market, acquisition and employment of information about fundamentals and strategy switch are investigated to explain stock price dynamics. Investors could obtain the information from both market and neighbors resided on their social networks. Depending on information status and performances of different strategies, an informed investor may switch to the strategy of fundamentalist. This in turn affects the information acquisition process, since fundamentalists are more inclined to search and spread the information than chartists. Further investigation into price dynamics generated from three typical networks, i.e. regular lattice, small-world network and random graph, are conducted after general relation between network structures and price dynamics is revealed. In each network, integrated effects of different combinations of information efficiency and switch intensity are investigated. Results have shown that, along with increasing switch intensity, market and social information efficiency play different roles in the formation of price distortion, standard deviation and kurtosis of returns.

  4. Cardiovascular effects of radiation therapy

    International Nuclear Information System (INIS)

    Alvarez, Jose A.G.; Leiva, Gustavo

    2001-01-01

    Therapeutic mediastinal irradiation can induce heart disease with variable degree of cardiac engagement. Heart disease manifestations depend on the grade of involvement of the different cardiac structures. During the first two years following irradiation, pericarditis with or without pericardial effusion is the most common manifestation of toxicity related to radiation therapy. Later on, after a latency period of five to ten years, a constrictive pericarditis may develop. Other type of late cardiac toxicities due to irradiation are restrictive cardiomyopathy, multiple valvular disease, coronary artery disease and different atrioventricular conduction disturbances. The therapeutic approach to this kind of heart disease has to be focused on its progressive course and in the possibility of a global involvement of all the cardiac structures. Pericardiectomy is strongly recommended for recurrent pericardial effusion with cardiac tamponade. Cardiac surgery for myocardial revascularization or valvular disease can be performed with variable results; the presence of myocardial fibrosis can significantly affect perioperative management and long-term results. Cardiac transplantation is a promissory option for those patients with end-stage cardiac failure. Immunosuppressive regimens are not associated with recurrence of malignancy. (author) [es

  5. Radiation effects, nuclear energy and comparative risks

    International Nuclear Information System (INIS)

    Gopinath, D.V.

    2007-01-01

    Nuclear energy had a promising start as an unlimited, inexpensive and environmentally benign source of energy for electricity generation. However, over the decades its growth was severely retarded due to concerns about its possible detrimental effects on the well-being of mankind and the environment. Since such concerns are essentially due to the gigantic magnitude of radioactivity and ionizing radiations associated with nuclear energy, this article starts with a comprehensive account of effects of the ionizing radiation on living systems. Quantitative description of types of radiation exposure and their varied effects is given. The origin, type and magnitude of mutagenic effects of radiation are described. The concept of radiation risk factors, basis for their evaluation and their currently accepted values are presented. With this background, origin and magnitude of radioactivity and associated ionizing radiations in nuclear reactors are presented and the elaborate measures to contain them are described. It is recognized that notwithstanding all the measures taken in the nuclear industry, certain amount of radiation exposure, however small, is inevitable and the values, based on the experience world over, are presented. Estimated health risk due to such exposures is evaluated. For a comparative analysis, risks in other options of electricity generation such as hydel and fossil-fuelled plants are described. It is seen that on an overall basis, the nuclear option is no more risky than the other commonly employed options, and is in fact, significantly less. Lastly, since every option of electricity generation entails some risk, the case of 'no addition of electricity, and its impact on the society are considered. Based on the analysis of extensive data provided by UNDP on the human development parameters for different countries in the world, it is shown that at least for developing countries, any option of addition of electricity would be far more desirable than the

  6. Ionizing radiation effect on human reproduction

    International Nuclear Information System (INIS)

    Jirous, J.

    1987-01-01

    A review is presented of the existing knowledge on the adverse effects of ionizing radiation on human reproduction. Some interesting findings have been obtained by interapolating the results of studies in mouse embryos to humans, important knowledge has been obtained in studies involving the population of Hiroshima and Nagasaki. The review summarizes the knowledge in the following conclusions: (1) prior to the blastocyst stage, the mammalian embryo is insensitive to teratogenic and growth retarding radiation effects but is highly sensitive to the lethal radiation effect; (2) in the early organogenesis, the embryo is very sensitive to growth retarding, teratogenic and lethal radiation effects. It can, however, partly offset growth retardation in the post-natal period; (3) in the early fetal development stage, the fetus shows reduced sensitivity to teratogenic damage of many organs; sensitivity of the central nervous system and growth retardation remain which can only be compensated post-natally with difficulties; (4) in the late stage of pregnancy the fetus is not significantly deformed as a result of irradiation but permanent cellular depletion can result in various organs and tissues post-natally if radiation doses are high. (L.O.). 22 refs

  7. Effects of UV radiation on freshwater metazooplankton

    International Nuclear Information System (INIS)

    Tartarotti, B.

    1999-06-01

    There is evidence that fluxes of solar ultraviolet-B radiation (UV-B, 290-320 nm) are increasing over wide parts of the earth's surface due to stratospheric ozone depletion. UV radiation (290-400 nm) can have damaging effects on biomolecules and cell components that are common to most living organisms. The aim of this thesis is to gain a more thorough understanding of the potential impacts of solar radiation on freshwater metazooplankton. To detect UV-vulnerability in zooplankton populations dominating the zooplankton community of two clear-water, high mountain lakes located one in the Austrian Alps and another in the Chilean Andes, the survival of two copepod species was studied. The organisms were exposed to a 10- to 100-fold increase in UV-B radiation compared to those levels found at their natural, maximum daytime distribution. Both species vertically migrate and are pigmented. UV-absorbing compounds with a maximum absorption at ∼334 nm were also detected. Cyclops abyssorum tatricus, a common cyclopoid copepod species of Alpine lakes, was highly resistant to UV-B radiation and no significant lethal effect was observed. The calanoid copepod Boeckella gracilipes, frequent in Andean lakes, had a mortality ∼5 times higher in the treatment receiving full sunlight than in the UV-B excluded treatment (3.2 %) only when exposed for 70 h. The resistance of B. gracilipes was higher than that reported in the literature for the same species suggesting the existence of intraspecific differences in UV sensitivity. Survival, fecundity and development of the zooplankton community of a clear-water, high elevation Andean lake (33 o S) were studied with mesocosms experiments after prolonged UV exposure (48 days). When exposed to full sunlight, the population of the cladoceran Chydorus sphaericus and the rotifer Lepadella ovalis were strongly inhibited by UV-B, whereas both species were resistant to UV-A radiation. Conversely, UV-B radiation had no effect on the survival of the

  8. Cytogenetic effects of low-dose radiation

    International Nuclear Information System (INIS)

    Metalli, P.

    1983-01-01

    The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

  9. The late biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-15

    Full text: The principal objective of the symposium was to review the current status of understanding of the late biological effects of ionizing radiation from external and internal sources. A second objective was to critically evaluate information obtained from epidemiological studies of human population groups as well as from animal experimentation in order to provide a solid scientific basis upon which problems of current concern, such as radiation protection standards and risk-benefit analysis, could be deliberated. Eighty-one papers were presented in 10 sessions which covered epidemiological studies of late effects in human populations exposed to internal and/or external ionizing radiation; quantitative and qualitative data from animal experimentation of late effects; methodological problems and modern approaches; factors influencing susceptibility or expression of late radiation injury; comparative evaluation of late effects induced by radiation and other environmental pollutants, and problems of risk assessment. In addition, there were two evening sessions for free discussion of problems of interpreting animal data, and of the epidemiological studies of occupationally exposed populations. Reports on atomic bomb survivors showed that these epidemiological studies are providing dependable data, such as dose-related excess infant mortality. The reports also revealed the need for consensus in the method employed in the interpretation of data. That was also the case with studies on occupationally exposed populations at Hanford plant, where disparate results were presented on radiation-induced neoplasia among radiation workers. These data are, however, considered not so significant in relative terms when compared to risks involved in other industries. It was recommended that national registry systems for the dosimetry and medical records of radiation workers be established and co-ordinated internationally in order to facilitate reliable epidemiological

  10. Long-term effects of radiation

    International Nuclear Information System (INIS)

    Smith, J.; Smith, T.

    1981-01-01

    It is pointed out that sources of long-term damage from radiation are two-fold. People who have been exposed to doses of radiation from initial early fallout but have recovered from the acute effects may still suffer long-term damage from their exposure. Those who have not been exposed to early fallout may be exposed to delayed fallout, the hazards from which are almost exclusively from ingesting strontium, caesium and carbon isotopes present in food; the damage caused is relatively unimportant compared with that caused by the brief doses from initial radiation and early fallout. A brief discussion is presented of the distribution of delayed long-lived isotope fallout, and an outline is sketched of late biological effects, such as malignant disease, cataracts, retarded development, infertility and genetic effects. (U.K.)

  11. Radiation effects on Brassica seeds and seedlings

    Science.gov (United States)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  12. Effects of radiation on DNA

    International Nuclear Information System (INIS)

    Medina, V.F.O.

    1978-01-01

    Irradiation has been shown to depress DNA (deoxyribonucleic acid) synthesis resulting in deficient DNA synthesis. In one experiment, Hela S 3 cells completed the next division after a dose of 500 rads to 200 kw X-rays. Another experiment showed that the amount of DNA synthesized was dependent on the stage in the generation cycle at which the cells are irradiated (Giffites and Tolmach, 1975). DNA synthesis was measured by radioactive thymidine incorporation. The smallest deficiency (20-35%) after a dose of 500 rad X-ray was observed in Hela S 3 cells irradiated in early G 1 or early G 2 , while the greatest deficiency (55-70*) after 500 rad X-ray was found in cells irradiated at mitosis or at the Gsub(1)/S transition. Using velocity sedimentation in alkaline gradients of the DNA from hamster, Elkind, et al 1972, studied repair processes as a function of X-ray dose. DNA containing material released by alkaline lysis was found initially contained in a complex-containing lipid, the sedimentation of which was anomalous relative to denatured RNA from unirradated cells. Doses of X-rays small enough to be in the range that permits high survival (100-800 rads) speed the resolution of single-stranded DNA from this DNA complex, giving rise to a species having a number average molecular weight of 2 x 10 8 daltons. Larger doses greater than 1000 to 2000 rads resulted in a degradation of these DNA strands. Incubation after irradiation resulted in the rapid repair of damage, although the rate of repair of damage to the complex resulted in a reassociation of lipid and DNA. This evidence supports the possibility that a large DNA-membrane structure is a principal target of radiation

  13. DOE fundamentals handbook: Material science

    International Nuclear Information System (INIS)

    1993-01-01

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the structure and properties of metals. This volume contains the following modules: thermal shock (thermal stress, pressurized thermal shock), brittle fracture (mechanism, minimum pressurization-temperature curves, heatup/cooldown rate limits), and plant materials (properties considered when selecting materials, fuel materials, cladding and reflectors, control materials, nuclear reactor core problems, plant material problems, atomic displacement due to irradiation, thermal and displacement spikes due to irradiation, neutron capture effect, radiation effects in organic compounds, reactor use of aluminum)

  14. Pedagogical Approaches to and Effects of Fundamental Movement Skill Interventions on Health Outcomes: A Systematic Review.

    Science.gov (United States)

    Tompsett, Claire; Sanders, Ross; Taylor, Caitlin; Cobley, Stephen

    2017-09-01

    Fundamental movement skills (FMS) are assumed to be the basic prerequisite motor movements underpinning coordination of more integrated and advanced movement capabilities. FMS development and interventions have been associated with several beneficial health outcomes in individual studies. The primary aim of this review was to identify FMS intervention characteristics that could be optimised to attain beneficial outcomes in children and adolescents, while the secondary aim was to update the evidence as to the efficacy of FMS interventions on physiological, psychological and behavioural health outcomes. A systematic search [adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines] was conducted in seven databases. Studies were included if they conducted an FMS intervention and targeted at least one physiological, behavioural or psychological outcome in school-aged children (5-18 years). Twenty-nine studies examining the effect of FMS interventions relative to controls were identified. Specialist-led interventions, taught in conjunction with at-home practice and parent involvement, appeared more efficacious in enhancing FMS proficiency than school physical education alone. Intervention environments encouraging psychological autonomy were likely to enhance perceived and actual competence in FMS alongside physical activity. FMS interventions had little influence on overweight/obesity reduction, strength or flexibility. In 93% of studies, evidence indicated interventions improved FMS motor proficiency. Favourable specific physiological, psychological and behavioural outcomes were also identified across a variety of interventions. With reference to clinical and normative school-age populations, future studies should be directed toward determining validated standard FMS assessments to enable accurate effect estimates, permit intervention comparisons and improve the efficacy of FMS development.

  15. Ultra violet radiation : effects on animals

    International Nuclear Information System (INIS)

    Stockdale, P.H.G.

    1993-01-01

    The paper deals with the evolutionary and historical events that have increased the susceptibility of certain genotypes of humanity and domestic animals to ultra violet radiation. Further it discusses the general effects of ultraviolet B (UVB) on vertebrates and then the clinical syndromes seen in such animals as a result of prolonged exposure to this form of radiation. Finally it gives anecdotal comments on evidence for changes in the immediately above types of disease and describes the need for a better recording system for these conditions so that these hypothetical changes could be effectively monitored. (author). 12 refs

  16. Genetic and chromosomal effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The genetic and chromosomal effects of ionizing radiations deal with those effects in the descendants of the individuals irradiated. The information base concerning genetic and chromosomal injury to humans from radiation is less adequate than is the information base for cancer and leukemia. As a result, it is not possible to make the kinds of quantitative estimates that have been made for carcinogenesis in previous chapters of this book. The chapter includes a detailed explanation of various types of genetic injuries such as chromosomal diseases, x-linked diseases, autosomal dominant diseases, recessive diseases, and irregularly inherited diseases. Quantitative estimates of mutation rates and incidences are given based on atomic bomb survivors data

  17. Additive effects in radiation grafting and curing

    International Nuclear Information System (INIS)

    Viengkhou, V.; Ng, L.

    1996-01-01

    Full text: Detailed studies on the accelerative effect of novel additives in radiation grafting and curing using acrylated monomer/oligomer systems have been performed in the presence of ionising radiation and UV as sources. Methyl methacrylate (MMA) is used as typical monomer for these grafting studies in the presence of the additives with model backbone polymers, cellulose and propropylene. Additives which have been found to accelerate these grafting processes are: mineral acid, occlusion compounds like urea, thermal initiators and photoinitiators as well as multifunctional monomers such as multifunctional acrylates. The results from irradiation with gamma rays have also been compared with irradiation from a 90W UV lamp. The role of the above additives in accelerating the analogous process of radiation curing has been investigated. Acrylated urethanes, epoxies and polyesters are used as oligomers together with acrylated monomers in this work with uv lamps of 300 watts/inch as radiation source. In the UV curing process bonding between film and substrate is usually due to physical forces. In the present work the presence of additives are shown to influence the occurrence of concurrent grafting during cure thus affecting the nature of the bonding of the cured film. The conditions under which concurrent grafting with UV can occur will be examined. A mechanism for accelerative effect of these additives in both grafting and curing processes has been proposed involving radiation effects and partitioning phenomena

  18. Overview of the fundamental safety principles

    International Nuclear Information System (INIS)

    Chishinga, Milton Mulenga

    2015-02-01

    The primary objective of this work was to provide an overview of the International Atomic Energy (IAEA) document; 'Fundamental Safety principles, SF.1'. The document outlines ten (10) fundamental principles which provide the basis for an effective the radiation protection framework. The document is the topmost in the hierarchy of the IAEA Safety Standards Series. These principles are the foundation of the nuclear safety put stringent obligations on Parties under the Convention on Nuclear Safety. The fundamental safety objective is to protect people and the environment from harmful effects of ionizing radiation. The fundamental Safety objective of protecting people individually and collectively and the environment has to be achieved without unduly limiting the operation of facilities or the conduct of activities that give rise to risks. The thematic areas covered are; responsibility for safety, role of government, leadership and management for safety, justification of facilities and activities, optimization of protection, limitation of risks to individuals, protection of present and future generations, prevention of accidents, emergency preparedness and response and protective actions to reduce existing or unregulated radiation risks. Appropriate recommendations have been provided for effective application of the principles by Governments, Regulatory Bodies and Operating Organizations of facilities and Nuclear Installations the give rise to radiation risks. (au)

  19. Radiation effects on custom MOS devices

    International Nuclear Information System (INIS)

    Harris, R.

