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Sample records for frequency radiation effects

  1. Effects of GSM-Frequency Electromagnetic Radiation on Some Physiological and Biochemical Parameters in Rats.

    Science.gov (United States)

    Khirazova, E E; Baizhumanov, A A; Trofimova, L K; Deev, L I; Maslova, M V; Sokolova, N A; Kudryashova, N Yu

    2012-10-01

    Single exposure of white outbred rats to electromagnetic radiation with a frequency 905 MHz (GSM frequency) for 2 h increased anxiety, reduced locomotor, orientation, and exploration activities in females and orientation and exploration activities in males. Glucocorticoid levels and antioxidant system activity increased in both males and females. In addition to acute effects, delayed effects of radiation were observed in both males and females 1 day after the exposure. These results demonstrated significant effect of GSM-range radiation on the behavior and activity of stress-realizing and stress-limiting systems of the body.

  2. Effects of radio frequency identification-related radiation on in vitro biologics.

    Science.gov (United States)

    Uysal, Ismail; Hohberger, Clive; Rasmussen, R Scott; Ulrich, David A; Emond, Jean-Pierre; Gutierrez, Alfonso

    2012-01-01

    The recent developments on the use of e-pedigree to identify the chain of custody of drugs suggests the use of advanced track and trace technologies such as two-dimensional barcodes and radio frequency identification (RFID) tags. RFID technology is used mainly for valuable commodities such as pharmaceutical products while incorporating additional functionalities like monitoring environmental variables to ensure product safety and quality. In its guidance for the use of RFID technologies for drugs (Compliance Policy Guide Section 400.210), the Food and Drug Administration outlined multiple parameters that would apply to any study or application using RFID. However, drugs approved under a Biologics License Application or protein drugs covered by a New Drug Application were excluded mainly due to concerns about the effects of radio frequency radiation (thermal and/or non-thermal) on biologics. Even though the thermal effects of radio frequency on biologics are relatively well understood, there are few studies in the literature about the non-thermal effects of radio frequency with regards to the protein structure integrity. In this paper, we analyze the non-thermal effects of radio frequency radiation by exposing a wide variety of biologics including biopharmaceuticals with vaccines, hormones, and immunoglobulins, as well as cellular blood products such as red blood cells and whole blood-derived platelets as well as fresh frozen plasma. In order to represent the majority of the frequency spectrum used in RFID applications, five different frequencies (13.56 MHz, 433 MHz, 868 MHz, 915 MHz, and 2.4 GHz) are used to account for the most commonly used international frequency bands for RFID. With the help of specialized radio frequency signal-generating hardware, magnetic and electromagnetic fields are created around the exposed products with power levels greater than Federal Communications Commission-regulated limits. The in vitro test results on more than 100

  3. Features of anti-inflammatory effects of modulated extremely high-frequency electromagnetic radiation.

    Science.gov (United States)

    Gapeyev, Andrew B; Mikhailik, Elena N; Chemeris, Nikolay K

    2009-09-01

    Using a model of acute zymosan-induced paw edema in NMRI mice, we test the hypothesis that anti-inflammatory effects of extremely high-frequency electromagnetic radiation (EHF EMR) can be essentially modified by application of pulse modulation with certain frequencies. It has been revealed that a single exposure of animals to continuous EHF EMR for 20 min reduced the exudative edema of inflamed paw on average by 19% at intensities of 0.1-0.7 mW/cm(2) and frequencies from the range of 42.2-42.6 GHz. At fixed effective carrier frequency of 42.2 GHz, the anti-inflammatory effect of EHF EMR did not depend on modulation frequencies, that is, application of different modulation frequencies from the range of 0.03-100 Hz did not lead to considerable changes in the effect level. On the contrary, at "ineffective" carrier frequencies of 43.0 and 61.22 GHz, the use of modulation frequencies of 0.07-0.1 and 20-30 Hz has allowed us to restore the effect up to a maximal level. The results obtained show the critical dependence of anti-inflammatory action of low-intensity EHF EMR on carrier and modulation frequencies. Within the framework of this study, the possibility of changing the level of expected biological effect of modulated EMR by a special selection of combination of carrier and modulation frequencies is confirmed.

  4. Investigation into the Effects of VHF and UHF Band Radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    National Research Council Canada - National Science Library

    Dickens, Andrew

    1994-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards...

  5. Micronuclei Frequency in Radiation Worker

    International Nuclear Information System (INIS)

    Sudprasert, Wanwisa; Jungtanasombut, Amornrat; Pakkong, Pannee

    2009-07-01

    Full text: The purpose of this study is to determine the micronuclei (MN) frequency in peripheral blood lymphocytes of 31 individuals occupationally exposed to radiation compared to 24 controls. The effect of donor gender, age, alcoholic consumption, tea/coffee consumption and radiation burden on MN frequency was studied. The results showed that MN frequencies observed for exposed employees were significantly higher than in controls (p = 0.000). The average MN frequency in control was 39.1 ± 3.7 MN/1000 BN while those of exposed group were 60.9 ± 12.3, 61.6 ± 13.0 and 62.6 ± 11.8 MN/1000 BN for the range of accumulative doses at 0.01-3.00, 3.01-6.00 and 6.01-9.00 mSv, respectively. Moreover, MN frequency showed a positive trend with increased accumulative doses as a linear-quadratic relation (R 2 = 0.4754). No correlation of MN frequency with gender, age and alcoholic consumption could be observed in both exposed and control groups. However, the effect of tea/coffee consumption on MN frequency was clearly observed in the exposed individuals (t-test = -2.018, sig. (2-tailed) = 0.030). These results indicate that the increased MN frequency, an indicator of chromosomal aberration, is associated with occupational exposure to low doses of ionizing radiation

  6. On board electronic devices safety subject to high frequency electromagnetic radiation effects

    Science.gov (United States)

    Nikitin, V. F.; Smirnov, N. N.; Smirnova, M. N.; Tyurenkova, V. V.

    2017-06-01

    Spacecraft on board electronic devices are subjected to the effects of Space environment, in particular, electromagnetic radiation. The weight limitations for spacecraft pose an important material and structures problem: developing effective protection for on board electronic devices from high frequency electromagnetic radiation. In the present paper the problem of the effect of external high frequency electromagnetic field on electronic devices shielding located on orbital platforms is investigated theoretically. It is demonstrated that the characteristic time for the unsteady stage of the process is negligibly small as compared with characteristic time of electromagnetic field diffusion into a conductor for the studied range of governing parameters. A system of governing material parameters is distinguished, which contribute to protecting electronic devices from induced electrical currents.

  7. Effect of Ultra High Frequency Mobile Phone Radiation on Human Health

    Science.gov (United States)

    Moradi, Mosa; Naghdi, Nasrollah; Hemmati, Hamidreza; Asadi-Samani, Majid; Bahmani, Mahmoud

    2016-01-01

    Introduction Public and occupational exposure to electromagnetic fields due to the growing trend of electronic devices may cause adverse effects on human health. This paper describes the risk of mutation and sexual trauma and infertility in masculine sexual cell by mobile phone radiations. Methods In this study, we measured the emitted dose from a radiofrequency device, such as switching high voltage at different frequencies using a scintillation detector. The switching high voltage power supply (HVPS) was built for the Single Photon Emission Computed Tomography (SPECT) system. For radiation dosimetry, we used an ALNOR scintillator that can measure gamma radiation. The simulation was performed by MATLAB software, and data from the International Commission on Non-Ionizing Radiation Protection (ICNIRP) were used to verify the simulation. Results We investigated the risks that result from the waves, according to a report by International Commission on Non Ionizing Radiation Protection (ICNIRP), to every organ of the body is defined by the beam and electromagnetic radiation from this electronic device on people. The results showed that the maximum personal dose over a 15-min period working at the mentioned HVPS did not exceed 0.31 μSV/h (with an aluminum shield). So, according to other sources of radiation, continuous working time of the system should not be more than 10 hours. Finally, a characteristic curve for secure working with modules at different frequencies was reported. The RF input signal to the body for maximum penetration depth (δ) and electromagnetic energy absorption rate (SAR) of biological tissue were obtained for each tissue. Conclusion The results of this study and International Commission of Non Ionization Radiation Protection (ICNIRP) reports showed the people who spend more than 50 minutes a day using a cell phone could have early dementia or other thermal damage due to the burning of glucose in the brain. PMID:27382458

  8. [Effects of extremely low frequency electromagnetic radiation on cardiovascular system of workers].

    Science.gov (United States)

    Zhao, Long-yu; Song, Chun-xiao; Yu, Duo; Liu, Xiao-liang; Guo, Jian-qiu; Wang, Chuan; Ding, Yuan-wei; Zhou, Hong-xia; Ma, Shu-mei; Liu, Xiao-dong; Liu, Xin

    2012-03-01

    To observe the exposure levels of extremely low frequency electromagnetic fields in workplaces and to analyze the effects of extremely low frequency electromagnetic radiation on cardiovascular system of occupationally exposed people. Intensity of electromagnetic fields in two workplaces (control and exposure groups) was detected with EFA-300 frequency electromagnetic field strength tester, and intensity of the noise was detected with AWA5610D integral sound level. The information of health physical indicators of 188 controls and 642 occupationally exposed workers was collected. Data were analyzed by SPSS17.0 statistic software. The intensity of electric fields and the magnetic fields in exposure groups was significantly higher than that in control group (P 0.05). The results of physical examination showed that the abnormal rates of HCY, ALT, AST, GGT, ECG in the exposure group were significantly higher than those in control group (P 0.05). Exposure to extremely low frequency electromagnetic radiation may have some effects on the cardiovascular system of workers.

  9. Investigation into the effects of VHF and UHF band radiation on Hewlett-Packard (HP) Cesium Beam Frequency Standards

    Science.gov (United States)

    Dickens, Andrew

    1995-01-01

    This paper documents an investigation into reports which have indicated that exposure to VHF and UHF band radiation has adverse effects on the frequency stability of HP cesium beam frequency standards. Tests carried out on the basis of these reports show that sources of VHF and UHF radiation such as two-way hand held police communications devices do cause reproducible adverse effects. This investigation examines reproducible effects and explores possible causes.

  10. Standards for Measurements in the Field of High Frequency Electromagnetic Radiation for the Purpose of Protection Against Adverse Health Effects

    International Nuclear Information System (INIS)

    Tanatarec, B.; Nikolic, N.

    2011-01-01

    In this paper standards for measurements in the field of high frequency electromagnetic radiation are described with a view to protection from its hazardous action. Beside the standards which directly deal with high frequency electromagnetic radiation measurements, guidelines which describe hazardous influences of high frequency electromagnetic radiation on human body in the form of specific absorption rate (SAR) are given. Special attention is dedicated to standards and regulations, which are dealing with social responsibility, as well as with social responsibility in the field of high frequency radiation. This area is new and insufficiently known, rarely extended in everyday life. (author)

  11. Effects of radiation on frequency of chromosomal aberrations and sister chromatid exchange in the benthic worm Neanthes arenaceodentata

    International Nuclear Information System (INIS)

    Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.; Varela, M.

    1983-04-01

    Traditional bioassays are unsuitable for assessing sublethal effects of low levels of radioactivity because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration (CA) and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. Newly hatched larvae were exposed to two radiation exposure regimes. Groups of 100 larvae were exposed to either x rays delivered at high dose rates (0.7 Gy min -1 ) or to 60 Co gamma rays delivered at low dose rates (4.8 X 10 -5 to 1.2 X 10 -1 Gy h -1 ). After irradiation, the larvae were exposed to 3 X 10 -5 M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h ( 60 Co-irradiated larvae). Slides of larval cells were prepared for observation of CAs and SCEs. Frequencies of CAs were determined in first division cells; frequencies of SCEs were determined in second division cells. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but an x-ray dose greater than or equal to 2 Gy was required to observe a significant increase. Worm larvae receiving 60 Co irradiation showed elevated SCE frequencies; a significant increase in SCE frequency was observed at 0.6 Gy. 49 references, 2 figures

  12. Effects of GSM modulated radio-frequency electromagnetic radiation on permeability of blood-brain barrier in male & female rats.

    Science.gov (United States)

    Sırav, Bahriye; Seyhan, Nesrin

    2016-09-01

    With the increased use of mobile phones, their biological and health effects have become more important. Usage of mobile phones near the head increases the possibility of effects on brain tissue. This study was designed to investigate the possible effects of pulse modulated 900MHz and 1800MHz radio-frequency radiation on the permeability of blood-brain barrier of rats. Study was performed with 6 groups of young adult male and female wistar albino rats. The permeability of blood-brain barrier to intravenously injected evans blue dye was quantitatively examined for both control and radio-frequency radiarion exposed groups. For male groups; Evans blue content in the whole brain was found to be 0.08±0.01mg% in the control, 0.13±0.03mg% in 900MHz exposed and 0.26±0.05mg% in 1800MHz exposed animals. In both male radio-frequency radiation exposed groups, the permeability of blood-brain barrier found to be increased with respect to the controls (pmale animals (pfemale groups; dye contents in the whole brains were 0.14±0.01mg% in the control, 0.24±0.03mg% in 900MHz exposed and 0.14±0.02mg% in 1800MHz exposed animals. No statistical variance found between the control and 1800MHz exposed animals (p>0.01). However 900MHz pulse modulated radio-frequency exposure was found effective on the permeability of blood-brain barrier of female animals. Results have shown that 20min pulse modulated radio-frequency radiation exposure of 900MHz and 1800MHz induces an effect and increases the permeability of blood-brain barrier of male rats. For females, 900MHz was found effective and it could be concluded that this result may due to the physiological differences between female and male animals. The results of this study suggest that mobile phone radation could lead to increase the permeability of blood-brain barrier under non-thermal exposure levels. More studies are needed to demonstrate the mechanisms of that breakdown. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. [Effect of Low-Intensity 900 MHz Frequency Electromagnetic Radiation on Rat Brain Enzyme Activities Linked to Energy Metabolism].

    Science.gov (United States)

    Petrosyan, M S; Nersesova, L S; Gazaryants, M G; Meliksetyan, G O; Malakyan, M G; Bajinyan, S A; Akopian, J I

    2015-01-01

    The research deals with the effect of low-intensity 900 MHz frequency electromagnetic radiation (EMR), power density 25 μW/cm2, on the following rat brain and blood serum enzyme activities: creatine kinase (CK), playing a central role in the process of storing and distributing the cell energy, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that play a key role in providing the conjunction of carbohydrate and amino acid metabolism. The comparative analysis of the changes in the enzyme activity studied at different times following the two-hour single, as well as fractional, radiation equivalent of the total time showed that the most radiosensitive enzyme is the brain creatine kinase, which may then be recommended as a marker of the radio frequency radiation impact. According to the analysis of the changing dynamics of the CK, ALT and AST activity level, with time these changes acquire the adaptive character and are directed to compensate the damaged cell energy metabolism.

  14. Entropic effects in formation of chromosome territories: towards understanding of radiation-induced gene translocation frequency

    Science.gov (United States)

    Gudowska-Nowak, Ewa; Ritter, Sylvia; Durante, Marco; Deperas-Standylo, Joanna; Ciesla, Michal

    2012-07-01

    . The degree of condensation of the chromatin fiber is modeled by changing length of the string: e.g. loosening of the structure is achieved by distributing the chromosome mass into a higher number of smaller beads and tighter configuration corresponds to a lower number of fragments (balls) with a bigger radius. Additionally, for each configuration, a degree of possible overlapping between domains is assumed. This procedure effectively intensifies loosening/tightening of the chromosome structure by changing the radial dimension of the domain while keeping a constant volume of the polymer chain. Such a positioning model is confronted with a minimalistic molecular dynamics model [5] on a similar structure, in which a chain of beads becomes connected by entropic spring energy and subjected to thermal fluctuations. Comparison of both Monte Carlo models allows to discuss variability of possible configurations as observed in static and dynamic models of chromosome territories along with the effect of compaction and relative arrangements of territorial polymer structures. Acknowledgements: Project is operated within the Foundation for Polish Science International Ph.D. Projects Programme co-financed by the European Regional Development Fund covering, under the agreement no. MPD/2009/6, the Jagiellonian University International Ph.D. Studies in Physics of Complex Systems. References: [1] F. Ballarini, M. Biaggi, and A. Ottolenghi, Radiation Protection Dosimetry 99, 175 (2002). [2] M. Nicodemi and A. Prisco, Biophysical Journal 96, 2168 (2009). [3] P. Cook and D. Marenduzzo, Journal of Cell Biology 186, 825 (2009). [4] M. Tark-Dame, R. van Driel, and D. Heermann, Journal of Cell Science 124, 839 (2011). [5] W. Swope, H. Andersen, P. Berens, and K. Wilson, J. Chem. Phys. 76, 637 (1982).

  15. Analysis of certain kinetic regularities of cultured cell growth. Part 2. Effect of ionizing radiation, an alkylating agent and low frequency electromagnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Khokhlov, A.N.; Golovina, M.E.; Chirkova, E.Y.; Nadzharyan, T.L.

    1985-09-01

    The effects of gamma radiation, the alkylating agent thiophosphamide, and a low-frequency electromagnetic field on the growth kinetics of cultured hamster cell were studied. Gamma radiation decreased both the steepness of the growth curve and the height of the plateau on the curve. Plateau height and curve steepness were also reduced almost in direct proportion to the dose of alkylating agent used. The electromagnetic radiation also reduced somewhat the height of the growth plateau, but did not decrease the steepness of the growth curve. Low frequency electromagnetic radiation is considered a geropromoter on the basis of its reduction of the growth plateau in this experiment. 17 references, 5 figures.

  16. [Pulse-modulated Electromagnetic Radiation of Extremely High Frequencies Protects Cellular DNA against Damaging Effect of Physico-Chemical Factors in vitro].

    Science.gov (United States)

    Gapeyev, A B; Lukyanova, N A

    2015-01-01

    Using a comet assay technique, we investigated protective effects of. extremely high frequency electromagnetic radiation in combination with the damaging effect of X-ray irradiation, the effect of damaging agents hydrogen peroxide and methyl methanesulfonate on DNA in mouse whole blood leukocytes. It was shown that the preliminary exposure of the cells to low intensity pulse-modulated electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, 20-min exposure, modulation frequencies of 1 and 16 Hz) caused protective effects decreasing the DNA damage by 20-45%. The efficacy of pulse-modulated electromagnetic radiation depended on the type of genotoxic agent and increased in a row methyl methanesulfonate--X-rays--hydrogen peroxide. Continuous electromagnetic radiation was ineffective. The mechanisms of protective effects may be connected with an induction of the adaptive response by nanomolar concentrations of reactive oxygen species formed by pulse-modulated electromagnetic radiation.

  17. Ionizing radiation effects on conduction and low frequency noise in bipolar transistors

    International Nuclear Information System (INIS)

    Blasquez, G.; Roux-Nogatchewsky, M.

    1980-01-01

    Gate controlled NPN bipolar transistors were irradiated with doses ranging between 10 and 10 4 Gy X rays supplied by a generator functioning at 150 kV. An increase of great amplitude of the base current and of the low frequency noise were observed for both depleted and inverted base surface conditions. It has been shown that these increases were due to the enhancement of the total surface recombination velocity, of the positive charge within the oxide and also of the density of noise traps. Positive correlations were observed between these three surface parameters. These results have been attributed to the ionization of silica by X rays. The transistors partially recovered by means of thermal treatments. It has been suggested that it does not exist specific hardening methods to minimize the noise sensitivity to irradiation [fr

  18. [Effect of low-intensity 900 MHz frequency electromagnetic radiation on rat liver and blood serum enzyme activities].

    Science.gov (United States)

    Nersesova, L S; Petrosian, M S; Gazariants, M G; Mkrtchian, Z S; Meliksetian, G O; Pogosian, L G; Akopian, Zh I

    2014-01-01

    The comparative analysis of the rat liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and purine nucleoside phosphorylase post-radiation activity levels after a total two-hour long single and fractional exposure of the animals to low-intensity 900 MHz frequency electromagnetic field showed that the most sensitive enzymes to the both schedules of radiation are the liver creatine kinase, as well as the blood serum creatine kinase and alkaline phosphatase. According to the comparative analysis of the dynamics of changes in the activity level of the liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase and purine nucleoside phosphorylase, both single and fractional radiation schedules do not affect the permeability of a hepatocyte cell membrane, but rather cause changes in their energetic metabolism. The correlation analysis of the post-radiation activity level changes of the investigated enzymes did not reveal a clear relationship between them. The dynamics of post-radiation changes in the activity of investigated enzyme levels following a single and short-term fractional schedules of radiation did not differ essentially.

  19. Effect of imaging frequency on PTV margins and geographical miss during image guided radiation therapy for prostate cancer.

    Science.gov (United States)

    Gupta, Meetakshi; Gamre, Poonam; Kannan, Sadhana; Rokde, Ganesh; Krishnatry, Rahul; Murthy, Vedang

    The relationship between frequency of imaging during image guided radiation therapy (IGRT) and planning target volume (PTV) margin remains unclear. This issue is of practical significance given resource and time intensive nature of IGRT. The purpose of this study was to evaluate PTV margins with predefined and commonly used less-than-daily IGRT schedules using data obtained from patients treated with daily IGRT for prostate cancer. Daily setup error and 3-dimensional daily alignment data for a total of 108 consecutive patients with prostate cancer treated with 2700 fractions of daily image guidance on tomotherapy were retrospectively analyzed. Five IGRT scenarios were simulated: alternate day, twice weekly, once weekly, first 3 days only, and no image guidance. The daily alignment data were modeled to simulate the 5 predefined scenarios by applying appropriate corrections to determine the PTV margin for each image guidance scenario. The data were also analyzed to predict possible geographical miss in any direction using 2 frequently used PTV margins of 7 and 5 mm for all the scenarios. Decreasing the frequency of image guidance increased the mean systematic error and the standard deviation of the systematic error. With decreased image guidance frequency, an increase in PTV margins was required to achieve adequate coverage of the clinical target volume. With reduction in image guidance from 50% to 12%, a gradual increase in percentage of fractions with predicted geographical miss using an isotropic PTV margin of 7 or 5 mm was seen. With every 15% decrease in imaging, a 5% increased risk of geographical miss was estimated. The use of less-than-daily IGRT requires larger PTV margins for patients treated with intensity modulated radiation therapy for prostate cancer. With every 15% reduction, a 5% increased risk of geographical miss was estimated. Copyright © 2017 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  20. Radiation effects

    International Nuclear Information System (INIS)

    Collings, E.W.

    1986-01-01

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

  1. Observation of Frequency Locked Coherent Transition Radiation

    CERN Document Server

    Marsh, Roark A; Temkin, Richard J

    2005-01-01

    Measurements of frequency locked, coherent transition radiation (CTR) were performed at the 17 GHz high-gradient accelerator facility built by Haimson Research Corporation at MIT PSFC. CTR produced from a metallic foil placed in the beam path was extracted through a window, and measured with a variety of detectors, including: diode, Helium cooled Si Bolometer, and double heterodyne receiver system. The angular energy distribution measured by the diode and bolometer are in agreement and consistent with calculations for a 15 MeV 200 mA 110 ns beam of 1 ps bunches. Heterodyne receiver measurements were able to show frequency locking, namely inter-bunch coherence at integer multiples of the accelerator RF frequency of 17.14 GHz. At the locked frequencies the power levels are enhanced by the number of bunches in a single beam pulse. The CTR was measured as a comb of locked frequencies up to 240 GHz, with a bandwidth of 50 MHz.

  2. Gamma radiation effects on the frequency of toxigenic fungus on sene (Cassia angustifolia) and green tea (Camelia sinensis) samples

    International Nuclear Information System (INIS)

    Aquino, S.; Villavicencio, A.L.C.H.

    2006-01-01

    The levels of contamination and gamma radiation effects were analyzed in the reduction of toxigenic filamentous fungus in two types of medicinal plants. Aspergillus and Penicillium were the predominant genders and 73,80% of the samples showed high levels of fungus contamination

  3. Possibility of the effect of absolute negative conductivity in quantum superlattice exposed to the high-frequency electromagnetic radiation

    Science.gov (United States)

    Kryuchkov, S. V.; Kukhar', E. I.

    2015-07-01

    Current density in superlattice placed in quantizing electric field and in high-frequency field of electromagnetic wave was calculated. The calculations were performed by taking into account an inelastic scattering of charge carriers by phonons. Possibility of the effect of absolute negative conductivity, i.e. the effect of appearance of electric current flowing in opposite direction than that of vector of quantizing electric field intensity, was shown. Such effect in graphene superlattices was discussed.

  4. Effect of low dose gamma radiation on stamen-hairs of different clones of Tradescantia presenting variability in the frequency of spontaneous mutations

    International Nuclear Information System (INIS)

    Takahashi, C.S.

    1976-01-01

    Changes in the frequency of spontaneous somatic mutations were studied for three different clones of Tradescantia heterozygotes for flower and stamen-hair color keeping them under controlled or natural conditions in order to verify the effect of different environmental conditions on the different genotypes. The effect of inflorescence age on the variation of spontaneous mutations was studied choosing young and old inflorescences of a same plant. Low dose irradiation experiments were carried out with those clones to elucidate the radiation effects on the clones presenting changes in the frequency of spontaneous mutations. The chronic-and acute irradiation effects of low dose irradiation of the stamen-hair of Tradescantia were also studied. Results are discussed. (M.A.) [pt

  5. Sensors for low frequency electromagnetic radiation

    International Nuclear Information System (INIS)

    Huber, E.; Urban, M.

    1996-01-01

    For estimating the personal exposure from low fequency electric and magnetic fields suitable measurement systems are necessary. Investigations of appropriate magnetic and electric field probes and sensors have been done as a basis for a pocket sized personal dosimeter. There exist many different sensors, which can be used for the measurement of static and low frequency magnetic fields, such as inductive transducers, hall generators, tunnel diode oscillators, flux gate sensors and magnetoresistive sensors. In contrast to the magnetic sensors there are less different sensor types based on different physical detection principles available showing a sufficient sensitivity for low frequency electrical fields. Important is the knowledge on the feed back of the sensor itself on the detected field strength. Whether a sensor is suitable for a certain application is depending on its frequency related sensitivity, its signal to noise ratio, linearity and detection range, sensitivity to environmental influences as temperature, humidity etc. This presentation will focus on some important basic aspects of the measurement of low frequency electrical and magnetic fields for radiation protection purposes. (author)

  6. Micronuclei frequency in albino rats exposed to high natural radiation

    International Nuclear Information System (INIS)

    Aneesh, D.; Godwin Wesley, S.

    2013-01-01

    Genotoxicity and DNA damage endpoints are used to evaluate results in the context of cell survival. Genotoxicity in mammalian cells is monitored mostly by using cytokinesis-block micronucleus (CBMN) assay. The score of micronuclei (MN) in peripheral blood lymphocytes can be used as a biomarker and also as a bio-dosimeter of radiation exposure. In the present study the effect of natural radiation on albino rats has been investigated, to find out if there is any increase in MN frequency in peripheral blood lymphocytes. Animals at the age of 2-3 weeks were exposed to natural radiation, at the dose of 10.38 μGyh -1 for a period of 6 months. A parallel control set was also maintained (0.12 μGy h -1 '). Blood samples were collected from both test (exposed to natural radiation) and control rats. Lymphocyte culture was done following 'microculture techniques' for 72 h. Cytochalasin B, at a concentration of 6.0 μg/ml, was added to the lymphocyte cultures at 44 h to block cytokinesis. The frequency of MN was evaluated by scoring a total of 1000 binucleated (BN) cells from one slide. The frequency of MN among the rats exposed to natural radiation was found to be 1.83±0.05 per 1000 BN cells and in the control it was 1.82±0.07 per 1000 BN cells. No statistically significant difference in the MN frequencies of exposed and control groups (p>0.05) was seen. The lower MN frequency in natural radiation exposed rats could be an indication of adaptive response. (author)

  7. 47 CFR 15.33 - Frequency range of radiated measurements.

    Science.gov (United States)

    2010-10-01

    ... current system not intended to radiate, shall be investigated from the lowest radio frequency generated or... with the antenna conduction limits specified in § 15.111. The frequency range of measurements for AC... 47 Telecommunication 1 2010-10-01 2010-10-01 false Frequency range of radiated measurements. 15.33...

  8. Effect of sterol metabolism in the yeast-Drosophila system on the frequency of radiation-induced aneuploidy in the Drosophila melanogaster oocytes

    International Nuclear Information System (INIS)

    Savitskii, V.V.; Luchnikova, E.M.; Inge-Vechtomov, S.G.

    1986-01-01

    The effect of sterol metabolism on induced mutagenesis of Drosophila melanogaster was studied in the ecogenetic system of yeast-Drosophila. Sterol deficiency was created in Drosophila by using the biomass of live cells of Saccharomyces cerevisiae strain 9-2-P712 till mutation in locus nys/sup r1/ blocking the synthesis of ergosterol as the food. It was found that rearing of Drosophila females on the mutant yeast increases the frequency of loss and nondisjunction of X chromosomes induced in mature oocytes by X rays (1000 R). Addition of 0.1% of cholesterol solution in 10% ethanol to the yeast biomass restores the resistance of oocyte to X irradiation to the control level. The possible hormonal effect on membrane leading to increased radiation-induced aneuploidy in Drosophila and the role of sterol metabolism in determining the resistance to various damaging factors are discussed

  9. [The effect of electromagnetic waves of very high frequency of molecular spectra of radiation and absorption of nitric oxide on the functional activity of platelets].

    Science.gov (United States)

    Kirichuk, V F; Maĭborodin, A V; Volin, M V; Krenitskiĭ, A P; Tupikin, V D

    2001-01-01

    A study was made of the effect of electromagnetic EMI MMD-fluctuation on the frequencies of molecular spectra of radiation, and nitric oxide absorption under in vitro conditions on the functional activity of platelets in patients with unstable angina pectoris, with the help of a specially created generator. At amplitude-modulated and continuous modes of EMI MMD-irradiation of platelet-rich plasma for 5, 15 and 30 min the platelet functional activity decreases, which was shown up in reduction of their activation and fall of aggregative ability. The degree, to which platelet functional activity was inhibited, depended on the mode of irradiation and on duration of EMI MMD effect. The most obvious changes in platelet activation and in their readiness to aggregative response were observed at a continuous mode of irradiation within a 15 min interval.

  10. Effects of aluminum and extremely low frequency electromagnetic radiation on oxidative stress and memory in brain of mice.

    Science.gov (United States)

    Deng, Yuanxin; Zhang, Yanwen; Jia, Shujie; Liu, Junkang; Liu, Yanxia; Xu, Weiwei; Liu, Lei

    2013-12-01

    This study was aimed to investigate the effect of aluminum and extremely low-frequency magnetic fields (ELF-MF) on oxidative stress and memory of SPF Kunming mice. Sixty male SPF Kunming mice were divided randomly into four groups: control group, ELF-MF group (2 mT, 4 h/day), load aluminum group (200 mg aluminum/kg, 0.1 ml/10 g), and ELF-MF + aluminum group (2 mT, 4 h/day, 200 mg aluminum/kg). After 8 weeks of treatment, the mice of three experiment groups (ELF-MF group, load aluminum group, and ELF-MF + aluminum group) exhibited firstly the learning memory impairment, appearing that the escaping latency to the platform was prolonged and percentage in the platform quadrant was reduced in the Morris water maze (MWM) task. Secondly are the pathologic abnormalities including neuronal cell loss and overexpression of phosphorylated tau protein in the hippocampus and cerebral cortex. On the other hand, the markers of oxidative stress were determined in mice brain and serum. The results showed a statistically significant decrease in superoxide dismutase activity and increase in the levels of malondialdehyde in the ELF-MF group (P < 0.05 or P < 0.01), load aluminum group (P < 0.01), and ELF-MF + aluminum group (P < 0.01). However, the treatment with ELF-MF + aluminum induced no more damage than ELF-MF and aluminum did, respectively. In conclusion, both aluminum and ELF-MF could impact on learning memory and pro-oxidative function in Kunming mice. However, there was no evidence of any association between ELF-MF exposure with aluminum loading.

  11. Is there any possible genotoxic effect in exfoliated bladder cells of rat under the exposure of 1800 MHz GSM-like modulated radio frequency radiation (RFR)?

    Science.gov (United States)

    Gurbuz, Neslihan; Sirav, Bahriye; Yuvaci, Hilal Uslu; Turhan, Nilgun; Coskun, Zafer Kutay; Seyhan, Nesrin

    2010-08-01

    People are exposed to many carcinogenic and mutagenic chemicals in their everyday lives. These include antineoplastic drugs, Polycyclic aromatic hydrocarbons (PAH)s, aromatic amines, nitrosamines, metals, and electromagnetic radiation. Based on the state of knowledge acquired during the last 50 years of research on possible biological effects of electromagnetic fields (EMF), the majority of the scientific community is convinced that exposure to EMF below the existing security limits does not cause a risk to the health of the general public. However, this position is questioned by others, who are of the opinion that the available research data are contradictory or inconsistent and, therefore, unreliable. In this study, we aimed to investigate if there is any effect of 1800 MHz GSM modulated radio frequency radiation (RFR) on the number of micronucleus in exfoliated bladder cells of rat which will be informative about the genotoxic damage. Exposure period was 20 min/day, 5 days/week during a month. Six female Wistar rats were used for two groups: Group I (n=6): controls; Group II (n=6): 1.8 GHz exposed animals. 1800 MHz RFR did not showed a significant MN frequencies in rat bladder cells when compared with the control group (p>0.05). 1800 MHz RFR-exposed animals did not produce any genotoxic effect when compared with the control group ( p>0.05). Kinetic studies are important for any biomarker, especially those in which tissue differentiation and maturation processes will heavily influence the time between induction of damage and collection of damaged cells for micronucleus analysis.

  12. Discrete diffusion Monte Carlo for frequency-dependent radiative transfer

    Energy Technology Data Exchange (ETDEWEB)

    Densmore, Jeffrey D [Los Alamos National Laboratory; Kelly, Thompson G [Los Alamos National Laboratory; Urbatish, Todd J [Los Alamos National Laboratory

    2010-11-17

    Discrete Diffusion Monte Carlo (DDMC) is a technique for increasing the efficiency of Implicit Monte Carlo radiative-transfer simulations. In this paper, we develop an extension of DDMC for frequency-dependent radiative transfer. We base our new DDMC method on a frequency-integrated diffusion equation for frequencies below a specified threshold. Above this threshold we employ standard Monte Carlo. With a frequency-dependent test problem, we confirm the increased efficiency of our new DDMC technique.

  13. The effect of 1800MHz radio-frequency radiation on NMDA receptor subunit NR1 expression and peroxidation in the rat brain in healthy and inflammatory states.

    Science.gov (United States)

    Bodera, Paweł; Makarova, Katerina; Zawada, Katarzyna; Antkowiak, Bożena; Paluch, Małgorzata; Sobiczewska, Elżbieta; Sirav, Bahriye; Siwicki, Andrzej K; Stankiewicz, Wanda

    2017-08-01

    The aim of this study was to evaluate the effect of repeated exposure (5 times for 15min) of 1800MHz radio-frequency radiation (RFR) on N-methyl-d-aspartate receptor subunit NR1 (NMDA-NR1) expression in the brains of rats in a persistent inflammatory state. We also measured the effect of RFR combined with tramadol (TRAM) to determine the potential antioxidant capacity of this agent. The effects of the Global System for Mobile Communication (GSM) modulated 1800MHz RFR exposure on the expression and activity of glutamate receptor channels with antioxidative activity in brain tissue was measured using oxygen radical absorbance capacity (ORAC) and electron spin resonance (ESR) detection of the hydroxyl radical generated by the Fenton reaction. NMDA-NR1 was measured in the cerebral tissue of rats with inflammation (complete Freund's adjuvent) and those injected with tramadol after RFR exposure (RFR, RFR/TRAM) and in non-exposed (baseline, TRAM) rats. No differences between the baseline group and the exposed group (RFR) were observed. NMDA-NR1 expression decreased after CFA injection and RFR exposure, and an elevated expression of NMDA-NR1 was observed in healthy control rats of both groups: TRAM/RFR and RFR. ORAC assessment revealed a robust effect of RFR, however the other experiments revealed equivocal effects. Further studies examining the combination of ORAC with NMDA are warranted to elucidate more clearly the effect of RFR on the brain. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  14. Reconciling Ground-Based and Space-Based Estimates of the Frequency of Occurrence and Radiative Effect of Clouds around Darwin, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Protat, Alain; Young, Stuart; McFarlane, Sally A.; L' Ecuyer, Tristan; Mace, Gerald G.; Comstock, Jennifer M.; Long, Charles N.; Berry, Elizabeth; Delanoe, Julien

    2014-02-01

    The objective of this paper is to investigate whether estimates of the cloud frequency of occurrence and associated cloud radiative forcing as derived from ground-based and satellite active remote sensing and radiative transfer calculations can be reconciled over a well instrumented active remote sensing site located in Darwin, Australia, despite the very different viewing geometry and instrument characteristics. It is found that the ground-based radar-lidar combination at Darwin does not detect most of the cirrus clouds above 10 km (due to limited lidar detection capability and signal obscuration by low-level clouds) and that the CloudSat radar - Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) combination underreports the hydrometeor frequency of occurrence below 2 km height, due to instrument limitations at these heights. The radiative impact associated with these differences in cloud frequency of occurrence is large on the surface downwelling shortwave fluxes (ground and satellite) and the top-of atmosphere upwelling shortwave and longwave fluxes (ground). Good agreement is found for other radiative fluxes. Large differences in radiative heating rate as derived from ground and satellite radar-lidar instruments and RT calculations are also found above 10 km (up to 0.35 Kday-1 for the shortwave and 0.8 Kday-1 for the longwave). Given that the ground-based and satellite estimates of cloud frequency of occurrence and radiative impact cannot be fully reconciled over Darwin, caution should be exercised when evaluating the representation of clouds and cloud-radiation interactions in large-scale models and limitations of each set of instrumentation should be considered when interpreting model-observations differences.

  15. Effects of terahertz radiation at atmospheric oxygen frequency of 129 GHz on blood nitrite concentrations under conditions of different types of stress against the background of administration of nonselective inhibitor of constitutive NO-synthases.

    Science.gov (United States)

    Kirichuk, V F; Tsymbal, A A

    2012-02-01

    We studied the effect of terahertz radiation at atmospheric oxygen frequency 129 GHz on blood nitrite concentration in different types of experimental stress against the background of administration of nonselective inhibitor of constitutive NO-synthases. Normalizing effects of radiation on blood nitrite dynamics in animals with acute stress was shown after 15-min exposure and in animals with chronic stress after 30-min exposure. No positive effect of terahertz radiation was observed on altered blood nitrite concentration in male rats after preliminary administration of nonselective constitutive NO-synthase isoform inhibitor L-NAME.

  16. Low frequency interference between short synchrotron radiation sources

    Directory of Open Access Journals (Sweden)

    F. Méot

    2001-06-01

    Full Text Available A recently developed analytical formalism describing low frequency far-field synchrotron radiation (SR is applied to the calculation of spectral angular radiation densities from interfering short sources (edge, short magnet. This is illustrated by analytical calculation of synchrotron radiation from various assemblies of short dipoles, including an “isolated” highest density infrared SR source.

