WorldWideScience

Sample records for gamma radiation emitted

  1. Decay Curves and Half-Lives of Gamma-Emitting States from a Study of Prompt Fission Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

    1971-04-15

    Measurements were made on the time distributions of the prompt gamma radiation emitted from fragments in the thermal-neutron induced fission of 235U. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fragments. In this way decay curves were obtained from which half-lives could be estimated. Time components with half-lives of 7.5, 18 and 60 ps were found and their relative intensities were calculated. Half-lives and associated intensities are in good agreement with earlier data from uranium and californium fission. Problems involved in this type of study are discussed. The collimator technique has proved to be effective for determination of half lives down to less than 10 ps

  2. Volatiles emitted from flowers by gamma-radiated and nonradiated Jasminum polyanthum Franch. in situ

    International Nuclear Information System (INIS)

    Christensen, L.P.; Jakobsen, H.B.; Kristiansen, K.; Moller, J.

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%), eugenol (3.5%), 2-methoxy-p-cresol (3.1%), linalool (3.0%), phenethyl acetate (2.1%), and (Z)3-hexenyl butyrate (1.9%). The strong scent of Pepita reduces its production potentialities as a pot plant, thus the possibility to reduce or modify the emission of volatiles from Pepita by mutagenesis was investigated. The average total yields of volatiles in Pepita were approximately 2800 ng flower-1 h-1, and in one gamma-radiated clone a significantly lower yield of 1050 ng flower-1 h-1 was found. The volatile profiles of the gamma-radiated plants were made up of the same 32 compounds found in Pepita. Significant differences in the headspace composition between Pepita and gamma-radiated plants were found for some of the major volatiles

  3. Prompt Gamma Radiation from Fragments in the Thermal Fission of 235U

    International Nuclear Information System (INIS)

    Albinsson, H.; Lindow, L.

    1970-06-01

    Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from 252 Cf-fission. Attention is drawn to some features which seem to be the same in 235 U and 252 Cf-fission

  4. Preliminary results on soil-emitted gamma radiation and its relation with the local atmospheric electric field at Amieira (Portugal)

    International Nuclear Information System (INIS)

    Lopes, F; Barbosa, S M; Silva, H G; Bárias, S

    2015-01-01

    The atmospheric electric field near the Earth's surface is dominated by atmospheric pollutants and natural radioactivity, with the latter directly linked to radon ( 222 Rn) gas. For a better comprehension on the temporal variability of both the atmospheric electric field and the radon concentration and its relation with local atmospheric variables, simultaneous measurements of soil-emitted gamma radiation and potential gradient (defined from the vertical component of the atmospheric electric field) were taken every minute, along with local meteorological parameters (e.g., temperature, atmospheric pressure, relative humidity and daily solar radiation). The study region is Amieira, part of the Alqueva lake in Alentejo Portugal, where an interdisciplinary meteorological campaign, ALEX2014, took place from June to August 2014. Soil gamma radiation is more sensitive to small concentrations of radon as compared with alpha particles measurements, for that reason it is more suited for sites with low radon levels, as expected in this case. Preliminary results are presented here: statistical and spectral analysis show that i) the potential gradient has a stronger daily cycle as compared with the gamma radiation, ii) most of the energy of the gamma signal is concentrated in the low frequencies (close to 0), contrary to the potential gradient that has most of the energy in frequency 1 (daily cycle) and iii) a short-term relation between gamma radiation and the potential gradient has not been found. Future work and plans are also discussed. (paper)

  5. Prompt Gamma Radiation from Fragments in the Thermal Fission of {sup 235}U

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goteborg (Sweden); Lindow, L [AB Atomenergi, Nykoeping (Sweden)

    1970-06-15

    Measurements were made on the gamma radiation emitted from fission fragments in slow neutron induced fission of {sup 235}U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way a decay curve was obtained from which the life-time of one of the gamma-emitting states could be estimated. The relative yield of the gamma-rays was determined as a function of mass for different gamma-ray energy portions and two specific time intervals after the fission events. Comparisons were made with data obtained from {sup 252} Cf-fission. Attention is drawn to some features which seem to be the same in {sup 235}U and {sup 252} Cf-fission.

  6. Ore sorting using natural gamma radiation

    International Nuclear Information System (INIS)

    Clark, G.J.; Dickson, B.L.; Gray, F.E.

    1980-01-01

    A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

  7. Mixed gamma emitting gas standard and method

    International Nuclear Information System (INIS)

    McFarland, R.C.; McFarland, P.A.

    1986-01-01

    The invention in one aspect pertains to a method of calibrating gamma spectroscopy systems for gas counting in a variety of counting containers comprising withdrawing a precision volume of a mixed gamma-emitting gas standard from a precision volume vial and delivering the withdrawn precision volume of the gas standard to the interior of a gas counting container. Another aspect of the invention pertains to a mixed gamma-emitting gas standard, comprising a precision spherical vial of predetermined volume, multiple mixed emitting gas components enclosed within the vial, and means for withdrawing from the vial a predetermined amount of the components wherein the gas standard is used to calibrate a gamma spectrometer system for gas counting over a wide energy range without the use of additional standards. A third aspect comprehends a gamma spectrometer calibration system for gas counting, comprising a precision volume spherical glass vial for receiving mixed multiisotope gas components, and two tubular arms extending from the vial. A ground glass stopcock is positioned on each arm, and the outer end of one arm is provided with a rubber septum port

  8. An improved in situ method for determining depth distributions of gamma-ray emitting radionuclides

    International Nuclear Information System (INIS)

    Benke, R.R.; Kearfott, K.J.

    2001-01-01

    In situ gamma-ray spectrometry determines the quantities of radionuclides in some medium with a portable detector. The main limitation of in situ gamma-ray spectrometry lies in determining the depth distribution of radionuclides. This limitation is addressed by developing an improved in situ method for determining the depth distributions of gamma-ray emitting radionuclides in large area sources. This paper implements a unique collimator design with conventional radiation detection equipment. Cylindrically symmetric collimators were fabricated to allow only those gamma-rays emitted from a selected range of polar angles (measured off the detector axis) to be detected. Positioned with its axis normal to surface of the media, each collimator enables the detection of gamma-rays emitted from a different range of polar angles and preferential depths. Previous in situ methods require a priori knowledge of the depth distribution shape. However, the absolute method presented in this paper determines the depth distribution as a histogram and does not rely on such assumptions. Other advantages over previous in situ methods are that this method only requires a single gamma-ray emission, provides more detailed depth information, and offers a superior ability for characterizing complex depth distributions. Collimated spectrometer measurements of buried area sources demonstrated the ability of the method to yield accurate depth information. Based on the results of actual measurements, this method increases the potential of in situ gamma-ray spectrometry as an independent characterization tool in situations with unknown radionuclide depth distributions

  9. Variation of Neutron Moderating Power on HDPE by Gamma Radiation

    International Nuclear Information System (INIS)

    Park, Kwang June; Ju, June Sik; Kang, Hee Young; Shin, Hee Sung; Kim, Ho Dong

    2009-01-01

    High density polyethylene (HDPE) is degraded due to a radiation-induced oxidation when it is used as a neutron moderator in a neutron counter for a nuclear material accounting of spent fuels. The HDPE exposed to the gamma-ray emitted from the fission products in a spent nuclear fuel results in a radiation-induced degradation which changes its original molecular structure to others. So a neutron moderating power variation of HDPE, irradiated by a gamma radiation, was investigated in this work. Five HDPE moderator structures were exposed to the gamma radiation emitted from a 60 Co source to a level of 10 5 -10 9 rad to compare their post-irradiation properties. As a result of the neutron measurement test with 5 irradiated HDPE structures and a neutron measuring system, it was confirmed that the neutron moderating power for the 105 rad irradiated HDPE moderator revealed the largest decrease when the un-irradiated pure one was used as a reference. It implies that a neutron moderating power variation of HDPE is not directly proportional to the integrated gamma dose rate. To clarify the cause of these changes, some techniques such as a FTIR, an element analysis and a densitometry were employed. As a result of these analyses, it was confirmed that the molecular structure of the gamma irradiated HDPEs had partially changed to others, and the contents of hydrogen and oxygen had varied during the process of a radiation-induced degradation. The mechanism of these changes cannot be explained in detail at present, and thus need further study

  10. Influence of radiation-dose pattern from inhaled beta--gamma-emitting radionuclides on canine peripheral lymphocytes

    International Nuclear Information System (INIS)

    Jones, R.K.; Boecker, B.B.; Pickrell, J.A.; Hobbs, C.H.; McClellan, R.O.

    1976-01-01

    As part of studies assess the biological hazards associated with inhaled radionuclides, periodic hematologic evaluations were performed on beagle dogs given a single nose-only exposure to aerosols of beta--gamma-emitting isotopes. The physical form and specific radionuclides selected produced radiation-dose patterns representative of those which might be encountered in the event of human accidental exposures. Dogs received graded lung burdens of either 90 Y, 91 Y, 144 Ce, or 90 Sr, each in fused clay. Differences in the effective half-lives of these radionuclides resulted in a spectrum of cumulative radiation doses to lung delivered at a variety of dose rates. Since the form in which the radionuclides were inhaled was relatively insoluble, the lung and intrathoracic tissues represented the primary recipient of the dose. Regardless of the effective half-life of radionuclide retention, a dose-related depression of peripheral lymphocytes was observed at various times after inhalation exposure. The time at which maximum depression and subsequent recovery occurred, however, was most directly related to the effective half-life of the radionuclide. Of special interest was the persistence of lymphopenia through 2 1 / 2 years after exposure to 144 Ce and 90 Sr in fused clay where, other than tracheobronchial lymph nodes, the lymphoid tissue received very little radiation dose. The possible mechanisms responsible for lymphocyte depression from these various radiation-dose patterns are discussed

  11. Experimental arrangement for production and use of gamma radiation from neutron capture

    International Nuclear Information System (INIS)

    Mafra, Olga Yajgunovitch

    1969-01-01

    This dissertation presents the main characteristics and construction details of collimator system for gamma radiation emitted by atomic nuclei after capturing thermal neutrons. This construction was made in one of the cross channels of IEAR-1 swimming pool reactor of the Atomic Energy Institute of Sao Paulo, Brazil. The energies of gamma radiation available vary range from about 4 MeV and 11 MeV, discreetly. With this experimental arrangement is obtained: high intensity, good collimation and monochrome gamma radiation, important for conducting experiments with gamma radiation. It is also present in this dissertation the description of the techniques employed in determining the intensity of gamma radiation and the extent of contamination in the neutron beam as well as the program list GAMAU that adjusts the gamma spectrum photopeak taken as a Gaussian curve. We intend to use this experimental arrangement for the measurement of cross sections of photonuclear reactions

  12. Neutron emission from 9Be nucleus under the action of β+ and γ radiation emitted in radioactive decay

    International Nuclear Information System (INIS)

    Vo Dak Bang; Gangrskij, Yu.P.; Miller, M.B.; Mikhajlov, L.V.; Fam Zui Khien; Kharisov, I.F.

    1980-01-01

    The neutron yield from the 9 Be nucleus under the action of beta and gamma-radiation emitted at the radiative decay of 11 C, 62 Cu, 66 Ga, 74 Br isotopes is measured. These isotopes differ essentially by the emitted radiation spectra. The contribution of various processes ((γ, n)-reactions, inelastic scattering and positron nonradiative annihilation) to the neutron yield observed is determined [ru

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

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Javad Mortazavi

    2017-04-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  15. Feasibility Study on Fiber-optic Radiation Sensor for Remote Gamma-ray Spectroscopy

    International Nuclear Information System (INIS)

    Jeon, Hyesu; Jang, Kyoung Won; Shin, Sang Hun and others

    2014-01-01

    In this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors. As a result, the BGO was suitable for the sensing probe of fiber-optic radiation sensor due to its high scintillation output and exact photoelectric peak for the gamma-ray energy. The basic principle of radiation detection is to detect the signals caused by interactions between radiations and materials. There are various types of radiation detectors depending on types of radiation to be detected and physical quantities to be measured. As one of the radiation detectors, a fiber-optic radiation sensor using a scintillator and an optical fiber has two advantages such as no space restraint and remote sensing. Moreover, in nuclear environments, this kind of sensor has immunities for electromagnetic field, temperature, and pressure. Thus, the fiber-optic radiation sensor can be used in various fields including nondestructive inspection, radioactive waste management, nuclear safety, radiodiagnosis and radiation therapy. As a fundamental study of the fiber-optic radiation sensor for remote gamma-ray spectroscopy, in this study, we fabricated a fiber-optic radiation sensor using an optical fiber and various scintillators. To select an adequate inorganic scintillator for the sensing probe of fiber-optic radiation sensor, 5 types of scintillators were evaluated. The spectra of gamma-rays emitted from a Na-22 radiation source were measured by using the manufactured sensors

  16. Propagation speed of {gamma}-radiation in air

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcante, Jose T.P.D.; Silva, Paulo R.J.; Saitovitch, Henrique [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Macedo Junior, Marcelo A.V. [Centro Federal de Educacao Tecnologica de Quimica de Nilopolis (CEFET), RJ (Brazil)

    2008-07-01

    To perform such measurements the availability of a gamma radiation source in which two {gamma}-rays are emitted simultaneously in opposite directions -as already used(5,6) as well as applied in the present case- turns out to be essential to the feasibility of the experiment, as far as no reflection techniques could be used. Such suitable source was the positron emitter {sup 22}Na placed in a metal container in which the positrons are stopped and annihilated when reacting with the medium electrons, in such way originating -as it is very well established from momentum/energy conservation laws(7)- two {gamma}-rays, energy 511 KeV each, both emitted simultaneously in opposite directions. In all these previous experiments were used photomultiplier detectors coupled to NaI(Tl) crystal scintillators, which have a good energy resolution but a deficient time resolution for such purposes. Presently, as an innovatively improvement, were used BaF{sub 2} and CsF crystal scintillators which display a much better time resolution. (author)

  17. Radiation emitting devices act

    International Nuclear Information System (INIS)

    1970-01-01

    This Act, entitled the Radiation Emitting Devices Act, is concerned with the sale and importation of radiation emitting devices. Laws relating to the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of these devices are listed as well as penalties for any person who is convicted of breaking these laws

  18. Radiation emitting devices regulations

    International Nuclear Information System (INIS)

    1970-01-01

    The Radiation Emitting Devices Regulations are the regulations referred to in the Radiation Emitting Devices Act and relate to the operation of devices. They include standards of design and construction, standards of functioning, warning symbol specifications in addition to information relating to the seizure and detention of machines failing to comply with the regulations. The radiation emitting devices consist of the following: television receivers, extra-oral dental x-ray equipment, microwave ovens, baggage inspection x-ray devices, demonstration--type gas discharge devices, photofluorographic x-ray equipment, laser scanners, demonstration lasers, low energy electron microscopes, high intensity mercury vapour discharge lamps, sunlamps, diagnostic x-ray equipment, ultrasound therapy devices, x-ray diffraction equipment, cabinet x-ray equipment and therapeutic x-ray equipment

  19. Automatic control by natural gamma radiation emitted by coal; Control Automatico mediante Radiometria Gamma Natural de la Cenizas de los Carbones

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    Due to the characteristics of its coal and orebody, Monsacro shaft was chosen to host the test. The ash percentage of the different coal seams was carried out by two different methods: Traditional analysis in laboratory. Analysis by means of natural gamma radiation emitted by coal. The following conclusions were obtained after the test: Neither during the mounting nor during the test, a problem was encountered in the working of the radioactive methods. The absolute error between the two methods was minimum. The radioactive analysis is total (this means that the whole coal is analysed) and it is carried out in short period of time. The traditional one is just partial, and could take a few hours to accomplish it. The radioactive one is done in the wagon or in the belt conveyor directly, meanwhile the traditional one needs sample takers permanently. The investment cost of the radioactivity method is amortized within two years. (Author)

  20. Recombining plasma in the gamma-ray-emitting mixed-morphology supernova remnant 3C 391

    Energy Technology Data Exchange (ETDEWEB)

    Ergin, T.; Sezer, A. [TUBITAK Space Technologies Research Institute, ODTU Campus, 06531 Ankara (Turkey); Saha, L.; Majumdar, P.; Chatterjee, A. [Saha Institute of Nuclear Physics, Kolkata, West Bengal 700064 (India); Bayirli, A.; Ercan, E. N., E-mail: tulun.ergin@tubitak.gov.tr [Physics Department, Bogazici University, Bebek, 34342 Istanbul (Turkey)

    2014-07-20

    A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MCs) has been discovered to be strong GeV gamma-ray emitters by the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope (Fermi-LAT). The recent observations of the Suzaku X-ray satellite have revealed that some of these interacting gamma-ray-emitting SNRs, such as IC443, W49B, W44, and G359.1-0.5, have overionized plasmas. 3C 391 (G31.9+0.0) is another Galactic MM SNR interacting with MCs. It was observed in GeV gamma rays by Fermi-LAT as well as in the 0.3-10.0 keV X-ray band by Suzaku. In this work, 3C 391 was detected in GeV gamma rays with a significance of ∼18σ and we showed that the GeV emission is point-like in nature. The GeV gamma-ray spectrum was shown to be best explained by the decay of neutral pions assuming that the protons follow a broken power-law distribution. We revealed radiative recombination structures of silicon and sulfur from 3C 391 using Suzaku data. In this paper, we discuss the possible origin of this type of radiative plasma and hadronic gamma rays.

  1. The secondary biogenic radiation of gamma-irradiated human blood

    International Nuclear Information System (INIS)

    Kuzin, A.M.; Surkenova, G.N.; Budagovskij, A.V.; Gudi, G.A.

    1997-01-01

    The sample of blood freshly taken from healthy men were gamma-irradiated with a dose of 10 Gy. It was shown that after the treatment the blood gained the capacity to emit secondary biogenic radiation. Emission lasted for some hours, passed through quartz-glass curette and was revealed by stimulating influence on biological detector (sprouting seeds)

  2. Multiplicity and correlated energy of gamma rays emitted in the spontaneous fission of Californium-252

    International Nuclear Information System (INIS)

    Brunson, G.S. Jr.

    1982-06-01

    An array of eight high-speed plastic scintillation detectors has been used to infer a mathematical model for the emission multipliciy of prompt gammas in the spontaneous fission of 252 Cf. Exceptional time resolution and coincidence capability permitted the separation of gammas from fast neutrons over a flight path of approximately 10 cm. About 20 different distribution models were tested. The average energy of the prompt gammas is inversely related to the number emitted; however, this inverse relationship is not strong and the total gamma energy does increase with increasing gamma number. An extension of the experiment incorporated a lithium-drifted germanium gamma spectrometer that resolved nearly 100 discrete gammas associated with fission. Of these gammas, some were preferentially associated with fission in which few gammas were emitted. Certain others were more frequent when many gammas were emitted. Results are presented

  3. Field Deployable Gamma Radiation Detectors for DHS Use

    Energy Technology Data Exchange (ETDEWEB)

    Sanjoy Mukhopadhyay

    2007-08-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER{trademark}, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack{trademark} that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant

  4. Field Deployable Gamma Radiation Detectors for DHS Use

    International Nuclear Information System (INIS)

    Sanjoy Mukhopadhyay

    2007-01-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER(trademark), which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack(trademark) that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant

  5. Effects of 60Co gamma radiation on crotamine

    Directory of Open Access Journals (Sweden)

    Boni-Mitake M.

    2001-01-01

    Full Text Available Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (pI 10.3 from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (LD50. Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3%, but did not eliminate it.

  6. SEARCHING FOR OVERIONIZED PLASMA IN THE GAMMA-RAY-EMITTING SUPERNOVA REMNANT G349.7+0.2

    Energy Technology Data Exchange (ETDEWEB)

    Ergin, T.; Sezer, A. [TUBITAK Space Technologies Research Institute, ODTU Campus, 06531, Ankara (Turkey); Saha, L.; Majumdar, P. [Saha Institute of Nuclear Physics, Kolkata, West Bengal 700064 (India); Gök, F. [Akdeniz University, Faculty of Education, Department of Secondary Science and Mathematics Education, Antalya, 07058 (Turkey); Ercan, E. N., E-mail: tulun.ergin@tubitak.gov.tr [Bogazici University, Physics Department, Bebek, 34342, Istanbul (Turkey)

    2015-05-10

    G349.7+0.2 is a supernova remnant (SNR) expanding in a dense medium of molecular clouds and interacting with clumps of molecular material emitting gamma-rays. We analyzed the gamma-ray data of the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope and detected G349.7+0.2 in the energy range of 0.2–300 GeV with a significance of ∼13σ, showing no extended morphology. Modeling of the gamma-ray spectrum revealed that the GeV gamma-ray emission dominantly originates from the decay of neutral pions, where the protons follow a broken power-law distribution with a spectral break at ∼12 GeV. To search for features of radiative recombination continua in the eastern and western regions of the remnant, we analyzed the Suzaku data of G349.7+0.2 and found no evidence for overionized plasma. In this paper, we discuss possible scenarios to explain the hadronic gamma-ray emission in G349.7+0.2 and the mixed morphology nature of this SNR.

  7. Continuous weighing of conveyor-transported materials based on gamma radiation conversion to electric current

    International Nuclear Information System (INIS)

    The principle is described of the continuous weighing of conveyer-transported materials applied in the food industry. The weighing technique is based on the measurement of the absorption of gamma radiation emitted by a source located behind the material to be scaled. (Z.M.)

  8. Effects of {sup 60} Co gamma radiation on crotamine

    Energy Technology Data Exchange (ETDEWEB)

    Boni-Mitake, M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Radioprotecao Ocupacional; Costa, H.; Spencer, P.J. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Dept. de Bioengenharia; Rogero, J.R [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Diretoria de Materiais; Vassilieff, V.S. [UNESP, Botucatu, SP (Brazil). Instituto de Biociencias. Ceatox - Centro de Assistencia Toxicologica]. E-mail: mbmitake@net.ipen.br

    2001-12-01

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide (p I 10.3) from Crotalus durissus terrificus venom composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of the present study was to carry out a biochemical study and a toxic activity assay on native and irradiated crotamine. Crotamine was purified from C.d. terrificus venom by Sephadex G-100 gel filtration followed by ion-exchange chromatography, and irradiated at 2 mg/ml in 0.15 M NaCl with 2.0 kGy gamma radiation emitted by a 60 Co source. The native and irradiated toxins were evaluated in terms of structure and toxic activity (Ld50). Irradiation did not change the protein concentration, the electrophoretic profile or the primary structure of the protein although differences were shown by spectroscopic techniques. Gamma radiation reduced crotamine toxicity by 48.3%, but did not eliminate it. (author)

  9. Gamma radiation a help to archeological woods

    International Nuclear Information System (INIS)

    Balibar, F.

    1981-01-01

    Waterlogged archeological wood falls into dust once extracted from the water. In order to prevent this destruction several processes have been thought up. In France, the Grenoble Nuclear Study Centre has developed a method of consolidation by resin impregnation and gamma irradiation. The object is first immersed in a vessel containing liquid resin which spreads throughout the wood thereby driving off the water. During the second stage of the treatment, the impregnated objects are irradiated by gamma radiation emitted by a rectangular grid of cobalt 60, so as to polymerize the resin inside the wood. The irradiated objects are Gallo-Roman statuettes discovered during digs at the sources of the river Seine. The wood consolidated right through to the core then becomes sufficiently solid for the restorer to work on the surface of these objects [fr

  10. Energy–angle correlation of neutrons and gamma-rays emitted from an HEU source

    Energy Technology Data Exchange (ETDEWEB)

    Miloshevsky, G., E-mail: gennady@purdue.edu; Hassanein, A.

    2014-06-01

    Special Nuclear Materials (SNM) yield very unique fission signatures, namely correlated neutrons and gamma-rays. A major challenge is not only to detect, but also to rapidly identify and recognize SNM with certainty. Accounting for particle multiplicity and correlations is one of standard ways to detect SNM. However, many parameter data such as joint distributions of energy, angle, lifetime, and multiplicity of neutrons and gamma-rays can lead to better recognition of SNM signatures in the background radiation noise. These joint distributions are not well understood. The Monte Carlo simulations of the transport of neutrons and gamma-rays produced from spontaneous and interrogation-induced fission of SNM are carried out using the developed MONSOL computer code. The energy spectra of neutrons and gamma-rays from a bare Highly Enriched Uranium (HEU) source are investigated. The energy spectrum of gamma-rays shows spectral lines by which HEU isotopes can be identified, while those of neutrons do not show any characteristic lines. The joint probability density function (JPDF) of the energy–angle association of neutrons and gamma-rays is constructed. Marginal probability density functions (MPDFs) of energy and angle are derived from JPDF. A probabilistic model is developed for the analysis of JPDF and MPDFs. This probabilistic model is used to evaluate mean values, standard deviations, covariance and correlation between the energy and angle of neutrons and gamma-rays emitted from the HEU source. For both neutrons and gamma-rays, it is found that the energy–angle variables are only weakly correlated.

  11. Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

    International Nuclear Information System (INIS)

    Arrieta-Lobo, Maialen; Boisson, Catherine; Zech, Andreas

    2017-01-01

    Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert 1 (NLSy1) galaxies has put them on the spotlight as a new class of gamma-ray emitting AGN. In this respect, gamma-ray emitting NLSy1s seem to be situated between blazars (dominated by non-thermal emission) and Seyferts (accretion disc dominated). In this work, we model the Spectral Energy Distribution (SED) of two gamma-loud NLSy1s, 1H 0323+342 and B2 0954+25A, during quiescent and flaring episodes via a multi-component radiative model that features a relativistic jet and external photon fields from the torus, disc, corona and Broad Line Region (BLR). We find that the interpretation of the high-energy emission of jetted NLSy1s requires taking into account Inverse Compton emission from particles in the relativistic jet that interact with external photon fields. Minimal changes are applied to the model parameters to transition from average to flaring states. In this scenario, the observed variability is explained mainly by means of changes in the jet density and Doppler factor.

  12. Modeling the Broad-Band Emission from the Gamma-Ray Emitting Narrow-Line Seyfert-1 Galaxies 1H 0323+342 and B2 0954+25A

    Energy Technology Data Exchange (ETDEWEB)

    Arrieta-Lobo, Maialen; Boisson, Catherine; Zech, Andreas, E-mail: maialen.arrieta@obspm.fr [Laboratoire Univers et Theories, Observatoire de Paris, CNRS, Université Paris-Diderot, PSL Research University, Meudon (France)

    2017-12-08

    Prior to the Fermi-LAT era, only two classes of Active Galactic Nuclei (AGN) were thought to harbor relativistic jets that radiate up to gamma-ray energies: blazars and radio galaxies. The detection of variable gamma-ray emission from Narrow Line Seyfert 1 (NLSy1) galaxies has put them on the spotlight as a new class of gamma-ray emitting AGN. In this respect, gamma-ray emitting NLSy1s seem to be situated between blazars (dominated by non-thermal emission) and Seyferts (accretion disc dominated). In this work, we model the Spectral Energy Distribution (SED) of two gamma-loud NLSy1s, 1H 0323+342 and B2 0954+25A, during quiescent and flaring episodes via a multi-component radiative model that features a relativistic jet and external photon fields from the torus, disc, corona and Broad Line Region (BLR). We find that the interpretation of the high-energy emission of jetted NLSy1s requires taking into account Inverse Compton emission from particles in the relativistic jet that interact with external photon fields. Minimal changes are applied to the model parameters to transition from average to flaring states. In this scenario, the observed variability is explained mainly by means of changes in the jet density and Doppler factor.

  13. Some problems of the detection of the high energy gamma-radiation in space

    Science.gov (United States)

    Fradkin, M. I.; Ginzburg, V. L.; Kurnosova, L. V.; Labensky, A. G.; Razorenov, L. A.; Rusakovich, M. A.; Topchiev, N. P.; Kaplin, V. A.; Runtso, M. F.; Gorchakov, E. V.; Ignatiev, P. P.

    1995-05-01

    Diffuse gamma radiation in the Galaxy has been measured with instruments onboard the COS-B and Compton Gamma Ray Observatory (CGRO) satellites from the tens of keV up to about 30 GeV. There is no experimental data at higher energies, but this data is very important for the spectrum of primary cosmic rays and the existence of neutralinos (hypothetical supersymmetrical particles which are supposed to constitute dark matter in the Galaxy and create gamma-quanta in the process of annihilation). The GAMMA-400 collaboration is working on the design of a telescope for gamma-ray measurements in the 10-1000 GeV range. The electronics of the GAMMA-400 eliminate some hindering effects, in particular the influence of backscattered gammas emitted by the very massive calorimeter (calorimeter albedo). The GAMMA-400 project may be realized in the near future if economic conditions in Russia are favorable.

  14. Gamma response study of radiation sensitive MOSFETs for their use as gamma radiation sensor

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Saurabh; Kumar, A. Vinod [Radiation Safety Systems Division, Bhabha Atomic Research Centre, Mumbai (India); Aggarwal, Bharti; Singh, Arvind; Topkar, Anita, E-mail: anita@barc.gov.in [Electronics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2016-05-23

    Continuous monitoring of gamma dose is important in various fields like radiation therapy, space-related research, nuclear energy programs and high energy physics experiment facilities. The present work is focused on utilization of radiation-sensitive Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) to monitor gamma radiation doses. Static characterization of these detectors was performed to check their expected current-voltage relationship. Threshold voltage and transconductance per unit gate to source voltage (K factor) were calculated from the experimental data. The detector was exposed to gamma radiation in both, with and without gate bias voltage conditions, and change in threshold voltage was monitored at different gamma doses. The experimental data was fitted to obtain equation for dependence of threshold voltage on gamma dose. More than ten times increase in sensitivity was observed in biased condition (+3 V) compared to the unbiased case.

  15. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde, Raymond Keegan

    2008-07-01

    The countrate response of a gamma spectrometry system from a neutron radiation source behind a plane of moderating material doped with a nuclide of a large radiative neutron capture cross-section exhibits a countrate response analogous to a gamma radiation source at the same position from the detector. Using a planar, surface area of the neutron moderating material exposed to the neutron radiation produces a larger area under the prompt gamma ray peak in the detector than a smaller area of dimensions relative to the active volume of the gamma detection system.

  16. Energy spectrum of lightning gamma emission

    Energy Technology Data Exchange (ETDEWEB)

    Chubenko, A.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Karashtin, A.N. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Ryabov, V.A., E-mail: ryabov@x4u.lebedev.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shepetov, A.L. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Antonova, V.P.; Kryukov, S.V. [Ionosphere Institute, Almaty (Kazakhstan); Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Ptitsyn, M.O., E-mail: ptitsyn@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shalamova, S.Ya. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Shlyugaev, Yu.V. [Research Radiophysics Institute, Nizhny Novgorod (Russian Federation); Vildanova, L.I. [Tien-Shan Mountain Cosmic Ray Station, Almaty (Kazakhstan); Zybin, K.P. [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation); Gurevich, A.V., E-mail: alex@lpi.r [P.N. Lebedev Physical Institute of RAS, Moscow (Russian Federation)

    2009-08-10

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10{sup -3}-10{sup -2} J. The experimental results are in an agreement with the runaway breakdown mechanism.

  17. Energy spectrum of lightning gamma emission

    International Nuclear Information System (INIS)

    Chubenko, A.P.; Karashtin, A.N.; Ryabov, V.A.; Shepetov, A.L.; Antonova, V.P.; Kryukov, S.V.; Mitko, G.G.; Naumov, A.S.; Pavljuchenko, L.V.; Ptitsyn, M.O.; Shalamova, S.Ya.; Shlyugaev, Yu.V.; Vildanova, L.I.; Zybin, K.P.; Gurevich, A.V.

    2009-01-01

    The results of gamma emission observations obtained during thunderstorms at Tien-Shan Mountain Cosmic Ray Station are presented. The energy spectrum radiation of the stepped leader gamma radiation is measured. The total energy of stepped leader emitted in gamma rays is estimated as 10 -3 -10 -2 J. The experimental results are in an agreement with the runaway breakdown mechanism.

  18. Procedure for the elaboration of extended sources beta and/or gamma emitting

    International Nuclear Information System (INIS)

    Tejera R, A.; Cortes P, A.; Becerril V, A.

    1991-12-01

    In the laboratory of radioactive standards they have been come manufacturing punctual sources gauged gamma emitting during several years. Before the demand of extended radioactive homogeneous sources of beta particles emitting, in particular with nuclides that are simultaneously gamma and beta emitting, it was designed a procedure for it elaboration based on the one that we use at the moment for the elaboration of the punctual gamma sources. This procedure consists on the integration of a compact group of this type of sources on a single extended support, sealed one of its faces with a film of transparent material in satisfactory grade to the beta particles. In this work this procedure is described and it is applied in the elaboration of two sources that its were requested by the Laguna Verde Central (CFE), one with area of 20 cm 2 and the other one of 100 cm 2 . The homogeneity, measure as the dispersion of the activities of the aliquot ones distributed in the active surfaces was inside 2%. The percentage of attenuation of the beta particles was also measured by the film (window) with the one that the sources were sealed. (Author)

  19. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere

    International Nuclear Information System (INIS)

    Boclet, D.

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [fr

  20. SOR/72-43 Radiation Emitting Devices Regulations

    International Nuclear Information System (INIS)

    1972-01-01

    These Regulations of 10 February 1972, supplemented by SOR/77-895, lay down the classes of radiation emitting devices for the purposes of the Radiation Emitting Devices Act. They lay down their standards of design and construction and warning sign specifications and provide for the procedure to be followed by inspectors of such devices. The devices include inter alia extra-oral dental x-ray equipment, baggage inspection x-ray devices, laser scanners, television receivers. (NEA)

  1. ''Strong gammas''. List of strong gamma-rays emitted from radionuclides. Documentation of the PC diskette

    International Nuclear Information System (INIS)

    Ichimiya, T.; Narita, T.; Kitao, K.

    1994-01-01

    The PC diskette containing the ''List of strong gamma-rays emitted from radionuclides'' as published by T. Narita et al. in the report JAERI-M-94-059, March 1994, is described. The diskette is available from the IAEA Nuclear Data Section, costfree, upon request. (author)

  2. Yield of Prompt Gamma Radiation in Slow-Neutron Induced Fission of 235U as a Function of the Total Fragment Kinetic Energy

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

    1971-07-01

    Fission gamma radiation yields as functions of the total fragment kinetic energy were obtained for 235U thermal-neutron induced fission. The fragments were detected with silicon surface-barrier detectors and the gamma radiation with a Nal(Tl) scintillator. In some of the measurements mass selection was used so that the gamma radiation could also be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. Fission-neutron and gamma-ray data of previous experiments were used for comparisons of the yields, and estimates were made of the variation of the prompt gamma-ray energy with the total fragment kinetic energy

  3. Radiation-emitting Electronic Product Codes

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database contains product names and associated information developed by the Center for all products, both medical and non-medical, which emit radiation. It...

  4. The distribution and abundance of gamma emitting radionuclides in Lake Ontario sediments

    International Nuclear Information System (INIS)

    McKinley, R.S.

    1985-03-01

    The distribution of gamma emitting radionuclides in Lake Ontario sediments was investigated. Samples were collected using a systematic design in the vicinity of Pickering and Darlington, and supplemented by lakewide offshore samples. Naturally occurring 40 K was the predominant source of gamma activity. 60 Co was the only potentially CANDU released radionuclide which showed a distributional association with the Pickering 'A' NGS discharge

  5. A rotating-slit-collimator-based gamma radiation mapper.

    Science.gov (United States)

    Nilsson, Jonas M C; Finck, Robert R; Rääf, Christopher L

    2017-10-01

    For situations with radioactive material out of control where it may be physically difficult or prohibited to access areas close to the source, measurements from distance may be the only way to assess the radiation environment. Using collimated detectors will provide means to locate the direction of the radiation from the source. To investigate the possibilities of mapping gamma emitting radioactive material in a closed non-enterable area, a tentative system for mapping radioactive materials from a distance was built. The system used a computer controlled cylindrical rotating slit collimator with a high purity germanium detector placed in the cylinder. The system could be placed on a car-towed trailer, with the centre of the detector about 1.4 m above ground. Mapping was accomplished by the use of a specially developed image reconstruction algorithm that requires measurements from two or more locations around the area to be investigated. The imaging capability of the system was tested by mapping an area, 25 by 25 m 2 , containing three 330 MBq 137 Cs point sources. Using four locations outside the area with about 20 min measuring time in each location and applying the image reconstruction algorithm on the deconvoluted data, the system indicated the three source locations with an uncertainty of 1-3 m. The results demonstrated the potential of using collimated mobile gamma radiometry combined with image reconstruction to localize gamma sources inside non-accessible areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Astrophysical applications of Delbrück scattering: Dust scattered gamma radiation from gamma ray bursts

    International Nuclear Information System (INIS)

    Kunwar, B.; Bhadra, A.; Gupta, S.K. Sen

    2014-01-01

    A preliminary, and perhaps the first, study of astrophysical applications of Delbrück scattering in a gamma-ray emitting celestial object like a gamma-ray burst (GRB) has been made. At energies≥100 MeV the elastic scattering of gamma-ray photons off the molecular dust surrounding the GRB site is dominated by Delbrück scattering. Expressions for Delbrück-scattered gamma-ray flux as a function of time has been obtained for a few selected energies by assuming a simple model of GRB. These are compared with Compton-scattered flux. At certain situations, interestingly, the former is found to exceed the latter for the first few milliseconds of the burst. The issue of detectability of Delbrück-scattered gamma-ray echo from the cloud of a GRB is discussed. Although it is observed that the detection of such an echo is not within the capability of the presently operating gamma-ray missions such as Fermi LAT, a rough estimate shows that one can be optimistic that future generation gamma-ray telescopes might be able to see such photons' contribution to the total flux. - Highlights: ► Astrophysical application of Delbrück scattering in a GRB has been made. ► Initially, the Delbrück scattering may dominate the scattering of GeV γ-rays. ► The issue of detectability of such radiations is discussed

  7. Tunable radiation emitting semiconductor device

    NARCIS (Netherlands)

    2009-01-01

    A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

  8. Iron influence in self-attenuation of gamma radiation in sand samples

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Reginaldo R.; Cavalcante, Fernanda; Pecequilo, Brigitte R.S, E-mail: raquino@ipen.br, E-mail: fcavalcante@ipen.br, E-mail: brigitte@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Self-attenuation of gamma rays are usually observed in sand samples, due to the presence of iron particles of natural or anthropogenic causes, which may lead to misleading activities concentrations results. As iron atoms are often present in sand samples, the self-attenuation contribution from this mineral requires special attention when assessing sand samples radioactivity. This contributions in verified in the in the present study, using several silica (sand-like) samples doped with different concentrations of iron. The samples were arranged with pure SiO{sub 4} (98,9%) mineral from the region of Setiba, (Espirito Santo state, Brazil) and Itabirito mineral, from Itabira (Minas Gerais state, Brazil), using standard 100 mL high density polyethylene (HDPE) flat-botton cylindrical flasks, each sealed using a 52.5 mm plan screw cap and bubble spigot. Three samples were arranged in different concentrations - Fe 25% and SiO{sub 4} 75%; Fe 50% and SiO{sub 4} 50%; Fe 75% and SiO{sub 4} 25% and two other samples were assembled in the same geometry, using 100% SiO{sub 4} and 100% Fe. These samples were exposed to a large spectrum of gamma radiation (121 keV to 1408 keV) emitted by sources of {sup 60}Co, {sup 137}Cs and {sup 152}Eu. These gamma radiations were collimated and directed over the doped samples in a high resolution gamma ray spectrometer, whose spectra were analyzed with the Winner Gamma software. The matrix effect intensity is inferred by the percentage differences observed in varying the iron concentration that proved to be more intense for lower energy radiation. (author)

  9. Device for characterization of fissile materials comprising at least a neutron detector embedded inside a scintillator for gamma radiation detection

    International Nuclear Information System (INIS)

    Bernard, P.; Dherbey, J.R.; Bosser, R.; Berne, R.

    1989-01-01

    Fissile materials, for instance in radioactive wastes, are characterized by measurement of prompt and delayed neutrons and gamma radiation from induced fission by a neutron source. Gamma radiation is detected with a scintillation detector associated to a photomultiplier, the scintillation material is at the same time a moderator for thermalization of fast neutrons emitted by the neutron source and also of neutrons from spontaneous fission, (α, n) reactions and neutrons from induced fission in the fissile material. Preferentially the moderator is made of Altustipe (Plexiglas with anthracene as additive) [fr

  10. Gamma-ray detection with an UV-enhanced photodiode and scintillation crystals emitting at short wavelengths

    International Nuclear Information System (INIS)

    Johansen, G.A.

    1997-01-01

    A low-noise ion implanted photodiode with high spectral response in the deep blue/UV region has been tested as read-out device for scintillation crystals with matching emission spectra (YAP(Ce), GSO(Ce), BGO and CsI(Tl)). This gamma-ray detector concept is attractive in many industrial applications where compactness, reliability and ambient temperature operation are important. The results show that the amount of detected scintillation light energy falls rapidly off as the wavelength of the scintillation light decreases. It is concluded that the dynamic spectral response of the photodiode, due to increasing carrier collection times, is considerably less than the DC response at short wavelengths. The diode is not useful in pulse mode operation with scintillation crystals emitting at wavelengths below about 400 nm. For read-out of CsI(Tl) with 661.6 keV gamma-radiation, however, the photodiode concept shows better energy resolution (7.1%) than other detectors. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

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

  12. gamma. radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Curie, I

    1948-12-08

    Following the work of Ward (Proc Cambridge Phil Soc 35 322(1939)), the ..gamma..-radiation of ionium (from an IoTh preparation) was studied with the aid of Ta and W screens, and an aluminum counter. The screen measurements confirmed Ward's findings of two radiations, of 68 keV and of about 200 keV. The number of quanta per second of each radiation was determined with the counter, which has been calibrated on certain L lines of radium. The global quanta number of L lines of ionium was also determined. The results were as follows: 0.7 quanta ..gamma.. of 68 keV for 100 ..cap alpha..-particles; 0.2 quanta ..gamma.. of 200 keV for 100 ..cap alpha..-particles; 10 quanta L for 100 ..cap alpha..-particles. These data, which show an important internal conversion, agree with the findings of Teillac (Compt Rend 227 1227 (1948)), who investigated the ..beta..-radiation of ionium. It is the radiation 68 keV which is highly converted. On the other hand, these results do no agree with the data on the fine structure of ionium found by Rosenblum, Valadares, and Vial (Compt Rend 227 1088(1948)).

  13. Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

    Energy Technology Data Exchange (ETDEWEB)

    Albinsson, H [Chalmers Univ. of Technology, Goeteborg (SE)

    1971-04-15

    Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

  14. Energies and Yields of Prompt Gamma Rays from Fragments in Slow-Neutron Induced Fission of 235U

    International Nuclear Information System (INIS)

    Albinsson, H.

    1971-04-01

    Measurements were made on the gamma radiation emitted from fission fragments in slow-neutron induced fission of 235 U. The fragments were detected with solid state detectors of the surface barrier type and the gamma radiation with a Nal(Tl) scintillator. Mass selection was used so that the gamma radiation could be measured as a function of fragment mass. Time discrimination between the fission gammas and the prompt neutrons released in the fission process was employed to reduce the background. The gamma radiation emitted during different time intervals after the fission event was studied with the help of a collimator, the position of which was changed along the path of the fission fragments. In this way it was possible to select various collimator settings and let gamma radiation of different half-lives be enhanced. Gamma-ray energy spectra from these time components were then recorded as function of mass. The spectrum shape differed greatly depending on the half-life of the radiation and the fragment from which it was emitted. The results of the present measurements were discussed in the light of existing fission models, and comparisons were made with prompt gamma-ray and neutron data from other fission experiments

  15. Metrological aspects of radiochemical methods for determining activity of gamma-emitting nuclides

    International Nuclear Information System (INIS)

    Shcherbakov, B.Y.

    1986-01-01

    The author considers the problem of metrological compatibility of the two stages in the radiochemical method of determining the activity of a gamma-emitting nuclide: chemical isolation of the nuclide and radiometric measurement of its activity. The authors show that preparation of the specimen in liquid form provides for important advantages compared with the traditional application of the solid residue onto a flat substate. The work here is of interest for analytical chemists who are involved with determination of the activity of gamma emitting nuclides such as Ru 103, Rh 106, Sn 113, Cs 134, Cs 137, La 140, Ce 141, Ce 144, Hg 203, Na 24, Mn 54, Fe 59, Co 60, Zn 65, Zr 95, and Nb 95, for example, in waste water or in emissions to the atmosphere, with the goal of protecting the environment

  16. Project Marna Natural Gamma Radiation MAP

    International Nuclear Information System (INIS)

    Suarez, E.; Fernandez, J.A.

    1997-01-01

    The confusion created by the accident that occurred in one of the Chernobyl reactors in April of 1986 made the general public and governments aware of the need for improved monitoring of environmental radiation levels. The levels of total gamma radiation or total gamma exposure rate over large areas reached values as high as 400 micro Roentgen/hour (mu R/h) and at points exceeded 1000 mu R/h. It should be borne in mind that, depending on the type of geological formations, normal values range from 5 to 30 mu R/h. The IAEA recommended to all countries that natural gamma radiation maps be made available to evaluate the levels of natural gamma radiation and possible increases, and it also indicated its concern that information be standardized. In addition, it stressed the advisability of using data obtained from uranium prospecting. (Author)

  17. Gamma irradiators for radiation processing

    International Nuclear Information System (INIS)

    2006-01-01

    Radiation technology is one of the most important fields which the IAEA supports and promotes, and has several programmes that facilitate its use in the developing Member States. In view of this mandate, this Booklet on 'Gamma Irradiators for Radiation Processing' is prepared which describes variety of gamma irradiators that can be used for radiation processing applications. It is intended to present description of general principles of design and operation of the gamma irradiators available currently for industrial use. It aims at providing information to industrial end users to familiarise them with the technology, with the hope that the information contained here would assist them in selecting the most optimum irradiator for their needs. Correct selection affects not only the ease of operation but also yields higher efficiency, and thus improved economy. The Booklet is also intended for promoting radiation processing in general to governments and general public

  18. Natural gamma ray spectrum analysis technique

    International Nuclear Information System (INIS)

    Chevalier, P.; Seeman, B.

    1976-01-01

    In accordance with an illustrative embodiment of the present invention, a method and apparatus is disclosed for determining the presence of a selected number of naturally radioactive materials in an earth formation from the spectrum of natural gamma radiation emitted by the materials in the formation by deriving representations of portions of the detected gamma radiation spectrum and combining the representations to determine therefrom the presence of the selected materials

  19. Localization of the gamma-radiation sources using the gamma-visor

    Directory of Open Access Journals (Sweden)

    Ivanov Kirill E.

    2008-01-01

    Full Text Available The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehabilitation procedures allowed localizing the new gamma-source.

  20. Localization of the gamma-radiation sources using the gamma-visor

    International Nuclear Information System (INIS)

    Ivanov, K. E.; Ponomaryev-Stepnoi, N. N.; Stepennov, B. S.; Teterin, Y. A.; Teterin, A. Y.; Kharitonov, V. V.

    2008-01-01

    The search of the main gamma-radiation sources at the site of the temporary storage of solid radioactive wastes was carried out. The relative absorbed dose rates were measured for some of the gamma-sources before and after the rehabilitation procedures. The effectiveness of the rehabilitation procedures in the years 2006-2007 was evaluated qualitatively and quantitatively. The decrease of radiation background at the site of the temporary storage of the solid radioactive wastes after the rehabilitation procedures al lowed localizing the new gamma-source. (author)

  1. Observation of galactic gamma radiation

    International Nuclear Information System (INIS)

    Paul, J.A.

    1982-09-01

    A complete and deep survey of the galactic high-energy gamma radiation is now available, thanks to the gamma-ray telescopes on board of the SAS-2 and COS-B spacecrafts. A comparison of the COS-B gamma-ray survey with a fully sampled CO survey together with an Hsub(I) survey is used to show that a simple model, in which uniformly distributed cosmic rays interact with the interstellar gas, can account for almost all the gamma-ray emission observed in the first galactic quadrant. At medium galactic latitudes, it is shown that a relationship exists between the gamma radiation and the interstellar absorption derived from galaxy counts. Therefore gamma rays from the local galactic environment can be used as a valuable probe of the content and structure of the local interstellar medium. The large scale features of the local interstellar gas are revealed, in particular wide concentrations of nearby molecular hydrogen. On a smaller scale, the detection of numerous localized gamma-ray sources focuses the attention on some particular phases of clusters of young and massive stars where diffuse processes of gamma-ray emission may also be at work

  2. SGR-76 gamma radiation level indicator

    International Nuclear Information System (INIS)

    Chubinskij-Nadezhdin, I.V.

    1978-01-01

    The design of a gamma-radiation level indicator is described; the instrument is part of a mobile radiometric laboratory (MRL). The design of the instrument permits gamma-radiation dose rates recording at 0.2-200 R/hr, and signals on gamma-background levels. The instrument has two separate threshold levels of signalling actuation. The light signalling at the first level is precautionary, and the sound signalling at the second level indicates the necessity of taking a decision as to whether or not the MRL can remain in the gamma-radiation field. Halogenic counters operating in a current mode are used as detectors. The basic error in recording the dose rate amounts to +-25%. Overall dimensions of the instrument 150x280x100 mm; weight less than 2.5 kg

  3. Calculation of the gamma-dose rate from a continuously emitted plume

    International Nuclear Information System (INIS)

    Huebschmann, W.; Papadopoulos, D.

    1975-06-01

    A computer model is presented which calculates the long term gamma dose rate caused by the radioactive off-gas continuously emitted from a stack. The statistical distribution of the wind direction and velocity and of the stability categories is taken into account. The emitted activity, distributed in the atmosphere according to this statistics, is assumed to be concentrated at the mesh points of a three-dimensional grid. The grid spacing and the integration limits determine the accuracy as well as the computer time needed. When calculating the dose rate in a given wind direction, the contribution of the activity emitted into the neighbouring sectors is evaluated. This influence is demonstrated in the results, which are calculated with a error below 3% and compared to the dose rate distribution curves of the submersion model and the model developed by K.J. Vogt. (orig.) [de

  4. Radiation Emitting Product Corrective Actions and Recalls

    Data.gov (United States)

    U.S. Department of Health & Human Services — This database provides descriptions of radiation-emitting products that have been recalled under an approved corrective action plan to remove defective and...

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  6. Gamma radiation shielding analysis of lead-flyash concretes

    International Nuclear Information System (INIS)

    Singh, Kanwaldeep; Singh, Sukhpal; Dhaliwal, A.S.; Singh, Gurmel

    2015-01-01

    Six samples of lead-flyash concrete were prepared with lead as an admixture and by varying flyash content – 0%, 20%, 30%, 40%, 50% and 60% (by weight) by replacing cement and keeping constant w/c ratio. Different gamma radiation interaction parameters used for radiation shielding design were computed theoretically and measured experimentally at 662 keV, 1173 keV and 1332 keV gamma radiation energy using narrow transmission geometry. The obtained results were compared with ordinary-flyash concretes. The radiation exposure rate of gamma radiation sources used was determined with and without lead-flyash concretes. - Highlights: • Concrete samples with lead as admixture were casted with flyash replacing 0%, 20%, 30%, 40%, 50% and 60% of cement content (by weight). • Gamma radiation shielding parameters of concretes for different gamma ray sources were measured. • The attenuation results of lead-flyash concretes were compared with the results of ordinary flyash concretes

  7. Environmental Gamma Radiation Measurements in Baskil District

    International Nuclear Information System (INIS)

    Canbazoglu, C.

    2008-01-01

    In this study, we have determined environmental gamma radiation dose rate in Baskil district which has very high granite content in its geographical structure. Gamma radiation dose rate measurements were achieved by portable radiation monitoring equipment based on the energy range between 40 keV and 1.3 MeV. The measurements were performed on asphalt and soil surface level and also one meter above the ground surface. The gamma dose rate was also performed inside and outside of buildings over the district. The dose rates were found to be between 8.46μR/h and 34.66 μR/h. Indoor and outdoor effective dose rate of the gamma radiation exposure has been calculated to be 523μSv/y and 196μSv/y, respectively

  8. Investigation of epigenetic gene regulation in Arabidopsis modulated by gamma radiation

    International Nuclear Information System (INIS)

    Woo, Hye Ryun; Kim, Jae Sung; Lee, Myung Jin; Lee, Dong Joon; Kim, Young Min; Jung, Joon Yong; Han, Wan Keun; Kang, Soo Jin

    2011-12-01

    To investigate epigenetic gene regulation in Arabidopsis modulated by gamma radiation, we examined the changes in DNA methylation and histone modification after gamma radiation and investigated the effects of gamma radiation on epigenetic information and gene expression. We have selected 14 genes with changes in DNA methylation by gamma radiation, analyzed the changes of histone modification in the selected genes to reveal the relationship between DNA methylation and histone modification by gamma radiation. We have also analyzed the effects of gamma radiation on gene expression to investigate the relationship between epigenetic information and gene expression by gamma radiation. The results will be useful to reveal the effects of gamma radiation on DNA methylation, histone modification and gene expression. We anticipate that the information generated in this proposal will help to find out the mechanism underlying the changes in epigenetic information by gamma radiation

  9. Calculation of the secondary gamma radiation by the Monte Carlo method at displaced sampling from distributed sources

    International Nuclear Information System (INIS)

    Petrov, Eh.E.; Fadeev, I.A.

    1979-01-01

    A possibility to use displaced sampling from a bulk gamma source in calculating the secondary gamma fields by the Monte Carlo method is discussed. The algorithm proposed is based on the concept of conjugate functions alongside the dispersion minimization technique. For the sake of simplicity a plane source is considered. The algorithm has been put into practice on the M-220 computer. The differential gamma current and flux spectra in 21cm-thick lead have been calculated. The source of secondary gamma-quanta was assumed to be a distributed, constant and isotropic one emitting 4 MeV gamma quanta with the rate of 10 9 quanta/cm 3 xs. The calculations have demonstrated that the last 7 cm of lead are responsible for the whole gamma spectral pattern. The spectra practically coincide with the ones calculated by the ROZ computer code. Thus the algorithm proposed can be offectively used in the calculations of secondary gamma radiation transport and reduces the computation time by 2-4 times

  10. Environmental gamma radiation monitoring at Visakhapatnam using thermoluminescence dosimeters

    International Nuclear Information System (INIS)

    Swarnkar, M.; Sahu, S.K.; Takale, R.A.; Shetty, P.G.; Pundit, G.G.; Puranik, V.D.

    2012-01-01

    The gamma rays are the most significant part of environmental dose due to its large range and deep penetrating power. The environmental gamma radiation is mainly originated from two sources natural radiation and artificially produced radiation. The natural radiation dose arises from the cosmic radiation (galactic and solar) and from the Earth (terrestrial) surface. In the last few decades there is a growing concern all over the world about radiation and their exposure to population. Thus it is necessary to conduct radiological environmental surveillance. The radiation survey data are useful to establish the natural background gamma radiation levels. Extensive gamma radiation survey was carried out around the surroundings of Vishakhapatnam using Thermoluminescence Dosimeters (TLDs). The CaSO 4 :(0.2 mole %) Dy Teflon TLD discs, specifically designed for environmental gamma radiation monitoring purpose were used. These TLD badge are having very high TL sensitivity, a negligible fading rate and a stable TL response. TLDs were deployed on quarterly basis for two years to obtain the cumulative gamma background radiation levels in the study area. The radiological survey was also carried out by using a calibrated radiation survey meter. The annual dose rates were computed from quarterly values actually found and normalised to 365 days. The environmental gamma radiation levels around Vishakhapatnam were found to be in the range of 0.79 mGy/y to 1.86 mGy/y. It is clearly seen from the results that location to location there is a large variation in external gamma radiation levels. During the cycle of the TLD survey, spot readings of the background radiation levels were taken, both while placing the TLDs and while removing them. The instantaneous dose rates measured using survey meter, are also following the large variation as found in TLDs. It varies between 110 nGy/hr to 210 nGy/hr. (author)

  11. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    De Guzman, Zenaida M. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Cervancia, Cleofas R. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Dimasuay, Kris Genelyn B.; Tolentino, Mitos M.; Abrera, Gina B.; Cobar, Ma. Lucia C. [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Fajardo, Alejandro C.; Sabino, Noel G.; Manila-Fajardo, Analinda C. [Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines, Los Banos, Laguna (Philippines); Feliciano, Chitho P., E-mail: cpfeliciano@pnri.dost.gov.ph [Microbiological Research and Service Laboratory, Atomic Research Division, Philippine Nuclear Research Institute, Diliman, Quezon City (Philippines); Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City (Philippines)

    2011-10-15

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a {sup 60}Co source. Surviving spores were counted and used to estimate the decimal reduction (D{sub 10}) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10{sup 5}-9x10{sup 3} spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D{sub min}) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to {gamma}-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. - Highlights: > We characterized Paenibacillus larvae and determined its radiation sensitivity. > We investigated the effectiveness of gamma rays in inactivating P. larvae. > Gamma radiation inactivates P. larvae. > 15 kGy is effective for the sterilization of P. larvae-infected hives. > Irradiation produces no visible changes in the hives' body, waxes and frames.