    1999-05-01

    This Thesis consists of four chapters: The first is primarily for background information on the effects of radiation on MOS devices and the theory of wafer bonding; the second gives a full discussion of all practical work carried out for manufacture of Field Effect test Capacitors, the third discusses manufacture of vacuum insulator Field Effect Transistors (FET's) and the fourth discusses the testing of these devices. Using a thermally bonded field effect capacitor structure, a vacuum dielectric was studied for use in high radiation environments with a view to manufacturing a CMOS compatible, micro machined transistor. Results are given in the form of high frequency C-V curves before and after a 120 kGy(Si), 12 MRad(Si), dose from a Co 60 source showing a 1 Volt shift. The work is then extended to the design and manufacture of a micro machined, under-etch technique, Field Effect Transistor for use in high radiation areas. Results are shown for Threshold, Subthreshold and Transfer characteristics before and after irradiation up to a total dose of 100kGy or 10MRad. The conclusion from this work is that it should be possible to commercially manufacture practical vacuum dielectric field effect transistors which are radiation hard to at least 120 kGy(Si). (author)

  20. Ceramics radiation effects issues for ITER

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1993-01-01

    The key radiation effects issues associated with the successful operation of ceramic materials in components of the planned International Thermonuclear Experimental Reactor (ITER) are discussed. Radiation-induced volume changes and degradation of the mechanical properties should not be a serious issue for the fluences planned for ITER. On the other hand, radiation-induced electrical degradation effects may severely limit the allowable exposure of ceramic insulators. Degradation of the loss tangent and thermal conductivity may also restrict the location of some components such as ICRH feedthrough insulators to positions far away from the first wall. In-situ measurements suggest that the degradation of physical properties in ceramics during irradiation is greater than that measured in postirradiation tests. Additional in-situ data during neutron irradiation are needed before engineering designs for ITER can be finalized

  1. Effects of radiation rays on construction materials

    International Nuclear Information System (INIS)

    Akkurt, I.; Kilicarslan, S.; Basyigit, C.; Kacar, A.

    2006-01-01

    Molecules that are bring into existence material determined as gas, liquid and stiff according to their internal structures and heat. Materials show various reaction to various effects that is result from all kind of materials have various internal structures. Radiation is covert materials' mechanical, physical and chemical properties. Nowadays in construction formation there isn't using only one material it is preferred that kind of materials composition because of there are run into some problems about choosing and decision sort of material. Material that using in construction is classified as metals, plastics and ceramics in three groups. About sixty percent of construction cost is being formed from construction materials. In this study effects of various radiations on construction materials are being investigated and the end of study it is being suggestion some useful construction materials according to usage land and radiation properties

  2. Radiology fundamentals

    CERN Document Server

    Singh, Harjit

    2011-01-01

    ""Radiology Fundamentals"" is a concise introduction to the dynamic field of radiology for medical students, non-radiology house staff, physician assistants, nurse practitioners, radiology assistants, and other allied health professionals. The goal of the book is to provide readers with general examples and brief discussions of basic radiographic principles and to serve as a curriculum guide, supplementing a radiology education and providing a solid foundation for further learning. Introductory chapters provide readers with the fundamental scientific concepts underlying the medical use of imag

  3. Atoms and light. Matter radiation interaction. DEA in quantum physics, year 2003. 2nd year Master: Fundamental concepts in Physics, Cursus: Quantum Physics. Year 2006-2007

    International Nuclear Information System (INIS)

    Fabre, Claude

    2003-01-01

    This document contains two nearly identical courses on the interaction between matter and electromagnetic radiation. The second one addresses a few more issues in sub-paragraphs, but follows the same organisation and plan. A first part addresses tools in quantum optics. It presents phenomenological approaches (the Lorentz and Einstein models), the semi-conventional approach (isolated atom, effect of the environment with the Bloch equations, interaction with a non-monochromatic field, oscillator force), the quantum description of the free electromagnetic field (corpuscular aspect of the thermal radiation field, decomposition of the conventional electromagnetic field into modes, quantification of free radiation, radiation kinetic moment and pulse, radiation stationary states, value of the electric field in a quantum state), the interaction between atom and quantum field (interaction Hamiltonian, interaction process, photo-detection). The second part addresses some phenomena of quantum optics such as spontaneous emission, quasi-resonant interactions in two-level systems, three-level systems, fluctuations and correlations in the matter-radiation interaction. Appendices contain elements on atom structure, and on the density matrix

  4. Radiation research contracts: Biological effects of small radiation doses

    International Nuclear Information System (INIS)

    Hug, O.

    1959-01-01

    According to its Statute the IAEA has to fulfil a dual function - to help individual countries in solving their specific problems and to undertake tasks in the common interest of all its Member States. With this latter aim in mind the Agency has placed a number of research contracts with national research institutes. The purpose and scope of two of them is described below by the scientists responsible for their execution. The Agency has contributed to this work by putting at the institutes' disposal scientists from its own staff apparatus and financial aid.IAEA placed a research contract concerning the effects of small radiation doses on cells, in particular on nervous cells, with the Pharmacological Institute of the University of Vienna. This Institute appeared well suited to deal with the problem owing to the type of its previous research work. The Director, Prof. Franz Bruecke, and his collaborator Dr. Otto Kraupp, have long been interested in the functioning of the nervous system and in the influence of different drugs upon it. It was particularly fortunate that the electrical properties and functions of cells had been measured by a method specially developed at this Institute. From the above mentioned observations one could expect that instantaneous reactions of cells to radiation would also lead to changes of the electrical status. Consequently, this method is now being applied to the research undertaken for IAEA. Different cells of plants and animals, ranging from algae to muscle fibres of mammals, were chosen as objects. So far changes of potentials-had been observed only during irradiation with very high doses. During these investigations another useful test for small radiation doses was developed, namely the measurement of the through-flow of an artificial blood solution through the blood vessels of an intestinal loop. It was observed that a few seconds after irradiation the flow rate diminishes, and returns to its normal level only when irradiation ends

  5. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O

    1959-01-15

    According to its Statute the IAEA has to fulfil a dual function - to help individual countries in solving their specific problems and to undertake tasks in the common interest of all its Member States. With this latter aim in mind the Agency has placed a number of research contracts with national research institutes. The purpose and scope of two of them is described below by the scientists responsible for their execution. The Agency has contributed to this work by putting at the institutes' disposal scientists from its own staff apparatus and financial aid.IAEA placed a research contract concerning the effects of small radiation doses on cells, in particular on nervous cells, with the Pharmacological Institute of the University of Vienna. This Institute appeared well suited to deal with the problem owing to the type of its previous research work. The Director, Prof. Franz Bruecke, and his collaborator Dr. Otto Kraupp, have long been interested in the functioning of the nervous system and in the influence of different drugs upon it. It was particularly fortunate that the electrical properties and functions of cells had been measured by a method specially developed at this Institute. From the above mentioned observations one could expect that instantaneous reactions of cells to radiation would also lead to changes of the electrical status. Consequently, this method is now being applied to the research undertaken for IAEA. Different cells of plants and animals, ranging from algae to muscle fibres of mammals, were chosen as objects. So far changes of potentials-had been observed only during irradiation with very high doses. During these investigations another useful test for small radiation doses was developed, namely the measurement of the through-flow of an artificial blood solution through the blood vessels of an intestinal loop. It was observed that a few seconds after irradiation the flow rate diminishes, and returns to its normal level only when irradiation ends

  6. Effects of gamma radiation in annatto seeds

    International Nuclear Information System (INIS)

    Franco, Camilo F. de Oliveira; Arthur, Valter; Arthur, Paula B.; Harder, Marcia N.C.; Filho, Jose C.; Neto, Miguel B.

    2015-01-01

    The annatto bixin has emerged as a major source of natural dyes used in the world notably by the substitution of synthetics harmful to human health and ecologic tendency in obtaining industrial products free of additives with applications in industries textiles; cosmetics; pharmaceutical and food mainly. The aim of this research was to obtain increased of germination rate and dormancy breaking on annatto seeds by gamma radiation. Annatto dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.456 kGy/hour dose rate. In order to study stimulation effects of radiation on germination rate and dormancy breaking in the seeds. Five treatments with gamma radiation doses were applied as follows: 0 (control); 100; 125; 150 and 175 Gy. After irradiation the annatto seeds were planted as for usual seed production. According to the results obtained in this experiment we can conclude that the low doses of gamma radiation utilized on the annatto seeds did not presented significantly effect on the germination of plants. But the best dose to increase the germination of seeds was 150 Gy. (author)

  7. Effects of gamma radiation in soybean

    International Nuclear Information System (INIS)

    Franco, Jose Gilmar; Franco, Suely Salumita Haddad; Arthur, Valter; Arthur, Paula Bergamin; Franco, Caio Haddad

    2015-01-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Soya dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.245 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. Five treatments radiation doses were applied as follows: 0 (control); 25; 50; 75 and 100 Gy. Seed germination and harvest of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were doses of 25, 50 and 75 Gy. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  8. Effects of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Jose Gilmar; Franco, Suely Salumita Haddad; Arthur, Valter; Arthur, Paula Bergamin, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio Haddad [Centro Nacional de Pesquisa em Energia e Materiais (LNBio/CNPEM), Campinas, SP (Brazil). Laboratorio Nacional de Biociencias; Villavicencio, Anna Lucia, E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Soya dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.245 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. Five treatments radiation doses were applied as follows: 0 (control); 25; 50; 75 and 100 Gy. Seed germination and harvest of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were doses of 25, 50 and 75 Gy. There are evidences that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  9. Effects of gamma radiation in annatto seeds

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Camilo F. de Oliveira, E-mail: camilo.urucum@hotmail.com [Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA/EMEPA), Joao Pessoa, PB (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Harder, Marcia N.C., E-mail: marcia.harder@fatec.sp.gov.br [Centro Paula Souza, Curso Superior de Tecnologia em Bicombustiveis (FATEC), Piracicaba, SP (Brazil); Filho, Jose C.; Neto, Miguel B., E-mail: jorgecazefilho@yahoo.com.br [Empresa Estadual de Pesquisa Agropecuaria da Paraiba (EMEPA), Joao Pessoa, PB (Brazil)

    2015-07-01

    The annatto bixin has emerged as a major source of natural dyes used in the world notably by the substitution of synthetics harmful to human health and ecologic tendency in obtaining industrial products free of additives with applications in industries textiles; cosmetics; pharmaceutical and food mainly. The aim of this research was to obtain increased of germination rate and dormancy breaking on annatto seeds by gamma radiation. Annatto dry seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.456 kGy/hour dose rate. In order to study stimulation effects of radiation on germination rate and dormancy breaking in the seeds. Five treatments with gamma radiation doses were applied as follows: 0 (control); 100; 125; 150 and 175 Gy. After irradiation the annatto seeds were planted as for usual seed production. According to the results obtained in this experiment we can conclude that the low doses of gamma radiation utilized on the annatto seeds did not presented significantly effect on the germination of plants. But the best dose to increase the germination of seeds was 150 Gy. (author)

  10. Gamma and electron radiation effects on straw

    International Nuclear Information System (INIS)

    Leonhardt, J.W.; Baer, M.; Huebner, G.

    1983-01-01

    Gamma and electron radiation effects on wheat straw, oat straw, barley straw and rye straw are reported. In vitro and in vivo studies show that the digestibility of these agricultural rough materials can be increased up to 80% and more at high doses. The increase of the digestibility is connected with a depolymerisation of cellulose and hemicellulose. (author)

  11. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1985-09-01

    Written for the layman, this booklet describes the effects of ionising radiation on people, and discusses the somatic hereditary risk estimates, and the measures taken to ensure the safe operation of the nuclear industry. New edition based on the sievert. (U.K.)

  12. Antiproton radiation found effective in cancer research

    CERN Multimedia

    2003-01-01

    "An international collaboration of scientists has completed the first ever antiproton beam experiments designed to reveal the biological effectiveness of antiproton radiation in terminating cells used for cancer research...PBar Labs assembled the collaboration at CERN (European Organization for Nuclear Research in Geneva) to perform the measurements" (1 page).

  13. Aerosol effects on UV radiation

    International Nuclear Information System (INIS)

    Koepke, P.; Reuder, J.; Schwander, H.

    2000-01-01

    The reduction of erythemally weighted UV-irradiance (given as UV index, UVI) due to aerosols is analyzed by variation of the tropospheric particles in a wide, but realistic range. Varied are amount and composition of the particles and relative humidity and thickness of the mixing layer. The reduction of UVI increases with aerosol optical depth and the UV change is around 10% for a change aerosol optical depth from 0.25 to 0.1 and 0.4 respectively. Since both aerosol absorption and scattering are of relevance, the aerosol effect depends besides total aerosol amount on relative amount of soot and on relative humidity

  14. How to increase treatment effectiveness and efficiency in psychiatry: creative psychopharmacotherapy - part 1: definition, fundamental principles and higher effectiveness polypharmacy.

    Science.gov (United States)

    Jakovljević, Miro

    2013-09-01

    Psychopharmacotherapy is a fascinating field that can be understood in many different ways. It is both a science and an art of communication with a heavily subjective dimension. The advent of a significant number of the effective and well tolerated mental health medicines during and after 1990s decade of the brain has increased our possibilities to treat major mental disorders in more successful ways with much better treatment outcome including full recovery. However, there is a huge gap between our possibilities for achieving high treatment effectiveness and not satisfying results in day-to-day clinical practice. Creative approach to psychopharmacotherapy could advance everyday clinical practice and bridge the gap. Creative psychopharmacotherapy is a concept that incorporates creativity as its fundamental tool. Creativity involves the intention and ability to transcend limiting traditional ideas, rules, patterns and relationships and to create meaningful new ideas, interpretations, contexts and methods in clinical psychopharmacology.

  15. Loading Effect on Tire Noise Radiation

    OpenAIRE

    Cao, Rui; Bolton, J Stuart

    2016-01-01

    Noise radiated by tires is a prominent noise pollution source and it is affected by many different parameters. Here, the effect of static load on tire noise radiation in a laboratory environment was investigated. The measurement was conducted by using the Tire Pavement Testing Apparatus (TPTA), on which a loaded tire can be run at speeds up to 50 km/hr; the tire noise was measured using a nearfield microphone method. The tire loading was varied from 500 to 900 pounds, and several different co...

