WorldWideScience

Sample records for abscopal radiation effects

  1. Investigation of Abscopal and Bystander Effects in Immunocompromised Mice After Exposure to Pencilbeam and Microbeam Synchrotron Radiation.

    Science.gov (United States)

    Fernandez-Palomo, Cristian; Schültke, Elisabeth; Bräuer-Krisch, Elke; Laissue, Jean Albert; Blattmann, Hans; Seymour, Colin; Mothersill, Carmel

    2016-08-01

    Out-of-field effects are of considerable interest in radiotherapy. The mechanisms are poorly understood but are thought to involve signaling processes, which induce responses in non-targeted cells and tissues. The immune response is thought to play a role. The goal of this research was to study the induction of abscopal effects in the bladders of NU-Foxn1 mice after irradiating their brains using Pencil Beam (PB) or microbeam (MRT) irradiation at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. Athymic nude mice injected with F98 glioma cells into their right cerebral hemisphere 7 d earlier were treated with either MRT or PB. After recovery times of 2, 12, and 48 h, the urinary bladders were extracted and cultured as tissue explants for 24 h. The growth medium containing the potential signaling factors was harvested, filtered, and transferred to HaCaT reporter cells to assess their clonogenic survival and calcium signaling potential. The results show that in the tumor-free mice, both treatment modalities produce strong bystander/abscopal signals using the clonogenic reporter assay; however, the calcium data do not support a calcium channel mediated mechanism. The presence of a tumor reduces or reverses the effect. PB produced significantly stronger effects in the bladders of tumor-bearing animals. The authors conclude that immunocompromised mice produce signals, which can alter the response of unirradiated reporter cells; however, a novel mechanism appears to be involved. PMID:27356059

  2. Radiation carcinogenesis. Progress report IV, 15 March 1976--15 May 1977. [Abscopal effects of radiation on parabiant rats

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S.; Gates, O.

    1977-01-01

    The series of parabiont and irradiated rats has been completed, the lesions diagnosed and the data pertinent to tumors computerized and partly analyzed. The same series yielded 74 percent incidence of cataract in the irradiated partner following a whole-body dose of 1000 R with 0.2 percent in the shielded partner and also in controls. There was no abscopal effect. Other structures of the eye beside the lens, particularly the retina, showed extensive radiation damage. Parabiosis increased the incidence rate of leukemia from one percent in control single rats to five percent. Irradiation of one partner decreased the rate to 2.5 percent. Similar effects were noted for solid lymphoid tumors. A pilot study of prostatic cancer in irradiated parabiont rats demonstrated a tenfold increase in incidence. Experimental protocols bearing on cocarcinogenesis have been initiated in mice and rats, using radiation, asbestos and chemical carcinogens, but no results have been as yet obtained. We have obtained additional evidence suggesting the importance of prolactin as a cocarcinogen with radiation for induction of mammary tumors in the rat and are continuing our collaborative study of hormonal aasays in the blood of parabiont rats.

  3. The Abscopal Effect Associated With a Systemic Anti-melanoma Immune Response

    Energy Technology Data Exchange (ETDEWEB)

    Stamell, Emily F. [Division of Dermatology, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York (United States); Wolchok, Jedd D. [Melanoma and Sarcoma Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ludwig Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ludwig Center for Cancer Immunotherapy, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Weill-Cornell Medical College, New York, New York (United States); Gnjatic, Sacha [Ludwig Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Ludwig Center for Cancer Immunotherapy, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Lee, Nancy Y. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Brownell, Isaac, E-mail: Isaac.brownell@nih.gov [Dermatology Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Dermatology Branch, National Cancer Institute, Bethesda, Maryland (United States)

    2013-02-01

    The clearance of nonirradiated tumors after localized radiation therapy is known as the abscopal effect. Activation of an antitumor immune response has been proposed as a mechanism for the abscopal effect. Here we report a patient with metastatic melanoma who received palliative radiation to his primary tumor with subsequent clearance of all his nonirradiated in-transit metastases. Anti-MAGEA3 antibodies were found upon serological testing, demonstrating an association between the abscopal effect and a systemic antitumor immune response. A brain recurrence was then treated with a combination of stereotactic radiosurgery and immunotherapy with ipilimumab. The patient experienced a complete remission that included resolution of nodal metastases, with a concomitant increase in MAGEA3 titers and a new response to the cancer antigen PASD1. This case supports the immune hypothesis for the abscopal effect, and illustrates the potential of combining radiotherapy and immunotherapy in the treatment of melanoma.

  4. The Abscopal Effect Associated With a Systemic Anti-melanoma Immune Response

    International Nuclear Information System (INIS)

    The clearance of nonirradiated tumors after localized radiation therapy is known as the abscopal effect. Activation of an antitumor immune response has been proposed as a mechanism for the abscopal effect. Here we report a patient with metastatic melanoma who received palliative radiation to his primary tumor with subsequent clearance of all his nonirradiated in-transit metastases. Anti-MAGEA3 antibodies were found upon serological testing, demonstrating an association between the abscopal effect and a systemic antitumor immune response. A brain recurrence was then treated with a combination of stereotactic radiosurgery and immunotherapy with ipilimumab. The patient experienced a complete remission that included resolution of nodal metastases, with a concomitant increase in MAGEA3 titers and a new response to the cancer antigen PASD1. This case supports the immune hypothesis for the abscopal effect, and illustrates the potential of combining radiotherapy and immunotherapy in the treatment of melanoma.

  5. Immune Modulation and Stereotactic Radiation: Improving Local and Abscopal Responses

    Directory of Open Access Journals (Sweden)

    Jing Zeng

    2013-01-01

    Full Text Available New and innovative treatment strategies for cancer patients in the fields of immunotherapy and radiotherapy are rapidly developing in parallel. Among the most promising preclinical treatment approaches is combining immunotherapy with radiotherapy where early data suggest synergistic effects in several tumor model systems. These studies demonstrate that radiation combined with immunotherapy can result in superior efficacy for local tumor control. More alluring is the emergence of data suggesting an equally profound systemic response also known as “abscopal” effects with the combination of radiation and certain immunotherapies. Studies addressing optimal radiation dose, fractionation, and modality to be used in combination with immunotherapy still require further exploration. However, recent anecdotal clinical reports combining stereotactic or hypofractionated radiation regimens with immunotherapy have resulted in dramatic sustained clinical responses, both local and abscopal. Technologic advances in clinical radiation therapy has made it possible to deliver hypofractionated regimens anywhere in the body using stereotactic radiation techniques, facilitating further clinical investigations. Thus, stereotactic radiation in combination with immunotherapy agents represents an exciting and potentially fruitful new space for improving cancer therapeutic responses.

  6. Therapeutic efficacy of pre-operative radiotherapy on breast carcinoma; In special reference to its abscopal effect on metastatic lymph-nodes

    Energy Technology Data Exchange (ETDEWEB)

    Konoeda, Koichi (National Medical Center of Hospital, Tokyo (Japan))

    1990-06-01

    The abscopal effect is the radiation response in tissue at a distance from the irradiated site invoked by local irradiation. It is reported that the abscopal effect is observed occasionally in radiotherapy for malignant lymphoma, malignant melanoma and seminioma. The aim of this study was to investigate the pathophysiology and mechanism of the abscopal effect in patients with breast carcinoma. Sixty two female patients, from 29 to 84 years old (mean 54 years). Their stages were stage II 12 cases, stage IIIa 16 cases and stage IV 12 cases. They were irradiated pre-operatively using less fractionated large dose irradiation. They underwent mastectomy or tumor resection. The abscopal effect on metastatic lymph nodes was observed in 15 out of 42 cases (35.7%) by palpation. The histopathological abscopal effect was noted in 22 of 42 cases (52.4%). Incidence of the abscopal effect was significantly higher in patients under 55 years old than that in patients over 56 years old (p<0.05). The abscopal effect was highly observed in patients who had the infiltrating lymphocytes around the degenerated cancer cells in the irradiated primary tumor nests (p<0.01). The subsets of the infiltrative lymphocytes were analyzed immunohistologically using monoclonal antibodies. The infiltrative lymphocytes were found to be CD8 and CD4 positive lymphocytes. Those findings suggest that the abscopal effect was caused by activated cellular immunity in hosts. Both the five- and ten-year survival rates for stage IIIa was 71.4%. Stage IIIb showed 62.5% for 5 year survival rate and 54.7% for 10 year survival rate. The survival rate was higher in patients with the abscopal effect than those without it; however, this was not statistically significant. No complications such as pneumonia was observed. (author).

  7. PD-1 Restrains Radiotherapy-Induced Abscopal Effect

    OpenAIRE

    Park, Sean S.; Dong, Haidong; Liu, Xin; Harrington, Susan M.; Krco, Christopher J.; Grams, Michael P.; Aaron S. Mansfield; Furutani, Keith M.; Olivier, Kenneth R; Kwon, Eugene D

    2015-01-01

    We investigated the influence of PD-1 expression on the systemic antitumor response (abscopal effect) induced by stereotactic ablative radiotherapy (SABR) in preclinical melanoma and renal cell carcinoma models. We compared the SABR-induced antitumor response in PD-1-expressing wild-type (WT) and PD-1-deficient knockout (KO) mice, and found that PD-1 expression compromises the survival of tumor-bearing mice treated with SABR. None of the PD-1 WT mice survived beyond 25 days, whereas 20% of th...

  8. A Peculiar Case of the Abscopal Effect: Radioactive Iodine Therapy Incidentally Palliating Marginal Zone Lymphoma

    OpenAIRE

    Kornas, Robert C.; Sarah-Kim Shields; Goldman, Lyle S.

    2015-01-01

    The abscopal effect is an extremely rare phenomenon occurring when irradiation or treatment of a primary tumor burden not only results in debulking of the targeted site but also reduces tumor size at distant sites from the intended treatment area. We present the abscopal effect occurring in a patient with low-grade marginal zone lymphoma who subsequently received radioactive iodine therapy for papillary thyroid carcinoma. She was 67 years old when a routine complete blood count at her primary...

  9. Abscopal signals mediated bio-effects in low-energy ion irradiated Medicago truncatula seeds

    International Nuclear Information System (INIS)

    The mutagenic effects of low-energy ions have been identified by genetic studies for decades. Due to the short penetration distance of ions, however, the underlying mechanism(s) is still not quite clarified. Recently, increasing data have been accumulated concerning the existence and manifestation of radiation induced bystander/abscopal effects in vivo in the whole-organism environment. In this study, the bio-effects and the preliminary mechanisms of low energy ion beam irradiation on Medicago truncatula were investigated. The results show that both development and biochemical parameters, such as seed germination, seedling, superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly affected by ion beam irradiation. It was also found that ion beam irradiation significantly increased the ROS generation and DNA strand breaks in Medicago truncatula. To further investigate the mechanism(s) underlying the responses, seeds were treated with dimethyl sulfoxide (DMSO), an effective reactive oxygen species (ROS) scavenger, and the results showed that DMSO treatment effectively rescued the seed germination and seedling rates and the morphological parameters of development, suggesting that ROS might play an essential role in the mechanisms of the bio-effects of ion-beam irradiated Medicago truncatula. (author)

  10. A peculiar case of the abscopal effect: radioactive iodine therapy incidentally palliating marginal zone lymphoma.

    Science.gov (United States)

    Kornas, Robert C; Shields, Sarah-Kim; Goldman, Lyle S

    2015-01-01

    The abscopal effect is an extremely rare phenomenon occurring when irradiation or treatment of a primary tumor burden not only results in debulking of the targeted site but also reduces tumor size at distant sites from the intended treatment area. We present the abscopal effect occurring in a patient with low-grade marginal zone lymphoma who subsequently received radioactive iodine therapy for papillary thyroid carcinoma. She was 67 years old when a routine complete blood count at her primary care physician's office yielded a persistent leukocytosis of 14,500/μL with lymphocytosis of 9,870/μL. Immunophenotyping and fluorescence in situ hybridization (FISH) analysis confirmed low-grade marginal zone lymphoma. Over eight years, her peak leukocyte and lymphocyte counts were 24,100/μL and 18,100/μL, respectively. Subsequently, she was diagnosed with papillary thyroid carcinoma after presenting with a new complaint of dysphagia. A total thyroidectomy was performed, followed by 172.1 millicuries of oral I-131 sodium iodine radioactive ablation therapy. Following treatment, her leukocyte and lymphocyte counts were 3,100/μL and 1,100/μL, respectively. Over the next four years, her leukocyte and lymphocyte counts remained within normal limits and she remained symptom free. To our knowledge, there has never been a published report describing the use of radioactive iodine causing abscopal effect benefits for patients with underlying lymphoproliferative diseases. PMID:25709847

  11. A Peculiar Case of the Abscopal Effect: Radioactive Iodine Therapy Incidentally Palliating Marginal Zone Lymphoma

    Directory of Open Access Journals (Sweden)

    Robert C. Kornas

    2015-01-01

    Full Text Available The abscopal effect is an extremely rare phenomenon occurring when irradiation or treatment of a primary tumor burden not only results in debulking of the targeted site but also reduces tumor size at distant sites from the intended treatment area. We present the abscopal effect occurring in a patient with low-grade marginal zone lymphoma who subsequently received radioactive iodine therapy for papillary thyroid carcinoma. She was 67 years old when a routine complete blood count at her primary care physician’s office yielded a persistent leukocytosis of 14,500/μL with lymphocytosis of 9,870/μL. Immunophenotyping and fluorescence in situ hybridization (FISH analysis confirmed low-grade marginal zone lymphoma. Over eight years, her peak leukocyte and lymphocyte counts were 24,100/μL and 18,100/μL, respectively. Subsequently, she was diagnosed with papillary thyroid carcinoma after presenting with a new complaint of dysphagia. A total thyroidectomy was performed, followed by 172.1 millicuries of oral I-131 sodium iodine radioactive ablation therapy. Following treatment, her leukocyte and lymphocyte counts were 3,100/μL and 1,100/μL, respectively. Over the next four years, her leukocyte and lymphocyte counts remained within normal limits and she remained symptom free. To our knowledge, there has never been a published report describing the use of radioactive iodine causing abscopal effect benefits for patients with underlying lymphoproliferative diseases.

  12. The relevance of radiation induced bystander effects for low dose radiation carcinogenic risk

    International Nuclear Information System (INIS)

    Full text: Where epidemiology studies lack the ability to prescribe radiation doses, customise sample sizes and replicate findings, radiobiology experiments provide greater flexibility to control experimental conditions. This control simplifies the process of answering questions concerning carcinogenic risk after low dose radiation exposures. However, the flexibility requires critical evaluation of radiobiology findings to ensure that the right questions are being asked, the experimental conditions are relevant to human exposure scenarios and that the data are cautiously interpreted in the context of the experimental model. In particular, low dose radiobiology phenomena such as adaptive responses, genomic instability and bystander effects need to be investigated thoroughly, with continual reference to the way these phenomena might occur in the real world. Low dose radiation induced bystander effects are of interest since their occurrence in vivo could complicate the shape of the radiation dose-response curve in the low dose range for a number of biological endpoints with subsequent effects on radiation-induced cancer risk. Conversely, radiation-induced abscopal effects implicate biological consequences of radiation exposure outside irradiated volumes, and complicate the notion of effective dose calculations. Achieving a consensus on the boundaries that distinguish the radiobiology phenomena of bystander and abscopal effects will aid progress towards understanding their relevance to in vivo radiation exposures. A proposed framework for discussing bystander effects and abscopal effects in their appropriate context will be outlined, with a discussion on the future investigation of radiation-induced bystander effects. Such frameworks can assist the integration of results from experimental radiobiology to risk evaluation and management practice. This research was funded by the Low Dose Radiation Research Program, BioI. and Environ. Research, US Dept. of Energy, Grant DE

  13. The Effect of Radiation on the Immune Response to Cancers

    Directory of Open Access Journals (Sweden)

    Bonggoo Park

    2014-01-01

    Full Text Available In cancer patients undergoing radiation therapy, the beneficial effects of radiation can extend beyond direct cytotoxicity to tumor cells. Delivery of localized radiation to tumors often leads to systemic responses at distant sites, a phenomenon known as the abscopal effect which has been attributed to the induction and enhancement of the endogenous anti-tumor innate and adaptive immune response. The mechanisms surrounding the abscopal effect are diverse and include trafficking of lymphocytes into the tumor microenvironment, enhanced tumor recognition and killing via up-regulation of tumor antigens and antigen presenting machinery and, induction of positive immunomodulatory pathways. Here, we discuss potential mechanisms of radiation-induced enhancement of the anti-tumor response through its effect on the host immune system and explore potential combinational immune-based strategies such as adoptive cellular therapy using ex vivo expanded NK and T cells as a means of delivering a potent effector population in the context of radiation-enhanced anti-tumor immune environment.

  14. Epistemology of radiation protection

    International Nuclear Information System (INIS)

    The scientific committee had assess Status of levels, effects and risks of ionizing radiation for General assembly, scientific community and public. The review of levels, sources and exposures. The natural sources of radiation include cosmic rays, terrestrial and artificial sources include medical issues, military activities, civil nuclear power occupational exposure and accidents. The global average exposure is 80% natural source, 20% medical examination 0.2% weapon fallout < 0.1% cherbonyl accidents and < 0.1 nuclear power. The effects of radiation incudes health effects, hereditable effects, bystander effects, and abscopal effects. The randon risks include lancer risk, plant and animal

  15. Contralateral effects following ipsilateral pulmonary radiation: gene expression and growth factor release

    International Nuclear Information System (INIS)

    Purpose/Objective: The abscopal effects of irradiation have not been well understood, but with the introduction of molecular biologic tools, new insights have been gained. An excellent illustration is the molecular evidence of contralateral inflammatory changes following ipsilateral lung irradiation shown in our unilateral rabbit model. Stimulated by recent findings of Morgan and Breit et al. (Ann. Int. Med. 118; 1993) who reported contralateral alveolar lymphocytosis induced by unilateral lung irradiation in breast cancer patients, we have more rigorously pursued similar studies in our laboratory. Materials/Methods: Using our established rabbit model, male New Zealand White rabbits were exposed to unilung radiation at varying doses (5, 10, 17.5 Gy); the animals were sacrificed between 1 to 24 weeks post-irradiation. Alveolar macrophages (AM) were obtained by broncho-alveolar lavage (BAL) and were cultured in vitro in serum-free media. After 24 hrs., the AM conditioned media was evaluated for its effects on a fibroblast cell line through the measurement of [3H]thymidine incorporation. Surfactant apoprotein levels was analyzed by a immunoflourescent technique which identifies its gene expression. Results: The effect of irradiation on macrophage cell numbers, as obtained by BAL, showed a dramatic decline in numbers on the irradiated side at 1-2 weeks post-irradiation followed by a rebound to 2-3 times baseline values at 4 weeks. No change in macrophage numbers occurred on the contralateral side at these times. However, [3H]thymidine incorporation, which reflects growth factor expression, was increased on the ipsilateral side immediately, but was highest at 4 weeks whereas changes were noted at 8 weeks on the contralateral side and from 8 to 24 weeks, the signal for fibroblast proliferation persisted. Even more remarkable is that surfactant apoprotein gene was expressed immediately post-irradiation in the ipsilateral lung in type II pneumocytes. No gene expression was

  16. Space radiation effects

    International Nuclear Information System (INIS)

    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

  17. Biological effects of radiation

    International Nuclear Information System (INIS)

    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

  18. 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

  19. Biophysical radiation effects

    International Nuclear Information System (INIS)

    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.)

  20. Radiation Effects In Space

    Science.gov (United States)

    Tripathi, Ram K.

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  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 effects on living systems

    International Nuclear Information System (INIS)

    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)

  3. Radiation damage effects

    International Nuclear Information System (INIS)

    The summarized data suggest that both glass and crystalline waste forms may sustain substantial doses of α-decay damage and still retain their durability. Radiation effects in glasses are less pronounced and less complicated than that in single or poly-phase ceramics; thus, the latter category requires careful research and consideration. Perhaps the most important conclusion is that short-term actinide doping experiments in crystalline phases provide a realistic simulation of long-term effects based on the comparison of observed radiation effects in Pu-doped zircon and naturally damaged zircon (there is a 107 difference in dose rate). Deviations from the similarity in effect (e.g., saturation dose) may be attributed to low-temperature, long-term annealing effects

  4. Genetic effects of radiation

    International Nuclear Information System (INIS)

    Data are reviewed from studies on the genetic effects of x radiation in mice and the extrapolation of the findings for estimating genetic hazards in man is discussed. Data are included on the frequency of mutation induction following acute or chronic irradiation of male or female mice at various doses and dose rates

  5. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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)

  6. Radiation effects in glasses

    Energy Technology Data Exchange (ETDEWEB)

    Ehrt, D.; Vogel, W. (Otto-Schott-Inst., Chemische Fakultaet, Friedrich-Schiller-Univ., Jena (Germany))

    1992-03-01

    Glass was produced by man about 4000 years ago. The scientific exploration of glass is very young and closely connected with Jena. Fraunhofer, Goethe, Dobereiner, Abbe, Zeiss and Schott are famous names on this field. Both crystals and glasses are solids. However, there are fundamental differences in their properties and behavior. Glass is a thermodynamically unstable state and has a defect structure compared to the crystal. Glass and its properties are subject to a variety of changes under the influence of high energy radiation. In general, effects extend from the reduction of specific ions to the collapse of the entire network. Ultraviolet and X-ray radiation effects on UV-transmitting glasses will be discussed. (orig.).

  7. Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    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.)

  8. Cumulative radiation effect

    International Nuclear Information System (INIS)

    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)

  9. Radiation Effects: Core Project

    Science.gov (United States)

    Dicello, John F.

    1999-01-01

    The risks to personnel in space from the naturally occurring radiations are generally considered to be one of the most serious limitations to human space missions, as noted in two recent reports of the National Research Council/National Academy of Sciences. The Core Project of the Radiation Effects Team for the National Space Biomedical Research Institute is the consequences of radiations in space in order to develop countermeasure, both physical and pharmaceutical, to reduce the risks of cancer and other diseases associated with such exposures. During interplanetary missions, personnel in space will be exposed to galactic cosmic rays, including high-energy protons and energetic ions with atomic masses of iron or higher. In addition, solar events will produce radiation fields of high intensity for short but irregular durations. The level of intensity of these radiations is considerably higher than that on Earth's surface, and the biological risks to astronauts is consequently increased, including increased risks of carcinogenesis and other diseases. This group is examining the risk of cancers resulting from low-dose, low-dose rate exposures of model systems to photons, protons, and iron by using ground-based accelerators which are capable of producing beams of protons, iron, and other heavy ions at energies comparable to those encountered in space. They have begun the first series of experiments using a 1-GeV iron beam at the Brookhaven National Laboratory and 250-MeV protons at Loma Linda University Medical Center's proton synchrotron facility. As part of these studies, this group will be investigating the potential for the pharmaceutical, Tamoxifen, to reduce the risk of breast cancer in astronauts exposed to the level of doses and particle types expected in space. Theoretical studies are being carried out in a collaboration between scientists at NASA's Johnson Space Center and Johns Hopkins University in parallel with the experimental program have provided

  10. Biological radiation effects

    International Nuclear Information System (INIS)

    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

  11. Radiation effects on living systems

    International Nuclear Information System (INIS)

    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

  12. Chemical effects of radiation

    International Nuclear Information System (INIS)

    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)

  13. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    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

  14. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

    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

  15. 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

  16. Radiation effects on structural materials

    International Nuclear Information System (INIS)

    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

  17. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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)

  18. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. Radiation-induced cardiovascular effects

    Science.gov (United States)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  1. 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.

  2. Radiation Effects in Carbon Nanoelectronics

    OpenAIRE

    Cory D. Cress; McMorrow, Julian J.; Robinson, Jeremy T.; Landi, Brian J.; Seth M. Hubbard; Messenger, Scott R.

    2012-01-01

    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.

  3. Biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Blaylock, B.G. [SENES Oak Ridge Inc., Oak Ridge, TN (United States); Theodorakis, C.W.; Shugart, L.R. [Oak Ridge National Lab., Oak Ridge, TN (United States). Environmental Sciences Division

    1996-12-31

    Natural populations have always been exposed to background levels of ionizing radiation; however, with the event of the nuclear age, studies about the effects of higher-than-background levels of ionizing radiation on individuals or populations of organisms became important. Originally, concern was focused on survival after large, acute radiation doses, and numerous studies document the somatic and genetic effects of acute ionizing radiation. However, there is a growing realization that chronic long-term exposure to higher-than-background levels of environmental radiation is more likely than is large acute exposure. Less than 10% of the literature on ionizing radiation effects deals with chronic long-term effects, and very few studies involve natural populations. In 1977, mosquito fish, Gambusia affinis, were experimentally introduced into a 0,45 ha, decommissioned, radioactive waste pond where the measured dose at the sediment-water interface was 1,150 rad/year. One year later, the fecundity of the population had not changed significantly. Eighteen years later, studies of the fish showed an inverse correlation between DNA strand breakage and fecundity in the contaminated pond. More recent studies have provided evidence that genetic diversity of the fish has increased in the contaminated site. These fish also have a greater prevalence of certain DNA banding patterns. Individuals displaying these banding patterns have a higher fecundity and lower degree of DNA strand breakage than individuals with less common banding patterns. Gambusia affinis has apparently adapted to the high background radiation, successfully surviving for approximately 50 generations. 31 refs, 5 figs.

  4. The effects and control of radiation

    International Nuclear Information System (INIS)

    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.)

  5. Radiation monitoring by radiation effect of aerosol

    International Nuclear Information System (INIS)

    The high energy and high intensity accelerator facilities need the radiation monitoring with temporal and spatial resolutions. Numerical estimations are made for the radiation monitoring using the sampling method of aerosol Alanine. The aerosol Alanine put into the monitoring area through the duct. The intensity of radicals in the collected throughput Alanine of about 50 mg after passing through the monitoring area is measured by the ESR (Electron Spin Resonance) method. Key parameters in the system are the aerosol particle diameter and its intensity, the duct diameter and length, and the aerosol flow rate inside the duct. The maximum dose rate more than 108 Gy/h is possible to measure assuming the duct of 100 cm2 in area and 10 m in length, and the aerosol flow rate of 1000 L/min. The temporal resolution of the order of minutes is obtainable when the aerosol particle size is 0.1 μm. As a result of numerical estimation based on empirical simulations, it is to be promising to apply a proposed scheme to the radiation monitoring for accelerator fields. (Y. Tanaka)

  6. Closing Remarks (by A. Gonzalez) [IRPA12: 12. Congress of the International Radiation Protection Association: Strengthening Radiation Protection Worldwide - Highlights, Global Perspective and Future Trends, Buenos Aires, Argentina, 19-24 October 2008

    International Nuclear Information System (INIS)

    The 12th International Congress of the International Radiation Protection Association (IRPA12) has reconfirmed the strong scientific basis on which radiation protection is founded. On one hand, physical sciences characterizing radiation exposure have reached a high level of sophistication. On the other hand, the biological sciences that estimate radiation health effects have undergone a great deal of development in the last years, reaching a level of insight that was unimaginable just a few years ago. Significant advances in the description and quantification of ionizing radiation, as well as a better understanding of radiation exposure effects were presented at the Congress. They have transformed our related knowledge from implicit simplicity to intricate complexity. The final outcome of an exposure situation will probably continue to be simply described by a bare nominal radiation risk coefficient, expressed as probability per unit of effective dose incurred, but the biological mechanisms leading to health effects from radiation have proven to be extremely sophisticated and complex. IRPA12 has shown that radiobiology has come far from the simple target model for radiation effects, which was the preferred paradigm for expressing radiation induced harm as recently as the IRPA10 Congress just a decade ago. Plenty of papers were submitted to the Congress describing complex mechanisms for the interaction of radiation with living matter. Bystander effects, genomic instability, adaptive responses, abscopal effects, and clastogenic plasma factors are among the great variety of recently discovered cell and tissue response mechanisms that were discussed at the Congress. A new understanding of radiation effects is emerging which describes how complex the outcome of radiation interaction with cell structure is. IRPA12 has shown how much is known about this complicated phenomenon, perhaps much more than is known about the interaction of other pollutants with cells; but the

  7. Thermal effects in radiation processing

    International Nuclear Information System (INIS)

    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

  8. Radiative effects of tropospheric ionisation

    Directory of Open Access Journals (Sweden)

    K. L. Aplin

    2003-06-01

    Full Text Available Despite the increasing evidence that cosmic ray variations may influence clouds and climate, there has been little discussion of the direct radiative effects of atmospheric ionisation. Laboratory experiments show that hydrated molecular cluster-ions, formed in the atmosphere by cosmic rays, absorb in the infra-red continuum at wavelengths of 9–12 μm. The tropospheric magnitude of this effect is estimated: transmittance anomalies from clear sky ion concentrations peak at ~2% at 10 km in the mid-latitudes. A simple isothermal clear sky atmospheric model suggests the integrated effect of the absorption is ~2 Wm−2. The effect appears detectable in existing surface data sets; surface micrometeorological data shows a significant anticorrelation between downwelling infra-red radiation and atmospheric cosmic ray ionisation. This is consistent with the infra-red attenuation observed in laboratory studies of cluster-ion absorption. If atmospheric ionisation from cosmic rays has universally direct radiative effects, then reinterpretation of satellite cloud data may be necessary.

  9. Research on radiation effect and radiation protection at JAEA

    International Nuclear Information System (INIS)

    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)

  10. Abscopal induction of leukaemia and osteosarcoma following administration of alpha-emitting radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Lord, B.I. (Paterson Institute for Cancer Research, Christie Hospital Manchester, Manchester (United Kingdom))

    2008-12-15

    Alpha-particle-emitting, bone-seeking radionuclides can induce leukaemia and/ or osteosarcoma in mice. Furthermore, plutonium-239, given to male mice before mating with normal females, while not directly leading to leukaemia in the progeny does lead to enhanced susceptibility to leukaemogenic agents. In the first case, the amounts of radionuclide are very small in experimental terms; and zero in the case of transgenerational activity. In both cases, the development of the disorders is remote in time and location relative to that of the contaminating radionuclide, making interpretation of the mechanisms and estimation of radiation risk problematic. It is necessary, then, to address questions involving the basis of haemopoiesis itself. Cellular kinetics of the development of blood from the pluripotent stem cells to the mature functional cells are outlined, describing compensatory proliferation mechanisms and extensive movement of cells throughout the marrow space. The locations of potential oncogenic target cells are identified and the nature of the stromal microenvironment that regulates haemopoiesis is defined. Plutonium-239, given to male mice, targets spermatogenesis at the stem cell level leaving unidentified damage that is inherited by his offspring. This leaves the offspring susceptible to a leukaemogenic agent encountered later in life. The characteristics of this, corroborated by consideration of the cellular kinetics, are of an inherited genomic instability. Cells of the microenvronment, inheriting the same genetic damage, probably act in the role of an enhancing 'bystander'. In adult mice, the mechanisms are different. Bone turnover results in radioactivity being gradually transported through the marrow by long-lived macrophages. A model based on temporal microdistributions of activity, defining specific target cell regions, is able to illustrate that considering bone marrow as a uniform mass of cells is inadequate to describe the observed

  11. Radiation effects on pharmaceuticals and related materials

    International Nuclear Information System (INIS)

    Radiation sterilization is the method of choice for many medical supplies and devices. However, because of the ionizing nature of gamma radiation, one must consider the effect of such radiation on the physical and chemical properties and on the biological behaviour of pharmaceutical and related materials before the feasibility of radiation sterilization for such products is established. The results of such feasibility studies can lead to an appropriate decision on the suitability of radiation sterilization for a particular pharmaceutical. (author)

  12. 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.

  13. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1949-11-16

    This paper discusses procedures for research on biological effects of radiation, using mouse tissue: activation trace analysis including methods and proceedures for handling samples before during and after irradiation; methods and procedures for ion exchange study; method of separation and recovery of copper, iron, zinc, cobalt, pubidium and cesium. Also included are studies of trace elements with radioactive isotopes: the distribution of cobalt 60, zinc 65, and copper 64 in the cytoplasm and nuclei of normal mice and those with tumors. 16 figs., 2 tabs.

  14. Radiation effects on superconducting materials

    International Nuclear Information System (INIS)

    Superconducting magnets will be used in plasma confinement of future fusion reactors. They will be subjected to neutron irradiation at low temperatures, so information is required on the effects of irradiation at low temperatures upon superconducting properties (critical current density, superconducting transition temperature, etc.) of the superconducting materials, electrical resistivity of the stabilizing materials such as Cu, multifilamentary composite materials of the magnets, and mechanical and electrical properties of the electrical insulating materials. A review is made of the existing data of radiation effects on the superconducting magnets. The superconducting transition temperature of the elements, alloys and compounds decreases with neutron irradiation, more in the compounds than in the alloys. The critical current density J sub(c) of the alloys decreases with fast neutron irradiation at low temperatures. In Nb3Sn, J sub(c) increases by low temperature fast neutron irradiation below the fluence of about 1018n/cm2, and the degradation of J sub(c) appears at over 1018n/cm2. Fast neutron irradiation causes resitivity increase of Cu and Al. Radiation damage in the materials may have large influence on stability characteristics of the composite wires. Extensive studies are necessary to clarify the problems, especially the irradiation effect at low temperatures. (auth.)

  15. 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.

  16. Radiation Therapy: Preventing and Managing Side Effects

    Science.gov (United States)

    ... yourself during radiation therapy Radiation therapy can damage healthy body tissues in or near the area being treated, which can cause side effects. Many people worry about this part of their cancer treatment. Before ...

  17. Doses and biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Basic values and their symbols as well as units of physical dosimetry are given. The most important information about biological radiation effects is presented. Polish radiation protection standards are cited. (A.S.)

  18. Schwinger Effect, Hawking Radiation, and Unruh Effect

    CERN Document Server

    Kim, Sang Pyo

    2016-01-01

    We revisit the Schwinger effect in de Sitter, anti-de Sitter spaces and charged black holes, and explore the interplay between quantum electrodynamics and the quantum gravity effect at one-loop level. We then advance a thermal interpretation of the Schwinger effect in curved spacetimes. Finally, we show that the Schwinger effect in a near-extremal black hole differs from Hawking radiation of charged particles in a non-extremal black hole and is factorized into those in an anti-de Sitter space and a Rindler space with the surface gravity for acceleration.

  19. Schwinger Effect, Hawking Radiation, and Unruh Effect

    OpenAIRE

    Kim, Sang Pyo

    2016-01-01

    We revisit the Schwinger effect in de Sitter, anti-de Sitter spaces and charged black holes, and explore the interplay between quantum electrodynamics and the quantum gravity effect at one-loop level. We then advance a thermal interpretation of the Schwinger effect in curved spacetimes. Finally, we show that the Schwinger effect in a near-extremal black hole differs from Hawking radiation of charged particles in a non-extremal black hole and is factorized into those in an anti-de Sitter space...

  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. Applying radiation health effects data to radiation protection policies

    International Nuclear Information System (INIS)

    Data from the peer-reviewed scientific literature establish a sound basis to define a low-dose, low-dose-rate, dose-response. These data include human health dose-response studies; immunologically 'whole' animal studies; and cellular and molecular biological studies of complete biological systems for the relevant immunological and physiological responses. Initiatives are required to constructively apply these data to both radiation research and radiation protection policies. First, current low level radiation health effects research must apply existing data to define research projects to integrate and confirm existing dose-response data, with specific emphasis on the biological bases that exist in definitive and reproducible cellular and biological dose-response. Second, dose-response assessment must identify and incorporate all existing substantial and confirmed data, including natural radiation sources, to establish the bases for radiation protection policy for interventions to protect public health and safety. A preliminary assessment of these data is applied to: 1) Specify research that can be constructively applied to describe radiation health effects dose-response. 2) Apply health effects dose-response to radiation and radioactivity applications policies to maximize radiation health effects interventions for occupational applications, medical applications, and other radiation and radioactive materials applications controls to cost-effectively assure public health and safety. An assessment of the proposed revisions to ICRP radiation protection policies is provided that associates the basis for administrative limits with the previous proposal of the US NRC for a 'Below Regulatory Concern' (BRC) policy. This proposal ignores the context of the fact that very low levels of radiation exposure are far within the variations of natural radiation exposures, and therefore can have no gross net consequences. The equivalent failure of the BRC proposal resulted in quick

  2. Spallation radiation effects in materials

    Energy Technology Data Exchange (ETDEWEB)

    Mansur, L.K.; Farrell, K.; Wechsler, M.S. [Oak Ridge National Lab., TN (United States)

    1996-06-01

    Spallation refers to the process whereby particles (chiefly neutrons) are ejected from nuclei upon bombardment by high-energy protons. Spallation neutron sources (SNS`s) use these neutrons for neutron scattering and diffraction research, and SNS`s are proposed as the basis for systems for tritium production and transmutation of nuclear waste. Materials in SNS`s are exposed to the incident proton beam (energies typically about 1000 MeV) and to the spallation neutrons (spectrum of energies extending up to about 1000 MeV). By contrast the fission neutrons in nuclear reactors have an average energy of only about 2 MeV, and the neutrons in fusion reactors would have energies below about 14 MeV. Furthermore, the protons and neutrons in SNS`s for scattering and diffraction research are pulsed at frequencies of about 10 to 60 Hz, from which significant changes in the kinetics of point and extended defects may be expected. In addition, much higher transmutation rates occur in SNS-irradiated materials, On the whole, then, significant differences in microstructural development and macroscopic properties may result upon exposure in SNS systems, as compared with fission and fusion irradiations. In a more general sense, subjecting materials to new radiation environments has almost routinely led to new discoveries. To the extent that data are avaiable, however, the spallation environment appears to increase the degree of damage without introducing totally new effects. The first part of this presentation is an overview of radiation effects in materials, outlining essential concepts and property changes and their physical bases. This background is followed by a description of SNS irradiation environments and the effects on materials of exposure to these environments. A special discussion is given of the selection of target (e.g., liquid mercury), container (e.g., austenitic stainless steel or ferritic/martensitic steel), and structural materials in SNS systems.

  3. Molecular and cellular effects of radiations

    International Nuclear Information System (INIS)

    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

  4. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

    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

  5. Radiation carcinogenesis. Progress report IV, 15 March 1976--15 May 1977

    International Nuclear Information System (INIS)

    The series of parabiont and irradiated rats has been completed, the lesions diagnosed and the data pertinent to tumors computerized and partly analyzed. The same series yielded 74 percent incidence of cataract in the irradiated partner following a whole-body dose of 1000 R with 0.2 percent in the shielded partner and also in controls. There was no abscopal effect. Other structures of the eye beside the lens, particularly the retina, showed extensive radiation damage. Parabiosis increased the incidence rate of leukemia from one percent in control single rats to five percent. Irradiation of one partner decreased the rate to 2.5 percent. Similar effects were noted for solid lymphoid tumors. A pilot study of prostatic cancer in irradiated parabiont rats demonstrated a tenfold increase in incidence. Experimental protocols bearing on cocarcinogenesis have been initiated in mice and rats, using radiation, asbestos and chemical carcinogens, but no results have been as yet obtained. We have obtained additional evidence suggesting the importance of prolactin as a cocarcinogen with radiation for induction of mammary tumors in the rat and are continuing our collaborative study of hormonal aasays in the blood of parabiont rats

  6. Radiation effects on CCD image sensors

    International Nuclear Information System (INIS)

    In the past decade, the micro process technology has advanced and some elaborate semiconductor devices with many microscopic elements in a cell of about 10 μm x 10 μm can be successfully used as radiation detectors and related parts in the field of nuclear physics and engineering. A CCD image sensor, for example, effectively measures details of particle-beam profiles in accelerator applications. This paper describes radiation effects on CCD image sensors. Some CCD samples were irradiated with 60Co gamma-rays and DD and DT neutrons for the examination of the reliability of CCDs used in radiation environments. This paper shows experimental data on radiation effects on CCDs and then discusses the difference in the radiation effects between gamma-rays and neutrons. The following two radiation effects on CCDs are described. One is the transient effect, which is induced by the ionisation process of radiations and is not permanent but recoverable. A CCD responds to radiations as well as light and outputs pseudo signals induced by radiation reactions in the normal video signals during irradiation. The other is the permanent effect, which is caused by the generation of the defects. A CCD image sensor is easily influenced by the trapped holes produced by ionisation in the gate oxide. The defects cause the generation of the leakage current within the depletion region, the trapping of signal charge within the channel of the charge shift register, and the flat band voltage shift which affects the CCD operating bias. (author)

  7. Potential health effects of space radiation

    Science.gov (United States)

    Yang, Chui-Hsu; Craise, Laurie M.

    1993-01-01

    Crewmembers on missions to the Moon or Mars will be exposed to radiation belts, galactic cosmic rays, and possibly solar particle events. The potential health hazards due to these space radiations must be considered carefully to ensure the success of space exploration. Because there is no human radioepidemiological data for acute and late effects of high-LET (Linear-Energy-Transfer) radiation, the biological risks of energetic charged particles have to be estimated from experimental results on animals and cultured cells. Experimental data obtained to date indicate that charged particle radiation can be much more effective than photons in causing chromosome aberrations, cell killing, mutation, and tumor induction. The relative biological effectiveness (RBE) varies with biological endpoints and depends on the LET of heavy ions. Most lesions induced by low-LET radiation can be repaired in mammalian cells. Energetic heavy ions, however, can produce large complex DNA damages, which may lead to large deletions and are irreparable. For high-LET radiation, therefore, there are less or no dose rate effects. Physical shielding may not be effective in minimizing the biological effects on energetic heavy ions, since fragments of the primary particles can be effective in causing biological effects. At present the uncertainty of biological effects of heavy particles is still very large. With further understanding of the biological effects of space radiation, the career doses can be kept at acceptable levels so that the space radiation environment need not be a barrier to the exploitation of the promise of space.

  8. Some characteristics and effects of natural radiation

    International Nuclear Information System (INIS)

    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)

  9. High-Intensity Synchrotron Radiation Effects

    CERN Document Server

    Suetsugu, Y

    2016-01-01

    Various effects of intense synchrotron radiation on the performance of particle accelerators, especially for storage rings, are discussed. Following a brief introduction to synchrotron radiation, the basic concepts of heat load, gas load, electron emission, and the countermeasures against these effects are discussed.

  10. Managing the adverse effects of radiation therapy.

    Science.gov (United States)

    Berkey, Franklin J

    2010-08-15

    Nearly two thirds of patients with cancer will undergo radiation therapy as part of their treatment plan. Given the increased use of radiation therapy and the growing number of cancer survivors, family physicians will increasingly care for patients experiencing adverse effects of radiation. Selective serotonin reuptake inhibitors have been shown to significantly improve symptoms of depression in patients undergoing chemotherapy, although they have little effect on cancer-related fatigue. Radiation dermatitis is treated with topical steroids and emollient creams. Skin washing with a mild, unscented soap is acceptable. Cardiovascular disease is a well-established adverse effect in patients receiving radiation therapy, although there are no consensus recommendations for cardiovascular screening in this population. Radiation pneumonitis is treated with oral prednisone and pentoxifylline. Radiation esophagitis is treated with dietary modification, proton pump inhibitors, promotility agents, and viscous lidocaine. Radiation-induced emesis is ameliorated with 5-hydroxytryptamine3 receptor antagonists and steroids. Symptomatic treatments for chronic radiation cystitis include anticholinergic agents and phenazopyridine. Sexual dysfunction from radiation therapy includes erectile dysfunction and vaginal stenosis, which are treated with phosphodiesterase type 5 inhibitors and vaginal dilators, respectively. PMID:20704169

  11. Total aerosol effect: radiative forcing or radiative flux perturbation?

    Directory of Open Access Journals (Sweden)

    U. Lohmann

    2010-04-01

    Full Text Available Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of precipitation formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, with global aerosol-climate models simulating interactively aerosols and cloud microphysical properties, a quantification of the aerosol forcings in the traditional way is difficult to define properly. Here we argue that fast feedbacks should be included because they act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP, that takes these fast feedbacks and interactions into account. Based on our results, we recommend RFP as a valid option to compare different forcing agents, and to compare the effects of particular forcing agents in different models.

  12. Total aerosol effect: radiative forcing or radiative flux perturbation?

    Directory of Open Access Journals (Sweden)

    D. Koch

    2009-11-01

    Full Text Available Uncertainties in aerosol radiative forcings, especially those associated with clouds, contribute to a large extent to uncertainties in the total anthropogenic forcing. The interaction of aerosols with clouds and radiation introduces feedbacks which can affect the rate of rain formation. In former assessments of aerosol radiative forcings, these effects have not been quantified. Also, with global aerosol-climate models simulating interactively aerosols and cloud microphysical properties, a quantification of the aerosol forcings in the traditional way is difficult to properly define. Here we argue that fast feedbacks should be included because they act quickly compared with the time scale of global warming. We show that for different forcing agents (aerosols and greenhouse gases the radiative forcings as traditionally defined agree rather well with estimates from a method, here referred to as radiative flux perturbations (RFP, that takes these fast feedbacks and interactions into account. Based on our results, we recommend RFP as a valid option to compare different forcing agents, and to compare the effects of particular forcing agents in different models.

  13. Toxicity risk of non-target organs at risk receiving low-dose radiation: case report

    International Nuclear Information System (INIS)

    The spine is the most common site for bone metastases. Radiation therapy is a common treatment for palliation of pain and for prevention or treatment of spinal cord compression. Helical tomotherapy (HT), a new image-guided intensity modulated radiotherapy (IMRT), delivers highly conformal dose distributions and provides an impressive ability to spare adjacent organs at risk, thus increasing the local control of spinal column metastases and decreasing the potential risk of critical organs under treatment. However, there are a lot of non-target organs at risk (OARs) occupied by low dose with underestimate in this modern rotational IMRT treatment. Herein, we report a case of a pathologic compression fracture of the T9 vertebra in a 55-year-old patient with cholangiocarcinoma. The patient underwent HT at a dose of 30 Gy/10 fractions delivered to T8-T10 for symptom relief. Two weeks after the radiotherapy had been completed, the first course of chemotherapy comprising gemcitabine, fluorouracil, and leucovorin was administered. After two weeks of chemotherapy, however, the patient developed progressive dyspnea. A computed tomography scan of the chest revealed an interstitial pattern with traction bronchiectasis, diffuse ground-glass opacities, and cystic change with fibrosis. Acute radiation pneumonitis was diagnosed. Oncologists should be alert to the potential risk of radiation toxicities caused by low dose off-targets and abscopal effects even with highly conformal radiotherapy

  14. Radiation friction vs ponderomotive effect

    CERN Document Server

    Fedotov, A M; Gelfer, E G; Narozhny, N B; Ruhl, H

    2014-01-01

    The concept of ponderomotive potential is upgraded to a regime in which radiation friction becomes dominant. The radiation friction manifests itself in novel features of long-term capturing of the particles released at the focus and impenetrability of the focus from the exterior. We apply time scales separation to the Landau-Lifshitz equation splitting the particle motion into quivering and slow drift of a guiding center. The drift equation is deduced by averaging over fast motion.

  15. 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

  16. 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)

  17. Radiation effects in optoelectronic devices. [Review

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    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

  19. Radiation effects after exposure during prenetal development

    International Nuclear Information System (INIS)

    The embryo and fetus are very radiosensitive during the total prenatal development period. The quality and extent of radiation effects depend strongly on the developmental stage at which the exposure occurs. During the preimplantation period radiation exposure can cause death of the embryo after radiation doses of 0.2 Gy and higher. Malformations are only observed in very rare cases when genetic predispositions exist. Macroscopic-anatomical malformations are induced only after irradiation during the major organogenesis. On the basis of experimental data with mammals it is assumed that a radiation dose of about 0.2 Gy doubles the malformation risk. Studies in humans give rise to the assumption that the human embryo is more radioresistant than the embryos of mice and rats. Radiation exposure during the major organogenesis and the early fetal period lead to disturbances in the growth and developmental processes. During early fetogenesis (week 8-15 post coruption) high radiosensitity exists for the development of the central nervous system. Radiation doses of 1 Gy cause severe mental retardation in about 50% of exposed fetuses. Analysis of the dose-effect curves shows that there is probably a dose-effect curve with a threshold for this effect. It must be taken into account that radiation exposure during the fetal period also induces cancer. The studies, however, do not allow quantitative estimate of this radiation risk at present. It is therefore generally assumed that the risk is about the same level as for children. (orig.)

  20. Dose-effect relationship in radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Oberhausen, E.

    1983-01-01

    As criterion for the evaluation of risk in connection with nuclear accidents the diminishing of life expectance is assumed. This would allow a better weighting of the different detriments. The possible dose-effect relations for the different detriments caused by radiation are discussed. Some models for a realistic evaluation of the different radiation detriments are proposed.