  12. Radiation inactivation of Paenibacillus larvae and sterilization of American Foul Brood (AFB) infected hives using Co-60 gamma rays

    International Nuclear Information System (INIS)

    De Guzman, Zenaida M.; Cervancia, Cleofas R.; Dimasuay, Kris Genelyn B.; Tolentino, Mitos M.; Abrera, Gina B.; Cobar, Ma. Lucia C.; Fajardo, Alejandro C.; Sabino, Noel G.; Manila-Fajardo, Analinda C.; Feliciano, Chitho P.

    2011-01-01

    The effectiveness of gamma radiation in inactivating the Philippine isolate of Paenibacillus larvae was investigated. Spores of P. larvae were irradiated at incremental doses (0.1, 0.2, 0.4, 0.8 and 1.6 kGy) of gamma radiation emitted by a 60 Co source. Surviving spores were counted and used to estimate the decimal reduction (D 10 ) value. A dose of 0.2 kGy was sufficient to inactivate 90% of the total recoverable spores from an initial count of 10 5 -9x10 3 spores per glass plate. The sterilizing effect of high doses of gamma radiation on the spores of P. larvae in infected hives was determined. In this study, a minimum dose (D min ) of 15 kGy was tested. Beehives with sub-clinical infections of AFB were irradiated and examined for sterility. All the materials were found to be free of P. larvae indicating its susceptibility to γ-rays. After irradiation, there were no visible changes in the physical appearance of the hives' body, wax and frames. Thus, a dose of 15 kGy is effective enough for sterilization of AFB-infected materials. - Highlights: → We characterized Paenibacillus larvae and determined its radiation sensitivity. → We investigated the effectiveness of gamma rays in inactivating P. larvae. → Gamma radiation inactivates P. larvae. → 15 kGy is effective for the sterilization of P. larvae-infected hives. → Irradiation produces no visible changes in the hives' body, waxes and frames.

  13. Bill C-5, an act to amend the radiation emitting devices act

    International Nuclear Information System (INIS)

    1984-01-01

    This Act, entitled Bill C-5, allows for a series of amendments to the Radiation Emitting Devices Act. The amendments relate to regulations concerned with the sale, lease or import, labelling, advertising, packaging, safety standards and inspection of radiation emitting devices

  14. Mathematical simulation of gamma-radiation angle distribution measurements

    International Nuclear Information System (INIS)

    Batij, V.G.; Batij, E.V.; Egorov, V.V.; Fedorchenko, D.V.; Kochnev, N.A.

    2008-01-01

    We developed mathematical model of the facility for gamma-radiation angle distribution measurement and calculated response functions for gamma-radiation intensities. We developed special software for experimental data processing, the 'Shelter' object radiation spectra unfolding and Sphere detector (ShD) angle resolution estimation. Neuronet method using for detection of the radiation directions is given. We developed software based on the neuronet algorithm, that allows obtaining reliable distribution of gamma-sources that make impact on the facility detectors at the measurement point. 10 refs.; 15 figs.; 4 tab

  15. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E. [Lawrence Livermore National Lab., CA (United States)

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC.

  16. Relative risk analysis in regulating the use of radiation-emitting medical devices. A preliminary application

    International Nuclear Information System (INIS)

    Jones, E.D.; Banks, W.W.; Altenbach, T.J.; Fischer, L.E.

    1995-09-01

    This report describes a preliminary application of an analysis approach for assessing relative risks in the use of radiation- emitting medical devices. Results are presented on human-initiated actions and failure modes that are most likely to occur in the use of the Gamma Knife, a gamma irradiation therapy device. This effort represents an initial step in a US Nuclear Regulatory Commission (NRC) plan to evaluate the potential role of risk analysis in regulating the use of nuclear medical devices. For this preliminary application of risk assessment, the focus was to develop a basic process using existing techniques for identifying the most likely risk contributors and their relative importance. The approach taken developed relative risk rankings and profiles that incorporated the type and quality of data available and could present results in an easily understood form. This work was performed by the Lawrence Livermore National Laboratory for the NRC

  17. Sterilization plants equipped with the isotopic gamma radiation sources

    International Nuclear Information System (INIS)

    Mehta, K.; Chmielewski, A.G.

    2007-01-01

    Presentation describes different isotopic gamma radiation sources applicable for sterilization of food and medical materials. Certain gamma pallet irradiators, mini gamma irradiators and different scale gamma tote irradiators are presented. It is concluded, that about two hundreds plants with gamma radiation sources operates in different countries. However, industrially developed countries must construct much more plants than operates now

  18. Development of radiation safety monitoring system at gamma greenhouse gamma facility

    International Nuclear Information System (INIS)

    Hairul Nizam Idris; Azimawati Ahmad, Ahmad Zaki Hussain; Ahmad Fairuz Mohd Nasir

    2009-01-01

    This paper is discussing about installation of radiation safety monitoring system at Gamma Greenhouse Gamma facility, Agrotechnology and Bioscience Division (BAB). This facility actually is an outdoor type irradiation facility, which first in Nuclear Malaysia and the only one in Malaysia. Source Cs-137 (801 Curie) was use as radiation source and it located at the centre of 30 metres diameter size of open irradiation area. The radiation measurement and monitoring system to be equipped in this facility were required the proper equipment and devices, specially purpose for application at outside of building. Research review, literature study and discussion with the equipment manufacturers was being carried out, in effort to identify the best system should be developed. Factors such as tropical climate, environment surrounding and security were considered during selecting the proper system. Since this facility involving with panoramic radiation type, several critical and strategic locations have been fixed with radiation detectors, up to the distance at 200 meter from the radiation source. Apart from that, this developed system also was built for capable to provide the online real-time reading (using internet). In general, it can be summarized that the radiation safety monitoring system for outdoor type irradiation facility was found much different and complex compared to the system for indoor type facility. Keyword: radiation monitoring, radiation safety, Gamma Greenhouse, outdoor irradiation facility, panoramic radiation. (Author)

  19. 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)

  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. Study of the gamma radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Curie, I

    1949-12-01

    A Geiger counter study has been made of the ..gamma.. radiation of ionium. Eleven quanta of the L radiation of radium were observed for every hundred ..cap alpha.. disintegrations, and three ..gamma.. rays were found with energies of 68, 140, and 240 keV at a rate of 0.85, 0.33, 0.05 quanta, respectively, for 100 disintegrations. It is noted that the radiation spectrum of ionium as a whole is difficult to interpret. In the course of this work, the author calculated the efficiency of a thin-walled aluminum counter, both for the L radiation of radium and for ..gamma.. rays of 68 keV. The author also measured, for soft radiation, the ratio between the efficiency of a thin-walled aluminum counter and that of a similar counter lined with 0.11 mm of lead.

  2. Cosmic gamma-ray background radiation. Current understandings and problems

    International Nuclear Information System (INIS)

    Inoue, Yoshiyuki

    2015-01-01

    The cosmic gamma-ray background radiation is one of the most fundamental observables in the gamma-ray band. Although the origin of the cosmic gamma-ray background radiation has been a mystery for a long time, the Fermi gamma-ray space telescope has recently measured it at 0.1-820 GeV and revealed that the cosmic GeV gamma-ray background is composed of blazars, radio galaxies, and star-forming galaxies. However, Fermi still leaves the following questions. Those are dark matter contribution, origins of the cosmic MeV gamma-ray background, and the connection to the IceCube TeV-PeV neutrino events. In this proceeding, I will review the current understandings of the cosmic gamma-ray background and discuss future prospects of cosmic gamma-ray background radiation studies. (author)

  3. OBSERVATIONAL SIGNATURES OF SUB-PHOTOSPHERIC RADIATION-MEDIATED SHOCKS IN THE PROMPT PHASE OF GAMMA-RAY BURSTS

    International Nuclear Information System (INIS)

    Levinson, Amir

    2012-01-01

    A shock that forms below the photosphere of a gamma-ray burst (GRB) outflow is mediated by Compton scattering of radiation advected into the shock by the upstream fluid. The characteristic scale of such a shock, a few Thomson depths, is larger than any kinetic scale involved by several orders of magnitude. Hence, unlike collisionless shocks, radiation-mediated shocks cannot accelerate particles to nonthermal energies. The spectrum emitted by a shock that emerges from the photosphere of a GRB jet reflects the temperature profile downstream of the shock, with a possible contribution at the highest energies from the shock transition layer itself. We study the properties of radiation-mediated shocks that form during the prompt phase of GRBs and compute the time-integrated spectrum emitted by the shocked fluid following shock breakout. We show that the time-integrated emission from a single shock exhibits a prominent thermal peak, with the location of the peak depending on the shock velocity profile. We also point out that multiple shock emission can produce a spectrum that mimics a Band spectrum.

  4. Radiation hormesis in plant

    International Nuclear Information System (INIS)

    Kim, Jae Sung; Lee, Young Keun; Lee, Sang Jae and others; Park, Youn Il; Kwon, Soon Tae

    2003-05-01

    This research was performed to investigate the effects of low dose gamma radiation on germination, early growth and yield in a wide range of vegetable crops. The stimulating effects of gamma radiation was evaluated through investigating germination rate, early growth and physiological activities such as enzyme activities, hormones and photosynthetic responses etc. Induction of increased shikonin production in the plants by low dose gamma radiation was challenged to open up the possibility of applying radiation hormesis to the industrial mass production system of the natural materials useful to humans. Effects of natural radiation emitted from solid ceramics was compared on the plants with those of low dose gamma radiation. Finally, activation of aged seeds by low dose gamma radiation, probably facilitating their commercial circulation in the agriculture, was challenged in association with an industrial seed company. Moreover, the shift in resistance of the crops to environmental stresses including UV and low temperature was addressed as well as DNA damage, repair and protein expression after gamma irradiation

  5. The effect of gamma-radiation on bilirubin

    International Nuclear Information System (INIS)

    Iqbal, M.S.; Shad, M.A.; Akhtar, M.I.

    2001-01-01

    The effect of gamma-radiations on bilirubin, in vitro, has been studied. It was found that gamma-radiation causes oxidation of bilirubin to biliverdine as one of the products. The likely implication of this effect in transformation of bilirubin to excretable products, in vino, in case of jaundice is discussed. (author)

  6. Dosimetry and Shielding of X and Gamma Radiation

    International Nuclear Information System (INIS)

    Oncescu, M.; Panaitescu, I.

    1992-01-01

    This book covers the following problems: 1. X and Gamma radiations, 2. Interaction of X-ray and gamma radiations with matter, 3. Interaction of electrons with matter, 4. Principles and basic concepts of dosimetry, 5. Ionization dosimetry, 6. Calorimetric chemical and photographic dosimetry, 7. Solid state dosimetry, 8. Computation of dosimetric quantities, 9. Dosimetry in radiation protection, 10. Shielding of X and gamma radiations. The authors, well-known Romanian experts in Radiation Physics and Engineering, gave an up-dated, complete and readable account of this subject matter. The analyses of physical principles and concepts, of materials and instruments and of computational methods and applications are all well balanced to meat the needs of a broad readership

  7. Bioaccumulation of gamma emitting radionuclides in Polysiphonia fucoides

    International Nuclear Information System (INIS)

    Tamara Zalewska

    2014-01-01

    The article presents the results of a study on the bioaccumulation abilities of Polysiphonia fucoides, a red algae specific to the southern Baltic Sea, towards (of) gamma emitting isotopes. A laboratory experiment was carried out to determine changes in the activities of some isotopes - 54 Mn, 57 Co, 65 Zn, 110m Ag, 113 Sn, 134 Cs, 137 Cs and 241 Am - occurring in P. fucoides exposed to a seawater medium containing these isotopes over the course of 1 month. All analyzed isotopes showed the greatest increase of radioactive activity in plant tissue in the first 24 h of exposure. The temporary concentration factors of cesium isotopes were increasing linearly during the experiment from 114 to 274 in the case of 137 Cs, and from 144 to 351 in the case of 134 Cs. The level of the initial concentration factor of cesium isotopes in the plant proved to be independent of the initial concentration of the isotope in seawater and it took the lowest (125 dm 3 kg -1 ) level among the studied isotopes. In the case of a mixture of gamma emitting isotopes, a linear relation between the individual isotope activity in P. fucoides and its initial concentration in seawater was established after the first day of exposure; the isotopes initial concentration factors ranged from 767 to 874 dm 3 kg -1 . Having reached the maximal concentration level, a statistically significant decline in radioactivity concentrations of the five isotopes in the plant tissue was observed. A half-life of biological removal of the isotopes from the plant tissue was established at: 3.8 days in the case of 54 Mn, 4 days- 57 Co, 4 days- 60 Co, 4.2 days- 137 Cs and 241 Am-3.5 days. (author)

  8. Effect of gamma radiation on growth and survival of common seed-borne fungi in India

    Energy Technology Data Exchange (ETDEWEB)

    Maity, J.P. [Department of Environmental Science, University of Kalyani, Nadia 741235, WB (India); Department of Atomic Energy Consortium for Scientific Research, University Grant Commission, Kolkata Center, 3/LB-8, Salt Lake, Kolkata 700098 (India); Center for Study of Man and Environment, CK-11, Sector-II, Kolkata 700091 (India)], E-mail: jyoti_maity@yahoo.com; Chakraborty, A. [Department of Atomic Energy Consortium for Scientific Research, University Grant Commission, Kolkata Center, 3/LB-8, Salt Lake, Kolkata 700098 (India); Chanda, S. [Center for Study of Man and Environment, CK-11, Sector-II, Kolkata 700091 (India); Santra, S.C. [Department of Environmental Science, University of Kalyani, Nadia 741235, WB (India)

    2008-07-15

    The present work describes radiation-induced effects of major seeds like Oryza sativa Cv-2233, Oryza sativa Cv-Shankar, Cicer arietinum Cv-local and seed-borne fungi like Alternaria sp., Aspergillus sp., Trichoderma sp. and Curvularia sp. {sup 60}Co gamma source at 25 deg. C emitting gamma ray at 1173 and 1332 keV energy was used for irradiation. Dose of gamma irradiation up to 3 kGy (0.12 kGy/h) was applied for exposing the seed and fungal spores. Significant depletion of the fungal population was noted with irradiation at 1-2 kGy, whereas germinating potential of the treated grain did not alter significantly. However, significant differential radiation response in delayed seed germination, colony formation of the fungal spores and their depletion of growth were noticed in a dose-dependent manner. The depletion of the fungal viability (germination) was noted within the irradiation dose range of 1-2 kGy for Alternaria sp. and Aspergillus sp., while 0.5-1 kGy for Trichoderma sp. and Curvularia sp. However, complete inhibition of all the selected fungi was observed above 2.5 kGy.

  9. Effect of gamma radiation on growth and survival of common seed-borne fungi in India

    International Nuclear Information System (INIS)

    Maity, J.P.; Chakraborty, A.; Chanda, S.; Santra, S.C.

    2008-01-01

    The present work describes radiation-induced effects of major seeds like Oryza sativa Cv-2233, Oryza sativa Cv-Shankar, Cicer arietinum Cv-local and seed-borne fungi like Alternaria sp., Aspergillus sp., Trichoderma sp. and Curvularia sp. 60 Co gamma source at 25 deg. C emitting gamma ray at 1173 and 1332 keV energy was used for irradiation. Dose of gamma irradiation up to 3 kGy (0.12 kGy/h) was applied for exposing the seed and fungal spores. Significant depletion of the fungal population was noted with irradiation at 1-2 kGy, whereas germinating potential of the treated grain did not alter significantly. However, significant differential radiation response in delayed seed germination, colony formation of the fungal spores and their depletion of growth were noticed in a dose-dependent manner. The depletion of the fungal viability (germination) was noted within the irradiation dose range of 1-2 kGy for Alternaria sp. and Aspergillus sp., while 0.5-1 kGy for Trichoderma sp. and Curvularia sp. However, complete inhibition of all the selected fungi was observed above 2.5 kGy

  10. 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)

  11. 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)

  12. 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)

  13. Exposure of luminous marine bacteria to low-dose gamma-radiation.

    Science.gov (United States)

    Kudryasheva, N S; Petrova, A S; Dementyev, D V; Bondar, A A

    2017-04-01

    The study addresses biological effects of low-dose gamma-radiation. Radioactive 137 Cs-containing particles were used as model sources of gamma-radiation. Luminous marine bacterium Photobacterium phosphoreum was used as a bioassay with the bioluminescent intensity as the physiological parameter tested. To investigate the sensitivity of the bacteria to the low-dose gamma-radiation exposure (≤250 mGy), the irradiation conditions were varied as follows: bioluminescence intensity was measured at 5, 10, and 20°С for 175, 100, and 47 h, respectively, at different dose rates (up to 4100 μGy/h). There was no noticeable effect of gamma-radiation at 5 and 10°С, while the 20°С exposure revealed authentic bioluminescence inhibition. The 20°С results of gamma-radiation exposure were compared to those for low-dose alpha- and beta-radiation exposures studied previously under comparable experimental conditions. In contrast to ionizing radiation of alpha and beta types, gamma-emission did not initiate bacterial bioluminescence activation (adaptive response). As with alpha- and beta-radiation, gamma-emission did not demonstrate monotonic dose-effect dependencies; the bioluminescence inhibition efficiency was found to be related to the exposure time, while no dose rate dependence was found. The sequence analysis of 16S ribosomal RNA gene did not reveal a mutagenic effect of low-dose gamma radiation. The exposure time that caused 50% bioluminescence inhibition was suggested as a test parameter for radiotoxicity evaluation under conditions of chronic low-dose gamma irradiation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Measurement of the radiative decay width {gamma}[{lambda}(1520)->{lambda}{gamma}] with the SPHINX spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Yu.M. [Institute for High Energy Physics, Protvino (Russian Federation); Artamonov, A.V. [Institute for High Energy Physics, Protvino (Russian Federation); Batarin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Vavilov, D.V. [Institute for High Energy Physics, Protvino (Russian Federation); Victorov, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Eroshin, O.V. [Institute for High Energy Physics, Protvino (Russian Federation); Golovkin, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Gorin, Yu.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kolganov, V.Z. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Kozhevnikov, A.P. [Institute for High Energy Physics, Protvino (Russian Federation); Konstantinov, A.S. [Institute for High Energy Physics, Protvino (Russian Federation); Kubarovsky, V.P. [Institute for High Energy Physics, Protvino (Russian Federation); Kurshetsov, V.F. [Institute for High Energy Physics, Protvino (Russian Federation); Landsberg, L.G. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: lgl@mx.ihep.su; Leontiev, V.M. [Institute for High Energy Physics, Protvino (Russian Federation); Lomkatsi, G.S. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Molchanov, V.V. [Institute for High Energy Physics, Protvino (Russian Federation)]. E-mail: molchanov@mx.ihep.su; Mukhin, V.A. [Institute for High Energy Physics, Protvino (Russian Federation); Nilov, A.F. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Patalakha, D.I. [Institute for High Energy Physics, Protvino (Russian Federation); Petrenko, S.V. [Institute for High Energy Physics, Protvino (Russian Federation); Smolyankin, V.T. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

    2004-12-16

    The radiative decay {lambda}(1520)->{lambda}{gamma} was measured directly in the study of the exclusive diffractive-like reaction p+N->{lambda}(1520)K{sup +}+N, {lambda}(1520)->{lambda}{gamma} with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR[{lambda}(1520)->{lambda}{gamma}]=(1.02+/-0.21(stat)+/-0.15(syst))x10{sup -2} and {gamma}[{lambda}(1520)->{lambda}{gamma}]=159+/-33(stat)+/-26(syst)-bar keV.

  15. Development of DL-alanine systems for gamma radiation and electron dosimetry

    International Nuclear Information System (INIS)

    Costa, Zelia Maria da

    1994-01-01

    Two different dosimetric systems using DL-Alanine samples were employed to determine the absorbed dose from 60 Co gamma-rays source and electrons emitted from an accelerator. The first dosimetric system is based on the relationship between free radicals produced and the absorbed dose using the electron spin resonance (ESR) technique. Details on the sample preparation, the spectrometer parameter setting, the analysis of the ESR signal to dose, the influence of dose rate and the radiation type dependence are described. The second dosimetric system is based on the determination by absorbance spectrophotometry of the complex produced, which are formed when the irradiated alanine is dissolved in a solution containing ferrous ammonium sulphate xylenol in 0,05 N H 2 SO 4 . Different concentrations for each reagents has been analyzed in the preparation of this solution as well as the influence caused by radiation type and dose rate in the absorbance. (author)

  16. Gamma Radiation from Fission Fragments

    International Nuclear Information System (INIS)

    Higbie, Jack

    1969-10-01

    The gamma radiation from the fragments of the thermal neutron fission of 235 U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10 -10 sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass

  17. Gamma Radiation from Fission Fragments

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-10-15

    The gamma radiation from the fragments of the thermal neutron fission of {sup 235}U has been investigated, and the preliminary data are presented here with suggestions for further lines of research and some possible interpretations of the data. The data have direct bearing on the fission process and the mode of fragment de-excitation. The parameters measured are the radiation decay curve for the time interval (1 - 7) x 10{sup -10} sec after fission, the photon yield, the total gamma ray energy yield, and the average photon energy. The last three quantities are measured as a function of the fragment mass.

  18. Radiation geophysics Implementation of the theory

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    The gamma spectrometry allows to measure directly a source from the surface of the ground without penetration at great deepness. The fact that it collects data in surface allows to establish links between contrasts measured for the radioelements and the cartography of the geology of the rocky substratum or formations in, surface and the modifications associated to the ore deposits. Each rock or materials contents radioactive elements. the gamma spectrometer is conceived to detect the gamma radiation emitted by these radioactive elements and allows to class precisely the detected radiations according to the energy they emit. It is this function of classification that distinguishes the spectrometer from the others instruments used to measure only the whole radioactivity. (N.C.)

  19. THE PROBLEMS OF USING EXEMPTION ACTIVITY VALUES FOR REGULATING THE MANAGEMENT OF SEALED RADIONUCLIDE SOURCES OF GAMMA-RADIATION

    Directory of Open Access Journals (Sweden)

    A. N. Barkovsky

    2017-01-01

    Full Text Available The article focuses on the procedure for exemption of the sealed and unsealed radionuclide sources of gamma radiation from regulatory control. The contradictory nature of the existing set of exemption criteria has been noted, leading, in some cases, to paradoxical situations. It is shown that the exempt activity values determined in NRB-99/2009 and in the international basic safety standards of the IAEA are significantly overestimated (in comparison with the activity values of a point source creating the ambient dose equivalent rate of 1 μSv / h at a distance of 0.1 m for a number of the most widely used gamma-emitting radionuclides, including 22Na, 54Mn, 75Se, 152Eu and 154Eu. It is proposed to revise the current values of exempt activity, bringing them in line with the dose rate criterion for the exempt of sealed radionuclide sources of gamma radiation, and to present them with one significant digit. The corrected values of exempt activity for  seven selected radionuclides are proposed for further use in the process of revision of the national radiation safety standards.

  20. 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)

  1. Investigation of zones with increased ground surface gamma radiation

    International Nuclear Information System (INIS)

    Butkus, D.V.; Morkunas, G.S.; Styro, B.I.

    1989-01-01

    Measurements of the increased gamma radiation zones of soils were conducted in the South-Western part of the Litvinian. The shores of lakes in the north-eastern part of the Suduva high land were investigated. the maximum values of the gamma radiation dose rates were distributed along the lake shores at a distance of 1 m from the water surface, while farther than 1.5 m from it the dose rate was close to the natural value. The increased gamma radiation intensity zones on the ground surface were found only at the northern (Lake Reketija) or the western shore (other lakes under investigation). The highest values of the gamma radiation dose 200-600 μR/h (0.5-1.5 nGy/s) were observed in the comparatively small areas (up to several square metres). The gamma radiation intensity of soil surface increased strongly moving towards the point where the maximum intensity was obsered. 10 figs

  2. Radiation breeding researches in gamma field. Results of researches

    International Nuclear Information System (INIS)

    Morishita, Toshikazu

    2006-01-01

    Abstract of radiation breeding researches and outline of gamma field in IRB (Institute of Radiation Breeding) are described. The gamma field is a circular field of 100 m radius with 88.8TBqCo-60 source at the center. The field is surrounded by a shielding dike of 8 m in height. The effects of gamma irradiation on the growing plants, mutant by gamma radiation and plant molecular biological researches using mutant varieties obtained by the gamma field are explained. For examples, Japanese pear, chrysanthemum, Cytisus, Eustoma grandiflorum, Manila grass, tea and rose are reported. The mutant varieties in the gamma field, nine mutant varieties of flower colors in chrysanthemum, evergreen mutant lines in Manila grass, selection of self-compatible mutants in tea plant, and the plants of the gamma field recently are shown. (S.Y.)

  3. Measurement of the X and gamma radiation after muon-catalyzed pd-, dd-, and dt-fusion

    International Nuclear Information System (INIS)

    Bossy, H.

    1987-01-01

    The muonic X radiation emitted after muon-catalyzed fusion of two hydrogen nuclei has been measured for the fusion reactions of pd, dd, and dt (p=proton, d=deuteron, t=triton). The quantum yields (per fusion) of the μHe(2-1) transition were evaluated to be 3.2(4)% (pd fusion), 1.6(2)% (dd fusion), and 0.21(5)% (dt fusion, preliminary value). The intensity ratios of the transitions μHe(3-1)/μHe(2-1) were found to be 0.052(5) (pd fusion) and 0.13(2) (dd fusion). The investigation of the gamma radiation intensities for pd fusion yielded excitement probabilities of the μHe atom. (orig.) [de

  4. Study of radiation detectors response in standard X, gamma and beta radiation standard beams

    International Nuclear Information System (INIS)

    Nonato, Fernanda Beatrice Conceicao

    2010-01-01

    The response of 76 Geiger-Mueller detectors, 4 semiconductor detectors and 34 ionization chambers were studied. Many of them were calibrated with gamma radiation beams ( 37 Cs and 60 Co), and some of them were tested in beta radiation ( 90 Sr+ 9' 0Y e 204 Tl) and X radiation (N-60, N-80, N-100, N-150) beams. For all three types of radiation, the calibration factors of the instruments were obtained, and the energy and angular dependences were studied. For beta and gamma radiation, the angular dependence was studied for incident radiation angles of 0 deg and +- 45 deg. The curves of the response of the instruments were obtained over an angle interval of 0 deg to +- 90 deg, for gamma, beta and X radiations. The calibration factors obtained for beta radiation were compared to those obtained for gamma radiation. For gamma radiation, 24 of the 66 tested Geiger-Mueller detectors presented results for the energy dependence according to international recommendation of ISO 4037-2 and 56 were in accordance with the Brazilian ABNT 10011 recommendation. The ionization chambers and semiconductors were in accordance to national and international recommendations. All instruments showed angular dependence less than 40%. For beta radiation, the instruments showed unsatisfactory results for the energy dependence and angular dependence. For X radiation, the ionization chambers presented results for energy dependence according to the national recommendation, and the angular dependence was less than 40%. (author)

  5. Relativistic motion in gamma-ray bursts

    International Nuclear Information System (INIS)

    Krolik, J.H.; Pier, E.A.

    1991-01-01

    Three fundamental problems affect models of gamma-ray bursts, i.e., the energy source, the ability of high-energy photons to escape the radiation region, and the comparative weakness of X-ray emission. It is indicated that relativistic bulk motion of the gamma-ray-emitting plasma generically provides a solution to all three of these problems. Results show that, if the plasma that produces gamma-ray bursts has a bulk relativistic velocity with Lorentz factor gamma of about 10, several of the most troubling problems having to do with gamma-ray bursts are solved. 42 refs

  6. Some factors affecting urokinase inactivation. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Hiroo; Iketa, Yoshito

    1985-10-01

    The enzymatic activity of urokinase adsorbed on various polymer surfaces was measured to study the interaction between protein and polymers. The polymer films on which urokinase was adsorbed were exposed to either a high temperature or ..gamma..-radiation. The thermal inactivation rates were higher on hydrophobic polymers such as poly(ethylene terephthalate), nylon 6, and poly(vinylidene fluoride) than hydrophilic polymers like cellulose and ethylene-vinyl alcohol copolymer, indicating their substantial dependence on the interfacial free energy between the polymer and water. A similar dependence was also seen for the ..gamma..-radiation inactivation. Urokinase adsorbed on the hydrophobic polymers lost more easily its enzymatic activity by exposure to ..gamma..-radiation. The interfacial free energy seems to be one of the driving forces to denaturate proteins on polymers.

  7. ORNL shielded facilities capable of remote handling of highly radioactive beta--gamma emitting materials

    International Nuclear Information System (INIS)

    Whitson, W.R.

    1977-09-01

    A survey of ORNL facilities having adequate shielding and containment for the remote handling of experimental quantities of highly radioactive beta-gamma emitting materials is summarized. Portions of the detailed descriptions of these facilities previously published in ORNL/TM-1268 are still valid and are repeated

  8. Gamma radiation in ceramic capacitors: a study for space missions

    Science.gov (United States)

    dos Santos Ferreira, Eduardo; Sarango Souza, Juliana

    2017-10-01

    We studied the real time effects of the gamma radiation in ceramic capacitors, in order to evaluate the effects of cosmic radiation on these devices. Space missions have electronic circuits with various types of devices, many studies have been done on semiconductor devices exposed to gamma radiation, but almost no studies for passive components, in particular ceramic capacitors. Commercially sold ceramic capacitors were exposed to gamma radiation, and the capacitance was measured before and after exposure. The results clearly show that the capacitance decreases with exposure to gamma radiation. We confirmed this observation in a real time capacitance measurement, obtained using a data logging system developed by us using the open source Arduino platform.

  9. Power output and efficiency of beta-emitting microspheres

    International Nuclear Information System (INIS)

    Cheneler, David; Ward, Michael

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire’s theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer. - Highlights: • Range-energy relationship for the beta particles in yttrium-90 is calculated. • Formalism for the semi-analytical calculation of self-absorption coefficients. • Energy-dependent self-absorption coefficient calculated for yttrium-90. • Flux rate of beta particles from a self-attenuating radioactive sphere is shown. • The efficiency of beta particle emitting radioactive microspheres is calculated

  10. Residual water treatment for gamma radiation

    International Nuclear Information System (INIS)

    Mendez, L.

    1990-01-01

    The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs

  11. Assembly of gamma radiation detection with directivity properties

    International Nuclear Information System (INIS)

    Stoica, M.; Talpalariu, C.

    2016-01-01

    An assembly of gamma radiation detection with directivity properties and small size enables the development of portable equipment or robots specialized in finding and signaling radioactively contaminated areas in case of nuclear incidents or decommissioning of nuclear installations. Directivity characteristic of the assembly of gamma radiation detection is very important when aiming to build an equipment for searching radioactively contaminated areas. In order to obtain a suitable directivity characteristics in terms of detection of gamma rays, it was necessary to construct a lead collimator with a cylindrical shape. The detector, preamplifier and amplifier pulse were placed inside the collimator and pulse discriminator circuit and power source were placed beside the collimator, all being disposed within the housing cylindrical experimental. A PIN photodiode type was used as a detector of gamma radiation. (authors)

  12. An assessment of ultraviolet radiation components of light emitted ...

    African Journals Online (AJOL)

    An assessment of ultraviolet radiation components of light emitted from electric arc and their possible exposure risks. ... The study of Ultraviolet Radiation has of recent become interesting because of the health hazards it poses to human. Apart from its intensity reaching the earth from the sun, other man-made sources have ...

  13. Low doses of gamma radiation in soybean

    International Nuclear Information System (INIS)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C.; Arthur, Valter; Arthur, Paula B.; Franco, Caio H.

    2017-01-01

    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. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number 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 the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  14. Low doses of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

    Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

    2017-07-01

    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. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number 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 the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  15. Improving degradation of paracetamol by integrating gamma radiation and Fenton processes.

    Science.gov (United States)

    Cruz-González, Germán; Rivas-Ortiz, Iram B; González-Labrada, Katia; Rapado-Paneque, Manuel; Chávez-Ardanza, Armando; Nuevas-Paz, Lauro; Jáuregui-Haza, Ulises J

    2016-10-14

    Degradation of paracetamol (N-(4-hydroxiphenyl)acetamide) in aqueous solution by gamma radiation, gamma radiation/H2O2 and gamma radiation/Fenton processes was studied. Parameters affecting the radiolysis of paracetamol such as radiation dose, initial concentration of pollutant, pH and initial oxidant concentration were investigated. Gamma radiation was performed using a (60)Co source irradiator. Paracetamol degradation and mineralization increased with increasing absorbed radiation dose, but decreased with increasing initial concentration of the drug in aqueous solution. The addition of H2O2 resulted in an increased effect on irradiation-driven paracetamol degradation in comparison with the performance of the irradiation-driven process alone: paracetamol removal increased from 48.9% in the absence of H2O2 to 95.2% for H2O2 concentration of 41.7 mmol/L. However, the best results were obtained with gamma radiation/Fenton process with 100% of the drug removal at 5 kGy, for optimal H2O2 and Fe(2+) concentrations at 13.9 and 2.3 mmol/L, respectively, with a high mineralization of 63.7%. These results suggest gamma radiation/H2O2 and gamma radiation/Fenton processes as promising methods for paracetamol degradation in polluted wastewaters.

  16. Polyvinyl Alcohol-Lead Nitrate Paint for Gamma Radiation Installations

    International Nuclear Information System (INIS)

    EI-Ahdal, M.A.

    2007-01-01

    Dealing with gamma ray installations represents an important problem for radiation protection workers. Radiation shielding is used to avoid the risk resulting from these gamma sources. This study suggested the use of polyvinyl alcohol (PVA) solution that contains lend nitrate (with lead metal/PVA= 1.72) to lower the gamma radiation intensity and reduce its risk to workers. This can be achieved by painting the radiation shielding with this solution Temperature relief of the irradiated solution shows the degradation of the polymer content up to 50 degree C, which starts to crosslink increasing the protection capability of this solution

  17. Differential sensitivity of Chironomus and human hemoglobin to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Pallavi S. [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India); Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Panicker, Lata [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Mohole, Madhura; Sawant, Sangeeta [Bioinformatics Center, Savitribai Phule Pune University, Pune, 411007 (India); Mukhopadhyaya, Rita [Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai, 400085 (India); Nath, Bimalendu B., E-mail: bbnath@gmail.com [Stress Biology Research Laboratory, Department of Zoology, Savitribai Phule University, Pune, 411007 (India)

    2016-08-05

    Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. -- Highlights: •Comparison of radiation tolerant Chironomus Hb and radiation sensitive Human Hb. •Amino acid composition of midge and human heme confer differential hydrophobicity. •Heme pocket of evolutionarily ancient midge Hb provide gamma radiation resistivity.

  18. Differential sensitivity of Chironomus and human hemoglobin to gamma radiation

    International Nuclear Information System (INIS)

    Gaikwad, Pallavi S.; Panicker, Lata; Mohole, Madhura; Sawant, Sangeeta; Mukhopadhyaya, Rita; Nath, Bimalendu B.

    2016-01-01

    Chironomus ramosus is known to tolerate high doses of gamma radiation exposure. Larvae of this insect possess more than 95% of hemoglobin (Hb) in its circulatory hemolymph. This is a comparative study to see effect of gamma radiation on Hb of Chironomus and humans, two evolutionarily diverse organisms one having extracellular and the other intracellular Hb respectively. Stability and integrity of Chironomus and human Hb to gamma radiation was compared using biophysical techniques like Dynamic Light Scattering (DLS), UV-visible spectroscopy, fluorescence spectrometry and CD spectroscopy after exposure of whole larvae, larval hemolymph, human peripheral blood, purified Chironomus and human Hb. Sequence- and structure-based bioinformatics methods were used to analyze the sequence and structural similarities or differences in the heme pockets of respective Hbs. Resistivity of Chironomus Hb to gamma radiation is remarkably higher than human Hb. Human Hb exhibited loss of heme iron at a relatively low dose of gamma radiation exposure as compared to Chironomus Hb. Unlike human Hb, the heme pocket of Chironomus Hb is rich in aromatic amino acids. Higher hydophobicity around heme pocket confers stability of Chironomus Hb compared to human Hb. Previously reported gamma radiation tolerance of Chironomus can be largely attributed to its evolutionarily ancient form of extracellular Hb as evident from the present study. -- Highlights: •Comparison of radiation tolerant Chironomus Hb and radiation sensitive Human Hb. •Amino acid composition of midge and human heme confer differential hydrophobicity. •Heme pocket of evolutionarily ancient midge Hb provide gamma radiation resistivity.

  19. Measurement of background gamma radiation in the northern Marshall Islands.

    Science.gov (United States)

    Bordner, Autumn S; Crosswell, Danielle A; Katz, Ainsley O; Shah, Jill T; Zhang, Catherine R; Nikolic-Hughes, Ivana; Hughes, Emlyn W; Ruderman, Malvin A

    2016-06-21

    We report measurements of background gamma radiation levels on six islands in the northern Marshall Islands (Enewetak, Medren, and Runit onEnewetak Atoll; Bikini and Nam on Bikini Atoll; and Rongelap on Rongelap Atoll). Measurable excess radiation could be expected from the decay of (137)Cs produced by the US nuclear testing program there from 1946 to 1958. These recordings are of relevance to safety of human habitation and resettlement. We find low levels of gamma radiation for the settled island of Enewetak [mean = 7.6 millirem/year (mrem/y) = 0.076 millisievert/year (mSv/y)], larger levels of gamma radiation for the island of Rongelap (mean = 19.8 mrem/y = 0.198 mSv/y), and relatively high gamma radiation on the island of Bikini (mean = 184 mrem/y = 1.84 mSv/y). Distributions of gamma radiation levels are provided, and hot spots are discussed. We provide interpolated maps for four islands (Enewetak, Medren, Bikini, and Rongelap), and make comparisons to control measurements performed on the island of Majuro in the southern Marshall Islands, measurements made in Central Park in New York City, and the standard agreed upon by the United States and the Republic of the Marshall Islands (RMI) governments (100 mrem/y = 1 mSv/y). External gamma radiation levels on Bikini Island significantly exceed this standard (P = <0.01), and external gamma radiation levels on the other islands are below the standard. To determine conclusively whether these islands are safe for habitation, radiation exposure through additional pathways such as food ingestion must be considered.

  20. Effect of gamma radiation on graphite – PTFE dry lubrication system

    International Nuclear Information System (INIS)

    Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

    2017-01-01

    An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties. - Highlights: • Novel dry lubrication system of graphite -PTFE using gamma radiation. • Gamma radiation processing. • Reduction in coefficient of friction, frictional torque and wear loss of developed dry lubrication system.

  1. Well logging with natural gamma radiation

    International Nuclear Information System (INIS)

    Ellis, D.V.

    1983-01-01

    An invention is described for use in natural gamma radiation well logging in which measurements taken in a borehole are used in the search for valuable underground resources such as oil or gas. The invention comprises deriving a log of natural gamma radiation detected in selected energy windows for a selected borehole depth interval and converting it into a log of the selected subsurface materials, e.g. Th, U, K. This log is corrected for the effects of 1) either a gamma ray emitter in the borehole fluid, e.g. potassium salts and/or 2) a gamma ray attenuator in the borehole fluid, e.g. a strong attenuator such as barite and/or hematite. The Th, U, K log is particularly useful in the exploration of oil and gas resources since the Th, U, K concentrations are a good indication as to the presence, type and volume of shale and clay in the formations surrounding the borehole. (U.K.)

  2. Measuring element for the detection and determination of radiation doses of gamma radiation and neutrons

    International Nuclear Information System (INIS)

    Jahn, W.; Piesch, E.

    1975-01-01

    A measuring element detects and proves both gamma and neutron radiation. The element includes a photoluminescent material which stores gamma radiation and particles of arsenic and phosphorus embedded in the photoluminescent material for detecting neutron radiation. (U.S.)

  3. Activity concentrations and mean annual effective dose from gamma-emitting radionuclides in the Lebanese diet

    International Nuclear Information System (INIS)

    Nasreddine, L.; Hwalla, N.; El Samad, O.; Baydoun, R.; Hamze, M.; Parent-Massin, D.

    2008-01-01

    Since the primary factor contributing to the internal effective dose in the human organism is contaminated food, the control of radionuclides in food represents the most important means of protection. This study was conducted to determine the levels of the dietary exposure of the Lebanese population to gamma-emitting radioisotopes. The activity concentrations of gamma-emitting radioisotopes have been measured in food samples that represent the market basket of an adult urban population in Lebanon. The artificial radionuclide 137 Cs was measured above detection limits in only fish, meat and milk-based deserts. The most abundant natural radionuclide was 40 K (31-121 Bq kg -1 ), with the highest content in fish and meat samples. The annual mean effective dose contributed by 40 K in the reference typical diet was estimated equal to 186 μSv y -1 , a value reasonably consistent with findings reported by several other countries. (authors)

  4. GammaCam trademark radiation imaging system

    International Nuclear Information System (INIS)

    1998-02-01

    GammaCam trademark, a gamma-ray imaging system manufactured by AIL System, Inc., would benefit a site that needs to locate radiation sources. It is capable of producing a two-dimensional image of a radiation field superimposed on a black and white visual image. Because the system can be positioned outside the radiologically controlled area, the radiation exposure to personnel is significantly reduced and extensive shielding is not required. This report covers the following topics: technology description; performance; technology applicability and alternatives; cost; regulatory and policy issues; and lessons learned. The demonstration of GammaCam trademark in December 1996 was part of the Large-Scale Demonstration Project (LSDP) whose objective is to select and demonstrate potentially beneficial technologies at the Argonne National Laboratory-East (ANL) Chicago Pile-5 Research Reactor (CP-5). The purpose of the LSDP is to demonstrate that by using innovative and improved decontamination and decommissioning (D and D) technologies from various sources, significant benefits can be achieved when compared to baseline D and D technologies

  5. Gamma-ray vulnerability of light-emitting diodes injection-laser diodes and pin-photodiodes for 1.3 μm wavelength-fiber optics

    International Nuclear Information System (INIS)

    Breuze, G.; Serre, J.

    1992-01-01

    With the increasing use of optical data links, it becomes essential to test for radiation vulnerability not only the transmission support - fiber and cable - but also fiber-end electro-optical components that could be exposed to hostile environment. Presently there is a significant number of radiation tests of optical fibers [1,2,3[. Here are only given a few results obtained on gradient index multimode fibers with and without phosphor. These data provide an important contribution to the improvement of all standard electro-optical pigtailed components working on the 1.3 μm wavelength: light-emitting diodes (LED), injection-laser diode modules (LDM) and pin-photodiodes (PD). Multicomponent LDM behaviour under CO 60 exposure was extensively tested. Hardened optical data links allow now to ensure medium data transmission rates on appreciable fiber - lengths despite medium steady - state gamma-ray exposure

  6. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  7. On the honeybee resistance to gamma radiation

    International Nuclear Information System (INIS)

    Courtois, G.; Lecomte, J.

    1960-01-01

    The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [fr

  8. Effect of gamma radiation on graphite - PTFE dry lubrication system

    Science.gov (United States)

    Singh, Sachin; Tyagi, Mukti; Seshadri, Geetha; Tyagi, Ajay Kumar; Varshney, Lalit

    2017-12-01

    An effect of gamma radiation on lubrication behavior of graphite -PTFE dry lubrication system has been studied using (TR-TW-30L) tribometer with thrust washer attachment in plane contact. Different compositions of graphite and PTFE were prepared and irradiated by gamma rays. Gamma radiation exposure significantly improves the tribological properties indicated by decrease in coefficient of friction and wear properties of graphite -PTFE dry lubrication system. SEM and XRD analysis confirm the physico-chemical modification of graphite-PTFE on gamma radiation exposure leading to a novel dry lubrication system with good slip and anti friction properties.

  9. Detailed deposition density maps constructed by large-scale soil sampling for gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident.

    Science.gov (United States)

    Saito, Kimiaki; Tanihata, Isao; Fujiwara, Mamoru; Saito, Takashi; Shimoura, Susumu; Otsuka, Takaharu; Onda, Yuichi; Hoshi, Masaharu; Ikeuchi, Yoshihiro; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi

    2015-01-01

    Soil deposition density maps of gamma-ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant (NPP) accident were constructed on the basis of results from large-scale soil sampling. In total 10,915 soil samples were collected at 2168 locations. Gamma rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that of June 14, 2011 by considering the intrinsic decay constant of each nuclide. Finally the deposition maps were created for (134)Cs, (137)Cs, (131)I, (129m)Te and (110m)Ag. The radioactivity ratio of (134)Cs-(137)Cs was almost constant at 0.91 regardless of the locations of soil sampling. The radioactivity ratios of (131)I and (129m)Te-(137)Cs were relatively high in the regions south of the Fukushima NPP site. Effective doses for 50 y after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from the other radioactive nuclides. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Fluorescent L-radiation and the. gamma. -radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Riou, M

    1949-02-21

    Irene Curie, Compt. rend. 227, 1225(1948), has shown that the ..gamma..-radiation of ionium is accompanied by a soft radiation that can be identified with the fluorescent L-lines of radium. The present author submitted these radiations to a further study, using as a source a ionium--thorium mixture, (100 mg of hydrate), containing 9% ionium. The Geiger--Mueller counters had 5 mg/cm/sup 2/ aluminum ends and were filled with alcohol + xenon at 10-21 cm Hg. The absorption curves in Cu, Mo, and Ag showed that the energy of the soft radiation was about 14 keV. For the separation of lines, the selective absorption was determined in elements from Z = 28 to Z = 53. The results confirmed the attribution of the spectrum to the L-radiation of Ra. Similar measurements on radioactinium revealed the same lines with approximately the same intensities. In both cases a radium isotope is formed: /sub 90/Th/sup 230/(Io) ..-->.. /sub 88/Ra/sup 226/ ..-->.. ..cap alpha.., /sub 90/Th/sup 227/ (RaAc) ..-->.. /sub 88/Ra/sup 223/ (AcX) + ..cap alpha... The identity of the spectra shows that the atomic number of the formed atom alone determines the L-spectrum, and that in both cases the L level is excited as a result of an internal conversion of ..gamma..-lines: the line 68 keV in the case of ionium, eight lines 26-100 keV in that of radioactinium. On the basis of the intensities found, the relative numbers of photons corresponding to the levels L/sub I/, L/sub II/, and L/sub III/ could be calculated; they are L/sub I/:L/sub II/:L/sub III/ = 50:20:26. The ..gamma..-rays of ionium, as determined from the absorption in Cu, Ta, and Pb, are 68 and 200 kev. By assuming that the efficiency of the counters is equal to 1 - exp (-m..mu../rho), (where m is the efficient superficial mass of xenon, and ..mu../rho is the absorption coefficient in xenon), the intensities of the L- and ..gamma..-radiations of ionium can be given in terms of numbers of quanta per 100 disintegrations.

  11. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  13. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma secondaire emis par le meme processus pour les autres corps

  14. X-ray and radium gamma radiation injuries

    International Nuclear Information System (INIS)

    Fokkema, R.E.

    1993-05-01

    During the period 1896-1939 a number of maxima could be distinguished in the incidence of X-ray and radium gamma ray injuries in patients. An explanation for these fluctuations is investigated in this study. The first distinguishable maximum in the number of reported cases of X-ray injuries can be found in the period 1896-1897 and mainly concerns skin lesions, caused by the lack of shielding and ignorance of the effects. In the period 1904-1905 there was once again an apparent prevalence of radiation injuries to patients. After 1905 the incidence of radiation injuries decreased due to a wider use of dosimetric methods. The third phase of increased injuries may be subdivided into three components. In diagnostic roentgenology from 1896 to 1926 a number of causes of roentgen burns persisted: multiple or long exposures, the use of a short focus-skin-distance and a lack of suitable dosimetric methods. The reduction of complications after 1923 can be attributed to several factors: systematic training of physics who wished to become roentgenologists, greater care of doctors, the use of an alternative method of radiotherapy according to Coutard's method, the introduction of dosimetry with ionization chambers (after 1924), the consensus reached over the roentgen as a unit of applied dosage (in 1928), and the introduction of absorption curves for radiation quality (in 1933). Around 1920 a high complication rate arose as a result of exposure to radiation emitted by radium. In 1922 the first reliable radium dosimetry method came available. This applied to external radium therapy by regular shaped applicators. After 1938 reliable dosimetry was achieved in the field of interstitial radium therapy (brachytherapy). Injuries from radium therapy, however, persisted till about 1940, caused not only by the delayed availability of radium dosimetry, but also to the use of radium therapy by poorly trained radium therapists. 28 figs., 5 tabs

  15. Research progress in airborne surveys of terrestrial gamma radiation

    International Nuclear Information System (INIS)

    Burson, Z.G.

    1974-01-01

    Progress during the last few years in airborne surveys of terrestrial gamma radiation, i.e. in the measuring, recording, and interpreting of gamma ray signals in NaI(Tl) crystals, is discussed. Non-terrestrial background contributions have been accurately characterized. The feasibility of determining the water equivalent of snow cover by aerial survey techniques has been demonstrated. Repeat surveys over areas surrounding reactor sites can now be used to detect average differences of less than 1.0 μR/hr in terrestrial gamma radiation levels. New data acquisition and recording systems allow isotope concentrations and total inventories to be measured in spatial resolutions of a few hundred feet. Aerial survey data have been combined with population distribution data to obtain population exposure values from natural terrestrial gamma radiation around reactor sites

  16. Increase in. gamma. -radiation from powdered milk and beef

    Energy Technology Data Exchange (ETDEWEB)

    Sievert, R M; Gustafsson, S; Sylander, C G

    1956-01-01

    Samples of powdered milk and beef preserved during the years 1953 to 1956 were examined for the presence of ..gamma..-radiation. The higher ..gamma..-radiation found in the last year was attributed to an increase in fission products. Data are compared with measurements on a series of children.

  17. Environmental gamma radiation levels around various DAE research centres

    International Nuclear Information System (INIS)

    Takale, R.A.; Swarnakar, M.; Shetty, P.G.; Sahu, S.K.; Pandit, G.G.

    2014-01-01

    This paper presents the gamma radiation levels of four research centres viz. Bhabha Atomic Research Centre (BARC), Trombay; Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam; Variable Energy Cyclotron Centre (VECC), Kolkata; Raja Ramanna Centre for Advanced Technology (RRCAT), Indore; and an industry Board of Radiation and Isotope Technology (BRIT), Vashi. BARC is India's premier nuclear research facility and is a multi-disciplinary research centre with extensive infrastructure for advanced research and development (R and D). IGCAR, Kalpakkam is engaged in scientific research and advanced engineering programme towards the development of Fast Breeder Reactor technology. VECC Kolkata is dedicated to carry out frontier R and D in the fields of Accelerator Science and Technology, Nuclear Science (Theoretical and Experimental), and Material Science etc. RRCAT, Indore has rapidly grown into a premier institute for R and D in lasers, accelerators and their applications. BRIT, Vashi unit is involved in production, development, and supply of radioisotope based products and provision of isotope applications, radiation processing, radio analytical services etc. With an objective to keep a watch on the prevailing environmental background gamma radiation level around all the DAE installations, routine monitoring programme are being carried out using the Thermo Luminescent Dosimeters (TLDs). TLDs provide the simple, inexpensive and precise measurement of small, integrated, external gamma radiation dose rate. The general practice of this programme is to observe the outdoor gamma radiation levels. This paper summarizes the methodology and gamma radiation levels of four research centres viz. BARC, IGCAR, VECC, RRCAT and an industry BRIT, Vashi

  18. Effect of gamma radiation on honey quality control

    International Nuclear Information System (INIS)

    Bera, A.; Almeida-Muradian, L.B.; Sabato, S.F.

    2009-01-01

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

  19. Effect of gamma radiation on honey quality control

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-15

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

  20. Gamma radiation in dwellings

    International Nuclear Information System (INIS)

    Mjoenes, L.

    1981-08-01

    A nationwide investigation has been made into the gamma radiation in Swedish dwellings. The measurements were made with small detectors containing thermoluminescent dosimeters. The detectors were sent to the selected participants by mail. 1300 dwellings were included in the investigation. In each dwelling three measurements were made: one detector was placed in the kitchen, one in the living-room and one in the bedroom. The mean annual absorbed tissue dose in dwellings in Sweden was found to be 0.65 mGy (corresponding to an exposition rate of 12 μR/h) when the contribution from cosmic radiation had been subtracted. That represents an annual collective dose of about 4000 mansieverts to the population of Sweden. From a previous investigation we have calculate the mean value for the gamma radiation in Swedish dwellings for 1950 to be 0.4 mGy/a (8μR/h). The reason for the relatively large increase in the mean value is an increased use of building materials on stone, particularly of lightweight concrete based on alum shale, from 1940 to middle 1960s. The production of this type of lightweight concrete was discontinued in 1975 and the use of other stone-based building materials has decreased. The mean value of gamma radiation in Swedish dwellings is therefore expected to decrease slowly in the future if this tendency holds. Sweden has some 3.5 million dwellings. About 10 % of them have mean values of 1 mGy/a (19 μR/h) or more, 0.2 % have 3 mGy/a (57 μR/h) or more and a couple of hundred 5 mGy/a (95 μR/h or more. The mean value for detached houses was found to be 0.43 mGy/a (8 μR/h) and for dwellings in multi-family houses 0.80 mGy/a (15 μR/h). The investigation dwellings have also been classified according to the building materials, the year of construction and the degree of urbanization of the area. (author)

  1. Designing equipment for use in gamma radiation environments

    International Nuclear Information System (INIS)

    Vandergriff, K.U.

    1990-05-01

    High levels of gamma radiation are known to cause degradation in a variety of materials and components. When designing systems to operate in a high radiation environment, special precautions and procedures should be followed. This report (1) outlines steps that should be followed in designing equipment and (2) explains the general effects of radiation on various engineering materials and components. Much information exists in the literature on radiation effects upon materials. However, very little information is available to give the designer a step-by-step process for designing systems that will be subject to high levels of gamma radiation, such as those found in a nuclear fuel reprocessing facility. In this report, many radiation effect references are relied upon to aid in the design of components and systems. 11 refs., 4 tabs

  2. Can a tachyon emit light radiation in all directions

    Energy Technology Data Exchange (ETDEWEB)

    Ramanujam, G A [NGM Coll., Tamil Nadu (India). Dept. of Physics

    1976-03-01

    It is shown here that a critical analysis of the approaches employed by various authors to accommodate tachyons into special relativity leads one to the conclusion that a tachyon can emit light radiation only along its line of motion.