  16. Effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    2008-01-01

    Ionizing radiation of cosmic or terrestrial origin is part of the environment in which all living things have evolved since the creation of the universe. The artificial radioactivity generated by medical diagnostic and treatment techniques, some industrial activities, radioactive fallout, etc. has now been added to this natural radioactivity. This article reviews the biological effects of the low doses of ionizing radiation to which the population is thus exposed. Their carcinogenic risk cannot simply be extrapolated from what we know about high-dose exposure. (author)

  17. Radiation effects on cultured human lymphoid cells

    International Nuclear Information System (INIS)

    Johansson, L.; Nilsson, K.; Carlsson, J.; Larsson, B.; Jakobsson, P.

    1981-01-01

    The cloning efficiency of human normal and malignant lymphoid cells is usually low. Radiation effects in vitro on such cells can therefore not be analysed with conventional cloning. However, this problem can be circumscribed by using the growth extrapolation method. A panel of human leukemia-lymphoma cell-lines representing Epstein-Barr virus carrying lymphoblastoid cells of presumed non-neoplastic derivation and neoplastic T- and B-lymphocytes was used to test the efficiency of this method. The sensitivity to radiation could be determined for all these cell types. The growth extrapolation method gave generally the same result as conventional cloning demonstrated by comparison with one exceptional cell-line with capacity for cloning in agar. The sensitivity varied largely between the different cell types. A common feature was that none of the cell lines had a good capacity to accumulate sublethal radiation injury. (Auth.)

  18. Radiation effects in brain and spinal cord

    International Nuclear Information System (INIS)

    Franke, H.D.; Lierse, W.

    1978-01-01

    Radiation sensitivity of both the brain and spinal cord in prenatal and postnatal stages, in infancy and adult age is represented also in consideration of a combined treatment with methotrexate. In adults, application of important doses of high-energy radiation increases the risk of injurious effects to the central nervous system. If the spinal cord is involved, more than 60% of the radiolesions have a progredient course ending with death. The pathogenesis and disposing factors are referred to, and the incidence of radiation necrosis with regard to age and sex, the degrees of injury and their frequence within different ranges of dosage are analyzed on the basis of data from universal literature. An examination of 'tolerance doses' for the spinal cord is made by means of Strandquist-diagrams and of the Ellis-formula. The slopes of regression lines are reported for various 'degrees of response' in skin, brain and spinal cord following radiation therapy. In the Strandquist-diagram, slopes of regression lines are dependent on the 'degree of response', flattening if skin and spinal cord are affected by radiation in the same degree, necroses having the same slope for both the organs. (orig./MG) [de

  19. Effect of domperidone on radiation sickness

    Energy Technology Data Exchange (ETDEWEB)

    Sakakibara, T; Sato, K [Nihon Univ., Tokyo. School of Medicine; Watari, T; Tanaka, T; Furuta, A

    1981-07-01

    Domperidone was administered to 95 patients with radiation sickness following radiotherapy for various cancers. The chest and the mediastinum were irradiated in 43 patients, the upper and lower abdomen in 40 patients, and the head, neck, and supraclavicular region in 12 patients. As to radiation source, x-ray was used for 46 patients, ..gamma..-ray for 41 patients, electron beam for 3 patients, and more than one radiation was used for 5 patients. The dose given before the onset of radiation sickness totaled 3000 rad in 20 patients, 1000 rad -- 3000 rad in 41, and less than 1000 rad in 34. Domperidone was given to the patients one tablet (5 mg or 10 mg) P.O., 3 times per day before meals, for 1 -- 2 weeks. The overall effective rate of the drug was 68.4%. The 10 mg tablets were slightly more effective than the 5 mg ones. In the patients who were given the drug in a dose of 10 mg, the ameliorating rate of subjective symptoms was 68.1% for nausea, 88.9% for vomiting, 44.6% for anorexia, 17.5% for general fatigue, and 69.2% for dizziness. Laboratory findings showed no abnormal effects of the drug. One patient had itching with eruptions, which, however, was mild and disappeared immediately after withdrawal of the medication.

  20. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  1. Effectiveness of a Fundamental Motor Skill Intervention for 4-Year-Old Children with Autism Spectrum Disorder: A Pilot Study

    Science.gov (United States)

    Bremer, Emily; Balogh, Robert; Lloyd, Meghann

    2015-01-01

    A wait-list control experimental design was employed to investigate the effectiveness of a fundamental motor skill intervention at improving the motor skills, adaptive behavior, and social skills of 4-year-old children with autism spectrum disorder (experimental n?=?5, control n?=?4); the impact of intervention intensity was also explored. The…

  2. Radiation doses and possible radiation effects of low-level, chronic radiation in vegetation

    International Nuclear Information System (INIS)

    Rhoads, W.A.; Franks, L.A.

    1975-01-01

    Measurements were made of radiation doses in soil and vegetation in Pu-contaminated areas at the Nevada Test Site with the objective of investigating low-level, low-energy gamma radiation (with some beta radiation) effects at the cytological or morphological level in native shrubs. In this preliminary investigation, the exposure doses to shrubs at the approximate height of stem apical meristems were estimated from 35 to 140 R for a ten-year period. The gamma exposure dose estimated for the same period was 20.7 percent +- 6.4 percent of that recorded by the dosimeters used in several kinds of field instrument surveys. Hence, a survey instrument reading made at about 25 cm in the tops of shrubs should indicate about 1 / 5 the dosimeter-measured exposures. No cytology has yet been undertaken because of the drought since last winter. (auth)

  3. Radiation effects in mammalian cells in vitro

    International Nuclear Information System (INIS)

    Hill, C.K.; Han, A.; Elkind, M.M.; Wells, R.L.; Buess, E.M.; Lin, C.M.

    1985-01-01

    The purpose of this research effort is to elucidate the mechanisms for the radiation-induced changes in mammalian cells that lead to cell death, mutation, neoplastic transformation, DNA damage, and chromosomal alterations. Of particular interest are the effects of low-dose-rate and fractionated irradiation on these end points with respect to the mechanisms whereby these effects are influenced by cellular repair processes, inhibitors, and promoters that act at the genetic or biochemical level. 17 refs

  4. Effects of UV-B radiation on wax biosynthesis

    International Nuclear Information System (INIS)

    Barnes, J.; Paul, N.; Percy, K.; Broadbent, P.; McLaughlin, C.; Mullineaux, P.; Creissen, G.; Wellburn, A.

    1994-01-01

    Two genotypes of tobacco (Nicotiana tabacum L.) were exposed in controlled environment chambers to three levels of biologically effective ultraviolet-B radiation (UV-B BE ; 280-320nm): 0, 4.54 (ambient) and 5.66 (∼ 25% enhancement) kJ m -2 d -1 . After 28 days, the quantity of wax deposited on leaf surfaces was determined gravimetrically; epicuticular wax chemical composition was determined by capillary gas chromatography with homologue assignments confirmed by gas chromatography-mass spectrometry. Leaf wettability was assessed by measuring the contact angle of water droplets placed on leaf surfaces. Tobacco wax consisted of three major hydrocarbon classes: Straight-chain alkanes (C 27 -C 33 ) which comprised ∼ 59% of the hydrocarbon fraction, containing a predominance of odd-chain alkanes with C 31 as the most abundant homologue; branched-chain alkanes (C 25 -C 32 ) which comprised ∼38% of the hydrocarbon fraction with anteiso 3-methyltriacontane (C 30 ) as the predominant homologue; and fatty acids (C 14 -C 18 ) which comprised ∼ 3% of the wax. Exposure to enhanced UV-B radiation reduced the quantity of wax on the adaxial surface of the transgenic mutant, and resulted in marked changes in the chemical composition of the wax on the exposed leaf surface. Enhanced UV-B decreased the quantity of straight-chain alkanes, increased the quantity of branched-chain alkanes and fatty acids, and resulted in shifts toward shorter straight-chain lengths. Furthermore, UV-B-induced changes in wax composition were associated with increased wettability of tobacco leaf surfaces. Overall, the data are consistent with the view that UV-B radiation has a direct and fundamental effect on wax biosynthesis. Relationships between the physico-chemical nature of the leaf surface and sensitivity to UV-B radiation are discussed. (orig.)

  5. Exploring gamma radiation effect on exoelectron emission properties of bone

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V. [Riga Technical Univ., Biomedical Engineering and Nanotechnology Institute (Latvia)

    2006-07-01

    Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

  6. Exploring gamma radiation effect on exoelectron emission properties of bone

    International Nuclear Information System (INIS)

    Zakaria, M.; Dekhtyar, Y.; Bogucharska, T.; Noskov, V.

    2006-01-01

    Gamma radiation is used for radiation therapy to treat carcinogenic diseases including bone cancer. Ionising radiation kills carcinogenic calls. However, there are side effects of the gamma radiation on the bone surface electron structure. One of the effects is in the form of altering electron density of states of bone that, with time, influences biomedical reactions on bone life condition. (authors)

  7. Fundamental Astronomy

    CERN Document Server

    Karttunen, Hannu; Oja, Heikki; Poutanen, Markku; Donner, Karl Johan

    2007-01-01

    Fundamental Astronomy gives a well-balanced and comprehensive introduction to the topics of classical and modern astronomy. While emphasizing both the astronomical concepts and the underlying physical principles, the text provides a sound basis for more profound studies in the astronomical sciences. The fifth edition of this successful undergraduate textbook has been extensively modernized and extended in the parts dealing with the Milky Way, extragalactic astronomy and cosmology as well as with extrasolar planets and the solar system (as a consequence of recent results from satellite missions and the new definition by the International Astronomical Union of planets, dwarf planets and small solar-system bodies). Furthermore a new chapter on astrobiology has been added. Long considered a standard text for physical science majors, Fundamental Astronomy is also an excellent reference and entrée for dedicated amateur astronomers.

  8. Proceedings of the workshop on 'effect of radiation on non-human biota'

    International Nuclear Information System (INIS)

    Takahashi, Sentaro; Takahashi, Tomoyuki

    2011-03-01

    Safety assessment and protection for the radiation exposure were so far mainly based on the radiation effects on human health, because it has been generally recognized that, when human beings are protected, other environmental life, at least in the level of species or groups, will be protected from the radiation hazards, even if individuals may be affected. Recently, with increasing concern on environmental protection, a new framework of radiation protection has been proposed, where non-human biota as well as human beings is included. Researches on the environmental radiation protection need a contribution of multi-disciplinary researchers as similar to the other environmental sciences. Especially, a research field on the biological effect of radiation on non-human biota is fundamental and essential. Therefore, we planned the Workshop entitled Effect of Radiation on the Non-human Biota this time. All the 13 papers presented at the entitled meeting are indexed individually. (J.P.N.)

  9. Radiation effect on PVC/ENR blends

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan

    1997-01-01

    The effect of irradiation on the physical properties of Polyvinyl Chloride / Epoxidised Natural Rubber Blends (PVC/ENR blends) were investigated. The enhancement in tensile strength, elongation at break, hardness and aging properties of the blends have confirmed the positive effect of irradiation on the blends. It is evident from gel fraction and infra red spectroscopic studies that the blends of PVC and ENR cross-linked upon irradiation. The results also revealed that at any blend composition, the enhancement in properties depend on irradiation dose which controls the degree of radiation induced cross-linking. In an attempt to maximize the constructive effect of irradiation, the influence of various additives such as stabilizers, radiation sensitizers, fillers and processing aids on the blend properties were studied. The changes in blend properties upon irradiation with the presents of above additives were also presented in this paper

  10. Effects of Scattering of Radiation on Wormholes

    Directory of Open Access Journals (Sweden)

    Alexander Kirillov

    2018-02-01

    Full Text Available Significant progress in the development of observational techniques gives us the hope to directly observe cosmological wormholes. We have collected basic effects produced by the scattering of radiation on wormholes, which can be used in observations. These are the additional topological damping of cosmic rays, the generation of a diffuse background around any discrete source, the generation of an interference picture, and distortion of the cosmic microwave background (CMB spectrum. It turns out that wormholes in the leading order mimic perfectly analogous effects of the scattering of radiation on the standard matter (dust, hot electron gas, etc.. However, in higher orders, a small difference appears, which allows for disentangling effects of wormholes and ordinary matter.

  11. Neurophysiological appropriateness of ionizing radiation effects

    International Nuclear Information System (INIS)

    Nyagu, A.I.; Loganovsky, K.N.

    1997-01-01

    The goal of this study was to compare bioelectrical activity of the brain in remote period of acute radiation sickness (ARS), chronic and prenatal irradiation as a result of the Chernobyl disaster. Registration of computerized 19-channel EEG, visual and somato-sensory evoked potentials have been carried out for 70 patients who had a verified ARS, 100 Chernobyl disaster survivors, who have been working in the Chernobyl exclusion zone since 1986-87 during 5 and more years, 50 prenatally irradiated children, and relevant controls. The relative risks of neurophysiological abnormalities are 4.5 for the ARS-patients, 3.6 for the chronically irradiated persons and 3.7 for the prenatally irradiated children. The data obtained testify to possibility of radiation-induced neurophysiological abnormalities in examined Chernobyl accident survivors which seems to be non-stochastic effects of ionizing radiation. For all examined irradiated patients it was typically an increasing of δ- and β- powers of EEG, particularly, in the frontal lobe shifted to the left fronto-temporal region, but spectral power of both θ- and α-range was significantly depressed. Aforesaid signs together with data of evoked potentials reflect the structural and functional abnormalities of limbic system and the left hemisphere as the first revealed neurophysiological appropriateness of ionizing radiation effects. (author)

  12. Neurophysiological appropriateness of ionizing radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Nyagu, A I; Loganovsky, K N [Department of Neurology, Inst. of Clinical Radiology, Scientific Centre for Radiation Medicine of Academy of Medical Sciences of Ukraine, Kiev (Ukraine)

    1997-11-01

    The goal of this study was to compare bioelectrical activity of the brain in remote period of acute radiation sickness (ARS), chronic and prenatal irradiation as a result of the Chernobyl disaster. Registration of computerized 19-channel EEG, visual and somato-sensory evoked potentials have been carried out for 70 patients who had a verified ARS, 100 Chernobyl disaster survivors, who have been working in the Chernobyl exclusion zone since 1986-87 during 5 and more years, 50 prenatally irradiated children, and relevant controls. The relative risks of neurophysiological abnormalities are 4.5 for the ARS-patients, 3.6 for the chronically irradiated persons and 3.7 for the prenatally irradiated children. The data obtained testify to possibility of radiation-induced neurophysiological abnormalities in examined Chernobyl accident survivors which seems to be non-stochastic effects of ionizing radiation. For all examined irradiated patients it was typically an increasing of {delta}- and {beta}- powers of EEG, particularly, in the frontal lobe shifted to the left fronto-temporal region, but spectral power of both {theta}- and {alpha}-range was significantly depressed. Aforesaid signs together with data of evoked potentials reflect the structural and functional abnormalities of limbic system and the left hemisphere as the first revealed neurophysiological appropriateness of ionizing radiation effects. (author). 25 refs.

  13. Ultraviolet radiation and its biological effects

    International Nuclear Information System (INIS)

    Rames, J.; Bencko, V.