  1. 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

  2. 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) are ...

  3. Effects of radiation therapy in microvascular anastomoses

    Energy Technology Data Exchange (ETDEWEB)

    Fried, M.P.

    1985-07-01

    The otolaryngologist, as a head and neck surgeon, commonly cares for patients with upper aerodigestive tract malignancies. Therapy of these neoplasms often requires wide excision. One standard reconstructive procedure utilizes pedicled regional flaps, both dermal and myodermal which have some disadvantages. The shortcomings of these pedicled regional flaps have led to the use of the vascularized free flap in certain cases. The occasional case may lead to catastrophe if microanastomoses fail when combined with radiation. Notwithstanding, many surgical series have reported success when radiation has been given. The present investigation was undertaken to assess the effects of radiation therapy on microvascular anastomoses when radiation is administered pre- or postoperatively or when nonradiated tissue is transferred to an irradiated recipient site. These effects were observed serially in an experimental rat model using a tubed superficial epigastric flap that adequately reflected tissue viability and vascular patency. The histologic changes were then noted over a three month period after completion of both radiation and surgery. This study adds credence to the observation of the lack of deleterious effects of radiation on experimental microvascular anastomotic patency whether the radiation is given before or after surgery or if radiated tissue is approximated to nonradiated vessels.

  4. Effects of gamma radiation in tomato seeds

    International Nuclear Information System (INIS)

    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. 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)

  6. Fast Neutron Radiation Effects on Bacillus Subtili

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoming; REN Zhenglong; ZHANG Jianguo; ZHENG Chun; TAN Bisheng; YANG Chengde; CHU Shijin

    2009-01-01

    To examine the sterilizing effect and mechanism of neutron radiation, Bacillus sub-tilis vat. 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 D10 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 obvi-ously 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

  7. Radiative effects of global MODIS cloud regimes

    Science.gov (United States)

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

    2016-03-01

    We update previously published Moderate Resolution Imaging Spectroradiometer (MODIS) global cloud regimes (CRs) using the latest MODIS cloud retrievals in the Collection 6 data set. 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 data sets. Our results clearly show that 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 data sets 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.

  8. Inverse Faraday Effect driven by Radiation Friction

    CERN Document Server

    Liseykina, T V; Macchi, A

    2015-01-01

    In the interaction of extremely intense ($>10^{23}~\\mbox{W cm}^{-2}$), circularly polarized laser pulses with thick targets, theory and simulations show that a major fraction of the laser energy is converted into incoherent radiation because of collective electron motion during the "hole boring" dynamics. The effective dissipation due to radiative losses allows the absorption of electromagnetic angular momentum, which in turn leads to the generation of an axial magnetic field of tens of gigagauss value. This peculiar "inverse Faraday effect" is demonstrated in three-dimensional simulations including radiation friction.

  9. 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...

  10. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    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 106 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

  11. Radiation Effects in Nuclear Waste Materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, William J.; Corrales, L. Rene; Ness, Nancy J.; Williford, Ralph E.; Heinisch, Howard L.; Thevuthasan, Suntharampillai; Icenhower, Jonathan P.; McGrail, B. Peter; Devanathan, Ramaswami; Van Ginhoven, Renee M.; Song, Jakyoung; Park, Byeongwon; Jiang, Weilin; Begg, Bruce D.; Birtcher, R. B.; Chen, X.; Conradson, Steven D.

    2000-10-02

    Radiation effects from the decay of radionuclides may impact the long-term performance and stability of nuclear waste forms and stabilized nuclear materials. In an effort to address these concerns, the objective of this project was the development of fundamental understanding of radiation effects in glasses and ceramics, particularly on solid-state radiation effects and their influence on aqueous dissolution kinetics. This study has employed experimental, theoretical and computer simulation methods to obtain new results and insights into radiation damage processes and to initiate the development of predictive models. Consequently, the research that has been performed under this project has significant implications for the High-Level Waste and Nuclear Materials focus areas within the current DOE/EM mission. In the High-Level Waste (HLW) focus area, the results of this research could lead to improvements in the 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 focus area, the results of this research could 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. Ultimately, this research could 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.

  12. Radiation abuse and its effects

    International Nuclear Information System (INIS)

    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)

  13. Radiation effects on branched polysilanes

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, K.; Seki, S.; Tagawa, S. [Osaka Univ., Ibaraki (Japan). Inst. of Scientific and Industrial Research; Shibata, H.; Iwai, T. [Tokyo Univ. (Japan). Research Center for Nuclear Science and Technology

    2000-03-01

    We observed crosslinking and scission caused by gamma radiation in linear and branched polysilanes which have from 5% to 33% of the branching points. The crosslinking reactions become predominant for the irradiation with branching density increasing. The cleavage did not take place exclusively at the branching points and branching polysilanes are sensitive to radiation extraordinary as compared with linear polysilane from a careful study of the radiolysis products of a series of polysilanes. This is due to the increasing Si {center_dot} contributing to the crosslinking reaction and that they are not resonance-stabilized by double bonds as the reaction mechanism in the irradiated polysilanes. However, the gelation curve in linear PMPS irradiated by 2 MeV He{sup +} is almost consistent with that in branching PMPS, indicating that the size of chemical track is responsible for the gel fraction. The crosslinking G value for high molecular weight PMPS irradiated by 2 MeV He{sup +} was drastically decreased as compared with that for low molecular weight. It suggests that there are a large number of intramolecular crosslinking points for high molecular weight PMPS. (author)

  14. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    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

  15. Fallout radiation effects analysis methodology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1988-03-31

    Fallout radiation is viewed by the weapons effects community as a potentially serious impediment to maintaining or restoring critical National Security Emergency Preparedness (NSEP) telecommunication capabilities in a nuclear environment. The OMNCS' Electromagnetic Pulse Mitigation Program is designed, in part, to identify the survival probability (survivability) of the nation's NSEP telecommunications infrastructure against fallout radiation effects. The OMNCS (Office of the Manager National Communications System) is developing a balanced approach consisting of fallout radiation stress tests on the electronic piece-parts and the use of estimated performance measures of telecommunication network elements in network simulation models to predict user connectivity levels. It is concluded that, given limited available data, the proposed method can predict fallout radiation effects on network telecommunication equipment. The effects of fallout radiation are small at low dosage levels (bin 1 and bin 2). More pronounced variations in equipment performance were exhibited for radiation dosage in the 1k-5k Rads(Si) bin. Finally, the results indicate that by increasing the sample size to approximately 200 samples, the statistical quality of survivability predictions can be significantly improved.

  16. 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.

  17. Measuring transient radiation effects in optical fibers

    International Nuclear Information System (INIS)

    We propose a new method for measuring transient radiation effects in optical fibers on a nanosecond timescale. The method, which incorporates a streak camera, allows more precise time resolution than other methods and has the advantage of measuring the radiation-induced attenuation as a function of wavelength and time simultaneously. By choosing different light sources and sweep speeds, radiation-induced attenuation may be measured under a variety of experimental configurations. Examples of the type of output obtained with our method are given

  18. Ionizing radiation effects in MOS oxides

    CERN Document Server

    Oldham, Timothy R

    1999-01-01

    This volume is intended to serve as an updated critical guide to the extensive literature on the basic physical mechanisms controlling the radiation and reliability responses of MOS oxides. The last such guide was Ionizing Radiation Effects in MOS Devices and Circuits, edited by Ma and Dressendorfer and published in 1989. While that book remains an authoritative reference in many areas, there has been a significant amount of more recent work on the nature of the electrically active defects in MOS oxides which are generated by exposure to ionizing radiation. These same defects are also critical

  19. Therapeutic efficacy of pre-operative radiotherapy on breast carcinoma

    International Nuclear Information System (INIS)

    The abscopal effect is the radiation response in tissue at a distance from the irradiated site invoked by local irradiation. It is reported that the abscopal effect is observed occasionally in radiotherapy for malignant lymphoma, malignant melanoma and seminioma. However, pathophysiology and mechanism of the abscopal effect have not been well defined. The aim of this study was to investigate the pathophysiology and mechanism of the abscopal effect in patients with breast carcinoma. Sixty two patients entered this study. Age distribution was from 29 to 84 years old (mean 54.0 years old) and all cases were females. Their stages were as follows: stage II 12 cases, stage IIIa 16 cases and stage IV 12 cases. They were irradiated pre-operatively using less fractionated large dose irradiation. They underwent mastectomy or tumor resection. The abscopal effect on metastatic lymph nodes was observed in 15 out of 42 cases (35.7%) by palpation. The histopathological abscopal effect was noted in 22 of 42 cases (52.4%). Incidence of the abscopal effect was significantly higher in patients under 55 years old than that in patients over 56 years old (p<0.05). The abscopal effect was highly observed in patients who had the infiltrating lymphocytes around the degenerated cancer cells in the irradiated primary tumor nests (p<0.01). The subsets of the infiltrative lymphocytes were analyzed immunohistologically using monoclonal antibodies. The infiltrative lymphocytes were found to be CD8 and CD4 positive lymphocytes. Those findings suggest that the abscopal effect was caused by activated cellular immunity in hosts. Both the five- and ten-year survival rates for stage IIIa was 71.4%. Stage IIIb showed 62.5% for 5 year survival rate and 54.7% for 10 year survival rate. The survival rate was higher in patients with the abscopal effect than those without it; however, this was not statistically significant. No complications such as pneumonia was observed. (author)

  20. Effect of gamma radiation on Campylobacter jejuni

    Energy Technology Data Exchange (ETDEWEB)

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

    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/sup 0/C, at 0-5/sup 0/C, and at 30 +/- 10/sup 0/C. Irradiation at -30/sup 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/sub 10/ value for C. jejuni was 32 Krad, which was less than D/sub 10/ values commonly reported for salmonellae. 20 references, 4 figures.

  1. Radiation effects on DNA methylation in mice

    International Nuclear Information System (INIS)

    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)

  2. The radiation effects on the living cell

    International Nuclear Information System (INIS)

    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.)

  3. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. Medical exposure and the effects of radiation

    International Nuclear Information System (INIS)

    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)

  6. Effects of radiation on aquatic organisms

    International Nuclear Information System (INIS)

    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)

  7. Plutonium, Mineralogy and Radiation Effects

    Science.gov (United States)

    Ewing, R. C.

    2006-05-01

    During the past fifty years, more than 1,800 metric tonnes of Pu and substantial quantities of other "minor" actinides, such as Np, Am and Cm, have been generated in nuclear reactors. Some of these transuranic elements can be a source of energy in fission reactions (e.g., 239Pu), a source of fissile material for nuclear weapons (e.g., 239Pu and 237Np), or are of environmental concern because of their long half- lives and radiotoxicity (e.g., 239Pu, t1/2 = 24,100 years, and 237Np, t1/2 = 2.1 million years). There are two basic strategies for the disposition of these elements: 1.) to "burn" or transmute the actinides using nuclear reactors or accelerators; 2.) to "sequester" the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of actinide-bearing minerals, such as zircon or isometric pyrochlore, A2B2O7 (A = rare earths; B = Ti, Zr, Sn, Hf; Fd3m; Z=8), for the immobilization of actinides, particularly plutonium. One of the principal concerns has been the accumulation of structural damage caused by alpha-decay events, particularly from the recoil nucleus. Systematic ion beam irradiation studies of rare-earth pyrochlores have led to the discovery that certain compositions (B = Zr, Hf) are stable to very high fluences of alpha-decay event damage. Some compositions, Gd2Ti2O7, are amorphized at relatively low doses (0.2 displacements per atom, dpa, at room temperature), while other compositions, Gd2Zr2O7, do not amorphize (even at doses of > 40 dpa at 25K), but instead disorder to a defect fluorite structure. By changing the composition of the A-site (e.g., substitution of different rare earth elements), the temperature above which the pyrochlore composition can no longer be amorphized, Tc, varies by >600 K (e.g., Lu2Ti2O7: Tc = 480 K; Gd2Ti2O7: Tc = 1120 K). The variation in response to irradiation as a function of composition can be used to model the long

  8. The late biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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

  9. Oide Effect and Radiation in Bending Magnets

    CERN Document Server

    Blanco, Oscar; Bambade, Philip

    2014-01-01

    Including radiation effects during lattice design optimization is crucial in high energy accelerators. Oide effect and radiation in bending magnets are reviewed aiming to include them in the optical design process to minimize the IP beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations, concluding in how longer quadrupoles with lower gradients may help reducing the Oide effect. Radiation in bending magnets is reviewed for linear lattices, generalizing to the case when the final dispersion is different from zero and making comparisons with theoretical results and particle tracking. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional tracking in PLACET has been found.

  10. Radiative transfer effects in primordial hydrogen recombination

    CERN Document Server

    Ali-Haïmoud, Yacine; Hirata, Christopher M

    2010-01-01

    The calculation of a highly accurate cosmological recombination history has been the object of particular attention recently, as it constitutes the major theoretical uncertainty when predicting the angular power spectrum of Cosmic Microwave Background anisotropies. Lyman transitions, in particular the Lyman-alpha line, have long been recognized as one of the bottlenecks of recombination, due to their very low escape probabilities. The Sobolev approximation does not describe radiative transfer in the vicinity of Lyman lines to a sufficient degree of accuracy, and several corrections have already been computed in other works. In this paper, the impact of some previously ignored radiative transfer effects is calculated. First, the effect of Thomson scattering in the vicinity of the Lyman-alpha line is evaluated, using a full redistribution kernel incorporated into a radiative transfer code. The effect of feedback of distortions generated by the optically thick deuterium Lyman-alpha line blueward of the hydrogen ...

  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. Radiation Effect Mechanisms in Electronic Devices

    International Nuclear Information System (INIS)

    The development of the electronics industry worldwide achieved great advances from the 70s, with studies on oxidation process in field effect silicon transistors. Thus, there was a need for knowledge of the mechanisms that are present in oxides and interfaces between silicon and silicon oxides, as well as other compound semiconductors due to critical differences between the properties of silicon. Against this background, many studies have been performed to understand reliability and ionization radiation effects on electronic devices. Reliability problems and effects of ionizing radiation on electronic devices are critical, depending on the environment in which the devices are exposed. This is the case of space, avionics, particle accelerators, nuclear reactors. This research area is strategic for space and defense areas. Thus, it is of fundamental importance to conduct tests to qualify electronic devices submitted to irradiation, based on Total Ionizing Dose (Tid), Single Event Effects (SEE) and Displacement Damage (D D). This work shows tests using X-ray and ion beams to test commercial MOS(Metal Oxide Semiconductor Field Effect Transistor). The integrated circuits, CD4007, were exposed to 60 MeV 35Cl ion beams using the Sao Paulo 8UD Pelletron Accelerator and 10 keV X-ray radiation using a Shimadzu XRD-7000. The total dose effects due to ionizing radiation in MOSFET devices can lead to trapping of charges in the oxide and at the interface Si/SiO2, which increases or decreases the transistors off-current and leakage currents, and shifts the threshold voltage. Characteristic curves of current as a function of gate voltage, in different irradiation conditions, for p and n-MOSFET transistors, which compose the commercial device, were studied. In Figure it is possible to note different behaviors of the devices as a function of radiation dose due to X-ray radiation and the incidence a 60 MeV 35Cl ion beam

  13. Radiation damage effects in zircon

    Science.gov (United States)

    Trachenko, Kostya; Dove, Martin; Salje, Ekhard

    2002-03-01

    Zircon, ZrSiO_4, is important for geology and geochronology, and has been proposed as a host material to immobilize highly radioactive materials from dismantled weapons and nuclear waste from power stations [1]. In these applications zircon is exposed to alpha-irradiation. Computer simulations have started to be employed to simulate radiation damage in zircon [2], but the origin and microscopic mechanisms of the most important structural changes in zircon - unit cell expansion and large macroscopic swelling at higher doses, strong shear deformation of the crystalline lattice, and polymerization of SiOn units [3], remain unknown. Here, we perform the molecular dynamics simulation of highly energetic recoils in zircon. Basing on the simulation results, we propose the simple picture of the density change in the damaged region that consists of the depleted and densified matter. We find that the experimentally observed structural changes originate from the interaction of the damaged region with the surrounding crystalline lattice: the shear of the lattice around the damaged region causes shear deformation and expansion of the unit cells. The polymers of connected SiOn polyhedra are most commonly present in the densified shell at the periphery of the damaged region. [1] R C Ewing et al, J. Mater. Res. 10, 243 (1995); W J Weber et al, B E Burakov et al, in Scientific Basis for Nuclear Waste Management XIX, 25-32 and 33-40 (Plenum, New York, 1996); R C Ewing, et al in Crystalline Ceramics: Waste Forms for the Disposal of Weapons Plutonium, NATO Workshop Proceedings 65 (Academic Publishers, Dordrecht, The Netherlands, 1996). [2] B Park et al, Phys. Rev. B, 64, 174108 (1-16) (2001); J P Crocombette and D Ghaleb, J. Nucl. Mater., 295, 167 (2001); K Trachenko et al, J. Appl. Phys., 87, 7702 (2000); K Trachenko et al, J. Phys.: Cond. Matt., 13, 1947 (2001). [3] T Murakami et al, Am. Min., 76, 1510 (1991); H D Holland and D Gottfried, Acta Cryst. 8, 291 (1955).; W J Weber, J. Am

  14. Predictive biochemical assays for late radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, P.; Finkelstein, J.N.; Siemann, D.W.; Shapiro, D.L.; Van Houtte, P.; Penney, D.P.

    1986-04-01

    Surfactant precursors or other products of Type II pneumocytes have the potential to be the first biochemical marker for late radiation effects. This is particularly clinically important in the combined modality era because of the frequent occurrence of pneumonitis and pulmonary fibrosis secondary to radiation or chemotherapy. Accordingly, correlative studies have been pursued with the Type II pneumocyte as a beginning point to understand the complex pathophysiology of radiation pneumonitis and fibrosis. From our ultrastructural and biochemical studies, it is evident that Type II pneumocytes are an early target of radiation and the release of surfactant into the alveolus shortly after exposure persists for days and weeks. Through the use of lavaging techniques, alveolar surfactant has been elevated after pulmonary irradiation. In three murine strains and in the rabbit, there is a strong correlation with surfactant release at 7 and/or 28 days in vivo with later lethality in months. In vitro studies using cultures of type II pneumocytes also demonstrate dose response and tolerance factors that are comparable to the in vivo small and large animal diagnostic models. New markers are being developed to serve as a predictive index for later lethal pneumonopathies. With the development of these techniques, the search for early biochemical markers in man has been undertaken. Through the use of biochemical, histological, and ultrastructural techniques, a causal relationship between radiation effects on type II pneumocytes, pulmonary cells, endothelial cells of blood vessels, and their roles in the production of pneumonitis and fibrosis will evolve.

  15. 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)

  16. Effects of gamma radiation in annatto seeds

    International Nuclear Information System (INIS)

    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)

  17. Effects of gamma radiation in soybean

    International Nuclear Information System (INIS)

    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)

  18. Predictive biochemical assays for late radiation effects

    International Nuclear Information System (INIS)

    Surfactant precursors or other products of Type II pneumocytes have the potential to be the first biochemical marker for late radiation effects. This is particularly clinically important in the combined modality era because of the frequent occurrence of pneumonitis and pulmonary fibrosis secondary to radiation or chemotherapy. Accordingly, correlative studies have been pursued with the Type II pneumocyte as a beginning point to understand the complex pathophysiology of radiation pneumonitis and fibrosis. From our ultrastructural and biochemical studies, it is evident that Type II pneumocytes are an early target of radiation and the release of surfactant into the alveolus shortly after exposure persists for days and weeks. Through the use of lavaging techniques, alveolar surfactant has been elevated after pulmonary irradiation. In three murine strains and in the rabbit, there is a strong correlation with surfactant release at 7 and/or 28 days in vivo with later lethality in months. In vitro studies using cultures of type II pneumocytes also demonstrate dose response and tolerance factors that are comparable to the in vivo small and large animal diagnostic models. New markers are being developed to serve as a predictive index for later lethal pneumonopathies. With the development of these techniques, the search for early biochemical markers in man has been undertaken. Through the use of biochemical, histological, and ultrastructural techniques, a causal relationship between radiation effects on type II pneumocytes, pulmonary cells, endothelial cells of blood vessels, and their roles in the production of pneumonitis and fibrosis will evolve

  19. 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)

  20. Effects of the neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Alcober, V. (Junta de Energia Nuclear, Madrid (Spain)); Martinez Ruis, F.; Manuzi, M.A. (Dpto. de Traumatologia Centro Ramon y Cajal, Madrid (Spain))

    1984-01-01

    An introduction to the cortical bone neutron irradiation subject and to the effect of the irradiation on the mechanical properties of bone considered as a composite material is presented. Only the special case of the simple flexion has been treated. The evolution of the load-deflection curve as a function of the epithermal neutron dose has been studied. Some hypotheses on the role performed by the organic and mineral phases are introduced.

  1. 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).

  2. The effects and control of radiation

    International Nuclear Information System (INIS)

    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.)

  3. Effects of Low Dose Radiation on Mammals 1

    OpenAIRE

    Okumura, Yutaka; Mine, Mariko; Kishikawa, Masao

    1991-01-01

    Radiation has been applied widely to clinics, researches and industries nowadays. Irradiation by atomic bomb produced many victims in Hiroshima and Nagasaki. Radiation effects on animals and human belings have been reported extensively, especially at a dose range of high amount of radiation. As radiation effects at low dose have not been well studied, it is believed that even a small amount of radiation produces hazardous effects. However, it might not be true. Beneficial effects of a low dos...

  4. Biological effects of synchrotron radiation on crops

    Institute of Scientific and Technical Information of China (English)

    唐掌雄; 董保中; 等

    1996-01-01

    The sensitivity of germinating seeds of barley,winter wheat and spring one to synchrotron ultraviolet radiation is barley>winter wheat and spring one.But when dry seeds of the three crops are irradiated by 3.5-22keV X-rays,the sequence of their sensitivity to radiation can be changed.for irradiation of 0.6-3keV ultra soft X-rays,0.40-0.90 of the seedlings of the first generation appear mutation of striped chlorophyll defect.This biological effect has never been found for irradiation of other rays.

  5. Effects of XUV radiation on circumbinary planets

    CERN Document Server

    Sanz-Forcada, J; Micela, G

    2014-01-01

    Several circumbinary planets have recently been discovered. The orbit of a planet around a binary stellar system poses several dynamic constraints. The effects that radiation from the host stars may have on the planet atmospheres must be considered. Because of the configuration of a close binary system, these stars have a high rotation rate, which causes a permanent state of high stellar activity and copious XUV radiation. The accumulated effects are stronger than for exoplanets around single stars, and cause a faster evaporation of their atmospheres. We evaluate the effects that stellar radiation has on the evaporation of exoplanets around binary systems and on the survival of these planets. We considered the XUV spectral range to account for the photons that are easily absorbed by a planet atmosphere that is mainly composed of hydrogen. A more complex atmospheric composition is expected to absorb this radiation more efficiently. We used direct X-ray observations to evaluate the energy in the X-rays range an...

  6. Radiation effects and crystallinity in polyethylene

    Science.gov (United States)

    Keller, A.; Ungar, G.

    A survey is presented of a series of works on the influence of crystallinity on the radiation induced effects, cross-linking in particular, in polyethylene and paraffins. The principal theme is that the usual conception of random introduction of cross-links into a random assembly of chains needs to be modified in the presence of crystallinity in general and chain folding in particular. A long series of varied investigations on polyethylene have indeed demonstrated through a series of conspicuous effects that not only the ordering intrinsic to crystals and the increased intrachain contacts due to chain folding, but the higher level morphology, the nature and mutual arrangement in particular, have a major influence on the effectivity of the radiation leading to networks. Extension of the works to paraffins identified unsuspected mobility of both the radiation precursor species and the paraffin molecule itself (cross-linked and uncross-linked) within the crystal lattice, leading to phase segregation of the cross-linked species into microscopically identifiable domains together with identifying a trend for the cross-links themselves to form non-randomly in groups. The latter phenomenon, observed also in the molten state, indicates that the departure from randomness in the cross-linking process is much more deep-rooted than originally anticipated, and calls for a general reassessment of our knowledge of cross-linking. Other topics included as part of the general enquiry are the destruction of crystallinity, the promotion of hexagonal phase through radiation, the effect of morphology on chain scission and the general, still unsolved issue of how to assess cross-links by a direct analytical method (involving NMR). The hope is expressed that the bringing together of these varied pieces of work will serve the unification of presently widely diverse areas of experience and might influence developments in the radiation studies of paraffinoid substances.

  7. Radiation effect on PVC/ENR blends

    International Nuclear Information System (INIS)

    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

  8. Working group written presentation: Trapped radiation effects

    Science.gov (United States)

    Vampola, Alfred L.; Stuckey, Wayne K.; Coulter, D.; Friebele, E. J.; Hand, K. J.; Hardy, D. A.; Higby, P.; Kolasinski, W. A.; Santoro, R. T.; Tompkins, Stephen S.

    1989-01-01

    The results of the Trapped Radiation Effects Panel for the Space Environmental Effects on Materials Workshop are presented. The needs of the space community for new data regarding effects of the space environment on materials, including electronics are listed. A series of questions asked of each of the panels at the workshop are addressed. Areas of research which should be pursued to satisfy the requirements for better knowledge of the environment and better understanding of the effects of the energetic charged particle environment on new materials and advanced electronics technology are suggested.

  9. Effects of radiation damage on SYNROC

    International Nuclear Information System (INIS)

    Concern has been expressed in several quarters that the integrity of SYNROC as a waste form might be compromised by the effects of alpha radiation damage on its constituent minerals. The evidence discussed herein addresses that concern. Radiation damage to crystal lattices is caused dominantly by alpha emitters (actinide elements) present in zirconolite and perovskite phases. We have seen that the zirconolite phase in SYNROC containing 10% of HLW would require about 106 years before becoming completely metamict, i.e., losing the capacity to diffract X-rays. By this time, the alpha activity in SYNROC would have declined to a value smaller than that present in a natural uranium ore body. This level of activity can be considered effectively safe for a waste form buried in a suitable geologic repository. Moreover, even when metamict, the zirconolite continues to demonstrate a remarkable capacity to immobilize U, Th and their decay daughter products. The isotopic measurements on Sri Lanka and Jimberlana zirconolites demonstrated that these metamict minerals had behaved as closed systems for U, Th and Pb for periods of 560 and 2500 million years, respectively, despite intense radiation damage (SYNROC equivalent ages, about or greater than 109 years). Moreover, the Sri Lanka zirconolite was sufficiently tight to immobilize a considerable proportion of radiogenic helium, one of the most mobile of elements, for 560 million years. Our data on perovskite are limited and more work remains to be done. Nevertheless, present results indicate that perovskites are even more resistant to radiation damage than zirconolite

  10. Neurophysiological appropriateness of ionizing radiation effects

    International Nuclear Information System (INIS)

    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)

  11. Literature survey: health effects of radiation

    International Nuclear Information System (INIS)

    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.)

  12. Radiation Effects in Nuclear Waste Materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, William J.

    2005-09-30

    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.

  13. Radiation Effects in Nuclear Waste Materials

    Energy Technology Data Exchange (ETDEWEB)

    Weber, William J.

    2005-06-01

    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.

  14. Microwave radiation: biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1981-01-01

    The thermal effects of microwave radiation are well recognized and are discussed with particular reference to cataractogenesis; the possibility of an association cannot be questioned. Postulated nonthermal effects comprise an asthenic syndrome, and for the most part the disturbances lie within clinical norms and tolerances, and are reversible. World opinion on safe exposure levels for microwave radiation is varied, and this had led to national standards disparate by three to four orders of magnitude. The US and UK exposure standard of 10 mW/cm/sup 2/ was determined over two decades ago; the possibility of a change to a more restrictive level, in line with other countries, in the near future is examined. It is concluded that such a change, without scientific rationale, is not justified. Some biological implications of the microwave radiation from the solar power satellite are considered in terms of precautions to be taken by personnel working in the vicinity of the rectenna, effects on cardiac pacemakers, and any potential effects on birds. 14 references.

  15. Radiation Effects in the Space Telecommunications Environment

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 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.

  18. Radiation effects on algae and its application

    International Nuclear Information System (INIS)

    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)

  19. Casimir Effect, Hawking Radiation and Trace Anomaly

    CERN Document Server

    Setare, M R

    2001-01-01

    The Casimir energy for massless scalar field of two parallel conductor, in two dimensional Schwarzchild black hole background, with Dirichlet boundary conditions is calculated by making use of general properties of renormalized stress tensor. We show that vacuum expectation value of stress tensor can be obtain by Casimir effect, trace anomaly and Hawking radiation. Four-dimensional of this problem, by this method, is under progress by this author.

  20. 47 CFR 95.855 - Transmitter effective radiated power limitation.

    Science.gov (United States)

    2010-10-01

    ... Transmitter effective radiated power limitation. The effective radiated power (ERP) of each CTS and RTU shall... with an ERP exceeding 20 watts. No mobile RTU may transmit with an ERP exceeding 4 watts....

  1. 47 CFR 22.867 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... Effective radiated power limits. The effective radiated power (ERP) of ground and airborne stations... peak ERP of airborne mobile station transmitters must not exceed 12 Watts. (b) The peak ERP of...

  2. Gamma radiation effects on nestling Tree Swallows

    International Nuclear Information System (INIS)

    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

  3. 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

  4. Radiation and transmutation effects relevant to solid nuclear waste forms

    International Nuclear Information System (INIS)

    Radiation effects in insulating solids are discussed in a general way as an introduction to the quite sparse published work on radiation effects in candidate nuclear waste forms other than glasses. Likely effects of transmutation in crystals and the chemical mitigation strategy are discussed. It seems probable that radiation effects in solidified HLW will not be serious if the actinides can be wholly incorporated in such radiation-resistant phases as monazite or uraninite

  5. Annual report of Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    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.)

  6. 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.

  7. Radiation piezoelectric effect in germanium single crystals

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-06-01

    Irradiation with ionizing particles of a germanium single crystal and uniaxial deformation at right-angles to the particle beam produced an electric field and a corresponding emf due to the radiation piezoelectric effect. Measurements were carried out when such a single crystal was irradiated with ..cap alpha.. particles and protons. The piezoelectric emf increased linearly with the compressive stress and the ..cap alpha..-particle flux intensity. The emf depended weakly on the particle energy. The observed effect was due to the anisotropy resulting from uniaxial deformation.

  8. Effect of Gamma radiation on mycotoxins solutions

    OpenAIRE

    Calado, Thalita; António, Amilcar L.; Rodrigues, Paula; Cabo Verde, Sandra; Abrunhosa, Luís; Venâncio, Armando

    2013-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in degradation of some mycotoxins from food. The aim of this study was to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2), ochatoxin A (OTA) and zearelone (ZEA). The effect of the presence of moisture during the i...

  9. Effect of gamma radiation on mycotoxins solutions

    OpenAIRE

    Calado, Thalita; Antonio, Amilcar L.; Rodrigues, Paula; Cabo Verde, Sandra; Venâncio, Armando

    2013-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in degradation of some mycotoxins from food. The aim of this study was to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1) aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2), ochatoxin A (OTA) and zearelone (ZEA). The effect of the presence of moisture during the i...

  10. Nonlocal Effects in Black Body Radiation

    CERN Document Server

    Bremm, G N

    2016-01-01

    Nonlocal electrodynamics is a formalism developed to include nonlocal effects in the measurement process caused by the non-inertial state of the observers. This theory modifies Maxwell's electrodynamics by eliminating the hypothesis of locality that assumes an accelerated observer simultaneously equivalent to a comoving inertial frame of reference. In this scenario, the transformation between an inertial and accelerated observer is generalized which affects the properties of physical fields. In particular, we analyze how an uniformly accelerated observer perceives a homogeneous and isotropic blackbody radiation. We show that all nonlocal effects are transient and most relevant in the first period of acceleration.

  11. Radiation effects on active pixel sensors (APS)

    International Nuclear Information System (INIS)

    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 60Co 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

  12. Effect of radiation on hydrotalcites with chromates

    International Nuclear Information System (INIS)

    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 (MgAl2O4) 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)

  13. 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...

  14. Modern Radiotherapy Concepts and the Impact of Radiation on Immune Activation.

    Science.gov (United States)

    Deloch, Lisa; Derer, Anja; Hartmann, Josefin; Frey, Benjamin; Fietkau, Rainer; Gaipl, Udo S

    2016-01-01

    Even though there is extensive research carried out in radiation oncology, most of the clinical studies focus on the effects of radiation on the local tumor tissue and deal with normal tissue side effects. The influence of dose fractionation and timing particularly with regard to immune activation is not satisfactorily investigated so far. This review, therefore, summarizes current knowledge on concepts of modern radiotherapy (RT) and evaluates the potential of RT for immune activation. Focus is set on radiation-induced forms of tumor cell death and consecutively the immunogenicity of the tumor cells. The so-called non-targeted, abscopal effects can contribute to anti-tumor responses in a specific and systemic manner and possess the ability to target relapsing tumor cells as well as metastases. The impact of distinct RT concepts on immune activation is outlined and pre-clinical evidence and clinical observations on RT-induced immunity will be discussed. Knowledge on the radiosensitivity of immune cells as well as clinical evidence for enhanced immunity after RT will be considered. While stereotactic ablative body radiotherapy seem to have a beneficial outcome over classical RT fractionation in pre-clinical animal models, in vitro model systems suggest an advantage for classical fractionated RT for immune activation. Furthermore, the optimal approach may differ based on the tumor site and/or genetic signature. These facts highlight that clinical trials are urgently needed to identify whether high-dose RT is superior to induce anti-tumor immune responses compared to classical fractionated RT and in particular how the outcome is when RT is combined with immunotherapy in selected tumor entities. PMID:27379203

  15. Radiation Effects on DC-DC Converters

    Science.gov (United States)

    Zhang, De-Xin; AbdulMazid, M. D.; Attia, John O.; Kankam, Mark D. (Technical Monitor)

    2001-01-01

    In this work, several DC-DC converters were designed and built. The converters are Buck Buck-Boost, Cuk, Flyback, and full-bridge zero-voltage switched. The total ionizing dose radiation and single event effects on the converters were investigated. The experimental results for the TID effects tests show that the voltages of the Buck Buck-Boost, Cuk, and Flyback converters increase as total dose increased when using power MOSFET IRF250 as a switching transistor. The change in output voltage with total dose is highest for the Buck converter and the lowest for Flyback converter. The trend of increase in output voltages with total dose in the present work agrees with those of the literature. The trends of the experimental results also agree with those obtained from PSPICE simulation. For the full-bridge zero-voltage switch converter, it was observed that the dc-dc converter with IRF250 power MOSFET did not show a significant change of output voltage with total dose. In addition, for the dc-dc converter with FSF254R4 radiation-hardened power MOSFET, the output voltage did not change significantly with total dose. The experimental results were confirmed by PSPICE simulation that showed that FB-ZVS converter with IRF250 power MOSFET's was not affected with the increase in total ionizing dose. Single Event Effects (SEE) radiation tests were performed on FB-ZVS converters. It was observed that the FB-ZVS converter with the IRF250 power MOSFET, when the device was irradiated with Krypton ion with ion-energy of 150 MeV and LET of 41.3 MeV-square cm/mg, the output voltage increased with the increase in fluence. However, for Krypton with ion-energy of 600 MeV and LET of 33.65 MeV-square cm/mg, and two out of four transistors of the converter were permanently damaged. The dc-dc converter with FSF254R4 radiation hardened power MOSFET's did not show significant change at the output voltage with fluence while being irradiated by Krypton with ion energy of 1.20 GeV and LET of 25

  16. Basic radiation effects in nuclear power electronics technology

    International Nuclear Information System (INIS)

    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

  17. Gamma Radiation Effects on Peanut Skin Antioxidants

    Directory of Open Access Journals (Sweden)

    Adriano Costa de Camargo

    2012-03-01

    Full Text Available Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ. Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h, measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts’ antioxidative properties when added to soybean oil.

  18. Gamma radiation effects on peanut skin antioxidants.

    Science.gov (United States)

    de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D'Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached-deodorized (RBD) soybean oil. The oxidative stability of the oil samples was determined using the Oil Stability Index method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. All extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Oil Stability Index method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative properties when added to soybean oil.

  19. The effects of solar radiation and black body re-radiation on thermal comfort.

    Science.gov (United States)

    Hodder, Simon; Parsons, Ken

    2008-04-01

    When the sun shines on people in enclosed spaces, such as in buildings or vehicles, it directly affects thermal comfort. There is also an indirect effect as surrounding surfaces are heated exposing a person to re-radiation. This laboratory study investigated the effects of long wave re-radiation on thermal comfort, individually and when combined with direct solar radiation. Nine male participants (26.0 +/- 4.7 years) took part in three experimental sessions where they were exposed to radiation from a hot black panel heated to 100 degrees C; direct simulated solar radiation of 600 Wm(-2) and the combined simulated solar radiation and black panel radiation. Exposures were for 30 min, during which subjective responses and mean skin temperatures were recorded. The results showed that, at a surface temperature of 100 degrees C (close to maximum in practice), radiation from the flat black panel provided thermal discomfort but that this was relatively small when compared with the effects of direct solar radiation. It was concluded that re-radiation, from a dashboard in a vehicle, for example, will not have a major direct influence on thermal comfort and that existing models of thermal comfort do not require a specific modification. These results showed that, for the conditions investigated, the addition of re-radiation from internal components has an effect on thermal sensation when combined with direct solar radiation. However, it is not considered that it will be a major factor in a real world situation. This is because, in practice, dashboards are unlikely to maintain very high surface temperatures in vehicles without an unacceptably high air temperature. This study quantifies the contribution of short- and long-wave radiation to thermal comfort. The results will aid vehicle designers to have a better understanding of the complex radiation environment. These include direct radiation from the sun as well as re-radiation from the dashboard and other internal surfaces.

  20. 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

  1. Gamma Radiation Effects on Peanut Skin Antioxidants

    OpenAIRE

    de Camargo, Adriano Costa; Vieira, Thais Maria Ferreira de Souza; Regitano-d’Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia; Solange Guidolin CANNIATTI-BRAZACA

    2012-01-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to...

  2. Effects of ionizing radiations on insects

    International Nuclear Information System (INIS)

    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

  3. Late effects of ionizing radiation on testis; Effets tardifs des radiations ionisantes sur le testicules

    Energy Technology Data Exchange (ETDEWEB)

    Bardet, E. [Centre Regional de Lutte Contre le Cancer Rene-Gauducheau, 44 - Nantes (France)

    1997-12-01

    Most of the basic data regarding the effect of radiation on the testis are issued from animal studies. They demonstrate the extreme radiosensitivity on the germ cell lineage but little is known about the reversible or definitive aspects of these radiation induced effects. In man, the late non stochastic effects of radiation to the testicle are mainly related to persisting spermatogenesis disturbances or/and hormone related problems. Morphological, physiological, radiobiological specificities of the human testis along with numerous parameters depending on radiation conditions make it difficult to evaluate the late effects and radiation tolerance doses. Evaluation of such effects based on a common scale for therapeutic radiation schedules would improve the present understanding and possibility prevent the occurrence of these delayed effects, for the benefit of patients. (author)

  4. Effects of Nuclear Interactions in Space Radiation Transport

    Science.gov (United States)

    Lin, Zi-Wei; Barghouty, A. F.

    2005-01-01

    Space radiation transport codes have been developed to calculate radiation effects behind materials in human mission to the Moon, Mars or beyond. We study how nuclear fragmentation processes affect predictions from such radiation transport codes. In particular, we investigate the effects of fragmentation cross sections at different energies on fluxes, dose and dose-equivalent from galactic cosmic rays behind typical shielding materials.

  5. Radiative Effects in the Standard Model Extension

    CERN Document Server

    Zhukovskii, V C; Murchikova, E M

    2006-01-01

    The possibility of radiative effects induced by the Lorentz and CPT non-invariant interaction term for fermions in the Standard Model Extension is investigated. In particular, electron-positron photo-production and photon emission by electrons and positrons were studied. The rates of these processes were calculated in the Furry picture. It was demonstrated that the rates obtained in the framework of the model adopted strongly depend on the polarization states of the particles involved. Indeed, ultra-relativistic particles should occupy states with a preferred spin orientation, i.e., photons have the sign of polarization opposite to the sign of the effective potential, while charged particle are preferably in the state with the helicity coinciding with the sign of the effective potential. This leads to evident spatial asymmetries which may have certain consequences observable in astrophysical and cosmological studies.

  6. Conditions for effects of radiation pulsing

    CERN Document Server

    Trinkaus, H

    2002-01-01

    The possibility of pulsing effects on radiation damage is due to differences in the delay times of relevant defect reactions and/or to the non-linear dependence of such reactions on defect production rates. Thus, significant pulsing effects require (1) proper relationships of the internal time scales of defect production and reaction to the time scales of pulsing and (2) sufficiently large pulsing induced fluctuations in relevant microstructural variables. We show that the first condition, which we quantify by a 'relative dynamic bias', is indeed fulfilled in wide ranges of the main irradiation parameters. The second condition, quantified by an 'absolute dynamic bias', is, however, found to restrict the parameter ranges of possible pulsing effects substantially. For planned spallation neutron sources and similar accelerator driven systems facilities we find, for instance, that, in the temperature range of interest, the defect yield of one pulse (controlling the absolute dynamic bias) is much too small to allo...

  7. Radiative transfer effects during primordial helium recombination

    CERN Document Server

    Chluba, Jens; Switzer, Eric R

    2011-01-01

    In this paper we refine the calculation of primordial helium recombination, accounting for several additional effects that were neglected or treated more approximately in previous studies. These include consideration of (i) time-dependent radiative transfer interaction between the 2^1 P_1 - 1^1 S_0 and 2^3 P_1 - 1^1 S_0 resonances; (ii) time-dependent radiative transfer for the partially overlapping n^1 P_1 - 1^1 S_0, n^1 D_2 - 1^1 S_0 and n^3 P_1 - 1^1 S_0 series with 3 \\leq n \\leq 10; (iii) electron scattering within a kernel approach. We also briefly discuss the effect of electron scattering and HI quadrupole lines on the recombination of hydrogen. Although the physics of all the considered processes is interesting and subtle, for the standard cosmology the overall correction to the ionization history during helium recombination with respect to the previous treatment remains smaller than |DeltaNe/Ne| \\sim 0.05%. For models with a large helium fraction Y_p \\sim 0.4, the difference can reach |\\DeltaNe/Ne| \\s...

  8. MEDICAL AND ENVIRONMENTAL EFFECTS OF UV RADIATION.

    Energy Technology Data Exchange (ETDEWEB)

    SUTHERLAND, B.M.

    2001-07-26

    Organisms living on the earth are exposed to solar radiation, including its ultraviolet (UV) components (for general reviews, the reader is referred to Smith [1] and Young et al. [2]). UV wavelength regions present in sunlight are frequently designated as UVB (290-320 nm) and UVA (320-400 nm). In today's solar spectrum, UVA is the principal UV component, with UVB present at much lower levels. Ozone depletion will increase the levels of UVB reaching the biosphere, but the levels of UVA will not be changed significantly [3]. Because of the high efficiency of UVB in producing damage in biological organisms in the laboratory experiments, it has sometimes been assumed that UVA has little or no adverse biological effects. However, accumulating data [4, 5], including action spectra (efficiency of biological damage as a function of wavelength of radiation; see Section 5) for DNA damage in alfalfa seedlings [6], in human skin [7], and for a variety of plant damages (Caldwell, this volume) indicate that UVA can induce damage in DNA in higher organisms. Thus, understanding the differential effects of UVA and UVB wavebands is essential for estimating the biological consequences of stratospheric ozone depletion.

  9. Biological effects of space radiation and development of effective countermeasures

    Science.gov (United States)

    Kennedy, Ann R.

    2014-04-01

    As part of a program to assess the adverse biological effects expected from astronauts' exposure to space radiation, numerous different biological effects relating to astronauts' health have been evaluated. There has been major focus recently on the assessment of risks related to exposure to solar particle event (SPE) radiation. The effects related to various types of space radiation exposure that have been evaluated are: gene expression changes (primarily associated with programmed cell death and extracellular matrix (ECM) remodeling), oxidative stress, gastrointestinal tract bacterial translocation and immune system activation, peripheral hematopoietic cell counts, emesis, blood coagulation, skin, behavior/fatigue (including social exploration, submaximal exercise treadmill and spontaneous locomotor activity), heart functions, alterations in biological endpoints related to astronauts' vision problems (lumbar puncture/intracranial pressure, ocular ultrasound and histopathology studies), and survival, as well as long-term effects such as cancer and cataract development. A number of different countermeasures have been identified that can potentially mitigate or prevent the adverse biological effects resulting from exposure to space radiation.

  10. Deterministic effects of the ionizing radiation

    International Nuclear Information System (INIS)

    Full text: The deterministic effect is the somatic damage that appears when radiation dose is superior to the minimum value or 'threshold dose'. Over this threshold dose, the frequency and seriousness of the damage increases with the amount given. Sixteen percent of patients younger than 15 years of age with the diagnosis of cancer have the possibility of a cure. The consequences of cancer treatment in children are very serious, as they are physically and emotionally developing. The seriousness of the delayed effects of radiation therapy depends on three factors: a)- The treatment ( dose of radiation, schedule of treatment, time of treatment, beam energy, treatment volume, distribution of the dose, simultaneous chemotherapy, etc.); b)- The patient (state of development, patient predisposition, inherent sensitivity of tissue, the present of other alterations, etc.); c)- The tumor (degree of extension or infiltration, mechanical effects, etc.). The effect of radiation on normal tissue is related to cellular activity and the maturity of the tissue irradiated. Children have a mosaic of tissues in different stages of maturity at different moments in time. On the other hand, each tissue has a different pattern of development, so that sequelae are different in different irradiated tissues of the same patient. We should keep in mind that all the tissues are affected in some degree. Bone tissue evidences damage with growth delay and degree of calcification. Damage is small at 10 Gy; between 10 and 20 Gy growth arrest is partial, whereas at doses larger than 20 Gy growth arrest is complete. The central nervous system is the most affected because the radiation injuries produce demyelination with or without focal or diffuse areas of necrosis in the white matter causing character alterations, lower IQ and functional level, neuro cognitive impairment,etc. The skin is also affected, showing different degrees of erythema such as ulceration and necrosis, different degrees of

  11. Radiation

    International Nuclear Information System (INIS)

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  12. Radiation effects in SYNROC-D

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, R.A.; Guinan, M.W.

    1981-09-30

    This paper describes SYNROC-D and the irradiation it will be subjected to over the first million years of storage. This will include about 8 x 10/sup 24/ alpha decays per m/sup 3/ and a total ionization dose of about 1 x 10/sup 11/ rads. Methods of simulating the radiation effects are discussed. Previous work by others is reviewed and compared on a dpa basis. /sup 238/Pu doping experiments to simulate internal alpha decay are described, and the progress is discussed. It is concluded that dose rate effects on swelling and metamictization of perovskite and zirconolite are small over a wide range of dose rate, and that swelling and metamictization in these minerals does not anneal significantly over geological time periods.

