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Sample records for gamma-ray irradiated elastomer

  1. Detecting onset of chain scission and crosslinking of gamma-ray irradiated elastomer surfaces using frictional force microscopy

    OpenAIRE

    Banerjee, S.(); Sinha, N. K.; Gayathri, N; Ponraju, D; Dash, S.; Tyagi, A.K.; Raj, Baldev

    2005-01-01

    We report here that atomic force microscope (AFM) in frictional force mode can be used to detect onset of chain scission and crosslinking in polymeric and macromolecular samples upon irradiation. A systematic investigation to detect chain scission and crosslinking of two elastomers: (1) Ethylene-propylene-diene monomer rubber (EPDM) and (2) Fluorocarbon rubber (FKM) upon gamma-ray irradiation has been carried out using frictional force microscopy (FFM). From the AFM results ...

  2. Detecting onset of chain scission and crosslinking of gamma-ray irradiated elastomer surfaces using frictional force microscopy

    CERN Document Server

    Banerjee, S; Gayathri, N; Ponraju, D; Dash, S; Tyagi, A K; Raj, B; Raj, Baldev

    2005-01-01

    We report here that atomic force microscope (AFM) in frictional force mode can be used to detect onset of chain scission and crosslinking in polymeric and macromolecular samples upon irradiation. A systematic investigation to detect chain scission and crosslinking of two elastomers: (1) Ethylene-propylene-diene monomer rubber (EPDM) and (2) Fluorocarbon rubber (FKM) upon gamma-ray irradiation has been carried out using frictional force microscopy (FFM). From the AFM results we observed that both the elastomers show a systematic smoothening of its surfaces, as the gamma-ray dose rate increases. However, the frictional property studied using FFM of the sample surfaces show an initial increase and then a decrease as a function of dose rate. This behavior of increase in its frictional property has been attributed to the onset of chain scission and the subsequent decrease in friction has been attributed to the onset of crosslinking of the polymer chains. The evaluated qualitative and semi-quantitative changes obse...

  3. Gamma-ray spectroscopy on irradiated fuel rods

    International Nuclear Information System (INIS)

    The recording of gamma-ray spectra along an irradiated fuel rod allows the fission products to be qualitatively and quantitatively examined. Among all nondestructive examinations performed on irradiated fuel rods by gamma-ray spectroscopy, the most comprehensive one is the average burnup measurement, which is quantitative. Moreover, burnup measurements by means of gamma-ray spectroscopy are less time-consuming and waste-generating than burnup measurements by radiochemical, destructive methods. This work presents the theoretical foundations and experimental techniques necessary to measure, using nondestructive gamma-ray spectroscopy, the average burnup of irradiated fuel rods in a laboratory equipped with hot cells. (author)

  4. Gamma-ray spectroscopy on irradiated fuel rods

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis Antonio Albiac [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear], e-mail: laaterre@ipen.br

    2009-07-01

    The recording of gamma-ray spectra along an irradiated fuel rod allows the fission products to be qualitatively and quantitatively examined. Among all nondestructive examinations performed on irradiated fuel rods by gamma-ray spectroscopy, the most comprehensive one is the average burnup measurement, which is quantitative. Moreover, burnup measurements by means of gamma-ray spectroscopy are less time-consuming and waste-generating than burnup measurements by radiochemical, destructive methods. This work presents the theoretical foundations and experimental techniques necessary to measure, using nondestructive gamma-ray spectroscopy, the average burnup of irradiated fuel rods in a laboratory equipped with hot cells. (author)

  5. Operating experience with gamma ray irradiators

    International Nuclear Information System (INIS)

    The experience of Atomic Energy of Canada, Limited (AECL) with radioisotopes dates back to the mid-1940s when radium was marketed for medical purposes. Cobalt-60 came on the scene in 1949 and within a few years a thriving business in cancer teletherapy machines and research irradiators was developed. AECL's first full-scale cobalt-60 gamma ray sterilizer for medical products was installed in 1964. AECL now has over 50 plants and 30 million curies in service around the world. Sixteen years of design experience in cobalt-60 sources, radiation shielding, safety interlock systems, and source pass mechanisms have made gamma irradiators safe, reliable, and easy to operate. This proven technology is being applied in promising new fields such as sludge treatment and food preservation. Cesium-137 is expected to be extensively utilized as the gamma radiation source for these applications

  6. Effects of gamma ray irradiation on sensitivity of photochromic glasses

    International Nuclear Information System (INIS)

    Photochromic glasses exposed to certain amount of gamma rays in advance of heat treatment show much higher photosensitivity than non-irradiated glasses. It was clarified that the crystal size of AgCl formed in the glass during the heat treatment shifted smaller, and that the number of the crystals in unit volume increased with increasing gamma irradiation dose. Size and number density of the AgCl crystals in the sample glasses are observed by electron microscope and X-ray diffraction method. The effects of gamma ray irradiation are possibly explained that gamma ray produces nuclei, each of which grows into AgCl crystal during the subsequent heat treatment. Photoabsorption spectrum of each photochromic glass sample exposed to visible light was observed, and it shows that the wavelength of absorption peak depends on gamma ray irradiation dose. (auth.)

  7. Inactivation of citrus tristeza virus by gamma ray irradiation

    International Nuclear Information System (INIS)

    The total exposure of gamma ray and the intensity of gamma ray per hour for the inactivation of citrus tristeza virus (CTV) and also the effect on citrus tissues are described. The budwoods of Morita navel orange infected with a severe seedling-yellow strain of CTV were irradiated with gamma ray from a 60Co source for 20 -- 52 hours. The buds or small tissue pieces of the irradiated budwoods were subsequently grafted onto Mexcan lime. CTV was easily inactivated by the irradiation from 10 to 18 kR for from 20 to 52 hours. The higher the total exposure, the higher the rate of inactivation. The CTV in the budwoods was almost inactivated after the irradiation with 20 kR. When the total exposure to gamma ray on budwoods was the same, CTV was more efficiently inactivated by the irradiation for long period with low intensity of gamma ray per hour than that for short period with high intensity per hour. Gamma ray irradiation was effective to eliminate CTV from citrus tissues. (Mori, K.)

  8. Inactivation of citrus tristeza virus by gamma ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ieki, Hiroyuki; Yamaguchi, Akira

    1984-12-01

    The total exposure of gamma ray and the intensity of gamma ray per hour for the inactivation of citrus tristeza virus (CTV) and also the effect on citrus tissues are described. The budwoods of Morita navel orange infected with a severe seedling-yellow strain of CTV were irradiated with gamma ray from a /sup 60/Co source for 20 - 52 hours. The buds or small tissue pieces of the irradiated budwoods were subsequently grafted onto Mexcan lime. CTV was easily inactivated by the irradiation from 10 to 18 kR for from 20 to 52 hours. The higher the total exposure, the higher the rate of inactivation. The CTV in the budwoods was almost inactivated after the irradiation with 20 kR. When the total exposure to gamma ray on budwoods was the same, CTV was more efficiently inactivated by the irradiation for long period with low intensity of gamma ray per hour than that for short period with high intensity per hour. Gamma ray irradiation was effective to eliminate CTV from citrus tissues. (Mori, K.).

  9. Gamma ray irradiation to semi-purified diet

    International Nuclear Information System (INIS)

    Semi-purified diet containing 10% soybean oil was irradiated with gamma rays at levels of 0.6, 3 and 6 Mrad and was fed to chicks. Crude fat contents of the diets decreased and a considerable amount of peroxide was formed with high doses of irradiation. Feed consumption and feed efficiency of the highly irradiated diets were less than those of control. Metabolizable energy and digestibility of the diets, especially of fat, were decreased with the irradiation. The chicks fed with irradiated diets showed marked dilatation of the small intestine and the liver, and their erythrocytes were more fragile than those of control. The same phenomena were found with the chicks fed the diet containing the oil highly oxidized by autoxidation. Irradiation of the diet excluding oil showed little effect on the growth of chicks. It was considered that these phenomena were caused by the peroxide or other oxidation products of fat which were formed with gamma ray irradiation. (auth.)

  10. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Lambertin, D., E-mail: david.lambertin@cea.fr [CEA, DEN, DTCD/SPDE/LP2C, F-30207 Bagnols-sur-Cèze (France); Boher, C. [CEA, DEN, DTCD/SPDE/LP2C, F-30207 Bagnols-sur-Cèze (France); Dannoux-Papin, A. [CEA, DEN, DTCD/SPDE/LCFI, F-30207 Bagnols-sur-Cèze (France); Galliez, K.; Rooses, A.; Frizon, F. [CEA, DEN, DTCD/SPDE/LP2C, F-30207 Bagnols-sur-Cèze (France)

    2013-11-15

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with {sup 60}Co sources up to 1000 kGy. Various Na-geopolymer with three H{sub 2}O/Na{sub 2}O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation.

  11. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    International Nuclear Information System (INIS)

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with 60Co sources up to 1000 kGy. Various Na-geopolymer with three H2O/Na2O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation

  12. Influence of gamma ray irradiation on metakaolin based sodium geopolymer

    Science.gov (United States)

    Lambertin, D.; Boher, C.; Dannoux-Papin, A.; Galliez, K.; Rooses, A.; Frizon, F.

    2013-11-01

    Effects of gamma irradiation on metakaolin based Na-geopolymer have been investigated by external irradiation. The experiments were carried out in a gamma irradiator with 60Co sources up to 1000 kGy. Various Na-geopolymer with three H2O/Na2O ratios have been studied in terms of hydrogen radiolytic yield. The results show that hydrogen production increases linearly with water content. Gamma irradiation effects on Na-geopolymer microstructure have been investigated with porosity measurements and X-ray pair distribution function analysis. A change of pore size distribution and a structural relaxation have been found after gamma ray irradiation.

  13. Gamma ray-irradiation in fresh allo-joint transplantation

    International Nuclear Information System (INIS)

    In the first of a series of experiments in rat designed to assess the efficacy of gamma ray irradiation in fresh allo-joint transplantation, it was found that the optimal gamma ray dosage was 4 Gy. At this dosage level, the irradiation rays suppressed the viability of marrow cells which had the highest antigenicity, with no injury to the bone or articular cartilage. In a second experiment, a fresh homologous knee joint was irradiated at 4 Gy and then transplanted while administering the donor's splenic cell suspension (for specific immunosuppression) and the immunosuppressive agent cyclosporine (5 mg/kg) to the recipient rat. All the rats that received a pre-irradiated knee joint graft survived until sacrificed for evaluation without showing any sign of host rejection. In these rats, bone fusion had occurred between the host bone and the graft by the 8th postoperative week. Degeneration of the articular cartilage was similar between the rats that had received a pre-irradiated graft and those that had not. These findings indicated that 4 Gy gamma ray irradiation to a graft before transplantation provided an effective means of immunosuppression. (author)

  14. Synthesis of Au Nanorods by Using Gamma-ray Irradiation

    Science.gov (United States)

    Okamoto, Akihiko; Nagata, Koichiro; Taguchi, Noboru; Iwase, Akihiro; Hori, Fuminobu

    2012-11-01

    To synthesize Au nanorods without the use of seed crystals, we applied gamma-ray irradiation from 60Co radioactive source to reduce aqueous solution containing Au ions. The total dose was fixed to 6.0 kGy with various dose rates from 0.4 to 13.6 kGy/h. After the irradiation, two surface plasmon bands in the range around 530 nm and above 700 nm were observed in UV/vis spectra. We observed by a transmission electron microscopy (TEM) that rod-shaped Au nanoparticles with the length of 20-25 nm, and the width of about 7-15 nm were produced as well as a small amount of spherical particles. The size and the aspect ratio of the Au nanorods are well correlated with gamma-ray irradiation dose rate; with increasing the dose rate, their size decreases and the aspect ratio increases.

  15. Induced mutations by gamma ray irradiation to Argomulyo soybean (Glycine max) variety

    OpenAIRE

    DESTA WIRNAS; SUDIRMAN YAHYA; TRIKOESOEMANINGTYAS; DIANA SOFIA HANAFIAH

    2010-01-01

    Hanafiah DS, Trikoesoemaningtyas, Yahya S, Wirnas D. 2010. Induced mutations by gamma ray irradiation to Argomulyo soybean (Glycine max) variety. Nusantara Bioscience 2: 121-125. Induced mutation by gamma ray irradiation is one way to increase genetic variability of plants. This research used gamma ray irradiation on low doses (micro mutation). The aim of this research was to know the respons of doses level by micro mutation on gamma ray irridation to the growing and development of Argomulyo ...

  16. Dosimetry for high dose rate gamma ray irradiation equipment

    International Nuclear Information System (INIS)

    The dose rate and distribution of the machine gamma ray in the title were studied at the opportunity of its move to Gamma-ray Facilities using a glass dosimeter calibrated. The machine, Gammator M M38-3 (Radiation Machinery Corp.), W 24 in. x D 24 in. x H 63 in., had a source of 88.8 TBq 137Cs to irradiate samples of 60Co gamma source. For measuring the dose rate and distribution, glass dosimeters were fixed on an acryl plate stand of 3 in. x 8 in. by arranging in 3 rows (x axis) x 7 columns (y axis), and the stand was irradiated by gamma ray for 1 min. Irradiation was performed with either rotating or resting condition of the sample turntable and each exposure dose was read out. From the dosimeters at the center of rotation, water absorbed dose D =8.465 Gy was obtained (Mar. 30, 2010). The dose distribution along y axis was found to have 2 peaks of 1.18 and 1.08 times higher than the center above. Fluctuation was high at measurement on the resting turntable. As above, the distribution was not homogeneous depending on the feature of the sample, and turntable should be rotated during irradiation. The machine was operable from April, 2010. (T.T.)

  17. Apoptosis and necrosis in testes irradiated with gamma rays

    International Nuclear Information System (INIS)

    The present study focused on sub-microscopical investigation of apoptotic and necrotic cells in the testes of dogs subjected to single local irradiation with gamma rays at three different doses, 1.5 Gy, 3 Gy and 4 Gy, on days 1, 15, 30, 45, 120 and 150 after irradiation. On day 1 after irradiation, no necrotic cells were observed in the testicular tissue. The first cells in which apoptosis was observed on days 15 and 30 after irradiation with the lower dose were spermatogonia, spermatocytes and round spermatids. These cells showed morphological changes typical of apoptosis. Their depletion was observed on day 45 after irradiation and they were found in the lumen of seminiferous tubuli. Some dead cells were eliminated from seminiferous tubuli by phagocytosis by means of Sertoli cells. After irradiation with higher doses of gamma rays some cells of seminiferous epithelium showed morphological signs of apoptosis while other manifested necrosis. Sertoli cells and Leydig cells were considerably resistant to radiation. However, after irradiation with the highest dose of 4 Gy sporadic cells showed signs of apoptosis. On day 120 after irradiation the testes contained no necrotic cells and by day 150 spermiogenesis was recovered. (authors)

  18. Synergistic effects of neutron and gamma ray irradiation of a commercial CHMOS microcontroller

    International Nuclear Information System (INIS)

    This paper presents the experimental results of a combined irradiation environment of neutron and gamma rays on 80C196KC20, which is a 16-bit high performance member of the MCS96 microcontroller family. The electrical and functional tests were made in three irradiation environments: neutron, gamma rays, combined irradiation of neutron and gamma rays. The experimental results show that the neutron irradiation can affect the total ionizing dose behaviour. Compared with the single radiation environment, the microcontroller exhibits considerably more severe degradation in neutron and gamma ray synergistic irradiation. This phenomenon may cause a significant hardness assurance problem. (condensed matter: structure, thermal and mechanical properties)

  19. A commercial gamma-ray irradiation plant in Japan

    International Nuclear Information System (INIS)

    In 1973, a commercial gamma-ray irradiation plant was constructed in Takasaki, about 100 km north of Tokyo. The plant has been used for both production of irradiated commercial products and irradiation services. The irradiation services are being made available for sterilization of both medical appliances such as disposable medical syringes, catheters, surgical sutures, and sterilization of feed stuffs for animals. Treatment of plastic materials and colouring of both crystals and glass wares are also undertaken. This facility can accommodate 600 kCi of 60Co and has a monthly treating capacity of 12,000 packages ( a standard carton of 340 mm x 400 mm x 500 mm) at an irradiation dose of 1 Mrad/hr. A receiving port for packages is on the second floor and the outlet of the irradiated packages on the first floor, with three lines of connecting loop conveyors between them, and the irradiation compartment in the center section. The space arrangement of the facility is well designed and gravity can be utilized for the transportation of the packages. Polymer impregnated coral is put on the market for ornamental building material on an order contract basis. (author)

  20. Gamma-ray spectroscopy on irradiated MTR fuel elements

    International Nuclear Information System (INIS)

    The availability of burnup data is an important requirement in any systematic approach to the enhancement of safety, economics and performance of a nuclear research reactor. This work presents the theory and experimental techniques applied to determine, by means of nondestructive gamma-ray spectroscopy, the burnup of Material Testing Reactor (MTR) fuel elements irradiated in the IEA-R1 research reactor. Burnup measurements, based on analysis of spectra that result from collimation and detection of gamma-rays emitted in the decay of radioactive fission products, were performed at the reactor pool area. The measuring system consists of a high-purity germanium (HPGe) detector together with suitable fast electronics and an on-line microcomputer data acquisition module. In order to achieve absolute burnup values, the detection set (collimator tube+HPGe detector) was previously calibrated in efficiency. The obtained burnup values are compared with ones provided by reactor physics calculations, for three kinds of MTR fuel elements with different cooling times, initial enrichment grades and total number of fuel plates. Both values show good agreement within the experimental error limits

  1. Gamma-ray spectroscopy on irradiated MTR fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, L.A.A. E-mail: laaterre@net.ipen.br; Zeituni, C.A.; Perrotta, J.A.; Silva, J.E.R. da

    2000-08-11

    The availability of burnup data is an important requirement in any systematic approach to the enhancement of safety, economics and performance of a nuclear research reactor. This work presents the theory and experimental techniques applied to determine, by means of nondestructive gamma-ray spectroscopy, the burnup of Material Testing Reactor (MTR) fuel elements irradiated in the IEA-R1 research reactor. Burnup measurements, based on analysis of spectra that result from collimation and detection of gamma-rays emitted in the decay of radioactive fission products, were performed at the reactor pool area. The measuring system consists of a high-purity germanium (HPGe) detector together with suitable fast electronics and an on-line microcomputer data acquisition module. In order to achieve absolute burnup values, the detection set (collimator tube+HPGe detector) was previously calibrated in efficiency. The obtained burnup values are compared with ones provided by reactor physics calculations, for three kinds of MTR fuel elements with different cooling times, initial enrichment grades and total number of fuel plates. Both values show good agreement within the experimental error limits.

  2. Effects of Combined Irradiation of Neutrons and {gamma}-Rays on the Pink Mutation Frequencies in Tradescantia

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, Young Keun; Kim, Jae Sung [KAERI, Daejeon (Korea, Republic of); Shin, Hae Shick [Chungnam National Univ., Daejeon (Korea, Republic of); Hyun, Soung Hee [Eulji Univ., Daejeon (Korea, Republic of)

    2000-06-15

    The effects of combined irradiation of neutrons and {gamma}-rays were analysed by means of Tradescantia Stamen Hair (TSH) assay. Potted plants were irradiated with 0{approx}2 Gy of {gamma}-rays. For the combined treatments, the plants were irradiated with neutrons from {sup 252}Cf 24 hours before or after {gamma}-irradiation. The slopes of dose-response curves were 5.98, 6.17 and 7.48, in {gamma}-rays, {gamma}-rays+neutrons, and neutrons+{gamma}-rays irradiated groups, respectively. The biological efficacy of radiations in the induction of pink mutations increased by 25% in neutrons+{gamma}-rays irradiated group, while it increased by 12% in {gamma}-rays+neutrons irradiated group. The combined irradiation with two kinds of radiations results in the different efficacy of radiation depending on the order of irradiations, which is of great importance in the related fields such as sterilization and radiotherapy.

  3. Induced parthenocarpy with pollen irradiated with gamma rays

    International Nuclear Information System (INIS)

    The results of serial experiments carried out during 1971-1974 using different vegetable crops for the purpose of obtaining parthenocarpous fruits with pollen irradiated with gamma rays are summed. Different varieties of tomatoes, cucumbers and sugar melons are used. The pollen was irradiated on the day on which it was collected with 1 to 500 kR (1500-1000 R/min) with immediate pollination of the respective flowers. The pollination of the flower was conducted with or without castration and with or without isolation depending on the varieties and the conditions of cultivating the plants. The fruits thus obtained were normal in size and shape and contained degenerated seed (flakes) witout cavities. Degustations in all cases established a fuller and richer taste in comparison with the control fruits. Biochemical indices for the same tomatoes varieties (sugars, vitamin C, acidity, dry substance determined refractometrically) show that the quality of the experimental fruits is better than the control ones. (A.B.)

  4. Degradation behavior of poly (L-lactide-co-glycolide) films through gamma-ray irradiation

    International Nuclear Information System (INIS)

    Gamma-ray irradiation is a very useful tool to improve the physicochemical properties of various biodegradable polymers without the use of a heating and crosslinking agent. The purpose of this study was to investigate the degradation behavior of poly (L-lactide-co-glycolide) (PLGA) depending on the applied gamma-ray irradiation doses. PLGA films prepared through a solvent casting method were irradiated with gamma radiation at various irradiation doses. The irradiation was performed using 60Co gamma-ray doses of 25–500 kGy at a dose rate of 10 kGy/h. The degradation of irradiated films was observed through the main chain scission. Exposure to gamma radiation dropped the average molecular weight (Mn and Mw), and weakened the mechanical strength. Thermograms of irradiated film show various changes of thermal properties in accordance with gamma-ray irradiation doses. Gamma-ray irradiation changes the morphology of the surface, and improves the wettability. In conclusion, gamma-ray irradiation will be a useful tool to control the rate of hydrolytic degradation of these PLGA films. - Highlights: ? The degradation behavior of PLGA depending on the radiation dose is investigated. ? The main degradation mechanisms by radiation seem to be a main chain scission. ? Radiation can be a potential tool to control the rate of degradation.

  5. Effect of gamma-ray irradiation on starch in sweet popato roots

    International Nuclear Information System (INIS)

    Starch contents, as well as the size and molecular weight, in sweet potato roots decreased during steerage at 30 degrees C after gamma-ray irradiation, accompanying the increase of sucrose content. No change in the starch and sucrose contents was observed in unirradiated specimens. By microscopy damaged starch granules were observed only in gamma-ray irradiated root. The results suggested that starch was converted into sucrose unirradiated sweet potato roots by the enzymes responsible for starch-sugar interconversion of which the activities were enhanced by gamma-ray irradiation

  6. Comparative study on disinfection potency of spore forming bacteria by electron-beam irradiation and gamma-ray irradiation

    International Nuclear Information System (INIS)

    Along with gamma-ray irradiation, electron-beam irradiation (EB) is a method to disinfect microorganisms which cause food decomposition and food-poisoning. The present study was undertaken to compare sterilization efficacy of EB and gamma-ray irradiation on bacterial spores and vegetative cells under various conditions. Spores of Bacillus pumilus, a marker strain for irradiation study, and Bacillus stearothermophilus known as a thermophilic bacteria were irradiated by electron-beam and gamma-ray separately at irradiation dose of 0 to 10 kGy on combination of wet/dry and aerobic/anaerobic conditions. Sterilization effect of irradiation on spores was evaluated by colony counting on agar plates. Results showed that both EB and gamma-ray irradiation gave sufficient sterilization effect on spores, and the sterilization effect increased exponentially with irradiation dose. The sterilization effect of gamma-ray irradiation was higher than that of EB in all cases. Higher disinfection effect was observed under aerobic condition. The present study suggests that oxygen supply in EB is more important than gamma-ray irradiation. No results suggesting that chlorine ion at 0.1 ppm (as available chlorine concentration) enhanced the sterilization efficacy of either EB or gamma-ray irradiation was obtained under any conditions examined. (author)

  7. Assays of residual antibiotics after treatment of {gamma}-ray and UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ji Hye; Nam, Ji Hyun; Lee, Dong Hun [Chungbuk National University, Cheongju (Korea, Republic of); Yu, Seung Ho; Lee, Myun Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-03-15

    The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and {gamma}-ray irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after {gamma}-ray and UV irradiation. Most samples were degraded by {gamma}-ray irradiation (1 {approx} 2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with {gamma}-ray and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of {gamma}-ray irradiated cephradine measured by AMS test were 2 times higher than of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that {gamma}-ray irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation.