  3. Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

    2009-11-21

    In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

  4. A NuSTAR Observation of the Gamma-Ray Emitting Millisecond Pulsar PSR J1723–2837

    Energy Technology Data Exchange (ETDEWEB)

    Kong, A. K. H. [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Hui, C. Y. [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of); Takata, J. [Institute of Particle Physics and Astronomy, Huazhong University of Science and Technology (China); Li, K. L. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Tam, P. H. T., E-mail: akong@phys.nthu.edu.tw, E-mail: cyhui@cnu.ac.kr [School of Physics and Astronomy, Sun Yat-sen University, Zhuhai 519082 (China)

    2017-04-20

    We report on the first NuSTAR observation of the gamma-ray emitting millisecond pulsar binary PSR J1723–2837. X-ray radiation up to 79 keV is clearly detected, and the simultaneous NuSTAR and Swift spectrum is well described by an absorbed power law with a photon index of ∼1.3. We also find X-ray modulations in the 3–10, 10–20, 20–79, and 3–79 keV bands at the 14.8 hr binary orbital period. All of these are entirely consistent with previous X-ray observations below 10 keV. This new hard X-ray observation of PSR J1723–2837 provides strong evidence that the X-rays are from the intrabinary shock via an interaction between the pulsar wind and the outflow from the companion star. We discuss how the NuSTAR observation constrains the physical parameters of the intrabinary shock model.

  5. Effect of gamma radiation on chemical composition and storability of lime RTS

    International Nuclear Information System (INIS)

    Pandey, S.K.; Bisen, A.; Dwivedi, V.

    2008-01-01

    In the present investigation, the RTS was irradiated with different doses of gamma radiation to study their effect on chemical composition and storability of lime RTS and vitamin C content only was influenced significantly by 50 Gy gamma radiation during storage (16 days) without adversely affecting the quality of lime fruits, whereas, under control and higher doses of gamma radiation, the quality of lime RTS was deteriorated. The irradiation of lime with 50 Gy gamma radiation may be useful for extending storability of lime of RTS and stabilizing the market demand. (author)

  6. SYSTEMATIC STUDY OF GAMMA-RAY-BRIGHT BLAZARS WITH OPTICAL POLARIZATION AND GAMMA-RAY VARIABILITY

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Ryosuke; Fukazawa, Yasushi; Kanda, Yuka; Shiki, Kensei; Kawabata, Miho; Nakaoka, Tatsuya; Takaki, Katsutoshi; Takata, Koji; Ui, Takahiro [Department of Physical Science, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Nalewajko, Krzysztof; Madejski, Greg M. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford University, 2575 Sand Hill Road M/S 29, Menlo Park, CA 94025 (United States); Uemura, Makoto; Tanaka, Yasuyuki T.; Kawabata, Koji S.; Akitaya, Hiroshi; Ohsugi, Takashi [Hiroshima Astrophysical Science Center, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Schinzel, Frank K. [Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States); Moritani, Yuki [Kavli Institute for the Physics and Mathematics of the Universe (WPI), The University of Tokyo Institutes for Advanced Study, The University of Tokyo, Kashiwa, Chiba 277-8583 (Japan); Sasada, Mahito [Institute for Astrophysical Research, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Yamanaka, Masayuki, E-mail: itoh@hep01.hepl.hiroshima-u.ac.jp, E-mail: itoh@hp.phys.titech.ac.jp [Department of Physics, Faculty of Science and Engineering, Konan University, Okamoto, Kobe, Hyogo 658-8501 (Japan); and others

    2016-12-10

    Blazars are highly variable active galactic nuclei that emit radiation at all wavelengths from radio to gamma rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies, and it also varies dramatically. The polarization of blazars is of interest for understanding the origin, confinement, and propagation of jets. However, even though numerous measurements have been performed, the mechanisms behind jet creation, composition, and variability are still debated. We performed simultaneous gamma-ray and optical photopolarimetry observations of 45 blazars between 2008 July and 2014 December to investigate the mechanisms of variability and search for a basic relation between the several subclasses of blazars. We identify a correlation between the maximum degree of optical linear polarization and the gamma-ray luminosity or the ratio of gamma-ray to optical fluxes. Since the maximum polarization degree depends on the condition of the magnetic field (chaotic or ordered), this result implies a systematic difference in the intrinsic alignment of magnetic fields in parsec-scale relativistic jets between different types of blazars (flat-spectrum radio quasars vs. BL Lacs) and consequently between different types of radio galaxies (FR I versus FR II).

  7. Sensitiveness of jasmine cuttings to gamma radiation

    International Nuclear Information System (INIS)

    Devaiah, K.A.; Srivastava, H.C.

    1989-01-01

    Half lethal dose (LD 50 ) gamma radiation for five genotypes of jasmine and the effect of such radiation on their rooting parameters were studied. The LD 50 was close to 2.5 krad for Jasminum grandiflorum var. Pink Pin, 0.5 krad for var. Pink Thrum, 2.5 krad for J. flexile Valh., 1 krad for J. calophyllum Wall and 2 krad for J. sambac Ait var. 'Gundumalli'. Percentage of rooting, number of roots per cutting, length and thickness of roots decreased with increase in intensity of gamma irradiation. (author) 8 refs.; 4 tabs

  8. Study of gamma radiation shielding properties of ZnO-TeO_2 glasses

    International Nuclear Information System (INIS)

    Issa, Shama A.M.; Sayyed, M.I.; Kurudirek, Murat

    2017-01-01

    Mass attenuation coefficient (μm), half value layer (HVL) and mean free path (MFP) for xZnO-(100-x)TeO_2, where x=10, 15, 20, 25, 30, 35 and 40 mol%, have been measured for 0.662, 1.173 and 1.33 MeV photons emitted from "1"3"7Cs and "6"0Co using a 3 x 3 inch NaI (Tl) detector. Some relevant parameters such as effective atomic numbers (Z_e_f_f) and electron densities (Nel) of glass samples have been also calculated in the photon energy range of 0.015-15 MeV. Moreover, gamma-ray energy absorption buildup factor (EABF) and exposure buildup factor (EBF) were estimated using a five-parameter Geometric Progression (GP) fitting approximation, for penetration depths up to 40 MFP and in the energy range 0.015-15 MeV. The measured mass attenuation coefficients were found to agree satisfactorily with the theoretical values obtained through WinXcom. Effective atomic numbers (Z_e_f_f) and electron densities (N_e_l) were found to be the highest for 40ZnO-60TeO_2 glass in the energy range 0.04-0.2 MeV. The 10ZnO-90TeO_2 glass sample has lower values of gamma-ray EBFs in the intermediate energy region. The reported new data on radiation shielding characteristics of zinc tellurite glasses should be beneficial from the point of proper gamma shield designs when intended to be used as radiation shields. (author)

  9. Effect of gamma radiation on optical and electrical properties of ...

    Indian Academy of Sciences (India)

    Wintec

    Tellurium dioxide; thin films; optical bandgap; gamma radiation dose; dosimeter. 1. Introduction. It is now ... material to ionizing radiations (such as X-rays, gamma rays, beta ..... Mag. 19 19. Mott N F and Davis E 1979 Electronic process in non-.

  10. The diagnosis of the gastric cancer using catheter-type semiconductor radiation detector. Comparison of diagnostic values of. beta. -emitting radionuclide label with. gamma. -emitting label

    Energy Technology Data Exchange (ETDEWEB)

    Sassa, R; Iwase, T [Asahi Life Foundation, Tokyo (Japan). Inst. for Adult Diseases; Sugita, T; Iio, M

    1975-06-01

    The diagnostic usefulness of /sup 32/P-phosphate for human gastric cancer, using a catheter-type semiconductor radiation detector (CASRAD) combined with gastrofiberscope technique, has already been reported by the authors. They have in addition used sup(99m)Tc-bleomycin, sup(99m)Tc-tetracycline in the diagnosis of experimental rabbit gastric cancer, too. In the present study, further refinement of the technique for the ..beta..-ray labeled substance (/sup 32/P-phosphate) for detection of the gastric cancer was compared with that of ..gamma..-ray labeled substance (sup(99m)Tc-tetracycline). A more correct diagnosis of the gastric cancer by in vivo measurement of beta activity could be obtained, when the collimater, made of stainless steel, was attached to the top of the detector. In this way contribution to the count from the adjacent tissues or organs could be eliminated. They were unable to produce an effective and useful collimater for ..gamma..-ray labeled substance which could to be used safely in vivo. Because of the unsatisfactory collimater, radioactivities of the adjacent organs caused on increase in the radioactivity of the background. Therefore inspite of the recent introduction of various sup(99m)Tc-tumor agents, these labels were not applicable to the CASRAD method. For such a small detector system, ..beta..-labels, represented by /sup 32/P-phosphate, was still prefererable to ..gamma..-labels.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-01

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

  12. Gamma emitting radionuclides of the Test Reactor Area leaching ponds

    International Nuclear Information System (INIS)

    Millard, J.B.; Whicker, F.W.; Markham, O.D.

    1978-01-01

    Radioactive leaching ponds adjacent to the Test Reactor Area (TRA) located on the Idaho National Engineering Laboratory (INEL) Site were investigated to determine the seasonal distribution and ecological behavior of gamma emitting radionuclides. The potential hazards to man and the environment were considered through the biological export of radioactive materials from the ponds. Both biotic and abiotic pond compartments were sampled. Fall and winter biomass estimates showed that benthic periphyton comprised 52%, macrophytes and littoral vegetation 35%, and seston 10% of the total for all biotic compartments. Concentrations and concentration factors (CFs) for fall and winter are presented for Cr-51, Co-60, Zr-95, I-131, Cs-137, Ba-140, and Ce-141. Concentrations and CFs ranged over seven orders of magnitude for the various nuclides and compartments. Seston and zooplankton had the highest concentrations followed by periphyton, sediment, macrophytes, littoral plants, willow, and filtered water. Arthropods had variable concentrations and CFs. Significant seasonal differences were observed for concentrations and CFs in seston, macrophytes, and littoral vegetation. A compartmental inventory of total gamma emitting activity accounted for 254 Ci (9.25 TBq) of the 731 Ci (24.8 TBq) estimated to remain in the ponds at the time of sampling. Filtered water and surface sediments contained 99% of the total radioactivity, while periphyton and seston had most of the remaining 1%. An estimate of the avian export rate of radioactivity from the TRA ponds showed that potentially harvestable mourning doves had the lowest rate with 0.02 μCi/y. External tissues of migratory waterfowl were found to contribute 90% of the total exported activity for all birds. The total avian export rate was estimated to be 1350 μCi/y during 1975

  13. Residual water treatment for gamma radiation. Tratamiento de aguas residuales por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, L [Universidad Nacional Mayor de San Marcos. Facultad de Quimica (Peru)

    1990-07-01

    The treatment of residual water by means of gamma radiation for its use in agricultural irrigation is evaluated. Measurements of physical, chemical, biological and microbiological contamination indicators were performed. For that, samples from the treatment center of residual water of San Juan de Miraflores were irradiated up to a 52.5 kGy dose. The study concludes that gamma radiation is effective to remove parasites and bacteria, but not for removal of the organic and inorganic matter. (author). 15 refs., 3 tabs., 4 figs.

  14. Effect of gamma radiation on ''in vitro''' efficiency of fungicides

    International Nuclear Information System (INIS)

    Menten, J.O.M.; Oliveira, G.C.X.

    1984-01-01

    The activity of 60 Co gamma radiation on eight fungicides used in post-harvesting treatment of agricultural products, was studied. Rhizoctonia solani was used in biological test as indicator-fungus. The fungicides were submitted to gamma radiation doses of O (control), 1, 10, 100, 1000 and 10.000 kR, samples of the fungicides were added to the PSA culture media to obtain 0, 1, 10 and 100 ppm concentrations of the active component of each product and of each radiation dose. The ED 50 (concentration of fungicide necessary to cause 50% radial reduction of the fungic mycelium) of each fungicide in the different gamma radiation doses was determined. (M.A.C.) [pt

  15. Dose Rate of Environmental Gamma Radiation in Java Island

    International Nuclear Information System (INIS)

    Gatot Suhariyono; Buchori; Dadong Iskandar

    2007-01-01

    The dose rate Monitoring of environmental gamma radiation at some locations in Java Island in the year 2005 / 2006 has been carried out. The dose rate measurement of gamma radiation is carried out by using the peripheral of Portable Gamma of Ray Spectrometer with detector of NaI(Tl), Merck Exploranium, Model GR-130- MINISPEC, while to determine its geographic position is used by the GPS (Global Positioning System), made in German corporation of GPS III Plus type. The division of measurement region was conducted by dividing Java Island become 66 parts with same distance, except in Jepara area that will built PLTN (Nuclear Energy Power), distance between measurement points is more closed. The results of dose rate measurement are in 66 locations in Java Island the range of (19.24 ± 4.05) nSv/hour until (150.78 ± 12.26) nSv/hour with mean (51.93 ± 36.53) nSv/h. The lowest dose rate was in location of Garut, while highest dose rate was in Ujung Lemah Abang, Jepara location. The data can be used for base line data of dose rate of environmental gamma radiation in Indonesia, specially in Java Island. The mean level of gamma radiation in Java monitoring area (0.46 mSv / year) was still lower than worldwide average effective dose rate of terrestrial gamma rays 0.5 mSv / year (report of UNSCEAR, 2000). (author)

  16. Transition undulator radiation as bright infrared sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K.J. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Undulator radiation contains, in addition to the usual component with narrow spectral features, a broad-band component in the low frequency region emitted in the near forward direction, peaked at an angle 1/{gamma}, where {gamma} is the relativistic factor. This component is referred to as the transition undulator radiation, as it is caused by the sudden change in the electron`s longitudinal velocity as it enters and leaves the undulator. The characteristic of the transition undulator radiation are analyzed and compared with the infrared radiation from the usual undulator harmonics and from bending magnets.

  17. Seasonal distribution and uptake of gamma emitting radionuclides at the test reactor area leaching ponds

    International Nuclear Information System (INIS)

    Millard, J.B.

    1986-01-01

    Radioactive leaching ponds adjacent to the Test Reactor Area (TRA) located on the Idaho National Engineering Laboratory (INEL) site were investigated to determine the seasonal distribution and ecological behavior of gamma emitting radionuclides in various pond compartments. The physical, chemical and biological properties of the TRA ponds were documented including basic morphometry, water chemistry and species identification. Penetrating radiation exposure rates at the ponds ranged from 35 to 65 mR/d at the water surface and up to 3400 mR/d one meter above bottom sediments. Seasonal concentrations and concentration ratios were determined for 16 principle radionuclides in filtered water, sediment, seston, zooplankton, net plankton, nannoplankton, periphyton, macrophytes, thistle, speedwell and willow. Seston and nannoplankton had the highest concentration ratios with substantial decreases observed for higher trophic level compartments. Significant (P < 0.01 to P < 0.001) seasonal effects wee found for concentration ratios. Radionuclides without nutrient analogs had the highest ratios in spring for periphyton, macrophytes and littoral plants. Concentration ratios were highest in summer, fall or winter for radionuclides with nutrient analogs

  18. Gamma radiation effects on peanut skin antioxidants

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  19. Gamma radiation effects on peanut skin antioxidants

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  20. DISCERNING THE GAMMA-RAY-EMITTING REGION IN THE FLAT SPECTRUM RADIO QUASARS

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. G. [Department of Physics, Yunnan Normal University, Kunming, 650092 (China); Yang, C. Y.; Wang, J. C. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Zhang, L., E-mail: ynzyg@ynu.edu.cn, E-mail: chyy@ynao.ac.cn [Department of Astronomy, Yunnan University, Kunming, 650091 (China)

    2017-01-01

    A model-dependent method is proposed to determine the location of the γ -ray-emitting region for a given flat spectrum radio quasar (FSRQ). In the model, the extra-relativistic electrons are injected at the base of the jet and non-thermal photons are produced by both synchrotron radiation and inverse-Compton (IC) scattering in the energy dissipation region. The target photons dominating IC scattering originate from both synchrotron photons and external ambient photon fields, and the energy density of external radiation field is a function of the distance between the position of the dissipation region and a central supermassive black hole, and their spectra are seen in the comoving frame. Moreover, the energy dissipation region could be determined by the model parameter through reproducing the γ -ray spectra. Such a model is applied to reproduce the quasi-simultaneous multi-wavelength observed data for 36 FSRQs. In order to define the width of the broad-line region (BLR) shell and dusty molecular torus (MT) shell, a simple numerical constraint is used to determine the outer boundary of the BLR and dusty MT. Our results show that (1) the γ -ray-emitting regions are located at the range from 0.1 to 10 pc; (2) the γ -ray-emitting regions are located outside the BLRs and within the dusty molecular tori; and (3) the γ -ray-emitting regions are located closer to the dusty MT ranges than the BLRs. Therefore, it may be concluded that direct evidence for the far site scenario could be obtained on the basis of the model results.

  1. Design, construction and calibration of a polarimeter for gamma radiation

    International Nuclear Information System (INIS)

    Macchiavelli, A.O.; Marti, G.V.; Gimenez, C.R.; Laffranchi, J.A.; Behar, M.

    1980-01-01

    Information on different nuclear states can be obtained from the analysis of the angular distribution of the emitted gamma radiation. When the information is not sufficient to determine certain relevant parameters, or is ambiguous, a measurement of the linear polarization of radiation together with the angular distribution allows, in many cases, to resolve this ambiguity. This in turn, necessitates of a detector radiation: this is a Ge(Li) planar detector with a width d of the compensated zone smaller than the length L (L/d greater than 1), built from a germanium block with a square section of 33 mm side, compensated with lithium up to 3 mm depth, by means of usual techniques. The detector characteristics, measured by conventional electronics, were: system's total resolution (Full Width at Half Maximum) 2.4 keV; pico-Compton relation of 6/1 and relative efficiency of 0. for γ rays of 1.33 MeV from 60 Co. Using γ-γ fast-slow coincidence techniques (Ge(Li)-INa system), the curve of polarization efficiency in the 0.1.5 MeV energy range was determined and a polarization efficiency of approximately 17% was obtained for said energy range. This value is comparable to the results obtained in previous works for polarimeters of similar dimensions and can be used to determine multipolarity of nuclear states. (M.E.L.) [es

  2. Development of a novel gamma probe for detecting radiation direction

    Science.gov (United States)

    Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

  3. Development of a novel gamma probe for detecting radiation direction

    International Nuclear Information System (INIS)

    Pani, R.; Pellegrini, R.; Cinti, M.N.; Longo, M.; Donnarumma, R.; Borrazzo, C.; D'Alessio, A.; Pergola, A.; Ridolfi, S.; Vincentis, G. De

    2016-01-01

    Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security

  4. Effect of gamma radiation on polyvinylpyrrolidone hydrogels

    International Nuclear Information System (INIS)

    Oliveira, M.J.A.; Vásquez, P.A.S.; Alcântara, M.T.S.; Munhoz, M.M.L.; Lugão, A.B.

    2017-01-01

    Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy. (author)

  5. Effect of gamma radiation on polyvinylpyrrolidone hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, M.J.A.; Vásquez, P.A.S.; Alcântara, M.T.S.; Munhoz, M.M.L.; Lugão, A.B., E-mail: mariajhho@yahoo.com.br, E-mail: pavsalva@ipen.br, E-mail: ablugao@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Polyvinylpyrrolidone (PVP) hydrogels have been investigated as drug delivery matrices for the treatment of wounds, such as cutaneous leishmaniasis, and matrices with silver nanoparticles for chronic wounds and burns. The preparation of such hydrogels can occur by various cross-linking methods, such as gamma, chemical, physical, among others. The most feasible for wound dressings is gamma irradiation from cobalt-60, because gamma irradiation simultaneously promotes crosslinking and sterilization, leaving the wound dressing ready for use. The objective of this work was to investigate the effect on physico- chemical properties of gamma radiation on PVP hydrogel according to the radiation absorbed dose variation. The PVP hydrogels were irradiated with doses of 5, 15, 25, 35, 45, 55, 65, 75 and 95kGy at dose rate of 5 kGy/h and characterized by swelling, thermogravimetric and mechanical analysis. Results shown a favorable dose range window for processing of these hydrogels related to the application. The results showed that mechanical strength was affected at doses starting at 25 kGy. (author)

  6. Bioburden assessment and gamma radiation inactivation patterns in parchment documents

    International Nuclear Information System (INIS)

    Nunes, Inês; Mesquita, Nuno; Cabo Verde, Sandra; Carolino, Maria Manuela; Portugal, António; Botelho, Maria Luísa

    2013-01-01

    Parchment documents are part of our cultural heritage and, as historical artifacts that they are, should be preserved. The aim of this study was to validate an appropriate methodology to characterize the bioburden of parchment documents, and to assess the growth and gamma radiation inactivation patterns of the microbiota present in that material. Another goal was to estimate the minimum gamma radiation dose (D min ) to be applied for the decontamination of parchment as an alternative treatment to the current toxic chemical and non-chemical decontamination methods. Two bioburden assessment methodologies were evaluated: the Swab Method (SM) and the Destructive Method (DM). The recovery efficiency of each method was estimated by artificial contamination, using a Cladosporium cladosporioides spore suspension. The parchment samples' microbiota was typified using morphological methods and the fungal isolates were identified by ITS-DNA sequencing. The inactivation pattern was assessed using the DM after exposure to different gamma radiation doses, and using C. cladosporioides as reference. Based on the applied methodology, parchment samples presented bioburden values lower than 5×10 3 CFU/cm 2 for total microbiota, and lower than 10 CFU/cm 2 for fungal propagules. The results suggest no evident inactivation trend for the natural parchment microbiota, especially regarding the fungal community. A minimum gamma radiation dose (D min ) of 5 kGy is proposed for the decontamination treatment of parchment. Determining the minimal decontamination dose in parchment is essential for a correct application of gamma radiation as an alternative decontamination treatment for this type of documents avoiding the toxicity and the degradation promoted by the traditional chemical and non-chemical treatments. - Highlights: • Characterization of the microbial population of parchment documents. • Study the inactivation pattern of parchment microbiota by gamma radiation. • Assessment of

  7. Non-radiative recombination losses in polymer light-emitting diodes

    NARCIS (Netherlands)

    Kuik, M.; Koster, L. J. A.; Dijkstra, A. G.; Wetzelaer, G. A. H.; Blom, P. W. M.

    We present a quantitative analysis of the loss of electroluminescence in light-emitting diodes (LEDs) based on poly[2-methoxy-5-(2'-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) due to the combination of non-radiative trap-assisted recombination and exciton quenching at the metallic cathode. It is

  8. Gamma radiation effect study in polycarbonate optical and mechanics properties

    International Nuclear Information System (INIS)

    Araujo, E.S. de.

    1991-02-01

    Polycarbonates (PC) are used in different industrial applications due to their excellent dielectric characteristics, impact resistance, and high temperature resistance. In some of these applications, the polycarbonates are exposed to gamma radiation which produces molecular scissions, causing changes in the polycarbonate properties. To estimate the radiation effects in the Durolon polycarbonate, samples were irradiated with 60 Co gamma rays with doses between 0,2 kGy and 300 kGy. The results obtained showed that the PC mechanical properties are not changed due to the gamma radiation. However the results showed an expressive variation in the yellowness index for doses above 1 kGy. The results showed that it is possible to use the gamma sterilization of PC in applications where the coloration of PC is not critical. (author). 21 refs, 25 figs, 3 tabs

  9. Studying and measuring the gamma radiation doses in Homs city

    International Nuclear Information System (INIS)

    Sofaan, A. H.

    2001-01-01

    The gamma radiation dose was measured in Homs city by using many portable dosimeters (electronic dosimeter and Geiger-Muller). The measurements were carried out in the indoor and outdoor buildings, for different time period, through one year (1999-2000). High purity germanium detector with low back ground radiation (HpGe) was used to determine radiation element contained in some building and the surrounding soil. The statistical analysis laws were applied to make sure that the measured dose distribution around average value is normal distribution. The measurement indicates that the gamma indoor dose varies from 312μSv/y to 511μSv/y, with the average annual dose of 385μSv/y. However the gamma outdoor dose rate varies from 307μSv/y to 366μSv/y with an average annual dose 385μSv/y. The annual outdoor gamma radiation dose is about %16 lower than the outdoor dose in Homs City. These measurements have indicated that environmental gamma doses in Homs City are relatively low. This is because that most of the soils and rocks in the area are limestone. (author)

  10. Synchrotron Radiation

    International Nuclear Information System (INIS)

    Asfour, F.I

    2000-01-01

    Synchrotron light is produced by electron accelerators combined with storage rings. This light is generated over a wide spectral region; from infra-red (IR) through the visible and vacuum ultraviolet (VUV), and into the X-ray region. For relativistic electrons (moving nearly with the speed of light), most radiation is concentrated in a small cone with an opening angle of 1/gamma(some 0.1 to 1 milliradian),where gamma is the electron energy in units of rest energy (typically 10 3 -10 4 ). In synchrotron radiation sources (storage rings) highly relativistic electrons are stored to travel along a circular path for many hours. Radiation is caused by transverse acceleration due to magnetic forces(bending magnets). The radiation is emitted in pulses of 10-20 picosecond, separated by some 2 nanosecond or longer separation

  11. Study of the effect of gamma radiation on some physical-mechanical properties of wood used in Brazilian cultural and artistic heritage

    International Nuclear Information System (INIS)

    Severiano, Lucio Cesar

    2010-01-01

    Wood is considered a natural composite of extreme complexity, basically composed by cellulose, lignin, hemicellulose (polyosis) and extractives. Its composition favors biological attacks from different species. In this context, several techniques have been studied and applied for disinfecting and decontaminating wood-made works of art and cultural heritage, which have been damaged by fungi, bacteria and insects. Gamma radiation emitted by unstable isotopes, such as 60- cobalt, has also been studied as an alternative to the conventional wood preservatives. So, gamma rays treatment has been shown to be efficient to the removal of infestations by insects and microorganisms in wood-made artifacts, to be fast and not to require quarantine because it does not generate toxic waste. Similar to other techniques, this process does not prevent the irradiated material of re-infestation or recontamination. In this context, the effects of relatively high disinfestation gamma radiation doses (up to 100 kGy) on cedro rosa and imbuia, two typical Brazilian wood species, are accompanied by the changes on the following attributes: apparent density, retracting, parallel compression to fibers, bending in the modulus of elasticity, hardness, shear and thermal stability. Results have shown that gamma radiation, in the studied dose range, does not promote alterations on properties of investigated wood species. In case of a re-infestation, these observations indicate that the wood species can be submitted to repeatedly irradiation processes without causing damage to their structure up to the studied dose range, in despite of radiation effects be always cumulative. (author)

  12. Calculating concentration of inhaled radiolabeled particles from external gamma counting: External counting efficiency and attenuation coefficient of thorax

    International Nuclear Information System (INIS)

    Langenback, E.G.; Foster, W.M.; Bergofsky, E.H.

    1989-01-01

    We determined the overall external counting efficiency of radiolabeled particles deposited in the sheep lung. This efficiency permits the noninvasive calculation of the number of particles and microcuries from gamma-scintillation lung images of the live sheep. Additionally, we have calculated the attenuation of gamma radiation (120 keV) by the posterior chest wall and the gamma-scintillation camera collection efficiency of radiation emitted from the lung. Four methods were employed in our experiments: (1) by light microscopic counting of discrete carbonized polystyrene particles with a count median diameter (CMD) of 2.85 microns and tagged with cobalt-57, we delineated a linear relationship between the number of particles and the emitted counts per minute (cpm) detected by well scintillation counting; (2) from this conversion relationship we determined the number of particles inhaled and deposited in the lungs by scintillation counting fragments of dissected lung at autopsy; (3) we defined a linear association between the number of particles or microcuries contained in the lung and the emitted radiation as cpm detected by a gamma scintillation camera in the live sheep prior to autopsy; and (4) we compared the emitted radiation from the lungs of the live sheep to that of whole excised lungs in order to calculate the attenuation coefficient (ac) of the chest wall. The mean external counting efficiency was 4.00 X 10(4) particles/cpm (5.1 X 10(-3) microCi/cpm), the camera collection efficiency was 1 cpm/10(4) disintegrations per minute (dpm), and the ac had a mean of 0.178/cm. The external counting efficiency remained relatively constant over a range of particles and microcuries, permitting a more general use of this ratio to estimate number of particles or microcuries depositing after inhalation in a large mammalian lung if a similarly collimated gamma camera system is used

  13. Dibasic calcium phosphate dihydrate, USP material compatibility with gamma radiation

    Science.gov (United States)

    Betancourt Quiles, Maritza

    Gamma radiation is a commonly used method to reduce the microbial bioburden in compatible materials when it is applied at appropriate dose levels. Gamma irradiation kills bacteria and mold by breaking down the organism’s DNA and inhibiting cell division. The purpose of this study is to determine the radiation dosage to be used to treat Dibasic Calcium Phosphate Dihydrate, USP (DCPD) and to evaluate its physicochemical effects if any, on this material. This material will be submitted to various doses of gamma radiation that were selected based on literature review and existing regulations that demonstrate that this method is effective to reduce or eliminate microbial bioburden in natural source and synthetic materials. Analytical testing was conducted to the DCPD exposed material in order to demonstrate that gamma radiation does not alter the physicochemical properties and material still acceptable for use in the manufacture of pharmaceutical products. The results obtained through this study were satisfactory and demonstrated that the gamma irradiation dosages from 5 to 30 kGy can be applied to DCPD without altering its physicochemical properties. These are supported by the Assay test data evaluation of lots tested before and after gamma irradiation implementation that show no significant statistical difference between irradiated and non irradiated assay results. The results of this study represent an achievement for the industry since they provide as an alternative the use of Gamma irradiation technology to control the microbial growth in DCPD.

  14. Volatiles emitted from flowers of gamma-radiated and nonradiated Jasminum polyanthum Franch

    DEFF Research Database (Denmark)

    Christensen, Lars P; Jakobsen, Henrik B; Kristiansen, Kell

    1997-01-01

    Volatile compounds emitted from flowers of Jasminum polyanthum Pepita in situ were collected by dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 32 compounds were identified. The flower scent was dominated by benzyl acetate (57.8%), p-cresol (12.2%), (E)-isoeugenol (9.7%),...

  15. Quality assurance of environmental gamma radiation monitoring in Slovenia

    International Nuclear Information System (INIS)

    Stuhec, M.; Zorko, B.; Mitic, D.; Miljanic, S.; Ranogajec-Komor, M.

    2006-01-01

    Environmental gamma radiation monitoring established in Slovenia consists of a network of multifunctional gamma monitors (MFMs) based on pairs of Geiger-Mueller counters and a network of measuring sites with high-sensitive thermoluminescence dosemeters. The measuring points are evenly spread across Slovenia, located at the meteorological stations and more densely on additional locations around the Krsko NPP. The MFM network has a 2-fold function with one sensor used for the purpose of early warning system in near surroundings of the NPP and the other, more sensitive, for natural radiation monitoring. The paper summarises activities to establish quality assurance of the environmental gamma radiation measurements in Slovenia, with a critical view of the results in comparison with the international standards and recommendations. While the results of linearity and energy dependence tests were satisfying, on-field intercomparison showed that the inherent signal of one of the monitors (MFM) has to be taken into account in the range of environmental background radiation. (authors)

  16. Gamma radiation from PSR B1055-52

    DEFF Research Database (Denmark)

    Thompson, D.J.; Bailes, M.; Bertsch, D.L.

    1999-01-01

    The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics that distinguish this pulsar: the light...... curve is complex; there is no detectable unpulsed emission; the energy spectrum is hat, with no evidence of a sharp high-energy cutoff up to greater than 4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same...

  17. Ornithogalum virens as a plant assay for beta and gamma radiation effects

    International Nuclear Information System (INIS)

    Herron, V.J.

    1979-01-01

    The purpose of this study was to determine if the monocotyledonous angiosperm, Ornithogalum virens (Quintanilha and Cabral, 1947), could be used in such a biological assay system. After exposing O. virens plants to acute ( 60 Co) and chronic ( 137 Cs) gamma radiation and internal beta radiation ( 32 P), lethality (LD 50 , LD 100 ), growth inhibition, and chromosome aberrations were investigated. The LD 50 and LD 100 for acute gamma radiation were estimated to be between 0.91 to 1.8 krad and less than 3.6 krad, respectively. Though growth inhibition and abnormal growth were observed in the acute and chronic gamma radiation studies, the changes in the growth of the plants were so variable that these parameters were found to be unreliable measures of radiation effects. Chromosome aberrations were a more reliable measure of radiation damage because linear relationships between total aberrations and dose were found for both gamma and beta radiation

  18. Lethality of gamma radiation and malathion to the indian meal moth, plodia interpunctella

    International Nuclear Information System (INIS)

    Eesa, N.M.; Moursy, L.E.

    1991-01-01

    The lethality of gamma radiation and the organo phosphorous insecticide, malathion, as well as the combined action of both was determined for the five larval instars of the indian meal moth, plodia interpunctella (Hubner). The younger instars were more susceptible to both gamma radiation and malathion. The L D 50 values of gamma radiation increased gradually with the instar. Malathion was highly toxic to the first four instars, but the fifth instar required a much larger dose. Gamma radiation combined with malathion at the L D 25 values was antagonistic when evaluated against each of the five larval instars of the indian meal moth. Thus, the use of gamma radiation with malathion does not seem to be a promising control strategy. However, further research investigations are needed to confirm this finding.3 tab

  19. Preparation of cobra (Naja naja) venom toxoid using gamma-radiations. Part I

    International Nuclear Information System (INIS)

    Gaitonde, B.B.; Kankonkar, S.R.

    1975-01-01

    Detoxification of venom by radiation was investigated. Two concentrations i.e. 0.01% of venom solution were irradiated with different doses of gamma-radiations from cobalt-60 source. The results obtained indicate that the toxicity of venom is markedly attenuated by gamma-radiation. (author)

  20. Measurement of gamma radiation doses in nuclear power plant environment

    International Nuclear Information System (INIS)

    Bochvar, I.A.; Keirim-Markus, I.B.; Sergeeva, N.A.

    1976-01-01

    Considered are the problems of measuring gamma radiation dose values and the dose distribution in the nuclear power plant area with the aim of estimating the extent of their effect on the population. Presented are the dosimeters applied, their distribution throughout the controlled area, time of measurement. The distribution of gamma radiation doses over the controlled area and the dose alteration with the increase of the distance from the release source are shown. The results of measurements are investigated. The conclusion is made that operating nuclear power plants do not cause any increase in the gamma radiation dose over the area. Recommendations for clarifying the techniques for using dose-meters and decreasing measurement errors are given [ru

  1. Report on the IAEA-CU-2006-08 proficiency test on the determination of gamma emitting radionuclides in sea water

    International Nuclear Information System (INIS)

    Shakhashiro, A.; Sansone, U.; Martin, P.; Makarewicz, M.; Mohagheghi, A.

    2007-03-01

    The Cooperative Monitoring Centre of Sandia National Laboratories of the United States (SNL) has initiated the Radiation Measurements Cross Calibration (RMCC) project. The RMCC aims to promote regional cooperation in the Middle East for preparedness for radiological emergencies. The International Atomic Energy Agency (IAEA) is cooperating with Sandia National Laboratories in this project. On a practical level, the initial aim of the RMCC is to establish a network of experts to cooperatively standardize nuclear monitoring and measurement capabilities in the Middle East by applying internationally recognized standards for laboratory radiation measurements. One of the project activities is to assist selected radiation measurement laboratories to participate in a quality assurance program and proficiency tests. During the second Workshop of the RMCC Project, organised by Sandia National Laboratories in Doha, Qatar, 12-17 November 2005, it was agreed to request the Chemistry Unit at the Agency's Seibersdorf laboratories to organise a special Proficiency Test (PT) for participants, for gamma-emitters in sea water. It is well known that proficiency testing is a method for regularly assessing the accuracy of the analytical data produced by the laboratories of particular measurements. According to the requirements of the RMCC project the IAEA-CU-2006-08 proficiency test (PT) on the determination of gamma emitting radionuclides in sea water was conducted by the Chemistry Unit of the IAEA's Laboratories located in Seibersdorf (Austria). The Chemistry Unit is actively involved in the production and characterization of matrix reference materials of terrestrial origin, widely used for method validation and organization of proficiency tests and intercomparison studies. The Chemistry Unit is a part of the Physics, Chemistry and Instrumentation Laboratory. This report describes the sample preparation methodology, data evaluation approach, summary evaluation of each nuclide and

  2. The selection of radiation tolerant electrical/electronic components for gamma radiation environments in the nuclear power industry

    International Nuclear Information System (INIS)

    Garlick, D.R.

    1984-09-01

    This report briefly describes the mechanisms, units and effects of 1 MeV range gamma radiation on electrical/electronic components and materials. Information is tabulated on the gamma radiation tolerance of a wide range of components and materials. A radiation testing service, based at Harwell, is described. Lists of interested manufacturers and organisations are given. (author)

  3. Detection of gamma-neutron radiation by solid-state scintillation detectors. Detection of gamma-neutron radiation by novel solid-state scintillation detectors

    Energy Technology Data Exchange (ETDEWEB)

    Ryzhikov, V.; Grinyov, B.; Piven, L.; Onyshchenko, G.; Sidletskiy, O. [Institute for Scintillation Materials of the NAS of Ukraine, Kharkov, (Ukraine); Naydenov, S. [Institute for Single Crystals of the National Academy of Sciences of Ukraine, Kharkov, (Ukraine); Pochet, T. [DETEC-Europe, Vannes (France); Smith, C. [Naval Postgraduate School, Monterey, CA (United States)

    2015-07-01

    It is known that solid-state scintillators can be used for detection of both gamma radiation and neutron flux. In the past, neutron detection efficiencies of such solid-state scintillators did not exceed 5-7%. At the same time it is known that the detection efficiency of the gamma-neutron radiation characteristic of nuclear fissionable materials is by an order of magnitude higher than the efficiency of detection of neutron fluxes alone. Thus, an important objective is the creation of detection systems that are both highly efficient in gamma-neutron detection and also capable of exhibiting high gamma suppression for use in the role of detection of neutron radiation. In this work, we present the results of our experimental and theoretical studies on the detection efficiency of fast neutrons from a {sup 239}Pu-Be source by the heavy oxide scintillators BGO, GSO, CWO and ZWO, as well as ZnSe(Te, O). The most probable mechanism of fast neutron interaction with nuclei of heavy oxide scintillators is the inelastic scattering (n, n'γ) reaction. In our work, fast neutron detection efficiencies were determined by the method of internal counting of gamma-quanta that emerge in the scintillator from (n, n''γ) reactions on scintillator nuclei with the resulting gamma energies of ∼20-300 keV. The measured efficiency of neutron detection for the scintillation crystals we considered was ∼40-50 %. The present work included a detailed analysis of detection efficiency as a function of detector and area of the working surface, as well as a search for new ways to create larger-sized detectors of lower cost. As a result of our studies, we have found an unusual dependence of fast neutron detection efficiency upon thickness of the oxide scintillators. An explanation for this anomaly may involve the competition of two factors that accompany inelastic scattering on the heavy atomic nuclei. The transformation of the energy spectrum of neutrons involved in the (n, n

  4. Search for gamma-ray emitting AGN among unidentified Fermi-LAT sources using machine learning algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Doert, Marlene [Technische Universitaet Dortmund (Germany); Ruhr-Universitaet Bochum (Germany); Einecke, Sabrina [Technische Universitaet Dortmund (Germany); Errando, Manel [Barnard College, Columbia University, New York City (United States)

    2015-07-01

    The second Fermi-LAT source catalog (2FGL) is the deepest all-sky survey of the gamma-ray sky currently available to the community. Out of the 1873 catalog sources, 576 remain unassociated. We present a search for active galactic nuclei (AGN) among these unassociated objects, which aims at a reduction of the number of unassociated gamma-ray sources and a more complete characterization of the population of gamma-ray emitting AGN. Our study uses two complimentary machine learning algorithms which are individually trained on the gamma-ray properties of associated 2FGL sources and thereafter applied to the unassociated sample. The intersection of the two methods yields a high-confidence sample of 231 AGN candidate sources. We estimate the performance of the classification by taking inherent differences between the samples of associated and unassociated 2FGL sources into account. A search for infra-red counterparts and first results from follow-up studies in the X-ray band using Swift satellite data for a subset of our AGN candidates are also presented.

  5. Sewage sterilization through gamma radiation

    International Nuclear Information System (INIS)

    Vieira, D.V.; Teixeira, W.M.S.; Silva, F.C.A. da

    2017-01-01

    Lack of sewage treatment and adequate sanitation conditions can contribute to the proliferation of numerous parasitic and infectious diseases in addition to water degradation. Approximately fifty types of infections can be transmitted from a sick to a healthy person through different pathways involving human excreta. Untreated sewage can contaminate water, food, hands, soil, etc. Epidemics of certain diseases such as typhoid, cholera, dysenteries, etc., and countless cases of worms are responsible for high mortality rates in third world countries. In the work the different techniques of sewage treatment by disinfestation and sterilization were analyzed, highlighting the use and the advantages of the gamma radiation as well as the aspects of the radiological protection involved. The technique of sewage sterilization using gamma radiation is a method of controlling bacteria and microorganisms. It is estimated that more than 200 large irradiators are in operation worldwide, of which 5 are in Brazil, for general sterilization use. These facilities use a large amount of radioactive material, in the order of millions of Becquerel, for sterilization with high doses of radiation, which can generate lethal doses in a few minutes. These industrial facilities use Cobalt-60, being classified by the International Atomic Energy Agency - IAEA as Category 1 of high risk, and must possess a high level of radiological protection to carry out the sterilization, standing out the defense in depth. Specific legislation on radiological protection should be drafted for safe work and avoid future radiation accidents

  6. Sensitivity of an autoradiographic film to ionizing radiation of different types and energies

    International Nuclear Information System (INIS)

    Kras, A.B.; Lutzke-Birk, A.; Kalicki, A.

    1984-01-01

    The ORWO-AF3 autoradiographic film has been studied with regard to its sensitivity to beta radiation (E/sub max/ = 0.155 and 0.306 MeV, resp.), gamma radiation of more than 1 MeV and K/sub α/ and K/sub β/ radiation of about 5.9 KeV. The obtained data can be used for the correction of depth distribution profiles if elements are labelled with radioisotopes emitting mixed radiation, e.g., beta and gamma radiation

  7. Gamma radiation in apartments

    International Nuclear Information System (INIS)

    Grindborg, J.-E.

    1983-05-01

    This investigation forms the basis for the description of methods for the detection of gamma radiation. The aim is to control that the dose limit will not exceed 50 μR/h in a room where people reside. The distribution of dose rates in different rooms has been calculated and the results have been compared with experimental data. Various instruments have been calibrated and their specifications are discussed. (G.B.)

  8. Comparison of gamma- and beta radiation stress responses on anti-oxidative defense system and DNA modifications in Lemna minor

    Energy Technology Data Exchange (ETDEWEB)

    Van Hoeck, Arne [SCK.CEN, Boeretang 200 2400 Mol (Belgium); University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Horemans, Nele; Van Hees, May; Nauts, Robin; Vandenhove, Hildegarde [SCK.CEN, Boeretang 200 2400 Mol (Belgium); Knapen, Dries; Blust, Ronny [University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

    2014-07-01

    The biological effects and interactions of different radiation types in plants are still far from understood. Additional knowledge on the impact of various kinds of ionizing radiation in plants on individual, biochemical and molecular level is needed to unravel and compare the toxic mode of action. Among different radiation types, external gamma radiation treatments have been mostly studied both in lab and field studies to derive the biological impact of radiation toxicity in organisms. However, environmental relevant studies on chronic low-dose gamma exposures are scarce. The radio-ecologically relevant radionuclide {sup 90}Sr is a pure beta emitting isotope and originates from nuclear activities and accidents. Although this radionuclide is not essential for plant metabolism, it bears a chemical analogy with the essential plant macro-nutrient Ca{sup 2+} thereby taking advantage of Ca{sup 2+} transport systems to contaminate plant organs and tissues. Ones plants are exposed to radiation stress, ionization events can cause an increase in reactive oxygen species (ROS) and can induce damage to biological material like DNA, lipids and structural proteins. The following work aimed at evaluating individual, biochemical and molecular endpoints to understand and to compare the mode of action of gamma- and beta radiation stress in plants. Having an equal relative biological effectiveness to non-human biota, it is still not clear in how plants differ or overlap in sensing and interpreting highly penetrating electromagnetic radiation with short-range particle radiation. The floating plant Lemna minor was chosen as model system. Following the OECD guidelines Lemna plants were being exposed separately to an external gamma radiation source or to a {sup 90}Sr-contaminated growth medium to obtain single-dose response curves for each type of radiation. In order to acquire accurate dose rate quantifications for beta radiation exposures, {sup 90}Sr uptake and accumulation of root and

  9. Gamma radiation effects on physical properties of parchment documents: Assessment of Dmax

    International Nuclear Information System (INIS)

    Nunes, Inês; Mesquita, Nuno; Cabo Verde, Sandra; João Trigo, Maria; Ferreira, Armando; Manuela Carolino, Maria; Portugal, António; Luísa Botelho, Maria

    2012-01-01

    Parchments are important documents that give testimony for History; therefore these materials should be respected and preserved. Considering incremental biodeterioration problems that have to be faced daily, the Archive of the University of Coimbra (AUC) is involved in different scientific projects in order to evaluate and determine new methods for document decontamination and preservation. The aim of this study was to evaluate gamma radiation effects on the colour and texture of the AUC parchment documents. The assessment of these effects was used to estimate the maximum gamma radiation dose (D max ) that could guarantee parchment documents′ decontamination treatment, without significant alteration of their physical properties. Parchment samples were exposed to gamma radiation doses ranging from 10 to 30 kGy. The texture and colour of samples were assessed before and after the irradiation procedure, using a texture analyser and an electronic colorimeter. Hardness and springiness were determined based on texture spectra. Lightness (L⁎), Chroma (C), greenness vs. redness (a*) and yellowness vs. blueness (b*) values were obtained from colorimetric measures. Results indicate no significant effects of gamma radiation on the texture and colour of parchment for the studied doses. - Highlights: ► Study on the effects of gamma radiation in parchment physical properties. ► Evaluation of the uniformity of parchment samples′ physical parameters. ► Proposal of a maximum gamma radiation dose for parchment decontamination treatment.

  10. Measurement of Gamma-ray Energy Spectrum According to Temperature Variation Using a Fiber-Optic Radiation Sensor Based on YSO:Ce Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, H.; Yoo, W. J.; Shin, S. H.; Jang, J. S.; Kim, J. S.; Kwon, G.; Lee, D. E.; Jang, K. W.; Lee, B. [BK21 Plus Research Institute of Biomedical Engineering, Konkuk University, Chungju (Korea, Republic of)

    2015-05-15

    As an alternative to conventional radiation detectors, various fiber-optic radiation sensors (FORSs) have been investigated for gamma-ray monitoring because of their various desirable advantages, such as their small sensing volume, substantial flexibility, remote operation, ability to make real-time measurement, and immunity to high electromagnetic interference. In general, the basic principle of a radiation detection using scintillators is to measure the scintillating light signals generated from the interactions between the scintillators and the radiations. To measure gamma-ray, the inorganic scintillators used in the FORS should have some properties, such as high atomic material, high light yields, fast decay time, high density, and high stopping power. For these reasons, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal has been introduced as a promising scintillator in various radiation sensor applications. According to the recent studies, however, LYSO:Ce crystal is impossible to be applied in high-temperature conditions because it serves the fluctuations of its light yields with the temperature variation (i.e., thermosluminescence). In this study, to obtain gamma-ray energy spectra by measuring scintillating light signals emitted from the scintillators in high-temperature conditions, we first fabricated an FORS system using various inorganic scintillator crystals and then evaluated the light yields of each inorganic scintillator. As a promising scintillator for use in high-temperature conditions, a cerium-doped yttrium orthosilicate (YSO:Ce) crystal was selected and evaluated its thermal property according to the elevated temperature up to 300 .deg. C. We fabricated an FORS using inorganic scintillator and an optical fiber bundle. To select an adequate scintillator to apply in high-temperature conditions, the gamma-ray energy spectra were obtained by using four kinds of inorganic scintillators. From the experimental results, we selected YSO

  11. Instrumentation measurement and testing complex for detection and identification of radioactive materials using the emitted radiation

    International Nuclear Information System (INIS)

    Samossadny, V.T.; Dmitrenko, V.V.; Kadlin, V.V.; Kolesnikov, S.V.; Ulin, S.E.; Grachev, V.M.; Vlasik, K.F.; Dedenko, G.L.; Novikov, D.V.; Uteshev, Z.M.

    2006-01-01

    Simultaneous measurement of neutron and gamma radiation is a very usefull method for effective nuclear materials identification and control. The gamma-ray-neutron complex described in the paper is based on two multi-layer 3 He neutrons detectors and two High Pressure Xenon gamma-ray spectrometers assembled in one unit. All these detectors were callibrated on neutron and gamma-ray sources. The main characteristics of the instrumentation , its testing results and gamma-ray and neutron radiation parameters, which have been measured are represented in the paper. The gamma-neutron sources and fissile materials reliable detection and identification capability was demonstrated

  12. Poster - 11: Radiation barrier thickness calculations for the GammaPod

    International Nuclear Information System (INIS)

    La Russa, Daniel; Vandervoort, Eric; Wilkins, David

    2016-01-01

    A consortium of radiotherapy centers in North America is in the process of evaluating a novel new 60 Co teletherapy device, called the GammaPod™ (Xcision Medical Systems, Columbia Maryland), designed specifically for breast SBRT. The GammaPod consists of 36 collimated 60 Co sources with a total activity of 4320 Ci. The sources are housed in a hemispherical source carrier that rotates during treatment to produce a cylindrically symmetric cone of primary beam spanning 16° – 54° degrees from the horizontal. This unique beam geometry presents challenges when designing or evaluating room shielding for the purposes of meeting regulatory requirements, and for ensuring the safety of staff and the public in surrounding areas. Conventional methods for calculating radiation barrier thicknesses have been adapted so that barrier transmission factors for the GammaPod can be determined from a few relevant distances and characteristics of the primary beam. Simple formalisms have been determined for estimating shielding requirements for primary radiation (with a rotating and non-rotating source carrier), patient-scattered radiation, and leakage radiation. When making worst case assumptions, it was found that conventional barrier thicknesses associated with linac treatment suites are sufficient for shielding all sources of radiation from the GammaPod.

  13. Poster - 11: Radiation barrier thickness calculations for the GammaPod

    Energy Technology Data Exchange (ETDEWEB)

    La Russa, Daniel; Vandervoort, Eric; Wilkins, David [Radiation Medicine Program, The Ottawa Hospital (Canada)

    2016-08-15

    A consortium of radiotherapy centers in North America is in the process of evaluating a novel new {sup 60}Co teletherapy device, called the GammaPod™ (Xcision Medical Systems, Columbia Maryland), designed specifically for breast SBRT. The GammaPod consists of 36 collimated {sup 60}Co sources with a total activity of 4320 Ci. The sources are housed in a hemispherical source carrier that rotates during treatment to produce a cylindrically symmetric cone of primary beam spanning 16° – 54° degrees from the horizontal. This unique beam geometry presents challenges when designing or evaluating room shielding for the purposes of meeting regulatory requirements, and for ensuring the safety of staff and the public in surrounding areas. Conventional methods for calculating radiation barrier thicknesses have been adapted so that barrier transmission factors for the GammaPod can be determined from a few relevant distances and characteristics of the primary beam. Simple formalisms have been determined for estimating shielding requirements for primary radiation (with a rotating and non-rotating source carrier), patient-scattered radiation, and leakage radiation. When making worst case assumptions, it was found that conventional barrier thicknesses associated with linac treatment suites are sufficient for shielding all sources of radiation from the GammaPod.

  14. Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

    Science.gov (United States)

    Sui, H. L.; Liu, X. Y.; Zhong, F. C.; Li, X. Y.; Wang, L.; Ju, X.

    2013-07-01

    Polydimethylsiloxane rubber foams were irradiated by gamma ray under different radiation conditions designed by orthogonal design method. Compression set measurement, infrared attenuated total reflectance spectroscopy (ATR) and X-ray induced photoelectron spectroscopy (XPS) were used. Three aging factors' influence effects on the mechanical property and chemical structure were studied. It was found that among the three factors and the chosen levels, both properties were affected most by radiation dose, while radiation dose rate had no obvious influence on both properties. The stiffening of the rubber foams was caused by cross-linking reactions in the Si-CH3. At the same radiation dose, the rigidity of the foams irradiated in air was lower than that in nitrogen. When polydimethylsiloxane was irradiated at a high dose in sealed nitrogen atmosphere, carbon element distribution would be changed. Hydrocarbons produced by gamma ray in the sealed tube would make the carbon content in the skin-deep higher than that in the middle, which indicated that polydimethylsiloxane rubber foams storing in a sealed atmosphere filled with enough hydrocarbons should be helpful to extend the service life.

  15. Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Sui, H.L. [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China); Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Liu, X.Y.; Zhong, F.C. [Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Li, X.Y. [Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900 (China); Wang, L. [Institute of Chemical Materials, CAEP, Mianyang 621900 (China); Ju, X., E-mail: jux@ustb.edu.cn [Department of Physics, University of Science and Technology Beijing, Beijing 100083 (China)

    2013-07-15

    Polydimethylsiloxane rubber foams were irradiated by gamma ray under different radiation conditions designed by orthogonal design method. Compression set measurement, infrared attenuated total reflectance spectroscopy (ATR) and X-ray induced photoelectron spectroscopy (XPS) were used. Three aging factors’ influence effects on the mechanical property and chemical structure were studied. It was found that among the three factors and the chosen levels, both properties were affected most by radiation dose, while radiation dose rate had no obvious influence on both properties. The stiffening of the rubber foams was caused by cross-linking reactions in the Si–CH{sub 3}. At the same radiation dose, the rigidity of the foams irradiated in air was lower than that in nitrogen. When polydimethylsiloxane was irradiated at a high dose in sealed nitrogen atmosphere, carbon element distribution would be changed. Hydrocarbons produced by gamma ray in the sealed tube would make the carbon content in the skin-deep higher than that in the middle, which indicated that polydimethylsiloxane rubber foams storing in a sealed atmosphere filled with enough hydrocarbons should be helpful to extend the service life.

  16. Null bactericidal effect of ultraviolet radiation emitted by LEDs.

    Directory of Open Access Journals (Sweden)

    Francisco Alcántara Muñoz

    2016-11-01

    Full Text Available This research has aimed to assess the bactericidal effect of ultraviolet light emitted by LEDS on the growth on Petri dishes of microorganisms whose legal limits in foods have been established. An electrically fed apparatus has been designed with precise timing and a camera to prevent light spillage, in which two ultraviolet radiation emission devices were connected by LED technology at different wavelengths: through an array of LEDS emitting at around 350nm, and a single specific emission LED at 280nm. 1000 cfu of E. Coli and S. aureus sown on PCA were used as prototypes of gram negative and positive bacteria, respectively, onto which ultraviolet light was radiated at different time intervals, by means of both devices, with the whole experiment being carried out in triplicate . In none of the three series of treatments at the two wavelengths were reductions in microbial growth observed. The series of sowings on PCA were done on unseeded plates in order to be able to discard the likelihood of subsequent recontamination.

  17. Very Strong TeV Emission as $\\gamma$-Ray Burst Afterglows

    CERN Document Server

    Totani, T

    1998-01-01

    Gamma-ray bursts (GRBs) and following afterglows are considered to be produced by dissipation of kinetic energy of a relativistic fireball and radiation process is widely believed as synchrotron radiation or inverse Compton scattering of electrons. We argue that the transfer of kinetic energy of ejecta into electrons may be inefficient process and hence the total energy released by a GRB event is much larger than that emitted in soft gamma-rays, by a factor of \\sim (m_p/m_e). We show that, in this case, very strong emission of TeV gamma-rays is possible due to synchrotron radiation of protons accelerated up to \\sim 10^{21} eV, which are trapped in the magnetic field of afterglow shock and radiate their energy on an observational time scale of \\sim day. This suggests a possibility that GRBs are most energetic in TeV range and such TeV gamma-rays may be detectable from GRBs even at cosmological distances, i.e., z gives a quantitative explanation for the famous long-duration GeV photons detected from GRB940217. ...

  18. Resistance of Salmonella enteritidis variety typhimurium to gamma radiation

    International Nuclear Information System (INIS)

    Norberg, A.N.; Maliska, C.