  13. Radiation effects in SYNROC-D

    International Nuclear Information System (INIS)

    This paper describes SYNROC-D and the irradiation it will be subjected to over the first million years of storage. This will include about 8 x 1024 alpha decays per m3 and a total ionization dose of about 1 x 1011 rads. Methods of simulating the radiation effects are discussed. Previous work by others is reviewed and compared on a dpa basis. 238Pu doping experiments to simulate internal alpha decay are described, and the progress is discussed. It is concluded that dose rate effects on swelling and metamictization of perovskite and zirconolite are small over a wide range of dose rate, and that swelling and metamictization in these minerals does not anneal significantly over geological time periods

  14. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  15. Gamma radiation effects on peanut skin antioxidants

    International Nuclear Information System (INIS)

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The viability of using natural sources of antioxidants to replace synthetic antioxidants was assessed. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays at a dose rate of 7.5 kGy/h using a 60Co source. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached deodorized (RBD) soybean oil that was free from synthetic antioxidants. The oxidative stability of the oil samples was determined using the Rancimat method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. Ethanolic extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Rancimat method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT but lower than THBQ. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative level when added to soybean oil. The induction period of the control soybean oil was 5.7 h, while soybean oil with added ethanolic peanut skin extract had an induction period of 7.2 h, on average. (author)

  16. Gamma radiation effects on peanut skin antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Adriano Costa de [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Canniatti-Brazaca, Solange Guidolin; Vieira, Thais Maria Ferreira de Souza; Regitano-d' Arce, Marisa Aparecida Bismara; Calori-Domingues, Maria Antonia, E-mail: sgcbraza@usp.b, E-mail: tvieira@esalq.usp.b, E-mail: mabra@esalq.usp.b, E-mail: macdomin@esalq.usp.b [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao

    2011-07-01

    Peanut skin, which is removed in the peanut blanching process, is rich in bioactive compounds with antioxidant properties. The viability of using natural sources of antioxidants to replace synthetic antioxidants was assessed. The aims of this study were to measure bioactive compounds in peanut skins and evaluate the effect of gamma radiation on their antioxidant activity. Peanut skin samples were treated with 0.0, 5.0, 7.5, or 10.0 kGy gamma rays at a dose rate of 7.5 kGy/h using a {sup 60}Co source. Total phenolics, condensed tannins, total flavonoids, and antioxidant activity were evaluated. Extracts obtained from the peanut skins were added to refined-bleached deodorized (RBD) soybean oil that was free from synthetic antioxidants. The oxidative stability of the oil samples was determined using the Rancimat method and compared to a control and synthetic antioxidants (100 mg/kg BHT and 200 mg/kg TBHQ). Gamma radiation changed total phenolic content, total condensed tannins, total flavonoid content, and the antioxidant activity. Ethanolic extracts, gamma irradiated or not, presented increasing induction period (h), measured by the Rancimat method, when compared with the control. Antioxidant activity of the peanut skins was higher than BHT but lower than THBQ. The present study confirmed that gamma radiation did not affect the peanut skin extracts' antioxidative level when added to soybean oil. The induction period of the control soybean oil was 5.7 h, while soybean oil with added ethanolic peanut skin extract had an induction period of 7.2 h, on average. (author)

  17. Effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  18. Ambient radiation exposure: measurements and effects

    International Nuclear Information System (INIS)

    A brief review of the available literature, data and reports of various radiation exposure and protection studies and various measurements techniques are presented. A linear quadratic model has been given illustrating the validity of radiation hormesis

  19. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    This report firstly summarises information on the biological hazards of radiation and their relation to radiation dose, and hence estimates the biological risks associated with nuclear power production. Secondly, it describes the basis and present status of radiation protection standards in the nuclear power industry

  20. Radiation physical chemistry effects on organic detectors

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, C.H.; Duarte, C.L.; Hamada, M.M. E-mail: mmhamada@net.ipen.br

    2003-06-01

    The radiation damage effect on a liquid scintillating system was evaluated in the PPO and POPOP solutes. Samples containing PPO (1%w/v) and POPOP (0.2%w/v) diluted in toluene were irradiated at different doses, using a {sup 60}Co irradiator at 1.8 Gy/s. The transmittance and the chemical degradation of those solutes were evaluated as a function of dose. The PPO transmittance at 360 nm decayed exponentially with the dose, while the POPOP transmittance at 420 nm decayed linearly. The chemical degradation on the PPO and POPOP was fitted to a bi-exponential mathematical model as a function of dose. The first exponential (fast slope) was interpreted as damage produced by toluene radiolytics whereas the second exponential (slow slope) was interpreted as the damage caused by primary interaction of the {gamma}-radiation with targets, i.e., {gamma} photons that hit PPO and POPOP directly. The w (eV/damage molecule) and G (damaged molecules/100 eV) parameters were estimated in this paper.

  1. Health effects of atomic-bomb radiation

    International Nuclear Information System (INIS)

    This review described carcinogenic and genetic effects of A-bomb radiation. Effects have been investigated on 120,000 exposed people for their life span, 20,000 for health examinations, 3,000 people exposed in the womb and 80,000 second-generations of the exposed people. Epidemiological data revealed the presence of carcinogenic effects: Cancer death amounted to 9% from 1950 to 1990. However, carcinogenic mechanism is unknown yet. Genetic effects have been studied from the points of lesion at birth, sex ratio, chromosome aberration, biochemical test and mortality rate of children of exposed people and, although the effects have been experimentally shown in animals, are not observed in those children. This may be derived from the fact that there are few people who were exposed to such a high dose as used experimentally (0.2 Sv exposure to people within 2.5 km diameter-area from the explosion point vs >3 Sv in animals). Data are presented in Research Foundation home page. (K.H.)

  2. Effects of radiation and chemical substances on cells and organism

    International Nuclear Information System (INIS)

    The book treats the radiation chemistry part of biophysics and applied biophysics in the sphere of ionizing radiation. Discussed are the concepts of radiation units and radioactivity units and the relative biological efficiency. The effects of ionizing and UV radiations are analyzed at the level of macromolecular changes. Chapters dealing with genetic radiation effects discuss the effects at the cellular level with respect to cell proliferation. All these problems are used to illustrate the effect on the organism as a whole. The chapters on applied biophysics deal with the indications of radiation and chemical damage, sensitivity of cells and the organism, and the study and influencing of growth at the cellular level. The concluding chapter is devoted to the environmental impact of radiation. (J.P.)

  3. Effects of radiation on MOS structures and silicon devices

    International Nuclear Information System (INIS)

    A comprehensive view of radiation effects on MOS structures and silicon devices is given. In the introduction, the interaction of radiation with semiconductor material is presented. In the next section, the electrical degradation of semiconductor devices due to this interaction is discussed. The commonly used hardening techniques are shown. The last section deals with testing of radiation hardness of devices. (orig.)

  4. Statistical issues in modelling radiation effects on disease incidence

    International Nuclear Information System (INIS)

    The author attempts to outline an overview of some models which have proven useful in recent work with radiation effects data. Topics addressed are mathematical models for radiation effects on disease incidence, modelling of background rates, relative versus excess risk models, dose-response effects, dose effect modification (sex and age at exposure), temporal variation in risks. (Author)

  5. Therapeutic effects of low radiation doses

    International Nuclear Information System (INIS)

    This editorial explores the scientific basis of radiotherapy with doses of < 1 Gy for various non-malignant conditions, in particular dose-effect relationships, risk-benefit considerations and biological mechanisms. A review of the literature, particularly clinical and experimental reports published more than 50 years ago was conducted to clarify the following problems. 1. The dose-response relationships for the therapeutic effects on three groups of conditions: non-malignant skin disease, arthrosis and other painful degenerative joint disorders and anti-inflammatory radiotherapy; 2. risks after radiotherapy and after the best alternative treatments; 3. the biological mechanisms of the different therapeutic effects. Radiotherapy is very effective in all three groups of disease. Few dose-finding studies have been performed, all demonstrating that the optimal doses are considerable lower than the generally recommended doses, yet few of these studies meet the required standard. In different conditions, risk-benefit analysis of radiotherapy versus the best alternative treatment yields very different results: whereas radiotherapy for acute postpartum mastitis may not be justified any more, the risk-benefit ratio of radiotherapy of other conditions and particularly so in dermatology and some anti-inflammatory radiotherapy appears to be more favourable than the risk-benefit ratio of the best alternative treatments. Radiotherapy can be very effective treatment for various non-malignant conditions such as eczema, psoriasis, periarthritis humeroscapularis, epicondylitis, knee arthrosis, hydradenitis, parotitis and panaritium and probably be associated with less acute and long-term side effects than similarly effective other treatments. Randomized clinical studies are required to find the optimal dosage which, at present, may be unnecessarily high. Since no adequate experimental studies have been performed nothing is known about the mechanisms of these therapeutic radiation

  6. Gamma radiation effects on silicon photonic waveguides.

    Science.gov (United States)

    Grillanda, Stefano; Singh, Vivek; Raghunathan, Vivek; Morichetti, Francesco; Melloni, Andrea; Kimerling, Lionel; Agarwal, Anuradha M

    2016-07-01

    To support the use of integrated photonics in harsh environments, such as outer space, the hardness threshold to high-energy radiation must be established. Here, we investigate the effects of gamma (γ) rays, with energy in the MeV-range, on silicon photonic waveguides. By irradiation of high-quality factor amorphous silicon core resonators, we measure the impact of γ rays on the materials incorporated in our waveguide system, namely amorphous silicon, silicon dioxide, and polymer. While we show the robustness of amorphous silicon and silicon dioxide up to an absorbed dose of 15 Mrad, more than 100× higher than previous reports on crystalline silicon, polymer materials exhibit changes with doses as low as 1 Mrad. PMID:27367099

  7. Radiation effects in ceramic nuclear waste forms

    International Nuclear Information System (INIS)

    This paper reports on alpha-decay event damage (a particle and recoil-nucleus) that results in atomic-scale disorder which causes changes in the molar volume, corrosion rate, stored energy, mechanical properties, and macrostructure of ceramics. These changes particularly of volume and corrosion rate, have critical implications for the long-term durability of nuclear waste forms, such as the polyphase. Ti-based ceramic Synroc. This paper reviews data on actinide-bearing (U and Th) phases of great age (>100 m.y.) found in nature and compares these results to observation on actinide-doped phases (Pu and Cm) of nearly equivalent α-decay doses. Of particular interest is evidence for annealing of radiation damage effects over geologic periods of time under ambient conditions

  8. Stimulating effects of low doses of radiation

    International Nuclear Information System (INIS)

    Different ionizing radiations cause biochemical and biophysical changes in the cells of the genotypes according to the application of the doses applied to different organs of the plants, and the manner of their application (acute, chronic, or acute and chronic). The sensitivity of different genotypes, and their tissues, depends on the stage at which their tissues were irradiated as well as on the environmental conditions under which the irradiation was made. Relatively strong doses usually cause some genetic changes in the somatic and generative cells. Small doses can, in some genotypes, stimulate the growth of some tissues to some extent. The stimulating effect on the growth of seedlings of the M2 generation, developed from acute seed irradiation of some genotypes of wheat, barley, and inbred lines of maize and their hybrids is described here. 3 refs, 5 tabs

  9. Actinide Waste Forms and Radiation Effects

    Science.gov (United States)

    Ewing, R. C.; Weber, W. J.

    Over the past few decades, many studies of actinides in glasses and ceramics have been conducted that have contributed substantially to the increased understanding of actinide incorporation in solids and radiation effects due to actinide decay. These studies have included fundamental research on actinides in solids and applied research and development related to the immobilization of the high level wastes (HLW) from commercial nuclear power plants and processing of nuclear weapons materials, environmental restoration in the nuclear weapons complex, and the immobilization of weapons-grade plutonium as a result of disarmament activities. Thus, the immobilization of actinides has become a pressing issue for the twenty-first century (Ewing, 1999), and plutonium immobilization, in particular, has received considerable attention in the USA (Muller et al., 2002; Muller and Weber, 2001). The investigation of actinides and

  10. Numerical analysis of radiation effects in a metallic foam by means of the radiative conductivity model

    International Nuclear Information System (INIS)

    The aim of this work is the evaluation of the radiation contribution to the steady-state heat transfer in metallic foams by means of the radiative conductivity model. Because of the complexity of the structure, reference is made to a simplified physical radiative model, where the elementary cell of the foams is treated as a cubic cell. The contribution of the radiation heat transfer is investigated on a local basis. The local radiative conductivity has been used to evaluate the influence of radiative heat transfer in a two dimensional conductive-convective-radiative problem involving a forced fluid flow within a heated channel filled with a metallic foam. The effect of the solid emissivity and the foam porosity is pointed out for different foams.

  11. Light-Cone Effect of Radiation Fields in Cosmological Radiative Transfer Simulations

    CERN Document Server

    Ahn, Kyungjin

    2015-01-01

    We present a novel method to implement time-delayed propagation of radiation fields in cosmological radiative transfer simulations. Time-delayed propagation of radiation fields requires construction of retarded-time fields by tracking the location and lifetime of radiation sources along the corresponding light-cones. Cosmological radiative transfer simulations have, until now, ignored this "light-cone effect" or implemented ray-tracing methods that are computationally demanding. We show that radiative transfer calculation of the time-delayed fields can be easily achieved in numerical simulations when periodic boundary conditions are used, by calculating the time-discretized retarded-time Green's function using the Fast Fourier Transform (FFT) method and convolving it with the source distribution. We also present a direct application of this method to the long-range radiation field of Lyman-Werner band photons, which is important in the high-redshift astrophysics with first stars.

  12. Golden Rule of Radiation Hardness: a Study of Strain Effect on Controlled Radiation Damage

    Science.gov (United States)

    Peng, Qing; Ji, Wei; de, Suvranu

    2012-02-01

    Stain is widely presented in microstructures. Strain effect to radiation hardness is critical in understanding and engineering nano-materials. Here we studied the strain effect on the controlled radiation damage in monolayer hexagonal boron nitride (h-BN) through ab initio density functional theory calculations. We observed a general behavior of reduction in the radiation hardness by the strain, for both B-vacancy and N-vacancy configurations, in both compressive and tensive strain states, at the directions of zigzag, armchair and bi-axial. We proposed a golden rule of the radiation hardness states that any effort adding energy to the system will reduce the radiation hardness. Such golden rule of radiation hardness could be widely applied to material design and engineering for those devices working in irradiation-enrich environments, for example, electronic and optoelectronic devices in outer space.

  13. II. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1948-05-24

    With the completion of the 184 inch cyclotron in Berkeley and the successful construction of a deflector system, it was possible to bring the 190 Mev deuteron and the 380 Mev alpha beams out into the air and to begin a study of the effects of high-energy deuteron beams by direct irradiation of biological specimens. The direct biological use of deuteron beams was attempted earlier in Berkeley by Marshak, MacLeish, and Walker in 1940. These and other investigators have been aware for some time of the potential usefulness of high energy particle beams for radio-biological studies and their suitability for biological investigations. R.R. Wilson advanced the idea of using fast proton beams to deliver radiation and intervening tissues. R.E. Zirkle pointed out that such particle beams may be focused or screened until a cross-section of the beam is small enough to study effects of irradiation under the microscope on single cells or on parts of single cells. This article gives an overview of the radiological use of high energy deuteron beams, including the following topics: potential uses of high energy particle beams; experiments on the physical properties of the beam; lethal effect of the deuteron beam on mice.

  14. Radiation effects on impurity diffusion in silicon

    International Nuclear Information System (INIS)

    Coherently combined experiments have been made in order to investigate certain parameters of the problem of diffusion under hydrogen irradiation. The physical basis of the problem (diffusion in semiconductors, particle irradiation, defect creation) is reviewed and the characterisation methods are then presented whilst laying emphasis on the way they restrict those experiments that are possible. The role of the parameters which are made to vary (temperature, current of the irradiation beam, irradiation time) is shown, using boron, arsenic or phosphorus as doping agent. The limitations of the single two-impurity model (one slow, one fast) is shown. It is also shown that with this model it is not possible to account integrally for the profiles obtained by ionic analysis. To complete the model, it was necessary to introduce defect precipitation as well as its effect on the diffusion length of the impurities. It was also possible to show the fundamental importance of the irradiation current parameter (and not of the total dose) and its interconnexion with the irradiation temperature parameter. With electric measurements an endeavour was also made to show the effect of residual defects on the conductivity and mobility of irradiated layers. The balancing of these layers led to studying the annealing of the defects and the experiments enabled the radiation enhanced to be oberved. The effect of the Fermi level position on the exo-diffusion of fast impurities was also shown, interpreted in terms of the formation and fast diffusion of a vacancy-impurity complex

  15. Radiative Effect on Particle Acceleration via Relativistic Electromagnetic Expansion

    CERN Document Server

    Noguchi, K

    2005-01-01

    The radiation damping effect on the diamagnetic relativistic pulse accelerator (DRPA) is studied in two-and-half dimensional Particle-in-Cell (PIC) simulation with magnetized electron-positron plasmas. Self-consistently solved radiation damping force converts particle energy to radiation energy. The DRPA is still robust with radiation, and the Lorentz factor of the most high energy particles reach more than two thousand before they decouple from the electromagnetic pulse. Resulted emitted power from the pulse front is lower in the radiative case than the estimation from the non-radiative case due to the radiation damping. The emitted radiation is strongly linearly polarized and peaked within few degrees from the direction of Poynting flux.

  16. Aharonov-Bohm Effect in Cyclotron and Synchrotron Radiations

    CERN Document Server

    Bagrov, V G; Levin, A; Tlyachev, V B

    2000-01-01

    We study the impact of Aharonov-Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. With this aim in view, exact solutions of Klein-Gordon and Dirac equations are found in the magnetic-solenoid field. Using such solutions, we calculate exactly all the characteristics of one-photon spontaneous radiation both for spinless and spinning particle. Considering non-relativistic and relativistic approximations, we analyze cyclotron and synchrotron radiations in detail. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov-Bohm effect in the radiation. In particular, it is shown that new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra

  17. 2001 international symposium on radiation and health (2001 ISRH): low dose radiation effects on human health

    International Nuclear Information System (INIS)

    The symposium was co-organised by the Radiation Health Research Institute (RHRI) of Korea Hydro and Nuclear Power Co Ltd (KHNP) and the Institute of Radiation Medicine of Seoul National University Medical Research Center, and supported by the Korean Ministry of Science and Technology. The main topic of the meeting was the health effects of exposure to low levels of ionising radiation and this was presented and discussed in two sessions dealing with epidemiological and molecular studies

  18. Aerosol radiative effects over BIMSTEC regions

    Science.gov (United States)

    Kumar, Sumit; Kar, S. C.; Mupparthy, Raghavendra S.

    Aerosols can have variety of shapes, composition, sizes and other properties that influence their optical characteristics and thus the radiative impact. The visible impact of aerosol is the formation of haze, a layer of particles from vehicular, industrial emissions and biomass burning. The characterization of these fine particles is important for regulators and researchers because of their potential impact on human health, their ability to travel thousands of kilometers crossing international borders, and their influence on climate forcing and global warming. The Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) with Member Countries Bangladesh, Bhutan, India, Myanmar, Nepal, Sri Lanka and Thailand has emerged as an important regional group for technical and economic Cooperation. Continuing the quest for a deeper understanding of BIMSTEC countries weather and climate, in this paper we focused on aerosols and their direct radiative effects. Because of various contrasts like geophysical, agricultural practices, heterogeneous land/ocean surface, population etc these regions present an excellent natural laboratory for studying aerosol-meteorology interactions in tropical to sub-tropical environments. We exploited data available on multiple platforms (such as MISR, MODIS etc) and models (OPAC, SBDART etc) to compute the results. Ten regions were selected with different surface characteristics, also having considerable differences in the long-term trends and seasonal distribution of aerosols. In a preliminary analysis pertaining to pre-monsoon (March-April-May) of 2013, AOD _{555nm} is found to be maximum over Bangladesh (>0.52) and minimum over Bhutan (0.22), whereas other regions have intermediate values. Concurrent to these variability of AOD we found a strong reduction in incoming flux at surface of all the regions (> -25 Wm (-2) ), except Bhutan and Sri Lanka (< -18Wm (-2) ). The top of the atmosphere (TOA) forcing values are

  19. The effect of radiative feedback on disc fragmentation

    CERN Document Server

    Mercer, Anthony

    2016-01-01

    Protostellar discs may become massive enough to fragment producing secondary low-mass objects: planets, brown dwarfs and low-mass stars. We study the effect of radiative feedback from such newly-formed secondary objects using radiative hydrodynamic simulations. We compare the results of simulations without any radiative feedback from secondary objects with those where two types of radiative feedback are considered: (i) continuous, and (ii) episodic. We find that: (i) continuous radiative feedback stabilizes the disc and suppresses further fragmentation, reducing the number secondary objects formed; (ii) episodic feedback from secondary objects heats and stabilises the disc when the outburst occurs, but shortly after the outburst stops, the disc becomes unstable and fragments again. However, fewer secondary objects are formed compared to the the case without radiative feedback. We also find that the mass growth of secondary objects is mildly suppressed due to the effect of their radiative feedback. However, th...

  20. Radiation effects on organic materials in nuclear plants. Final report

    International Nuclear Information System (INIS)

    A literature search was conducted to identify information useful in determining the lowest level at which radiation causes damage to nuclear plant equipment. Information was sought concerning synergistic effects of radiation and other environmental stresses. Organic polymers are often identified as the weak elements in equipment. Data on radiation effects are summarized for 50 generic name plastics and 16 elastomers. Coatings, lubricants, and adhesives are treated as separate groups. Inorganics and metallics are considered briefly. With a few noted exceptions, these are more radiation resistant than organic materials. Some semiconductor devices and electronic assemblies are extremely sensitive to radiation. Any damage threshold including these would be too low to be of practical value. With that exception, equipment exposed to less than 104 rads should not be significantly affected. Equipment containing no Teflon should not be significantly affected by 105 rads. Data concerning synergistic effects and radiation sensitization are discussed. The authors suggest correlations between the two effects

  1. Terrestrial radiation effects in ULSI devices and electronic systems

    CERN Document Server

    Ibe, Eishi H

    2014-01-01

    A practical guide on how mathematical approaches can be used to analyze and control radiation effects in semiconductor devices within various environments Covers faults in ULSI devices to failures in electronic systems caused by a wide variety of radiation fields, including electrons, alpha -rays, muons, gamma rays, neutrons and heavy ions. Readers will learn the environmental radiation features at the ground or avionics altitude. Readers will also learn how to make numerical models from physical insight and what kind of mathematical approaches should be implemented to analyze the radiation effects. A wide variety of mitigation techniques against soft-errors are reviewed and discussed. The author shows how to model sophisticated radiation effects in condensed matter in order to quantify and control them. The book provides the reader with the knowledge on a wide variety of radiation fields and their effects on the electronic devices and systems. It explains how electronic systems including servers and rout...

  2. Radiation effects on organic materials in nuclear plants. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, M B; Davis, M V

    1981-11-01

    A literature search was conducted to identify information useful in determining the lowest level at which radiation causes damage to nuclear plant equipment. Information was sought concerning synergistic effects of radiation and other environmental stresses. Organic polymers are often identified as the weak elements in equipment. Data on radiation effects are summarized for 50 generic name plastics and 16 elastomers. Coatings, lubricants, and adhesives are treated as separate groups. Inorganics and metallics are considered briefly. With a few noted exceptions, these are more radiation resistant than organic materials. Some semiconductor devices and electronic assemblies are extremely sensitive to radiation. Any damage threshold including these would be too low to be of practical value. With that exception, equipment exposed to less than 10/sup 4/ rads should not be significantly affected. Equipment containing no Teflon should not be significantly affected by 10/sup 5/ rads. Data concerning synergistic effects and radiation sensitization are discussed. The authors suggest correlations between the two effects.

  3. Radiation effects on electronic devices in space

    Energy Technology Data Exchange (ETDEWEB)

    Duzellier, S. [Office National d' Etudes et de Recherches Aerospatiales (ONERA/DESP), 31 - Toulouse (France)

    2005-01-01

    The natural space environment is responsible for many disturbances on electronics systems on-board spacecraft. This paper focuses on the Single Event Effects (SEE) at the origin of most observed in-flight anomalies. SEE are probabilistic failures induced by single high-energy ionising particles (protons, heavy ions and electrons) in any kind of devices. Insight on the underlying physical mechanisms and criticality of such events is provided through actual examples. The methodologies to assess the devices sensitivities (testing and modelling) and to predict the mission operation are described with emphasis on the critical parameters to deal with. The trend towards higher integration of devices may lead to abnormal response of devices to radiation. The inappropriateness of standard models when dealing with modern devices lies in the size reduction to the point that dimensions of sensitive volume are now of the order of the particle track size. During the past 20 years, SEE rates of devices dropped by several order of magnitude. In fact, the critical charge to trigger an event got fainter leading to an enhanced sensibility but this effect was compensated by a strong decrease in the cross-section due to the reduction of dimensions. However, as on-board electronics is developing, it concerns now computation and storage and as it uses advanced and high-performance devices (mainly COTS), the criticality remains and new failure modes can be observed. (A.C.)

  4. Genetic effects of radiofrequency radiation (RFR)

    International Nuclear Information System (INIS)

    The possible effects of radiofrequency (RF) exposure on the genetic material of cells are considered very important since damage to the DNA of somatic cells can be linked to cancer development or cell death whereas damage to germ cells can lead to genetic damage in next and subsequent generations. This is why the scientific literature reports many investigations on the subject. According to a number of review papers, the conclusion so far is that there is little evidence that RFR is directly mutagenic and that adverse effects that were reported in some of the papers are predominantly the result of hyperthermia. Yet, some subtle indirect effects on DNA replication and/or transcription of genes under relatively restricted exposure conditions cannot be ruled out. Furthermore, the possibility of combined effects of RFR with environmental carcinogens/mutagens merits further attention. The present paper takes into account more recent investigations but the conclusion remains the same. A majority of studies report no increased (cyto)genetic damage but yet, a considerable number of investigations do. However, many studies were not sufficiently characterized, are therefore difficult to replicate and cannot be compared to others. Experimental protocols were very different from one study to another and investigations from a single laboratory were very often limited in the sample size or number of cells investigated, preventing a robust statistical analysis. Subtle, but significant differences between RFR-exposed and sham-exposed cells cannot be found in such conditions. For the above reasons, it was concluded at a workshop in Loewenstein (November 2002) that further investigations by individual laboratories most probably will not add much to the discussion of radiofrequency radiation (RFR) genotoxicity. Large, well coordinated, international collaborative studies involving participation of several experienced scientists are considered an alternative of uttermost importance

  5. Effective education in radiation safety for nurses

    International Nuclear Information System (INIS)

    In order to establish an efficient training program of radiation safety for nurses, studies have been carried out on the basis of questionnaires. Collaboration of nurses, who are usually standing closest to the patient, is necessary in order to offer safe radiological diagnostics/treatment. The authors distributed the questionnaire to 134 nurses in five polyclinic hospitals in Japan. Important questions were: fear of radiation exposure, knowledge on the radiation treatment, understanding the impact on pregnancy, and so on. Most of the nurses feel themselves uneasy against exposure to radiation. They do not have enough knowledge of radiological treatment. They do not know exactly what is the impact of the radiation on pregnant women. Such tendency is more pronounced, when nurses spend less time working in the radiological department. Nurses play important roles in radiological diagnostics/treatment. Therefore, a well-developed education system for radiation safety is essential. The training for the radiation safety in medicine should be done in the context of general safety in medicine. Education programs in undergraduate school and at the working place should be coordinated efficiently in order to ensure that both nurses and patients are informed about the meaning of radiation safety. (authors)

  6. Plenary panel 1: The scientific bases of radiation protection. Non-targeted effects of ionising radiation - Implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Salomaa, S. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. 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 should 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 (L.N.T.) 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. (authors)

  7. Combined effects of radiation and trauma

    Science.gov (United States)

    Messerschmidt, Otfried

    Injuries, caused by both whole-body irradiation and wounds or burns, have been relatively little studied. Possibly because many investigators think that these injuries are just modified radiation-induced diseases for which the same treatment principles are valid. Other authors had the impression that, for instance, the radiation burn trauma is a new kind of disease which differs significantly from either radiation syndrome alone or from burn disease. There are many experimental data on animals which suggest that the pathology of combined injuries differs significantly from that of radiation-induced disease or of thermal or mechanical traumas. Wounds or burns which, in general, do not cause septicaemia could become entrance ports for bacteria when animals are exposed to whole-body irradiation. Thrombocytopenia is the reason for hemorrhages in wounds. The susceptibility to shock is increased considerably in combined injuries and the formation of callus in the bone fractures is significantly delayed. The healing of wounds and burns in the initial phase of the radiation syndrome does not always differ from healing in the non-irradiated organism. However, a few days or weeks later very serious wound infections and hemorrhages can occur. The additional injuries almost always worsen the development and prognosis of radiation-induced disease. The recommended treatment for combined injuries will differ in many respects from the treatment of wounds and burns or the radiation syndrome.

  8. ANNUAL REPORT. RADIATION EFFECTS IN NUCLEAR WASTE MATERIALS

    Science.gov (United States)

    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. This study will provide the underpinning science to develop improved gl...

  9. Field-ion-microscope observations of radiation effects

    International Nuclear Information System (INIS)

    This article briefly reviews the unique advantages and capabilities of the field-ion microscope (FIM) and atom-probe FIM for the study of the effects of particle radiation on metals, discusses some contrast effects caused by radiation-induced defects, and gives a number of problems that have been studied using these techniques

  10. Electronic effects in radiation damage simulations

    International Nuclear Information System (INIS)

    A methodology for including electronic effects in classical radiation damage simulations is presented. The method is used to calculate the number of residual defects for low energy (10 keV) cascades in Fe, as a function of the electron-phonon coupling strength. It was found that strong electron-phonon coupling reduced the number of residual defects by rapidly removing energy from the cascade and reducing the thermal spike. Intermediate coupling increased the number of defects by quenching the thermal spike and reducing defect recombination. Thermostatting the cascade with the local, time dependent electronic temperature, rather than the ambient temperature, reduced the number of residual defects by enhancing defect recombination. Swift heavy ion irradiation in tungsten was modeled using the same methodology. In this case we found that the number of residual defects created by a given electronic stopping power was strongly dependent on the temperature variation of the electronic heat capacity. In contrast to cascade simulations, the interstitials were located closer to the core of the ion track than the vacancies.

  11. Radiation effect studies on anticancer drugs, cyclophosphamide and doxorubicin for radiation sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Varshney, L. E-mail: lalitv@magnum.barc.ernet.in; Dodke, P.B

    2004-12-01

    Two anticancer drugs, cyclophosphamide (CPH) and doxorubicin hydrochloride (DOXO), in powder form were exposed to a range of doses of {sup 60}Co gamma and electron beam radiation to study the effects of ionizing radiation. Pharmacopoeia tests, discolouration, degradation products, effect of irradiation temperature and dose rate were investigated. CPH undergoes less than 2% degradation at 30 kGy. Chromatographic studies revealed formation of several trace level degradation products, discolouration and free radicals in the irradiated CPH. N,N-bis (2-chloroethyl) group in the molecule is particularly sensitive to radiation degradation. Irradiation to 5 kGy at low temperature (77 K) did not result in significant changes. DOXO was observed to be quite radiation resistant and did not undergo significant changes in its physico-chemical properties and degradation product profile. It can be radiation sterilized at normal sterilization dose of 25 kGy.

  12. Current issues in carcinogenic effect of low-dose radiation

    International Nuclear Information System (INIS)

    A review of publications dealing with study of radiation sources and biological evaluation of increasing doses of people irradiation under occupational and usual living conditions is presented. The existing natural and artifial irradiation sources are considered. It is noted that all types of ionizing radiations are characterized by high carcinogenic efficiency and can induce benign and malignant tumors practically in all organs. Statistically reliable data in experimental and epidemiological investigations were recorded under the effect of large and mean doses. Minor radiation doses not responsible for visible functional and morphological changes in early periods can cause pathological changes in delayed periods. The data on carcinogenic effect of relatively small radiation doses are available

  13. Studies on EB radiation effect on PA610

    Energy Technology Data Exchange (ETDEWEB)

    Yang Kebin; Zhang Huaming; Li Xiurong; Xiong Ruilin [Sichuan Forever Group Co. Ltd., China Academy of Engineering Physics, Miangany (China)

    2000-03-01

    Radiation effect of PA610 with polyfunctional monomer trially isocyanurate (TAIC) was studied, the results show that crosslinking effect of EB radiation on PA610 is obvious. After the PA610 samples were radiated by EB with dosage 75KGY, the physical characters of PA610 materials were greatly improved, especially their tensile strength being increased about 18% and their impact strength about 50%, but their water and oil absorption were decreased. So, EB radiation can enhance PA610 materials physical strength, resistance to solvents and water and increase their thermal-deformation temperature. (author)

  14. Radiative budget and cloud radiative effect over the Atlantic from ship-based observations

    Directory of Open Access Journals (Sweden)

    J. Kalisch

    2012-10-01

    Full Text Available The aim of this study is to determine cloud-type resolved cloud radiative budgets and cloud radiative effects from surface measurements of broadband radiative fluxes over the Atlantic Ocean. Furthermore, based on simultaneous observations of the state of the cloudy atmosphere, a radiative closure study has been performed by means of the ECHAM5 single column model in order to identify the model's ability to realistically reproduce the effects of clouds on the climate system.

    An extensive database of radiative and atmospheric measurements has been established along five meridional cruises of the German research icebreaker Polarstern. Besides pyranometer and pyrgeometer for downward broadband solar and thermal radiative fluxes, a sky imager and a microwave radiometer have been utilized to determine cloud fraction and cloud type on the one hand and temperature and humidity profiles as well as liquid water path for warm non-precipitating clouds on the other hand.

    Averaged over all cruise tracks, we obtain a total net (solar + thermal radiative flux of 144 W m−2 that is dominated by the solar component. In general, the solar contribution is large for cirrus clouds and small for stratus clouds. No significant meridional dependencies were found for the surface radiation budgets and cloud effects. The strongest surface longwave cloud effects were shown in the presence of low level clouds. Clouds with a high optical density induce strong negative solar radiative effects under high solar altitudes. The mean surface net cloud radiative effect is −33 W m−2.

    For the purpose of quickly estimating the mean surface longwave, shortwave and net cloud effects in moderate, subtropical and tropical climate regimes, a new parameterisation was created, considering the total cloud amount and the solar zenith angle.

    The ECHAM5 single column model provides a surface net cloud effect that is more

  15. Radiative budget and cloud radiative effect over the Atlantic from ship based observations

    Directory of Open Access Journals (Sweden)

    J. Kalisch

    2012-03-01

    Full Text Available The aim of this study is to determine cloud-type resolved cloud radiative budgets and cloud radiative effects from surface measurements of broadband radiative fluxes over the Atlantic Ocean. Furthermore, based on simultaneous observations of the state of the cloudy atmosphere a radiative closure study has been performed by means of the ECHAM5 single column model in order to identify the models ability to realistically reproduce the effects of clouds on the climate system.

    An extensive data base of radiative and atmospheric measurements has been established along five meridional cruises of the German research icebreaker POLARSTERN. Besides pyranometer and pyrgeometer for downward broadband solar and thermal radiative fluxes, a sky imager and a microwave radiometer have been utilized to determine cloud fraction and cloud type on the one hand and temperature and humidity profiles as well as liquid water path for warm non-precipitating clouds on the other hand.

    Averaged over all cruise tracks we obtain a total net (solar + thermal radiative flux of 144 W m−2 that is dominated by the solar component. In general, the solar contribution is large for cirrus clouds and small for stratus clouds. No significant meridional dependencies were found for the surface radiation budgets and cloud effects. The strongest surface longwave cloud effects were shown in the presence of low level clouds. Clouds with a high optical density induce strong negative solar radiative effects under high solar altitudes. The mean surface net cloud radiative effect is −34 W m−2.

    For the purpose of quickly estimating the mean surface longwave, shortwave and net cloud effects in moderate, subtropical and tropical climate regimes a new parameterisation was created, considering the total cloud amount and the solar zenith angle.

    The ECHAM5 single column model provides a surface net cloud effect that is more cooling by 16 W

  16. The effects of small doses of radiation

    International Nuclear Information System (INIS)

    The following topics were discussed in outline at a two day conference organized by I.B.C. Technical Services Ltd, February 1989, in London: radiation carcinogenesis mechanisms, environmental exposure, occupational exposure trends and comparisons, ICRP risk assessment and use of data including that of A-Bomb survivors, the ankylosing spondylitis study, UKAEA and AWE mortality studies, Sellafield, leukemia clusters and radiation hormesis. (UK)

  17. Radiation irradiation effects: knowledge and doubts

    International Nuclear Information System (INIS)

    People are ever submitted to natural ionizing radiations. But nuclear power plant workers have this natural exposure and one complementary irradiation, in case of nuclear installation serious accident. In normal running, people, people, particularly those in neighbourhood of the installation, are exposed permanently to liquid and gaseous disposal. In case of accident, exposure increases mainly according to usual state. Only the accident states may induce for people or one worker exposure to high dose ionizing radiations. 1 tab

  18. Studies of the hemolytic effect of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, S.; Katz, E.; Porter, L.M.; Jacobson, L.O.; Watson, C.J.

    1945-07-10

    These studies were aimed at elucidating affects of radiation in inducing hemolysis independent of inhibition of erythropoiesis. Research studies were conducted both on human patients and dogs. Phosphorus-32 in mc amounts were administered either intravenously or orally to patients suffering Polycythemia rubra vera. Dogs were treated with either P-32 or x-radiation. Hemoglobin metabolism was monitored in all test subjects by hematology, blood chemistry, and fecal excretion of hemoglobin catabolites.

  19. Space radiation effects on plant and mammalian cells

    Science.gov (United States)

    Arena, C.; De Micco, V.; Macaeva, E.; Quintens, R.

    2014-11-01

    The study of the effects of ionizing radiation on organisms is related to different research aims. The current review emphasizes the studies on the effects of different doses of sparsely and densely ionizing radiation on living organisms, with the final purpose of highlighting specific and common effects of space radiation in mammals and plants. This topic is extremely relevant in the context of radiation protection from space environment. The response of different organisms to ionizing radiation depends on the radiation quality/dose and/or the intrinsic characteristics of the living system. Macromolecules, in particular DNA, are the critical targets of radiation, even if there is a strong difference between damages encountered by plant and mammalian cells. The differences in structure and metabolism between the two cell types are responsible for the higher resistance of the plant cell compared with its animal counterpart. In this review, we report some recent findings from studies performed in Space or on Earth, simulating space-like levels of radiation with ground-based facilities, to understand the effect of ionizing radiation on mammalian and plant cells. In particular, our attention is focused on genetic alterations and repair mechanisms in mammalian cells and on structures and mechanisms conferring radioresistance to plant cells.

  20. Health Effects of Exposure to Low Dose of Radiation

    International Nuclear Information System (INIS)

    Human beings are exposed to natural radiation from external sources include radionuclides in the earth and cosmic radiation, and by internal radiation from radionuclides, mainly uranium and thorium series, incorporated into the body. Living systems have adapted to the natural levels of radiation and radioactivity. But some industrial practices involving natural resources enhance these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Biological effects of ionizing radiation are the outcomes of physical and chemical processes that occur immediately after the exposure, then followed by biological process in the body. These processes will involve successive changes in the molecular, cellular, tissue and whole organism levels. Any dose of radiation, no matter how small, may produce health effects since even a single ionizing event can result in DNA damage. The damage to DNA in the nucleus is considered to be the main initiating event by which radiation causes damage to cells that results in the development of cancer and hereditary disease. It has also been indicated that cytogenetic damage can occur in cells that receive no direct radiation exposure, known as bystander effects. This paper reviews health risks of low dose radiation exposure to human body causing stochastic effects, i.e. cancer induction in somatic cells and hereditary disease in genetic cells. (author)

  1. Radiation effects on the drosophila melanogaster genoma

    International Nuclear Information System (INIS)

    When DNA of living beings has been damaged, the cells show different responses depending on their physiological state. Repair mechanisms can be classified into two groups: constitutive which are always present in the cells and inductible, which must be stimulated to show themselves. It is suggested that a repair mechanism exists in the drosophila ovules which act upon the damage present in mature spermatozoids. Our aim is to verify whether or not a radiation dosis applied to the female drosophila will modify the frequency of individuals which have lost the paternal sex chromosomes. YW/YW virgin females and XEZ males and fbb-/bS Y y+ y were mated for two days in order to collect radiation treated spermatozoids. The results were consistent as to the parameters being evaluated and lead one to suppose that the radiation applied to the female drosophila produced some changes in the ovule metabolism which reduced the frequency of individuals with lost chromosomes. It is believed that ionizing radiation interferes with the repair mechanisms that are existent and constitutive, retarding and hindering the restoration of chromosome fragments and this brings about death of the zygote or death of the eggs which lessens the frequencies of individuals carriers of chromosomic aberrations. Ionizing radiations applied to the female drosophila modifies the frequency of loss of patternal chromosomes and comes about when the radiation dose to the female is 700 rad. (Author)

  2. Basic mechanisms of radiation effects in the natural space radiation environment

    Energy Technology Data Exchange (ETDEWEB)

    Schwank, J.R.

    1994-06-01

    Four general topics are covered in respect to the natural space radiation environment: (1) particles trapped by the earth`s magnetic field, (2) cosmic rays, (3) radiation environment inside a spacecraft, (4) laboratory radiation sources. The interaction of radiation with materials is described by ionization effects and displacement effects. Total-dose effects on MOS devices is discussed with respect to: measurement techniques, electron-hole yield, hole transport, oxide traps, interface traps, border traps, device properties, case studies and special concerns for commercial devices. Other device types considered for total-dose effects are SOI devices and nitrided oxide devices. Lastly, single event phenomena are discussed with respect to charge collection mechanisms and hard errors. (GHH)

  3. Review of radiation effects in solid-nuclear-waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J.

    1981-09-01

    Radiation effects on the stability of high-level nuclear waste (HLW) forms are an important consideration in the development of technology to immobilize high-level radioactive waste because such effects may significantly affect the containment of the radioactive waste. Since the required containment times are long (10/sup 3/ to 10/sup 6/ years), an understanding of the long-term cumulative effects of radiation damage on the waste forms is essential. Radiation damage of nuclear waste forms can result in changes in volume, leach rate, stored energy, structure/microstructure, and mechanical properties. Any one or combination of these changes might significantly affect the long-term stability of the nuclear waste forms. This report defines the general radiation damage problem in nuclear waste forms, describes the simulation techniques currently available for accelerated testing of nuclear waste forms, and reviews the available data on radiation effects in both glass and ceramic (primarily crystalline) waste forms. 76 references.

  4. Effects of ionizing radiation; Effecten van ioniserende straling

    Energy Technology Data Exchange (ETDEWEB)

    Loos, M.; Hardeman, F.; Holmstock, L.; Hurtgen, C.; Mahieu, L.; Sohier, A.; Vandecasteele, C.; Vanhavere, F.; Vanmaercke, H.; Zeevaert, T

    1998-12-01

    Starting with a brief introduction to radiation protection, the report gives an overview of exposure to ionising radiation in Belgium due to activities in relation to the nuclear fuel cycle, processing and disposal of radioactive waste and other artificial or natural sources. Where appropriate, the Belgian situation discussed from an international perspective. The radiological impact of reprocessing and non-reprocessing are compared. The biological effects of ionizing radiation, epidemiological studies as well as surveillance programmes on the Belgian territory are reported on.

  5. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  6. Treatment of cloud radiative effects in general circulation models

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.C.; Dudek, M.P.; Liang, X.Z.; Ding, M. [State Univ. of New York, Albany, NY (United States)] [and others

    1996-04-01

    We participate in the Atmospheric Radiation Measurement (ARM) program with two objectives: (1) to improve the general circulation model (GCM) cloud/radiation treatment with a focus on cloud verticle overlapping and layer cloud optical properties, and (2) to study the effects of cloud/radiation-climate interaction on GCM climate simulations. This report summarizes the project progress since the Fourth ARM Science Team meeting February 28-March 4, 1994, in Charleston, South Carolina.

  7. Effect of. gamma. radiation on sorption properties of polymethylphenylsiloxane films

    Energy Technology Data Exchange (ETDEWEB)

    Eremina, N.S.; Minakova, T.S.; Komissarova, V.N.

    1988-11-01

    The effect of ..gamma.. radiation in the 0.01-1 MGy dose range on the capacity of polymethylphenylsiloxane films to sorb water vapors was studied. It was shown that the character of the change in the sorption capacity of the polymer films is a function of the dose of radiation. The results of measurements of the IR spectra were used in discussing the causes of the change in the sorption properties of the films on exposure to ..gamma.. radiation.

  8. Chronic radiation effects on dental hard tissue (''radiation carries''). Classification and therapeutic strategies

    International Nuclear Information System (INIS)

    Objectives: Since the first description of rapid destruction of dental hard tissues following head and neck radiotherapy 80 years ago, 'radiation caries' is an established clinical finding. The internationally accepted clinical evaluation score RTOG/EORTC however is lacking a classification of this frequent radiogenic alteration. Material and Methods: Medical records, data and images of radiation effects on the teeth of more than 1,500 patients, who underwent periradiotherapeutic care, were analyzed. Macroscopic alterations regarding the grade of late lesions of tooth crowns were used for a classification into 4 grades according to the RTOG/EORTC guidelines. Results: No early radiation effects were found by macroscopic inspection. In the first 90 days following radiotherapy 1/3 of the patients complained of reversible hypersensitivity, which may be related to a temporary hyperemia of the pulp. It was possible to classify radiation caries as a late radiation effect on a graded scale as known from RTOG/EORTC for other organ systems. This is a prerequisite for the integration of radiation caries into the international nomenclature of the RTOG/EORTC classification. Conclusions: The documentation of early radiation effects on dental hard tissues seems to be neglectable. On the other hand the documentation of late radiation effects has a high clinical impact. The identification of an initial lesion at the high-risk areas of the neck and incisal part of the tooth can lead to a successful therapy as a major prerequisite for orofacial rehabilitation. An internationally standardized documentation is a basis for the evaluation of the side effects of radiooncotic therapy as well as the effectiveness of protective and supportive procedures. (orig.)

  9. Effects of radiation on DNA's double helix

    Science.gov (United States)

    2003-01-01

    The blueprint of life, DNA's double helix is found in the cells of everything from bacteria to astronauts. Exposure to radiation(depicted at right) such as X-rays (upper) or heavy ion particles (lower), can damage DNA and cause dire consequences both to the organism itself and to future generations. One of NASA's main goals is to develop better radiation shielding materials to protect astronauts from destructive radiation in space. This is particularly important for long space missions. NASA has selected researchers to study materials that provide better shielding. This research is managed by NASA's Office of Biological and Physical Research and is supported by the Microgravity Science and Applications Department at NASA's Marshall Center. During International Space Station Expedition Six, the Extravehicular Activity Radiation Monitoring (EVARM) will continue to measure radiation dosage encountered by the eyes, internal organs and skin during specific spacewalks, and relate it to the type of activity, location and other factors. An analysis of this information may be useful in mitigating potential exposure to space walkers in the future. (Illustration by Dr. Frank Cucinotta, NASA/Johnson Space Center, and Prem Saganti, Lockheed Martin)

  10. Non-targeted effects of ionising radiation - Implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Sisko Salomaa [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. 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 should 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. (author)

  11. Radiation hydrodynamics of triggered star formation: the effect of the diffuse radiation field

    CERN Document Server

    Haworth, Thomas J

    2011-01-01

    We investigate the effect of including diffuse field radiation when modelling the radiatively driven implosion of a Bonnor-Ebert sphere (BES). Radiation-hydrodynamical calculations are performed by using operator splitting to combine Monte Carlo photoionization with grid-based Eulerian hydrodynamics that includes self-gravity. It is found that the diffuse field has a significant effect on the nature of radiatively driven collapse which is strongly coupled to the strength of the driving shock that is established before impacting the BES. This can result in either slower or more rapid star formation than expected using the on-the-spot approximation depending on the distance of the BES from the source object. As well as directly compressing the BES, stronger shocks increase the thickness and density in the shell of accumulated material, which leads to short, strong, photo-evaporative ejections that reinforce the compression whenever it slows. This happens particularly effectively when the diffuse field is includ...

  12. The effects of cosmic radiation on implantable medical devices

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, P. [Wollongong Univ., NSW (Australia)

    1996-12-31

    Metal oxide semiconductor (MOS) integrated circuits, with the benefits of low power consumption, represent the state of the art technology for implantable medical devices. Three significant sources of radiation are classified as having the ability to damage or alter the behavior of implantable electronics; Secondary neutron cosmic radiation, alpha particle radiation from the device packaging and therapeutic doses(up to 70 G{gamma}) of high energy radiation used in radiation oncology. The effects of alpha particle radiation from the packaging may be eliminated by the use of polyimide or silicone rubber die coatings. The relatively low incidence of therapeutic radiation incident on an implantable device and the use of die coating leaves cosmic radiation induced secondary neutron single event upset (SEU) as the main pervasive ionising radiation threat to the reliability of implantable devices. A theoretical model which predicts the susceptibility of a RAM cell to secondary neutron cosmic radiation induced SEU is presented. The model correlates well within the statistical uncertainty associated with both the theoretical and field estimate. The predicted Soft Error Rate (SER) is 4.8 x l0{sup -12} upsets/(bit hr) compared to an observed upset rate of 8.5 x 10{sup -12} upsets/(bit hr) from 20 upsets collected over a total of 284672 device days. The predicted upset rate may increase by up to 20% when consideration is given to patients flying in aircraft The upset rate is also consistent with the expected geographical variations of the secondary cosmic ray neutron flux, although insufficient upsets precluded a statistically significant test. This is the first clinical data set obtained indicating the effects of cosmic radiation on implantable devices. Importantly, it may be used to predict the susceptibility of future to the implantable device designs to the effects of cosmic radiation.