  8. Degradation of SiGe HBT with reactor pulse neutron and gamma rays irradiation

    International Nuclear Information System (INIS)

    The typical dc electronic parameters degradation of SiGe HBT irradiated by reactor pulse neutron and gamma rays were measured. The mechanisms of transient radiation-induced damage in SiGe HBT were preliminary analyzed

  9. Gamma-ray irradiation tests of CMOS sensors used in imaging techniques

    OpenAIRE

    Cappello Salvatore G.; Pace Calogero; Parlato Aldo; Rizzo Salvatore; Tomarchio Elio

    2014-01-01

    Technologically-enhanced electronic image sensors are used in various fields as diagnostic techniques in medicine or space applications. In the latter case the devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same equipment. In this paper we report the results of gamma-ray irradiation tests on CMOS image sensors simulating the space radiation over a long time period. Gamma-ray irradiation tests were carrie...

  10. Application of nondestructive gamma-ray and neutron techniques for the safeguarding of irradiated fuel materials

    International Nuclear Information System (INIS)

    Nondestructive gamma-ray and neutron techniques were used to characterize the irradiation exposures of irradiated fuel assemblies. Techniques for the rapid measurement of the axial-activity profiles of fuel assemblies have been developed using ion chambers and Be(?,n) detectors. Detailed measurements using high-resolution gamma-ray spectrometry and passive neutron techniques were correlated with operator-declared values of cooling times and burnup

  11. Induced mutations by gamma ray irradiation to Argomulyo soybean (Glycine max variety

    Directory of Open Access Journals (Sweden)

    DESTA WIRNAS

    2010-11-01

    Full Text Available Hanafiah DS, Trikoesoemaningtyas, Yahya S, Wirnas D. 2010. Induced mutations by gamma ray irradiation to Argomulyo soybean (Glycine max variety. Nusantara Bioscience 2: 121-125. Induced mutation by gamma ray irradiation is one way to increase genetic variability of plants. This research used gamma ray irradiation on low doses (micro mutation. The aim of this research was to know the respons of doses level by micro mutation on gamma ray irridation to the growing and development of Argomulyo variety of soybean [Glycine max (L Merr]. The seeds were irradiated by gamma ray micro mutation doses, namely 0 gray, 50 gray, 100 gray, 150 gray, and 200 gray. Variations that were obtained of each characters at generation M1 and M2 influences plants growth and development either through qualitative and quantitative that finally will influence plant’s production. The average highest genetic variation at M2 generation of soybean was on 200 Gray doses. Results of the research indicated that gamma ray irradiation on 200 Gray doses effectively caused of plant variation genetic.

  12. Effect of gamma ray irradiation on the ferroelectric and piezoelectric properties of barium stannate titanate ceramics

    International Nuclear Information System (INIS)

    Tin doped barium titanate ceramics has been obtained by solid state reaction method followed by high energy ball milling. The effect of heavy dose gamma ray irradiation on the ferroelectric and piezoelectric properties of the synthesized barium stannate titanate ceramics has been observed. It has been found that on irradiation the ferroelectric property decreases with decreasing values of Pr and Ec. The piezoelectric properties including d33, electrostrictive strain and electromechanical coupling coefficient (Kp) also decrease following the same trend of Pr and Ec. Grain size decreases and grain patterns become irregular after irradiation as observed from SEM micrographs. The Thermoluminescence (TL) property of the barium stannate titanate ceramics has also been investigated and reported. - Highlights: • Gamma ray irradiation effects have been reported. • The ferroelectric property decreases due to gamma ray irradiation. • Values of different piezoelectric constants decrease upon irradiation. • TL glow curve shows thermoluminescence property of the ceramic system

  13. Comparison of electrical properties of ceramic insulators under gamma ray and ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T. [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)]. E-mail: teru@nifs.ac.jp; Nagayasu, R. [Department of Electronic, Information Systems and Energy Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Sato, F. [Department of Electronic, Information Systems and Energy Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Muroga, T. [Fusion Engineering Research Center, National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Ikeda, T. [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihoga-oka, Ibaragi, Osaka 567-0047 (Japan); Iida, T. [Department of Electronic, Information Systems and Energy Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2006-02-15

    The electrical properties of ceramic insulators of Y{sub 2}O{sub 3}, CaZrO{sub 3} and Er{sub 2}O{sub 3} were examined under gamma ray and low energy ion beam irradiation. The gamma ray induced currents increased with the bias voltage. Their radiation-induced conductivity (RIC) evaluated from the induced current was almost within one order of magnitude of that predicted from the previous fusion neutron and fission reactor irradiations. Under low energy ion beam irradiation, the induced current from the positive bias voltage was strongly suppressed. From the point of the energy deposition, the magnitude of the ion-induced current was significantly lower than that under gamma ray and neutron irradiations. A transient change in the induced current at the start of beam irradiation implies that the electric field in the specimen was affected by the unevenness of the distribution of the released electrons and holes.

  14. Simulation and Characterization of Gamma Ray Production by Petawatt Lasers Irradiating High-Z Solid Targets

    Science.gov (United States)

    Henderson, Alexander; Liang, Edison; Yepes, Pablo; Chaguine, Petr; Riley, Nathan; Dyer, Gillis; Pennington, Scott

    2012-10-01

    On interaction with a solid target an ultra-intense short pulse high-energy laser, such as the Texas Petawatt Laser (TPW), accelerates a sub-pico-second burst of electrons into the target at high energies. These electrons then undergo bremsstrahlung, producing a beam of high-energy gamma rays. Even for mm thick gold targets, most of the bremsstrahling gamma rays escape, while many hot electrons do not. Here we attempt to characterize the angular distribution, energy spectrum and total yield of these gamma rays as produced by the TPW irradiating mm thick gold targets. GEANT4 Monte-Carlo simulation results are then fitted to the data and used to extrapolate the results beyond the limits of the measurements. We will also discuss potential applications of such intense gamma-ray beams.

  15. Morphological Changes of Polystyrene Sorbents after Gamma-Rays Irradiation.

    Czech Academy of Sciences Publication Activity Database

    Aleksieva, Krasimira; Sasso, A.; Je?ábek, Karel

    Praha : ?eská spole?nost chemického inženýrství, 2009 - (Halfar, R.), s. 234 ISBN 978-80-86059-51-8. [Konference chemického a procesního inženýrství CHISA 2009 /56./. Srní, Šumava (CZ), 19.10.2009-22.10.2009] Institutional research plan: CEZ:AV0Z40720504 Keywords : gamma-rays * porosity * crosslinking Subject RIV: CI - Industrial Chemistry, Chemical Engineering www.chisa.cz/2009

  16. Effect of. gamma. -ray irradiation on colour and fluorescence of pearls

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Yasunori; Miyoshi, Tadaki.

    1988-02-01

    The colour of cultured pearls of P. fucata can be changed by ..gamma..-ray irradiation, which has been applied to pearl processing. The effect of ..gamma..-ray irradiation on the colour and fluorescence of pearls was investigated experimentally. The experimental results show that a colour change of pearls to bluish-grey is mainly responsible for a decrease in the reflection factor of the nuclei. Furthermore, a significant change in the fluorescence spectra has been observed for pearls and nuclei. These changes are considered to be caused by the degradation of conchiolin contained in the nacre. Fluorescence from pearls is not affected by the nuclei, but the colour of pearls is affected. Thus, the fluorescence method is suitable for investigating the effect of ..gamma..-ray irradiation on the nacre.

  17. Sterilization of commercial spices by gamma-ray irradiation and its effect to essencial oil

    International Nuclear Information System (INIS)

    Eleven kinds of commercial spices were irradiated with gamma-ray at the dose of 0 to 5 kGy. The microbial counts of almost all the samples were decreased under 103/g by the dose of 5 kGy. The D10 value of microbials contaminated to these spices were 1.1 to 4.3. Five kGy of gamma-ray irradiation affected to the recoveries of essencial oil from the spices. The effect was varied between spices. While the recoveries from some spices were increased, the others were decreased. (author)

  18. Sterilization of commercial spices by gamma-ray irradiation and its effect to essencial oil

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, Makoto (National Food Research Inst., Tsukuba, Ibaraki (Japan)); Hossain, Tarib

    1989-11-01

    Eleven kinds of commercial spices were irradiated with gamma-ray at the dose of 0 to 5 kGy. The microbial counts of almost all the samples were decreased under 10{sup 3}/g by the dose of 5 kGy. The D{sub 10} value of microbials contaminated to these spices were 1.1 to 4.3. Five kGy of gamma-ray irradiation affected to the recoveries of essencial oil from the spices. The effect was varied between spices. While the recoveries from some spices were increased, the others were decreased. (author).

  19. The Cellular Differences between Acute and Chronic Neutron and Gamma-Ray Irradiation in Mice

    International Nuclear Information System (INIS)

    Data on the shortening of the life span in mice by radiation show that an acute dose of gamma-rays may be as much as four times as effective as an equal dose of the same radiation administered chronically. However, for neutrons, chronic and acute administrations are equally effective. An analysis of these effects shows that for gamma-rays a certain fraction of the radiation injury is reparable, and that the value of this fraction depends on the dose and the dose rate. With neutrons, none of the damage appears reparable. For acute irradiation, the RBE is about 2 for shortening of the life span, but for chronic, may be as high as 8. Chromosome aberrations have been scored in liver cells of mice when treated with both chronic and acute doses of both gamma-rays and thermal neutrons. In all cases the percentage of aberrent cells is proportional to the shortening of the life span produced by the treatment. Further, with neutrons, acute and chronic irradiation is equally effective in producing chromosome abberations. For gamma-rays, acute irradiation may produce as much as four times the chromosomal damage as does chronic irradiation. This shows that some chromosomes can heal themselves following small doses of gamma-rays, but there is no chromosome healing following any dose of neutrons. The RBE using chromosome aberrations as a criterion is the same as for life shortening. These results give a firm cellular basis for the known biological differences between gamma rays and neutrons, and in addition give strong support to the concept that natural and radiation-induced aging are caused by spontaneous and radiation-induced mutations, respectively, in the somatic cells of animals. (author)

  20. Mutation induction in Philippine bananas c.v. 'Lakatan' thru gamma ray irradiation

    International Nuclear Information System (INIS)

    Banana is the most important crop grown in the Philippines. Among the cultivars grown, 'Lakatan' is the most popular and commands a higher price in the local market. Despite high production, losses due to over ripening, bruising and short shelf life is one of the major constraints in a successful banana industry. The use of chemicals for delayed ripening however, remains an issue of concern due to economic and organic products advocacy. Thus, development and generation of new improved 'Lakatan' cultivar through gamma ray irradiation was carried out. Mutation was induced in 'Lakatan', a popular Philippine cultivar using gamma ray irradiation. Radio sensitivity was established at 50Gy. Morphological, cytological and molecular analysis done showed significant variations between the irradiated samples and the non-irradiated plants. In terms of morphological parameters, gamma ray irradiation affected leaf traits resulting to increased leaf width, leaf length, and number of leaves. Stem girth on the other hand was significantly reduced. Cytological observations showed that gamma irradiation increased the epidermal width, leaf thickness and size of stomates but reduced the number of stomates. For post harvest attributes, gamma irradiation prolonged the shelf life of banana fruits from 11 days to 14 days. Molecular analysis showed that some markers (RAPD and AFLP) were able to detect unique bands in samples irradiated with 50Gy while the SSR markers did not detect any band difference between the irradiated samples and the control. (author)

  1. Influence of irradiation of gamma-ray on the pulping and paper making, (2)

    International Nuclear Information System (INIS)

    In kraft pulping and neutral sulphite pulping of gamma-ray irradiated chips, the influence of irradiation on the defiberability of the yielded pulps were investigated. The results were summerized as follows: 1) In kraft pulping, the defiberability becomes inferior by the irradiation of 5 x 105R. 2) In neutral sulphite pulping, the defiberability seems to become somewhat better by the irradiation of 106R. And kapper number does not change within the area of the high pulp yield but it becomes smaller according to the decrease of the total pulping yield by the irradiation of 106R, in comparison with the case of no-irradiation. (author)

  2. Modifications in the Morphology of Poly(styrene-co-divinylbenzenes) Induced by Gamma-ray Irradiation.

    Czech Academy of Sciences Publication Activity Database

    Aleksieva, Krasimira; Sassi, A.; Je?ábek, Karel

    2010-01-01

    Ro?. 70, ?. 6 (2010), s. 361-365. ISSN 1381-5148 Institutional research plan: CEZ:AV0Z40720504 Keywords : gamma-ray irradiation * specific surface area * polymer morphology Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.546, year: 2010

  3. Effect of gamma-ray irradiation on cord blood lymphocyte proliferation and NK cell activity

    International Nuclear Information System (INIS)

    Objective: To investigate the effects of gamma-ray irradiation on cord blood lymphocyte proliferation and NK cell activity. Methods: Freshly isolated mononuclear cells from human cord blood were irradiated with different doses (0.248-15.872 Gy) of gamma-rays. The lymphocyte proliferation and NK cell activity were measured using 3H-TdR incorporation assay and 3H-TdR release assay, respectively. Results: In dose range of 0.248-15.872 Gy, lymphocyte proliferation was inhibited and the inhibition rate was positively correlated with the irradiation dose(r=0.839, P<0.05). Lymphocyte proliferation was not found in dose range of 3.968-15.872 Gy. Irradiation doses from 0.248 to 1.984 Gy could enhance NK cell activity. The activity of NK cells was reserved after irradiated with 3.968 Gy. Within the dose range of 5.952-15.872 Gy, NK cell activity was significantly inhibited. Conclusion: Lymphocyte proliferation is inhibited and the activity of NK cell is reserved when irradiated with the dose of 3.968 Gy gamma-rays. So if the lymphocytes are irradiated with such a dose before donor lymphocytes infusion or mix-cord blood transplantation, the effect of graft versus host disease (GVHD) could be decreased whereas the effect of graft versus leukemia (GVL) reaction could be reserved simultaneously during adoptive cellular immunotherapy. (authors)

  4. Effects of gamma-ray irradiation on cellulase secretion of Trichoderma reesei

    International Nuclear Information System (INIS)

    Trichoderma reesei was irradiated with gamma rays to investigate the effects of different dosages on cellulase production. Doses above 0.7 kGy induced cell lysis. Cell growth began to be obstructed at 2.0 kGy. As a result, the cells irradiated at 2.0 kGy secreted 1.8 times as much cellulase as the untreated cells

  5. Studies of Gamma-Ray-Irradiated Human Immunoglobulin G

    International Nuclear Information System (INIS)

    Freeze-dried IgG with incomplete anti-Rh0(D) activity retained its reactivity after irradiation with a dose of 1.5 - 2.5 Mrad ?-rays. A portion of the irradiated protein was insoluble. Gel-filtration on Sephadex G-200 indicated the presence of aggregated IgG in addition to the non-aggregated form. Proteolytic experiments revealed an altered digestibility of the protein with papain after irradiation. (author)

  6. Gamma-ray irradiation induced bulk photochromism in WO3-P2O5 glass

    Science.gov (United States)

    Shen, Wei; Baccaro, Stefania; Cemmi, Alessia; Xu, Xiaoqing; Chen, Guorong

    2015-11-01

    In the present work, photochromism of WO3-P2O5 glass under gamma-ray irradiation was reported. As-prepared glass samples with different WO3 content are all optically transparent in the visible wavelength range thanks to the addition of a small amount of oxidizing couple Sb2O3-NaNO3. The photochromic properties are identified by transmission spectra of the glasses before and after irradiation. The results show that the irradiation induced darkening results from the reduction of W6+ to W5+ or W4+. The existence of WO6 clusters in glasses of high WO3 content is proved by XPS, which is the main reason for the obvious photochromic effects. The WO3-P2O5 glass is a promising candidate in gamma-ray sensitive detector.

  7. Gamma-ray irradiation tests of CMOS sensors used in imaging techniques

    Directory of Open Access Journals (Sweden)

    Cappello Salvatore G.

    2014-01-01

    Full Text Available Technologically-enhanced electronic image sensors are used in various fields as diagnostic techniques in medicine or space applications. In the latter case the devices can be exposed to intense radiation fluxes over time which may impair the functioning of the same equipment. In this paper we report the results of gamma-ray irradiation tests on CMOS image sensors simulating the space radiation over a long time period. Gamma-ray irradiation tests were carried out by means of IGS-3 gamma irradiation facility of Palermo University, based on 60Co sources with different activities. To reduce the dose rate and realize a narrow gamma-ray beam, a lead-collimation system was purposely built. It permits to have dose rate values less than 10 mGy/s and to irradiate CMOS Image Sensors during operation. The total ionizing dose to CMOS image sensors was monitored in-situ, during irradiation, up to 1000 Gy and images were acquired every 25 Gy. At the end of the tests, the sensors continued to operate despite a background noise and some pixels were completely saturated. These effects, however, involve isolated pixels and therefore, should not affect the image quality.

  8. Effects of gamma-ray irradiation on leaching of simulated 133Cs+ radionuclides from geopolymer wasteforms

    Science.gov (United States)

    Deng, Ning; An, Hao; Cui, Hao; Pan, Yang; Wang, Bing; Mao, Linqiang; Zhai, Jianping

    2015-04-01

    Leaching of simulated 133Cs+ radionuclides from geopolymer wasteforms was examined with regard to effects from gamma-ray irradiation. Specifically, the compressive strengths, microstructures, pore structures, and leaching resistance of geopolymer wasteforms before and after irradiation were characterized. The leaching experiments were performed by immersion of wasteforms in deionized water, ground water, and seawater. It was found that gamma rays did not produce significant morphological changes, except for changes in the pore size distribution. The cumulative leaching fraction of all the leachants from the irradiated samples increased relative to the non-radiated samples, particularly during long leaching periods (11-42 days). These results, and those from a mercury intrusion porosimeter analysis, can be attributed to irradiation-induced changes in pore structure. All the leaching indexes were greater than the minimum acceptable value of 6.0 set by the American Nuclear Society Standards committee, which indicated that the fly-ash geopolymers are suitable for radionuclide immobilization. However, the effects of gamma-ray irradiation on the immobilization of radionuclides cannot be ignored.

  9. Effect of gamma-ray and electron irradiation on the response of solid-state track detectors

    International Nuclear Information System (INIS)

    Specimens of muscovite mica were first exposed to fission fragments and then to various gamma-ray fields from a 60Co source ranging from 1.9 x 103 to 1.6 x 104 Mrad dose. The results show that the average etched width of fission-fragment tracks decreases with increasing gamma-ray dose. Shallow pits were observed in etched specimens when the gamma-ray dose exceeded 5 x 103 Mrad. Numerous shallow etch pits caused by the gamma-ray irradiation interfered with the observation of fission tracks in the specimens. No shallow etch pits were observed in the specimen annealed for 100 min at 6000C before the gamma-ray irradiation. Pre-annealing extends the ''safety limits'' of gamma background below which muscovite mica can be used to observe fission tracks without any gamma-ray interference. Gamma-ray and electron irradiation caused significant increase of the resistance to thermal decomposition of muscovite mica. The resistance increased markedly in the dose range from 5 x 103 to 8 x 103 Mrad. These phenomena suggest the use of mica to assess radiation doses of gamma rays and electrons up to several thousand megarads. (author)

  10. Gamma-ray irradiation of a boreal forest ecosystem

    International Nuclear Information System (INIS)

    A long-term radiation ecology research project called Field Irradiator - Gamma (FIG) began at the Whiteshell Nuclear Research Establishment in 1968. The experimental area is in southeastern Manitoba and is located on the western edge of the Precambrian shield. The project studies the ecological effects continuous exposure to a gradient of gamma radiation has on a mixed boreal forest ecosystem. The gradient ranges from 1 to 460,000 times the natural background radiation level. This paper describes the forest, the gamma irradiator and its radiation field, and the research program

  11. Digested livestock wastewater treatment using gamma-ray irradiation and struvite crystallization

    International Nuclear Information System (INIS)

    Livestock wastewater generally contains high strength of organics (COD), ammonia nitrogen (NH4+ -N), phosphate phosphorus (PO43- -P) and suspended solids. It is very difficult to treat by conventional wastewater treatment techniques. In this study, struvite crystallization was carried out to treat the digested livestock wastewater. 1.0 :1.2 :1.2 was determined as an optimal NH4+ :Mg2+ : PO43- mol ratio of struvite crystallization. For the digested livestock wastewater, COD, NH4+ -N and PO43- -P removal efficiencies by struvite crystallization were 72.4%, 98.9%, and 74.8%, respectively. Gamma-ray irradiation was carried out prior to struvite crystallization of livestock wastewater. The enhancement of struvite crystallization efficiency could be obtained by the pretreatment of gamma-ray irradiation due to the decrease of COD, NH4+ -N and PO43- -P concentration

  12. Post irradiation changes of haematological parameters in mammals blood after high dose gamma rays

    International Nuclear Information System (INIS)

    In our experiment we monitored post irradiation changes of haematological parameters in rats after single total - body dose of gamma rays 15 Gy. Significant decrease was in the erythrocyte count at 6th day (P th day (P th day. In the white blood picture in all experimental groups was leukopenia (P < 0.001), which was characterized by neutrophilia (P < 0.001) and lymphopenia (P < 0.001). (authors)

  13. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages

    International Nuclear Information System (INIS)

    The purpose was to investigate the uptake and endocytosis of 2000 Gy 60Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy 60 Co ?-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays (60 Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  14. Glasses, Coatings, Glues and Gamma-ray Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Barcala, J.M.; Fernandez, M. G.; Ferrando, A.; Fuentes, J.; Josa, M. I.; Molinero, A.; Oller, J. C. [Ciemat. Madrid (Spain); Arce, P.; Calvo, E.; Figueroa, C. F.; Rodrigo, T.; Vila, I.; Virto, A. L. [Universidad de Cantabria. Santander (Spain); Beigveder, J. M.; Genova, I.; Perez, G.; Ruiz, J. A. [CIDA. Madrid (Spain)

    2001-07-01

    Most of the alignment systems for LHC experiments use optomechanical elements confirming a network of points that are monitored by laser beams. LHC experiments, working at the expected nominal luminosity, will induce an extremely high irradiation. basic components such as glasses, coatings and glues may change and their performance may degrade significantly. We have tested various components and identified some of them that can stand 10 years of LHC operation. (Author) 11 refs.

  15. Glasses, Coatings, Glues and Gamma-ray Irradiation

    International Nuclear Information System (INIS)

    Most of the alignment systems for LHC experiments use optomechanical elements confirming a network of points that are monitored by laser beams. LHC experiments, working at the expected nominal luminosity, will induce an extremely high irradiation. basic components such as glasses, coatings and glues may change and their performance may degrade significantly. We have tested various components and identified some of them that can stand 10 years of LHC operation. (Author) 11 refs

  16. Gamma ray irradiation to roots of tea-plants and induced mutant system

    International Nuclear Information System (INIS)

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.)

  17. Gamma ray irradiation to roots of tea-plants and induced mutant system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yoshiyuki; Nekaku, Koji; Wada, Mitsumasa (National Research Inst. of Vegetables, Ornamental Plants and Tea, Ano, Mie (Japan))

    1990-11-01

    In order to utilize the useful mutation which is induced by irradiation for the breeding of tea-plants, the gamma-ray irradiation to the roots of tea-plants was carried out. The samples were the roots of tea-plants of four varieties dug up in February, 1984, and were adjusted to about 20 cm, then, put in the cold storage at 5degC for 9 months till the time of irradiation in November, 1984. However, a part of them was taken out in August, and planted in a field for 76 days to germinate, thereafter, used as the samples. The gamma-ray from a Co-60 source was irradiated in the radiation breeding laboratory of Agriculture Bioresources Research Institute at the total dose of 1, 2 and 3 kR and the dose rate of 500 R/h. The irradiated roots were planted as they are or in the state of being cut, and the rate of germination, the number of buds and the induced mutation were examined. Clear difference was not observed in the rate of germination and the number of buds between the irradiated samples and those without irradiation. The long roots were superior to the short roots regarding these items. The types of the induced mutation were mostly thin leaves, and also yellowing, mottling, fascination and so on occurred. The mutant system lacking trichomes on the back of new leaves is considered to be strong against tea anthracnose, and is valuable. (K.I.).