    1988-01-01

    The use of ionizing radiations to kill microrganisms responsible for food deterioration, and toxinfections is an example of peaceful use of nuclear energy. Food toxinfections are, amongus, produced mostly by Salmonella enteritidis var. typhimurium. Due to the pauncity of information on the resistance to gamma radiation of Salmonella enteritidis var. typhimurium this paper has the aim to define the 60-Cobalt gamma radiation lethal dose to these bacteria, in experimentally contaminated milk by samples recovered from our geographycal area. One hundred nineteen samples of milk containing about 150.000 bacteria per ml were irradiated with doses ranging from 100 to 1.100 Gy. Two samples of surving bacteria were again irradiated by doses up to 2.500 Gy. The bacteria not previously irradiated were killed by doses of 1.100 Gy. It was concluded that the 60-Cobalt gamma radiation minimal lethal dose to Salmonella enteritidis var. typhimurium is 1.200 Gy. The surviving strains to smaller doses than 1.200 Gy when re-irradiated prompt the forthcoming of more radio-resistant germs. (author) [pt

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

    International Nuclear Information System (INIS)

    Nunes, Thaise C.F.; Rogovschi, Vladimir D.; Thomaz, Fernanda S.; Trindade, Reginaldo A.; Villavicencio, Anna L.C.H.; Alencar, Severino M.

    2007-01-01

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

  20. Effect of gamma-radiation on a water-insoluble arabinoxylan

    International Nuclear Information System (INIS)

    Ebringerová, A.; Pružinec, J.; Kačuráková, M.; Hromádková, Z.

    1989-01-01

    The effect of gamma radiation on a water-insoluble L-arabino-D-xylan has been studied by functional group and structural analysis using chemical methods and IR spectroscopy, by sugar composition analysis, and by viscosity measurements. The gamma irradiation has been shown to modify both sugar components of the arabinoxylan, accompanied by cleavage of the glycosidic linkages, depolymerization, and sugar decomposition, depending on the applied radiation dose, thus increasing the molecular and chemical heterogeneity of the polysaccharide. (author)

  1. Insect disinfestation of packed dates by gamma-radiation

    International Nuclear Information System (INIS)

    Ahmed, M.S.H.; Hameed, A.A.; Kadhum, A.A.; Ali, S.R.

    1985-01-01

    The effect of gamma-radiation on insect disinfestation of commercially packed dry dates was studied in collaboration with the Iraqui Date Administration. The wrapping of ''window carton lunch boxes'' (each holding 250 g of dry dates, Zahdi variety) with polyethylene film, compared to cellophane, prevented reinfestation for a long period of storage if treated with 0.70 kGy of gamma-radiation. All live insects that were found in the irradiated boxes and tested were genetically sterile, and those in different developmental stages died within a short period of time without passing through metamorphosis. In all cases (treated or control batches), cellophane-sealed boxes proved to be more vulnerable to reinfestation. Dates packed in plastic cups, used for N/sub 2/ vacuum packaging, were also effectively disinfested by the same dose of radiation. The value of airtight packaging will certainly add to the advantage of the high penetration power of gamma-radiation relative to methyl bromide fumigation. Results of the assessment of the damaging ability of irradiated insects indicate that treatment of packed dates with 0.70 kGy is sufficient as far as quarantine measures are concerned where the possible increase in infestation rate, brought about by radio-resistant insect stages that usually constitute a small fraction in nature, is negligible

  2. CLASSICS Handbook of Solar Radiation Data for India

    Indian Academy of Sciences (India)

    Srimath

    Handbook of Solar Radiation Data for India. By Anna Mani. CHAPTER 1. Introduction. 1.1. The sun and its radiation. The electromagnetic radiation emitted by the sun covers a very large range of wave- lengths, from radiowaves through the infrared, visible and ultraviolet to X-rays and gamma rays. However, 99 per cent of ...

  3. Cherenkov radiation; La radiation Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  4. Gamma radiation detectors for safeguards applications

    International Nuclear Information System (INIS)

    Carchon, R.; Moeslinger, M.; Bourva, L.; Bass, C.; Zendel, M.

    2007-01-01

    The IAEA uses extensively a variety of gamma radiation detectors to verify nuclear material. These detectors are part of standardized spectrometry systems: germanium detectors for High-Resolution Gamma Spectrometry (HRGS); Cadmium Zinc Telluride (CZT) detectors for Room Temperature Gamma Spectrometry (RTGS); and NaI(Tl) detectors for Low Resolution Gamma Spectrometry (LRGS). HRGS with high-purity Germanium (HpGe) detectors cooled by liquid nitrogen is widely used in nuclear safeguards to verify the isotopic composition of plutonium or uranium in non-irradiated material. Alternative cooling systems have been evaluated and electrically cooled HpGe detectors show a potential added value, especially for unattended measurements. The spectrometric performance of CZT detectors, their robustness and simplicity are key to the successful verification of irradiated materials. Further development, such as limiting the charge trapping effects in CZT to provide improved sensitivity and energy resolution are discussed. NaI(Tl) detectors have many applications-specifically in hand-held radioisotope identification devices (RID) which are used to detect the presence of radioactive material where a lower resolution is sufficient, as they benefit from a generally higher sensitivity. The Agency is also continuously involved in the review and evaluation of new and emerging technologies in the field of radiation detection such as: Peltier-cooled CdTe detectors; semiconductor detectors operating at room temperature such as HgI 2 and GaAs; and, scintillator detectors using glass fibres or LaBr 3 . A final conclusion, proposing recommendations for future action, is made

  5. Gamma radiation effects on vitamin C standard solutions

    International Nuclear Information System (INIS)

    Amaro, Jose Daniel V.; Mansur Netto, Elias

    1995-01-01

    This word shows the physical - chemical effects of gamma radiation on standard solutions of vitamin C. Samples with concentration of 50 mg/ml were exposed to different doses of gamma radiations: 1,0 2,5 and 5,0 kGy, using a cobalt-60 source, with storing periods of 0,15 and 30 days. The results showed a vitamin C concentration loss, with a minimum of 17% for the dose of 1,0 kGy immediately after irradiation and a maximum of 81% for the dose of 5 kGy and 30 days after irradiation. (author). 3 refs., 2 tabs

  6. Study of local Agregate for Gamma radiation concrete shield

    International Nuclear Information System (INIS)

    Tochrul-Binowo; Endro-Kismolo; Darsono

    1996-01-01

    Investigation on the composition of gamma radiation concrete shield made of local barite, manganese fine and coarse aggregates from Kulon Progo, Yogyakarta has been done. The purpose of the research was to find out the quality of these local material for an aggregate of gamma radiation concrete shield. The research was done where each mineral was used as coarse aggregate and the fine aggregate from Kulon Progo was used as fine basic aggregate. Firstly a normal concrete was made by mixing cement, fine aggregate, coarse aggregate and water at a weight ratio of cement: fine aggregate: coarse: water 1: 2.304: 3.456: 0.58. The gamma radiation absorption capacity of the concrete tested by using Cs-137 as source standard. The same method was done on barite concrete at the weight ratio of cement: fine aggregate: barite aggregate: water 1: 2.303: 3.456: 0.58 and manganese concrete at the weight ratio of cement: fine aggregate: manganese aggregate: and water 1: 1.896: 2.844: 0.58. The result of the study showed that the gamma radiation absorption capacity of barite aggregate was greater than that of normal concrete and manganese concrete. The coefficient linear attenuation (for 6.0 cm thickness) of each concrete were μ barite concrete = 0.23071 cm -1 , μ manganese concrete = 0.08401 cm -1 and μ normal concrete = 0.1669 cm -1

  7. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of Co60

    International Nuclear Information System (INIS)

    Mitake, M.B.

    2000-01-01

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms, leading to a spastic paralysis of hind limbs in mice. The objective was to carry out biochemical and pharmacological studies of native and irradiated crotamine with Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 m NaCl with 2.0 kGy gamma radiation emitted by a Co source. Native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD50), and biodistribution. The native and irradiated crotamine were labeled with 29.6 MBq of I using chloramine T method and separated in a Sephadex G-50 column. Male Swiss mice (35 @ 5 g) were injected IP with 0.1 mL (2.4x10 cpm/mouse) of I native crotamine or with 0.4 mL (1.3 x 10 cpm/mouse) of I irradiated crotamine. The animals were sacrificed by ether inhalation at 0.08, 0.25, 0.5,1, 2, 3, 4, 8, 12, and 24 hours. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change protein concentration, electrophoretic profile, or protein primary structure, although differences could be seen by spectroscopic techniques. Gamma radiation reduced crotamine toxicity, but did not eliminate bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. Native and irradiated crotamine have an affinity to skeletal muscle and did not cross the blood-brain barrier. (author)

  8. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of 60Co

    International Nuclear Information System (INIS)

    Mitake, Malvina Boni

    2000-01-01

    Ionizing radiation can change the molecular structure and affect the biological properties of biomolecules. This has been employed to attenuate animal toxins. Crotamine is a strongly basic polypeptide from the South American rattlesnake venom, composed of 42 amino acid residues. It induces skeletal muscle spasms leading to a spastic paralysis of hind limbs in mice. The objective of this thesis was carry out biochemical and pharmacological studies of native and irradiated crotamine with 60 Co. Crotamine was purified from Crotalus durissus terrificus venom by Sephadex G-100 gel filtration followed by ion exchange chromatography, using a Fast Performance Liquid Chromatography (FPLC) system. It was irradiated at 2 mg/ml in 0.15 M Na Cl with 2.0 kGy gamma radiation emitted by a 60 Co source. The native and irradiated crotamine were evaluated by biochemical characterization, toxic activity (LD 50 and biodistribution. The native and irradiated crotamine were labelled with 29.6 MBq of 125 I using chloramine T method, and separated in a Sephadex G-50 column. Male Swiss mice (35± 5 g), were injected i.p. with o.1 mL (2.4 x 10 6 cpm/mouse) of 125 I native crotamine or with 0.4 mL (1.3 x 10 6 cpm/mouse) of 125 I irradiated crotamine. At 0.08; 0.25; 0.5; 1; 2; 4; 8; 12 and 24 hours the animal were killed by ether inhalation. Blood, spleen, liver, kidneys, brain, lungs, heart, and skeletal muscle were collected in order to determine radioactivity content. The results showed that gamma radiation did not change the protein concentration, the electroforetic profile or the primary structure of the protein, although differences were shown by spectroscopic techniques. The gamma radiation diminished the toxicity of crotamine, but it did not abolish bioactivity. Biodistribution studies showed that native and irradiated crotamine have hepatic metabolism and renal elimination. The native and irradiated crotamine have affinity by skeletal muscle and they did not pass the blood - brain

  9. Development of a Compact Gamma-ray Detector for a Neural-Network Radiation Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H. S.; Ha, J. H.; Lee, K. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, C. H. [Hanyang Univ., Seoul (Korea, Republic of)

    2012-03-15

    Radiation monitoring is very important to secure safety in nuclear-related facilities and against nuclear terrorism. For wide range of radiation monitoring, neutral network system of radiation detection is most efficient way. Thus, a compact radiation detector is useful to install in wide range to be concerned. A compact gamma-ray detector was fabricated by using a CsI(Tl) scintillator, which was matched with the formerly developed PIN photodiode, for a neural network radiation monitoring. At room temperature, the fabricated compact gamma-ray detector demonstrates an energy resolution of 13.3 % for 662 keV 6.9% for 1330 keV. The compactness, the low-voltage power consumption and the physical hardness are very useful features for a neural network radiation monitoring. In this study, characteristics of a fabricated compact gamma-ray detector were presented. An important aspect to consider in a neural-network radiation monitoring such as reaction probability of the fabricated compact detector for angle of incident gamma-ray was also addressed.

  10. Concrete for. gamma. radiation shielding

    Energy Technology Data Exchange (ETDEWEB)

    de Azevedo e Souza, A.C. (Rio de Janeiro Univ. (Brazil). Inst. de Quimica); Rogers, J D [Rio de Janeiro Univ. (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

    1980-06-01

    The attenuation characteristics of ..gamma.. radiation in concrete slabs, considering their mechanical resistence and densities were determined. One heavy concrete which was used, was prepared using as additives iron ore and Fe/sub 2/ O/sub 3/ pellets in various grain sizes. Fortran programs were used for analysing data and determining the absorption coefficients and attenuation factors.

  11. Extended gamma sources modelling using multipole expansion: Application to the Tunisian gamma source load planning

    International Nuclear Information System (INIS)

    Loussaief, Abdelkader

    2007-01-01

    In this work we extend the use of multipole moments expansion to the case of inner radiation fields. A series expansion of the photon flux was established. The main advantage of this approach is that it offers the opportunity to treat both inner and external radiation field cases. We determined the expression of the inner multipole moments in both spherical harmonics and in cartesian coordinates. As an application we applied the analytical model to a radiation facility used for small target irradiation. Theoretical, experimental and simulation studies were performed, in air and in a product, and good agreement was reached.Conventional dose distribution study for gamma irradiation facility involves the use of isodose maps. The establishment of these maps requires the measurement of the absorbed dose in many points, which makes the task expensive experimentally and very long by simulation. However, a lack of points of measurement can distort the dose distribution cartography. To overcome these problems, we present in this paper a mathematical method to describe the dose distribution in air. This method is based on the multipole expansion in spherical harmonics of the photon flux emitted by the gamma source. The determination of the multipole coefficients of this development allows the modeling of the radiation field around the gamma source. (Author)

  12. Radiation hazard control report

    International Nuclear Information System (INIS)

    Morishima, Hiroshige; Koga, Taeko; Hisanaga, Saemi; Miki, Ryota; Kawai, Hiroshi; Aoki, Yutaka; Sone, Koji; Okada, Hirokazu

    1990-01-01

    The report describes the radiation hazard control activities performed at the Atomic Energy Research Institute of Kinki University, Japan, during the one-year period from April 1989 to March 1990. Personal radiation hazard control is outlined first focusing on results of physical examination and data of personal exposure dose equivalent. Radiation control in laboratory is then described. Dose equivalent at various places is discussed on the basis of monthly total dose equivalent measured on film badges, measurements made by TLD, and observations made through a continuous radiations monitoring system. The concentration of radiations in air and water is discussed focusing on their measured concentrations in air at the air outlets of tracer/accelerator facilities, and radioactivity in waste water sampled in the reactor facilities and tracer/accelerator facilities. Another discussion is made on the surface contamination density over the floors, draft systems, sink surface, etc. Concerning outdoor radiation hazard control, furthermore, TLD measurements of environmental gamma-rays, data on total gamma-ray radioactivity in environmental samples, and analysis of gamma-ray emitting nuclides in environmental samples are described and discussed. (N.K.)

  13. Characterization of crumb rubber modified by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory, E-mail: sfaldini@yahoo.com.br, E-mail: mauroterence@yahoo.com.br [Universidade Presbiteriana Mackenzie (UPM), Sao Paulo, SP (Brazil). Escola de Engenharia. Engenharia de Materiais

    2013-07-01

    The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

  14. Characterization of crumb rubber modified by gamma radiation

    International Nuclear Information System (INIS)

    Faldini, Sonia B.; Terence, Mauro C.; Miranda, Leila F.; Munhoz, Antonio H.; Domingues, Leandro S.; Coghetto, Gregory

    2013-01-01

    The use of crumb rubber from scrap tires has become a common practice in the construction of roads, leading to improved properties of the asphalt and decreasing the environmental pollution. In this study, crumb rubber was modified by gamma radiation to eventually incorporate it into the asphalt and verify potential improvements of their properties. The crumb rubber modified by gamma radiation in the dose 500 kGy and 1000kGy was characterized by thermal analysis, infrared spectroscopy and scanning electron microscopy. The dose of radiation used has no effect on degradation temperatures. It is observed that the IV spectra of untreated rubbers and rubbers irradiated have substantially the same profile. The results indicate that despite small morphological changes in the irradiated rubber, they do not influence its degradation temperature and composition. (author)

  15. Observations of nesting avifauna under gamma-radiation exposure

    International Nuclear Information System (INIS)

    Buech, R.R.

    1977-01-01

    An opportunity arose to observe the nesting success of birds (up to the time of fledging) when the Enterprise Forest Radiation Facility was established for a study of the effects of gamma radiation on the flora and fauna of northern forest communities. The results of these observations on the fate of the nest occupants in relation to radiation exposure are presented

  16. Galactic structure and gamma radiation

    International Nuclear Information System (INIS)

    Casse, Michel; Cesarsky, Catherine; Paul Jacques

    1977-01-01

    A model of spiral structure of the Galaxy is outlined from radiosynchrotron and gamma observations. The most interesting observations in the galactic context, obtained by the SAS II American satellite are concerned with the distribution of the γ photoemission at energies higher than 10 8 eV, along the galactic equator. The model proposed is in quantitative agreement with the present ideas on the spiral structure of the Galaxy, the galactic magnetic field, and the confinement of cosmic rays by the magnetic field and of the magnetic field by matter. Following the American era, the European COS-B satellite opens the European phase towards an identification of the discrete gamma radiation sources [fr

  17. Combined effect of gamma radiation and stress cracking in polystyrene

    International Nuclear Information System (INIS)

    Amorim, Fernando A.; Rabello, Marcelo S.; Silva, Leonardo G.A.

    2011-01-01

    This study aimed to evaluate the combined effect of gamma radiation and stress cracking in polystyrene. Three different grades of polystyrene were analysed. The material was submitted to tensile tests and relaxation, analysis of molecular weight and determination of crosslinking. The results showed an increase in tensile strength in the specimens that had been exposed to radiation. The higher the molecular weight polystyrene showed better mechanical properties and after suffering the effects of gamma radiation there was an increase of 5.67% in the resistance to stress cracking effects. (author)

  18. Study of gamma radiation between 0.1 and 1.0 MeV in the earth's atmosphere; Etude du rayonnement gamma entre 0,1 et 1 Mev dans l'atmosphere terrestre

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-01-01

    The present work is devoted to some of the particular problems arising in the detection and localisation of sources of gamma radiation situated outside the earth's atmosphere. These weak sources can only be detected and localized if care is taken to eliminate gamma and particle radiations coming from other sources in the earth's atmosphere and in space. In order to separate the various sources of background noise, generally much stronger than the radiation under study, use is made of a directional detector whose characteristics are determined as described in the first part of the following report. The closest diffuse source considered is that constituted by the earth's atmosphere. Its detailed study will make it possible both to eliminate its effect when sources outside the earth are to be measured, and to predict the amount of secondary gamma radiation emitted by the same process in other celestial bodies, the moon in particular. This work considered in the 2. and 3. parts of the report. (author) [French] La presente etude est consacree a certains des problemes particuliers poses par la detection et la localisation des sources de rayonnement gamma situees hors de l'atmosphere terrestre. Ces sources faibles ne peuvent etre detectees et localisees que si l'on se protege des rayonnements gamma et particulaires provenant d'autres sources situees dans l'atmosphere terrestre et dans l'espace. Pour separer ces divers composants parasites, en general beaucoup plus intenses que le rayonnement a etudier, nous emploierons un detecteur directif dont nous determinons les caracteristiques dans la premiere partie de l'expose qui suit. La source diffuse la plus proche que nous considerons comme parasite est constituee par l'atmosphere terrestre. Son etude detaillee nous permettra d'une part de nous en proteger lorsque nous voudrons etudier les sources {gamma} extra-terrestres, d'autre part de prevoir le rayonnement gamma

  19. Self-powered radiation detector

    International Nuclear Information System (INIS)

    Playfoot, K.C.; Bauer, R.F.; Goldstein, N.P.

    1980-01-01

    This invention relates to a self powered radiation detector requiring no excitation potential to generate a signal indicating a radiation flux. Such detectors comprise two electrically insulated electrodes, at a distance from each other. These electrodes are made of conducting materials having a different response for neutron and/or gamma ray radiation flux levels, as in nuclear power stations. This elongated detector generates an electric signal in terms of an incident flux of radiations cooperating with coaxial conductors insulated from each other and with different radiation reaction characteristics. The conductor with the greatest reaction to the radiations forms the central emitting electrode and the conductor with the least reaction to the radiations forms a tubular coaxial collecting electrode. The rhodium or cobalt tubular emitting electrode contains a ductile central conducting cable placed along the longitudinal axis of the detector. The latter is in high nickel steel with a low reaction to radiation [fr

  20. Gamma radiation combined with cinnamon oil to maintain fish quality

    Science.gov (United States)

    Lyu, Fei; Zhang, Jing; Wei, Qianqian; Gao, Fei; Ding, Yuting; Liu, Shulai

    2017-12-01

    Effects of gamma radiation combined with cinnamon oil on quality of Northern Snakehead fish fillets were observed during storage at 4 °C. Fish fillets were treated with 1-5 kGy gamma radiation, 0.05-0.5% cinnamon oil or the combination of radiation and cinnamon oil. The antimicrobial activity increased with radiation dose and cinnamon oil concentration. During storage, the combination of 1 kGy radiation and 0.5% cinnamon oil displayed better inhibiting activities on aerobic plate counts, total volatile basic nitrogen, thiobarbituric acid reaction substances than 1 kGy radiation or 0.5% cinnamon oil used alone. Moreover, the combination could arrive at the similar inhibiting activities of cinnamon oil with higher concentration of 0.5% or radiation with higher dose of 5 kGy. Thus, the combination could decrease the radiation dose and cinnamon oil concentration without decreasing the effect of them on maintaining fish quality.

  1. Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

    International Nuclear Information System (INIS)

    Singh, Durgeshwer; Singh, Rita

    2012-01-01

    Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin–papain membranes without glycerol was 14.30±6.57% in 6 h. Incorporation of glycerol resulted in significant (p 2 /24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25–35 kGy. The irradiated chitin–papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin–papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity. - Highlight: ► Use of gamma radiation for sterilization of papain wound dressing was studied. ► Fluid handling and antimicrobial properties of irradiated dressings was evaluated. ► Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings.

  2. Comparison of gamma radiation - induced effects in two human prostate cancer cells

    International Nuclear Information System (INIS)

    Vucic, V.; Adzic, M.; Ruzdijic, S.; Radojcic, M.B. . E-mail address of corresponding author: vesnav@vin.bg.ac.yu; Vucic, V.)

    2005-01-01

    In this study, the effects of gamma radiation on two hormone refractory human prostate cancer cell lines, DU 145 and PC-3, were followed. It was shown that gamma radiation induced significant inhibition of cell proliferation and viability in dose dependent manner. Antiproliferative effects of radiation were similar in both cell lines, and more pronounced than cytotoxic effects. In addition to that, PC-3 cell line was more resistant to radiation -induced cytotoxicity. (author)

  3. Application of LiF for determining the gamma-radiation characteristics of the shut-down reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ibragimova, E M; Musaeva, M A; Ashrapov, U T; Kalanov, M U; Muminov, M I [Inst. of Nuclear Physics, Tashkent (Uzbekistan)

    2005-07-01

    Full text: The power of {sup 60}Co {approx}1.25 MeV gamma-radiation source at the INP AS RUz is limited by 8 Gy/s, which does not satisfy several tasks of material science now. Therefore, we were first to suggest the irradiation of materials with gamma-rays of 0.1-7 MeV, which are emitted by the uranium fission products ({sup 41}Ar, {sup 135}Xe, {sup 125}Xe, {sup 125}I,{sup 137}Cs, {sup 134}Cs, {sup 144}Ce, {sup 95}Zr, {sup 140}Ba, {sup 140}La, {sup 99}Mo, {sup 60}Co) and {sup l6}N, {sup 24}Na, {sup 28}Al radio-nuclides in water during prophylactic shut-downs of our nuclear reactor WWR-SM. The gamma-dose rate kinetics was monitored with the ion current in ionization chambers KNK-53M fixed outside the reactor core from the stop-moment. The current kinetics comprised 4 steps with a high reproducibility at 2 and 0.5 {mu}A, then 50 and 10 nA, each lasting for 1,10, 40 and up to 200 hours, according to the isotope life-times. LiF crystal is known as a thermal luminescence dosimeter of mixed radiations up to 100 Gy. Yet in this work the absorbed gamma-energy dose D{sub {gamma}} was determined by accumulation of the known stable structure defects in thin cleaved LiF crystals: by induced optical absorption and luminescence of F- and M-centers. The samples were irradiated in Al-containers filled with water to keep the temperature of {approx}40 deg. C in the time range from 30 minutes to 150 hours. Optical absorption spectra were registered at spectrometer Specord M-40. Then the induced color center concentration was calculated by the Smakula relation, which is proportional to the absorbed dose D{gamma}. For a better reliability the photoluminescence center content was also determined. Selecting comparable close intensities of the induced absorption and luminescence bands obtained after irradiations of LiF references in the certified {sup 60}Co gamma-sources of the known gamma fluxes 0.7 and 7.5 Gy/s, the gamma-radiation intensity of the shut-down reactor was estimated in

  4. Investigation of the effect of gamma radiation on lincomycin

    International Nuclear Information System (INIS)

    Al-Zier, A; Al- Kassiri, H.; Al Aji, Z.

    2001-01-01

    Sterilization of materials used in medical applications is necessary. Since the use of ethylene oxide will be forbidden in the next future and other sterilization methods as wet, and dry hot sterilization are not suitable for sterilization of drugs, further methods are needed which do not cause a significant decrease in the physical and chemical drug properties. Radiation sterilization can help in many cases. So Gamma or electron radiations were used for sterilization of antibiotics in the solid state as mentioned in the literature. Some antibiotics are already exposed to gamma or electron beam irradiation, and showed significant radiation resistance for low doses, but even small amounts of degradation products are not desirable

  5. Qualitative evaluation of the DNA degradation in plague insects exposed to gamma radiation

    International Nuclear Information System (INIS)

    Ortega, Yuriko; Agapito, Juan; Vargas, Johnny; Vivanco, Monica; Martinez, Norberta

    2014-01-01

    Insects produce large losses in stored grain depending on the type of cereal and storage time and other factors. The rice weevil Sitophilus oryzae L and the false flour beetle Tribolium confusum are important pests of stored grain. The study aimed to qualitatively evaluate the effect of gamma radiation on the DNA of two species of insect pests from samples stored Chullpi and white corn infested with adult weevils. Samples were treated with radiation doses of 100, 400, 1000 and 2000 Gy and DNA extraction was obtained by three methods: TNES-urea, CTAB and NaOH. The DNA damage induced by gamma radiation in weevils was determined by gel electrophoresis. As a result, it was found that exposure of adult weevils to a radiation dose of 100 Gy and 400 caused an average mortality of the insects, showing a degree of resistance to gamma radiation. However, radiation doses of 1000 and 2000 Gy caused 100 % mortality of insects. Preliminary results show that DNA damage is proportional to the amount of gamma radiation. (authors).

  6. Repair effects of exogenous SOD on Bacillus subtilis against gamma radiation exposure

    International Nuclear Information System (INIS)

    Chen, Xiaoming; Zhang, E.; Fang, Liu; Zhang, Jianguo; Zhu, Jie; He, Wei; Luo, Xuegang

    2013-01-01

    Superoxide dismutase (SOD) is an enzyme that removes free radicals from cells in many organisms. In order to further characterize these repair effects and their mechanism when subjected to radiation, Bacillus subtilis cells were exposed to gamma radiation and the cell survival rate, intracellular SOD activity, and DNA double-strand breakage were investigated. Vegetative cells of B. subtilis were irradiated by 60 Co gamma radiation at varying doses and subsequently exposed to varying levels of exogenous SOD. Standard plate-count, xanthine oxidase, and pulsed-field gel electrophoresis (PFGE) methods were employed to investigate the repair effects. The results showed that the exogenous SOD could significantly improve cell survival rate and intracellular SOD activity after gamma radiation. The cell survival rate was elevated 30–87 times above levels observed in control samples. Adding exogenous SOD into gamma irradiated cells may dramatically increase intracellular SOD activity (p 60 Co γ radiation and exposed to exogenous SOD. • Adding exogenous SOD into γ-irradiated cells may dramatically increase cell survival rate. • DNA strand scission may be prevented by addition of SOD. • Exogenous SOD may have the ability to repair cell damage after γ-rays radiation

  7. Gamma radiation and gamma ray protection factors of ships in various situations of radioactive fall-out

    International Nuclear Information System (INIS)

    Brehm, E.H.; Holst, T.

    1975-01-01

    In this report the development of methods of evaluating gamma ray protection factors (GSF) of ships for various situations of radioactive fall-out is described. The joining calculations of gamma ray protection factors are performed by the newly developed computer procedure GASUFA. These protection factors determine - in connection with a measured gamma radiation dose at a given detector point - the gamma radiation in different compartments of the ships. The computer program GASUFA is able to perform calculations considering the dependence of energy, place and time for the following situations: - the ship is under a radioactive cloud without fall-out; - the ship is under a radioactive cloud with fall-out; - the ship is contaminated by radioactive fall-out; - the clean or decontaminated ship is going through a zone, which is contaminated by radioactive fall-out; - the ship and the surrounding water surface are contaminated by radioactive fall-out. (orig.) [de

  8. Observation of solar gamma-ray by Hinotori

    International Nuclear Information System (INIS)

    Yoshimori, Masato; Okudaira, Kiyoaki; Hirashima, Yo; Kondo, Ichiro.

    1982-01-01

    The solar gamma-ray emitted by solar flare was observed. The gamma-ray is the electromagnetic radiation with the energy more than 300 keV. The line gamma-ray intensity and the time profile were observed. The gamma-ray detector CsI (Tl) was loaded on Hinotori, and the observed gamma-ray was analyzed by a multi-channel analyzer. The observed line gamma-ray was the radiation from Fe-56 and Ne-20. The line gamma-ray from C-12 and O-16 was also seen. These gamma-ray is the direct evidence of the nuclear reaction on the sun. The observed spectrum suggested the existence of the lines from Mg-24 and Si-28. The intensity of the 2.22 MeV gamma-line was small. This fact showed that the origin of this line was different from other nuclear gamma-ray. Two kinds of hard X-ray bursts were detected. The one was impulsive burst, and the other was gradual burst. There was no time difference between the hard X-ray and the gamma-ray of the impulsive burst. The impulsive burst may be explained by the beam model. The delay of time profile in the high energy gamma-ray of the gradual burst was observed. This means that the time when accelerated electrons cause bremsstrahlung depends on the electron energy. The long trapping of electrons at the top of magnetic loop is suggested. (Kato, T.)

  9. Risk to Krakow population of gamma radiation from building materials

    International Nuclear Information System (INIS)

    Koperski, J.; Jasinska, M.

    1980-01-01

    A statistics was made of 7128 dwelling-houses considering their age, types of building materials and density of population. Gamma dose rates were measured by means of the TL and pressurized ionization chamber techniques inside 300 buildings and in 44 points outdoors over different kinds of beddings. Personal doses of 49 inhabitants of the buildings monitored were also recorded. By means of the spectrometric analysis of gamma radiation, and basing on a specially developed computational programme ''DOZA'' mean concentrations of 40 K, 226 Ra and 232 Th in 61 samples of building materials were evaluated. It was found that the mean personal dose rate as well as the mean indoor dose rate equals 5.7 urad/h /15.8 pGy/s/ and is about 19% higher than the dose outdoors which equals 4.8 urad/h /13.3 pGy/s/. Gamma dose rates inside the buildings made of gravel-sand concrete elements are about 10% lower than those in the buildings made of red bricks. Mean annual dose equivalent per capita from gamma radiation of building materials equals 40.6 mrem/y /406 uSv/y/, which constitutes about 57% of total annual dose equivalent per capita from all environmental sources of gamma radiation in the residential districts in Krakow. (author)

  10. Propagation speed of gamma radiation in brass

    International Nuclear Information System (INIS)

    Cavalcante, Jose T.P.D.; Silva, Paulo R.J.; Saitovich, Henrique

    2009-01-01

    The propagation speed (PS) of visible light -represented by a short frequency range in the large frame of electromagnetic radiations (ER) frequencies- in air was measured during the last century, using a great deal of different methods, with high precision results being achieved. Presently, a well accepted value, with very small uncertainty, is c= 299,792.458 Km/s) (c reporting to the Latin word celeritas: 'speed swiftness'). When propagating in denser material media (MM), such value is always lower when compared to the air value, with the propagating MM density playing an important role. Until present, such studies focusing propagation speeds, refractive indexes, dispersions were specially related to visible light, or to ER in wavelengths ranges dose to it, and with a transparent MM. A first incursion in this subject dealing with γ-rays was performed using an electronic coincidence counting system, when the value of it's PS was measured in air, C γ(air) 298,300.15 Km/s; a method that went on with later electronic improvements. always in air. To perform such measurements the availability of a γ-radiation source in which two γ-rays are emitted simultaneously in opposite directions -as already used as well as applied in the present case- turns out to be essential to the feasibility of the experiment, as far as no reflection techniques could be used. Such a suitable source was the positron emitter 22 Na placed in a thin wall metal container in which the positrons are stopped and annihilated when reacting with the medium electrons, in such way originating -as it is very well established from momentum/energy conservation laws - two gamma-rays, energy 511 KeV each, both emitted simultaneously in opposite directions. In all the previous experiments were used photomultiplier detectors coupled to NaI(Tl) crystal scintillators, which have a good energy resolution but a deficient time resolution for such purposes. Presently, as an innovative improvement, were used BaF 2

  11. Degradation of electrical insulation of polyethylene under thermal and radiation environment, (4). [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Shuhei; Murabayashi, Fumio; Sawa, Goro [Mie Univ., Tsu (Japan); Yamaguchi, Shinji; Ieda, Masayuki

    1982-12-01

    Although the quality assurance guideline for the cables used for the safety and protection systems of nuclear power plants is given by IEEE Standards 323 and 383-1974, in addition, it is important to clarify the aging process under the complex environment of heat and radiation and the equivalence of the accelerated aging test of insulating materials. The authors performed the sequential (H.T-..gamma.. or ..gamma..-HT) and simultaneous (..gamma.., HT) application of respective aging factors of heat and radiation to non-additive low density polyethylene films by changing dose rate as the first stage, to clarify the dose rate dependence of the aging. They mainly investigated the dielectric properties, and forwarded investigation based on the change of carbonyl group by infrared spectrometry and residual free radicals by ESR analysis. In the samples irradiated with ..gamma..-ray only and those irradiated with ..gamma..-ray after thermal treatment for 7 hours at 90 deg C, the absorption coefficient ..cap alpha.. of carbonyl group increased with dose in the range from 3 Mrad to 60 Mrad, and both samples showed approximately the same ..cap alpha.. value. The ..cap alpha.. value of the samples thermally treated after irradiation was larger than that of the samples treated in the reverse order, and the difference between them increased with the increase of dose. The values of dielectric tangent delta at room temperature and 1 kHz for the samples (..gamma..) and (HT-..gamma..) increased with dose, and were almost the same, but those for the samples (..gamma..-HT) and (..gamma.., HT) were larger than the former two.

  12. Portable neutron and gamma-radiation instruments

    International Nuclear Information System (INIS)

    Murray, W.S.; Butterfield, K.B.

    1990-01-01

    This paper reports on the design and building of a smart neutron and gamma-radiation detection systems with embedded microprocessors programmed in the FORTH language. These portable instruments can be battery-powered and can provide many analysis functions not available in most radiation detectors. Local operation of the instruments is menu-driven through a graphics liquid crystal display and hex keypad; remote operation is through a serial communications link. While some instruments simply count particles, others determine the energy of the radiation as well as the intensity. The functions the authors have provided include absolute source-strength determination. Feynmann variance analysis, sequential-probability ratio test, and time-history recording

  13. Co-60 gamma radiation assisted diffusion of iodine in polypropylene

    Energy Technology Data Exchange (ETDEWEB)

    Mathakari, N.L.; Bhoraskar, V.N. [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune, Maharashtra 411007 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ernet.i [Microtron Accelerator Laboratory, Department of Physics, University of Pune, Pune, Maharashtra 411007 (India)

    2010-09-15

    Thin films of polypropylene having dimensions 50 mm x 15 mm x 350 {mu}m were immersed in 1 N iodine solution and then irradiated with Co-60 gamma radiation for the periods of 48, 96 and 144 h at the doses varying from 14.4 to 43.2 kGy. The films were also kept immersed in iodine solution for similar periods but without irradiation. Furthermore, the films were also directly-irradiated with Co-60 gamma radiation for similar periods and doses. The radiation-iodinated, plain-iodinated and directly-irradiated samples were characterized by using various techniques such as weight gain EDS, SEM, FTIR, UV-visible spectroscopy, contact angle and XRD. Weight gain, EDS and SEM collectively reveal that gamma irradiation enhances iodine intake in polypropylene. FTIR, EDS and contact angle measurements indicate that presence of iodine during irradiation resists radiation induced carbonylation of polypropylene. FTIR also shows presence of HOI (Hypoiodous acid) species instead of expected C-I bonds. UV-visible analysis unambiguously shows that presence of iodine enhances radiation induced band gap reduction process of polypropylene. XRD indicates that iodine decreases the crystallinity of polypropylene.

  14. Level of terrestrial gamma radiation and doses to population in Jiangsu province

    International Nuclear Information System (INIS)

    1985-01-01

    In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

  15. Disinfection of sewage water and sludge using gamma radiation

    International Nuclear Information System (INIS)

    Musaad, R.M.A.

    2008-04-01

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6 0 cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D 10 ) and 50% (D 50 ) were determined for each species. The D 10 values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D 50 fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  16. SWEPP gamma-ray spectrometer system software user's guide

    International Nuclear Information System (INIS)

    Femec, D.A.

    1994-08-01

    The SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurement and Development Unit of the Idaho National Engineering Laboratory to assist in the characterization of the radiological contents of contact-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP). In addition to determining the concentrations of gamma-ray-emitting radionuclides, the software also calculates attenuation-corrected isotopic mass ratios of specific interest, and provides controls for SGRS hardware as required. This document serves as a user's guide for the data acquisition and analysis software associated with the SGRS system

  17. Inhaled /sup 147/Pm and/or total-body gamma radiation: Early mortality and morbidity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Filipy, R.E.; Lauhala, K.E.; McGee, D.R.; Cannon, W.C.; Buschbom, R.L.; Decker, J.R.; Kuffel, E.G.; Park, J.F.; Ragan, H.A.; Yaniv, S.S.; Scott, B.R.

    1989-05-01

    Rats were given doses of /sup 60/Co gamma radiation and/or lung burdens of /sup 147/Pm (in fused aluminosilicate particles) within lethal ranges in an experiment to determine and compare morbidity and mortality responses for the radiation insults within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Acute mortality and morbidity from inhaled promethium were caused primarily by radiation pneumonitis and pulmonary fibrosis that occurred more than 53 days after exposure. Acute mortality and morbidity from total-body gamma irradiation occurred within 30 days of exposure and resulted from the bone-marrow radiation syndrome. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell levels and by reduced body weight gain in animals that survived the acute gamma radiation syndrome. Inhaled promethium caused a loss of body weight and diminished pulmonary function, but its only effect on blood cell levels was lymphocytopenia. Combined gamma irradiation and promethium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Promethium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the later effect of promethium lung burdens. 70 refs., 68 figs., 21 tabs.

  18. Characteristics of liver tissue for attenuate the gamma radiation

    International Nuclear Information System (INIS)

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R.

    2005-01-01

    It was determined the lineal attenuation coefficient of hepatic tissue before gamma radiation of a source of 137 Cs. When exposing organic material before X or gamma radiation fields, part of the energy of the photons is absorbed by the material, while another part crosses it without producing any effect. The quantity of energy that is absorbed is a measure of the dose that receives the material. The three main mechanisms by means of which the gamma rays interacting with the matter are: The Photoelectric Effect, the Compton dispersion and the Even production; the sum of these three processes is translated in the attenuation coefficient of the radiation. In this work we have used hepatic tissue of bovine, as substitute of the human hepatic tissue, and we have measured the lineal attenuation coefficient for photons of 0.662 MeV. Through a series of calculations we have determined the lineal attenuation coefficient for photons from 10 -3 to 10 -5 MeV and the measured coefficient was compared with the one calculated. (Author)

  19. Prompt Gamma Ray Spectroscopy for process monitoring

    International Nuclear Information System (INIS)

    Zoller, W.H.; Holmes, J.L.

    1991-01-01

    Prompt Gamma Ray Spectroscopy (PGRS) is a very powerful analytical technique able to measure many metallic, contamination problem elements. The technique involves measurement of gamma rays that are emitted by nuclei upon capturing a neutron. This method is sensitive not only to the target element but also to the particular isotope of that element. PGRS is capable of measuring dissolved metal ions in a flowing system. In the field, isotopic neutron sources are used to produce the desired neutron flux ( 252 Cf can produce neutron flux of the order of 10 8 neutrons/cm 2 --sec.). Due to high penetrating power of gamma radiation, high efficiency gamma ray detectors can be placed in an appropriate geometry to maximize sensitivity, providing real-time monitoring with low detection level capabilities

  20. Measurements of the gamma-quanta angular distributions emitted from neutron inelastic scattering on 28Si

    Science.gov (United States)

    Fedorov, N. A.; Grozdanov, D. N.; Bystritskiy, V. M.; Kopach, Yu. N.; Ruskov, I. N.; Skoy, V. R.; Tretyakova, T. Yu.; Zamyatin, N. I.; Wang, D.; Aliev, F. A.; Hramco, C.; Gandhi, A.; Kumar, A.; Dabylova, S.; Bogolubov, E. P.; Barmakov, Yu. N.

    2018-04-01

    The characteristic gamma radiation from the interaction of 14.1 MeV neutrons with a natural silicon sample is investigated with Tagged Neutron Method (TNM). The anisotropy of gamma-ray emission of 1.779 MeV was measured at 11 azimuth angles with a step of ∠15°. The present results are in good agreement with some recent experimental data.

  1. High-energy Emission from Nonrelativistic Radiative Shocks: Application to Gamma-Ray Novae

    Science.gov (United States)

    Vurm, Indrek; Metzger, Brian D.

    2018-01-01

    The observation of GeV gamma-rays from novae by Fermi/LAT demonstrates that the nonrelativistic radiative shocks in these systems can accelerate particles to energies of at least ∼10 GeV. The low-energy extension of the same nonthermal particle distribution inevitably gives rise to emission in the hard X-ray band. Above ≳ 10 {keV}, this radiation can escape the system without significant absorption/attenuation, and can potentially be detected by NuSTAR. We present theoretical models for hard X-ray and gamma-ray emission from radiative shocks in both leptonic and hadronic scenarios, accounting for the rapid evolution of the downstream properties due to the fast cooling of thermal plasma. We find that due to strong Coulomb losses, only a fraction of {10}-4{--}{10}-3 of the gamma-ray luminosity is radiated in the NuSTAR band; nevertheless, this emission could be detectable simultaneously with the LAT emission in bright gamma-ray novae with a ∼50 ks exposure. The spectral slope in hard X-rays is α ≈ 0 for typical nova parameters, thus serving as a testable prediction of the model. Our work demonstrates how combined hard X-ray and gamma-ray observations can be used to constrain properties of the nova outflow (velocity, density, and mass outflow rate) and particle acceleration at the shock. A very low X-ray to gamma-ray luminosity ratio ({L}{{X}}/{L}γ ≲ 5× {10}-4) would disfavor leptonic models for the gamma-ray emission. Our model can also be applied to other astrophysical environments with radiative shocks, including SNe IIn and colliding winds in massive star binaries.

  2. In vitro cell culture lethal dose submitted to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: carolina_sm@hotmail.com; Ikeda, Tamiko I.; Cruz, Aurea S. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil)

    2009-07-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that {sup 60}Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  3. In vitro cell culture lethal dose submitted to gamma radiation

    International Nuclear Information System (INIS)

    Moreno, Carolina S.; Rogero, Sizue O.; Rogero, Jose Roberto; Ikeda, Tamiko I.; Cruz, Aurea S.

    2009-01-01

    The present study was designed to evaluate the in vitro effect of gamma radiation in cell culture of mouse connective tissue exposed to different doses of gamma radiation and under several conditions. The cell viability was analyzed by neutral red uptake methodology. This assay was developed for establish a methodology to be used in the future in the study of resveratrol radioprotection. Resveratrol (3,4',5- trihydroxystilbene), a phenolic phytoalexin that occurs naturally in some spermatophytes, such as grapevines, in response to injury as fungal infections and exposure to ultraviolet light. In the wines this compound is found at high levels and is considered one of the highest antioxidant constituents. The intense antioxidant potential of resveratrol provides many pharmacological activities including cardioprotection, chemoprevention and anti-tumor effects. Our results demonstrated that 60 Co gamma radiation lethal dose (LD50) on NCTC clone 929 cells was about 340Gy. (author)

  4. Control device intended for a gamma radiation measuring instrument

    International Nuclear Information System (INIS)

    1976-01-01

    This invention concerns a monitoring device for a gamma radiation measuring instrument or radiation meter, in which the radiation to be measured brings about, inter alia, the ionisation of a gas and the generation of current pulses. The dial of this meter is generally calibrated in roentgens per hour, i.e. in radiation rate units. This instrument of very simple design is remarkable for its operating reliability. Preferably placed at the inlet to a radioactive area, it enables every user of a ratemeter to check, over the entire measuring range of this instrument, its proper operation prior to entering the area. To this effect, the monitoring device in question has a thick wall lead castle, having an internal cavity in which is mounted a radioactive source delivering a gamma radiation with given constant characteristics, through a measurement window closed by a calibrated plug. Lead doors articulated on the castle can be superimposed on this window to bring about a given attenuation of the radiation coming from the source and delivered to the exterior of the castle [fr

  5. Radiation anomaly detection algorithms for field-acquired gamma energy spectra

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ron; Guss, Paul; Mitchell, Stephen

    2015-08-01

    The Remote Sensing Laboratory (RSL) is developing a tactical, networked radiation detection system that will be agile, reconfigurable, and capable of rapid threat assessment with high degree of fidelity and certainty. Our design is driven by the needs of users such as law enforcement personnel who must make decisions by evaluating threat signatures in urban settings. The most efficient tool available to identify the nature of the threat object is real-time gamma spectroscopic analysis, as it is fast and has a very low probability of producing false positive alarm conditions. Urban radiological searches are inherently challenged by the rapid and large spatial variation of background gamma radiation, the presence of benign radioactive materials in terms of the normally occurring radioactive materials (NORM), and shielded and/or masked threat sources. Multiple spectral anomaly detection algorithms have been developed by national laboratories and commercial vendors. For example, the Gamma Detector Response and Analysis Software (GADRAS) a one-dimensional deterministic radiation transport software capable of calculating gamma ray spectra using physics-based detector response functions was developed at Sandia National Laboratories. The nuisance-rejection spectral comparison ratio anomaly detection algorithm (or NSCRAD), developed at Pacific Northwest National Laboratory, uses spectral comparison ratios to detect deviation from benign medical and NORM radiation source and can work in spite of strong presence of NORM and or medical sources. RSL has developed its own wavelet-based gamma energy spectral anomaly detection algorithm called WAVRAD. Test results and relative merits of these different algorithms will be discussed and demonstrated.

  6. Measurement of gamma radiation doses at the RA reactor by thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Prokic, M.

    1974-01-01

    This paper presents the procedures and gamma radiation doses measured at the exit from the horizontal experimental channel HK-5, vertical experimental channel VK-5 and in the thermal column of the RA reactor in Vinca. Measurement of gamma radiation dose in the mixed intense gamma and neutron radiation field was done by two types of thermoluminescent dosemeters, LiF (TLD-700) and CaF 2 (TLD-08). Gamma dose in the VK-5 was measured in the air and on the bottle filled with tissue-equivalent solution. Increase of the dose on the surface of the bottle was 2.3 compared to the gamma dose value in the air. Correction for the influence of neutrons having different energies was done by using the known sensitivity values of both TL dosemeter types for thermal, intermediate and fast neutrons. Results showed that the TLD-700 dosemeter contains 5 time more Li-6 isotopes (0.035%) than the declared value causing increased neutron sensitivity of this dosemeter. This paper includes numerical sensitivity data for neutrons of different energies for both types of TL dosemeters. Neutron sensitivity values for TLD-700 are related to LiF with 0.035% of Li-6 isotope. Result of measurement have also shown that the CaF 2 :Mn (TLD-08) thermoluminescent dosemeter is more suitable for gamma radiation dose measurements in mixed n-gamma fields with intensive neutron fluxes due to lower neutron sensitivity compared to TLD-700 [sr

  7. Gamma-spectrometric examination of hot particles emitted during the Chernobyl accident

    International Nuclear Information System (INIS)

    Balashazy, I.; Szabadine-Szende, G.; Loerinc, M.; Zombori, P.

    1987-05-01

    Ge(Li) gamma-spectrometric examination of hot particles prepared from air filtered dust of Budapest air after the Chernobyl accident is presented. The method of separating hot particles is described and their concentration in the air is determined. The radioactive isotope composition of hot particles is discussed and compared with that of dust samples. Finally, the inhalation probability and radiation burden of hot particles are evaluated. (author)

  8. Silicon detectors for x and gamma-ray with high radiation resistance

    International Nuclear Information System (INIS)

    Cimpoca, Valerica; Popescu, Ion V.; Ruscu, Radu

    2001-01-01

    Silicon detectors are widely used in X and gamma-ray spectroscopy for direct detection or coupled with scintillators in high energy nuclear physics (modern collider experiments are representative), medicine and industrial applications. In X and gamma dosimetry, a low detection limit (under 6 KeV) with silicon detectors becomes available. Work at the room temperature is now possible due to the silicon processing evolution, which assures low reverse current and high life time of carriers. For several years, modern semiconductor detectors have been the primary choice for the measurement of nuclear radiation in various scientific fields. Nowadays the recently developed high resolution silicon detectors found their way in medical applications. As a consequence many efforts have been devoted to the development of high sensitivity and radiation hardened X and gamma-ray detectors for the energy range of 5 - 150 keV. The paper presents some results concerning the technology and behaviour of X and Gamma ray silicon detectors used in physics research, industrial and medical radiography. The electrical characteristics of these detectors, their modification after exposure to radiation and the results of spectroscopic X and Gamma-ray measurements are discussed. The results indicated that the proposed detectors enables the development of reliable silicon detectors to be used in controlling the low and high radiation levels encountered in a lot of application

  9. Applying the new gamma ray imager diagnostic to measurements of runaway electron Bremsstrahlung radiation in the DIII-D Tokamak (invited)

    International Nuclear Information System (INIS)

    Cooper, C. M.; Pace, D. C.; Paz-Soldan, C.; Eidietis, N. W.; Commaux, N.; Shiraki, D.; Hollmann, E. M.

    2016-01-01

    A new gamma ray imager (GRI) is developed to probe the electron distribution function with 2D spatial resolution during runaway electron (RE) experiments at the DIII-D tokamak. The diagnostic is sensitive to 0.5–100 MeV gamma rays, allowing characterization of the RE distribution function evolution during RE growth and dissipation. The GRI consists of a lead “pinhole camera” mounted on the DIII-D midplane with 123 honeycombed tangential chords 20 cm wide that span the vessel interior. Up to 30 bismuth germanate (BGO) scintillation detectors capture RE bremsstrahlung radiation for Pulse Height Analysis (PHA) capable of discriminating up to 20 000 pulses per second. Digital signal processing routines combining shaping filters are performed during PHA to reject noise and record gamma ray energy. The GRI setup and PHA algorithms will be described and initial data from experiments will be presented. A synthetic diagnostic is developed to generate the gamma ray spectrum of a GRI channel given the plasma information and a prescribed distribution function. Magnetic reconstructions of the plasma are used to calculate the angle between every GRI sightline and orient and discriminate gamma rays emitted by a field-aligned RE distribution function.

  10. Applying the new gamma ray imager diagnostic to measurements of runaway electron Bremsstrahlung radiation in the DIII-D Tokamak (invited)

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, C. M., E-mail: coopercm@fusion.gat.com [Oak Ridge Associated Universities, Oak Ridge, Tennessee 37830 (United States); Pace, D. C.; Paz-Soldan, C.; Eidietis, N. W. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Commaux, N.; Shiraki, D. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Hollmann, E. M. [University of California, San Diego, La Jolla, California 92093-0533 (United States)

    2016-11-15

    A new gamma ray imager (GRI) is developed to probe the electron distribution function with 2D spatial resolution during runaway electron (RE) experiments at the DIII-D tokamak. The diagnostic is sensitive to 0.5–100 MeV gamma rays, allowing characterization of the RE distribution function evolution during RE growth and dissipation. The GRI consists of a lead “pinhole camera” mounted on the DIII-D midplane with 123 honeycombed tangential chords 20 cm wide that span the vessel interior. Up to 30 bismuth germanate (BGO) scintillation detectors capture RE bremsstrahlung radiation for Pulse Height Analysis (PHA) capable of discriminating up to 20 000 pulses per second. Digital signal processing routines combining shaping filters are performed during PHA to reject noise and record gamma ray energy. The GRI setup and PHA algorithms will be described and initial data from experiments will be presented. A synthetic diagnostic is developed to generate the gamma ray spectrum of a GRI channel given the plasma information and a prescribed distribution function. Magnetic reconstructions of the plasma are used to calculate the angle between every GRI sightline and orient and discriminate gamma rays emitted by a field-aligned RE distribution function.

  11. Calibration and simulation of a gamma array for DRAGON at ISAC

    CERN Document Server

    Gigliotti, D G; Hussein, A H

    2003-01-01

    A gamma ray detector has been built for the DRAGON facility at TRIUMF to detect the gamma ray emitted in astrophysically important proton and alpha radiative capture reactions. The gamma detector was designed to balance cost with maximum solid angle coverage and efficiency. To study the properties of the current design, GEANT simulations are being carried out and compared with prototype measurements using calibration sources and radioactive beams supplied by ISAC. Simulations will be compared with data allowing a realistic simulation to be produced. This modified simulation will then be used to provide efficiency predictions of the gamma array when an actual experiment's parameters are inputted. Using the simulated efficiency of the array, cross sections for radiative capture can be calculated from the measured gamma ray yields, for the individual reactions. The following will outline some initial results of background suppression of beam related experiments. Also shown, are some preliminary comparison of poi...

  12. Gamma-radiation effect on diamond and steel during their irradiation in WWER type reactors

    International Nuclear Information System (INIS)

    Nikolaenko, V.A.; Karpukhin, V.I.; Amaev, A.D.; Vikhrov, V.I.; Korolev, Yu.N.; Krasikov, E.A.

    1996-01-01

    A study is made into the influence of reactor gamma radiation on expansion of crystal lattice in diamond. The data obtained are compared to those on radiation embrittlement of reactor vessel steels. The necessity of taking into consideration gamma radiation effects on WWER reactor vessel radiation resistance during long-term operation is shown [ru

  13. Gamma radiation influences postharvest disease incidence of pineapple fruits

    International Nuclear Information System (INIS)

    Damayanti, M.; Sharma, G.J.; Kundu, S.C.

    1992-01-01

    The application of gamma radiation for improving the storage of pineapple fruits [Ananas comosus (L.) Merr. cv. Queen] has been studied in an attempt to reduce decay caused by fungal pathogens such as Ceratocystis paradoxa (Dade)-Moreau and Penicillium purpurogenum Stoll. Gamma radiation at 50, 75, 100, 150, and 250 Gy improved shelf life. The maximum tolerable dose was approximately 250 Gy. Fruits irradiated with up to 150 Gy and then stored at 25 to 28C maintained their texture better than did the controls. Radiation, particularly at doses 250 Gy, caused browning of the skin and softening of tissues. Browning increased with increasing radiation dose and storage duration. Excessively high doses promoted spoilage. Doses in the range of 50 to 250 Gy, in combination with storage at 11 to 13C, can be used to reduce postharvest losses in pineapple due to fungal diseases and senescence, thereby extending shelf life

  14. Investigation of Electricity Generation by Using Gamma Radiation from Spent Fuels

    International Nuclear Information System (INIS)

    Lee, Haneol; Yim, Man-Sung Yim

    2015-01-01

    The purpose of this study is to investigate the electric power generation with scale spent fuel. OrigenArp has analyzed gamma radiation environment of spent fuel assembly, MCNPX has analyzed the scintillator behavior, and experimental work has analyzed the electric output of photovoltaic cell. Gamma radiation environment analysis result indicates gamma source rapidly decreases for the early storage period. Scintillator analysis result calculates the photon flux distribution which enters photovoltaic cell. Photovoltaic cell experiment calculates electric current, voltage current generation per each system unit. Generated electric power can be used to cope with existing safety system (i.e. storage monitoring system) under severe accident or to operate security system under external invasion situation (i.e. passive physical barrier system). Several researchers have shown that converting radiation energy into electric energy is possible. Karl Scharf studied the direct electric conversion of radiation energy by using photovoltaic cells. Researchers in University of Massachusetts Lowell have studied radiation-electric energy conversion by using gadolinium oxide scintillator and dye sensitized solar cell (DSSCs) and N. Horuichi et al. studied radiation-electric energy conversion by using inorganic scintillators and amorphous and crystal photovoltaic cells

  15. Quality control of gamma radiation measuring systems

    International Nuclear Information System (INIS)

    Surma, M.J.