  13. Effects of ionizing radiation on extracellular matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, F. [School of Physics, University of Exeter, Exeter EX44QL (United Kingdom)], E-mail: f.mohamed@ex.ac.uk; Bradley, D.A. [Department of Physics, University of Surrey, Guildford GU72XH (United Kingdom); Winlove, C.P. [School of Physics, University of Exeter, Exeter EX44QL (United Kingdom)

    2007-09-21

    The extracellular matrix is a ubiquitous and important component of tissues. We investigated the effects of ionizing radiation on the physical properties of its principal macromolecular components, pericardial collagen, ligament elastin and hyaluronan, a representative glycosaminoglycan. Samples were exposed to X-rays from an electron linear accelerator in the range of 10-100 Gy to cover the range of irradiation exposure during radiotherapy. A uniaxial mechanical testing protocol was used to characterize the fibrous proteins. For pericardial tissue the major change was an increase in the elastic modulus in the toe region of the curve ({<=}20% strain), from 23{+-}18 kPa for controls to 57{+-}22 kPa at a dose of 10 Gy (p=0.01, {alpha}=0.05). At larger strain ({>=}20% strain), the elastic modulus in the linear region decreased from 1.92{+-}0.70 MPa for control pericardium tissue to 1.31{+-}0.56 MPa (p=0.01, {alpha}=0.05) for 10 Gy X-irradiated sample. Similar observations have been made previously on tendon collagen at larger strains. For elastin, the stress-strain relationship was linear up to 30% strain, but the elastic modulus decreased significantly with irradiation (controls 626{+-}65 kPa, irradiated 474{+-}121 kPa (p=0.02, {alpha}=0.05), at 10 Gy X-irradiation). The results suggest that for collagen the primary effect of irradiation is generation of additional cross-links, while for elastin chain scissions are important. The viscosity of HA (at 1.25% w/v and 0.125% w/v) was measured by both cone and plate and capillary viscometry, the former providing measurement at uniform shear rate and the latter providing a more sensitive indication of changes at low viscosity. Both techniques revealed a dose-dependent reduction in viscosity (from 3400{+-}194 cP for controls to 1500{+-}88 cP at a shear rate of 2 s{sup -1} and dose of 75 Gy), again suggesting depolymerization.

  14. Collective effects in the radiation pressure force

    CERN Document Server

    Bachelard, R; Guerin, W; Kaiser, R

    2016-01-01

    We discuss the role of diffuse, Mie and cooperative scattering on the radiation pressure force acting on the center of mass of a cloud of cold atoms. Even though a mean-field Ansatz (the `timed Dicke state'), previously derived from a cooperative scattering approach, has been shown to agree satisfactorily with experiments, diffuse scattering also describes very well most features of the radiation pressure force on large atomic clouds. We compare in detail an incoherent, random walk model for photons and a diffraction approach to the more complete description based on coherently coupled dipoles. We show that a cooperative scattering approach, although it provides a quite complete description of the scattering process, is not necessary to explain the previous experiments on the radiation pressure force.

  15. The study of the radiation protection of propolis to the radiation effects in mice

    International Nuclear Information System (INIS)

    The profit which radiation brought to the Homo sapiens is very big. But, radiation has even harmful parameter for the human besides one case. After effect on man to the radiation is thought about, the individual of which sensibility is the highest is a fetus. Therefore, even an effects to this fetus is grasped precisely, and protection criterion and resource are decided from the viewpoint of the protection of radiation as well. If it does so, a child and maturitas aren't so difficult as in the protection of radiation and the managerial side. It was examined about control group, propolis administration chisels for medical use group, 1.5 Gy independent exposure group and propolis pluse 1.5 Gy group in this study. It was examined about the protection of radiation of propolis which to malformation, fetal death, arrested development, and so on in the organogenesis (8 days post conception) being done when sensibility is the highest against the teratogenesis. Preimplantation death rate was compared with the control group and the sham control group, and statistical significant difference wasn't recognized by a 1.5 Gy radiation independent exposure group, propolis administration 1.5 Gy radiation exposure group. As for the embryonic death rate, propolis was administered, and obviously embryonic death rate was poorer than the 1.5 Gy independent exposure group, and significant difference was recognized by a 1.5 Gy radiation exposure group (p<0.001). It has a 1.5 Gy radiation exposure group made clear by this research fetal death rate propolis administer more only 1.5 Gy exposure fetal death rate development low (p<0.001). Fetal death rate wasn't recognized by propolis administration group (Sham control). As for the teratogenesis rate, propolis was administered, and the teratogenesis rate of the 1.5 Gy radiation exposure group was higher than the 1.5 Gy radiation independent exposure group. But, this is thought anamorphosis appear by propolis administration so long as there was

  16. The study of the radiation protection of propolis to the radiation effects in mice

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Y.H.; Suzuki, Ikukatsu; Hasegawa, Takeo; Muto, H. [Suzuka Univ. of Medical Science, Mie (Japan); Yanagisawa, Takaharu; Iwasa, Toshihiro; Bamen, K.

    2000-05-01

    The profit which radiation brought to the Homo sapiens is very big. But, radiation has even harmful parameter for the human besides one case. After effect on man to the radiation is thought about, the individual of which sensibility is the highest is a fetus. Therefore, even an effects to this fetus is grasped precisely, and protection criterion and resource are decided from the viewpoint of the protection of radiation as well. If it does so, a child and maturitas aren't so difficult as in the protection of radiation and the managerial side. It was examined about control group, propolis administration chisels for medical use group, 1.5 Gy independent exposure group and propolis pluse 1.5 Gy group in this study. It was examined about the protection of radiation of propolis which to malformation, fetal death, arrested development, and so on in the organogenesis (8 days post conception) being done when sensibility is the highest against the teratogenesis. Preimplantation death rate was compared with the control group and the sham control group, and statistical significant difference wasn't recognized by a 1.5 Gy radiation independent exposure group, propolis administration 1.5 Gy radiation exposure group. As for the embryonic death rate, propolis was administered, and obviously embryonic death rate was poorer than the 1.5 Gy independent exposure group, and significant difference was recognized by a 1.5 Gy radiation exposure group (p<0.001). It has a 1.5 Gy radiation exposure group made clear by this research fetal death rate propolis administer more only 1.5 Gy exposure fetal death rate development low (p<0.001). Fetal death rate wasn't recognized by propolis administration group (Sham control). As for the teratogenesis rate, propolis was administered, and the teratogenesis rate of the 1.5 Gy radiation exposure group was higher than the 1.5 Gy radiation independent exposure group. But, this is thought anamorphosis appear by propolis administration so

  17. Ionizing radiation effects on implanted pacemakers

    International Nuclear Information System (INIS)

    Fourteen multi-programmable pacemakers and 2 intercardial defibrillators were exposed to 60Co radiation, to 9 MeV electrons and to 6 MV and 10 MV photon radiation. The pacemakers were placed into a water phantom. The following parameters were examined: telemetry, battery, pulse frequency, pulse amplitude, and period at accumulated doses from 2 Gy to 100 Gy. It is concluded that pacemakers in CMOS/Bipolar technology and in 8μ CMOS technology should not be exposed to an absorbed dose exceeding 5 Gy, the latest generation of pacemakers in the 3μm technology will perform satisfactorily up to 70 Gy. (P.A.)

  18. On the instability effects in radiation-sensitive chalcogenide glasses

    International Nuclear Information System (INIS)

    The features of application of radiation-sensitive media based on chalcogenide glasses of As-Ge-S system for registration of high-energy γ-radiation are analysed. It is shown that compositional features of the observed time-instability effect should be taken into account in order to ensure a higher accuracy of the developed dosimeters

  19. On the instability effects in radiation-sensitive chalcogenide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Balitska, V. [Lviv State University for Vital Activity Safety, 35 Kleparivska str., Lviv, UA-79007 (Ukraine); Lviv Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv, UA-79031 (Ukraine); Kovalskiy, A. [Lviv Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv, UA-79031 (Ukraine); International Materials Institute for New Functionality in Glass, Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States); Shpotyuk, O. [Lviv Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv, UA-79031 (Ukraine); International Materials Institute for New Functionality in Glass, Lehigh University, 5 East Packer Avenue, Bethlehem, PA 18015-3195 (United States)], E-mail: shpotyuk@novas.lviv.ua; Vakiv, M. [Lviv Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv, UA-79031 (Ukraine)

    2007-04-15

    The features of application of radiation-sensitive media based on chalcogenide glasses of As-Ge-S system for registration of high-energy {gamma}-radiation are analysed. It is shown that compositional features of the observed time-instability effect should be taken into account in order to ensure a higher accuracy of the developed dosimeters.

  20. 47 CFR 22.659 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... radiated power limits. The purpose of the rules in this section, which limit effective radiated power (ERP... subsequently relocated. (a) Maximum ERP. The ERP of base transmitters must not exceed 100 Watts under any circumstances. The ERP of mobile transmitters must not exceed 60 Watts under any circumstances. (b)...

  1. 47 CFR 22.913 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... radiated power (ERP) of transmitters in the Cellular Radiotelephone Service must not exceed the limits in this section. (a) Maximum ERP. In general, the effective radiated power (ERP) of base transmitters and... areas, as those areas are defined in § 22.949, the ERP of base transmitters and cellular repeaters...

  2. 47 CFR 22.627 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... radiated power limits. The effective radiated power (ERP) of transmitters operating on the channels listed in § 22.621 must not exceed the limits in this section. (a) Maximum ERP. The ERP must not exceed the applicable limits in this paragraph under any circumstances. Frequency range (MHz) Maximum ERP (watts)...

  3. Effects produced by nuclear radiation in powdery milk

    International Nuclear Information System (INIS)

    The objective of this work is to determine the chemical effects produced by the gamma rays and beta particles radiations on the powdery milk. This work treats on the Pre-dose analysis, sampling radiating, electron spin resonance, acidity, proteins, aminoacids, lactose, fatty acids, peroxides, as well as its experimental results. (Author)

  4. Effects of space-relevant radiation on pre-osteoblasts

    International Nuclear Information System (INIS)

    Until now limited research has been conducted to address the mechanisms leading ionizing radiation exposure induced bone loss. This is relevant for cancer radiotherapy and human spaceflight. Exposure to radiation can result in elevated bone fracture risk in patients receiving cancer radiotherapy. In human spaceflight, astronauts are exposed to space radiation which is a very complex mixture consisting primarily of high-energy charged particles. Osteoblasts are of mesenchymal origin and responsible for creating and maintaining skeletal architecture; these cells produce extracellular matrix proteins and regulators of matrix mineralization during initial bone formation and later bone remodeling. The aim of this work was to investigate the effects of ionizing radiation on pre-osteoblasts including cellular survival, cell cycle regulation and differentiation modification. Experiments with the pre-osteoblast cell line OCT-1 and the mesenchymal stem cell line C3H10T1/2 showed that radiation cell killing depends on dose and linear energy transfer (LET) and is most effective at an LET of ∝150 keV/μm. High-LET radiation has a much more pronounced ability to induce cell cycle arrest in the G2/M phase. After both X-rays and heavy ions exposure, expression of the cell cycle regulator CDKN1A was significantly up-regulated in a dose-dependent manner. The findings suggest that cell cycle regulation is more sensitive to high-LET radiation than cell survival, which is not solely regulated through elevated CDKN1A expression. Radiation exposure enhances osteoblastic differentiation and maturation, and mediates Runx2 and TGF-β1 expression during early differentiation of pre-osteoblasts. Osteogenic differentiation did not alter cellular radiosensitivity, DNA repair of radiation-induced damages and the effects of radiation on proliferation. Further experiments are needed to elucidate possible synergistic effects of microgravity and radiation on osteoblast differentiation. This may

  5. Effects of space-relevant radiation on pre-osteoblasts

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Yueyuan

    2014-02-12

    Until now limited research has been conducted to address the mechanisms leading ionizing radiation exposure induced bone loss. This is relevant for cancer radiotherapy and human spaceflight. Exposure to radiation can result in elevated bone fracture risk in patients receiving cancer radiotherapy. In human spaceflight, astronauts are exposed to space radiation which is a very complex mixture consisting primarily of high-energy charged particles. Osteoblasts are of mesenchymal origin and responsible for creating and maintaining skeletal architecture; these cells produce extracellular matrix proteins and regulators of matrix mineralization during initial bone formation and later bone remodeling. The aim of this work was to investigate the effects of ionizing radiation on pre-osteoblasts including cellular survival, cell cycle regulation and differentiation modification. Experiments with the pre-osteoblast cell line OCT-1 and the mesenchymal stem cell line C3H10T1/2 showed that radiation cell killing depends on dose and linear energy transfer (LET) and is most effective at an LET of ∝150 keV/μm. High-LET radiation has a much more pronounced ability to induce cell cycle arrest in the G2/M phase. After both X-rays and heavy ions exposure, expression of the cell cycle regulator CDKN1A was significantly up-regulated in a dose-dependent manner. The findings suggest that cell cycle regulation is more sensitive to high-LET radiation than cell survival, which is not solely regulated through elevated CDKN1A expression. Radiation exposure enhances osteoblastic differentiation and maturation, and mediates Runx2 and TGF-β1 expression during early differentiation of pre-osteoblasts. Osteogenic differentiation did not alter cellular radiosensitivity, DNA repair of radiation-induced damages and the effects of radiation on proliferation. Further experiments are needed to elucidate possible synergistic effects of microgravity and radiation on osteoblast differentiation. This may

  6. Cooperative Effect Radiation Loss of Optical Pump Solid Laser

    Institute of Scientific and Technical Information of China (English)

    NING Guo-bin; SONG Gui-cai

    2006-01-01

    The cooperative effect radiation loss of the optical pumped solid laser has been investigated. The characteristics and the cause of coherent spontaneous are discussed using Maxwell-Bloch equation in the paper. By laser rate equation, the expression of upper energy level lifetime shortening due to the cooperative effect radiation is given.The influence of the cooperative effect on laser threshold and the loss are analyzed. By a series of experiments, the relation ship of coherent spontaneous radiation intensity and direction with reversal population and the power of optical pump are obtained.

  7. Radiation effects on science instruments in Grand Tour type missions

    Science.gov (United States)

    Parker, R. H.

    1972-01-01

    The extent of the radiation effects problem is delineated, along with the status of protective designs for 15 representative science instruments. Designs for protecting science instruments from radiation damage is discussed for the various instruments to be employed in the Grand Tour type missions. A literature search effort was undertaken to collect science instrument components damage/interference effects data on the various sensitive components such as Si detectors, vidicon tubes, etc. A small experimental effort is underway to provide verification of the radiation effects predictions.

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

    International Nuclear Information System (INIS)

    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)

  9. The development and purpose of the FREDERICA radiation effects database.

    Science.gov (United States)

    Copplestone, D; Hingston, J; Real, A

    2008-09-01

    Any system for assessing the impact of a contaminant on the environment requires an analysis of the possible effects on the organisms and ecosystems concerned. To facilitate this, the FREDERICA radiation effects database has been developed to provide an online search of the known effects of ionising radiation on non-human species, taken from papers in the scientific peer reviewed literature. The FREDERICA radiation effects database has been produced by merging the work done on radiation effects under two European funded projects (FASSET and EPIC) and making the database available online. This paper highlights applications for the database, gaps in the available data and explains the use of quality scores to help users of the database determine which papers may benefit their research in terms of techniques and reproducibility.

  10. Rays Sting: The Acute Cellular Effects of Ionizing Radiation Exposure.

    Science.gov (United States)

    Franco, A; Ciccarelli, M; Sorriento, D; Napolitano, L; Fiordelisi, A; Trimarco, B; Durante, M; Iaccarino, G

    2016-05-01

    High-precision radiation therapy is a clinical approach that uses the targeted delivery of ionizing radiation, and the subsequent formation of reactive oxygen species (ROS) in high proliferative, radiation sensitive cancers. In particular, in thoracic cancer ratdiation treatments, can not avoid a certain amount of cardiac toxicity. Given the low proliferative rate of cardiac myocytes, research has looked at the effect of radiation on endothelial cells and consequent coronary heart disease as the mechanism of ratdiation induced cardiotoxicity. In fact, little is known concerning the direct effect of radiation on mitochondria dynamis in cardiomyocyte. The main effect of ionizing radiation is the production of ROS and recent works have uncovered that they directly participates to pivotal cell function like mitochondrial quality control. In particular ROS seems to act as check point within the cell to promote either mitochondrial biogenesis and survival or mitochondrial damage and apoptosis. Thus, it appears evident that the functional state of the cell, as well as the expression patterns of molecules involved in mitochondrial metabolism may differently modulate mitochondrial fate in response to radiation induced ROS responses. Different molecules have been described to localize to mitochondria and regulate ROS production in response to stress, in particular GRK2. In this review we will discuss the evidences on the cardiac toxicity induced by X ray radiation on cardiomyocytes with emphasis on the role played by mitochondria dynamism.

  11. Rays Sting: The Acute Cellular Effects of Ionizing Radiation Exposure.

    Science.gov (United States)

    Franco, A; Ciccarelli, M; Sorriento, D; Napolitano, L; Fiordelisi, A; Trimarco, B; Durante, M; Iaccarino, G

    2016-05-01

    High-precision radiation therapy is a clinical approach that uses the targeted delivery of ionizing radiation, and the subsequent formation of reactive oxygen species (ROS) in high proliferative, radiation sensitive cancers. In particular, in thoracic cancer ratdiation treatments, can not avoid a certain amount of cardiac toxicity. Given the low proliferative rate of cardiac myocytes, research has looked at the effect of radiation on endothelial cells and consequent coronary heart disease as the mechanism of ratdiation induced cardiotoxicity. In fact, little is known concerning the direct effect of radiation on mitochondria dynamis in cardiomyocyte. The main effect of ionizing radiation is the production of ROS and recent works have uncovered that they directly participates to pivotal cell function like mitochondrial quality control. In particular ROS seems to act as check point within the cell to promote either mitochondrial biogenesis and survival or mitochondrial damage and apoptosis. Thus, it appears evident that the functional state of the cell, as well as the expression patterns of molecules involved in mitochondrial metabolism may differently modulate mitochondrial fate in response to radiation induced ROS responses. Different molecules have been described to localize to mitochondria and regulate ROS production in response to stress, in particular GRK2. In this review we will discuss the evidences on the cardiac toxicity induced by X ray radiation on cardiomyocytes with emphasis on the role played by mitochondria dynamism. PMID:27326395

  12. A new solvent suppression method via radiation damping effect

    Institute of Scientific and Technical Information of China (English)

    Cui Xiao-Hong; Peng Ling; Zhang Zhen-Min; Cai Shu-Hui; Chen Zhong

    2011-01-01

    Radiation damping effects induced by the dominated solvent in a solution sample can be applied to suppress the solvent signal.The precession pathway and rate back to equilibrium state between solute and solvent spins are different under radiation damping.In this paper,a series of pulse sequences using radiation damping were designed for the solvent suppression in nuclear magnetic resonance (NMR) spectroscopy.Compared to the WATERGATE method,the solute signals adjacent to the solvent would not be influenced by using the radiation damping method.The one-dimensional (1D) 1H NMR,two-dimensional (2D) gCOSY,and J-resolved experimental results show the practicability of solvent suppression via radiation damping effects in 1D and 2D NMR spectroscopy.

  13. Effects of Nuclear Interactions on Accuracy of Space Radiation Transport

    Science.gov (United States)

    Lin, Zi-Wei; Barghouty, A. F.

    2005-01-01

    Space radiation risk to astronauts and electronic equipments is one major obstacle in long term human space explorations. Space radiation transport codes have been developed to calculate radiation effects behind materials in human missions to the Moon, Mars or beyond. We study how nuclear fragmentation processes affect the accuracy of predictions from such radiation transport. In particular, we investigate the effects of fragmentation cross sections at different energies on fluxes, dose and dose-equivalent from galactic cosmic rays behind typical shielding materials. These results tell us at what energies nuclear cross sections are the most important for radiation risk evaluations, and how uncertainties in our knowledge about nuclear fragmentations relate to uncertainties in space transport predictions.

  14. Quantifying Aerosol influences on the Cloud Radiative Effect

    Science.gov (United States)

    Feingold, Graham; McComiskey, Allison; Sena, Elisa; Yamaguchi, Takanobu

    2016-04-01

    Although evidence of aerosol influences on the microphysical properties of shallow liquid cloud fields abounds, a rigorous assessment of aerosol effects on the radiative properties of these clouds has proved to be elusive because of adjustments in the evolving cloud system. We will demonstrate through large numbers of idealized large eddy simulation and 14 years of surface-based remote sensing at a continental US site that the existence of a detectable cloud microphysical response to aerosol perturbations is neither a necessary, nor a sufficient condition for detectability of a radiative response. We will use a new framework that focuses on the cloud field properties that most influence shortwave radiation, e.g., cloud fraction, albedo, and liquid water path. In this framework, scene albedo is shown to be a robust function of cloud fraction for a variety of cloud systems, and appears to be insensitive to averaging scale. The albedo-cloud fraction framework will be used to quantify the cloud radiative effect of shallow liquid clouds and to demonstrate (i) the primacy of cloud field properties such as cloud fraction and liquid water path for driving the cloud radiative effect; and (ii) that the co-variability between meteorological and aerosol drivers has a strong influence on the detectability of the cloud radiative effect, regardless of whether a microphysical response is detected. A broad methodology for systematically quantifying the cloud radiative effect will be presented.

  15. X-ray diffraction radiation in conditions of Cherenkov effect

    NARCIS (Netherlands)

    Tishchenko, A. A.; Potylitsyn, A. P.; Strikhanov, M. N.

    2006-01-01

    X-ray diffraction radiation from ultra-relativistic electrons moving near an absorbing target is considered. The emission yield is found to increase significantly in conditions of Cherenkov effect. (c) 2006 Elsevier B.V. All rights reserved.

  16. Proceedings of a Workshop on Genetic Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Nine papers were presented at this workshop held to mark the retirement of Dr. D.K. Myers. The papers reviewed recent literature on the heritable effects of ionizing radiation and identified areas of uncertainty. (L.L.)

  17. FALLOUT RADIATION: EFFECTS ON THE SKIN

    Energy Technology Data Exchange (ETDEWEB)

    Conard, R. A.; Cronkite, E. P.; Bond, V. P.

    1963-02-06

    Until recently it has been generally assumed that injury to the skin from ionizing radiation was not a serious hazard associated with the detonation of nuclear dcvices. However, in 1954 the importance of this hazard became apparent when widespread lesions of the skin developed in a large group of people accidentally exposed to fallout radiation in the Marshall Islands following the experimental detonation of a large nuclear device. The accident in the Marshall Islands affords an example of large numbers of lesions of the skin in human beings from the fallout. Studies have been documented and will be referred to frequently in this chapter. The possibility of such accidents must be considered seriously in view of the increasingly widespread use of radioisotopes.

  18. Radiative Feedback Effects during Cosmic Reionization

    Science.gov (United States)

    Sullivan, David; Iliev, Ilian T.

    2016-10-01

    We present coupled radiation hydrodynamical simulations of the epoch of reionization, aimed at probing self-feedback on galactic scales. Unlike previous works, which assume a (quasi) homogeneous UV background, we self-consistently evolve both the radiation field and the gas to model the impact of previously unresolved processes such as spectral hardening and self-shielding. We find that the characteristic halo mass with a gas fraction half the cosmic mean, Mc (z), a quantity frequently used in semi-analytical models of galaxy formation, is significantly larger than previously assumed. While this results in an increased suppression of star formation in the early Universe, our results are consistent with the extrapolated stellar abundance matching models from Moster et al. 2013.

  19. Effect of impurity radiation on tokamak equilibrium

    International Nuclear Information System (INIS)

    The energy loss from a tokamak plasma due to the radiation from impurities is of great importance in the overall energy balance. Taking the temperature dependence of this loss for two impurities characteristic of those present in existing tokamak plasmas, the condition for radial power balance is derived. For the impurities considered (oxygen and iron) it is found that the radiation losses are concentrated in a thin outer layer of the plasma and the equilibrium condition places an upper limit on the plasma paraticle number density in this region. This limiting density scales with mean current density in the same manner as is experimentally observed for the peak number density of tokamak plasmas. The stability of such equilibria is also discussed. (author)

  20. Study of radiation effects on semiconductor devices

    International Nuclear Information System (INIS)

    Due to the demand for high integration and scaling down, recent integrated circuits have been designed with the design rule less than 100 nm. SEUs (Single-Event Upset) and SETs (Single-Event Transient) are serious problems for those devices because of the lower supply voltage and the lower threshold voltage of the transistors that makes more sensitive to smaller charge generated by an ion passage. To attain higher radiation tolerance for high integrated circuits, a DICE (Dual Interlocked Storage Cell)-based flip-flop with an SET pulse discriminator circuit on a 90-nm bulk CMOS was designed and fabricated and its performance was examined through radiation testing. SEU/SET sensitivity in the angular irradiation was measured and analyzed in this study. The test of edge-on irradiation was performed for the first time and the importance of the angular irradiation for the memory cells that have redundant memory nodes was demonstrated. (author)

  1. Application of radiation damage effects in dosimetry

    International Nuclear Information System (INIS)

    some general aspects of radiation dosimetry are outlined. The techniques of radiophotoluminescence, radiothermoluminescence and exo-electron emission are discussed individually. It is thought that the trend in personnel dosimetry is such that thermoluminescence will steadily replace film and photoluminescence techniques over the next decade, and that more unusual techniques, such as exo-electron emission, will make inroads only for special purposes. (B.R.H.)

  2. Effect of absorbing grounds on acoustic radiation of tyres

    OpenAIRE

    Duhamel, D.; HAMET,JF; Klein, P; ANFOSSO,F; YIN, HP; GAUTIER,JL; MAUNIER,Y

    2006-01-01

    Tyre noise is generated by surface vibrations or by air pumping and can be amplified by the horn effect which is the increase in radiation by the geometric horn between the tyre and the ground. The global efficiency of this radiation depends on the absorbing properties of the ground and an accurate model of tyre noise radiation must take this effect into account. Here the results of a detailed boundary element model including three dimensional real geometries and the impedance of the ground a...

  3. Effect of absorbing grounds on acoustic radiation of tyres

    OpenAIRE

    Duhamel, D.; HAMET,JF; Klein, P; ANFOSSO LEDEE, F; Yin , H.; GAUTIER,JL; Meunier, Y.

    2006-01-01

    Tyre noise is generated by surface vibrations or by air pumping and can be amplified by the horn effect which is the increase in radiation by the geometric horn between the tyre and the ground. The global efficiency of this radiation depends on the absorbing properties of the ground and an accurate model of tyre noise radiation must take this effect into account. Here the results of a detailed element model including three dimensional real geometries and the impedance of the ground are presen...

  4. Effective UV radiation dose in polyethylene exposed to weather

    Science.gov (United States)

    González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Calero Marín, S. P.; Vega-Durán, J. T.; Moreno-Virgen, R.

    2009-09-01

    In this work we quantified the effective UV radiation dose in orange and colorless polyethylene samples exposed to weather in the city of Aguascalientes, Ags. Mexico. The spectral distribution of solar radiation was calculated using SMART 2.9.5.; the samples absorption properties were measured using UV-Vis spectroscopy and the quantum yield was calculated using samples reflectance properties. The determining factor in the effective UV dose is the spectral distribution of solar radiation, although the chemical structure of materials is also important.

  5. Effect of particle clustering on radiative transfer in turbulent flows

    CERN Document Server

    Liberman, M; Rogachevskii, I; Haugen, N E L

    2016-01-01

    The effect of particle clustering on the radiation penetration length in particle laden turbulent flows is studied using a mean-field approach. Particle clustering in temperature stratified turbulence implies the formation of small-scale clusters with a high concentration of particles, exceeding the mean concentration by a few orders of magnitude. We show that the radiative penetration length increases by several orders of magnitude due to the particle clustering in a turbulent flow. Such strong radiative clearing effect plays a key role in a number of atmospheric and astrophysical phenomena, and can be of fundamental importance for understanding the origin of dust explosions.

  6. Coherent Radiation Effects in the LCLS Undulator

    CERN Document Server

    Reiche, Sven

    2004-01-01

    For X-ray Free-Electron Lasers, a change in the electron energy while amplifying the FEL radiation can shift the resonance condition out of the bandwidth of the FEL. The largest sources of energy loss is incoherent undulator radiation. Because the loss per electron depends only on the undulator parameters and the beam energy, which are fixed for a given resonant wavelength, the average energy loss can be compensated for by a fixed taper of the undulator. Coherent radiation has a strong enhancement proportional to the number of electrons in the bunch for wavelengths comparable to or longer than the bunch dimension or bunch sub-structures. If the coherent loss is comparable to that of the incoherent the required taper depends on the bunch charge and the applied compression scheme and a change of these parameters would require a change of the taper. This imposes a limitation on the operation of FELs, where the taper can only be adjusted manually. In this presentation we analyze the coherent emission of undulator...

  7. Expected radiation effects in plutonium immobilization ceramic

    Energy Technology Data Exchange (ETDEWEB)

    Van Konynenburg, R.A., LLNL

    1997-09-01

    The current formulation of the candidate ceramic for plutonium immobilization consists primarily of pyrochlore, with smaller amounts of hafnium-zirconolite, rutile, and brannerite or perovskite. At a plutonium loading of 10.5 weight %, this ceramic would be made metamict (amorphous) by radiation damage resulting from alpha decay in a time much less than 10,000 years, the actual time depending on the repository temperature as a function of time. Based on previous experimental radiation damage work by others, it seems clear that this process would also result in a bulk volume increase (swelling) of about 6% for ceramic that was mechanically unconfined. For the candidate ceramic, which is made by cold pressing and sintering and has porosity amounting to somewhat more than this amount, it seems likely that this swelling would be accommodated by filling in the porosity, if the material were tightly confined mechanically by the waste package. Some ceramics have been observed to undergo microcracking as a result of radiation-induced anisotropic or differential swelling. It is unlikely that the candidate ceramic will microcrack extensively, for three reasons: (1) its phase composition is dominated by a single matrix mineral phase, pyrochlore, which has a cubic crystal structure and is thus not subject to anisotropic swelling; (2) the proportion of minor phases is small, minimizing potential cracking due to differential swelling; and (3) there is some flexibility in sintering process parameters that will allow limitation of the grain size, which can further limit stresses resulting from either cause.

  8. Studies on chronic effect on radiation

    International Nuclear Information System (INIS)

    This experiment was carried out to evaluate the chronic harzard of Co-60 low dose irradiation on ICR mice. There is now considerable evidence from human studies that age, both at exposure to radiation and at observation for risk, can be a major determinant of radiation induced cancer risk. For this reason, ICR mice at different ages as specified below were exposed to 60 m rads/week, 500 m rads/biweek of whole body Co-60 radiation at a dose rate of 3.6 rads/min. ICR mice were irradiated during pregnant period and each period from the 1st week to the 3rd week to the 52nd week, from the 6th week to the 52nd week and from the 22nd week to the 52nd week after the birth. All the experimental mice were autopsied immediately after sacrificed at the 52nd week. And all of their major organs were examined grossly and weighed. After fixation histo-pathological preparations were made for microscopical study. Blood cells-W.B.C., R.B.C., Hb-from eye's vein were counted by hemocytometer and hemometer. (Author)

  9. Numerical simulation of neutron radiation effects in avalanche photodiodes

    OpenAIRE

    Osborne, M.; Hobson, PR; Watts, SJ

    2000-01-01

    A new one-dimensional (1-D) device model developed for the simulation of neutron radiation effects in silicon avalanche photodiodes is described. The model uses a finite difference technique to solve the time-independent semiconductor equations across a user specified structure. The model includes impact ionization and illumination allowing accurate simulation with minimal assumptions. The effect of neutron radiation damage is incorporated via the introduction of deep acceptor levels subject ...

  10. Effective temperature and exergy of monochromic blackbody radiation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new parameter named monochromic effective temperature Tλ is proposed, which represents the thermodynamic quality of monochromic blackbody radiation. The exergy of the monochromic blackbody radiation is expressed by Tλ. The monochromic effective temperature equation is developed, which shows that the produci of Tλ and the wavelength is constant, which equals 5.33016×10-3 tion in photosynthesis can be explained by the results of this work.

  11. The effects of temperature on the radiation chemistry of polymers

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.J.T. [Queensland Univ., Brisbane, QLD (Australia)

    1995-03-01

    The effects of high energy radiation on polymers is dependent on a number of factors. One of the most important factors is the radiolysis temperature. This paper discusses the effects of the {alpha}-transition and the other secondary transitions, as well as the ceiling and melting temperatures, on the nature of the radiolysis reactions which occur for a number of polymers. Some implications of changes in the radiation chemistry of polymers with a change in the temperature are also considered. (author).

  12. The effects of temperature on the radiation chemistry of polymers

    International Nuclear Information System (INIS)

    The effects of high energy radiation on polymers is dependent on a number of factors. One of the most important factors is the radiolysis temperature. This paper discusses the effects of the α-transition and the other secondary transitions, as well as the ceiling and melting temperatures, on the nature of the radiolysis reactions which occur for a number of polymers. Some implications of changes in the radiation chemistry of polymers with a change in the temperature are also considered. (author)

  13. Parameterisation of radiation effects on CVD diamond for proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hartjes, F.; Adam, W.; Bauer, C.; Berdermann, E.; Bergonzo, P.; Bogani, F.; Borchi, E.; Brambilla, A.; Bruzzi, M.; Colledani, C.; Conway, J.; Dabrowski, W.; Delpierre, P.; Deneuville, A.; Dulinski, W.; Eijk, B. van; Fallou, A.; Fizzotti, F.; Foulon, F.; Friedl, M.; Gan, K.K.; Gheeraert, E.; Grigoriev, E.; Hallewell, G.; Hall-Wilton, R.; Han, S.; Hrubec, J.; Husson, D.; Kagan, H.; Kania, D.; Kaplon, J.; Karl, C.; Kass, R.; Knoepfle, K.T.; Krammer, M.; Logiudice, A.; Lu, R.; Manfredi, P.F.; Manfredotti, C.; Marshall, R.D.; Meier, D.; Mishina, M.; Oh, A.; Pan, L.S.; Palmieri, V.G.; Pernicka, M.; Peitz, A.; Pirollo, S.; Polesello, P.; Pretzl, K.; Procario, M.; Re, V.; Riester, J.L.; Roe, S.; Roff, D.; Rudge, A.; Runolfsson, O.; Russ, J.; Schnetzer, S.; Sciortino, S.; Speziali, V.; Stelzer, H.; Stone, R.; Suter, B.; Tapper, R.J.; Tesarek, R.; Trawick, M.; Trischuk, W.; Vittone, E.; Wagner, A.; Walsh, A.M.; Wedenig, R.; Weilhammer, P.; White, C.; Zeuner, W.; Ziock, H.; Zoeller, M

    1999-08-01

    The paper reviews measurements of the radiation hardness of CVD diamond for 24 GeV/c proton irradiation at fluences up to 5{sup *}10{sup 15} protons/cm{sup 2}. The results not only show radiation damage but also an annealing effect that is dominant at levels around 10{sup 15} protons/cm{sup 2}. A model describing both effects is introduced, enabling a prediction of the distribution curve of the charge signal for other levels.

  14. Parameterisation of radiation effects on CVD diamond for proton irradiation

    International Nuclear Information System (INIS)

    The paper reviews measurements of the radiation hardness of CVD diamond for 24 GeV/c proton irradiation at fluences up to 5*1015 protons/cm2. The results not only show radiation damage but also an annealing effect that is dominant at levels around 1015 protons/cm2. A model describing both effects is introduced, enabling a prediction of the distribution curve of the charge signal for other levels

  15. Effect of ionizing radiation on human skeletal muscle precursor cells

    OpenAIRE

    Marš, Tomaž; Čemažar, Maja; Jurdana, Mihaela; Pegan, Katarina

    2015-01-01

    Background. Long term effects of different doses of ionizing radiation on human skeletal muscle myoblast proliferation, cytokine signalling and stress response capacity were studied in primary cell cultures.Materials and methods. Human skeletal muscle myoblasts obtained from muscle biopsies were cultured and irradiated with a Darpac 2000 X-ray unit at doses of 4, 6 and 8 Gy. Acute effects of radiation were studied by interleukin - 6 (IL-6) release and stress response detected by the heat shoc...

  16. Nonlinear vacuum polarization in intense blackbody radiation and its effects on the radiation spectrum

    Science.gov (United States)

    Wu, Sheldon; Hartemann, Frederic; Siders, Craig; Barty, Christopher

    2009-11-01

    A study of thermally induced vacuum polarization stemming from the Euler-Heisenberg radiation correction to Maxwell equations is conducted. While nonlinear effects associated with interactions of electromagnetic pulse with a background photon gas had been previously calculated, we examine the possibility of nonlinear corrective terms to the blackbody radiation spectrum. Suitable conditions can be found in both astrophysical and laboratory environments. Inertial confined, ignited thermonuclear plasmas will produce intense blackbody radiation at temperatures in excess of 20 keV. In this theoretical investigation, our analysis shows that in an ideal incoherent blackbody the radiation spectrum is unaffected in the regime studied. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  17. Spatial interpolation of biologically effective UV radiation over Poland

    Science.gov (United States)

    Walawender, J.; Ustrnul, Z.

    2010-09-01

    The ultraviolet(UV) radiation plays an important role in the Earth-Atmosphere System. It has a positive influence on both human health and natural environment but it may also be very harmful if UV exposure exceeds "safe" limits. For that reason knowledge about spatial distribution of biologically effective UV doses seems to be crucial in minimization or complete elimination of the negative UV effects. The main purpose of this study is to find the most appropriate interpolation method in order to create reliable maps of the biologically effective UV radiation over Poland. As the broadband UV measurement network in Poland is very sparse, erythemaly weighted UV radiation data reconstructed from homogeneous global solar radiation records were used. UV reconstruction model was developed in Centre of Aerology (Institute of Meteorology and Water Management) within COST Action 726 - ‘Long term changes and climatology of UV radiation over Europe'. The model made it possible to reconstruct daily erythemal UV doses for 21 solar radiation measurement stations in the period 1985 - 2008. Mapping methodology included the following processing steps: exploratory spatial data analysis, verification of additional variables, selection and parameterization of interpolation model, accuracy assessment and cartographic visualization. Several different stochastic and deterministic interpolation methods along with various empirical semivariogram models were tested. Multiple regression analysis was performed in order to examine statistical relationship between UV radiation and additional environmental variables such as: elevation, latitude, stratospheric ozone content and cloud cover. The data were integrated, processed and visualized within GIS environment.

  18. Effects of high let radiation at the cellular level

    International Nuclear Information System (INIS)

    The complete evaluation of the impact of nuclear energy technologies on human health requires: identification and characterization of hazardous agents and their effects, which is well advanced; quantitative dose-effect relations for important effects under various conditions of radiation exposure and biological variation, which needs more work but which has been advancing fairly well, particularly in experimental animal research; an understanding of the cellular and tissue mechanisms of the hazardous effects in relation to the microdosimetry of the agents, which has advanced slowly and to a relatively limited degree; and integration of the dose-effect relations and mechanistic knowledge into theories and models which are intended to be predictive for estimation of human health risks at pertinent low levels of exposure. Several theories, hypotheses or models of radiation carcinogenesis, and some for alpha radiation in particular, have been developed on the basis of dose-effect relations in the necessary attempt to predict the hazards of low levels of radiation exposure for purposes of radiation protection in advance of adequate data on dose-effect relations and mchanisms. As such these theories or models have necessarily involved strings of explicit and implicit assumptions concerning mechanisms and the nature of dose-effect relations below the dose regions at which effects have been observed. Nevertheless, they have been useful in stimulating research to test their assumptions and in assuming the interpretation of data

  19. Effects of ionizing radiation on aquatic organisms and ecosystems

    International Nuclear Information System (INIS)

    A panel of experts in November 1971 specifically considered the effects of ionizing radiation on aquatic organisms and ecosystems and formulated detailed suggestions for research in the area. A further panel meeting took place in April 1974. The results of the work are presented in this report which is divided into 3 chapters in the first chapter the concentrations of natural and artificial radionuclides in aquatic environments and the radiation dose rates received by aquatic organisms are discussed. In particular, simple dosimetry models for phytoplankton, zooplankton, mollusca, crustacea and fish are presented which permit the estimation of the dose rates from incorporated radionuclides and from radionuclides in the external environment. In the second chapter the somatic and genetic effects of ionizing radiation on aquatic organisms are reviewed. Somatic effects are discussed separately as effects due to short-term (acute) exposure to near-lethal doses of radiation. Great attention is paid to the effects due to long-term (chronic) exposure at lower doses rates. Consideration is given to behaviour, repair mechanisms and metabolic stimulation after exposure, and also the influence of environmental factors on radiation effects. In the third chapter the potential effects of low-level irradiation on aquatic populations are considered. First, the possible consequences of somatic effects on egg and larval mortality, stock-recruitment, fecundity and ecosystem stability are discussed. Subsequently, the assessment of genetic effects as they relate to population genetics and increased mutation rates are considered

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

    International Nuclear Information System (INIS)

    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)

  1. Studies of Non-Targeted Effects of Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  2. Environmental Radiation Effects on Mammals A Dynamical Modeling Approach

    CERN Document Server

    Smirnova, Olga A

    2010-01-01

    This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef...

  3. Radiation effects on reactor pressure vessel supports

    International Nuclear Information System (INIS)

    The purpose of this report is to present the findings from the work done in accordance with the Task Action Plan developed to resolve the Nuclear Regulatory Commission (NRC) Generic Safety Issue No. 15, (GSI-15). GSI-15 was established to evaluate the potential for low-temperature, low-flux-level neutron irradiation to embrittle reactor pressure vessel (RPV) supports to the point of compromising plant safety. An evaluation of surveillance samples from the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory (ORNL) had suggested that some materials used for RPV supports in pressurized-water reactors could exhibit higher than expected embrittlement rates. However, further tests designed to evaluate the applicability of the HFIR data to reactor RPV supports under operating conditions led to the conclusion that RPV supports could be evaluated using traditional method. It was found that the unique HFIR radiation environment allowed the gamma radiation to contribute significantly to the embrittlement. The shielding provided by the thick steel RPV shell ensures that degradation of RPV supports from gamma irradiation is improbable or minimal. The findings reported herein were used, in part, as the basis for technical resolution of the issue

  4. More Abstracts on Effects of Radiation on Electronic Devices

    Science.gov (United States)

    Bouquet, Frank L.

    1987-01-01

    Second volume of bibliography summarizes literature on radiation effects on new electronic devices. Includes those of protons, electrons, neutrons, gamma rays, and cosmic rays at energies up to about 20 GeV. Volume contains 219 abstracts from unclassified sources. Organized into four sections: dose-rate effects, new technology, post-irradiaton effects, and test environments.

  5. Radiation induced effects in the developing central nervous system

    International Nuclear Information System (INIS)

    The embryo and the human foetus are particularly sensitive to ionizing radiation and this sensitivity presents various qualitative and quantitative functional changes during intra-uterine development. Apart from radiation induced carcinogenesis, the most serious consequence of prenatal exposure in human beings is severe mental retardation. The principal data on radiation effects on human beings in the development of the central nervous system come form epidemiological studies carried out in individuals exposed in utero during the atomic explosion at Hiroshima and Nagasaki. These observations demonstrate the existence of a time of maximum radiosensitivity between the weeks 8 and 15 of the gestational period, a period in which the proliferation and neuronal migration takes place. Determination of the characteristics of dose-response relationship and the possible existence of a threshold dose of radiation effects on the development of the central nervous system is relevant to radiation protection against low dose radiation and the establishment of dose limits for occupational exposure and the public. Studies were conducted on the generation of nitrous-oxide and its relation with the production of active species of oxygen in brains of exposed rats in utero exposed to doses of up to 1 Gy during their maximum radiosensitivity. The possible role of the mechanism of radiation induced damage in the development of the central nervous system is discussed

  6. Internal Radiation Effects in Zirconia Thermal Barrier Coatings

    Science.gov (United States)

    Siegel, Robert

    1996-01-01

    Using thermal barrier coatings on combustor liners, turbine vanes, and rotating blades is important for reducing metal temperatures in current and advanced aircraft engines. Zirconia is a common coating material, and it is partially transparent to thermal radiation. Radiation becomes more significant as temperatures are raised for higher efficiency in advanced engines. Calculations are often made with radiation effects neglected inside the coating. The effect of radiation is illustrated here, where an analytical procedure is provided by using the two-flux method for the radiative contribution. A detailed study was made of ceramic thermal barrier coatings for diesel engines, and a two-flux analysis was developed for radiation in semitransparent multilayer composites. These efforts provide the basis for the present analysis where illustrative solutions are obtained for typical conditions in an aircraft engine. The formulation and solution of the exact spectral radiative transfer equations including large scattering, as is characteristic of zirconia, are rather complicated. The two-flux method is used here to provide a simplified method.

  7. Effects of gamma radiation on commercial operational amplifiers

    International Nuclear Information System (INIS)

    The operational amplifiers are widely used in nuclear instrumentation. Their applications span the signal conditioning circuits, analog instrumentation, amplifiers, converters, oscillators and others. If an operational amplifier is used to work in a radiation environment, the device suffers degradation in its performance leading to the bad work in the systems. Some of these devices are designed as rad-hard components and therefore the effects of radiation damage are minimized, however its main disadvantage is the high cost and difficult to find in the market. As an alternative one can use the conventional electronic components available in the market and named COTS (Commercially Available Off-The-Shelf) but they must be tested under a radiation environment. In this work the effect of the radiation damage is studied in two typical operational amplifiers. Some electric parameters of these devices were measured for different gamma radiation doses and they were working at different input signal frequencies. A 60Co isotopic radiation source was used and the results show that there is a certain degradation of the device depending on the radiation absorbed dose. (author)

  8. Risk calculations for hereditary effects of ionizing radiation in humans.

    Science.gov (United States)

    Vogel, F

    1992-05-01

    A prediction of the extent to which an additional dose of ionizing radiation increases the natural germ cell mutation rate, and how much such an increase will affect the health status of future human populations is part of the service that human geneticists are expected to offer to human society. However, more detailed scrutiny of the difficulties involved reveals an extremely complex set of problems. A large number of questions arises before such a prediction can be given with confidence; many such questions cannot be answered at our present state of knowledge. However, such predictions have recently been attempted. The 1988 report of the United Nations Scientific Committee for the Effects of Atomic Radiation and the fifth report of the Committee on Biological Effects of Ionizing Radiation of the US National Research Council have presented a discussion of the human genetics problems involved. Empirical data from studies on children of highly radiation-exposed parents, e.g. parents exposed to the atomic bombs of Hiroshima and Nagasaki, or parents belonging to populations living on soil with high background radiation, have been mentioned in this context. Whereas precise predictions are impossible as yet because of deficiencies in our knowledge of medical genetics at various levels, the bulk of the existing evidence points to only small effects of low or moderate radiation doses, effects that will probably be buried in the "background noise" of changing patterns of human morbidity and mortality. PMID:1587523

  9. Adaptation hypothesis of biological effectiveness of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kudritsky, Yu.K.; Georgievsky, A.B.; Karpov, V.I.

    1993-12-31

    The adoptation hypothesis of biological effectiveness of ionizing radiations is based on the recognition of the invariability of general biological laws for radiobiology and on the comprehension of life evolution regularities and axiomatic principles of environment and biota unity. The ionizing radiation factor is essential for life which could not exist beyond the radiation field. The possibility of future development of the adaptation hypothesis serves as a basis for it`s transformation into the theoretical foundation of radiobiology. This report discusses the aspects of the adaptation theory.

  10. Temperature effects on radiation damage to silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Barberis, E.; Cartiglia, N.; Leslie, J.; Pitzl, D.; Rowe, W.A.; Sadrozinski, H.F.W. (SCIPP, Univ. California, Santa Cruz, CA (United States)); Boissevain, J.G.; Ferguson, P.; Holzscheiter, K.; Kapustinsky, J.S.; Palounek, A.P.T.; Sommer, W.F.; Sondheim, W.E.; Ziock, H.J. (Los Alamos National Lab., NM (United States)); Ellison, J.A.; Fleming, J.K.; Jerger, S.; Joyce, D.; Lietzke, C.; Wimpenny, S.J. (Univ. California, Riverside, CA (United States)); Matthews, J.A.J.; Skinner, D. (Univ. New Mexico, Albuquerque, NM (United States))

    1993-03-01

    Motivated by the large particle fluences anticipated for the SSC and LHC, we are performing a systematic study of radiation damage to silicon microstrip detectors. Here we report radiation effects on detectors cooled to 0deg C (the proposed operating point for a large SSC silicon tracker) including leakage currents and change in depletion voltage. We also present results on the annealing behavior of the radiation damage. Finally, we report results of charge collection measurements of the damaged detectors made with an [sup 241]Am [alpha] source. (orig.).