  17. Radiation effects in space

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1986-01-01

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

  18. Modifying effects of low-intensity extremely high-frequency electromagnetic radiation on content and composition of fatty acids in thymus of mice exposed to X-rays.

    Science.gov (United States)

    Gapeyev, Andrew B; Aripovsky, Alexander V; Kulagina, Tatiana P

    2015-03-01

    The effects of extremely high-frequency electromagnetic radiation (EHF EMR) on thymus weight and its fatty acids (FA) content and FA composition in X-irradiated mice were studied to test the involvement of FA in possible protective effects of EHF EMR against ionizing radiation. Mice were exposed to low-intensity pulse-modulated EHF EMR (42.2 GHz, 0.1 mW/cm(2), 20 min exposure, 1 Hz modulation) and/or X-rays at a dose of 4 Gy with different sequences of the treatments. In 4-5 hours, 10, 30, and 40 days after the last exposure, the thymuses were weighed; total FA content and FA composition of the thymuses were determined on days 1, 10, and 30 using a gas chromatography. It was shown that after X-irradiation of mice the total FA content per mg of thymic tissue was significantly increased in 4-5 h and decreased in 10 and 30 days after the treatment. On days 30 and 40 after X-irradiation, the thymus weight remained significantly reduced. The first and tenth days after X-rays injury independently of the presence and sequence of EHF EMR exposure were characterized by an increased content of polyunsaturated FA (PUFA) and a decreased content of monounsaturated FA (MUFA) with unchanged content of saturated FA (SFA). Exposure of mice to EHF EMR before or after X-irradiation prevented changes in the total FA content in thymic tissue, returned the summary content of PUFA and MUFA to the control level and decreased the summary content of SFA on the 30th day after the treatments, and promoted the restoration of the thymus weight of X-irradiated mice to the 40th day of the observations. Changes in the content and composition of PUFA in the early period after treatments as well as at the restoration of the thymus weight under the combined action of EHF EMR and X-rays indicate to an active participation of FA in the acceleration of post-radiation recovery of the thymus by EHF EMR exposure.

  19. Ultra-Wideband Printed Slot Radiators with Controllable Frequency Characteristics

    Directory of Open Access Journals (Sweden)

    S. L. Chernyshev

    2015-01-01

    Full Text Available We have studied the possibility of creating ultra-wideband (UWB antennas with controlled frequency response of matching based on the printed slot antenna Vivaldi by introducing controlled resonators directly into the structure of the radiator. In the area of irregular slotline there are printed switched resonators with variable capacitance (varactor model, which allow tuning the frequency characteristics for each state of switching cavities, providing bandpass and band-barrage properties of the antenna. The investigation of reconfigurable printed resonators in the system of reconfigurable resonators of a bandpass filter is conducted. The paper considers filter to provide restructuring in the band (3-9 GHz. Electrodynamic simulation of the device was carried out in the time domain using a finite integration method. A bandstop reconfigurable filter is also investigated. The filter located on the substrate opposite the slit is based on tunable L-shaped resonator that has one end connected to the short-circuitor through the board metallization; the other end remains open and is brought into the region of interaction with the slotline. Such filter provides an effective narrow-band suppression and can be easily tuned to the desired frequency channel. The combination of these two types of filters allows you to create a controlled print Vivaldi slot antenna with combined properties. The paper investigates parameters of the scattering and radiation pattern of the antenna in different modes.

  20. Radiation effects on polymers

    International Nuclear Information System (INIS)

    Clough, R.L.; Shalaby, S.W.

    1991-01-01

    This book covers polymer radiation effects to be available in more than a decade. This volume reviews the fundamental chemistry and physics of polymer-radiation interaction and examines recent progress in most major areas of the field. Its 38 chapters, cover: fundamentals of polymer radiation chemistry; technological applications of radiation to polymers (including radiation processing; radiation curing; sterilization; cross-linking, polymerization, grafting, x-ray resists, and others); and degradation of stabilization of irradiated polymers (including nuclear plants, scintillation detectors for particle physics, and others)

  1. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

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

  2. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

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

  3. 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

  4. Measurements of the frequency spectrum of transition radiation

    Science.gov (United States)

    Cherry, M. L.; Mueller, D.

    1977-01-01

    We report a measurement of the frequency spectrum of X-ray transition radiation. X rays were generated by electrons of 5 and 9 GeV in radiators of multiple polypropylene foils, and detected in the range 4 to 30 keV with a calibrated single-crystal Bragg spectrometer. The experimental results closely reproduce the features of the theoretically predicted spectrum. In particular, the pronounced interference pattern of multifoil radiators and the expected hardening of the radiation with increasing foil thickness are clearly observed. The overall intensity of the radiation is somewhat lower than predicted by calculations.

  5. Effects of the action of microwave-frequency electromagnetic radiation on the spike activity of neurons in the supraoptic nucleus of the hypothalamus in rats.

    Science.gov (United States)

    Minasyan, S M; Grigoryan, G Yu; Saakyan, S G; Akhumyan, A A; Kalantaryan, V P

    2007-02-01

    Acute experiments on white rats anesthetized with Nembutal (40 mg/kg, i.p.) were performed with extracellular recording and analysis of background spike activity from neurons in the supraoptic nucleus of the hypothalamus after exposure to electromagnetic radiation in the millimeter range. The distribution of neurons was determined in terms of the degree of regularity, the nature of the dynamics of neural streams, and the modalities of histograms of interspike intervals; the mean neuron spike frequency was calculated, along with the coefficient of variation of interspike intervals. These studies demonstrated changes in the background spike activity, predominantly affecting the internal structure of the spike streams recorded. The major changes were in the duration of interspike intervals and the degree of regularity of spike activity. Statistically significant changes in the mean spike frequencies of neuron populations in individual frequency ranges were also seen.

  6. High frequency radiation from dynamic earthquake fault models

    International Nuclear Information System (INIS)

    Madariaga, R.

    1983-01-01

    We study the radiation of high frequency waves from a simple antiplane model of an earthquake source. In this model only antiplane waves are generated so that the mathematics is relatively simple, but the physics is the same as in the more complex plane or three dimensional models where P and S waves are radiated. An exact solution is found for the problem of an arbitrary moving semi-infinite crack in the presence of a general dynamic stress drop. In the case when friction is independent of time, an algebraic expression is obtained for particle velocity. This result is exploited to understand the origin of high frequency waves, and the role of rupture velocity and stress intensity on the radiation. We show that barriers and asperities dominate the radiation, but that they are indistinguishable from a high frequency point of view

  7. Development of Radio Frequency Antenna Radiation Simulation Software

    International Nuclear Information System (INIS)

    Mohamad Idris Taib; Rozaimah Abd Rahim; Noor Ezati Shuib; Wan Saffiey Wan Abdullah

    2014-01-01

    Antennas are widely used national wide for radio frequency propagation especially for communication system. Radio frequency is electromagnetic spectrum from 10 kHz to 300 GHz and non-ionizing. These radiation exposures to human being have radiation hazard risk. This software was under development using LabVIEW for radio frequency exposure calculation. For the first phase of this development, software purposely to calculate possible maximum exposure for quick base station assessment, using prediction methods. This software also can be used for educational purpose. Some results of this software are comparing with commercial IXUS and free ware NEC software. (author)

  8. Evaluation of gamma radiation response of electrolyte, MKP and MKT capacitors in various frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Malekie, Shahryar [Nuclear Science and Technology Research Institute, Karaj (Iran, Islamic Republic of). Radiation Application Research School; Salehpour, Behrooz [Tabriz Univ. (Iran, Islamic Republic of). Faculty of Physics

    2017-09-01

    In this experimental work, the effect of gamma irradiation on the capacitance and impedance of some commercial capacitors namely electrolytic, MKP, and MKT capacitors in different radiation doses up to 120 kGy and a wide range of frequencies between 42 Hz and 5 MHz were studied. Results showed that the capacitances of the electrolytic capacitors exhibited a linear decrease by increasing the radiation dose and frequencies, which can be used for high dosimetry purposes, but non-ceramic capacitors as MKP and MKT showed much higher radiation resistance, particularly for the frequencies less than ∝1 MHz.

  9. Radiation effects in space

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1987-07-01

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

  10. Radiation effects and radioprotectors

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  11. Radio Frequency Electromagnetic Radiation From Streamer Collisions

    Science.gov (United States)

    Luque, Alejandro

    2017-10-01

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  12. Radio Frequency Electromagnetic Radiation From Streamer Collisions.

    Science.gov (United States)

    Luque, Alejandro

    2017-10-16

    We present a full electromagnetic model of streamer propagation where the Maxwell equations are solved self-consistently together with electron transport and reactions including photoionization. We apply this model to the collision of counter-propagating streamers in gaps tens of centimeters wide and with large potential differences of hundreds of kilovolts. Our results show that streamer collisions emit electromagnetic pulses that, at atmospheric pressure, dominate the radio frequency spectrum of an extended corona in the range from about 100 MHz to a few gigahertz. We also investigate the fast penetration, after a collision, of electromagnetic fields into the streamer heads and show that these fields are capable of accelerating electrons up to about 100 keV. By substantiating the link between X-rays and high-frequency radio emissions and by describing a mechanism for the early acceleration of runaway electrons, our results support the hypothesis that streamer collisions are essential precursors of high-energy processes in electric discharges.

  13. RETRACTED — Studies on the effect of instability of divergence, pointing and amplitude of green and yellow radiation pulses of copper vapour laser in second harmonic and sum frequency conversion

    Science.gov (United States)

    Prakash, Om; Mahakud, Ramakanta; Nakhe, Shankar V.; Dixit, Sudhir K.

    2013-02-01

    This paper presents the effect of single pulse stability of divergence angle, beam pointing angle and amplitude of green and yellow radiation pulses of an unstable resonator copper vapour laser (CVL) oscillator in the sum frequency mixing and second harmonic. The conversion efficiency of sum frequency generation was lower compared to second harmonic processes despite larger fundamental power being used in sum frequency experiments. However the net UV power obtained at the sum frequency was higher than both of the second harmonic UV frequencies. Lower SFG conversion efficiency (12.4%—271 nm) compared to SHG (16.7%—255 nm, 14.5%—289 nm) of individual CVL radiations is attributed to difference in single pulse stability of beam pointing, divergence and amplitude fluctuation of both CVL radiations in addition to commonly known fact of spatio-temporal mis-match. At the same fundamental input power (2.7 W), higher SH conversion efficiency of yellow (12.7%) compared to green (11.0%) is attributed to its better single pulse stability of beam pointing and divergence.

  14. Handbook of radiation effects

    International Nuclear Information System (INIS)

    Holmes-Siedle, A.; Adams, L.

    1993-01-01

    This handbook is intended to serve as a tool for designers of equipment and scientific instruments when they are required to ensure the survival of the equipment in radiation environments. High technology materials, especially semiconductors, optics and organic materials, tend to degrade on exposure to radiation in many different ways. Hence the need for a guidebook to that set of radiation effects. As for the radiation environments, first, space has a naturally high radiation level. Secondly, the surface of the Earth is radioactive at a low level. When we go down a uranium mine or explore space, we run into much higher levels. Man makes even higher levels for a multitude of purposes. Intense high-energy radiation environments are found in nuclear reactors and accelerators, machines for radiation therapy, and industrial sterilization. Some engineers have to build equipment which will survive a nuclear explosion from a hostile source. Finally, there is the huge problem of machining or handling intensely radioactive isotopes such as spent nuclear fuel rods or radiotherapy capsules and dealing with the dispersed radioactivity from a nuclear accident. Having provided an introductory background on the main types of radiation, radiation environments and the interaction of radiation and solids, we go into detail on the more sensitive technologies and discuss in depth the best solutions for spacecraft, terrestrial robots and imagers. (Author)

  15. Effective switching frequency multiplier inverter

    Science.gov (United States)

    Su, Gui-Jia; Peng, Fang Z.

    2007-08-07

    A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

  16. Biophysical radiation effects

    International Nuclear Information System (INIS)

    Fidorra, J.

    1982-07-01

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

  17. Nonlinear radiation of waves at combination frequencies due to radiation-surface wave interaction in plasmas

    International Nuclear Information System (INIS)

    El Naggar, I.A.; Hussein, A.M.; Khalil, Sh.M.

    1992-09-01

    Electromagnetic waves radiated with combination frequencies from a semi-bounded plasma due to nonlinear interaction of radiation with surface wave (both of P-polarization) has been investigated. Waves are radiated both into vacuum and plasma are found to be P-polarized. We take into consideration the continuity at the plasma boundary of the tangential components of the electric field of the waves. The case of normal incidence of radiation and rarefield plasma layer is also studied. (author). 7 refs

  18. Effects of ionizing radiations

    International Nuclear Information System (INIS)

    Gaussens, G.

    1984-08-01

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

  19. Controlling Energy Radiations of Electromagnetic Waves via Frequency Coding Metamaterials.

    Science.gov (United States)

    Wu, Haotian; Liu, Shuo; Wan, Xiang; Zhang, Lei; Wang, Dan; Li, Lianlin; Cui, Tie Jun

    2017-09-01

    Metamaterials are artificial structures composed of subwavelength unit cells to control electromagnetic (EM) waves. The spatial coding representation of metamaterial has the ability to describe the material in a digital way. The spatial coding metamaterials are typically constructed by unit cells that have similar shapes with fixed functionality. Here, the concept of frequency coding metamaterial is proposed, which achieves different controls of EM energy radiations with a fixed spatial coding pattern when the frequency changes. In this case, not only different phase responses of the unit cells are considered, but also different phase sensitivities are also required. Due to different frequency sensitivities of unit cells, two units with the same phase response at the initial frequency may have different phase responses at higher frequency. To describe the frequency coding property of unit cell, digitalized frequency sensitivity is proposed, in which the units are encoded with digits "0" and "1" to represent the low and high phase sensitivities, respectively. By this merit, two degrees of freedom, spatial coding and frequency coding, are obtained to control the EM energy radiations by a new class of frequency-spatial coding metamaterials. The above concepts and physical phenomena are confirmed by numerical simulations and experiments.

  20. Effect of chlorophyllin on frequency radiation-induced of sister chromatid exchanges (SCE) and other cytogenetic events in mice bone marrow cells In Vivo

    International Nuclear Information System (INIS)

    Garcia Rodriguez, M.C.

    1992-01-01

    The effect of chlorophyllin on gamma radiation induced Sister chromatid exchanges (SCE) and on the mitotic index (IM) and average generation time was determined. Groups of mice were treated in one of the following regimens: (1) untreated, (2) treated with chlorophyllin only, (3) irradiated and (4) treated with chlorophyllin and irradiated intraperitoneal administration of chlorophyllin preceding gamma radiation exposure protected again SCE induction and diminution of IM. However, radioprotection was not reflected in the average generation time for the chlorophyllin per se acceleration the average generation time. The results suggest that, under the experimental conditions of the study the SCE and IM are caused by free radicals produced by radiation and wat the action mechanics of chlorophyllin is scavenger free radicals. (Author)

  1. Radio Frequency Radiation Dosimetry Handbook (Fifth Edition)

    Science.gov (United States)

    2009-07-01

    BODY TO RFR .............................. 213 7.4 THERMAL WAVE EFFECTS...249 8.12 SIGNS AND SYMPTOMS OF RFR OVEREXPOSURE...INSTRUMENTATION FOR MEASURING RFR FIELDS ............................... 267 9.4 DEVELOPMENT OF RFR INSTRUMENTATION

  2. Therapeutic possibilities of electromagnetic radiation of very high frequency

    OpenAIRE

    Chwaleba, Augustyn; Jatsunenko, Anatoly; Kamkov, V.; Szczurko, Jan; Szmitkowski, Józef; Yatsunenko, Sergey; Wilczkowski, Stefan

    2012-01-01

    Virtually the entire spectrum of electromagnetic radiation is applied in medicine, with the fact tha t the radiation in the frequency band from 30 GHz to 300 GHz has been used recently. The authors developed (and continue to improve) the therapeutic method that uses electromagnetic fields of very high frequency (vhf) in the band from 40 GHz to 70 GHz and sublow intensity the power flux density does not exceed 1 μW / cm ². This field acts informationally on cells, causing the reactivation proc...

  3. Electromagnetic radiation trapped in the magnetosphere above the plasma frequency

    Science.gov (United States)

    Gurnett, D. A.; Shaw, R. R.

    1973-01-01

    An electromagnetic noise band is frequently observed in the outer magnetosphere by the Imp 6 spacecraft at frequencies from about 5 to 20 kHz. This noise band generally extends throughout the region from near the plasmapause boundary to near the magnetopause boundary. The noise typically has a broadband field strength of about 5 microvolts/meter. The noise band often has a sharp lower cutoff frequency at about 5 to 10 kHz, and this cutoff has been identified as the local electron plasma frequency. Since the plasma frequency in the plasmasphere and solar wind is usually above 20 kHz, it is concluded that this noise must be trapped in the low-density region between the plasmapause and magnetopause boundaries. The noise bands often contain a harmonic frequency structure which suggests that the radiation is associated with harmonics of the electron cyclotron frequency.

  4. Micronuclei Frequencies in Lymphocytes of Nuclear Malaysia Radiation Workers

    International Nuclear Information System (INIS)

    Mohd Rodzi Ali; Aisyah Mohd Yusof; Rahimah Abdul Rahim; Juliana Mahamat Napiah; Yahaya Talib; Shafii Khamis

    2016-01-01

    The objective of the study is to investigate the frequency of cell aberration in lymphocytes of the Nuklear Malaysia radiation workers. A total of 58 blood samples were collected from the radiation workers during their routine medical examination. The donor age range is between 23 to 58 years, 31 male and 27 female. Blood samples were cultured according to the standard protocol recommended by the International Atomic Energy Agency. The mean micronuclei (MN) is 23.5 ± 0.9 MN/ 1000 binucleate, with the median value of 24 MN/ 1000 binucleate. The lowest number of MN was 9, and the highest was 43. There is no correlation between the number of MN in blood and yearly cumulative dose for radiation workers. The results indicate the MN expression due to small radiation exposure is almost negligible in Nuclear Malaysia radiation workers. (author)

  5. Does the cellphone radio-frequency electromagnetic radiation ...

    African Journals Online (AJOL)

    Debate regarding the biological effect of electromagnetic radiation has been recently raised. The effects of this radiation on locomotor activity are not well known. Hence, in this study, we used Drosophila melanogaster as a model organism to investigate the possible effects of short-term exposure to ringing or talking ...

  6. Management of radio frequency radiation exposures in telecom Australia

    International Nuclear Information System (INIS)

    Joyner, K.H.; Hocking, B.

    1992-01-01

    Telecom Australia is the largest non-military user of radio frequency radiation (RFR) in Australia and the management of risks to health from RFR exposure are discussed. The Australian RFR Exposure Standard forms that basis of risk assessment. Risk assessment and control procedures including the health surveillance of workers, other special occupational groups and members of the general public are outlined. (author)

  7. Vacuum amplification of the high-frequency electromagnetic radiation

    OpenAIRE

    Vilkovisky, G. A.

    1998-01-01

    When an electrically charged source is capable of both emitting the electromagnetic waves and creating charged particles from the vacuum, its radiation gets so much amplified that only the backreaction of the vacuum makes it finite. The released energy and charge are calculated in the high-frequency approximation. The technique of expectation values is advanced and employed.

  8. High density terahertz frequency comb produced by coherent synchrotron radiation

    Science.gov (United States)

    Tammaro, S.; Pirali, O.; Roy, P.; Lampin, J.-F.; Ducournau, G.; Cuisset, A.; Hindle, F.; Mouret, G.

    2015-07-01

    Frequency combs have enabled significant progress in frequency metrology and high-resolution spectroscopy extending the achievable resolution while increasing the signal-to-noise ratio. In its coherent mode, synchrotron radiation is accepted to provide an intense terahertz continuum covering a wide spectral range from about 0.1 to 1 THz. Using a dedicated heterodyne receiver, we reveal the purely discrete nature of this emission. A phase relationship between the light pulses leads to a powerful frequency comb spanning over one decade in frequency. The comb has a mode spacing of 846 kHz, a linewidth of about 200 Hz, a fractional precision of about 2 × 10-10 and no frequency offset. The unprecedented potential of the comb for high-resolution spectroscopy is demonstrated by the accurate determination of pure rotation transitions of acetonitrile.

  9. Effects of ionizing radiation

    International Nuclear Information System (INIS)

    Tadmor, J.

    1984-05-01

    A sound evaluation of the consequences of releases of radioactivity into the environment, especially of those large amounts, and of the effectiveness of different protective measures, requires thorough concern of the various aspects of the radiological effects. The effects of ionizing radiation were reviewed according to the following characterization: Affected subject (somatic, genetic and psychological effects); Duration of irradiation (acute and chronic irradiation); Latent period (early and late effects); Dose-effect relationship (stochastic and non-stochastic effects); Population affected (e.g. children, pregnant women). In addition to the lethal effects which are generally considered extensively in all the evaluations of the consequences of radioactivity releases, such effects as early symptoms and morbidity are emphasized in this review. The dependence of the effects on dose rates, repair mechanism and medical treatment is discussed, and the uncertainties involved with their evaluation is highlighted. The differences between QF (quality factor) and RBE (relative biological effectiveness) of different radiation sources are interpreted. Synergystic effects and the effectiveness of various means of medication are discussed. It is suggested that all radiological effects, including those resulting from relatively low radiation doses, e.g. foetus deformations, fertility impairment, prodomal - leading to psychological effects, should be considered within the evaluation of the consequences of radioactivity releases and of the effectiveness of protective measures. Limits of the repair factors to be considered within the evaluation of the effects of chronic exposures are proposed

  10. Changes in Frequency of Electromagnetic Radiation from Loaded Coal Rock

    Science.gov (United States)

    Song, Dazhao; Wang, Enyuan; Song, Xiaoyan; Jin, Peijian; Qiu, Liming

    2016-01-01

    To understand the relationship between the frequency of electromagnetic radiation (EMR) emitted from loaded coal rock and the micro-crack structures inside it, and assess the stress state and the stability of coal rock by analyzing frequency changes in characteristics of its emitted EMR, we first experimentally studied the changes in time sequence and the frequency spectrum characteristics of EMR during uniaxial compression, then theoretically derived the relationship between the principal frequency of EMR signals and the mechanical parameters of coal crack and analyzed the major factors causing the changes in the principal frequency, and lastly verified the results at Nuodong Coal Mine, Guizhou Province, China. The experimental results showed that (1) EMR intensity increased with the applied stress on loaded coal rock during its deformation and failure and could qualitatively reflect the coal's stress status; (2) with the applied stress increasing, the principal frequency gradually increased from near zero to about 60 kHz and then dropped to less than 20 kHz. During this period, coal rock first stepped into the linearly and elastically deformed stage and then ruptured around the peak load. Theoretical analysis showed that there was a negative correlation between the principle frequency and the size of internal cracks. Field detection showed that a lower principle frequency was generated from coal rock applied by a greater load, while a higher principal frequency was generated from coal rocks suffering a weaker load.

  11. Handbook of radiation effects

    International Nuclear Information System (INIS)

    Holmes-Siedle, A.; Adams, L.

    1993-01-01

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

  12. 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.

  13. Biological Effects of Radiation

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  14. Radiation effects on living systems

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1980-10-01

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

  15. Effects of 415 MHz frequency on human lymphocyte genome

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Fucic, A.; Kubelka, D.; Vojvodic, S.

    1996-01-01

    The continuously increasing use of artificial sources of electromagnetic radiation in industry and medicine has been accompanied in everyday life with telecommunication systems which is followed with great interest in possible hazardous effects of this type of radiation. The interesting applications of mobile telecommunications and the use of cellular phones are of topic interest. Numerous cytogenetic investigations are focused on the effects of microwave radiation from mobile communications frequency of 450 and 950 MHz on isolated cells in vitro. The aim of this work was to investigate the effects of microwaves from mobile telephone frequencies on human peripheral blood lymphocytes cultured in vitro. (author)

  16. The distinguishing effects of low-intensity electromagnetic radiation of different extremely high frequencies on Enterococcus hirae: growth rate inhibition and scanning electron microscopy analysis.

    Science.gov (United States)

    Hovnanyan, K; Kalantaryan, V; Trchounian, A

    2017-09-01

    A low-intensity electromagnetic field of extremely high frequency has inhibitory and stimulatory effects on bacteria, including Enterococcus hirae. It was shown that the low-intensity (the incident power density of 0·06 mW cm -2 ) electromagnetic field at the frequencies of 51·8 GHz and 53 GHz inhibited E. hirae ATCC 9790 bacterial growth rate; a stronger effect was observed with 53 GHz, regardless of exposure duration (0·5 h, 1 h or 2 h). Scanning electron microscopy analysis of these effects has been done; the cells were of spherical shape. Electromagnetic field at 53 GHz, but not 51·8 GHz, changed the cell size-the diameter was enlarged 1·3 fold at 53 GHz. These results suggest the difference in mechanisms of action on bacteria for electromagnetic fields at 51·8 GHz and 53 GHz. A stronger inhibitory effect of low-intensity electromagnetic field on Enterococcus hirae ATCC 9790 bacterial growth rate was observed with 53 GHz vs 51·8 GHz, regardless of exposure duration. Scanning electron microscopy analysis showed that almost all irradiated cells in the population have spherical shapes similar to nonirradiated ones, but they have increased diameters in case of irradiated cells at 53 GHz, but not 51·8 GHz. The results are novel, showing distinguishing effects of low-intensity electromagnetic field of different frequencies. They could be applied in treatment of food and different products in medicine and veterinary, where E. hirae plays an important role. © 2017 The Society for Applied Microbiology.

  17. Radiation effects in normal tissues

    International Nuclear Information System (INIS)

    Trott, K.R.; Herrmann, T.; Doerr, W.

    2002-01-01

    Knowledge of radiation effects in normal tissues is fundamental for optimal planning of radiotherapy. Therefore, this book presents a review on the following aspects: General pathogenesis of acute radiation effects in normal tissues; general pathogenesis of chronic radiation effects in normal tissues; quantification of acute and chronic radiation effects in normal tissues; pathogenesis, pathology and radiation biology of various organs and organ systems. (MG) [de

  18. Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M. (Universite du Quebec a Montreal (Canada))

    1989-10-01

    The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population.

  19. Mutant frequency of radiotherapy technicians appears to be associated with recent dose of ionizing radiation

    International Nuclear Information System (INIS)

    Messing, K.; Ferraris, J.; Bradley, W.E.; Swartz, J.; Seifert, A.M.

    1989-01-01

    The frequency of hypoxanthine phosphoribosyl transferase (HPRT) mutants among peripheral T-lymphocytes of radiotherapy technicians primarily exposed to 60Co was measured by the T-cell cloning method. Mutant frequencies of these technicians in 1984 and 1986 were significantly higher than those of physiotherapy technicians who worked in a neighboring service, and correlated significantly with thermoluminescence dosimeter readings recorded during the 6 mo preceding mutant frequency determination. Correlations decreased when related to dose recorded over longer time intervals. HPRT mutant frequency determination in peripheral lymphocytes is a good measure of recently received biologically effective radiation dose in an occupationally exposed population

  20. Nonlinearity of radiation health effects.

    OpenAIRE

    Pollycove, M

    1998-01-01

    The prime concern of radiation protection policy since 1959 has been to protect DNA from damage. In 1994 the United Nations Scientific Community on the Effects of Atomic Radiation focused on biosystem response to radiation with its report Adaptive Responses to Radiation of Cells and Organisms. The 1995 National Council on Radiation Protection and Measurements report Principles and Application of Collective Dose in Radiation Protection states that because no human data provides direct support ...

  1. Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

    Science.gov (United States)

    Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

    2017-08-01

    Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

  2. Frequency Tuning of IR First-Overtone CO Laser Radiation by Diffraction Grating and Frequency Selective Output Couplers

    National Research Council Canada - National Science Library

    Ionin, Andre

    1999-01-01

    ...: The contractor will investigate, both experimentally and theoretically, the feasibility of frequency tuning the first overtone carbon monoxide laser radiation by the use of diffraction gratings...

  3. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1981-05-01

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

  4. THE RELATION OF FREQUENCY TO THE PHYSIOLOGICAL EFFECTS OF ULTRA-HIGH FREQUENCY CURRENTS.

    Science.gov (United States)

    Christie, R V; Loomis, A L

    1929-01-31

    1. Biological effects of electromagnetic waves emitted by a vacuum tube oscillator have been studied at frequencis ranging from 8,300,000 to 158,000,000 cycles per second (1.9 to 38 meters wave-length). 2. The effects produced on animals can be fully explained on the basis of the heat generated by high frequency currents which are induced in them. 3. No evidence was obtained to support the theory that certain wave-lengths have a specific action on living cells. 4. At frequencies below 50,000,000 cycles, the effect of these radiations on animals is proportionate to the intensity of the electro-magnetic field. As the frequency is increased beyond this point, the amount of induced current is diminished and the apparent lethality of the radiation is decreased. This can be explained by changes occurring in the dielectric properties of tissues at low wave-lengths.

  5. Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    1979-01-01

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

  6. [Effect of American Ginseng Capsule on the liver oxidative injury and the Nrf2 protein expression in rats exposed by electromagnetic radiation of frequency of cell phone].

    Science.gov (United States)

    Luo, Ya-ping; Ma, Hui-Rong; Chen, Jing-Wei; Li, Jing-Jing; Li, Chun-xiang

    2014-05-01

    To observe the effect of American Ginseng Capsule (AGC) on the liver oxidative injury and the Nrf2 protein expression in the liver tissue of rats exposed by 900 MHz cell phone electromagnetic radiation. Totally 40 male SD rats were randomly divided into the normal control group, the model group, the Shuifei Jibin Capsule (SJC) group, and the AGC group,10 in each group. Rats in the normal control group were not irradiated. Rats in the rest three groups were exposed by imitated 900 MHz cellular phone for 4 h in 12 consecutive days. Meanwhile, rats in the SJC group and the AGC group were intragastrically administrated with suspension of SJC and AGC (1 mL/200 g body weight) respectively. Normal saline was administered to rats in the normal control group and the model group. The histolomorphological changes of the liver tissue were observed by HE staining. Contents of malonic dialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-PX)were detected by colorimetry. The Nrf2 protein expression of hepatocytes was detected by immunohistochemical assay and Western blot. Compared with the normal control group, hepatocyte nucleus was atrophied or partially disappeared, the contents of liver MDA and Nrf2 protein obviously increased (P electromagnetic radiation induced by 900 MHz cell phone could affect the expression of Nrf2 protein, induce oxidative injury, and induce abnormal morphology of liver cells. SJC and AGC could promote the morphological recovery of the liver cells. Its mechanism might be related to affecting the expression of Nrf2 protein and attenuating oxidative damage of liver cells.

  7. Radiation Bystander Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Shokohzaman Soleymanifard

    2009-06-01

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

  8. Impact of radiation frequency, precipitation radiative forcing, and radiation column aggregation on convection-permitting West African monsoon simulations

    Science.gov (United States)

    Matsui, Toshi; Zhang, Sara Q.; Lang, Stephen E.; Tao, Wei-Kuo; Ichoku, Charles; Peters-Lidard, Christa D.

    2018-03-01

    In this study, the impact of different configurations of the Goddard radiation scheme on convection-permitting simulations (CPSs) of the West African monsoon (WAM) is investigated using the NASA-Unified WRF (NU-WRF). These CPSs had 3 km grid spacing to explicitly simulate the evolution of mesoscale convective systems (MCSs) and their interaction with radiative processes across the WAM domain and were able to reproduce realistic precipitation and energy budget fields when compared with satellite data, although low clouds were overestimated. Sensitivity experiments reveal that (1) lowering the radiation update frequency (i.e., longer radiation update time) increases precipitation and cloudiness over the WAM region by enhancing the monsoon circulation, (2) deactivation of precipitation radiative forcing suppresses cloudiness over the WAM region, and (3) aggregating radiation columns reduces low clouds over ocean and tropical West Africa. The changes in radiation configuration immediately modulate the radiative heating and low clouds over ocean. On the 2nd day of the simulations, patterns of latitudinal air temperature profiles were already similar to the patterns of monthly composites for all radiation sensitivity experiments. Low cloud maintenance within the WAM system is tightly connected with radiation processes; thus, proper coupling between microphysics and radiation processes must be established for each modeling framework.

  9. Effects Of Radiation On Elastomers

    Science.gov (United States)

    Bouquet, Frank L.

    1988-01-01

    Report provides data on effects of radiation on elastomers. Quantifies effects by giving minimum radiation levels to induce changes of 1 percent and 25 percent in given properties. Electrical, mechanical, and chemical properties included in data. Combined effects of heat and radiation briefly considered. Data summarized in graphic form useful to designers.

  10. Cumulative radiation effect

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  11. Radiation effects on polyethylenes

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  12. Biological effects of ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

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

  13. [Cardiac effects of radiation therapy].

    Science.gov (United States)

    Tuohinen, Suvi; Turpeinen, Anu; Skyttä, Tanja; Kellokumpu-Lehtinen, Pirkko-Liisa

    2015-01-01

    Because of increased life-expentancy cancer patients having undergone radiation therapy nowadays live longer, and late-appearing adverse effects are therefore playing a more significant role. Radiation therapy given to the chest is known to approximately double the risk of heart disease, the cumulative total radiation dose being the most important risk-increasing factor. The most significant adverse effects appear only years after the treatment. The mortality from late manifestations reduces the total benefit of radiation therapy. Patients with radiation therapy due to a cancer of the left breast or Hodgkin's lymphoma are particularly susceptible to cardiac effects. A safe radiation dose is not known.

  14. Cumulative radiation effect

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  15. Biological radiation effects

    International Nuclear Information System (INIS)

    Sejourne, Michele.

    1977-01-01

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

  16. Effects of radiation on DNA

    International Nuclear Information System (INIS)

    Braddock, M.

    1985-07-01

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

  17. Potent radio-protective effects of vitamins E and C on radiation induced DNA damage in gametes leading to lower frequencies of chromosomal aberrations and micronuclei in subsequent embryos

    International Nuclear Information System (INIS)

    Hossein Mozdarani

    2007-01-01

    Complete text of publication follows. Objective: To compare the effects of parental and maternal exposure of NMRI mice with γ-rays on gametes in the absence or presence of vitamins E and C and subsequent cytogenetic damage in pre-implantation embryos generated from irradiated gametes. Materials and Methods: Male and female NMRI mice were whole body irradiated in the presence of 200 IU/Kg vitamin E and 100 μg/ml vitamin C. Various mating schemes were designed for mating of irradiated mice, e.g. mating irradiated male with non-irradiated female, irradiated female with non irradiated male or both male and female irradiated. About 68 h post coitus, 4-8-cell embryos were flushed out from oviducts and fixed on slides using standard methods in order to screen for chromosome abnormalities and micronuclei. Results: In control embryos, frequencies of abnormal metaphase and embryos with micronuclei was low and there was no significant difference between vitamins treated samples and controls. However there was an increase in both abnormal metaphases and micronuclei frequency in embryos generated after parental or maternal irradiation or both. Vitamin E effectively reduced the frequency of aneuploidy in all irradiated groups and vitamin C was very effective in reducing the frequencies of micronuclei. DRF calculated for both vitamins indicate that vitamin C is more potent than vitamin E in reducing clastogenic effects of gamma-rays in pre-implantation embryos. Conclusion: Data indicate that γ-irradiation affects spermatogenesis and preovulatory stage oocytes in male and female mice respectively. These effects might be due to DNA alterations in sperms and oocytes affecting meiotic segregations that may lead to chromosome abnormalities in subsequent embryos expressed as numerical chromosome abnormalities or micronuclei. Administration of vitamins E and C before irradiation effectively reduced the frequency of chromosomal abnormalities. The way these vitamins reduces genotoxic

  18. Frequency effects in compound production

    NARCIS (Netherlands)

    Bien, H.; Levelt, W.J.M.; Baayen, R.H.

    2005-01-01

    Four experiments investigated the role of frequency information in compound production by independently varying the frequencies of the first and second constituent as well as the frequency of the compound itself. Pairs of Dutch noun-noun compounds were selected such that there was a maximal contrast

  19. Effects of radiation

    International Nuclear Information System (INIS)

    Masse, R.

    2006-01-01

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

  20. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1991-12-01

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

  1. Radiation effects on living systems

    International Nuclear Information System (INIS)

    Hawley, N.J.

    1984-04-01

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

  2. Study of extremely low frequency electromagnetic field (ELF EMF) radiation produced by consumer products

    International Nuclear Information System (INIS)

    Roha Tukimin; Ahmad Fazli Ahmad Sanusi; Rozaimah Abd Rahim; Mohd Yusof Mohd Ali; Mohamad Amirul Nizam Mohamad Thari

    2006-01-01

    Extremely low frequency electromagnetic field ( ELF EMF) radiation falls under category of non-ionising radiation (NIR).ELF EMF consists of electric and magnetic fields. Excessive exposure to ELF EMF radiation may cause biological and health effects to human beings such as behavioral changes, stochastic and as initiator of cancer. In daily life, the main source of extremely low frequency electromagnetic radiation are consumer products in our home and office. Due to its ability to cause hazard, a study of ELF EMF radiation produced by consumer product was conducted. For this preliminary study, sample of 20 types electrical appliances were selected. The measurement was covered electric and magnetic field strength produced by the sample. PMM model EHP50A were used for measurement and data analysis. The results were compared with the permissible limits recommended by International Commission of Non-Ionising Radiation Protection (ICNIRP) for members of public (1000 mGauss and 5000 V/m). The results showed that all tested sample produced magnetic and electric field but still under the permissible limit recommended by ICNIRP. Besides that we found that field strengths can be very high at closer distance to the sample. (Author)

  3. Low intensity radiation in diapazone of high frequency as factor of the survival modification of differentiated plant cells

    International Nuclear Information System (INIS)

    Tordiya, N.V.

    2005-01-01

    The combined effect of low intensity electromagnetic emission in high frequency range (EMI HF) and ionizing radiation on survival of the differential cells of high plant water Elodea canadensis is investigated. It was established, that EMI HF is radioprotective modification of the radiation injury of plant cell

  4. Biology of ionizing radiation effects

    International Nuclear Information System (INIS)

    Ferradini, C.; Pucheault, J.

    1983-01-01

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

  5. Radio frequency radiation (RFR) exposures from mobile phones

    International Nuclear Information System (INIS)

    Joyner, K.H.; Lubinas, V.; Wood, M.P.; Saribalas, J.; Adams, J.A.

    1992-01-01

    Measurements of the free space levels of radio frequency radiation (RFR) around a hand-held mobile phone and the specific absorption rate (SAR) induced in the ocular region of a phantom head exposed to RFR from a mobile phone are presented. The level of RFR measured 5 cm from the antenna of a mobile phone transmitting 600 mW was 0.27 mW/cm 2 . The average SAR level measured in the nearside eye of the phantom head containing tissue equivalent jellies was 0.7 W/kg for a 600 mW transmit power which is very much less than the spatial peak limit of 8 W/kg underlying the Australian and other national and international RFR exposure standards. (author)

  6. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

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

  7. Radiation effects on lymphocytes

    International Nuclear Information System (INIS)

    Roser, B.