    2002-01-01

    The problem of quality control and assurance of gamma radiation measuring systems has been described in detail. The factors deciding of high quality of radiometric measurements as well as statistical testing and calibration of measuring systems have been presented and discussed

  16. Automated TLD system for gamma radiation monitoring

    International Nuclear Information System (INIS)

    Nyberg, P.C.; Ott, J.D.; Edmonds, C.M.; Hopper, J.L.

    1979-01-01

    A gamma radiation monitoring system utilizing a commercially available TLD reader and unique microcomputer control has been built to assess the external radiation exposure to the resident population near a nuclear weapons testing facility. Maximum use of the microcomputer was made to increase the efficiency of data acquisition, transmission, and preparation, and to reduce operational costs. The system was tested for conformance with an applicable national standard for TLD's used in environmental measurements

  17. High-energy gamma-ray emission in compact binaries

    International Nuclear Information System (INIS)

    Cerutti, Benoit

    2010-01-01

    Four gamma-ray sources have been associated with binary systems in our Galaxy: the micro-quasar Cygnus X-3 and the gamma-ray binaries LS I +61 degrees 303, LS 5039 and PSR B1259-63. These systems are composed of a massive companion star and a compact object of unknown nature, except in PSR B1259-63 where there is a young pulsar. I propose a comprehensive theoretical model for the high-energy gamma-ray emission and variability in gamma-ray emitting binaries. In this model, the high-energy radiation is produced by inverse Compton scattering of stellar photons on ultra-relativistic electron-positron pairs injected by a young pulsar in gamma-ray binaries and in a relativistic jet in micro-quasars. Considering anisotropic inverse Compton scattering, pair production and pair cascade emission, the TeV gamma-ray emission is well explained in LS 5039. Nevertheless, this model cannot account for the gamma-ray emission in LS I +61 degrees 303 and PSR B1259-63. Other processes should dominate in these complex systems. In Cygnus X-3, the gamma-ray radiation is convincingly reproduced by Doppler-boosted Compton emission of pairs in a relativistic jet. Gamma-ray binaries and micro-quasars provide a novel environment for the study of pulsar winds and relativistic jets at very small spatial scales. (author)

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

    Directory of Open Access Journals (Sweden)

    Sudhanshu Saxena

    2014-01-01

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

  19. Towards a new thickness-independent gamma radiation plastic film dosimeter

    International Nuclear Information System (INIS)

    Vieira, Marli Barbosa; Araujo, Patricia L.; Araujo, Elma S.

    2013-01-01

    A 100% national single-use gamma radiation plastic film dosimeter is presented in this work. A new approach for the development of this material allowed a step forward in the performance of poly (methyl metacrylate) films (PMMA) colored with bromothymol blue (BTB) acid-base indicator. We manage to improve dosimeter performance by introducing a gamma radiation insensitive dye to compensate film thickness variations. By doing so, we were able to obtain consistent dose-response correlations within a set of samples presenting 46 to 110 micrometers in thickness. Hence, our PMMA/BTB-P film dosimeter is suitable to measure absorbed dose in the 2-100kGy range even when film thickness undergoes more than 100% of variation. In addition, dose response data remain practically unaltered for four months after the exposure, when dosimeter films are kept in dark conditions and under refrigeration. The radiation effects on the optical properties were evaluated for Ultraviolet-Visible (UV-Vis) spectrophotometric analysis. Data of characteristic dose-response correlation in terms of changes in the maximum UV-Vis absorption due to radiation, and stability in time are also described. This potential new product is a promising tool for industrial radiation facilities, especially in gamma sterilization of medical supplies. (author)

  20. The effect of gamma radiation and caffeine during the embrionic development of Biomphalaria glabrata

    International Nuclear Information System (INIS)

    Kawano, T.

    1982-01-01

    Some experiments have been carried out, dealing with the interations of caffeine and gamma radiation in the embryonic development of Biomphalaria glabrata. Gamma radiation was used in a dosis of 1000r (exposure time of 1/2 hour) and caffeine concentration was 0.1% (Exposure time of 24 hours). Experiment I. The embryos were irradiated before treatment with caffeine. In this experiment we have observed a synergistic effect between caffeine and gamma radiation. Experiment II. The embryos in the caffeine solution were irradiated 8 hours after the beginning of the experiment. The synergistic effect observed in this experiment was reduced when compared with the first one. Experiment III. In this experiment we made the pre-treatment with caffeine. We have not observed any synergistic effect between the drug and gamma radiation. Experiment IV. Embryos were irradiated, and after 24 hours treated with caffeine during another 24 hours. As in the previous experiment, we have not observed any synergism between the radiation and the drug. According to the above results, we conclude that the synergistic effect between caffeine and gamma radiation in the embryos was more effective when the embryos have been treated with caffeine after irradiation. (Author) [pt

  1. Disinfection of sewage water and sludge using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Musaad, R M.A. [Department of Radiation Chemistry, Atomic Energy Research Coordination Council, Sudan Academy of Sciences, Khartoum (Sudan)

    2008-04-15

    This study has been carried out to assess the efficiency of gamma radiation in disinfecting sewage water and sludge from harmful pathogenic bacteria (e.g. Streptococcus, Salmonella, Shigella, total E-coli and total coliform), parasites (Ascaris ova) as well as its ability to degrade organic matter (BOD). Samples were exposed to gamma-radiation doses ranging from 0.5 to 8 KGy using Co''6{sup 0} cell. Amongst pathogenic bacteria which are subjected to different doses of gamma-radiation Streptococcus faecalis revealed to be the most resistance bacterial indicator since complete elimination of these bacteria could be attained at 3.5 KGy. While total e-coli shown to be the most sensitive with lethal dose at 2 KGy. The radiation doses that required for reducing the bacterial population by 90% (D{sub 10}) and 50% (D {sub 50}) were determined for each species. The D{sub 10} values found ranged from 0.75 KGy for Streptococcus and 2.75 KGy for total count bacteria. On the other hand, D{sub 50} fall within the range of 0.5 KGy for total count bacteria, total coliform and Streptococcus, and 1.0 KGy for total e-coli. With regard to the efficiency of radiation treatment to destroy Ascaris ova viability it was found that no larvae were viable after exposure to 1.0 KGy following incubation of exposed ova for four weeks period.(Author)

  2. Density measurement using gamma radiation - theory and application

    International Nuclear Information System (INIS)

    Springer, E.K.

    1979-01-01

    There are still widespread uncertainties about the use and safety of gamma radiation in industries. This paper describes, by the example of radiometric density measurement, the theory of gamma radiation. The differences and advantages of both types of detectors, the ionization chamber and the scintillation counter, are discussed. The degree of accuracy which can be expected from the radiometric density meter will be defined, and the inter-relationship: source strength - measuring range - measuring length(normally the pipe diameter) in relation to the measuring accuracy required will be explained in detail. The use of radioactive material requires the permission of the Atomic Energy Board. The formalities involved to receive a user's licence and the implementations of safety standards set by the local authorities are discussed in depth [af

  3. Gamma radiation in pest control at the storehouses

    International Nuclear Information System (INIS)

    Tsvetkov, D.; Atanasov, Khr.; Berberov, D.

    1974-01-01

    The prospects of radiation control of wheat grain pests in Bulgaria are shown, drawing the following main conclusions: The lethal doses of gamma rays for the granary weevil, grain borer and confused flour beetle are fairly high - of the order of 300,000-400,000 r; the sterilizing doses of gamma rays arrest the reproduction of granary and rice weevils as well as of confused flour beetles. The irradiated insects, however, retain their sex activity and so may inhibit the reproduction of fertile populations. Irradiation strongly reduces the life span of, and consequently the damage done by, the insects; radiation control of stored-grain pests by using sterilizing doses does not deteriorate the technological quality of the wheat grain. (E.T.)

  4. Sensitivity of hyperthermia-treated human cells to killing by ultraviolet or gamma radiation

    International Nuclear Information System (INIS)

    Mitchel, R.E.; Smith, B.P.; Wheatly, N.; Chan, A.; Child, S.; Paterson, M.C.

    1985-01-01

    Human xeroderma pigmentosum (XP) or Fanconi anemia (FA) fibroblasts displayed shouldered 45 0 C heat survival curves not significantly different from normal fibroblasts, a result similar to that previously found for ataxia telangiectasia (AT) cells, indicating heat resistance is not linked to either uv or low-LET ionizing radiation resistance. Hyperthermia (45 0 C) sensitized normal and XP fibroblasts to killing by gamma radiation but failed to sensitize the cells to the lethal effects of 254 nm uv radiation. Thermal inhibition of repair of ionizing radiation lesions but not uv-induced lesions appears to contribute synergistically to cell death. The thermal enhancement ratio (TER) for the synergistic interaction of hyperthermia (45 0 C, 30 min) and gamma radiation was significantly lower in one FA and two strains (TER = 1.7-1.8) than that reported previously for three normal strains (TER = 2.5-3.0). These XP and FA strains may be more gamma sensitive than normal human fibroblasts. Since hyperthermia treatment only slightly increases the gamma-radiation sensitivity of ataxia telangiectasia (AT) fibroblasts compared to normal strains, it is possible that the degree of thermal enhancement attainable reflects the genetically inherent ionizing radiation repair capacity of the cells. The data indicate that both repair inhibition and particular lesion types are required for lethal synergism between heat and radiation. We therefore postulate that the transient thermal inhibition of repair results in the conversion of gamma-induced lesions to irrepairable lethal damage, while uv-type damage can remain unaltered during this period

  5. Detection of gamma rays using scintillation optical fibers

    International Nuclear Information System (INIS)

    Park, J. W.; Hong, S. B.

    2002-01-01

    Scintillating optical fibers have several advantages over other conventional materials used for radiation detection. We have used glass and plastic scintillating fibers to detect gamma rays emitted from 60 Co and 137 Cs, and beta rays from 90 Sr. The sensors are constructed of single strand or multi-strand fibers of 1 mm diameter. The glass scintillating fiber used contains cerium-activated lithium-silicate as scintillating material and the plastic scintillating fiber used is Bicron model BCF-12. In this paper, we report the pulse-height spectra obtained by both sensor types, and analyze them in the aspect of their usability for radiation detectors. Our investigation suggests that the glass fiber can be used to develop gamma ray detectors which will function in high and low gamma ray flux environments. Use of the sensor for the beta ray detection was not satisfactory. The plastic fiber sensor did not work satisfactorily for the weak gamma sources, but did produce somewhat promising results. The scintillating plastic fiber offers some feasibility as beta ray sensor material

  6. Research of pulse gamma ray radiation effect on microcontroller system

    International Nuclear Information System (INIS)

    Yang Shanchao; Ma Qiang; Jin Xiaoming; Li Ruibin; Lin Dongsheng; Chen Wei; Liu Yan

    2012-01-01

    An experimental result of power chip LM7805 and microcontroller EE80C196KC20 based on the EE80C196KC20 testing system was presented. The pulse gamma ray radiation effect was investigated using 'Qiangguang-Ⅰ' accelerator. Latchup threshold of the microcontroller was obtained, and the relationship of supply current and I/O output with the transient dose rate was observed. The result shows that the restrainability of power chip on pulse gamma ray radiation induces microcontroller latchup effect. (authors)

  7. Gamma radiation effects in vertically aligned carbon nanotubes

    OpenAIRE

    Lubkowski, Grzegorz; Kuhnhenn, Jochen; Suhrke, Michael; Weinand, Udo; Endler, Ingolf; Meißner, Frank; Richter, Sylvia

    2011-01-01

    This paper describes an experimental study of gamma radiation effects in low-density arrays of vertically aligned carbon nanotubes. These arrays are characterized by excellent anti-reflective and absorbing properties for wavelengths from UV to IR, which makes them an interesting option for stray light control in optical space applications. Gamma irradiation equivalent to an estimated surface lifetime exposition in geostationary orbit does not affect the reflectivity of the structures. First h...

  8. Application of LiF for determining the gamma-radiation characteristics of the shut-down reactor

    International Nuclear Information System (INIS)

    Ibragimova, E.M.; Musaeva, M.A.; Ashrapov, U.T.; Kalanov, M.U.; Muminov, M.I.

    2005-01-01

    Full text: The power of 60 Co ∼1.25 MeV gamma-radiation source at the INP AS RUz is limited by 8 Gy/s, which does not satisfy several tasks of material science now. Therefore, we were first to suggest the irradiation of materials with gamma-rays of 0.1-7 MeV, which are emitted by the uranium fission products ( 41 Ar, 135 Xe, 125 Xe, 125 I, 137 Cs, 134 Cs, 144 Ce, 95 Zr, 140 Ba, 140 La, 99 Mo, 60 Co) and l6 N, 24 Na, 28 Al radio-nuclides in water during prophylactic shut-downs of our nuclear reactor WWR-SM. The gamma-dose rate kinetics was monitored with the ion current in ionization chambers KNK-53M fixed outside the reactor core from the stop-moment. The current kinetics comprised 4 steps with a high reproducibility at 2 and 0.5 μA, then 50 and 10 nA, each lasting for 1,10, 40 and up to 200 hours, according to the isotope life-times. LiF crystal is known as a thermal luminescence dosimeter of mixed radiations up to 100 Gy. Yet in this work the absorbed gamma-energy dose D γ was determined by accumulation of the known stable structure defects in thin cleaved LiF crystals: by induced optical absorption and luminescence of F- and M-centers. The samples were irradiated in Al-containers filled with water to keep the temperature of ∼40 deg. C in the time range from 30 minutes to 150 hours. Optical absorption spectra were registered at spectrometer Specord M-40. Then the induced color center concentration was calculated by the Smakula relation, which is proportional to the absorbed dose Dγ. For a better reliability the photoluminescence center content was also determined. Selecting comparable close intensities of the induced absorption and luminescence bands obtained after irradiations of LiF references in the certified 60 Co gamma-sources of the known gamma fluxes 0.7 and 7.5 Gy/s, the gamma-radiation intensity of the shut-down reactor was estimated in correlation with the ion current as 10 nA = 15 Gy/s. At short times of irradiation the linear dose dependence

  9. CaSO4: Dy + Teflon dosimetric pellets for X, beta and gamma radiation detection

    International Nuclear Information System (INIS)

    Campos, L.L.; Lima, M.F.

    1987-08-01

    CaSO 4 : Dy + TEFLON dosimetric pellets with high sensitivity and low cost for X, beta and gamma radiation monitoring were studied and developed by the Dosimetric Material Production Laboratory of the Radiological Protection Departament and are disposable for sale. The thickness of the pellets are suitable for X, beta and gamma radiation measurements. The dosimetric properties of these pellets were determined and presented in this work. The results show the usefulness of 0,20mm thick pellets for beta radiation monitoring and 0,80mm thick pellets for x and gamma radiation detection. (Author) [pt

  10. Gamma radiation scanning of nuclear waste storage tile holes

    International Nuclear Information System (INIS)

    Das, A.; Yue, S.; Sur, B.; Johnston, J.; Gaudet, M.; Wright, M.; Burton, N.

    2010-01-01

    Nuclear waste management facilities at Chalk River Laboratories use below-ground 'tile holes' to store solid waste from various activities such as medical radioisotope production. A silicon PIN (p-type-intrinsic-n-type semiconductor) diode based gamma radiation scanning system has been developed and used to profile the gamma radiation fields along the depth of waste storage tile holes by deploying the sensor into verification tubes adjacent to the tile holes themselves. The radiation field measurements were consistent with expected radiation fields in the tile holes based on administrative knowledge of the radioactive contents and their corresponding decay rates. Such measurements allow non-invasive verification of tile hole contents and provide input to the assessment of radiological risk associated with removal of the waste. Using this detector system, radioactive waste that has decayed to very low levels may be identified based on the radiation profile. This information will support planning for possible transfer of this waste to a licensed waste storage facility designed for low level waste, thus freeing storage space for possible tile hole re-use for more highly radioactive waste. (author)

  11. X-Ray and Gamma-Ray Radiation Detector

    DEFF Research Database (Denmark)

    2015-01-01

    Disclosed is a semiconductor radiation detector for detecting X-ray and / or gamma-ray radiation. The detector comprises a converter element for converting incident X-ray and gamma-ray photons into electron-hole pairs, at least one cathode, a plurality of detector electrodes arranged with a pitch...... (P) along a first axis, a plurality of drift electrodes, a readout circuitry being configured to read out signals from the plurality of detector electrodes and a processing unit connected to the readout circuitry and being configured to detect an event in the converter element. The readout circuitry...... is further configured to read out signals from the plurality of drift electrodes, and the processing unit is further configured to estimate a location of the event along the first axis by processing signals obtained from both the detector electrodes and the drift electrodes, the location of the event along...

  12. Responses of a grassland arthropod community to chronic beta and gamma radiation

    International Nuclear Information System (INIS)

    Styron, C.E.; Dodson, G.J.; Beauchamp, J.J.; Miller, F.L. Jr.

    1976-01-01

    A long-term project was initiated in 1968 at Oak Ridge National Laboratory to assess effects of mixed beta and gamma radiation from simulated fallout on a grassland ecosystem. Beta and gamma radiation dose rates in microhabitats of the experimentally contaminated enclosure were measured with LiF thermoluminescent microdosimeters. Extensive statistical analyses of data on numbers of individuals collected for each of 76 arthropod and 2 molluscan taxa have identified no lasting significant changes in similarity or species diversity of experimental versus control communities as the result of the long-term irradiation at low dose rates. Natural fluctuations in community dynamics obscured any possible radiation effects. Thus, the apparent threshold for mixed beta and gamma radiation inducing changes in community structure must be above the exposure rate range of 2.3 to 13 rad/day delivered during the 5 yr of observation. Establishing such a threshold is of importance in assessing the impact of communities subjected to chronic, low level environmental exposure to ionizing radiation

  13. Fuzzy correlations of gamma-ray bursts

    International Nuclear Information System (INIS)

    Hartmann, D.H.; Linder, E.V.; Blumenthal, G.R.

    1991-01-01

    The origin of gamma-ray bursts is not known, both in the sense of the nature of the source emitting the radiation and literally, the position of the burst on the sky. Lacking unambiguously identified counterparts in any wavelength band studied to date, statistical approaches are required to determine the burster distance scale. Angular correlation analysis is one of the most powerful tools in this regard. However, poor detector resolution gives large localization errors, effectively beam smearing the positions. The resulting fuzzy angular correlation function is investigated and the generic isotropization that smearing induces on any intrinsic clustering is discussed. In particular, the extent to which gamma-ray burst observations by the BATSE detector aboard the Gamma-Ray Observatory might recover an intrinsic source correlation is investigated. 16 refs

  14. Effect of gamma radiation on growth, productivity and protein content of chlorella pyrenoidosa

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella Pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella Pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gy) produced a little growth stimulation that as not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (author)

  15. Effect of gamma radiation on growth, productivity and protein content of Chlorella Pyrenoidosa

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

    The effect of five doses of gamma radiation: 10, 100, 500, 1000 and 5000 Gy at a dose rate of 4.500 Gy/h on growth, productivity and protein content of Chlorella pyroneidosa has been studied. High doses of gamma radiation have been observed to inhibit cellular division of Chlorella pyrenoidosa. Culture growth stopped 48 hours after irradiation at 5.000 Gy and 72 hours after irradiation at 500 and 1000 Gy. The lowest dose (10 Gyl produced a little growth stimulation that not statistically significative. Protein and aminoacid content did not show any change for gamma radiation doses studied. (Author) 32 refs

  16. Gamma radiation utilization for polymers synthesis

    International Nuclear Information System (INIS)

    Santos, L.G. dos; Silva Filho, E.

    1990-01-01

    Samples of styrene monomer were irradiated with gamma rays from a sup(60)Co source, with doses in the range of zero to 32600 Gray (Gy). Viscosity analysis performed by using the method of Stokes showed an increase in the viscosity of the material. This result characterizes the occurrence of polymerization induced by the radiation. (author)

  17. Radiation Build-Up Of High Energy Gamma In Shielding Of High Atomic Number

    International Nuclear Information System (INIS)

    Yuliati, Helfi; Akhadi, Mukhlis

    2000-01-01

    Research to observe effect of radiation build-up factor (b) in iron (Fe) and lead (Pb) for high energy gamma shielding from exp.137 Cs (E gamma : 662 keV) and exp.60 Co (E gamma : 1332 keV) sources has been carried out. Research was conducted bt counting of radiation intensity behind shielding with its thickness vary from 1 to 5 times of half value thickness (HVT). NaI (TI) detector which connected to multi channel analyzer (MCA) was used for the counting. Calculation result show that all of b value are near to 1 (b∼1) both for Fe and Pb. Without inserting b in calculation, from the experiment it was obtained HVT value of Fe for high gamma radiation of 662 and 1332 keV were : (12,94 n 0,03) mm and (17,33 n 0,01) mm with their deviation standards were 0,2% and 0,06% respectively. Value of HVT for Pb with the same energy were : (6,31 n 0,03) mm and (11,86 n 0,03) mm with their deviation standars were : 0,48% and 0,25% respectively. HVL concept could be applied directly to estimate shielding thickness of high atomic number of high energy gamma radiation, without inserting correction of radiation build-up factor

  18. Snowpack snow water equivalent measurement using the attenuation of cosmic gamma radiation

    International Nuclear Information System (INIS)

    Osterhuber, R.; Condreva, K.

    1998-01-01

    Incoming, background cosmic radiation constantly fluxes through the earth's atmosphere. The high energy gamma portion of this radiation penetrates many terrestrial objects, including the winter snowpack. The attenuation of this radiation is exponentially related to the mass of the medium through which it penetrates. For the past three winters, a device measuring cosmic gamma radiation--and its attenuation through snow--has been installed at the Central Sierra Snow Laboratory, near Donner Pass, California. This gamma sensor, measuring energy levels between 5 and 15 MeV, has proved to be an accurate, reliable, non-invasive, non-mechanical instrument with which to measure the total snow water equivalent of a snowpack. This paper analyzes three winters' worth of data and discusses the physics and practical application of the sensor for the collection of snow water equivalent data from a remote location

  19. Gamma-ray lines from radiative dark matter decay

    International Nuclear Information System (INIS)

    Garny, Mathias; Ibarra, Alejandro; Tran, David; Weniger, Christoph

    2011-01-01

    The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though the dark matter itself is electrically neutral, the tree-level decay of dark matter into charged lepton pairs will generically induce radiative two-body decays of dark matter at the quantum level. Using an effective theory of leptophilic dark matter decay, we calculate the rates of radiative two-body decays for scalar and fermionic dark matter particles. Due to the absence of astrophysical sources of monochromatic gamma rays, the observation of a line in the diffuse gamma-ray spectrum would constitute a strong indication of a particle physics origin of these photons. We estimate the intensity of the gamma-ray line that may be present in the energy range of a few TeV if the dark matter decay interpretation of the leptonic cosmic-ray anomalies is correct and comment on observational prospects of present and future Imaging Cherenkov Telescopes, in particular the CTA

  20. Inactivation and stability of viral diagnostic reagents treated by gamma radiation

    International Nuclear Information System (INIS)

    White, L.A.; Freeman, C.Y.; Hall, H.E.; Forrester, B.D.

    1990-01-01

    The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4 0 C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author)

  1. Inactivation and stability of viral diagnostic reagents treated by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    White, L A; Freeman, C Y; Hall, H E; Forrester, B D [Department of Health and Human Services, Atlanta, GA (USA)

    1990-10-01

    The objective of this study was to apply the pertinent findings from gamma inactivation of virus infectivity to the production of high quality diagnostic reagents. A Gammacell 220 was used to subject 38 viruses grown in either susceptible tissue cultures or embryonated chicken eggs to various doses of gamma radiation from a cobalt-60 source. The radiation required to reduce viral infectivity was 0.42 to 3.7 megarads (Mrad). The effect of gamma treatment on the antigenic reactivity of reagents for the complement fixation (CF), hemagglutination (HA) and neuraminadase assays was determined. Influenza antigens inactivated with 1.7 Mrad displayed comparable potency, sensitivity, specificity and stability to those inactivated by standard procedures with beta-propiolactone (BPL). Significant inactivation of influenza N1 and B neuraminidase occurred with >2.4 Mrad radiation at temperatures above 4{sup 0}C. All 38 viruses were inactivated, and CF or HA antigens were prepared successfully. Antigenic potency remained stable with all antigens for 3 years and with 83% after 5 years storage. Influenza HA antigens evaluated after 9 years of storage demonstrated 86% stability. Gamma radiation is safer than chemical inactivation procedures and is a reliable and effective replacement for BPL in preparing diagnostic reagents. (author).

  2. Radiative flux emitted by a burning PMMA slab

    International Nuclear Information System (INIS)

    Parent, G; Acem, Z; Collin, A; Berfroi, R; Boulet, P; Pizzo, Y; Mindykowski, P; Kaiss, A; Porterie, B

    2012-01-01

    The degradation of a PMMA sample has been studied based on experimental results obtained for the radiation emission by a burning slab. Observations of the infrared emission perpendicular to the plate, in the range where the optically thin flame is weakly emitting, indicate a plate temperature close to 680 K which is an indication on the surface temperature during the degradation process. Observations from the side allow a flame characterization without the plate emission superimposition. This is a promising way for evaluating data regarding the flame characteristics: temperature, gaz concentration and soot volumetric fraction.

  3. Inactivation of bacteria in sewage sludge by gamma radiation

    International Nuclear Information System (INIS)

    Pandya, G.A.; Kapila, Smita; Kelkar, V.B.; Negi, Shobha; Modi, V.V.

    1987-01-01

    The survival of certain bacterial cultures suspended in sewage sludge and exposed to gamma-radiation was studied. The inactivation patterns of most of the organisms were significantly different when irradiation was performed using sewage samples collected in the summer and monsoon seasons. The summer sample collected from the anaerobic digester afforded significant protection to both Gram negative and Gram positive organisms. This was evident by the increase in dose required to bring about a 6 log cycle reduction in viable count of the bacterial cultures, when suspended in sewage samples instead of phosphate buffer. The observations made using monsoon digester samples were quite different. This sewage sludge greatly enhanced inactivation by gamma-radiation in most cases. The effects of certain chemicals on the inactivation patterns of two organisms - Salmonella typhi and Shigella flexneri - were examined. Arsenate, mercury and lead salts sensitised S. typhi, while barium acetate and sodium sulphide protected this culture against gamma-radiation. In the case of Sh. flexneri, barium acetate and iodacetamide proved to be radioprotectors. The effects of some chemicals on the inactivation pattern of Sh. flexneri cells irradiated in sludge are also discussed. (author)

  4. Analysis of portable gamma flaw detectors concerning radiation hygiene

    International Nuclear Information System (INIS)

    Makarova, T.V.

    1982-01-01

    Design and shields of gamma flaw detectors as one of the main factors responsible for personnel dose were studied. The analysis was conducted using the results of radiation hygienic surveys of gamma flaw detection laboratories functioning constantly in Estonia. It is shown that recently the replacement of GUP apparatuses by flaw detectors of RID and ''Gamma-RID'' (types which have design and shielding advantages is observed. However personnel doses have not reduced considerably for the last 10 years. This fact is attributed to design disadvantages of the RID and ''Gamma-RID'' apparatuses the removing of which will give the decreasing of annual personnel dose by 80 %

  5. Geometric radiation exchange factors for axial radiative transfer in an LWR core filled with absorbing-emitting gases

    International Nuclear Information System (INIS)

    Chan, S.H.; Cho, D.H.

    1984-01-01

    A reactor core filled with an emitting-absorbing mixture (like steam, hydrogen gas and fission gases) is considered. Analysis is provided to evaluate axial radiative heat exchange of a rod bundle with a nonuniform axial temperature distribution. The necessary radiation exchange shape factors (geometric mean absorptance, emittance and transmittance) between segments of the complex rod bundle arrangement are presented. They are applicable to arbitrary sizes of segments, well suited for numerical computations

  6. Effect of neutron and gamma radiations on zeolite and zeotype materials

    International Nuclear Information System (INIS)

    Durrani, S.K.

    1994-01-01

    The influence of gamma and (n, gamma)-radiation on the cation exchange and the structure of zeolite and zeotype materials has been studied. Samples were subjected to different doses of gamma-irradiation varying between 0.5 and 10 MGy and Neutron irradiation flux varied from 1.14 x 10/sup 17/ to 3.88 x /sup 10/sup 17/n cm/sup -2/. Structural effects consequent to gamma irradiation were examined by x-ray diffraction, electron scanning micrographs and FTIR measurements. Neutron and gamma-irradiation and not lead by any appreciable change in the structure, however, the displacement cations to locked-in sites results partial reduced barium and caesium uptake. The decrease of the intensities of the absorption bands of the hydroxy-groups reveals that gamma-irradiation has a strong dehydrating influence. THe effects of gamma-radiation on (UO/sub 2/)/sup 2+/ and Am/sup 3+/ uptake into NH/sub 4/-L and NH/sub 4/-SAPO-34 was also observed. K alpha of the uranyl ions increased with increasing pH up to 6.3. At pH > 3.5, the uranyl ions were precipitated and consequently K alpha values were continued to increased. (author)

  7. Enhancement of ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor

    Energy Technology Data Exchange (ETDEWEB)

    Noor Azmy, Noor Azwen [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Bakar, Ahmad Ashrif A., E-mail: ashrif@ukm.edu.my [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Arsad, Norhana [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Idris, Sarada [Department of Electrical, Electronic and System Engineering, Faculty of Engineering and Built Environment, 43650, UKM, Bangi, Selangor (Malaysia); Radiation Facilities Division, Block 42, Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Mohmad, Abdul Rahman [MEMS-NEMS and Nanoelectronics, Institute of Microengineering and Nanoelectronics (IMEN), 43650 UKM, Bangi, Selangor (Malaysia); Abdul Hamid, Aidil [School of Biosciences and Biotechnology, Faculty of Science and Technology, 43650 UKM, Bangi, Selangor (Malaysia)

    2017-01-15

    Highlights: • ZnO-rGO nanocomposite thin films by gamma radiation for E. coli sensor were fabricated for the first time. • Exposed to gamma radiation leads to the change the microstructure of the films. • The optical behaviors of thin films were found to be gamma dose dependent. • The sensors had a linear response with GO concentration. • The sensors exhibited enhanced sensitivity at higher gamma radiation. - Abstract: The fabricated E. coli sensor of ZnO-rGO nanocomposite thin films by gamma radiation was investigated. Nanocomposite films were prepared via sol–gel method and were irradiated at 10 kGy at room temperature. The surface characteristic of as-prepared samples have been characterized by x-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The proposed structure shows that exposed gamma radiation may change the microstructure of the films occurs as a result of their flexible structure. Uv–vis spectra of nanocomposite were studied to investigate the optical behavior of ZnO-rGO films and the optical energy band gap and Urbach energy were found to be gamma dose dependent. The sensing properties were identified by measuring the changes of conductivity of film using I-V measurement. Upon exposure to E. coli, the radiated ZnO-rGO films (1.00 vol% GO) exhibited higher sensitivity, as much as 4.62 × 10{sup −3}, than un-radiated films, 1.04 × 10{sup −3}. This enhancement of the I-V response was attributed to a positive influence of the gamma radiation in these films. The results prove that our ZnO-rGO nanocomposites thin films by gamma radiation demonstrate a strong performance for the detection of microbiological organisms in water.

  8. Gamma radiation in space and in the atmosphere; Rayonnement gamma dans l'espace et dans l'atmosphere

    Energy Technology Data Exchange (ETDEWEB)

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

    1966-07-01

    We have shown that the {gamma} radiation existing in the atmosphere is caused mainly by the Bremsstrahlung of the electrons of the electromagnetic cascades ({approx} 50 per cent of the measured radiation), by the 511 keV radiation produced by the annihilation of positrons created in cascades (8 per cent of the measured intensity) and by the Compton {gamma} degradation of this line (30 per cent of the measured intensity). The rest, slightly over 10 per cent, must be attributed to secondary causes such as the nuclear de-excitation {gamma} to the internal Bremsstrahlung of charged particles created in nuclear stars, and to charged particles crossing our detector, since the latter was not fitted with a device for rejecting these particles. Experiments carried out in rockets at Colomb-Bechar confirm these results and have made it possible to detect and measure a primary {gamma} radiation having an intensity of {approx} 2 {gamma} cm{sup 2} s{sup -1} above 100 keV. The primary spectrum obeys an approximate E{sup -2} law. (author) [French] Nous avons montre que le rayonnement {gamma} existant dans l'atmosphere est provoque principalement por le bremsstrohlung des electrons des cascades electromagnetiques ({approx} 50 pour cent du rayonnement mesure), au rayonnement 511 keV provoque par l'annihilation des positrons crees dans les cascades (8 pour cent de l'intensite mesuree) et aux {gamma} de degradation Compton de cette raie (30 pour cent de l'intensite mesuree). Le reste, soit un peu plus de 10 pour cent, doit etre attribue a des causes secondaires telles que les {gamma} de desexcitation nucleaire, le bremsstrahlung interne des particules chargees creees dans les etoiles nucleaires, et aux particules chargees traversant notre detecteur car celui-ci ne comportait pas de dispositif de rejet de ces particules. Les experiences faites en fusees a Colomb-Bechar ont confirme ces resultats et permis de detecter et mesurer un rayonnement {gamma} primaire dont l

  9. Cherenkov radiation

    International Nuclear Information System (INIS)

    Hubert, P.

    1955-01-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  10. Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Tânia, E-mail: tania.gomes@niva.no [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Xie, Li [Norwegian Institute for Water Research (NIVA), Section of Ecotoxicology and Risk Assessment, Gaustadalléen 21, N-0349, Oslo (Norway); Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Brede, Dag; Lind, Ole-Christian [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); Solhaug, Knut Asbjørn [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Postbox 5003, N-1432, Ås (Norway); Salbu, Brit [Centre for Environmental Radioactivity, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432 Ås (Norway); Department for Environmental Sciences, Faculty of Environmental Science & Technology, Norwegian University of Life Sciences (NMBU), Post Box 5003, N-1432, Ås (Norway); and others

    2017-02-15

    Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H{sub 2}DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first

  11. Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation

    International Nuclear Information System (INIS)

    Gomes, Tânia; Xie, Li; Brede, Dag; Lind, Ole-Christian; Solhaug, Knut Asbjørn; Salbu, Brit

    2017-01-01

    Highlights: • Chlorophyll fluorescence parameters affected at higher dose rates. • Changes in PSII associated with electron transport and energy dissipation pathways. • Dose-dependent ROS production in algae exposed to gamma radiation. • Decrease in photosynthetic efficiency connected to ROS formation. - Abstract: The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49–1677 mGy/h) for 6 h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H 2 DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6 h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first report

  12. Effects of chemical sensitizers on gamma radiation processing of ...

    African Journals Online (AJOL)

    The potential of gamma radiation processing in cross-linking natural rubber latex (NRL) for production of dipped goods has been studied. NRL produced in Ghana was irradiated to 10, 20, 30, 40 and 50 kGy, respectively, in a Gamma Chamber of dose rate 0.65 kGy/h. Irradiation of the NRL was also carried out in the ...

  13. On the honeybee resistance to gamma radiation; Sur la resistance au rayonnement gamma de l'abeille ouvriere

    Energy Technology Data Exchange (ETDEWEB)

    Courtois, G.; Lecomte, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Section des Applications des Radioelements, Centre d' Etudes Nucleaires, Saclay, Station de Recherches Apicoles, Bures-sur-Yvette (France)

    1960-07-01

    The honeybee, when irradiated by gamma radiations from a cobalt-60 source can stand a 18000 r dose without any apparent harm. Noticeable harm is observed for 90000 r. while immediate death of 100% of the individuals is obtained with a 200000 r dose. The physiological condition of the honeybee plays an important role in its resistance to gamma radiation. Reprint of a paper published in Annales de l'abeille, IV, 1959, p. 285-290 [French] L'Abeille butineuse irradiee par le rayonnement gamma issu d'une source de Cobalt 60 supporte sans dommages apparents une dose de 18000 r. Des dommages tres appreciables sont observes pour 90000 r. Une dose de 200000 r entraine la mort immediate de 100% des individus. L'etat physiologique de l'Abeille joue un role important dans la resistance au rayonnement gamma. Reproduction d'un article publie dans Annales de l'abeille, IV, 1959, p. 285-290.

  14. Gamma radiation effects on photorefractive and photoelectric properties of lithium niobate crystals

    Energy Technology Data Exchange (ETDEWEB)

    Vartanyan, Eh.S.; Ovsepyan, R.K.; Pogosyan, A.R.; Timofeev, A.L.

    1984-08-01

    Investigations into the gamma radiation effect on the photorefractive aned photoelectric properties of lithium niobate crystals have been carried out for the first time. Gamma irradiation has been found to lead to an increase in the photorefractive sensitivity. The effect of optical decoloration has been discovered for the first time along with photorelaxation currents resulting from radiation center decay under the action of light. It has been shown that an increase of photorefractive sensitivity in gamma-irradiated lithium niobate crystals is caused by a new photorefraction mechanism - photorelaxation currents.

  15. Re-evaluation of atomic bomb radiation

    International Nuclear Information System (INIS)

    Okajima, Shunzo

    1984-01-01

    The background and current status of the re-evaluation of atomic bomb (A-bomb) radiation doses are presented. Problems in re-evaluating radiation doses are discussed: spectra of gamma-rays and neutrons emitted in the air, A-bomb structures, and meterological elements should be taken into account. In Japan, in an attempt to estimate A-bomb radiation doses, radioactive residues contained in roof tiles, bricks, rocks, and teeth and shell button of clothes are being actually measured. (Namekawa, K.)

  16. A cannonball model of gamma-ray bursts superluminal signatures

    CERN Document Server

    Dar, Arnon; Dar, Arnon; Rujula, Alvaro De

    2000-01-01

    Recent observations suggest that the long-duration gamma ray bursts (GRBs) and their afterglows are produced by highly relativistic jets emitted in supernova explosions. We propose that the result of the event is not just a compact object plus the ejecta: within a day, a fraction of the parent star falls back to produce a thick accretion disk. The subsequent accretion generates jets and constitutes the GRB ``engine'', as in the observed ejection of relativistic ``cannonballs'' of plasma by microquasars and active galactic nuclei. The GRB is produced as the jetted cannonballs exit the supernova shell reheated by the collision, re-emitting their own radiation and boosting the light of the shell. They decelerate by sweeping up interstellar matter, which is accelerated to cosmic-ray energies and emits synchrotron radiation: the afterglow. We emphasize here a smoking-gun signature of this model of GRBs: the superluminal motion of the afterglow, that can be searched for ---the sooner the better--- in the particular...

  17. SWEPP Gamma-Ray Spectrometer System software design description

    International Nuclear Information System (INIS)

    Femec, D.A.; Killian, E.W.

    1994-08-01

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system

  18. SWEPP Gamma-Ray Spectrometer System software design description

    Energy Technology Data Exchange (ETDEWEB)

    Femec, D.A.; Killian, E.W.

    1994-08-01

    To assist in the characterization of the radiological contents of contract-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP), the SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory. The SGRS system software controls turntable and detector system activities. In addition to determining the concentrations of gamma-ray-emitting radionuclides, this software also calculates attenuation-corrected isotopic mass ratios of-specific interest. This document describes the software design for the data acquisition and analysis software associated with the SGRS system.

  19. Mechanism of obtaining carbon monoxide and hydrogen during brown coal radiolysis. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rustamov, V R; Kurbanov, M A; Dzantiev, B T; Kerimov, V K; Musaeva, P F

    1982-05-01

    This article analyzes effects of gamma radiation on the yield of products of coal gasification: hydrogen and carbon monoxide. Samples of brown coal from the Kansk-Achins basin were treated by gamma radiation with cobalt 60 radiation source. Analyses show that accumulation of hydrogen and carbon monoxide in brown coal under influence of gamma radiation is characterized by a constant rate. Yields of carbon monoxide and hydrogen amount to 0.16 molecule/100 electro volt and 0.21 molecule/electro volt respectively. Reducing radiation dose from 2.5 to 0.7 millirad/h reduces yields of hydrogen and carbon monoxide. Increasing temperature of vacuum brown coal pyrolysis from 200 to 600 C causes decrease of hydrogen yield. Hydrogen yield decrease during temperature increase is caused by a high content of aromatic nuclei in the samples used in the radiolysis. (5 refs.)

  20. STUDIES CONCERNING THE EFFECT OF GAMMA RADIATION AND MAGNETIC FIELD EXPOSURE ON GLADIOLUS

    Directory of Open Access Journals (Sweden)

    M CANTOR

    2003-04-01

    Full Text Available Gladiolus (Gladiolus sp. is one of the most floral species cultivated over in the world and in Romania. There are many studies concerning the effect of gamma radiation on ornamental plants but little is known about the synergetic effect of gamma radiation and exposure to magnetic fields on Gladiolus. In our investigation we have tested the effect of gamma irradiation and magnetic field exposure of gladiolus corms and cormels of the cultivars: Her Majesty, Applause and Speranţa. The corms and cormels were irradiated for 72 hrs with 137 Cs gamma source on cylindrical exposure geometry. At medium dose of 1 Gy has been accumulated for each corm and cormel. For each variety we used 10 corms and 30 cormels in five variants. The comportment of various varieties was evaluated by recording the following characteristics: length of roots and growth tip. Significant effect was obtained at the variants which was irradiated with 1 Gy gamma radiation and 3 Gauss magnetic fields.

  1. Modeling gamma radiation dose in dwellings due to building materials.

    Science.gov (United States)

    de Jong, Peter; van Dijk, Willem

    2008-01-01

    A model is presented that calculates the absorbed dose rate in air of gamma radiation emitted by building materials in a rectangular body construction. The basis for these calculations is formed by a fixed set of specific absorbed dose rates (the dose rate per Bq kg(-1) 238U, 232Th, and 40K), as determined for a standard geometry with the dimensions 4 x 5 x 2.8 m3. Using the computer codes Marmer and MicroShield, correction factors are assessed that quantify the influence of several room and material related parameters on the specific absorbed dose rates. The investigated parameters are the position in the construction; the thickness, density, and dimensions of the construction parts; the contribution from the outer leave; the presence of doors and windows; the attenuation by internal partition walls; the contribution from building materials present in adjacent rooms; and the effect of non-equilibrium due to 222Rn exhalation. To verify the precision, the proposed method is applied to three Dutch reference dwellings, i.e., a row house, a coupled house, and a gallery apartment. The averaged difference with MCNP calculations is found to be 4%.

  2. Measurement of angularly dependent spectra of betatron gamma-rays from a laser plasma accelerator with quadrant-sectored range filters

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Rhee, Yong Joo; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Shin, Jung Hun; Yoo, Byung Ju; Jo, Sung Ha; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seong Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 61005 (Korea, Republic of); Hojbota, Calin; Bae, Lee Jin; Jung, Jaehyung; Cho, Min Sang; Cho, Byoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 61005 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 61005 (Korea, Republic of)

    2016-07-15

    Measurement of angularly dependent spectra of betatron gamma-rays radiated by GeV electron beams from laser wakefield accelerators (LWFAs) are presented. The angle-resolved spectrum of betatron radiation was deconvolved from the position dependent data measured for a single laser shot with a broadband gamma-ray spectrometer comprising four-quadrant sectored range filters and an unfolding algorithm, based on the Monte Carlo code GEANT4. The unfolded gamma-ray spectra in the photon energy range of 0.1–10 MeV revealed an approximately isotropic angular dependence of the peak photon energy and photon energy-integrated fluence. As expected by the analysis of betatron radiation from LWFAs, the results indicate that unpolarized gamma-rays are emitted by electrons undergoing betatron motion in isotropically distributed orbit planes.

  3. Gamma radiation effects on different sorts of onions

    International Nuclear Information System (INIS)

    Burov, B.A.

    1977-01-01

    Gamma radiation effects on different sorts of onions were studied to improve ways of obtaining agricultural vegetation mutations and to find out the genotype role in induced mutagenesis. It is established that rhizome onion seeds are more radiosensitive than bulbous ones, ephemeroide form seeds are most stable among bulbous plants. Table data on dependence of seed germination and plant survival on radiation dose are presented

  4. Sensitivity of the green algae Chlamydomonas reinhardtii to gamma radiation: Photosynthetic performance and ROS formation.

    Science.gov (United States)

    Gomes, Tânia; Xie, Li; Brede, Dag; Lind, Ole-Christian; Solhaug, Knut Asbjørn; Salbu, Brit; Tollefsen, Knut Erik

    2017-02-01

    The aquatic environment is continuously exposed to ionizing radiation from both natural and anthropogenic sources, making the characterization of ecological and health risks associated with radiation of large importance. Microalgae represent the main source of biomass production in the aquatic ecosystem, thus becoming a highly relevant biological model to assess the impacts of gamma radiation. However, little information is available on the effects of gamma radiation on microalgal species, making environmental radioprotection of this group of species challenging. In this context, the present study aimed to improve the understanding of the effects and toxic mechanisms of gamma radiation in the unicellular green algae Chlamydomonas reinhardtii focusing on the activity of the photosynthetic apparatus and ROS formation. Algal cells were exposed to gamma radiation (0.49-1677mGy/h) for 6h and chlorophyll fluorescence parameters obtained by PAM fluorometry, while two fluorescent probes carboxy-H 2 DFFDA and DHR 123 were used for the quantification of ROS. The alterations seen in functional parameters of C. reinhardtii PSII after 6h of exposure to gamma radiation showed modifications of PSII energy transfer associated with electron transport and energy dissipation pathways, especially at the higher dose rates used. Results also showed that gamma radiation induced ROS in a dose-dependent manner under both light and dark conditions. The observed decrease in photosynthetic efficiency seems to be connected to the formation of ROS and can potentially lead to oxidative stress and cellular damage in chloroplasts. To our knowledge, this is the first report on changes in several chlorophyll fluorescence parameters associated with photosynthetic performance and ROS formation in microalgae after exposure to gamma radiation. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Development of defects in the structure of PIN dosimetry diodes exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sopko, V. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Sopko, B., E-mail: bruno.sopko@cern.ch [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Faculty of Production Technology and Management, J. E. Purkyně Univerzity in Ústí nad Labem, Na Okraji 1001, 400 01 Ústí nad Labem (Czech Republic); Chren, D. [Department of Physics, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technicka 4, CZ 16000 Prague 6 (Czech Republic); Dammer, J. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, CZ-18081 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Charles University in Prague, First Faculty of Medicine, Salmovská 1,CZ-12000 Prague 2 (Czech Republic)

    2013-12-01

    Studies of radiation induced defects continue to be relevant as they find an ever greater application due to the increasing radiation doses to which semiconductor detectors are exposed. Efforts of figuring out the changes due to high radiation doses provide the fundamental motivation for this type of experiments. The PIN diode is described, and a developmental disorder caused thereto by 60Co source gamma quanta ranging from 100 kGy to 1 MGy. The calibration curve shows the effect of disturbances on the volt-ampere characteristics as a function of the dose of gamma radiation. The results are compared with earlier published data. Highlights: •We have studied Si PIN diode dosimeters irradiated by gamma. •We measured DLTS spectra and calculated energy traps caused by gamma irradiation. •Increasing dose caused creation of new traps and disappearance of others.

  6. Effects of chronic gamma radiation on the lichen Parmelia sulcata Tayl. in the Enterprise Radiation Forest

    International Nuclear Information System (INIS)

    Erbisch, F.H.

    1977-01-01

    Within the Enterprise Radiation Forest, the foliose lichen Parmelia sulcata Tayl. exhibited radiation damage. Only those lichens which received in excess of 100 krad manifested damage. The damage was evidenced as a lifting and subsequent breaking of lobes, a coalescing of fungal hyphae, a formation of a brown pigment by the coalescing hyphae, a distortion of the chloroplastid of the algal component, and eventual death of the lichen. The radiation also affected thallus growth by slowing it and rhizinae branching by increasing the number of branches. Damage was not manifested until the late spring (June) of the year following radiation. Apparently P. sulcata is able to maintain itself until conditions are favorable for growth, after receiving a large dose of gamma radiation. Under favorable growth conditions, the lichen cannot carry out its normal growth functions and deteriorates. Although environmental changes did occur within the forest, evidence obtained indicates that gamma radiation was the principal factor affecting the lichens

  7. Effect of ionizing (gamma and non-ionizing (UV radiation on the development of Trichogramma euproctidis (Hymenoptera: Trichogrammatidae

    Directory of Open Access Journals (Sweden)

    Tuncbilek Aydin S.

    2012-01-01

    Full Text Available The potential of using gamma and ultraviolet radiation as an alternative treatment to increase the efficiency of Trichogramma euproctidis (Girault 1911 (Hymenoptera: Trichogrammatidae was investigated in the laboratory. The developmental and adult stages of T. euproctidis were exposed to gamma radiation of different doses (0-30 Gy and ultraviolet radiation of 254 nm wavelengths (UV-C for different durations (0-10 min to assess their effect on each of the instars and their potential in breaking the developmental cycle of the egg parasitoid. The LD50 values for eggs, prepupae, pupae and adults were 8.1, 10.0, 22.7 and 9.5 Gy for gamma radiation and 9.5, 0.12, 2.0 and 11.9 min for UV radiation, respectively. The pupa and adult stages were more radioresistant to both gamma and UV radiation. The most interesting and unexpected result obtained for the prepupal stage was that UV radiation has a greater effect on prepupal stages than gamma radiation.

  8. A study of gamma-emitting radionuclides present into the sediments and algae of the ''Baie de l'Orne'' (Central Normandy Coast) collecting during the years 1980 - 1982

    International Nuclear Information System (INIS)

    Lepy, M.C.

    1982-01-01

    The present status of some environmental effects of existing sources of gamma-emitting radionuclides, along the Central part of the Normandy Coast (Calvados shores and river Orne mouth) was determined. A systematic study was made on the behaviour of the marine sediments and brown alga 'Laminaria digitata' with regard to their properties as indicators of radioactive contamination. Marine sediments were collected into the river Orne at fixed locations and into the sea in and around the estuary from 1977 to 1982. Algae samples were picked up along the coast from 1980 to 1982, mostly on the western part of the Orne estuary. Dosimetry techniques employed have produced accurate and reliable results, despite the very low levels of activity involved. Gamma-emitting radionuclides present in the environment (chiefly 106 Ru, 137 Cs, 95 Zr) were identified and measured. Their behaviour into the marine sediments and into Laminaria Digitata were determined. This study provides evidence on the presence of numerous gamma-emitting radionuclides into the marine environment of the Central part of the Normandy coast, but, altogether with very low levels of radioactivity [fr

  9. Investigations on insect disinfestation of dried dates by using gamma radiation

    International Nuclear Information System (INIS)

    Ahmed, M.S.H.

    1981-01-01

    Reviews the laboratory experiments carried out in Iraq to control the most important insect pests of dates in storage, viz. the fig moth, Ephestia cautella and the saw-toothed grain beetle, oryzaephilus surinamensis by gamma-radiation. Developmental stages of Ecutella in general had a much higher resistance to gamma-radiation than the corresponding stages of O-surinamensis. Treatment with a dose of 20 Krad resulted in 100 mortality in the most damaging developmental stages of the species. (46 refs.)

  10. BC404 scintillators as gamma locators studied via Geant4 simulations

    Science.gov (United States)

    Cortés, M. L.; Hoischen, R.; Eisenhauer, K.; Gerl, J.; Pietralla, N.

    2014-05-01

    In many applications in industry and academia, an accurate determination of the direction from where gamma rays are emitted is either needed or desirable. Ion-beam therapy treatments, the search for orphan sources, and homeland security applications are examples of fields that can benefit from directional sensitivity to gamma-radiation. Scintillation detectors are a good option for these types of applications as they have relatively low cost, are easy to handle and can be produced in a large range of different sizes. In this work a Geant4 simulation was developed to study the directional sensitivity of different BC404 scintillator geometries and arrangements. The simulation includes all the physical processes relevant for gamma detection in a scintillator. In particular, the creation and propagation of optical photons inside the scintillator was included. A simplified photomultiplier tube model was also simulated. The physical principle exploited is the angular dependence of the shape of the energy spectrum obtained from thin scintillator layers when irradiated from different angles. After an experimental confirmation of the working principle of the device and a check of the simulation, the possibilities and limitations of directional sensitivity to gamma radiation using scintillator layers was tested. For this purpose, point-like sources of typical energies expected in ion-beam therapy were used. Optimal scintillator thicknesses for different energies were determined and the setup efficiencies calculated. The use of arrays of scintillators to reconstruct the direction of incoming gamma rays was also studied. For this case, a spherical source emitting Bremsstrahlung radiation was used together with a setup consisting of scintillator layers. The capability of this setup to identify the center of the extended source was studied together with its angular resolution.

  11. Aerial Radiation Detection

    International Nuclear Information System (INIS)

    Quam, W. M.

    1999-01-01

    An airborne system designed for the detection of radioactive sources on the soil surface from an aircraft normally senses gamma rays emitted by the source. Gamma rays have the longest path length (least attenuation) through the air of any of the common radioactive emissions and will thus permit source detection at large distances. A secondary benefit from gamma rays detection if that nearly all radioactive isotopes can be identified by the spectrum of gammas emitted. Major gaseous emissions from fuel processing plants emit gammas that may be detected and identified. Some types of special nuclear material also emit neutrons which are also useful for detection at a distance

  12. Titanium-Water Thermosyphon Gamma Radiation Exposure and Results

    Science.gov (United States)

    Sanzi, James, L.A; Jaworske, Donald, A.; Goodenow, Debra, A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of water over time may render portions of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature under accelerated gamma irradiation, with exposures on the same order of magnitude as that expected in 8 years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon: evaporator, condenser, and condenser end cap. Some noncondensable gas was evident; however, thermosyphon performance was not affected because the noncondensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of noncondensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the noncondensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of one thermosyphon in a vacuum chamber and at temperature revealed that the noncondensable gas diffused out of the thermosyphon over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  13. Titanium-Water Thermosyphon Gamma Radiation Effects and Results

    Science.gov (United States)

    Sanzi, James L.; Jaworske, Donald A.; Goodenow, Debra A.

    2012-01-01

    Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some exposure to gamma irradiation. Non-condensable gas formation from radiation may breakdown water over time and render a portion of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature with accelerated gamma irradiation exposures on the same order of magnitude that is expected in eight years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon; evaporator, condenser, and condenser end cap. Some non-condensable gas was evident, however thermosyphon performance was not affected because the non-condensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of non-condensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the non-condensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of selected thermosyphons at temperature and in a vacuum chamber revealed that the non-condensable gas likely diffused out of the thermosyphons over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

  14. Preservation of photographic and cinematographic films by gamma radiation: Preliminary analyses

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Maria Luiza E.; Santos, Paulo S.; Otubo, Larissa; Oliveira, Maria José A.; Vasquez, Pablo A.S., E-mail: malunagai@usp.br, E-mail: pavsalva@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    Brazilian weather conditions affect directly tangible materials causing deterioration notably getting worse by insects and fungi attack. In this sense, gamma radiation provided from the cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because it has biocidal action. Radiation processing using gamma radiation for cultural heritage materials for disinfection has been widely used around the world in the last decades. Many cultural heritage objects especially made on paper and wood were studied in scientific publications aiming mechanical, physical and chemical properties changes. Over the last fifteen years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute located inside the Sao Paulo University campus has been irradiated many collections of archived materials, books, paintings and furniture. Adequate storage of photographic and cinematographic materials is a challenge for conservators from preservation institutions. Contamination by fungi is one of leading causes of problem in photographic and cinematographic collections. Several Sao Paulo University libraries have been affected by fungi in their photographic and cinematographic collections making it impossible to research on these materials either manipulate them for health and safety reasons. In this work are presented preliminary results of effects of the ionizing radiation in photographic and cinematographic films. Selected film samples made on cellulose acetate were prepared and characterized by FTIR-ATR spectroscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 50 kGy. Irradiated samples were analyzed by UV-VIS spectroscopy and electron microscopy techniques. Results shown that disinfection by gamma radiation can be achieved safely applying the disinfection dose between 6 kGy to 15 kGy with no significant change or modification of main properties of the constitutive materials. (author)

  15. Preservation of photographic and cinematographic films by gamma radiation: Preliminary analyses

    International Nuclear Information System (INIS)

    Nagai, Maria Luiza E.; Santos, Paulo S.; Otubo, Larissa; Oliveira, Maria José A.; Vasquez, Pablo A.S.