    1993-01-01

    In connexion with contamination of the atmosphere with freons, the interest is increasing in geophysical and health aspects of 'ozone holes' - the seasonal incidence of increased intensity of UV radiation. Its biological effects depend on the intensity of the radiation, the exposure time and the wavelength. There is a wide range of various sorts of damage, local as well as general. In addition to skin pigmentation and symptoms produced by an elevated histamine blood level, also changes are found which may have more serious and permanent consequences: changes in the number and structure of Langerhans islets, changes of the peripheral capillary walls, dimerization of pyrimidine and thymine in DNA. These changes demonstrably contribute to the development of skin malignancies. After exposure of the eye, changes in pigmentation are found, and depending on the dose, possibly also development of conjunctivitis or retinal damage. Recently the interaction of UV radiation with arsenic was investigated. On the other side, therapeutic effects of UV radiation combined with chemotherapy are used in dermatology, eg., for inhibition of contact sensitization. (author) 42 refs

  14. Effect of ionizing radiation on cardiovascular system

    International Nuclear Information System (INIS)

    Milliat, F.; Benderitter, M.; Gaugler, M.H.

    2011-01-01

    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)

  15. The effects of radiation on electronic systems

    International Nuclear Information System (INIS)

    Messenger, G.C.; Ash, M.S.

    1986-01-01

    This book is the first unified treatment of the analysis and design methods for protection of principally electronic systems from the deleterious effects of nuclear and electro-magnetic radiation. Coverage spans from a detailed description of the nuclear radiation sources to pertinent semiconductor physics, then to hardness assurance. This work combines the disciplines of solid state physics, semiconductor physics, circuit engineering, nuclear physics, together with electronics and electromagnetic theory into a book that can be used as a text with problems at the end of the majority of the chapters. Written by veterans in the field, the most significant feature of this book is its comprehensive treatment of the phenomena involved. This treatment includes the analysis and design of the effect of nuclear radiation on electronic systems from the experimental, theoretical, and engineering viewpoints. Unique pedagogical attempts are employed to make the material more understandable from the position of an enlightened engineering and scientific readership whose task is the design and analysis of radiation hardened electronic systems

  16. Radiation effects on two-dimensional materials

    Energy Technology Data Exchange (ETDEWEB)

    Walker, R.C. II; Robinson, J.A. [Department of Materials Science, Penn State, University Park, PA (United States); Center for Two-Dimensional Layered Materials, Penn State, University Park, PA (United States); Shi, T. [Department of Mechanical and Nuclear Engineering, Penn State, University Park, PA (United States); Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI (United States); Silva, E.C. [GlobalFoundries, Malta, NY (United States); Jovanovic, I. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI (United States)

    2016-12-15

    The effects of electromagnetic and particle irradiation on two-dimensional materials (2DMs) are discussed in this review. Radiation creates defects that impact the structure and electronic performance of materials. Determining the impact of these defects is important for developing 2DM-based devices for use in high-radiation environments, such as space or nuclear reactors. As such, most experimental studies have been focused on determining total ionizing dose damage to 2DMs and devices. Total dose experiments using X-rays, gamma rays, electrons, protons, and heavy ions are summarized in this review. We briefly discuss the possibility of investigating single event effects in 2DMs based on initial ion beam irradiation experiments and the development of 2DM-based integrated circuits. Additionally, beneficial uses of irradiation such as ion implantation to dope materials or electron-beam and helium-beam etching to shape materials have begun to be used on 2DMs and are reviewed as well. For non-ionizing radiation, such as low-energy photons, we review the literature on 2DM-based photo-detection from terahertz to UV. The majority of photo-detecting devices operate in the visible and UV range, and for this reason they are the focus of this review. However, we review the progress in developing 2DMs for detecting infrared and terahertz radiation. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Controlling of degradation effects in radiation processing of polymers. Second RCM report

    International Nuclear Information System (INIS)

    2005-08-01

    The research and development works carried out by the participants of the CRP (Coordinated Research Project) dealt with natural polymers, synthetic polymers and new techniques for better understanding of radiation degradation of polymers. It includes progress in radiation degradation of polysaccharides from agricultural products (including sodium alginate, carrageenans, chitosan and gum acacia); use of radiation-degradation for doping of conductive polymers; controlling degradation processes in artificial joint implants, surface treatment of materials and food packaging; stabilizer additives for radiation environments; surface treatment of materials; and application of specialized analytical techniques (positron annihilation spectroscopy, ESR, RBS, ERDA, NMR/isotopic-labeling) to gain improved understanding of radiation degradation effects and mechanisms. Projects within the RCM group span the spectrum from fundamental studies through specific technological applications. Participants from Czech Republic, Spain and Turkey benefited from scientific collaboration with Bulgaria on PAS

  18. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  19. Literature survey: health effects of radiation

    International Nuclear Information System (INIS)

    Tveten, U.; Garder, K.

    This report was originally written as a chapter of a report entitled 'Air pollution effects of electric power generation, a literature survey', written jointly by the Norwegian Institute for Air Research (NILU) and the Institutt for Atomenergi (IFA). (INIS RN242406). A survey is presented of the health effects of radiation. It has not, however, been the intention of the authors to make a complete list of all the literature relevant to this subject. The NILU/IFA report was meant as a first step towards a method of comparing the health effects of electric power generation by fission, gas and oil. Consequently information relevant to quantification of the health effects on humans has been selected. It is pointed out that quantitative information on the health effects of low radiation and dose rates, as are relevant to routine releases, does not exist for humans. The convention of linear extrapolation from higher doses and dose rates is used worldwide, but it is felt by most that the estimates are conservative. As an example of the use of the current best estimates, a calculation of normal release radiation doses is performed. (Auth.)

  20. Narrowing the Gap in Quantification of Aerosol-Cloud Radiative Effects

    Science.gov (United States)

    Feingold, G.; McComiskey, A. C.; Yamaguchi, T.; Kazil, J.; Johnson, J. S.; Carslaw, K. S.

    2016-12-01

    Despite large advances in our understanding of aerosol and cloud processes over the past years, uncertainty in the aerosol-cloud radiative effect/forcing is still of major concern. In this talk we will advocate a methodology for quantifying the aerosol-cloud radiative effect that considers the primacy of fundamental cloud properties such as cloud amount and albedo alongside the need for process level understanding of aerosol-cloud interactions. We will present a framework for quantifying the aerosol-cloud radiative effect, regime-by-regime, through process-based modelling and observations at the large eddy scale. We will argue that understanding the co-variability between meteorological and aerosol drivers of the radiative properties of the cloud system may be as important an endeavour as attempting to untangle these drivers.

  1. Radiation effects in semiconductor laser diode arrays

    International Nuclear Information System (INIS)

    Carson, R.F.

    1988-01-01

    The effects of radiation events are important for many of the present and future applications that involve optoelectronic components. Laser diodes show a strong resistance to degradation by gamma rays, prompt x-rays and (to a lesser extent), neutrons. This is due to the short carrier lifetime that is associated with stimulated emission and the high current injection conditions that are present in these devices. Radiation-resistant properties should carry over to many of the more recently developed devices such as multi-stripe array and broad area laser diodes. There are, however, additional considerations for radiation tolerance that are introduced by these devices. Arrays and other high power laser diodes have larger active region volumes than lower power single stripe devices. In addition, evanescent field coupling between stripes, the material quality available from newer MOCVD epitaxial growth techniques, and stripe definition methods may all influence the radiation tolerance of the high power laser diode devices. Radiation tests have been conducted on various GaAs-GaAlAs laser diode array and broad area devices. Tests involving total gamma dose have indicated that high power laser diodes and arrays have small degradations in light power output with current input after 4 MRad(Si) of radiation from a Co 60 source. Additional test results involving flash x-rays indicate that high power diode lasers and arrays are tolerant to 10 12 rads(Si)/sec, when observed on microsecond or millisecond time scales. High power diode laser devices were also irradiated with neutrons to a fluence of 10 14 neutrons/cm 2 with some degradation of threshold current level

  2. Radiation Quality Effects on Transcriptome Profiles in 3-D Cultures After Charged Particle Irradiation

    Science.gov (United States)

    Patel, Zarana S.; Kidane, Yared H.; Huff, Janice L.

    2014-01-01

    In this work, we evaluated the differential effects of low- and high-LET radiation on 3-D organotypic cultures in order to investigate radiation quality impacts on gene expression and cellular responses. Current risk models for assessment of space radiation-induced cancer have large uncertainties because the models for adverse health effects following radiation exposure are founded on epidemiological analyses of human populations exposed to low-LET radiation. Reducing these uncertainties requires new knowledge on the fundamental differences in biological responses (the so-called radiation quality effects) triggered by heavy ion particle radiation versus low-LET radiation associated with Earth-based exposures. In order to better quantify these radiation quality effects in biological systems, we are utilizing novel 3-D organotypic human tissue models for space radiation research. These models hold promise for risk assessment as they provide a format for study of human cells within a realistic tissue framework, thereby bridging the gap between 2-D monolayer culture and animal models for risk extrapolation to humans. To identify biological pathway signatures unique to heavy ion particle exposure, functional gene set enrichment analysis (GSEA) was used with whole transcriptome profiling. GSEA has been used extensively as a method to garner biological information in a variety of model systems but has not been commonly used to analyze radiation effects. It is a powerful approach for assessing the functional significance of radiation quality-dependent changes from datasets where the changes are subtle but broad, and where single gene based analysis using rankings of fold-change may not reveal important biological information.

  3. Radiation effects on man health, environment, safety, security. Global Chernobyl mapping

    International Nuclear Information System (INIS)

    Bebeshko, V.; Bazyka, D.; Volovik, S.; Loganovsky, K.; Sushko, V.; Siedow, J.; Cohen, H.; Ginsburg, G.; Chao, N.; Chute, J.

    2007-01-01

    Complete text of publication follows. Objectives: Ionizing radiation is a primordial terrestrial and extraterrestrial background and archetypal environmental stress-factor for life origin, evolution, and existence. We all live in radiation world inevitably involving nuclear energy production, nuclear weapon, nuclear navy, radioactive waste, pertinent medical diagnostics and treatment, etc with connected certain probability of relevant accidents and terrorist attack, space and jet travels, high natural background radiation, etc - actual and potential sources of radiation exposures and effects. State-of- the art integral fundamental research on radiation effects on man health, environment, safety, and security (REMHESS) is nowadays paramount necessity and challenge. Methods and results: In given generalized conceptual framework unique 20 years Chernobyl multidimensional research and databases for radiation effects on man's all organism systems represent invaluable original basis and resources for mapping Chernobyl data and REMHESS challenge. Granted by DOE brand new Chernobyl Research and Service Project based on 'Sarcophagus-II' (Object 'Shelter') workers only one in radiation history baseline cohort, corresponding biorepository prospective dynamic data, integrated conceptual database system, and 'state of the art' 'omics' (genomics, proteomics, metabolomics) analysis is designed specifically for coherent addressing global REMHESS problems. In this connection 'Sarcophagus-II' is only one unique universal model. Conclusions: The fundamental goals of novel strategic Project and global Chernobyl mapping are to determine specific 'omics' signatures of radiation for man depending of exposure peculiarity to understand ultimate molecular mechanisms of radiation effects, gene environment interactions, etiology of organisms systems disorders and diseases, and to develop new biomarkers and countermeasures to protect man health in the framework of global REMHESS challenge

  4. Lock-in effects in competitive bidding schemes for payments for ecosystem services: Revisiting the fundamental transformation

    OpenAIRE

    Vogt, Nora; Bizer, Kilian

    2013-01-01

    Competitive bidding is considered to be a cost-effective allocation mechanism for payments for ecosystem services. This article shows that competition is not a necessary condition for sustaining cost-effectiveness in the long run. In a repeated conservation auction, learning, specific investments and the creation of social capital bias the chances of winning a follow-up contract in favour of former auction winners. Applying the concept of fundamental transformation (Williamson 1985), we argue...

  5. Radiation effects in IRAS extrinsic infrared detectors

    Science.gov (United States)

    Varnell, L.; Langford, D. E.

    1982-01-01

    During the calibration and testing of the Infrared Astronomy Satellite (IRAS) focal plane, it was observed that the extrinsic photoconductor detectors were affected by gamma radiation at dose levels of the order of one rad. Since the flight environment will subject the focal plane to dose levels of this order from protons in single pass through the South Atlantic Anomaly, an extensive program of radiation tests was carried out to measure the radiation effects and to devise a method to counteract these effects. The effects observed after irradiation are increased responsivity, noise, and rate of spiking of the detectors after gamma-ray doses of less than 0.1 rad. The detectors can be returned almost to pre-irradiation performance by increasing the detector bias to breakdown and allowing a large current to flow for several minutes. No adverse effects on the detectors have been observed from this bias boost, and this technique will be used for IRAS with frequent calibration to ensure the accuracy of observations made with the instrument.

  6. EFFECT OF “FIFA 11+” ON THE PATTERN OF FUNDAMENTAL MOVEMENTS IN UNDER-14 SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Gerald Baeza

    Full Text Available ABSTRACT Introduction: Increasing youth participation in soccer has several benefits, but it also brings risks of injury. The use of neuromuscular techniques is effective in preventing injuries, especially in periods of growth as occurs in puberty, which coincides with the development of fundamental basic movements. Therefore, it is important to implement and evaluate prevention programs that focus on neuromuscular control during this stage. Objective: To determine the effect of the FIFA 11+ over a six-week training period in order to quickly improve fundamental movement patterns in under-14 soccer players. Method: A quasi-experimental study that evaluated the fundamental movement patterns through the Functional Movement Screen (FMS in 22 athletes who were divided into a control group (CG; N=11 and an experimental group (EG; N=11, submitted to the program FIFA 11+ for six weeks. The SPSS 20.0 program was used to analyze the data. Results: Statistically significant improvements were found in the in-line lunge (IL and in the post-intervention FMS total scores in EG, as well as intergroup improvements when testing the deep squat (DS in the EG, but not in both groups. Conclusions: The six week FIFA 11+ program did not produce significant improvements in players’ fundamental movements.

  7. Skill-Based and Planned Active Play Versus Free-Play Effects on Fundamental Movement Skills in Preschoolers.

    Science.gov (United States)

    Roach, Lindsay; Keats, Melanie

    2018-01-01

    Fundamental movement skill interventions are important for promoting physical activity, but the optimal intervention model for preschool children remains unclear. We compared two 8-week interventions, a structured skill-station and a planned active play approach, to a free-play control condition on pre- and postintervention fundamental movement skills. We also collected data regarding program attendance and perceived enjoyment. We found a significant interaction effect between intervention type and time. A Tukey honest significant difference analysis supported a positive intervention effect showing a significant difference between both interventions and the free-play control condition. There was a significant between-group difference in group attendance such that mean attendance was higher for both the free-play and planned active play groups relative to the structured skill-based approach. There were no differences in attendance between free-play and planned active play groups, and there were no differences in enjoyment ratings between the two intervention groups. In sum, while both interventions led to improved fundamental movement skills, the active play approach offered several logistical advantages. Although these findings should be replicated, they can guide feasible and sustainable fundamental movement skill programs within day care settings.

  8. Clarifying the paradigm on radiator effects and safety management: unscear report on attribution on effects and inference of risks

    International Nuclear Information System (INIS)

    Gonzaelez, Abel J.

    2014-01-01

    The aim of this paper is to describe a relatively recent international agreement on the widely debated concepts of: (i) attributing effects to low dose radiation exposure situations that have occurred in the past and, (ii) inferring radiation risk to situations that are planned to occur in the future. An important global consensus has been recently achieved on these fundamental issues at the level of the highest international intergovernmental body: the General Assembly of the United Nations. The General Assembly has welcomed with appreciation a scientific report on attributing health effects to radiation exposure and inferring risks that had been prepared the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) following a formal request by the General Assembly.