    1976-01-01

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

  8. 21 CFR 179.30 - Radiofrequency radiation for the heating of food, including microwave frequencies.

    Science.gov (United States)

    2010-04-01

    ..., including microwave frequencies. 179.30 Section 179.30 Food and Drugs FOOD AND DRUG ADMINISTRATION... for the heating of food, including microwave frequencies. Radiofrequency radiation, including microwave frequencies, may be safely used for heating food under the following conditions: (a) The radiation...

  9. Health effects of ionizing radiation

    International Nuclear Information System (INIS)

    Pathak, B.

    1989-12-01

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

  10. Radiation hazards and their effects

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  11. Chemical effects of radiation

    International Nuclear Information System (INIS)

    Philips, G.O.

    1986-01-01

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

  12. Morphological aspects of poly-organic impact of radio frequency electromagnetic radiation in experiment

    OpenAIRE

    TASHPULATOVA GUZAL ALIEVNA; MAVLYAN-HODZHAEV RAVSHAN SHUKHRATOVICH

    2015-01-01

    The impact of radio frequency electromagnetic radiation (RFEMR) on morphological responses of some organs of experimental animals has been studied. The RFEMR effect was shown to manifest itself by pathological changes in the structure of the majority of organs and tissues with the critical impact of the micro-vascular bed impairment on not only morphological, metabolic but also many other homeostasis shifts that occurred.

  13. EFFECTS OF LOW FREQUENCY ELECTROMAGNETIC FIELDON THE HUMAN BODY

    Directory of Open Access Journals (Sweden)

    PETRICA POPOV

    2016-06-01

    Full Text Available International standardization institutions, which play an important role in assessing the effects o f the field and determining the need to take protective measures for the human factor, developed safety standards on human exposure to electromagnetic field, differentiated for electric and magnetic fields of low frequency ( near fields, as well as to ele ctromagnetic radiation fields (far fields. Until recently, many studies has shown that the main harmful effect on the human body was produced by high frequency electromagnetic field, but in recent years, more and more information also reveals that the serious damage can be caused by low frequency electric and magnetic fields. These low -frequency electromagnetic fields interact with human tissue causing harmful effects, the degree of destruction depending on factors such as: intensity, frequency, energy f ield level and duration of exposure.

  14. Spallation radiation effects in materials

    International Nuclear Information System (INIS)

    Mansur, L.K.; Farrell, K.; Wechsler, M.S.

    1996-01-01

    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

  15. Radiation effect on polytetrafluoroethylene

    International Nuclear Information System (INIS)

    Deng Pengyang; Zhong Xiaoguang; Sun Jiazhen

    1999-01-01

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

  16. Health Effects of UV Radiation

    Science.gov (United States)

    ... Related Topics: Sun Safety Contact Us Share Health Effects of UV Radiation Ozone layer depletion decreases our ... against these invaders. Fact Sheet Download the Health Effects of Overexposure to the Sun (PDF) Did You ...

  17. Radiation effects in optoelectronic devices

    International Nuclear Information System (INIS)

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

    1984-05-01

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

  18. Low-frequency oscillations in radiative-convective models

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qi; Randall, D.A.

    1991-12-31

    Although eastward propagation is usually regarded as an essential feature of the low-frequency ``Madden-Julian oscillation`` observed in the tropical atmosphere, many observations indicate that there is an important stationary or quasi-stationary component of the oscillation. Yasunari (1979), for example, investigated the stationary 30--60 day variation in upper tropospheric cloudiness in the Asian summer monsoon region. In a case study of the 30--60 day oscillation. Hsu et al. (1990) found a strong stationary oscillation of the divergence, outgoing longwave mdiadon and other fields. A recent observational study by Weickmann and Khalsa (1990) offers further evidence that the Madden-Julian oscillation has an important stationary component. In this paper, we present evidence that intraseasonal oscillations can be produced by local radiative and convective processes. This suggests that the observed propagating Madden-Julian wave is produced by interactions between these local processes and the large scale motion field, and is not essential for the existence of the observed oscillation.

  19. Low-frequency oscillations in radiative-convective models

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Qi; Randall, D.A.

    1991-01-01

    Although eastward propagation is usually regarded as an essential feature of the low-frequency Madden-Julian oscillation'' observed in the tropical atmosphere, many observations indicate that there is an important stationary or quasi-stationary component of the oscillation. Yasunari (1979), for example, investigated the stationary 30--60 day variation in upper tropospheric cloudiness in the Asian summer monsoon region. In a case study of the 30--60 day oscillation. Hsu et al. (1990) found a strong stationary oscillation of the divergence, outgoing longwave mdiadon and other fields. A recent observational study by Weickmann and Khalsa (1990) offers further evidence that the Madden-Julian oscillation has an important stationary component. In this paper, we present evidence that intraseasonal oscillations can be produced by local radiative and convective processes. This suggests that the observed propagating Madden-Julian wave is produced by interactions between these local processes and the large scale motion field, and is not essential for the existence of the observed oscillation.

  20. 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

  1. Genetic effects of ionising radiation

    International Nuclear Information System (INIS)

    Saunders, P.

    1981-01-01

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

  2. Epigenetic effects of ionizing radiation

    International Nuclear Information System (INIS)

    EI-Naggar, A.M.

    2007-01-01

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

  3. Bibliography of the Radio Frequency Radiation Branch, Directed Energy Bioeffects Division, Human Effectiveness Directorate, Air Force Research Laboratory: 1997-2003

    Science.gov (United States)

    2004-02-01

    Society, Maui, HI, 22-27 June 2003. Mylacraine, K. S., P. A. Mason, W .D. Hurt, J. M. Ziriax, and V. M. Swegle. Using 3-D CAD objects to populate ... Guilin , China, 18-22 April 2003. Scholl, D., L. Sayegh, R. Constable, and P. A. Mason. Development of predictive models of crowd behavior for users...R. Murphy. Effects of extremely high power microwave pulses on the population spike and long-term potentiation in rat hippocampal slices

  4. Effects of ionizing radiations on roses, 2

    International Nuclear Information System (INIS)

    Lata, P.

    1975-01-01

    A comparative study of the male meiosis in the rose cultivar ''Pink Parfait'' and its two, Deep and Light pink flowered mutants was conducted. ''Pink Parfait'' was found to be a segmental allotetraploid. The frequency of univalents and quadrivalents at metaphase I was higher in the mutants. Anaphase I revealed a higher incidence of lagging chromosomes in Deep pink mutant and an increased frequency of chromosome bridges in both the mutants. The deleterious effects of radiations were evident from the higher percentage of chromosomal aberrations and pollen sterility found in mutants as compared with the control. (auth.)

  5. Genetic effects of ionizing radiation

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  6. Effects of chronic exposure to 950 MHz ultra-high-frequency electromagnetic radiation on reactive oxygen species metabolism in the right and left cerebral cortex of young rats of different ages.

    Science.gov (United States)

    Furtado-Filho, Orlando V; Borba, Juliana B; Maraschin, Tatiana; Souza, Larissa M; Henriques, João A P; Moreira, José C F; Saffi, Jenifer

    2015-01-01

    To assess the effect of 950 MHz ultra-high-frequency electromagnetic radiation (UHF-EMR) on biomarkers of oxidative damage to DNA, proteins and lipids in the left cerebral cortex (LCC) and right cerebral cortex (RCC) of neonate and 6-day-old rats. Twelve rats were equally divided into two groups as controls (CR) and exposed (ER), for each age (0 and 6 days). The LCC and RCC were examined in ER and CR after exposure. Radiation exposure lasted 30 min per day for up to 27 days (throughout pregnancy and 6 days postnatal). The specific absorption rate ranged from 1.32-1.14 W/kg. The damage to lipids, proteins and DNA was verified by thiobarbituric acid reactive substances, carbonylated proteins (CP) and comets, respectively. The concentration of glucose in the peripheral blood of the rats was measured by the Accu-Chek Active Kit due to increased CP in RCC. In neonates, no modification of the biomarkers tested was detected. On the other hand, there was an increase in the levels of CP in the RCC of the 6-day-old ER. Interestingly, the concentration of blood glucose was decreased in this group. Our results indicate that there is no genotoxicity and oxidative stress in neonates and 6 days rats. However, the RCC had the highest concentration of CP that do not seem to be a consequence of oxidative stress. This study is the first to demonstrate the use of UHF-EMR causes different damage responses to proteins in the LCC and RCC.

  7. Radiation effects on structural materials

    International Nuclear Information System (INIS)

    Ghoniem, N.M.

    1991-01-01

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

  8. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

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

  9. Radiation Effects in Zircon

    International Nuclear Information System (INIS)

    Ewing, Rodney C.; Meldrum, Alkiviathes; Wang, L. M.; Weber, William J.; Corrales, Louis R.

    2003-01-01

    The widespread distribution of zircon in the continental crust, its tendency to concentrate trace elements, particularly lanthanides and actinides, its use in age-dating, and its resistance to chemical and physical degradation have made zircon the most important accessory mineral in geologic studies. Because zircon is highly refractory, it also has important industrial applications, including its use as a lining material in high-temperature furnaces. However, during the past decade, zircon has also been proposed for advanced technology applications, such as a durable material for the immobilization of plutonium or, when modified by ion-beam irradiation, as an optic waveguide material. In all of these applications, the change in properties as a function of increasing radiation dose is of critical importance. In this chapter, we summarize the state-of-knowledge on the radiation damage accumulation process in zircon

  10. Aerosol effects in radiation transfer

    International Nuclear Information System (INIS)

    Binenko, V.I.; Harshvardhan, H.

    1993-01-01

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

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

    International Nuclear Information System (INIS)

    Seoung, Youl Hun

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-06-15

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

  13. Effects of radiation on bone.

    Science.gov (United States)

    Pacheco, Rafael; Stock, Harlan

    2013-12-01

    Ionizing radiation produces its deleterious biologic effects by both direct (DNA strand breaks) and indirect processes (formation of free oxygen radicals). Mitotically active cells are more susceptible to the detrimental effects of ionizing radiation. These effects are most severe locally within the treatment field but can also occur systemically, possibly reflecting hormonal influences and inflammatory cytokine mediators. Specific bone complications of radiation include osteopenia, growth arrest, fracture and malignancy. Some of these complications, such as osteopenia, are reversible and severity is dose dependent. Insufficiency fractures are a common complication after radiation therapy and generally affect those bones under most physiologic stress and with the highest ratio of trabecular to cortical bone. Familiarity with the radiographic appearance of irradiated bone, including computed tomography (CT) and magnetic resonance imaging (MRI), will improve image interpretation and facilitate accurate diagnosis.

  14. 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.

  15. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.

    1997-01-01

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

  16. 1950MHz Radio Frequency Electromagnetic Radiation Inhibits Testosterone Secretion of Mouse Leydig Cells.

    Science.gov (United States)

    Lin, Yan-Yun; Wu, Tao; Liu, Jun-Ye; Gao, Peng; Li, Kang-Chu; Guo, Qi-Yan; Yuan, Meng; Lang, Hai-Yang; Zeng, Li-Hua; Guo, Guo-Zhen

    2017-12-23

    More studies that are focused on the bioeffects of radio-frequency (RF) electromagnetic radiation that is generated from the communication devices, but there were few reports with confirmed results about the bioeffects of RF radiation on reproductive cells. To explore the effects of 1950 MHz RF electromagnetic radiation (EMR) on mouse Leydig (TM3) cells. TM3 cells were irradiated or sham-irradiated continuously for 24 h by the specific absorption rate (SAR) 3 W/kg radiation. At 0, 1, 2, 3, 4, and 5 days after irradiation, cell proliferation was detected by cell counting kit-8 (CCK-8) method, cell cycle distribution, percentage of apoptosis, and cellular reactive oxygen species (ROS) were examined by flow cytometry, Testosterone level was measured using enzyme-linked immunosorbent assay (ELISA) assay, messenger ribonucleic acid (mRNA) expression level of steroidogenic acute regulatory protein (StAR) and P450scc in TM3 cells was detected by real-time polymerase chain reaction (PCR). After being irradiated for 24 h, cell proliferation obviously decreased and cell cycle distribution, secretion capacity of Testosterone, and P450scc mRNA level were reduced. While cell apoptosis, ROS, and StAR mRNA level did not change significantly. The current results indicated that 24 h of exposure at 1950 MHz 3 W/kg radiation could cause some adverse effects on TM3 cells proliferation and Testosterone secretion, further studies about the biological effects in the reproductive system that are induced by RF radiation are also needed.

  17. 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) 470...

  18. 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.

  19. Electromagnetic Radiation Influence With Molecular Spectrum Absorption and Nitric Oxide Radiation Frequency on Superoxide Dismutase Bacteria Activity

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-06-01

    Full Text Available The dynamics of superoxide dismutase activity level under the influence of electromagnetic radiation with spectrum absorption and nitric oxide radiation frequency in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa has been described. The panoramic spectrometric measuring complex, developed in Saratov Central Scientific Research Institute of Measuring Equipment Public Corporation has been used while carrying out the research. Electromagnetic vibrations of extremely high frequencies stimulated in this complex imitate the structure of molecular spectrum absorption and nitric oxide radiation. The activity of superoxide dismutase has been detected. The most significant changes have been observed under 45 and 60-minute exposition.

  20. Resonance-Based Time-Frequency Manifold for Feature Extraction of Ship-Radiated Noise

    Directory of Open Access Journals (Sweden)

    Jiaquan Yan

    2018-03-01

    Full Text Available In this paper, a novel time-frequency signature using resonance-based sparse signal decomposition (RSSD, phase space reconstruction (PSR, time-frequency distribution (TFD and manifold learning is proposed for feature extraction of ship-radiated noise, which is called resonance-based time-frequency manifold (RTFM. This is suitable for analyzing signals with oscillatory, non-stationary and non-linear characteristics in a situation of serious noise pollution. Unlike the traditional methods which are sensitive to noise and just consider one side of oscillatory, non-stationary and non-linear characteristics, the proposed RTFM can provide the intact feature signature of all these characteristics in the form of a time-frequency signature by the following steps: first, RSSD is employed on the raw signal to extract the high-oscillatory component and abandon the low-oscillatory component. Second, PSR is performed on the high-oscillatory component to map the one-dimensional signal to the high-dimensional phase space. Third, TFD is employed to reveal non-stationary information in the phase space. Finally, manifold learning is applied to the TFDs to fetch the intrinsic non-linear manifold. A proportional addition of the top two RTFMs is adopted to produce the improved RTFM signature. All of the case studies are validated on real audio recordings of ship-radiated noise. Case studies of ship-radiated noise on different datasets and various degrees of noise pollution manifest the effectiveness and robustness of the proposed method.

  1. Measuring space radiation shielding effectiveness

    OpenAIRE

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

    2017-01-01

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

  2. Environmental dosimetry and radiation effects

    International Nuclear Information System (INIS)

    Woodhead, D.S.

    1997-01-01

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

  3. Analysis of unstable chromosome alterations frequency induced by neutron-gamma mixed field radiation

    International Nuclear Information System (INIS)

    Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F.; Calixto, Merilane S.; Santos, Neide

    2009-01-01

    Nowadays monitoring chromosome alterations in peripheral blood lymphocytes have been used to access the radiation absorbed dose in individuals exposed accidental or occupationally to gamma radiation. However there are not many studies based on the effects of mixed field neutron-gamma. The radiobiology of neutrons has great importance because in nuclear factories worldwide there are several hundred thousand individuals monitored as potentially receiving doses of neutron. In this paper it was observed the frequencies of unstable chromosome alterations induced by a gamma-neutron mixed field. Blood was obtained from one healthy donor and exposed to mixed field neutron-gamma sources 241 AmBe (20 Ci) at the Neutron Calibration Laboratory (NCL-CRCN/NE-PE-Brazil). The chromosomes were observed at metaphase, following colcemid accumulation and 1000 well-spread metaphases were analyzed for the presence of chromosome alterations by two experienced scorers. The results suggest that there is the possibility of a directly proportional relationship between absorbed dose of neutron-gamma mixed field radiation and the frequency of unstable chromosome alterations analyzed in this paper. (author)

  4. Analysis of thermal radiation in ion traps for optical frequency standards

    Science.gov (United States)

    Doležal, M.; Balling, P.; Nisbet-Jones, P. B. R.; King, S. A.; Jones, J. M.; Klein, H. A.; Gill, P.; Lindvall, T.; Wallin, A. E.; Merimaa, M.; Tamm, C.; Sanner, C.; Huntemann, N.; Scharnhorst, N.; Leroux, I. D.; Schmidt, P. O.; Burgermeister, T.; Mehlstäubler, T. E.; Peik, E.

    2015-12-01

    In many of the high-precision optical frequency standards with trapped atoms or ions that are under development to date, the ac Stark shift induced by thermal radiation leads to a major contribution to the systematic uncertainty. We present an analysis of the inhomogeneous thermal environment experienced by ions in various types of ion traps. Finite element models which allow the determination of the temperature of the trap structure and the temperature of the radiation were developed for five ion trap designs, including operational traps at PTB and NPL and further optimized designs. Models were refined based on comparison with infrared camera measurement until an agreement of better than 10% of the measured temperature rise at critical test points was reached. The effective temperature rises of the radiation seen by the ion range from 0.8 K to 2.1 K at standard working conditions. The corresponding fractional frequency shift uncertainties resulting from the uncertainty in temperature are in the 10-18 range for optical clocks based on the Sr+ and Yb+ E2 transitions, and even lower for Yb+ E3, In+ and Al+. Issues critical for heating of the trap structure and its predictability were identified and design recommendations developed.

  5. Radiation effects at the SSC

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-06-01

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

  6. Influence of electromagnetic radiation of industrial frequency on the peripheral blood hematological parameters of the rodents

    Directory of Open Access Journals (Sweden)

    Solovyev Vladimir Sergeevich

    2016-06-01

    Full Text Available The authors studied the hematological parameters of peripheral blood in outbred white mice, which were exposed to electromagnetic radiation of industrial frequency. It was shown that the long-term staying in the zone affected by this factor causes the shift in an erythron system and the change in the total number of leucocytes in animals’ blood. The effects caused by electromagnetic action are not specific and can reflect the general reaction of an organism to the extreme physical and chemical influence. Sensitivity to the studied factor depends on animal’s sex.

  7. The stochastics of radiation effects

    International Nuclear Information System (INIS)

    Hug, O.; Kellerer, A.

    1966-01-01

    As the usual interpretations of dose-effect relationships are based on a static concept, the kinetics can be included only a posteriori by rather complicated corrections. The mathematical treatment of radiation effects proposed by some authors and summarized in this section is an attempt to include the kinetics of radiation-induced processes as well as the dynamical character of the vital objects. As will be shown, the 'hit and target' interpretations are special cases in this scheme. The proposed treatment is, however, more than a mere generalization of target theory; it covers the different stochastic factors which determine the radiation effect whereas target theory is concerned with only one of the stochastic factors, namely the random nature of energy deposition. A separate chapter is devoted the limitations of the conventional models. So far we have kept the target theory assumption that the stochastic nature of biological effects reflects the random nature of energy absorption. This is obviously the most natural assumption in radiation chemistry including also the inactivation of macromolecules such as enzymes and viruses, and point mutations produced by all types of radiation. This assumption is also justified in more complicated cellular processes such as cell death if densely ionizing radiation is applied. However, its applicability to the lethal effect of low LET radiation on cells and multicellular organisms is questionable. There are several objections. Until now, attempts to relate the hypothetical targets to cytological elements have been unsuccessful except in genetic effects. Where in the cell is the centre of macromolecular size which governs life and death?

  8. Frequency-independent approach to calculate physical optics radiations with the quadratic concave phase variations

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yu Mao, E-mail: yumaowu@fudan.edu.cn [Key Laboratory for Information Science of Electromagnetic Waves (MoE), School of Information Science and Technology, Fudan University, Shanghai 200433 (China); Teng, Si Jia, E-mail: sjteng12@fudan.edu.cn [School of Information Science and Technology, Fudan University, Shanghai 200433 (China)

    2016-11-01

    In this work, we develop the numerical steepest descent path (NSDP) method to calculate the physical optics (PO) radiations with the quadratic concave phase variations. With the surface integral equation method, the physical optics (PO) scattered fields are formulated and further reduced to the surface integrals. The high frequency physical critical points contributions, including the stationary phase points, the boundary resonance points and the vertex points are comprehensively studied via the proposed NSDP method. The key contributions of this work are twofold. One is that together with the PO integrals taking the quadratic parabolic and hyperbolic phase terms, this work makes the NSDP theory be complete for treating the PO integrals with quadratic phase variations. Another is that, in order to illustrate the transition effect of the high frequency physical critical points, in this work, we consider and further extend the NSDP method to calculate the PO integrals with the coalescence of the high frequency critical points. Numerical results for the highly oscillatory PO integral with the coalescence of the critical points are given to verify the efficiency of the proposed NSDP method. The NSDP method could achieve the frequency independent computational workload and error controllable accuracy in all the numerical experiments, especially for the case of the coalescence of the high frequency critical points.

  9. A general low frequency acoustic radiation capability for NASTRAN

    Science.gov (United States)

    Everstine, G. C.; Henderson, F. M.; Schroeder, E. A.; Lipman, R. R.

    A new capability called NASHUA is described for calculating the radiated acoustic sound pressure field exterior to a harmonically-excited arbitrary submerged 3-D elastic structure. The surface fluid pressures and velocities are first calculated by coupling a NASTRAN finite element model of the structure with a discretized form of the Helmholtz surface integral equation for the exterior fluid. After the fluid impedance is calculated, most of the required matrix operations are performed using the general matrix manipulation package (DMAP) available in NASTRAN. Far field radiated pressures are then calculated from the surface solution using the Helmholtz exterior integral equation. Other output quantities include the maximum sound pressure levels in each of the three coordinate planes, the rms and average surface pressures and normal velocities, the total radiated power and the radiation efficiency. The overall approach is illustrated and validated using known analytic solutions for submerged spherical shells subjected to both uniform and nonuniform applied loads.

  10. Stabilization and Low-Frequency Oscillation of Capillary Bridges with Modulated Acoustic Radiation Pressure

    Science.gov (United States)

    Marston, Philip L.; Marr-Lyon, Mark J.; Morse, S. F.; Thiessen, David B.

    1996-01-01

    In the work reported here it is demonstrated that acoustic radiation pressure may be used in simulated low gravity to produce stable bridges significantly beyond the Rayleigh limit with S as large as 3.6. The bridge (PDMS mixed with a dense liquid) has the same density as the surrounding water bath containing an ultrasonic standing wave. Modulation was first used to excite specific bridge modes. In the most recent work reported here the shape of the bridge is optically sensed and the ultrasonic drive is electronically adjusted such that the radiation stress distribution dynamically quenches the most unstable mode. This active control simulates passive stabilization suggested for low gravity. Feedback increases the mode frequency in the naturally stable region since the effective stiffness of the mode is increased.

  11. Health effects of ionising radiation

    International Nuclear Information System (INIS)

    Mohammadi, S.

    2000-01-01

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

  12. Biological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Hotz, G.

    1975-01-01

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

  13. 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.

  14. Bystander Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Little, John B.

    2017-01-01

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

  15. Bystander Effects of Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-01-17

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

  16. Extremely high-frequency electromagnetic radiation enhances neutrophil response to particulate agonists.

    Science.gov (United States)

    Vlasova, Irina I; Mikhalchik, Elena V; Gusev, Alexandr A; Balabushevich, Nadezhda G; Gusev, Sergey A; Kazarinov, Konstantin D

    2018-02-01

    The growing use of extremely high-frequency electromagnetic radiation (EHF EMR) in information and communication technology and in biomedical applications has raised concerns regarding the potential biological impact of millimeter waves (MMWs). Here, we elucidated the effects of MMW radiation on neutrophil activation induced by opsonized zymosan or E. coli in whole blood ex vivo. After agonist addition to blood, two samples were prepared. A control sample was incubated at ambient conditions without any treatment, and a test sample was exposed to EHF EMR (32.9-39.6 GHz, 100 W/m 2 ). We used methods that allowed us to assess the functional status of neutrophils immediately after exposure: oxidant production levels were measured by luminol-dependent chemiluminescence, and morphofunctional changes to neutrophils were observed in blood smears. Results revealed that the response of neutrophils to both agonists was intensified if blood was exposed to MMW radiation for 15 min. Neutrophils were intact in both the control and irradiated samples if no agonist was added to blood before incubation. Similarly, exposing suspensions of isolated neutrophils in plasma to MMW radiation enhanced cell response to both zymosan and E. coli. Heating blood samples was shown to be the primary mechanism underlying enhanced EHF EMR-induced oxidant production by neutrophils in response to particulate agonists. Bioelectromagnetics. 39:144-155, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Radiation effects in brain and spinal cord

    International Nuclear Information System (INIS)

    Franke, H.D.; Lierse, W.

    1978-01-01

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

  18. Design of Multi Bubble Sonoluminescence Reactor for Low Frequency Pressure Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Seok; Lee, Jae Young [Handong Global University, Pohang (Korea, Republic of)

    2012-05-15

    Sonoluminescence phenomenon has been intensively studied due to its extraordinary capability to produce very high temperature and pressure within micro bubbles exposed by the pressure radiation. In general, it has been widely used for the chemical treatment including dissociation of the toxics and synthesis of functional materials such as nano catalysis. As for the nuclear applications, some of researchers tried to realization of the bubble fusion and change of the decay constant. Unfortunately applications to the nuclear industry are very skeptically accepted in the academic society. In spite of all such skepticism, the studies on sonoluminescence still have the room to be explored. In the present study, we investigated the relation among the reactor size, power and frequency of the pressure radiation. Main motivation of the present study came from some mismatch in the degradation rate of TCE in the multibubble sonoluminescence reactors (MBSL reactor) between Lee et al (2011) and Oh and Lee (2010). Both studies utilized horn type ultrasound source with the frequency of 20 kHz. However, the shape and volume of the reactors were different form each other. In the present study, we simply measured the light emission from the luminol solution in the reactors to evaluate the effectiveness of the MBSL. As noted in the study of Lee et al, the hot spot of MBSL dissociate water molecules into OH radicals which dissociate luminol in the solution to emit radiation. Therefore, the intensity and distribution of the radiation of luminol dissociation in the reactor are key index of the population of hot spots. Results and discussions are made by comparing the light emission intensity with different operating powers

  19. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1982-12-01

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

  20. Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons

    OpenAIRE

    Su, Zhenpeng; Zhu, Hui; Xiao, Fuliang; Zong, Q.-G.; Zhou, X.-Z.; Zheng, Huinan; Wang, Yuming; Wang, Shui; Hao, Y.-X.; Gao, Zhonglei; He, Zhaoguo; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Blake, J. B.

    2015-01-01

    Van Allen radiation belts are typically two zones of energetic particles encircling the Earth separated by the slot region. How the outer radiation belt electrons are accelerated to relativistic energies remains an unanswered question. Recent studies have presented compelling evidence for the local acceleration by very-low-frequency (VLF) chorus waves. However, there has been a competing theory to the local acceleration, radial diffusion by ultra-low-frequency (ULF) waves, whose importance ha...

  1. Thermal Injury in Human Subjects Due to 94-GHz Radio Frequency Radiation Exposures

    Science.gov (United States)

    2016-02-24

    Waves RFR Radio Frequency Radiation USAF United States Air Force vi Distribution A: Approved for public release; distribution unlimited...many radio frequency radiation ( RFR ) emitters. The recent developments of hardware systems capable of generating millimeter waves (MMWs) and the...Specifically, this experiment seeks to determine if the dose-response relationship for Yucatan minipigs to 94-GHz RFR as reported in Parker et al. (2015b) is

  2. Effects of hypersonic field and anharmonic interactions on channelling radiation

    International Nuclear Information System (INIS)

    George, Juby; Pathak, Anand P; Goteti, L N S Prakash; Nagamani, G

    2007-01-01

    The effects of a hypersonic field on positron channelling radiation are considered. Anharmonic effects of the transverse potential induced by these longitudinal fields are incorporated and the wavefunction of the planar channelled positron is found by the solution of Dirac equation under the resonant influence of hypersound. An expression for the resonant frequency is estimated. The transition probabilities and the intensity of the channelling radiation are also calculated. It is found that the anharmonic effects change the spectral distributions considerably

  3. Measurement of radio frequency radiation (RFR) power levels from ...

    African Journals Online (AJOL)

    With the upsurge in the number of network providers and the attendant increase in the installation of mast in Nigeria, the environment is being inundated with radiofrequency radiation (RFR). There is, therefore, increasing concern about the health implications of this development. In this study measurements of RFR output ...

  4. Low doses of gamma ionizing radiation increase hprt mutant frequencies of TK6 cells without triggering the mutator phenotype pathway

    Energy Technology Data Exchange (ETDEWEB)

    Ayres, Flavio Monteiro; Glickman, Barry W.; Steele, Patricia [University of Victoria, BC (Canada). Dept. of Biology. Centre for Environmental; Cruz, Aparecido Divino da [Universidade Estadual de Goias, Anapolis, GO (Brazil). Dept. de Biologia. Nucleo de Pesquisas Replicon]. E-mail: acruz@ucg.br

    2006-07-01

    The TK6 lymphoblastoid cell line is known to be mismatch repair (MMR) and p53 proficient. Deficiency in MMR results in a mutator phenotype characterized by microsatellite instability (MSI) and increased hprt mutant frequency (MF). Increased hprt MF is also a biomarker of effect for exposure to ionizing radiation. In order to test if a mutator phenotype could be induced by low doses of gamma ionizing radiation, an hprt cloning assay and a MSI investigation were performed after radiation exposure. The spontaneous MF was 1.6 x 10-6. The groups exposed to 0.2, 0.5 and 1.0 Gy had hprt MFs of 2.3, 3.3 and 2.2 x 10-6, respectively. The spontaneous MSI frequency per allele in non-selected cells was 5.4 x 10-3, as evidenced at the loci D11S35, nm23-H1, D8S135 and p53. MSI frequencies in the groups exposed to 0.2, 0.5 and 1.0 Gy were found to be < 4.7, < 7.7 and < 12 x 10-3, respectively. The frequencies of hprt mutants and MSI found in this study suggest that low doses of ionizing radiation increase hprt mutant frequency without triggering the mutator phenotype pathway. (author)

  5. Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants.

    Science.gov (United States)

    Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

    2014-09-15

    Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles (GLV). These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. Copyright © 2014 Elsevier GmbH. All rights reserved.

  6. Influence of microwave frequency electromagnetic radiation on terpene emission and content in aromatic plants

    Science.gov (United States)

    Soran, Maria-Loredana; Stan, Manuela; Niinemets, Ülo; Copolovici, Lucian

    2015-01-01

    Influence of environmental stress factors on both crop and wild plants of nutritional value is an important research topic. The past research has focused on rising temperatures, drought, soil salinity and toxicity, but the potential effects of increased environmental contamination by human-generated electromagnetic radiation on plants have little been studied. Here we studied the influence of microwave irradiation at bands corresponding to wireless router (WLAN) and mobile devices (GSM) on leaf anatomy, essential oil content and volatile emissions in Petroselinum crispum, Apium graveolens and Anethum graveolens. Microwave irradiation resulted in thinner cell walls, smaller chloroplasts and mitochondria, and enhanced emissions of volatile compounds, in particular, monoterpenes and green leaf volatiles. These effects were stronger for WLAN-frequency microwaves. Essential oil content was enhanced by GSM-frequency microwaves, but the effect of WLAN-frequency microwaves was inhibitory. There was a direct relationship between microwave-induced structural and chemical modifications of the three plant species studied. These data collectively demonstrate that human-generated microwave pollution can potentially constitute a stress to the plants. PMID:25050479

  7. Biopositive Effects of Ionizing Radiation?

    International Nuclear Information System (INIS)

    Broda, E.

    1972-01-01

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

  8. Radiation effects on video imagers

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  9. Extremely high frequency RF effects on electronics.

    Energy Technology Data Exchange (ETDEWEB)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  10. Radiation effects on eye components

    Science.gov (United States)

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

    1999-08-01

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

  11. Modification of radiation effects

    International Nuclear Information System (INIS)

    Lindenbaum, A.

    1975-01-01

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

  12. Two-dimensional electrophoretic analysis of radio frequency radiation-exposed MCF7 breast cancer cells

    International Nuclear Information System (INIS)

    Kim, Ki-Bum; Ko, Young-Gyu; Byun, Hae-Ok; Han, Na-Kyung; Lee, Jae-Seon; Choi, Hyung-Do; Kim, Nam; Pack, Jeong-Ki

    2010-01-01

    Although many in vitro studies have previously been conducted to elucidate the biological effects of radio frequency (RF) radiation over the past decades, the existence and nature of any effects is still inconclusive. In an effort to further elucidate this question, we have monitored changes in protein expression profiles in RF-exposed MCF7 human breast cancer cells using two-dimensional gel electrophoresis. MCF7 cells were exposed to 849 MHz RF radiation for 1 h per day for three consecutive days at specific absorption rates (SARs) of either 2 W/Kg or 10 W/kg. During exposure, the temperature in the exposure chamber was kept in an isothermal condition. Twenty-four hours after the final RF exposure, the protein lysates from MCF cells were prepared and two-dimensional electrophoretic analyses were conducted. The protein expression profiles of the MCF cells were not significantly altered as the result of RF exposure. None of the protein spots on the two-dimensional electrophoretic gels showed reproducible changes in three independent experiments. To determine effect of RF radiation on protein expression profiles more clearly, three spots showing altered expression without reproducibility were identified using electrospray ionization tandem mass spectrometry analysis and their expressions were examined with reverse transcription polymerase chain reaction (RT-PCR) and Western blot assays. There was no alteration in their mRNA and protein levels. As we were unable to observe any significant and reproducible changes in the protein expression profiles of the RF radiation-exposed MCF7 cells using high throughput and non-high throughput techniques, it seems unlikely that RF exposure modulates the protein expression profile. (author)

  13. Measuring space radiation shielding effectiveness

    Directory of Open Access Journals (Sweden)

    Bahadori Amir

    2017-01-01

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

  14. Measuring space radiation shielding effectiveness

    Science.gov (United States)

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

    2017-09-01

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

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

    International Nuclear Information System (INIS)

    Gonzalez, A.J.; Anderer, J.

    1991-01-01

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

  16. Gamma radiation effects on the frequency of toxigenic fungus on sene (Cassia angustifolia) and green tea (Camelia sinensis) samples; Efeito da radiacao gama na frequencia de fungos toxigenicos em amostras de sene (Cassia angustifolia) e cha verde (Camellia sinensis)

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, S.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes]. E-mail: siaq06@hotmail.com; Reis, T.A.; Zorzete, P.; Correa, B. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia; Goncalez, E.; Rossi, M.H. [Instituto Biologico, Sao Paulo, SP (Brazil)

    2006-11-15

    The levels of contamination and gamma radiation effects were analyzed in the reduction of toxigenic filamentous fungus in two types of medicinal plants. Aspergillus and Penicillium were the predominant genders and 73,80% of the samples showed high levels of fungus contamination.

  17. Low-frequency analogue Hawking radiation: The Korteweg-de Vries model

    Science.gov (United States)

    Coutant, Antonin; Weinfurtner, Silke

    2018-01-01

    We derive analytic expressions for the low-frequency properties of the analogue Hawking radiation in a general weak-dispersive medium. A thermal low-frequency part of the spectrum is expected even when dispersive effects become significant. We consider the two most common class of weak-dispersive media and investigate all possible anomalous scattering processes due inhomogeneous background flows. We first argue that under minimal assumptions, the scattering processes in near-critical flows are well described by a linearized Korteweg-de Vries equation. Within our theoretical model grey-body factors are neglected, that is, the mode comoving with the flow decouples from the other ones. We also exhibit a flow example with an exact expression for the effective temperature. We see that this temperature coincides with the Hawking one only when the dispersive length scale is much smaller than the flow gradient scale. We apply the same method in inhomogeneous flows without an analogue horizon. In this case, the spectrum coefficients decrease with decreasing frequencies. Our findings are in agreement with previous numerical works, generalizing their findings to arbitrary flow profiles. Our analytical expressions provide estimates to guide ongoing experimental efforts.

  18. Research on radiation effect and radiation protection at JAEA

    International Nuclear Information System (INIS)

    Saito, Kimiaki

    2007-01-01

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

  19. Genomic instability and radiation effects

    International Nuclear Information System (INIS)

    Christian Streffer

    2007-01-01

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

  20. Radio frequency radiation (RFR) from TV and radio transmitters at a pilot region in Turkey

    International Nuclear Information System (INIS)

    Sirav, B.; Seyhan, N.

    2009-01-01

    For the last 30 y, the biological effects of non-ionising radiation (NIR: 0-300 GHz) have been a major topic in bio-electromagnetism. Since the number of radiofrequency (RF) systems operating in this frequency range has shown an incredible increase over the last few decades, the dangers of exposure to the fields generated thereby has become an important public health issue. In this study, the aim was to evaluate the level of RF electromagnetic radiation in Yenimahalle Sentepe Dededoruk Hill in Ankara (Turkey) that is a multiple-transmitter site hosting 64 different TV and radio towers and one base station for mobile phone communication. The site has been of interest as it is nearby a residential community. Within the technical input data available on 31 of the radio and TV transmitters, the calculated radiation level in this particular region was found to be approximately four times higher than the permitted standards of Turkey, which are the same as the ICNIRP standards. Electromagnetic field measurement is needed in the site. (authors)

  1. Radio frequency radiation (RFR) from TV and radio transmitters at a pilot region in Turkey.

    Science.gov (United States)

    Sirav, Bahriye; Seyhan, Nesrin

    2009-09-01

    For the last 30 y, the biological effects of non-ionising radiation (NIR: 0-300 GHz) have been a major topic in bioelectromagnetism. Since the number of radiofrequency (RF) systems operating in this frequency range has shown an incredible increase over the last few decades, the dangers of exposure to the fields generated thereby has become an important public health issue. In this study, the aim was to evaluate the level of RF electromagnetic radiation in Yenimahalle Sentepe Dededoruk Hill in Ankara, Turkey that is a multiple-transmitter site hosting 64 different TV and radio towers and one base station for mobile phone communication. The site has been of interest as it is nearby a residential community. Within the technical input data available on 31 of the radio and TV transmitters, the calculated radiation level in this particular region was found to be approximately four times higher than the permitted standards of Turkey, which are the same as the ICNIRP standards. Electromagnetic field measurement is needed in the site.

  2. Radiation effects in silicate glasses

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  3. Thermal effects in radiation processing

    International Nuclear Information System (INIS)

    Zagorski, Z.P.

    1984-01-01

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

  4. Passive, broadband suppression of radiation of low-frequency sound.

    Science.gov (United States)

    Godin, Oleg A; Baynes, Alexander B

    2018-02-01

    Anthropogenic noise pollution of the ocean is an acute and growing problem. This letter explores one possible mechanism of noise abatement. The far-field acoustic pressure due to a compact underwater source can be suppressed by placing a small compliant body in the vicinity of the source. Here, the feasibility and efficiency of the suppression are evaluated by quantifying the reduction in radiated acoustic energy for several simple geometries, which include sound sources in an unbounded fluid, near a reflecting boundary, or in a shallow-water waveguide. The analysis is streamlined using analytic solutions for sound diffraction by simple shapes.