  18. Gamma ray spectra from targets irradiated by picosecond lasers

    Science.gov (United States)

    Seely, J. F.; Szabo, C. I.; Feldman, Uri; Chen, Hui; Hudson, L. T.; Henins, A.

    2011-09-01

    Photon spectra in the energy range 60 keV to 1 MeV were recorded from targets irradiated by the LLNL Titan and LLE EP picosecond lasers. The radiation consisted of K-shell radiation, bremsstrahlung radiation from MeV electrons, and preliminary evidence for 511 keV positron annihilation radiation. The spectra were recorded by two instruments, an energy-dispersive CCD detector with a CsI phosphor coating that operated in the single-hit per pixel mode and was absolutely calibrated using a Cs-137 662 keV source, and a wavelength-dispersive Cauchois type spectrometer employing a curved Ge(220) transmission crystal that operated in the first and second diffraction orders with high spectral resolution. The calibrated photon energy distributions from Au, Eu, and Al targets are compared to the energetic electron distributions emerging from the targets.

  19. Allogenic bone rods with freeze drying and gamma rays irradiation for treatment of fracture

    International Nuclear Information System (INIS)

    Opened reduction and internal fixation are the usual treatment of fracture, but both methods need a second operation for removal implants. The benefits of the bone rods are that they can avoid the removement of internal fixation and will be absorbed spontaneously. The bone rods are made of allogeneic compact bones with freeze-drying and gamma rays irradiation supplied by Shanxi Provincial Tissue Bank. The purpose of this study is to evaluate allograft reaction, the stability of the internal fixation, osteoinduction in the treatment of fracture using allogeneic bone rods with freeze drying and gamma rays irradiation. From May 1997 to May 1998, fourteen cases (male 12, female 2) of treatment were reviewed. The mean age was 37.3 (21-5 1). There were 3 medial malleolus fractures, 7 tibia and fibula fractures, 1 ulna and radius fracture, 1 lateral condyle of humerus fracture. The clinical results were satisfactory. Because the strength of the bone rods are weaker than that of screws, the bone rods are only indicated in the fixation of cancellous bones fracture and unloaded bone fracture. It can be used as a supplementary fixation of loaded bone. It is not indicated for fixation of comminuted fracture. More than two bone rods may be used in the fixation of fracture in order to get stability of the fracture and decrease stress between rods which will prevent the break of the bone rods. Allogeneic bone rods with freeze-drying and gamma rays irradiation can be used as implants of non-immunogenicity. There are no allograft reactions in all cases (including fever, leukocytosis, exudation or swelling in the wound). Although plenty of experimental studies have showed that freeze drying with gamma rays irradiation (below 50 KGy) would not destroy BMP of bone allograft, but there is no osteoinduction in our cases. The healing of a fracture and bridging external callus are similar as other operations. This new technique may have the following advantages compare with the screws: 1) there is no stress shielding, 2) no need for second operation for removing implants. Because there is no allograft reaction and lower price compared with other absorbable fixation material, we believe allogeneic bone rods with freeze drying and gamma rays irradiation are one of the excellent materials foic internal fixation

  20. Effect of cumulated dose on hydrogen emission from polyethylene irradiated under oxidative atmosphere using gamma rays and ion beams

    Science.gov (United States)

    Ferry, M.; Pellizzi, E.; Boughattas, I.; Fromentin, E.; Dauvois, V.; de Combarieu, G.; Coignet, P.; Cochin, F.; Ngono-Ravache, Y.; Balanzat, E.; Esnouf, S.

    2016-01-01

    This work reports the effect of very high doses, up to 10 MGy, on the H2 emission from high density polyethylene (HDPE) irradiated with gamma rays and ion beams, in the presence of oxygen. This was obtained through a two-step procedure. First, HDPE films were pre-aged, at different doses, using either gamma rays or ion beams. In the second step, the pre-aged samples were irradiated in closed glass ampoules for gas quantification, using the same beam type as for pre-ageing. The hydrogen emission rate decreases when dose increases for both gamma rays and ion beams. However, the decreasing rate appears higher under gamma rays than under ion beam irradiations and this is assigned to a lesser oxidation level under the latter. Herein, we show the effectiveness of the radiation-induced defects scavenging effect under oxidative atmosphere, under low and high excitation densities.

  1. Dielectric properties of wood irradiated with gamma-rays

    International Nuclear Information System (INIS)

    Molecular structure changes in wood resulting from gamma irradiation are discussed from the result of measurements on dielectric properties, X-ray diffraction, infrared spectra and moisture regain. Up to about 3 x 106 rad no marked structure changes are detected. In the range 3 x 106 to 107 rad, the moisture-regain value decreases, but little change in the dielectric absorption is observed. In the range 107 to 108 rad, the moisture-regain value decreased, and this would suggest some alteration in the submicroscopic structure and the chemical structure from chain cleavage and carbonyl and carboxyl group formation. On the other hand, the dielectric absorption increases and this would indicate that the number of methylol group contributing to the reorientation increases in the crystalline region (increase of crystalline defects) as well as in the amorphous region contributing to water absorption. At dose levels greater than 108 rad, the moisture-regain value starts to rise again, whereas the dielectric absorption decreases rapidly. These would suggest that marked reduction of the crystalline region and oxidization of methylol group take place. Furthermore, the mechanism of an additional dielectric relaxation process occurred in low frequency range resulting from is discussed. (auth.)

  2. Deep hole traps created by gamma-ray irradiation of GaInP

    Energy Technology Data Exchange (ETDEWEB)

    Sung Wei-Jer; Liu Tong-Yuan; Yang Su-Lin; Huang Kai-Feng; Tseng Tseung-Yuen [National Chiao Tung Univ., Hsinchu, Taiwan (China); Chou, Fong-In; Wei, Yuan-Yaw [NSTDC of National Tsing Hua Univ., Hsinchu, Taiwan (China)

    2001-12-01

    Deep hole traps created by gamma-ray irradiation of Al/GaInP Schottky diodes grown by metal-organic chemical vapor deposition (MOCVD) were studied by using deep level transient spectroscopy (DLTS) technique. Two distinct deep hole traps, A and B, were observed in the irradiated GaInP samples. According to the analysis of trap concentration in various samples, the trap A is verified as a bulk defect located at 0.29 eV above the valance band. Meanwhile, the trap B is an interface state originated from the junctions of Al/Mg-doped GaInP contacts. (author)

  3. Deep hole traps created by gamma-ray irradiation of GaInP

    International Nuclear Information System (INIS)

    Deep hole traps created by gamma-ray irradiation of Al/GaInP Schottky diodes grown by metal-organic chemical vapor deposition (MOCVD) were studied by using deep level transient spectroscopy (DLTS) technique. Two distinct deep hole traps, A and B, were observed in the irradiated GaInP samples. According to the analysis of trap concentration in various samples, the trap A is verified as a bulk defect located at 0.29 eV above the valance band. Meanwhile, the trap B is an interface state originated from the junctions of Al/Mg-doped GaInP contacts. (author)

  4. Radiation resistance of elastomers

    International Nuclear Information System (INIS)

    Various data has indicated that some elastomers have much higher radiation resistance than Viton. Nine samples of elastomers were irradiated with gamma rays. Two Ethylene Propylene Diene compounds, EPDM's, were found to exhibit acceptable properties for o-rings after radiation levels of 5x108 rads, while Viton failed at 1x107 rads. Vacuum tests also were favorable so EPDM o-rings were chosen as seals in the Energy Saver cryostat vacuum system

  5. Radiation resistance of elastomers

    International Nuclear Information System (INIS)

    Various data has indicated that some elastomers have much higher radiation resistance than Viton. Nine samples of elastomers were irradiated with gamma rays. Two Ethylene Propylene Diene compounds, EPDM's, were found to exhibit acceptable properties for o-rings after radiation levels of 5 x 108 rads, while Viton failed at 1 x 107 rads. Vacuum tests also were favorable so EPDM o-rings were chosen as seals in the Energy Saver cryostat vacuum system

  6. method of fabricating gamma ray irradiation source filled in a plastic tube

    International Nuclear Information System (INIS)

    Purpose: To fabricate gamma ray irradiation source with safety and effectively by filling target substances and spacers in a cylindrical covering material made of radiation resistant plastics and then mounting the tube into a radiation resistant irradiation capsule for radioactivation. Constitution: Each types of targets are previously filled together with fine wire spacers made of radiation resistant plastics in the covering material made of radiation resistant fine plastic tube, and the tube is filled within a radiation resistant plastic irradiation capsule. Then, by the irradiation of neutron rays, each of the targets can be activated. Various forms of targets can be used such as elemental metals, alloys and compounds depending on purposes of use and experiments. After the irradiation of the neutron rays, the polyethylene covering material and the nylon fine wire are not denatured by the radiation damages and the fabrication can be conducted with safety and effectively. (Seki, T.)

  7. Effect of gamma-ray irradiation on the deoxygenation of salt-containing water using hydrazine

    International Nuclear Information System (INIS)

    In spent fuel pools at the Fukushima Daiichi nuclear power plant, hydrazine was added to salt-containing water in order to reduce dissolved oxygen. Hydrazine is known to reduce dissolved oxygen in high-temperature pure water, but its deoxygenation behavior in salt-containing water at ambient temperature in the presence of radiation is unknown. Deoxygenation using hydrazine in salt-containing water was thus investigated using a 60Co gamma-ray source and artificial seawater at room temperature. Water samples containing a small amount of hydrazine were irradiated at dose rates of 100 - 10,000 Gy/h. The concentration of dissolved oxygen in the water samples was measured before and after irradiation. Notably, a decrease in the dissolved oxygen was only observed after irradiation, and the dissolved oxygen concentration decreased with increasing dose rate and irradiation time. The rate of decrease in the amount of dissolved oxygen using hydrazine was slow in the presence of salts. Kinetic considerations suggested that the deoxygenation of the salt-containing water exposed to gamma-ray irradiation using hydrazine was suppressed by chloride ions. (author)

  8. Spatial charge in low density polyethylene irradiated with low dose gamma-ray

    International Nuclear Information System (INIS)

    The research on the effect that radiation exerts on polymer insulation materials is indispensable for the improvement of safety in nuclear power generation, future nuclear fusion power generation and the expansion of space utilization, and it is important also as the technique for examining the electrical properties of polymer insulation materials themselves. However, in the case of carrying out irradiation at relatively low dose, the example of the research on the initial state of deterioration is few. Therefore, in this study, through the measurements of thermal pulse current, residual voltage, thermal stimulation currents, radiation-induced electrical conduction and other experiment, the behavior of spatial charges in the low density polyethylene irradiated with low dose gamma-ray was investigated. Gamma ray was irradiated at room temperature in the atmosphere at the dose rate of 200 Gy/h. The samples and the experimental method and the results are reported. In the irradiated samples, at a relatively low electric field of 0.1 MV/cm, hetero spatial charges were formed near both electrodes. In the irradiation of 0.2 - 5 kGy, either many carriers are generated or the mobility of carriers increases, which is one of the causes of initial deterioration. (K.I.)

  9. Genetic variation of natural orchid phalaenopsis amabilis (L.) blume produce gamma ray irradiation

    International Nuclear Information System (INIS)

    New cultivars of Phalaenopsis amabilis (L.) Blume were obtained through gamma-rays Co-60 irradiation. The result showed phenotypic variation which justifies a molecular biology observation to investigate whether the variation was caused by the change on cultivar’s genotypic traits. A study to describe the genetic variability among individuals of the irradiated cultivars was then conducted using RAPD Technique. The materials used were cultivars obtained by 0, 15, 20, 25, 20+20 and 40 Gray irradiations. DNA genome of each plant was isolated and was amplified with 22 primers randomly. The PCR analysis was done with 1.5 % agarose. The DNA analysis used 8 selected primers out of 22. Polymorphism and molecular diversity were analyzed with Nei’s gene diversity method through GenAlex 6.1 program. The study showed that genetic diversity might be detected at the early growth stage of the gamma ray Co-60 irradiated cultivars using RAPD, and irradiation dose of 15 and 40 Gray gave high genetic diversity compared to control. (author)

  10. An aberration in gamma-ray enhanced reactivation of irradiated adenovirus in ataxia telangiectasia fibroblasts

    International Nuclear Information System (INIS)

    Ataxia telangiectasia (AT) is a rare human genetic disorder which includes a predisposition to lymphoreticular cancers and a hypersensitivity to conventional radiotherapy. Furthermore, AT cells in vitro exhibit a hypersensitivity to ionising radiation that appears to be correlated with an increased frequency of chromosomal aberrations, a resistance of de novo DNA synthesis to inhibition by radiation-induced DNA damage, a reduced mitotic delay and possible defects in DNA repair. A sensitive viral assay has been used to investigate the capacity of gamma-irradiated AT cells to support the replication of undamaged virus, as well as the extent to which the survival of radiation-damaged virus was affected by gamma-irradiation of these host cells prior to infection. The expression of such enhanced reactivation (ER) of both u.v.-irradiated and gamma-irradiated adenovirus type 2 (Ad2) was examined in a variety of normal and AT human fibroblast strains. For immediate infection of normal human fibroblasts, both a decrease in unirradiated virus expression and an increase in ER were observed with increasing gamma-ray dose to the cells. In contrast, AT fibroblasts were found to be deficient in gamma-ray ER of irradiated Ad2, and this defect appeared to be related to a marked relative radioresistance of unirradiated virus expression in AT compared to normal cells. (author)

  11. Neutron, gamma ray and post-irradiation thermal annealing effects on power semiconductor switches

    International Nuclear Information System (INIS)

    The effects of neutrons and gamma rays on the electrical and switching characteristics of power semiconductor switches must be known and understood by the designer of the power conditioning, control, and transmission subsystem of space nuclear power systems. The SP-100 radiation requirements at 25 m from the nuclear source are a neutron fluence of 1013 n/cm 2 and a gamma dose of 0.5 Mrads. Experimental data showing the effects of neutrons and gamma rays on the performance characteristics of power-type NPN Bipolar Junction Transistors (BJTs), Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs), and Static Induction Transistors (SITs) are given in this paper. These three types of devices were tested at radiation levels which met or exceeded the SP-100 requirements. For the SP-100 radiation requirements, the BJTs were found to be most sensitive to neutrons, the MOSFETs were most sensitive to gamma rays, and the SITs were only slightly sensitive to neutrons. Post-irradiation thermal anneals at 300 K and up to 425 K were done on these devices and the effectiveness of these anneals are also discussed

  12. Fractionated Irradiation of Mice with Fission Neutrons and Co60 Gamma Rays

    International Nuclear Information System (INIS)

    This paper deals with the comparative effects of fission neutrons and Co60 gamma-rays, delivered at low dose rates over a 13-week period, on survival in CF No. 1 female mice. Animals were exposed in the gamma-neutron chamber at Argonne's CP-5 research reactor. The dose rate was approximately 0.75 rad/min for the neutrons and 0.25 rad/min for the gamma-rays. Fractionation of the weekly neutron dose into one, three, or six doses did not appear to have a significant effect on the mean survival times of the irradiated mice. Thymic tumours were observed in at least 90% of the mice that died following these fractionated exposures to either neutrons or gamma-rays. The RBE (n/?) for these 13-week exposures at low dose rates appears to resemble the acute RBE (2.8) rather than the higher value (5 to 15) reported when mice are exposed for the length of their lives to small daily doses. (author)

  13. Influence of gamma-ray irradiation on Faraday effect of Cu-doped germano-silicate optical fiber

    International Nuclear Information System (INIS)

    Influence of gamma-ray irradiation on the Faraday effect of the Cu-doped germano-silicate optical fiber was investigated. The Verdet constant of the gamma-ray irradiated optical fiber at 660 nm was measured to be 3.07 rad T?1 m?1, 1.46 times larger than that of before the irradiation at total dose of 1200 Gy. Cu-related radiation-induced defect centers and Cu metal particles which were reduced from Cu2+ ions by the irradiation are thought to be responsible for the increase in the Verdet constant of the optical fiber

  14. Effect of gamma ray irradiation on deoxygenation by hydrazine in artificial seawater

    International Nuclear Information System (INIS)

    At the spent nuclear fuel pools in the Fukushima Daiichi Nuclear Power Plant, hydrazine has been added to reduce dissolved oxygen in the pool water containing salts. The reduction behavior of dissolved oxygen in seawater with hydrazine in the presence of radiation is unknown. The effect of gamma ray irradiation on deoxygenation by hydrazine in artificial seawater was investigated at room temperature. We placed the artificial seawater with a small amount of hydrazine under gamma ray irradiation at dose rates of 0.3-7.5 kGy/h. The concentration of dissolved oxygen in the solutions was measured before and after the irradiation. The concentration of dissolved oxygen hardly decreased in the absence of gamma radiation in a few hours, whereas it markedly decreased in the presence of gamma radiation. The concentration of dissolved oxygen decreased with irradiation time. At this moment, hydrazine concentration decreased more than twice the dissolved oxygen concentration. This shows that some gamma radiolysis products of hydrazine act as deoxidizers. The concentration of dissolved oxygen in artificial seawater could be decreased by the addition of a small amount of hydrazine in the presence of gamma radiation at room temperature. (author)

  15. Chemical and physical changes of packaging materials for food by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Film and sheet of polyethylene and polystyrene added with BHT, Irganox 1076, Irgafos 168 and Irganox 1010 as antioxidant were treated by gamma-ray irradiation. The change of additive residues, monomer and decomposition products of additives, the tensile strength and change of tone and odor were studied. Polystyrene was the most stable for irradiation. Polypropylene products and large amount of decomposition products indicated very decrease of tensile strength. Polyethylene was more stable than polypropylene, but yellowing was very large. Acetic acid, propion acid, 2-butanone and 2, 4-penyanedione in the decomposition products were controlled by adding antioxidants. Their irradiated decompositions, DTBBQ and 2, 4-DP, were observed. Decreasing of the tensile strength of polypropylene was improved by addition of Irganox 1010 and Irgafos 168. The antioxidants were decreased by irradiation, especially BHC and Irgafos 168. (S.Y.)

  16. Evaluation of the effect of gamma-ray irradiation on starch by near-infrared spectroscopy

    International Nuclear Information System (INIS)

    In order to evaluate the effect of gamma-ray irradiation on starch, near-infrared absorption spectra of four groups of starch samples, control, 10, 20 and 30 kGy irradiated, were measured. By the preliminary analysis, it was revealed that 1 702 and 2 100 nm were effective in predicting the irradiation dose on starch. On the other hand, samples were divided into calibration and validation set. The multi-regression analysis of the calibration set was carried out with adopting 1702 or 2100nm as the first wavelength, and the resulting calibration curves were named calibration A and B. Using these calibration curves, the irradiation dose of the validation set was predicted. Although the accuracy of the prediction was poor, it seemed that the non-irradiated and the irradiated samples could be discriminated by an appropriate borderline. Therefore, a new irradiation index was defined as non-irradiated = 0 and irradiated = 1. In the same way as the case of four groups, calibration C and D, in addition, calibration E, which using 1702 nm only, were developed and the irradiation index of the validation set was predicted. Although there were a few samples that could not be accurately predicted with calibration C and D, there was only one wrong discrimination with calibration E and its prediction accuracy was 96.2%

  17. Effect of neutron and gamma-ray irradiation on the transmittance power of glasses and glues

    Energy Technology Data Exchange (ETDEWEB)

    Beigveder, J.M.; Genova, I.; Perez, G.; Ruiz, J.A.; Arce, P.; Barcala, J.M.; Fernandez, M.G.; Ferrando, A. E-mail: ferrando@ae.ciemat.es; Fuentes, J.; Josa, M.I.; Molinero, A.; Oller, J.C.; Calvo, E.; Figueroa, C.F.; Rodrigo, T.; Vila, I.; Virto, A.L.; Fenyvesi, A.; Molnar, J.; Sohler, D

    2002-11-11

    LHC, working at the expected nominal luminosity, will induce an extremely high irradiation in the CMS experiment. The CMS alignment system uses optical elements to build the laser beams paths. Optical properties of basic components such as glasses and glues may be affected and their transmission power may degrade significantly. We have proceeded to a first test of various glasses and glues and identified some of them that can stand up to 150 kGy of gamma-rays plus 5x10{sup 14} neutrons/cm{sup 2}.

  18. Effect of neutron and gamma-ray irradiation on the transmittance power of glasses and glues

    International Nuclear Information System (INIS)

    LHC, working at the expected nominal luminosity, will induce an extremely high irradiation in the CMS experiment. The CMS alignment system uses optical elements to build the laser beams paths. Optical properties of basic components such as glasses and glues may be affected and their transmission power may degrade significantly. We have proceeded to a first test of various glasses and glues and identified some of them that can stand up to 150 kGy of gamma-rays plus 5x1014 neutrons/cm2

  19. Safeguards on the depleted uranium used in gamma ray irradiator as shield material

    International Nuclear Information System (INIS)

    Depleted uranium used in gamma ray irradiator as the shielding material was not completely investigated and properly reported by the Atomic Energy Act until now, The IAEA required to report the status of the companies using small amount of uranium and information for 42 NDT companies was declared in 1999. And IAEA inspector visited some company to confirm their declarations. The Additional protocol proposed as the strengthened safeguards system by the IAEA, which was ratified through the national assembly on February 9, 2004, and was entered into force on February 19, 2004. The government is investigating the amount, purpose and location of depleted uranium in the area of non-nuclear use.