  9. Simulation of first-wall radiation effects

    International Nuclear Information System (INIS)

    Logan, C.M.; Anderson, J.D.; Hansen, L.F.

    1975-01-01

    Many of the effects induced in metals as a result of exposure to a radiation environment are intimately associated with the energy of primary recoil atoms (PKAs). Protons with an energy of 16 MeV closely reproduce the PKA energy spectrum which will be present at the first wall in a D--T fusion reactor and should therefore closely reproduce the radiation effects induced by PKAs in the first wall. A preliminary experiment with protons was conducted to measure the sputtering rate and to look for the phenomenon of chunk emission recently observed by Kaminsky and co-workers in samples exposed to 14-MeV neutrons. We are also able to observe the average projected transport range of activated PKAs. (U.S.)

  10. Thermal radiation effects on hydromagnetic flow

    International Nuclear Information System (INIS)

    Abdelkhalek, M.M.

    2005-01-01

    Numerical results are presented for the effects of thermal radiation, buoyancy and heat generation or absorption on hydromagnetic flow over an accelerating permeable surface. These results are obtained by solving the coupled nonlinear partial differential equations describing the conservation of mass, momentum and energy by a perturbation technique. This qualitatively agrees with the expectations, since the magnetic field exerts a retarding force on the free convection flow. A parametric study is performed to illustrate the influence of the radiation parameter, magnetic parameter, Prandtl number, Grashof number and Schmidt number on the profiles of the velocity components and temperature. The effects of the different parameters on the velocity and temperature profiles as well as the skin friction and wall heat transfer are presented graphically. Favorable comparisons with previously published work confirm the correctness of numerical results

  11. Effect of laser radiation on rat radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Laprun, I.B.

    1979-03-01

    Quite a few experimental data have been obtained to date indicating that radioresistance of the organism is enhanced under the influence of electromagnetic emissions in the radiofrequency and optical ranges. But no studies were made of the possible radioprotective properties of coherent laser radiation. At the same time, it was demonstrated that the low-energy emission of optical quantum generators (lasers) in the red band stimulates the protective forces of the organism and accelerates regenerative processes; i.e., it induces effects that are the opposite of that of ionizing radiation. Moreover, it was recently demonstrated that there is activation of catalase, a radiosensitive enzyme that plays an important role in the metabolism of peroxide compounds, under the influence of lasers. For this reason, the effect of pre-exposure to laser beams on radiosensitivity of rats was tested.

  12. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russel, L.B.

    1979-01-01

    Interactions of chemicals and radiation are complex and there may exist other unexpected patterns that are not mentioned. We show some examples. Photodynamic mutation induction by fluorescein dyes and Radiosensitization with iodine compounds are classified as Interactions of chemicals and radiation outside of the cell. On the other hand, the Antimutagenic effects of cobaltous chloride is concerned with events taking place in cells that had already been exposed to a mutagenic agent. It is likely that the action of a mutagenic agent is not direct and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agent. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, the two agents can also act on separate cells (male and female germcells) which subsequently fuse. Interaction effects of all types will be useful in future research in shedding light on the main pathways of mutagenesis

  13. Radiation Effects in the Space Telecommunications Environment

    International Nuclear Information System (INIS)

    Fleetwood, Daniel M.; Winokur, Peter S.

    1999-01-01

    Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space

  14. Radiation Effects in the Space Telecommunications Environment

    Energy Technology Data Exchange (ETDEWEB)

    Fleetwood, Daniel M.; Winokur, Peter S.

    1999-05-17

    Trapped protons and electrons in the Earth's radiation belts and cosmic rays present significant challenges for electronics that must operate reliably in the natural space environment. Single event effects (SEE) can lead to sudden device or system failure, and total dose effects can reduce the lifetime of a telecommmiications system with significant space assets. One of the greatest sources of uncertainty in developing radiation requirements for a space system is accounting for the small but finite probability that the system will be exposed to a massive solar particle event. Once specifications are decided, standard laboratory tests are available to predict the total dose response of MOS and bipolar components in space, but SEE testing of components can be more challenging. Prospects are discussed for device modeling and for the use of standard commercial electronics in space.

  15. Marketing fundamentals.

    Science.gov (United States)

    Redmond, W H

    2001-01-01

    This chapter outlines current marketing practice from a managerial perspective. The role of marketing within an organization is discussed in relation to efficiency and adaptation to changing environments. Fundamental terms and concepts are presented in an applied context. The implementation of marketing plans is organized around the four P's of marketing: product (or service), promotion (including advertising), place of delivery, and pricing. These are the tools with which marketers seek to better serve their clients and form the basis for competing with other organizations. Basic concepts of strategic relationship management are outlined. Lastly, alternate viewpoints on the role of advertising in healthcare markets are examined.

  16. Radiation effects on algae and its application

    International Nuclear Information System (INIS)

    Dwivedi, Rakesh Kumar

    2013-01-01

    The effects of radiation on algae have been summarized in this article. Today, algae are being considered to have the great potential to fulfill the demand of food, fodder, fuel and various pharmaceutical products. Red algae are particularly rich in the content of polysaccharides present in their cell wall. For isolation of these polysaccharides, separation of cells cemented together by middle lamella is essential. The gamma rays are known to bring about biochemical changes in the cell wall and cause the breakdown of the middle lamella. These rays ate also known to speed up the starch sugar inter-conversion in the cells which is very useful for the tapping the potential of algae to be used as biofuel as well as in pharmaceutical industries. Cyanobacteria, among algae and other plants are more resistant to the radiation. In some cyanobacteria the radiation treatment is known to enhance the resistance against the antibiotics. Radiation treatment is also known to enhance the diameter of cell and size of the nitrogen fixing heterocyst. (author)

  17. Effect of γ-radiation on the saccharification of cellulose

    International Nuclear Information System (INIS)

    De la Rosa, A.M.; Banzon, R.B.; Abad, L.V.; Nuguid, Z.F.; Bulos, A.S.

    1985-01-01

    The effect of gamma radiation on the acid and saccharification of agricultural cellulosic wastes was investigated. Radiation doses of 200 KGy and higher significantly increased the saccharification of rice straw, rice hull and corn husk. The observed radiation effects varied with the cellulosic material. Rice straw exhibited the greatest radiosensitivity while rice hull showed the least susceptibility to gamma radiation. Possible mechanisms for the radiation-induced degradation of cellulose and agricultural cellulosic wastes are discussed. (author)

  18. Advanced CMOS Radiation Effects Testing and Analysis

    Science.gov (United States)

    Pellish, J. A.; Marshall, P. W.; Rodbell, K. P.; Gordon, M. S.; LaBel, K. A.; Schwank, J. R.; Dodds, N. A.; Castaneda, C. M.; Berg, M. D.; Kim, H. S.; hide

    2014-01-01

    Presentation at the annual NASA Electronic Parts and Packaging (NEPP) Program Electronic Technology Workshop (ETW). The material includes an update of progress in this NEPP task area over the past year, which includes testing, evaluation, and analysis of radiation effects data on the IBM 32 nm silicon-on-insulator (SOI) complementary metal oxide semiconductor (CMOS) process. The testing was conducted using test vehicles supplied by directly by IBM.

  19. Transistor Small Signal Analysis under Radiation Effects

    International Nuclear Information System (INIS)

    Sharshar, K.A.A.

    2004-01-01

    A Small signal transistor parameters dedicate the operation of bipolar transistor before and after exposed to gamma radiation (1 Mrad up to 5 Mrads) and electron beam(1 MeV, 25 mA) with the same doses as a radiation sources, the electrical parameters of the device are changed. The circuit Model has been discussed.Parameters, such as internal emitter resistance (re), internal base resistance, internal collector resistance (re), emitter base photocurrent (Ippe) and base collector photocurrent (Ippe). These parameters affect on the operation of the device in its applications, which work as an effective element, such as current gain (hFE≡β)degradation it's and effective parameter in the device operation. Also the leakage currents (IcBO) and (IEBO) are most important parameters, Which increased with radiation doses. Theoretical representation of the change in the equivalent circuit for NPN and PNP bipolar transistor were discussed, the input and output parameters of the two types were discussed due to the change in small signal input resistance of the two types. The emitter resistance(re) were changed by the effect of gamma and electron beam irradiation, which makes a change in the role of matching impedances between transistor stages. Also the transistor stability factors S(Ico), S(VBE) and S(β are detected to indicate the transistor operations after exposed to radiation fields. In low doses the gain stability is modified due to recombination of induced charge generated during device fabrication. Also the load resistance values are connected to compensate the effect

  20. Radiation protection standards: a summary of the biological effects of ionising radiation and principles of radiation protection

    International Nuclear Information System (INIS)

    1994-01-01

    This leaflet in the NRPB At-a-Glance-Series briefly summarises the biological effects of radiation, harm and sensitivity to radiation, radiation protection principles, acceptability of risk and the control of doses to workers, the public and in medical procedures in the UK. (UK)

  1. Radiation-induced bystander effects and the DNA paradigm: An 'out of field' perspective

    International Nuclear Information System (INIS)

    Mothersill, Carmel; Seymour, C.B.

    2006-01-01

    Over the past 20 years there has been increasing evidence that cells and the progeny of cells surviving a very low dose of ionizing radiation [μ-mGy] can exhibit a wide range of non-monotonic effects such as adaptive responses, low dose hypersensitivity and other delayed effects. These effects are inconsistent with the expected dose-response, when based on extrapolation of high dose data and cast doubt on the reliability of extrapolating from high dose data to predict low dose effects. Recently the cause of many of these effects has been tentatively ascribed to so-called 'bystander effects'. These are effects that occur in cells not directly hit by an ionizing track but which are influenced by signals from irradiated cells and are thus highly relevant in situations where the dose is very low. Not all bystander effects may be deleterious although most endpoints measured involve cell damage or death. In this commentary, we consider how these effects impact the historical central dogma of radiobiology and radiation protection, which is that DNA double strand breaks are the primary radiation-induced lesion which can be quantifiably related to received dose and which determine the probability that a cancer will result from a radiation exposure. We explore the low dose issues and the evidence and conclude that in the very low dose region, the primary determinant of radiation exposure outcome is the genetic and epigenetic background of the individual and not solely the dose. What this does is to dissociate dose from effect as a quantitative relationship, but it does not necessarily mean that the effect is ultimately unrelated to DNA damage. The fundamental thesis we present is that at low doses fundamentally different mechanisms underlie radiation action and that at these doses, effect is not quantitatively related to dose

  2. Side Effects of Chemotherapy and Radiation (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Side Effects of Chemotherapy and Radiation KidsHealth / For Parents / Side Effects of Chemotherapy and Radiation What's in this article? What to ...

  3. Relative biological effectiveness and radiation weighting factors in the context of animals and plants

    International Nuclear Information System (INIS)

    Higley, K.A.; Kocher, D.C.; Real, A.G.; Chambers, D.B.

    2012-01-01

    Radiation weighting factors have long been employed to modify absorbed dose as part of the process of evaluating radiological impact to humans. Their use represents an acknowledgement of the fundamental difference in energy deposition patterns of charged and uncharged particles, and how this can translate into varying degrees of biological impact. Weighting factors used in human radiation protection are derived from a variety of endpoints taken from in-vitro experiments that include human and animal cell lines, as well as in-vivo experiments with animals. Nonetheless, the application of radiation weighting factors in the context of dose assessment of animals and plants is not without some controversy. Specifically, radiation protection of biota has largely focused on limiting deterministic effects, such as reduced reproductive fitness. Consequently, the application of conventional stochastic-based radiation weighting factors (when used for human protection) appears inappropriate. While based on research, radiation weighting factors represent the parsing of extensive laboratory studies on relative biological effectiveness. These studies demonstrate that the magnitude of a biological effect depends not just on dose, but also on other factors including the rate at which the dose is delivered, the type and energy of the radiation delivering the dose, and, most importantly, the endpoint under consideration. This article discusses the efforts taken to develop a logical, transparent, and defensible approach to establishing radiation weighting factors for use in assessing impact to non-human biota, and the challenges found in differentiating stochastic from deterministic impacts.

  4. Gamma radiation effects on nestling Tree Swallows

    International Nuclear Information System (INIS)

    Zach, R.; Mayoh, K.R.

    1984-01-01

    The sensitivity of Tree Swallows (Tachycineta bicolor) to the stress of ionizing radiation was investigated with growth analysis. Freshly hatched nestlings were temporarily removed from nests, taken to the laboratory and acutely exposed to 0.9, 2.7, or 4.5 Gy gamma radiation. Some of the unirradiated control nestlings were also taken to the laboratory whereas others were left in the nests. Growth of all the nestlings was measured daily and analyzed by fitting growth models. There was no detectable radiation-induced mortality up to fledgling, approx. = 20 d after irradiation. Radiation exposure did not affect the basic growth pattern; the logistic growth model was most suitable for body mass and foot length, and the von Bertalanffy model for primary-feather length, irrespective of treatment. Parameter values from these models indicated pronounced growth depression in the 2.7-Gy and 4.5-Gy groups, particularly for body mass. Radiation also affected the timing of development. The growth depression of the 2.7-Gy group was similar to that caused by hatching asynchrony in unirradiated nestlings. The 4.5-Cy nestlings grew as well as unexposed nestlings that died from natural causes. Chronic irradiation at approx. = 1.0 Cy/d caused more severe growth effects than acute exposure to 4.5 Gy and may have caused permanent stunting. Growth analysis is a potent tool for assessing man-made environmental stresses. Observed body-mass statistics and model parameters seem to be most sensitive to environmental stresses, but coefficients of variation are not necessarily correlated with sensitivity. 34 references, 2 figures, 4 tables

  5. UV radiation and its effects. Proceedings

    International Nuclear Information System (INIS)

    1993-01-01

    The National Science Strategy Committee for Climate Change was established in 1991 by the New Zealand Minister of Research, Science and Technology. It advises government through the Minister on research priorities and on levels of expenditure appropriate in various topics relating to climate change. An additional role is to promote coordination between research groups and the user communities to ensure an appropriate range of research strategies. To assist with implementing the latter aspects the NSS Committee will organise workshops on specific aspects of atmosphere and climate change, with a broad spectrum of participants. The first of these was the Workshop on UV Radiation and its Effects held in Christchurch on 20-21 May 1993. The workshop had 40 participants, including representatives from specialist science groups, medicine, veterinary science, farming, forestry and environmental groups. This publication will update the interested reader, whether scientist or lay-person, on the current state of knowledge on changing UV radiation levels and potential problems. As the summaries of papers show, research on ozone levels and on UV radiation and its effects is particularly appropriate for New Zealand scientists with their access to sites covering a wide range of latitudes from Antarctica to the Pacific Islands. New Zealand is part of an important international monitoring network, measuring local stratospheric ozone levels and related surface UV radiation levels. There are concerns about increasing UVB levels and the consequent effects on human health, plant and tree growth, and phytoplankton growth in the oceans. Priorities for further work on these areas are included in the summary of the workshop. (author). 13 figs.; 5 tabs

  6. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  7. Effects of Ionizing Radiation in Atopic Patients Exposed to Radiation

    International Nuclear Information System (INIS)

    Radwan, N.K.A.