  5. Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons.

    Science.gov (United States)

    Su, Zhenpeng; Zhu, Hui; Xiao, Fuliang; Zong, Q-G; Zhou, X-Z; Zheng, Huinan; Wang, Yuming; Wang, Shui; Hao, Y-X; Gao, Zhonglei; He, Zhaoguo; Baker, D N; Spence, H E; Reeves, G D; Blake, J B; Wygant, J R

    2015-12-22

    Van Allen radiation belts are typically two zones of energetic particles encircling the Earth separated by the slot region. How the outer radiation belt electrons are accelerated to relativistic energies remains an unanswered question. Recent studies have presented compelling evidence for the local acceleration by very-low-frequency (VLF) chorus waves. However, there has been a competing theory to the local acceleration, radial diffusion by ultra-low-frequency (ULF) waves, whose importance has not yet been determined definitively. Here we report a unique radiation belt event with intense ULF waves but no detectable VLF chorus waves. Our results demonstrate that the ULF waves moved the inner edge of the outer radiation belt earthward 0.3 Earth radii and enhanced the relativistic electron fluxes by up to one order of magnitude near the slot region within about 10 h, providing strong evidence for the radial diffusion of radiation belt relativistic electrons.

  6. Low frequency electromagnetic radiation from gravitational waves generated by neutron stars

    Science.gov (United States)

    Jones, Preston; Gretarsson, Andri; Singleton, Douglas

    2017-12-01

    We investigate the possibility of observing very low frequency (VLF) electromagnetic radiation produced from the vacuum by gravitational waves. We review the calculations leading to the possibility of vacuum conversion of gravitational waves into electromagnetic waves and show how this process evades the well-known prohibition against particle production from gravitational waves. Using Newman-Penrose scalars, we estimate the luminosity of this proposed electromagnetic counterpart radiation coming from gravitational waves produced by neutron star oscillations. The detection of electromagnetic counterpart radiation would provide an indirect way of observing gravitational radiation with future spacecraft missions, especially lunar orbiting probes.

  7. Radiated field of rotating charged parallel plates and its frequency spectrum

    Science.gov (United States)

    Wang, Zongxin; Cao, Zhenxin; Yang, Fei

    2018-02-01

    Antennas in the ultra low frequency (ULF, 300 Hz to 3 kHz) and very low frequency (VLF, 3˜30 kHz) bands are usually very large. In this study, we developed a very small antenna, which can radiate electromagnetic waves in these frequency bands. The antenna consisted of two rotating charged plates (RCPs), which were charged by the voltage source. Numerical results of the radiated far field and its frequency spectrum are presented for three cases: (a) the antenna is charged with DC voltage, (b) the antenna is charged with AC voltage, and (c) the antenna rotates with variable speed and is fed with DC voltage. The predominant frequency component was equal to the rotating frequency of the RCPs fed with DC voltage. If the RCPs were fed with AC voltage two dominant frequencies were generated, which were determined by the difference in frequency between the RCP rotation frequency and the AC source frequency. When the RCPs rotated with variable speed and were fed with DC voltage, many frequency components were generated, which were determined by the initial rotational speed of the RCPs and their acceleration.

  8. A correlative study on the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mammals

    International Nuclear Information System (INIS)

    Buul, P.P.W. van

    1976-01-01

    A series of investigations on the correlation between the frequencies of radiation-induced chromosome aberrations in somatic and germ cells of mouse and rhesus monkey is described. In the mouse the induction of reciprocal translocations in bone-marrow cells was compared with that in spermatogonia (as scored in the descending spermatocytes). In the rhesus monkey frequencies of radiation-induced chromosome aberrations in spermatogonia and peripheral blood lymphocytes were studied. Furthermore the effect of multigeneration irradiation (69 generations with 200 rads X-rays) on the sensitivity for translocation induction in spermatogonia of male mice was studied. Frequencies of dicentric chromosomes and chromosomal deletions in cultured peripheral blood lymphocytes of 5 different types of mice were determined following in vitro irradiation with doses of 100 and/or 200 rad X-rays. To obtain more insight into the processes underlying translocation induction in spermatogonia of the mouse, fractionation experiments were conducted

  9. Analysis of the frequency response of a TeO{sub 2} slow shear wave acousto-optic cell exposed to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Erteza, I.A.

    1995-04-01

    Radiation testing of photonic components is not new, however component level testing to date has not completely addressed quantities which are important to system behavior. One characteristic that is of particular importance for optical processing systems is the frequency response. In this report, we present the analysis of data from an experiment designed to provide a preliminary understanding of the effects of radiation on the frequency response of acousto-optic devices. The goal of the analysis is to describe possible physical mechanisms responsible for the radiation effects and to discuss the effects on signal processing functionality. The experiment discussed in this report was designed by Sandia National Laboratories and performed by Sandia and Phillips Laboratory personnel at White Sands Missile Range (WSMR). In the experiment, a TeO{sub 2} slow shear wave acousto-optic cell was exposed to radiation from the WSMR linear accelerator. The TeO{sub 2} cell was placed in an experimental configuration which allowed swept frequency diffracted power measurements to be taken during radiation exposure and recovery. A series of exposures was performed. Each exposure consisted of between 1 to 800, 1{mu}sec radiation pulses (yielding exposures of 2.25 kRad(Si) to 913 kRad(Si)), followed by recovery time. At low total and cumulative doses, the bandshape of the frequency response (i.e. diffracted power vs. frequency) remained almost identical during and after radiation. At the higher exposures, however, the amplitude and width of the frequency response changed as the radiation continued, but returned to the original shape slowly after the radiation stopped and recovery proceeded. It is interesting to note that the location of the Bragg degeneracy does not change significantly with radiation. In this report, we discuss these effects from the perspective of anisotropic Bragg diffraction and momentum mismatch, and we discuss the effect on the signal processing functionality.

  10. Health effects of radiation damage

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  11. Superconducting magnet radiation effects in fusion reactors

    International Nuclear Information System (INIS)

    Sawan, M.E.; Walstrom, P.L.

    1986-01-01

    Radiation effects in superconducting magnets of fusion reactors are analyzed and experimental data reviewed. The interaction between the different radiation effects and impact on reactor design is discussed. The need for experimental data with higher irradiation levels is assessed

  12. Review on patients radiation dose and frequency of procedures during medical exposure in Sudan

    International Nuclear Information System (INIS)

    Abu Baker, Samah Mohamed Nasr

    2015-09-01

    The aim of this study was to estimate patient dose, the annual frequency and the number of staff and devices in the medical applications of ionizing radiation in Sudan. Survey was conducted on diagnostic radiology, nuclear medicine and radiotherapy. With respect to diagnostic radiology, only patient radiation dose was estimated. The data for diagnostic radiology was obtained from 24 peer reviewed scientific published literatures during the years ( 2006 - 2015). The collected publications included about 64 Sudanese hospitals covering different types of diagnostic exams. A values of the effective dose for pediatrics and adult patients were within the ranges of similar worldwide values published by UNSCEAR report in 2008 with exceptional to fluoroscopy hysterosalpingography for adult patients. For nuclear medicine procedures, questionnaires were distributed to five hospitals representing the whole existing NM department in Sudan at the time of of study. The estimated total annual frequency of diagnostic procedures was 0.2 per 1000 population. The estimated total annual collective and annual per caput effective dose from all NM procedures were 16.268 man Sv and 0.5 μSv, respectively. Comparing the annual per caput effective dose with UNSCEAR value our results was less than the worldwide value and greater than the value for heath care level 111-1 v countries. Questionnaires were also distributed to collect data on radiotherapy procedures performed in the two existing radioisotopes Sudanese hospitals. The prescribed dose and the number of fractions were comparable between the two hospitals. The minimum prescribed dose was 20 Gy with 5 fractions for nasopharynx (NPH) palliative and the maximum prescribed dose was 64 Gy with 32 fractions for prostate.(Author)

  13. Health hazards and safety considerations during use of radio-frequency radiation: an overview (Paper No. IT 7)

    International Nuclear Information System (INIS)

    Sachdev, R.N.

    1990-01-01

    In recent years, increased public awarness of the potential health risk from radio-frequency radiation (RFR) has surfaced. This paper summarises the latest thinking on the health and safety related aspects of RFR and highlights some of the experimental work done at Trombay to collect systematic exposure data around various types of RFR generating equipment. Thermal and non-thermal effects on the biological system as a consequences of absorption of RFR and resonance frequency dependence of biological phenomena have been discussed. Salient features of the basis of occupational exposure guide-lines prepared by International Radiation Protection Association have been outlined. It is emphasised that the present understanding of the mechanism of interaction of RFR with human body is incomplete as regards non-thermal effects, possible combined effects of RF electromagnetic energy with chemical or other physical agents in the environment. These are the areas which require further study. (author). 7 refs., 3 figs., 3 tabs

  14. Genetic effects of natural radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B.L.

    1982-01-01

    Genetic defects from mutations affect about 3% of the population. Studies of spontaneously-occurring mutations because of radiation show that the Law of Natural Selection precludes the genetic destruction of the human race. Although exposure to radiation from expanding nuclear industry could shift the occurrence of mutations a few hundredths of one percent, natural radiation causes only about 3% of all genetic effects. The Nuclear Regulatory Commission assesses the risk of an all-nuclear power society at 32 cases per year, or 0.03% above the natural incidence of genetic disease. Public concern over nuclear accidents focuses on the potential for a catastrophic accident, but the statistical genetic effects of a worst-case accident would be undetectable. Efforts to understand and deal with the genetic hazards of delayed parenthood and chemical mutagens coupled with new developments in medical intervention depend upon a continual improvement in the standard of living and the abundant supplies of cheap energy that nuclear power can help to provide. 3 footnotes. (DCK)

  15. Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy

    Science.gov (United States)

    Tamarov, Konstantin P.; Osminkina, Liubov A.; Zinovyev, Sergey V.; Maximova, Ksenia A.; Kargina, Julia V.; Gongalsky, Maxim B.; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P.; Sentis, Marc; Ivanov, Andrey V.; Nikiforov, Vladimir N.; Kabashin, Andrei V.; Timoshenko, Victor Yu

    2014-11-01

    Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

  16. Radiation and radiation protection; Strahlung und Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Bartholomaeus, Melanie (comp.)

    2017-04-15

    The publication of the Bundesamt fuer Strahlenschutz covers the following issues: (i) Human beings in natural and artificial radiation fields; (ii) ionizing radiation: radioactivity and radiation, radiation exposure and doses; measurement of ionizing radiation, natural radiation sources, artificial radiation sources, ionizing radiation effects on human beings, applied radiation protection, radiation exposure of the German population, radiation doses in comparison; (iii) non-ionizing radiation; low-frequency electric and magnetic fields, high-frequency electromagnetic fields, optical radiation; (iiii) glossary, (iv) units and conversion.

  17. A New Microwave Shield Preparation for Super High Frequency Range: Occupational Approach to Radiation Protection.

    Science.gov (United States)

    Zaroushani, Vida; Khavanin, Ali; Jonidi Jafari, Ahmad; Mortazavi, Seyed Bagher

    2016-01-01

    Widespread use of X-band frequency (a part of the super high frequency microwave) in the various workplaces would contribute to occupational exposure with potential of adverse health effects.  According to limited study on microwave shielding for the workplace, this study tried to prepare a new microwave shielding for this purpose. We used EI-403 epoxy thermosetting resin as a matrix and nickel oxide nanoparticle with the diameter of 15-35 nm as filler. The Epoxy/ Nickel oxide composites with 5, 7, 9 and 11 wt% were made in three different thicknesses (2, 4 and 6 mm). According to transmission / reflection method, shielding effectiveness (SE) in the X-band frequency range (8-12.5 GHz) was measured by scattering parameters directly given by the 2-port Vector Network Analyzer. The fabricated composites characterized by X-ray Diffraction and Field Emission Scanning Electron Microscope. The best average of shielding effectiveness in each thickness of fabricated composites obtained by 11%-2 mm, 7%-4 mm and 7%-6 mm composites with SE values of 46.80%, 66.72% and 64.52%, respectively. In addition, the 11%-6 mm, 5%-6 mm and 11%-4 mm-fabricated composites were able to attenuate extremely the incident microwave energy at 8.01, 8.51 and 8.53 GHz by SE of 84.14%, 83.57 and 81.30%, respectively. The 7%-4mm composite could be introduced as a suitable alternative microwave shield in radiation protection topics in order to its proper SE and other preferable properties such as low cost and weight, resistance to corrosion etc. It is necessary to develop and investigate the efficacy of the fabricated composites in the fields by future studies.

  18. Modeling of high‐frequency seismic‐wave scattering and propagation using radiative transfer theory

    Science.gov (United States)

    Zeng, Yuehua

    2017-01-01

    This is a study of the nonisotropic scattering process based on radiative transfer theory and its application to the observation of the M 4.3 aftershock recording of the 2008 Wells earthquake sequence in Nevada. Given a wide range of recording distances from 29 to 320 km, the data provide a unique opportunity to discriminate scattering models based on their distance‐dependent behaviors. First, we develop a stable numerical procedure to simulate nonisotropic scattering waves based on the 3D nonisotropic scattering theory proposed by Sato (1995). By applying the simulation method to the inversion of M 4.3 Wells aftershock recordings, we find that a nonisotropic scattering model, dominated by forward scattering, provides the best fit to the observed high‐frequency direct S waves and S‐wave coda velocity envelopes. The scattering process is governed by a Gaussian autocorrelation function, suggesting a Gaussian random heterogeneous structure for the Nevada crust. The model successfully explains the common decay of seismic coda independent of source–station locations as a result of energy leaking from multiple strong forward scattering, instead of backscattering governed by the diffusion solution at large lapse times. The model also explains the pulse‐broadening effect in the high‐frequency direct and early arriving S waves, as other studies have found, and could be very important to applications of high‐frequency wave simulation in which scattering has a strong effect. We also find that regardless of its physical implications, the isotropic scattering model provides the same effective scattering coefficient and intrinsic attenuation estimates as the forward scattering model, suggesting that the isotropic scattering model is still a viable tool for the study of seismic scattering and intrinsic attenuation coefficients in the Earth.

  19. Possible Explanation for Cancer in Rats due to Cell Phone Radio Frequency Radiation

    Science.gov (United States)

    Feldman, Bernard J.

    Very recently, the National Toxicology Program reported a correlation between exposure to whole body 900 MHz radio frequency radiation and cancer in the brains and hearts of Sprague Dawley male rats. Assuming that the National Toxicology Program is statistically significant, I propose the following explanation for these results. The neurons around the brain and heart form closed electrical circuits and, following Faraday's Law, 900 MHz radio frequency radiation induces 900 MHz electrical currents in these neural circuits. In turn, these 900 MHz currents in the neural circuits generate sufficient localized heat in the neural cells to shift the equilibrium concentration of carcinogenic radicals to higher levels and thus, to higher incidences of cancer.

  20. [Application of low-intensity and ultrahigh frequency electromagnetic radiation in modern pediatric practice].

    Science.gov (United States)

    Azov, N A; Azova, E A

    2009-01-01

    The use of an Amfit-0,2/10-01 apparatus generating low-intensity ultrahigh frequency (UHF) electromagnetic radiation improved efficiency of therapy of sick children. This treatment allowed to reduce the frequency of intake of anesthetics in the post-operative period, correct metabolic disorders in children with type 1 diabetes mellitus, reduce severity of diabetic nephropathy and polyneuropathy, prevent formation of fresh foci of lipoid necrobiosis. The results of the study indicate that the use of low-intensity UHF electromagnetic radiation may be recommended for more extensive introduction into practical clinical work of pediatric endocrinologists and surgeons.

  1. Effect of radiation in radiotherapy

    International Nuclear Information System (INIS)

    Hirata, Hideki; Fujibuchi, Toshio; Saito, Tsutomu

    2013-01-01

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

  2. Effects of Radiation on MEMS

    OpenAIRE

    Shea, Herbert

    2011-01-01

    The sensitivity of MEMS devices to radiation is reviewed, with an emphasis on radiation levels representative of space missions. While silicon and metals generally do not show mechanical degradation at the radiation levels encountered in most missions, MEMS devices have been reported to fail at doses of as few krad, corresponding to less than one year in most orbits. Radiation sensitivity is linked primarily to the impact on device operation of radiation-induced trapped charge in dielectrics...

  3. Radiation Effects in Advanced Microelectonic Technologies

    Science.gov (United States)

    Johnston, A. H.

    1997-01-01

    Several new radiation phenomena have been observed in laboratory testing of advanced microelectonics that are not yet of sufficient importance for typical space applications, but provide insight into the likely effects of scaling and device design on radiation hardness.

  4. RADIATION AND EFFECTS ON HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Hakan YAREN

    2005-08-01

    Full Text Available In modern world, living without radiation is impossible. Radiation is defined as ?energy transmitted through space as waves or particles? and also determined as ?particles or waves emitted from the nucleus of unstable radioactive atoms to become stable? Mainly two types of radiation are exist; ionising radiation and non-ionising radiation. Ionising radiation is consist of alpha, beta particules, neutrons, x rays and gamma rays. Ionising radiation which can be measured by ion chambers, geiger-Mueller detectors, Scintillation Counters, fluorescent counters etc. Has harmfull effects on human health in levels of molecular, cellular, tissue, organs and organ systems. These harmfull effects can also be named somatic and genetic. One of the most encountered problem is ?Acute Radiation Syndrom? which has three sub syndroms called haematopoetic syndrom, gastrointestinal syndrom and neurovascular syndrom. Exposure time, distance and armorisation are the key elements of protection from radiation. [TAF Prev Med Bull 2005; 4(4.000: 199-208

  5. Increased frequency of micronucleated exfoliated cells among humans exposed in vivo to mobile telephone radiations

    International Nuclear Information System (INIS)

    Manoj Kumar Sharma; Abhay Singh Yadav

    2007-01-01

    Complete text of publication follows. The health concerns have been raised following the enormous increase in the use of wireless mobile telephones through out the world. This investigation had been taken, with the motive to find out whether mobile phone radiations cause any in vivo effects on the frequency of micronucleated exfoliated cells in the exposed subjects. A total of 109 subjects including 85 regular mobile phone users (exposed) and 24 non-users (controls) had participated in this study. Exfoliated cells were obtained by swabbing the buccal-mucosa from exposed as well as sex-age-matched controls. One thousand exfoliated cells were screened from each individual for nuclear anomalies including micronuclei (MN), karyolysis (KL), karyorrhexis (KH), broken egg (BE) and bi-nucleated (BN) cells. The average daily duration of exposure to mobile phone radiations is 61.26 minutes with an overall average duration of exposure in term of years is 2.35 years in exposed subjects along with the 9.84±0.745 MNC (micronucleated cells) and 10.72±0.889 TMN (total micronuclei) as compared to zero duration of exposure along with average 3.75±0.774 MNC and 4.00±0.808 TMN in controls. The means are significantly different in case MNC and TMN at 0.01% level of significance. For all other nuclear anomalies (KL, KH, BE and BN cells) the means are found statistically nonsignificant. A positive correlation was found in the frequency of MNC and TMN with respect to duration of exposure time.

  6. The Brookhaven Radiation Effects Facility

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  7. The Brookhaven Radiation Effects Facility

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  8. Effects of ionizing radiation on vitamins

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  9. Effect of high-frequency excitation on natural frequencies of spinning discs

    DEFF Research Database (Denmark)

    Hansen, Morten Hartvig

    2000-01-01

    The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural frequenc......The effect of high-frequency, non-resonant parametric excitation on the low-frequency response of spinning discs is considered. The parametric excitation is obtained through a non-constant rotation speed, where the frequency of the pulsating overlay is much higher than the lowest natural...

  10. Radiation effects on the drosophila melanogaster genoma

    International Nuclear Information System (INIS)

    Arceo-Maldonado, C.

    1989-01-01

    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)

  11. 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 43...

  12. The influence of large deletions on the mutation frequency induced by tritiated water and X-radiation in male Drosophila melanogaster post-meiotic germ cells

    International Nuclear Information System (INIS)

    Fossett, N.G.; Byrne, B.J.; Kelley, S.J.; Tucker, A.B.; Arbour-Reily, P.; Lee, W.R.

    1994-01-01

    Tritium beta radiation ( 3 H β-radiation) in the form of tritiated water was used to induce mutations at the alcohol dehydrogenase (Adh) locus in male Drosophila melanogaster post-meiotic germ cells. All 23 Adh null mutations were large deletions (>20 kb), determined by genetic complementation and Southern blot analyses. 27 Adh null mutations have been induced by 100-kVp X-rays and have been genetically and molecularly characterized. In contrast to 3 H β-radiation, 100-kVp X-rays induced a bimodal distribution of Adh null mutations, intragenic mutations, ≤250 bp, and large deletions, >100 kb. A statistically significant difference was observed between the frequency of large deletions (23/23 or 1.0) induced by 3 H β-radiation and the frequency of large deletions (19/27 or 0.7) induced by 100-kVp X-rays. However, a statistical difference was not observed between the size distribution of the large deletions induced by 3 H β-radiation and X-rays. The relative deletion frequency (RDF) induced by 3 H β-radiation and 100-kVp X-rays was (1.0/0.7=1.4). The relative biological effectiveness (RBE) of these two radiation sources was 1.4, determined from the ratio of the regression coefficients of the respective 3 H β-radiation and X-ray sex-linked recessive lethal (SLRL) dose-response data. The large difference in size between the two classes of X-ray-induced Adh null mutations and the increase in mutation frequency and deletion frequency for 3 H β-radiation with respect to X-rays may indicate that the relative deletion frequency (RDF) is the molecular biological basis for the increase in the RBE for radiation sources with a mean LET value ≤10 keV/μm

  13. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl.

    Science.gov (United States)

    Lehmann, Philipp; Boratyński, Zbyszek; Mappes, Tapio; Mousseau, Timothy A; Møller, Anders P

    2016-01-27

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glareolus collected from natural populations in areas with varying levels of background radiation in Chernobyl. We found high frequencies of cataracts in voles collected from different areas in Chernobyl. The frequency of cataracts was positively correlated with age, and in females also with the accumulated radiation dose. Furthermore, the number of offspring in female voles was negatively correlated with cataract severity. The results suggest that cataracts primarily develop as a function of ionizing background radiation, most likely as a plastic response to high levels of oxidative stress. It is therefore possible that the elevated levels of background radiation in Chernobyl affect the ecology and fitness of local mammals both directly through, for instance, reduced fertility and indirectly, through increased cataractogenesis.

  14. [Reparative Osteogenesis and Angiogenesis in Low Intensity Electromagnetic Radiation of Ultra-High Frequency].

    Science.gov (United States)

    Iryanov, Y M; Kiryanov, N A

    2015-01-01

    Non-drug correction of reparative bone tissue regeneration in different pathological states - one of the most actual problems of modern medicine. Our aim was to conduct morphological analysis of the influence of electromagnetic radiation of ultra-high frequency and low intensity on reparative osteogenesis and angiogenesis in fracture treatment under transosseous osteosynthesis. A controlled nonrandomized study was carried out. In the experiment conducted on rats we modeled tibial fracture with reposition and fixation of the bone fragments both in control and experimental groups. In the animals of the experimental group the fracture zone was exposed to low intensity electromagnetic radiation of ultra-high frequency. Exposure simulation was performed in the control group. The operated bones were examined using radiography, light and electronic microscopy, X-ray electronic probe microanalysis. It has been established that electromagnetic radiation of ultra-high frequency sessions in fracture treatment stimulate secretory activity and degranulation of mast cells, produce microcirculatory bed vascular permeability increase, endotheliocyte migration phenotype expression, provide endovascular endothelial outgrowth formation, activate reparative osteogenesis and angiogenesis while fracture reparation becomes the one of the primary type. The full periosteal, intermediary and intraosteal bone union was defined in 28 days. Among the therapeutic benefits of electromagnetic radiation of ultra-high frequency in fracture treatment we can detect mast cell secretorv activity stimulation and endovascular anziozenesis activation.

  15. Effects of ionizing radiation on life

    International Nuclear Information System (INIS)

    Rausch, L.

    1982-01-01

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

  16. Ecological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Jordan, C.F.

    1986-01-01

    Particular kinds of environmental perturbation are essentially replicated in many places. Because no two sites are identical, detailed prediction of effects requires knowledge of the ecosystem in question. Much can be learned, however, by carrying out generic studies designed to discover results of general applicability to many conditions. Studies supported by the U.S. Atomic Energy Commission to determine the effects of radiation on living organisms and how radionuclides move through natural environments have been the most extensive attempts to use a generic approach to obtain information required for making major policy decisions. This case study summarizes and analyzes these studies and their contributions both to the solution of problems at which they were directed and to ecological theory generally

  17. 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.

  18. Increase in radiation-induced HPRT gene mutation frequency after nonthermal exposure to nonionizing 60 Hz electromagnetic fields.

    Science.gov (United States)

    Walleczek, J; Shiu, E C; Hahn, G M

    1999-04-01

    It is widely accepted that moderate levels of nonionizing electric or magnetic fields, for example 50/60 Hz magnetic fields of about 1 mT, are not mutagenic. However, it is not known whether such fields can enhance the action of known mutagens. To explore this question, a stringent experimental protocol, which included blinding and systematic negative controls, was implemented, minimizing the possibility of observer bias or experimental artifacts. As a model system, we chose to measure mutation frequencies induced by 2 Gy gamma rays in the redox-sensitive hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene in Chinese hamster ovary cells. We tested whether a 12-h exposure to a 60 Hz sinusoidally oscillating magnetic-flux density (Brms = 0.7 mT) could affect the mutagenic effects of ionizing radiation on the HPRT gene locus. We determined that the magnetic-field exposure induced an approximate 1.8-fold increase in HPRT mutation frequency. Additional experiments at Brms = 0.23 and 0.47 mT revealed that the effect was reduced at lower flux densities. The field exposure did not enhance radiation-induced cytotoxicity or mutation frequencies in cells not exposed to ionizing radiation. These results suggest that moderate-strength, oscillating magnetic fields may act as an enhancer of mutagenesis in mammalian cells.

  19. Greenhouse Effect, Radiative Forcing and Climate Sensitivity

    Science.gov (United States)

    Ponater, Michael; Dietmüller, Simone; Sausen, Robert

    Temperature conditions and climate on Earth are controlled by the balance between absorbed solar radiation and outgoing terrestrial radiation. The greenhouse effect is a synonym for the trapping of infrared radiation by radiatively active atmospheric constituents. It generally causes a warming of the planet's surface, compared to the case without atmosphere. Perturbing the radiation balance of the planet, e.g., by anthropogenic greenhouse gas emissions, induces climate change. Individual contributions to a total climate impact are usually quantified and ranked in terms of their respective radiative forcing. This method involves some limitations, because the effect of the external forcing is modified by radiative feedbacks. Here the current concept of radiative forcing and potential improvements are explained.

  20. Radiation effects on lubricants. Final report

    International Nuclear Information System (INIS)

    Bolt, R.O.

    1986-08-01

    This report discusses the radiolysis of lubricants; how to predict radiation resistance; and when to use radiation resistant products. It also discusses the effects of dose rate, temperature and exposure to the atmosphere on lubricant degradation. It should be of interest to those designing, using or maintaining equipment which may be exposed to radiation

  1. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

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

  2. Molecular and cellular effects of radiations

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  3. Effects of Radiation on Coatings

    Science.gov (United States)

    Bouquet, F. L.; Hribar, V. F.; Metzler, E. C.

    1986-01-01

    Tests help to insure reliability in hostile environment. Tests of radiation damage to materials used in outer coverings of spacecraft described in 25-page report. Materials exposed to ionizing radiation then examined for degradation of desirable mechanical, electrical, and optical properties. Experimental results and test methods applicable to aircraft, scientific instrumentation, and other equipment subject to ionizing radiation, electrostatic discharge, or both.

  4. Radiation effects on biochemical systems

    International Nuclear Information System (INIS)

    Seddon, G.M.

    2000-04-01

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

  5. Graphene Field Effect Transistor for Radiation Detection

    Science.gov (United States)

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

    2016-01-01

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

  6. Radio frequency radiation (RFR): the nature of exposure and carcinogenic potential.

    Science.gov (United States)

    Valberg, P A

    1997-05-01

    Epidemiologic evidence on the relation between radio-frequency radiation (RFR) and cancer is reviewed. Radio-wave communications are used extensively in modern society; thus, we are all subject to RFR created by radio, television, wireless telephony, emergency communications, radar, etc. Interest in the health effects of RFR has been motivated by the rapid growth in wireless communications and by media reports expressing concern that specific diseases may be caused by RFR exposure, e.g., from cellular telephone handsets. Due to the ubiquitous presence of RFR, the public health implication of any connection between RFR and cancer risk is potentially significant. (It is important to keep RFR distinct from power-line electromagnetic fields.) Comparison of potential risks from RFR exposure with other occupational and environmental health risks requires evaluating the level of support from available epidemiology, from studies with laboratory animals, and from mechanistic or biophysical information about the interaction of RFR with living tissues. A large number of studies have been done with laboratory animals and with in vitro systems; a more limited set of epidemiologic studies is available. Effects from RFR exposure that lead to temperature increases have been consistently reported, but 'non-thermal' effects have not been substantiated. Also, there are no mechanistic theories that support 'non-thermal' interactions with biology. Evidence to support a causal relationship between exposure to RFR and human cancers is scant. Our present state of knowledge about exposure, mechanisms, epidemiology, and animal studies does not identify significant cancer risks.

  7. Biological effect of non-ionizing radiations on microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, Kikuo; Yamamoto, Takayoshi [Osaka Univ., Radioisotope Research Center, Suita, Osaka (Japan); Nakaoka, Yasuo [Osaka Univ., Graduate School of Engineering Science, Department of Biophysical Engineering, Toyonaka, Osaka (Japan)

    2000-05-01

    We studied the effect of extremely low frequency magnetic fields (ELF-MF) of 60-Hz and 500 mT on the growth and the mutation frequency of the budding yeast S.cerevisiae and on the behavior of the ciliate Paramecium multimicronucleatum. The growth rate and mutation frequencies of several strains of S.cerevisiae (wild type and radiation sensitive mutants, rad or rev) were examined but no significant difference was observed. Moreover, the behavior of P.multimicronucleatum under the ELF-MF was examined. When exposed to a vertical field of 0.6 T, the cells accumulated at the upper end of the cuvette. (author)

  8. Biological effect of non-ionizing radiations on microorganisms

    International Nuclear Information System (INIS)

    Shimizu, Kikuo; Yamamoto, Takayoshi; Nakaoka, Yasuo

    2000-01-01

    We studied the effect of extremely low frequency magnetic fields (ELF-MF) of 60-Hz and 500 mT on the growth and the mutation frequency of the budding yeast S.cerevisiae and on the behavior of the ciliate Paramecium multimicronucleatum. The growth rate and mutation frequencies of several strains of S.cerevisiae (wild type and radiation sensitive mutants, rad or rev) were examined but no significant difference was observed. Moreover, the behavior of P.multimicronucleatum under the ELF-MF was examined. When exposed to a vertical field of 0.6 T, the cells accumulated at the upper end of the cuvette. (author)

  9. Absolute scale power measurements of frequency-locked coherent transition radiation

    Directory of Open Access Journals (Sweden)

    Roark A. Marsh

    2007-08-01

    Full Text Available We report the absolute power measurement of frequency-locked terahertz coherent transition radiation (CTR from a train of electron bunches produced by a 17.14 GHz accelerator. Frequency measurements were obtained by two independent techniques: a wave meter with a video diode detector, and a double heterodyne system. Good agreement was seen between these two techniques. The emitted radiation was observed to be a comb of frequencies that are harmonics of the 17.14 GHz accelerator frequency. The heterodyne receiver system showed that each of the emitted harmonics has a very narrow bandwidth, about 25 MHz, which corresponds to the transform-limited bandwidth for the bunch train length of 40 ns. The highest observed frequency was 377.08 GHz, the 22nd harmonic of the 17.14 GHz accelerator frequency. The emitted CTR power was measured on an absolute scale to test the theory of CTR. The power was compared with calculations made using an electric field integral equation (EFIE formulation and excellent agreement was obtained. This agreement serves as a valuable benchmark of the EFIE code, proof of both its validity and usefulness.

  10. Radiation Induced Bystander Effect in vivo

    OpenAIRE

    Chai, Yunfei; Hei K. Tom

    2009-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand breaks, the mechanism(s) as well as the pres...

  11. Self and Mutual Radiation Impedances for Modeling of Multi-Frequency CMUT Arrays.

    Science.gov (United States)

    Maadi, Mohammad; Zemp, Roger J

    2016-09-01

    Multi-frequency capacitive micromachined ultrasonic transducers (CMUTs) consist of interlaced large and small membranes for multiband operation. In modeling these devices, accurate and computationally efficient methods are required for computing self- and mutual-acoustic-radiation impedances. However, most previous works considered mutual-acoustic impedance between radiators of identical size. A need was thus found to revisit the fundamental framework for mutual-acoustic impedance for its applicability to radiators, especially flexural disks, of differing size. The Bouwkamp integral method is used to achieve infinite series expressions for self- and mutual-acoustic radiation impedances. Polynomial-fitting-based approximate relations of the mutual-acoustic impedance are developed for arbitrary array geometries and are in good agreement with exact expressions. The derived mutual-acoustic impedance is incorporated into equivalent circuit models of multi-frequency CMUTs showing excellent agreement with finite element modeling. The results demonstrate that mutual-acoustic interactions significantly impact device performance. The framework presented here may prove valuable for future design of multi-frequency arrays for novel multiscale imaging, superharmonic contrast imaging, and image therapy applications.

  12. Beneficial effects of radiation and regulatory policy

    Energy Technology Data Exchange (ETDEWEB)

    Jaworowski, Z. [Central Laboratory for Radiological Protection, Warsaw, (Poland)

    1997-09-01

    Adaptive and simulating effects of ionizing radiation occur at near natural doses. This disagrees with linear, no-threshold hypothesis on the dose/effect relationship, which is a basis of the current radiation protection. vast literature demonstrates that such effects, usually known as hormetic ones, occur at molecular, cellular and population levels, and often result in increased longevity and decreased cancer incidence. Exposure to lower than natural radiation causes deficiency symptoms in protozoa and bacteria. Hormetic effects suggest that the current radiation protection regulations may be too conservative. After the Chernobyl accident, adverse health effects and vast material losses were induced in the former USSR by practical implementation of the ICRP radiation protection recommendations. A revision of the current approach to managing the risks of ionizing radiation is needed for the public interest. (author). 67 refs., 8 tabs., 4 figs.

  13. A-bomb radiation effects digest

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  14. The photoelectric effect. Fundamentals of radiation measurement

    International Nuclear Information System (INIS)

    Herrmann, K.H.

    1994-01-01

    This handbook presents the physical backgrounds of the photoelectric effect (emission and capture) and indicates applications in solid state physics as photoelectron spectroscopy and photoelectric radiation measurements

  15. Atmospheric-radiation boundary conditions for high-frequency waves in time-distance helioseismology

    Science.gov (United States)

    Fournier, D.; Leguèbe, M.; Hanson, C. S.; Gizon, L.; Barucq, H.; Chabassier, J.; Duruflé, M.

    2017-12-01

    The temporal covariance between seismic waves measured at two locations on the solar surface is the fundamental observable in time-distance helioseismology. Above the acoustic cut-off frequency ( 5.3 mHz), waves are not trapped in the solar interior and the covariance function can be used to probe the upper atmosphere. We wish to implement appropriate radiative boundary conditions for computing the propagation of high-frequency waves in the solar atmosphere. We consider recently developed and published radiative boundary conditions for atmospheres in which sound-speed is constant and density decreases exponentially with radius. We compute the cross-covariance function using a finite element method in spherical geometry and in the frequency domain. The ratio between first- and second-skip amplitudes in the time-distance diagram is used as a diagnostic to compare boundary conditions and to compare with observations. We find that a boundary condition applied 500 km above the photosphere and derived under the approximation of small angles of incidence accurately reproduces the "infinite atmosphere" solution for high-frequency waves. When the radiative boundary condition is applied 2 Mm above the photosphere, we find that the choice of atmospheric model affects the time-distance diagram. In particular, the time-distance diagram exhibits double-ridge structure when using a Vernazza Avrett Loeser atmospheric model.

  16. Frequency Effects in Second Language Acquisition: An Annotated Survey

    Science.gov (United States)

    Kartal, Galip; Sarigul, Ece

    2017-01-01

    The aim of this study is to investigate the relationship between frequency and language acquisition from many perspectives including implicit and explicit instruction, frequency effects on morpheme acquisition in L2, the relationship between frequency and multi-word constructions, frequency effects on phonetics, vocabulary, gerund and infinitive…

  17. Long-term effects of ionizing radiation

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  18. Modeling of the propagation of low-frequency electromagnetic radiation in the Earth’s magnetosphere

    International Nuclear Information System (INIS)

    Lebedev, N. V.; Rudenko, V. V.

    2015-01-01

    A numerical algorithm for solving the set of differential equations describing the propagation of low-frequency electromagnetic radiation in the magnetospheric plasma, including in the presence of geomagnetic waveguides in the form of large-scale plasma density inhomogeneities stretched along the Earth’s magnetic field, has been developed. Calculations of three-dimensional ray trajectories in the magnetosphere and geomagnetic waveguide with allowance for radiation polarization have revealed characteristic tendencies in the behavior of electromagnetic parameters along the ray trajectory. The results of calculations can be used for magnetospheric plasma diagnostics

  19. Strong Field-Induced Frequency Conversion of Laser Radiation in Plasma Plumes: Recent Achievements

    Directory of Open Access Journals (Sweden)

    R. A. Ganeev

    2013-01-01

    Full Text Available New findings in plasma harmonics studies using strong laser fields are reviewed. We discuss recent achievements in the growth of the efficiency of coherent extreme ultraviolet (XUV radiation sources based on frequency conversion of the ultrashort pulses in the laser-produced plasmas, which allowed for the spectral and structural studies of matter through the high-order harmonic generation (HHG spectroscopy. These studies showed that plasma HHG can open new opportunities in many unexpected areas of laser-matter interaction. Besides being considered as an alternative method for generation of coherent XUV radiation, it can be used as a powerful tool for various spectroscopic and analytical applications.

  20. Definition of magnetic liquid parameters on reflection of superhigh frequency radiation

    CERN Document Server

    Usanov, D A; Skripal, A V; Kurganov, A V

    2001-01-01

    The results of studies on the interaction of the superhigh frequency radiation within the frequency range of 20 up to 40 GHz with the magnetic liquid, completely filling the waveguide and limited by the dielectric fuse, are presented. The dependence of the position at the frequency axis of the alternating interference maxima and minima, connected with the reflection from the dielectric fuse and back walls, on the applied magnetic field value, is shown, This dependence is conditioned by the change in the complex magnetic susceptibility of the magnetic liquid. The solution of the reverse task on determination of the magnetic liquid parameters - the ferrimagnetic particles diameter and voluminous part of the magnetic liquid solid phase by the results of measuring the frequency dependence of the reflection coefficient is presented

  1. Radiation effects on biochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Seddon, G.M

    2000-04-01

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

  2. Some characteristics and effects of natural radiation

    International Nuclear Information System (INIS)

    Mc Laughlin, J.P.