  11. Short-term effects of radiation in glioblastoma spheroids

    DEFF Research Database (Denmark)

    Asferg Petterson, Stine; Pind Jakobsen, Ida; Jensen, Stine Skov;

    2016-01-01

    and five days. We found a small reduction in primary spheroid size after radiation and an associated small increase in uptake of the cell death marker propidium iodide. Using immunohistochemistry, P53 expression was found to be significantly increased, whereas the Ki-67 proliferation index...... capacity. Gene expression analysis of nine stem cell- and two hypoxia-related genes did not reveal any upregulation after radiation. In conclusion, this study suggests that a major short-term effect of radiation is pronounced reduction of tumor cell proliferation. We found no upregulation of stem cell...

  12. Effects of ionizing radiation on gelatine films added with antioxidant

    International Nuclear Information System (INIS)

    This work evaluates the effect of ionizing radiation on the gelatin films in presence of antioxidant. Gelatin solutions of glycerine and poly vinil alcohol, with and without the addition were prepared until the complete homogenization. The films were irradiated with 20 and 40 kGy in a electron accelerator, in the presence of air and at the room temperature. The use of ionizing radiation and the addition of antioxidant changed the properties of the film. The result of water absorption test revealed that with increasing of radiation dose occurred a reduction in the absorption, suggesting that happen a reticulation

  13. A consideration of low dose radiation effects on human health

    International Nuclear Information System (INIS)

    On March 11, 2011, an earthquake categorized as 9 Mw occurred off the northeast coast of Japan. The subsequent destructive tsunami disabled emergency units of Fukushima Dai'ichi Nuclear Power Plant and caused partial meltdown of reactors and explosions. Resulting radiation releases forced large evacuations, bore concerns about food and water and fears against human health. In this manuscript, we described the effect of radiation, especially low dose radiation below 100 mSv, on cancer risk, focusing on fetuses and children. (author)

  14. Controlling of degradation effects in radiation processing of polymers

    International Nuclear Information System (INIS)

    The interest of Member States of the IAEA in introducing radiation technology into the polymer and plastics industry is growing. This publication summarizes a number of studies conducted in the framework of a coordinated research project (CRP) on controlling of degradation effects on polymers by radiation processing technologies. It reviews a variety of applications and details the most important results and achievements of the participating centres and laboratories during the course of the CRP. The publication is intended to be of use to scientists implementing the technology and managers of radiation processing facilities

  15. Radiation Damage to Artemia Cysts:Effects of Water Vapor.

    Science.gov (United States)

    Snipes, W C; Gordy, W

    1963-10-25

    Water vapor altered the form and greatly increased the rate of decay of the electron-spin resonance pattern of long-lived free radicals obtained upon gamma irradiation of Artemia salina cysts ( brine shrimp eggs). These results, combined with data on radiation survival, indicate that the water vapor protects the cysts from radiation damage, or heals the damage. They also indicate that water protects the cysts from the effect of oxygen by neutralizing the radiation-induced free radicals before they can interact with oxygen to produce irreversible damage. PMID:17748168

  16. Effects of gamma-Radiation on Select Lipids and Antioxidants

    Science.gov (United States)

    Gandolph, Jacob; Mauer, Lisa; Perchonok, Michele

    2006-01-01

    Radiation encountered on an extended duration space mission (estimates of 3 Sieverts for a mission to Mars) poses a threat not only to human health, but also to the quality, nutritional value, and palatability of the food system. Free radicals generated by radiation interaction with foods may initiate many unwanted reactions including: 1) autoxidation in lipids that alters flavor, odor, and concentrations of essential fatty acids, and 2) depletion of antioxidants food products and dietary supplements. Studies have shown that antioxidants may provide long term health protection from oxidative stress caused by radiation exposure; therefore, consumption of antioxidants will be important. Stability of essential fatty acids is also important for astronauts long-term health status. The objectives of this study were to characterize the effects of low dose gamma-radiation on lipids and antioxidants by monitoring oxidation and reducing power, respectively, in model systems. Select oils and antioxidants were exposed to levels of gamma-radiation ranging from 0 to 1000 Gy (1 Gy = 1 Sv) using a Gammacell 220 and stored at ambient or elevated temperatures (65 C) for up to 3 months prior to analysis. A Fricke dosimeter was used to verify differences between the radiation doses administered. Primary and secondary products of lipid oxidation in soybean and peanut oils were monitored using conjugated diene and 2-thiobarbituric acid (TBARs) assays. Changes in fatty acid composition and formation and vitamin E levels were also measured. The reducing power of antioxidant compounds, including vitamins C and E and beta-carotene, was determined using the ferric reducing antioxidant power (FRAP) assay. Significant differences (alpha =0.05) were present between all radiation doses tested using the Fricke dosimeter. Increasing radiation doses above 3 Sv resulted in significantly (alpha =0.05) elevated levels of oxidation and free fatty acids in soybean and peanut oils. Decreases in

  17. Effect of radiative cooling on collapsing charged grains

    Indian Academy of Sciences (India)

    B P Pandey; Vinod Krishan; M Roy

    2001-01-01

    The effect of the radiative cooling of electrons on the gravitational collapse of cold dust grains with fluctuating electric charge is investigated. We find that the radiative cooling as well as the charge fluctuations, both, enhance the growth rate of the Jeans instability. However, the Jeans length, which is zero for cold grains and nonradiative plasma, becomes finite in the presence of radiative cooling of electrons and is further enhanced due to charge fluctuations of grains resulting in an increased threshold of the spatial scale for the Jeans instability.

  18. Delayed effects of ionizing radiation on the ear

    Energy Technology Data Exchange (ETDEWEB)

    Bohne, B.A.; Marks, J.E.; Glasgow, G.P.

    1985-07-01

    The question of damage to the ear from exposure to ionizing radiation was addressed by exposing groups of chinchillas to fractioned doses of radiation (2 Gy per day) for total doses ranging from 40 to 90 Gy. In order to allow any delayed effects of radiation to become manifest, the animals were sacrificed two years after completion of treatment and their temporal bones were prepared for microscopic examination. The most pronounced effect of treatment was degeneration of sensory and supporting cells and loss of eighth nerve fibers in the organ of Corti. Damage increased with increasing dose of radiation. The degree of damage found in many of these ears was of sufficient magnitude to produce a permanent sensorineural hearing loss.

  19. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed. PMID:25722878

  20. Advances in the biological effects of terahertz wave radiation

    Institute of Scientific and Technical Information of China (English)

    Li Zhao; Yan-Hui Hao; Rui-Yun Peng

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  1. Effects of ionizing radiation on plants and animals at levels implied by current radiation protection standards

    International Nuclear Information System (INIS)

    The 1977 Recommendations of the International Commission on Radiological Protection stated that the commission believes that if man is adequately protected from radiation, other organisms are also likely to be sufficiently protected. The present report examines this statement by considering the effects of ionizing radiation on animals and plants in both terrestrial and aquatic ecosystems. The conclusions are that chronic dose rates of IMGy.d-1 or less are unlikely to cause measurable deleterious effects in terrestrial populations, and that in the aquatic environment limiting chronic dose rates to 10MGy.d-1 to the maximally exposed individuals would provide adequate protection for the population. Thus specific radiation protection standards for non-human organisms are not needed. 193 refs, 2 figs, 7 tabs

  2. Effects of ionizing radiation in ginkgo and guarana

    Energy Technology Data Exchange (ETDEWEB)

    Rabelo Soriani, Renata [Departamento de Farmacia, Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Avenida professor Lineu Prestes, 580-Bloco13, Cidade Universitaria, CEP 05508900 Sao Paulo (Brazil); Satomi, Lucilia Cristina [Departamento de Farmacia, Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Avenida professor Lineu Prestes, 580-Bloco13, Cidade Universitaria, CEP 05508900 Sao Paulo (Brazil); Pinto, Terezinha de Jesus A. [Departamento de Farmacia, Faculdade de Ciencias Farmaceuticas, Universidade de Sao Paulo, Avenida professor Lineu Prestes, 580-Bloco13, Cidade Universitaria, CEP 05508900 Sao Paulo (Brazil)]. E-mail: tjapinto@usp.br

    2005-07-01

    Raw plant materials normally carry high bioburden due to their origin, offering potential hazards to consumers. The use of decontamination processes is therefore an important step towards the consumer safety and therapeutical efficiency. Several authors have reported the treatment of medicinal herbs with ionizing radiation. This work evaluated the effects of different radiation doses on the microbial burden and chemical constituents of ginkgo (Ginkgo biloba L.) and guarana (Paullinia cupana H.B.K.)

  3. Unravelling the effects of radiation forces in water

    OpenAIRE

    Astrath, Nelson G. C.; Malacarne, Luis C.; Mauro L. Baesso; Lukasievicz, Gustavo V. B.; Bialkowski, Stephen E.

    2014-01-01

    The effect of radiation forces at the interface between dielectric materials has been a long-standing debate for over a century. Yet there has been so far only limited experimental verification in complete accordance with the theory. Here we measure the surface deformation at the air–water interface induced by continuous and pulsed laser excitation and match this to rigorous theory of radiation forces. We demonstrate that the experimental results are quantitatively described by the numerical ...

  4. Effects of ionizing radiation in ginkgo and guarana [rapid communication

    Science.gov (United States)

    Rabelo Soriani, Renata; Cristina Satomi, Lucilia; Pinto, Terezinha de Jesus A.

    2005-07-01

    Raw plant materials normally carry high bioburden due to their origin, offering potential hazards to consumers. The use of decontamination processes is therefore an important step towards the consumer safety and therapeutical efficiency. Several authors have reported the treatment of medicinal herbs with ionizing radiation. This work evaluated the effects of different radiation doses on the microbial burden and chemical constituents of ginkgo ( Ginkgo biloba L.) and guaraná ( Paullinia cupana H.B.K.).

  5. Effects of electron radiation on properties of PLA

    OpenAIRE

    Malinowski, R.; P. Rytlewski; M. Żenkiewicz

    2011-01-01

    Purpose: The aim of the paper was to examine the effects of electron radiation on physicochemical properties of pristine poly(lactic acid) (PLA), or polylactide, and of polylactide containing a selected crosslinking agent.Design/methodology/approach: Samples to be examined were prepared in granulated forms or as moulded pieces and then treated with the high-energy electron radiation (ca. 10 MeV). The methods of gel permeation chromatography (GPC), rheology, Fourier transform infrared (FTIR) s...

  6. The global land Cryosphere Radiative Effect during the MODIS era

    OpenAIRE

    Singh, D; M. G. Flanner; J. Perket

    2015-01-01

    Cryosphere Radiative Effect (CrRE) is the instantaneous influence of snow- and ice-cover on Earth's top of atmosphere (TOA) solar energy budget. Here, we apply measurements from the Moderate Resolution Imaging Spectrometer (MODIS), combined with microwave retrievals of snow presence and radiative kernels produced from 4 different models, to derive CrRE over global land during 2001–2013. We estimate global annual mean land CrRE during this period of −2.6 W m...

  7. Some results of simulation on radiation effects in crystals

    International Nuclear Information System (INIS)

    Simulations concerning radiation in oriented silicon and tungsten crystals of different thicknesses are developed. Conditions are those of experiments done at Kharkov (Ukraine) and Tomsk (Russia) with electron beams in the 1 GeV range. Systematic comparisons between experimental and simulated spectra associated to real spectrum, radiation energy and angular distribution of the photons are developed. The ability of the simulation program to describe crystal effects in the considered energy range is analysed. (author) 11 refs.; 8 figs

  8. Plasma effects in high frequency radiative transfer

    International Nuclear Information System (INIS)

    This paper is intended as a survey of collective plasma processes which can affect the transfer of high frequency radiation in a hot dense plasma. We are rapidly approaching an era when this subject will become important in the laboratory. For pedagogical reasons we have chosen to examine plasma processes by relating them to a particular reference plasma which will consist of fully ionized carbon at a temperature kT=1 KeV (1070K) and an electron density N = 3 x 1023cm-3, (which corresponds to a mass density rho = 1 gm/cm3 and an ion density N/sub i/ = 5 x 1022 cm-3). We will consider the transport in such a plasma of photons ranging from 1 eV to 1 KeV in energy. Such photons will probably be frequently used as diagnostic probes of hot dense laboratory plasmas

  9. Radiation Effects on Polymers-X

    DEFF Research Database (Denmark)

    Aly, M. I.; Singer, Klaus Albert Julius; Ghanem, N. A.;

    1978-01-01

    Films of low-density polyethylene grafted with various amounts of polyacrylic acid were prepared by the direct irradiation method, using a 10 MeV linear electron accelerator. Aqueous solutions of acrylic acid were used with FeSO4 · 7H2O as a redox system. The best graft/homopolymer ratios were...... obtained at radiation doses between 2 and 3 Mrad, at acrylic acid concentrations of 40–60% and at FeSO4 · 7H2O concentrations of 0.25-0.5% by weight. The grafted films were tested for reverse osmosis properties. A membrane with 60% polyacrylic acid content gave 87% salt rejection and a water flux of 0...

  10. RADIATION EFFECTS ON EPOXY CARBON FIBER COMPOSITE

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E

    2008-05-30

    Carbon fiber-reinforced bisphenol-A epoxy matrix composite was evaluated for gamma radiation resistance. The composite was exposed to total gamma doses of 50, 100, and 200 Mrad. Irradiated and baseline samples were tested for tensile strength, hardness and evaluated using FTIR (Fourier transform infrared) spectroscopy and DSC (differential scanning calorimetry) for structural changes. Scanning electron microscopy was used to evaluate microstructural behavior. Mechanical testing of the composite bars revealed no apparent change in modulus, strain to failure, or fracture strength after exposures. However, testing of only the epoxy matrix revealed changes in hardness, thermal properties, and FTIR results with increasing gamma irradiation. The results suggest the epoxy within the composite can be affected by exposure to gamma irradiation.

  11. Radiation effects on lead silicate glass surfaces

    International Nuclear Information System (INIS)

    Radiation-induced changes in the microstructure of lead silicate glass were investigated in situ under Mg Kα irradiation in an ultra-high vacuum (UHV) environment by X-ray photoelectron spectroscopy (XPS). Lead-oxygen bond breaking resulting in the formation of pure lead was observed. The segregation, growth kinetics and the structural relaxation of the lead, with corresponding changes in the oxygen and silicon on the glass surfaces were studied by measuring the time-dependent changes in concentration, binding energy shifts, and the full width at half maximum. A bimodal distribution of the oxygen XPS signal, caused by bridging and non-bridging oxygens, was found during the relaxation process. All experimental data indicate a reduction of the oxygen concentration, a phase separation of the lead from the glass matrix, and the metallization of the lead occurred during and after the X-ray irradiation. (author)

  12. Fundamental radiation effects parameters in metals and ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J. [Oak Ridge National Lab., TN (United States)

    1998-03-01

    Useful information on defect production and migration can be obtained from examination of the fluence-dependent defect densities in irradiated materials, particularly when a transition from linear to sublinear accumulation is observed. Further work is needed on several intriguing reported radiation effects in metals. The supralinear defect cluster accumulation regime in thin foil irradiated metals needs further experimental confirmation, and the physical mechanisms responsible for its presence need to be established. Radiation hardening and the associated reduction in strain hardening capacity in FCC metals is a serious concern for structural materials. In general, the loss of strain hardening capacity is associated with dislocation channeling, which occurs when a high density of small defect clusters are produced (stainless steel irradiated near room temperature is a notable exception). Detailed investigations of the effect of defect cluster density and other physical parameters such as stacking fault energy on dislocation channeling are needed. Although it is clearly established that radiation hardening depends on the grain size (radiation-modified Hall-Petch effect), further work is needed to identify the physical mechanisms. In addition, there is a need for improved hardening superposition models when a range of different obstacle strengths are present. Due to a lack of information on point defect diffusivities and the increased complexity of radiation effects in ceramics compared to metals, many fundamental radiation effects parameters in ceramics have yet to be determined. Optical spectroscopy data suggest that the oxygen monovacancy and freely migrating interstitial fraction in fission neutron irradiated MgO and Al{sub 2}O{sub 3} are {approximately}10% of the NRT displacement value. Ionization induced diffusion can strongly influence microstructural evolution in ceramics. Therefore, fundamental data on ceramics obtained from highly ionizing radiation sources

  13. Radiation-induced non-targeted effects: some open questions

    International Nuclear Information System (INIS)

    The existence of non-targeted effects (NTEs) of radiation (genomic instability and bystander effects) has been generally accepted for >20 y; however, there is research, which was largely ignored going back to 1915 reporting these effects. Despite today's general acceptance of the phenomenon of NTE, there is little agreement about the mechanisms involved and the implications in radiation biology and radiation protection. The aim of this review was to consider some of the odd data, which have been published in the field with a view to obtaining insights or stimulating new ways of thinking about this field. By highlighting some key challenges and controversies, concerning the mechanisms and more importantly, the reason these effects exist, current ideas about the wider implications of NTEs in evolution and biology are also discussed. (authors)

  14. Effect of wheel load on wheel vibration and sound radiation

    Science.gov (United States)

    Han, Jian; Wang, Ruiqian; Wang, Di; Guan, Qinghua; Zhang, Yumei; Xiao, Xinbiao; Jin, Xuesong

    2015-01-01

    The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation. The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t, the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the effect of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.

  15. Effect of Wheel Load on Wheel Vibration and Sound Radiation

    Institute of Scientific and Technical Information of China (English)

    HAN Jian; WANG Ruiqian; WANG Di; GUAN Qinghua; ZHANG Yumei; XIAO Xinbiao; JIN Xuesong

    2015-01-01

    The current researches of wheel vibration and sound radiation mainly focus on the low noise damped wheel. Compared with the traditional research, the relationship between the sound and wheel/rail contact is difficulty and worth studying. However, there are few studies on the effect of wheel load on wheel vibration and sound radiation. In this paper, laboratory test carried out in a semi-anechoic room investigates the effect of wheel load on wheel natural frequencies, damping ratios, wheel vibration and its sound radiation. The laboratory test results show that the vibration of the wheel and total sound radiation decrease significantly with the increase of the wheel load from 0 t to 1 t. The sound energy level of the wheel decreases by 3.7 dB. When the wheel load exceeds 1 t, the attenuation trend of the vibration and sound radiation of the wheel becomes slow. And the increase of the wheel load causes the growth of the wheel natural frequencies and the mode damping ratios. Based on the finite element method (FEM) and boundary element method (BEM), a rolling noise prediction model is developed to calculate the influence of wheel load on the wheel vibration and sound radiation. In the calculation, the used wheel/rail excitation is the measured wheel/rail roughness. The calculated results show that the sound power level of the wheel decreases by about 0.4 dB when the wheel load increases by 0.5 t. The sound radiation of the wheel decreases slowly with wheel load increase, and this conclusion is verified by the field test. This research systematically studies the effect of wheel load on wheel vibration and sound radiation, gives the relationship between the sound and wheel/rail contact and analyzes the reasons, therefore, it provides a reference for further research.

  16. Effect of ionizing radiation on starch and cellulose

    International Nuclear Information System (INIS)

    The investigation is reported of the effects of ionizing radiation both on macromolecular systems generally and on polysaccharides, starch and cellulose. Attention is focused on changes in the physical and physico-chemical properties of starch and cellulose, such as starch swelling, gelation, viscosity, solubility, reaction with iodine, UV, IR and ESR spectra, chemical changes resulting from radiolysis and from the effect of amylases on irradiated starch, changes in cellulose fibre strength, water absorption, stain affinity, and also the degradation of cellulose by radiation and the effect of cellulases on irradiated cellulose. Practical applications of the findings concerning cellulose degradation are discussed. (author)

  17. Long-term effects of radiation exposure on health.

    Science.gov (United States)

    Kamiya, Kenji; Ozasa, Kotaro; Akiba, Suminori; Niwa, Ohstura; Kodama, Kazunori; Takamura, Noboru; Zaharieva, Elena K; Kimura, Yuko; Wakeford, Richard

    2015-08-01

    Late-onset effects of exposure to ionising radiation on the human body have been identified by long-term, large-scale epidemiological studies. The cohort study of Japanese survivors of the atomic bombings of Hiroshima and Nagasaki (the Life Span Study) is thought to be the most reliable source of information about these health effects because of the size of the cohort, the exposure of a general population of both sexes and all ages, and the wide range of individually assessed doses. For this reason, the Life Span Study has become fundamental to risk assessment in the radiation protection system of the International Commission on Radiological Protection and other authorities. Radiation exposure increases the risk of cancer throughout life, so continued follow-up of survivors is essential. Overall, survivors have a clear radiation-related excess risk of cancer, and people exposed as children have a higher risk of radiation-induced cancer than those exposed at older ages. At high doses, and possibly at low doses, radiation might increase the risk of cardiovascular disease and some other non-cancer diseases. Hereditary effects in the children of atomic bomb survivors have not been detected. The dose-response relation for cancer at low doses is assumed, for purposes of radiological protection, to be linear without a threshold, but has not been shown definitively. This outstanding issue is not only a problem when dealing appropriately with potential health effects of nuclear accidents, such as at Fukushima and Chernobyl, but is of growing concern in occupational and medical exposure. Therefore, the appropriate dose-response relation for effects of low doses of radiation needs to be established. PMID:26251392

  18. Non-Targeted Effects Induced by Ionizing Radiation: Mechanisms and Potential Impact on Radiation Induced Health Effects

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, William F.; Sowa, Marianne B.

    2015-01-01

    Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing radiation only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher radiation doses (> 1Gy), at low doses (< 100mGy) non-targeted effects associated with radiation exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes.

  19. Thermal effects of radiation from cellular telephones

    Science.gov (United States)

    Wainwright, Peter

    2000-08-01

    A finite element thermal model of the head has been developed to calculate temperature rises generated in the brain by radiation from cellular telephones and similar electromagnetic devices. A 1 mm resolution MRI dataset was segmented semiautomatically, assigning each volume element to one of ten tissue types. A finite element mesh was then generated using a fully automatic tetrahedral mesh generator developed at NRPB. There are two sources of heat in the model: firstly the natural metabolic heat production; and secondly the power absorbed from the electromagnetic field. The SAR was derived from a finite difference time domain model of the head, coupled to a model `mobile phone', namely a quarter-wavelength antenna mounted on a metal box. The steady-state temperature distribution was calculated using the standard Pennes `bioheat equation'. In the normal cerebral cortex the high blood perfusion rate serves to provide an efficient cooling mechanism. In the case of equipment generally available to the public, the maximum temperature rise found in the brain was about 0.1 °C. These results will help in the further development of criteria for exposure guidelines, and the technique developed may be used to assess temperature rises associated with SARs for different types of RF exposure.

  20. Cloud Radiative Effect in dependence on Cloud Type

    Science.gov (United States)

    Aebi, Christine; Gröbner, Julian; Kämpfer, Niklaus; Vuilleumier, Laurent

    2015-04-01

    Radiative transfer of energy in the atmosphere and the influence of clouds on the radiation budget remain the greatest sources of uncertainty in the simulation of climate change. Small changes in cloudiness and radiation can have large impacts on the Earth's climate. In order to assess the opposing effects of clouds on the radiation budget and the corresponding changes, frequent and more precise radiation and cloud observations are necessary. The role of clouds on the surface radiation budget is studied in order to quantify the longwave, shortwave and the total cloud radiative forcing in dependence on the atmospheric composition and cloud type. The study is performed for three different sites in Switzerland at three different altitude levels: Payerne (490 m asl), Davos (1'560 m asl) and Jungfraujoch (3'580 m asl). On the basis of data of visible all-sky camera systems at the three aforementioned stations in Switzerland, up to six different cloud types are distinguished (Cirrus-Cirrostratus, Cirrocumulus-Altocumulus, Stratus-Altostratus, Cumulus, Stratocumulus and Cumulonimbus-Nimbostratus). These cloud types are classified with a modified algorithm of Heinle et al. (2010). This cloud type classifying algorithm is based on a set of statistical features describing the color (spectral features) and the texture of an image (textural features) (Wacker et al. (2015)). The calculation of the fractional cloud cover information is based on spectral information of the all-sky camera data. The radiation data are taken from measurements with pyranometers and pyrgeometers at the different stations. A climatology of a whole year of the shortwave, longwave and total cloud radiative effect and its sensitivity to integrated water vapor, cloud cover and cloud type will be calculated for the three above-mentioned stations in Switzerland. For the calculation of the shortwave and longwave cloud radiative effect the corresponding cloud-free reference models developed at PMOD/WRC will be

  1. Genomic instability. New insight into the health effects of radiation

    International Nuclear Information System (INIS)

    New research findings question the validity of some traditionally accepted theories in radiobiology. It has been discovered that new chromosome damage and gene mutations, as well as cell death, occur frequently in the descendants of cells that have survived radiation exposure. These late effects of radiation cannot be explained using the previous model, because the phenomena occur much more often than direct mutations among individual genes. It has commonly been thought that the mutagenic and carcinogenic effects of radiation result from radiation-derived damage to DNA. During the division of DNA, or as a consequence of faulty correction, the damage becomes permanent and is transferred to the next cell generations (cloning). It has been assumed that the changes occur in cell divisions that take place immediately after the exposure to radiation. The new observations concerning genomic instability force researchers to reconsider the correctness of their theories and to seek new explanations of old, sometimes even 'odd' observations. They also give reason to exercise caution when making generalizations about epidemiological data and risk estimates form one population to another, or from one type of radiation to another. (orig.)

  2. New Scientific Pearl about Biologic Effect of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. A. Alamdaran

    2008-01-01

    Full Text Available Soon after the discovery of X-ray by Rontgen in 1895, it became evident that radiation can cause some somatic damage to tissues. The hazards of X-ray exposure were clearly known when many large hospitals had radiology departments. The greatest increased in knowledge about X-ray risks had accrued from the dropping of the two atomic bombs in Japan in 1945 and some other atomic accident. For example, among the Japanese bomb survivors from Hiroshima and Nagasaki, there have been about 400 extra cancer deaths. These were the origin of radiology personnel and people fear from radiation exposure and resistant in against simple X-ray exam (radiophobia. However, new scientific data on the effects radiation on survivors, especially about biologic effect of ionizing rays, background radiation exposure, amount of endogenous radiation, hormosis phenomenon and comparison radiation risk with other risk over lifetime are still being continuously revised and risk estimates updated. Fundamentally, this risk is much"nlower than whatever already estimated and it is insignificant in diagnostic domain. Better perception of physician from these instances help to prevent of false radiophobia and to make proper use of diagnostic and therapeutic advantages of ionizing beam.

  3. [Effect of ionizing radiation on the living body].

    Science.gov (United States)

    Kojima, Shuji

    2014-01-01

    Since the Fukushima nuclear plant accident following the great East Japan earthquake on March 11, 2011, we have been warned to be careful about possible radiation exposure almost every day in newspapers and on TV. Radioactive iodine ((131)I) and cesium ((134)Cs, (137)Cs) produced by nuclear reactions were released into the air during and after the accident, and have been scattered by the winds in Tohoku and in the Kanto district. Even today, 2 years after the accident, there is great public concern about possible pollution of foodstuffs and fishery products with radioactive cesium, not only in Japan, but also in other countries. On the other hand, decontamination work has been proceeding, including removal of contaminated soil near the accident site. Since the accident, many media reports have continued to tell us only that current dose levels of radiation are not dangerous to human health. But, many people are not satisfied with such vague statements, and want to understand the situation in more detail. So, it is important to provide basic education about the effects of radiation to the general public. I am a professor of the Department of Radiation Biosciences at Tokyo University of Science, and so I am very familiar with radiation and its dangers. So, in my lecture today, we would like to explain the effects of radiation and put the present situation into perspective, so that people will better understand the risks, and not be unnecessarily afraid.

  4. Radiative instabilities in plasmas: impurity motion and recombination effects

    International Nuclear Information System (INIS)

    Radiative instabilities in an impurity-seeded plasma are investigated when the plasma is supposed to be highly but partially ionized. Since in such plasmas radiative losses strongly depend on neutral and impurity densities, their dynamics are taken into account. As a result, a new radiative-recombination instability is found and described. We show that the influence of the ionization-recombination balance on plasma stability is sufficient for plasma densities above 1014 cm-3. The effects of a finite impurity Larmor radius are not small and play a stabilizing role as well as the thermal forces. On the other hand, compressibility of the magnetic field leads to plasma destabilization. We note that this radiative-recombination instability accumulates impurities in a cold zone while cleaning other regions. (Author)

  5. Unravelling the effects of radiation forces in water.

    Science.gov (United States)

    Astrath, Nelson G C; Malacarne, Luis C; Baesso, Mauro L; Lukasievicz, Gustavo V B; Bialkowski, Stephen E

    2014-01-01

    The effect of radiation forces at the interface between dielectric materials has been a long-standing debate for over a century. Yet there has been so far only limited experimental verification in complete accordance with the theory. Here we measure the surface deformation at the air-water interface induced by continuous and pulsed laser excitation and match this to rigorous theory of radiation forces. We demonstrate that the experimental results are quantitatively described by the numerical calculations of radiation forces. The Helmholtz force is used for the surface radiation pressure. The resulting surface pressure obtained is consistent with the momentum conservation using the Minkowski momentum density expression assuming that the averaged momentum per photon is given by the Minkowski momentum. Considering the total momentum as a sum of that propagating with the electromagnetic wave and that deposited locally in the material, the Abraham momentum interpretation also appears to be appropriate. PMID:24999561

  6. Effects of radiation environment on reusable nuclear shuttle system

    Science.gov (United States)

    Lane, A. G.

    1972-01-01

    Parametric tradeoff analyses of a wide spectrum of alternate tank configurations to minimize both primary and secondary, direct and scattered radiation sources emanating from the NERVA are reported. The analytical approach utilizing point kernel techniques is described and detailed data are presented on the magnitude of neutron/gamma doses for different locations. Single-tank configurations utilizing smaller cone angles and end cap radii were found to minimize integral radiation levels, hence, stage shielding-weight penalties for shuttle missions. Hybrid configurations employing an upper tank with a reduced cone angle and end cap radius result in low integral payload doses primarily due to the increased separation distance caused by the elongation of the larger capacity upper tank. A preliminary radiation damage assessment is discussed of possible reusable nuclear shuttle materials, components, and subsystems, and the possible effects of the radiation environment on various phases of RNS mission operations.

  7. The effects of acute radiation exposure on the serum components

    International Nuclear Information System (INIS)

    The blood samples were collected from the experimental animals 24 hrs after irradiation of gamma doses upto 80 Gy. Native PAGE showed a decreasing trend in gamma globulin fraction of serum from the irradiated group compared to control, while SDS PAGE indicated an enhanced tendency in protein of molecular weight 30,000 to 40,000. Serum albumin slightly decreased with radiation doses as a result of decrease in total protein amount. Radiation exposure had little or no effects on such lipid related components as phospholipid, triglyceride, and cholesterol, respectively. Among others, glutamic pyryvic transaminase (GPT) showed a drastic decrease in its amount 24 hrs after radiation exposure, which can be applied to the health care program for radiation workers. (Author)

  8. Controlling of degradation effects in radiation processing of polymers

    International Nuclear Information System (INIS)

    Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great effort should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. This not only reduces the cost of radiation but also improve the quality of the end use products. The end product of irradiated natural products such as carboxymethylcellulose and chitosan alginate may be used as food additive or benefited in agricultural purposes. (author)

  9. Radiation sterilization of fluoroquinolones in solid state: Investigation of effect of gamma radiation and electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Babita K., E-mail: singhbab2001@rediffmail.co [Department of Chemistry, RTM Nagpur University Campus, Amravati Road, Nagpur 440033 (India); Central Forensic Science Laboratory, Ramanthapur, Hyderabad 500013 (India); Parwate, Dilip V. [Department of Chemistry, RTM Nagpur University Campus, Amravati Road, Nagpur 440033 (India); Dassarma, Indrani B. [Jhulelal Institute of Technology, Nagpur (India); Shukla, Sudhir K. [Central Forensic Science Laboratory, Ramanthapur, Hyderabad 500013 (India)

    2010-09-15

    The effect of gamma radiation from {sup 60}Co source and 2 MeV electron beam was studied on two fluoroquinolone antibiotics viz norfloxacin and gatifloxacin in the solid state. The changes in reflectance spectrum, yellowness index, vibrational characteristics, thermal behavior, UV spectrum, chemical potency (HPLC) and microbiological potency were investigated. ESR measurement gave the number of free radical species formed and their population. The nature of final radiolytic impurities was assessed by studying the HPLC impurity profile. Both norfloxacin and gatifloxacin were observed to be radiation resistant, and did not show significant changes in their physico-chemical properties. They could be radiation sterilized at a dose of 25 kGy.

  10. Radiation effects in nuclear waste materials. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J.; Corrales, L.R. [Pacific Northwest National Lab., Richland, WA (US); Birtcher, R.C. [Argonne National Lab., IL (US); Nastasi, M. [Los Alamos National Lab., NM (US)

    1998-06-01

    'The objective of this multidisciplinary, multi-institutional research effort is to develop a fundamental understanding of radiation effects in glasses and ceramics at the atomic, microscopic, and macroscopic levels. The goal is to provide the underpinning science and models necessary to assess the performance of glasses and ceramics designed for the immobilization and disposal of high-level tank waste, plutonium residues, excess weapons plutonium, and other highly radioactive waste streams. A variety of experimental and computer simulation methods are employed in this effort. In general, research on glasses focuses on the electronic excitations due to ionizing radiation emitted from beta decay, since this is currently thought to be the principal mechanism for deleterious radiation effects in nuclear waste glasses. Research on ceramics focuses on defects and structural changes induced by the elastic interactions between alpha-decay particles and the atoms in the structure. Radiation effects can lead to changes in physical and chemical properties that may significantly impact long-term performance of nuclear waste materials. The current lack of fundamental understanding of radiation effects in nuclear waste materials makes it impossible to extrapolate the limited existing data bases to larger doses, lower dose rates, different temperature regimes, and different glass compositions or ceramic structures. This report summarizes work after almost 2 years of a 3-year project. Work to date has resulted in 9 publications. Highlights of the research over the past year are presented.'

  11. Effects of radiation on development, especially of the nervous system

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, S.P.; D' Amato, C.J.

    1980-12-01

    Humans and other organisms are exposed to ionizing radiations from a variety of natural and man-made sources. Radiation may cause mutations and chromosome abnormalities, cell-killing, alterations and transformations in cell growth, and carcinogenetic changes. This paper considers principally the cell-killing and nonlethal cell alterations in developing laboratory mammals and humans, especially the nervous system, that follow irradiation and often lead to malformation and disturbed function, but at certain stages to restitution of the injury. Most of what researchers know about the mechanisms of these radiation effects in man is derived from animal experiments, especially with rats. The few observations in humans have corresponded closely to them. Researchers illustrate the cellular effects and malformative results with an example of cell-killing in the developing cortex of a human fetus exposed to therapeutic radiation in utero; a current timetable of the malformative and other effects of radiation on rats during development from which expectations of human effects might be extrapolated; examples of hydrocephalus produced in rats; low-dose alterations of nerve cells in rats; and a microcephalic Japanese boy exposed in utero to the atomic bomb at Hiroshima in 1945.

  12. Biotropic Effect of Radiation Conditions on Orbital Cosmic Stations

    Science.gov (United States)

    Tsetlin, Vladimir; Ushakov, Igor; Gurieva, Tamar; Moisa, Svetlana; Zotin, Alexei; Lobanov, Alexei

    On the orbit of pilot orbital stations the crews undergo to low doses of chronic irradiation of cosmic radiation. The studying of radiobiological effects in different living systems were carried out in the ship’s side (OC “MIR” and ICS) and model surface experiments (power dose 200 mGy/day, density of neutron flow 30 particles/sm2 sec). It was shown that ionized radiation effects on embryonal development of Japanese quail embryo, inducing morphological disturbances in 12% of embryos. Many years ontogenesis (more 15 years of life in OC “MIR”) of microbial association evoked replacement of dominant types of micromycetes and bacterium and increasing of colony-formed units (CFU) in four orders. In laboratory low doses of γ-radiation induced the increasing of flight strain biomass of Aspergillus niger that corresponds to a radiation hormezis and also the increasing of radio-sensitivity. Moreover, under γ-neutron radiation were marked some deviations in morphology of supporting cell and numerous head falls of Aspergillus niger. The irradiation of Protozoa by low doses led to that spontaneous motion activity of spirostoms (Spirostomum ambiguum Ehbg.) accommodated in water processing by mixed γ-neutron radiation decreased twice that testified the fact that the definite factor of γ-neutron radiation effect is the changing of water medium state. In dry seeds of the highest plants wetting in water of preliminary low doses α-and γ-irradiation cultivating in the conditions of normal geomagnetic field, preferred the conditions with maximal induction, but cultivating in the conditions of hypomagnetic camera, on the contrary, the conditions with minimal induction. Model experiments accompanied with the control of oxidative-reduction properties of water. It is revealed that under the chronic ionized irradiation the value of oxidative-reduction potential increased, pH decreased and electrical currents in water electrochemical cells gradually decreased. In

  13. Resolving the controversy over beneficial effects of ionizing radiation

    International Nuclear Information System (INIS)

    In spite of the extensive research carried out during the past century, intense controversy continues over the health effects of low-level radiation. This controversy is largely due to political, social and economic issues among scientists and analysts in a variety of disciplines. These issues cloud objectivity and strengthen paradigms. Over the past ten years, in 14 universities and two research institutes, Japanese scientists have conducted exceptional research which clearly demonstrates beneficial effects of low-level radiation and cancer cures following therapy with low doses of radiation. Assessment, replication and extension of this work in North America could lead to greater appreciation of its significance. Cancer patients would demand such treatments, leading to universal acceptance of these bio-positive effects and reducing public fear of nuclear technology. (author)

  14. Radiation and Health Effects and Inferring Radiation Risks from the Fukushima Daiichi Accident. Annex X of Technical Volume 4

    International Nuclear Information System (INIS)

    Anxieties about the risk of harm from radiation are often out of proportion to the actual likelihood of harm. Therefore, in order to deal sensibly with situations involving exposure to radiation, it is important to clarify what is known and what is not known about radiation and health effects. This annex provides a general qualitative overview of what is known about radiation-induced health effects, followed by a more detailed exploration of the quantitative inferences that may be drawn from past analyses of the relationships between radiation exposure and risk

  15. Neurological Adverse Effects after Radiation Therapy for Stage II Seminoma

    DEFF Research Database (Denmark)

    Ebbeskov Lauritsen, Liv; Meidahl Petersen, Peter; Daugaard, Gedske

    2012-01-01

    We report 3 cases of patients with testicular cancer and stage II seminoma who developed neurological symptoms with bilateral leg weakness about 4 to 9 months after radiation therapy (RT). They all received RT to the para-aortic lymph nodes with a total dose of 40 Gy (36 Gy + 4 Gy as a boost....../or to the spinal cord. RT is believed to produce plexus injury by both direct toxic effects and secondary microinfarction of the nerves, but the exact pathophysiology of RT-induced injury is unclear. Since reported studies of radiation-induced neurological adverse effects are limited, it is difficult to estimate...

  16. Geometric doppler effect: spin-split dispersion of thermal radiation.

    Science.gov (United States)

    Dahan, Nir; Gorodetski, Yuri; Frischwasser, Kobi; Kleiner, Vladimir; Hasman, Erez

    2010-09-24

    A geometric Doppler effect manifested by a spin-split dispersion relation of thermal radiation is observed. A spin-dependent dispersion splitting was obtained in a structure consisting of a coupled thermal antenna array. The effect is due to a spin-orbit interaction resulting from the dynamics of the surface waves propagating along the structure whose local anisotropy axis is rotated in space. The observation of the spin-symmetry breaking in thermal radiation may be utilized for manipulation of spontaneous or stimulated emission.

  17. Evaluating Shielding Effectiveness for Reducing Space Radiation Cancer Risks

    Science.gov (United States)

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

    2007-01-01

    We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDF s are used in significance tests of the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDF s. Competing mortality risks and functional correlations in radiation quality factor uncertainties are treated in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the 95% confidence level (CL) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions (risk, however one that is mitigated effectively by shielding, especially for carbon composites structures with high hydrogen content. In contrast, for long duration lunar (>180 d) or Mars missions, GCR risks may exceed radiation risk limits, with 95% CL s exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding can not be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection.

  18. Effect of radiofrequency radiation in cultured mammalian cells: A review.

    Science.gov (United States)

    Manna, Debashri; Ghosh, Rita

    2016-01-01

    The use of mobile phone related technologies will continue to increase in the foreseeable future worldwide. This has drawn attention to the probable interaction of radiofrequency electromagnetic radiation with different biological targets. Studies have been conducted on various organisms to evaluate the alleged ill-effect on health. We have therefore attempted to review those work limited to in vitro cultured cells where irradiation conditions were well controlled. Different investigators have studied varied endpoints like DNA damage, cell cycle arrest, reactive oxygen species (ROS) formation, cellular morphology and viability to weigh the genotoxic effect of such radiation by utilizing different frequencies and dose rates under various irradiation conditions that include continuous or pulsed exposures and also amplitude- or frequency-modulated waves. Cells adapt to change in their intra and extracellular environment from different chemical and physical stimuli through organized alterations in gene or protein expression that result in the induction of stress responses. Many studies have focused on such effects for risk estimations. Though the effects of microwave radiation on cells are often not pronounced, some investigators have therefore combined radiofrequency radiation with other physical or chemical agents to observe whether the effects of such agents were augmented or not. Such reports in cultured cellular systems have also included in this review. The findings from different workers have revealed that, effects were dependent on cell type and the endpoint selection. However, contradictory findings were also observed in same cell types with same assay, in such cases the specific absorption rate (SAR) values were significant.

  19. Therapeutic effects of low radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Trott, K.R. (Dept. of Radiation Biology, St. Bartholomew' s Medical College, London (United Kingdom))

    1994-01-01

    This editorial explores the scientific basis of radiotherapy with doses of < 1 Gy for various non-malignant conditions, in particular dose-effect relationships, risk-benefit considerations and biological mechanisms. A review of the literature, particularly clinical and experimental reports published more than 50 years ago was conducted to clarify the following problems. 1. The dose-response relationships for the therapeutic effects on three groups of conditions: non-malignant skin disease, arthrosis and other painful degenerative joint disorders and anti-inflammatory radiotherapy; 2. risks after radiotherapy and after the best alternative treatments; 3. the biological mechanisms of the different therapeutic effects. Radiotherapy is very effective in all three groups of disease. Few dose-finding studies have been performed, all demonstrating that the optimal doses are considerable lower than the generally recommended doses. In different conditions, risk-benefit analysis of radiotherapy versus the best alternative treatment yields very different results: whereas radiotherapy for acute postpartum mastitis may not be justified any more, the risk-benefit ratio of radiotherapy of other conditions and particularly so in dermatology and some anti-inflammatory radiotherapy appears to be more favourable than the risk-benefit ratio of the best alternative treatments. Radiotherapy can be very effective treatment for various non-malignant conditions such as eczema, psoriasis, periarthritis humeroscapularis, epicondylitis, knee arthrosis, hydradenitis, parotitis and panaritium and probably be associated with less acute and long-term side effects than similarly effective other treatments. Randomized clinical studies are required to find the optimal dosage which, at present, may be unnecessarily high.

  20. Occultation Modeling for Radiation Obstruction Effects on Spacecraft Systems

    Science.gov (United States)

    de Carufel, Guy; Li, Zu Qun; Harvey, Jason; Crues, Edwin Z.; Bielski, Paul

    2016-01-01

    A geometric occultation model has been developed to determine line-of-sight obstruction of radiation sources expected for different NASA space exploration mission designs. Example applications includes fidelity improvements for surface lighting conditions, radiation pressure, thermal and power subsystem modeling. The model makes use of geometric two dimensional shape primitives to most effectively model space vehicles. A set of these primitives is used to represent three dimensional obstructing objects as a two dimensional outline from the perspective of an observing point of interest. Radiation sources, such as the Sun or a Moon's albedo is represented as a collection of points, each of which is assigned a flux value to represent a section of the radiation source. Planetary bodies, such as a Martian moon, is represented as a collection of triangular facets which are distributed in spherical height fields for optimization. These design aspects and the overall model architecture will be presented. Specific uses to be presented includes a study of the lighting condition on Phobos for a possible future surface mission, and computing the incident flux on a spacecraft's solar panels and radiators from direct and reflected solar radiation subject to self-shadowing or shadowing by third bodies.

  1. Effect of ionizing radiation on rat parotid gland

    Energy Technology Data Exchange (ETDEWEB)

    Boraks, George; Tampelini, Flavio Silva; Pereira, Kleber Fernando; Chopard, Renato Paulo [University of Sao Paulo (USP), SP (Brazil). Inst. of Biomedical Sciences. Dept. of Anatomy]. E-mail: rchopard@usp.br

    2008-01-15

    A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolisation, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis). (author)

  2. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  3. Effect of troglitazone on radiation sensitivity in cervix cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    An, Zheng Zhe; Liu, Xian Guang; Song, Hye Jin; Choi, Chi Hwan; Kim, Won Dong; Park, Woo Yoon [Chungbuk National University College of Medicine, Cheongju (Korea, Republic of); Yu, Jae Ran [Konkuk University College of Medicine, Chungju (Korea, Republic of)

    2012-06-15

    Troglitazone (TRO) is a peroxisome proliferator-activated receptor {gamma} (PPAR{gamma} ) agonist. TRO has antiproliferative activity on many kinds of cancer cells via G1 arrest. TRO also increases Cu{sup 2+}/Zn{sup 2+} -superoxide dismutase (CuZnSOD) and catalase. Cell cycle, and SOD and catalase may affect on radiation sensitivity. We investigated the effect of TRO on radiation sensitivity in cancer cells in vitro. Three human cervix cancer cell lines (HeLa, Me180, and SiHa) were used. The protein expressions of SOD and catalase, and catalase activities were measured at 2-10 {mu}M of TRO for 24 hours. Cell cycle was evaluated with flow cytometry. Reactive oxygen species (ROS) was measured using 2',7'-dichlorofluorescin diacetate. Cell survival by radiation was measured with clonogenic assay. By 5 {mu}M TRO for 24 hours, the mRNA, protein expression and activity of catalase were increased in all three cell lines. G0- G1 phase cells were increased in HeLa and Me180 by 5 {mu}M TRO for 24 hours, but those were not increased in SiHa. By pretreatment with 5 {mu}M TRO radiation sensitivity was increased in HeLa and Me180, but it was decreased in SiHa. In Me180, with 2 {mu}M TRO which increased catalase but not increased G0-G1 cells, radiosensitization was not observed. ROS produced by radiation was decreased with TRO. TRO increases radiation sensitivity through G0-G1 arrest or decreases radiation sensitivity through catalasemediated ROS scavenging according to TRO dose or cell types. The change of radiation sensitivity by combined with TRO is not dependent on the PPAR {gamma} expression level.

  4. Radiation shielding effectiveness of newly developed superconductors

    Science.gov (United States)

    Singh, Vishwanath P.; Medhat, M. E.; Badiger, N. M.; Saliqur Rahman, Abu Zayed Mohammad

    2015-01-01

    Gamma ray shielding effectiveness of superconductors with a high mass density has been investigated. We calculated the mass attenuation coefficients, the mean free path (mfp) and the exposure buildup factor (EBF). The gamma ray EBF was computed using the Geometric Progression (G-P) fitting method at energies 0.015-15 MeV, and for penetration depths up to 40 mfp. The fast-neutron shielding effectiveness has been characterized by the effective neutron removal cross-section of the superconductors. It is shown that CaPtSi3, CaIrSi3, and Bi2Sr2Ca1Cu2O8.2 are superior shielding materials for gamma rays and Tl0.6Rb0.4Fe1.67Se2 for fast neutrons. The present work should be useful in various applications of superconductors in fusion engineering and design.