    2017-01-01

    Brazilian weather conditions affect directly tangible materials causing deterioration notably getting worse by insects and fungi attack. In this sense, gamma radiation provided from the cobalt-60 is an excellent alternative tool to the traditional preservation process mainly because it has biocidal action. Radiation processing using gamma radiation for cultural heritage materials for disinfection has been widely used around the world in the last decades. Many cultural heritage objects especially made on paper and wood were studied in scientific publications aiming mechanical, physical and chemical properties changes. Over the last fifteen years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute located inside the Sao Paulo University campus has been irradiated many collections of archived materials, books, paintings and furniture. Adequate storage of photographic and cinematographic materials is a challenge for conservators from preservation institutions. Contamination by fungi is one of leading causes of problem in photographic and cinematographic collections. Several Sao Paulo University libraries have been affected by fungi in their photographic and cinematographic collections making it impossible to research on these materials either manipulate them for health and safety reasons. In this work are presented preliminary results of effects of the ionizing radiation in photographic and cinematographic films. Selected film samples made on cellulose acetate were prepared and characterized by FTIR-ATR spectroscopy. Samples were irradiated by gamma rays with absorbed dose between 2 kGy and 50 kGy. Irradiated samples were analyzed by UV-VIS spectroscopy and electron microscopy techniques. Results shown that disinfection by gamma radiation can be achieved safely applying the disinfection dose between 6 kGy to 15 kGy with no significant change or modification of main properties of the constitutive materials. (author)

  16. Miniaturized radiation chirper

    International Nuclear Information System (INIS)

    Umbarger, C.J.; Wolf, M.A.

    1980-01-01

    A miniaturized radiation chirper for use with a small battery supplying on the order of 5 volts is described. A poor quality CdTe crystal which is not necessarily suitable for high resolution gamma ray spectroscopy is incorporated with appropriate electronics so that the chirper emits an audible noise at a rate that is proportional to radiation exposure level. The chirper is intended to serve as a personnel radiation warning device that utilizes new and novel electronics with a novel detector, a CdTe crystal. The resultant device is much smaller and has much longer battery life than existing chirpers

  17. Gamma radiation and chickens

    International Nuclear Information System (INIS)

    Toropilova, D.; Takac, L.; Toropila, M.; Tomko, M. M.

    2014-01-01

    In our work, we focused the effect of low doses of gamma radiation on metabolic parameters in chickens. In the first group of chickens we monitor changes of the concentration in glucose and cholesterol after whole body irradiation dose of chicken (3 Gy). In the second group of chickens we studied the combined effect of radiation and intraperitoneal application solution of zinc chloride to changes of the concentration in glucose and total cholesterol. In the tissues of organisms are found only in a very small amount of microelements however are of particular importance in a number of enzymatic catalytic and regulatory processes. Zinc is found in all cells of the body. However, it is the highest percentage of zinc contained in muscle and bone cells. Resorption takes place in the small intestine, especially in the duodenum. For both groups of chickens, we performed analyzes on the 3 rd , 7 th , 14 th , 21 st and 30 day. Results and an overview of the work can be helpful in the peaceful uses of nuclear energy and in preventing diseases from exposure to radiation, but also in the case of the consequences after nuclear accidents. (authors)

  18. A comparison of ionizing radiation damage in CMOS devices from 60Co gamma rays, electrons and protons

    International Nuclear Information System (INIS)

    He Baoping; Yao Zhibin; Zhang Fengqi

    2009-01-01

    Radiation hardened CC4007RH and non-radiation hardened CC4011 devices were irradiated using 60 Co gamma rays, 1 MeV electrons and 1-9 MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. For all devices examined, with experimental uncertainty, the radiation induced threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays are equal to that of 1 MeV electron and 1-7 MeV proton radiation under 0 gate bias condition. Under 5 V gate bias condition, the distinction of threshold voltage shifts (ΔV th ) generated by 60 Co gamma rays and 1 MeV electrons irradiation are not large, and the radiation damage for protons below 9 MeV is always less than that of 60 Co gamma rays. The lower energy the proton has, the less serious the radiation damage becomes. (authors)

  19. Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

    Science.gov (United States)

    Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

    2016-01-01

    The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

  20. Photon Activation Analysis Of Light Elements Using 'Non-Gamma' Radiation Spectroscopy - The Instrumental Determination Of Phosphorus

    International Nuclear Information System (INIS)

    Segebade, Christian; Goerner, Wolf

    2011-01-01

    Unlike metal determinations the analysis of light elements (e.g., carbon, oxygen, phosphorus) is frequently problematic, in particular if analysed instrumentally. In photon activation analysis (PAA) the respective activation products do not emit gamma radiation in the most cases. Usually, annihilation quanta counting and subsequent decay curve analysis have been used for determinations of C, N, O, and F. However, radiochemical separation of the respective radioisotopes mostly is indispensable. For several reasons, some of the light elements cannot be analysed following this procedure, e.g. phosphorus. In this contribution the instrumental PAA of phosphorus in organic matrix by activation with bremsstrahlung of an electron linear accelerator and subsequent beta spectroscopy is described. The accuracy of the results was excellent as obtained by analysis of a BCR Reference Material.

  1. Safety in the design and use of gamma and electron irradiation facilities. 2. ed.

    International Nuclear Information System (INIS)

    1998-01-01

    Radioisotopes which emit gamma radiation and high-energy electron beam generators have been used in industry, medicine and research for many years in the UK and throughout the world. Their main application has been in medical product sterilisation, various food treatments, plastics curing and polymerisation, semiconductor manufacture and gemstone irradiation to bring about colour changes. The radiation safety of these applications is the subject of this guidance

  2. Gamma-ray detectors for intelligent, hand-held radiation monitors

    International Nuclear Information System (INIS)

    Fehlau, P.E.

    1983-01-01

    Small radiation detectors based on HgI 2 , bismuth germanate (BGO), plastic, or NaI(Tl) detector materials were evaluated for use in small, lighweight radiation monitors. The two denser materials, HgI 2 and BGO, had poor resolution at low-energy and thus performed less well than NaI(Tl) in detecting low-energy gamma rays from bare, enriched uranium. The plastic scintillator, a Compton recoil detector, also performed less well at low gamma-ray energy. Two small NaI(Tl) detectors were suitable for detecting bare uranium and sheilded plutonium. One became part of a new lightweight hand-held monitor and the other found uses as a pole-mounted detector for monitoring hard-to-reach locations

  3. Effects of gamma radiation in vitro culture on protocorm development of dendrobium pattaya beauty

    International Nuclear Information System (INIS)

    Flores, John Martin R.; Lanic, Alvin D.; Matuto, Mark Anthony C.; Vidal, John Faustus C.

    2006-01-01

    This study sought to determine if gamma radiation had an efect on in-vitro cultured orchids in its regeneration of a protocorm into plantlet within 20 days duration. To find the effects of gamma radiation in terms of weight development, the method used was experimental procedure. The design used in this study was Random Complete Block Design. The researchers used dendrobium pattaya beauty as a subject of the study. Applying gamma radiation to change the maturing time of the protocorm. The researchers' findings about the study shows that the average weights increase of each treatment/s in the three (3) data observation after inoculation vary from sample to sample. As can be seen in the table that the average weight increase of dendrobium pattaya beauty protocorm does not have an obvious trend considering the increase of gamma radiation on the diferent treatments. It can be seen that the converted f average of 1.5 is lower than the critical f value of 4.07 at 0.05 level of significance with the degree s of freedom of 3/8. The null hypothesis stating that gamma radiation has no effects on the weight of dendrobium pattaya beauty protocorm is accepted. Therefore the researchers concluded, that out of the eight (8) samples the general average weight increase for the control (1.01 grams), 30 Gy (1.22 grams), 50 Gy (1.06 grams), 70 Gy (0.44 grams). Hence, it can be concluded that the radiation does not show positive effect on the weight of dendrobium pattaya beauty protocorm. One-way Anova shows that there is no significant effect on the weight of dendrobium protocorm. The researchers recommend that dendrobium pattaya beauty is a good example of plant, to have undergone this kind of experiment. The researchers also recommend that gamma radiation would not affect the growth of the protocorm upon the result of one-way Anova that there is no significance using gamma radiation. The researchers would like to recommend continuing this study, from embryo to complete plantlet

  4. Measuring stations for gamma radiation - measured results 1982

    International Nuclear Information System (INIS)

    Kjelle, P.E.

    1983-01-01

    Gamma radiation is recorded continuously at 25 stations in Sweden. The evaluation of the data from five of the stations is made in a most accurate way, and the results are presented in this report. (G.B.)

  5. Gamma radiation and HZE treatment of seedlings in Arabidopsis

    Data.gov (United States)

    National Aeronautics and Space Administration — Plants exhibit a robust transcriptional response to gamma radiation which includes the induction of transcripts required for homologous recombination and the...

  6. Influence of gamma radiation onto polymeric matrix with papain

    International Nuclear Information System (INIS)

    Zulli, Gislaine; Lopes, Patricia Santos; Velasco, Maria Valeria Robles; Alcantara, Mara Tania Silva; Rogero, Sizue Ota; Lugao, Ademar Benevolo; Mathor, Monica Beatriz

    2010-01-01

    Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

  7. Physiological quality of rice seed submitted to gamma radiation

    International Nuclear Information System (INIS)

    Miranda, Helen Lucia da Cruz; Tillmann, Maria Angela Andre; Meneghello, Geri Eduardo

    2009-01-01

    The objective of this research was to evaluate the effects of the gamma radiation ( 60 Co) on the physiological quality of rice seeds. The research was carried out through three tests; in the first test rice seeds were irradiated at dosages of 0; 1; 2.5 and 5Gy, while for the second and third tests the seeds were subjected to accelerated aging before being irradiated. For the second test the seeds were divided into wet and dry and both groups subjected to accelerated aging previous to irradiation at dosages of 0; 1; 2.5 and 5Gy. For the third test the seeds were dried after being subjected to accelerated aging, and then irradiated at dosages of 0, 10, 25 and 50Gy. To assess the physiological effects of the gamma radiation, all seeds were tested for germination and their germination speed index recorded. Seedling growth was graded through the measurement of the lengths of the first leaf and seminal root system and total seedling dry weight, across all tests. The enzymatic activity of acid phosphatase and alpha-amylase was measured on dry seeds from the second test. The results from all tests indicate that the applied gamma radiation dosages did not cause any changes to the physiological quality of rice seeds. (author)

  8. Influence of gamma radiation onto polymeric matrix with papain

    Energy Technology Data Exchange (ETDEWEB)

    Zulli, Gislaine [Nuclear and Energetic Research Institute, IPEN-CNEN/SP, Sao Paulo, SP 05508-000 (Brazil); Lopes, Patricia Santos, E-mail: patricia.lopes@prof.uniso.b [Pharmacy Department, University of Sorocaba, Sorocaba, SP 18023-000 (Brazil); Velasco, Maria Valeria Robles [Pharmacy Department, University of Sao Paulo, Sao Paulo, SP 05508-900 (Brazil); Alcantara, Mara Tania Silva; Rogero, Sizue Ota; Lugao, Ademar Benevolo; Mathor, Monica Beatriz [Nuclear and Energetic Research Institute, IPEN-CNEN/SP, Sao Paulo, SP 05508-000 (Brazil)

    2010-03-15

    Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

  9. Influence of gamma radiation onto polymeric matrix with papain

    Science.gov (United States)

    Zulli, Gislaine; Lopes, Patrícia Santos; Velasco, Maria Valéria Robles; Alcântara, Mara Tânia Silva; Rogero, Sizue Ota; Lugao, Ademar Benévolo; Mathor, Monica Beatriz

    2010-03-01

    Papain is a proteolytic enzyme that has been widely used as debridement agent for scars and wound healing treatment. However, papain presents low stability, which limits its use to extemporaneous or short shelf-life formulations. The purpose of this study was to entrap papain into a polymeric matrix in order to obtain a drug delivery system that could be used as medical device. Since these systems must be sterile, gamma radiation is an interesting option and presents advantages in relation to conventional agents: no radioactive residues are formed; the product can be sterilized inside the final packaging and has an excellent reliability. The normative reference for the establishment of the sterilizing dose determines 25 kGy as the inactivation dose for viable microorganisms. A silicone dispersion was selected to prepare membranes containing 2% (w/w) papain. Irradiated and non-irradiated membranes were simultaneously assessed in order to verify whether gamma radiation interferes with the drug-releasing profile. Results showed that irradiation does not affect significantly papain release and its activity. Therefore papain shows radioresistance in the irradiation conditions applied. In conclusion, gamma radiation can be easily used as sterilizing agent without affecting the papain release profile and its activity onto the biocompatible device is studied.

  10. Effect of temperature and gamma radiation on pupae of tenebrio molitor LINNE

    International Nuclear Information System (INIS)

    Arthur, Valter; Arthur, Paula Bergamin

    2001-01-01

    Among insect pests of grains and stored products Tenebrio molitor (Coleoptera : Tenebriodae) is one of the species of insects that attack flours, corn meal, rations, macaronis and damages grains. Chemical treatment is not always the remedy because it causes problems of residue on treated food. One alternative method of control is the application of ionization radiations as suggested by Hunter, some others recommended the use of gamma radiation to control insects that attack grains and stored products. Arthur and Wiendl reported that the sterilizing dose to adults of this species is 60 Gy. The effect of temperature after and before the gamma radiation to Laemophleous spp. Zabrotes subfasciatus and Sitophilus oryzae has been studied by many workers. Since no study with radiological effects in combination with temperature is reported on T. molitor, research work has been carried out to study the synergistic effects of gamma radiation and temperature on pupae of this insect

  11. General description and first results with the ORIS-LMRI 4 {pi} {gamma} metering chamber; Descripcion general y primeros resultados con la camara 4 {pi} {gamma} metrologica ORIS-LMRI

    Energy Technology Data Exchange (ETDEWEB)

    Tejera R, A; Becerril V, A; Cortes P, A

    1990-04-15

    A problem that present the ionization chambers is that the response for the radiation is global, that is to say that it cannot discriminate against selectively the relating responses at different energies, if these impact simultaneously in the active volume. This is a reason to calibrate the chambers, if is possible, with gamma monoenergetic emitting and by average calculations to complete the response curve with gamma emitting of well-known yields. To obtain the calibration coefficients and may used them, it is necessary that so much the standardized radioisotopes as the solutions by calibrating, are contained in vessels with the same geometry and the same quantity. In the exposed case, pattern solutions of 5 ml were used contained in glass cruets of 10 ml. The problem solutions are contained in same cruets to those of the patterns. The first results obtained with the ORIS-LMRI 4 {pi} {gamma} metering chamber are presented. (Author)

  12. Application of Glycine-TTC dosimeter in gamma radiation processing facility

    International Nuclear Information System (INIS)

    Shinde, S.H.; Mondal, S.; Kulkarni, M.S.

    2018-01-01

    Glycine-TTC dosimeter was found to have a useful dose range of 5 to 30 kGy using spectro-photometric read-out method. Potential use of this dosimeter was demonstrated by measuring dose-rate in gamma chamber GC 900. The aim of the present study was to verify the performance of this dosimeter in actual industrial processing conditions encountered in radiation processing facility such as Gamma Radiation Processing Plant for Spices (GRPPS), BRIT, Vashi. Accordingly, glycine-TTC dosimeters were irradiated along with routine dosimeter viz. ceric-cerous of GRPPS and reference standard dosimeter viz. alanine EPR

  13. Methods of computer experiment in gamma-radiation technologies using new radiation sources

    CERN Document Server

    Bratchenko, M I; Rozhkov, V V

    2001-01-01

    Presented id the methodology of computer modeling application for physical substantiation of new irradiation technologies and irradiators design work flow. Modeling tasks for irradiation technologies are structured along with computerized methods of their solution and appropriate types of software. Comparative analysis of available packages for Monte-Carlo modeling of electromagnetic processes in media is done concerning their application to irradiation technologies problems. The results of codes approbation and preliminary data on gamma-radiation absorbed dose distributions for nuclides of conventional sources and prospective Europium-based gamma-sources are presented.

  14. A phoswich detector for simultaneous alpha–gamma spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Moghadam, S. Rajabi [Department of Radiation Application, Shahid Beheshti University G.C., Tehran (Iran, Islamic Republic of); Feghhi, S.A.H., E-mail: A_feghhi@sbu.ac.ir [Department of Radiation Application, Shahid Beheshti University G.C., Tehran (Iran, Islamic Republic of); Safari, M.J. [Amirkabir University of Technology, Department of Energy Engineering and Physics, Tehran (Iran, Islamic Republic of)

    2015-11-01

    Phoswich detectors are of value for radiation spectroscopy, especially in cases where a low-cost solution for a mixed radiation field is desired. Meanwhile, simultaneous spectroscopy of alpha particles and gamma-rays has many applications in quantification and distinguishing the alpha-emitting radionuclides which usually occur in the analysis of environmental solid samples. Here, we have developed a system for detection of radioactive actinides (e.g., {sup 241}Am) based on the alpha–gamma coincidence technique. The underlying concept, is to assemble two appropriately selected scintillators (i.e., a fast and a slow one) together with a discriminating unit for analysis of their data. Detailed Monte Carlo simulation procedure has been developed using the GEANT4 toolkit to design and find enough knowledge about the response of the system in the studied radiation field. Various comparisons were made between experimental and simulation data which showed appropriate agreement between them. The calibration was performed and the MDA was estimated as 60 mBq for the phoswich system.

  15. A phoswich detector for simultaneous alpha–gamma spectroscopy

    International Nuclear Information System (INIS)

    Moghadam, S. Rajabi; Feghhi, S.A.H.; Safari, M.J.

    2015-01-01

    Phoswich detectors are of value for radiation spectroscopy, especially in cases where a low-cost solution for a mixed radiation field is desired. Meanwhile, simultaneous spectroscopy of alpha particles and gamma-rays has many applications in quantification and distinguishing the alpha-emitting radionuclides which usually occur in the analysis of environmental solid samples. Here, we have developed a system for detection of radioactive actinides (e.g., 241 Am) based on the alpha–gamma coincidence technique. The underlying concept, is to assemble two appropriately selected scintillators (i.e., a fast and a slow one) together with a discriminating unit for analysis of their data. Detailed Monte Carlo simulation procedure has been developed using the GEANT4 toolkit to design and find enough knowledge about the response of the system in the studied radiation field. Various comparisons were made between experimental and simulation data which showed appropriate agreement between them. The calibration was performed and the MDA was estimated as 60 mBq for the phoswich system

  16. Particle-gamma and particle-particle correlations in nuclear reactions using Monte Carlo Hauser-Feshback model

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Los Alamos National Laboratory; Talou, Patrick [Los Alamos National Laboratory; Watanabe, Takehito [Los Alamos National Laboratory; Chadwick, Mark [Los Alamos National Laboratory

    2010-01-01

    Monte Carlo simulations for particle and {gamma}-ray emissions from an excited nucleus based on the Hauser-Feshbach statistical theory are performed to obtain correlated information between emitted particles and {gamma}-rays. We calculate neutron induced reactions on {sup 51}V to demonstrate unique advantages of the Monte Carlo method. which are the correlated {gamma}-rays in the neutron radiative capture reaction, the neutron and {gamma}-ray correlation, and the particle-particle correlations at higher energies. It is shown that properties in nuclear reactions that are difficult to study with a deterministic method can be obtained with the Monte Carlo simulations.

  17. Neutron counting and gamma spectroscopy with PVT detectors

    International Nuclear Information System (INIS)

    Mitchell, Dean James; Brusseau, Charles A.

    2011-01-01

    Radiation portals normally incorporate a dedicated neutron counter and a gamma-ray detector with at least some spectroscopic capability. This paper describes the design and presents characterization data for a detection system called PVT-NG, which uses large polyvinyl toluene (PVT) detectors to monitor both types of radiation. The detector material is surrounded by polyvinyl chloride (PVC), which emits high-energy gamma rays following neutron capture reactions. Assessments based on high-energy gamma rays are well suited for the detection of neutron sources, particularly in border security applications, because few isotopes in the normal stream of commerce have significant gamma ray yields above 3 MeV. Therefore, an increased count rate for high-energy gamma rays is a strong indicator for the presence of a neutron source. The sensitivity of the PVT-NG sensor to bare 252 Cf is 1.9 counts per second per nanogram (cps/ng) and the sensitivity for 252 Cf surrounded by 2.5 cm of polyethylene is 2.3 cps/ng. The PVT-NG sensor is a proof-of-principal sensor that was not fully optimized. The neutron detector sensitivity could be improved, for instance, by using additional moderator. The PVT-NG detectors and associated electronics are designed to provide improved resolution, gain stability, and performance at high-count rates relative to PVT detectors in typical radiation portals. As well as addressing the needs for neutron detection, these characteristics are also desirable for analysis of the gamma-ray spectra. Accurate isotope identification results were obtained despite the common impression that the absence of photopeaks makes data collected by PVT detectors unsuitable for spectroscopic analysis. The PVT detectors in the PVT-NG unit are used for both gamma-ray and neutron detection, so the sensitive volume exceeds the volume of the detection elements in portals that use dedicated components to detect each type of radiation.

  18. Gamma radiation sterilises bacteria-contaminated waste

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The use of gamma radiation for the sterilisation of sewage and hospital waste etc., is briefly described. A sterilisation plant delivered by Sulzer is illustrated diagrammatically and its functioning explained, while a photograph illustrates a similar plant delivered by Geodel Systems, of Canada. The latter firm has adapted this type of plant for the radiolytical destruction of phenols, cyanides, alkyl benzenesulphonates and similar wastes. (JIW)

  19. Gamma-ray flares from the Crab Nebula.

    Science.gov (United States)

    Abdo, A A; Ackermann, M; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bouvier, A; Brandt, T J; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Cannon, A; Caraveo, P A; Casandjian, J M; Çelik, Ö; Charles, E; Chekhtman, A; Cheung, C C; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Costamante, L; Cutini, S; D'Ammando, F; Dermer, C D; de Angelis, A; de Luca, A; de Palma, F; Digel, S W; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Dubois, R; Dumora, D; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M-H; Grove, J E; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashi, K; Hayashida, M; Hays, E; Horan, D; Itoh, R; Jóhannesson, G; Johnson, A S; Johnson, T J; Khangulyan, D; Kamae, T; Katagiri, H; Kataoka, J; Kerr, M; Knödlseder, J; Kuss, M; Lande, J; Latronico, L; Lee, S-H; Lemoine-Goumard, M; Longo, F; Loparco, F; Lubrano, P; Madejski, G M; Makeev, A; Marelli, M; Mazziotta, M N; McEnery, J E; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Naumann-Godo, M; Nolan, P L; Norris, J P; Nuss, E; Ohsugi, T; Okumura, A; Omodei, N; Ormes, J F; Ozaki, M; Paneque, D; Parent, D; Pelassa, V; Pepe, M; Pesce-Rollins, M; Pierbattista, M; Piron, F; Porter, T A; Rainò, S; Rando, R; Ray, P S; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Romani, R W; Sadrozinski, H F-W; Sanchez, D; Saz Parkinson, P M; Scargle, J D; Schalk, T L; Sgrò, C; Siskind, E J; Smith, P D; Spandre, G; Spinelli, P; Strickman, M S; Suson, D J; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J B; Thompson, D J; Tibaldo, L; Torres, D F; Tosti, G; Tramacere, A; Troja, E; Uchiyama, Y; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Wang, P; Wood, K S; Yang, Z; Ziegler, M

    2011-02-11

    A young and energetic pulsar powers the well-known Crab Nebula. Here, we describe two separate gamma-ray (photon energy greater than 100 mega-electron volts) flares from this source detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The first flare occurred in February 2009 and lasted approximately 16 days. The second flare was detected in September 2010 and lasted approximately 4 days. During these outbursts, the gamma-ray flux from the nebula increased by factors of four and six, respectively. The brevity of the flares implies that the gamma rays were emitted via synchrotron radiation from peta-electron-volt (10(15) electron volts) electrons in a region smaller than 1.4 × 10(-2) parsecs. These are the highest-energy particles that can be associated with a discrete astronomical source, and they pose challenges to particle acceleration theory.

  20. Gamma-ray flares from the Crab nebula

    International Nuclear Information System (INIS)

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Allafort, A.; Baldini, L.; Ballet, J.; Casandjian, J.M.; Grenier, I.A.; Naumann-Godo, M.; Pierbattista, M.; Tibaldo, L.

    2011-01-01

    A young and energetic pulsar powers the well-known Crab Nebula. Here, we describe two separate gamma-ray (photon energy greater than 100 mega-electron volts) flares from this source detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The first flare occurred in February 2009 and lasted approximately 16 days. The second flare was detected in September 2010 and lasted approximately 4 days. During these outbursts, the gamma-ray flux from the nebula increased by factors of four and six, respectively. The brevity of the flares implies that the gamma rays were emitted via synchrotron radiation from peta-electron-volt (10 15 electron volts) electrons in a region smaller than 1.4 * 10 -2 parsecs. These are the highest-energy particles that can be associated with a discrete astronomical source, and they pose challenges to particle acceleration theory. (authors)

  1. Radiation protection in category III large gamma irradiators

    International Nuclear Information System (INIS)

    Costa, Neivaldo; Furlan, Gilberto Ribeiro; Itepan, Natanael Marcio

    2011-01-01

    This article discusses the advantages of category III large gamma irradiator compared to the others, with emphasis on aspects of radiological protection, in the industrial sector. This category is a kind of irradiators almost unknown to the regulators authorities and the industrial community, despite its simple construction and greater radiation safety intrinsic to the model, able to maintain an efficiency of productivity comparable to those of category IV. Worldwide, there are installed more than 200 category IV irradiators and there is none of a category III irradiator in operation. In a category III gamma irradiator, the source remains fixed in the bottom of the tank, always shielded by water, negating the exposition risk. Taking into account the benefits in relation to radiation safety, the category III large irradiators are highly recommended for industrial, commercial purposes or scientific research. (author)

  2. Gamma radiation effects on rice, substrate for Sitophilus oryzae (L.) rearing

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Arthur, V.; Walder, J.M.M.; Domarco, R.E.

    1987-01-01

    The gamma radiation effects (800 Krad, 60 Co) on rice are studied. Degraded substances by the radiation and how this degradation affects the biology of Sitophilus oryzae (L.) are searched. The vitamins, proteins and stard of the rice are affected by the radiation. (M.A.C.) [pt

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

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Priscilla L.G.; Brandao, Jose Odinilson de C.; Vale, Carlos H.F.P.; Santos, Joelan A.L.; Vilela, Eudice C.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)], e-mail: psouza@cnen.gov.br, e-mail: jodinilson@cnen.gov.br; Calixto, Merilane S.; Santos, Neide [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica

    2009-07-01

    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 {sup 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 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)

  5. Protective role of radish oil (raphson sativus) against gamma radiation on lipids and carbohydrate in male rats

    International Nuclear Information System (INIS)

    Omran, M.F.; Soliman, N.K.I.

    2005-01-01

    The present work was carried out to investigate the effects of ionizing radiation on some biochemical parameters in rats. The rats were exposed to sublethal whole body gamma irradiation dose (1Gy x 4). The protective role of radish oil (Raphanus sativus) was evaluated by oral administration to rats before gamma radiation exposure and the lipid profile, serum glucose and liver glycogen were investigated. Exposed rats to gamma radiation showed significant alterations in the assayed parameters indicating disturbances in lipid and carbohydrate metabolisms. Oral administration of radish oil (Raphanus sativus) before gamma irradiation exerted marked ameliorations in the disorders induced by gamma radiation in most of the tested parameters such as lipid profile, serum glucose and liver glycogen

  6. Study of stability of chloramphenicol in different forms to gamma radiation

    International Nuclear Information System (INIS)

    Tawfik, Z.S.

    1985-01-01

    The effect of radiation dose, in the range from 5 KGY to 250 KGY, on chloramphenicol in either the solid form or as aqueous solution was studied. The results obtained showed that the radiation had no effect on the antibiotic when it was irradiated in the solid form. Minor changes were detected when the antibiotic was exposed to radiation in solution, at doses as small as 5 KGY. These changes were detected by UV-visible, infrared and HPLC techniques. Bioassay experiments performed using the antibiotic concentration recommended by pharmacopoeia were not sensitive enough to detect these small changes. Lower concentrations of the studied antibiotic in the chloramphenicol as a result of exposure to radiation in solution or as eye drops. Accordingly, sterilization of chloramphenicol using gamma radiation could be considered a safe process if the antibiotic is in the solid form but aqueous solutions of the studied antibiotic are not recommended for sterilization by gamma radiation. (author)

  7. Effects of gamma radiation on lichens and lichen-forming fungi and algae

    International Nuclear Information System (INIS)

    Erbisch, F.H.

    1977-06-01

    Initial literature reports indicated that lichens were highly resistant to gamma radiation. A series of experiments were undertaken to determine why lichens were so resistant. In experiments with Cladonia mitis, C. sylvatica, C. verticillata, Parmelia sulcata and P. subaurifera, using both acute and chronic radiation, it was found that these lichens were not highly resistant to gamma radiation. The lichens appeared to be resistant as long as they were in a dormant condition. But, when allowed to pass through a period which was suitable for growth, radiation damage was quickly manifested. Radiation damage was seen in various ways, including the change of thallus color, disintegration of phycobiant chloroplastids, coalescing of fungal hyphae, reduced CO 2 uptake, and reduction in thallus tensile strength

  8. Focused detection logging technique

    International Nuclear Information System (INIS)

    Turcotte, R.E.

    1977-01-01

    In accordance with an illustrative embodiment of the present invention, a method and apparatus is disclosed for determining a characteristic of the media surrounding a borehole by emitting gamma radiation in at least one tightly collimated beam toward an earth formation adjacent a borehole, by detecting from a plurality of tightly collimated paths that are focused at a zone of intersection with and aligned to intersect with each emitted beam the gamma radiation scattered by the interaction of the emitted gamma radiation and the media at the zones of intersection, by misaligning the emitted beams and the tightly collimated paths to prevent their intersection, by detecting gamma radiation scattered by the interaction of the emitted gamma radiation and the media with the emitted beams and the tightly collimated paths misaligned and by determining from the detected gamma radiation a media characteristic. In one embodiment, the detection collimater used is formed of a material that is essentially opaque to gamma radiation at the energies of interest and includes a plurality of passageways that are spherically focused at a zone of intersection with one of the emitted beams of gamma radiation and that are arranged in a number of surfaces that are curved to be azimuthally symmetrical about the axis of the intersected beam. 14 figures

  9. Effect of glucocorticoids and gamma radiation on epidermal Langerhans cells

    International Nuclear Information System (INIS)

    Belsito, D.V.; Baer, R.L.; Thorbecke, G.J.; Gigli, I.

    1984-01-01

    The effect of 750 rads of gamma radiation on the rate of return of epidermal Langerhans cells (LC) following suppressive doses of topical glucorticoids was studied in guinea pigs. Gamma radiation alone had no effect on the LC as assessed by staining for cell membrane ATPase activity and Ia antigen. It did, however, delay the expected return of Ia but not ATPase surface markers on the LC after perturbation with glucocorticoids. The delayed return of surface Ia antigen is possibly related to a radiation-induced defect in the production of a required lymphokine and/or in intracellular Ia transport. Although our data do not rule out a cytolytic effect of steroids on the LC, they do strongly suggest that, at least in part, glucocorticoids act on the LC by altering cell surface characteristics

  10. The gamma-ray radiation preservation technology for files and books

    International Nuclear Information System (INIS)

    Fan Chengfa; Tian Kaizen; Zhang Yunlu; Gan Saohan; Wang Zhengfu; Xiang Jiafang

    1988-01-01

    In this paper, a radiation appliance using CO-60 Gamma-ray to preserve the files and books is introduced. The lump and transport radiation techniques for processing files and books with this radiation appliance is described. The cost of preserving files and books with this method has been estimated. Comparison of this method with other processing techniques has been taken. (author)

  11. Gamma radiation sterilization of Bactrocera invadens (Diptera ...

    African Journals Online (AJOL)

    The African invader fly, Bactrocera invadens, an invasive pest in Africa since 2003, causes damage and poses a threat to the mango and horticultural industry. Its control is therefore needed. Sterilization of males using gamma radiation doses (25, 50 and 75 Gy) as a means of population control was investigated. Irradiation ...

  12. Effect of ionizing radiations on bacterial endotoxins: comparison between gamma radiations and accelerated electrons

    Energy Technology Data Exchange (ETDEWEB)

    Guyomard, S; Goury, V; Darbord, J C

    1988-01-01

    Determinations of the effect of radiation sterilization processing on purified endotoxins, in aqueous solution or on dried support, are reported. These observations allow us to accept gamma radiations for sterilization of parenteral devices with an estimated probability of existence of non apyrogenic items, based upon a similar definition of the usual Sterility Assurance Level (SAL = 10/sup -6/).

  13. Inactivation of rabies diagnostic reagents by gamma radiation

    International Nuclear Information System (INIS)

    Gamble, W.C.; Chappell, W.A.; George, E.H.

    1980-01-01

    Treatment of CVS-11 rabies adsorbing suspensions and street rabies infected mouse brains with gamma radiation resulted in inactivated reagents that are safer to distribute and use. These irradiated reagents were as sensitive and reactive as the nonirradiated control reagents

  14. Effect of Gamma Radiation on Nutritional Indices of Larval and Adults Stages of Tribolium castaneum (Coleoptera: Tenebrionidae)

    International Nuclear Information System (INIS)

    Ahmadi, M.; Moharramipour, S.

    2012-01-01

    In this study antifeedant effect of different doses of gamma radiation as a controlling safe method on flour weevil, Tribolium castaneum (Herbst) larvae and adult was studied. Doses of 100, 400, 600, 800 and 1000 Gy of gamma radiation were used and after 72 hours, nutritional indices were evaluated. The relative growth rate, relative consumption rate, efficiency of conversion of ingested food and feeding deterrence index as nutritional indices were evaluated. Treatments were assessed by flour wheat disc at 27±1 d egree C and 65 p ercent h umidity in a dark condition. The results showed that the relative growth rate of flour weevil larvae and adults decreased significantly (P<0.05) by gamma radiation and the severity of this reduction in larvae was higher than the adults. Although the relative growth rates decreased in adults, this rate in doses of 400, 600, 800 and 1000 Gy showed no significant difference. The relative food consumption rate also decreased with the gamma radiation and its value found to be inversely proportional to the dose radiation. Our experiments showed that the use of gamma radiation exposure to 800 Gy had no significant effect on the efficiency of conversion of ingested food of larvae and reduction was observed only when the gamma radiation was used in 1000 Gy. The feeding deterrence effect of gamma radiation, especially on the larvae was high but no significant difference between doses of 100 to 800 Gy was observed. The results showed that gamma radiation that induces antifeedant effect can be applied as an effective method in control of T. castaneum.

  15. Apparatus for gamma ray radiography

    International Nuclear Information System (INIS)

    Kobayashi, Masatoshi; Enomoto, Shigemasa; Oga, Hiroshi

    1979-01-01

    This is the standard of Japan Non-Destructive Inspection Society, NDIS 1101-79, which stipulates on the design, construction and testing method of the apparatuses for gamma ray radiography used for taking industrial radiograms. The gamma ray apparatuses stipulated in this standard are those containing sealed radioactive isotopes exceeding 100 μCi, which emit gamma ray. The gamma ray apparatuses are classified into three groups according to their movability. The general design conditions, the irradiation dose rate and the sealed radiation sources for the gamma ray apparatuses are stipulated. The construction of the gamma ray apparatuses must be in accordance with the notification No. 52 of the Ministry of Labor, and safety devices and collimators must be equipped. The main bodies of the gamma ray apparatuses must pass the vibration test, penetration test, impact test and shielding efficiency test. The method of each test is described. The attached equipments must be also tested. The tests according to this standard are carried out by the makers of the apparatuses. The test records must be made when the apparatuses have passed the tests, and the test certificates are attached. The limit of guarantee by the endurance test must be clearly shown. The items to be shown on the apparatuses are stipulated. (Kako, I.)

  16. Characterization of the gamma radiation in space and in the atmosphere

    International Nuclear Information System (INIS)

    Lee, M.A.

    1986-05-01

    A characterization of the gamma-ray fields found in space and in the atmosphere is given. Included are values for the energies and intensities of gamma rays as observed in several experiments and reported in the open literature. Characteristics of the diffuse gamma-ray continuum are presented along with a brief discussion of the sources of this radiation. Also given are discrete gamma-ray line energies and intensities which have been observed in space and in the atmosphere. 37 refs., 7 figs., 12 tabs

  17. Synergistic interaction between the neutron and gamma radiation on LACA mice hemopoietic stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, H

    1982-02-01

    Based on the radiation action dual theory of DNA single and double strand breaks, a hypothetical RBE mathematical model for the effect of the mixed radiation of neutron and gamma rays on LACA mice hemopoietic stem cells was formulated. In comparison of the RBE values of different ratio of neutron and gamma-ray mixed radiation with their theoretical additive RBE values, the preliminary impression is that the mixed radiation is more effective than that of the theoretical additive effect. It seems that the existence of synergist in the mixed radiation might be valid.

  18. The effect of gamma radiation on the properties of activated carbon cloth

    Directory of Open Access Journals (Sweden)

    DANIJELA R. SEKULIĆ

    2009-09-01

    Full Text Available Activated carbon cloth dressing is an appropriate wound healing material due to its biocompatibility and adsorption characteristics. The in-fluence of gamma radiation as a sterilization process on the adsorption and mechanical properties of activated carbon cloth was investigated. The specific surface area, micropore volume, pore size distribution, surface chemistry as well as the breaking load of activated carbon cloth before and after gamma radiation were examined. Characterization by nitrogen adsorption showed that the activated carbon cloth was a microporous material with a high specific surface area and micropores smaller than 1 nm. Gamma radiation decreased the specific surface area and micropore volume but increased the pore width. The sterilization process changed the surface chemistry quantitatively, but not qualitatively. In addition, the breaking load decreased but without any influence considering the further application of this material.

  19. Effect of Gamma Radiation and Microwave Cooking on Aeromonas Hydrophila in Bolti Fish Fillet

    International Nuclear Information System (INIS)

    Mohamad, W.S.; Megahed, A.A.; El-Ghaiaty, H.A.; Hafez, T.A.

    2016-01-01

    The objective of this study is to determine the bactericidal effect of gamma and microwave radiation on Aeromonas hydrophila inoculated in fish fillets. The study revealed that treatment of fish fillets with a dose of 1 kGy gamma radiation reduced the population of A.hydrophila by 104 cfu/g, while the dose of 2 and 3 kGy completely eliminated the microorganism. Treatment of fish fillets with microwave cooking for 1 and 2 minutes completely eliminated the microorganism. The physical examination of fish after gamma radiation treatment revealed that the used doses had no significant changes on fish fillets. The changes in protein profile (amino acids %) depended on radiation dose and period of cooking in microwave alongside controls while the total protein content was not affected.

  20. Discrete level schemes and their gamma radiation branching ratios (CENPL-DLS). Pt. 1

    International Nuclear Information System (INIS)

    Su Zongdi; Zhang Limin; Zhou Chunmei; Sun Zhengjun

    1994-01-01

    The DLS data file, which is a sub-library (version 1) of Chinese Evaluated Nuclear Parameter Library (CENPL), consists of data and information of discrete levels and gamma radiations. The data and information of this data file are translated from the Evaluated Nuclear Structure Data File (ENSDF). The transforming code from ENSDF to DLS was written. In the DLS data file, there are the data on discrete levels with determinate energy and their gamma radiations. At present, this file contains the data of 79456 levels and 100411 gammas for 1908 nuclides

  1. Environmental gamma radiation measurements in Bangladeshi houses

    International Nuclear Information System (INIS)

    Idrish Miah, M.

    2002-01-01

    The indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54±0.26 mGy.y -1 . The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d = 160 + 65 cos p/6 (m -1 ), where d is the indoor dose rate (nGy.h -1 ) and m the month, was observed. This might be due to seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv respectively based on the indoor gamma exposure. (author)

  2. Environmental gamma radiation measurements in Bangladeshi houses

    International Nuclear Information System (INIS)

    Miah, M.I.

    2004-01-01

    Indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54±0.26 mGy y -1 . The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d=160+65 cos π/6 (m-1), where d is the indoor dose rate (nGy h -1 ) and m the month. This might be due to the seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv, respectively, based on the indoor gamma exposure

  3. Environmental gamma radiation measurements in Bangladeshi houses

    Energy Technology Data Exchange (ETDEWEB)

    Miah, M.I. E-mail: idrish_physics@yahoo.com

    2004-06-01

    Indoor gamma dose rate in air measured using TLDs in the Dhaka district is not wide ranging and follows a normal distribution with an arithmetic mean of 1.54{+-}0.26 mGy y{sup -1}. The result has been compared with those found by other investigators for different locations of the world. Measurements were made on a monthly basis for a year period, and a sinusoidal variation of monthly indoor gamma radiation of the type: d=160+65 cos {pi}/6 (m-1), where d is the indoor dose rate (nGy h{sup -1}) and m the month. This might be due to the seasonally varied air exchange rates of the houses. The average annual effective dose and the collective dose equivalent for the residents were estimated to be 0.86 mSv and 172.20 man-Sv, respectively, based on the indoor gamma exposure.

  4. Very-high-energy gamma rays from a distant quasar: how transparent is the universe?

    Science.gov (United States)

    Albert, J; Aliu, E; Anderhub, H; Antonelli, L A; Antoranz, P; Backes, M; Baixeras, C; Barrio, J A; Bartko, H; Bastieri, D; Becker, J K; Bednarek, W; Berger, K; Bernardini, E; Bigongiari, C; Biland, A; Bock, R K; Bonnoli, G; Bordas, P; Bosch-Ramon, V; Bretz, T; Britvitch, I; Camara, M; Carmona, E; Chilingarian, A; Commichau, S; Contreras, J L; Cortina, J; Costado, M T; Covino, S; Curtef, V; Dazzi, F; De Angelis, A; De Cea Del Pozo, E; de Los Reyes, R; De Lotto, B; De Maria, M; De Sabata, F; Mendez, C Delgado; Dominguez, A; Dorner, D; Doro, M; Errando, M; Fagiolini, M; Ferenc, D; Fernández, E; Firpo, R; Fonseca, M V; Font, L; Galante, N; López, R J García; Garczarczyk, M; Gaug, M; Goebel, F; Hayashida, M; Herrero, A; Höhne, D; Hose, J; Hsu, C C; Huber, S; Jogler, T; Kneiske, T M; Kranich, D; La Barbera, A; Laille, A; Leonardo, E; Lindfors, E; Lombardi, S; Longo, F; López, M; Lorenz, E; Majumdar, P; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Mariotti, M; Martínez, M; Mazin, D; Meucci, M; Meyer, M; Miranda, J M; Mirzoyan, R; Mizobuchi, S; Moles, M; Moralejo, A; Nieto, D; Nilsson, K; Ninkovic, J; Otte, N; Oya, I; Panniello, M; Paoletti, R; Paredes, J M; Pasanen, M; Pascoli, D; Pauss, F; Pegna, R G; Perez-Torres, M A; Persic, M; Peruzzo, L; Piccioli, A; Prada, F; Prandini, E; Puchades, N; Raymers, A; Rhode, W; Ribó, M; Rico, J; Rissi, M; Robert, A; Rügamer, S; Saggion, A; Saito, T Y; Salvati, M; Sanchez-Conde, M; Sartori, P; Satalecka, K; Scalzotto, V; Scapin, V; Schmitt, R; Schweizer, T; Shayduk, M; Shinozaki, K; Shore, S N; Sidro, N; Sierpowska-Bartosik, A; Sillanpää, A; Sobczynska, D; Spanier, F; Stamerra, A; Stark, L S; Takalo, L; Tavecchio, F; Temnikov, P; Tescaro, D; Teshima, M; Tluczykont, M; Torres, D F; Turini, N; Vankov, H; Venturini, A; Vitale, V; Wagner, R M; Wittek, W; Zabalza, V; Zandanel, F; Zanin, R; Zapatero, J

    2008-06-27

    The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.

  5. Detection of 16 Gamma-Ray Pulsars Through Blind Frequency Searches Using the Fermi LAT

    International Nuclear Information System (INIS)

    Anderson, B.; Atwood, W.B.; Dormody, M.; Johnson, R.P.; Porter, T.A.; Primack, J.R.; Sadrozinski, H.F.W.; Parkinson, P.M.S.; Ziegler, M.; Abdo, A.A.; Dermer, C.D.; Grove, J.E.; Gwon, C.; Johnson, W.N.; Lovellette, M.N.; Makeev, A.; Ray, P.S.; Strickman, M.S.; Wolff, M.T.; Wood, K.S.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R.D.; Borgland, A.W.; Cameron, R.A.; Chiang, J.; Claus, R.; Digel, S.W.; Silva, E.D.E.; Drell, P.S.; Dubois, R.; Funk, S.; Glanzman, T.; Godfrey, G.; Hayashida, M.; Johannesson, G.; Kamae, T.; Kocian, M.L.; Lande, J.; Madejski, G.M.; Michelson, P.F.; Mitthumsiri, W.; Monzani, M.E.; Moskalenko, I.V.; Murgia, S.; Nolan, P.L.; Paneque, D.; Reimer, A.; Reimer, O.; Rochester, L.S.; Romani, R.W.; Tajima, H.; Tanaka, T.; Thayer, J.G.; Tramacere, A.; Uchiyama, Y.; Usher, T.L.; Van Etten, A.; Waite, A.P.; Wang, P.; Watters, K.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Bloom, E.D.; Borgland, A.W.; Cameron, R.A.; Chiang, J.; Claus, R.; Digel, S.W.; Silva, E.D.E.; Drell, P.S.; Dubois, R.; Glanzman, T.; Godfrey, G.; Hayashida, M.; Johannesson, G.; Kamae, T.; Kocian, M.L.; Lande, J.; Madejski, G.M.; Michelson, P.F.; Mitthumsiri, W.; Monzani, M.E.; Moskalenko, I.V.; Murgia, S.; Nolan, P.L.; Paneque, D.; Reimer, A.; Reimer, O.; Rochester, L.S.; Romani, R.W.; Tajima, H.; Tanaka, T.; Thayer, J.G.; Tramacere, A.; Uchiyama, Y.; Usher, T.L.; Van Etten, A.; Waite, A.P.; Wang, P.; Watters, K.; Axelsson, M.; Conrad, J.; Meurer, C.; Ryde, F.; Ylinen, T.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Brez, A.; Kuss, M.; Latronico, L.; Omodei, N.; Pesce-Rollins, M.; Razzano, M.; Sgro, C.; Spandre, G.; Ballet, J.; Casandjian, J.M.; Grenier, I.A.; Pierbattista, M.; Starck, J.L.

    2009-01-01

    Pulsars are rapidly rotating, highly magnetized neutron stars emitting radiation across the electromagnetic spectrum. Although there are more than 1800 known radio pulsars, until recently only seven were observed to pulse in gamma rays, and these were all discovered at other wavelengths. The Fermi Large Area Telescope (LAT) makes it possible to pinpoint neutron stars through their gamma-ray pulsations. We report the detection of 16 gamma-ray pulsars in blind frequency searches using the LAT. Most of these pulsars are coincident with previously unidentified gamma-ray sources, and many are associated with supernova remnants. Direct detection of gamma-ray pulsars enables studies of emission mechanisms, population statistics, and the energetics of pulsar wind nebulae and supernova remnants. (authors)

  6. Effects of gamma radiations on certain tissues of heteropneustes fossils bloch

    International Nuclear Information System (INIS)

    Purohit, R.K.; Rathore, N.; Ahluwalia, P.; Srivastava, M.; Gupta, M.L.

    1992-01-01

    In the present investigation effect of gamma radiation on certain tissues (kidney, stomach and gills) of Heteropneustes fossilis Bloch, an Indian Cat fish, were studied. The fish were irradiated with 10 Gy of gamma radiations at the dose rate of 1.60 Gy/minute from a 60 Co source. Five fish were autopsied at each post-irradiation time of 1,2,3,7,15 and 30 days. Radiation induced histopathology was observed in all the tissues studied. The radio lesions appeared on day-1 after exposure which became exaggerated on day-2 and 3. Signs of recovery were noticed on day-7 which progressed on day-15 and normal histology was observed on day-30. (author). 18 refs

  7. The development of gamma energy identify algorithm for compact radiation sensors using stepwise refinement technique

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyun Jun [Div. of Radiation Regulation, Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Kim, Ye Won; Kim, Hyun Duk; Cho, Gyu Seong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Yi, Yun [Dept. of of Electronics and Information Engineering, Korea University, Seoul (Korea, Republic of)

    2017-06-15

    A gamma energy identifying algorithm using spectral decomposition combined with smoothing method was suggested to confirm the existence of the artificial radio isotopes. The algorithm is composed by original pattern recognition method and smoothing method to enhance the performance to identify gamma energy of radiation sensors that have low energy resolution. The gamma energy identifying algorithm for the compact radiation sensor is a three-step of refinement process. Firstly, the magnitude set is calculated by the original spectral decomposition. Secondly, the magnitude of modeling error in the magnitude set is reduced by the smoothing method. Thirdly, the expected gamma energy is finally decided based on the enhanced magnitude set as a result of the spectral decomposition with the smoothing method. The algorithm was optimized for the designed radiation sensor composed of a CsI (Tl) scintillator and a silicon pin diode. The two performance parameters used to estimate the algorithm are the accuracy of expected gamma energy and the number of repeated calculations. The original gamma energy was accurately identified with the single energy of gamma radiation by adapting this modeling error reduction method. Also the average error decreased by half with the multi energies of gamma radiation in comparison to the original spectral decomposition. In addition, the number of repeated calculations also decreased by half even in low fluence conditions under 104 (/0.09 cm{sup 2} of the scintillator surface). Through the development of this algorithm, we have confirmed the possibility of developing a product that can identify artificial radionuclides nearby using inexpensive radiation sensors that are easy to use by the public. Therefore, it can contribute to reduce the anxiety of the public exposure by determining the presence of artificial radionuclides in the vicinity.

  8. Influence of gamma-radiation on the nutritional and functional qualities of lotus seed flour.

    Science.gov (United States)

    Bhat, Rajeev; Sridhar, Kandikere Ramaiah; Karim, Alias A; Young, Chiu C; Arun, Ananthapadmanabha B

    2009-10-28

    In the present study, we investigated the physicochemical and functional properties of lotus seed flour exposed to low and high doses of gamma-radiation (0-30 kGy; the dose recommended for quarantine and hygienic purposes). The results indicated raw seed flour to be rich in nutrients with minimal quantities of antinutritional factors. Irradiation resulted in a dose-dependent increase in some of the proximal constituents. The raw and gamma-irradiated seeds meet the Food and Agricultural Organization-World Health Organization recommended pattern of essential amino acids. Some of the antinutritional factors (phytic acid, total phenolics, and tannins) were lowered with gamma-irradiation, while the seed flours were devoid of lectins, L-3,4-dihydroxyphenylalanine, and polonium-210. The functional properties of the seed flour were significantly improved with gamma-radiation. gamma-radiation selectively preserved or improved the desired nutritional and functional traits of lotus seeds, thus ensuring a safe production of appropriate nutraceutically valued products.

  9. Gamma ray emission from pulsars

    International Nuclear Information System (INIS)

    Salvati, M.; Massaro, E.

    1978-01-01

    A model for the production of gamma rays in a pulsar environment is presented, together with numerical computations fitted to the observations of PSR 0833-45. It is assumed that the primary particles are accelerated close to the star surface and then injected along the open field lines, which cause them to emit curvature radiation. The equation describing the particles' braking is integrated exactly up to the first order in the pulsar rotational frequency, and the transfer problem for the curvature photons is solved with the aberration, the Doppler shif, and the pair production absorption being taken into account. The latter effect is due not only to the transverse component of the magnetic field, but also to the electric field induced by the rotation. The synchrotron radiation emitted by the secondary particles is also included, subject to the 'on-the-spot' approximation. It is found that the observed gamma rays originate in the innermost regions of the magnetosphere, where the open lines' bundle is narrow and the geometrical beaming is effective. As shown by the computed pulse profiles, the duty cycle turns out to be equal to a few percent, comparable to the one of PSR 0833-45. The averaged spectra indicate that a substantial fraction of the primary photons do outlive the interaction with the magnetisphere; furthermore, the agreement in shape with the observational curves suggests that the acceleration output is fiarly close to a monoenergetic beam of particles. (orig.) [de

  10. SENSITIVITY OF THE CUMIN SEEDS ASSOCIATED FUNGI TO GAMMA RADIATION

    International Nuclear Information System (INIS)

    BOTROS, H.W.; HELAL, I.M.; EL TOBGY, K.M.K.

    2008-01-01

    The present study was carried out to investigate the sensitivity of fungi associated to cumin seeds for gamma radiation. In this regard, the isolated seed associated fungi from the cumin seeds were fifteen fungal species belonging to five genera. The fungal species concerning, Aspergillus ochraceus, Fusarium oxysporium and Aspergillus flavus were the predominant fungi in percentages of 17.8, 15.83 and 12.78 %, respectively. Aspergillus ochraceus was the most effective prevalent fungi on the seed germination causing highest percentage of seed invasion followed by Fusarium oxysporium and Aspergillus flavus. The amylolytic, proteolytic and lipolytic activity and mycotoxin production of the three predominant fungi were negatively influenced by gamma radiation when exposed to doses of 1.0 , 1.5 , 2.5 , 3.5 , 5.0 and 7.5 kGy a behaviour which was parallel to the inhibition in the amount of growth by gamma irradiation

  11. Standard radiation protection instructions. Vol. 1

    International Nuclear Information System (INIS)

    Schroeder, F.; Bauer, N.; Haug, T.; Koehler, G.; Poulheim, K.F.

    1992-01-01

    The booklet presents case-specific standard instructions compiled by the Arbeitskreis Ausbildung of the Fachverband Strahlenschutz (Radiation Protection Association) for: (1) work requiring a permit according to section 20 of the Radiation Protection Ordinance, performed by external personnel; (2) the installation, maintenance, transport and storage of ionization smoke detectors; (3) application of gamma-ray and X-ray equipment; (4) the testing of X-ray equipment and equipment emitting stray radiation at the stage of manufacturing; (5) application of Ni-63 electron capture detectors. (HP) [de

  12. Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation

    International Nuclear Information System (INIS)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

    1987-01-01

    Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y

  13. Investigation of gamma-ray fingerprint identifying mechanism for the types of radiation sources

    International Nuclear Information System (INIS)

    Liu Suping; Wu Huailong; Gu Dangchang; Gong Jian; Hao Fanhua; Hu Guangchun

    2002-01-01

    Radiation fingerprints sometimes can be used to label and identify the radiation resources. For instance, in a future nuclear reduction treaty that requires verification of irreversible dismantling of reduced nuclear warheads, the radiation fingerprints of nuclear warheads are expected to play a key role in labelling and identifying the reduced warheads. It would promote the development of nuclear warheads deep-cuts verification technologies if authors start right now some investigations on the issues related to the radiation fingerprints. The author dedicated to the investigation of gamma-ray fingerprint identifying mechanism for the types of radiation resources. The purpose of the identifying mechanism investigation is to find a credible way to tell whether any two gamma-ray spectral fingerprints that are under comparison are radiated from the same resource. The authors created the spectrum pattern comparison (SPC) to study the comparability of the two radiation fingerprints. Guided by the principle of SPC, the authors programmed a software dedicated to identify the types of radiation resources. The efficiency of the software was tested by a series of experiments with some laboratory gamma-ray resources. The experiments were designed to look into the relations between comparability and radioactive statistics, and the relations between comparability and some measurement conditions such as real time, resource activity and background etc. Two main results can be drawn from the investigation: 1) it is quite feasible to use the concept of spectral comparability to answer the question whether any two gamma-ray fingerprints are identity or not; 2) the identifying mechanism can only identify the types of radiation resources, and cannot identify the individuals with the same type and small differences

  14. A national-wide survey of radon and gamma radiation levels in Australian homes

    International Nuclear Information System (INIS)

    Langaroo, M.K.; Wise, K.N.; Duggleby, J.K.; Kotler, L.H.