    2015-01-01

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

  3. Radiation effects on bullfrog tadpoles

    International Nuclear Information System (INIS)

    Kawamura, Kosuke

    1980-01-01

    Effects of γ-rays on the metamorphosing Rana catesbeiana was studied. When 180 premetamorphic tadpoles were irradiated with 1 - 4 kR, 50% of them survived for 21 days. However, in the case of the late prometamorphic or the climax tabpoles, stage-specific lethal effect seemed to be causally related to metamorphic transformations which take place near stage XXI. During normal development, the larval intestinal epithelium began to degenerate at stage XX. At the same time, the besally-situated stem cells began to multiply to form small colonies. Before stage XXI, they fused to form a continuous layer of secondary epithelium. Finally, the intestinal villi developed at about stage XXIV. The number of stem cell colonies decreased dose-dependency, after irradiation, as follows: 13 (0 R), 4.0 (750 R), 1.0 (1 kR), and 0.0 (4 kR) colonies per cross-section. The secondary epithelium was depleted of cells and hardly covered the luminal surface of the intestine, suggesting that the secondary epithelial stem cells were sensitive to radiation and that the damage was expressed with the onset of epithelial replacement. The irradiated tadpoles, well before the metamorphic climax, the future adult-type stem cells precociously began to multiply, which was suggestive of the existence of population control mechanisms common to the primary and the secondary epithelial cells. (Nakanishi, T.)

  4. Effects Of Radiation On Insulators

    Science.gov (United States)

    Bouquet, Frank L.

    1988-01-01

    Report presents data on responses of electrically insulating thermosetting and thermoplastic polymers to radiation. Lowest-threshold-dose (LTD) levels and 25-percent-change levels presented for such properties as tensile strength and electrical resistivity. Data on radiation-induced outgassing also given.

  5. Apparatus for isotopic separation using a high-frequency wave and coherent radiation

    International Nuclear Information System (INIS)

    Mourier, G.

    1983-11-01

    The purpose of the present invention is an apparatus for industrial separation of isotopes, using a high-frequency electromagnetic field and coherent radiation such as that from a laser. Separation of isotopes by isotopically selective ionization, followed by entrainment of the ions by means of a magnetic field, is known. The selective ionization operation can be carried out in two consecutive stages: excitation of the chosen isotope, from the ground energy state to a specified excited level, near ionization; the energy required for this first stage can be supplied by means of a laser, the laser radiation being characterized for high power and well-defined frequency; this stage offers the advantage of being easily made isotopically selective; then ionization of the excited atoms by means of supplying relatively weak energy which should be insufficient to ionize the nonexcited ions; this second stage can also be carried out by means of a laser

  6. Fitness costs of increased cataract frequency and cumulative radiation dose in natural mammalian populations from Chernobyl

    OpenAIRE

    Lehmann, Philipp; Boraty?ski, Zbyszek; Mappes, Tapio; Mousseau, Timothy A.; M?ller, Anders P.

    2016-01-01

    A cataract is a clouding of the lens that reduces light transmission to the retina, and it decreases the visual acuity of the bearer. The prevalence of cataracts in natural populations of mammals, and their potential ecological significance, is poorly known. Cataracts have been reported to arise from high levels of oxidative stress and a major cause of oxidative stress is ionizing radiation. We investigated whether elevated frequencies of cataracts are found in eyes of bank voles Myodes glare...

  7. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    OpenAIRE

    Peter W. Gaiser; Magdalena D. Anguelova

    2012-01-01

    Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam ...

  8. Radiation effects of ion beams on polymers

    International Nuclear Information System (INIS)

    Tagawa, Seiichi

    1993-01-01

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

  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. Health effects of low frequency electric and magnetic fields

    International Nuclear Information System (INIS)

    1992-06-01

    The US Department of Labor and the President's Office of Science and Technology Policy (STP) requested that the Committee on interagency Radiation Research and Policy Coordination (CIRRPC) conduct an independent evaluation of the reported health effects from exposure to low-frequency electric and magnetic fields (ELF-EMF), especially reports of carcinogenesis and reproductive and neurophysiological effects focusing on frequencies which appeared to be of greatest public concern. Oak Ridge Associated Universities (ORAU) was tasked by the CIRRPC to oversee the review by a panel of independent, non-Federal, scientists. Following their review of over 1000 journal articles, the ORAU Panel concluded ''... that there is no convincing evidence ... to support the contention that exposure to ELF-EMF generated by sources such as household appliances, video display terminals (10 to 30 KHz), and local power lines (15 to 180 Hz) are demonstrable health hazards.'' Although the Panel noted that some biological effects produced by these fields may be of scientific interest and warrant consideration for future research, it concluded that ''... in the broad scope of research needs in basic science and health research, any health concerns over exposures to these fields should not receive a high priority.'' This executive summary outlines the panel's investigation

  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. Generation of extremely low frequency chorus in Van Allen radiation belts

    Science.gov (United States)

    Xiao, Fuliang; Liu, Si; Tao, Xin; Su, Zhenpeng; Zhou, Qinghua; Yang, Chang; He, Zhaoguo; He, Yihua; Gao, Zhonglei; Baker, D. N.; Spence, H. E.; Reeves, G. D.; Funsten, H. O.; Blake, J. B.

    2017-03-01

    Recent studies have shown that chorus can efficiently accelerate the outer radiation belt electrons to relativistic energies. Chorus, previously often observed above 0.1 equatorial electron gyrofrequency fce, was generated by energetic electrons originating from Earth's plasma sheet. Chorus below 0.1 fce has seldom been reported until the recent data from Van Allen Probes, but its origin has not been revealed so far. Because electron resonant energy can approach the relativistic level at extremely low frequency, relativistic effects should be considered in the formula for whistler mode wave growth rate. Here we report high-resolution observations during the 14 October 2014 small storm and firstly demonstrate, using a fully relativistic simulation, that electrons with the high-energy tail population and relativistic pitch angle anisotropy can provide free energy sufficient for generating chorus below 0.1 fce. The simulated wave growth displays a very similar pattern to the observations. The current results can be applied to Jupiter, Saturn, and other magnetized planets.

  13. The Effect of Radiation "Memory" in Alkali-Halide Crystals

    Science.gov (United States)

    Korovkin, M. V.; Sal'nikov, V. N.

    2017-01-01

    The exposure of the alkali-halide crystals to ionizing radiation leads to the destruction of their structure, the emergence of radiation defects, and the formation of the electron and hole color centers. Destruction of the color centers upon heating is accompanied by the crystal bleaching, luminescence, and radio-frequency electromagnetic emission (REME). After complete thermal bleaching of the crystal, radiation defects are not completely annealed, as the electrons and holes released from the color centers by heating leave charged and locally uncompensated defects. Clusters of these "pre centers" lead to electric microheterogeneity of the crystal, the formation of a quasi-electret state, and the emergence of micro-discharges accompanied by radio emission. The generation of REME associated with residual defectiveness, is a manifestation of the effect of radiation "memory" in dielectrics.

  14. Physics of intense, high energy radiation effects.

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-02-01

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

  15. 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...

  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. Effects of Radiation on Commercial Power Devices

    Science.gov (United States)

    Selva, Luis; Becker, Heidi; Chavez, Rosa; Scheick, Leif

    2006-01-01

    The effects of radiation on various commercial power devices are presented. The devices have proved to be very fragile to single event effects, with some of the devices actually succumbing to catastrophic SEE with protons.

  18. 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.

  19. Radiation effects in the lung

    International Nuclear Information System (INIS)

    Coggle, J.E.; Lambert, B.E.; Moores, S.R.

    1986-01-01

    This article outlines the principles of radiobiology that can explain the time of onset, duration, and severity of the complex reactions of the lung to ionizing radiation. These reactions have been assayed biochemically, cell kinetically, physiologically, and pathologically. Clinical and experimental data are used to describe the acute and late reactions of the lung to both external and internal radiation including pneumonitis, fibrosis and carcinogenesis. Acute radiation pneumonitis, which can be fatal, develops in both humans and animals within 6 months of exposure to doses greater than or equal to 8 Gy of low LET radiation. It is divisible into a latent period lasting up to 4 weeks; an exudative phase (3-8 weeks) and with an acute pneumonitic phase between 2 and 6 months. There is much evidence to suggest that pneumonitis is an epithelial reaction and some evidence to suggest that this early damage may not be predictive of late fibrosis. However, despite detailed work on collagen metabolism, the pathogenesis of radiation fibrosis remains unknown. The data on radiation-induced pulmonary cancer, both in man and experimental animals from both external and internal irradiation following the inhalation of both soluble and insoluble alpha and beta emitting radionuclides are reviewed. 312 references. (Abstract Truncated)

  20. Deterministic effects of the ionizing radiation

    International Nuclear Information System (INIS)

    Raslawski, Elsa C.

    2001-01-01

    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

  1. The ultra low frequency electromagnetic radiation observed in the topside ionosphere above boundaries of tectonic plates

    Directory of Open Access Journals (Sweden)

    Michael A. Athanasiou

    2015-01-01

    Full Text Available In this paper we present results of a comparison between ultra low frequency (ULF electromagnetic (EM radiation, recorded by an electric field instrument onboard the satellite detection of electromagnetic emissions transmitted from earthquake regions in the topside ionosphere, and the seismicity of regions with high and low seismic activity. In particular, we evaluated the energy variations of the ULF Ezelectric field component during a period of four years (2006-2009, in order to examine the possible relation of ULF EM radiation with seismogenic regions located in Central America, Indonesia, the Eastern Mediterranean Basin and Greece. As a tool for evaluating the ULF Ez energy variations we used singular spectrum analysis techniques. The results of our analysis clearly show a significant increase of the ULF EM energy emitted from regions of highest seismic activity at the boundaries tectonic plates. Furthermore, we found that higher electromagnetic radiation was detected in a region above the northern- western Greek Arc (R1 than above the adjacent region including Athens and its urban area. We interpret these results of the present study as suggesting that: i the seismogenic regions at the boundary of tectonic plates radiate ULF EM emissions observed by satellites in the topside ionosphere; and ii that this EM radiation is not only related with the occurrence time of great (M≥5 earthquakes, but it is often present in intermediate times and it appears as a quasi-permanent phenomenon.

  2. Radio frequency radiation-related cancer: assessing causation in the occupational/military setting.

    Science.gov (United States)

    Peleg, Michael; Nativ, Or; Richter, Elihu D

    2018-05-01

    We reexamine whether radio frequency radiation (RFR) in the occupational and military settings is a human carcinogen. We extended an analysis of an already-reported case series of patients with cancer previously exposed to whole-body prolonged RFR, mainly from communication equipment and radar. We focused on hematolymphatic (HL) cancers. We used analysis by percentage frequency (PF) of a cancer type, which is the proportion of a specific cancer type relative to the total number of cancer cases. We also examined and analyzed the published data on three other cohort studies from similar military settings from different countries. The PF of HL cancers in the case series was very high, at 40% with only 23% expected for the series age and gender profile, confidence interval CI95%: 26-56%, pRFR in Israeli defense industry, the PF of HL cancers was 60% versus 17% expected for the group age and gender profile, pRFR and highly elevated HL cancer risk in the four groups spread over three countries, operating different RFR equipment types and analyzed by different research protocols, suggests a cause-effect relationship between RFR and HL cancers in military/occupational settings. While complete measurements of RFR exposures were not available and rough exposure assessments from patients interviews and from partial exposure data were used instead, we have demonstrated increased HL cancers in occupational groups with relatively high RFR exposures. Our findings, combined with other studies, indicate that exposures incurred in the military settings evaluated here significantly increased the risk of HL cancers. Accordingly, the RFR military exposures in these occupations should be substantially reduced and further efforts should be undertaken to monitor and measure those exposures and to follow cohorts exposed to RFR for cancers and other health effects. Overall, the epidemiological studies on excess risk for HL and other cancers together with brain tumors in cellphone users and

  3. Effective masking bandwidths at low frequencies.

    Science.gov (United States)

    Fidell, S; Horonjeff, R; Teffeteller, S; Green, D M

    1983-02-01

    Masking of low-frequency sinusoids of varying durations by Gaussian noise of varying spectral shape was measured in three different studies. Common solutions to technical problems associated with control and specification of low-frequency signals were used in the three studies. If interpreted in terms of Fletcher's critical ratio assumptions, data from the first study lead to the inference that the masking bandwidth is inversely related to signal frequency below about 200 Hz. Data from the second study rule out the likelihood that the apparent increase in masking bandwidth is attributable to changes in auditory integration times at low frequencies. The data of the third study suggest that the apparent increase in auditory filter bandwidth at low frequencies is more adequately explained by a decrease in observers' detection efficiency than by broadening of the filter bandpass.

  4. Chernobyl health effects: radiation or stress?

    International Nuclear Information System (INIS)

    Grinkhal', G.

    1996-01-01

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

  5. Computing effective properties of nonlinear structures exposed to strong high-frequency loading at multiple frequencies

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2006-01-01

    Effects of strong high-frequency excitation at multiple frequencies (multi-HFE) are analyzed for a class of generally nonlinear systems. The effects are illustrated for a simple pendulum system with a vibrating support, and for a parametrically excited flexible beam. For the latter, theoretical...

  6. Late effects of radiation: host factors

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  7. [Radiation effects of exposure during prenatal development].

    Science.gov (United States)

    Streffer, C

    1995-03-01

    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 corruption) high radiosensitivity 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.

  8. Radiation effects on Fischer-Tropsch syntheses

    International Nuclear Information System (INIS)

    Hatada, M.; Matsuda, K.

    1977-01-01

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

  9. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    Clerc, H.

    1991-03-01

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

  10. Gamma radiation effect to prostaglandin

    International Nuclear Information System (INIS)

    Coelho, Fernando Rodrigues; Lima, Wothan Tavares de; Rogero, Sizue Ota; Lugao, Ademar Benevolo

    2005-01-01

    Prostaglandins and their analogs are of great physiological importance used to prepare drugs by pharmaceutical industry. But the resistance to radiation sterilization process is not too much studied. This work had the objective of study the relaxation activity of irradiated prostaglandin type E1 on the muscle of respiratory tract. 1% HPMC prostaglandin dried dispersion was submitted to radiation from Co-60 gamma source with 10 kGy/h dose rate at 0, 50, 75 e 100 kGy doses. After irradiation degradation measurement was performed by HPLC analysis and the biological activity by in vitro assay of relaxation activity of muscle, in trachea isolated from rats. The results showed in the maximum radiation dose (]100 kGy) about 5% loss of prostaglandin relaxation activity and degradation of about 30% in relation to non irradiated sample. Prostaglandin dispersion in HPMC can be considered steady after irradiation in the dose used for medical products sterilization. (author)

  11. Effective properties of mechanical systems under high-frequency excitation at multiple frequencies

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2008-01-01

    Effects of strong high-frequency excitation at multiple frequencies (multi-HFE) are analyzed for a class of generally nonlinear systems. The effects are illustrated for a simple pendulum system with a vibrating support, and for a parametrically excited flexible beam. For the latter, theoretical...... contribution of slowly oscillating stiffness appears. This may cause strong parametric resonance at conditions that might not appear obvious, i.e. when the difference in two HFE frequencies is near twice an effective system natural frequency, which due to the HFE itself is shifted away from the natural......-HFE with non-close frequencies. The general results may be used to investigate or utilize general effects, or as a shortcut to calculate effective properties for specific systems, or to calculate averaged equations of motion that may be much faster to simulate numerically....

  12. Effects of Radiation on Oxide Materials.

    Science.gov (United States)

    1981-11-01

    AD-All 149 MCA LASS PRINCETON J. F/6 18/8 EFFECTS OF RADIATION ON OXIDE MATERIALS.(U) NO0V 51 S W HUGSES. N1 THOMAS CAA3-77-C-0159 UNCLASSIFIED PRRL...79-CR-12 NDL-CR-79-159-1 N 111 1 4 9HDL-CR-79-159-1 L E- November 1981 EFFECTS OF RADIATION ON OXIDE MATERIALS by Gary W. Hughes and John H. Thomas...COVERED FINAL REPORT (9-26-77 to 9-25-78) EFFECTS OF RADIATION ON OXIDE MATERIALS 6, PERFORMING ORG. REPORT NUMBER PRRL-79-CR- 12 7. AUTHOR(s) S

  13. Physics of radiation effects in crystals

    CERN Document Server

    Johnson, RA

    1986-01-01

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

  14. Testing hypotheses on frequency effects in first language acquisition

    DEFF Research Database (Denmark)

    Kjærbæk, Laila; Basbøll, Hans

    2015-01-01

    On the basis of extensive literature studies, Ambridge, Kidd, Rowland and Theakston (2015) present five theses on frequency effects on language acquisition: i) the Levels and Kinds Thesis argues that frequency effects exist at all levels and are of many different kinds (e.g., type and token...... frequency effects as well as absolute and relative frequency effects); ii) the Age of Acquisition Thesis argues that all other things being equal, frequent forms will be acquired before less frequent forms. Since all other things are not equal, this claim does not entail a one-to-one relationship between...... frequency and age of acquisition; iii) the Prevent Error Thesis argues that high-frequency forms prevent (or reduce) errors in contexts in which they are the target; iv) the Cause Error Thesis argues that high-frequency forms also cause errors in contexts in which a competing, related lower-frequency form...

  15. Conventional radiation-biological dosimetry using frequencies of unstable chromosome aberrations

    International Nuclear Information System (INIS)

    Ramalho, Adriana T.; Costa, Maria Lucia P.; Oliveira, Monica S.

    1998-01-01

    Frequency of chromosome aberrations detected by conventional cytogenetics is a very useful parameter in biological radiodosimetry. It can be used for estimating absorbed doses in individuals working with radioactive sources and individuals accidentally exposed to radiation. In the first case subjects wear physical dosimeters as a routine safety habit. The laboratory at the Institute of Radioprotection and Dosimetry (IRD, Brazil) has been using conventional cytogenetic analysis to complement data obtained by physical dosimetry since 1983. Until now, more than one hundred cases were investigated where individual physical dosimeters detected occupational exposure (above the safety limits allowed). In total, only 34% of these cases were confirmed by conventional cytogenetic dosimetry. Also, conventional cytogenetic analysis following the radiation accident of Goiania (Brazil) in 1987 have been used. Peripheral lymphocytes from 129 exposed or potentially exposed individuals were analyzed for the frequencies of unstable chromosomal aberrations (dicentrics, centric rings and acentrics fragments) to estimate absorbed radiation doses. During the emergency period, doses were estimated to help immediate medical treatment using in vitro calibration curves produced before the accident. Later on, doses were assessed once more using new in vitro calibration curves. A drawback of this technique is that unstable aberrations are lost after exposure. To investigate the mean lifespan of lymphocytes containing dicentric and ring aberrations, we have followed 15 victims of the Goiania accident over all these years. Results suggest that the disappearance of unstable aberrations is dose-dependent. This could explain the variation in the results found among studies in this field

  16. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  17. Frequency detuning effects for parametrically and directly excited elastic structures

    DEFF Research Database (Denmark)

    Neumeyer, Stefan; van Gastel, M. H. M.; Sorokin, Vladislav

    2015-01-01

    This study investigates the frequency detuning effects of parametric and direct excitation for near-resonant nonlinear structural vibrations. Specifically, the detuning effects of a two-to-one frequency ratio between the parametric and direct excitation, and of a drift in natural frequency...... numerical integration and experiments showing good agreement. For frequency detuned superthreshold parametric excitation some of the theoretical frequency-amplitude solution branches appear to merge. For some ranges of parametric excitation frequency a drop in experimental steady-state vibration amplitude...... was found, indicating performance degradation whereas for other frequency ranges, frequency detuning may yield an increased steady-state vibration amplitude. This makes frequency detuning a feature which can purposefully be avoided or utilized, dependent on the application....

  18. Biological and sanitary effects of non ionizing radiations

    International Nuclear Information System (INIS)

    Brugere, H.; Hours, M.; Seze, R. de; Bernier, M.; Letertre, Th.; Aurengo, A.; Burais, N.; Bedja, M.; Merckel, O.; Decat, G.; Lagroye, I.; Perrin, A.; Poulletier de Gannes, F.; Aurengo, A.; Souques, M.; Cesarini, J.P.; Lagroye, I.; Aurengo, A.; Cesarini, J.P.

    2008-01-01

    The objective of this day was to encourage the collaborations, especially multidisciplinary, on the biological, clinical, epidemiological and dosimetry aspects. The different presentations are as follow: the magneto reception among animals; the health and radio frequencies foundation; expo-metry to radio frequency fields: dosemeters evaluation; the electro-optical probes as tool of hyper frequency dosimetry; characterisation of emissions produced by the low consumption fluo-compact lamps in the perspective of persons exposure; strong and weak points of epidemiology; numerical dosimetry in low frequency magnetic and/or electric field; exposure of the French population to the 50 Hz magnetic field: first results for the Ile-de-france and Rhone alpes areas; characterisation of the exposure to the very low frequency magnetic fields in the town of Champlan; measurement of the residential exposure of children to the extremely low frequency, very low frequency and radiofrequency (E.L.F., V.L.F. and R.F.) fields and modeling of the high voltage magnetic field face to the child leukemia; effects of radiofrequency signals of wireless communications on the young animals; study of combined effects of 2.45 GHz microwaves and a known mutagen on DNA by two different approaches; effects on the oxidizing stress of nervous cells exposure to an (enhanced data rates for GSM evolution) E.D.G.E. signal; is environmental epidemiology still a science; cardiac implants and exposure to 50 Hz electromagnetic fields in occupational environment; the tanning by artificial UV radiation: norms and legislation; mobiles phones, Wi Fi and other wireless communications; effects on health of 50-60 Hz electromagnetic fields; natural and artificial ultraviolet radiations: a proved risk. (N.C.)

  19. Health effects of low level radiation: carcinogenesis, teratogenesis, and mutagenesis

    Energy Technology Data Exchange (ETDEWEB)

    Ritenour, E.R.

    1986-04-01

    The carcinogenic effects of radiation have been demonstrated at high dose levels. At low dose levels, such as those encountered in medical diagnosis, the magnitude of the effect is more difficult to quantify. Three reasons for this difficulty are (1) the effects in human populations are small compared with the natural incidence of cancer in the populations; (2) it is difficult to transfer results obtained in animal studies to the human experience; and (3) the effects of latency period and plateau increase the complexity of population studies. In spite of these difficulties, epidemiologic studies of human populations exposed to low levels of radiation still play a valuable role in the determination of radiation carcinogenecity. They serve to provide upper estimates of risk and to rule out the appearance of new effects that may be masked by the effects of high doses. While there is evidence for mutagenic effects of radiation in experimental animals, no conclusive human data exist at the present. It is not possible to rule out the presence of genetic effects of radiation in humans, however, because many problems exist with regard to the epidemiologic detection of small effects when the natural incidence is relatively large. In animals, subtle effects (eg, a decrease in the probability of survival from egg to adult) may occur with greater frequency than more dramatic disorders in irradiated populations. However, these types of genetic abnormalities are difficult to quantitate. Current risk estimates are based primarily upon data pertaining to dominant mutations in rodents. Some specific locus studies also permit identification of recessive mutation rates. The embryo and fetus are considered to be at greater risk for adverse effects of radiation than is the adult.

  20. Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

    Science.gov (United States)

    Narayanan, Sareesh Naduvil; Kumar, Raju Suresh; Paval, Jaijesh; Kedage, Vivekananda; Bhat, M Shankaranarayana; Nayak, Satheesha; Bhat, P Gopalakrishna

    2013-07-01

    In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 μW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

  1. Effects of gamma radiation in tomato seeds

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  2. Effects of gamma radiation in tomato seeds

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  3. Radiative effects of global MODIS cloud regimes

    Science.gov (United States)

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

    2018-01-01

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

  4. Predicted solar cell edge radiation effects

    International Nuclear Information System (INIS)

    Gates, M.T.

    1993-01-01

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

  5. The Effects of Ionizing Radiation on Mammalian Cells.

    Science.gov (United States)

    Biaglow, John E.

    1981-01-01

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

  6. The effects of ionizing radiation on man

    International Nuclear Information System (INIS)

    Watson, G.M.

    1975-08-01

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

  7. Changing of Bacteria Catalase Activity Under the Influence of Electro-Magnetic Radiation on a Frequency of Nitric Oxide Absorption and Radiation Molecular Spectrum

    Directory of Open Access Journals (Sweden)

    G.M. Shub

    2009-09-01

    Full Text Available The dynamics of catalase activity degree changing in Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa is described under the influence of electro-magnetic radiation on a frequency of nitric oxide absorption and radiation molecular spectrum. The panoramic spectrometric measuring complex, developed in Central Scientific Research Institute of measuring equipment Public corporation, Saratov, was used while carrying out the research. Electromagnetic vibrations of extremely high frequencies were stimulated in this complex imitating the structure of nitric oxide absorption and radiation molecular spectrum. The growth of activity of the mentioned enzyme of the strains under research was detected. The most significant changes were observed under 60-minutes exposure.

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

    Science.gov (United States)

    Kamiya, Kenji; Sasatani, Megumi

    2012-03-01

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

  9. Effects of radiations on ornamental fish

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  10. Sterilizing radiation effects on selected polymers

    International Nuclear Information System (INIS)

    Skiens, W.E.

    1979-03-01

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

  11. Graphene Field Effect Transistors for Radiation Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This is propose to develop Graphene Field Effect Transistor based Radiation Sensors (GFET-RS) for NASA Manned Spaceflight Missions anticipated in next several...

  12. Peak radiated power measurement of the DOE Mark II container tag with integrated ST-676 sensor radio frequency identification device.

    Energy Technology Data Exchange (ETDEWEB)

    Jursich, Mark

    2010-04-01

    The total peak radiated power of the Department of Energy Mark II container tag was measured in the electromagnetic reverberation chamber facility at Sandia National Laboratories. The tag's radio frequency content was also evaluated for possible emissions outside the intentional transmit frequency band. No spurious emissions of any significance were found, and the radiated power conformed to the manufacturer's specifications.

  13. Effect of ionizing radiations on connective tissue

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  14. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Science.gov (United States)

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10-13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  15. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    Directory of Open Access Journals (Sweden)

    Ariko Fukushima

    Full Text Available The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs above the human audible range (max. 20 kHz activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz to observe changes in the alpha2 frequency component (10-13 Hz of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG, which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC. When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect, while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect. These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC.

  16. Modifiers of radiation effects in the eye.

    Science.gov (United States)

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

    2017-11-01

    World events, including the threat of radiological terrorism and the fear of nuclear accidents, have highlighted an urgent need to develop medical countermeasures to prevent or reduce radiation injury. Similarly, plans for manned spaceflight to a near-Earth asteroid or journey to Mars raise serious concerns about long-term effects of space radiation on human health and the availability of suitable therapeutic interventions. At the same time, the need to protect normal tissue from the deleterious effects of radiotherapy has driven considerable research into the design of effective radioprotectors. For more than 70 years, animal models of radiation cataract have been utilized to test the short and long-term efficacy of various radiation countermeasures. While some compounds, most notably the Walter Reed (WR) class of radioprotectors, have reported limited effectiveness when given before exposure to low-LET radiation, the human toxicity of these molecules at effective doses limits their usefulness. Furthermore, while there has been considerable testing of eye responses to X- and gamma irradiation, there is limited information about using such models to limit the injurious effects of heavy ions and neutrons on eye tissue. A new class of radioprotector molecules, including the sulfhydryl compound PrC-210, are reported to be effective at much lower doses and with far less side effects. Their ability to modify ocular radiation damage has not yet been examined. The ability to non-invasively measure sensitive, radiation-induced ocular changes over long periods of time makes eye models an attractive option to test the radioprotective and radiation mitigating abilities of new novel compounds. Copyright © 2017. Published by Elsevier Ltd.

  17. Modifiers of radiation effects in the eye

    Science.gov (United States)

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

    2017-11-01

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

  18. Spectrum and Frequency of Mutations Induced by Gamma Radiations in Three Varieties of Nigerian Sesame (Sesamum indicum L.

    Directory of Open Access Journals (Sweden)

    Muhammad Liman MUHAMMAD

    2018-03-01

    Full Text Available Insufficient genetic variability is one of the major problems of plant breeding programmes, especially in sesame. Gamma radiation has been reported to be very effective in creating genetic variability in plants. Three varieties of Nigerian sesame were assessed for spectrum and frequency of mutation induced by Gamma radiations in M1 and M2 generations. The varieties (NCRIBEN-04E, NCRIBEN-01M and NCRIBEN-03L were treated with four different doses of gamma rays (250, 350, 450 and 550 Gy. The treated and untreated seeds (control were sown in planting bags (under field condition to raise M1 plants. Four treatments: V1D5, V2D3, V3D2 and V3D4 (from M1 plants were selected and bulked to obtain M2 populations. The results of M1 revealed four mutant fruit traits: multicarpellate capsule, multiple capsule per leaf axil, indehiscent capsule and terminal capsules. The highest frequencies of the traits in M1 generation were 2.50×10-2, 9.17×10-2, 1.67×10-2and3.33×10-2 respectively. The highest branching (7 was from NCRIBEN-01M, while the least (2 was from NCRIBEN-04E. The M2 plants were grouped into eight M2 lines. The dose range (250-550 Gy was proved to be effective in inducing viable mutations in sesame.

  19. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

    1999-01-01

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

  20. The origin of high frequency radiation in earthquakes and the geometry of faulting

    Science.gov (United States)

    Madariaga, R.

    2004-12-01

    In a seminal paper of 1967 Kei Aki discovered the scaling law of earthquake spectra and showed that, among other things, the high frequency decay was of type omega-squared. This implies that high frequency displacement amplitudes are proportional to a characteristic length of the fault, and radiated energy scales with the cube of the fault dimension, just like seismic moment. Later in the seventies, it was found out that a simple explanation for this frequency dependence of spectra was that high frequencies were generated by stopping phases, waves emitted by changes in speed of the rupture front as it propagates along the fault, but this did not explain the scaling of high frequency waves with fault length. Earthquake energy balance is such that, ignoring attenuation, radiated energy is the change in strain energy minus energy released for overcoming friction. Until recently the latter was considered to be a material property that did not scale with fault size. Yet, in another classical paper Aki and Das estimated in the late 70s that energy release rate also scaled with earthquake size, because earthquakes were often stopped by barriers or changed rupture speed at them. This observation was independently confirmed in the late 90s by Ide and Takeo and Olsen et al who found that energy release rates for Kobe and Landers were in the order of a MJ/m2, implying that Gc necessarily scales with earthquake size, because if this was a material property, small earthquakes would never occur. Using both simple analytical and numerical models developed by Addia-Bedia and Aochi and Madariaga, we examine the consequence of these observations for the scaling of high frequency waves with fault size. We demonstrate using some classical results by Kostrov, Husseiny and Freund that high frequency energy flow measures energy release rate and is generated when ruptures change velocity (both direction and speed) at fault kinks or jogs. Our results explain why super shear ruptures are

  1. A theoretical study on directivity control of multiple-loudspeaker system with a quadrupole radiation pattern in low frequency range

    Science.gov (United States)

    Irwansyah, Kuse, Naoyuki; Usagawa, Tsuyoshi

    2017-08-01

    Directivity pattern of an ordinary loudspeaker becomes more directive at higher frequencies. However, because a single loudspeaker tends to radiate uniformly in all directions at low frequencies, reverberation from surrounding building walls may affect speech intelligibility when installing a multiple-loudspeaker system at crossroads. As an alternative, a sharply directive sound source is recommended to be used, but in many cases the directivity of an ordinary loudspeaker is less sharp at lower frequencies. Therefore, in order to overcome such a limitation, this paper discusses the possibility of using four loudspeakers under active control to realize a quadrupole radiation pattern in low frequency range. In this study, the radiation pattern of a primary loudspeaker and three secondary loudspeakers has been modelled. By placing the loudspeakers close together in the direction of 0°, 90°, 180°, and 270°, it was theoretically demonstrated that a quadrupole radiation pattern can be shaped in the target frequency range up to 600 Hz by simply controlling the directivity in three of four directions which are 45°, 135°, 225°, and 315°. Although, the radiation pattern model is far from realistic configurations and conditions, it is possible to realize a quadrupole radiation pattern in the low frequency range.

  2. Method for generation of THz frequency radiation and sensing of large amplitude material strain waves in piezoelectric materials

    Science.gov (United States)

    Reed, Evan J.; Armstrong, Michael R.

    2010-09-07

    Strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. Such radiation is of detectable amplitude and contains sufficient information to determine the time-dependence of the strain wave with unprecedented subpicosecond, nearly atomic time and space resolution.

  3. [Use of terahertz electromagnetic radiation at nitric oxide frequencies for the correction of thyroid functional state during stress].

    Science.gov (United States)

    Kirichuk, V F; Tsymbal, A A

    2010-01-01

    The influence of terahertz electromagnetic radiation at nitric oxide frequencies (150.176-150.664 Ghz) on the functional activity of rat thyroid gland subjected to acute immobilization stress has been studied. It is shown that terahertz radiation totally normalizes thyroid activity in stressed animals within 30 min after application.

  4. Frequencies of chromosomal aberrations and sister chromatid exchanges in the benthic worm Neanthes arenaceodentata exposed to ionizing radiation

    International Nuclear Information System (INIS)

    Harrison, F.L.; Rice, D.W. Jr.; Moore, D.H.

    1984-07-01

    Traditional bioassays are unsuitable for assessing sublethal effects from ocean disposal of low-level radioactive waste because mortality and phenotypic responses are not anticipated. We compared the usefulness of chromosomal aberration and sister chromatid exchange (SCE) induction as measures of low-level radiation effects in a sediment-dwelling marine worm, Neanthes arenaceodentata. The SCEs, in contrast to chromosomal aberrations, do not alter the overall chromosome morphology and in mammalian cells appear to be a more sensitive indicator of DNA alterations caused by environmental mutagens. Newly hatched larvae were exposed to two radiation-exposure regimes of either x rays at a high dose rate of 0.7 Gy (70 rad)/min for as long as 5.5 min or to 60 Co gamma rays at a low dose rate of from 4.8 x 10 -5 to 1.2 x 10 -1 Gy (0.0048 to 12 rad)/h for 24 h. After irradiation, the larvae were exposed to 3 x 10 -5 M bromodeoxyuridine (BrdUrd) for 28 h (x-ray-irradiated larvae) or for 54 h ( 60 Co-irradiated larvae). Larval cells were examined for the proportion of cells in first, second, and third or greater division. Frequencies of chromosomal aberrations and SCEs were determined in first and second division cells, respectively. Results from x-ray irradiation indicated that dose-related increases occur in chromosome and chromatid deletions, but a dose of equal or greater 2 Gy (equal to or greater than 200 rad) was required to observe a significant increase. Worm larvae receiving 60 Co irradiation showed elevated SCE frequencies with a significant increase of 0.6 Gy (60 rad). We suggest that both SCEs and chromosomal aberrations may be useful for measuring effects on genetic material induced by radiation. 56 references, 7 figures, 9 tables

  5. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats☆

    Science.gov (United States)

    Mohammed, Haitham S.; Fahmy, Heba M.; Radwan, Nasr M.; Elsayed, Anwar A.

    2012-01-01

    In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day). EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS) and rapid eye movement sleep (REM sleep) revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR) than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested. PMID:25685416

  6. Non-thermal continuous and modulated electromagnetic radiation fields effects on sleep EEG of rats

    Directory of Open Access Journals (Sweden)

    Haitham S. Mohammed

    2013-03-01

    Full Text Available In the present study, the alteration in the sleep EEG in rats due to chronic exposure to low-level non-thermal electromagnetic radiation was investigated. Two types of radiation fields were used; 900 MHz unmodulated wave and 900 MHz modulated at 8 and 16 Hz waves. Animals has exposed to radiation fields for 1 month (1 h/day. EEG power spectral analyses of exposed and control animals during slow wave sleep (SWS and rapid eye movement sleep (REM sleep revealed that the REM sleep is more susceptible to modulated radiofrequency radiation fields (RFR than the SWS. The latency of REM sleep increased due to radiation exposure indicating a change in the ultradian rhythm of normal sleep cycles. The cumulative and irreversible effect of radiation exposure was proposed and the interaction of the extremely low frequency radiation with the similar EEG frequencies was suggested.

  7. Correlated Uncertainties in Radiation Shielding Effectiveness

    Science.gov (United States)

    Werneth, Charles M.; Maung, Khin Maung; Blattnig, Steve R.; Clowdsley, Martha S.; Townsend, Lawrence W.

    2013-01-01

    The space radiation environment is composed of energetic particles which can deliver harmful doses of radiation that may lead to acute radiation sickness, cancer, and even death for insufficiently shielded crew members. Spacecraft shielding must provide structural integrity and minimize the risk associated with radiation exposure. The risk of radiation exposure induced death (REID) is a measure of the risk of dying from cancer induced by radiation exposure. Uncertainties in the risk projection model, quality factor, and spectral fluence are folded into the calculation of the REID by sampling from probability distribution functions. Consequently, determining optimal shielding materials that reduce the REID in a statistically significant manner has been found to be difficult. In this work, the difference of the REID distributions for different materials is used to study the effect of composition on shielding effectiveness. It is shown that the use of correlated uncertainties allows for the determination of statistically significant differences between materials despite the large uncertainties in the quality factor. This is in contrast to previous methods where uncertainties have been generally treated as uncorrelated. It is concluded that the use of correlated quality factor uncertainties greatly reduces the uncertainty in the assessment of shielding effectiveness for the mitigation of radiation exposure.

  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. Effects of feed refreshing frequency on growth and carcass ...

    African Journals Online (AJOL)

    UPuser

    2006) meal frequency referred to the frequency with which animals actually consume feed, not to the frequency with which animals were presented with fresh feed. The literature is inconclusive on the effect of feed refreshening on the growth performance and carcass characteristics of lambs. Therefore, the present study was ...

  10. Low-frequency noise in planar Hall effect bridge sensors

    DEFF Research Database (Denmark)

    Persson, Anders; Bejhedb, R.S.; Bejhed, R.S.

    2011-01-01

    The low-frequency characteristics of planar Hall effect bridge sensors are investigated as function of the sensor bias current and the applied magnetic field. The noise spectra reveal a Johnson-like spectrum at high frequencies, and a 1/f-like excess noise spectrum at lower frequencies, with a kn...

  11. 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...

  12. Biological effects of electromagnetic radiations - 7. International Conference, La Valette, Malta, 8-12 October 2012

    International Nuclear Information System (INIS)

    Demaret, P.