    2014-01-01

    Atopic dermatitis is a chronic relapsing inflammatory skin disease that arises most commonly during early infancy, and is characterized by severe pruritus, age-dependant skin manifestations, and a fluctuating clinical course. Hereditary, environmental and immunological factors are involved in the aetiopathogenesis of AD. Also the differentiation of helper T- cells, local cytokine profile, IgE, infectious agents and superantigens are factors identified as being involved in the pathogenesis of AD. One hundred patients with AD were selected from the outpatient clinic of the National Center for Radiation Research and Technology in Cairo, Egypt. They were divided into 2 groups; group 1 included radiation workers in the Hall of gamma irradiation unit and group 2 included workers outside controlled area and not exposed to radiation with comparable age and sex. The severity of the disease was evaluated according to the grade of atopic dermatitis. Total and specific serum IgE was measured and Complete Blood Count was also carried out. Four Malassezia species were isolated from AD patients M. globosa, M. furfur, M. sympodialis and M. obtusa. The clinical isolates consisted of two bacterial strains, S. aureus and S. epidermidis. The significant increase of AD severity seems to be more closely related to the prevalence of S. aureus and Malassezia on the skin of radiation workers. This was proved by the presence of high IgE and eosinophils in radiation workers. So, the interactions of low gamma radiation and skin seems to further complicate the risk of assessments of atopic dermatitis

  8. Analytic approximate radiation effects due to Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi I.

    2012-02-01

    The purpose of this note is to provide analytic approximate expressions that can provide quick estimates of the various effects of the Bremsstrahlung radiation produced relatively low energy electrons, such as the dumping of the beam into the beam stop at the ERL or field emission in superconducting cavities. The purpose of this work is not to replace a dependable calculation or, better yet, a measurement under real conditions, but to provide a quick but approximate estimate for guidance purposes only. These effects include dose to personnel, ozone generation in the air volume exposed to the radiation, hydrogen generation in the beam dump water cooling system and radiation damage to near-by magnets. These expressions can be used for other purposes, but one should note that the electron beam energy range is limited. In these calculations the good range is from about 0.5 MeV to 10 MeV. To help in the application of this note, calculations are presented as a worked out example for the beam dump of the R&D Energy Recovery Linac.

  9. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russell, L.B.

    1979-01-01

    The interactions of chemicals and radiation are complex, and there may exist other unexpected patterns. The photodynamic induction of mutation by fluorescein dyes, and the radiosensitization with iodine compounds are classified as the interactions of chemicals and radiation outside cells. On the other hand, the antimutagenic effects of cobaltous chloride is concerned with the events taking place in the cells that had already been exposed to mutagenic agents. It is likely that the action of mutagenic agents is not direct, and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agents. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, two agents can also act on separate cells (male and female germ cells) which subsequently fuse. In mice, the experiments combining the radiation applied to one sex with the chemicals given to the other sex are only in early stages. Males were irradiated with X-ray (spermatozoa and spermatids sampled) and females (mature oocytes) were treated with caffeine. When the endpoint was dominant lethal, the level of X-ray effect induced in the male genome was independent of the caffeine treatment of the female. However, when the endpoint was sex-chromosome-loss, and a different strain of female was used, the caffeine potentiation was statistically significant at 5% level. (Yamashita, S.)

  10. Analytic approximate radiation effects due to Bremsstrahlung

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    2012-01-01

    The purpose of this note is to provide analytic approximate expressions that can provide quick estimates of the various effects of the Bremsstrahlung radiation produced relatively low energy electrons, such as the dumping of the beam into the beam stop at the ERL or field emission in superconducting cavities. The purpose of this work is not to replace a dependable calculation or, better yet, a measurement under real conditions, but to provide a quick but approximate estimate for guidance purposes only. These effects include dose to personnel, ozone generation in the air volume exposed to the radiation, hydrogen generation in the beam dump water cooling system and radiation damage to near-by magnets. These expressions can be used for other purposes, but one should note that the electron beam energy range is limited. In these calculations the good range is from about 0.5 MeV to 10 MeV. To help in the application of this note, calculations are presented as a worked out example for the beam dump of the R and D Energy Recovery Linac.

  11. Annual report of Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    1980-01-01

    The Radiation Effects Research Foundation was established in April, 1975, as a private nonprofit Japanese Foundation supported equally by the Government of Japan through the Ministry of Health and Welfare, and the Government of the United States through the National Academy of Sciences under contract with the Energy Research and Development Administration. First, the messages from the chairman and the vice-chairman are described. In the annual report, the review of ABCC-RERF studies of atomic bomb survivors, the summary of research activities, the research projects, the technical report abstracts, the research papers published in Japanese and foreign journals, and the oral presentation and lectures, all from April 1, 1978, to March 31, 1979, are reported. Also the report from the Secretariat and the appendixes are given. The surveys and researches carried out in Hiroshima and Nagasaki have offered very valuable informations to the atomic bomb survivors. Many fears were eliminated, medical interests were given to the serious effects of the exposure to atomic bombs, and many things concerning the cancer induced by radiation were elucidated. The knowledges obtained will save many human lives in future by utilizing them for setting up the health and safety standard in the case of handling ionizing radiation. The progress in researches such as life span study, adult health study, pathology study, genetics program, special cancer program and so on is reported. (Kako, I.)

  12. Characterization of ionizing radiation effects on human skin allografts

    International Nuclear Information System (INIS)

    Bourroul, Selma Cecilia

    2004-01-01

    The skin has a fundamental role in the viability of the human body. In the cases of extensive wounds, allograft skin provides an alternative to cover temporarily the damaged areas. After donor screening and preservation in glycerol (above 85%), the skin can be stored in the Skin Banks. The glycerol at this concentration has a bacteriostatic effect after certain time of preservation. On the other hand, skin sterilization by ionizing radiation may reduces the quarantine period for transplantation in patients and its safety is considered excellent. The objectives of this work were to establish procedures using two sources of ionizing radiation for sterilization of human skin allograft, and to evaluate the skin after gamma and electron beam irradiation. The analysis of stress-strain intended to verify possible effects of the radiation on the structure of preserved grafts. Skin samples were submitted to doses of 25 kGy and 50 kGy in an irradiator of 60 Co and in an electron beam accelerator. Morphology and ultra-structure studies were also accomplished. The samples irradiated with a dose of 25 kGy seemed to maintain the bio mechanic characteristics. The gamma irradiated samples with a dose of 50 kGy and submitted to an electron beam at doses of 25 kGy and 50 kGy presented significant differences in the values of the elasticity modulus, in relation to the control. The analysis of the ultramicrographies revealed modifications in the structure and alterations in the pattern of collagen fibrils periodicity of the irradiated samples. (author)

  13. Effective spectrum width of the synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V. G., E-mail: bagrov@phys.tsu.ru [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of High Current Electronics, SB RAS, Tomsk (Russian Federation); Gitman, D. M., E-mail: gitman@if.usp.br [Department of Physics, Tomsk State University, Tomsk (Russian Federation); Institute of Physics, University of São Paulo, São Paulo (Brazil); P.N.Lebedev Physical Institute, Moscow (Russian Federation); Levin, A. D., E-mail: alevin@if.usp.br [Institute of Physics, University of São Paulo, São Paulo (Brazil); Loginov, A. S.; Saprykin, A. D. [Department of Physics, Tomsk State University, Tomsk (Russian Federation)

    2015-11-25

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory.

  14. Effective spectrum width of the synchrotron radiation

    International Nuclear Information System (INIS)

    Bagrov, V. G.; Gitman, D. M.; Levin, A. D.; Loginov, A. S.; Saprykin, A. D.

    2015-01-01

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory

  15. Effective spectrum width of the synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bagrov, V.G. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); SB RAS, Institute of High Current Electronics, Tomsk (Russian Federation); Gitman, D.M. [Tomsk State University, Department of Physics, Tomsk (Russian Federation); University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); P.N. Lebedev Physical Institute, Moscow (Russian Federation); Levin, A.D. [University of Sao Paulo, Institute of Physics, Sao Paulo (Brazil); Loginov, A.S.; Saprykin, A.D. [Tomsk State University, Department of Physics, Tomsk (Russian Federation)

    2015-11-15

    For an exact quantitative description of spectral properties of synchrotron radiation (SR), the concept of effective width of the spectrum is introduced. In the most interesting case, which corresponds to the ultrarelativistic limit of SR, the effective width of the spectrum is calculated for the polarization components, and new physically important quantitative information on the structure of spectral distributions is obtained. For the first time, the spectral distribution for the circular polarization component of the SR for the upper half-space is obtained within classical theory. (orig.)

  16. Effects of gluon radiation in hadronic collisions

    International Nuclear Information System (INIS)

    Gustafson, Goesta.

    1989-10-01

    In this talk I discuss effects of gluon emission in soft collisions, the so-called 'soft radiation' in the Fritjof model. It is seen e.g. that the pT in the fragmentation regions, the seagull effect, increases with energy in fair agreement with experiments. I also discuss the content of strange and heavier quarks in high-pT gluon jets. Within the dipole scheme for QCD cascades on finds a larger production of heavier quarks than in previous approaches. Qualitative agreement with data is obtained for the K/π ratio and D meson production

  17. MOS modeling hierarchy including radiation effects

    International Nuclear Information System (INIS)

    Alexander, D.R.; Turfler, R.M.

    1975-01-01

    A hierarchy of modeling procedures has been developed for MOS transistors, circuit blocks, and integrated circuits which include the effects of total dose radiation and photocurrent response. The models were developed for use with the SCEPTRE circuit analysis program, but the techniques are suitable for other modern computer aided analysis programs. The modeling hierarchy permits the designer or analyst to select the level of modeling complexity consistent with circuit size, parametric information, and accuracy requirements. Improvements have been made in the implementation of important second order effects in the transistor MOS model, in the definition of MOS building block models, and in the development of composite terminal models for MOS integrated circuits

  18. Radiation in the human environment: health effects, safety and acceptability

    International Nuclear Information System (INIS)

    Gonzalez, A.J.; Anderer, J.

    1990-01-01

    This paper reports selectively on three other aspects of radiation (used throughout to mean ionizing radiation) in the human environment: the human health effects of radiation, radiation safety policy and practices, and the acceptability of scientifically justified practices involving radiation exposures. Our argument is that the science of radiation biology, the judgemental techniques of radiation safety, and the social domain of radiation acceptability express different types of expertise that should complement - and not conflict with or substitute for - one another. Unfortunately, communication problems have arisen among these three communities and even between the various disciplines represented within a community. These problems have contributed greatly to the misperceptions many people have about radiation and which are frustrating a constructive dialogue on how radiation can be harnessed to benefit mankind. Our analysis seeks to assist those looking for a strategic perspective from which to reflect on their interaction with practices involving radiation exposures. (author)

  19. Effects of UV radiation on genetic recombination

    International Nuclear Information System (INIS)

    Vlahovic, K.; Zahradka, D.; Petranovic, M.; Petranovic, D.

    1996-01-01

    We have used the model consisting of Escherichia coli cells and l phage to study the effects of UV radiation on genetic recombination. We found two radiation induced processes that reduce or inhibit genetic recombination. One such process leads to the inability of prophage to excise itself from the irradiated bacterial chromosome by the site-specific recombination. The other process was shown to inhibit a type of general recombination by which the prophage transfers one of its genetic markers to the infecting homologous phage. Loss of the prophage ability to take part in both site-specific and general recombination was shown to develop in recB + but not in recB cells. From this we infer that the loss of prophage recombinogenicity in irradiated cells is a consequence of one process in which RecBCD enzyme (the product of recB, recC and recD genes) plays an essential role. (author)

  20. Effects of gamma radiation on fish lipids

    Energy Technology Data Exchange (ETDEWEB)

    Sofyan, R [National Atomic Energy Agency, Jakarta (Indonesia). Pasar Djumat Research Centre

    1982-04-01

    Investigations on the changes of free fatty acid (FFA) value and thiobarbituric acid (TBA) value of fish muscle lipids during chilled storage were carried out. Experimental results showed significant increases in FFA and TBA values during storage. The FFA and TBA values of unirradiated fish were also determined. It was observed that radiation treatments at doses of 2.5 and 5.0 kGy gave no significant effects on FFA values. On the other hand the TBA values of irradiated samples were significantly higher than those of unirradiated samples, indicating that oxidative changes have occured due to radiation. TLC investigations on muscle nonpolar-, phospho- and glycolipids of control and fish samples, irradiated at doses up to 10 kGy revealed that the lipid components or irradiated fish were identical with those of control.

  1. Radiation effects on structural ceramics in fusion

    International Nuclear Information System (INIS)

    Hopkins, G.R.; Price, R.J.; Trester, P.W.

    1986-01-01

    Ceramics are required to serve in a conventional role as electrical and thermal insulators and dielectrics in fusion power reactors. In addition, certain ceramic materials can play a unique structural role in fusion power reactors by virtue of their very low induced radioactivity from fusion neutron capture. The aspects of safety, long-term radioactive waste management, and personnel access for maintenance and repair can all be significantly improved by applying the low-activation ceramics to the structural materials of the first-wall and blanket regions of a fusion reactor. Achievement of long service life at high structural loads and thermal stresses on the materials exposed to high-radiation doses presents a critical challenge for fusion. In this paper, we discuss radiation effects on structural ceramics for fusion application

  2. Effect of radiation on hydrotalcites with chromates

    International Nuclear Information System (INIS)

    Martinez G, S.; Bulbulian, S.

    2002-01-01

    Nowadays the generation of radioactive wastes is matter of several studies. In this work anion material, chromates, in hydrotalcite are retained which are anion exchangers. It was proposed to heat the hydrotalcite until temperature of 1200 C with the purpose to form the (MgAl 2 O 4 ) spinel is very stable and in this way to immobilize strongly the anions. The effect of radiation on this compound and in particular the chromium lixiviation with solution 1N NaCl. It was found that in all case, the anions are strongly retained in the spinel formed. The radiation dose used for this was 100 Mrad, the samples were treated with NaCl 1N for studying the Cr lixiviation. The results show that for the calcined samples at 1200 C and irradiated there are not chromium escapes, which indicates that it is strongly retained in the spinel that is the formed structure after of the material calcination. (Author)

  3. Radiation effects on active pixel sensors (APS)

    International Nuclear Information System (INIS)

    Cohen, M.; David, J.P.

    1999-01-01

    Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using 60 Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity

  4. Reliability and radiation effects in compound semiconductors

    CERN Document Server

    Johnston, Allan

    2010-01-01

    This book discusses reliability and radiation effects in compound semiconductors, which have evolved rapidly during the last 15 years. Johnston's perspective in the book focuses on high-reliability applications in space, but his discussion of reliability is applicable to high reliability terrestrial applications as well. The book is important because there are new reliability mechanisms present in compound semiconductors that have produced a great deal of confusion. They are complex, and appear to be major stumbling blocks in the application of these types of devices. Many of the reliability problems that were prominent research topics five to ten years ago have been solved, and the reliability of many of these devices has been improved to the level where they can be used for ten years or more with low failure rates. There is also considerable confusion about the way that space radiation affects compound semiconductors. Some optoelectronic devices are so sensitive to damage in space that they are very difficu...

  5. Radiations effects on polymeric materials used in CERN particles accelerators

    International Nuclear Information System (INIS)

    Tavlet, M.