    1990-04-01

    A nation-wide survey of Australian homes has been conducted to determine the average annual doses to the Australian population from exposure to radon and gamma radiation. The exposure to radon was measured using solid state track detectors (SSTD) whilst the gamma radiation dose was concurrently determined using thermoluminescent dosimetry. Dosemeters were placed in approximately 3400 randomly distributed homes (representing about 1 in 1400 occupied dwellings) for twelve months. The measured annual average radon concentration in Australian homes is 12 Bq m -3 . Using appropriate conversion factors, the annual average effective dose equivalents to the Australian population were determined to be 0.6 mSv and 0.9 mSv for radon and gamma radiation respectively. 20 refs., 3 tabs., 7 figs

  15. Radiation processing of food and agricultural commodities

    International Nuclear Information System (INIS)

    Sharma, Arun

    2014-01-01

    Reducing post-harvest food losses is becoming increasingly important for sustaining food supplies. Appropriate post-harvest processing, handling, storage and distribution practices are as important as the efforts to increase productivity for improving food security, food safety and international trade in agricultural commodities. Preservation of food by ionizing radiation involves controlled application of energy of ionizing radiation such as gamma rays, X-rays, and accelerated electrons to agricultural commodities, food products and ingredients, for improving their storage life, hygiene and safety. The process employs either gamma rays emitted by radioisotopes such as cobalt-60 or high-energy electrons or X-rays generated from machine sources

  16. Development of aerial gamma radiation survey system, 1

    International Nuclear Information System (INIS)

    Tsutsumi, Masahiro; Saito, Komei; Sakamoto, Ryuichi; Nagaoka, Toshi; Moriuchi, Shigeru

    1986-05-01

    JAERI has started to develop an aerial gamma radiation survey system by a helicopter in 1980. The development of measuring instruments, the experiments in the field of natural and artificial radiation sources, and the imaginary emergency survey at a real site, were executed. This report describes mainly about the hardware and software of this system. The system consists of gamma-ray measuring instruments with NaI(Tl) scintillation detectors, microwave positioning instruments, and a data processing system for postflight data. A foreign-made geological survey system is improved on for radiation measurements. For covering the wide radiation range, detectors of various shapes and sizes are prepared, from a large volume detector, DET-1024 - four 4'' x 4'' x 16'' crystals assembly - to a 2'' diameter x 2'' NaI(Tl) crystal. Radiation and position data are recorded on a magnetic tape, and computer-processed afterwards. Moreover, scene below flight courses and internal communication are recorded on video tape with the information of clock and position superimposed. In consequence of field experiments carried out five times, basic radiation data for evaluating airborne acquired data are accumulated, and flight survey procedures are established. As more practical use, a system has been produced more compactly and functionally. Exposure rates (> 1 mR/h), energy distribution spectra, and energy window counts are obtained for radiation data. Using the Spectrum-Dose Conversion Method, the accurate exposure rates are directly calculated from pulse height spectra. Numerical tables of G(E) function converting pulse height spectra into exposures are shown in this report. As regards the analysis of survey data, process codes have been completed with either large-computer or mini-computer. (author)

  17. Observations of Galactic gamma-radiation with the SMM spectrometer

    Science.gov (United States)

    Share, G. H.; Kinzer, R. L.; Messina, D. C.; Purcell, W. R.; Chupp, E. L.

    1986-01-01

    Preliminary results from the SMM gamma-ray spectrometer are reported which indicate the detection of a constant source of 0.511-MeV annihilation radiation from the Galaxy. Year-to-year variability appears to be less than 30 percent. The radiation probably comes from a diffuse source and is not associated with the reported compact object at the Galactic center.

  18. Papain incorporated chitin dressings for wound debridement sterilized by gamma radiation

    Science.gov (United States)

    Singh, Durgeshwer; Singh, Rita

    2012-11-01

    Wound debridement is essential for the removal of necrotic or nonviable tissue from the wound surface to create an environment conducive to healing. Nonsurgical enzymatic debridement is an attractive method due to its effectiveness and ease of use. Papain is a proteolytic enzyme derived from the fruit of Carica papaya and is capable of breaking down a variety of necrotic tissue substrates. The present study was focused on the use of gamma radiation for sterilization of papain dressing with wound debriding activity. Membranes with papain were prepared using 0.5% chitin in lithium chloride/dimethylacetamide solvent and sterilized by gamma radiation. Fluid absorption capacity of chitin-papain membranes without glycerol was 14.30±6.57% in 6 h. Incorporation of glycerol resulted in significant (p<0.001) increase in the absorption capacity. Moisture vapour transmission rate of the membranes was 4285.77±455.61 g/m2/24 h at 24 h. Gamma irradiation at 25 kGy was found suitable for sterilization of the dressings. Infrared (IR) spectral scanning has shown that papain was stable on gamma irradiation at 25-35 kGy. The irradiated chitin-papain membranes were impermeable to different bacterial strains and also exhibited strong bactericidal action against both Gram-positive and Gram-negative bacteria. The fluid handling characteristics and the antimicrobial properties of chitin-papain membranes sterilized by gamma radiation were found suitable for use as wound dressing with debriding activity.

  19. Optical radiation emitted by a silver surface bombarded by low-energy electrons

    International Nuclear Information System (INIS)

    Miserey, F.; Lebon, P.; Septier, A.; Trehin, F.; Beaugrand, C.

    1975-01-01

    Thick silver targets are obtained on flat glass discs by evaporation in a UHV cell (p -10 torr) and their optical coefficients measured by ellipsometry. A field-emission electron gun bombards a limited region of the target, corresponding to the entry pupil of a light spectrometer. Radiation emitted in the domain 250-600nm is analyzed for both normal and parallel polarizations. Spectral distributions of photons are obtained by using a very sensitive counting device including a multi channel analyzer. First experimental results concerning optical radiation generated by 6keV electrons are reported and compared to Transition Radiation and Bremsstrahlung theoretical spectra [fr

  20. Characteristics of liver tissue for attenuate the gamma radiation; Caracteristicas del tejido hepatico para atenuar la radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2005-07-01

    It was determined the lineal attenuation coefficient of hepatic tissue before gamma radiation of a source of {sup 137} Cs. When exposing organic material before X or gamma radiation fields, part of the energy of the photons is absorbed by the material, while another part crosses it without producing any effect. The quantity of energy that is absorbed is a measure of the dose that receives the material. The three main mechanisms by means of which the gamma rays interacting with the matter are: The Photoelectric Effect, the Compton dispersion and the Even production; the sum of these three processes is translated in the attenuation coefficient of the radiation. In this work we have used hepatic tissue of bovine, as substitute of the human hepatic tissue, and we have measured the lineal attenuation coefficient for photons of 0.662 MeV. Through a series of calculations we have determined the lineal attenuation coefficient for photons from 10{sup -3} to 10{sup -5} MeV and the measured coefficient was compared with the one calculated. (Author)

  1. Effects of gamma radiation on codling moth, Cydia pomonella (L.), eggs

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F

    2005-01-01

    The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1-24 to 97-120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1-24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25-48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation. (Author)

  2. Effects of gamma radiation on codling moth, Cydia pomonella (L.), eggs

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F.

    2004-01-01

    The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1-24 to 97-120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1-24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25-48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation

  3. The combined effect of gamma radiation and stress cracking in polycarbonate

    International Nuclear Information System (INIS)

    Melo, Raphaela N. de; Rabello, Marcelo S.

    2009-01-01

    In this work the combined effect of gamma irradiation and stress cracking was studied in polycarbonate (PC). Tensile test bars were produced by injection moulding and then exposed to different doses of gamma radiation. After that they were submitted to the contact with isopropanol, the stress cracking agent used in this work. The specimens were tested for mechanical properties, viscosity molecular weight and fractography. The results indicated that the previous radiation intensified the stress cracking effects, as evidenced by the reduction in tensile properties and surface damage caused to the samples. (author)

  4. Gamma Radiation Effects on the Electrical Parameters of Some Operational Amplifiers

    International Nuclear Information System (INIS)

    Ashry, H.A.; Soliman, F.A.S.; Swidan, A.M.; El-Ghana, M.; Abdel Rahman, W.A.

    2008-01-01

    In this work, the effect of gamma-radiation on different types of operational amplifiers (HA17741 OK, HA17741 1D1, LM741 CN and μtA741 CN) was studied. It is shown that a serious effect occurs on the electrical characteristics of the op-amp's, and consequently the devices lose their main features. The input offset voltage, offset current, and bias current are shown to increase with increasing gamma dose. Also, the closed loop gain of the op-amp's is shown to decrease with increasing gamma dose, where its rate of decrease is a function of frequency. As a result, the slew rate, common mode rejection ratio and input impedance were shown to decrease with increasing gamma dose levels. On the other hand, the output impedance is inversely proportion to the gain; so, its value increases with increasing gamma exposure. Finally, it is clearly shown that the radiation dependence of the op-amp electrical parameters is a function of the fabrication technique of the op-amp's, where, the op-amps of the types HA17741 IDI and HA17741 OK are shown to be less sensitive to gamma rays than the op-amps of the types LM741 CN and μtA741 CN

  5. Radiation-induced reduction of diuron by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Zhang Jibiao; Zheng Zheng; Zhao Tan; Zhao Yongfu; Wang Lianhong; Zhong Yun; Xu Yue

    2008-01-01

    Diuron degradation efficiencies and the proposed mechanism by gamma-ray irradiation were investigated. Several factors that might affect the degradation values were further examined. The UV absorbances at 200-400 nm and diuron concentration decreased with the increase of radiation dose. When diuron initial concentration was 18.5 mg L -1 and 1.0 kGy was selected as the radiation dose, diuron removal value and loss of total organic carbon were 100 and 34.1%, respectively. However, the concentration of Cl - ion increased with the increase of radiation dose. The process could be depicted by first order reaction kinetics and the reaction was mainly caused by the reaction of diuron with ·OH and e aq - . The degradation efficiency decreased with the increase of initial concentration at the same radiation dose. H 2 O 2 , HCO 3 - , NO 3 - , NO 2 - , CH 3 OH and humic acid as additives reduced the degradation efficiency. Furthermore, the increase of NO 3 - , NO 2 - , CH 3 OH and humic acid would result in the decrease of the degradation values. The pH value could affect the removal efficiency and the degradation process was enhanced in acid condition. The pH value became lower with increasing radiation dose after gamma-ray irradiation

  6. Gamma radiation induced sensitization and photo-transfer in Mg2SiO4:Tb TLD phosphor

    International Nuclear Information System (INIS)

    Lakshmanan, A.R.; Vohra, K.G.

    1979-01-01

    Mg 2 SiO 4 :Tb TLD phosphor was found to show enhanced TL sensitivity to both gamma and UV radiations after high pre-gamma exposures (>100 R) and a post-annealing treatment at 300 0 C for 1 h. Maximum sensitization factors of 2.8 and 55 were obtained at the pre-expsoure levels of 5.2x10 1 C/kg and 1.3x10 3 C/kg for gamma and UV test radiations respectively. The near constancy of the intensity of the residual TL (RTL) peak at 500 0 C for the sensitized sample with increasing test-gamma exposures has ruled out the re-trapping model proposed earlier for the gamma radiation induced sensitization in this phosphor. The Tsub(max) for the sensitized phosphor was found to occur at a higher temperature compared to that for the virgin phosphor. The dependence of sensitization on RTL was explained qualitatively on the basis of competition between sensitization traps (having higher energy than the dosimetry traps) and RTL traps while capturing the charge carriers generated during the test-gamma exposure. The sensitization observed in this phosphor to UV test radiation was found to be a consequence of the photo-transfer of charge carriers from deep (RTL) traps to the shallow (dosimetry) traps. The reduction in RTL peak (500 0 C) intensity of the sensitized sample with increasing test-UV exposure has demonstrated the photo-transfer mechanism in this phosphor. The TL response of the virgin Mg 2 SiO 4 :Tb phosphor was found to be supralinear to both gamma and UV radiations. The TL response of the sensitized phosphor was found to be linear to gamma radiation and sublinear to UV radiation. (Auth.)

  7. Antibody Level Upon Newcastle Disease Virus In Chicken After Exposure To GAMMA Radiation

    International Nuclear Information System (INIS)

    Pejakovic-Hlede, J.; Dotur, J.; Pasic, S.; Gottstein, Z.; Majer, M.; Vilic, M.

    2015-01-01

    The aim of this study was to investigate the effect of gamma radiation upon Newcastle disease virus antibody level after acute exposure with dose of 0.05 Gy and 0.8 Gy gamma radiation. The experiment was made on light chicken breeds irradiated with dose of 0.05 Gy and 0.8 Gy gamma radiation with dose rate of 0.0117 Gy/s on the first and on the third day after hatching. Chicken were vaccinated by nebulization on the first day after hatching. Antibody level upon Newcastle disease in blood serum of chicken was quantified by hemagglutination inhibition assay on 1th, 7th, 14th and 28th day after vaccination. Results demonstrate that antibody titre against Newcastle disease in blood serum of chicken irradiated with dose of 0.05 Gy and 0.8 Gy gamma radiation on the first and on the third day after hatching was not statistically significant. Therefore, these results suggest that irradiation of light chicken breeds on the first and third day after vaccination with dose of 0.05 Gy and 0.8 Gy does not change antibody titre upon Newcastle disease. (author).

  8. Ex-situ and in-situ observations of the effects of gamma radiation on lithium ion battery performance

    Science.gov (United States)

    Tan, Chuting; Bashian, Nicholas H.; Hemmelgarn, Chase W.; Thio, Wesley J.; Lyons, Daniel J.; Zheng, Yuan F.; Cao, Lei R.; Co, Anne C.

    2017-07-01

    Radiation effects induced by gamma rays on battery performance were investigated by measuring the capacity and resistance of a series of battery coin cells in-situ directly under gamma radiation and ex-situ. An experimental setup was developed to charge and discharge batteries directly under gamma radiation, equipped with precise temperature control, at The Ohio State University Nuclear Reactor Lab. Latent effects induced by gamma radiation on battery components directly influence their performance. Charge and discharge capacity and overall resistance throughout a time span of several weeks post irradiation were monitored and compared to control groups. It was found that exposure to gamma radiation does not significantly alter the available capacity and the overall cell resistance immediately, however, battery performance significantly decreases with time post irradiation. Also, batteries exposed to a higher cumulative dose showed close-to-zero capacity at two-week post irradiation.

  9. Effect of gamma radiation on lipids by the TBARS and NMR

    International Nuclear Information System (INIS)

    Silva, Adriana Cristina de Oliveira; Cortez, Marco Antonio Sloboda; Marsico, Eliane Teixeira; Guimaraes, Carlos Frederico; Jesus, Edgar Francisco Oliveira de

    2011-01-01

    The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co 60 in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR) and Thiobarbituric Acid Test (2-TBARS). The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected. (author)

  10. Effect of gamma radiation on lipids by the TBARS and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adriana Cristina de Oliveira; Cortez, Marco Antonio Sloboda, E-mail: vetdri@gmail.com [Lab. de Inspecao e Tecnologia de Leite e Derivados Lacteos, Faculdade de Medicina Veterinaria, Universidade Federal Fluminense, Niteroi - RJ (Brazil); Marsico, Eliane Teixeira; Guimaraes, Carlos Frederico [Laboratorio de Controle Fisico-Quimico de Produtos de Origem Animal, Faculdade de Medicina Veterinaria, Universidade Federal Fluminense, Niteroi - RJ (Brazil); Jesus, Edgar Francisco Oliveira de [Laboratorio de Instrumentacao Nuclear, Instituto Alberto Luiz Coimbra de Pos-graduacao e Pesquisa de Engenharia, Universidade Federal do Rio de Janeiro, Rio de Janeiro - RJ (Brazil)

    2011-11-15

    The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co{sup 60} in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR) and Thiobarbituric Acid Test (2-TBARS). The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected. (author)

  11. Sterilization of peat by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F E; Vincent, J M [New South Wales Univ., Kensington (Australia). School of Microbiology

    1981-01-01

    The effect of gamma-radiation on the survival of microorganisms has been quantified for the natural population of two types of peat. Data for several microbial types have been separately determined by regular plating and by indirect statistical probability estimates including, a wholly enclosed 'inverted-bottle' technique for higher dose levels to exclude any possibility of post-treatment contamination. The most persistent microorganisms at intermediate dosage (2.5-3.5 Mrad) were commonly a micrococcus (which closely resembled Micrococcus radiodurans) arthrobacter-like rods, myxobacteria and amoeboid forms. The persistent organisms all survived because of high resistance to ..gamma..-irradiation, not because of high initial numbers. The most numerous true bacteria (including spore-formers), actinomycetes, filamentous fungi and yeasts were all readily destroyed. Although the safety margin with the commercially recommended dose of 5 Mrad is low for some of the more resistant organisms, no change is justified at this stage since the organisms most likely to survive such a dose do not seem to seriously affect the subsequent growth and survival of rhizobia. Moreover there would be some risk of radiation-induced peat toxicity if higher doses were applied and some post-irradiation contamination will be difficult to avoid in commercial production.

  12. Gamma and electron radiation effects on straw

    International Nuclear Information System (INIS)

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

    1983-01-01

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

  13. Limits on the space density of gamma-ray burst sources

    International Nuclear Information System (INIS)

    Epstein, R.I.

    1985-01-01

    Gamma-ray burst spectra which extend to several MeV without significant steepening indicate that there is negligible degradation due to two-photon pair production. The inferred low rate of photon-photon reactions is used to give upper limits to the distances to the sources and to the intensity of the radiation from the sources. These limits are calculated under the assumptions that the bursters are neutron stars which emit uncollimated gamma rays. The principal results are that the space density of the gamma-ray burst sources exceeds approx.10 -6 pc -3 if the entire surface of the neutron star radiates and exceeds approx.10 -3 pc -3 if only a small cap or thin strip in the stellar surface radiates. In the former case the density of gamma-ray bursters is approx.1% of the inferred density of extinct pulsars, and in the latter case the mean mass density of burster sources is a few percent of the density of unidentified dark matter in the solar neighborhood. In both cases the X-ray intensity of the sources is far below the Rayleigh-Jeans limit, and the total flux is at most comparable to the Eddington limit. This implies that low-energy self-absorption near 10 keV is entirely negligible and that radiation-driven explosions are just barely possible

  14. Advanced multi-dimensional imaging of gamma-ray radiation

    International Nuclear Information System (INIS)

    Woodring, Mitchell; Beddingfield, David; Souza, David; Entine, Gerald; Squillante, Michael; Christian, James; Kogan, Alex

    2003-01-01

    The tracking of radiation contamination and distribution has become a high-priority US DOE task. To support DOE needs, Radiation Monitoring Devices Inc. has been actively carrying out research and development on a gamma-radiation imager, RadCam 2000 TM . The imager is based upon a position-sensitive PMT coupled to a scintillator near a MURA coded aperture. The modulated gamma flux detected by the PSPMT is mathematically decoded to produce images that are computer displayed in near real time. Additionally, we have developed a data-manipulation scheme which allows a multi-dimensional data array, comprised of x position, y position, and energy, to be used in the imaging process. In the imager software a gate can be set on a specific isotope energy to reveal where in the field of view the gated data lies or, conversely, a gate can be set on an area in the field of view to examine what isotopes are present in that area. This process is complicated by the FFT decoding process used with the coded aperture; however, we have achieved excellent performance and results are presented here

  15. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    Science.gov (United States)

    Norman, Eric B [Oakland, CA; Prussin, Stanley G [Kensington, CA

    2009-01-27

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  16. Method to calculating an internal electromagnetic pulse generated in a system under gamma radiation effect; Metod rascheta vnutrennego ehlektromagnitnogo impul`sa, generiruemogo v sisteme pri vozdejstvii gamma-izlucheniya

    Energy Technology Data Exchange (ETDEWEB)

    Ogorodnikov, S N

    1994-12-31

    A method of calculating internal electromagnetic pulse, generated in the system under effect of gamma radiation is developed. Ratios for basic electron flux characteristics and components of electric and magnetic fields generated by gamma radiation, are indicated for a cylindrical cavity under gamma radiation effect on its surface. To illustrate this a case is considered when a single flux velocity component is present.

  17. Gamma radiation and the conservation of natural orange juice

    International Nuclear Information System (INIS)

    Iemma, Juliana; Alcarde, Andre Ricardo; Domarco, Rachel Elisabeth; Spoto, Marta Helena Fillet; Blumer, Lucimara; Matraia, Clarice

    1999-01-01

    The effect of gamma radiation was evaluated on the microbiological population, soluble solids content, acidity, p H and ascorbic acid content of natural orange juice. Microbial activity may cause deterioration of orange juice. Irradiation is a process of food conservation which eliminates microorganisms. nevertheless radiation may affect some characteristics of irradiated food. The experimental design was a 4 x 5 factorial scheme, including control and 3 rates of irradiation (2.0, 4.0 and 6.0 kGy) and 5 storage periods (1, 7, 14, 21 and 28 days), with 2 replicates. Samples of juice were extracted from variety Pera oranges and irradiated at a rate of 2.0 kGy/h ( 60 Cobalt) and thereafter stored at 5 +- 3 deg C. Results showed small changes in soluble solids content, acidity and p H, for all treatments. The ratio soluble solids/acidity was also determined and showed little variation for all treatments. There was a reduction on ascorbic acid content of the orange juice with increased radiation dosage and storage time. Gamma radiation was effective in reducing the microbiological population of the juice. (author)

  18. Evaluation of optical fibres as gamma radiation dosimeter

    International Nuclear Information System (INIS)

    Bohra, Dinesh; Chaudhary, H.S.; Panwar, Lalit; Vaijapurkar, S.G.; Bhatnagar, P.K.; Dasgupta, K.

    2005-01-01

    Semiconductor base gamma and neutron sensors are the fastest and popular dosimeters and are in competition with Thermoluminescence (TL) and Radio photoluminescence (RPL) dosimeters. All over the world armed forces require a dosimeter which records cumulative doses of ionizing radiations from mcGy to 10 Gy and is readable repeatedly without loss of dose information. TL dosimeters do not meet the criteria and RPL dosimeter meet the expectations and are in use by armed forces. Technologists have used laser as an excitation source to stimulate the glass and have achieved success in recording gamma doses of occupational/accidental span (mcGy to 10 Gy). However synthesizing RPL glass batches with exactly same characteristics predoses is a difficult task. Silicon base phosphorous doped step index multimode optical fibre can be made in a significant quantity and large number of dosimeters from it can be achieved with uniform predose. The radiation induced transmission loss gives a measure of gamma dose which is cumulative, readable repeatedly without loss of information. Assorted composition, core dia optical fibres have been synthesized and evaluated for dose linearity, dose rate independence, fading, length optimization. Here in is described some results of recent experiments and sensitivities achieved. (author)

  19. Radiation exposures of workers resulting from the transport of gamma radiography sources in Germany

    International Nuclear Information System (INIS)

    Sentuc, F.N.; Schwarz, G.

    2006-01-01

    Gamma radiation sources are widely used for industrial purposes e.g. for non-destructive material testing. Many of these sources are permanently installed at a facility within instruments e.g. for level or thickness gauging. Other radioactive sources are implemented in portable devices for industrial gamma radiography which have to be carried to the various remote usage sites. In Germany, approximately 20 000 - 25 000 shipments of gamma radiography sources are proceeding annually on public transport routes. Since routine radiation monitoring programmes do not permit task-specific determination of occupational doses e.g. doses incurred during the movement phase and handling related doses, work has been carried out with the objective to determine the radiation exposures of the personnel attributable to transportation. For this purpose, a survey was launched in 2005 collecting data about e.g. the number and conditions of transports, the activity and type of transported radiation sources and the radiation level within the driver's cab to allow a dose assessment to be made for transport workers. The results of this survey covering the most important companies for gamma radiography services in Germany are presented in this paper. (authors)

  20. Measurement of Inclusive Radiative B -Meson Decay B -> X_s gamma

    Energy Technology Data Exchange (ETDEWEB)

    Ozcan, V.E.; /SLAC /Stanford U., Appl. Phys. Dept.

    2006-01-06

    Radiative decays of the B meson, B {yields} X{sub s}{gamma}, proceed via virtual flavor changing neutral current processes that are sensitive to contributions from high mass scales, either within the Standard Model of electroweak interactions or beyond. In the Standard Model, these transitions are sensitive to the weak interactions of the top quark, and relatively robust predictions of the inclusive decay rate exist. Significant deviation from these predictions could be interpreted as indications for processes not included in the minimal Standard Model, like interactions of charged Higgs or SUSY particles. The analysis of the inclusive photon spectrum from B {yields} X{sub s}{gamma} decays is rather challenging due to high backgrounds from photons emitted in the decay of mesons in B decays as well as e{sup +}e{sup -} annihilation to low mass quark and lepton pairs. Based on 88.5 million B{bar B} events collected by the BABAR detector, the photon spectrum above 1.9 GeV is presented. By comparison of the first and second moments of the photon spectrum with QCD predictions (calculated in the kinetic scheme), QCD parameters describing the bound state of the b quark in the B meson are extracted: m{sub b} = (4.45 {+-} 0.16) GeV/c{sup 2}; {mu}{sub {pi}}{sup 2} = (0.65 {+-} 0.29) GeV{sup 2}. These parameters are useful input to non-perturbative QCD corrections to the semileptonic B decay rate and the determination of the CKM parameter |V{sub ub}|. Based on these parameters and heavy quark expansion, the full branching fraction is obtained as: {Beta}(B {yields} X{sub s}{gamma}){sup E{sub {gamma}}>1.6 GeV} = (4.05 {+-} 0.32(stat) {+-} 0.38(syst) {+-} 0.29(model)) x 10{sup -4}. This result is in good agreement with previous measurements, the statistical and systematic errors are comparable. It is also in good agreement with the theoretical Standard Model predictions, and thus within the present errors there is no indication of any interactions not accounted for in the

  1. Gate Simulation of a Gamma Camera

    International Nuclear Information System (INIS)

    Abidi, Sana; Mlaouhi, Zohra

    2008-01-01

    Medical imaging is a very important diagnostic because it allows for an exploration of the internal human body. The nuclear imaging is an imaging technique used in the nuclear medicine. It is to determine the distribution in the body of a radiotracers by detecting the radiation it emits using a detection device. Two methods are commonly used: Single Photon Emission Computed Tomography (SPECT) and the Positrons Emission Tomography (PET). In this work we are interested on modelling of a gamma camera. This simulation is based on Monte-Carlo language and in particular Gate simulator (Geant4 Application Tomographic Emission). We have simulated a clinical gamma camera called GAEDE (GKS-1) and then we validate these simulations by experiments. The purpose of this work is to monitor the performance of these gamma camera and the optimization of the detector performance and the the improvement of the images quality. (Author)

  2. Radon adsorbed in activated charcoal—a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    Science.gov (United States)

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

    2012-07-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, a ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 g of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity the students also get practical experience about the existence of natural sources of radiation in the environment.

  3. Radon adsorbed in activated charcoal- a simple and safe radiation source for teaching practical radioactivity in schools and colleges

    International Nuclear Information System (INIS)

    Al-Azmi, D.S.

    2014-01-01

    Simple procedures for teaching practical radioactivity are presented in a way that attracts students' attention and does not make them apprehensive about their safety. The radiation source is derived from the natural environment. It is based on the radioactivity of radon, an ubiquitous inert gas, and the adsorptive property of activated charcoal. Radon gas from ambient air in the laboratory was adsorbed into about 70 gram of activated charcoal inside metallic canisters. Gamma radiation was subsequently emitted from the canisters, following the radioactive decay of radon and its progenies. The intensities of the emitted gamma-rays were measured at suitable intervals using a NaI gamma-ray detector. The counts obtained were analysed and used to demonstrate the radioactive decay law and determine the half-life of radon. In addition to learning the basic properties of radioactivity, the students also get practical experience about the existence of natural sources of radiation in the environment. (author)

  4. Study of local Agregate for Gamma radiation concrete shield; Studi pemakaian Agregat lokal pada pembuatan beton perisai radiasi Gamma

    Energy Technology Data Exchange (ETDEWEB)

    Tochrul-Binowo,; Endro-Kismolo,; Darsono, [Yogyakarta Nuclear Research Centre, National Atomic Energy Agency, Yogyakarta (Indonesia)

    1996-04-15

    Investigation on the composition of gamma radiation concrete shield made of local barite, manganese fine and coarse aggregates from Kulon Progo, Yogyakarta has been done. The purpose of the research was to find out the quality of these local material for an aggregate of gamma radiation concrete shield. The research was done where each mineral was used as coarse aggregate and the fine aggregate from Kulon Progo was used as fine basic aggregate. Firstly a normal concrete was made by mixing cement, fine aggregate, coarse aggregate and water at a weight ratio of cement: fine aggregate: coarse: water 1: 2.304: 3.456: 0.58. The gamma radiation absorption capacity of the concrete tested by using Cs-137 as source standard. The same method was done on barite concrete at the weight ratio of cement: fine aggregate: barite aggregate: water 1: 2.303: 3.456: 0.58 and manganese concrete at the weight ratio of cement: fine aggregate: manganese aggregate: and water 1: 1.896: 2.844: 0.58. The result of the study showed that the gamma radiation absorption capacity of barite aggregate was greater than that of normal concrete and manganese concrete. The coefficient linear attenuation (for 6.0 cm thickness) of each concrete were {mu} barite concrete = 0.23071 cm{sup -1}, {mu} manganese concrete = 0.08401 cm{sup -1} and {mu} normal concrete = 0.1669 cm{sup -1}.

  5. SWEPP gamma-ray spectrometer system software test plan and report

    International Nuclear Information System (INIS)

    Femec, D.A.

    1994-09-01

    The SWEPP Gamma-Ray Spectrometer (SGRS) System has been developed by the Radiation Measurements and Development Unit of the Idaho National Engineering Laboratory to assist in the characterization of the radiological contents of contact-handled waste containers at the Stored Waste Examination Pilot Plant (SWEPP). In addition to determining the concentrations of gamma-ray-emitting radionuclides, the software also calculates attenuation-corrected isotopic mass ratios of specific interest, and provides controls for SGRS hardware as required. This document presents the test plan and report for the data acquisition and analysis software associated with the SGRS system

  6. Degradation of polycarbonate induced by gamma radiation

    International Nuclear Information System (INIS)

    Araujo, E.S. de; Guedes, S.M.L.

    1992-01-01

    Polycarbonate (PC) DUROLON amorphous, of molecular weight 22000 g/mol is used in medical supplies and may be sterilized by gamma radiation. The main chain scission and polymer degradation occur when this polymer is irradiated. The value G = 1.54 to DUROLON was obtained by equation: 10 6 /M v = 10 6 /M v' + 0.054 G R. The degradation without crosslinking it is not general rule to all types of polycarbonates; an comparison was realized. The infrared (FT-IR) spectra of irradiated PC by gamma rays with different doses showed the main chain scissions in carbonyl groups. The mechanism of polymeric degradation to DUROLON, observed by NMR spectra, is a recombination of phenoxy and phenyl radicals. (author)

  7. Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Song, You, E-mail: you.song@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian; Heier, Lene Sørlie [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås (Norway); Tollefsen, Knut Erik [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway)

    2014-11-15

    Highlights: • First study on early stress responses in salmon exposed to low-dose gamma radiation. • Dramatic dose-dependent transcriptional responses characterized. • Multiple modes of action proposed for gamma radiation. - Abstract: Due to the production of free radicals, gamma radiation may pose a hazard to living organisms. The high-dose radiation effects have been extensively studied, whereas the ecotoxicity data on low-dose gamma radiation is still limited. The present study was therefore performed using Atlantic salmon (Salmo salar) to characterize effects of low-dose (15, 70 and 280 mGy) gamma radiation after short-term (48 h) exposure. Global transcriptional changes were studied using a combination of high-density oligonucleotide microarrays and quantitative real-time reverse transcription polymerase chain reaction (qPCR). Differentially expressed genes (DEGs; in this article the phrase gene expression is taken as a synonym of gene transcription, although it is acknowledged that gene expression can also be regulated, e.g., at protein stability and translational level) were determined and linked to their biological meanings predicted using both Gene Ontology (GO) and mammalian ortholog-based functional analyses. The plasma glucose level was also measured as a general stress biomarker at the organism level. Results from the microarray analysis revealed a dose-dependent pattern of global transcriptional responses, with 222, 495 and 909 DEGs regulated by 15, 70 and 280 mGy gamma radiation, respectively. Among these DEGs, only 34 were commonly regulated by all radiation doses, whereas the majority of differences were dose-specific. No GO functions were identified at low or medium doses, but repression of DEGs associated with GO functions such as DNA replication, cell cycle regulation and response to reactive oxygen species (ROS) were observed after 280 mGy gamma exposure. Ortholog-based toxicity pathway analysis further showed that 15 mGy radiation

  8. Dosimetry techniques of thermal neutrons and {gamma} radiation in reactor cores; Techniques de dosimetrie des neutrons thermiques et du rayonnement {gamma} dans les piles

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, J; Draganic, I; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Chemical studies under radiation done in the reactor cores require to be followed by dosimetry. When the irradiations are done in the reflector, one can limit to the measure of the {gamma} and the neutron radiation. For the dosimetry of the {gamma} radiation, a dosimeter of ferrous sulfate is convenient until doses of about 10{sup 6} rep. The use of aired oxalic acid solutions permits to reach 10{sup 7} rep. The dosimetry of thermal neutrons has been made with solutions of cobalt sulphate or paper filter impregnated with this salt. The total chemical effect of the {gamma} and of the slow neutrons radiation is obtained with solutions of ferrous sulfate added with lithium sulphate. (M.B.) [French] Les etudes de chimie sous radiation faites dans les piles exigent d'etre suivies par dosimetrie. Lorsque les irradiations sont effectues dans le reflecteur, on peut se limiter a doser le rayonnement {gamma} et les neutrons. Pour la dosimetrie du rayonnement {gamma}, un dosimetre a sulfate ferreux convient jusqu'a des doses d'environ 10{sup 6} rep. L'emploi de solutions aerees d'acide oxalique permet d'atteindre 10{sup 7} rep. La dosimetrie des neutrons thermiques a ete faite avec des solutions de sulfate de cotalt ou du papier filtre impregne de ce sel. L'effet chimique total du rayonnement {gamma} et des neutrons lents est obtenu avec des solutions de sulfate ferreux additionne de sulfate de lithium. (M.B.)

  9. Radiation in dwellings and cancer in children

    International Nuclear Information System (INIS)

    Stjernfeldt, M.; Samuelsson, L.; Ludvigsson, J.

    1987-01-01

    Indoor radiation, especially radon exposure, has been in focus in the public domain during the past several years. The growing concern among parents of children with cancer possibly having high radiation levels in their homes led us to study the levels of gamma- and alpha-radiation levels in the homes of a group of children in the county of Ostergoetland. The indoor concentration of alpha-emitting radon daughters was measured by a high-voltage method. The gamma activity was measured with a standard detector scintillation meter. The yearly average for radon-daughter concentration in both cases (57 Bq/m3) and controls (61 Bq/m3) corresponds fairly well with the national average of 53 Bq/m3. The yearly average for gamma radiation (cases 0.37 mGy, controls 0.36 mGy) is much lower than the permissible upper level in dwellings (2.5 mGy/year). The values seem to be of the same order as the subtracted cosmic radiation, which is 0.24-0.26 mGy. No appreciable difference could thus be found between cases and controls either from gamma radiation or radon-daughter exposure. We cannot from our study rule out the possibility of an effect of low-level radiation in susceptible individuals, but it seems clear that children who get cancer do not live in more radioactive homes than other children

  10. Variation of the optical energy gap with {gamma}-radiation and thickness in Bi-thin films

    Energy Technology Data Exchange (ETDEWEB)

    Al-Houty, L.; Kassem, M.E.; Abdel Kader, H.I. [Qatar Univ., Doha (Qatar). Dept. of Physics

    1995-02-01

    The effect of {gamma}-radiation and thickness on the optical energy gap of Bi-thin films has been investigated by measuring their optical absorbance. The measurements were carried out on thermally evaporated films having thicknesses in the range 5-20 nm. Different {gamma}-radiation doses were used ranging from 0-300 Mrad. The optical energy gap as well as the absorption coefficient were found to be {gamma}-dose dependent. (author).

  11. Study of the contribution of the radon in the measurement with an automatic gamma probe

    International Nuclear Information System (INIS)

    Caveda Ramos, C.A.; Dominguez Levy, O.; Alonso Abad, D.; Montalvan Estrada, A.; Fabelo Bonet, O.

    2008-01-01

    In this work, study about the influence of the radon in the daily measurements of the dose rate absorbed in air due to the environmental gamma radiation is achieved. This magnitude is measured each ten minutes for the Gamma Tracer probe, which is located in the western station of the National Network of Environmental Radiological Surveillance of the Republic of Cuba, this station belongs to the Center of Protection and Hygiene of the Radiations (CPHR). For achieving such study approximately 157 680 measurements of the gamma dose rate corresponding the period 2004-2006 were analyzed. The gamma probe used has two independent counter channels which are both complemented with a Geiger-Muller detector; also it can only detect gamma radiation and perform measurements of the gamma dose rate between 8.7 n Gy/h and 8.7 mGy/h. This probe is located at the height of 3.5 m and is exposed to the sun rays directly. For improving the interpretation of the data, the average of all the values of gamma dose rate was calculated, for each hour of the 365 days of the year. The values were also monthly averaged out. The data were processed by employing the software Gamma Red which was improved by adding some options. A comparison between the results obtained and the annual radon variation internationally published was made. With the present study, it was proved that the main contribution to the daily measurements of the dose rate absorbed in the air due to environmental gamma radiation, on stable weather conditions, is associated with the radon daughters which emit gamma radiation. (author)

  12. Estimating the Infrared Radiation Wavelength Emitted by a Remote Control Device Using a Digital Camera

    Science.gov (United States)

    Catelli, Francisco; Giovannini, Odilon; Bolzan, Vicente Dall Agnol

    2011-01-01

    The interference fringes produced by a diffraction grating illuminated with radiation from a TV remote control and a red laser beam are, simultaneously, captured by a digital camera. Based on an image with two interference patterns, an estimate of the infrared radiation wavelength emitted by a TV remote control is made. (Contains 4 figures.)

  13. Treatment of tannery effluent by irradiation. [gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Roszak, W; Pekala, W

    1983-01-01

    Different samples of tannins were exposed to gamma radiation at room temperature. Some of them were aerated during irradiation.In irradiated samples the concentration of phenol and organic substances decreased and their biodegradability increased. Aerated samples had a higher decrease of phenol concentration. (E.G.M.).

  14. Effect of gamma radiation on properties of a composite rocket propellant

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.; Pol, V.G.; Navle, P.B.; Ghorpade, V.G.; Wani, V.S.

    2000-01-01

    Gamma radiation was employed for modifying the properties of a composite rocket propellant prepared in a standard way. It was observed that when the same gamma dose was imparted to hydroxy terminated polybutadiene (HTPB) then converted into propellant, the enhancement in the properties was much larger than the irradiated propellant samples. (author)

  15. Inactivation of bacterial spores by combination processes: ultraviolet plus gamma radiation. [Streptococcus faecium, micrococcus radiodurans, clostridium botulinum

    Energy Technology Data Exchange (ETDEWEB)

    Grecz, N; Durban, E

    1973-01-01

    Bacterial spores, viruses and some vegetative bacteria such as Streptococcus faecium and Micrococcus radiodurans are distinguished by high radiation resistance. In order to lay a theoretical basis for biomedical sterilization applications, we have investigated the combined action of uv and gamma rays. Spores of two strains of C. botulinum were selected, a highly radiation resistant strain, 33A having a D/sub 10/-value of 0.32 Mrad, and a relatively radiation sensitive strain, 51B having a D/sub 10/-value of 0.12 Mrad. Strain 33A exhibits an extensive initial ''shoulder'' in its uv as well as gamma ray survival curves; strain 51B shows only a slight shoulder. The shoulder in the gamma ray survival curve of spores of strain 33A could be reduced or completely eliminated by preirradiation with uv. Simultaneously the D/sub 10/-value for gamma inactivation of spores of 33A was reduced substantially. For example, the gamma resistance was reduced almost to half of its original D/sub 10/-value by uv-preirradiation for only one minute under an 8 watt GE germicidal lamp. The effect of uv-preirradiation on the radiation sensitive strain 51B was less pronounced. In fact, there was about seven fold higher positive interaction (synergism) between uv and gamma radiation in 33A spores than in 51B spores. The experiments suggest that interference with DNA repair enzymes in the radiation resistant strain are responsible for lethal synergism between uv and gamma radiation. A hypothesis is developed attempting to explain the combined effect of these two radiations in terms of a special summation of known DNA lesions in the cell. These observations emphasize the potential practical advantages of combining uv and gamma rays for effective sterilization of certain biomedical devices, drugs and biologicals.

  16. The First Step in Studying the Ability of Destroying the Antibiotics by Gamma Radiation

    International Nuclear Information System (INIS)

    Nguyen Mong Giao; Tran Hung Manh; Nguyen Thi Ai Thu; Nguyen Quoc Thai; Tran, Khac An; Tran, Van Hung

    2010-12-01

    This paper presents the research results of the possibility to destroy the antibiotics in the form of liquid by gamma radiation to break the molecular bond of antibiotics. The 60 Co gamma radiation with the doses of 4.7 kGy to 29.3 kGy was irradiated on chloramphehicol and flumequine solution to define the content of antibiotics by the high performance liquid chromotography method. After irradiating, concentration of antibiotics is reduced from 30.26% to 98.89%. Based on the results, we can draw the conclusion that, with appropriate doses, the gamma radiation can destroy antibiotics. This result can be used to destroy after-content of antibiotics in seafood products. (author)

  17. Dose rate modelled for the outdoors of a gamma irradiation

    International Nuclear Information System (INIS)

    Mangussi, J

    2012-01-01

    A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach's the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation as far as 200 m is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on graphics (author)

  18. Electron equilibrium for parallel plate ionization chambers in gamma radiation fields

    International Nuclear Information System (INIS)

    Caldas, L.; Albuquerque, M. da P.P.

    1989-08-01

    Parallel plate ionization chambers, designed and constructed for use in low energy X-radiation fields, were tested in gamma radiation beams ( 6 Co and 137 Cs) of two different Calibration Laboratories, in order to study the electron equilibrium occurrence and to verify the possibility of their use for the detection of the kind of radiation too. (author) [pt

  19. Polycrystalline Materials as a Cold Neutron and Gamma Radiation Filter

    International Nuclear Information System (INIS)

    Habib, N.

    2009-01-01

    The total neutron cross-section of polycrystalline beryllium, graphite and iron has been calculated beyond their cut-off wavelength using a general formula. The computer Cold Filter code was developed in order to provide the required calculations. The code also permits the calculation of attenuation of reactor gamma radiation, The calculated neutron transmissions through polycrystalline Be graphite and iron at different temperatures were compared with the experimental data measured at the ETRR-1 reactor using two TOF spectrometers. An overall agreement is obtained between the formula fits and experimental data at different temperatures. A feasibility study is carried on using polycrystalline Be, graphite and iron an efficient filter for cold neutrons and gamma radiation.

  20. Sterilization of sera and vaccines by cobalt gamma radiation

    International Nuclear Information System (INIS)

    Guidolin, R.; Morais, J.F.; Higashi, H.G.; Correa, A.; Cicarelli, R.M.B.; Previde, E.

    1988-01-01

    Diphtheria, tetanus, anti-snake venom sera and Diphtheria-Pertussis-Tetanus vaccine were submitted to different intensities of gamma radiation, in order to: verify the resistance of their specific activities to the action of gamma rays; evaluate the possibility of using this type of energy to sterilize some heterogeneous hyper immune sera and vaccines commonly utilized in Public Health. The results, according to the range employed, show the possibility of sterilizing the products tested, without any alteration to specific biological and chemical properties. (author)

  1. The annual terrestrial gamma radiation dose to the population of the urban Christchurch area

    International Nuclear Information System (INIS)

    Chapman, R.H.

    1983-01-01

    Natural terrestrial gamma radiation dose rates were measured with a high pressure ionization chamber at 70 indoor (195 site measurements) and 58 outdoor locations in the metropolitan Christchurch area. Based on these site measurements, the average gonad dose rate to the population from natural terrestrial gamma radiation was estimated to be 273+-56 microgray per annum. (auth)

  2. Effects of gamma radiation in mechanical and optical properties of polycarbonate

    International Nuclear Information System (INIS)

    Araujo, E.S.; Khoury, H.J.; Silveira, S.V. da; Dallolio, A.

    1990-01-01

    The polycarbonates are used in different industrial applications due to their excellent dielectric proprieties, impact resistance and high temperature resistance. For some of this applications, the polycarbonates are exposed to gamma radiation which produces a molecular scission, occasioning changes in the polycarbonate proprieties. To estimate the radiation effects in the DUROLON polycarbonate, samples were irradiated with sup(60)Co gamma beam with doses between 0,2kGy and 50kGy. The results obtained shown variations in the yellowness index above 1kGy dose. Their mechanical proprieties are not changed in the above dose interval. (author)

  3. Principles of medical rehabilitation of survivors of acute radiation sickness induced by gamma and beta and gumma and neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nedejina, N.M.; Galstian, I.A.; Savitsky, A.A.; Sachkov, A.V.; Rtisheva, J.N.; Uvatcheva, I.V.; Filin, S.V. [State Research Center of Russia, Moscow (Russian Federation). Inst. of Biophysics

    2000-05-01

    The purpose of this study is to reveal the principles of medical rehabilitation different degree acute radiation syndrome (ARS) survivors, who exposed {gamma}{beta}- and {gamma}{eta}-irradiation in different radiation accidents. The main reasons of working disability in the late consequences of ARS period are consequences of local radiation injures (LRI) and joining somatic diseases. Its revealing and treatment considerably improves quality of life of the patients. The heaviest consequence of LRI of a skin at {gamma}{beta}- radiation exposure is the development of late radiation ulcers and radiation fibrosis, which require repeated plastic surgery. LRI at {gamma}{eta}-radiation exposure differ by the greater depth of destruction of a underlying tissues and similar defects require the early amputations. Last 10 years microsurgery methods of plastic surgery allow to save more large segments of extremities and to decrease expression of the late consequences (radiation fibrosis and late radiation ulcers) LRI severe and extremely severe degrees. Medical rehabilitation of radiation cataract (development at doses more than 2.0 Gy) includes its extraction and artificial lens implantation, if acuity of vision is considerably decreased. Changes of peripheral blood, observed at the period of the long consequences, as a rule, different, moderate, transient and not requiring treatment. Only one ARS survivor dead from chronic myeloid leukemia. Thyroid nodes, not requiring operative intervention, are found out in Chernobyl survivors. Within the time course the concurrent somatic disease become the major importance for patients disability growth, which concurrent diseases seem to be unrelated to radiation dose and their structure does not differ from that found in general public of Russia. The rehabilitation of the persons who have transferred ARS as a result of radiating failure, should be directed on restoration of functions critical for ionizing of radiation of bodies and

  4. The effect of Low-dose Gamma Radiation on the Bio-chemical ...

    African Journals Online (AJOL)

    Low-dose gamma radiation has been applied to intravenous fluids to enhance the sterility assurance levels. This study was undertaken to determine the stability of gamma irradiated 2.5 % dextrose, 2.5 % dextrose in saline, Ringers lactate and Gastrointestinal replacement fluid at doses of 0, 2, 4, 6, 8, 10 and 20 kGy.

  5. Gamma radiation influence on technological characteristics of wheat flour

    International Nuclear Information System (INIS)

    Teixeira, Christian A.H.M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L.d.

    2012-01-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it. - Highlights: ► We study the influence of gamma radiation on wheat flour and properties of breads. ► Falling number decreased with radiation remaining almost constant up to one month. ► Ionizing radiation may confer an increase in texture parameters, weight and height on the bread.

  6. Analysis of coupled neutron-gamma radiations, applied to shieldings in multigroup albedo method

    International Nuclear Information System (INIS)

    Dunley, Leonardo Souza

    2002-01-01

    The principal mathematical tools frequently available for calculations in Nuclear Engineering, including coupled neutron-gamma radiations shielding problems, involve the full Transport Theory or the Monte Carlo techniques. The Multigroup Albedo Method applied to shieldings is characterized by following the radiations through distinct layers of materials, allowing the determination of the neutron and gamma fractions reflected from, transmitted through and absorbed in the irradiated media when a neutronic stream hits the first layer of material, independently of flux calculations. Then, the method is a complementary tool of great didactic value due to its clarity and simplicity in solving neutron and/or gamma shielding problems. The outstanding results achieved in previous works motivated the elaboration and the development of this study that is presented in this dissertation. The radiation balance resulting from the incidence of a neutronic stream into a shielding composed by 'm' non-multiplying slab layers for neutrons was determined by the Albedo method, considering 'n' energy groups for neutrons and 'g' energy groups for gammas. It was taken into account there is no upscattering of neutrons and gammas. However, it was considered that neutrons from any energy groups are able to produce gammas of all energy groups. The ANISN code, for an angular quadrature order S 2 , was used as a standard for comparison of the results obtained by the Albedo method. So, it was necessary to choose an identical system configuration, both for ANISN and Albedo methods. This configuration was six neutron energy groups and eight gamma energy groups, using three slab layers (iron aluminum - manganese). The excellent results expressed in comparative tables show great agreement between the values determined by the deterministic code adopted as standard and, the values determined by the computational program created using the Albedo method and the algorithm developed for coupled neutron-gamma

  7. Study of mechanical behavior of PMMA in bending and after UV irradiation and gamma radiation

    International Nuclear Information System (INIS)

    Todt, M.L.; Kienen, V.D.; Azevedo, E.C.

    2014-01-01

    PMMA is a polymer that has density similar to water and refractive index alike to glass. It has been used in the substitution to roofing tiles and coverages, affording to be exposed to UV radiation and gamma radiation. This paper had the objective to study the effect in the flexural proprieties of the PMMA exposed to these types of radiations and the evaluation of the wettability through a contact angle measurer. The PMMA specimens have been submitted to 1500 h of UVA radiation, 1500 h of UVC radiation and to 25kGy of gamma radiation. The results show that the PMMA. (author)

  8. Gamma Knife

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Gamma Knife Gamma Knife® is a radiation therapy that uses computerized ... If you're scheduled for radiation therapy using Gamma Knife®, a treatment team consisting of a radiation ...

  9. Radiation-induced reduction of diuron by gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jibiao [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zheng Zheng [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)], E-mail: zzheng@nju.edu.cn; Zhao Tan [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhao Yongfu [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Institute of Atomic Energy, Jiangsu Academy of Agriculture Sciences, Nanjing 210014 (China); Wang Lianhong; Zhong Yun; Xu Yue [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2008-03-01

    Diuron degradation efficiencies and the proposed mechanism by gamma-ray irradiation were investigated. Several factors that might affect the degradation values were further examined. The UV absorbances at 200-400 nm and diuron concentration decreased with the increase of radiation dose. When diuron initial concentration was 18.5 mg L{sup -1} and 1.0 kGy was selected as the radiation dose, diuron removal value and loss of total organic carbon were 100 and 34.1%, respectively. However, the concentration of Cl{sup -} ion increased with the increase of radiation dose. The process could be depicted by first order reaction kinetics and the reaction was mainly caused by the reaction of diuron with {center_dot}OH and e{sub aq}{sup -}. The degradation efficiency decreased with the increase of initial concentration at the same radiation dose. H{sub 2}O{sub 2}, HCO{sub 3}{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, CH{sub 3}OH and humic acid as additives reduced the degradation efficiency. Furthermore, the increase of NO{sub 3}{sup -}, NO{sub 2}{sup -}, CH{sub 3}OH and humic acid would result in the decrease of the degradation values. The pH value could affect the removal efficiency and the degradation process was enhanced in acid condition. The pH value became lower with increasing radiation dose after gamma-ray irradiation.

  10. Effect of gamma radiation on the titrable acidity and vitamin c content of citrus fruits

    Directory of Open Access Journals (Sweden)

    Iftekhar Ahmad

    2012-06-01

    Full Text Available The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora and Citrus assamensis (Ginger lime. Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased with increase of radiation does as well as storage time and this changes of vitamin C and titrable acidity content with gamma radiation and increasing storage period have found statistically significant.

  11. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    International Nuclear Information System (INIS)

    Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

    2013-01-01

    The testing techniques and experimental methods of the 60 Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established. The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically, and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out. The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated, and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained. (authors)

  12. External gamma radiation survey for oil wellheads in Saudi Arabia

    International Nuclear Information System (INIS)

    Nassar, Rafat M.; Mously, Khalid A.; Cowie, Michael I.

    2008-01-01

    Naturally occurring radioactive material (NORM) is known to be associated with oil and gas extraction. As part of a comprehensive NORM management strategy, Saudi Aramco needed to determine the extent of NORM contamination associated with their oil and gas operations. As part of that strategy, this study focused on external gamma survey of oil producing wellheads at various locations. The study aimed to: 1-) Identify wellheads with elevated gamma radiation dose rate; 2-) Specify the exact locations of the high dose rates on the wellheads; 3-) Identify the radioisotopes responsible for the high dose rates; and 4-) Propose worker protection requirements during maintenance. The majority (∼92%) of the surveyed wellheads showed no enhanced gamma dose-rate above background level. From the remaining ∼8%, only a few wellheads showed dose rates between 1,000-3,700 n Sv/h. The study revealed that NORM contamination tends to accumulate at turns of the pipes, around pipe diameter changes, the joints, the back of valves, and at the base of the wellhead. Also, for a given location, NORM build up on the interior of pipework varies over time and continues to migrate down stream until it reaches the Gas and Oil Separation Plants (GOSP). There NORM is expected to accumulate and reside in the form of sludge. Gamma spectroscopy analysis revealed that 226 Ra and its progeny are responsible for the high radiation dose rates detected. It was concluded that NORM will not pose significant radiation hazards to workers as long as the tubing and piping are not opened. (author)

  13. Implementation of the Prompt Gamma facility in the ININ; Implementacion de la instalacion del Prompt Gamma en el ININ

    Energy Technology Data Exchange (ETDEWEB)

    Macias B, L.R.; Delfin L, A.; Aguilar H, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2002-07-01

    The Prompt Gamma Neutron Activation Analysis (PGNAA) technique is based on the reaction of a neutron and an atom emitting gamma radiation in an immediate form and it is used for the elemental identification and characterization. This is a non-destructive technique and presents advantages compared with the X-ray fluorescence analysis technique since it has the advantage of the ability for the neutron penetration which allows a complete analysis in volume of material while the X-ray penetration is not very deep, it is superficial and other advantage of PGNAA is that can detects light elements while by mean of the X-ray fluorescence technique it is not possible. In this work it is shown the implementation of this technique un the National Institute of Nuclear Research (ININ) and the way in which this technique is applied with a radiation source of the TRIGA Mark III reactor from which thermal neutrons were isolated. (Author)

  14. Correlation of electromagnetic radiation emitted from coal or rock to supporting resistance

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Hui-lin; Wang, En-yuan; Song, Xiao-yan; Zhang, Hong-jie; Li, Zhong-hui [China University of Mining & Technology, Xuzhou (China). School of Safety Engineering

    2009-05-15

    More accurate forecasting of rock burst might be possible from observations of electromagnetic radiation emitted in the mine. We analyzed experimental observations and field data from the Muchengjian coal mine to study the relationship between electromagnetic radiation signal intensity and stress during the fracturing of coal, or rock, and samples under load. The results show that the signal intensity is positively correlated with stress. In addition, we investigated the change in the electromagnetic radiation intensity, the supporting resistance in a real coal mine environment, and the coal or rock stress in the mining area. The data analysis indicates that: (1) electromagnetic radiation intensity can accurately reflect the distribution of stress in the mining area; and, (2) there is a correlation between electromagnetic radiation intensity and supporting resistance. The research has some practical guiding significance for rock burst forecasting and for the prevention of accidents in coal mines. 9 refs., 6 figs.