  20. Ageing evaluation for low voltage cables with low dose rate gamma ray irradiation accelerated ageing tests

    Energy Technology Data Exchange (ETDEWEB)

    Tatsuoka, T.; Ibusuki, Y.; Furuhashi, Y.; Takamori, K.; Tezuka, H. [RD Center, Tokyo Electric Power Company (Japan); Hashimoto, A. [Nuclear Asset Management Department, Tokyo Electric Power Company (Japan)

    2011-07-01

    Low voltage cables are installed in nuclear power plants to supply electric power and signals. Long-term reliability of cables in nuclear power plants is expected from some experimental results reported in Institute of Electrical Engineering of Japan (IEEJ). Significant ageing of real cables has never been observed in nuclear power plants. However, some cables may get oxidation slowly under irradiation and thermal environments during normal operation. For lifetime extension of nuclear power plants, cable ageing evaluation has become very important. To optimize lifetime prediction method of cables and to understand cable ageing mechanism, ageing evaluation of low voltage cables, especially insulators, with gamma ray irradiation and thermal accelerated ageing tests were conducted. Two kinds of gamma ray irradiation and thermal accelerated ageing tests with low dose rate (around 3.5 Gy/h) and low temperature (room temperature and 80 C) and two kinds of thermal accelerated ageing tests at 80 C in different oxygen concentration (5 and 20 % O{sub 2}) were performed, respectively. The accelerated ageing tests conditions are relatively milder than those had conducted by many researchers for many years. The studies are focused on Flame Retardant Ethylene-propylene Rubber (FR-EPR) insulators and Cross-linked Polyethylene (C-PE) insulators. Insulators had almost no indication of ageing after several thousand hours of the accelerated ageing tests. (authors)

  1. Effects of gamma-ray irradiation on discharge characteristics of organic insulating materials

    International Nuclear Information System (INIS)

    Organic insulating materials have been widely used as insulators for electrical elements in various environmental conditions. These investigations are further enhanced due to the increasing of organic insulating materials being used in radiation environment of space and nuclear power facilities. This paper describes the effects of gamma-rays irradiation on the discharge characteristics of organic insulating materials. The samples of modified polyphenylene oxide, polybutylene, epoxy resin and polybutylene terephthalate which were irradiated in air up to 100 kGy and 1 MGy with a dose rate of 10 kGy/h using a 60Co gamma source. The experiment was carried out on the sample surface by applied a dc impulse voltage between a plate and needle electrode. The solution droplet was placed on the plate of sample in contact with the needle electrode. The total dose effects on the discharge quantity, contact angles and extending length of droplet have been studied. As the total doses are increased, the tendency of discharge quantity decreased with modified polyphenylene oxide, polybutylene and epoxy resin, on the other hand the discharge quantity increases with polybutylene terephthalate. The author found that the effects of gamma-rays irradiation on surface discharging quantity are due to radiation-induced degradation and cross-linking of organic insulating materials. (author)

  2. Influence of gamma rays irradiation to chlorphyriphos insecticides residues in grapes (vitis vinifera L.)

    International Nuclear Information System (INIS)

    Simulation methods to determination of chlorphyriphos insecticides residue in grapes cause effect gamma rays, was done. Fruits of grapes soaked with chlorpyriphos insecticide solution high level concentrated (100 ppm; 200 ppm; and 300 ppm) for 3 (three minutes). The treatment of the sample was direct of extraction after soaks; extract after storage for one week after soak, and extract after soak after storage for one week after irradiation at 0.5 kGy; 1.0 kGy; and 1.5 kGy dose. Extraction methods using ethyl acetate solvent, and using sodium sulphate as to dryed water level in grapes, and then extractan was injected to chromatography gas use electron capture detector. The result indicated that occur of descent of chlorpyrifos residues from eachs soaked consequence at storage for one week was amount 7,55; 8,42; and 18,88% respectively, while of consequence irradiation of gamma ray at 0,5 kGy doses, will be descent of chlorpyrifos residues in amount 13,90; 19,16; and 52,79% respectively, and at 1,0 kGy doses irradiation will be descent in amount 34,45; 36,15 and 49,79%, respectively. (author)

  3. Behavioral changes in rats prenatally irradiated with low dose of gamma-rays

    International Nuclear Information System (INIS)

    In this work, the effects of prenatal gamma-irradiation on behavior in adult Sprague-Dawley rats were studied. Four months old female rats were irradiated with a dose of 1 Gy of gamma-rays on day 15 of gestation. The offspring of irradiated mothers (n=26) and that of control, non-irradiated mothers (n=36) of both sexes at the age of 3 month were tested in Morris's water maze and in open field test. All experimental groups showed a tendency to shortening the time needed to reach the platform in each trial in Morris water maze. Statistically significant difference between irradiated and control rats was detected only in males on 3rd experimental day. The ability to remember the position of the platform was not altered in irradiated animals after a 4 day pause. In open field test, statistically significant differences in comparison with controls were detected in number of squares entered and in crossings of the central square (P ? 0.05) in males. These findings suggest, when comparing with results of other authors, that irradiation effects on postnatal behavior in rats are extremely dependent on the time point of irradiation and that a correlation exist between the developmental stage of the individual brain structures at time of irradiation and the late behavioral effects. (authors)

  4. Thermal, tensile and rheological properties of low density polyethylene (LDPE) processed irradiated by gamma-ray

    Energy Technology Data Exchange (ETDEWEB)

    Ferreto, Helio F.R.; Oliveira, Ana C.F. de; Parra, Duclerc F.; Lugao, Ademar B., E-mail: hferreto@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of this paper is to investigate structural changes of low density polyethylene (LDPE) modified by ionizing radiation (gamma rays). The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. The samples were prepare in hydraulic press in temperature 180 deg C after was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h in inert atmosphere. The changes in molecular structure of LDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere. (author)

  5. Mutation induction in chrysanthemum through in vitro acute and chronic irradiations with gamma rays

    International Nuclear Information System (INIS)

    In Vitro culture of chrysanthemum variety 'Reagan Dark Splendid' was established using explants from axillary buds and ray florets. Shoots produced in vitro culture from axillary buds were irradiated with acute gamma rays of 30 Gy. While multiple shoots produced from in vitro culture of ray florets were irradiated with chronic gamma rays of 112 and 140 Gy. The irradiated shoots were then multiplied two times by single-node cuttings from M1V1 to M1V3. Controls and irradiated shoots were rooted, transferred to soil in the greenhouse, and finally transplanted in the field. Observation and measurement were made at flowering time for height, number of nodes per plant and flower colour mutation frequency. Flower colour mutation frequency among the irradiated plants with 30, 112 and 140 Gy was 8.2, 9.3 and 15.3% respectively. Eleven variants were selected among the M1V3 plants from 30 Gy dose treatment. Selected variants had flower colour varying from red, red-purple and yellow-orange. Nine variants were selected among the M1V3 plants from 112 Gy dose treatment. Selected variants had flower colour varying from red, red-purple, purple and yellow-orange. Sixteen variants were selected from 140 Gy dose treatment. They had flower colour varying from red-purple, purple, orange-red, yellow-orange and yellow. These variants were multiplied through in vitro culture as well as by conventional cutting. They will be evaluated for their performance, stability and uniformity in the field, and for market value during the next planting season. (author)

  6. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS

    Energy Technology Data Exchange (ETDEWEB)

    Clark, E.

    2011-09-22

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Polymeric materials become damaged by exposure over time to ionizing radiation. Despite the limited lifetime, polymers have unique engineering material properties and polymers continue to be used in tritium handling systems. In tritium handling systems, polymers are employed mainly in joining applications such as valve sealing surfaces (eg. Stem tips, valve packing, and O-rings). Because of the continued need to employ polymers in tritium systems, over the past several years, programs at the Savannah River National Laboratory have been studying the effect of tritium on various polymers of interest. In these studies, samples of materials of interest to the SRS Tritium Facilities (ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, Teflon{reg_sign}), Vespel{reg_sign} polyimide, and the elastomer ethylene propylene diene monomer (EPDM)) have been exposed in closed containers to tritium gas initially at 1 atmosphere pressure. These studies have demonstrated the degradation of properties when exposed to tritium gas. Also, the radiolytic production of significant amounts of hydrogen has been observed for UHMW-PE and EPDM. The study documented in this report exposes two similar formulations of EPDM elastomer to gamma irradiation in a closed container backfilled with deuterium. Deuterium is chemically identical to protium and tritium, but allows the identification of protium that is radiolytically produced from the samples. The goal of this program is to compare and contrast the response of EPDM exposure to two different types of ionizing radiation in a similar chemical environment.

  7. Effect of gamma rays on sex ratio, emergence and lifespan of cucurbits fruit fly dacus ciliatus (low) irradiated as pupae

    International Nuclear Information System (INIS)

    The result showed the pupae at the age 1 or 2 days old was very sensitive to all doses of gamma rays, the percentage of adults emerged was zero at the dose of 45 gray and highest and the gigh percentage of adults emergence was recorded when the pupae irradiated at five days ald and the mean percentage of emerged adults was approximated with that of the control group. This study also showed that there was an effect of gamma radiation on the average percentage of deformed at adult stage and it was about 1:1 (male: female). On the other hand, the mean lifespan of females and mice s adult were decreased as the dose of gamma rays increases and the pupae irradiated at youngest ages. The longest life span of females was recorded when the pipa irradiated at five days old with any of the gamma rays dose. (Author)

  8. Survival of embryo irradiated with gamma rays by embryo culture in Brassica pekinensis Rupr

    International Nuclear Information System (INIS)

    The effect of irradiation on the survival rates and embryonic development of Brassica pekinensis RUPR. (Varieties; Kashin, Kohai 65 nichi and kairyochitose) was investigated. The purpose of this study was to seek ways of increasing the survival rates of embryos such as B.oleracea obtained through embryo culture techniques after irradiation doses affecting seed fertility and germination, for the purpose of increasing mutation rates. Embryos at different developmental stages ranging from the globular to the early heart stages were irradiated with 20 KR of gamma rays at the daily rate 0L 20 KR or 10 KR (Fig.1 and Table 1). The embryos were excised from ovules 4 to 10 days after irradiation and cultured on White's medium. The shooting and rooting rates on the 34th day of culture were higher at the dose of 10 KR/day than 20 KR/day and were lower when the materials were irradiated at the young embryonic stage (Table 3). Varietal differences in the shooting and rooting rates were also observed. The irradiated embryos survived mainly in the state of callus. It was concluded that the embryo culture technique was successful when applied to irradiated embryos excised at the young embryonic stage and that the technique affected B.pekinensis less than B.oleracea

  9. Chemical and Biological Studies on Cumin Fruits Irradiated by GAMMA Rays for Conservation

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the effect of different doses of gamma irradiation (0, 5, 10 and 15 KGy) and different storage periods (0, 3 and 6 months) in different package materials (cotton or polyethylene bags) on essential oil quality and chemical composition of cumin (Cuminum cyminum) fruits. On the other hand antimicrobial activity of treated cumin fruits essential oil and its extracts at 0, 5000, 10000, 20000 and 40000 ppm were investigated. Results showed that the highest essential oil % was obtained from fruits stored for 3 months in cotton bag without gamma irradiation. Concerning the effect of essential oil as antimicrobial agent, the highest antibacterial activity was obtained by essential oil isolated from irradiated polyethylene packed fruits at 5 KGy then stored for 3 months (Staphylococcus aureus) or irradiated polyethylene packed ones at 15 KGy without storage (Salmonella typhimurium). On the other hand, the highest antifungal activity against Aspergillus niger and Penicillium digitatum was obtained by essential oil isolated from unirradiated packed in polyethylene fruits then stored for 6 months. Non-stored packed in cotton bag fruits irradiated with gamma rays at 10 KGy produced essential oil with highest antiyeastal activity. Cumin fruits extract at 40000 ppm when combined with different treatments presented the highest antimicrobial activity (represents as inhibition zone) against all studied microbes except with P. digitatum. Cumin extract at 40000 ppm when extracted from irradiated packed fruits in polyethylene bags with gamma rays at 5 KGy without storage or with 6 months storage or irradiated at 15 KGy of packed fruits in cotton bag with storage for 3 months presented the highest significant inhibition zones against S. aureus. The same concentration of extracted cumin from uni radiated packed in cotton bag fruits and storage for 6 months presented the highest inhibition zone of S. typhimurium. Also, with the same concentration, extracted cumin from irradiated at 10 KGy of packed in cotton bag fruits without storage or in polyethylene and stored for 3 months presented the highest inhibition zones of A. niger. Cumin extract at 5000 ppm when extracted from irradiation at 10 KGy of packed in cotton bag fruits and stored for 3 months presented the highest values of P. digitatum. On the other hand, the superior concentration of cumin extract (40000 ppm) presented the highest antiyeastal effect when extracted from irradiated packed in polyethylene fruits at 10 KGy and stored for 6 months.

  10. TL and PTTL in natural fluorite previously irradiated with gamma rays and heavy ions

    International Nuclear Information System (INIS)

    The effect of annealing temperature on the phototransfer thermoluminescence (PTTL) signal was studied to determine the appropriate annealing temperature for treating the natural powder before irradiation. The temperatures used to anneal virgin natural fluorite samples (only natural dose without giving the samples any artificial doses) were 150, 250, 350, 450, 550, 650 and 750oC for a duration of 1 h in each case. The results show that the PTTL response did not change for anneal temperatures up to 450oC, but at higher temperatures the signal decreased rapidly. The height of the 90oC peak decreased by two orders of magnitude as the anneal temperature increased from 450 to 750oC, whilst the height of the 180oC peak decreased by three orders of magnitude between the same two annealing temperatures. In order to investigate the effect of previous gamma rays and heavy ion irradiation on thermoluminescence (TL) and PTTL signals, powdered samples of natural fluorite from Cornwall, England, were annealed at 500oC and then irradiated (at GSI, Darmstadt, Germany) with 161Dy ions of energy 13 Mev/n; the range of fluences used was from 104to 1012 ion cm-2. Identical samples were given gamma doses in the range 1 Gy to 2.6 x 104 Gy in order to compare the effects of gamma rays and heavy ions. The sensitivities of TL and PTTL were studied by giving the samples a gamma test dose of 1 Gy after annealing the samples at 500oC for 30 min in order to eliminate the TL resulting from previous gamma or heavy ion irradiation. (Author)

  11. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of 60Co

    International Nuclear Information System (INIS)

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with 60Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective in lowering the vas deferens twitch in rats in comparison to native crotamine. In addition, the behavior of irradiated toxin in tonic contraction, modulated by noradrenaline, was different from that observed for the native toxin. (author)

  12. Gamma-Ray Irradiation Experiments of Collimator Key Components for the 3GeV-RCS of J-PARC

    CERN Document Server

    Kinsho, Michikazu; Masukawa, Fumihiro; Ogiwara, Norio; Takeda, Osamu; Yamamoto, Kazami

    2005-01-01

    The turbo molecular pump and the stepping motor which can be operated exposed to high radiation has been under development at JAERI for use in the 3GeV-RCS of the J-PARC. In order to determine the extent of radiation damage to those instruments, gamma-ray irradiation testing was performed at JAERI. It was succeed that the turbo molecular pump and stepping motor could operate properly when given an absorption dose more than 15 MGy in a gamma-ray irradiation environment.

  13. A comparative experiments for tube agglutination test of pullorum antiserum with gamma ray Co60 irradiated salmonella pullorum

    International Nuclear Information System (INIS)

    An agglutinability between naturally infected positive chicken serum of pullorum disease and hyperimmunized rabbit antiserum was compared. And the following results were obtained and summarized. On the agglutinability, Salmonella pullorum antigen which irradiated gamma-ray was better than another both formalized and heated antigen. Time of judgemented as positive titer in the tube agglutination test to the naturally infected positive chicken serum was it most suitable for 12 hours at 37°C. Agglutination titer of positive immune chicken serum against gamma-ray irradiate Salmonella pullorum were as 320 approximately 640x. (author).

  14. Technical data on electron beam and gamma ray irradiation facilities. Electron accelerator and 60Co irradiation facility

    International Nuclear Information System (INIS)

    Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), have an electron beam facility employing an industrial-scale electron accelerator with the maximum acceleration voltage of 2 MV, and world-class cobalt 60 gamma ray irradiation facilities consisting of 3 buildings and 8 irradiation rooms which cover 6 decade of dose rate range. These facilities are in operation as a world Center of Excellence, widely for users inside and outside of JAEA to perform research and testing or collaborative work on multipurpose such as material developments, environmental technology, and biotechnology. The present report describes characteristics of irradiation field, auxiliary utilities in irradiation rooms, and basic data for irradiation and dose evaluation of a sample. (author)

  15. EFFECT OF GAMMA RAY IRRADIATION ON INTERLAMINAR SHEAR STRENGTH OF GLASS FIBER REINFORCED PLASTICS AT 77 K

    International Nuclear Information System (INIS)

    It is known that an organic material is damaged by gamma ray irradiation, and the strength after irradiation has dependence on the gamma ray dose. These issues are important not only to make global understanding of electric insulating performance of glass fiber reinforced plastics (GFRP) under irradiation condition but also to develop new insulation materials. This paper presents the dependence of fracture mode and interlaminar shear strength (ILSS) on the material and the gamma ray irradiation effect on the fracture mode and the ILSS. 6 mm radius loading nose and supports were used to prompt ILS fracture for a short beam test. A 2.5 mm thick small specimen machined out of a 13 mm thick G-10CR GFRP plate (sliced specimen) showed lower ILSS and translaminar shear (TLS) fracture, although the same size specimen prepared from a 2.5 mm G-10CR GFRP plate (non-sliced specimen) showed ILS fracture and the higher ILSS. Both type of specimens showed the degradation of ILSS after gamma ray irradiation. The fracture mode of the non-sliced specimen changed from ILS to TLS fracture and no bending fracture was observed. The resistance to shear deformation of glass cloth/epoxy laminate structure would be damaged by the irradiation

  16. Effects of gamma Rays Irradiation on resistance of Pseudomonas aeruginosa in various condition

    International Nuclear Information System (INIS)

    The investigation of gamma tays 60Co irradiation effect on resistance of bacteri P.aeruginosa has been done.The objective of the research was to know the D10 value of bacteria P.aeruginosa. By using of distilled water,talc and peanut powder as carrier in dry,wet,O2 and N2 condition the bacteria of P.aeruginosa were irradiated on gamma rays of 60Co with dose of O to 2.5 kGy,and with dose rate of 5 and 10 kGy/h.After irradiation the bacteria of P. aeruginosa were cultured in media of the Tryptone Soya Agar and incubatedat temperature of 32±2oC for 3 days. The survival colonies were calculated,and the data were used to make the curve and to determine the D10 value. The results of the experiments showed that D10 value of irradiated bacteria of P.aeruginosain the disitilled water,talc and peanut powder as carrier were not high significant.Nevertheless the D10 value of the irradiated at dose rate 10kGy/h show more higher tendency than at dose rate 5kGy/h. The D10 value of irradiated bacteria in the N2 condition was higher,if compared with in the O2 condition

  17. Sterilizing efficiencies of high energy electrons and gamma rays and judgment of irradiation history of medical products

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, Masayuki; Imai, Masahiko; Tabei, Masae [Tokyo Metropolitan Isotope Research Center (Japan); Yamada, Yoshio; Shimizu, Harumichi

    1995-03-01

    Polymer materials, used for medical products, were irradiated with gamma rays or with high energy electron beams, then the post-irradiation changes of radical concentrations in those materials were examined with a electron spin resonance spectroscopy. As the radical concentrations in polystyrene, silicon and some of polypropylene samples formed by gamma ray irradiation, and those in polystyrene, polyvinyl chloride and some of polypropylene samples formed by electron beam irradiation, were decreased rapidly, it was difficult to judge whether those materials were irradiated in the past days or not. However, radical concentrations in the other materials were high enough to measure even two years after irradiation. The radicals, resided in polypropylene needle cups after 5-11 months after irradiation, were relatively stable. The radical concentrations in the needle cups were higher in the case of gamma ray irradiation than electron beam irradiation. The radical concentrations in the needle cups about 4 years after irradiation, increased rapidly by heat treatment but those in non-irradiated needle cups increased a little. The changes of radical concentrations in polypropylene model samples, polytetrafluoroethylene and alanine dosimeter were examined, too. (author).

  18. Sterilizing efficiencies of high energy electrons and gamma rays and judgment of irradiation history of medical products

    International Nuclear Information System (INIS)

    Polymer materials, used for medical products, were irradiated with gamma rays or with high energy electron beams, then the post-irradiation changes of radical concentrations in those materials were examined with a electron spin resonance spectroscopy. As the radical concentrations in polystyrene, silicon and some of polypropylene samples formed by gamma ray irradiation, and those in polystyrene, polyvinyl chloride and some of polypropylene samples formed by electron beam irradiation, were decreased rapidly, it was difficult to judge whether those materials were irradiated in the past days or not. However, radical concentrations in the other materials were high enough to measure even two years after irradiation. The radicals, resided in polypropylene needle cups after 5-11 months after irradiation, were relatively stable. The radical concentrations in the needle cups were higher in the case of gamma ray irradiation than electron beam irradiation. The radical concentrations in the needle cups about 4 years after irradiation, increased rapidly by heat treatment but those in non-irradiated needle cups increased a little. The changes of radical concentrations in polypropylene model samples, polytetrafluoroethylene and alanine dosimeter were examined, too. (author)

  19. biotechnological studies on the irradiated potato (solanum tuberosum) with gamma rays

    International Nuclear Information System (INIS)

    Bacterial wilt or brown rot disease caused by Ralstonia solanacearum causes extensive annual losses of different crops especially potato crop. It is considered as one of the limiting factors for potato production and exportation in Egypt. Therefore, the main purposes of this study were to investigate the effect of gamma rays on two potato cultivars (Diamant and Spunta). And, to obtain new genotypes of potato resistant to bacterial wilt disease. This study was carried out in the field and Biotechnology laboratory of the Plant Res. Dept., Nuclear Res. Center, Inshas, Egypt and Genetics Dept., Faculty of Agricultural., Cairo Univ., during 2008-2011. In the field experiment, dry tubers of potato cultivars were irradiated by different doses of gamma rays (20, 30 and 40 Gy) to study the effect of gamma rays on the vegetative and yield traits. The results showed that there are no significant differences between cultivars for all studied traits except a number of tubers per plant trait. Also, there are only highly significant and significant differences between treatments for weight of tubers per plant and number of tubers per plant traits, respectively. However, there are only significant differences between the interactions of cultivars and treatments for plant height and weight of tubers per plant traits. Six genotypes were selected from M1V2 generation depending on high yield for RAPD analysis to determine their genetic variability from its parents at molecular level using 11 primers. The results of RAPD analysis showed that 11 primers generated 56 distinct bands of which 31 (55.4%) were considered as polymorphic. The similarity indices of six genotypes of potato and its parents ranged from 70 to 91%. The highest genetic similarity 91% was found between D20 genotype and its parent D0 (Diamant control). On the other hand, the lowest genetic similarity 70% was found between S30, S40 genotypes and its parent S0 (Spunta control). In the artificial infection experiment under in vitro condition, the irradiated and non-irradiated plantlets of potato were cultured on medium inoculated with local virulent isolate of R. solanacearum. The results showed that all in vitro plantlets of the treatments in Diamant and Spunta cultivars were susceptible except S20 treatment was resistant to the infection with R. solanacearum. Protein analysis showed that S20 genotype (resistant mutant) displayed 2 negative unique bands that may be responsible for resistance to R. solanacearum.

  20. The effect of red ginseng extract on superoxide dismutase activity in the kidney of gamma-ray irradiated mice

    International Nuclear Information System (INIS)

    This study was prepared to observe the change of enzyme activities in kidney treated with red ginseng extract in the gamma ray irradiated mice. Determine the activity of SOD, peroxidase, catalase in the kidney a period of 1 day, 2 day, 3 day, 4 day, 5 day after a saline injection or injection of red ginseng extract or gamma ray irradiated group into four classify. The activity SOD and catalase showed a tendency to increase and recovery at the early state but pay no regard. Where ase, the activity of peroxide restored and increased pay regard. A physiological saline injection group after gamma ray irradiation showed a tendency to diminish after remarkable increase of activity of SOD, peroxidase and catalase than control group. Injection group of red ginseng extract after gamma ray irradiation observed rapid recovery on activity of SOD, peroxidase, catalase than a saline injection group. Experimental result suggested that injection of red ginseng extract after irradiation have the recovery effect on the changed of activity of SOD, peroxidase and catalase against radiation injury

  1. Stability of polyvinylpolypyrrolidone against gamma-ray irradiation in HNO3 media

    International Nuclear Information System (INIS)

    Polyvinylpolypyrrolidone (PVPP) is a resin with adsorption selectivity for U(VI) in HNO3 media. The stability of this resin has been examined against gamma-ray irradiation using HNO3 solutions of various concentrations. Samples of PVPP immersed in HNO3 solutions up to 6 mol·dm-3 (=M) were irradiated by a 60Co source at 3.6 kGy·h-1 to reach 0.90 MGy at room temperature under ambient atmosphere. As a result, no clear decrease in the capacity for U(VI) when added in 3 M HNO3 was observed for any samples, or rather the capacity was found to increase by approximately 50 % for PVPP irradiated in 6 M HNO3. It was indicated from some spectroscopic analyses of the irradiated samples that the irradiation causes the cleavage of the pyrrolidone ring of PVPP. This occurs by the addition of an oxygen atom originating from HNO3, followed by the formation of straight-chain groups with multiple coordinative atoms by the successive addition of oxygen, finally leading to the generation of a primary-amine-type weakly-basic anion exchange resin. The increase in the U(VI) capacity would be due to the formation of the straight-chain groups. However, such structural changes were not observed by heating at 323 K in up to 6 M HNO3 for 20 days. Thus, it was shown that PVPP is a heat-resistant resin. (author)

  2. Gamma rays irradiation process on a restored painting from the XVII century

    International Nuclear Information System (INIS)

    The aim of this work is to emphasize the importance of a previous study of the materials composition and behavior of any art work which will be treated by gamma radiation, as well as to use complementary procedures to prevent recontamination after the treatment, since this is a non residual method. As an example the object of study is a Peruvian painting from the 17th century, which has been restored, contaminated by mould, treated by gamma rays, put in a hermetic acrylic box and showed microorganisms growth after six years. A new treatment was performed using the same process and a complementary method using cloistering with anoxia atmosphere to prevent recontamination. Before the first irradiation the influence of irradiation process on the original painting and on the materials used in the restoration process were investigated. These data were extremely important in the decision of the use gamma irradiation again on the same art work. The results obtained allowed concluding that the irradiation with the recommended dose of 6.0 kGy (at the first time) was not sufficient to kill all the fungi specimens in the art work. On the other hand the irradiation with the dose of 6.0 kGy (at the first time) and 9.0 kGy (at the second time), according to the literature, would not damage the restored painting. (author)

  3. Development of high yielding rice mutant variety through gamma rays irradiation

    International Nuclear Information System (INIS)

    A high yielding rice mutant IR8-151 was selected from gamma rays irradiated population of a coarse (non-aromatic) rice variety IR8. The mutant IR8-151 was significantly better than its mother variety IR8 in all the yield contributing parameters except 1000 grain weight. The mutant showed promising performance for paddy yield in varietal trials. It produced the highest paddy yield per unit area in zonal trials conducted for 3 consecutive years at 10 locations with diverse agro-climatic conditions. It maintained superiority over all the entries by yielding 9196, 7976 and 8021 kg of paddy yield per hectare during the years 1989, 1990 and 1991, respectively. On the basis of over all performance, IR8-151 mutant showed an increase of 10% and 9% in paddy yield over its parent IR8 and check variety IR6, respectively. (author)