  5. Functional proteomic analysis revealed ground-base ion radiations cannot reflect biological effects of space radiations of rice

    Science.gov (United States)

    Wang, Wei; Sun, Yeqing; Zhao, Qian; Han, Lu

    2016-07-01

    Highly ionizing radiation (HZE) in space is considered as main factor causing biological effects. Radiobiological studies during space flights are unrepeatable due to the variable space radiation environment, ground-base ion radiations are usually performed to simulate of the space biological effect. Spaceflights present a low-dose rate (0.1˜~0.3mGy/day) radiation environment inside aerocrafts while ground-base ion radiations present a much higher dose rate (100˜~500mGy/min). Whether ground-base ion radiation can reflect effects of space radiation is worth of evaluation. In this research, we compared the functional proteomic profiles of rice plants between on-ground simulated HZE particle radiation and spaceflight treatments. Three independent ground-base seed ionizing radiation experiments with different cumulative doses (dose range: 2˜~20000mGy) and different liner energy transfer (LET) values (13.3˜~500keV/μμm) and two independent seed spaceflight experiments onboard Chinese 20th satellite and SZ-6 spacecraft were carried out. Alterations in the proteome were analyzed by two-dimensional difference gel electrophoresis (2-D DIGE) with MALDI-TOF/TOF mass spectrometry identifications. 45 and 59 proteins showed significant (pmetabolic process, protein folding and phosphorylation. The results implied that ground-base radiations cannot truly reflect effects of spaceflight radiations, ground-base radiation was a kind of indirect effect to rice causing oxidation and metabolism stresses, but space radiation was a kind of direct effect leading to macromolecule (DNA and protein) damage and signal pathway disorders. This functional proteomic analysis work might provide a new evaluation method for further on-ground simulated HZE radiation experiments.

  6. Functional proteomic analysis revealed ground-base ion radiations cannot reflect biological effects of space radiations of rice

    Science.gov (United States)

    Wang, Wei; Sun, Yeqing; Zhao, Qian; Han, Lu

    2016-07-01

    Highly ionizing radiation (HZE) in space is considered as main factor causing biological effects. Radiobiological studies during space flights are unrepeatable due to the variable space radiation environment, ground-base ion radiations are usually performed to simulate of the space biological effect. Spaceflights present a low-dose rate (0.1˜~0.3mGy/day) radiation environment inside aerocrafts while ground-base ion radiations present a much higher dose rate (100˜~500mGy/min). Whether ground-base ion radiation can reflect effects of space radiation is worth of evaluation. In this research, we compared the functional proteomic profiles of rice plants between on-ground simulated HZE particle radiation and spaceflight treatments. Three independent ground-base seed ionizing radiation experiments with different cumulative doses (dose range: 2˜~20000mGy) and different liner energy transfer (LET) values (13.3˜~500keV/μμm) and two independent seed spaceflight experiments onboard Chinese 20th satellite and SZ-6 spacecraft were carried out. Alterations in the proteome were analyzed by two-dimensional difference gel electrophoresis (2-D DIGE) with MALDI-TOF/TOF mass spectrometry identifications. 45 and 59 proteins showed significant (price causing oxidation and metabolism stresses, but space radiation was a kind of direct effect leading to macromolecule (DNA and protein) damage and signal pathway disorders. This functional proteomic analysis work might provide a new evaluation method for further on-ground simulated HZE radiation experiments.

  7. Effect of electronic radiation in Nb monocrystals

    International Nuclear Information System (INIS)

    The effect of the electronic irradiation in the Nb monocrystalline samples is studied. The irradiation source were the electrons from the high voltage electronic microscopy from the Argonne National Laboratory operating in 900 KeV. With the irradiation and deformation 'in-situ' experiments, dislocations in the samples were observed and the effect of the electrons in those dislocations during 59m of irradiation was studied. The follow applied deformation, show the differences in the displacements behavior of the non-irradiated and irradiated region. The growth rate of the displacements rings were determined. (E.G.)

  8. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 ± 0.3 to 111 ± 7.4 KBq/m3 equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m3, this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author)

  9. The effects of polaprezinc on radiation-induced taste alterations

    International Nuclear Information System (INIS)

    The effects of polaprezinc (an insoluble zinc complex of L-carnosine) on taste abnormalities were investigated in 22 patients receiving radiation therapy to head and neck malignancies. The total doses to the tongue were 25.5-46.0 Gy (mean, 37.9 Gy). All patients received 75 mg of polaprezinc two times a day with an interval of 0-1,561 days (mean, 305.3 days) after the completion of radiation therapy. The duration of the drug administration was 25-353 days (mean, 96.9 days). Twenty patients (90.9%) were aware of an improvement of a partial or complete loss of taste. Polaprezinc is effective in improving loss of taste after radiation therapy. (author)

  10. Effects of beta/gamma radiation on nuclear waste glasses

    Energy Technology Data Exchange (ETDEWEB)

    Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-07-01

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  11. The effects of polaprezinc on radiation-induced taste alterations

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Katsumasa; Togao, Osamu [Kyushu Univ., Fukuoka (Japan). Graduate School of Medical Sciences; Shikama, Naoto (and others)

    2001-06-01

    The effects of polaprezinc (an insoluble zinc complex of L-carnosine) on taste abnormalities were investigated in 22 patients receiving radiation therapy to head and neck malignancies. The total doses to the tongue were 25.5-46.0 Gy (mean, 37.9 Gy). All patients received 75 mg of polaprezinc two times a day with an interval of 0-1,561 days (mean, 305.3 days) after the completion of radiation therapy. The duration of the drug administration was 25-353 days (mean, 96.9 days). Twenty patients (90.9%) were aware of an improvement of a partial or complete loss of taste. Polaprezinc is effective in improving loss of taste after radiation therapy. (author)

  12. Intermittent Jolts of Galactic UV Radiation Mutagenetic Effects

    CERN Document Server

    Scalo, J M; Williams, P; Scalo, John M.; Williams, Peter

    2001-01-01

    We estimate the frequency of intermittent hypermutation events and disruptions of planetary/satellite photochemistry due to ultraviolet radiation from core collapse supernova explosions. Calculations are presented for planetary systems in the local Milky Way, including the important moderating effects of vertical Galactic structure and UV absorption by interstellar dust. The events are particularly frequent for satellites of giant gas planets at \\gtrsim 5-10 AU distance from solar-type parent stars, or in the conventional habitable zones for planets orbiting spectral type K and M parent stars, with rates of significant jolts about 10^3 - 10^4 per Gyr. The steep source spectra and existing data on UVA and longer-wavelength radiation damage in terrestrial organisms suggest that the mutational effects may operate even on planets with ozone shields. We argue that the mutation doubling dose for UV radiation should be much smaller than the mean lethal dose, using terrestrial prokaryotic organisms as our model, and ...

  13. Effects of solar radiation on hair and photoprotection.

    Science.gov (United States)

    Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

    2015-12-01

    In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity.

  14. Effects of beta/gamma radiation on nuclear waste glasses

    International Nuclear Information System (INIS)

    A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted β-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of β/γ radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

  15. Effects of solar radiation on hair and photoprotection.

    Science.gov (United States)

    Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

    2015-12-01

    In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. PMID:26454659

  16. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    Institute of Scientific and Technical Information of China (English)

    JIANG Erkang; WU Lijun

    2009-01-01

    A bstract In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy a-particle irradiated and non-irradiated by- stander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensi- tive to damage signals. Treated by c-PTIO(2-(4-carboxy-phenyl)-4,4,5,5-tetramethyl-imidazoline- 1-oxyl-3-oxide), a nitric oxide (NO) scavenger, the MN frequencies were effectively inhibited, showing that nitric oxide might be very important in mediating the enhanced damage. These results indicated that caffeine enhanced the low dose a-particle radiation-induced damage in ir- radiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

  17. Effects of radiation on direct-drive laser target interaction

    Science.gov (United States)

    Colombant, D. G.

    1999-11-01

    Radiation may be useful for reducing laser imprint and Rayleigh-Taylor (RT) growth in direct-drive target pellets. We will discuss the important role of radiation in a proposed direct-drive X-ray preheated target concept(S.Bodner et al., Phys. Plasmas 5,1901(1998)). In this design, a high-Z coating surrounds a thin plastic coat, over a DT-wicked foam and on top of the DT fuel. Radiation effects will be examined and discussed in the context of this design. The soft X-ray radiation emitted during the foot of the laser pulse - at a few 10^12W/cm^2- preheats the foam ablator which contributes to the reduction of the RT instability. The ablator also stops the radiation, allowing the fuel to stay on a low adiabat. Radiation in the blow-off corona of the target establishes a long scalelength plasma. This separates the ablation region from the laser absorption region where the remaining defects in laser uniformity/pellet surface finish constitute the seed for hydrodynamic instabilities. However, when the pulse intensity rises, the pressure generated by the laser in combination with the changing opacity of the plasma causes the plasma to be pushed back toward the ablator. This is called a Radiative Plasma Structure (RPS)(J.Dahlburg et al., J.Q.S.R.T. 54,113(1995)). These RPS's are a potential problem because they may carry with them the imprint which was present in the low-density corona. We will show and discuss these various effects, as well as some of the experimental work(C.Pawley et al., this conference) under way in connection with this program. These experiments are essential in order to validate both the design concepts and the numerical models, which include on-line state-of-the-art atomic physics modeling(M.Klapisch et al.,Phys. Plasmas 5,1919(1998)).

  18. Attributability of Health Effects at Low Radiation Doses

    International Nuclear Information System (INIS)

    Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: (i) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

  19. Attributability of health effects at low radiation doses

    International Nuclear Information System (INIS)

    Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose-response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: 1) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either. In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

  20. Rheology of Indian Honey: Effect of Temperature and Gamma Radiation

    Directory of Open Access Journals (Sweden)

    Sudhanshu Saxena

    2014-01-01

    Full Text Available Honey brands commonly available in Indian market were characterized for their rheological and thermal properties. Viscosity of all the honey samples belonging to different commercial brands was found to decrease with increase in temperature (5–40°C and their sensitivity towards temperature varied significantly as explained by calculating activation energy based on Arrhenius model and ranged from 54.0 to 89.0 kJ/mol. However, shear rate was not found to alter the viscosity of honey indicating their Newtonian character and the shear stress varied linearly with shear rate for all honey samples. Honey is known to contain pathogenic microbial spores and in our earlier study gamma radiation was found to be effective in achieving microbial decontamination of honey. The effect of gamma radiation (5–15 kGy on rheological properties of honey was assessed, and it was found to remain unchanged upon radiation treatment. The glass transition temperatures (Tg of these honey analyzed by differential scanning calorimetry varied from −44.1 to −54.1°C and remained unchanged upon gamma radiation treatment. The results provide information about some key physical properties of commercial Indian honey. Radiation treatment which is useful for ensuring microbial safety of honey does not alter these properties.

  1. Skyglow effects in UV and visible spectra: Radiative fluxes

    Science.gov (United States)

    Kocifaj, Miroslav; Solano Lamphar, Hector Antonio

    2013-09-01

    Several studies have tried to understand the mechanisms and effects of radiative transfer under different night-sky conditions. However, most of these studies are limited to the various effects of visible spectra. Nevertheless, the invisible parts of the electromagnetic spectrum can pose a more profound threat to nature. One visible threat is from what is popularly termed skyglow. Such skyglow is caused by injudiciously situated or designed artificial night lighting systems which degrade desired sky viewing. Therefore, since lamp emissions are not limited to visible electromagnetic spectra, it is necessary to consider the complete spectrum of such lamps in order to understand the physical behaviour of diffuse radiation at terrain level. In this paper, the downward diffuse radiative flux is computed in a two-stream approximation and obtained ultraviolet spectral radiative fluxes are inter-related with luminous fluxes. Such a method then permits an estimate of ultraviolet radiation if the traditionally measured illuminance on a horizontal plane is available. The utility of such a comparison of two spectral bands is shown, using the different lamp types employed in street lighting. The data demonstrate that it is insufficient to specify lamp type and its visible flux production independently of each other. Also the UV emissions have to be treated by modellers and environmental scientists because some light sources can be fairly important pollutants in the near ultraviolet. Such light sources can affect both the living organisms and ambient environment.

  2. Evaluating shielding effectiveness for reducing space radiation cancer risks

    International Nuclear Information System (INIS)

    We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDFs are used in significance tests for evaluating the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDFs. Competing mortality risks and functional correlations in radiation quality factor uncertainties are included in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the upper value of 95% confidence interval (CI) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions (180d) or Mars missions, GCR risks may exceed radiation risk limits that are based on acceptable levels of risk. For example, the upper 95% CI exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection

  3. Evaluation of delayed effects of ionizing radiation: an historical perspective.

    Science.gov (United States)

    Stewart, A M

    1991-01-01

    It is widely assumed that after the bombing of Hiroshima and Nagasaki there were no lasting effects of the acute injuries (which included extensive damage to blood forming tissues by the radiation) or the massively high death rate (which was caused by environmental effects of the blast as well as personal injuries). However, close inspection of the dose response curves for non-cancer deaths has shown that this could be a false impression caused by one effect of marrow aplasia being confused with leukemia (defective erythropoiesis) and a second effect being confused with early selection in favor of general fitness (defective immune responses). Possible consequences of such confusion (for cancer risk coefficients) are discussed in relation to what is known about late effects of prenatal x-rays and occupational exposures to radiation. PMID:1805618

  4. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2013-04-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  5. Effective aerosol optical depth from pyranometer measurements of surface solar radiation (global radiation at Thessaloniki, Greece

    Directory of Open Access Journals (Sweden)

    A. V. Lindfors

    2012-12-01

    Full Text Available Pyranometer measurements of the solar surface radiation (SSR are available at many locations worldwide, often as long time series covering several decades into the past. These data constitute a potential source of information on the atmospheric aerosol load. Here, we present a method for estimating the aerosol optical depth (AOD using pyranometer measurements of the SSR together with total water vapor column information. The method, which is based on radiative transfer simulations, was developed and tested using recent data from Thessaloniki, Greece. The effective AOD calculated using this method was found to agree well with co-located AERONET measurements, exhibiting a correlation coefficient of 0.9 with 2/3 of the data found within ±20% or ±0.05 of the AERONET AOD. This is similar to the performance of current satellite aerosol methods. Differences in the AOD as compared to AERONET can be explained by variations in the aerosol properties of the atmosphere that are not accounted for in the idealized settings used in the radiative transfer simulations, such as variations in the single scattering albedo and Ångström exponent. Furthermore, the method is sensitive to calibration offsets between the radiative transfer simulations and the pyranometer SSR. The method provides an opportunity of extending our knowledge of the atmospheric aerosol load to locations and times not covered by dedicated aerosol measurements.

  6. Genetic effects of radiation in man

    International Nuclear Information System (INIS)

    Information obtained through three different surveys among Brazilian physicians is presented. Data have been classified according to survey, medical specialty, protection used and pregnancy order. Events under consideration are abortions, stillbirths, neo-natal mortality, infant-juvenile mortality, marbidity and sex ratio. A number of statistically sugnificant diferences have been found in the direction expected according to the radio-genetics theory and a few ones against it. Two of the surveys revealed an effect of the pregnancy order on abortions which was larger inthe exposed samples than in the control ones

  7. Effect of ionizing radiation on Amphistome metacercariae

    International Nuclear Information System (INIS)

    The effect of gamma irradiation on amphistome metacercariae and the parasitological and cytological findings of the resultant flukes were studied in lambs and kids. The flukes recovered from the metacercariae irradiated at 2.0 Krad were less in percentage with stunted growth, degenerative changes of gonads, absence of eggs in uterus and hampered spermatogenesis. The metacercariae irradiated at 2.5 and 3.0 Krad could be developed into flukes and seen only 15 days post exposure but not 87/120 days. Fifteen days flukes were showing retarded development and without any reproductive organs. 39 refs., 3 tables. (author)

  8. Radiation-electromagnetic effect in germanium single crystals

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-10-01

    An experimental study was made of the radiation-electromagnetic effect in germanium single crystals when excess carriers were generated by bombardment with ..cap alpha.. particles, protons, or x rays in magnetic fields up to 8 kOe. The source of ..cap alpha.. particles and protons was a cyclotron and x rays were provided by a tube with a copper anode. The radiation-electromagnetic emf increased linearly on increase in the magnetic field and was directly proportional to the flux of charged particles at low values of the flux, reaching saturation at high values of the flux (approx.5 x 10/sup 11/ particles .cm/sup -2/ .sec/sup -1/). In the energy range 4--40 MeV the emf was practically independent of the ..cap alpha..-particle energy. The sign of the emf was reversed when samples with a ground front surface were irradiated. Measurements of the photoelectromagnetic and Hall effects in the ..cap alpha..-particle-irradiated samples showed that a p-n junction was produced by these particles and its presence should be allowed for in investigations of the radiation-electromagnetic effect. The measured even radiation-electromagnetic emf increased quadratically on increase in the magnetic field. An investigation was made of the barrier radiation-voltaic effect (when the emf was measured between the irradiated and unirradiated surfaces). Special masks were used to produce a set of consecutive p-n junctions in germanium crystals irradiated with ..cap alpha.. particles. A study of the photovoltaic and photoelectromagnetic effects in such samples showed that the method could be used to increase the efficiency of devices utilizing the photoelectromagnetic effect.

  9. Research of Fast Neutron Radiation Effect on Rats

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In order to research the fast neutron radiation effect on rats,the 8 weeks Wistar male rats were wholly irradiated by 14 MeV fast neutron with 5 Gy. In the experiment,the rats were divided into normal and irradiation group, and killed

  10. Effect of arc on radiation thermometry in welding process

    Institute of Scientific and Technical Information of China (English)

    李亮玉; 王燕; 武宝林

    2002-01-01

    The effect of arc on radiation thermometry is analyzed in a field close to the arc during the welding process, and the ratio of signal to noise and other factors are obtained for a small current arc .The method of the temperature measurement is feasible when the arc current is decreased to a smaller value in the welding process.

  11. Thermal effects of laser radiation in biological tissue.

    OpenAIRE

    Cummins, L; Nauenberg, M.

    1983-01-01

    A theoretical model is presented that simulates the thermal effects of laser radiation incident on biological tissue. The multiple scattering and absorption of the laser beam and the thermal diffusion process in the tissue are evaluated by a numerical technique that is well suited for microcomputers. Results are compared with recent empirical observations.

  12. 47 CFR 22.535 - Effective radiated power limits.

    Science.gov (United States)

    2010-10-01

    ... limits. The effective radiated power (ERP) of transmitters operating on the channels listed in § 22.531 must not exceed the limits in this section. (a) Maximum ERP. The ERP must not exceed the applicable limits in this paragraph under any circumstances. Frequency range (MHz) Maximum ERP (Watts) 35-36 600...

  13. Radiation Effects Research Foundation bibliography of published papers, 1988

    International Nuclear Information System (INIS)

    This issue is the bibliography of the publication by the staffs of the Radiation Effects Research Institute (RERF) in 1988. Titles in original and English language with author names are enumerated. Indeces by research areas and by author name are also attached. (J.P.N.) 99 refs

  14. Late effects of radiation on the spinal cord

    International Nuclear Information System (INIS)

    The author describes experiments concerned with the mechanisms of the development of late radiation damage in the spinal cord. Male rats were used in most of the experiments. The effects of 300 kV X-rays or 15 MeV neutrons were evaluated for different regions of the spinal cord. (Auth.)

  15. Effect of bremsstrahlung radiation emission on fast electrons in plasmas

    Science.gov (United States)

    Embréus, O.; Stahl, A.; Fülöp, T.

    2016-09-01

    Bremsstrahlung radiation emission is an important energy loss mechanism for energetic electrons in plasmas. In this paper we investigate the effect of spontaneous bremsstrahlung emission on the momentum-space structure of the electron distribution, fully accounting for the emission of finite-energy photons by modeling the bremsstrahlung interactions with a Boltzmann collision operator. We find that electrons accelerated by electric fields can reach significantly higher energies than predicted by the commonly used radiative stopping-power model. Furthermore, we show that the emission of soft photons can contribute significantly to the dynamics of electrons with an anisotropic distribution by causing pitch-angle scattering at a rate that increases with energy.

  16. Tunnelling Effect and Hawking Radiation from a Vaidya Black Hole

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Yi; ZHAO Zheng

    2006-01-01

    @@ We extend Parikh's study to the non-stationary black hole. As an example of the non-stationary black hole, we investigate the tunnelling effect and Hawking radiation from a Vaidya black hole whose Bondi mass is identical to its mass parameter. The Hawking radiation is considered as a tunnelling process across the event horizon and we calculate the tunnelling probability. It is found that the result is different from Parikh's study because drH/dv is the function of Bondi mass m(v).

  17. QED effects and radiation generation in relativistic laser plasma

    Science.gov (United States)

    Kostyukov, I. Yu.; Nerush, E. N.; Bashmakov, V. F.

    2011-06-01

    The radiative and quantum effects in laser plasmas are discussed. The self-consistent numerical model based on particle-in-cell and Monte-Carlo methods are developed. First we analyze the spectra of Compton backscattered photons and betatron radiation in the classical and quantum regimes. Then we address an interaction between intense laser pulse and relativistic electron beam. Finally we discuss the electron-positron pair plasma production in extremely-intense laser field. It is shown that such plasma can be an efficient source of energetic gammaquanta.

  18. Radiation damage to DNA: the effect of LET

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.F.; Milligan, J.R. [California Univ., San Diego, La Jolla, CA (United States). School of Medicine

    1997-03-01

    Mechanisms whereby ionizing radiation induced damage are introduced into cellular DNA are discussed. The types of lesions induced are summarized and the rationale is presented which supports the statement that radiation induced singly damaged sites are biologically unimportant. The conclusion that multiply damaged sites are critical is discussed and the mechanisms whereby such lesions are formed are presented. Structures of multiply damaged sites are summarized and problems which they present to cellular repair systems are discussed. Lastly the effects of linear energy transfer on the complexity of multiply damaged sites are surveyed and the consequences of this increased complexity are considered in terms of cell survival and mutation. (author)

  19. Effects of solar radiation on collagen-based biomaterials

    OpenAIRE

    Alina Sionkowska; Marcin Wisniewski; Joanna Skopinska; Diego Mantovani

    2006-01-01

    The effect of solar radiation on collagen and collagen/synthetic polymer blends in the form of thin films and solutions has been studied by UV-VIS and FTIR spectroscopies. Films and solutions of collagen blended with poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) were irradiated by solar light. It was found that UV-VIS spectra, which characterize collagen, collagen/PVA, and collagen/PVP blended films, were significantly altered by solar radiation. FTIR spectra of collagen, collag...

  20. Direct Radiative Effect of Intense Dust Outbreaks in the Mediterranean

    Science.gov (United States)

    Gkikas, A.; Obiso, V.; Basart, S.; Jorba, O.; Pérez García-Pando, C.; Hatzianastassiou, N.; Gassó, S.; Baldasano, J. M.

    2015-12-01

    The broader Mediterranean basin is affected by intense desert dust outbreaks in spring. In the present study, we make use of satellite observations and modelling to investigate dust radiative impacts during three consecutive dust outbreaks occurred over the Mediterranean in the period 9/4-15/4/2008. The direct radiative effect (DRE) is estimated by using two simulations run with the NMMB/BSC-Dust model, where the interaction between dust aerosols and radiation is activated and deactivated, respectively. The simulation domain covers the North Africa, the Middle East and Europe at 0.25ºx0.25° and 40σ-layers. The first outbreak took place over the central and eastern Mediterranean on the 9th reaching aerosol optical depths (AODs) close to 1. The second one, with AODs up to 2, lasted from 10th to 14th affecting mainly the central Mediterranean. The third one, with AODs up to 5, affected the Iberian Peninsula on the 15th. DREs are computed for the outgoing radiation at the top of the atmosphere (TOA), the absorbed radiation into the atmosphere (ATMAB), for the downwelling (SURF) and the absorbed (NETSURF) radiation at surface, for the shortwave (SW), longwave (LW) and NET (SW+LW) radiation. According to our results, it is evident that DREs' spatial patterns are driven by those of AOD. Negative (cooling) instantaneous DRETOA, DRESURF and DRENETSURF values up to -500W/m2, -700W/m2 and -600W/m2, respectively, and positive (warming) instantaneous DREATMAB up to 340W/m2 are found for the SW spectrum, during daytime. Opposite but less pronounced effects are encountered for the LW radiation and during nightime. Due to these perturbations on the radiation field, the surface temperature is reduced locally by up to 8°C during daytime and increased by up to 4°C during nightime. It is found that the regional average NET DREs can be as large as -12W/m2, -45W/m2, -30W/m2 and 27W/m2 for TOA, SURF, NETSURF and ATMAB, respectively. Impacts on atmospheric stability and dust

  1. Two Effective Heuristics for Beam Angle Optimization in Radiation Therapy

    CERN Document Server

    Yarmand, Hamed

    2013-01-01

    In radiation therapy, mathematical methods have been used for optimizing treatment planning for delivery of sufficient dose to the cancerous cells while keeping the dose to critical surrounding structures minimal. This optimization problem can be modeled using mixed integer programming (MIP) whose solution gives the optimal beam orientation as well as optimal beam intensity. The challenge, however, is the computation time for this large scale MIP. We propose and investigate two novel heuristic approaches to reduce the computation time considerably while attaining high-quality solutions. We introduce a family of heuristic cuts based on the concept of 'adjacent beams' and a beam elimination scheme based on the contribution of each beam to deliver the dose to the tumor in the ideal plan in which all potential beams can be used simultaneously. We show the effectiveness of these heuristics for intensity modulated radiation therapy (IMRT) and stereotactic body radiation therapy (SBRT) on a clinical liver case.

  2. Long-Term Lunar Radiation Degradation Effects on Materials

    Science.gov (United States)

    Rojdev, Kristina; ORourke, Mary Jane; Koontz, Steve; Alred, John; Hill, Charles; Devivar, Rodrigo; Morera-Felix, Shakira; Atwell, William; Nutt, Steve; Sabbann, Leslie

    2010-01-01

    The National Aeronautics and Space Administration (NASA) is focused on developing technologies for extending human presence beyond low Earth orbit. These technologies are to advance the state-of-the-art and provide for longer duration missions outside the protection of Earth's magnetosphere. One technology of great interest for large structures is advanced composite materials, due to their weight and cost savings, enhanced radiation protection for the crew, and potential for performance improvements when compared with existing metals. However, these materials have not been characterized for the interplanetary space environment, and particularly the effects of high energy radiation, which is known to cause damage to polymeric materials. Therefore, a study focusing on a lunar habitation element was undertaken to investigate the integrity of potential structural composite materials after exposure to a long-term lunar radiation environment. An overview of the study results are presented, along with a discussion of recommended future work.

  3. Effects of gamma radiation in cauliflower (Brassica spp) minimally processed

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Thaise C.F.; Rogovschi, Vladimir D.; Thomaz, Fernanda S.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: villavic@ipen.br; thaisecfnunes@hotmail.com; Alencar, Severino M. [Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, SP (Brazil)

    2007-07-01

    Consumers demand for health interests and the latest diet trends. The consumption of vegetables worldwide has increased every year over the past decade, consequently, less extreme treatments or additives are being required. Minimally processed foods have fresh-like characteristics and satisfy the new consumer demand. Food irradiation is an exposure process of the product to controlled sources of gamma radiation with the intention to destroy pathogens and to extend the shelf life. Minimally processed cauliflower (Brassica oleraceae) exposed to low dose of gamma radiation does not show any change in sensory attributes. The aim of this study was to analyze the effects of the low doses of gamma radiation on sensorial aspects like appearance, texture and flavor of minimally processed cauliflower. (author)

  4. Self-consistent radiative effect on relativistic electromagnetic particle acceleration

    CERN Document Server

    Noguchi, K; Nishimura, K

    2005-01-01

    We study the radiation damping effect on the relativistic acceleration of electron-positron plasmas with two-and-half-dimensional particle-in-cell (PIC) simulation. Particles are accelerated by Poynting flux via the diamagnetic relativistic pulse accelerator (DRPA), and decelerated by the self-consistently solved radiation damping force. With $\\Omega_{ce}/\\omega_{pe}\\geq 10$, the Lorentz factor of the highest energy particles reaches gamma>100, and the acceleration still continues. The emitted radiation is peaked within few degrees from the direction of Poynting flux and strongly linearly polarized, which may be detectable in gamma-ray burst(GRB) observations. We also show that the DRPA is insensitive to the initial supporting currents.

  5. CLIC 3TeV Beamsize Optimization with Radiation Effects

    CERN Document Server

    Blanco, OR; Tomas, R

    2013-01-01

    Oide effect and radiation in bending magnets are reviewed aiming to include this in the optical design process to minimize the beam size. The Oide double integral is expressed in simpler terms in order to speed up calculations. Part of the Oide function is used to evaluate how prone is a quadrupole magnet to contribute to the beam size increase, concluding in larger magnets with lower gradients. Radiation in bending magnets is reviewed for linear lattices, solving the case when the dispersion is different from zero and using the result to compare with theoretical results and a tracking code. An agreement between the theory, the implemented approximation included in MAPCLASS2 and the six-dimensional radiation in PLACET has been found.

  6. Effect of gamma radiation on honey quality control

    Energy Technology Data Exchange (ETDEWEB)

    Bera, A. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: berale@usp.br; Almeida-Muradian, L.B. [Av. Prof. Lineu Prestes, 580-Cidade Universitaria, Sao Paulo (Brazil); Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, A. Lineu Prestes, 2242, 05508-000 Sao Paulo (Brazil)], E-mail: sfsabato@ipen.br

    2009-07-15

    Honey is one of the most complex substances produced by bees, mainly from the nectar of flowers. Gamma radiation is a technique that can be used to decrease the number of microbiological problems associated with food and increase the shelf life of certain products. The objective of this study was to verify the effect of gamma radiation with source of cobalto-60 (10 kGy) on some parameters used in honey quality control. Seven samples of pure honey were obtained from local markets in Sao Paulo, Brazil, in 2007. The methods used are in accordance with Brazilian Regulations. The physicochemical parameters analyzed were: moisture, HMF, free acidity, pH, sugars and ash. The results showed that gamma radiation, in the dose mentioned above, did not cause significant physicochemical alterations.

  7. AGGLOMERATION AND RADIATION EFFECT OF THE PULL OF URBANIZATION

    Institute of Scientific and Technical Information of China (English)

    QI Jin-li

    2003-01-01

    In order to explore the train of thought for China's urbanizing development and coordinated rural eco-nomic development, and to find good ways of solving rural problems through urbanization, this paper absorbs the push-and-pull forces theory and the systematic dynamic theory in the traditional population migration theories, views urbanization as a dynamic system, makes research on the push-and-pull mechanism of urbanization. The pull ingpower of urbanization is analyzed according to two aspects, the agglomeration effect and the radiation effect of cities. The agglomeration effect provides continuous propelling force for urbanization, and the radiation effect furtheraccelerates the urbanization process by pushing forward the development of rural economy. Of course, the slow de-velopment of urbanization can result in the hindrance to rural economic development.

  8. Radiation effects testing at the 88-inch cyclotron at LBNL

    International Nuclear Information System (INIS)

    The effects of ionizing particles on sensitive microelectronics is an important component of the design of systems as diverse as satellites and space probes, detectors for high energy physics experiments and even internet server farms. Understanding the effects of radiation on human cells is an equally important endeavor directed towards future manned missions in space and towards cancer therapy. At the 88-Inch Cyclotron at the Berkeley Laboratory, facilities are available for radiation effects testing (RET) with heavy ions and with protons. The techniques for doing these measurements and the advantages of using a cyclotron will be discussed, and the Cyclotron facilities will be compared with other facilities worldwide. RET of the same part at several facilities of varying beam energy can provide tests of the simple models used in this field and elucidate the relative importance of atomic and nuclear effects. The results and implications of such measurements will be discussed

  9. Radiation effects testing at the 88-Inch Cyclotron at LBNL

    International Nuclear Information System (INIS)

    The effects of ionizing particles on sensitive microelectronics is an important component of the design of systems as diverse as satellites and space probes, detectors for high energy physics experiments and even internet server farms. Understanding the effects of radiation on human cells is an equally important endeavor directed towards future manned missions in space and towards cancer therapy. At the 88-Inch Cyclotron at the Berkeley Laboratory, facilities are available for radiation effects testing (RET) with heavy ions and with protons. The techniques for doing these measurements and the advantages of using a cyclotron will be discussed, and the Cyclotron facilities will be compared with other facilities worldwide. RET of the same part at several facilities of varying beam energy can provide tests of the simple models used in this field and elucidate the relative importance of atomic and nuclear effects. The results and implications of such measurements will be discussed

  10. Effects of corpuscular radiation on weather and climate

    Science.gov (United States)

    Bucha, V.

    1989-01-01

    There is no doubt that the antropogenic effect play an important role in the effects of corpuscular radiation on weather and climate. The task, however, is to distinguish between antropogenic effect in the atmosphere due to human activities and natural climatic fluctuations influencing biological systems. The increase in global temperature during the past 100 years is in relatively good coincidence with the increase in geomagnetic (corpuscular) activity. It is concluded that it could have been the increase in temperature on the Northern Hemisphere, due to the processes occurring in the auroral oval under enhanced corpuscular radiation which led to an increased atmospheric concentration of CO2 in the past. Both processes, i.e., antropogenic and solar activity effects, should be therefore intensively studied due to their important role for elucidating the past and present global change mainly in temperature, climate and biological systems.

  11. [Effects of ionizing radiation on scintillators and other particle detectors

    International Nuclear Information System (INIS)

    It is my task to summarise the great variety of topics (covering a refreshing mix of physics, chemistry and technology) presented at this conference, which has focused on the effects of ionising radiation on scintillators and other particle detectors. One of the reasons and the central interest of many of the participants was the use of such detectors in experiments at two future large hadron colliders: the Superconducting Super Collider to be operating outside of Dallas in the United States by the turn of the decade and its European counterpart the Large Hadron Collider to be operating outside of Geneva in Switzerland on a similar time scale. These accelerators are the ''apple of the high energy physicist's eye.'' Their goal is to uncover the elusive Higgs particle and thereby set the cornerstone in our current knowledge of elementary particle interactions. This is the Quest, and from this lofty height the presentations rapidly moved on to the specific questions of experimental science: how such an experiment is carried out; why radiation damage is an issue; how radiation damage affects detectors; which factors affect radiation damage characteristics; which factors are not affected by radiation damage; and how better detectors may be constructed. These were the substance of this conference

  12. Effects of the ionizing radiation in natural food colours

    International Nuclear Information System (INIS)

    The world's fast growing population and its consequent increase in demand for food has driven mankind into improving technologies which ensure a safer supply of such commodities. Both food radiation processing and its constituents are highlighted as a feasible alternative technique capable of meeting food safety standards. Natural dyes are extensively employed in the food industry thanks to their colour enhancing properties on food products. This paper has aimed at studying the effects of ionizing radiation on three natural dyes: carminic acid and its derivatives (cochineal dyes), bixine and its salts (annatto dyes) and curcumin (turmeric dyes), used in the food and cosmetic industries within dilutions and doses those goods might eventually be processed in. It also envisages clarifying the compatibility of the irradiation technique with the keeping of such relevant sensorial attribute which is the product colour. Spectrophotometry and capillary electrophoresis were the analytic methods employed. All in all, a colour decrease proportional to the increase on the applied gamma radiation (1 to 32 kGy) has been observed. The annatto dyes have proven moderately stable whereas turmeric has shown to be highly sensitive to radiation. Those results shall be taken into account as far as the need to alter the formulae additive amount in the product is concerned whenever undergoing radiation processing. (author)

  13. Greenhouse effect from the point of view of radiative transfer

    CERN Document Server

    Barcza, Szabolcs

    2016-01-01

    Radiative power balance of a planet in the solar system is delineated. The terrestrial powers are transformed to average global flux in an effective atmospheric column (EAC) approximation, its components are delineated. The estimated and measured secular changes of the average global flux are compared to the fluxes derived from the Stefan-Boltzmann law using the observed global annual temperatures in the decades between 1880 and 2010. The conclusion of this procedure is that the radiative contribution of the greenhouse gas ${\\rm CO}_2$ is some $21\\pm 7$~\\% to the observed global warming from the end of the XIXth century excluding the feedback mechanisms playing determining role in the climate system. Stationary radiative flux transfer is treated in an air column as a function of the column density of the absorbent. Upper and lower limit of radiative forcing is given by assuming true absorption and coherent scatter of the monochromatic radiation. An integral formula is given for the outgoing long wave radiatio...

  14. Effect of Antarctic solar radiation on sewage bacteria viability

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, K.A. [National Environment Research Council, Cambridge (United Kingdom). British Antarctic Survey

    2005-06-01

    The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment. (author)

  15. Effects of gamma radiation on perfluorinated polymer optical fibers

    Science.gov (United States)

    Stajanca, Pavol; Mihai, Laura; Sporea, Dan; Neguţ, Daniel; Sturm, Heinz; Schukar, Marcus; Krebber, Katerina

    2016-08-01

    The paper presents the first complex study of gamma radiation effects on a low-loss perfluorinated polymer optical fiber (PF-POF) based on Cytop® polymer. Influence of gamma radiation on fiber's optical, mechanical and climatic performance is investigated. The radiation-induced attenuation (RIA) in the visible and near-infrared region (0.4 μm-1.7 μm) is measured and its origins are discussed. Besides attenuation increase, radiation is also shown to decrease the thermal degradation stability of the fiber and to increase its susceptibility to water. With regard to complex fiber transmission performance upon irradiation, the optimal operation wavelength region of PF-POF-based systems intended for use in radiation environments is determined to be around 1.1 μm. On the other hand, the investigated fiber holds potential for low-cost RIA-based optical fiber dosimetry applications with sensitivity as high as 260 dBm-1/kGy in the visible region.

  16. Underground shelters for protection against blast and radiation effects

    International Nuclear Information System (INIS)

    Underground shelters are generally designed and developed for the protection of personnel, arms and ammunitions, equipment and other materials against direct effects of nuclear explosion like blast, nuclear radiation, thermal radiation etc. Lightweight underground shelters made of thin mild steel corrugated sheets in cylindrical and hairpin shapes are developed for the protection of civil population and defence purpose. Each part of these shelters can be easily carried by man and can be assembled in short period by special fasteners. These shelters are designed for 1.5 m of earth pressure, peak blast overpressure and nuclear radiations produced by a nuclear blast. These shelters are analysed using a finite element package called ANSYS. The effect of soil -structure interaction is considered by using four values of modulus of sub-grade reaction. These shelters are analysed for static and transient loading, modal and buckling analyses. Maximum stresses and deflections, natural frequencies, mode shapes, buckling load factors and buckled mode shapes are found out and are presented in this paper. Limited simulated trials are also conducted to find out the suitability of these shelters against the blast and nuclear radiation effects in the field conditions and their results are also presented in this paper. (author)

  17. Effect of Deep Space Radiation on Human Hematopoietic Cells

    Science.gov (United States)

    Kalota, Anna; Bennett, Paula; Swider, Cezary R.; Sutherland, Betsy M.; Gewirtz, Alan M.

    Astronaut flight crews on long-term missions in deep space will be exposed to a unique radiation environment as a result of exposure to galactic cosmic rays (GCR) and solar particle events (SPE). This environment consists predominantly of high energy protons, helium and high charge, high energy (HZE) atomic nuclei from iron predominantly, but all other elements as well. The effect of such particles, alone, or in combination, on human hematopoietic stem and progenitor cells (HSPC) has not been well studied but is clearly of interest since blood forming cells are known to be sensitive to radiation, and irreversible damage to these cells could quickly compromise a mission due to loss of marrow function. To better understand the effects of GCR and SPE on human stem/progenitor cell function, we have exposed partially purified CD34+ normal human marrow cells to protons, radioactive Fe, and Ti, alone, and in combination at varying doses up to 70cGy, and down to 1, 2, and 4 particle hits per nucleus. We then examined the effects of these radiations on HSPC function, as assessed by the ability to form CFU-GEMM, and LTCIC colonies in semi-solid culture medium. At the highest doses (50 and 70cGy), all radiation types tested significantly diminished the ability of CD34+ cells to form such colonies. The number of CFU-GEMM in irradiated samples was 70-90

  18. Effect of 60CO radiation processing in mate (Ilex paraguariensis)

    International Nuclear Information System (INIS)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  19. Effect of 60Co radiation processing in mate (Ilex paraguariensis)

    International Nuclear Information System (INIS)

    The mate (Ilex paraguariensis), a native species from South America, is mainly consumed as typical beverage called chimarrao and terere. An important problem that has been afflicting this product since a long time is its natural fungal contamination responsible to affect its physical, health and nutritional qualities. In order to improve this product quality, radiation processing can be effective in reducing pathogens levels, with minimal nutritional and sensory changes. The aim of this study was to evaluate the effectiveness of gamma radiation from 60Co at doses 0, 3, 5, 7 and 10 kGy in reducing fungal contamination in mate, as well as analyze its nutritional and sensory characteristics. The following methodologies were applied: analysis of yeast and mold, total phenolic compounds analysis, antioxidant analysis, quantification of phenolic compounds and xanthines by liquid chromatography and sensory analysis. Microbiological analysis showed a decreasing molds and yeasts growth with increasing radiation doses. Regardless of the radiation dose applied there were no decrease of total phenolic compounds in both infusions. Chimarrao samples irradiated with 7 and 10 kGy showed a decrease in the DPPH radical-scavenger activity, nevertheless for terere samples, there were no significant difference. Chimarrao chromatographic profile did not show a variation on xanthines quantification, however a 10 kGy radiation dose caused a change to phenolic compounds quantitative profile. Terere samples did not show any significant difference to any analyzed compounds. Sensory analysis did not exhibit a significant difference between irradiated and non irradiated chimarrao samples, as well as between irradiated and non irradiated terere samples. It could be concluded that gamma radiation processing of mate may be a feasible alternative to industry, since there was a reduction on fungal contamination, without changes in sensory qualities and with minimum alterations in quantitative and

  20. Radiation effects on rare-earth doped optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Girard, S.; Marcandella, C. [CEA Bruyeres-le-Chatel, DIF 91 (France); Ouerdane, Y.; Tortech, B.; Boukenter, A.; Meunier, J.P.; Vivona, M. [Lab. Hubert Curien, CNRS, 42 - Saint-Etienne (France); Vivona, M.; Robin, Th.; Cadier, B. [iXFiber SAS, 22 - lannion (France)

    2010-07-01

    In this paper, we reviewed our previous work concerning the responses of rare-earth (RE) doped fibers (Yb, Er and Er/Yb) to various types of radiations like gamma-rays, X-rays and protons. For all these harsh environments, the main measured macroscopic radiation-induced effect is an increase of the linear attenuation of these waveguides due to the generation of point defects in the RE-doped core and silica-based cladding. To evaluate the vulnerability of this class of optical fibers for space missions, we characterize the growth and decay kinetics of their radiation-induced attenuation (RIA) during and after irradiation for various compositions. Laboratory testing reveals that this class of optical fibers is very sensitive to radiations compared to passive (RE-free) samples. As a consequence, despite the small length used for space applications, the understanding of the radiation-induced effects in this class of optical fibers becomes necessary before their integration as part of fiber-based systems like gyroscopes or communication systems. In this paper, we more particularly discussed about the relative influence of the rare-earth ions (Er{sup 3+} and/or Yb{sup 3+}) and of the glass matrix dopants (Al, P, ... ) on the optical degradation due to radiations. This has been done by using a set of five prototype optical fibers designed by the fiber manufacturer iXFiber SAS to enlighten the role of these parameters. Additional spectroscopic tools like con-focal microscopy of luminescence are also used to detect possible changes in the spectroscopy of the rare-earth ions and their consequences on the functionality of the active optical fibers. (authors)

  1. Profiling Transboundary Aerosols over Taiwan and Assessing Their Radiative Effects

    Science.gov (United States)

    Wang, Sheng-Hsiang; Lin, Neng-Huei; Chou, Ming-Dah; Tsay, Si-Chee; Welton, Ellsworth J.; Hsu, N. Christina; Giles, David M.; Liu, Gin-Rong; Holben, Brent N.

    2010-01-01

    A synergistic process was developed to study the vertical distributions of aerosol optical properties and their effects on solar heating using data retrieved from ground-based radiation measurements and radiative transfer simulations. Continuous MPLNET and AERONET observations were made at a rural site in northern Taiwan from 2005 to 2007. The aerosol vertical extinction profiles retrieved from ground-based lidar measurements were categorized into near-surface, mixed, and two-layer transport types, representing 76% of all cases. Fine-mode (Angstrom exponent, alpha, approx.1.4) and moderate-absorbing aerosols (columnar single-scattering albedo approx.0.93, asymmetry factor approx.0.73 at 440 nm wavelength) dominated in this region. The column-integrated aerosol optical thickness at 500 nm (tau(sub 500nm)) ranges from 0.1 to 0.6 for the near-surface transport type, but can be doubled in the presence of upper-layer aerosol transport. We utilize aerosol radiative efficiency (ARE; the impact on solar radiation per unit change of tau(sub 500nm)) to quantify the radiative effects due to different vertical distributions of aerosols. Our results show that the ARE at the top-of-atmosphere (-23 W/ sq m) is weakly sensitive to aerosol vertical distributions confined in the lower troposphere. On the other hand, values of the ARE at the surface are -44.3, -40.6 and -39.7 W/sq m 38 for near-surface, mixed, and two-layer transport types, respectively. Further analyses show that the impact of aerosols on the vertical profile of solar heating is larger for the near-surface transport type than that of two-layer transport type. The impacts of aerosol on the surface radiation and the solar heating profiles have implications for the stability and convection in the lower troposphere.

  2. Control of synchrotron radiation effects during recirculation with bunch compression

    International Nuclear Information System (INIS)

    Studies of beam quality during recirculation have been extended to an arc providing bunch compression with positive momentum compaction. It controls both incoherent and coherent synchrotron radiation (ISR and CSR) using methods including optics balance and generates little microbunching gain. We detail the dynamical basis for the design, discuss the design process, give an example, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of microbunching effects.

  3. Control of synchrotron radiation effects during recirculation with bunch compression

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Benson, Stephen [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Li, Rui [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Roblin, Yves [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Tennant, Christopher [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Krafft, Geoffrey [Old Dominion Univ., Norfolk, VA (United States); Terzic, Balsa [Old Dominion Univ., Norfolk, VA (United States); Tsai, Cheng [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2015-05-01

    Studies of beam quality during recirculation have been extended to an arc providing bunch compression with positive momentum compaction. It controls both incoherent and coherent synchrotron radiation (ISR and CSR) using methods including optics balance and generates little microbunching gain. We detail the dynamical basis for the design, discuss the design process, give an example, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of microbunching effects.

  4. Radiative Neutron Capture on Carbon-14 in Effective Field Theory

    OpenAIRE

    Rupak, Gautam; Fernando, Lakma; Vaghani, Akshay

    2012-01-01

    The cross section for radiative capture of neutron on carbon-14 is calculated using the model-independent formalism of halo effective field theory. The dominant contribution from E1 transition is considered, and the cross section is expressed in terms of elastic scattering parameters of the effective range expansion. Contributions from both resonant and non-resonant interaction are calculated. Significant interference between these leads to a capture contribution that deviates from simple Bre...

  5. The effects on populations of exposure to low levels of ionizing radiation. Report of the Advisory Committee on the Biological Effects of Ionizing Radiations

    International Nuclear Information System (INIS)

    In the summer of 1970, the Federal Radiation Council (whose activities have since been transferred to the Radiation Office of the EPA) asked the National Academy of Sciences for information relevant to an evaluation of present radiation protection guides. This report is in response to that request. It presents a summary and analysis, by members of the Advisory Committee on the Biological Effects of Ionizing Radiations and its subcommittees, of current knowledge relating to risks from exposure to ionizing radiation. In many respects, the report is a sequel to the reports of the Committee on the Biological Effects of Atomic Radiation, published by the NAS-NRC from 1956 to 1961

  6. Internal photoradiation effect. Radiation-induced luminescence and its influence on radiation processes

    International Nuclear Information System (INIS)

    Effect of radiation-induced luminescence on stabilization and reactions of intermediate charged particles in polymers in course of radiolysis is experimentally and theoretically investigated. The subjects of inquiry are polystyrene and polyvinyl alcohol films. Irradiation was carried out by 60Co γ-quanta in liquid nitrogen up to 5-10 kGy, the dose rate being approximately 5 Gy/s. It is stated that polymer luminescence results in decrease of concentration of stabilized charged particles, determines inequality of their distribution with respect to polymer volume and causes photochemical reactions. Contribution of photoradiation processes to radiation changes of material properties is defined by molecule properties, irradiation conditions, form and size of irradiated sample

  7. The Radiation Reaction Effects in the BMT Model of Spinning Charge and the Radiation Polarization Phenomenon

    CERN Document Server

    Lebedev, S L

    2005-01-01

    The effect of radiation polarization attended with the motion of spinning charge in the magnetic field could be viewed through the classical theory of self-interaction. The quantum expression for the polarization time follows from the semiclassical relation $T_{QED}\\sim \\hbar c^{3}/\\mu_{B}^2\\omega_{c}^3$, and needs quantum explanation neither for the orbit nor for the spin motion. In our approach the polarization emerges as a result of natural selection in the ensenmble of elastically scattered electrons among which the group of particles that bear their spins in the 'right' directions has the smaller probability of radiation. The evidence of non-complete polarization degree is also obtained.