    1997-01-01

    For fundamental research on the basis structure of matter, the European Organization for Nuclear Research (CERN) operates several high-energy particle accelerators around which materials and components are exposed to ionizing radiation. To ensure a safe and reliable operation, the radiation behaviour of most of the components is systematically tested prior to their selection. The long-term radiation-test programme allows to assess the component lifetime in the environment or our accelerators where the absorbed doses are continuously recorded. This article presents organic materials in use at CERN, and some recent results are given on their behaviour under irradiation. (authors)

  6. The Paper of the ILO in the Effectiveness of International Standards of Fundamental Rights in Labor Relations

    OpenAIRE

    Misailidis, Mirta Gladys Lerena Manzo de; Junior, Waldomiro Antonio Rizato

    2017-01-01

    Labor Law is historically seen as legal instrument of the affirmation of human dignity. And for good reason, its effectiveness promotes the social bias of inclusion and full citizenship, fostering the distribution of income and the boosting of economy. Dissociating Labor Law from human dignity is to recede to the mercantilization of human labor. Nowadays, we will enhance the search for the international protection of the Fundamental Rights of workers, standing out the vanguard of ILO. From a ...

  7. Fundamental principles of heat transfer

    CERN Document Server

    Whitaker, Stephen

    1977-01-01

    Fundamental Principles of Heat Transfer introduces the fundamental concepts of heat transfer: conduction, convection, and radiation. It presents theoretical developments and example and design problems and illustrates the practical applications of fundamental principles. The chapters in this book cover various topics such as one-dimensional and transient heat conduction, energy and turbulent transport, forced convection, thermal radiation, and radiant energy exchange. There are example problems and solutions at the end of every chapter dealing with design problems. This book is a valuable int

  8. Fundamentals of nuclear chemistry

    International Nuclear Information System (INIS)

    Majer, V.

    1982-01-01

    The author of the book has had 25 years of experience at the Nuclear Chemistry of Prague Technical University. In consequence, the book is intended as a basic textbook for students of this field. Its main objectives are an easily understandable presentation of the complex subject and in spite of the uncertainty which still characterizes the definition and subjects of nuclear chemistry - a systematic classification and logical structure. Contents: 1. Introduction (history and definition); 2. General nuclear chemistry (physical fundamentals, hot atom chemistry, interaction of nuclear radiation with matter, radioactive elements, isotope effects, isotope exchange, chemistry of radioactive trace elements); 3. Methods of nuclear chemistry of nuclear chemistry (radiochemical methods, activation, separation and enrichment chemistry); 4. Preparative nuclear chemistry (isotope production, labelled compounds); 5. Analytival nuclear chemistry; 6. Applied nuclear chemistry (isotope applications in general physical and analytical chemistry). The book is supplemented by an annex with tables, a name catalogue and a subject index which will facilitate access to important information. (RB) [de

  9. Health effects of low-level radiations

    International Nuclear Information System (INIS)

    Tubiana, M.

    1982-01-01

    Epidemiological surveys have attempted to assess the carcinogenic risk induced by exposure to low doses of ionizing radiation. Such studies are difficult to carry out because the incidence of radiation induced cancers is of only a few per cent, even following relativity large doses, and because there is no way to distinguish radiation induced cancer from the background of natural human cancers; moreover these surveys are exposed to many biases due to relatively small sizes of the populations studied and the difficulties of finding an appropriate control group, of estimating the absorbed doses and of collecting the data. A few national or international expert committees have analysed the available data and evaluated the carcinogenic effects. Their estimations of the risk, are similar and allow one to quantify the carcinogenic risk for doses above 100 rads. The risks of lower doses must be determined by extrapolation from human data at high doses. This extrapolation requires the knowledge of the dose-effect relationship. A linear extrapolation is most common and probably leads to a conservative estimate of the risk. A linear-quadratic function is probably more realistic and in better accordance with most scientific data. However the validity of its use for the estimation of carcinogenic risk is still debated. In experimental animals, the influence of dose-rate is important and some data suggest that this is the same for the carcinogenic effect in human beings. The genetic effects are probably less important than was feared a few years ago. The most important recent observation is the absence of any significant genetic effect in the progeny of the survivors of the A. bombs in Hiroshima and Nagasaki. This allows a conservative estimate of the maximum genetic risk for human beings [fr

  10. Effects of small doses of ionising radiation

    International Nuclear Information System (INIS)

    Doll, R.

    1998-01-01

    Uncertainty remains about the quantitative effects of doses of ionising radiation less than 0.2 Sv. Estimates of hereditary effects, based on the atomic bomb survivors, suggest that the mutation doubling dose is about 2 Sv for acute low LET radiation, but the confidence limits are wide. The idea that paternal gonadal irradiation might explain the Seascale cluster of childhood leukaemia has been disproved. Fetal irradiation may lead to a reduction in IQ and an increase in seizures in childhood proportional to dose. Estimates that doses to a whole population cause a risk of cancer proportional to dose, with 0.1 Sv given acutely causing a risk of 1%, will need to be modified as more information is obtained, but the idea that there is a threshold for risk above this level is not supported by observations on the irradiated fetus or the effect of fallout. The idea, based on ecological observations, that small doses protect against the development of cancer is refuted by the effect of radon in houses. New observations on the atomic bomb survivors have raised afresh the possibility that small doses may also have other somatic effects. (author)

  11. Report of the 13th IEA workshop on radiation effects in ceramic insulators

    International Nuclear Information System (INIS)

    2004-03-01

    The 13th IEA Workshop on Radiation Effects in Ceramic Insulators, based on Annex II: Experimentation on Radiation Damage in Fusion Materials, to the IEA Implementing Agreement for a Programme of Research and Development on Radiation Damage in Fusion Materials, was held on the 9th, December, 2003, at Kyoto International Conference Center, in Kyoto, Japan, in conjunction with the 11th International Conference on Fusion Reactor Materials (ICFRM-11). 44 participants from 10 countries (26 from Japan, 5 from Spain, 3 from Belgium, 3 from USA, 2 from RF, each 1 from Austria, Greece, Italy, Romania, and UK) gathered together and discussed following issues extensively, with the newest experimental results, after the welcome remarks by one of the organizer and chairpersons, Dr. E.R. Hodgson of CIEMAT. Effects of electric field on radiation induced microstructural evolution, parasitic electrical current and voltage induced in cables and wires by radiation effects, optical materials, IFMIF related issues and fundamental aspects were discussed. Significant results such as an observation of γ-alumina and aluminum colloid formation for the Radiation Induced Electrical Degradation mechanism are obtained. This report is workshop summary, abstracts and documents of the 13th IEA Workshop on Radiation Effects in Ceramic Insulators. (author)

  12. Basic radiation effects in nuclear power electronics technology

    International Nuclear Information System (INIS)

    Gover, J.E.; Srour, J.R.

    1985-05-01

    An overview is presented of the effects of radiation in microelectronics technology. The approach taken throughout these notes is to review microscopic phenomena associated with radiation effects and to show how these lead to macroscopic effects in semiconductor devices and integrated circuits. Bipolar integrated circuits technology is reviewed in Appendix A. Appendix B gives present and future applications of radiation-tolerant microelectronics in nuclear power applications as well as the radiation tolerance requirements of these applications

  13. Ionising radiation effects on food packaging

    International Nuclear Information System (INIS)

    Ragni, P.; Segre, A. L.; Capitani, D.; Danesi, P.R.

    2001-01-01

    The main aim of any food irradiation treatment is to guarantee the best safe quality of the products, reducing the spreading risk ( c ross-contamination ) for several food-associated diseases. Actually, over 40 countries provide clearances for the treatment of about 45 different types of foodstuffs. EU has to homogenise the situation within the associated States. With the European directive 1999/2/EC Italy, as other EU countries, already has brought into force their regulations to comply. The current Italian regulation on irradiation treatment of foodstuffs is referred since 1996 as follows: a) potatoes, onions and garlic; b) spices, herbs and condiments microbial. The new (April 2001) Italian law allows the possibility to ask for special permission of treatment for other foodstuff which is possible to treat in other E.U. countries. Large majority of foods are submitted to irradiation treatment after they have been packaged. In Dutch cases the study of radiation effects on the package becomes crucial, also because polymeric materials may be affected by ionizing radiation. We performed our studies on several materials employed in food packaging, with a particular care to the role of anti-oxidant additives present in food packaging materials. The attention is pointed on the possible chemical-physical effects induced by radiation on foodstuff packaging. After irradiation in plastic materials two main effects may occur: degradation and cross-linking. The result depending on the comparative rates of the two actions. This kind of information was successfully obtained using NMR methods on a large number of polymers effectively used for the food packaging procedures

  14. Radiation-electromagnetic effect in germanium monocrystals

    International Nuclear Information System (INIS)

    Kikoin, I.K.; Kikoin, L.I.; Lazarev, S.D.

    1980-01-01

    Experimentally investigated is the radiation-electromagnetic effect (REM) in germanium monocrystals on excitation of excess current carriers by α particles, protons and X-rays in magnetic fields up to 8 kOe. A cyclotron was used as an α particle source, and a standard X-ray tube with a copper anode - as an X-ray source. The e.m.f. of the REM effect linearly increases with the increase of the magnetic field and is proportional to the charged particle flux at small flux values, saturation occurs at great flux values (approximately 5x10 11 part./cm 2 xs). In the 4-40 MeV energy range the e.m.f. of the REM effect practically does not depend on the α particle energy. On irradiation of the samples with a grinding front surface the REM e.m.f. changes its sign. The REM and Hall effect measurement on α particle irradiated samples has shown that during irradiation a p-n transition is formed in the samples, which must be taken into account while studying the REM effect. The e.m.f. measured for the even REM effect quadratically increases with the magnetic field increase. The barrier radiation-voltaic effect (the effect e.m.f. is measured between the irradiated and nonirradiated sample faces) is studied. Using special masks the samples with a set of consecutive p-n transitions are produced by irradiation of germanium crystals by α particles. Investigation of the photovoltaic and photoelectromagnetic effects on such samples has shown that using this method the efficiency of the REM devices can be increased

  15. Fundamentals of electronics

    CERN Document Server

    Schubert, Thomas F

    2015-01-01

    This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

  16. The radiation effects on lipid bilayers

    International Nuclear Information System (INIS)

    Ikigai, Hajime; Matsuura, Tomio; Narita, Noboru; Ozawa, Atsushi.

    1980-01-01

    The Radiation effects on lipid bilayers are studied by the electron spin resonance. Egg lecithin liposomes and human erythrocytes are labeled with spin probes (5 SAL, 12 SAL). Effects of membrane fluidity by X-Ray (or ultraviolet) irradiation are measured by change of the order parameter S. The results obtained are as follows: 1) A similar tendency is observed on the order parameter S between X-Ray irradiated egg lecithin liposomes and human erythrocytes. 2) The rapid changes of the membrane fluidity are observed below 1 krad. The fluctuation of membrane fluidity decreases above 1 krad, consequently the membrane has a tendency changing to a rigid state at low dose area. 3) It is suggested that the more effective radicals are hydroxyl radicals and superoxide radicals. 4) The effects of ultraviolet irradiation with hydrogen peroxide show that hydroxyl radicals lead to changes of membrane fluidity. (author)

  17. Radiation effects on transport and bubble formation in silicate glasses. 1998 annual progress report

    International Nuclear Information System (INIS)

    Trifunac, A.D.

    1998-01-01

    'To study the fundamental chemistry of radiation damage in silicate/borosilicate glasses and simulated high-level nuclear waste (HLW) forms. Special emphasis is on delineating molecular processes crucial for understanding the aggregation of defects and formation of oxygen bubbles. The knowledge obtained will provide the needed scientific basis for extrapolating long-term behavior of stored radiative waste glass forms. This report summarizes the first 6 months of a 3-year project. The following issues have been addressed: (i) the production of radiolytic oxygen, (ii) the chemistry of hydrogenous species, and (iii) the effect of glass composition and microstructure on the formation and accumulation of metastable point defects.'

  18. Effect of infrared radiation on the lens

    Directory of Open Access Journals (Sweden)

    Aly Eman

    2011-01-01

    Full Text Available Background: Infrared (IR radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye. Aim : The present study was designed to investigate the effect of IR radiation on rabbit′s crystalline lens and lens membrane. Materials and Methods: Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na + -K + ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE and Fourier transform infrared (FTIR spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001. Results: The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na + -K + ATPase significantly decreased for all groups. Conclusions: The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

  19. Physiological and pathological effects of thermal radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hymes, I.

    1983-09-15

    This report deals with man's response to abnormally high levels of thermal radiation. The early sections deal with the properties and biological roles of the skin in some detail as a basis for the definitions and descriptions of pathological damage. The estimation of hazard ranges in thermal radiation exposures requires a moderately accurate knowledge of the intensity and duration of the emitted flux. The (BLEVE) Boiling Liquid Expanding Vapor Explosion fireball conveniently meets this requirement as well as having the capability to inflict severe burn injuries over considerable distances. Liquid Petroleum Gas fireballs have been used as the source term for the thermal radiation calculations which predict threshold lethality and various categories of burn injury. Inevitably there are areas of uncertainty in such calculations, some contributory factors being atmospheric conditions, fuel container rupture pattern, type of clothing worn etc. The sensitivity of the predicted hazard ranges to these influential parameters is exemplified in several of the graphs presented. The susceptibility of everyday clothing to ignite or melt in thermal fluxes greater than about 70 kW/m/sup 2/ is shown to be a matter of some gravity since burning clothing can thwart escape and inflict serious, if not fatal, burns quite apart from injuries directly received from the incident radiation. The various means by which incident heat fluxes can be reduced or their effects mitigated are reviewed. Two major BLEVE case histories are discussed in some detail and the circumstances compared with those predicted by the theoretical calculations. 38 refs., 36 figs.

  20. Effects of UV radiation on phytoplankton

    Science.gov (United States)

    Smith, Raymond C.; Cullen, John J.

    1995-07-01

    It is now widely documented that reduced ozone will result in increased levels of ultraviolet (UV) radiation, especially UV-B (280-320nm), incident at the surface of the earth [Watson, 1988; Anderson et al., 1991; Schoeberl and Hartmann, 1991; Frederick and Alberts, 1991; WMO, 1991; Madronich, 1993; Kerr and McElroy, 1993], and there is considerable and increasing evidence that these higher levels of UV-B radiation may be detrimental to various forms of marine life in the upper layers of the ocean. With respect to aquatic ecosystems, we also know that this biologically- damaging mid-ultraviolet radiation can penetrate to ecologically- significant depths in marine and freshwater systems [Jerlov, 1950; Lenoble, 1956; Smith and Baker, 1979; Smith and Baker, 1980; Smith and Baker, 1981; Kirk et al., 1994]. This knowledge, plus the dramatic decline in stratospheric ozone over the Antarctic continent each spring, now known to be caused by anthropogenically released chemicals [Solomon, 1990; Booth et al., 1994], has resulted in increased UV-environmental research and a number of summary reports. The United Nations Environmental Program (UNEP) has provided recent updates with respect to the effects of ozone depletion on aquatic ecosystems (Hader, Worrest, Kumar in UNEP 1989, 1991, Hader, Worrest, Kumar and Smith UNEP 1994) and the Scientific Committee on Problems of the Environment (SCOPE) has provided [SCOPE, 1992] a summary of the effects of increased UV radiation on biological systems. SCOPE has also reported [SCOPE, 1993] on the effects of increased UV on the biosphere. In addition, several books have recently been published reviewing various aspects of environmental UV photobiology [Young et al., 1993], UV effects on humans, animals and plants [Tevini, 1993], the biological effects of UV radiation in Antarctica [Weiler and Penhale, 1994], and UV research in freshwater ecosystems [Williamson and Zagarese, 1994]. Several other reviews are relevant [NAS, 1984; Caldwell

  1. A Study of the Effect of Emotional State upon the Variation of the Fundamental Frequency of a Speaker

    Directory of Open Access Journals (Sweden)

    Marius Vasile GHIURCAU

    2010-01-01

    Full Text Available Telephone banking or brokering, building accesssystems or forensics are some of the areas in which speakerrecognition is continuously developing. Fundamental frequencyrepresents an important speech feature used in theseapplications. In this paper we present a study of the effect ofemotional state of a speaker upon the variation of thefundamental frequency of the speech signal. Human beings arequite frequently overwhelmed by various emotions and most ofthe time one can not really control these emotional states. Forthe purpose of our work we have used the Berlin emotionalspeech database which contains utterances of 10 speakers indifferent emotional situations: happy, angry, fearful, bored andneutral. The mean fundamental frequency and also the standarddeviation for every speaker in all the emotional states werecomputed. The results show a very strong influence of theemotional state upon frequency variation.