  4. Life shortening and carcinogenesis in mice irradiated at the perinatal period with gamma rays

    International Nuclear Information System (INIS)

    This study elucidates the life-span radiation effects in mice irradiated at the perinatal period in comparison to mice irradiated at the young adult period. B6C3F1 female mice were irradiated at 17 days of prenatal age, at 0 days of postnatal age, or as young adults at 15 weeks of age with 190, 380, or 570 rads of 137Cs gamma rays. Mice irradiated at the late fetal period showed dose-dependent life shortening of somewhat lesser magnitude than that seen after neonatal or young adult irradiation. Mice exposed at the late fetal period were highly susceptible to induction of pituitary tumors for which the latent period was the longest of all induced neoplasms. Incidence of lung tumors in mice irradiated at the late fetal period with 190 and 380 rads was higher than in controls. Malignant lymphomas of the lymphocytic type developed in excess, after a short latent period, in mice irradiated fetally with the highest dose; susceptibility of prenatally exposed mice was lower than that of early postnatally exposed mice. Liver tumors developed more frequently in mice irradiated in utero than in controls; susceptibility to induction of this type of neoplasm was highest at the neonatal period. In general, carcinogenic response of mice exposed at the late fetal period resembled that of neonatally exposed mice but was quite different from that of young adult mice. Mice exposed as young adults have no, or low, susceptibility to induction of pituitary, lung, and liver tumors; and a higher susceptibility to induction of myeloid leukemias and Harderian gland tumors. 19 refs., 4 figs., 3 tabs

  5. Long-term effects in mice irradiated with low-dose gamma rays at juvenile period

    International Nuclear Information System (INIS)

    The present study was aimed to obtain dose-response relationships for the excess mortality from all causes and carcinogenesis after irradiation at juvenile period with gamma rays from 137Cs. B6C3F1 female mice were irradiated at 0 or 7 days of age with doses ranging from 0.19 to 5.7 Gy, and all the mice were allowed to live out their entire life span under a specific pathogenfree condition. The excess mortality in mice irradiated with 0.19 Gy at 0 day of age was estimated to be 8.8%. Mice of 7 days of age seemed to be more sensitive to induction of lethal diseases, as the excess mortality reached 22.3% after irradiation with 0.19 Gy. Dose-response relationship for the excess mortality was well described by an equation EM(D)=1- exp(-aD), where EM(D) represents excess mortality in a group irradiated with dose D. Incidences of liver tumors, pituitary tumors, ovarian tumors and lung tumors were significantly higher than control group in mice irradiated with doses lower than 1 Gy at 0 day of age. Shape of dose-response curves for these tumors was convex upward. Dose-response relationships were analyzed using a model which includes tumorigenic activity of radiation, sterilization of potentially tumorigenic cells and competing risks. Analysis of the experimental data showed that tumorigenic activity was proportional to dose for induction of these tumors. Relative risks at 1 Gy were estimated to be 2.52, 2.79, 16.5 and 3.17 for induction of liver tumors, pituitary tumors, ovarian tumors and lung tumors, respectively. This result implies that mice of the neonatal period are highly susceptible to induction of these tumors. On the other hand, shape of dose-response curve for incidence of bone tumors was concave upward. Dose-response relationship for induction of bone tumors was fitted by a model that tumorigenic activity of gamma rays is proportional to square of dose. (author)

  6. Diversity analysis of mangosteen (Garcinia mangostana irradiated by gamma-ray based on morphological and anatomical characteristics

    Directory of Open Access Journals (Sweden)

    MUH RAHMAD SUHARTANTO

    2010-01-01

    Full Text Available Widiastuti A, Sobir, Suhartanto MR. 2010. Diversity analysis of mangosteen (Garcinia mangostana L. irradiated by gamma-ray based on morphological and anatomical characteristics. Nusantara Bioscience 2: 23-33. The aim of this research was to increase genetic variability of mangosteen (Garcinia mangostana L. irradiated by gamma rays dosage of 0 Gy, 20 Gy, 25 Gy, 30 Gy,35 Gy and 40 Gy. Plant materials used were seeds collected from Cegal Sub-village, Karacak Village, Leuwiliang Sub-district, Bogor District, West Java. Data was generated from morphological and anatomical characteristics. The result indicated that increasing of gamma ray dosage had inhibited ability of seed to growth, which needed longer time and decreased seed viability. Morphologically, it also decreased plant heigh, stem diameter, leaf seizure, and amount of leaf. Anatomically, stomatal density had positive correlation with plant height by correlation was 90% and 74%. Gamma rays irradiation successfully increase morphological variability until 30%. Seed creavage after irradiation increased variability and survival rate of mangosteen.

  7. Determination of optimum dose of gamma rays for regeneration of irradiated rice callus. Screening for salt tolerance

    International Nuclear Information System (INIS)

    Determination of optimum dose of gamma rays for regeneration of irradiated rice callus. Screening for salt tolerance. Callus were gamma irradiated with acute doses between 10 and 60 Gy, with fractionated doses at 2 x 10 Gy, 2 x 20 Gy and 2 x 30 Gy of one-hour intervals for recovery. Immediately after irradiation, callus were placed on differentation medium supplemented with 37.5% sea water. The highest shoots regeneration (55.3%) was obtained after 20 Gy treatment. The lowest shoots regeneration (24%) was obtained after 60 Gy. Fertility of plants was not parallel with total shoots formation. Plants obtained from irradiated callus with fractioned doses had high fertility. Fractioned dose of 2 x 30 Gy produced plants with 74% fertility. Acute dose at 60 Gy produced sterile plants. Based on the quotient 'number of shoots or fertilities per number of irradiated units', the calculated value for the 10 Gy irradiation was put at 1.00. The relative effectivity of gamma-rays for shoots formation at 0, 10, 20, 30, 40, 50, 60, 2 x 10, 2, 20, 2 x 30 Gy was 0.61, 1.00, 1.01, 0.70, 0.63, 0.49, 0.44, 0.73, 0.70 and 0.46, respectively. The relative effectivity of gamma-rays for fertility at 0, 10, 20, 30, 40, 50, 60, 2 x 10, 2 x 20, and 2 x 30 Gy was 0.40, 1.00, 0.75, 0.59, 0.40, 0, 1.43, 1.45 and 1.35 respectively. Considering to the highest relative effectivity of gamma-rays for shoots formation and plant fertilities, it was concluded that optimum dose of gamma-rays to induce salt tolerance was fractioned dose of 2 x 10 Gy. (author). 10 refs.; 1 figs

  8. EPR investigation of the gamma-ray irradiated natural and tanned collagen.

    Science.gov (United States)

    Duliu, O G; Epuras, M; Trandafir, V

    2001-06-01

    Free radicals produced in natural and tanned collagen by gamma-ray irradiation within 1-15 kGy absorbed dose ranges were investigated by EPR spectroscopy. Tanned collagen was prepared using formaldehyde as well as aluminum basic salts [Al(OH)SO4] tanning processes. Both natural and formaldehyde-tanned irradiated collagen show the same kind of EPR spectrum consisting of a single broad, slightly asymmetric line. Irradiated collagen tanned by aluminum basic salts process displayed a complex EPR spectrum consisting of a superposition of broad and narrow lines. A computer simulation of this spectrum allowed to evidence the presence of seven different kinds of paramagnetic centers, including those observed in the irradiated natural collagen. Corresponding Spin Hamiltonian parameters (g-factor, hyperfine splitting constant) as well as relative concentrations of these centers were calculated. Experimentally determined relative concentrations display a positive correlation with the absorbed dose described by a linear-type dependence. After three weeks of storage at room temperature, the concentration of some centers diminished by about 50%. The possible nature of these centers is discussed in connection with the local structure of the tanned collagen. PMID:11300401

  9. EPR investigation of the gamma-ray-irradiated natural and tanned collagen

    International Nuclear Information System (INIS)

    Free radicals produced in natural and tanned collagen by gamma-ray irradiation within 1-15 kGy absorbed dose ranges were investigated by EPR spectroscopy. Tanned collagen was prepared using formaldehyde as well as aluminum basic salts [Al(OH)SO4] tanning processes. Both natural and formaldehyde-tanned irradiated collagen show the same kind of EPR spectrum consisting of a single broad, slightly asymmetric line. Irradiated collagen tanned by aluminum basic salts process displayed a complex EPR spectrum consisting of a superposition of broad and narrow lines. A computer simulation of this spectrum allowed to evidence the presence of seven different kinds of paramagnetic centers, including those observed in the irradiated natural collagen. Corresponding Spin Hamiltonian parameters (g-factor, hyperfine splitting constant) as well as relative concentrations of these centers were calculated. Experimentally determined relative concentrations display a positive correlation with the absorbed dose described by a linear-type dependence. After three weeks of storage at room temperature, the concentration of some centers diminished by about 50%. The possible nature of these centers is discussed in connection with the local structure of the tanned collagen

  10. EPR investigation of the gamma-ray-irradiated natural and tanned collagen

    Energy Technology Data Exchange (ETDEWEB)

    Duliu, O.G. E-mail: odlu@scut.fizica.unibuc.ro; Epuras, M.; Trandafir, V

    2001-06-01

    Free radicals produced in natural and tanned collagen by gamma-ray irradiation within 1-15 kGy absorbed dose ranges were investigated by EPR spectroscopy. Tanned collagen was prepared using formaldehyde as well as aluminum basic salts [Al(OH)SO{sub 4}] tanning processes. Both natural and formaldehyde-tanned irradiated collagen show the same kind of EPR spectrum consisting of a single broad, slightly asymmetric line. Irradiated collagen tanned by aluminum basic salts process displayed a complex EPR spectrum consisting of a superposition of broad and narrow lines. A computer simulation of this spectrum allowed to evidence the presence of seven different kinds of paramagnetic centers, including those observed in the irradiated natural collagen. Corresponding Spin Hamiltonian parameters (g-factor, hyperfine splitting constant) as well as relative concentrations of these centers were calculated. Experimentally determined relative concentrations display a positive correlation with the absorbed dose described by a linear-type dependence. After three weeks of storage at room temperature, the concentration of some centers diminished by about 50%. The possible nature of these centers is discussed in connection with the local structure of the tanned collagen.

  11. Methodology of in vitro gamma rays irradiations from Lonicera species; mutant description and biochemical characterization

    International Nuclear Information System (INIS)

    Microcuttings from five species of honeysuckle were irradiated in Petri dishes at the time of subculturing. The criterion of bud survival was defined as the percentage of buds providing shoots longer than 10 mm, after four months of post-irradiation culture. Cultivar survival was investigated after irradiation with a range of gamma rays from 10 to 60 Gy. A methodology of mutants isolation was developed to increase the chance for a mutation induced in one cell to give rise to a mutated sector in the regenerated plant. Among 200 regenerated plants from irradiation tests on Lonicera nitida 'Maïgrün', nine phenotypically obvious mutants were observed. They differ in leaf morphology, growth habit and vigour, and for chlorophyllian deficiencies. No difference between the control and the mutants was found in peroxidase, malate deshydrogenase (MDH) and glutamate oxaloacetate tranferase (GOT) zymograms. Only one very slender mutant has been characterized by the lack of a 52 kD band on the banding pattern of denaturated soluble proteins. (author)

  12. Rhizobium sp. effects, irradiated with ultraviolet and gamma rays, on nodulation of P. vulgaris (L.) bean

    International Nuclear Information System (INIS)

    Indigenous isolates of Rhizobium sp. from the root nodules of bean were selected. There of these isolates and a R. leguminosarum biovar phaseoli (SEMIA 4064) strain, used as a reference, were irradiated with ultraviolet (UV) light and gamma-Rays (?-R). The relations between survival and fluence of UV, and survival and absorbed dose of ?-R were linear for the strain of reference. The D37 values, for this rhizobial strain were 43 j.m-2 for the UV-treatment, and 32 Gy for the ?-rays treatment. Through a greenhouse experiment the irradiated isolates were inoculated on bean seedlings (P. vulgaris L, Variety IPA-8), in an attempt to evaluate sensitivity of the host-plants and possible effects on their nodulation. Significant differences were observed only for root dry matter yield. For all the other evaluated parameters variance was of such magnitude that it was not possible to detect significance of the effects. The isolates tested showed difference in responses to nodulation, due to the effects of irradiations. The host plant (IPA-8) seemed to be sensitive to the possible modifications in the irradiated isolates. (author). 10 refs, 6 figs, 1 tab

  13. The destructive degradation of some organic textile dye compounds using gamma ray irradiation

    International Nuclear Information System (INIS)

    The destructive degradation of 8 coloured reactive and direct dye compounds currently used in the textile industry has been investigated. These dyes are: Levafix Blue ERA (LB), Levafix Brilliant Red E4BA (LBR), Levafix Brilliant Yellow EGA (LBY), Drimarene Scarlet F3G (DS), Drimarene Brilliant Green X3G (DBG), Fast Yellow RL (FY), Fast Violet 2RL (FV) and Fast Orange 3R (FO). The process of degradation of the respective dye has been followed spectrophotometrically at the characteristic lmax. The variation of the colour intensity of aerated aqueous solution of the investigated dyes has been measured as a function of gamma irradiation dose. In all cases, the amplitude of the absorption bands of the dye compound was found to decrease with the increase of the gamma dose. Irradiation was carried out for actual waste and distilled water. By comparing the heights of the absorption maxima in both the visible and ultraviolet ranges, it was found that complete decolouration is attained at lower doses than that needed for the process of degradation of the dye. The kinetics of the degradation process has been traced and the kinetic constant, k1, was calculated and found to be concentration dependent indicating a first order reaction in all cases. The radiation-chemical yield (G-value) as a measure of the efficiency of gamma ray to degrade the respective dye was calculated for all dye compounds and it was found that the G-value in all cases increases exponentially for low radiation doses and changes linearly for high radiation doses. Also the K* value (the efficiency coefficient of dye radiolysis) was calculated and compared for the different dye compounds e.g. for FO, FY and FV dyes, the K* values were found to range from 5.5x109 to 1.92x10-7 mol·L-1'·cm-1. In addition to the study of a single dye compound in solution, mixtures of different dyes (3 dyes) were also subjected to g-ray irradiation simulating more closely actual waste effluents. Also the effect of some other chemicals used in the textile industry such as H2O2 and NaOCI on the degradation process was investigated. The specific bimolecular rate constants of the reaction of dyes with the hydroxyl radical (OH) were determined by studying the effect of ethanol concentration on G-value using competition kinetics. The effect of pH, NaOCI and H2O2 on the degradation process was studied. In addition to the main objective of the use of gamma rays to achieve the destruction of the dye compounds, the eco-toxicity of the dyes and their irradiation products was assessed using some invertebrate animals (snails) for the three FO, FY and FV dyes. The FV dye and its degradation products were found to be toxic (results of hemocyte count, hemagglutination titter, total protein content and accumulation levels) and should be completely degraded and removed from the wastewater streams using high irradiation doses. Also, and for the purpose of comparison, the sorption of the FV, FY and FO dyes on conventional sorbents such as charcoal was tested, gamma ray irradiation, as compared with conventional sorption techniques, was found to be very rapid and the removal of organic pollutants from wastewaters can be achieved nearly instantaneously. It appears that, for the complete destruction and full removal of organic pollutants from waste effluents, the sequential adsorption using chemical techniques followed by gamma irradiation treatment may prove to be more effective and advantageous. (author)

  14. Study of irradiated bothropstoxin-1 with60Co gamma rays: immune system behavior

    Scientific Electronic Library Online (English)

    P, Caproni; JA, Baptista; TL de, Almeida; LAC, Passos; N, Nascimento.

    Full Text Available Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modifi [...] ed antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers). The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response.

  15. Study of irradiated bothropstoxin-1 with60Co gamma rays: immune system behavior

    Directory of Open Access Journals (Sweden)

    P Caproni

    2009-01-01

    Full Text Available Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers. The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response.

  16. Study of irradiated bothropstoxin-1 with {sup 60}Co gamma rays: immune system behavior

    Energy Technology Data Exchange (ETDEWEB)

    Caproni, P.; Baptista, J.A.; Almeida, T.L. de; Nascimento, N. [Nuclear and Energy Research Institute (IPEN/CNEN-SP), SP (Brazil). Biotechnology Center; Passos, L.A.C. [State University of Campinas (UNICAMP), SP (Brazil). Lab. of Genetics and Embryo Cryopreservation

    2009-07-01

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be very useful. Ionizing radiation has already been proven to be a powerful tool to attenuate snake venom toxicity without affecting, and even increasing, their immunogenic properties. However, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. In the present work, we investigated the immunological behavior of bothropstoxin-1, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were analyzed by SDS-PAGE. Isogenic mice were immunized with either the native or the irradiated toxin. The circulating antibodies were isotyped and titrated by ELISA. According to our data, irradiation promoted structural modifications in the toxin characterized by higher molecular weight forms of proteins (aggregates and oligomers). The results also indicated that irradiated toxins were immunogenic and antibodies elicited by them were able to recognize the native toxin in ELISA. These findings suggest that irradiation of toxic proteins can promote significant modifications in their structures; however they still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that irradiated proteins induce higher titers of IgG2a and IgG2b, suggesting that Th1 cells are predominantly involved in the immune response. (author)

  17. Corrosion of carbon steel and low-alloy steel in diluted seawater containing hydrazine under gamma-rays irradiation

    International Nuclear Information System (INIS)

    Seawater was injected into reactor cores of Units 1, 2, and 3 in the Fukushima Daiichi nuclear power station as an urgent coolant. It is considered that the injected seawater causes corrosion of steels of the reactor pressure vessel and primary containment vessel. To investigate the effects of gamma-rays irradiation on weight loss in carbon steel and low-alloy steel, corrosion tests were performed in diluted seawater at 50°C under gamma-rays irradiation. Specimens were irradiated with dose rates of 4.4 kGy/h and 0.2 kGy/h. To evaluate the effects of hydrazine (N2H4) on the reduction of oxygen and hydrogen peroxide, N2H4 was added to the diluted seawater. In the diluted seawater without N2H4, weight loss in the steels irradiated with 0.2 kGy/h was similar to that in the unirradiated steels, and weight loss in the steels irradiated with 4.4 kGy/h increased to approximate 1.7 times of those in the unirradiated steels. Weight loss in the steels irradiated in the diluted seawater containing N2H4 was similar to that in the diluted seawater without N2H4. When N2 was introduced into the gas phase in the flasks during gamma-rays irradiation, weight loss in the steels decreased. (author)

  18. Study of stability of humic acids from soil and peat irradiated by gamma rays

    International Nuclear Information System (INIS)

    Humic acids samples (one deriving from a sedimentary soil and other from a peat), in aqueous media, were irradiated with gamma rays, in doses of 10, 50 and 100 kGy, in order to understand their chemical behavior after the irradiation. The material, before and after irradiation, was analyzed by Elemental Analysis, Functional Groups (carboxylic acids and phenols), UV/Vis Spectroscopy (E4/E6 ratio), IR spectroscopy, CO2 content and Gel permeation Chromatography (GPC) ). The Elemental Analysis showed the humic acid derived from a peat had a most percentage quantity of Carbon and Hydrogen than the material from a sedimentary soil. From the UV/Vis Spectroscopy, it was observed a decrease of E4/E6 ratio with an increase of the applied dose. The data from GPC are in agreement with this. The results showed that the molecular weight of the material increased by exposing it to a larger radiolitical dose. The peat material was less affected by the gamma radiation than the soil material. The carboxylic groups were responsible by radiochemical behavior of the material. (author)

  19. Investigation of effects of gamma ray irradiation on pyrolysis properties of glove-box panel materials

    International Nuclear Information System (INIS)

    The glove box (GB) is a device with some plastic components and is used for the containment of radioactive materials. In a MOX fuel fabrication facility, MOX is also handled in the GB. Since the plastic panel, which has the largest area in the GB, is used over a long period, it is exposed to a high dose of MOX continuously. In this study, to confirm whether the containment capability of GB can be maintained even under external thermal stress, the effects of gamma ray irradiation with 60Co on the pyrolysis properties of the common panel materials were investigated by TG-DTA. As a result, polymethylmethacrylate showed a large peak of the mass loss rate at about 260 degrees under the nonirradiation and air condition, but it separated into lower and higher temperature sides above 25 kGy. This effect was not observed up to 10 kGy for polymethylmethacrylate and up to 880 kGy for polycarbonate. By comparison with the estimated total dose of the GB panel irradiated in the operation period, it was found that the irradiation from MOX does not significantly affect the pyrolysis properties of the GB panel in the actual facility. (author)

  20. Mutation Breeding of various spray chrysanthemum cultivars by gamma-ray irradiation

    International Nuclear Information System (INIS)

    This study was carried out to analyze mutation rate and spectrum of chrysanthemum by gamma-ray irradiation. Five flower types, 16 cultivars including 'Geumsu', 'Hwiparam', 'Ilwol', 'Magic', 'Moonlight', 'Noblewine', 'Pinky', 'Progy', 'Sangtte', 'Waterfog', 'Whitneypangpang', 'Yelloweye', 'Yellowpangpang', 'Yesmiso', 'Yesmorning', and 'Yestogether' were irradiated as 30, 50, and 70 Gy dose during 24 hours. As a result, mutation rate was identified as the highest in single type among five flower types, but there was a little difference according to cultivars. Mutation rate was increased in proportion to irradiation dose in anemone, pompon, and spider type cultivars, but there wasn't clear in single and semi-double type cultivars. Mutation spectrum was identified as the highest in the cultivar 'Noblewine'. The most sensitive cultivars to radiation were revealed as 'Noblewine' and 'Yesmorning' and the least were Moonlight', 'Waterfog', and 'Yellowpangpang'. Consequently, there was much difference in radio-sensitivity according to cultivars of chrysanthemum and flower type was correlated a little with mutation rate

  1. Meiotic chromosome behaviours in M1 generation of bread wheat irradiated by gamma-rays

    International Nuclear Information System (INIS)

    Growing plants of bread wheat (Triticum aestivum L. 2 n=6x=42, AABBDD) were subjected to acute or chronic irradiation by gamma-rays from 60Co and meiotic chromosome behaviours of PMCS in M1 generation were cytologically compared. Both acute and chronic irradiations produced different types of chromosomal aberrations at the meiotic stages. Among them, translocation type was the most frequent, followed by univalent type. A mixed type, i. e. translocation accompanying one or more univalents was often detected. Even normal type which lacked translocation and univalent included laggards and briclges without exception. Other meiotic abnormalities such as deletion, iso-chromosome and micronuclei were observed frequently in both treatments. Dose dependency of translocation frequency was not recognized in this experiment. In chronic irradiation, different chromosome numbers and meiotic behaviours were found not only among florets of a spike but also among anthers of a floret. A number of plants with aneuploid-like grass types occurred at a high frequency in M1, especially with low exposure

  2. Behavior of the dynamic magnetic susceptibility in ybco bula ceramics irradiated with gamma rays

    International Nuclear Information System (INIS)

    Using measurements of the ac susceptibility, the behavior with the irradiation dose of YBa2Cu3O7- bulk ceramics synthesized by the classic reaction method in solid state, was studied. A Co60 gamma chamber model MPX-G-25M and a Cs137 source were employed as gamma ray sources. The behavior of the beginning temperature of the normal - superconducting state transition with the exposition dose show, independently of the incident gamma energy, a monotonous growth until reaching a threshold dose, after which, observe a fall, more abrupt in the case of the Co60. This behavior can be explained using the model that postulates the ability of the gamma radiation, in certain dose intervals, to stimulate the structural reordering in the oxygen sublattice. When the irradiation process takes place in the Co60 gamma chamber, the behavior of the superconducting volume fraction of the sample characterizes by the initial sharp fall with the dose, followed with an attenuation of the decrement. In the case of Cs137 irradiation, the behavior of the superconducting volume fraction is similar to the behavior of the Ton with the dose

  3. Evaluation of myotoxic activity of Bothropstoxin-1 irradiated with 60Co gamma rays

    International Nuclear Information System (INIS)