  8. Effects of Ozonated Olive Oil on Acute Radiation Proctitis in Rats

    OpenAIRE

    Gültekin, Fatma Ayça; BAKKAL, Bekir Hakan; Sümer, Demet; Köktürk, Füruzan; Bektaş, Sibel

    2013-01-01

    Background: Acute radiation proctitis is a common complication of pelvic radiation and management of acute radiation proctitis is under evaluation. The beneficial effects of ozonated olive oil (OzOO) have already been shown in the treatment of chronic wounds. Thus, this study was designed to evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Aims: To evaluate the therapeutic effects of topical OzOO on acute radiation proctitis. Study Design: An...

  9. Effects of radiations on Spirogyra azygospora singh, 1

    International Nuclear Information System (INIS)

    The material Spirogyra azygospora (n = 12: chromosomes polycentric) belonging to the Order Conjugales, was used as an experimental material to study the morphological and cytological effects of gamma-rays. The doses administered range from 2 kR to 130 kR. Even the dose of 130 kR gamma radiation did not prove to be completely lethal to this alga. Among the various cytological effects chromosome and chromatid breaks, chromatid and isochromatid exchanges and ring chromosomes are noteworthy. Chromatid and isochromatid exchanges are reported for the first time in polycentric chromosomes. The results were discussed with those of others who studied the effects of ionizing radiations on the karyology of algae. (author)

  10. Evanescent radiation, quantum mechanics and the Casimir effect

    Science.gov (United States)

    Schatten, Kenneth H.

    1989-01-01

    An attempt to bridge the gap between classical and quantum mechanics and to explain the Casimir effect is presented. The general nature of chaotic motion is discussed from two points of view: the first uses catastrophe theory and strange attractors to describe the deterministic view of this motion; the underlying framework for chaos in these classical dynamic systems is their extreme sensitivity to initial conditions. The second interpretation refers to randomness associated with probabilistic dynamics, as for Brownian motion. The present approach to understanding evanescent radiation and its relation to the Casimir effect corresponds to the first interpretation, whereas stochastic electrodynamics corresponds to the second viewpoint. The nonlinear behavior of the electromagnetic field is also studied. This well-understood behavior is utilized to examine the motions of two orbiting charges and shows a closeness between the classical behavior and the quantum uncertainty principle. The evanescent radiation is used to help explain the Casimir effect.

  11. Effects of ultraviolet radiation on the immune system in humans

    International Nuclear Information System (INIS)

    In experimental animals, exposure to UV-B radiation produces selective alterations of immune function which are mainly in the form of suppression of normal immune responses. This immune suppression is important in the development of nonmelanoma skin cancer, may influence the development and course of infectious disease and possibly protects against autoimmune reactions. The evidence that this form of immune suppression occurs in humans is less compelling and very incomplete. The wavelengths of radiation most affected by a depletion of the stratospheric ozone layer are those known to be most immunosuppressive in animals and it is likely that such depletion will increase any suppressive effect of sunlight on immunity in humans. In addition to establishing whether or not UV-B radiation can cause suppression of immune function in humans, studies are required to determine if melanin can provide protection against such suppression, the role of this suppression in the pathogenesis of skin cancer, the development of infectious disease and vaccine effectiveness, and the capacity for humans to develop adaptive, protective mechanisms which may limit damage from continued exposure to UV-B radiation. (author)

  12. Early and late effects of radiation on normal tissues

    International Nuclear Information System (INIS)

    The key to successful radiation therapy is obviously not the dose that is required to sterilize the last clonogenic cell in a given tumor, but the dose that can be tolerate by the immediately surrounding and unavoidably irradiated normal tissues that are vital to the patient's survival and normal functioning. Throughout the development of radiation oncology as a treatment discipline, a major goal has been the improvement of dose distribution and dose localization so that less and less normal tissue is irradiated to high doses, and therefore tumor doses can be and have been significantly increased. Thus, it is extremely important to understand the nature of radiation injury in normal tissue, the effects of tissue type and volume of tissue irradiated on the tolerance, and indeed the definition and establishment of tolerance doses themselves. This paper outlines the general principles of radiation injury in various organs, the pathophysiology of injury, and the effect of volume irradiated on the level of injury and on tolerance doses

  13. Tunable acoustic radiation pattern assisted by effective impedance boundary

    Science.gov (United States)

    Qian, Feng; Quan, Li; Wang, Li-Wei; Liu, Xiao-Zhou; Gong, Xiu-Fen

    2016-02-01

    The acoustic wave propagation from a two-dimensional subwavelength slit surrounded by metal plates decorated with Helmholtz resonators (HRs) is investigated both numerically and experimentally in this work. Owing to the presence of HRs, the effective impedance of metal surface boundary can be manipulated. By optimizing the distribution of HRs, the asymmetric effective impedance boundary will be obtained, which contributes to generating tunable acoustic radiation pattern such as directional acoustic beaming. These dipole-like radiation patterns have high radiation efficiency, no fingerprint of sidelobes, and a wide tunable range of the radiation pattern directivity angle which can be steered by the spatial displacements of HRs. Project supported by the National Basic Research Program of China (Grant Nos. 2012CB921504 and 2011CB707902), the National Natural Science Foundation of China (Grant No.11474160), the Fundamental Research Funds for Central Universities, China (Grant No. 020414380001), the State Key Laboratory of Acoustics, Chinese Academy of Sciences (Grant No. SKLOA201401), the Priority Academic Program Development of Jiangsu Higher Education Institutions, and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.

  14. Delayed effects of external radiation exposure: a brief history.

    Science.gov (United States)

    Miller, R W

    1995-11-01

    Within months of Roentgen's discovery of X rays, severe adverse effects were reported, but not well publicized. As a result, over the next two decades, fluoroscope operators suffered lethal skin carcinomas. Later, case reports appeared concerning leukemia in radiation workers, and infants born with severe mental retardation after their mothers had been given pelvic radiotherapy early in pregnancy. Fluoroscopy and radiotherapy for benign disorders continued to be used with abandon until authoritative reports were published on the adverse effects of ionizing radiation by the U.S. NAS-NRC and the UK MRC in 1956. Meanwhile, exposure to the atomic bombs in Japan had occurred and epidemics of delayed effects began to be recognized among the survivors: cataracts (1949), leukemia (1952) and severe mental retardation among newborn infants after intrauterine exposure (1952). No statistically significant excess of germ-cell genetic effects was detected by six clinical measurements (1956), the F1 mortality (1981), cytogenetic studies (1987) or biochemical genetic studies (1988). Somatic cell effects were revealed by long-lasting chromosomal aberrations in peripheral lymphocytes (1968), and somatic cell mutations were found at the glycophorin A locus in erythrocytes (1992). Molecular biology is a likely focus of new studies based on the function of the gene for ataxia telangiectasia (1995), a disorder in which children have severe, even lethal acute radiation reactions when given conventional doses of radiotherapy for lymphoma, to which they are prone. Also, obligate heterozygote female relatives can be studied for increased susceptibility to radiation-induced breast cancer, as suggested by clinical studies. The tumor registries in Hiroshima and Nagasaki now provide incidence data that show the extent of increases in eight common cancers and no increase in eight others (1994). The possibility of very late effects of A-bomb exposure is suggested by recent reports of increased

  15. Genetic susceptibility: radiation effects relevant to space travel.

    Science.gov (United States)

    Peng, Yuanlin; Nagasawa, Hatsumi; Warner, Christy; Bedford, Joel S

    2012-11-01

    Genetic variation in the capacity to repair radiation damage is an important factor influencing both cellular and tissue radiosensitivity variation among individuals as well as dose rate effects associated with such damage. This paper consists of two parts. The first part reviews some of the available data relating to genetic components governing such variability among individuals in susceptibility to radiation damage relevant for radiation protection and discusses the possibility and extent to which these may also apply for space radiations. The second part focuses on the importance of dose rate effects and genetic-based variations that influence them. Very few dose rate effect studies have been carried out for the kinds of radiations encountered in space. The authors present here new data on the production of chromosomal aberrations in noncycling low passage human ATM+/+ or ATM+/- cells following irradiations with protons (50 MeV or 1 GeV), 1 GeV(-1) n iron ions and gamma rays, where doses were delivered at a high dose rate of 700 mGy(-1) min, or a lower dose rate of 5 mGy min(-1). Dose responses were essentially linear over the dose ranges tested and not significantly different for the two cell strains. Values of the dose rate effectiveness factor (DREF) were expressed as the ratio of the slopes of the dose-response curves for the high versus the lower (5 mGy min(-1)) dose rate exposures. The authors refer to this as the DREF5. For the gamma ray standard, DREF5 values of approximately two were observed. Similar dose rate effects were seen for both energies of protons (DREF5 ≈ 2.2 in both cases). For 1 GeV(-1) n iron ions [linear energy transfer (LET) ≈ 150 keV μ(-1)], the DREF5 was not 1 as might have been expected on the basis of LET alone but was approximately 1.3. From these results and conditions, the authors estimate that the relative biological effectiveness for 1 GeV(-1) n iron ions for high and low dose rates, respectively, were about 10 and 15

  16. Sources and effects of ionizing radiation. UNSCEAR 2000 report to the General Assembly, with scientific annexes. Volume II: Effects

    International Nuclear Information System (INIS)

    Over the past few years the United Nations Scientific Committee on the effects of Atomic Radiation has undertaken a broad review of the sources and effects of ionizing radiation. In the present report, the Committee, drawing on the main conclusions of its scientific assessment summarizes the developments in radiation science in the years leading up to the next millennium. It covers the following: the effects of radiation exposure; levels of radiation exposure; radiological consequences of the Chernobyl accident; sources of radiation exposure including natural exposures, man-made environmental exposures, medical and occupational exposures; radiation associated cancer. This volume includes five Annexes covering: DNA repair and mutagenesis; biological effects at low radiation doses; combined effects of radiation and other agents; epidemiological evaluation of radiation-induced cancer and exposure effects of the Chernobyl accident

  17. The aerosol radiative effects of uncontrolled combustion of domestic waste

    Science.gov (United States)

    Kodros, John K.; Cucinotta, Rachel; Ridley, David A.; Wiedinmyer, Christine; Pierce, Jeffrey R.

    2016-06-01

    Open, uncontrolled combustion of domestic waste is a potentially significant source of aerosol; however, this aerosol source is not generally included in many global emissions inventories. To provide a first estimate of the aerosol radiative impacts from domestic-waste combustion, we incorporate the Wiedinmyer et al. (2014) emissions inventory into GEOS-Chem-TOMAS, a global chemical-transport model with online aerosol microphysics. We find domestic-waste combustion increases global-mean black carbon and organic aerosol concentrations by 8 and 6 %, respectively, and by greater than 40 % in some regions. Due to uncertainties regarding aerosol optical properties, we estimate the globally averaged aerosol direct radiative effect to range from -5 to -20 mW m-2; however, this range increases from -40 to +4 mW m-2 when we consider uncertainties in emission mass and size distribution. In some regions with significant waste combustion, such as India and China, the aerosol direct radiative effect may exceed -0.4 W m-2. Similarly, we estimate a cloud-albedo aerosol indirect effect of -13 mW m-2, with a range of -4 to -49 mW m-2 due to emission uncertainties. In the regions with significant waste combustion, the cloud-albedo aerosol indirect effect may exceed -0.4 W m-2.

  18. Radiation sterilization and effective utilization of sewer sludge

    International Nuclear Information System (INIS)

    The treatment and disposal of the sludge that is generated in sewage treatment plants in large quantity have become a social problem. At present it is disposed mostly by landfill or reclamation. The research and development of the effective utilization of sewer sludge as fertilizer after sterilizing it by radiation have been carried out since relatively long ago. In this report, the technology of the sterilization and effective utilization of sludge by using radiation is introduced, centering around the research carried out by Japan Atomic Energy Research Institute. The general treatment process for sewage in Japan is explained. Sewer sludge is a useful resource, but when it is used for farmland as fertilizer, the problems are the possibility of the contamination with high concentration heavy metals, the possibility of the contamination by pathogenic bacteria and parasites and the bad smell of sludge. The radiation sterilization of sewer sludge, the electron sterilization of sewer sludge, the basic test and the pilot plant test on making compost, the effect of applying electron beam-sterilized sludge compost, and the economical efficiency of this process are reported. Accompanying recent environment pollution, small amount of harmful substances have become to be mixed in sludge, and it becomes the obstacle to the effective use of sludge. (K.I.)

  19. Radiation Effects and Protection for Moon and Mars Missions

    Science.gov (United States)

    Parnell, Thomas A.; Watts, John W., Jr.; Armstrong, Tony W.

    1998-01-01

    Manned and robotic missions to the Earth's moon and Mars are exposed to a continuous flux of Galactic Cosmic Rays (GCR) and occasional, but intense, fluxes of Solar Energetic Particles (SEP). These natural radiations impose hazards to manned exploration, but also present some constraints to the design of robotic missions. The hazards to interplanetary flight crews and their uncertainties have been studied recently by a National Research Council Committee (Space Studies Board 1996). Considering the present uncertainty estimates, thick spacecraft shielding would be needed for manned missions, some of which could be accomplished with onboard equipment and expendables. For manned and robotic missions, the effects of radiation on electronics, sensors, and controls require special consideration in spacecraft design. This paper describes the GCR and SEP particle fluxes, secondary particles behind shielding, uncertainties in radiobiological effects and their impact on manned spacecraft design, as well as the major effects on spacecraft equipment. The principal calculational tools and considerations to mitigate the radiation effects are discussed, and work in progress to reduce uncertainties is included.

  20. Highly physical penumbra solar radiation pressure modeling with atmospheric effects

    Science.gov (United States)

    Robertson, Robert; Flury, Jakob; Bandikova, Tamara; Schilling, Manuel

    2015-10-01

    We present a new method for highly physical solar radiation pressure (SRP) modeling in Earth's penumbra. The fundamental geometry and approach mirrors past work, where the solar radiation field is modeled using a number of light rays, rather than treating the Sun as a single point source. However, we aim to clarify this approach, simplify its implementation, and model previously overlooked factors. The complex geometries involved in modeling penumbra solar radiation fields are described in a more intuitive and complete way to simplify implementation. Atmospheric effects are tabulated to significantly reduce computational cost. We present new, more efficient and accurate approaches to modeling atmospheric effects which allow us to consider the high spatial and temporal variability in lower atmospheric conditions. Modeled penumbra SRP accelerations for the Gravity Recovery and Climate Experiment (GRACE) satellites are compared to the sub-nm/s2 precision GRACE accelerometer data. Comparisons to accelerometer data and a traditional penumbra SRP model illustrate the improved accuracy which our methods provide. Sensitivity analyses illustrate the significance of various atmospheric parameters and modeled effects on penumbra SRP. While this model is more complex than a traditional penumbra SRP model, we demonstrate its utility and propose that a highly physical model which considers atmospheric effects should be the basis for any simplified approach to penumbra SRP modeling.

  1. Health effect of low dose/low dose rate radiation

    International Nuclear Information System (INIS)

    The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

  2. Evaluation of the radiation effect on decomposition of NOx

    International Nuclear Information System (INIS)

    We have evaluated the radiation effect that contributes to the decomposition of nitrogen dioxides (NOx) in the atmosphere. Commercially available standard NO gas with concentrations of about 400 ppm was used for experiment of the evaluation. The NO gas was circulated in a loop including a container and an infrared spectrophotometer, irradiating the container with highly intensive 60Co gamma rays. The container forms a cylindrical electrode with the dimensions of a 30-mm inside diameter and a 150 mm-length, in which a stainless-steel electrode wire with a diameter of 245 μm is installed in the center. A high DC voltage is applied between both electrodes, and it can be closely controlled. The effectiveness of the radiation was evaluated by measuring the changing rate of NO concentration during the gamma irradiation. (author)

  3. Gamma radiation effects on pequi fruits (Caryocar brasiliense Camb.)

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcio Ramatiz L.; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia], e-mail: mramatiz@eafce.gov.br, e-mail: vaarthur@cena.usp.br; Salgado, Jocelem M.; Spoto, Marta H. Fillet; Canniatti-Brazaca, Solange G. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Agroindustria, Alimentos e Nutricao], e-mail: jmsalgad@esalq.usp.br, e-mail: mhfspoto@esalq.usp.br, e-mail: sgcbraza@esalq.usp.br

    2009-07-01

    The objective of this work was to evaluate the effects of gamma radiation on characteristics of pequi fruits (Caryocar brasiliense Camb.). Just now, they are gained attention of researchers due their nutritional properties, between then is the pequi fruits. Fruits come from Goias State was classified, washed and processed to separate the endocarp (edible part) from pericarp. The endocarps were packing in polyethylene bags with 150 g, labeled and submitted to radiation process (0.0, 0.4, 0.6 and 1.0 kGy doses) on multipurpose irradiator located in IPEN/USP. The samples were analyzed to chemical (pH, trititable acidity, deg Brix, ratio TSS/TTA, lipids, ash, humidity, protein, soluble and insoluble fiber, total carotenoids and antioxidant activity) and physical properties (loss weight, texture and color). The irradiation process using gamma rays from Co{sup 60} was effective to protect pequi fruits in postharvest period. (author)

  4. Radiation damage effects in standard float zone silicon diodes

    Energy Technology Data Exchange (ETDEWEB)

    Pascoalino, Kelly C.; Camargo, Fabio; Barbosa, Renata F.; Goncalves, Josemary A.C.; Tobias, Carmen C.B., E-mail: ccbueno@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The aim of this work was to study the radiation damage effects on the electrical properties of standard float zone diodes (STFZ). Such effects were evaluated by measuring the current and capacitance of these devices as a function of the reverse voltage. For comparison, current and capacitance measurements were carried out with a non-irradiated STFZ device. The irradiation was performed in the Radiation Technology Center (CTR) at IPEN/CNEN-SP using a {sup 60}Co irradiator (Gammacell 220 - Nordion) with a dose rate of about 2.2 kGy/h. Samples were irradiated at room temperature in steps variable from 50 kGy up 140 kGy which lead to an accumulated dose of 460 kGy. The results obtained have shown that the upper dose limit for a 'damageless' STFZ diode is about 50 kGy. (author)

  5. Gamma radiation effects on pequi fruits (Caryocar brasiliense Camb.)

    International Nuclear Information System (INIS)

    The objective of this work was to evaluate the effects of gamma radiation on characteristics of pequi fruits (Caryocar brasiliense Camb.). Just now, they are gained attention of researchers due their nutritional properties, between then is the pequi fruits. Fruits come from Goias State was classified, washed and processed to separate the endocarp (edible part) from pericarp. The endocarps were packing in polyethylene bags with 150 g, labeled and submitted to radiation process (0.0, 0.4, 0.6 and 1.0 kGy doses) on multipurpose irradiator located in IPEN/USP. The samples were analyzed to chemical (pH, trititable acidity, deg Brix, ratio TSS/TTA, lipids, ash, humidity, protein, soluble and insoluble fiber, total carotenoids and antioxidant activity) and physical properties (loss weight, texture and color). The irradiation process using gamma rays from Co60 was effective to protect pequi fruits in postharvest period. (author)

  6. A critical review of radiation effects on borosilicate glasses

    International Nuclear Information System (INIS)

    Most of the experimental values have been obtained by loading the glass with alpha emitters like Cm 244 and Pu 238. The data existing in literature on stored energy, and density variation are presented and discussed. Attention is given to the variation of the leaching rate due to the radiation effect. Samples loaded with alpha emitters have given data up to 0.17 dpa and such bombarded with heavy ions show large effects due to dose rate effects. A study on defect formation has shown that under electrons irradiation, formation of bubbles is possible. (DG)

  7. Stochastic Effects in Computational Biology of Space Radiation Cancer Risk

    Science.gov (United States)

    Cucinotta, Francis A.; Pluth, Janis; Harper, Jane; O'Neill, Peter

    2007-01-01

    Estimating risk from space radiation poses important questions on the radiobiology of protons and heavy ions. We are considering systems biology models to study radiation induced repair foci (RIRF) at low doses, in which less than one-track on average transverses the cell, and the subsequent DNA damage processing and signal transduction events. Computational approaches for describing protein regulatory networks coupled to DNA and oxidative damage sites include systems of differential equations, stochastic equations, and Monte-Carlo simulations. We review recent developments in the mathematical description of protein regulatory networks and possible approaches to radiation effects simulation. These include robustness, which states that regulatory networks maintain their functions against external and internal perturbations due to compensating properties of redundancy and molecular feedback controls, and modularity, which leads to general theorems for considering molecules that interact through a regulatory mechanism without exchange of matter leading to a block diagonal reduction of the connecting pathways. Identifying rate-limiting steps, robustness, and modularity in pathways perturbed by radiation damage are shown to be valid techniques for reducing large molecular systems to realistic computer simulations. Other techniques studied are the use of steady-state analysis, and the introduction of composite molecules or rate-constants to represent small collections of reactants. Applications of these techniques to describe spatial and temporal distributions of RIRF and cell populations following low dose irradiation are described.

  8. The effects of gamma radiation on soybean isoflavones contents

    International Nuclear Information System (INIS)

    Soybean (Glycine max) is the most common source of isoflavones in human feeding. It was suggested that there is a correlation among antioxidant activity of flavonoids and total phenolics content. Plants use isoflavones and their derivatives as part of the plant's defensive arsenal, to ward off disease-causing pathogenic fungi and other microbes. Highly processed foods made from legumes, such as tofu, retain most of their isoflavone content, with the exception of fermented miso, which has increased levels. Little is known about the influence of oxidative stress induced by radiation on the isoflavones contents. In the present paper, the effects of gamma irradiation on soybean isoflavones contents are presented. Samples from several Brazilian soybean cultivars were gamma irradiated with doses of 0, 1, 2, 5 e 10 kGy, dose rate about 3 kGy/h in a 60Co (Gammacell 220 - AECL). Isoflavones contents were determined after extraction with 70% ethanol containing 0.1% acetic acid by an HPLC method. The total isoflavone content remained almost unchanged with the increase of radiation dose up to 10 kGy. Although a general correlation among total isoflavone content and radiation dose was not found, some data suggest that for a few of the isoflavones from specific cultivars, the increase in the radiation dose induced a decrease in their content as for glucosyl glucosides and malonyl isoflavones, as well as an increase in their aglycone content. (author)

  9. The effects of gamma radiation on soybean isoflavones contents

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcos R.R. de; Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: nlmastro@ipen.br, e-mail: mrramos@ipen.br; Mandarino, Jose M.G. [EMBRAPA Soybean, Londrina, PR (Brazil)], e-mail: jmarcos@cnpso.embrapa.br

    2009-07-01

    Soybean (Glycine max) is the most common source of isoflavones in human feeding. It was suggested that there is a correlation among antioxidant activity of flavonoids and total phenolics content. Plants use isoflavones and their derivatives as part of the plant's defensive arsenal, to ward off disease-causing pathogenic fungi and other microbes. Highly processed foods made from legumes, such as tofu, retain most of their isoflavone content, with the exception of fermented miso, which has increased levels. Little is known about the influence of oxidative stress induced by radiation on the isoflavones contents. In the present paper, the effects of gamma irradiation on soybean isoflavones contents are presented. Samples from several Brazilian soybean cultivars were gamma irradiated with doses of 0, 1, 2, 5 e 10 kGy, dose rate about 3 kGy/h in a {sup 60}Co (Gammacell 220 - AECL). Isoflavones contents were determined after extraction with 70% ethanol containing 0.1% acetic acid by an HPLC method. The total isoflavone content remained almost unchanged with the increase of radiation dose up to 10 kGy. Although a general correlation among total isoflavone content and radiation dose was not found, some data suggest that for a few of the isoflavones from specific cultivars, the increase in the radiation dose induced a decrease in their content as for glucosyl glucosides and malonyl isoflavones, as well as an increase in their aglycone content. (author)

  10. New results on radiation effects on human health

    Science.gov (United States)

    Spurny, Frantisek; Dachev, Tsvetan

    2009-03-01

    Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating risks due to ionization radiation. During the Work Package 2400 of the COST-724/WG-2 action, a number of spacecraft and aircraft experiments have been performed with both active and passive detectors. A large data base has been created. In this contribution we would like to stress the results obtained and their importance in three particular directions: (i) Simultaneous investigation of galactic cosmic rays on aircraft and on the International Space Station (ISS); (ii) Onboard spacecraft neutron contribution as estimated on the basis of the comparison of results measured with MDU/Liulin equipment onboard ISS, foton capsule and a commercial aircraft flying at subsonic altitudes; (iii) Complex analysis of the results of long term measurements onboard a Czech Airlines aircraft. The results obtained are presented, analyzed, and discussed, and their complementary nature is underlined. The contribution represents a version of the Final Report of the Work Package 2400 of the COST-724/WG-2: Radiation Environment of the Earth.

  11. Interference effect of edge radiation at three-pole wiggler section

    Science.gov (United States)

    Koda, Shigeru; Takabayashi, Yuichi

    2016-09-01

    Radiation from a three-pole wiggler section is not simply treated as typical synchrotron radiation in a long-wavelength region. The interference effect between edge radiations from upstream and downstream straight subsections of the wiggler is considered to contribute significantly to the radiation. Our simple model roughly reproduced spectral and spatial distributions of the radiation. Under the maximum interference condition, the peak radiation intensity is four times larger than the edge radiation from a single straight section. Moreover, the longitudinal periodic alignment of three-pole wigglers, which satisfies the maximum interference condition, generates radiation of higher intensity proportional to the square of the periodic number.

  12. Development of Technologies to Utilize Laser Plasma Radiations Sources for Radiation Effects Sciences

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J F

    2007-01-31

    This final report will cover work performed over the period of November 11, 2005 to September 30, 2006 on the contract to develop technologies using laser sources for radiation effects sciences. The report will discuss four topic areas; the laser source experiments on the Gekko Laser at Osaka, Japan, planning for the Charge State Freeze Out experiments to be performed in calendar year 2007, a review of previous xenon gasbags on the LANL Trident laser to provide planning support to the May-June 2007 HELEN experiments.

  13. Biological effects of low-intensity millimetric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Betskiy, O.V.; Putvinskiy, A.V.

    1986-10-01

    The authors discuss a possible role of strong absorption of millimetric (MM) waves by water molecules in the primary mechanism of the reaction of biological systems to MM irradiation. Data are given on the interaction of MM radiation with simple aqueous systems. Primary attention is given to the phenomenon of convective mixing of aqueous solutions under the effect of low-intensity MM waves (1 ... 10 mW/cm/sup 2/). 12 references, 6 figures.

  14. Double humps and radiation effects of SOI NMOSFET

    Institute of Scientific and Technical Information of China (English)

    Cui Jiangwei; Yu Xuefeng; Ren Diyuan; He Chengfa; Gao Bo; Li Ming; Lu Jian

    2011-01-01

    Radiation experiments have been carried out with a SOI NMOSFET. The behavior of double humps was studied under irradiation. The characterization of the hump was demonstrated. The results have shown that the shape of the hump changed along with the total dose and the reason for this was analyzed. In addition, the coupling effect of the back-gate transistor was more important for the main transistor than the parasitic transistor.

  15. Analysis of destabilizing factors effect on hybrid reflector antenna radiation

    OpenAIRE

    Smorodin, G. N.; Braude, V. B.

    1995-01-01

    The paper deals with the effect of various destabilizing factors including manufacture inaccuracy on a hybrid reflector antenna (HRA) radiation pattern. Antenna designed for the airport precision approach radar (PAR) is considered as an example of HRA. Antenna uses a reflector 2.8*3.3 m cut of hyperboloid and an offset cylindrical phased array containing about seven hundred transmission-type waveguide phase shifters. The array is fed by a monopulse four-waveguide horn and is operated by a ste...

  16. Intermittent Jolts of Galactic UV Radiation: Mutagenetic Effects

    OpenAIRE

    Scalo, John M.; Wheeler, J. Craig; Williams, Peter

    2001-01-01

    We estimate the frequency of intermittent hypermutation events and disruptions of planetary/satellite photochemistry due to ultraviolet radiation from core collapse supernova explosions. Calculations are presented for planetary systems in the local Milky Way, including the important moderating effects of vertical Galactic structure and UV absorption by interstellar dust. The events are particularly frequent for satellites of giant gas planets at \\gtrsim 5-10 AU distance from solar-type parent...

  17. Studying laser radiation effect on steel structure and properties

    Directory of Open Access Journals (Sweden)

    А. М. Gazaliyev

    2016-07-01

    Full Text Available There was studied the effect of laser radiation on the structure and properties of annealed and tempered steel with different content of carbon. For surface hardening there was used a laser complex equipped with Nd: YAG pulse laser with power density up to 30 kW/сm2. As a result of the carried-out studies there were calculated characteristics of laser, steel microstructure and properties.

  18. CARES: Carbonaceous Aerosol and Radiative Effects Study Science Plan

    Energy Technology Data Exchange (ETDEWEB)

    Zaveri, RA; Shaw, WJ; Cziczo, DJ

    2010-05-27

    Carbonaceous aerosol components, which include black carbon (BC), urban primary organic aerosols (POA), biomass burning aerosols, and secondary organic aerosols (SOA) from both urban and biogenic precursors, have been previously shown to play a major role in the direct and indirect radiative forcing of climate. The primary objective of the CARES 2010 intensive field study is to investigate the evolution of carbonaceous aerosols of different types and their effects on optical and cloud formation properties.

  19. Runaway Greenhouse Effect in a Semigray Radiative-Convective Model

    OpenAIRE

    Pujol i Sagaró, Toni; North, Gerald R.

    2002-01-01

    The effects of the nongray absorption (i.e., atmospheric opacity varying with wavelength) on the possible upper bound of the outgoing longwave radiation (OLR) emitted by a planetary atmosphere have been examined. This analysis is based on the semigray approach, which appears to be a reasonable compromise between the complexity of nongray models and the simplicity of the gray assumption (i.e., atmospheric absorption independent of wavelength). Atmospheric gases in semigray atmospheres make use...

  20. Climatology of stratocumulus cloud morphologies: microphysical properties and radiative effects

    OpenAIRE

    Muhlbauer, A.; I. L. McCoy; R. Wood

    2014-01-01

    An artificial neural network cloud classification scheme is combined with A-train observations to characterize the physical properties and radiative effects of marine low clouds based on their morphology and type of mesoscale cellular convection (MCC) on a global scale. The cloud morphological categories are (i) organized closed MCC, (ii) organized open MCC and (iii) cellular but disorganized MCC. Global distributions of the frequency of occurrence of MCC types show clea...

  1. Double humps and radiation effects of SOI NMOSFET

    Energy Technology Data Exchange (ETDEWEB)

    Cui Jiangwei; Yu Xuefeng; Ren Diyuan; He Chengfa; Gao Bo; Li Ming; Lu Jian, E-mail: cuijiangwei@sina.cn [Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China)

    2011-06-15

    Radiation experiments have been carried out with a SOI NMOSFET. The behavior of double humps was studied under irradiation. The characterization of the hump was demonstrated. The results have shown that the shape of the hump changed along with the total dose and the reason for this was analyzed. In addition, the coupling effect of the back-gate transistor was more important for the main transistor than the parasitic transistor. (semiconductor devices)

  2. Radiation Effects of Commercial Resistive Random Access Memories

    Science.gov (United States)

    Chen, Dakai; LaBel, Kenneth; Berg, Melanie; Wilcox, Edward; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

    2014-01-01

    We present results for the single-event effect response of commercial production-level resistive random access memories. We found that the resistive memory arrays are immune to heavy ion-induced upsets. However, the devices were susceptible to single-event functional interrupts, due to upsets from the control circuits. The intrinsic radiation tolerant nature of resistive memory makes the technology an attractive consideration for future space applications.

  3. Radiation dosimetry using junction field-effect transistor detectors

    International Nuclear Information System (INIS)

    The use of junction field effect transistors (JFET) has been studied by connecting them in a bridge circuit. With a suitable back-up circuit, it was possible to measure doses as well as dose-rates. It was possible to alter the sensitivity of the JFET bridge by varying the biasing components of the JFET. Easy temperature compensation was also possible. However, response of the JFET to radiation showed energy dependency similar to that of semiconductor diodes. (author)

  4. Determining meson radiative widths from Primakoff-effect measurements

    International Nuclear Information System (INIS)

    We suggest that the measurement of vector-meson radiation decays V → Pγ in the Primakoff-effect experiments on nuclei should be reanalyzed including isovector hadronic exchange. Its inclusion invalidates the assumption, made in data analyses, of A independence of the strength of the strong-production amplitude and could well remove the disagreement between theory and experiment for GAMMA (rho → πγ) and GAMMA

  5. Some effects of fast neutrons and gamma radiation on rice

    International Nuclear Information System (INIS)

    Seeds of the Hungarian rice variety, Dungham Shali, were irradiated with doses of gamma radiation and fast neutrons. The effects of the irradiations on seedling growth, plant survival, fertility, and on chlorophyll mutations in M2 plants were studied. At the optimal dose level for mutation production in this material fast neutrons produced 2-3 times more chlorophyll mutations than gamma irradiation. (author). 6 refs, 4 figs, 2 tabs

  6. Atmospheric thermal radiation from historical measurements to investigations of the Earth's greenhouse effect

    OpenAIRE

    Rolf Philipona

    2013-01-01

    Here, we recall first quantitative measurements of terrestrial and atmospheric thermal infrared radiation that were made about hundred years ago, and relate them to present day radiation budget measurements and greenhouse effect investigations through the atmosphere. At the beginning of the 20th century measurements of the effective terrestrial radiation and the counter-radiation of the atmosphere were of great interest primarily to prove theoretical aspects of the Earth radiation balance...

  7. Topological magnetoelectric effects in microwave far-field radiation

    Science.gov (United States)

    Berezin, M.; Kamenetskii, E. O.; Shavit, R.

    2016-07-01

    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.

  8. Creation of a crystalline lens radiation exposure defense cover and the effect of radiation exposure decrease on neuro-interventions

    International Nuclear Information System (INIS)

    A variety of radiation hazards resulting from interventional radiology (IVR) have been reported in recent years. Particularly affected are the skin and the crystalline lens, with their high radiation sensitivity. During neurological interventions, the radiological technologist should consider decreasing radiation exposure. We found exposure projections where the exposure dose became a radiation hazard for the crystalline lens, and examined an efficient method of cover for the exposure projections used for neurological interventions. The exposure projection for maximum crystalline lens radiation exposure was a lateral projection. In the crystalline lens the maximum exposure to radiation was on the X-ray tube side. The method of defense adopted was that of installing a lead plate of the appropriate shape on the surface of the X-ray tube collimator. In other exposure projections, this cover did not become a redundant shadow. With the cover that was created, the X-ray side crystalline lens lateral projection could be defended effectively. (author)

  9. The regulatory effects of radiation and histone deacetylase inhibitor on liver cancer cell cycle

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Ho; Choi, Hyung Seok; Jang, Dong Gun; Lee, Hong Je; Yang, Seoung Oh [Dept. Nuclear Medicine, Dongnam Institute of Radiological and Medicine Sciences Cancer Center, Busan (Korea, Republic of)

    2013-11-15

    Radiation has been an effective tool for treating cancer for a long time. Radiation therapy induces DNA damage within cancer cells and destroys their ability to reproduce. Radiation therapy is often combined with other treatments, like surgery and chemotherapy. Here, we describe the effects of radiation and histone deacetylase inhibitor, Trichostain A, on cell cycle regulation in hepatoma cells. Results demonstrate that the treatment of radiation TSA induces cell cycle arrest, thereby stimulating cell death in hepatoma cells. In addition, since different cells or tissues have different reactivity to radiation and TSA, these results might be an indicator for the combination therapy with radiation and drugs in diverse cancers.

  10. A Model for Shear Layer Effects on Engine Noise Radiation

    Science.gov (United States)

    Nark, Douglas M.; Farassat, F.; Pope, D. Stuart; Vatsa, V.

    2004-01-01

    Prediction of aircraft engine noise is an important aspect of addressing the issues of community noise and cabin noise control. The development of physics based methodologies for performing such predictions has been a focus of Computational Aeroacoustics (CAA). A recent example of code development in this area is the ducted fan noise propagation and radiation code CDUCT-LaRC. Included within the code is a duct radiation model that is based on the solution of FfowcsWilliams-Hawkings (FW-H) equation with a penetrable data surface. Testing of this equation for many acoustic problems has shown it to provide generally better results than the Kirchhoff formula for moving surfaces. Currently, the data surface is taken to be the inlet or exhaust plane for inlet or aft-fan cases, respectively. While this provides reasonable results in many situations, these choices of data surface location lead to a few limitations. For example, the shear layer between the bypass ow and external stream can refract the sound waves radiated to the far field. Radiation results can be improved by including this effect, as well as the rejection of the sound in the bypass region from the solid surface external to the bypass duct surrounding the core ow. This work describes the implementation, and possible approximation, of a shear layer boundary condition within CDUCT-LaRC. An example application also illustrates the improvements that this extension offers for predicting noise radiation from complex inlet and bypass duct geometries, thereby providing a means to evaluate external treatments in the vicinity of the bypass duct exhaust plane.

  11. Low intensity gamma radiation effects in young plantlet assimilatory pigments

    International Nuclear Information System (INIS)

    In this paper we investigate the gamma radiation effects in young plants of Chelidonium majus, the Papaveraceae family, by spectrophotometric methods. We have recorded the absorption spectra and the fluorescence spectra at different irradiation times. The samples of Chelidonium majus caryopsides were exposed to gamma radiation produced by a 10 mCi cobalt source at different irradiation times: 0.5 h, 1 h, 1.5 h, 2 h, 6 h, 16.5 h. The samples for analysis were prepared by acetone (85%) extraction of the assimilatory pigments from the plantlets. We have studied the absorption spectra with a SPECORD UV-VIS spectrophotometer. The absorption spectra gave information about the A-chlorophyll concentration (CCla), B-chlorophyll concentration (CClb) and carotene pigments concentration (Cct) (in mg/g green mass accumulation). This information was based on the extinction bands at the 15.080 cm-1, 15.500 cm-1 and 21.190 cm-1. We observed the fluctuation of the concentrations as a function of the irradiation times. This fluctuation is more important in A-chlorophyll cases. The same observation was made in the case of the fluorescence spectra. The fluorescence spectra of the dilute solutions (1/10 ratio) was recorded with an installation made in our laboratory. For the excitation of fluorescence we have used the 23.740 cm-1 radiation for the red fluorescence band and the 29.720 cm-1 radiation for the blue fluorescence band. The fluorescence and absorption spectra of the assimilatory pigments were recorded. It is possible that irradiation with low gamma radiation dose, for different irradiation times, have an influence on the metabolic nuclei in plant cells. As a result, the A-chlorophyll synthesis may be inhibited or activated as compared to B-chlorophyll synthesis. These results represent preliminary studies to new experiments designed to elucidate the phenomenon. (author)

  12. The effect of radiation therapy on hemophilic arthropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jin Oh; Hong, Seong Eon; Kim, Sang Gi; Shin, Dong Oh [School of Medicine, KyungHee University, Seoul (Korea, Republic of)

    2005-06-15

    Repetitive bleeding into the joint space is the cause of debilitative hemophilic arthropathy. To interrupt this process, we treated the hemophilic patients suffering from repetitive joint bleeding with radiation therapy. From 1997 to 2001, a total of 41 joints from 37 hemophilic arthropathy patients were treated with radiation therapy at KyungHee University Hospital. The treated joints were 35 ankles, 3 knees and 3 elbows, respectively. The age of the patients ranged from 4 to 27 years (median age: 11 years). The radiation dose ranged from 900 cGy to 2360 cGy (median dose: 900 cGy). The fraction size was 150 cGy, 180 cGy or 200 cGy. The number of bleeding in one year before and after radiotherapy was compared. There was a tendency of frequent bleeding for the patients younger than 11 ({rho} 0.051) but there was also a tendency for more improvement in this group ({rho} 0.057). The number of joint bleedings was related with joint pain ({rho} 0.012) and joint swelling ({rho} = 0.033) but not with the Arbold-Hilgartner stage ({rho} 0.739),cartilage destruction ({rho} = 0.718) and synovial hypertrophy ({rho} = 0.079). The number of bleeding was reduced in thirty-three cases, and eight cases showed no improvement after radiation therapy. The average number of bleeding in a month was 2.52 before radiotherapy, but this was reduced to 1.4 after radiotherapy ({rho} = 0.017). Radiation therapy was effective for the hemophilia patients with repetitive joint bleeding to decrease the bleeding frequency and to prevent hemophilic arthropathy.

  13. The effect of aerosol on radiation fog life-cycle

    Science.gov (United States)

    Romakkaniemi, Sami; Maalick, Zubair; Tonttila, Juha; Kuhn, Thomas; Kokkola, Harri

    2016-04-01

    Radiation fog is formed during the night under clear skies when emission of long wave radiation cools the surface and air above it. After formation, the development of fog is further influenced by longwave cooling and turbulence entrainment-detrainment at the top of the fog layer, and microphysical processes through droplet activation and sedimentation. After sunrise, the fog is dissipated due heating of the surface and the air above it. Like in the case of clouds, atmospheric aerosol particles also affect the properties of fog and together with meteorological conditions determine their life cycle from formation to dissipation. To explore how aerosols are affecting radiation fog properties and lifetime, we have used a Large Eddy Model with explicit representation of aerosol particles and aerosol-fog droplet interactions. Our results show that the fog droplet concentration increases with increasing aerosol concentration. In the early stages of fog formation the radiative cooling at the top of the fog controls the maximum water supersaturation and droplet formation in a similar manner than the updraft velocity does at the base of a cloud. The liquid water content in the fog is mainly determined by the droplet concentration as large droplets are efficiently removed through sedimentation. Thus, with increasing aerosol particle concentration, the more numerous, but smaller fog droplets increase the fog's optical depth and thereby delay the fog dissipation after sunrise, because the surface warms more slowly. This effect is further enhanced if turbulence inside the fog leads to secondary activation of droplets. Overall, the radiation fog dissipation in polluted conditions can be delayed up to hours when compared to clean conditions.

  14. The effect of radiation dose on mouse skeletal muscle remodeling

    International Nuclear Information System (INIS)

    The purpose of this study was to determine the effect of two clinically relevant radiation doses on the susceptibility of mouse skeletal muscle to remodeling. Alterations in muscle morphology and regulatory signaling were examined in tibialis anterior and gastrocnemius muscles after radiation doses that differed in total biological effective dose (BED). Female C57BL/6 (8-wk) mice were randomly assigned to non-irradiated control, four fractionated doses of 4 Gy (4x4 Gy; BED 37 Gy), or a single 16 Gy dose (16 Gy; BED 100 Gy). Mice were sacrificed 2 weeks after the initial radiation exposure. The 16 Gy, but not 4x4 Gy, decreased total muscle protein and RNA content. Related to muscle regeneration, both 16 Gy and 4x4 Gy increased the incidence of central nuclei containing myofibers, but only 16 Gy increased the extracellular matrix volume. However, only 4x4 Gy increased muscle 4-hydroxynonenal expression. While both 16 Gy and 4x4 Gy decreased IIB myofiber mean cross-sectional area (CSA), only 16 Gy decreased IIA myofiber CSA. 16 Gy increased the incidence of small diameter IIA and IIB myofibers, while 4x4 Gy only increased the incidence of small diameter IIB myofibers. Both treatments decreased the frequency and CSA of low succinate dehydrogenase activity (SDH) fibers. Only 16 Gy increased the incidence of small diameter myofibers having high SDH activity. Neither treatment altered muscle signaling related to protein turnover or oxidative metabolism. Collectively, these results demonstrate that radiation dose differentially affects muscle remodeling, and these effects appear to be related to fiber type and oxidative metabolism

  15. Effect of low dose ionizing radiation upon concentration of

    Energy Technology Data Exchange (ETDEWEB)

    Viliae, M.; Kraljeviae, P.; Simpraga, M.; Miljaniae, S.

    2004-07-01

    It is known that low dose ionizing radiation might have stimulating effects (Luckey, 1982, Kraljeviae, 1988). This fact has also been confirmed in the previous papers of Kraljeviae et al. (2000-2000a; 2001). Namely, those authors showed that irradiation of chicken eggs before incubation by a low dose of 0.15 Gy gamma radiation increases the activity aspartateaminotrasferases (AST) and alanine-aminotransferases (ALT) in blood plasma of chickens hatched from irradiated eggs, as well as growth of chickens during the fattening period. Low doses might also cause changes in the concentration of some biochemical parameters in blood plasma of the same chickens such as changes in the concentration of total proteins, glucose and cholesterol. In this paper, an attempt was made to investigate the effects of low dose gamma radiation upon the concentration of sodium and potassium in the blood plasma of chickens which were hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy. Obtained results were compared with the results from the control group (chickens hatched from nonirradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from heart, and later from the wing vein on days 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of sodium and potassium was determined spectrophotometrically by atomic absorbing spectrophotometer Perkin-Elmer 1100B. The concentration of sodium and potassium in blood plasma of chickens hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy indicated a statistically significant increase (P>0.01) only on the first day of the experiment. Obtained results showed that irradiation of eggs on the 19th day of incubation by dose of 0.15 Gy gamma radiation could have effects upon the metabolism of electrolytes in chickens. (Author)

  16. Effects of {gamma}-radiation on white tea volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo B.; Silveira, Ana Paula M.; Nunes, Thaise C.F.; Costa, Helbert S.F.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: gbfanaro@ipen.br; Purgatto, Eduardo [Universidade de Sao Paulo (USP), SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental

    2009-07-01

    Tea is the second most widely consumed beverages in the world and is processed from two and a bud of Camellia sinensis (L.). Depending on the processing may give rise to four mainly teas (green, black, oolong and white tea). The white tea is the one that has recently awakened interest in scientific community due the fact that this tea has more antioxidant property and activity than green tea. A further industrialization and commercialization of these plants become a problem of public health. The presence of potentially toxigenic fungi can be found in these products, indicating a great potential for the presence of mycotoxins that can cause acute and chronic effects in different organs and systems of the human body. Ionizing radiation is one of the most effective means disinfecting dry food ingredients. This treatment can inhibit cellular life division, like microorganisms, promoting a molecular structural modification. The aim of this study was evaluate the effects of radiation on volatile formation in white tea. Samples were irradiated in room temperature at {sup 60}Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20-kGy. The volatiles organic compound was extracted by hydrodistillation and the extract was separated and identified by gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the quantities of volatiles formations are directly proportional to the increase of radiation dose. About 37.86% of the compounds were stable at all radiation doses and 47.53% of new compounds were identified after irradiation. (author)

  17. Effects of γ-radiation on white tea volatiles

    International Nuclear Information System (INIS)

    Tea is the second most widely consumed beverages in the world and is processed from two and a bud of Camellia sinensis (L.). Depending on the processing may give rise to four mainly teas (green, black, oolong and white tea). The white tea is the one that has recently awakened interest in scientific community due the fact that this tea has more antioxidant property and activity than green tea. A further industrialization and commercialization of these plants become a problem of public health. The presence of potentially toxigenic fungi can be found in these products, indicating a great potential for the presence of mycotoxins that can cause acute and chronic effects in different organs and systems of the human body. Ionizing radiation is one of the most effective means disinfecting dry food ingredients. This treatment can inhibit cellular life division, like microorganisms, promoting a molecular structural modification. The aim of this study was evaluate the effects of radiation on volatile formation in white tea. Samples were irradiated in room temperature at 60Co source Gammacell 220 (A.E.C. Ltda) at doses of 0, 5, 10, 15 and 20-kGy. The volatiles organic compound was extracted by hydrodistillation and the extract was separated and identified by gas chromatography-mass spectrometry (GC-MS) analysis. The results show that the quantities of volatiles formations are directly proportional to the increase of radiation dose. About 37.86% of the compounds were stable at all radiation doses and 47.53% of new compounds were identified after irradiation. (author)

  18. Effects of microwave radiation on peripheral lymphocyte subpopulations in rats

    Directory of Open Access Journals (Sweden)

    Jin-ling YIN

    2011-10-01

    Full Text Available Objective To investigate the effects and mechanisms of microwave radiation on peripheral lymphocyte subpopulations in Wistar rats.Methods A total of 100 Wistar rats(180-220g were exposed to microwave with different average power densities of 5,10,30 and 60 mW/cm2,and sham exposure of 0mW/cm2 was performed in a control group at the same time.At day 1,7,14 and 28 after microwave irradiation,the changes in peripheral CD3+,CD4+,CD8+ T cells,ratio of CD4+/CD8+ and CD45RA+ B lymphocyte in rats were analyzed by flow cytometry(FCM.Results The CD3+ T cells decreased significantly in 10-30mW/cm2 groups at day 7 and in 5-30 mW/cm2 groups at day 14 after radiation as compared with control group(P < 0.05,and CD4+ T cells decreased significantly in 10mW/cm2 group at day 14 after radiation as compared with control group(P < 0.01.From day 1 to day 14 after radiation,CD8+ T cells showed a reduction in number in all irradiated groups when compared with the control,but statistical significance was only found in the 30mW/cm2 group(P < 0.05.The CD4+/CD8+ ratio increased in 5mW/cm2 group on day 1,while decreased significantly in 5-30mW/cm2 groups on day 14 after radiation as compared with control group(P < 0.05.After microwave exposure,however,CD45RA+ B cells in 30mW/cm2 group at day 1 and in 30-60mW/cm2 groups at day 14 after radiation increased significantly in a dose-dependent manner.Conclusion A definite dosage of microwave radiation,ranging from 5-60mW/cm2,may induce changes in subpopulations of peripheral lymphocytes and cause acute immune function impairment in rats.