    2013-01-01

    This document proposes a synthesis of a conference on the biological effects of electromagnetic radiations. With reference to epidemiological studies, different issues have been addressed: pathological effects (either of static fields, or of extremely low frequencies, or of radio-frequencies), biological effects (methodological issues, case of extremely low frequencies and of radio-frequencies), medical applications of electromagnetic fields (tumour removal, neurological disorders, consolidation, wound healing and recovery), assessment of electromagnetic fields (existing directives and regulations, case of electric lines and of radio-frequencies), exposure to electromagnetic fields (occupational exposure in medical or industrial applications, specific devices such as telephones, regulation)

  13. Reflections on Frequency Effects in Language Processing.

    Science.gov (United States)

    Ellis, Nick C.

    2002-01-01

    An author reacts to a series of responses written in regard to an earlier article by the author on frequency in language processing, language use, and language acquisition. Addresses a number of issues raised in the responses and concludes by emphasizing that language acquisition is a process of dynamic emergence and learners' language is a…

  14. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  15. 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.

  16. Radiation Effects in Fission and Fusion Reactors

    Science.gov (United States)

    Odette, G. Robert; Wirth, Brian D.

    Since the prediction of "Wigner disease" [1] and the subsequent observation of anisotropic growth of the graphite used in the Chicago Pile, the effects of radiation on materials has been an important technological concern. The broad field of radiation effects impacts many critical advanced technologies, ranging from semiconductor processing to severe materials degradation in nuclear reactor environments. Radiation effects also occur in many natural environments, ranging from deep space to inside the Earth's crust. As selected examples that involve many basic phenomena that cross-cut and illustrate the broader impacts of radiation exposure on materials, this article focuses on modeling microstructural changes in iron-based ferritic alloys under high-energy neutron irradiation relevant to light water fission reactor pressure vessels. We also touch briefly on radiation effects in structural alloys for fusion reactor first wall and blanket structures; in this case the focus is on modeling the evolution of self-interstitial atom clusters and dislocation loops. Note, since even the narrower topic of structural materials for nuclear energy applications encompass a vast literature dating from 1942, the references included in this article are primarily limited to these two narrower subjects. Thus, the references cited here are presented as examples, rather than comprehensive bibliographies. However, the interested reader is referred to proceedings of continuing symposia series that have been sponsored by several organizations, several monographs [2-4] and key journals (e.g., Journal of Nuclear Materials, Radiation Effects and Defects in Solids).

  17. Biological Effects of Space Radiation and Development of Effective Countermeasures

    OpenAIRE

    Kennedy, Ann R.

    2014-01-01

    As part of a program to assess the adverse biological effects expected from astronaut exposure to space radiation, numerous different biological effects relating to astronaut 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 an...

  18. Cooperative Radiation Effects Simulation Program.

    Science.gov (United States)

    1977-09-01

    Andrew MING I Zeger OT ORGANIZATION NAME AND ADDRESS Magnavox/General Atronics Corporation 1200 Mermaid Lane Philadelphia PA 19118 S READ...7 S* + <«>oS/(*L * uo 1//EÜ • center frequency (2) Q. • R/2wnL - fn/Af, where A’f is the 3 dB L 00 bandwidth K - gain factOT A little

  19. The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

    NARCIS (Netherlands)

    De Visser, P.J.; Yates, S.J.C.; Guruswamy, T.; Goldie, D.J.; Withington, S.; Neto, A.; Llombart, N.; Baryshev, A.M.; Klapwijk, T.M.; Baselmans, J.J.A.

    2015-01-01

    We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the

  20. The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

    NARCIS (Netherlands)

    de Visser, P. J.; Yates, S. J. C.; Guruswamy, T.; Goldie, D. J.; Withington, S.; Neto, A.; Llombart, N.; Baryshev, A. M.; Klapwijk, T. M.; Baselmans, J. J. A.

    We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the

  1. Radiation effects on ion exchange materials

    International Nuclear Information System (INIS)

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

    1977-11-01

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

  2. 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.

  3. 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

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

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

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

  5. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Durand, J.L.

    2000-01-01

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

  6. Radiation effects on the integrity of paper

    International Nuclear Information System (INIS)

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

  7. Effect of gamma radiation on Campylobacter jejuni

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  8. Wip1 abrogation decreases intestinal tumor frequency in APC(Min/+) mice irrespective of radiation quality.

    Science.gov (United States)

    Suman, Shubhankar; Moon, Bo-Hyun; Thakor, Hemang; Fornace, Albert J; Datta, Kamal

    2014-09-01

    Low-linear energy transfer (low-LET) γ-ray exposure is a risk factor for colorectal cancer (CRC). Due to their high-LET nature, energetic iron ions found in space are expected to pose greater CRC risks to astronauts undertaking long-duration space missions beyond low Earth orbit. Wild-type p53-induced phosphatase 1 (Wip1) is important for cellular DNA damage response and its abrogation has been shown to inhibit spontaneous intestinal tumorigenesis in APC(Min/+) mice, a well-studied mouse model of human CRC. However, the relationship of Wip1 to radiation-induced intestinal tumorigenesis, especially by energetic iron ions, has not been investigated in APC(Min/+) mice. We have previously reported that there is a greater intestinal tumorigenic potential of iron-ion radiation relative to (137)Cs γ rays, so the purpose of the current study was to investigate whether Wip1 abrogation could influence high-LET dependent intestinal tumorigenesis in APC(Min/+) mice. Intestinal tumor frequency and grade were assessed in APC(Min/+)/Wip1(-/-) mice and results were compared to those in APC(Min/+)/Wip1(+/+) mice after exposure to a mean absorbed dose of 2 Gy from (137)Cs γ rays or 1.6 Gy from 1 GeV/n iron ions. Cellular differentiation and proliferation were also assessed in the intestinal tumors of sham-irradiated and irradiated mice. Decreased tumor frequency and lower tumor grade were observed in APC(Min/+)/Wip1(-/-) relative to APC(Min/+)/Wip1(+/+) mice. Notably, a similar decrease (∼6-fold in both groups) in tumor number was observed in sham-irradiated and γ-irradiated APC(Min/+)/Wip1(-/-) relative to APC(Min/+)/Wip1(+/+) mice. However, tumorigenesis in the energetic iron-ion exposed group was reduced ∼8-fold in APC(Min/+)/Wip1(-/-) relative to APC(Min/+)/Wip1(+/+) mice. A significantly lower proliferation/differentiation index in tumors of iron-ion exposed APC(Min/+)/Wip1(-/-) relative to APC(Min/+)/Wip1(+/+) mice suggests that reduced proliferation and enhanced

  9. Wip1 abrogation decreases intestinal tumor frequency in APCMin/+ mice irrespective of radiation quality

    Science.gov (United States)

    Suman, Shubhankar; Moon, Bo-Hyun; Thakor, Hemang; Fornace, Albert J; Datta, Kamal

    2017-01-01

    Low linear energy transfer (low-LET) γ-ray exposure is a risk factor for colorectal cancer (CRC). Due to high-LET nature, energetic iron ions are expected to pose greater CRC risks to astronauts undertaking long duration space missions beyond low earth orbit (LEO). Wild-type p53-induced phosphatase 1 (Wip1) is important for cellular DNA damage response and its abrogation is reported to inhibit spontaneous intestinal tumorigenesis in APCMin/+ mice, a well-studied mouse model of human CRC. However, Wip1 in relation to radiation-induced especially energetic iron ions-induced intestinal tumorigenesis has not been investigated in APCMin/+ mice. While we earlier demonstrated greater intestinal tumorigenic potential of energetic iron ions relative to 137Cs γ rays, the purpose of the current study was to investigate if Wip1 abrogation could influence radiation quality dependent intestinal tumorigenesis in APCMin/+ mice. Intestinal tumor frequency and grade was assessed in APCMin/+;Wip1−/− mice and results were compared to those in APCMin/+;Wip1+/+ mice after exposure to a mean absorbed dose of 2 Gy from 137Cs γ rays or 1.6 Gy from 1 GeV/n iron ions. Cellular differentiation and proliferation were also assessed in the intestinal tumors of irradiated and sham irradiated mice. Decreased tumor frequency and lower tumor grade was observed in APCMin/+;Wip1−/− relative to APCMin/+;Wip1+/+ mice. Notably, similar decrease (~6 fold in both groups) in tumor number was observed in sham-, and γ-irradiated APCMin/+;Wip1−/− relative to APCMin/+;Wip1+/+ mice. However, tumorigenesis in energetic iron ions group was reduced ~8 fold in APCMin/+;Wip1−/− relative to APCMin/+;Wip1+/+ mice. Significantly lower proliferation/differentiation index in tumors of energetic iron ions exposed APCMin/+;Wip1−/− relative to APCMin/+;Wip1+/+ mice suggests reduced proliferation and enhanced differentiation as a result of Wip1 abrogation. In conclusion, the current study demonstrates

  10. Radiation effects on DNA methylation in mice

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  11. Genetic effects of radiation. Annex I

    International Nuclear Information System (INIS)

    1982-01-01

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

  12. The radiation effects on the living cell

    International Nuclear Information System (INIS)

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

    1999-06-01

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

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

    International Nuclear Information System (INIS)

    Levin, S.M.

    1987-04-01

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

  14. Biological effect of radiation on human

    International Nuclear Information System (INIS)

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

    2000-04-01

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

  15. 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.

  16. Analysis and experimental evaluation of the frequency response of an indoor radiating cable in the UHF band

    OpenAIRE

    Seseña Osorio, Jorge A.; Zaldívar Huerta, Ignacio E.; Aragón Zavala, Alejandro; Castañón Ávila, Gerardo A.

    2015-01-01

    Abstract We present the modeling of the frequency response of the channel for a radiating cable system by using an autoregressive model for an indoor environment. The coefficients of the autoregressive model are determined from the experimental channel frequency response. Measurements were carried out in an indoor environment, in particular on the second floor of a university building in the frequency range of 1.3 to 1.8 GHz by using a vector network analyzer. It is demonstrated that the use ...

  17. Effects of ionizing radiation on Capsicum baccatum var. pendulum (Solanaceae)

    International Nuclear Information System (INIS)

    Scaldaferro, M.A.; Prina, A.R.; Moscone, E.A.; Kwasniewska, J.

    2013-01-01

    Cytogenetic and somatic effects of various x-ray treatments were evaluated in pepper, Capsicum baccatum var. pendulum cv. “Cayenne”, with the aim to assess optimal conditions for obtaining viable lines. The cytogenetic effects were quantified by counting chromosome aberrations. The level of DNA fragmentation was estimated with TUNEL test (terminal transferase mediated dUTP-fluorescein nick end labeling). Irradiation to 20 Gy with 16-h presoaking can be a suitable treatment of the selected pepper cultivar for a mutagenesis program. - Highlights: • Cytogenetic and somatic effects of x-rays treatments in Capsicum were evaluated. • Frequencies of chromosome aberrations correlated with radiation doses. • Highest frequency of chromosome aberrations occurred with 20 Gy+soaking seeds. • In TUNEL test, the nuclei with DNA fragmentation were higher than in the control. • The strongest effects were observed with doses of 300 Gy or 20 Gy after soaking

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

    International Nuclear Information System (INIS)

    Rudie, N.J.

    1976-01-01

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

  19. The effects of radiation on angiogenesis.

    Science.gov (United States)

    Grabham, Peter; Sharma, Preety

    2013-10-26

    The average human body contains tens of thousands of miles of vessels that permeate every tissue down to the microscopic level. This makes the human vasculature a prime target for an agent like radiation that originates from a source and passes through the body. Exposure to radiation released during nuclear accidents and explosions, or during cancer radiotherapy, is well known to cause vascular pathologies because of the ionizing effects of electromagnetic radiations (photons) such as gamma rays. There is however, another type of less well-known radiation - charged ion particles, and these atoms stripped of electrons, have different physical properties to the photons of electromagnetic radiation. They are either found in space or created on earth by particle collider facilities, and are of significant recent interest due to their enhanced effectiveness and increasing use in cancer radiotherapy, as well as a health risk to the growing number of people spending time in the space environment. Although there is to date, relatively few studies on the effects of charged particles on the vascular system, a very different picture of the biological effects of these particles compared to photons is beginning to emerge. These under researched biological effects of ion particles have a large impact on the health consequences of exposure. In this short review, we will discuss the effects of charged particles on an important biological process of the vascular system, angiogenesis, which creates and maintains the vasculature and is highly important in tumor vasculogenesis.

  20. Radiation effects in corundum monocrystal

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  1. FREQUENCY EFFECTS IN LEXICAL ACQUISITION: A CONTEXT OF GRAMMAR CLASS

    Directory of Open Access Journals (Sweden)

    Cüneyt DEMİR

    2014-04-01

    Full Text Available It is almost a century that Palmer (1937 first suggested about the significance of frequency in vocabulary acquisition. Since then on, countless discussions conducted over the issue from the points supporting and falsifying the claim. But what made all these studies similar to one another was the study context. All the studies aimed to reveal the frequency effect had preferred to study in reading classes; furthermore, they had divided the frequency only into two as high and low. However, could frequency not be regarded more than high and low? Then, Nation (2006 introduced a new term ‘mid-frequency’, which is a term studied few. All told so far was the hub where the present study stemmed from. This study aimed to reveal the possibility of lexical acquisition through frequency effect in a context where the focus is not vocabulary, but grammar. The second associative purpose was to investigate if there is mid-frequency effect or not. The vocabularies of the book that students studied through two terms were analysed, and categorized as high-, mid-, and low-frequency. Then each frequency vocabularies were asked to the participants. As last, which frequency type got the highest correct reply was detected, and each frequency was compared to one another through ANOVA analysis to see if there was any significant difference among high-, mid-, low-frequency vocabularies. The findings showed both parallelism and divisions to the studies in the literature.

  2. Solar Radiation effect on the bituminous binder

    International Nuclear Information System (INIS)

    Tadeo Rico, A.; Torres Perez, A.

    2010-01-01

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

  3. Fine structure in plasma waves and radiation near the plasma frequency in Earth's foreshock

    Science.gov (United States)

    Cairns, Iver H.

    1994-01-01

    Novel observations are presented of intrunsic fine structure in the frequency spectrum of electomagnetic (EM) radiation and plasma waves near the electron plasma frequency f(sub p) during a period of unusually high interplanetary magnetic field strength. Measured using the wideband receiver on the International Sun-Earth Explorer (ISEE) 1 spacecraft, fine-structured emissions are observed both in the solar wind and the foreshock, The fine structure is shown to correspond to emissions spaced above f(sub p) near half harmonies of the electon cyclotron frequency f(sub ce), i.e., near f(sub p) + nf(sub ce)/2. These appear to be the first space physics observations of emissions spaced by f(sub ce)/2. Indirect but strong arguments are used to discriminate between EM and electrostatic (ES) signals, to identify whether ISEE 1 is in the solar wind or the foreshock, and to determine the relative frequencies of the emissions and the local f(sub p). The data are consistent with generation of the ES and EM emissions in the foreshock, with subsequent propagation of the EM emissions into the solar wind. It remains possible that some emissions currently identified as ES have significant EM character. The ES and EM emisions often merge into one another with minimal changes in frequency, arguing that their source regions and generation mechanisms are related and imposing significant constraints on theories. The f(sub ce)/2 ES and EM fine structures observed may be intrinsic to the emission mechanisms or to superposition of two series of signals with f(sub ce) spacing that differ in starting frequency by f(sub ce)/2. Present theories for nonlinear wave coupling processes, cyclotron maser emission, and other linear instability processes are all unable to explain multiple EM and/or ES components spaced by approximately f(sub ce)/2 above f(sub p) for f(sub p)/f(sub ce) much greater than 1 and typical for shock beams parameters. Suitable avenues for further theoretical research are

  4. A study of frequency effects on conductivity measurements

    International Nuclear Information System (INIS)

    Nurul Ain Ahmad Latif; Mahmood Dollah; Mohd Khidir Kamaron; Suaib Ibrahim

    2010-01-01

    In eddy current testing (ET), different measurement can be carry out through the selection of the test frequency. In conductivity measurement, the selection of eddy current test frequencies permits to select the specific material properties to be measured. The test frequency selected should be sufficient high that eddy current penetration is limited only to fraction of the test material thickness. This paper describes the effects of test frequency on the conductivity measurement. This experiment done by applying different values of test frequency which is 20 kHz, 100 kHz and 1 MHz. (author)

  5. Anti-damping effect of radiation reaction

    International Nuclear Information System (INIS)

    Wang, G; Yuan, X Z; Li, H; Shen, Y F; Zi, J

    2010-01-01

    The anti-damping effect of radiation reaction, which means the radiation reaction does non-negative work on a radiating charge, is investigated at length by using the Lorentz-Dirac equation (LDE) for the motion of a point charge respectively acted on by (a) a pure electric field, (b) a pure magnetic field and (c) the fields of an electromagnetic wave. We found that the curvature of the charge's trajectory plays an important role in the radiation reaction force, and the anti-damping effect cannot take place for the real macroscopic motions of a point charge. The condition for this anti-damping effect to take place is that the gradient of the external force field must exceed a certain value over the region of magnitude of the classical radius of massive charges (∼10 -15 m). Our results are potentially helpful to lessen the controversy on LDE and justify it as the correct classical equation describing the radiating charge's motion. If this anti-damping effect of LDE were a real existing physical process, it could serve as a mechanism within the context of classical electrodynamics for the stability of hydrogen atoms. Using the picture of an electron in quantum electrodynamics, namely the negative bare charge surrounded by the polarized positive charges of vacuum, we can obtain a reasonable explanation for the energy transferred to the electron during the occurrence of the anti-damping effect, on which the venerable work of Wheeler and Feynman has thrown some light.

  6. Effects of radiation on aquatic organisms

    International Nuclear Information System (INIS)

    Kaur, Harbhajan; Lata, Poonam; Sharma, Ankush

    2012-01-01

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

  7. Phrase frequency effects in language production.

    Directory of Open Access Journals (Sweden)

    Niels Janssen

    Full Text Available A classic debate in the psychology of language concerns the question of the grain-size of the linguistic information that is stored in memory. One view is that only morphologically simple forms are stored (e.g., 'car', 'red', and that more complex forms of language such as multi-word phrases (e.g., 'red car' are generated on-line from the simple forms. In two experiments we tested this view. In Experiment 1, participants produced noun+adjective and noun+noun phrases that were elicited by experimental displays consisting of colored line drawings and two superimposed line drawings. In Experiment 2, participants produced noun+adjective and determiner+noun+adjective utterances elicited by colored line drawings. In both experiments, naming latencies decreased with increasing frequency of the multi-word phrase, and were unaffected by the frequency of the object name in the utterance. These results suggest that the language system is sensitive to the distribution of linguistic information at grain-sizes beyond individual words.

  8. Frequency shift due to blackbody radiation in a cesium atomic fountain and improvement of the clock performances

    International Nuclear Information System (INIS)

    Zhang, S.

    2004-07-01

    FO1 was the first caesium fountain primary frequency standard in the world. The most recent evaluation in 2002 before improvement reached an accuracy of 1*10 -15 when operated with optical molasses. Working as an extremely precise and stable instrument, FO1 has contributed to fundamental physics and technical measurements: - Frequency comparison between Cs and Rb fountains over an interval of 5 years sets an upper limit for a possible variation of the fine structure constant as |alpha/alpha| -15 /y. The resolution is about 5 times better than the previous test in our laboratory. The projected accuracy of the space clock PHARAO is 1*10 -16 . We confirmed its Ramsey cavity performance by testing the phase difference between the two interaction zones in FO1. The measured temperature T dependent frequency shift of the Cs clock induced by the blackbody radiation field is given as nu(T)=154(6)*10 -6 *(T/300) 4 [1+ε(T/300) 2 ] Hz with the theoretical value ε = 0,014. The obtained accuracy represents a 3 times improvement over the previous measurement by the PTB group. Some improvements have been carried out on FO1. The new FO1 version works directly with optical molasses loaded by a laser slowed atomic beam. The application of the adiabatic passage method to perform the state selection allows us to determine the atom number dependent frequency shifts due to the cold collision and cavity pulling effects at a level of of 10 -16 . Recently, the obtained frequency stability is 2,8*10 -14 *τ -1/2 for about 4*10 6 detected atoms. The accuracy is currently under evaluation, the expected value is a few times 10 -16 . (author)

  9. Radiation dose effects, hardening of electronic components

    International Nuclear Information System (INIS)

    Dupont-Nivet, E.

    1991-01-01

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

  10. Effects of Radiation on Silicon Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Jaspreet Singh

    2009-08-01

    Full Text Available The performance of MEMS based piezoresistive pressure sensors is affected by the radiations. This effect is of much importance for the sensors to be used in deep space environments. To reckon these effects in-house designed and developed piezoresistive sensor is exposed to the irradiation and the change in performance parameters is measured. And corrective measures have been suggested.

  11. Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency.

    Science.gov (United States)

    Dial, Christian; Weiss, Elisabeth; Siebers, Jeffrey V; Hugo, Geoffrey D

    2016-04-01

    To quantify the potential benefit associated with daily replanning in lung cancer in terms of normal tissue dose sparing and to characterize the tradeoff between adaptive benefit and replanning frequency. A set of synthetic images and contours, derived from weekly active breathing control images of 12 patients who underwent radiation therapy treatment for nonsmall cell lung cancer, is generated for each fraction of treatment using principal component analysis in a way that preserves temporal anatomical trends (e.g., tumor regression). Daily synthetic images and contours are used to simulate four different treatment scenarios: (1) a "no-adapt" scenario that simulates delivery of an initial plan throughout treatment, (2) a "midadapt" scenario that implements a single replan for fraction 18, (3) a "weekly adapt" scenario that simulates weekly adaptations, and (4) a "full-adapt" scenario that simulates daily replanning. An initial intensity modulated radiation therapy plan is created for each patient and replanning is carried out in an automated fashion by reoptimizing beam apertures and weights. Dose is calculated on each image and accumulated to the first in the series using deformable mappings utilized in synthetic image creation for comparison between simulated treatments. Target coverage was maintained and cord tolerance was not exceeded for any of the adaptive simulations. Average reductions in mean lung dose (MLD) and volume of lung receiving 20 Gy or more (V20lung) were 65 ± 49 cGy (p = 0.000 01) and 1.1% ± 1.2% (p = 0.0006), respectively, for all patients. The largest reduction in MLD for a single patient was 162 cGy, which allowed an isotoxic escalation of the target dose of 1668 cGy. Average reductions in cord max dose, mean esophageal dose (MED), dose received by 66% of the heart (D66heart), and dose received by 33% of the heart (D33heart), were 158 ± 280, 117 ± 121, 37 ± 77, and 99 ± 120 cGy, respectively. Average incremental reductions in MLD for

  12. Effects of UV radiation on freshwater metazooplankton

    International Nuclear Information System (INIS)

    Tartarotti, B.

    1999-06-01

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

  13. Cardiovascular effects of radiation therapy

    International Nuclear Information System (INIS)

    Alvarez, Jose A.G.; Leiva, Gustavo

    2001-01-01

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

  14. 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

  15. Cytogenetic effects of low-dose radiation

    International Nuclear Information System (INIS)

    Metalli, P.

    1983-01-01

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

  16. THE IMPACT OF SUPERHIGH FREQUENCY ELECTROMAGNETIC RADIATION ON THREONINE PRODUCER Brevibacterium flavum

    Directory of Open Access Journals (Sweden)

    L. V. Marynchenko

    2016-12-01

    Full Text Available The aim of the research was the impact of non-thermal electromagnetic radiation of superhigh frequencies with waves of millimeter range on threonine amino acid synthesis by bacteria Brevibacterium flavum for ordinary (not mutant and mutant strains. The frequencies of millimeter range waves were selected according to previous works as 41.76; 42.2 and 61.0 GHz. The exposition was 10 min. The control samples of bacterial suspension in the flasks were kept under the same conditions as the test ones. Irradiated suspensions were used as inoculum for fermentation on molasses wort at t = +30 ºC with aeration. After cultivation for 3 days the samples irradiated with frequency 42.2 and 61.0 GHz gave an increase in colonies forming units, respectively, 1.4 and 1.9 times compared to the control for the non-mutant strain. The quantity of synthesized threonine was determined by thin-layer chromatography on the plates of ciluprevir. A significant increase of the threonine content in the culture fluid was observed for the non-mutant strain (70% compared to control after the irradiation with frequency 61.0 GHz. The splitting of the colonies planted pigmentation was observed: the control samples were mostly pigmentated, and irradiated bacteria lost this ability immediately after exposure, but after the culturing the irradiated samples restored pigmentation. The pigmentation ability was confirmed by the data on the accumulation threonine in the culture fluid. The Brevibacterium flavum mutant strain did not respond to the irradiation, this influence was negative for generative abilities and accumulation of threonine in the culture fluid.

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

    Directory of Open Access Journals (Sweden)

    Dunja Rukavina

    2012-07-01

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

  18. EGFR mutation frequency and effectiveness of erlotinib

    DEFF Research Database (Denmark)

    Weber, Britta; Hager, Henrik; Sorensen, Boe S

    2014-01-01

    OBJECTIVES: In 2008, we initiated a prospective study to explore the frequency and predictive value of epidermal growth factor receptor (EGFR) mutations in an unselected population of Danish patients with non-small cell lung cancer offered treatment with erlotinib, mainly in second-line. MATERIALS...... AND METHODS: Four hundred and eighty eight patients with advanced NSCLC were included. The mutation status was assessed using the cobas EGFR Mutation Test. Erlotinib was administrated (150 mg/d) until disease progression or unacceptable toxicities occurred. The primary endpoint was progression-free survival....... Secondary endpoints were overall survival and response. RESULTS: Biopsies were retrieved from 467 patients, and mutation results obtained for 462. We identified 57 (12%) patients with EGFR mutations: 33 exon 19 deletions, 13 exon 21 mutations, 5 exon 18 mutations, 3 exon 20 insertions, 1 exon 20 point...

  19. [Biological effects of non-ionizing electromagnetic radiation].

    Science.gov (United States)

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  20. Dual-frequency sound-absorbing metasurface based on visco-thermal effects with frequency dependence

    Science.gov (United States)

    Ryoo, H.; Jeon, W.

    2018-03-01

    We investigate theoretically an acoustic metasurface with a high absorption coefficient at two frequencies and design it from subwavelength structures. We propose the use of a two-dimensional periodic array of four Helmholtz resonators in two types to obtain a metasurface with nearly perfect sound absorption at given target frequencies via interactions between waves emanating from different resonators. By considering how fluid viscosity affects acoustic energy dissipation in the narrow necks of the Helmholtz resonators, we obtain effective complex-valued material properties that depend on frequency and on the geometrical parameters of the resonators. We furthermore derive the effective acoustic impedance of the metasurface from the effective material properties and calculate the absorption spectra from the theoretical model, which we compare with the spectra obtained from a finite-element simulation. As a practical application of the theoretical model, we derive empirical formulas for the geometrical parameters of a metasurface which would yield perfect absorption at a given frequency. While previous works on metasurfaces based on Helmholtz resonators aimed to absorb sound at single frequencies, we use optimization to design a metasurface composed of four different Helmholtz resonators to absorb sound at two distinct frequencies.

  1. Modulation infrared thermometry of caloric effects at up to kHz frequencies

    Science.gov (United States)

    Döntgen, Jago; Rudolph, Jörg; Waske, Anja; Hägele, Daniel

    2018-03-01

    We present a novel non-contact method for the direct measurement of caloric effects in low volume samples. The adiabatic temperature change ΔT of a magnetocaloric sample is very sensitively determined from thermal radiation. Rapid modulation of ΔT is induced by an oscillating external magnetic field. Detection of thermal radiation with a mercury-cadmium-telluride detector allows for measurements at field frequencies exceeding 1 kHz. In contrast to thermoacoustic methods, our method can be employed in vacuum which enhances adiabatic conditions especially in the case of small volume samples. Systematic measurements of the magnetocaloric effect as a function of temperature, magnetic field amplitude, and modulation frequency give a detailed picture of the thermal behavior of the sample. Highly sensitive measurements of the magnetocaloric effect are demonstrated on a 2 mm thick sample of gadolinium and a 60 μm thick Fe80B12Nb8 ribbon.

  2. Effects of radiation on DNA

    International Nuclear Information System (INIS)

    Medina, V.F.O.

    1978-01-01

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

  3. Genetic and chromosomal effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

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

  4. Additive effects in radiation grafting and curing

    International Nuclear Information System (INIS)

    Viengkhou, V.; Ng, L.

    1996-01-01

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

  5. Radiation Effects Research Foundation bibliography of published papers, 1986

    International Nuclear Information System (INIS)

    1987-01-01

    The bibliography lists the titles of a total of 75 papers published by members of the Radiation Effects Research Foundation in 1986 (three of them published in 1985). The papers cover; 'The central nervous system and in utero exposure to ionizing radiation', 'Future directions for biostatistics and cancer epidemiology in Japan', 'Passive smoking and lung cancer among Japanese women', 'Late effects of atomic bomb radiation on human immune response', 'Delayed effects of atomic bomb radiation to human cellular immune competence', 'Characterization of three electrophoretic variants of human erythrocyte triosephosphate isomerase found in Japanese', 'A follow-up study of clonal T-lymphocytes with chromosome aberrations in Hiroshima A-bomb survivors', 'Comments on recent cytogenetic findings at RERF', 'Cytogenetic 'rogue' cells; What is their frequency, origin, and evolutionary sinificance?', 'A parallel analysis of cancer mortality among atomic bomb survivors and patients with ankylosing spondylitis given X-ray therapy', 'Cancer of the thyroid and salivary glands', 'Analysis of peripheral blood lymphocytes of atomic bomb survivors using monoclonal antibodies', 'Celluar immune competence of patients with lung cancer and other lung diseases. I. Analysis of peripheral blood lymphocyte subsets using monoclonal antibodies', etc. (N.K.) 75 refs

  6. Effect of Low Level Subchronic Microwave Radiation on Rat Brain.

    Science.gov (United States)

    Deshmukh, Pravin Suryakantrao; Megha, Kanu; Nasare, Namita; Banerjee, Basu Dev; Ahmed, Rafat Sultana; Abegaonkar, Mahesh Pandurang; Tripathi, Ashok Kumar; Mediratta, Pramod Kumari

    2016-12-01

    The present study was designed to investigate the effects of subchronic low level microwave radiation (MWR) on cognitive function, heat shock protein 70 (HSP70) level and DNA damage in brain of Fischer rats. Experiments were performed on male Fischer rats exposed to microwave radiation for 90 days at three different frequencies: 900, 1800, and 2450 MHz. Animals were divided into 4 groups: Group I: Sham exposed, Group II: animals exposed to microwave radiation at 900 MHz and specific absorption rate (SAR) 5.953 × 10-4 W/kg, Group III: animals exposed to 1800 MHz at SAR 5.835 × 10-4 W/kg and Group IV: animals exposed to 2450 MHz at SAR 6.672 × 10-4 W/kg. All the animals were tested for cognitive function using elevated plus maze and Morris water maze at the end of the exposure period and subsequently sacrificed to collect brain tissues. HSP70 levels were estimated by ELISA and DNA damage was assessed using alkaline comet assay. Microwave exposure at 900-2450 MHz with SAR values as mentioned above lead to decline in cognitive function, increase in HSP70 level and DNA damage in brain. The results of the present study suggest that low level microwave exposure at frequencies 900, 1800, and 2450 MHz may lead to hazardous effects on brain. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  7. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    Science.gov (United States)

    Jiang, Erkang; Wu, Lijun

    2009-04-01

    In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy α-particle irradiated and non-irradiated bystander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensitive 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 α-particle radiation-induced damage in irradiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

  8. Interaction of a relativistic electron beam with radiation in the THz frequency range

    Science.gov (United States)

    Sung, Chieh

    0.5-3 THz range with a maximum of ˜2 kW of peak power in a 200 ns pulse suitable as a seed for an FEL microbuncher. These sources represent the most powerful and the most energetic narrowband THz sources currently reported using nonlinear optical technique to our knowledge. During the FEL microbunching process, the wiggling electrons in the undulator also emit radiation coherently at the resonant frequency; as a result, the THz FEL microbuncher can double as a single pass THz amplifier tunable in the 0.5-3 THz range. It is shown that when seeded with a ˜1 kW THz pulse and driven by an electron beam with a peak current of 60A, a 2 m-long undulator can amplify the radiation power to ˜20MW. The frequency range can be further expanded to up to 9 THz via the High Gain Harmonic Generation (HGHG) FEL configuration. The results of these simulations are used as a guide in designing a single-pass THz FEL microbuncher/amplifier which is currently under construction. In order to study THz microbunching and amplification, several original techniques and diagnostics were also developed. Guiding a THz pulse through a hollow waveguide, filtering a short THz pulse using a Fabry-Perot interferometer and measuring the frequency components using a diffraction grating spectrometer were demonstrated.

  9. Theoretical studies of the heating of toroidal plasmas with radio frequency electromagnetic radiation. Final report

    International Nuclear Information System (INIS)

    Glasser, A.H.; Swanson, D.G.; Wersinger, J.M.

    1982-01-01

    The continuation of a program of theoretical studies of the heating of toroidal plasmas with radio frequency (RF) electromagnetic radiation is proposed. Funding for this project first began on September 3, 1981, and will expire on April 2, 1982. A summary of the principal accomplishments of the first five months of the project is presented. These include the acquisition of computer terminals and modems, the implementation of existing codes on the MFECC C Cray Computer, the extension of the LHTOR lower hybrid toroidal ray tracing code to the full electromagnetic dispersion relation, the implementation of graphic output from the code, the beginning of extensive parameter studies, the beginning of an analytical treatment of the mode conversion layer associated with singular harmonic absorption, and the introduction of a graduate student into the program

  10. Effects of radiation rays on construction materials

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  11. Radiation Effects on Current Field Programmable Technologies

    Science.gov (United States)

    Katz, R.; LaBel, K.; Wang, J. J.; Cronquist, B.; Koga, R.; Penzin, S.; Swift, G.

    1997-01-01

    Manufacturers of field programmable gate arrays (FPGAS) take different technological and architectural approaches that directly affect radiation performance. Similar y technological and architectural features are used in related technologies such as programmable substrates and quick-turn application specific integrated circuits (ASICs). After analyzing current technologies and architectures and their radiation-effects implications, this paper includes extensive test data quantifying various devices total dose and single event susceptibilities, including performance degradation effects and temporary or permanent re-configuration faults. Test results will concentrate on recent technologies being used in space flight electronic systems and those being developed for use in the near term. This paper will provide the first extensive study of various configuration memories used in programmable devices. Radiation performance limits and their impacts will be discussed for each design. In addition, the interplay between device scaling, process, bias voltage, design, and architecture will be explored. Lastly, areas of ongoing research will be discussed.

  12. Dielectric and Radiative Properties of Sea Foam at Microwave Frequencies: Conceptual Understanding of Foam Emissivity

    Directory of Open Access Journals (Sweden)

    Peter W. Gaiser

    2012-04-01

    Full Text Available Foam fraction can be retrieved from space-based microwave radiometric data at frequencies from 1 to 37 GHz. The retrievals require modeling of ocean surface emissivity fully covered with sea foam. To model foam emissivity well, knowledge of foam properties, both mechanical and dielectric, is necessary because these control the radiative processes in foam. We present a physical description of foam dielectric properties obtained from the foam dielectric constant including foam skin depth; foam impedance; wavelength variations in foam thickness, roughness of foam layer interfaces with air and seawater; and foam scattering parameters such as size parameter, and refraction index. Using these, we analyze the scattering, absorption, reflection and transmission in foam and gain insights into why volume scattering in foam is weak; why the main absorption losses are confined to the wet portion of the foam; how the foam impedance matching provides the transmission of electromagnetic radiation in foam and maximizes the absorption; and what is the potential for surface scattering at the foam layers boundaries. We put all these elements together and offer a conceptual understanding for the high, black-body-like emissivity of foam floating on the sea surface. We also consider possible scattering regimes in foam.

  13. Efficient combination of acceleration techniques applied to high frequency methods for solving radiation and scattering problems

    Science.gov (United States)

    Lozano, Lorena; Algar, Ma Jesús; García, Eliseo; González, Iván; Cátedra, Felipe

    2017-12-01

    An improved ray-tracing method applied to high-frequency techniques such as the Uniform Theory of Diffraction (UTD) is presented. The main goal is to increase the speed of the analysis of complex structures while considering a vast number of observation directions and taking into account multiple bounces. The method is based on a combination of the Angular Z-Buffer (AZB), the Space Volumetric Partitioning (SVP) algorithm and the A∗ heuristic search method to treat multiple bounces. In addition, a Master Point strategy was developed to analyze efficiently a large number of Near-Field points or Far-Field directions. This technique can be applied to electromagnetic radiation problems, scattering analysis, propagation at urban or indoor environments and to the mutual coupling between antennas. Due to its efficiency, its application is suitable to study large antennas radiation patterns and even its interactions with complex environments, including satellites, ships, aircrafts, cities or another complex electrically large bodies. The new technique appears to be extremely efficient at these applications even when considering multiple bounces.

  14. Syllable Frequency and Spoken Word Recognition: An Inhibitory Effect.

    Science.gov (United States)

    González-Alvarez, Julio; Palomar-García, María-Angeles

    2016-08-01

    Research has shown that syllables play a relevant role in lexical access in Spanish, a shallow language with a transparent syllabic structure. Syllable frequency has been shown to have an inhibitory effect on visual word recognition in Spanish. However, no study has examined the syllable frequency effect on spoken word recognition. The present study tested the effect of the frequency of the first syllable on recognition of spoken Spanish words. A sample of 45 young adults (33 women, 12 men; M = 20.4, SD = 2.8; college students) performed an auditory lexical decision on 128 Spanish disyllabic words and 128 disyllabic nonwords. Words were selected so that lexical and first syllable frequency were manipulated in a within-subject 2 × 2 design, and six additional independent variables were controlled: token positional frequency of the second syllable, number of phonemes, position of lexical stress, number of phonological neighbors, number of phonological neighbors that have higher frequencies than the word, and acoustical durations measured in milliseconds. Decision latencies and error rates were submitted to linear mixed models analysis. Results showed a typical facilitatory effect of the lexical frequency and, importantly, an inhibitory effect of the first syllable frequency on reaction times and error rates. © The Author(s) 2016.

  15. Investigation of the mechanisms of action of high-frequency radiation; Untersuchungen zu den Wirkungsmechanismen von Hochfrequenzstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, K.D.; Merker, H.J.; Glaser, R.; Lamprecht, I.