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules and has been proven to be a powerful tool to attenuate snake venoms toxicity without affecting their immunogenic properties. Snake venoms and their isolated toxins showed structural modifications after gamma radiation process, in aqueous solution, mainly by water radiolysis sub products. Free radical scavengers, such as NaNO3 and t-butanol, present selective effects on specific radical from water radiolysis. The NaNO3 has affinity by aqueous electron, while the t-butanol has affinity by hydroxyl radical. At the present work, we have investigated the myotoxic activity of Bothropstoxin-1 (BTHX-1), a K49 phospholipase, present in Bothrops jararacussu crude venom, before and after irradiation process, with or without scavenger substances presence. BTHX-1 was irradiated with 2 kGy of 60Co gamma rays, in aqueous solution and in the presence of oxygen. BALB/c mice were inoculated with either native or irradiated toxin, with or without scavenger substances. After 3 hours, blood samples were collected and the myotoxic activity was evaluated by LDH (lactate dehydrogenase) release. The muscular tissue damage was directly related to the LDH amounts released. Irradiated Bothropstoxin-1, with or without NaNO3 substance, caused less damage than their native counterpart. But irradiated toxin, in the presence of t-butanol, was so myotoxic as the native BTHX-1. These results indicate that irradiation of toxic proteins can promote significant modifications on their structures, but still retaining many of the original biological properties of their native counterparts. Additionally, some scavengers substances can change these gamma radiation effects. (author)

  4. Evaluation of myotoxic activity of Bothropstoxin-1 irradiated with {sup 60}Co gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Mirco, Jessica; Baptista, Janaina A.; Caproni, Priscila; Yoshito, Daniele; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: jessica.mirco@yahoo.com.br, e-mail: janabap@gmail.com, e-mail: pricaproni@hotmail.com, e-mail: daniyoshito@uol.com.br, e-mail: nnascime@ipen.br

    2009-07-01

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules and has been proven to be a powerful tool to attenuate snake venoms toxicity without affecting their immunogenic properties. Snake venoms and their isolated toxins showed structural modifications after gamma radiation process, in aqueous solution, mainly by water radiolysis sub products. Free radical scavengers, such as NaNO{sub 3} and t-butanol, present selective effects on specific radical from water radiolysis. The NaNO{sub 3} has affinity by aqueous electron, while the t-butanol has affinity by hydroxyl radical. At the present work, we have investigated the myotoxic activity of Bothropstoxin-1 (BTHX-1), a K49 phospholipase, present in Bothrops jararacussu crude venom, before and after irradiation process, with or without scavenger substances presence. BTHX-1 was irradiated with 2 kGy of {sup 60}Co gamma rays, in aqueous solution and in the presence of oxygen. BALB/c mice were inoculated with either native or irradiated toxin, with or without scavenger substances. After 3 hours, blood samples were collected and the myotoxic activity was evaluated by LDH (lactate dehydrogenase) release. The muscular tissue damage was directly related to the LDH amounts released. Irradiated Bothropstoxin-1, with or without NaNO{sub 3} substance, caused less damage than their native counterpart. But irradiated toxin, in the presence of t-butanol, was so myotoxic as the native BTHX-1. These results indicate that irradiation of toxic proteins can promote significant modifications on their structures, but still retaining many of the original biological properties of their native counterparts. Additionally, some scavengers substances can change these gamma radiation effects. (author)

  5. Continuous running test of radiation resistance motor driving equipment under high gamma ray irradiation

    International Nuclear Information System (INIS)

    The components in the vacuum vessel of ITER (International Thermonuclear Experimental Reactor), e.g. blanket and divertor, are replaced periodically using the dedicated remote handling systems. The environment conditions inside the vacuum vessel during the operation are temperature of 50degC, air or inert gas atmosphere at 1atm gamma ray radiation; therefore multiple factors shall be considered for establishment of durability of the remote handling systems. Concerning the dose rate of gamma ray under the anticipated operation of ITER, it was evaluated 10kG/h at the early stages of ITER EDA (Engineering Design Activity), but presently it decreases down to 0.5kGy/h after detailed design and evaluation have been done. However, a continual operation for one year at the longest is planned in the remote handling systems, therefore the systems it is desired to be able to operate longer than that. According to the requirements above, JAEA (Japan Atomic Energy Agency) advanced the development of radiation resistance components, major components of approximately 55 kinds which comprise the remote handling systems and that peripheral devices, since 1995 in ITER EDA. The dose rate and the target accumulation dose for the designated radiation resistance were set 10kGy/h and 10-100MGy, respectively. On the basis of the development results, the radiation resistance motor driving equipment, which comprised parts with different radiation resistance levels, was designed simulating mechanisms of ITER remote handling systems. The motor driving equipment, the servomotor turns the weight of 8kgf (dummy load) and controls, and continuous running test under high gamma ray irradiation was lasted approximately four years from March, 2000. Irradiation conditions on the test were; the dose rate of 3.6kGy/h, the accumulation dose of 30MGy at the minimum. The data were obtained, which are acquired motor electric current, temperatures and the breakdown event under the test conditions. In addition, appearance changes of every component and deice were observed. The irradiation test was performed in two stages, which was divided by a breakdown and successive overhaul of the equipment. The achieved accumulation dose and running time in those stages were approximately 47.6MGy/13,200hours and 23.9MGy/6,640hours, respectively. As a result, it has been confirmed that sufficient radiation resistance of the equipment, which is required against a dose rate of 0.5kGy/h at least, corresponding to the atmosphere inside the vacuum vessel, was achieved. Furthermore, the causes of breakdown at the 1st and the 2nd stages are hardening of the grease lubricant filled up in the reduction gear, and deterioration of electric insulation materials of power and signal lines, respectively. In this report, we describe design conditions and basic specifications of the radiation resistance motor driving equipment, the results of the 1st and the 2nd irradiation tests and the overhaul after the 1st stage irradiation test. (author)

  6. Analysis of cell kinetics after gamma ray irradiation using anti-BrdU monoclonal antibody

    International Nuclear Information System (INIS)

    The cell cycle was analyzed using anti-BrdU monoclonal antibody, and changes in cell kinetics after gamma ray irradiation as evaluated by this BrdU-PI double staining were compared with those evaluated by the DNA histogram method based on PI staining. The effect of irradiation on the cell kinetics has been studied according primarily to the number of G2 blocked cells. By the present BrdU method, rapid transition of the G1-S phase was observed within 2 hours of irradiation, and then G1 block was observed. Cells in the S phase progressed to the G2 + M cells returned to the G1 phase after 18 or more hours. These initial G1 blocked cells induced by irradiation were confirmed for the fist time by the present BrdU-PI double staining. By the conventional method based on the DNA histogram, accurate determination of S cell fraction was difficult due to overlapping of the DNA contents of G1 cells and early S cells and those of late S cells and G2 cells. On the other hand, BrdU-PI double staining allowed direct differentiation of G1, S, and G2 + M cells, especially between G1-S and S-G2 + M cells. The analysis of cell kinetics using BrdU is advantageous over the conventional autoradiographic methods in that it allowed more rapid assay with very high sensitivity. In addition, BrdU is alrady used clinically as an enhancement agent in radiation therapy for cancer. The present method is considered to be indispensable for evaluation of the percentage of S cells in the tumor tissue and analysis of cell kinetics after irradiation and chemotherapy against cancer. (author)

  7. Studying the Dosimetric Properties of GAMMA Rays Irradiated Chlorophyll Polyvinyl Alcohol

    International Nuclear Information System (INIS)

    Polyvinyl alcohol/chitosan/chlorophyll (PVA/Chit/Chl) films with about 2 mm thickness were prepared using gamma irradiation technique. The chlorophyll samples were extracted from fresh spinach leaves and PVA/Chit/Chl films were irradiated with gamma rays to study radiation-induced radicals as a dosimetric material using electron spin resonance (ESR), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). The ESR dose response and spectrophotometric analysis showed that chitosan decrease the response. The chlorophyll spectrum was characterized by dosimetric signal of spectroscopic splitting factor g = 2.0058. This signal is ascribed to the charge transfer complex of the molecular oxygen and the chlorophyll aggregate with strong pi-pi-interactions (aromatic interactions). The dose response was studied in the range from 1 to 500 kGy. Radical formation efficiency (G value) was obtained to be 0.15 ± 0.03. The dose conversion factors for chlorophyll in water and air were calculated to be 0.971 D water and 1.080 D air

  8. ESR study of free radicals in UHMW-PE fiber irradiated by gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Yanning [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, PO Box 800-204, Shanghai 201800 (China); College of Chemistry, Jilin Normal University, Jilin 136000 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wang Mouhua [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, PO Box 800-204, Shanghai 201800 (China); Tang Zhongfeng [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, PO Box 800-204, Shanghai 201800 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu Guozhong, E-mail: wuguozhong@sinap.ac.c [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, PO Box 800-204, Shanghai 201800 (China)

    2010-04-15

    ESR spectra of the trapped radicals in an ultra-high molecular weight polyethylene (UHMW-PE) fiber irradiated by gamma rays showed well-resolved hyperfine splitting at room temperature since the c-axis of the crystallites is aligned with the fiber direction and the radicals are trapped in crystallites. The alkyl radical (-CH{sub 2}-{sup c}entre dotCH-CH{sub 2}-) was the major product after irradiation in vacuum and in air at room temperature. Some of the alkyl radicals converted to allyl radicals (-CH{sub 2}-{sup c}entre dotCH-CH=CH-) and polyenyl radicals (-CH{sub 2}-{sup c}entre dotCH-(CH=CH){sub n}-CH{sub 2}-) during storage in vacuum. Upon storage in air atmosphere, the alkyl radicals decayed by reaction with oxygen. Of particular interest is the very slow decay rate of the alkyl radical trapped in UHMW-PE fiber, the half-life is 26 days in vacuum, and 13 days in air at room temperature, which is about 1/30 and 1/100 of that reported for high density polyethylene (HDPE), respectively. The extremely long lifetime of the alkyl radical is supposed to be caused by the large size of crystallites in UHMW-PE fiber. The rate of radical decay was accelerated by annealing at elevated temperature.

  9. Dose calculation method with 60-cobalt gamma rays in total body irradiation

    CERN Document Server

    Scaff, L A M

    2001-01-01

    Physical factors associated to total body irradiation using sup 6 sup 0 Co gamma rays beams, were studied in order to develop a calculation method of the dose distribution that could be reproduced in any radiotherapy center with good precision. The method is based on considering total body irradiation as a large and irregular field with heterogeneities. To calculate doses, or doses rates, of each area of interest (head, thorax, thigh, etc.), scattered radiation is determined. It was observed that if dismagnified fields were considered to calculate the scattered radiation, the resulting values could be applied on a projection to the real size to obtain the values for dose rate calculations. In a parallel work it was determined the variation of the dose rate in the air, for the distance of treatment, and for points out of the central axis. This confirm that the use of the inverse square law is not valid. An attenuation curve for a broad beam was also determined in order to allow the use of absorbers. In this wo...

  10. Perna perna (LINNAEUS, 1758) mussels irradiated by 60CO gamma rays cytotoxicity evaluation

    International Nuclear Information System (INIS)

    The aim of the present work was the study of ionizing radiation effects on aquatic biota regarding the location of nuclear facilities nearby coastal areas assuming the risk of leaks and nuclear accidents. Bivalve mollusks have been widely used in the monitoring of aquatic environment studies mainly for their sessile habit and pollutants bioconcentration ability. So marine mussel Perna perna (Bivalvia: Mytilidae) was used as organism test in this study. The study of radioactive toxicity was performed by cytotoxicity test exposing the organisms to 11Gy gamma radiation dose. After radiation the neutral red retention assay evaluated the lysosomal membrane integrity in the mussel hemocytes. 50% lethal dose assay (LD50) of gamma radiation on Perna perna mussels was carried out by exposure the organisms to 60Co gamma rays at doses ranging from 0 to 3000 Gy. The result of gamma radiation LD50 for these mussels was 1068 Gy and the neutral red retention time of irradiated organisms was about 47% lower than the control, non irradiated organisms. With the obtained results is expected to contribute in the study to identify the range of ionizing radiation doses which can cause toxic effects in marine invertebrates. (author)

  11. Immobilization of Simulated Transuranic Liquid Waste on Epoxy Acrylate Polymer by Gamma Ray Irradiation Method

    International Nuclear Information System (INIS)

    Immobilization of transuranic (TRU) liquid waste of spent solvent from the reprocessing of Light Water Reactor (LWR) spent fuel was done using epoxy acrylate polymer. Epoxy acrylate was mixed with tripropylene glycol diacrylate with a ratio of 4/1 by weight, and added with simulated TRU waste. The variations of waste concentrations in the mixture were 0, 10, 20, 30 and 40 weight %. Samples were irradiated in glass tubes of 14 mm diameter and 125 mm long by gamma ray from a Co-60 source of 70.6 kCi with dose of 7.5, 10.0 and 12.k kGy respectively, at a dose rate of 5 kGy/hour. These immobilization products were tested for their leaching rate in Soxhlet apparatus at 100oC for 6 hours and their compression strength by Paul Weber compressive strength apparaturs. The higher the radiation dose, the higher the compression strength and leaching rate. The higher the waste loading, the higher the compression strength and the leaching rate. Epoxy arcylate immobilization products with 20-40 weight % waste made under irradiation doses of 7.5 and 10.0 kGy can be considered for radiation durability testing. (author). 6 refs., 3 tabs., 2 figs

  12. Mechanical Property Of Zeolite-PVA Composite Mixture Irradiated By Gamma Ray Of Co-60

    International Nuclear Information System (INIS)

    Experiment on preparation of zeolite-polyvinyl alcohol composite for absorbance materials have been done by curring using Gamma ?-ray of Co-60. Zeolite with the particles size of 60 mesh was mixed with polyvinyl alcohol (PVA) at the concentration of the mixture were 6,9, and 12% by weight, than they were poured into glass tube (length = 100 mm; diameter = 10 mm) and irradiated at the doses of 10, 20, 30 dan 40 kGy with the dose rate of 7,5 kGy/ hr. Parameters observed were density, compressive strength, and hardness. Experimental results showed that polyvinyl alcohol in the mixture was significant effect to density and compressive strength, where as the irradiation dose was highly significant effect to compressive strength. The effect interaction between dose and polyvinyl alcohol concentration factors had significant effect to density or compressive strength. Almost all samples have pencil hardness of 4 - 5 H, for composite containing 6 % PVA, has pencil hardness of 2 - 3 H

  13. Manufacturing of a wood-plastic combination by irradiation of gamma-rays

    International Nuclear Information System (INIS)

    The studies on the wood-plastic combination (WPC) were carried out by gamma-ray irradiation. After impregnation of dry woods (Chamaecy Paris Obtusa ENDL., Cryptomeria japonica D.DON, Fagus renata BLUME., Acer mono MAXIM. and Shorea) with methyl methacrylate, emulsion of methyl methacrylate or unsaturated polyester (selfextinguishing type), the monomer in wood was polymerized by the irradiation. The percent of polymerization various monomers decreased remarkably in the presence of oxygen. WPC obtained were studied on the swelling, thermal and mechanical characteristics. The percent of welling in water of WPC impregnated with methyl methacrylate emulsion is less than that of WPC impregnated with methyl methacrylate (pure). WPC-polyester was shown to be non-inflammable. The pyrolysis gas of the WPC-methyl methcrylate and WPC-polyester is investigated, using a pyrolysis gas chromatography instrument. At the pyrolysis temperature of 3000C the decomposition gas prove to be mainly originated from the polymer in the WPC. The bending and compression strength of the WPC increased together with the weight of polymer in the wood. (auth.)

  14. Study on gamma-ray irradiation effects on corrosion resistance of canister material under the simulated disposal conditions

    International Nuclear Information System (INIS)

    The effects of gamma-ray irradiation on corrosion resistance have been studied about austenitic stainless steel as one of the candidate alloys for high-level radioactive waste canisters. The double U-bend specimens were used for the purpose of stress corrosion cracking (SCC) test on Type 304 ss and Type 309S ss. Sensitized Type 304 ss and Type 309S ss specimens were encapsuled respectively in capsules with a cubic granite and simulated groundwater. Test specimens were also encapsuled in a capsule with only humid bentonite in order to simulate the disposal environments. Capsules were irradiated with 137Cs source at WASTEF and with spent fuel in JMTR. The results showed that sensitized Type 304 ss have susceptibilities to SCC and sensitized 309S ss have not susceptibilities in the simulated disposal condition. On the other hand, no specimen was susceptible to SCC in deionized water even with gamma-ray irradiation. (author)

  15. Effects of gamma ray and electron-beam irradiations on survival of anaerobic and facultatively anaerobic bacteria

    International Nuclear Information System (INIS)

    An extension of the approval for food irradiation is desired due to the increase in the incidence of food poisoning in the world. One anaerobic (Clostridium perfringens) and four facultatively anaerobic (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Enteritidis) bacteria irradiated with gamma ray or electron beam (E-beam) were tested in terms of survival on agar under packaging atmosphere. Using pouch pack, effects of two irradiations on survival of anaerobic and facultatively anaerobic bacteria were evaluated comparatively. E-beam irradiation was more effective than gamma ray irradiation in decreasing the lethal dose 10% (D10) value of B. cereus at 4 deg C, slightly more effective in that of E. coli O157, and similarly effective in that of the other three bacteria at 4 deg C. The gamma irradiation of the bacteria without incubation at 4 deg C before irradiation was more effective than that of the bacteria with incubation overnight at 4 deg C before irradiation in decreasing the D10 values of these bacteria (B. cereus, E. coli O157, and L. monocytogenes). Furthermore, ground beef patties inoculated with bacteria were irradiated with 1 kGy by E-beam (5 MeV) at 4 deg C. The inoculated bacteria in the 1-9 mm beef patties were killed by 1 kGy E-beam irradiation and some bacteria in more than 9 mm beef patties were not killed by the irradiation. (author)

  16. Neutron and gamma ray irradiation effects on interlaminar shear strength of insulation materials with cyanate ester-epoxy blended resin

    International Nuclear Information System (INIS)

    A large scale fusion device like ITER requires high performance electric insulation materials against gamma ray and neutron irradiation, since fusion neutrons will reach superconducting magnets and activate them. Cyanate ester resin has been studied as a strong candidate for a new insulation material for fusion devices, and it has been clarified that the blended resin with epoxy has a potential to survive a design period in the radiation environment. This paper describes the results of molecular structure analysis of the blended resin, heat flux measurements by differential scanning calorimetry and the gamma ray and the fission neutron irradiation effects on interlaminar shear strength (ILSS) at 77 K. The gamma ray irradiation of 10 MGy did not change the ILSS significantly, but the neutron fluence of 1.0 x 1022 n/m2 (>0.1 MeV) with over 400 MGy degraded the ILSS. It suggests that cyanurate (triagine ring) will have a resistance against irradiation but oxazolidinon will lose the resistance after heavy irradiation.

  17. Effect of {gamma}-ray irradiation of the cell growth and the change of pigment contents of Phaeodactylum tricornutum

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Takaharu; Kubodera, Akiko [Science Univ. of Tokyo (Japan). Faculty of Pharmaceutical Science; Kikuchi, Masako; Kawakami, Yasushi

    1997-03-01

    The effects of gamma-ray irradiation to a marine pennate diatom Phaeodactylum tricornutum were investigated. The diatom is rich in carotenoid pigments, fucoxanthin and {beta}-carotene which are known to have antioxidative activity in vitro. The cell growth and the pigment contents were measured under various irradiation conditions. In every run, the algae grew 20 to 30-fold in 5 days after irradiation of up to 193 Gy, which was acutely fatal to animal body or cells. The cell growth and the pigment contents showed little differences between irradiated samples and its control when they were exposed to gamma-ray of up to 100 Gy for 12 min. But 60 min irradiation gave inhibitory effects on the cell growth and the fucoxanthin content decreased when 1.0 Gy dose was given. Conversely, low doses ranging from 0.2 Gy to 0.5 Gy did simulate the cell growth compared to its control though the doses over 0.5 Gy showed inhibitory effects. In contrast to the cell growth, both the amounts and contents of {beta}-carotene or fucoxanthin, however, considerably decreased under these low doses. Fucoxanthin decreased while {beta}-carotene increased compared to the control when the algae was exposed to gamma-ray for 60 min with over 1.0 Gy. There was no significant correlation between the doses and {beta}-carotene content below 1.0 Gy. (author)

  18. Peroxidation of blood plasma lipids after various regimes of external irradiation of rats by 60Co gamma-rays

    International Nuclear Information System (INIS)

    Peroxidation products of lipids in blood plasma of laboratory rats are studied after one-time, fractional and long-term external irradiation of the rats by 60Co gamma-rays. It was found, that different modes of a total external irradiation of rats lead to prominent features of dynamics and dose dependences of radio gene changes of the content of peroxidation products of lipids in blood plasma. It was shown that fractional irradiation is less effective for an organism, whereas long-term irradiation causes essentially big radiation induced changes than one-time action of radiation.

  19. Obtainment of a drug delivery system from PVAL irradiated by gamma rays

    International Nuclear Information System (INIS)

    The poly(vinyl alcohol) (PVAL) is a polymer used as biomaterial. In this work the PVAL was irradiated by gamma rays from 60Co source with doses up to 200 kGy. The PVAL was used to prepare hydrogels that may be used as a drug delivery system in ocular implant, for pair PVAL/dihidroxypropoximethyl guanine, where the last one is used for treatment of people with retinite caused by cytomegalovirus. The dose effect was studied on various properties of PVAL: the molecular weight by viscosity, the crosslink degree (Gcross-link= 8,5) calculated from gel dose (Dg = 7,8 kGy), the average molecular weight between crosslinks, crosslinking density, tensile strength at break and the degree of crystallinity by differential scanning calorimetry. Formation and thermal decay radical were studied by electronic paramagnetic resonance. It was used the technique of superposition and subtraction of spectra obtained at various temperatures (77 K, 125 K, 170 K, 230 K and 280 K). The radicals formed were identified on irradiated PVAL on vacuum and air at 77K with 20 kGy. The thermal decay showed that air caused polymer oxidation, even after end the irradiation, because the ·OH, RO· and ROO · radicals were formed. The dose effect on molecular structure of PVAL was studied by transmission spectroscopy on infrared region and nuclear magnetic resonance of proton. The PVAL structural alteration was not observed up to 200kGy, although crosslink occurred on PVAL. The PVAL hydrogel formation occurred at doses upper 70 kGy and drug controlled released occurred with zero order kinetic on PVAL hydrogel irradiated with 80 kGy. (author)

  20. Effects of gamma-ray irradiation on the growth of calli in Nicotiana species

    International Nuclear Information System (INIS)

    Haploid and diploid calli of Nicotiana glauca (n = 12) and N. langsdorffii (n = 9) together with dlploid calli of N. tabacum (n = 24) cv. Bright Yellow which were taken as control were ex-posed to various doses of 60Co gamma rays at 7 days and 10 days after incubation. Calli were subsequently weighed for a period of 12-14 days after radiation (19-24 clays after incubation) and the effect of irradiation on the growth was studied. A sigmoid curve was observed for the growth rate as well as for the growth pattern. The radiosensitivlty were estimate.d on the basis of the following different two criteria: 1) the difference in the diploid callus volumes at 12 or 14 days after irradiation and at the time of radiation, 2) the growth rate of diploid and haploid calli during these period. In 2 species except in N. langsdorffii, calli irradiated ten days after incubation (at the beginning of the actively growing stage) were more sensitive to gamma irradiation than calli lrradiated seven days after incubation (at a relatively slow growing stage). Each species had its own distinctive color before irradiation; golden yellow, green and yellow green for N. glauca, N. langsdorffii and N. tabacum, respectively. The color of some of the calli tended to darken with increasing irradiation doses. When the rate of increase of the irradiated calli to that of the unlrradiated ones was used as an indicator of radiosensitivity, there was a significant difference in the radiosen-sitivity of the calli among the species: N. tabacum was more sensitive followed by N. glauca and N. langsdorffii, which was the least sensitive. On the other hand, when the curve of the increase of the growth rate was used as the criterion of radiosensitivity, N. langsdorffii appeared to be more sensitive than N. tabacum and N. glauca. Haploid calli were more radiosensitive than diploid ones in N. glauca, but no significant difference was observed between them in N. lanegsdorffii. (author)

  1. Repair rates of DNA double-strand breaks under different doses of proton and {gamma}-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jingwen; Fu Qibin; Quan Yi; Wang Weikang; Mei Tao; Li Jia [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Yang Gen, E-mail: gen.yang@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Ren Xiaotang; Xue Jianming; Wang Yugang [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)

    2012-04-01

    It is known that DNA double-strand breaks (DSBs), which can be induced by a variety of treatments including ionizing radiation (IR), can cause most deleterious consequences among all kinds of DNA lesions. However, it is still under debate about whether DSBs repair is equally efficient after low and high-LET radiation, especially the basic biological responses after exposure to high-LET particles. In present study, synchronous fibroblast normal Human lung fibroblast (NHLF) cells were irradiated with graded doses of proton and {gamma}-ray. Then {gamma}-H2AX foci assay was used to monitor DSBs induction and repair at 0.5, 1, 2, 4, and 18 h post irradiation. The results showed that the {gamma}-ray irradiation could produce more {gamma}-H2AX foci than proton irradiation at the same dose. However, compared to low LET radiation with {gamma}-ray, the results also showed a much slower DSBs repair rate after high LET radiation with protons, suggesting that the cellular ability to eliminate DSBs after low and high-LET ionizing radiation is quite different.