  15. Attenuation of VHE Gamma Rays by the Milky Way Interstellar Radiation Field

    Energy Technology Data Exchange (ETDEWEB)

    Moskalenko, Igor V.; /Stanford U., HEPL; Porter, Troy A.; /Louisiana State U.; Strong, Andrew W.; /Garching, Max Planck Inst., MPE

    2006-04-19

    The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the energy density of the Galactic interstellar radiation field is higher, particularly in the Galactic center, than previously thought. We have made a calculation of the attenuation of very high energy gamma rays in the Galaxy using this new interstellar radiation field which takes into account its nonuniform spatial and angular distributions. We find that the maximum attenuation occurs around 100 TeV at the level of about 25% for sources located at the Galactic center, and is important for both Galactic and extragalactic sources.

  16. Preservation of yams by gamma radiation | Bansa | Journal of the ...

    African Journals Online (AJOL)

    Loss of yam in storage due to sprouting is very high. There is the need to investigate the possibility of inhibiting the sprouting of local varieties of yams using gamma radiation. The effect of radiation on the storage yams and the functionality of the irradiated yams in the Ghanaian food system was studied. Yams were ...

  17. The induced radioactivity danger parameter for gamma radiation

    International Nuclear Information System (INIS)

    Perry, D.R.

    1985-07-01

    Dosimetric and practical aspects of the induced radioactivity danger parameter, as used for calculating the gamma radiation dose rate near to objects that have been exposed to high energy radiation, are examined. A simplified and more generally applicable method of calculation is proposed, based on energy balance in homogeneous media. The problems of applying this in practice are discussed, and it is shown that corrections are generally small enough to be neglected in many practical applications. Examples of calculations by previous and proposed methods are given. (author)

  18. Isodose mapping of terrestrial gamma radiation dose rate of Selangor state, Kuala Lumpur and Putrajaya, Malaysia

    International Nuclear Information System (INIS)

    Sanusi, M.S.M.; Ramli, A.T.; Gabdo, H.T.; Garba, N.N.; Heryanshah, A.; Wagiran, H.; Said, M.N.

    2014-01-01

    A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h −1 to 500 nGy h −1 . The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h −1 . This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h −1 (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation. - Highlights: • A methodology is presented to reduce terrestrial gamma dose rate field survey. • Geological background of acid intrusive of granitic type has the highest dose rates. • The mean dose rate is 2 times higher than the world average. • Isodose map of terrestrial gamma radiation for Selangor, Kuala Lumpur and Putrajaya was produced

  19. Parameter changes in silicon IMPATT diodes for mm wavelength range exposed to gamma-radiation

    International Nuclear Information System (INIS)

    Shcherbina, L.V.; Torchinskaya, T.V.; Shcherbina, E.S.; Polupan, G.P.

    1999-01-01

    We investigated the p + -n-n + -silicon mesa-diodes fabricated using batch technique whose breakdown voltage was 19±1 V. The exposition of IMPATT diodes to 60 Co gamma-radiation was made in the 10 3 to 10 7 Gy dose range. When the gamma-irradiation dose was increased up to (5-8)*10 5 Gy, then the thermal-generation component of the reverse current was monotonously decreasing. The breakdown voltage remained the same during gamma-irradiation. It was shown experimentally that exposition of diodes to (5-8)*10 5 Gy doses of gamma-irradiation led to some drop of both the number of microplasmas in the avalanche breakdown region and the micro plasma noise level. 60 Co gamma-irradiation in the 10 3 -8*10 5 Gy dose range led also to the growth of the microwave output power P out . The decrease of the micro plasma number in the avalanche breakdown region and Pout growth may be explained if one assumes that gamma-irradiation in the 10 3 - 8*10 5 Gy dose range leads to 'healing' of structural defects in the semiconductor due to their interaction with the radiation-induced point defects. The gamma-irradiation dose increase over 8*10 5 Gy results in a storage of some radiation-induced defects in the IMPATT diode base and electrical parameters of diodes are degrading

  20. Dosimetry of electron and gamma radiation with DL-alanine

    International Nuclear Information System (INIS)

    Costa, Z.M. da; Campos, L.L.

    1996-01-01

    A dosimetric method based on the quantitative determination of stabilised free radicals in irradiated crystalline DL-alanine by electron spin resonance (ESR) spectroscopy was proposed as early in 1962. Since then, alanine dosemeters owing to their unique properties have been investigated by many authors and used in dosimetry of various types of radiation, namely gamma rays, electron and neutrons. Alanine is a simple aminoacid, on irradiation at room temperature predominantly free paramagnetic radicals of the type CH 3 -CH-COOH are produced. This paper reports the application of powder DL-alanine/ESR dosemeter for measurement of absorbed dose of gamma radiation from 60 Co sources and reactor nucleus and electron beams from accelerator. The obtained results give useful information about the instrumental care necessary to obtain the needed overall accuracy in determination of absorbed dose. (author)

  1. Slaughterhouse sewage treatment using gamma radiation - economical feasibility study

    International Nuclear Information System (INIS)

    Melo, Rita; Botelho, M. Luisa; Branco, Joaquim

    2005-01-01

    This paper presents preliminary results of a financial viability study for the implementation of gamma radiation technology on a slaughterhouse wastewater treatment industry. Five scenarios were studied, including the current practice, representing different types of treatments and goals, e.g.: water reuse and/or sludge add value as agriculture fertilizers. Cost-benefit analysis, including the net present value (NPV) of each scenario, was used as a technique to compare the relative value of various strategies. Taking in account that the initial investment is amortized after 20 years, the implementation of Co-60 treatment with 20% water reuse and sludge application as agriculture fertilizers represents the most profitable project with the highest NPV. Therefore, the implementation of gamma radiation technology on a slaughterhouse wastewater treatment industry is not only technically viable as well as economically feasible. (author)

  2. Alarm criteria for the fixed gamma radiation monitoring stations

    International Nuclear Information System (INIS)

    Kjelle, P.E.

    1987-01-01

    For the type of measurement considered here, an alarm based on the dose excess has been shown to be a more certain method of indicating that a true alarm situation exists than an alarm based on the dose-rate exceeding a given dose-rate level. The method offers a number of advantages: Dose-rate levels can be recorded over long periods without any necessity of making manual changes in the alarm level due to seasonal variations in the background level. A relatively low level can be specified without an unnecessary number of false alarms being triggered by gamma-emitting radon daughters. (orig./HP)

  3. Radiation hardness of GaAs sensors against gamma-rays, neutrons and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Šagátová, Andrea, E-mail: andrea.sagatova@stuba.sk [Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovičova 3, 812 19 Bratislava (Slovakia); University Centre of Electron Accelerators, Slovak Medical University, Ku kyselke 497, 911 06 Trenčín (Slovakia); Zaťko, Bohumír; Dubecký, František [Institute of Electrical Engineering, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava (Slovakia); Ly Anh, Tu [Faculty of Applied Science, University of Technology VNU HCM, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City (Viet Nam); Nečas, Vladimír; Sedlačková, Katarína; Pavlovič, Márius [Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovičova 3, 812 19 Bratislava (Slovakia); Fülöp, Marko [University Centre of Electron Accelerators, Slovak Medical University, Ku kyselke 497, 911 06 Trenčín (Slovakia)

    2017-02-15

    Highlights: • Radiation hardness of SI GaAs detectors against gamma-rays, neutrons and electrons was compared. • Good agreement was achieved between the experimental results and displacement damage factor of different types of radiation. • CCE and FWHM first slightly improved (by 1–8%) and just then degraded with the cumulative dose. • An increase of detection efficiency with cumulative dose was observed. - Abstract: Radiation hardness of semi-insulating GaAs detectors against {sup 60}Co gamma-rays, fast neutrons and 5 MeV electrons was compared. Slight improvements in charge collection efficiency (CCE) and energy resolution in FWHM (Full Width at Half Maximum) were observed at low doses with all kinds of radiation followed by their degradation. The effect occurred at a dose of about 10 Gy of neutrons (CCE improved by 1%, FWHM by 5% on average), at 1 kGy of electrons (FWHM decreased by 3% on average) and at 10 kGy of gamma-rays (CCE raised by 5% and FWHM dropped by 8% on average), which is in agreement with the relative displacement damage of the used types of radiation. Gamma-rays of MeV energies are 1000-times less damaging than similar neutrons and electrons about 10-times more damaging than photons. On irradiating the detectors with neutrons and electrons, we observed a global increase in their detection efficiency, which was caused probably by enlargement of the active detector area as a consequence of created radiation defects in the base material. Detectors were still functional after a dose of 1140 kGy of ∼1 MeV photons, 104 kGy of 5 MeV electrons but only up to 0.576 kGy of fast (∼2 to 30 MeV) neutrons.

  4. Origin of the diffuse background gamma radiation

    International Nuclear Information System (INIS)

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

    1974-05-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

  5. Radiation effect on silicon transistors in mixed neutrons-gamma environment

    Science.gov (United States)

    Assaf, J.; Shweikani, R.; Ghazi, N.

    2014-10-01

    The effects of gamma and neutron irradiations on two different types of transistors, Junction Field Effect Transistor (JFET) and Bipolar Junction Transistor (BJT), were investigated. Irradiation was performed using a Syrian research reactor (RR) (Miniature Neutron Source Reactor (MNSR)) and a gamma source (Co-60 cell). For RR irradiation, MCNP code was used to calculate the absorbed dose received by the transistors. The experimental results showed an overall decrease in the gain factors of the transistors after irradiation, and the JFETs were more resistant to the effects of radiation than BJTs. The effect of RR irradiation was also greater than that of gamma source for the same dose, which could be because neutrons could cause more damage than gamma irradiation.

  6. Spectroscopic Study of Radiation around the Leksell Gamma Knife for Room Shielding Applications

    OpenAIRE

    Hubert, Alexis

    2017-01-01

    Any center planning to install a Gamma Knife radiosurgery unit has to provide for an efficient shielding of the treatment room, to protect the patient, the staff and the public, against undesired radiation. The shielding barrier design is controlled by national and international recommendations; the reference documents for gamma ray radiotherapy facilities are the National Council on Radiation Protection and Measurements (NCRP) reports 49 and 151. However, some facts highlighted in this thesi...

  7. Degradation study of Durolon polycarbonate submitted to gamma radiation

    International Nuclear Information System (INIS)

    Miranda, A.; Sciani, V.

    1992-01-01

    The effect of gamma radiation from a cobalt 60 source in the 27000 Durolon polycarbonate irradiated with doses between 0,2 and 1000 kGy at 25 0 C was analyzed. For this reason the samples was submitted to the mechanical assay of tension, deformation and hardness and optical assay of transmittance. The obtained results show a good mechanical stability of the polycarbonate, when it was submitted to gamma irradiation in doses up to 20 kGy. (C.G.C.). 05 refs., 04 figs

  8. Gamma irradiation facilities for radiation tolerance assessment of components and systems at SCK.CEN

    International Nuclear Information System (INIS)

    Coenen, S.; Decreton, M.

    1999-01-01

    This paper presents the different gamma irradiation facilities available at SCK-CEN (Mol, Belgium). With gamma dose rates ranging from 1 Gy/h up to 50 kGy/h, extensive environmental control and on-line instrumentation possibilities, they offer ideal test environments for the radiation tolerance assessment of components and systems for many applications where radiation tolerance is a concern. (authors)

  9. Evaluation of radiation-shielding properties of the composite material

    International Nuclear Information System (INIS)

    Pavlenko, V.I.; Chekashina, N.I.; Yastrebinskij, R.N.; Sokolenko, I.V.; Noskov, A.V.

    2016-01-01

    The paper presents the evaluation of radiation-shielding properties of composite materials with respect to gamma-radiation. As a binder for the synthesis of radiation-shielding composites we used lead boronsilicate glass matrix. As filler we used nanotubular chrysotile filled with lead tungstate PbWO4. It is shown that all the developed composites have good physical-mechanical characteristics, such as compressive strength, thermal stability and can be used as structural materials. On the basis of theoretical calculation we described the graphs of the gamma-quanta linear attenuation coefficient depending on the emitted energy for all investigated composites. We founded high radiation-shielding properties of all the composites on the basis of theoretical and experimental data compared to materials conventionally used in the nuclear industry - iron, concrete, etc

  10. Investigation of gamma-ray fingerprint identifying mechanism for the types of radiation sources

    CERN Document Server

    Liu Su Ping; Gu Dang Chang; Gong-Jian; Hao Fan Hua; Hu Guang Chun

    2002-01-01

    Radiation fingerprints sometimes can be used to label and identify the radiation resources. For instance, in a future nuclear reduction treaty that requires verification of irreversible dismantling of reduced nuclear warheads, the radiation fingerprints of nuclear warheads are expected to play a key role in labelling and identifying the reduced warheads. It would promote the development of nuclear warheads deep-cuts verification technologies if authors start right now some investigations on the issues related to the radiation fingerprints. The author dedicated to the investigation of gamma-ray fingerprint identifying mechanism for the types of radiation resources. The purpose of the identifying mechanism investigation is to find a credible way to tell whether any two gamma-ray spectral fingerprints that are under comparison are radiated from the same resource. The authors created the spectrum pattern comparison (SPC) to study the comparability of the two radiation fingerprints. Guided by the principle of SPC,...

  11. Inhaled 239PuO2 and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

    International Nuclear Information System (INIS)

    Filipy, R.E.; Decker, J.R.; Lai, Y.L.

    1988-08-01

    Rats and beagle dogs were given doses of 60 Co gamma radiation and/or body burdens of 239 PuO 2 within lethal ranges in an experiment to determine and compare morbidity and mortality responses of both species within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell concentrations and by long-term loss of body weight and diminished pulmonary function in animals of both species that survived the acute gamma radiation syndrome. Inhaled plutonium caused a loss of body weight and diminished pulmonary function in both species, but its only effect on blood cell concentrations was lymphocytopenia in dogs. Combined gamma irradiation and plutonium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Plutonium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the long-term effect of plutonium lung burdens in both species. Rats were less sensitive to both kinds of radiation, whether administered alone or in combination. 71 refs., 105 figs., 48 tabs

  12. Effect of gamma radiation on electrical and optical properties of (TeO2)

    Indian Academy of Sciences (India)

    Employing dose dependence of the current, some real-time gamma radiation dosimeters have been prepared, which ... are on world over to investigate the influence of gamma radi- ... Employing thermal evaporation in a vacuum, thin films of.

  13. The split-sting trait in Apis mellifera induced by cobalt 60 gamma radiation

    International Nuclear Information System (INIS)

    Silva, Vera Lucia Maciel

    1993-01-01

    The Split-Sting (SS) trait in honey bees, induced by gamma radiation, was discovered by Soares (1975). Bees with this trait are unable to sting, because the parts that compose the sting are separated. Many studies have been done in order to understand this new mutation. We studied the effect of gamma radiation on induction of the SS trait in feral bee strains. The doses were applied to the phase of larvae of queens with 5 days old. The following results were obtained: all doses of radiation induced the SS trait. There was an increase in the percentage of queens with SS with an increase in radiation dose; the SS trait induced by radiation is probably phenocopy; SS bees were observed in nature; increase of the rate mortality and malformation with an increase in radiation dose. (author)

  14. Radiation graft polymerization of 4- vinylpyridine on polyvinylchloride-films. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kudryavtsev, V.N.; Shapiro, A.; Endrikhovska-Bonamur, A.M.

    1984-01-01

    Radiation graft liquid phase polymerization of 4-vinylpyridine on PVC-films by the method of direct radiation is investigated. The samples are irradiated by Co/sup 60/ ..gamma..-source at 20 deg C and the dose rate of 39 Gy/s for 4-vinylpyridine solutions in methonol, as well as at-78 deg C and dose rate of 1.3 kGy/s for monomer solutions in hexane. Modified polyvinylchloride films with grafted poly-4-vinylpyridine chains are prepared. Being introduced in grafted polyvinylpyridine chains of ion-exchange groups, materials are characterized by good swelling in water and are good to prepare anion-exchange membranes.

  15. Comparative uptake of gamma-emitting fission product nuclides by plants

    International Nuclear Information System (INIS)

    D'souza, T.J.; Mistry, K.B.

    1974-01-01

    The comparative uptake of long-lived gamma-emitting fission product nuclides 106 Ru, 125 Sb, 137 Cs and 144 Ce, present in global fallout from nuclear explosions, by maize (Zea mays L) plants was examined in water culture experiments. Over identical duration of plant growth, the extent of accumulation of the radionuclides in aerial tissues was in the following decreasing order: 137 Cs >, 125 Sb >, 106 Ru > and 144 Ce. In roots, however, the retention of 144 Ce and 106 Ru was greater than that of 137 Cs and 125 Sb. Complementary studies with maize and rice (Oryza sativa L) grown on two contrasting soil types, namely, laterite and black clay loam indicated that 137 Cs uptake by plants was markedly greater than that of the other radionuclides in both soil types. Plant uptake of 106 Ru and 125 Sb was significantly higher than that of 144 Ce in the black soil. In the laterite, however, 144 Ce uptake far exceeded that of 106 Ru and 125 Sb. In general, maize removed higher amounts of the radionuclides than rice from both soil types. (author)

  16. The use of gamma ray data to define the natural radiation environment

    International Nuclear Information System (INIS)

    1990-09-01

    The natural radiation environment is the major source of radiation exposure to man and consists of both internal and external sources. The most significant internal sources are the radioactive elements 40 K and 222 Rn which are taken into the body. The external sources are cosmic rays and naturally occurring radioactive isotopes of the 40 K, 238 U, and 232 Th decay series, some or all of which can be found in the ground, in construction materials, and in the air. This report has been prepared to provide a guide for the use of existing gamma ray survey data to define the natural radiation environment, but will only be concerned with the gamma ray exposure resulting from radiation originating in geological materials. The type of data needed to produce maps are available as a result of airborne, carborne, and ground gamma ray surveys in many parts of the world. Although most of these data were acquired for uranium and other mineral exploration and geological mapping purposes, they can be used to provide background radioactivity information. Standardized survey data can be compiled to produce regional maps of gamma ray air dose rates as well as single radioelement maps. Compilation procedures may use either manual or computer techniques. Although this work will primarily be done as national compilations, it will open the possibility of the compilation of radioelement geochemical maps on a regional and global scale. 48 refs, figs and tabs

  17. A simplified model of the source channel of the Leksell GammaKnife tested with PENELOPE

    OpenAIRE

    Al-Dweri, Feras M. O.; Lallena, Antonio M.; Vilches, Manuel

    2004-01-01

    Monte Carlo simulations using the code PENELOPE have been performed to test a simplified model of the source channel geometry of the Leksell GammaKnife$^{\\circledR}$. The characteristics of the radiation passing through the treatment helmets are analysed in detail. We have found that only primary particles emitted from the source with polar angles smaller than 3$^{\\rm o}$ with respect to the beam axis are relevant for the dosimetry of the Gamma Knife. The photons trajectories reaching the out...

  18. Composting of gamma-radiation disinfected sewage sludge

    International Nuclear Information System (INIS)

    Kawakami, W.; Hashimoto, S.; Watanabe, H.; Nishimura, K.; Watanabe, H.; Ito, H.; Takehisa, M.

    1981-01-01

    The composting of radiation disinfected sewage sludge has been studied since 1978, aiming to present a new process of sludge composting for agricultural uses. This process is composed of two steps: irradiation step to disinfect sludge, and composting step to remove odor and easily decomposable organics in sludge. In this paper, the gamma-irradiation effect on sludge cake and composting condition of irradiated sludge are discussed. (author)

  19. Computed temperature profile in materials exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Tso Chin; Choong, Yap Siew; Seon, Chan Kam

    1987-06-01

    Computed temperature profiles are presented for the materials of lead, steel, concrete and water in curved shells, when they are exposed to gamma radiation. The results are based on the usual simplified theory of thermal conduction with an exponential heat source.

  20. Study of effects gamma radiation linear low density polyethylene (LLDPE) injected

    International Nuclear Information System (INIS)

    Oliveira, Ana Claudia Feitoza de

    2014-01-01

    The use of package sterilization through gamma radiation aim to reduce the microbiological contamination. The linear low density polyethylene (LLDPE) can be obtained by a process in solution, suspension or gaseous phase, depending on the type of the catalyzer used, that can be heterogeneous, or homogeneous, or metallocenes Ziegler-Natta. According to the literature, the gamma radiation presents a high penetration at polymeric materials causing the appearing of scissions, reticulation, and degradation when oxygen presence. This paper were irradiated with 60 Co with 2000 kCi of activity, in presence of air, samples of LLDPE injected. Utilized doses of 5, 10, 20, 50 or 100 kGy, and about 5 kGy.h -1 dose rates, at room temperature. After irradiation, the samples were heated for 60 min at 100 deg C to promote recombination and annihilation of residual radicals. For characterization of PEBLD were used methods; Melt flow index, swelling, gel fraction, Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (DRX), Thermogravimetric Analysis (TG), Dynamic Mechanical Analysis (DMA), rheological measurements, Scanning Electronic Microscopy and mechanical tests to identify the effects or gamma radiation in polyethylene. (author)

  1. Gamma radiation hazard to miners in bituminous coal mines

    International Nuclear Information System (INIS)

    Skubacz, K.

    1986-01-01

    Radiation hazard to miners working in 16 bituminous coal mines was determined by a thermoluminescence method. While the miners exposure to gamma radiation is higher than that of the general population, the yearly dose was never found to exceed 5 mSv in any investigated person. Factors contributing to the estimate of the exposure hazard and the need for individual dose monitoring in mines are discussed in more detail. 3 refs., 4 figs. (author)

  2. Application of Gamma Radiation for Removal of Organic Pollutants from Wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Meguenni, H.; Mahlous, M.; Mansouri, B. [Centre de Recherche Nucléaire d' Alger, 2Bd Frantz Fanon BP-399 Alger (Algeria); Bouchfer, S. [ONA Office National de l’Assainissement, Alger (Algeria)

    2012-07-01

    The study of this research is focused on the possibility of using gamma radiation in order to decrease the concentration of polycyclic aromatic hydrocarbon (PAH) in effluents. The research was initiated with a concentration of 100ppm of synthetic naphthalene aqueous solution submitted to different absorbed doses. The HPLC analysis has shown that the dose of 30kGy degraded 99.96% of the naphthalene molecule. The identification program of NIST library has identified the by-products formed during the radiation process. Concerning the industrial effluent wastewater sample, we opted for analysis by GC-MS before and after gamma irradiation, to monitor the degradation of PAH and other pollutants from the refinery. The results show that in global view, gamma radiation decreases significantly the contaminated level, with the increase of the absorbed dose. In detailed view, the relative content of the naphthalene, 2,7 dimethyl in the effluent sample decreased with the increase of the absorbed dose. At the dose of 6 kGy the molecule was completely degraded. The COD of effluent sample presented a reduction of 58%, when 10 kGy dose was applied. After irradiation a secondary treatment, based on adsorption using a natural adsorbent, has to be applied in order to remove the by-products of radiation degradation, to get a better quality of effluent and consequently improve the environmental condition. (author)

  3. Application of Gamma Radiation for Removal of Organic Pollutants from Wastewater

    International Nuclear Information System (INIS)

    Meguenni, H.; Mahlous, M.; Mansouri, B.; Bouchfer, S.

    2012-01-01

    The study of this research is focused on the possibility of using gamma radiation in order to decrease the concentration of polycyclic aromatic hydrocarbon (PAH) in effluents. The research was initiated with a concentration of 100ppm of synthetic naphthalene aqueous solution submitted to different absorbed doses. The HPLC analysis has shown that the dose of 30kGy degraded 99.96% of the naphthalene molecule. The identification program of NIST library has identified the by-products formed during the radiation process. Concerning the industrial effluent wastewater sample, we opted for analysis by GC-MS before and after gamma irradiation, to monitor the degradation of PAH and other pollutants from the refinery. The results show that in global view, gamma radiation decreases significantly the contaminated level, with the increase of the absorbed dose. In detailed view, the relative content of the naphthalene, 2,7 dimethyl in the effluent sample decreased with the increase of the absorbed dose. At the dose of 6 kGy the molecule was completely degraded. The COD of effluent sample presented a reduction of 58%, when 10 kGy dose was applied. After irradiation a secondary treatment, based on adsorption using a natural adsorbent, has to be applied in order to remove the by-products of radiation degradation, to get a better quality of effluent and consequently improve the environmental condition. (author)

  4. Dose rate on the environment generated by a gamma irradiation plant

    International Nuclear Information System (INIS)

    Mangussi, J.

    2011-01-01

    A model for the absorbed dose rate calculation on the surroundings of a gamma irradiation plant is developed. In such plants, a part of the radiation emitted upwards reach the outdoors. The Compton scatterings on the wall of the exhausting pipes through de plant roof and on the outdoors air are modelled. The absorbed dose rate generated by the scattered radiation reaching the outdoors floor is calculated. The results of the models, to be used for the irradiation plant design and for the environmental studies, are showed on tables and graphics. (author) [es

  5. Non-destructive assay of mechanical components using gamma-rays and thermal neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Erica Silvani; Avelino, Mila R. [PPG-EM/UERJ, R. Sao Francisco Xavier, 524, Maracana - Rio de Janeiro - RJ (Brazil); Almeida, Gevaldo L. de; Souza, Maria Ines S. [IEN/CNEN, Rua Helio de Almeida, 75, Ilha do Fundao, Rio de Janeiro - RJ (Brazil)

    2013-05-06

    This work presents the results obtained in the inspection of several mechanical components through neutron and gamma-ray transmission radiography. The 4.46 Multiplication-Sign 10{sup 5} n.cm{sup -2}.s{sup -1} thermal neutron flux available at the main port of the Argonauta research reactor in Instituto de Engenharia Nuclear has been used as source for the neutron radiographic imaging. The 412 keV {gamma}-ray emitted by {sup 198}Au, also produced in that reactor, has been used as interrogation agent for the gamma radiography. Imaging Plates - IP specifically designed to operate with thermal neutrons or with X-rays have been employed as detectors and storage devices for each of these radiations.

  6. Radiation safety for operators of gamma irradiation plants

    International Nuclear Information System (INIS)

    1989-01-01

    These notes have been prepared by the UK Panel for Gamma and Electron Irradiation with advice from the HSE (Technology Division and Factory and Agricultural Inspectorate) to assist operators of Gamma irradiation plants to comply with the requirements of the Ionising Radiations Regulations (IRR 1985), and other relevant regulations (see below). The process is currently used for the sterilisation of medical devices and in the treatment of plastics materials etc. The Government has proposed that the process should also be permitted for the treatment of foodstuffs, and these notes will also be relevant to any irradiation plants which may be used in the UK for this purpose. (author)

  7. Spectral measurements of gamma radiation streaming through ducts

    International Nuclear Information System (INIS)

    Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

    1979-01-01

    The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

  8. Ultraviolet and gamma-radiation effect on the zymotic characteristics of turnip moth's granules

    Energy Technology Data Exchange (ETDEWEB)

    Khakimova, M A

    1975-01-01

    Virus granules of the winter cutworm (Agrotis segetum Schiff) were used as agents for biological control of this pest of field and vegetable crops. The authors first studied the effect of uv and gamma radiation on granules of the cutworm. A purified suspension of winter moth granules, 0.5 mg of granules per mm/sup 3/, was irradiated with a BUV-15 lamp at a distance of 9 cm from the radiation source. The dose rate was 6.6x10/sup 3/ ergs/cm/sup 2/.sec. The results showed that a uv dose of 71.1x10/sup 6/ ergs/cm/sup 2/ decreased the virulence of the granules by a factor of 3 compared to the original suspension (larval mortality of 27.5%) and a dose of 95x10/sup 6/ ergs/cm/sup 2/ completely inactivated the granules. With gamma radiation (/sup 60/Co or /sup 137/Cs) the inactivating dose was only 21.6x10/sup 5/ rads. The work indicated that cutworm granules are very resistant to uv and gamma radiation.

  9. Radiative decay of the eta-, eta'-mesons in the nonlocal quark model. [eta(eta'). --> gamma gamma. ; eta. -->. pi. /sup +/. pi. /sup -/. gamma. ; eta. -->. pi. /sup 0/2. gamma. ; eta'. -->. rho/sup 0/. gamma. ; eta'. -->. omega gamma. ;. pi. /sup 0/. -->. gamma. e/sup +/e/sup -/; eta(eta'). -->. gamma mu. /sup +/. mu. /sup -/

    Energy Technology Data Exchange (ETDEWEB)

    Efimov, G V; Ivanov, M A; Nogovitsyn, E A [Joint Inst. for Nuclear Research, Dubna (USSR)

    1981-07-01

    P..--> gamma gamma.. (P=..pi../sup 0/, eta, eta'), eta..--> pi../sup +/..pi../sup -/..gamma.., eta..--> pi../sup 0/..gamma gamma.., eta/sup 1/..-->..V..gamma.. (V=rho/sup 0/, ..omega..), p..--> gamma..l/sup +/l/sup -/ (p=..pi../sup 0/, eta, eta') radiation decays are studied for testing the applicability of the non-local quark model for description of the experimental data. The Feynman diagrams of these decays are presented, values of the widths of the Veta..--> gamma gamma.., eta..--> pi../sup +/..pi../sup -/..gamma.., eta..--> pi../sup 0/..gamma gamma.., eta'..--> gamma gamma.., eta'..-->..rho/sup 0/..gamma.., eta'..--> omega gamma.. decays are calculated and given in the form of a table. Calculations are carried out for two values of the eta eta'-crossing angle: THETA=-11 deg and -18 deg. Values of invariant amplitudes of these decays are determined for ..pi../sup 0/..--> gamma..e/sup +/e/sup -/, eta..--> gamma mu../sup +/..mu../sup -/, eta'..--> gamma mu../sup +/..mu../sup -/ decays at THETA=-11 deg and -18 deg. The best agreement with the experimental data is noted to take place at THETA=-11 deg, the determined width of the eta..--> pi../sup 0/..gamma gamma.. decays is underestimated as compared with the experimental one.

  10. Radiation chemical oxidation of propen under the influence of UV- and gamma radiation

    International Nuclear Information System (INIS)

    Litschke, P.I.

    1978-01-01

    The oxidation of propen is studied in the liquid state under the influence of electromagnetic radiation using hydrogenperoxide, organic hydroperoxides and oxygen. In this investigation propen oxide is of main interest. The study of systems with oxygen is based on the concept that the formation of hydroperoxide from organic oxygen compounds is enhanced by irradiation, thus favouring an in situ method for expoxidation with hydroperoxides. The influence of UV-radiation from high and low pressure mercury discharge lamps and 60 Co gamma radiation has been studied as well as the effect of solvents and catalysers, which are resolved in the system. (orig./WBU) [de

  11. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Science.gov (United States)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  12. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Pardo, M.E. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico)], E-mail: memp@nuclear.inin.mx; Ley-Chavez, E. [ISSEMYM Toluca, Mexico DF (Mexico); Reyes-Frias, M.L. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico); Rodriguez-Ferreyra, P. [Hospital ' Dr. Nicolas San Juan' , Toluca, Mexico DF (Mexico); Vazquez-Maya, L.; Salazar, M.A. [Hospital General de Mexico, Mexico DF (Mexico)

    2007-11-15

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  13. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    International Nuclear Information System (INIS)

    Martinez-Pardo, M.E.; Ley-Chavez, E.; Reyes-Frias, M.L.; Rodriguez-Ferreyra, P.; Vazquez-Maya, L.; Salazar, M.A.

    2007-01-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders

  14. PKI, Gamma Radiation Reactor Shielding Calculation by Point-Kernel Method

    International Nuclear Information System (INIS)

    Li Chunhuai; Zhang Liwu; Zhang Yuqin; Zhang Chuanxu; Niu Xihua

    1990-01-01

    1 - Description of program or function: This code calculates radiation shielding problem of gamma-ray in geometric space. 2 - Method of solution: PKI uses a point kernel integration technique, describes radiation shielding geometric space by using geometric space configuration method and coordinate conversion, and makes use of calculation result of reactor primary shielding and flow regularity in loop system for coolant

  15. Effect of gamma radiation and ethylene oxide on neomycin sulphate

    International Nuclear Information System (INIS)

    Gopal, N.G.S.; Rajagopalan, S.

    1981-01-01

    Neomycin is affected by ethylene oxide but not by gamma radiation (2.75 Mrad). Differential refractometry is more advantageous in quantitating neomycin A, B and C than is the ninhydrin method. (Auth.)

  16. KEEPING QUALITY OF YOGHURT FORTIFIED WITH WHEY PROTEIN CONCENTRATE AND SKIM MILK POWDER BY USING GAMMA RADIATION

    International Nuclear Information System (INIS)

    ANWAR, M.M.; YOUSEF, E.T.; ABD-ELHADI, Y.A.

    2009-01-01

    Four batches of yoghurt were prepared to study the effect of gamma radiation doses on the quality of yoghurt. All samples were prepared by the addition of 1.5% whey proteins concentrate and 1.5% skim milk powder (from buffalo's milk). The four yoghurt batches were treated with gamma radiation at doses of 0, 1, 2 and 3 kGy, respectively. All treated yoghurt was kept in a refrigerator at 7 0C and samples were examined every three days for chemical, microbiological and sensory evaluation. Control yoghurt that was not exposed to gamma radiation exhibited the highest total bacterial counts and lactic acid bacterial counts after 6 day from storage while the irradiated samples counts were decreased and this decrease was proportional to the dose of gamma radiation used. Applying gamma radiation improved the keeping quality of yoghurt, which provide that control yoghurt was still accepted till the 12 th day while the samples irradiated with 1, 2 and 3 kGy were still accepted till the 15, 24 and 30 days, respectively. Coliform bacteria were not detected in all yoghurt treatment and there were non-significant differences among yoghurt treatments considering the chemical composition. Therefore, gamma irradiation could be recommended for both increasing the shelf-life of yoghurt and enhance its overall quality.

  17. Effect of gamma radiation dose and sensitizer on the physical properties of irradiated natural rubber latex

    International Nuclear Information System (INIS)

    Komgrit, R.; Thawat, C.; B, Tripob; Wirach, T.

    2009-07-01

    Full text: The vulcanization of natural rubber latex can be induced by gamma radiation, which enhances cross-linking within the rubber matrix. The purpose of this research is to investigate the effect of gamma radiation dose and sensitizers on the physical properties of irradiated natural rubber. Three sensitizers n-butyl acrylate (n-B A), tetrachloroethylene (C 2 Cl 4 ) and trichloromethane (CHCl 3 ) were mixed with natural rubber latex before irradiation with gamma ray dose varied from 14 to 22 kGy. Results showed that the mixture of three sensitizers with specific ratios effectively induced the cross-linking of natural rubber latex. The cross-linking ratio and improved physical properties increased with increasing gamma dose. Therefore, the mixture ratios of n-B A, C 2 Cl 4 and CHCl 3 have shown to be a critical parameter in the vulcanization of natural rubber latex by gamma radiation

  18. Large arrays of discrete ionizing radiation detectors multiplexed using fluorescent optical converters

    International Nuclear Information System (INIS)

    Koslow, E.E.; Edelman, R.R.

    1985-01-01

    This invention provides a radiation imaging system employing arrays of scintillators. An object of the invention is to produce a detector with high spatial resolution, high gamma-photon absorption efficiency, excellent source and detector scatter rejection, and utilizing low-cost solid state opto-electronic devices. In one embodiment, it provides a radiation detection and conversion apparatus having an array of optically isolated radiation sensitive elements that emit optical radiation upon absorption of ionizing radiation. An array of channels, comprising a material that absorbs and traps the radiation emitted and transports it or radiation that has been shifted to longer wavelengths, is placed near the radiation-sensitive elements. Electro-optical detectors that convert the transported radiation into electrical signals are coupled to the channels. The activation of one of the electro-optical devices by radiation from one of the channels indicates that at least one of the radiation-sensitive elements near that channel has absorbed a quantity of radiation

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

    International Nuclear Information System (INIS)

    Santos, Marcio Ramatiz L.; Arthur, Valter; Salgado, Jocelem M.; Spoto, Marta H. Fillet; Canniatti-Brazaca, Solange G.

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  1. Observations and numerical studies of gamma-ray emission in colliding-wind binaries

    International Nuclear Information System (INIS)

    Reitberger, K.

    2014-01-01

    Massive stars in binary systems have long been regarded as potential sources of high-energy gamma rays. The emission is thought to arise in the region where the stellar winds collide, thereby producing accelerated particles which subsequently emit gamma rays.This scenario is supported by observations with the Fermi Large Area Telescope presented in this thesis. To address the underlying emission mechanisms in a quantitative way, numerical simulations that incorporate hydrodynamics, the acceleration of charged particles as well as the subsequent gamma-ray emission were found to be needed.This thesis presents the analysis of a high-energy gamma-ray source and its identification with the particle-accelerating colliding-wind binary system Eta Carinae. In order to go beyond the present understanding of such objects, this work provides detailed description of a new 3D-hydrodynamical model, which incorporates the line-driven acceleration of the winds, gravity, orbital motion and the radiative cooling of the shocked plasma, as well as the diffusive shock acceleration of charged particles in the wind collision region. In a subsequent step we simulate and study the resulting gamma-ray emission via relativistic bremsstrahlung, anisotropic inverse Compton radiation and neutral pion decay. (author) [de

  2. Environmental gamma radiation measurement in District Swat (Pakistan))

    International Nuclear Information System (INIS)

    Jabbar, T.; Khan, K.; Akhter, P.; Jabbar, A.; Subhani, M.S.

    2008-01-01

    External exposure to environmental gamma ray sources is an important component of exposure to the public. A survey was carried out to determine activity concentration levels and associated doses from 226 Ra, 232 Th, 40 K and 137 Cs by means of high-resolution gamma ray spectrometry in the Swat district, famous for tourism. The mean concentrations for 226 Ra, 232 Th and 40 K were found to be 50.4 ± 0.7, 34.8 ± 0.7 and 434.5 ± 7.4 Bq kg -1 , respectively, in soil samples, which are slightly more than the world average values. However, 137 Cs was only found in the soil sample of Barikot with an activity concentration of 34 ± 1.2 Bq kg -1 . Only 40 K was determined in vegetation samples with an average activity of 172.2 ± 1.7 Bq kg -1 , whereas in water samples, all radionuclides were found below lower limits of detection. The radium equivalent activity in all soil samples is lower than the limit set in the Organisation for Economic Cooperation and Development report (370 Bq kg -1 ). The value of the external exposure dose has been determined from the content of these radionuclides in soil. The average terrestrial gamma air absorbed dose rate was observed to be 62.4 nGy h -1 , which yields an annual effective dose of 0.08 mSv. The average value of the annual effective dose lies close to the global range of outdoor radiation exposure given in United Nations Scientific Committee on the Effects of Atomic Radiation. However, the main component of the radiation dose to the population residing in the study area arises from cosmic ray due to high altitude. (authors)

  3. Quality Of Starking Apples After Exposure To Gamma Radiation As A Quarantine Treatment

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F.; Al-Bachir, M.

    2004-01-01

    Starking apples approaching physiological maturity were exposed, immediately after harvest, to gamma radiation doses ranging from 100 to 400 Gy. The irradiated fruit were stored for six months in a cold storage facility at 1±1 deg. C and 90±5 % RH. Effects of gamma radiation on weight loss, fruit firmness, pH of fruit juice, fruit taste, color and visible injuries were evaluated. The results showed that gamma irradiation increased weight loss, particularly in the first 45 days of storage. Doses higher than 200 Gy, on the other hand, reduced apple firmness after 45 days of storage while a 400 Gy dose decreased fruit pH immediately after irradiation. (Authors)

  4. Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Silva Filho, Elias

    1999-01-01

    The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

  5. Continuum radiation emitted from transition metals under ion bombardment

    International Nuclear Information System (INIS)

    El Boujlaidi, A.; Kaddouri, A.; Ait El Fqih, M.; Hammoum, K.; Aouchiche, H.

    2012-01-01

    Optical emission of transition metals has been studied during 5 keV Kr + ions bombardment within and without oxygen atmosphere in the colliding chamber. The observed spectra consist of a series of discrete lines superimposed on a broad continuum. Generally, the emission intensity was influenced by the presence of oxygen giving rise to transient effects as well as to an increase in the line intensity. The behaviours of spectral lines were successfully explained in term of electron-transfer process between the excited sputtered atom and the solid surface. In this work, we have focused our study on the continuous radiation emitted during ion bombardment. The experimental results suggest that the continuum emission depends on the nature of metal and very probably related to its electronic structure. The collective deactivation of 3d-shell electrons appears to play a role in the emission of this radiation. The observed enhancement in the presence of oxygen is probably due to a significant contribution of the oxide molecules. (authors)

  6. The Study of Radiation of Gamma-Ray Background at Sedimentology Laboratorium, P3TIR, BATAN, Using Gamma Spectrometry

    International Nuclear Information System (INIS)

    Lubis, Ali Arman; Aliyanta, Barokah; Darman

    2002-01-01

    The measurement of background radiation of gamma-ray has been done at Sedimentology Laboratory, SDAL building, P3TIR, BATAN using gamma spectrometer. The measurement was done without shielding with the range of energy between 50 keV and 1500 keV. The identified radiations are coming from environmental radionuclide and man-made radionuclide as well with 32 energy peaks. The environmental radionuclides are from Uranium series, Thorium series, and 4 0 K having dose rate of 12.510 ± O.980, 36.408 ± 3.243, 9.455 ±O.016 n Sv/day, respectively, whilst man-made radionuclide is 6 O C o having dose rate of O.136 ±O.078 n Sv/day

  7. Some gamma radiation (60Co) effects on Chrysomya megacephala (Fabricius, 1794) (Diptira-Calliphoridae)

    International Nuclear Information System (INIS)

    Garcia, C.R.

    1987-03-01

    The effect of different gama radiation ( 60 Co) doses on Chrysomya megcephala (Fabricius) have been studied under laboratory conditions, in the Entomology Section of Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP, Brasil. The insects were collected close to sucking animals brooding areas, identified and reared on artificial diet, being kept in a temperature (26 +- 2 0 C) and humidity (66 +- 9%) controlled room, with 12L:12D photopheriod. A Gammabeam type 650 Cobalt-60 gamma irradiation source was used, with 28, 196x10 10 Bq activity at the beginning of the experiment. The pupae were submitted to increasing gamma radiation doses. To determine lethal doses, treatments were carried out at four different ages and to determine the sterilizing doses two-three day pupae were used. It was noted pupae radiosensitivity decreased with age, LD 50 varying from 14 - 513 Gy. The sterilizing dose for males was 40 Gy and for females 30 Gy. During the individuals life cycle, it was noted that there was a decrease in life expectancy (e x o ) of adults when the gamma radiation dose was increased. Treated males were more sensitive than females (Crossed with ''normals''), there occurring a marked reduction in the number of eggs and their viability when the used gamma radiation dose was increased. (author) [pt

  8. Gamma-irradiated onions as a biological indicator of radiation dose

    International Nuclear Information System (INIS)

    Vaijapurkar, S.G.; Agarwal, Deepshikha; Chaudhuri, S.K.; Ram Senwar, Kana; Bhatnagar, P.K.

    2001-01-01

    Post-irradiation identification and dose estimation are required to assess the radiation-induced effects on living things in any nuclear emergency. In this study, radiation-induced morphological/cytological changes i.e., number of root formation and its length, shooting length, reduction in mitotic index, micronuclei formation and chromosomal aberrations in the root tip cells of gamma-irradiated onions at lower doses (50-2000 cGy) are reported. The capabilities of this biological species to store the radiation-induced information are also studied

  9. Development of aerial gamma radiation survey system, 4

    International Nuclear Information System (INIS)

    Saito, Kimiaki; Nagaoka, Toshi; Sakamoto, Ryuichi; Tsutsumi, Masahiro; Moriuchi, Shigeru

    1985-02-01

    Field experiments have been performed by JAERI since 1982 to obtain fundamental data required for development of aerial radiation survey system. In order to supplement the fundamental radiation data, theoretical calculations have been carried out. The utilized Monte Carlo transport program was verified by simulative calculations of the field experiments, and characteristics data on environmental gamma rays have been accumulated. In this report, the field experiments in 1981 and 1982 were simulated making use of the Monte Carlo transport calculation code YURI developed in JAERI. Comparisons were made between experimental and calculated results for exposure rate and flux density originated from terrestrial sources, and from a point source at height of 2.5 m above the ground. Good agreements between the data verified the transport program. As fundamental characteristics data on environmental gamma rays, spatial distributions of exposure, fluence, energy spectra, angular spectra and average energy were reported and discussed, for terrestrial sources of 40 K, 232 Th-series and 238 U-series, for a plane source on the ground and for a point source at 2.5 m above the ground. (author)

  10. External exposure from gamma radiation in uranium mines

    International Nuclear Information System (INIS)

    Thomson, J.E.

    1982-01-01

    Radiation doses received by workers in a high ore grade uranium mine are compared to those of other radiation workers and the need to be able to calculate the exposure rate from an ore body is indicated. The uranium-238 decay chain is presented and particular reference is made to the main gamma emitters and secular equilibrium of the members of the chain. Difficulties in dealing with a self attenuating volume source, in which scattering is important, are pointed out and traditional methods of solution are mentioned. It is shown that in the special case of an infinite ore body a simple solution may be obtained using the energy conservation principle. A straightforward method for calculating the exposure rate from an arbitrarily shaped ore body is given and corrections due to air attenuation, different soil types and possible lack of secular equilibrium are dealt with. The gamma ray spectrum from the ore is discussed with specific reference to the selection of suitable exposure monitors and the calculation of transmission through shields

  11. Gamma radiation inside closed volumes with thin irradiating walls

    International Nuclear Information System (INIS)

    Karpov, V.I.

    1978-01-01

    The dose rate of gamma radiation inside a parallelepiped with thin radiating walls was calculated. The calculation was based on determining the dose rate from a rectangular plate and subsequently summing the dose rates from all the parallelepiped walls. The dose rate from the rectangular plate was calculated by reducing it to an equivalent plate of infinite length and certain fixed width. When the radiators had constant surface density, the dose rate in the geometric centre of volumes having the form of a parallelepiped was shown to have the least value in the case when the parallelepiped degenerates to a cube

  12. Mobility of gamma-emitting fission products in typical black and laterite soils

    International Nuclear Information System (INIS)

    D'Souza, T.J.; Mistry, K.B.

    1981-01-01

    Studies on the movement of the gamma-emitting fission products 106 Ru, 125 Sb, 137 Cs and 144 Ce, surface deposited on columns of the black and laterite soils revealed that the mobility of these nuclides in the two soils depended mainly on the ionic form of the nuclide, soil reaction and predominant clay mineral type in the soil. Results showed a rapid breakthrough of 106 Ru in the black soil and considerable migration to the lower layers in the laterite soil on leaching with rain water, or moderately high calcium or sodium irrigation waters. While near complete fixation of 144 Ce and 137 Cs in the top contaminated layer of both soils was observed, a slight movement of 125 Sb only in the black soil was noticed. Incorporation of organic matter had no effects on the movement of fission products in both soil types, whereas ethylenediaminetraacetic acid (EDTA) induced variable movement of the different radionuclides in the two soil types. (author)

  13. Estimation of neutron energy distributions from prompt gamma emissions

    Science.gov (United States)

    Panikkath, Priyada; Udupi, Ashwini; Sarkar, P. K.

    2017-11-01

    A technique of estimating the incident neutron energy distribution from emitted prompt gamma intensities from a system exposed to neutrons is presented. The emitted prompt gamma intensities or the measured photo peaks in a gamma detector are related to the incident neutron energy distribution through a convolution of the response of the system generating the prompt gammas to mono-energetic neutrons. Presently, the system studied is a cylinder of high density polyethylene (HDPE) placed inside another cylinder of borated HDPE (BHDPE) having an outer Pb-cover and exposed to neutrons. The emitted five prompt gamma peaks from hydrogen, boron, carbon and lead can be utilized to unfold the incident neutron energy distribution as an under-determined deconvolution problem. Such an under-determined set of equations are solved using the genetic algorithm based Monte Carlo de-convolution code GAMCD. Feasibility of the proposed technique is demonstrated theoretically using the Monte Carlo calculated response matrix and intensities of emitted prompt gammas from the Pb-covered BHDPE-HDPE system in the case of several incident neutron spectra spanning different energy ranges.

  14. Effects of gamma radiation on commercial operational amplifiers

    International Nuclear Information System (INIS)

    Claro, Luiz H.; Santos, Jose A. dos

    2009-01-01

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

  15. INFLUENCE OF INCUBATION TIME, GAMMA RAYS AND ELECTRON BEAM ON RADIATION RESISTANCE OF SOME SELECTED PATHOGENS

    International Nuclear Information System (INIS)

    EL-HIFNAWI, H.N.; EL-TABLAWY, S.Y.

    2009-01-01

    The effect of different growth phases on the radiation resistance, antibiotic susceptibility and pathogenicity of certain selected pathogens (Escherichia coli, Candida albicans and Staphylococcus aureus) was studied in mice. The obtained results showed that Escherichia coli was slightly more resistant to gamma radiation in 18 h than 24 h or 48 h but it was relatively more resistant to electron beam in 24 h and 48 h than 18 h. Candida albicans showed radiation resistance nearly the same in all incubation times in the case of gamma radiation while for electron beam, its radiation resistance was slightly more in 24 h and 48 h than in 18 h. On the other hand, Staphylococcus aureus recorded much more resistance to gamma radiation in the 48 h than in 24 h or 18 h whereas in the case of electron beam, it was slightly more resistant in 18 h than in 24 h and 48 h.The antibiotic susceptibility of Escherichia coli reported that the exposure to gamma radiation at 3 kGy and electron beam at 6 kGy increase the susceptibility to the nalidixic acid and nitrofurantoin. When Candida albicans was exposed to 3 kGy gamma radiation and 6 kGy electron beam, the same sensitivity to nystatin was observed in comparison with the unexposed one while the sensitivity of Staphylococcus aureus to some antibiotics (amoxicillin, nitrofurantoin and tetracycline) was decreased after exposure to gamma radiation at 0.75 and 2 kGy and electron beam at 6 kGy, but for other antibiotics (trimethoprim/ sulfamethoxazole), the sensitivity was increased at 6 kGy electron beam.The lethality percent recorded after the oral ingestion of the mice with the unexposed Escherichia coli and Candida albicans were 25% and 100%, respectively, and for 6 kGy exposure to electron beam was 0% . The cotaneous disease and abscesses caused by the intradermal injection of the mice with unexposed Staphylococcus aureus was 75% and for 6 kGy exposure to electron beam was 25%.

  16. Mobile robot prototype detector of gamma radiation

    International Nuclear Information System (INIS)

    Vazquez C, R.M.; Duran V, M. D.; Jardon M, C. I.

    2014-10-01

    In this paper the technological development of a mobile robot prototype detector of gamma radiation is shown. This prototype has been developed for the purpose of algorithms implementation for the applications of terrestrial radiation monitoring of exposed sources, search for missing radioactive sources, identification and delineation of radioactive contamination areas and distribution maps generating of radioactive exposure. Mobile robot detector of radiation is an experimental technology development platform to operate in laboratory environment or flat floor facilities. The prototype integrates a driving section of differential configuration robot on wheels, a support mechanism and rotation of shielded detector, actuator controller cards, acquisition and processing of sensor data, detection algorithms programming and control actuators, data recording (Data Logger) and data transmission in wireless way. The robot in this first phase is remotely operated in wireless way with a range of approximately 150 m line of sight and can extend that range to 300 m or more with the use of signal repeaters. The gamma radiation detection is performed using a Geiger detector shielded. Scan detection is performed at various time sampling periods and diverse positions of discrete or continuous angular orientation on the horizon. The captured data are geographical coordinates of robot GPS (latitude and longitude), orientation angle of shield, counting by sampling time, date, hours, minutes and seconds. The data is saved in a file in the Micro Sd memory on the robot. They are also sent in wireless way by an X Bee card to a remote station that receives for their online monitoring on a laptop through an acquisition program by serial port on Mat Lab. Additionally a voice synthesizing card with a horn, both in the robot, periodically pronounced in Spanish, data length, latitude, orientation angle of shield and detected accounts. (Author)

  17. Detection of the strange bodies on the conveyor belt using gamma radiation technique

    International Nuclear Information System (INIS)

    Barna, A.; Ochiana, G.; Oncescu, M.

    1990-01-01

    The aim of this paper is to present a method for the computation of the activity of a gamma radiation source used in a radiometric assembly designed to detect the strange bodies (iron, stone or wood-made granules) within the textile material on the conveyor belt. The mathematical modelling method based on the Monte Carlo procedure has been used, with different values of the errors of types I and II; the investigation method is the transmission of gamma radiations. (Author)

  18. Evaluation of gamma radiation effects on stationary phases using gas chromatografy

    International Nuclear Information System (INIS)

    Basso, M.A.; Collins, K.E.; Collins, C.H.

    1988-01-01

    The overall objetive of this project is a thorough study of the effect of gamma radiation on supported stationary phases used in packed-column gas chromatography. The phases studied were SP-2100 on Supelcoport and SE-30 on Chromsorb W. The fases were irradiated with cobalt-60 gamma rays to various doses and subsequently subjected to tests of extractability, termal stability and efficiency as a chromatographic column packing. Extraction tests indicate that low doses of radiation are sufficient to produce significant immobilization of these polymethylsilicones; that is, to produce chemical bonds between different polymer chains or between the stationary phase and the support. Thermal stability is also increased. The values calculated for the number of theoretical plates (n) and resolution (Rsub (s)) after analysis of four synthetic mixtures of organic compounds also increase, in most cases, indicating that the gamma irradiation has positively altered the behavior of these stationary phases. (author) [pt

  19. Mango conservation, Mangifera indica L., haden variety by gamma radiation

    International Nuclear Information System (INIS)

    Domarco, R.E.

    1989-02-01

    This paper evaluates the chemical characteristics and the mangoes sensorial quality after treatments with different doses of gamma radiation and during a period of storage, with constant conditions of temperature and relative humidity. (author)

  20. The use of gamma radiation in fluid flow measurements

    International Nuclear Information System (INIS)

    Tjugum, S.A.; Johansen, G.A.

    2000-01-01

    The use of gamma radiation in densitometry measurements is a well known principle. These measurements are often used in the oil industry where there is a need for finding the gas fraction of an oil/water/gas flow. The traditional gamma densitometer has a simple construction, where the measured parameter is the attenuation of a single gamma beam. High reliability, robustness and the clamp-on possibility are advantages that this type of instruments offer. More information can be found by studying how radiation is scattered and absorbed by matter. This information is needed in new multiphase flow meters. Problems to be solved in these instruments are how to find volume fractions of more than two components, how to handle different flow regimes in non-homogeneous flow, and how to do measurements independent of the salinity of the water. The new technology involves multi-energy, multi-mode and multi-sensor systems. At the University of Bergen the focus has been on how to do flow regime and salinity independent measurements by using multi-sensor and multi-mode systems. This paper gives an overview of the different techniques, and presents the latest results within this field of research at the University of Bergen. (author)