  19. Radiation-induced stress effects following low dose exposure

    International Nuclear Information System (INIS)

    Complete text of publication follows. Recent advances in our understanding of effects of radiation on living cells suggest that fundamentally different mechanisms are operating at low doses compared with high doses. Also, acute low doses appear to involve different response mechanisms compared with chronic low doses. Both genomic instability and so called 'bystander effects' show many similarities with well known cellular responses to oxidative stress. These predominate following low dose exposures and are maximally expressed at doses as low as 5mGy. At the biological level this is not surprising. Chemical toxicity has been known for many years to show these patterns of dose response. Cell signaling and coordinated stress mechanisms appear to dominate acute low dose exposure to chemicals. Adaptation to chemical exposures is also well documented although mechanisms of adaptive responses are less clear. In the radiation field adaptive responses also become important when low doses are protracted or fractionated. Recent data from our group concerning bystander effects following multiple low dose exposures suggest that adaptive responses can be induced in cells which only receive signals from irradiated neighbours. We have data showing delayed and bystander effects in humans, rodents 3 fish species and in prawns following in vitro and/or in vivo irradiation of haematopoietic tissues and, from the aquatic groups, gill and skin/fin tissue. Bystander signals induced by radiation can be communicated from fish to fish in vivo and are detectable as early as the eyed egg stage, i.e. as soon as tissue starts to develop. Using proteomic approaches we have determined that the bystander and the direct irradiation proteomes are different. The former show significant upregulation of 5 proteins with anti-oxidant, regenerative and restorative functions while the direct radiation proteome has 2 upregulated proteins both involved in proliferation. These data have implications for

  20. Ionizing radiation: effects upon acquisition and performance of behavior

    International Nuclear Information System (INIS)

    The present study, using rats as subjects, attempted to assess the effects of multiple exposures to gamma radiation upon behavior in two procedures of a multiple schedule of repeated acquisition and performance. With an experimental chamber containing three levers displaced horizontally, left (l), center (c) and right (r), different levels of complexity were programmed for procedures A and B. In both procedures a new sequence of three responses was programmed for each session (lcr, lrc, clr, crl, rlc) for the acquisition component, whereas for the performance component the same sequence was maintained throughout the sessions. The completion of three sequences (nine responses) was followed by reinforcement and incorrect responses were followed by time-out without correction procedures. In procedure A the sequences consisted of one response in each lever (for example, crl→crl→crl→reinforcement) while in procedure B a sequence consisted of three response in the same lever, with the following three responses having to occur in a different lever (for example, ccc→rrr→lll→reinforcement). Six subjects were trained in each procedure. Base line data showed, by means of error percentage, that procedure B regardless of being more complex represented a lower difficulty level than procedure A: subjects in procedure B displayed, in general, a lower number of errors per session. After training in these procedures of repeated acquisition and performance, the subjects were exposed to doses of ionizing radiation of 3.0, 4.5, 6.0 and 8.0 Gy, with an interval of 45 days between exposures. With measurements of response rate and obtained reinforcers, the data showed a dose-response relation, with higher doses producing lower rates of responses and reinforcers. Percentage of errors was higher after doses of 6.0 and 8.0 Gy in the performance component, while changes in error patterns occurred in the acquisition component. The effects of radiation was more evident and orderly

  1. [Effects of laser radiation on the periodontium. An animal model approach. Effects of usual radiation dosage].

    Science.gov (United States)

    Noguerol Rodriguez, B; Alandez Chamorro, J; Cañizares Garcia, J; Campos Muñoz, A; Sicilia Felechosa, A

    1989-05-01

    Twenty four albino mice of forty days old were selected. Twelve forty days old albino mice were irradiated with a Helium-Neon laser source, dose of 10.50566 Jul/cm2. They were divided in two groups according to time of animal sacrifice (immediately after irradiation and ten days after). As control were used twelve mice using the same time as the experimental groups, but without radiation. T.E.M. ultrathin sections showed alteration only in the conjunctiva and in the bone tissues, but not in the epithelial tissue. The bone showed two osteocyte population according to their response to irradiation. The first population showed characteristic comparable with the controls, and the second showed alterations suggestive of a degenerative process. The connective tissue also showed two fibroblasts populations, the first showed signs of a big synthesizing activity, and the second, degenerative signs. The first fibroblast population appeared in the animals sacrificed immediately after irradiation. PMID:2637054

  2. [Effects of laser radiation on the periodontium. An animal model approach. Effects of usual radiation dosage].

    Science.gov (United States)

    Noguerol Rodriguez, B; Alandez Chamorro, J; Cañizares Garcia, J; Campos Muñoz, A; Sicilia Felechosa, A

    1989-05-01

    Twenty four albino mice of forty days old were selected. Twelve forty days old albino mice were irradiated with a Helium-Neon laser source, dose of 10.50566 Jul/cm2. They were divided in two groups according to time of animal sacrifice (immediately after irradiation and ten days after). As control were used twelve mice using the same time as the experimental groups, but without radiation. T.E.M. ultrathin sections showed alteration only in the conjunctiva and in the bone tissues, but not in the epithelial tissue. The bone showed two osteocyte population according to their response to irradiation. The first population showed characteristic comparable with the controls, and the second showed alterations suggestive of a degenerative process. The connective tissue also showed two fibroblasts populations, the first showed signs of a big synthesizing activity, and the second, degenerative signs. The first fibroblast population appeared in the animals sacrificed immediately after irradiation.

  3. Genetics and ionizing radiations. 2. The genetic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Ionizing radiations are the best known mutagenic agents. Their relative importance as compared to other mutagens cannot be determined. Experiments show that male germinal cells are more sensitive than female germinal cells. This sensitivity is determined by the cell phase at the time of agression. Acute X-exposure results in a mutation rate of about 1.7x10-7 rad-1 per gamete and per gene in the male. This rate is lower in case of chronic exposure. Pathological effects will appear in the first (dominant genes, and unbalanced chromosomal anomalies) or n-th generation (recessive genes and balanced chromosomal rearrangements). Direct studies on humans have brought contradictory results. Only X or γ-emitters induce a true genetic risk, the other radiations being too little penetrating to reach the gonads. The doubling dose of the mutation rate is estimated at over 100 rad in males and over 1,000 rad in females. However, one cannot conclude that low doses are not harmless because their effects are difficult to demonstrate. The individual risk, that remains low, must be distinguished from the collective risk for which the safeguard of the quality of the genetic material of our species must remain our prime purpose

  4. Delayed effects of external radiation exposure: A brief history

    International Nuclear Information System (INIS)

    Within months of Roentgen's discovery of X rays, severe adverse effects were reported, but not well publicized. As a result, over the next two decades, fluoroscope operators suffered lethal skin carcinomas. Later, case reports appeared concerning leukemia in radiation workers, and infants born with severe mental retardation after their mothers had been given pelvic radiotherapy early in pregnancy. Fluoroscopy and radiotherapy for benign disorders continued to be used with abandon until authoritative reports were published on the adverse effects of ionizing radiation by the U.S. NAS-NRC and the UK MRC in 1956. Meanwhile, exposure to the atomic bombs in Japan had occurred and epidemics of delayed effects began to be recognized among the survivors: cataracts, leukemia and severe mental retardation among newborn infants after intra-uterine exposure. No statistically significant excess of germ-cell genetic effects was detected by six clinical measurements, the F1 mortality, cytogenetic studies or biochemical genetic studies. Somatic cell effects were revealed by long-lasting chromosomal aberrations in peripheral lymphocytes, and somatic cell mutations were found at the glycophorin A locus in erythrocytes. Molecular biology is a likely focus of new studies based on the function of the gene for ataxia telangiectasia, a disorder in which children have severe, even lethal acute radiation reactions when given conventional doses of radiotherapy for lymphoma, to which they are prone. The tumor registries in Hiroshima and Nagasaki now provide incidence data that show the extent of increases in eight common cancers and no increase in eight others. The possibility of very late effects of A-bomb exposure is suggested by recent reports of increased frequencies of hyperparathyroidism, parathyroid cancers and certain causes of death other than cancer. 88 refs., 1 fig

  5. Radiation-induced bystander effects in vivo are sex specific

    Energy Technology Data Exchange (ETDEWEB)

    Koturbash, Igor; Kutanzi, Kristy; Hendrickson, Karl; Rodriguez-Juarez, Rocio; Kogosov, Dmitry [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada); Kovalchuk, Olga [Department of Biological Sciences, University of Lethbridge, Alberta T1K 3M4 (Canada)], E-mail: olga.kovalchuk@uleth.ca

    2008-07-03

    Ionizing radiation (IR) effects span beyond the area of direct exposure and can be observed in neighboring and distant naive cells and organs. This phenomenon is termed a 'bystander effect'. IR effects in directly exposed tissue in vivo are epigenetically mediated and distinct in males and females. Yet, IR-induced bystander effects have never been explored in a sex-specificity domain. We used an in vivo mouse model, whereby the bystander effects are studied in spleen of male and female animals subjected to head exposure when the rest of the body is protected by a medical-grade lead shield. We analyzed the induction of DNA damage and alterations in global DNA methylation. Molecular parameters were correlated with cellular proliferation and apoptosis levels. The changes observed in bystander organs are compared to the changes in unexposed animals and animals exposed to predicted and measured scatter doses. We have found the selective induction of DNA damage levels, global DNA methylation, cell proliferation and apoptosis in exposed and bystander spleen tissue of male and female mice. Sex differences were significantly diminished in animals subjected to a surgical removal of gonads. These data constitute the first evidence of sex differences in radiation-induced bystander effects in mouse spleen in vivo. We show the role of sex hormones in spleen bystander responses and discuss implications of the observed changes.

  6. Study on the radiation effect of polyether-urethane in the γ radiation field

    International Nuclear Information System (INIS)

    Polyether-urethane (ETPU) is made up of hard and soft sections. The hard section which is mainly in crystalline state is carbamate, and soft section which is in amorphous state is polyether. Reference reports in detail the degradation of polyurethane deduced by thermal oxidation. The result shows that the thermal degradation begins with the caramate group. The polyalcohol is the weak point of polyurethane degradation in the presence of oxygen. Similarly, the anti-radiation of carbamate (hard section) is superior to that of polyether (soft section) In our former work, we have discussed the degradation of ETPU foam deduced by electron beam. And we have studied the composition and yields of gas products from the radiation degradation, and the changes of the thermal property, micro-phase separation and the microscopic form of irradiated samples. In this article, the radiation effect of γ-ray on polyether-urethane foam was studied. The gas products from irradiated samples were analyzed quantitatively and qualitatively by gas chromatography. Compared with the standard gas, the gas products are H2, CO2, CH4, C2H6 and so on. Among these gases, the gas yield of CO2 is the most, that of H2 is less, and those of CH4 and C2H6 are the least. The yields of different sorts of gases increase with the dose raising. Furthermore, the radiation degradation of the sample is the most serious in the oxygen atmosphere, less in air, and the least in vacuum. ESR of ETPU sample irradiated by γ ray in vacuum is shown in figurel, which is determined at the room temperature, and ESR of polyester-urethane (ESPU) irradiated by UV light is shown in figure 2. It can be seen from these two figures that the spectral shape is different. The radical peak in the sample irradiated by UV light is symmetrical, which indicates that there is only one sort of radical; but that is not the truth to the sample irradiated by gamma ray for its asymmetrical radical peak. According to the results of FTIR, GC and

  7. Early effects of selenium preparation on radiation pneumonia

    International Nuclear Information System (INIS)

    In order to provide experimental basis for drug efficacy of preventing and treating radiation pneumonia, the authors observed the early effects of selenium preparation on the radiation pneumonia. Wistar male rats were divided into three groups of 48 rats: the control group, the irradiated group and the irradiated plus selenium preparation treated group. The animals received thoracic irradiation of 15 Gy, and were killed at 0.5, 1,2,3 months post irradiation. Lung tissues were processed for light microscopy and isolation of RNA. Expression of type I(III) collagen was evaluated by dot-blot hybridization and image analysis technique. Pathological study showed marked lung injury in the irradiated group while only slight hyperemia, hemorrhage, exudation and thickness of alveolar walls in the lungs of selenium preparation-treated group. The synthesis of type I and III collagen mRNA also decreased in the selenium preparation-treated group. Selenium preparation could have protective and therapeutic effects on radiation pneumonia

  8. Mitochondrial mutagenesis induced by tumor-specific radiation bystander effects.

    LENUS (Irish Health Repository)

    Gorman, Sheeona

    2012-02-01

    The radiation bystander effect is a cellular process whereby cells not directly exposed to radiation display cellular alterations similar to directly irradiated cells. Cellular targets including mitochondria have been postulated to play a significant role in this process. In this study, we utilized the Random Mutation Capture assay to quantify the levels of random mutations and deletions in the mitochondrial genome of bystander cells. A significant increase in the frequency of random mitochondrial mutations was found at 24 h in bystander cells exposed to conditioned media from irradiated tumor explants (p = 0.018). CG:TA mutations were the most abundant lesion induced. A transient increase in the frequency of random mitochondrial deletions was also detected in bystander cells exposed to conditioned media from tumor but not normal tissue at 24 h (p = 0.028). The increase in both point mutations and deletions was transient and not detected at 72 h. To further investigate mitochondrial dysfunction, mitochondrial membrane potential and reactive oxygen species were assessed in these bystander cells. There was a significant reduction in mitochondrial membrane potential and this was positively associated with the frequency of random point mutation and deletions in bystander cells treated with conditioned media from tumor tissue (r = 0.71, p = 0.02). This study has shown that mitochondrial genome alterations are an acute consequence of the radiation bystander effect secondary to mitochondrial dysfunction and suggests that this cannot be solely attributable to changes in ROS levels alone.

  9. Modeling of radiation effects on nuclear waste package materials

    International Nuclear Information System (INIS)

    A methodology is developed for the assessment of radiation effects on nuclear waste package materials. An assessment of the current status of understanding with regard to waste package materials and their behavior in radiation environments is presented. The methodology is used to make prediction as to the chemically induced changes in the groundwater surrounding nuclear waste packages in a repository in tuff. The predictions indicate that mechanisms not currently being pursued by the Department of Energy may be a factor in the long-term performance of nuclear waste packages. The methodology embodies a physical model of the effects of radiation on aqueous solutions. Coupled to the physical model is a method for analyzing the complex nature of the physical model using adjoint sensitivity analysis. The sensitivity aid in both the physical understanding of the processes involved as well as aiding in eliminating portions of the model that have no bearing on the desired results. A computer implementation of the methodology is provided. 128 refs

  10. Radiation protection effect by the combination of propolis and agaricus

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Yeunhwa; Yamada, Katsunori; Ukawa, Yuuichi [Suzuka Univ. of Medical Science, Suzuka (Japan)] [and others

    2002-07-01

    The aims of the radioprotection are a human and the safety keeping of the environment. The leukocyte that much research is to do in the animals, and relations between the lymphocyte and the radiation are being made distinct until now. It paid attention to it in this determination stage, and lymphocyte toward the radiation was observed by using the ICR mice used for the lymphocyte simulation abundantly in this research. And, it was examined about the fetal effect toward the radiation. So, an excuse as a radioprotective agent of the effect on the fetus toward the radiation was examined experimentally by using the propolis and agaricus by this research. Therefore, it is a purpose to obtain information as a medicament of the radioprotection. ICR mice were used for the experiment. The pregnant mice were placed in plastic cages for radiation exposure, and were treated with a single whole-body X -radiation at 1 Gy and 2Gy with a dose rate of 35 cGy/min on 8 days after the conception. 100 mg/kg of propolis and agaricus. The total number of irradiated dams observed in this study was 40, a total of 38 non-irradiated control and sham control dams was also prepared, and 659 non-irradiated live fetuses served as controls. Statistical significant difference was recognized between the lymphocyte of the 1.0Gy and 2.0Gy group and the 1.0Gy and 2.0Gy + propolis and agaricus extracts of water solution administrated group toward the lymphocyte and embryonic death of control group and sham control group (p<0.01). But, when it was compared with the lymphocyte and embryonic death rate of the 1.0Gy and 2.0Gy group and the 1.0Gy and 2.0Gy + Propolis and agaricus group, the lymphocyte rate of the 1.0Gy and 2.0Gy + Propolis and agaricus group was decrease. And, if propolis and agaricus was administered, the embryo beyond the haploid number that did implantation was found out in the exposure beyond 1.0Gy or 2.0Gy.

  11. RADIATION EFFECT ON FLUORINATED SiO2 FILMS

    Institute of Scientific and Technical Information of China (English)

    张国强; 严荣良; 等

    1994-01-01

    A systematic investigation of γ radiation effects in gate SiO2 as a function of the fluorine ion implantation conditions was performed.It has been found that the generation of interface states and oxide trapped charges in fluorinated MOSFETs depends strongly on implantation conditions.The action of F in oxides is the conjunction of positive and negative effects.A model by forming Si-F bonds to substitute the other strained bonds which easily become charge traps under irradiation and to relax the bond stress on Si/SiO2 interface is used for experimental explanation.

  12. Effect of endotoxin on radiation syndrome - a review

    International Nuclear Information System (INIS)

    A review is given of studies on the effect of endotoxin on postirradiation syndrome. Recent knowledge is summed up on the compositions of endotoxins and on their general biological effects. Endotoxins of different bacteria are discussed such as are utilized for favourably affecting the postirradiation syndrome. For each bacterium the classification is shown in the microbe system. This, however, is not standard in the literature. General assessment is made of studies published so far on radiation protection of organisms with endotoxins. (B.S.)

  13. Tradescantia in studies of genetic effects of low level radiation

    International Nuclear Information System (INIS)

    Tradescantia in studies on genetic effects of low level radiation is briefly introduced. Radiosensitivity, method of screening stamen hair mutation, materials in current uses, spontaneous mutation rate, and modifying factors are refered. For stamen hair mutation b values in exponential model were lower in irradiation with low dose rate at high environmental temperature. The dose response curves under these modifying conditions, when extrapolated to low dose range, well fit to the line which was obtained by Sparrow's experiment of low level irradiation. In chronic irradiation, the frequency of stamen hair mutation reaches to the constant value after 17 days from the start of irradiation, and is as much as 4 times higher than the peak value in one day irradiation at the same exposure rate. The spontaneous mutation rate of KU-7 varied with temperature. The increase with 10C increment of mean temperature was -0.04%. Uses of Tradescantia in monitoring the environmental radiation is discussed. (auth.)

  14. Gamma radiation effects on molecular characteristic of vegetable tannins

    International Nuclear Information System (INIS)

    The influence of gamma radiation on tannins extracted from Pinus caribaea bark and on tannin acid has been investigated in this study with the aim of searching for evidences of structural and/or conformational changes. To fulfill this purpose, the samples of tannins, such as tannic acid and P. caribaea tannin bark, were irradiated at different doses (from 5 to 35 kGy) using a cobalt-60 gamma irradiator. The changes were analyzed by a Fourier transform infrared spectrometry and by high resolution liquid chromatography. The results pointed out some structural and conformational changes under the effects of gamma radiation for doses higher than 5 kGy for P. caribaea tannin bark. However, no changes were detected on the irradiated tannic acid. The observed behavior suggests the loss of carbonyl groups. This could be associated to a decarboxylation process with the corresponding release of CO2 from the molecule. Evidences of some conformational changes were also noted. (author)

  15. Ionizing radiation effects in MgAl2O4

    International Nuclear Information System (INIS)

    The effect of ionizing radiation in MgAl2O4 has been studied, paying special interest to the influence of the high concentration of intrinsic dsefects of this material. Optical absorption, ESR, photoluminiscence, radioluminiscence, and thermoluminiscence are the main techniques used. The ionizing radiation induces to formation of V centres. During the work its characteristics (structure, thermal stability, absorption spectra, etc.) has been studied. The thermoluminiscence spectra allowed the discovery of several charge release processes between 85 and 650 K, all of them associated to electron release. The V-centres and several impurities (Cr, Mn,...) appear as recombination centres. The obtained data show that the kinetic of these charge release processes is regulated by the presence of a point defect with a very high concentration. This defect is an electron trap and its structure is an Al ion in a lattice site of tetraedral symmetry. (Author)

  16. Effects of low doses of radiation on crop plants

    International Nuclear Information System (INIS)

    Claims for radiation-induced growth stimulations in plants have been made, starting almost from the time of the discovery of X-rays. However, there is general disagreement on this question, since the numerous studies designed to prove or disprove the existence of the phenomenon have produced inconclusively and erratic results. It is obvious that small, but significant, growth increases may be produced at times by ionizing radiations in certain crop plants, but such increases have not always been reproducible from one experiment to another, and marked inconsistencies often occur with regard to the optimal exposures to produce such effects. The purpose of the FAO/IAEA Panel meeting held in Rome on 1 June, 1964, was to review and evaluate the experimental results in this area and applications for increasing crop yields. Refs, figs and tabs

  17. Non-targeted effects of ionising radiation and radiotherapy.

    Science.gov (United States)

    Sjostedt, Svetlana; Bezak, Eva

    2010-09-01

    Modern radiobiology is undergoing rapid change due to new discoveries contradicting the target concept which is currently used to predict dose-response relationships. Thus relatively recently discovered radiation-induced bystander effects (RIBEs), that include additional death, mutation and radio-adaptation in non-irradiated cells, change our understanding of the target concept and broadens its boundaries. This can be significant from a radioprotection point of view and also has the potential to reassess radiation damage models currently used in radiotherapy. This article reviews briefly the general concepts of RIBEs such as the proposed underlying mechanisms of signal induction and propagation, experimental approaches and biological end points used to investigate these phenomena. It also summarises several mathematical models currently proposed in an attempt to quantify RIBE. The main emphasis of this article is to review and highlight the potential impact of the bystander phenomena in radiotherapy. PMID:20857259

  18. Activities and future plans of the radiation effects research foundation

    Energy Technology Data Exchange (ETDEWEB)

    Nagataki, Shigenobu [Radiation Effects Research Foundation, Hiroshima (Japan)

    2000-05-01

    The Radiation Effects Research Foundation (RERF) was established in 1975 as a binational research foundation supported by Japan and the United States. It continues the work of the Atomic Bomb Casualty Commission (ABCC) which was established in 1974. ABCC-RERF studies focus on several fixed cohorts of survivors and their children: the Life Span Study (LSS) cohort (120,000 survivors); the In-Utero cohort (3,300 people born within 9 months of the bombings); the F{sub 1} cohort (88,000 people born between mid-1946 and 1984), and the Adult Health Study (AHS) cohort (an ongoing clinical study of 17,000 LSS survivors and 1,100 people exposed in-utero). Epidemiological data have shown increased risks of leukemia and solid cancers by radiation exposure among the survivors. Excess leukemia risks, especially for children, were markedly elevated 5 to 10 years after exposure and have continued at reduced levels. Excess solid cancer rates became apparent within 10 years after exposure, increasing throughout life in rough proportion to background rates. For doses of interest in radiation protection excess leukemia risks exhibit an upward curving dose response pattern while the solid cancer excess appears to be linear by dose with no apparent threshold. In addition to malignancy, AHS data has shown dose-related increased risk for various non-malignant diseases; radiation cataracts, benign tumors of uterus, thyroid and parathyroid (hyperparathyroidism), and autoimmune thyroid diseases. Persons exposed in-utero exhibit a broad range of dose-related effects including delayed growth and development and higher rates of microcephaly. Studies of birth defects, chromosome aberrations, childhood mortality, and genetic variants of serum or erythrocyte proteins have provided no indication of heritable mutations in the F{sub 1} cohort. Continued follow-up of survivors exposed as children (90% are still alive) is essential to understanding the temporal pattern of excess risks and lifetime

  19. Multi-dimensional effects in radiation pressure acceleration of ions

    International Nuclear Information System (INIS)

    A laser carries momentum. On reflection from an ultra-thin overdense plasma foil, it deposits recoil momentum on the foil, i.e. exerts radiation pressure on the foil electrons and pushes them to the rear. The space charge field thus created takes the ions along, accelerating the electron-ion double layer as a single unit. When the foil has surface ripple, of wavelength comparable to laser wavelength, the radiation pressure acts non-uniformly on the foil and the perturbation grows as Reyleigh-Taylor (RT) instability as the foil moves. The finite spot size of the laser causes foil to bend. These effects limit the quasi-mono energy acceleration of ions. Multi-ion foils, e.g., diamond like carbon foil embedded with protons offer the possibility of suppressing RT instability

  20. Impacts of emission reductions on aerosol radiative effects

    Science.gov (United States)

    Pietikainen, J.-P.; Kupiainen, K.; Klimont, Z.; Makkonen, R.; Korhonen, H.; Karinkanta, R.; Hyvarinen, A.-P.; Karvosenoja, N.; Laaksonen, A.; Lihavainen, H.; Kerminen, V.-M.

    2015-05-01

    The global aerosol-climate model ECHAM-HAMMOZ was used to investigate changes in the aerosol burden and aerosol radiative effects in the coming decades. Four different emissions scenarios were applied for 2030 (two of them applied also for 2020) and the results were compared against the reference year 2005. Two of the scenarios are based on current legislation reductions: one shows the maximum potential of reductions that can be achieved by technical measures, and the other is targeted to short-lived climate forcers (SLCFs). We have analyzed the results in terms of global means and additionally focused on eight subregions. Based on our results, aerosol burdens show an overall decreasing trend as they basically follow the changes in primary and precursor emissions. However, in some locations, such as India, the burdens could increase significantly. The declining emissions have an impact on the clear-sky direct aerosol effect (DRE), i.e. the cooling effect. The DRE could decrease globally 0.06-0.4 W m-2 by 2030 with some regional increases, for example, over India (up to 0.84 W m-2). The global changes in the DRE depend on the scenario and are smallest in the targeted SLCF simulation. The aerosol indirect radiative effect could decline 0.25-0.82 W m-2 by 2030. This decrease takes place mostly over the oceans, whereas the DRE changes are greatest over the continents. Our results show that targeted emission reduction measures can be a much better choice for the climate than overall high reductions globally. Our simulations also suggest that more than half of the near-future forcing change is due to the radiative effects associated with aerosol-cloud interactions.

  1. Impacts of emission reductions on aerosol radiative effects

    Directory of Open Access Journals (Sweden)

    J.-P. Pietikäinen

    2015-05-01

    Full Text Available The global aerosol–climate model ECHAM-HAMMOZ was used to investigate changes in the aerosol burden and aerosol radiative effects in the coming decades. Four different emissions scenarios were applied for 2030 (two of them applied also for 2020 and the results were compared against the reference year 2005. Two of the scenarios are based on current legislation reductions: one shows the maximum potential of reductions that can be achieved by technical measures, and the other is targeted to short-lived climate forcers (SLCFs. We have analyzed the results in terms of global means and additionally focused on eight subregions. Based on our results, aerosol burdens show an overall decreasing trend as they basically follow the changes in primary and precursor emissions. However, in some locations, such as India, the burdens could increase significantly. The declining emissions have an impact on the clear-sky direct aerosol effect (DRE, i.e. the cooling effect. The DRE could decrease globally 0.06–0.4 W m−2 by 2030 with some regional increases, for example, over India (up to 0.84 W m−2. The global changes in the DRE depend on the scenario and are smallest in the targeted SLCF simulation. The aerosol indirect radiative effect could decline 0.25–0.82 W m−2 by 2030. This decrease takes place mostly over the oceans, whereas the DRE changes are greatest over the continents. Our results show that targeted emission reduction measures can be a much better choice for the climate than overall high reductions globally. Our simulations also suggest that more than half of the near-future forcing change is due to the radiative effects associated with aerosol–cloud interactions.

  2. Effects of lactic bacteria on immunological activation and radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Monzen, Hajime; Yuki, Rumio [Otsu Red Cross Hospital, Shiga (Japan); Gu, Yeunhwa; Hasegawa, Takeo [Suzuka Univ. of Medical Science, Mie (Japan). Graduate School

    2003-03-01

    Although some studies have suggested that certain substances, such as vitamins and glucan, found in natural food products may have protective effect against radiation injuries, no substance is used practically as radioprotectors. Safe radioprotectors without side effects are, however, yet to see. Enterococcus faecalis (Ef) in intestines is known to enhance immunity of the host as a biological response modifier. In this report, we have examined the radiation protection effect of Ef using C3H mice and assessed the effect of Ef on the natural killer (NK) cells activity of the splenic cells in the mice. Less body weight losses after irradiation were observed among Ef injection groups, in comparison with control groups. Our data showed a strong tendency to prolong the surviving fraction among the groups with the Ef injection. Hence, the Ef treatment appeared to have protected mucosal damage caused by the X-ray irradiation. The NK cells activities were markedly enhanced after the Ef injection as well. With the evidence mentioned above, we conclude that the Ef may have positive effect on patients who undergo a radiotherapy. (author)

  3. Investigations of the effects of UV and X-ray radiation and the repair of radiation damage in the ciliate Stylonychia mytilus

    International Nuclear Information System (INIS)

    Using the example of Stylomychia mytilus, the effects of UV-radiation and ionizing X-ray radiation are compared. The effects on cell division and on the repair of radiation damage in DNA are compared. Sensitivity to UV radiation differs between the stages of the cell cycle while the effects of X-ray radiation are independent of phase. There is no difference in repair processes. (AJ) 891 AJ/AJ 892 MKO

  4. Modeling and simulation of ionizing radiation effect on ferroelectric field-effect transistor

    Science.gov (United States)

    Yan, Shaoan; Li, Gang; Guo, Hongxia; Zhao, Wen; Xiong, Ying; Tang, Minghua; Li, Zheng; Xiao, Yongguang; Zhang, Wanli; Lei, Zhifeng

    2016-04-01

    A theoretical model is developed to investigate the ionizing radiation effect on electrical characteristics of a metal-ferroelectric-insulator-semiconductor structure ferroelectric gate field-effect transistor (MFIS FeFET). Modeling results show that gate capacitance versus gate voltage curves and transfer characteristic curves shift significantly and the memory window becomes worse with the total dose. Moreover, the drain current and I ON/I OFF ratio exhibit a considerable decrease under high incident dose rates. Finally, it is found that radiation-induced degradations can be affected strongly by the insulator layer thickness, and that MFIS FeFETs with a thin insulator buffer layer show a high radiation tolerance.

  5. Aerosol properties and associated radiative effects over Cairo (Egypt)

    Science.gov (United States)

    El-Metwally, M.; Alfaro, S. C.; Wahab, M. M. Abdel; Favez, O.; Mohamed, Z.; Chatenet, B.

    2011-02-01

    Cairo is one of the largest megacities in the World and the particle load of its atmosphere is known to be particularly important. In this work we aim at assessing the temporal variability of the aerosol's characteristics and the magnitude of its impacts on the transfer of solar radiation. For this we use the level 2 quality assured products obtained by inversion of the instantaneous AERONET sunphotometer measurements performed in Cairo during the Cairo Aerosol CHaracterization Experiment (CACHE), which lasted from the end of October 2004 to the end of March 2006. The analysis of the temporal variation of the aerosol's optical depth (AOD) and spectral dependence suggests that the aerosol is generally a mixture of at least 3 main components differing in composition and size. This is confirmed by the detailed analysis of the monthly-averaged size distributions and associated optical properties (single scattering albedo and asymmetry parameter). The components of the aerosol are found to be 1) a highly absorbing background aerosol produced by daily activities (traffic, industry), 2) an additional, 'pollution' component produced by the burning of agricultural wastes in the Nile delta, and 3) a coarse desert dust component. In July, an enhancement of the accumulation mode is observed due to the atmospheric stability favoring its building up and possibly to secondary aerosols being produced by active photochemistry. More generally, the time variability of the aerosol's characteristics is due to the combined effects of meteorological factors and seasonal production processes. Because of the large values of the AOD achieved during the desert dust and biomass burning episodes, the instantaneous aerosol radiative forcing (RF) at both the top (TOA) and bottom (BOA) of the atmosphere is maximal during these events. For instance, during the desert dust storm of April 8, 2005 RF BOA, RF TOA, and the corresponding atmospheric heating rate peaked at - 161.7 W/m 2, - 65.8 W/m 2

  6. Effects of radiation reaction in the interaction between cluster media and high intensity lasers in the radiation dominant regime

    Science.gov (United States)

    Iwata, Natsumi; Nagatomo, Hideo; Fukuda, Yuji; Matsui, Ryutaro; Kishimoto, Yasuaki

    2016-06-01

    Interaction between media composed of clusters and high intensity lasers in the radiation dominant regime, i.e., intensity of 10 22 - 23 W / cm 2 , is studied based on the particle-in-cell simulation that includes the radiation reaction. By introducing target materials that have the same total mass but different internal structures, i.e., uniform plasma and cluster media with different cluster radii, we investigate the effect of the internal structure on the interaction dynamics, high energy radiation emission, and its reaction. Intense radiation emission is found in the cluster media where electrons exhibit non-ballistic motions suffering from strong accelerations by both the penetrated laser field and charge separation field of clusters. As a result, the clustered structure increases the energy conversion into high energy radiations significantly at the expense of the conversion into particles, while the total absorption rate into radiation and particles remains unchanged from the absorption rate into particles in the case without radiation reaction. The maximum ion energy achieved in the interaction with cluster media is found to be decreased through the radiation reaction to electrons into the same level with that achieved in the interaction with the uniform plasma. The clustered structure thus enhances high energy radiation emission rather than the ion acceleration in the considered intensity regime.

  7. Significance of radiation effects in solid radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Permar, P H; McDonell, W R

    1980-01-01

    Proposed NRC criteria for disposal of high-level nuclear waste require development of waste packages to contain radionuclide for at least 1000 years, and design of repositories to prevent radionuclide release at an annual rate greater than 1 part in 100,000 of the total activity. The high-level wastes that are now temporarily stored as aqueous salts, sludges, and calcines must be converted to high-integrity solid forms that resist deterioration from radiation and other effects of long-term storage. Spent fuel may be encapsulated for similar long-term storage. Candidate waste forms beside the spent fuel elements themselves, include borosilicate and related glasses, mineral-like crystalline ceramics, concrete formulations, and metal-matrix glass or ceramic composites. these waste forms will sustain damage produced by beta-gamma radiation up to 10/sup 12/ rads, by alpha radiation up to 10/sup 19/ particles/g, by internal helium generation greater than about 0.1 atom percent, and by the atom transmutations accompanying radioactive decay. Current data indicate that under these conditions the glass forms suffer only minor volume changes, stored energy deposition, and leachability effects. The crystalline ceramics appear susceptible to the potentially more severe alterations accompanying metamictization and natural analogs of candidate materials are being examined to establish their suitability as waste forms. Helium concentrations in the waste forms are generally below thresholds for severe damage in either glass or crystalline ceramics at low temperatures, but microstructural effects are not well characterized. Transmutation effects remain to be established.

  8. Dosimetry for quantitative analysis of low dose ionizing radiation effects on humans in radiation therapy patients

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, J; Stern, R L; Daly, T P; Schwieter, C W; Jones, G E; Arnold, M L; Hartmann-Siantar, C L; Goldberg, Z

    2004-04-20

    We have successfully developed a practical approach to predicting the location of skin surface dose at potential biopsy sites that receive 1 cGy and 10 cGy, respectively, in support of in vivo biologic dosimetry in humans. This represents a significant technical challenge as the sites lie on the patient surface out side the radiation fields. The PEREGRINE Monte Carlo simulation system was used to model radiation dose delivery and TLDs were used for validation on a phantom and confirmation during patient treatment. In the developmental studies the Monte Carlo simulations consistently underestimated the dose at the biopsy site by approximately 15% for a realistic treatment configuration, most likely due to lack of detail in the simulation of the linear accelerator outside the main beam line. Using a single, thickness-independent correction factor for the clinical calculations, the average of 36 measurements for the predicted 1 cGy point was 0.985 cGy (standard deviation: 0.110 cGy) despite patient breathing motion and other real world challenges. Since the 10 cGy point is situated in the region of high dose gradient at the edge of the field, patient motion had a greater effect and the six measured points averaged 5.90 cGy (standard deviation: 1.01 cGy), a difference that is equivalent to approximately a 6 mm shift on the patient's surface.

  9. Dosimetry for quantitative analysis of low dose ionizing radiation effects on humans in radiation therapy patients

    International Nuclear Information System (INIS)

    We have successfully developed a practical approach to predicting the location of skin surface dose at potential biopsy sites that receive 1 cGy and 10 cGy, respectively, in support of in vivo biologic dosimetry in humans. This represents a significant technical challenge as the sites lie on the patient surface out side the radiation fields. The PEREGRINE Monte Carlo simulation system was used to model radiation dose delivery and TLDs were used for validation on a phantom and confirmation during patient treatment. In the developmental studies the Monte Carlo simulations consistently underestimated the dose at the biopsy site by approximately 15% for a realistic treatment configuration, most likely due to lack of detail in the simulation of the linear accelerator outside the main beam line. Using a single, thickness-independent correction factor for the clinical calculations, the average of 36 measurements for the predicted 1 cGy point was 0.985 cGy (standard deviation: 0.110 cGy) despite patient breathing motion and other real world challenges. Since the 10 cGy point is situated in the region of high dose gradient at the edge of the field, patient motion had a greater effect and the six measured points averaged 5.90 cGy (standard deviation: 1.01 cGy), a difference that is equivalent to approximately a 6 mm shift on the patient's surface

  10. Effects of Radiation Exposure From Cardiac Imaging: How Good Are the Data?

    OpenAIRE

    Einstein, Andrew J.

    2012-01-01

    Concerns about medical exposure to ionizing radiation have become heightened in recent years due to rapid growth in procedure volumes and the high radiation doses incurred from some procedures. This article summarizes the evidence base undergirding concerns about radiation exposure in cardiac imaging. After classifying radiation effects, explaining terminology used to quantify the radiation received by patients, and describing typical doses from cardiac imaging procedures, I address the major...

  11. Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice

    OpenAIRE

    Choi, Yu-Jin; Choi, Yun-Sik

    2015-01-01

    Objectives Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Methods Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spat...

  12. Non-Riemannian effective spacetime effects on Hawking radiation in superfluids

    CERN Document Server

    Garcia de Andrade, L C

    2005-01-01

    Riemannian effective spacetime description of Hawking radiation in $^{3}He-A$ superfluids is extended to non-Riemannian effective spacetime. An example is given of non-Riemannian effective geometry of the rotational motion of the superfluid vacuum around the vortex where the effective spacetime Cartan torsion can be associated to the Hawking giving rise to a physical interpretation of effective torsion recently introduced in the literature in the form of an acoustic torsion in superfluid $^{4}He$ (PRD-70(2004),064004). Curvature and torsion singularities of this $^{3}He-A$ fermionic superfluid are investigated. This Lense-Thirring effective metric, representing the superfluid vacuum in rotational motion, is shown not support Hawking radiation when the isotropic $^{4}He$ is restored at far distances from the vortex axis. Hawking radiation can be expressed also in topological solitons (moving domain walls) in fermionic superfluids in non-Riemannian (teleparallel) $(1+1)$ dimensional effective spacetime. A telep...

  13. Effect of radiation exerted to creep rate of resin

    International Nuclear Information System (INIS)

    One of the high performance composite materials which became to be manufactured by the progress of working techniques and the improvement of material performance is fiber-reinforced plastics (FRP). Carbon fiber-reinforced plastics (CFRP) are used as space and aircraft material, and glass fiber-reinforced plastics (GFRP) are expected as the structural material for superconducting magnets in nuclear fusion. In these materials, the use for long term must be considered, and the creep characteristics, of resin should be taken as one of the design factors. Therefore, the effect that radiation exerted to the stress relaxation of epoxy resin was measured, and its mechanism was investigated. The sample was bisphenol F system epoxy. The measurements of DSC, dynamic viscoelasticity and stress relaxation were carried out. The stress relaxation in bisphenol F system epoxy resin occurred down to 10 % of the initial stress only at 3 MGy. This is the dose far lower than the life in the radiation resistance of this resin. It is considered that the stress relaxation of the resin was caused by the change in molecular structure instead of the cut of molecular chain, as energy was given to the microscopic region by the interaction with radiation. (K.I.)

  14. Radiation effects on life span in Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, T.E.; Hartman, P.S.

    1988-09-01

    Wild-type and radiation-sensitive (Rad) mutants of Caenorhabditis elegans were irradiated using a /sup 137/Cs source (2.7 krads/min.) at several developmental stages and subsequently monitored for life span. Acute doses of radiation ranged from 1 krad to 300 krads. All stages required doses above 100 krads to reduce mean life span. Dauers and third stage larvae were more sensitive, and 8-day-old adults were the most resistant. Occasional statistically significant but nonrepeatable increases in survival were observed after intermediate levels of irradiation (10-30 krads). Unirradiated rad-4 and rad-7 had life spans similar to wild-type; all others had a significant reduction in survival. The mutants were about as sensitive as wild-type to the effects of ionizing radiation including occasional moderate life span extensions at intermediate doses. We conclude that the moderate life span extensions sometimes observed after irradiation are likely to be mediated by a means other than the induction of DNA repair enzymes.

  15. Effects of very high radiation on SiPMs

    Science.gov (United States)

    Heering, A.; Musienko, Yu; Ruchti, R.; Wayne, M.; Karneyeu, A.; Postoev, V.

    2016-07-01

    During the last 5 years we have successfully completed R&D for the instrumentation of silicon photo multipliers (SiPMs) for the CMS HCAL Phase 1 upgrade in 2018. Much focus was put on radiation damage during these years. For the HCAL we expect a maximum total dose of 1012 n/cm2 for a total lifetime integrated luminosity of 3000 fb-1. Good correlation between cell size and performance with high radiation was found during this R&D. To evaluate the possibility of using the SiPMs in the wider CMS environment we have exposed the current state of the art smallest cell SiPMs to radiation of 6×1012 p/cm2 in 62 MeV LIF beam line in 2014 at UCL Belgium and up to 1.3×1014 p/cm2 in the CERN PS 23 GeV proton beam in late 2014. The SiPM's main parameters were measured before and after irradiation. Here we report on the effects of noise increase and breakdown voltage shift due to the extremely high dose.

  16. Radiation effects on II-VI compound-based detectors

    CERN Document Server

    Cavallini, A; Dusi, W; Auricchio, N; Chirco, P; Zanarini, M; Siffert, P; Fougeres, P

    2002-01-01

    The performance of room temperature CdTe and CdZnTe detectors exposed to a radiation source can be strongly altered by the interaction of the ionizing particles and the material. Up to now, few experimental data are available on the response of II-VI compound detectors to different types of radiation sources. We have carried out a thorough investigation on the effects of gamma-rays, neutrons and electron irradiation both on CdTe : Cl and Cd sub 0 sub . sub 9 Zn sub 0 sub . sub 1 Te detectors. We have studied the detector response after radiation exposure by means of dark current measurements and of quantitative spectroscopic analyses at low and medium energies. The deep traps present in the material have been characterized by means of PICTS (photo-induced current transient spectroscopy) analyses, which allow to determine the trap apparent activation energy and capture cross-section. The evolution of the trap parameters with increasing irradiation doses has been monitored for all the different types of radiati...

  17. Effects of microgravity and cosmic radiations on human T lymphocytes

    Directory of Open Access Journals (Sweden)

    P. Pippia

    2011-01-01

    Full Text Available In space living organisms, including cells, are affected by two new environmental conditions: microgravity and cosmic radiations. Several experiments in dedicated space missions and in simulated microgravity have shown that low gravity causes a dramatic depression of the mitogenic in vitro activation of T lymphocytes. The goal of this reserch was to determine in space (on board the International Space Station the ability of adherent monocytes to migrate, as well as to interact with T-cells. A reduced motility of the J-111 cells and changes in the structures of actin, tubulin and vinculin were observed. Moreover, we demonstrated that LFA-I/ICAM-I interactions occur in space and are dependent on activation time but show differences in number, arrangement and fluorescence intensity, depending on time and experimental conditions. In order to evaluate the effects of cosmic radiations on the gene expression in human T lymphocytes we exposed these cells to high quote cosmic radiation during two stratospheric balloon trans-mediterranean flights (BIRBA missions. The gene expression was analized by cDNA microarray hybridization technology. Activated T cells react to the ionizing stress by activating genes involved in cell cycle check-point, oxidative stress response, heat shock proteins production or by repressing denes involved in antigen recognition.

  18. Algae as test organisms of harmful effects of various radiations

    International Nuclear Information System (INIS)

    The report describes a complex biotest in which algae serve as the test organisms and where a variety of algal characteristics are employed as indicators of the effects of harmful radiations on the cultures and single organisms. Rules for a successful choice of a suitable algal organism are discussed and the preparation of the latter for the test as well as the growth and morphogenic tests and some physiological responses of algae to harmful radiation are described. The survival and lethality are related to the interpretation of the test results particularly from the physiological and genetic points of view. The complex biotest concerns not only toxic but also mutagenic effects of the factors tested. Some easily detectable mutations in algae are mentioned and their spectra are recommended. The stability of the mutations and the possibility of their delayed manifestation are considered. The possibility of occurrence of teratogenic effects is also dealt with and the negative role of phenocopies in the correct evaluation of the mutation effects is mentioned. Advice for the breeding and laboratory maintenance of suitable algal strains for the biotest is given. Practical use of the biotest is demonstrated on the results of a test using modified samples of waste water from uranium industries. It is recommended that biotests confined to the evaluation of single characteristics of the test organism be replaced by this complex biotest whose results can be interpreted more extensively and exhibit a higher reliability. (author). 268 refs., 1 tab., 9 figs

  19. The relationships between radiation doses and their effects

    International Nuclear Information System (INIS)

    Dose-effect relationships have been developed both for the biological effects studied by Radiobiology and the long-term pathological effects (malignant diseases) studied by Radiation Protection. The former approach chiefly considers the primary biological injuries at the cellular level, and the relationship between the dependent variable characteristic of the effect and the dose -an independent variable- has an explanatory meaning. The parameters associated to the independent variable have a biophysical signification and fit into a model of the action of ionizing radiations. In the latter approach, the relationship is pragmatic and the previous parameters are just the results of a curve-fitting procedure realized on experimental or human data. The biophysical models have led to a general formulation associating a linear term to a quadratic term both of them weighted by an exponential term describing cellular killing at the highest doses. To a certain extent the curves obtained for leukemias, bronchopulmonary and breast cancers prove the validity of the pragmatic model

  20. Complementary strategies for the management of radiation therapy side effects.

    Science.gov (United States)

    Stubbe, Christine E; Valero, Meighan

    2013-07-01

    Patients with cancer utilize complementary and alternative medicine (CAM) for a variety of purposes, one of which is the reduction of side effects of conventional treatment. With a large number of their patients using CAM, it is important for advanced practitioners in oncology to have an understanding of these therapies to better guide their patients. Side effects of radiation therapy that may have dose-limiting poten-tial include diarrhea, mucositis, skin toxicity, and xerostomia. A com-mon side effect that is not necessarily dose-limiting but considerably troublesome to patients is cancer- and treatment-related fatigue. The CAM therapies that may alleviate some of the side effects of radiation therapy include probiotics, psyllium, exercise, melatonin, honey, acu-puncture, and calendula. Therapies that require more research or have been shown to be ineffective include aloe vera, glutamine, and deglyc-yrrhizinated licorice. This article provides an overview of these thera-pies as well as related research and analysis. PMID:25032003