    1997-04-01

    The final report summarizes the results of the preceding three progress reports of the research project. The first progress report presented details of the experimental devices for experiments with radiation at frequencies of 150, 450, and 900 Mhz. The second explained the systems examined, (neuroblast cells of mice, human erythrocytes, fibroblasts of mice, Saccharomyces cerevisiae, Escheria choli, organoid cultures of limb buds of embryonal chondrocytes of mice, Artemia franciscana, rat embryos, and human test persons), as well as the experimental findings. The third report was on approaches for modelling of effects observed. (orig./CB) [Deutsch] Der hier vorgelegte Abschlussbericht fasst die Ergebnisse der drei Zwischenberichte zusammen, die sich jeweils mit den experimentellen Aufbauten in den Frequenzbereichen 150, 450 und 900 Mhz, den untersuchten Systemen (Neuroblastomazellen der Maus, menschlichen Erythrozyten, Mausfibroblasten, Saccharomyces cerevisiae, Escherichia coli, Organoidkulturen von Gliedknospen embryonaler Knorpelzellen von Maeusen, Artemia franciscana, Rattenembryonen sowie menschlichen Probanden) nebst Ergebnissen, sowie Modellvorstellungen befassen. (orig./MG)

  16. RADIOFREQUENCY AND MICROWAVE RADIATION HEALTH EFFECTS AND OCCUPATIONAL EXPOSURE

    Directory of Open Access Journals (Sweden)

    Ivana Damnjanović

    2011-12-01

    Full Text Available In the recent years, there have been considerable discussion and concern about the possible hazards of RF/MW radiation. More recently, the growth and development in personal mobile communications have focused attention on the frequencies associated with this technology. A number of studies have examined the health effects of RF/MW electromagnetic fields (EMFs, originating from occupational exposure, hobbies, or residence near the radio or television transmitters. Particularly controversial are the biophysical mechanisms by which these RF fields may affect biological systems. General health effects reviews explore possible carcinogenic, reproductive and neurological effects. Health effects by exposure source have been observed in radar traffic devices, wireless communications with cellular phones, radio transmission, and magnetic resonance imaging (MRI. Several epidemiological surveys have suggested associations with non-specific complaints such as headache, tiredness, sleep disturbance, loss of memory, and dizziness. These findings, which echo reports of illness associated with other types of radiofrequency (RF radiation, relate not only to the use of mobile phones, but also to residence near the mobile phone base stations and other settings involving occupational exposure. The biological effects suggest that some precautions are necessary, and preventive approaches are highly recommended. Further researches are required to give more information about the effects of microwave radiation on our health, especially in occupational setting and professionally exposed workers.

  17. Effects of gamma radiation in soybean

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  18. Effects of gamma radiation in annatto seeds

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  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 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)

  1. Low-Frequency Extensions of the Saturn Kilometric Radiation as a Proxy for Magnetospheric Dynamics

    Science.gov (United States)

    Reed, J. J.; Jackman, C. M.; Lamy, L.; Kurth, W. S.; Whiter, D. K.

    2018-01-01

    Saturn Kilometric Radiation (SKR) is an auroral radio emission which can be detected quasi-continuously by the Cassini spacecraft. It has been shown to respond to magnetotail reconnection and to changes in solar wind conditions and thus offers the potential to be used as a remote proxy for magnetospheric dynamics. This work has developed criteria for the selection of low-frequency extensions (LFEs), powerful intensifications of the main SKR emission, accompanied by an expansion of the SKR to lower frequencies. Upon examination of data from the Cassini Radio and Plasma Wave Science instrument, we detect 282 LFE events which are further grouped into two categories. Shorter events (20 h), associated with increases in solar wind dynamic pressure, can last multiple planetary rotations, have a median waiting time of ˜20 days, and show no relationship with SKR phase. An analysis of the power emitted during LFEs suggests that tail reconnection is not always observed or detected in situ which may partially explain the low correlation between LFEs and tail reconnection. We conclude that short LFEs are a good proxy for reconnection in the tail.

  2. The frequency attenuation effect in identity and associative priming.

    Science.gov (United States)

    Nievas, Francisco

    2010-05-01

    Three lexical decision experiments were carried out, where the masked priming paradigm is used to study the role of the frequency attenuation effect (more priming in low-frequency target words than in high-frequency target words) in repetition and associative priming, manipulating Prime Duration (PD) and Stimulus Onset Asynchrony (SOA). A new concept was introduced, Minimum Time Threshold (MTT), this is, the minimum time interval of exposure to the masked word in order to become aware of it. Results support the notion that MTT is a key to the appearance of the frequency attenuation effect when enough word processing time is allowed. Results do not support the unified explanation of masked priming and long-term priming as proposed by Bodner and Masson (2001). Moreover, information feedback from the semantic level was not the reason for the frequency attenuation effect in repetition priming.

  3. Effects Of Irrigation Frequency On Soil Moisture Potential And ...

    African Journals Online (AJOL)

    Irrigation frequency affects soil properties with a residual influence on soil moisture potential, crop performance and shoot yield of vegetables. This study investigated the effect of irrigation frequency on the growth, shoot yield of large green, soil moisture potential, and soil chemical properties based on ramdomised complete ...

  4. Effect of Training Frequency on Maximum Expiratory Pressure

    Science.gov (United States)

    Anand, Supraja; El-Bashiti, Nour; Sapienza, Christine

    2012-01-01

    Purpose: To determine the effects of expiratory muscle strength training (EMST) frequency on maximum expiratory pressure (MEP). Method: We assigned 12 healthy participants to 2 groups of training frequency (3 days per week and 5 days per week). They completed a 4-week training program on an EMST trainer (Aspire Products, LLC). MEP was the primary…

  5. The effects and control of radiation

    International Nuclear Information System (INIS)

    Saunders, P.A.H.

    1985-09-01

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

  6. 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).

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  8. Radiation Effects in Interfaces and Thin Films

    Science.gov (United States)

    Mairov, Alexander

    One of the key approaches to developing materials with greater radiation damage resistance is to introduce a large fraction of internal interfaces. Interfaces act as sinks for recombination of radiation-induced defects and as sites for accumulation of helium bubbles, thereby diverting them away from grain boundaries, where they can induce embrittlement. The beneficial role of interfaces in mitigating radiation damage has been demonstrated in nanoscale multilayered structures and in nanograined materials. Another more common example is oxide dispersion strengthened (ODS) steels and nanostructured ferritic alloys (NFA) where a fine distribution of particles (clusters) of varying stoichiometries (e.g., Y2Ti2O7, Y2TiO 5, Y2O3, TiO2 and Y-Ti-O non-stoichiometric oxides) not only confer high creep strength, but also high radiation damage tolerance due to the large area of metal/oxide interfaces. However, the efficacy of these interfaces to act as defect sinks depends on their compositional and physical stability under radiation. With this background, this work focused on the stability of interfaces between Ti, TiO2, and Y2O 3 thin film deposited on Fe-12%Cr substrates after irradiation with 5MeV Ni+2 ions at various temperatures. TEM and STEM-EDS methods were used to understand the compositional changes at the interfaces. Additionally, accumulation of implanted helium at epitaxial and non-epitaxial Fe/Y 2O3 interfaces was also studied. Finally, the study was extended to study irradiation effects (up to 150 dpa) in novel Al2O 3 nanoceramic films with immediate potential applications as coatings for corrosion protection in the harsh high temperature environments of Gen IV reactors. This research is expected to have implications in the development of radiation damage tolerant nanostructured alloys for nuclear reactors while also expanding the scientific knowledge-base in the area of radiation stability of interfaces in solids and protective coatings.

  9. Interaction of electromagnetic radiation in the 20-200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles.

    Science.gov (United States)

    Atdayev, Agylych; Danilyuk, Alexander L; Prischepa, Serghej L

    2015-01-01

    The interaction of electromagnetic radiation with a magnetic nanocomposite based on carbon nanotubes (CNT) is considered within the model of distributed random nanoparticles with a core-shell morphology. The approach is based on a system composed of a CNT conducting resistive matrix, ferromagnetic inductive nanoparticles and the capacitive interface between the CNT matrix and the nanoparticles, which form resonance resistive-inductive-capacitive circuits. It is shown that the influence of the resonant circuits leads to the emergence of specific resonances, namely peaks and valleys in the frequency dependence of the permeability of the nanocomposite, and in the frequency dependence of the reflection and transmission of electromagnetic radiation.

  10. Interaction of electromagnetic radiation in the 20–200 GHz frequency range with arrays of carbon nanotubes with ferromagnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Agylych Atdayev

    2015-04-01

    Full Text Available The interaction of electromagnetic radiation with a magnetic nanocomposite based on carbon nanotubes (CNT is considered within the model of distributed random nanoparticles with a core–shell morphology. The approach is based on a system composed of a CNT conducting resistive matrix, ferromagnetic inductive nanoparticles and the capacitive interface between the CNT matrix and the nanoparticles, which form resonance resistive–inductive–capacitive circuits. It is shown that the influence of the resonant circuits leads to the emergence of specific resonances, namely peaks and valleys in the frequency dependence of the permeability of the nanocomposite, and in the frequency dependence of the reflection and transmission of electromagnetic radiation.

  11. Implications of various intensities of radio frequency electromagnetic radiation (462 MHz in the induction of oxidative stress during the germination of Hippophae rhamnoides seeds

    Directory of Open Access Journals (Sweden)

    Calin Lucian Maniu

    2010-02-01

    Full Text Available The data accumulated by now shows that the topic of biological effects of electromagnetic radiation is far from being exhausted. Is undoubtedly that a non-ionizing radiation field maintained on a biological entity has some effects on it. To try shaping issues regarding this, this work aims to study the impact of radiation generated by an emission-reception radio station that emits on 462.6875 MHz frequency. For this purpose, were used Hippophae rhamnoides L. seeds which germinated in the laboratory, under controlled conditions, concentrically arranged around the radiation source, in which case electromagnetic radiation has a different impact. Seed germination lasted 35 days, while the device has continuously worked, and the seeds were constantly irradiated. It was precisely measured the intensity of the magnetic component of the field in all places where the seeds were placed for germination. It was calculated the percentage of germination and it was determined the enzyme activity involved in eliminating the oxidative stress effects. It was found significant variations of the parameters mentioned above in conjunction with the radiation intensity depending on the distance from the source.

  12. Effects of extremely low frequency electromagnetic fields on human beings

    International Nuclear Information System (INIS)

    Lilien, J.L.; Dular, P.; Sabariego, R.; Beauvois, V.; Barbier, P.P.; Lorphevre, R.

    2010-01-01

    Since the early seventies, potential health risks from ELF (Extremely Low frequency electromagnetic Fields) exposure (50 Hz) have been extensively treated in the literature (more than 1000 references registered by WHO (World Health Organisation), 2007). After 30 years of worldwide research, the major epidemiological output is the possible modest increased risk (by a factor 2) of childhood leukaemia in case of a long exposure to an ambient magnetic flux density (B-field) higher than 0.4 μT. However, this fact has not been confirmed by in vivo and in vitro studies. Moreover it has not been validated by any adverse health biological mechanisms neither for adults nor for children. International recommendations (ICNIRP, International Commission on Non-Ionising Radiation Protection) are currently, for general public, not to exceed a B-field of 100 μT (50 Hz) and an E-field of 5 kV/m (50 Hz). Herein, a rough overview of typical values of ELF fields will be presented followed by a brief literature survey on childhood leukaemia and ELF The potential carcinogenic effect of ELF would be linked to electrical disturbances in cell behaviour. The major concern linking child-hood leukaemia and ELF is thus to determine the response of bone marrow cells under ELF fields. With that purpose, transmembrane potential will be targeted and linked to the E-field at that level. This paper is three-folded: (1) the electric interactions between ambient ELF fields and the body are studied both qualitatively and quantitatively. Different sources of internal E-field are analysed and classified according to their potential risk; (2) the hypothesis of contact current is detailed; (3) key actions to undertake are highlighted. Based on the current state of the art and some authors' own developments, this paper proposes simple low cost enhancements of private electrical installations in order to annihilate the major source of potential effects of ELF. (authors)

  13. Effective Strategies for Increasing Citation Frequency

    Science.gov (United States)

    Ebrahim, Nader Ale; Salehi, Hadi; Embi, Mohamed Amin; Tanha, Farid Habibi; Gholizadeh, Hossein; Motahar, Seyed Mohammad; Ordi, Ali

    2013-01-01

    Due to the effect of citation impact on The Higher Education (THE) world university ranking system, most of the researchers are looking for some helpful techniques to increase their citation record. This paper by reviewing the relevant articles extracts 33 different ways for increasing the citations possibilities. The results show that the article…

  14. Specific Electromagnetic Effects of Microwave Radiation on Escherichia coli▿

    OpenAIRE

    Shamis, Yury; Taube, Alex; Mitik-Dineva, Natasa; Croft, Rodney; Crawford, Russell J.; Ivanova, Elena P.

    2011-01-01

    The present study investigated the effects of microwave (MW) radiation applied under a sublethal temperature on Escherichia coli. The experiments were conducted at a frequency of 18 GHz and at a temperature below 40°C to avoid the thermal degradation of bacterial cells during exposure. The absorbed power was calculated to be 1,500 kW/m3, and the electric field was determined to be 300 V/m. Both values were theoretically confirmed using CST Microwave Studio 3D Electromagnetic Simulation Softwa...

  15. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  16. Alpha Radiation Effects on Silicon Oxynitride Waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Morichetti, Francesco; Grillanda, Stefano; Manandhar, Sandeep; Shutthanandan, Vaithiyalingam; Kimerling, Lionel; Melloni, Andrea; Agarwal, Anuradha M.

    2016-09-21

    Photonic technologies are today of great interest for use in harsh environments, such as outer space, where they can potentially replace current communication systems based on radiofrequency components. However, very much alike to electronic devices, the behavior of optical materials and circuits can be strongly altered by high-energy and high-dose ionizing radiations. Here, we investigate the effects of alpha () radiation with MeV-range energy on silicon oxynitride (SiON) optical waveguides. Irradiation with a dose of 5×1015 cm-2 increases the refractive index of the SiON core by nearly 10-2, twice as much that of the surrounding silica cladding, leading to a significant increase of the refractive index contrast of the waveguide. The higher mode confinement induced by -radiation reduces the loss of tightly bent waveguides. We show that this increases the quality factor of microring resonators by 20%, with values larger than 105 after irradiation.

  17. Frequencies of micronuclei in lymphocytes and complete blood picture of radiation worker at Al-Twuathia Site Iraq

    International Nuclear Information System (INIS)

    Amel, J.M.; Abdulsahib, K. A.; Abdullah, A.G.; Haider, Y.L.; Ali, H.F.

    2012-12-01

    The present study aims to use the frequency of micronuclei in lymphocyte and complete blood picture as a bio markers for detection of the effects of the low radiation doses in to decommissioning to radioactive contamination (Lama and Geo- Pilot) as a result of work, during January 2009 to November 2011 present study including collected 113 blood samples, including (103 male and female) aged (25 - 65) year for the exam of compete blood picture analysis, included 69 blood samples as first time before work in Al-Twuathia site, 22 blood samples as a second and third exam. While the cytogenetic analysis including 78 male blood samples aged (35 - 63) year, included 30 blood samples as first time be for work in Al-Twuathia site, 30 blood samples as a second exam and 18 blood samples as third exam, as well as 50 blood samples which are not smokers and alcohol as control group which including (40 male and 10 female) aged (30 - 55 year). Three cytogenetic parameter were employed such as frequency of micronuclei, mitotic index an nuclear and nuclear division index, which used for detection of biological effects of ionizing radiation. Also the current study included the detection of the effect of radiation in complete blood picture analysis of workers at Al-Tuwaitha site, which included (Hb, PCV, WBC count, differential count of WBCs, platelets count of WBCs, platelets count and ESR). From the study no significant differences in the rate of micronuclei and division index of workers in the first and second examination compared with the group of workers in the third exam, while observed a significant increase slightly at level (P <0.05) in these rates compared with the control group, as well as were recorded no significant differences in the rate of mitotic index for workers compared with the control group. Also, found no significant difference in complete blood picture analysis for workers compared with the control group. In conclusion, the significant slightly increase at the

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  19. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  20. Effects of Co60 gamma radiation on Biomphalaria glabrata (Say, 1818) Embryo. II. Malformations

    International Nuclear Information System (INIS)

    Okazaki, K.; Kawano, T.

    1990-01-01

    The morphogenetic effects of ionizing radiation were investigated in Biomphalaria glabrata embryos irradiated in the cleavage, blastula, gastrula, young trochophore and trochophore stages with 5 to 25 Gy doses of 60 CO gamma radiation. The number of malformed embryos rapidly increased with increasing radiation dose, reaching a maximum between 5th to 8th day after irradiation in all stages analyzed. Susceptibility to malformation induction was higher the younger than the age of the irradiated embryo. However, for the cleavage stage the frequency of malformed embryos was inversely proportional to radiation dose for the same radiation dose. Several types of morphogenetic malformations were obtained, among then cephalic malformations, exogastrula, shell malformations and embryos with everted stomodeum, unspecific malformations being the most frequent. The results show that the types of malformation induced by radiation probably are not radiation-specific and do not depend on the dose applied [pt

  1. Radiation effects in mammalian cells in vitro

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  2. Changes in mitochondrial functioning with electromagnetic radiation of ultra high frequency as revealed by electron paramagnetic resonance methods.

    Science.gov (United States)

    Burlaka, Anatoly; Selyuk, Marina; Gafurov, Marat; Lukin, Sergei; Potaskalova, Viktoria; Sidorik, Evgeny

    2014-05-01

    To study the effects of electromagnetic radiation (EMR) of ultra high frequency (UHF) in the doses equivalent to the maximal permitted energy load for the staffs of the radar stations on the biochemical processes that occur in the cell organelles. Liver, cardiac and aorta tissues from the male rats exposed to non-thermal UHF EMR in pulsed and continuous modes were studied during 28 days after the irradiation by the electron paramagnetic resonance (EPR) methods including a spin trapping of superoxide radicals. The qualitative and quantitative disturbances in electron transport chain (ETC) of mitochondria are registered. A formation of the iron-nitrosyl complexes of nitric oxide (NO) radicals with the iron-sulphide (FeS) proteins, the decreased activity of FeS-protein N2 of NADH-ubiquinone oxidoreductase complex and flavo-ubisemiquinone growth combined with the increased rates of superoxide production are obtained. (i) Abnormalities in the mitochondrial ETC of liver and aorta cells are more pronounced for animals radiated in a pulsed mode; (ii) the alterations in the functioning of the mitochondrial ETC cause increase of superoxide radicals generation rate in all samples, formation of cellular hypoxia, and intensification of the oxide-initiated metabolic changes; and (iii) electron paramagnetic resonance methods could be used to track the qualitative and quantitative changes in the mitochondrial ETC caused by the UHF EMR.

  3. Effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition

    International Nuclear Information System (INIS)

    Gao Yong; Zhang Weiguang

    2004-01-01

    Objective: To provide scientific information for the prevention and treatment of the radiation damage by analyzing the effects of smoke and tea on radiation-induced bone marrow cell mutation and marrow inhibition. Methods: 7 group mice were exposed to smoke and/or tea and/or radiation respectively. There were also b blank control group and a cyclophosphamide positive control group. The frequencies of micronucleated polychromatic erythrocytes (MPCE), the ratio of polychromatic erythrocytes (PCE) to mature erythrocytes (RBC) in marrow, and the count of peripheral blood hemoleukocyte were observed. Results: The frequencies of MPCE in the groups irradiated with γ-rays were significantly higher than that in the blank control group (P<0.05 or 0.01). The smoke + radiation group's frequency was significantly higher than single radiation group (P<0.05). The ratios of PCE to RBC in the groups irradiated were significantly lower than that in the blank control group (P<0.01). The counts of peripheral blood hemoleukocyte in the groups irradiated were significantly lower than the blank control group (P<0.01). Conclusion: Radiation were able to cause marrow cell mutation and induce marrow inhibition. Smoke increases the effect of radiation-induced marrow cell mutation. Tea and smoke could not affect radiation-induced bone marrow inhibition

  4. Low-frequency analogue Hawking radiation: The Bogoliubov-de Gennes model

    Science.gov (United States)

    Coutant, Antonin; Weinfurtner, Silke

    2018-01-01

    We analytically study the low-frequency properties of the analogue Hawking effect in Bose-Einstein condensates. We show that in one-dimensional flows displaying an analogue horizon, the Hawking effect is dominant in the low-frequency regime. This happens despite nonvanishing grey-body factors, that is, the coupling of the Hawking mode and its partner to the mode propagating with the flow. To show this, we obtained analytical expressions for the scattering coefficients, in general flows and taking into account the full Bogoliubov dispersion relation. We discuss the obtained expressions for the grey-body factors. In particular, we show that they can be significantly decreased if the flow obeys a conformal coupling condition. We argue that in the presence of a small but non-zero temperature, reducing grey-body factors greatly facilitates the observation of entanglement, that is, establishing that the state of the Hawking mode and its partner is non-separable.

  5. Syllable frequency and word frequency effects in spoken and written word production in a non-alphabetic script

    Directory of Open Access Journals (Sweden)

    Qingfang eZhang

    2014-02-01

    Full Text Available The effects of word frequency and syllable frequency are well-established phenomena in domain such as spoken production in alphabetic languages. Chinese, as a non-alphabetic language, presents unique lexical and phonological properties in speech production. For example, the proximate unit of phonological encoding is syllable in Chinese but segments in Dutch, French or English. The present study investigated the effects of word frequency and syllable frequency, and their interaction in Chinese written and spoken production. Significant facilitatory word frequency and syllable frequency effects were observed in spoken as well as in written production. The syllable frequency effect in writing indicated that phonological properties (i.e., syllabic frequency constrain orthographic output via a lexical route, at least, in Chinese written production. However, the syllable frequency effect over repetitions was divergent in both modalities: it was significant in the former two repetitions in spoken whereas it was significant in the second repetition only in written. Due to the fragility of the syllable frequency effect in writing, we suggest that the phonological influence in handwritten production is not mandatory and universal, and it is modulated by experimental manipulations. This provides evidence for the orthographic autonomy hypothesis, rather than the phonological mediation hypothesis. The absence of an interaction between word frequency and syllable frequency showed that the syllable frequency effect is independent of the word frequency effect in spoken and written output modalities. The implications of these results on written production models are discussed.

  6. Benefits of adaptive radiation therapy in lung cancer as a function of replanning frequency

    International Nuclear Information System (INIS)

    Dial, Christian; Weiss, Elisabeth; Hugo, Geoffrey D.; Siebers, Jeffrey V.

    2016-01-01

    Purpose: To quantify the potential benefit associated with daily replanning in lung cancer in terms of normal tissue dose sparing and to characterize the tradeoff between adaptive benefit and replanning frequency. Methods: A set of synthetic images and contours, derived from weekly active breathing control images of 12 patients who underwent radiation therapy treatment for nonsmall cell lung cancer, is generated for each fraction of treatment using principal component analysis in a way that preserves temporal anatomical trends (e.g., tumor regression). Daily synthetic images and contours are used to simulate four different treatment scenarios: (1) a “no-adapt” scenario that simulates delivery of an initial plan throughout treatment, (2) a “midadapt” scenario that implements a single replan for fraction 18, (3) a “weekly adapt” scenario that simulates weekly adaptations, and (4) a “full-adapt” scenario that simulates daily replanning. An initial intensity modulated radiation therapy plan is created for each patient and replanning is carried out in an automated fashion by reoptimizing beam apertures and weights. Dose is calculated on each image and accumulated to the first in the series using deformable mappings utilized in synthetic image creation for comparison between simulated treatments. Results: Target coverage was maintained and cord tolerance was not exceeded for any of the adaptive simulations. Average reductions in mean lung dose (MLD) and volume of lung receiving 20 Gy or more (V20 lung ) were 65 ± 49 cGy (p = 0.000 01) and 1.1% ± 1.2% (p = 0.0006), respectively, for all patients. The largest reduction in MLD for a single patient was 162 cGy, which allowed an isotoxic escalation of the target dose of 1668 cGy. Average reductions in cord max dose, mean esophageal dose (MED), dose received by 66% of the heart (D66 heart ), and dose received by 33% of the heart (D33 heart ), were 158 ± 280, 117 ± 121, 37 ± 77, and 99 ± 120 c

  7. Radiation effects on two-dimensional materials

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

  8. Neurophysiological appropriateness of ionizing radiation effects

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  9. Effect of ionizing radiation on cardiovascular system

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  10. Radiation effect on PVC/ENR blends

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan

    1997-01-01

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

  11. Effects of Scattering of Radiation on Wormholes

    Directory of Open Access Journals (Sweden)

    Alexander Kirillov

    2018-02-01

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

  12. Pulse-like partial ruptures and high-frequency radiation at creeping-locked transition during megathrust earthquakes

    Science.gov (United States)

    Michel, Sylvain; Avouac, Jean-Philippe; Lapusta, Nadia; Jiang, Junle

    2017-08-01

    Megathrust earthquakes tend to be confined to fault areas locked in the interseismic period and often rupture them only partially. For example, during the 2015 M7.8 Gorkha earthquake, Nepal, a slip pulse propagating along strike unzipped the bottom edge of the locked portion of the Main Himalayan Thrust (MHT). The lower edge of the rupture produced dominant high-frequency (>1 Hz) radiation of seismic waves. We show that similar partial ruptures occur spontaneously in a simple dynamic model of earthquake sequences. The fault is governed by standard laboratory-based rate-and-state friction with the aging law and contains one homogenous velocity-weakening (VW) region embedded in a velocity-strengthening (VS) area. Our simulations incorporate inertial wave-mediated effects during seismic ruptures (they are thus fully dynamic) and account for all phases of the seismic cycle in a self-consistent way. Earthquakes nucleate at the edge of the VW area and partial ruptures tend to stay confined within this zone of higher prestress, producing pulse-like ruptures that propagate along strike. The amplitude of the high-frequency sources is enhanced in the zone of higher, heterogeneous stress at the edge of the VW area.

  13. Literature survey: health effects of radiation

    International Nuclear Information System (INIS)

    Tveten, U.; Garder, K.

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

  14. Frequency Up-Converted Low Frequency Vibration Energy Harvester Using Trampoline Effect

    International Nuclear Information System (INIS)

    Ju, S; Chae, S H; Choi, Y; Jun, S; Park, S M; Lee, S; Ji, C-H; Lee, H W

    2013-01-01

    This paper presents a non-resonant vibration energy harvester based on magnetoelectric transduction mechanism and mechanical frequency up-conversion using trampoline effect. The harvester utilizes a freely movable spherical permanent magnet which bounces off the aluminum springs integrated at both ends of the cavity, achieving frequency up-conversion from low frequency input vibration. Moreover, bonding method of magnetoelectric laminate composite has been optimized to provide higher strain to piezoelectric material and thus obtain a higher output voltage. A proof-of-concept energy harvesting device has been fabricated and tested. Maximum open-circuit voltage of 11.2V has been obtained and output power of 0.57μW has been achieved for a 50kΩ load, when the fabricated energy harvester was hand-shaken

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

    International Nuclear Information System (INIS)

    1994-01-01

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

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

    International Nuclear Information System (INIS)

    Wei Luxin

    1997-01-01

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

  17. Radiation Effects in Nuclear Waste Materials

    International Nuclear Information System (INIS)

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

    2003-01-01

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

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  19. Spontaneous micronucleus frequencies in human peripheral blood lymphocytes as a screening test for an individual variation in a different population and radiation-induced micronucleus induction

    International Nuclear Information System (INIS)

    Kang, Chang-Mo; Jeon, Hye-Jeong; Cho, Chul-Koo

    2004-01-01

    Our studies were to evaluate the role of epigenetic factors in the variation of radiosensitivity on human peripheral blood lymphocytes by measuring the frequencies of micronucleus (MN) from 293 healthy subjects of different population for assessing the radiation health risk in Korea. We analyzed the frequencies of both spontaneous and in vitro 60 Co γ-rays or 50MeV neutron-induced MNs. The frequencies of spontaneous NMs not only vary greatly between individuals, but also working or living areas. The increased levels of cells with spontaneous MNs were observed with an increasing age. The frequencies of spontaneous MNs were significantly higher in females than in males. For both sexes, MN frequency was significantly and positively correlated with age. Age and gender are the most important demographic variables impacting on the MN index. Donors who had ever smoked showed significantly increased frequencies of MNs compared to nonsmokers. The main lifestyle factors influencing the MN index in the subjects are correlated significantly and positively with smoke while measuring the spontaneous frequencies of micronuclei. Therefore, it is evident that with regard to the application of MN assay all future studies to evaluate the association between radiosensitivity and susceptibility for radiation health risks in different populations should take into account the effect of age, gender and lifestyle. For the dose-response study, the induced MNs were observed at all doses, and the numerical changes according to doses. The dose-response curves were fitted with a linear-quadratic forms of the dose, and the results were different for γ-rays and neutrons significantly. Neutrons were more effective than γ-rays in producing MN with a dose-dependent manner. The frequency of MN varies with dose. The RBE for a micronuclei was 2.37 ± 0.17. The results suggested that the MN assay have a high potential to ensure appropriate quality control and a standard documentation protocol, which

  20. Radiation effects on algae and its application

    International Nuclear Information System (INIS)

    Dwivedi, Rakesh Kumar

    2013-01-01

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

  1. Combined genetic effects of chemicals and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kada, T. [National Institute of Genetics, Mishima (Japan); Inoue, T. [National Institute of Genetics, Mishima (Japan); Yokoiyama, A. [National Institute of Genetics, Mishima (Japan); Russel, L. B. [Oak Ridge National Lab., Oak Ridge, TN (United States)

    1979-05-01

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

  2. Radiation Effects in the Space Telecommunications Environment

    International Nuclear Information System (INIS)

    Fleetwood, Daniel M.; Winokur, Peter S.

    1999-01-01

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

  3. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  4. 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.

  5. Simulation of first-wall radiation effects

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  6. 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.

  7. [Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].

    Science.gov (United States)

    Polevik, N D

    2013-01-01

    The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.

  8. The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

    Energy Technology Data Exchange (ETDEWEB)

    Visser, P. J. de, E-mail: p.j.devisser@tudelft.nl [Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Yates, S. J. C. [SRON Netherlands Institute for Space Research, Landleven 12, 9747AD Groningen (Netherlands); Guruswamy, T.; Goldie, D. J.; Withington, S. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Neto, A.; Llombart, N. [Faculty of Electrical Engineering, Mathematics and Computer Science, Terahertz Sensing Group, Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands); Baryshev, A. M. [SRON Netherlands Institute for Space Research, Landleven 12, 9747AD Groningen (Netherlands); Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen (Netherlands); Klapwijk, T. M. [Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Physics Department, Moscow State Pedagogical University, Moscow 119991 (Russian Federation); Baselmans, J. J. A. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); Faculty of Electrical Engineering, Mathematics and Computer Science, Terahertz Sensing Group, Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands)

    2015-06-22

    We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the gap edge of the superconductor. From there on, the response drops to half the maximum response at twice the pair-breaking energy. At higher frequencies, the response rises again due to trapping of pair-breaking phonons in the superconductor. In practice, this is a measurement of the frequency dependence of the quasiparticle creation efficiency due to pair-breaking in a superconductor. The efficiency, calculated from the different non-equilibrium quasiparticle distribution functions at each frequency, is in agreement with the measurements.

  9. Radio-frequency radiation exposure from AM radio transmitters and childhood leukemia and brain cancer.

    Science.gov (United States)

    Ha, Mina; Im, Hyoungjune; Lee, Mihye; Kim, Hyun Joo; Kim, Byung-Chan; Gimm, Yoon-Myoung; Pack, Jeong-Ki

    2007-08-01

    Leukemia and brain cancer patients under age 15 years, along with controls with respiratory illnesses who were matched to cases on age, sex, and year of diagnosis (1993-1999), were selected from 14 South Korean hospitals using the South Korean Medical Insurance Data System. Diagnoses were confirmed through the South Korean National Cancer Registry. Residential addresses were obtained from medical records. A newly developed prediction program incorporating a geographic information system that was modified by the results of actual measurements was used to estimate radio-frequency radiation (RFR) exposure from 31 amplitude modulation (AM) radio transmitters with a power of 20 kW or more. A total of 1,928 leukemia patients, 956 brain cancer patients, and 3,082 controls were analyzed. Cancer risks were estimated using conditional logistic regression adjusted for residential area, socioeconomic status, and community population density. The odds ratio for all types of leukemia was 2.15 (95% confidence interval (CI): 1.00, 4.67) among children who resided within 2 km of the nearest AM radio transmitter as compared with those resided more than 20 km from it. For total RFR exposure from all transmitters, odds ratios for lymphocytic leukemia were 1.39 (95% CI: 1.04, 1.86) and 1.59 (95% CI: 1.19, 2.11) for children in the second and third quartiles, respectively, versus the lowest quartile. Brain cancer and infantile cancer were not associated with AM RFR.

  10. Transistor Small Signal Analysis under Radiation Effects

    International Nuclear Information System (INIS)

    Sharshar, K.A.A.

    2004-01-01

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

  11. Spatial frequency interference effects and interpolation in vernier acuity.

    Science.gov (United States)

    Morgan, M J; Watt, R J

    1984-01-01

    Discrete spatial sampling of sinusoidal gratings has a detrimental effect upon vernier acuity for such stimuli if the sampling rate is less than 20 c/deg. We have examined the possibility that interpolation failure is due to masking by spatial frequency components near to the signal frequency. In an explicit masking paradigm, vernier acuity for a sine wave grating was found to be adversely affected by the presence of a masking grating falling within a critical band of frequencies near the test target. In the sampled stimulus, removal of sampling replicas similar in frequency to the test improved acuity, but the extent of the residual interference by high frequency components could not be predicted from the masking data. The high frequency interference effect depended on fixed phase relations between frequency components, creating narrow bright bars in the spatial luminance profile, and was greatly reduced by phase randomizing the sampling replicas. Various explanations of this nonlinear behaviour are discussed, including the Marr-Hildreth theory of edge detection.

  12. Gamma radiations an effective way of monoclonal antibodies sterilization

    International Nuclear Information System (INIS)

    Lenay Barrera Barroso, Lenay; Otero Abreu, Isabel; Rodriguez Napoles, Dania; Bulte Ocanna, Dubhe; Caballero, Idania

    2006-01-01

    The sterilization for radiations of pharmaceutical products is an effective, sure and reliable procedure; that it have been proving technically and grateful for different pharmacopoeia. The Monoclonal Antibodies (Acm) produced in the Center of Molecular Immunology (CIM) are products parenteral for the one which results indispensable that they complete the requirements of established sterility. The radio sterilization result the method more recommend for the sterilization of the Acm deep drying, due to the contained first floor of humidity remnant that minimizes the formation of sub-product that they affect their properties. With the objective of proposing a good dose of irradiation for the sterilization, we were carried out a study of the radius sensibility so much of the product like of the polluting of greater frequency of isolation of the clean area of the CIM. The characterization of the radius sensibility of the different micro- organisms was determined by D 10 characteristic of each isolated strains. From the developed studies the Gram-positive rods endospore-forming were the most resistant strains at the deep drying, the radiations and they were of the greater frequency of apparition in the carried out isolations. We could conclude that utilizing a dose of 10 kGy it is possible to eliminate of the pollution more radio resistant, assuring the sterility required in the product, and without inducing effects under desire radiolytic in the same

  13. Clastogenic effects of radiofrequency radiations on chromosomes of Tradescantia.

    Science.gov (United States)

    Haider, T; Knasmueller, S; Kundi, M; Haider, M

    1994-06-01

    The clastogenicity of electromagnetic fields (EMF) has so far been studied only under laboratory conditions. We used the Tradescantia-micronucleus (Trad-MCN) bioassay in an in situ experiment to find out whether short-wave electromagnetic fields used for broadcasting (10-21 MHz) may show genotoxic effects. Plant cuttings bearing young flower buds were exposed (30 h) on both sides of a slewable curtain antenna (300/500 kW, 40-170 V/m) and 15 m (90 V/m) and 30 m (70 V/m) distant from a vertical cage antenna (100 kW) as well as at the neighbors living near the broadcasting station (200 m, 1-3 V/m). The exposure at both sides of the slewable curtain antenna was performed simultaneously within cages, one of the Faraday type shielding the field and one non-shielding mesh cage. Laboratory controls were maintained for comparison. Higher MCN frequencies than in laboratory controls were found for all exposure sites in the immediate vicinity of the antennae, where the exposure standards of the electric field strength of the International Radiation Protection Association (IRPA) were exceeded. The results at all exposure sites except one were statistically significant. Since the parallel exposure in a non-shielding and a shielding cage also revealed significant differences in MCN frequencies (the latter showing no significant differences from laboratory controls), the clastogenic effects are clearly attributable to the short-wave radiation from the antennae.

  14. 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 ground...

  15. 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. [64 FR 59663...

  16. The effects of radiation on the outer planets grand tour

    Science.gov (United States)

    1971-01-01

    A handbook is presented which was designed to accompany an oral presentation on the effects of radiation on the outer planets grand tour (OPGT). A summary of OPGT radiation environments expected from natural sources and the radioisotope thermoelectric generators and basic radiation effects and processes are reviewed, and ionization and displacement effects are examined. The presentation summarizes the effects of radiation on miscellaneous spacecraft materials and devices. The annealing and hardening of electronics are described. Special emphasis is placed on microcircuits. Mathematical modeling of circuits affected by radiation and radiation environmental testing are discussed. A review of means of evaluating the performance and correcting failures of irradiated devices is also presented.

  17. Studying the physical basis of global warming: thermal effects of the interaction between radiation and matter and greenhouse effect

    Energy Technology Data Exchange (ETDEWEB)

    Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo [Department of Physics ' A Volta' , University of Pavia, Via A Bassi 6, 27100 Pavia (Italy)], E-mail: ugo.besson@unipv.it, E-mail: anna.deambrosisvigna@unipv.it

    2010-03-15

    We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation frequency, as a result of interaction between matter and radiation. Multiple experiences are suggested to favour a progressive construction of knowledge on the physical aspects necessary to understand the greenhouse effect and global warming. Some results obtained with university students are briefly reported.

  18. Studying the physical basis of global warming: thermal effects of the interaction between radiation and matter and greenhouse effect

    International Nuclear Information System (INIS)

    Besson, Ugo; De Ambrosis, Anna; Mascheretti, Paolo

    2010-01-01

    We present a teaching module dealing with the thermal effects of interaction between radiation and matter, the infrared emission of bodies and the greenhouse effect devoted to university level and teacher education. The module stresses the dependence of the optical properties of materials (transparency, absorptivity and emissivity) on radiation frequency, as a result of interaction between matter and radiation. Multiple experiences are suggested to favour a progressive construction of knowledge on the physical aspects necessary to understand the greenhouse effect and global warming. Some results obtained with university students are briefly reported.

  19. Gamma radiation effects on nestling Tree Swallows

    International Nuclear Information System (INIS)

    Zach, R.; Mayoh, K.R.

    1984-01-01

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

  20. The effect of ultrasound and its combination with radiation on the genetic material of Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Silhankova, L.; Malkova-Kadlecova, Z.; Studlarova, Z.