  2. Effect of gamma-ray irradiation in vitro on the inhibition activity of hen's egg white ovomucoid

    International Nuclear Information System (INIS)

    The ovomucoid radiosensitivity is investigated under certain condition (irradiation dose, protein concentration, storage time after irradiation) and it is compared with that of ovomucoid substrate - trypsine. A chromatographically homogeneous ovomucoid preparation was used. The protein concentration of the solutions was determined on a UV-spectrophotometer UNICAM SP 180. The irradiation was performed with a 60Co-gamma-ray source at a dose rate, amounting to 6,6 and 225,2 rads per second, the temperature of the solutions before and during the irradiation and up to the post-irradiation assays were controlled at 00 C. Conclusion has been drawn out that just as other proteins, even though more slightly, the ovomucoid is sensitive to the indirect action of the ionizing, and to high gamma-ray doses in particular. The effect of irradiation depends on the protein concentration in the solution and on the post-irradiation storage time. In addition to the other reasons, such as an increase in the permeability of the cellular membrane and possibly the biosynthesis of the peptidehydrolases in the cell, adaptively intensified, the radioactivity of the natural proteinase inhibitors is the cause for the manifestation of the ''stimulating'' effect of the radioactive irradiation on the activity of proteases when irradiated in vivo. (K.M.)

  3. Induction of drought tolerance in tomato using 60Co gamma ray irradiation

    International Nuclear Information System (INIS)

    Drought is one of the environmental limitations that affects, on a higher degree, the production of different crops including tomato. A tomato breeding program was started to develop varieties suitable for growing under low water input conditions, which is not only important for saving this valuable liquid but also for diversifying food production in drought-affected areas. Two Cuban tomato varieties (INCA 9-1 and Amalia) were irradiated by 60Co gamma rays at doses of 300 and 500 Gy. In M2 generation, plants were cultivated in two zones of the country (Holguin and Havana province) in the months of lower precipitation (December-March). Irrigation was made three times at transplanting stage. Plants were grown in the short rainy season to keep suitable conditions for a promising genotype selection. During the following six generations selection was made for genotypes of high-yield, large fruit, high yield, disease resistance and fruit quality. In M6 generation, evaluation was conducted under water stress conditions for 60 plants of each of the best mutant lines, four of them from INCA 9-1 variety and three from Amalia variety.The mutant lines M15, M17 and M19 have been further evaluated in different areas of the country and they have shown very good behavior

  4. Stability Test For Sorghum Mutant Lines Derived From Induced Mutations with Gamma-Ray Irradiation

    Directory of Open Access Journals (Sweden)

    S. Human

    2011-12-01

    Full Text Available Sorghum breeding program had been conducted at the Center for the Application of Isotopes and Radiation Technology, BATAN. Plant genetic variability was increased through induced mutations using gamma-ray irradiation. Through selection process in successive generations, some promising mutant lines had been identified to have good agronomic characteristics with high grain yield. These breeding lines were tested in multi location trials and information of the genotypic stability was obtained to meet the requirements for officially varietal release by the Ministry of Agriculture. A total of 11 sorghum lines and varieties consisting of 8 mutant lines derived from induced mutations (B-100, B-95, B-92, B-83, B-76, B-75, B-69 and Zh-30 and 3 control varieties (Durra, UPCA-S1 and Mandau were included in the experiment. All materials were grown in 10 agro-ecologically different locations namely Gunungkidul, Bantul, Citayam, Garut, Lampung, Bogor, Anyer, Karawaci, Cianjur and Subang. In each location, the local adaptability test was conducted by randomized block design with 3 replications. Data of grain yield was used for evaluating genotypic stability using AMMI approach. Results revealed that sorghum mutation breeding had generated 3 mutant lines (B-100, B-76 and Zh-30 exhibiting grain yield significantly higher than the control varieties. These mutant lines were genetically stable in all locations so that they would be recommended for official release as new sorghum varieties to the Ministry of Agriculture

  5. Identification of PCB degradation products in gamma-ray irradiated solutions of PCB's in isopropanol

    International Nuclear Information System (INIS)

    Destruction of polychlorinated biphenyls (PCB's) and other halogenated wastes by incineration is meeting with increasingly stronger public opposition. As a result, significant effort is being directed at the development of alternative disposal methods for the PCB's. Towards this end, the authors have explored gamma-ray irradiation as a method for detoxifying halogenated wastes. Radiolysis offers numerous advantages over incineration, including minimization of gaseous and particulate effluents and the ability to verify that the hazardous materials have been reduced to acceptable limits prior to being discharged. The authors here the results of gamma radiolysis of octachlorobiphenyl (OCB) in aerated neutral isopropanol solutions. Unlike radiolysis under alkaline conditions, where PCB's undergo stoichiometric dechlorination to free chloride and lower chlorinated biphenyls, the degradation of OCB in neutral isopropanol produces not only the expected less chlorinated PCB species, but also a series of solvent altered PCB congeners. The identity of these altered PCB compounds is reported and a mechanism is proposed for the radiolytic degradation of OCB in neutral isopropanol

  6. Reaction of nuclear graphites with water vapor in helium under gamma ray irradiation

    International Nuclear Information System (INIS)

    The reaction of four kinds of nuclear graphites with water vapor in helium were carried out under Co-60 gamma ray irradiation of 1.25 x 106 R/hr, at temperatures 30 - 2430C and at concentrations 0.6 - 2.3 volume percent. Radiation induced reaction rate of the graphites were found to be in the order of 10-9 g/g.hr at the concentration 1.2 volume percent, showing some differences between the graphites. There was no closed relation between the reaction rate of the graphites and their specific surface area, as well as their prosity. Impurity contained in the graphite gave little effect on the radiation induced reaction rate, although the impurity accelerated the thermal reaction rate. 7477 and 7477PT graphites, which have a similar structure in texture, showed the same rate in magnitude. A very low energy of activation for the reaction, about 1 Kcal/mol was obtained in the study. The influence of water vapor concentration on the reaction rate was scarcely observed in the concentrations used in this experiment. Contribution of the radiation induced reaction rate to whole reaction rate at 10000C was discussed. (author)

  7. Measuring of hands irradiation by gamma-ray and positron of personnel of the departments of nuclear medicine by TL dosimetry

    International Nuclear Information System (INIS)

    The authors carried out measurement of hands irradiation by gamma-ray and positron of personnel of the departments of nuclear medicine by TL dosimetry. It was found that the estimated radiation doses are underestimated.

  8. Comparison of gamma ray and electron beam irradiation on extraction yield, morphological and antioxidant properties of polysaccharides from tamarind seed

    Science.gov (United States)

    Choi, Jong-il; Kim, Jae-Kyung; Srinivasan, Periasamy; Kim, Jae-Hun; Park, Hyun-Jin; Byun, Myung-Woo; Lee, Ju-Woon

    2009-07-01

    Tamarind ( Tamarindus indica L) seed polysaccharide (TSP) is of great important due to its various biological activities. The present investigation was carried out to compare extraction yield, morphological characteristics, average molecular weights and antioxidant activities of TSP from gamma- and electron beam (EB)-irradiated tamarind kernel powder. The tamarind kernel powder was irradiated with 0, 5 and 10 kGy by gamma ray (GR) and electron beam, respectively. The extraction yield of TSP was increased significantly by EB and GR irradiation, but there was no significant difference between irradiation types. Morphological studies by scanning electron microscope showed that TSP from GR-irradiated tamarind seed had a fibrous structure, different from that of EB irradiated with a particle structures. The average molecular weight of TSP was decreased by the irradiation, and EB treatment degraded more severely than GR. Superoxide radical scavenging ability and total antioxidant capacity of EB-treated TSP showed higher than those of GR-treated TSP.

  9. Comparison of gamma ray and electron beam irradiation on extraction yield, morphological and antioxidant properties of polysaccharides from tamarind seed

    International Nuclear Information System (INIS)

    Tamarind (Tamarindus indica L) seed polysaccharide (TSP) is of great important due to its various biological activities. The present investigation was carried out to compare extraction yield, morphological characteristics, average molecular weights and antioxidant activities of TSP from gamma- and electron beam (EB)-irradiated tamarind kernel powder. The tamarind kernel powder was irradiated with 0, 5 and 10 kGy by gamma ray (GR) and electron beam, respectively. The extraction yield of TSP was increased significantly by EB and GR irradiation, but there was no significant difference between irradiation types. Morphological studies by scanning electron microscope showed that TSP from GR-irradiated tamarind seed had a fibrous structure, different from that of EB irradiated with a particle structures. The average molecular weight of TSP was decreased by the irradiation, and EB treatment degraded more severely than GR. Superoxide radical scavenging ability and total antioxidant capacity of EB-treated TSP showed higher than those of GR-treated TSP.

  10. Comparison of gamma ray and electron beam irradiation on extraction yield, morphological and antioxidant properties of polysaccharides from tamarind seed

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong-il [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Jae-Kyung [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Graduate school of Food and Biotechnology, Korea University, Seoul 146-701 (Korea, Republic of); Srinivasan, Periasamy; Kim, Jae-Hun [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Park, Hyun-Jin [Graduate school of Food and Biotechnology, Korea University, Seoul 146-701 (Korea, Republic of); Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Tamarind (Tamarindus indica L) seed polysaccharide (TSP) is of great important due to its various biological activities. The present investigation was carried out to compare extraction yield, morphological characteristics, average molecular weights and antioxidant activities of TSP from gamma- and electron beam (EB)-irradiated tamarind kernel powder. The tamarind kernel powder was irradiated with 0, 5 and 10 kGy by gamma ray (GR) and electron beam, respectively. The extraction yield of TSP was increased significantly by EB and GR irradiation, but there was no significant difference between irradiation types. Morphological studies by scanning electron microscope showed that TSP from GR-irradiated tamarind seed had a fibrous structure, different from that of EB irradiated with a particle structures. The average molecular weight of TSP was decreased by the irradiation, and EB treatment degraded more severely than GR. Superoxide radical scavenging ability and total antioxidant capacity of EB-treated TSP showed higher than those of GR-treated TSP.

  11. Simulation of gamma-ray irradiation of lettuce leaves in a 137Cs irradiator using MCNP

    International Nuclear Information System (INIS)

    Ionizing radiation effectively reduces the number of common microbial pathogens in fresh produce. However, the efficacy of the process for pathogens internalized into produce tissue is unknown. The objective of this study was to understand gamma irradiation of lettuce leaf structure exposed in a 137Cs irradiator using MCNP. The simulated 137Cs irradiator is a self-shielded device, and its geometry and sources are described in the MCNP input file. When the irradiation chamber is filled with water, lower doses are found at the center of the irradiation volume and the dose uniformity ratio (maximum dose/minimum dose) is 1.76. For randomly oriented rectangular lettuce leaf segments in the irradiation chamber, the dose uniformity ratio is 1.25. It shows that dose uniformity in the Cs irradiator is strongly dependent of the density of the sample. To understand dose distribution inside the leaf, we divided a lettuce leaf into a low density (flat) region (0.72 g/cm3) and high density (rib) region (0.86 g/cm3). Calculated doses to the rib are 61% higher than doses to the flat region of the leaf. This indicates that internalized microorganisms can be inactivated more easily than organisms on the surface. This study shows that irradiation can effectively reduce viable microorganism internalized in lettuce. (author)

  12. Quality of gamma ray-irradiated iceberg lettuce and treatments to minimize irradiation-induced disorders

    Science.gov (United States)

    Irradiation of Iceberg lettuce was recently approved by the FDA to enhance microbial safety and to extend shelf-life at doses up to 4 kGy. However, the radiation tolerance of whole head lettuce is unclear. The present study was conducted to investigate the effects of irradiation on the quality of he...

  13. Effects of gamma-ray irradiation on optical properties of ZnO-PbO-B2O3 glasses

    DEFF Research Database (Denmark)

    Sharma, G.; Thind, K.S.; Manupriya, -; Klare, H.S.; Narang, S.B.; Gerward, Leif; Dangwal, V.K.

    2006-01-01

    Effects of gamma-ray irradiation on some optical properties of xZnO(.)2xPbO(.)(1-3x)B2O3 glasses have been studied in the wavelength range 300-800 nm. Decrease in transmittance indicates the formation of color-center defects. Values for the energy-band gap, the width of the energy tail above the mobility gap and the cut-off wavelength have been measured before and after irradiation. Changes in the optical properties are explained in terms of radiation-induced structural defects and the compositi...

  14. Production of acetic acid from ethanol solution by acetobactor acetigenum and effect of gamma-ray irradiation on the bacteria

    International Nuclear Information System (INIS)

    A preliminary study on fermentation of acetic acid by S. cerevisiae and A. acetigenum was carried out to obtain information to develop the effective utilization technology of agricultural liquid wastes. Aqueous solutions of glucose and/or ethanol were used as a model of agricultural liquid waste. The effect of gamma-ray irradiation on A. acetigenum for enhancement of the fermentation was also examined. In this study, irradiated A. acetigenum had activity to produce acetic acid even after loss the activity to grow. (author)

  15. The effects of prenatal irradiation with a low doses of gamma-rays on spatial memory in adult rats

    International Nuclear Information System (INIS)

    Pregnant females of Wistar-strain rats were irradiated (sham-irradiated) with a dose of 1 Gy of gamma-rays on the 16th day of pregnancy. The progeny of both irradiated and control animals was tested in Morris' water maze for spatial memory at age of 4 months. The time needed to find the hidden platform and the swimming-track were recorded using a computer aided video-tracking method. The test was repeated after 24 hours (short-time memory) and after one week (long-time memory). In short-time memory test the irradiated females needed in comparison with controls a statistically significantly longer time and a longer swimming track to find the platform. No significant differences were found in male. In long-term memory test no significant differences in both parameters followed were found in either of sexes. The results suggest, that irradiation with a low dose of gamma-rays during the period of the embryonic development of the brain can negatively influence the short-term spatial memory, but has no effect on long-time memory in rats. (authors)

  16. Array-type sensor to determine corrosive conditions in high temperature water under gamma rays irradiation

    International Nuclear Information System (INIS)

    One of the problems to determine electrochemical corrosion potential (ECP) in high temperature water under irradiation is to apply long-lived and reliable reference electrodes. In order to avoid troubles due to the reference electrode, a new concept to determine ECP without the reference electrode has been proposed. Several metal plates are applied as working electrodes and at the same time as the reference electrodes. Potential of the metal plates with stable oxide films on their surfaces show stable values in high temperature water. As a result of the combination of their potential values, ECP of each metal can be determined without any specific reference electrode. Array-type sensors consisting of several metal plates, e.g., Fe, Ni, Cr, Zr, Pt, Pd, Re, Ir, with well developed oxide films on their surface were prepared for ECP measurement in high temperature water under neutron/gamma ray irradiations. In order to confirm the feasibility of this concept, responses of the redox potentials of the pure metals to changes in the simulated BWR reactor water conditions were measured and the ECP was determined by the differences in potentials between a couple of metal plates. Major conclusions of the study are as follows: 1) The redox potentials of the Fe, Pt, Zr, Ir, Pd, and Re electrodes showed the different dependences on the changes in O2 and H2O2 concentrations. The redox potentials of the electrodes increased as the oxidant concentrations increased except for Zr electrode. The potential of the Zr electrode was kept the very low potential at the wide range of O2 and H2O2 concentrations differed form the other electrodes. 2) It was estimated that the redox potential of highly soluble metal may be increased, while that of low soluble metal may be decreased by an oxide film. The stable oxide film would cause the stable potential response of the electrode with oxide film. 3) The relationship between the oxidant concentrations and the redox potentials of the electrodes were determined by the theoretical calculations of the anodic and cathodic current densities to determine the ECP using the basic concept of the array-type sensor. 4) The feasibility of the concept for a new array-type sensor to determine the ECP was confirmed by the comparison between the ECP obtained by the array-type sensor and the measured ECP. To improve the sensor, more basic data and the optimization of the electrodes are required.

  17. Effects of oxygen and moisture content on the radiation damage in barley seeds irradiated with fast neutrons and gamma rays

    International Nuclear Information System (INIS)

    In gamma-irradiated barley seeds the effect of moisture content seems to modify the oxygen effect. If gamma-irradiated seeds (4% H2O content) are soaked in oxygen-free water before being transferred to oxygenated water, the oxygen-sensitive centres decay. The decay rate is a function of temperature and is shown to be most likely due to how fast the target molecules are hydrated. When low moisture content seeds were irradiated with fast neutrons in the SNIF, a moisture content effect was also obtained. However, contrary to what was found with gamma-irradiated seeds, no effect of oxygen was obtained. This excludes the possibility that gamma-contamination caused the moisture content effect. A model explaining the difference between the effect of neutrons and gamma-rays, respectively, is discussed. (author). 13 refs, 1 fig., 2 tabs

  18. Radiosensitivity of apricot budsticks exposed to acute gamma rays and nursery observations on the second vegetative generation from irradiated buds

    International Nuclear Information System (INIS)

    Varietal improvement is essential if a new impetus is to be given to the French apricot crop. We have accordingly started a mutation breeding programme by bud irradiation. Because of the scarcity of bibliographical data, the first step was to study the budwood radiosensitivity of the apricot cultivars used as starting material. Budsticks of various cultivars were exposed to increasing doses of acute gamma rays. The physiological effects induced by irradiation were evaluated from bud survival and growth. These results allowed us, in the first instance, to fix the optimal dose range for dormant buds irradiated at 6 to 7 Gy/mm. Observations in the nursery on scions from the second vegetative generation (V2) already showed the limits of bud irradiation. Further observations in the orchard are need to estimate the value of this method for apricot breeding

  19. Evaluation of induced radioactivity in 10 MeV-electron irradiated spices, (1); [gamma]-ray measurement

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Katayama, Tadashi; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Shibata, Setsuko; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

    1994-02-01

    Black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electrons from a linear accelerator to a dose of 100 kGy and radioactivity was measured in order to estimate induced radioactivity in the irradiated foods. Induced radioactivity could not be detected significantly by [gamma]-ray spectrometry in the irradiated samples except for spiked samples which contain some photonuclear target nuclides in the list of photonuclear reactions which could produce radioactivity below 10 MeV. From the amount of observed radioactivities of short-lived photonuclear products in the spiked samples and calculation of H[sub 50] according to ICRP Publication 30, it was concluded that the induced radioactivity and its biological effects in the 10 MeV electron-irradiated natural samples were negligible in comparison with natural radioactivity from [sup 40]K contained in the samples. (author).

  20. Gamma-ray irradiation and post-irradiation at room and elevated temperature response of pMOS dosimeters with thick gate oxides

    Directory of Open Access Journals (Sweden)

    Pejovi? Mom?ilo M.

    2011-01-01

    Full Text Available Gamma-ray irradiation and post-irradiation response at room and elevated temperature have been studied for radiation sensitive pMOS transistors with gate oxide thickness of 100 and 400 nm, respectively. Their response was followed based on the changes in the threshold voltage shift which was estimated on the basis of transfer characteristics in saturation. The presence of radiation-induced fixed oxide traps and switching traps - which lead to a change in the threshold voltage - was estimated from the sub-threshold I-V curves, using the midgap technique. It was shown that fixed oxide traps have a dominant influence on the change in the threshold voltage shift during gamma-ray irradiation and annealing.

  1. Genetic improvement of soybean seed proteins by {gamma}-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kitamura, Keisuke [Agriculture, Forestry and Fisheries Research Council Secretariat, MAFF, Research and Development Division (Japan)

    1998-12-31

    Although soybeans have the highest protein content among seed crops, the protein quality is poor due to the low content of the sulfur-containing amino acids, cysteine and methionine. Soybean 7S globulin and 11S globulin are the two major protein components, accounting for about 70% of the total seed protein. The 11S globulin contains three to four times more methionine and cysteine per unit protein than that of the 7S globulin. Furthermore, the two globulins show considerable differences in food processing properties such as gel-making ability and emulsifying capacity. The 7S globulin is composed of three kinds of polypeptides, designated as {alpha}, {alpha}` and {beta} subunits. A variety of soybean cv. Keburi, which lacks {alpha}` subunit was identified in a germplasm collection. An induced mutant line which lacks both {alpha} and {alpha}` subunits, was recently identified in the progeny of {gamma}-ray-irradiated seeds from a line lacking {alpha}` subunit. On the other hand, the 11S globulin is composed of the A{sub 1a}B{sub 2}, A{sub 1b}B{sub 1b}, A{sub 2}B{sub 1a}, A{sub 3}B{sub 4} and A{sub 4}A{sub 5}B{sub 3} subunits. It has become possible to breed soybeans with markedly modified protein composition from extremely high to extremely low 7S : 11S ratios using mutant genes for the subunits of the two globulins. Lipoxygenase catalyzes the hydroperoxydation of unsaturated fatty acids and polyunsaturated lipids. Soybean seeds contain three lipoxygenase isozymes, called L-1, L-2 and L-3, which are responsible for the generation of grassy-beany and bitter tastes, limiting the use of whole soybeans and soy proteins in certain food products. In the early 1980s, three types of spontaneous mutant soybean varieties lacking L-1, L-2 or L-3 were detected. Soybean cultivars having the lipoxygenase-null traits could become economically valuable for the manufacture of soy products such as soy milk due to their low levels of beany taste and their enhanced storage stability. (J.P.N.)

  2. Two CdZnTe Detector-Equipped Gamma-ray Spectrometers for Attribute Measurements on Irradiated Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hartwell, John Kelvin; Winston, Philip Lon; Marts, Donna Jeanne; Moore-McAteer, Lisa Dawn; Taylor, Steven Cheney

    2003-04-01

    Some United States Department of Energy-owned spent fuel elements from foreign research reactors (FRRs) are presently being shipped from the reactor location to the US for storage at the Idaho National Engineering and Environmental Laboratory (INEEL). Two cadmium zinc telluride detector-based gamma-ray spectrometers have been developed to confirm the irradiation status of these fuels. One spectrometer is configured to operate underwater in the spent fuel pool of the shipping location, while the other is configured to interrogate elements on receipt in the dry transfer cell at the INEEL’s Interim Fuel Storage Facility (IFSF). Both units have been operationally tested at the INEEL.