  2. Radiation-effects state of the art 1965-1966

    Energy Technology Data Exchange (ETDEWEB)

    Hamman, D.J.; Drennan, J.E.; Veazie, W.H.; Shober, F.R.; Leach, E.R.

    1966-06-30

    Developments in the field of radiation effects on electronic components including semiconductors, polymetric materials, lubricants, flotation fluids, hydraulic fluids, structural metals and alloys, ceramics, space radiation environment, dosimetry, and ceramic and metallic fuel materials are reviewed. Programs currently being conducted in radiation effects are briefly given for each section of the report.

  3. The environmental effects of radiation on flight crews

    International Nuclear Information System (INIS)

    Connor, C.W.

    1991-01-01

    A review is presented of a continuing investigation of flight deck radiation and its potential effects on flight crews. Attention is given to the various critical factors concerned in UV radiation exposure and detection including skin cancer classifications, skin types, effectiveness of different sun protection factors, and flight deck color configuration and sunglasses. Consideration is given to both UV and ionizing radiation

  4. Radiation effects on the human organs, app. A

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The appendix is subdivided into eleven chapters dealing with radiation effcts on organisms and comprising the following subjects: biological effects of ionizing radiations (dose, LET, RBE, formation of radicals, age and sex, cell types, biological repair), recommendations and protective measures for somatic risks, genetic risks, experimental models and dose-effect relationships, and internal radiation. The groups conclusions are given

  5. Intense Ion Pulses for Radiation Effects Research

    Science.gov (United States)

    2017-04-01

    induction linear accelerator that has been developed to deliver intense, up to 50 nC/pulse/mm2, sub-ns pulses of light ions with kinetic energy up to 1.2...II induction linear accelerator for intense ion beam pulses at Berkeley Lab. Figure 3. Helium current and integrated charge versus time at the...under contracts DE-AC02-205CH11231 and DE-AC52-07NA27344. JOURNAL OF RADIATION EFFECTS, Research and Engineering Vol. 35, No. 1, April 2017 158 INTENSE

  6. Radiation effects in corundum single crystals

    International Nuclear Information System (INIS)

    Gevorkyan, V.A.; Harutunyan, V.V.; Hakhverdyan, E.A.

    2005-01-01

    On the basis of new experimental results and analysis of publications it is shown that in the lattice of corundum crystals the high-energy particles create stable structural defects due to knocking out of atoms from normal sites of the anionic sublattice; this leads to the formation of F and F '+ centers as well as to other complex [Al i '+ F] type color centers. The essence of 'radiation memory' effect in corundum single crystals is that the high-energy particles irradiation, annealing at high temperatures and additional irradiation by X-rays result in the restoration of some spectral bands of the optical absorption in the range 200-650 nm

  7. Study of radiation effects on semiconductor devices

    International Nuclear Information System (INIS)

    Kuboyama, Satoshi; Shindou, Hiroyuki; Ikeda, Naomi; Iwata, Yoshiyuki; Murakami, Takeshi

    2004-01-01

    Fine structure of the recent semiconductor devices has made them more sensitive to the space radiation environment with trapped high-energy protons and heavy ions. A new failure mode caused by bulk damage had been reported on such devices with small structure, and its effect on commercial synchronous dynamic random access memory (SDRAMs) was analyzed from the irradiation test results performed at Heavy ion Medical Accelerator in Chiba (HIMAC). Single event upset (SEU) data of static random access memory (SRAMs) were also collected to establish the method of estimating the proton-induced SEU rate from the results of heavy ion irradiation tests. (authors)

  8. Radiation effects on the developing human brain

    International Nuclear Information System (INIS)

    1993-01-01

    The developing human brain has been shown to be especially sensitive to ionizing radiation. Mental retardation has been observed in the survivors of the atomic bombings in Japan exposed in utero during sensitive periods, and clinical studies of pelvically irradiated pregnant women have demonstrated damaging effects on the fetus. In this annex the emphasis is on reviewing the results of the study of the survivors of the atomic bombings in Japan, although the results of other human epidemiological investigations and of pertinent experimental studies are also considered. Refs, 3 figs, 10 tabs

  9. Space storms and radiation causes and effects

    CERN Document Server

    Schrijver, Carolus J

    2010-01-01

    Heliophysics is a fast-developing scientific discipline that integrates studies of the Sun's variability, the surrounding heliosphere, and the environment and climate of planets. The Sun is a magnetically variable star and for planets with intrinsic magnetic fields, planets with atmospheres, or planets like Earth with both, there are profound consequences. This 2010 volume, the second in this series of three heliophysics texts, integrates the many aspects of space storms and the energetic radiation associated with them - from causes on the Sun to effects in planetary environments. It reviews t

  10. Health effects of low level radiation exposure among radiation workers

    International Nuclear Information System (INIS)

    Murata, Motoi

    2003-01-01

    In Japan, a cohort study of radiation workers has been conducted since 1990. The cohort population consisted of about 176,000 workers (mostly males) who had been registered in the centralized radiation dose registry system and engaged in various radiation works at nuclear facilities. Statistical analyses were performed mainly on the 2,934 deaths, of which 1,191 were cancer cases, detected among 119,000 male subjects during the prospective follow-up. The standardized mortality ratio showed that for any cancers mortality was not different between this population and Japanese general population. By the trend test, though significantly increasing trend in accord with increasing doses was not observed for both cancer in all sites and leukemia, it was highly significant for esophagus cancer and external causes of deaths. Results of the questionnaire survey study of lifestyle of radiation workers suggested that increasing trend of these diseases was at least partly due to the influence of some confounding factors. As a result of reviewing published studies, including the present work, trend of mortality from cancer in all sites with increasing doses seems still unclear, whereas for leukemia it appears to stay flat under 100 mSv but rapidly rise up in the doses higher than this as if fitting to either a linear-quadratic or threshold models. (author)

  11. Effect of lateral radiative losses on radiative shock propagation

    Czech Academy of Sciences Publication Activity Database

    Busquet, M.; Audit, E.; González, M.; Stehlé, C.; Thais, F.; Acef, O.; Bauduin, D.; Barroso, P.; Rus, Bedřich; Kozlová, Michaela; Polan, Jiří; Mocek, Tomáš

    2007-01-01

    Roč. 3, - (2007), s. 8-11 ISSN 1574-1818 EU Projects: European Commission(XE) 506350 - LASERLAB-EUROPE Institutional research plan: CEZ:AV0Z10100523 Keywords : radiative shocks * laboratory astrophysics Subject RIV: BH - Optics, Masers, Lasers

  12. Information security fundamentals

    CERN Document Server

    Peltier, Thomas R

    2013-01-01

    Developing an information security program that adheres to the principle of security as a business enabler must be the first step in an enterprise's effort to build an effective security program. Following in the footsteps of its bestselling predecessor, Information Security Fundamentals, Second Edition provides information security professionals with a clear understanding of the fundamentals of security required to address the range of issues they will experience in the field.The book examines the elements of computer security, employee roles and r

  13. Effects of ionizing radiations on insects

    International Nuclear Information System (INIS)

    Goyffon, Max.

    1978-01-01

    The most traditional effects caused by irradiation are development and morphogenesis disorders since on the whole the sensitivity of the developing organism to ionizing radiations is all the greater as the growth rate is faster. During the development of higher insects two categories of cell divide: larval cells on the one hand, which differentiate immediately after segmentation and give rise to larval organisms, and embryonic cells on the other which divide actively to form various islets or imaginal discs destined, each to its own extent, to provide the organs of the adult. Two cell categories thus coexist in the larva, one undergoing differentiation and the other multiplication, the radiosensitivity of which will be quite different for this very reason and will account at least partly, where the lethal effect of ionizing radiations is concerned, for the results observed. Three chapters deal in turn with effects on longevity, on regeneration and restoration and on morphogenesis and development. Strong doses give rise beyond a certain threshold to the appearance of acute radiodermatitis; their clinical signs and different degrees of seriousness liken them to burns of a special type [fr

  14. Radiation effects after low dose chronic long-term exposure

    International Nuclear Information System (INIS)

    Fliedner, T.M.; Friesecke, I.

    1997-01-01

    This document approaches the radiation effects after low dose chronic long-term exposure, presenting examples occurred, the pathophysiologic mechanisms for cell system tolerance in elevated radiation fields, and the diagnostic and therapeutic possibilities

  15. Effect of radiation environment on radiation use efficiency and growth of sunflower

    International Nuclear Information System (INIS)

    Bange, M.P.; Hammer, G.L.; Rickert, K.G.

    1997-01-01

    The level of incident radiation and the proportion of radiation that is diffuse affects radiation use efficiency (RUE) in crops. However, the degree of this effect, and its importance to growth and yield of sunflower (Helianthus annuus L.) have not been established. A field experiment was conducted to investigate the effects of radiation environment on RUE, growth, and yield of sunflower. A fully irrigated crop was sown on an alluvial-prairie soil (Fluventic Haplustoll) and was exposed to three distinct radiation environments. In two treatments, the level of incident radiation was reduced by 14 and 20% by suspending two different types of polyethylene plastic films well above the crop. In addition to the reductions in incident radiation, the proportion of radiation that was diffuse was increased by about 14% in these treatments. Lower incident radiation and increased proportion of diffuse radiation had no effect on total biomass, phenology, leaf area, and the canopy light extinction coefficient (k = 0.89). However, yield was reduced in shaded treatments due to smaller grain size and lower harvest index. Although crop RUE measured over the entire crop cycle (1.25 g/MJ) did not differ significantly among treatments, there was a trend where RUE compensated for less intercepted incident radiation. Theoretical derivations of the response of RUE to different levels of incident radiation supported this finding. Shaded sunflower crops have the ability to produce biomass similar to unshaded crops by increasing RUE, but have lower harvest indices

  16. Testing the effects from dark radiation

    International Nuclear Information System (INIS)

    Zhang Yi; Gong Yungui

    2013-01-01

    In this paper, the effects of dark radiation (DR) are tested. Theoretically, the phase-space analysis method is applied to check whether the model is consist with the history of our universe which shows positive results. Observationally, by using the observational data (SuperNovae Legacy Survey (SNLS), Wilkinson Microwave Anisotropy Probe 9 Years Result (WMAP9), Planck First Data Release (PLANCK), baryon acoustic oscillations (BAO), Hubble parameter data (H(z)) and Big Bang nucleosynthesis (BBN)), the DR is found to have the effect of wiping out the tension between the SNLS data and the other data in a flat ΛCDM model. The effects of DR also make the best fit value of N eff slightly larger than 3.04. (paper)

  17. Gamma radiation effects on liofilized human serum

    International Nuclear Information System (INIS)

    Padron Soler, E.; Romay Penabad, Z.; Chavez Ardanza, A.; Hernandez Gonzalez, C.; Martin Gonzalez, O.; Garcia Gonzalez, I.; Prieto Miranda, E.

    1995-01-01

    Human freeze dried serum was artificially contaminated with Flavobacterium sp. for studying the effects of gamma radiation of it. The radiobiological parameters of the contaminator were determined and the sterilization dose was set. The quality of the product irradiated at both, calculated sterilization dose (8.5 kGy) an another one about 25 kGy was determined. It was made according to: sterility testing, total proteins, pH enzymes (alanina-aminotransferase, aspartato-aminotransferase, alkaline phosphatase), protein electrophoresis, fast performance liquid chromatographic and effect on the cellular growth. From the latter was concluded that the calculated sterilization dose was adequate form keeping the biological properties and viability of the irradiated serum. Nevertheless, the dose of 25 k Gy was not adequate because of its dangerous effects on the cell culture

  18. Radiation effects on foodstuffs. Pt. 1

    International Nuclear Information System (INIS)

    Kuehl, M.; Boegl, W.; Stockhausen, K.

    1980-01-01

    In this report, results of irradiation experiments at about 30 foodstuffs are compiled and analyzed. The only objective was to obtain a survey of the chemical changes of irradiated foodstuffs; therefore, neither microbiological nor toxicological aspects were considered. The results were taken from the original publications and compiled in a type of dictionary of foodstuffs listing all relevant data for each substance (foodstuff, irradiation conditions, investigation procedures, results etc.) in a defined order. The main radiation source was Co 60, and the doses ranged between 0,006 and 10 Mrad. The investigations were related not only to the effects of irradiation (in some cases using different absorbed doses per foodstuff), but also to the effects of storage after irradiation (for 16 foodstuffs) and the effects of temperature (for 3 foodstuffs). (orig./MG) [de

  19. Speech task effects on acoustic measure of fundamental frequency in Cantonese-speaking children.

    Science.gov (United States)

    Ma, Estella P-M; Lam, Nina L-N

    2015-12-01

    Speaking fundamental frequency (F0) is a voice measure frequently used to document changes in vocal performance over time. Knowing the intra-subject variability of speaking F0 has implications on its clinical usefulness. The present study examined the speaking F0 elicited from three speech tasks in Cantonese-speaking children. The study also compared the variability of speaking F0 elicited from different speech tasks. Fifty-six vocally healthy Cantonese-speaking children (31 boys and 25 girls) aged between 7.0 and 10.11 years participated. For each child, speaking F0 was elicited using speech tasks at three linguistic levels (sustained vowel /a/ prolongation, reading aloud a sentence and passage). Two types of variability, within-session (trial-to-trial) and across-session (test-retest) variability, were compared across speech tasks. Significant differences in mean speaking F0 values were found between speech tasks. Mean speaking F0 value elicited from sustained vowel phonations was significantly higher than those elicited from the connected speech tasks. The variability of speaking F0 was higher in sustained vowel prolongation than that in connected speech. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Perspectives and opportunities for research in radiation effects on materials in the 1990's

    International Nuclear Information System (INIS)

    Mansur, L.K.

    1992-01-01

    Needs for research in radiation effects on materials span a broad range, from investigations of fundamental mechanisms to requirements on irradiation parameters suitable for technological studies in no less than a dozen reactor systems and subsystems. In the 1970's, 1980's and again in 1990, workshops were convened to refocus attention on progress and needs in these areas. Critical review papers and smaller meetings have also considered more specialized questions and identified important needs. In the present report, one author's view of current status and desirable avenues for radiation effects research are presented. Issues are discussed covering point defect production and availability, considerations peculiar to widely different classes of materials and radiation effects phenomena, and irradiation conditions needed for current and planned reactor systems. Research recommendations cannot be made independently of the availability of experimental facilities. Needs in the latter area are reflected in the paper