    1978-01-01

    Ultrasonic radiation at 20 kHz with intensity 35 W/cm 2 and amplitude 15 to 25 μm applied to a diploid strain of Saccharomyces cerevisiae was found to act as a weak mutagen with maximum efficiency at the 20% survival of the cells. Under these conditions, the frequency of reversion of the suppressible allele ilv1-92 increased ten times, the frequency of mitotic gene conversion four times. Doses leading to survivals lower than 20% led to a slight increase in the frequency of cytoplasmic respiration-deficient mutants. Submutagenic doses applied immediately after γ or UV irradiation did not substantially increase the effect of these physical agents on the genetic material of the yeast strain investigated. Application of ultrasound prior to UV radiation did not considerably influence the effect of the UV radiation either. (author)

  1. Mechanism of low-level microwave radiation effect on nervous system.

    Science.gov (United States)

    Hinrikus, Hiie; Bachmann, Maie; Karai, Denis; Lass, Jaanus

    2017-01-01

    The aim of this study is to explain the mechanism of the effect of low-level modulated microwave radiation on brain bioelectrical oscillations. The proposed model of excitation by low-level microwave radiation bases on the influence of water polarization on hydrogen bonding forces between water molecules, caused by this the enhancement of diffusion and consequences on neurotransmitters transit time and neuron resting potential. Modulated microwave radiation causes periodic alteration of the neurophysiologic parameters and parametric excitation of brain bioelectric oscillations. The experiments to detect logical outcome of the mechanism on physiological level were carried out on 15 human volunteers. The 450-MHz microwave radiation modulated at 7, 40 and 1000 Hz frequencies was applied at the field power density of 0.16 mW/cm 2 . A relative change in the EEG power with and without radiation during 10 cycles was used as a quantitative measure. Experimental data demonstrated that modulated at 40 Hz microwave radiation enhanced EEG power in EEG alpha and beta frequency bands. No significant alterations were detected at 7 and 1000 Hz modulation frequencies. These results are in good agreement with the theory of parametric excitation of the brain bioelectric oscillations caused by the periodic alteration of neurophysiologic parameters and support the proposed mechanism. The proposed theoretical framework has been shown to predict the results of experimental study. The suggested mechanism, free of the restrictions related to field strength or time constant, is the first one providing explanation of low-level microwave radiation effects.

  2. Measurement of intense coherent synchrotron radiation at frequencies around 0.1 THz using the compact S-band linac

    International Nuclear Information System (INIS)

    Sei, Norihiro; Kuroda, Ryunosuke; Yasumoto, Masato; Toyokawa, Hiroyuki; Ogawa, Hiroshi; Koike, Masaki; Yamada, Kawakatsu

    2008-01-01

    We measured intense radiation from an electron bunch in a millimeter wave region using the compact S-band linac. The dependence of the radiation on the electron-bunch charge was measured with an rf detector system at frequencies around 0.1 THz and was confirmed to be a coherent synchrotron radiation (CSR). The total power of the horizontally and vertically polarized CSRs, which were extracted through the Z-cut quartz window within 1 ns, was calculated to be about 88 and 30 nJ/pulse, excluding the absorption by the window. The two-dimensional distribution of the vertically polarized CSR was measured at a distance of about 0.7 m from the radiation point. The CSR distribution was comparatively uniform in the horizontal plane. Intense CSR, which was reflected in the vacuum chamber, was extracted with a delay of about 6 ns. This suggests that measurement of temporal structure is needed for CSR applications

  3. Simulation of radiation from lightning return strokes - The effects of tortuosity

    Science.gov (United States)

    Levine, D. M.; Meneghini, R.

    1978-01-01

    A Monte Carlo simulation has been developed for the electromagnetic fields radiated from a tortuous lightning channel. This was done using a piecewise linear model for the channel and employing for each element the field radiated by a traveling wave on an arbitrarily oriented filament over a conducting plane. The simulation reproduces experimental data reasonably well and has been used to study the effects of tortuosity on the fields radiated by return strokes. Tortuosity can significantly modify the radiated waveform, tending to render it less representative of the current pulse and more nearly unipolar than one would expect based on the theory for a long straight channel. In the frequency domain the effect of tortuosity is an increase in high frequency energy as compared with an equivalent straight channel. The extent of this increase depends on the mean length of the elements comprising the channel and can be significant.

  4. Simulation of radiation from lightning return strokes: The effects of tortuosity

    Science.gov (United States)

    Levine, D. M.; Meneghini, R.

    1977-01-01

    A Monte Carlo simulation has been developed for the electromagnetic fields radiated from a tortuous lightning channel. This was done using a piecewise linear model for the channel and employing for each element the field radiated by a traveling wave on an arbitrarily oriented filament over a conducting plane. The simulation reproduces experimental data reasonably well and had been used to study the effects of tortuousity on the fields radiated by return strokes. Tortuosity can significantly modify the radiated waveform, tending to render it less representative of the current pulse and more nearly unipolar than one would expect based on the theory for a long straight channel. In the frequency domain the effect of tortuosity is an increase in high frequency energy as compared with an equivalent straight channel. The extent of this increase depends on the mean length of the elements comprising the channel and can be significant.

  5. Optical back-action in silicon nanowire resonators: bolometric versus radiation pressure effects

    Science.gov (United States)

    Gil-Santos, E.; Ramos, D.; Pini, V.; Llorens, J.; Fernández-Regúlez, M.; Calleja, M.; Tamayo, J.; San Paulo, A.

    2013-03-01

    We study optical back-action effects associated with confined electromagnetic modes in silicon nanowire resonators interacting with a laser beam used for interferometric read-out of the nanowire vibrations. Our analysis describes the resonance frequency shift produced in the nanowires by two different mechanisms: the temperature dependence of the nanowire's Young's modulus and the effect of radiation pressure. We find different regimes in which each effect dominates depending on the nanowire morphology and dimensions, resulting in either positive or negative frequency shifts. Our results also show that in some cases bolometric and radiation pressure effects can have opposite contributions so that their overall effect is greatly reduced. We conclude that Si nanowire resonators can be engineered for harnessing back-action effects for either optimizing frequency stability or exploiting dynamic phenomena such as parametric amplification.

  6. Testing hypotheses on frequency effects in first language acquisition

    DEFF Research Database (Denmark)

    Kjærbæk, Laila; Basbøll, Hans

    On the basis of extensive literature studies Ambridge, Kidd, Rowland & Theakston (JCL, 2015) present five theses on frequency effects on language acquisition: 1) Levels and Kinds Thesis. Frequency effects exist at all levels and are of many different kinds (e.g. type and token frequency effects...... with other effects. The acquisition of the Danish noun plural system is particularly interesting in this regard. The reason is, that where English is characterized by having one default inflectional marker for a grammatical category (e.g. the plural suffix -s) and a minor number of exceptions to this default...... rule, Danish has several competing inflectional markers. Furthermore, there are important interactions between phonetics/phonology and morphology in the Danish system (Kjærbæk, dePont Christensen & Basbøll, NJL, 2014).In this study we will test the theses in a phonetic/phonological perspective...

  7. 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

  8. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  9. 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.

  10. Annual report of Radiation Effects Research Foundation

    International Nuclear Information System (INIS)

    1980-01-01

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

  11. Analytic approximate radiation effects due to Bremsstrahlung

    International Nuclear Information System (INIS)

    Ben-Zvi, I.

    2012-01-01

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

  12. Radiation effects on structural ceramics in fusion

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  13. Effects of UV radiation on genetic recombination

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  14. Radiation effects on active pixel sensors (APS)

    International Nuclear Information System (INIS)

    Cohen, M.; David, J.P.

    1999-01-01

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

  15. Effect of radiation on hydrotalcites with chromates

    International Nuclear Information System (INIS)

    Martinez G, S.; Bulbulian, S.

    2002-01-01

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

  16. The effect of radiation therapy on hemophilic arthropathy

    International Nuclear Information System (INIS)

    Kang, Jin Oh; Hong, Seong Eon; Kim, Sang Gi; Shin, Dong Oh

    2005-01-01

    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 (ρ 0.051) but there was also a tendency for more improvement in this group (ρ 0.057). The number of joint bleedings was related with joint pain (ρ 0.012) and joint swelling (ρ = 0.033) but not with the Arbold-Hilgartner stage (ρ 0.739),cartilage destruction (ρ = 0.718) and synovial hypertrophy (ρ = 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 (ρ = 0.017). Radiation therapy was effective for the hemophilia patients with repetitive joint bleeding to decrease the bleeding frequency and to prevent hemophilic arthropathy

  17. 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.

  18. Exploring the Derivative Suffix Frequency Effect in Spanish Speaking Children

    Science.gov (United States)

    Lázaro, Miguel; Acha, Joana; de la Rosa, Saray; García, Seila; Sainz, Javier

    2017-01-01

    This study was designed to examine the developmental course of the suffix frequency effect and its role in the development of automatic morpho-lexical access. In Spanish, a highly transparent language from an orthographic point of view, this effect has been shown to be facilitative in adults, but the evidence with children is still inconclusive. A…

  19. Effect of mobile phone radiation on pentylenetetrazole-induced seizure threshold in mice

    Directory of Open Access Journals (Sweden)

    Ebrahim Kouchaki

    2016-07-01

    Full Text Available Objective(s: Scientific interest in potential mobile phone impact on human brain and performance has significantly increased in recent years. The present study was designed to evaluate the effects of mobile phone radiation on seizure threshold in mice. Materials and methods:BALB/c male mice were randomly divided into three groups: control, acute, and chronic mobile phone radiation for 30, 60, and 90 min with frequency 900 to 950 MHz and pulse of 217 Hz. The chronic group received 30 days of radiation, while the acute group received only once. The intravenous infusion of pentylenetetrazole (5 mg/ml was used to induce seizure signs. Results:  Although acute mobile radiation did not change seizure threshold, chronic radiation decreased the clonic and tonic seizure thresholds significantly. Conclusion: Our data suggests that thecontinued and prolonged contact with the mobile phone radiation might increase the risk of seizure attacks and should be limited.

  20. Effect of mobile phone radiation on pentylenetetrazole-induced seizure threshold in mice.

    Science.gov (United States)

    Kouchaki, Ebrahim; Motaghedifard, Morteza; Banafshe, Hamid Reza

    2016-07-01

    Scientific interest in potential mobile phone impact on human brain and performance has significantly increased in recent years. The present study was designed to evaluate the effects of mobile phone radiation on seizure threshold in mice. BALB/c male mice were randomly divided into three groups: control, acute, and chronic mobile phone radiation for 30, 60, and 90 min with frequency 900 to 950 MHz and pulse of 217 Hz. The chronic group received 30 days of radiation, while the acute group received only once. The intravenous infusion of pentylenetetrazole (5 mg/ml) was used to induce seizure signs. Although acute mobile radiation did not change seizure threshold, chronic radiation decreased the clonic and tonic seizure thresholds significantly. Our data suggests that the continued and prolonged contact with the mobile phone radiation might increase the risk of seizure attacks and should be limited.

  1. Frequency-dependent effects of rupture for the 2004 Parkfield mainshock, results from UPSAR

    Science.gov (United States)

    Fletcher, Jon B.

    2014-01-01

    The frequency-dependent effects of rupture propagation of the Parkfield, California earthquake (Sept. 28, 2004, M6) to the northwest along the San Andreas fault can be seen in acceleration records at UPSAR (USGS Parkfield Seismic Array) in at least two ways. First, we can see the effects of directivity in the acceleration traces at UPSAR, which is about 11.5 km from the epicenter. Directivity or the seismic equivalent of a Doppler shift has been documented in many cases by comparing short duration, high-amplitude pulses (P or S) in the forward direction with longer duration body waves in the backward direction. In this case we detect a change from a relatively large amplitude, coherent, high-frequency signal at the start of rupture to a low-amplitude, low-coherent, low-frequency signal at about the time the rupture front transfers from the forward azimuth to the back azimuth at about 34-36 s (time is UTC and are the seconds after day 272 and 17 hours and 15 minutes. S arrival is just after 30s) for rays leaving the fault and propagating to UPSAR. The frequency change is obvious in the band about 5 to 30 Hz, which is significantly above the corner frequency of the earthquake (about 0.11Hz). From kinematic source models, the duration of faulting is about 9.2 s and the change in frequency is during faulting as the rupture extends to the northwest. Understanding the systematic change in frequency and amplitude of seismic waves in relation to the propagation of the rupture front is important for predicting strong ground motion. Second, we can filter the acceleration records from the array to determine if the low frequency energy emerges from the same part of the fault as the high frequency signal (e.g. has the same back azimuth and apparent velocity at UPSAR) an important clue to the dynamics of rupture. Analysis of sources of strong motion (characterized by relatively high frequencies) compared to kinematic slip models (relatively low frequency) for the

  2. Effect of lexical and syllable frequency in anomic aphasia

    Directory of Open Access Journals (Sweden)

    Janeth Hernández Jaramillo

    2012-09-01

    Full Text Available Objective: this study compares the performance of two groups of participants with and without aphasia anomic in a lexical decision tasks (LDT and spelling, in relation to the effect of the variables of word frequency and syllable. Materials and methods: a prospective study with a 2x2x2 design, which administered the LDT, in which each she/he had to decide if it was a real Spanish word or not, pressing one of two keys. To the task of spelling, they had to spell orally each of words presented auditorily. Results: It was found that in the LTD, the experimental group made more errors in the high-frequency stimuli syllable while the control group had more errors in the low-frequency syllables. In terms of reaction times was evident that the experimental group took longer to solve the task than the control group. The spelling task performance showed no difference in groups or conditions (lexical frequency and syllable. Conclusions: similar than other researches in normalized population, the results of this study demonstrate the effect of lexical frequency facilitation and inhibition that generates high syllable frequency.

  3. RADIATION EFFECTS IN NUCLEAR WASTE MATERIALS

    International Nuclear Information System (INIS)

    Weber, William J.

    2000-01-01

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

  4. Basic radiation effects in nuclear power electronics technology

    International Nuclear Information System (INIS)

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

    1985-05-01

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

  5. The combined effects of MRI and X-radiation on ICR mouse embryos during organogenesis

    International Nuclear Information System (INIS)

    Gu, Y.H.; Hasegawa, T.; Yamamoto, Y.; Mori, T.; Bamen, K.; Iwasa, T.; Kai, M.; Kusama, T.

    2000-01-01

    The combined effects of X-radiation magnetic resonance imaging (MRI) malformations, fetal body weight and sex ratios of mice treated on day 8 of gestation were determined at day 18 of gestation. These were no significant differences in the frequency of prenatal death, fetal body weight and sex ratios between control and 0.5 T irradiated mice. The frequencies of embryonic deaths in mice irradiated with X-rays increased significantly. The frequencies of external malformations such as exencephaly and anophthalmia in mice irradiated with X-rays or MRI increased significantly. However the frequencies of external malformation and prenatal death in the mice irradiated with both X-rays and MRI decreased more than in mice irradiated with X-rays alone. The combined effects of radiation and MRI on the external malformations and embryonic death might be antagonistic. (author)

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

    International Nuclear Information System (INIS)

    Miller, R.W.

    1995-01-01

    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, 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 F 1 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.W. [National Cancer Institute, Bethesda, MD (United States)

    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, 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 F{sub 1} 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.

  8. Radiofrequency Radiation Effects on Excitable Tissues

    Science.gov (United States)

    1983-11-01

    particles are probably more significant than rectifica- tion at higher frequencies [45]. Models of RFR effects on membranes include one based on the Hodgkin ... Huxley equations [13] and one based on quantum mechanics [51]. With previous Air Force sponsorship, we studied the beat rates of individual heart cells...membrane capacitance. 10 _ *€ -.* ., N y :,. . , t. -., . - w - - 9 ’ ’ o ’ ’ . 3. Aggregates can be prepared in any size within a 30- to 300 im- diameter

  9. Effects of 900 MHz radiofrequency radiation on skin hydroxyproline contents.

    Science.gov (United States)

    Çam, Semra Tepe; Seyhan, Nesrin; Kavaklı, Cengiz; Çelikbıçak, Ömür

    2014-09-01

    The present study aimed to investigate the possible effect of pulse-modulated radiofrequency radiation (RFR) on rat skin hydroxyproline content, since skin is the first target of external electromagnetic fields. Skin hydroxyproline content was measured using liquid chromatography mass spectrometer method. Two months old male wistar rats were exposed to a 900 MHz pulse-modulated RFR at an average whole body specific absorption rate (SAR) of 1.35 W/kg for 20 min/day for 3 weeks. The radiofrequency (RF) signals were pulse modulated by rectangular pulses with a repetition frequency of 217 Hz and a duty cycle of 1:8 (pulse width 0.576 ms). A skin biopsy was taken at the upper part of the abdominal costa after the exposure. The data indicated that whole body exposure to a pulse-modulated RF radiation that is similar to that emitted by the global system for mobile communications (GSM) mobile phones caused a statistically significant increase in the skin hydroxyproline level (p = 0.049, Mann-Whitney U test). Under our experimental conditions, at a SAR less than the International Commission on Non-Ionizing Radiation Protection safety limit recommendation, there was evidence that GSM signals could alter hydroxyproline concentration in the rat skin.

  10. Effect of infrared radiation on the lens

    Directory of Open Access Journals (Sweden)

    Aly Eman

    2011-01-01

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

  11. Protective effect of red wine on the frequency of micronuclei in human lymphocytes irradiated in vitro

    International Nuclear Information System (INIS)

    Stankovic, M.; Joksic, G.

    2000-01-01

    The present investigation was undertaken to study the effect of red wines 'Cabernet Sauvignon' on the micronuclei formation in human lymphocytes. Blood samples of healthy volunteers were irratiated in vitro using 60 Co as a source of radiation, dose of 2Gy. Irradiated samples, as well as unirradiated controls, were treated with concentrations of red wine ranged from 100-500 ml/2x106 cells. Obtained results demonstrated significant decrease of the micronuclei frequency (t=9.14; p0.05) in treated samples versus untreated controls. The results of our study demonstrated radioprotective effect of red wine

  12. Effect of lateral radiative losses on radiative shock propagation

    Czech Academy of Sciences Publication Activity Database

    Busquet, M.; Audit, E.; González, M.; Stehlé, C.; Thais, F.; Acef, O.; Bauduin, D.; Barroso, P.; Rus, Bedřich; Kozlová, Michaela; Polan, Jiří; Mocek, Tomáš

    2007-01-01

    Roč. 3, - (2007), s. 8-11 ISSN 1574-1818 EU Projects: European Commission(XE) 506350 - LASERLAB-EUROPE Institutional research plan: CEZ:AV0Z10100523 Keywords : radiative shocks * laboratory astrophysics Subject RIV: BH - Optics, Masers, Lasers

  13. Health effects of low level radiation exposure among radiation workers

    International Nuclear Information System (INIS)

    Murata, Motoi

    2003-01-01

    In Japan, a cohort study of radiation workers has been conducted since 1990. The cohort population consisted of about 176,000 workers (mostly males) who had been registered in the centralized radiation dose registry system and engaged in various radiation works at nuclear facilities. Statistical analyses were performed mainly on the 2,934 deaths, of which 1,191 were cancer cases, detected among 119,000 male subjects during the prospective follow-up. The standardized mortality ratio showed that for any cancers mortality was not different between this population and Japanese general population. By the trend test, though significantly increasing trend in accord with increasing doses was not observed for both cancer in all sites and leukemia, it was highly significant for esophagus cancer and external causes of deaths. Results of the questionnaire survey study of lifestyle of radiation workers suggested that increasing trend of these diseases was at least partly due to the influence of some confounding factors. As a result of reviewing published studies, including the present work, trend of mortality from cancer in all sites with increasing doses seems still unclear, whereas for leukemia it appears to stay flat under 100 mSv but rapidly rise up in the doses higher than this as if fitting to either a linear-quadratic or threshold models. (author)

  14. The radiation effects on lipid bilayers

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  15. Effects of flow gradients on directional radiation of human voice.

    Science.gov (United States)

    Pulkki, Ville; Lähivaara, Timo; Huhtakallio, Ilkka

    2018-02-01

    In voice communication in windy outdoor conditions, complex velocity gradients appear in the flow field around the source, the receiver, and also in the atmosphere. It is commonly known that voice emanates stronger towards the downstream direction when compared with the upstream direction. In literature, the atmospheric effects are used to explain the stronger emanation in the downstream direction. This work shows that the wind also has an effect to the directivity of voice also favouring the downstream direction. The effect is addressed by measurements and simulations. Laboratory measurements are conducted by using a large pendulum with a loudspeaker mimicking the human head, whereas practical measurements utilizing the human voice are realized by placing a subject through the roof window of a moving car. The measurements and a simulation indicate congruent results in the speech frequency range: When the source faces the downstream direction, stronger radiation coinciding with the wind direction is observed, and when it faces the upstream direction, radiation is not affected notably. The simulated flow gradients show a wake region in the downstream direction, and the simulated acoustic field in the flow show that the region causes a wave-guide effect focusing the sound in the direction.

  16. Effect of radiation environment on radiation use efficiency and growth of sunflower

    International Nuclear Information System (INIS)

    Bange, M.P.; Hammer, G.L.; Rickert, K.G.

    1997-01-01

    The level of incident radiation and the proportion of radiation that is diffuse affects radiation use efficiency (RUE) in crops. However, the degree of this effect, and its importance to growth and yield of sunflower (Helianthus annuus L.) have not been established. A field experiment was conducted to investigate the effects of radiation environment on RUE, growth, and yield of sunflower. A fully irrigated crop was sown on an alluvial-prairie soil (Fluventic Haplustoll) and was exposed to three distinct radiation environments. In two treatments, the level of incident radiation was reduced by 14 and 20% by suspending two different types of polyethylene plastic films well above the crop. In addition to the reductions in incident radiation, the proportion of radiation that was diffuse was increased by about 14% in these treatments. Lower incident radiation and increased proportion of diffuse radiation had no effect on total biomass, phenology, leaf area, and the canopy light extinction coefficient (k = 0.89). However, yield was reduced in shaded treatments due to smaller grain size and lower harvest index. Although crop RUE measured over the entire crop cycle (1.25 g/MJ) did not differ significantly among treatments, there was a trend where RUE compensated for less intercepted incident radiation. Theoretical derivations of the response of RUE to different levels of incident radiation supported this finding. Shaded sunflower crops have the ability to produce biomass similar to unshaded crops by increasing RUE, but have lower harvest indices

  17. Effects of UV radiation on phytoplankton

    Science.gov (United States)

    Smith, Raymond C.; Cullen, John J.

    1995-07-01

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

  18. 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)

  19. Effect of ultraviolet-B radiation on biochemical and antioxidant ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology ... The results suggest that Indigofera tinctoria is resistant to UV-B radiation damage and the possible negative effect of additional UV-B radiation on the growth of seedling may have been effectively balanced by the UV-B radiation stress through increase in ...

  20. Effect of acyclovir on radiation- and chemotherapy-induced mouth lesions

    International Nuclear Information System (INIS)

    Bubley, G.J.; Chapman, B.; Chapman, S.K.; Crumpacker, C.S.; Schnipper, L.E.

    1989-01-01

    Several chemotherapeutic regimens and radiation therapy, if delivered to the oral mucosa, are associated with a high frequency of mouth lesions. The cause of this side effect is not known for certain, but in past studies it has sometimes been associated with the ability to culture herpes simplex virus type 1 from the mouth. In a double-blind prospective trial, patients with head and neck tumors treated with chemotherapy or radiation therapy were treated with either acyclovir or placebo. Although the frequency of culture-positive herpes simplex virus was low in the untreated group, it was significantly lower, zero, in the acyclovir-treated group. However, there were no differences in the frequency or type of mouth lesions experienced by patients receiving either radiation or chemotherapy who were taking acyclovir or placebo. These results suggest that herpes simplex virus is not a frequent cause or complication of oral lesions afflicting this patient population

  1. Protective Effect of Curcumin on γ - radiation Induced Chromosome Aberrations in Human Blood Lymphocytes

    International Nuclear Information System (INIS)

    AlSuhaibani, E.S

    2008-01-01

    The present work is aimed at evaluating the radioprotective effect of curcumin on γ radiation induced genetic toxicity. The DNA damage was analyzed by the frequencies of chromosome aberrations assay. Human lymphocytes were treated in vitro with 5.0 γg/ml of curcumin for 30 min at 37 degree C then exposed to 1, 2 and 4 Gy gamma-radiation. The lymphocytes which were pre-treated with curcumin exhibited a significant decrease in the frequency of chromosome aberration at 1 and 2 Gy radiation-induced chromosome damage as compared with the irradiated cells which did not receive the curcumin pretreatment. Thus, pretreatment with curcumin gives protection to lymphocytes against γ-radiation induced chromosome aberration at certain doses. (author)

  2. Radiation effects after low dose chronic long-term exposure

    International Nuclear Information System (INIS)

    Fliedner, T.M.; Friesecke, I.

    1997-01-01

    This document approaches the radiation effects after low dose chronic long-term exposure, presenting examples occurred, the pathophysiologic mechanisms for cell system tolerance in elevated radiation fields, and the diagnostic and therapeutic possibilities

  3. Synergistic effects of microgravity and space radiation (Nimblegen)

    Data.gov (United States)

    National Aeronautics and Space Administration — Space radiations and microgravity both could cause DNA damage in cells but the effects of microgravity on DNA damage response to space radiations are still...

  4. Study of radiation effects on semiconductor devices

    International Nuclear Information System (INIS)

    Kuboyama, Satoshi; Shindou, Hiroyuki; Ikeda, Naomi; Iwata, Yoshiyuki; Murakami, Takeshi

    2004-01-01

    Fine structure of the recent semiconductor devices has made them more sensitive to the space radiation environment with trapped high-energy protons and heavy ions. A new failure mode caused by bulk damage had been reported on such devices with small structure, and its effect on commercial synchronous dynamic random access memory (SDRAMs) was analyzed from the irradiation test results performed at Heavy ion Medical Accelerator in Chiba (HIMAC). Single event upset (SEU) data of static random access memory (SRAMs) were also collected to establish the method of estimating the proton-induced SEU rate from the results of heavy ion irradiation tests. (authors)

  5. 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

  6. [Biological effects of microwave radiation of low nonthermal intensity (regarding the maximal admissible values)].

    Science.gov (United States)

    Grigor'ev, Iu G; Shafirkin, A V; Vasin, A L

    2005-01-01

    There is still much controversy in scientific approaches to setting limits of exposure to radio-frequency electromagnetic radiation in Russia, Europe and USA. The stumbling stone is recognition or denial of potential risk of biological effects from nonthermal electromagnetic radiation (to 1 mW/cm2). The authors review results of experimental investigations performed in Russia over the years since 1960s to study the direct and delayed effects of ultra-high and microwave frequencies of low non-thermal intensity EMR, and delayed negative effects in employees based on the data of several follow-up epidemiological studies. This evidence was used as a baseline for establishing the Russian limits for chronic exposure to, thresholds of harmful effects and the maximal admissible values of EMR within the above frequencies.

  7. [Effects of electromagnetic radiation on health and immune function of operators].

    Science.gov (United States)

    Li, Yan-zhong; Chen, Shao-hua; Zhao, Ke-fu; Gui, Yun; Fang, Si-xin; Xu, Ying; Ma, Zi-jian

    2013-08-01

    To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P Electromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

  8. Effects of ionizing radiations on insects

    International Nuclear Information System (INIS)

    Goyffon, Max.

    1978-01-01

    The most traditional effects caused by irradiation are development and morphogenesis disorders since on the whole the sensitivity of the developing organism to ionizing radiations is all the greater as the growth rate is faster. During the development of higher insects two categories of cell divide: larval cells on the one hand, which differentiate immediately after segmentation and give rise to larval organisms, and embryonic cells on the other which divide actively to form various islets or imaginal discs destined, each to its own extent, to provide the organs of the adult. Two cell categories thus coexist in the larva, one undergoing differentiation and the other multiplication, the radiosensitivity of which will be quite different for this very reason and will account at least partly, where the lethal effect of ionizing radiations is concerned, for the results observed. Three chapters deal in turn with effects on longevity, on regeneration and restoration and on morphogenesis and development. Strong doses give rise beyond a certain threshold to the appearance of acute radiodermatitis; their clinical signs and different degrees of seriousness liken them to burns of a special type [fr

  9. Spatial Frequency Discrimination: Effects of Age, Reward, and Practice.

    Directory of Open Access Journals (Sweden)

    Carlijn van den Boomen

    Full Text Available Social interaction starts with perception of the world around you. This study investigated two fundamental issues regarding the development of discrimination of higher spatial frequencies, which are important building blocks of perception. Firstly, it mapped the typical developmental trajectory of higher spatial frequency discrimination. Secondly, it developed and validated a novel design that could be applied to improve atypically developed vision. Specifically, this study examined the effect of age and reward on task performance, practice effects, and motivation (i.e., number of trials completed in a higher spatial frequency (reference frequency: 6 cycles per degree discrimination task. We measured discrimination thresholds in children aged between 7 to 12 years and adults (N = 135. Reward was manipulated by presenting either positive reinforcement or punishment. Results showed a decrease in discrimination thresholds with age, thus revealing that higher spatial frequency discrimination continues to develop after 12 years of age. This development continues longer than previously shown for discrimination of lower spatial frequencies. Moreover, thresholds decreased during the run, indicating that discrimination abilities improved. Reward did not affect performance or improvement. However, in an additional group of 5-6 year-olds (N = 28 punishments resulted in the completion of fewer trials compared to reinforcements. In both reward conditions children aged 5-6 years completed only a fourth or half of the run (64 to 128 out of 254 trials and were not motivated to continue. The design thus needs further adaptation before it can be applied to this age group. Children aged 7-12 years and adults completed the run, suggesting that the design is successful and motivating for children aged 7-12 years. This study thus presents developmental differences in higher spatial frequency discrimination thresholds. Furthermore, it presents a design that can be

  10. Monitoring hprt mutant frequency over time in T-lymphocytes of people accidentally exposed to high doses of ionizing radiation

    International Nuclear Information System (INIS)

    Cruz, A.D. da; Curry, J.; Glickman, B.W.

    1996-01-01

    Modern technologies have provided the opportunity to monitor mutations in people in vivo. The subjects of this study were accidentally exposed to 137 Cesium in a radiological accident that occurred in September 1987 in Goiania, Brazil, during which more than 150 people received doses greater than 0.1 Gy and as high as 7 Gy. The objective of this study was to determine how long the hprt mutant T-cells in the peripheral blood contribute to mutant T-cells in the peripheral blood contribute to mutant frequency by examining the timecourse of the T-lymphocyte response to ionizing radiation. This report describes the results obtained over a period of 2.3 to 4.5 years subsequent to the accident, from 11 subjects with doses ranging from 1 to 7 Gy, and from nine control subjects selected from the same population. The mean In MF (±SE) of the control group was 2.5 (±0.2) + In10 -6 . The exposed group had a significantly increased mutant frequency; the mean ln MF (±SE) were 3.3 (±0.3) + In10 -6 , 2.8 (±0.2) + In10 -6 , and 2.3 (±0.2) + In10 -6 , in the years 1990-1992 respectively and using Buckton's models, we demonstrated that mutant T-cells have a short-term memory with a half-life of 2.1 years. This relatively short half-half limits the effective use of the hprt assay as the method of choice to monitor past exposure. The data also demonstrate a positive correlation with age, and an inverse correlation with plating efficiency. 77 refs., 3 figs., 4 tabs

  11. The synergistic effects of radiation and caffeine on embryonic development in mice

    International Nuclear Information System (INIS)

    Kusama, Tomoko; Yoshizawa, Yasuo

    1984-01-01

    The combined action of radiation with caffeine has been studied in mouse embryos. Radiation and/or caffeine were administered to ICR mice on day 7 of gestation, at which time the embryos were in the early stage of organogenesis. Intrauterine death, gross malformation, body weight and sex ratio were selected as indicators of effects. Doses of gamma irradiation were 0.5, 1.0 and 2.0 Gy and those of caffeine were 0.10 and 0.25 mg/g of body weight. Intrauterine mortality increased with increasing radiation dose and this trend was more remarkable in combination with caffeine. The malformation such as parietal hernia, exencephalia, hydrocephalia and cleft palate appeared frequently in the fetuses treated with both radiation and caffeine compared to the fetuses treated with each agent separately. Fetal body weight was a sensitive indicator of the effects on growth retardation of radiation and/or caffeine. The sex ratio of live fetuses did not change by means of treatment with radiation and/or caffeine. Intrauterine mortality and frequency of malformations in mice treated with both radiation and caffeine were higher than the sum of those induced by radiation and those by caffeine separately. The results demonstrated that the combined effects of radiation and caffeine were synergistic. (author)

  12. The ionizing radiation environment in space and its effects

    International Nuclear Information System (INIS)

    Adams, Jim; Falconer, David; Fry, Dan

    2012-01-01

    The ionizing radiation environment in space poses a hazard for spacecraft and space crews. The hazardous components of this environment are reviewed and those which contribute to radiation hazards and effects identified. Avoiding the adverse effects of space radiation requires design, planning, monitoring and management. Radiation effects on spacecraft are avoided largely though spacecraft design. Managing radiation exposures of space crews involves not only protective spacecraft design and careful mission planning. Exposures must be managed in real time. The now-casting and forecasting needed to effectively manage crew exposures is presented. The techniques used and the space environment modeling needed to implement these techniques are discussed.

  13. Combined effects of deterministic and statistical structure on high-frequency regional seismograms

    Science.gov (United States)

    Sanborn, Christopher J.; Cormier, Vernon F.; Fitzpatrick, Michele

    2017-08-01

    Radiative transport modelling can combine the effects of both large-scale (deterministic) and the small-scale (statistical) structure on the coda envelopes of high-frequency regional seismograms. We describe a computer code to implement radiative transport modelling that propagates packets of seismic body wave energy along ray paths through large-scale deterministic 3-D structure, including the effects of velocity gradients, intrinsic attenuation, source radiation pattern and multiple scattering by layer boundaries and small-scale heterogeneities specified by a heterogeneity spectrum. The spatial distribution of these energy packets can be displayed as time snapshots to aid in the understanding of regional phase propagation or displayed as a coda envelope by summing at receiver bins. These techniques are applied to earthquakes and explosions recorded in the Lop Nor, China region to model observed narrow band passed seismic codas in the 1-4 Hz band. We predict that source discriminants in this region based on P/Lg amplitude ratios will best separate earthquake and explosion populations at frequencies 2 Hz and higher.

  14. Propagation effects on the Doppler frequency shift of satellite transmissions

    Science.gov (United States)

    Millman, G. H.; Arabadjis, M. C.

    1984-10-01

    The refraction phenomenon in the troposphere and the ionosphere causes an error in the Doppler frequency shift of radio transmissions emitted from a nonstationary satellite and received on the ground. Estimates are made of the Doppler error for various atmospheric and solar-geophysical conditions and are applicable for frequencies in the VHF to UHF range and above. The Doppler error imposed by the troposphere is directly proportional to frequency while, in the case of the ionosphere, the error is approximately inversely proportional to the frequency and approximately directly proportional to the vertical electron content. Under average tropospheric conditions, the tropospheric contribution to the Doppler error is predominant for frequencies on the order of 400 MHz and above. Below about 400 MHz, the ionospheric refraction effects are prevalent. The Doppler effects can be compensated for, to some extent, when the angular bending and the space vehicle velocity are known. Estimates of the angular bending due to the troposphere can be made to a fair degree of accuracy, from measurements of the surface refractivity. For the ionosphere, the vertical electron content data can be used for the estimation of the refraction angle error.

  15. Neurodevelopment for the first three years following prenatal mobile phone use, radio frequency radiation and lead exposure.

    Science.gov (United States)

    Choi, Kyung-Hwa; Ha, Mina; Ha, Eun-Hee; Park, Hyesook; Kim, Yangho; Hong, Yun-Chul; Lee, Ae-Kyoung; Hwa Kwon, Jong; Choi, Hyung-Do; Kim, Nam; Kim, Suejin; Park, Choonghee

    2017-07-01

    Studies examining prenatal exposure to mobile phone use and its effect on child neurodevelopment show different results, according to child's developmental stages. To examine neurodevelopment in children up to 36 months of age, following prenatal mobile phone use and radiofrequency radiation (RFR) exposure, in relation to prenatal lead exposure. We analyzed 1198 mother-child pairs from a prospective cohort study (the Mothers and Children's Environmental Health Study). Questionnaires were provided to pregnant women at ≤20 weeks of gestation to assess mobile phone call frequency and duration. A personal exposure meter (PEM) was used to measure RFR exposure for 24h in 210 pregnant women. Maternal blood lead level (BLL) was measured during pregnancy. Child neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant Development-Revised at 6, 12, 24, and 36 months of age. Logistic regression analysis applied to groups classified by trajectory analysis showing neurodevelopmental patterns over time. The psychomotor development index (PDI) and the mental development index (MDI) at 6, 12, 24, and 36 months of age were not significantly associated with maternal mobile phone use during pregnancy. However, among children exposed to high maternal BLL in utero, there was a significantly increased risk of having a low PDI up to 36 months of age, in relation to an increasing average calling time (p-trend=0.008). There was also a risk of having decreasing MDI up to 36 months of age, in relation to an increasing average calling time or frequency during pregnancy (p-trend=0.05 and 0.007 for time and frequency, respectively). There was no significant association between child neurodevelopment and prenatal RFR exposure measured by PEM in all subjects or in groups stratified by maternal BLL during pregnancy. We found no association between prenatal exposure to RFR and child neurodevelopment during the first three years of life; however, a potential combined

  16. Radiation

    International Nuclear Information System (INIS)

    Davidson, J.H.

    1986-01-01

    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.)

  17. Gamma radiation effects on liofilized human serum

    International Nuclear Information System (INIS)

    Padron Soler, E.; Romay Penabad, Z.; Chavez Ardanza, A.; Hernandez Gonzalez, C.; Martin Gonzalez, O.; Garcia Gonzalez, I.; Prieto Miranda, E.

    1995-01-01

    Human freeze dried serum was artificially contaminated with Flavobacterium sp. for studying the effects of gamma radiation of it. The radiobiological parameters of the contaminator were determined and the sterilization dose was set. The quality of the product irradiated at both, calculated sterilization dose (8.5 kGy) an another one about 25 kGy was determined. It was made according to: sterility testing, total proteins, pH enzymes (alanina-aminotransferase, aspartato-aminotransferase, alkaline phosphatase), protein electrophoresis, fast performance liquid chromatographic and effect on the cellular growth. From the latter was concluded that the calculated sterilization dose was adequate form keeping the biological properties and viability of the irradiated serum. Nevertheless, the dose of 25 k Gy was not adequate because of its dangerous effects on the cell culture

  18. 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...

  19. Radiation effects on foodstuffs. Pt. 1

    International Nuclear Information System (INIS)

    Kuehl, M.; Boegl, W.; Stockhausen, K.

    1980-01-01

    In this report, results of irradiation experiments at about 30 foodstuffs are compiled and analyzed. The only objective was to obtain a survey of the chemical changes of irradiated foodstuffs; therefore, neither microbiological nor toxicological aspects were considered. The results were taken from the original publications and compiled in a type of dictionary of foodstuffs listing all relevant data for each substance (foodstuff, irradiation conditions, investigation procedures, results etc.) in a defined order. The main radiation source was Co 60, and the doses ranged between 0,006 and 10 Mrad. The investigations were related not only to the effects of irradiation (in some cases using different absorbed doses per foodstuff), but also to the effects of storage after irradiation (for 16 foodstuffs) and the effects of temperature (for 3 foodstuffs). (orig./MG) [de

  20. Effects of regrowth period, season and harvesting frequency on the ...

    African Journals Online (AJOL)

    Effects of regrowth period, season and harvesting frequency on the yield and nutritive value of Chloris gayana in the southern highlands of Tanzania. ... In vitro dry matter digestibility (IVDMD) and metabolisable energy (ME) declined faster with increasing periods of growth in the early than in the late wet season. ME ranged ...