  3. Dwarf Rice Mutant Derived from 0.2 kGy Gamma Rays Irradiated Seeds of Atomita 4 Variety

    International Nuclear Information System (INIS)

    Dwarf rice mutant was obtained when Atomita 4 seeds were irradiated by 0.2 kGy gamma rays. The results of segregation analyses in F2 populations and F3 lines derived from reciprocal crosses of mutant and Atomita 4 suggested that the dwarf was controlled by a single recessive gene. This gene was not located on rice cytoplasmic genome but on nuclear genome. The gene for dwarf obtained in this study tentatively could be assumed as a new finding until the allelic relationships with other dwarf genes are verified. (author)

  4. Modifications of heterosis in hybrids between two inbred lines of maize (Zea Mays L.) irradiated with gamma rays

    International Nuclear Information System (INIS)

    A study of the effect of gamma radiation (3700 R) on heterosis in maize was carried out. Seeds of two inbred lines were irradiated with 3700R and crossed. Hybrid seeds obtained from these crossings were sown in the field according to a balanced lattice square design, 4 x 4 with 10 repetitions, and various quantitative characters were scored and analyzed. It is concluded that gamma-rays may modify combining ability o these inbred lines, accompanied by change in plant height, car number, ear length, weight of 100 kernels and husked car weight of the hybrids. (Author)

  5. The influence of gamma rays irradiation on chlorophyll mutation and genetic variability of agronomic characters in soybean plant

    International Nuclear Information System (INIS)

    Seeds of soybean mutant line No. 13/PsJ with 12% moisture content were irradiated by 0,10;0,20;0.30 and 0.40 kGy of gamma rays treatment. Number of irradiated seed for each treatment was 1500 seeds. Irradiated of seeds were planted in the 4m X 5m plot size with 0,20m x 0,40m spacing and two seed each hole and were planted as M-1 plants in the wet season of 1996/1997 at PAIR field experiment in Pasar Jumat, Jakarta. The experiment was designed Randomized Block Design with three replication Plans of M-1 generation were harvested individuality and were planted as known M2 plants in the next generation in dry season of 1997 at PAIR field experiment. Seven days planting the chlorophyll mutation of plants were recorded by Frydenberg method and the genetic variability of plant height, number of fertile pods and nodes were calculated by Singh and Chaudhary formula. Results of the experiment showed that chlorophyll mutation and genetic variability of plant height and number of fertile pods could be improved be 0.10 and 0,20 kGy of gamma rays treatment. (authors)

  6. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    Energy Technology Data Exchange (ETDEWEB)

    Ferreto, H. F. R., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F., E-mail: hferreto@ipen.br, E-mail: ana-feitoza@yahoo.com.br; Parra, D. F., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br; Lugão, A. B., E-mail: dfparra@ipen.br, E-mail: ablugao@ipen.br [Center of Chemistry and Environment, Institute of Energy and Nuclear Research - IPEN (Brazil); Gaia, R., E-mail: renan-gaia7@hotmail.com [Faculdades Oswaldo Cruz (Brazil)

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  7. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    International Nuclear Information System (INIS)

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of 60Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere

  8. Thermal, tensile and rheological properties of linear low density polyethylene (LLDPE) irradiated by gamma-ray in different atmospheres

    International Nuclear Information System (INIS)

    The aim of this paper is to investigate structural changes of linear low density polyethylene (LLDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical–chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of 60Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of LLDPE, after gamma irradiations were evaluated using thermogravimetric analyzer (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  9. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    Science.gov (United States)

    Ferreto, H. F. R.; Oliveira, A. C. F.; Gaia, R.; Parra, D. F.; Lugão, A. B.

    2014-05-01

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of 60Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  10. Tuning the grade of graphene: Gamma ray irradiation of free-standing graphene oxide films in gaseous phase

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Gaseous gamma ray irradiation on graphene oxide. • Impact of the radicals formation on the surface functionalization. • Evaluation of morphological and crystallinity changes across the material. • New route to the formation of pre-assembled graphene oxide 3D architectures. - Abstract: A direct approach to functionalize and reduce pre-shaped graphene oxide 3D architectures is demonstrated by gamma ray irradiation in gaseous phase under analytical grade air, N2 or H2. The formation of radicals upon gamma ray irradiation is shown to lead to surface functionalization of the graphene oxide sheets. The reduction degree of graphene oxide, which can be controlled through varying the ?-ray total dose irradiation, leads to the synthesis of highly crystalline and near defect-free graphene based materials. The crystalline structure of the graphene oxide and ?-ray reduced graphene oxide was investigated by x-ray diffraction and Raman spectroscopy. The results reveal no noticeable changes in the size of sp2 graphitic structures for the range of tested gases and total exposure doses suggesting that the irradiation in gaseous phase does not damage the graphene crystalline domains. As confirmed by X-ray photoemission spectroscopy, the C/O ratio of ?-ray reduced graphene oxide is increasing from 2.37 for graphene oxide to 6.25 upon irradiation in hydrogen gas. The removal of oxygen atoms with this reduction process in hydrogen results in a sharp 400 times increase of the electrical conductivity of ?-ray reduced graphene oxide from 0.05 S cm?1 to as high as 23 S cm?1. A significant increase of the contact angle of the ?-ray reduced graphene oxide bucky-papers and weakened oxygen rich groups characteristic peaks across the Fourier transform infrared spectra further illustrate the efficacy of the ?-ray reduction process. A mechanism correlating the interaction between hydrogen radicals formed upon ?-ray irradiation of hydrogen gas and the oxygen rich groups on the surface of the graphene oxide bucky-papers is proposed, in order to contribute to the synthesis of reduced graphene materials through solution-free chemistry routes

  11. Effects of gamma-ray irradiation and crevice-like shape on the corrosion of type 316L stainless steel in high-temperature water

    International Nuclear Information System (INIS)

    The irradiation effect to high-temperature water in nuclear power plant has been regarded as one of important issues for preventing corrosion and stress corrosion cracking of plant materials. However, the effects of surface reaction and configurations of material on irradiated high-temperature water chemistry have been studied little because of the difficulty of measuring the environment. In this work, we have done a series of corrosion tests of Type 316L stainless steel in high-temperature water in order to estimate the effects of gamma-ray irradiation and crevice-like shape on the water chemistry. Test specimens immersed in high-temperature water of 288degC were gamma-ray irradiated for 500 hours. The absorbed dose rate of gamma-ray irradiation was estimated to be 30 kGy h-1. The dimensions of the disk-like specimens were 16 mm in diameter by 0.5 mm in thickness. The surfaces of the specimens were mechanically finished with no.800 emery paper. Sets of two specimens attached closely in order to simulate a crevice-like environment were also immersed. The surfaces of the specimens were analyzed using SEM, TEM, and laser Raman spectrometer. The results of surface analyses indicated that gamma-ray irradiation enhanced the precipitation of iron oxide on the surface and the thickness of inner oxide layer became thicker by gamma-ray irradiation. Gamma-ray irradiation also changed the morphology of oxide on the surface faced to the crevice-like environment. (author)

  12. Positron and Gamma-Ray Creation using the Texas Petawatt Laser Irradiating Gold Targets

    Science.gov (United States)

    Liang, Edison; Taylor, Devin; Clarke, Taylor; Henderson, Alexander; Chaguine, Petr; Wang, Xin; Dyer, Gilliss; Serratto, Kristina; Riley, Nathan; Donovan, Michael; Ditmire, Todd

    2012-10-01

    We report preliminary results of the positron and gamma-ray creation experiment performed at the Texas Petawatt Laser (TPW) during the summer of 2012. Of the shots using gold targets, preliminary results suggest that positrons were detected in many of the shots. TPW was operating at around 100 J and 0.5 -- 0.8 PW during this experiment, and 25% of the shots achieved peak intensity exceeding 10^21W.cm-2. We will report the measured positron spectra, positron angular distribution and positron to hot electron ratio, inferred positron yield and in-situ positron density. The positron energy data will be compared to simultaneous TNSA proton energy data to model sheath acceleration mechanisms. We also measured the bremsstrahlung gamma-ray spectra and angular distributions from the gold targets, using a combination of dosimeters, filter stack spectrometers and forward Compton spectrometer. Target activation data will also be reported.

  13. Monte Carlo simulation of prompt gamma-ray spectra from depleted uranium under D-T neutron irradiation and electron recoil spectra in a liquid scintillator detector

    CERN Document Server

    Qin, Jianguo; Liu, Rong; Zhu, Tonghua; Zhang, Xinwei; Ye, Bangjiao

    2015-01-01

    To overcome the problem of inefficient computing time and unreliable results in MCNP5 calculation, a two-step method is adopted to calculate the energy deposition of prompt gamma-rays in detectors for depleted uranium spherical shells under D-T neutrons irradiation. In the first step, the gamma-ray spectrum for energy below 7 MeV is calculated by MCNP5 code; secondly, the electron recoil spectrum in a BC501A liquid scintillator detector is simulated based on EGSnrc Monte Carlo Code with the gamma-ray spectrum from the first step as input. The comparison of calculated results with experimental ones shows that the simulations agree well with experiment in the energy region 0.4-3 MeV for the prompt gamma-ray spectrum and below 4 MeVee for the electron recoil spectrum. The reliability of the two-step method in this work is validated.

  14. Comparative study on hematopoietic damage of mice caused by high-dose of gamma-ray irradiation

    International Nuclear Information System (INIS)

    Objective: To study the effect of high-dose of gamma-ray irradiation on hematopoiesis injury and recovery of IRM-2 and C57BL/6 J mouse. Methods: The experiment was designed to study the effects of radiation (4 Gy) on spleen index, CFU-S and DNA damage on the 9 th day of IRM-2 and ICR mice and the effects of radiation (6 Gy) on WBC change and its absolute value on the 45 th days of IRM-2 and C57BL/6 J mice. Results: The IRM-2 mouse spleen index, CFU-S and DNA were higher than ICR mouse on the 9 th days, and there were significant difference in CFU-S and DNA (P<0.01). The IRM-2 mouse WBC, RMC, HGB and HCT were higher than C57BL/6 J mouse on the 45 th days, and there were significant difference (P<0.01). Conclusion: IRM-2 mouse hematopoiesis resumes quicker than C57BL/6 J and ICR do after high-dose of gamma-ray irradiation. (authors)

  15. Mutation induction by gamma-rays and carbon ion beam irradiation in banana (Musa spp.): a study with an emphasis on the response to Black sigatoka disease

    International Nuclear Information System (INIS)

    Gamma-rays and carbon ion beam irradiation methods were applied to study critical doses, genetic variability and the response to Black sigatoka disease. 'Cavendish Enano', 'Williams', 'Orito' and 'FHIA-01' cultivars of banana were studied. Both gamma-rays and carbon ion beam irradiation methods had different biological effects when banana explants were exposed to them. In both methods, increased dose caused increased mortality. 'FHIA-01' tolerated high doses of gamma-rays but was susceptible to high doses of carbon ion beam irradiation. The results suggest that the response in 'FHIA-01' can be explored using other dose intervals between 150 and 300 Gy. Weight and height were also reduced drastically when high doses of gamma-rays and carbon ion beams were applied. The LD50 of cultivars 'FHIA-01' and 'Orito' revealed high sensitivity to both gamma-rays and carbon ion beams. DNA deletion in 'FHIA-01' occurred by using gamma-rays at doses of 200 and 300 Gy, suggesting that 'FHIA-01' is definitely a promising cultivar with a high sensitivity response to gamma-ray exposure, and that there is a high chance of improving its fruit quality by mutation induction. Sigmoid drooping leaf, a putative mutation of 'FHIA-01', was generated. This mutation is heritable as mother plant and sucker showed the same characteristics. Future research could be conducted on the relationship of leaf shape to fruit quality and production. Hexaploid cells were detected by flow cytometry (five plants in 'Cavendish Enano' and one in 'Williams'), signifying that chromosome duplication can be induced by carbon ion beams. Variation in the leaves such as being abnormal, double, long, rudimentary, spindled and yellow spotted leaf was visible, suggesting that long-term chronic irradiation (gamma-rays) directly affects active cell division at the meristem level, resulting in severe damage or even death of the meristems. During the juglone toxin experiment on gamma-ray-irradiated plants, 20 plants were selected from the 'Orito' lot, eight in 'Williams' and five in 'Cavendish Enano'. In the carbon ion beam experiments, six plants of 'Williams' and two of 'Cavendish Enano' were selected as possible candidates with a better response to Black sigatoka disease. In addition, following irradiation with a carbon ion beam, a fast growing plant was observed and selected as earliness is an important characteristic for shortening the crop life cycle. Finally, field experiments throughout the whole plant cycle are needed to evaluate mutated traits for fruit quality, yield and post-harvest characteristics for a final selection. (author)

  16. Correlation between release of deuterium and annihilation of irradiation defects produced by gamma-ray in Li{sub 2}TiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Toda, Kensuke, E-mail: r0233019@ipc.shizuoka.ac.jp [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Kobayashi, Makoto; Fujishima, Tetsuo; Uchimura, Hiromichi; Miura, Ryo [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan); Fujii, Toshiyuki; Yamana, Hajimu [Research Reactor Institute, Kyoto University, Kumatori (Japan); Oya, Yasuhisa; Okuno, Kenji [Radioscience Research Laboratory, Faculty of Science, Shizuoka University, Shizuoka (Japan)

    2013-10-15

    The dependence of irradiation defect density on hydrogen isotope release behaviors in Li{sub 2}TiO{sub 3} was studied. Li{sub 2}TiO{sub 3} was exposed to gaseous deuterium and, thereafter, gamma-ray irradiation was performed with various gamma-ray doses to change the density of irradiation defects. The deuterium release behavior was measured by TDS. The density of the defects and the state of O-D bonds in the sample were elucidated by ESR and FT-IR, respectively. Most of deuterium was adsorbed on the surface or trapped by intrinsic defects after deuterium gas exposure. However, O-D bonds were increased as the gamma-ray dose was increased. In addition, the irradiation defects like E-center, O{sup ?}-center and O{sub 2}{sup ?}-center were observed in gamma-ray irradiated samples. This indicated that the density of irradiation defect control the deuterium stable trapping by oxygen. These facts conclude that tritium release temperature will be shifted toward higher temperature as the operation time increased and irradiation defects are accumulated.

  17. Temperature effects of gamma-rays irradiation on radiation resistance of organic insulator for super conducting magnet in fusion reactor

    International Nuclear Information System (INIS)

    If glass fiber reinforced plastic (GFRP) is used as insulator material for super conducting magnets in a fusion reactor, then the radiation resistance of GFRP in cryogenic environments must be evaluated. The irradiation temperature dependence of radiation degradation of GFRP (Bisphenol-A epoxy resin) was examined. GFRP was exposed to gamma rays at 77K and room temperature. The changes in mechanical properties and the gas evolution were investigated. The flexural strength at break decreased to half of the initial value with 25 MGy at 77K. The evolution of CO and CO2 was much less at 77K than at room temperature. The radiation degradation showed a large dependence on irradiation temperature

  18. Reoxygenation and recovery phenomena after potentially lethal damage of tumor cells EMT6 following thermal and epithermal neutron irradiation. Comparison with those after gamma-ray irradiation

    International Nuclear Information System (INIS)

    A lot of hypoxic cells exist usually in solid tumor. The humor cells, which need commonly oxygen for breeding, are killed selectively by irradiation, but almost all of the hypoxic cells survive. Fraction of hypoxic cell in the solid tumor after the irradiation increases relatively. The fraction of the survived hypoxic cell, however, decreases with time. Radiation sensitivity of the solid tumor increases again as a whole, Recovery phenomena after the potentially lethal damage (PLD) are recognized in normal culture cells, also. The reoxygenation in the tumor cells is considered as a relatively large recovery phenomena after the PLD. Tumor cells EMT6, which have chronically a large hypoxic fraction, are irradiated for investigating of the reoxygenation and the recovery phenomena by thermal, epithermal neutron and Co-60 gamma-ray in the heavy water neutron irradiation facility of Kyoto University Research Reactor (KUR). Absorbed doses of Balb/c female mice injected the EMT6 tumor cells are 15 Gy for thermal neutron, 27 Gy for epithermal neutron, and 15 Gy for gamma-ray, respectively. Surviving fraction and hypoxic fraction of the EMT6 tumor cells after the irradiation are determined by colony formation ratio. LET dependency of the recovery phenomena, however, is not recognized in the experiments. Reoxygenation phenomena caused by thermal and epithermal neutron irradiation have a tendency of more rapid than that by gamma-irradiation. (M. Suetake)

  19. On-Line High Dose-Rate Gamma Ray Irradiation Test of the CCD/CMOS Cameras

    International Nuclear Information System (INIS)

    In this paper, test results of gamma ray irradiation to CCD/CMOS cameras are described. From the CAMS (containment atmospheric monitoring system) data of Fukushima Dai-ichi nuclear power plant station, we found out that the gamma ray dose-rate when the hydrogen explosion occurred in nuclear reactors 1?3 is about 160 Gy/h. If assumed that the emergency response robot for the management of severe accident of the nuclear power plant has been sent into the reactor area to grasp the inside situation of reactor building and to take precautionary measures against releasing radioactive materials, the CCD/CMOS cameras, which are loaded with the robot, serve as eye of the emergency response robot. In the case of the Japanese Quince robot system, which was sent to carry out investigating the unit 2 reactor building refueling floor situation, 7 CCD/CMOS cameras are used. 2 CCD cameras of Quince robot are used for the forward and backward monitoring of the surroundings during navigation. And 2 CCD (or CMOS) cameras are used for monitoring the status of front-end and back-end motion mechanics such as flippers and crawlers. A CCD camera with wide field of view optics is used for monitoring the status of the communication (VDSL) cable reel. And another 2 CCD cameras are assigned for reading the indication value of the radiation dosimeter and the instrument. In the preceding assumptions, a major problem which arises when dealing with CCD/CMOS cameras in the severe accident situations of the nuclear power plant is the presence of high dose-rate gamma irradiation fields. In the case of the DBA (design basis accident) situations of the nuclear power plant, in order to use a CCD/CMOS camera as an ad-hoc monitoring unit in the vicinity of high radioactivity structures and components of the nuclear reactor area, a robust survivability of this camera in such intense gamma-radiation fields therefore should be verified. The CCD/CMOS cameras of various types were gamma irradiated at a dose rate of about 150 Gy/h till these cameras failed. A high dose-rate gamma ray radiation induced speckles in the camera image were heavily observed. In this paper we describe the evolution of their basic characteristics with high dose rate gamma irradiation and shortly explain the observed phenomena

  20. Investigations on the degradation, of visible laser diodes under, gamma-ray irradiation

    International Nuclear Information System (INIS)

    The possible use of semiconductor optoelectronic devices (laser diodes, light emitting diodes, photodetectors) as component parts of remote sensing and diagnostics systems, for different robotic setups in nuclear equipment or for optical fiber-based communication led to the intensive investigations of these components as they operate in radiation environment. We report our research on the evaluation of the gamma-ray induced degradation of several semiconductor laser diodes, emitting at three visible wavelengths, in order to make a preliminary assessment for their possible use in fusion installations

  1. Effect of gamma-ray irradiation on growth of calli derived from mature embryos or seeds in barley

    International Nuclear Information System (INIS)

    Radiosensitivity of barley varieties as expressed by callus growth was examined after exposure of seeds to gamma-rays and transfer of mature embryos detached from seeds or whole seeds onto medium for the initiation and growth of callus. Marked differences in the value of D50 about 7-fold at maximum were observed among the varieties employed (Figs. 1 a and b). Particularly all the naked varieties used showed much lower values of D50s than the covered ones (Table 1). These results correspond to the level of radiosensitivity expressed by seedling growth after seed irradiation (Figs. 2, 3). A major gene (rs) on chromosome I which has recently been found to control the latter radiosensitivity seemed to exert its effect on the radiosensitivity measured by the callus growth. When calli initiated from seeds were irradiated three days after inoculation on agar medium, the value of D50 for callus growth decreased markedly from 44 kR in seed irradiation to 5 kR in callus irradiation for the covered variety, while the change in the value of D50 was slight, changing from 7 to 3 kR for the naked variety. The difference in the value of D50 was not large, but still significant (Figs. 4 a, 4 b). The relationship between the value of D50 for seedling growth in the case of seed and seedling irradiation and that of D50 for callus growth after callus irradiation varied considerably with the varieties. (author)

  2. Effect Of Gamma Ray Irradiation On Streptococcus Agalactiae Growth For Vaccine Agent Of Mastitis Disease In Dairy Cattle

    International Nuclear Information System (INIS)

    A study has been conducted to determine the effect of gamma ray irradiation to attenuate infectivity of S. agalactiae as dominant bacteria causing mastitis in dairy cattle. The aim of the study is obtaining optimum irradiation dosage to provide radio vaccine for mastitis. S. agalactiae isolate bacteria of which has reach the mid log-phase was cultured and divided into 6 treatment groups of irradiation doses, i.e. 0, 0.2, 0.4, 0.6, 0.8, and 1.0 kGy. Following irradiation, bacteria were then cultured in BHI agar media for colony counting to determine the LD50, resulting 7.5x108; 5.0x107; 7.0x106; 9.5x105; 1.5x104; and 3.5x103 cell/ml, respectively. Result of this study shows the higher irradiation doses the lower number of bacteria per ml, and LD50, which found to be under 0.2 kGy of irradiation dose

  3. Molecular weight distribution of electron and {gamma}-ray irradiated PEEK measured by very high temperature GPC

    Energy Technology Data Exchange (ETDEWEB)

    Nakahara, H. [National Inst. of Materials and Chemical Research, Tsukuba, Ibaraki (Japan)

    1996-03-01

    Poly(ether ether ketone)(PEEK) films were irradiated with electron beam in air and in helium. Gel fractions of the PEEK samples were determined as the ratio of the weight of insoluble fraction/total weigh by extracting the samples with 1-chloronaphthalene (1-CN) at 260degC. While unirradiated PEEK samples were dissolved in 1-CN completely, PEEK samples highly (10 - 50 MGy) irradiated in air were almost insoluble in the solvent. The weight-average molecular weight M{sub w} of soluble fractions of the samples were measured by very high temperature gel permeation chromatography (VHTGPC): it was found that the M{sub w} decreases with increasing dose. On the other hand, PEEK samples irradiated in helium gave gel fractions at lower doses (0 - 5 MGy) than in air. The PEEK films were also irradiated with {sup 60}Co {gamma}-rays in the dose range, i.e. from 0 to 5 MGy. The {gamma}-irradiated PEEK samples were completely dissolved in 1-CN at 260degC. Their M{sub w} measured by VHTGPC decreases with increasing dose. (author)

  4. Fabrication and characterization of monodisperse zinc sulfide hollow spheres by gamma-ray irradiation using PSMA spheres as templates

    Science.gov (United States)

    Zhao, Yongbin; Chen, Tiantian; Zou, Jianhua; Shi, Wenfang

    2005-03-01

    The submicrometer monodisperse zinc sulfide (ZnS) hollow spheres were synthesized by gamma-ray irradiation at room temperature, using monodisperse poly (styrene-methyl methacrylate-acrylic acid) (PSMA) latex spheres as the templates. X-ray diffraction (XRD) spectroscopy, transmission electron microscopy, thermogravimetric analysis, and UV-vis spectroscopy were used to characterize these nanoparticles, indicating the formation of core-shell colloidal spheres, as well as hollow spheres. The TEM study for the ZnS-coated PSMA core-shell particles has revealed the uniform coating of ZnS on the PSMA core surface as a thin layer. The obtained ZnS hollow spheres are uniform having a diameter range of 365-375 nm, and wall thickness range of 25-35 nm.

  5. Selection and characterization of tomato plants for osmotic stress tolerance derived from a gamma ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kwon Kyoo; Jung, Yu Jin [Hankyong National University, Anseong (Korea, Republic of)

    2010-09-15

    The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000)through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines.

  6. Selection and characterization of tomato plants for osmotic stress tolerance derived from a gamma ray irradiation

    International Nuclear Information System (INIS)

    The present study has been performed to select the osmotic tolerant lines using polyethylene glycol (PEG 6000)through an in vitro and in vivo mutagensis with a gamma-ray. During the screening, we selected three mutant lines that seemed to confer elevated osmotic tolerance in high concentrations of PEG 6000. Fruits of these mutants (Os-HK101, Os-HK102 and Os-HK103) were those of the wild type. Also the chlorophyll contents were few decreased more in the three mutant lines than the WT plants. Our results suggest that the Os-HK101 is characterized as osmotic stress tolerance considering the sugar concentration and lycopine content. It is expected that the result of this study can be used for breeding more competitive species with respect to contents in sugar or functional chemicals from the selected osmotic resistant lines

  7. Radioprotection by dipyridamole. Effects on lipid peroxidation in mouse liver after whole-body X-ray and 60Co gamma-ray irradiation

    International Nuclear Information System (INIS)

    To investigate the mechanism of the radioprotective effect of dipyridamole, the lipid peroxide content in mouse liver irradiated by X-ray and 60Co gamma-ray were measured both before and after injection of dipyridamole. The lipid peroxide content was significantly increased in a time-related manner after whole-body irradiation, and the increase depended on the dose of irradiation. There was no significant difference on biological effects between X-ray and 60Co gamma-ray. Dipyridamole given before irradiation significantly inhibited the lipid peroxide increase by whole-body irradiation. The results suggest that inhibition of lipid-peroxidation is a possible factor in the radioprotective effect of dipyridamole. (author)

  8. Thermal behavior of organic free radicals in {gamma}-ray irradiated pepper studied by electron spin resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ichii, Akane; Abe, Aika; Ukai, Mitsuko [Hokkaido Univ. of Education, Hakodate (Japan)

    2003-04-01

    Using electron spin resonance (ESR) spectroscopy, we revealed heating effects on irradiated pepper. The representative ESR spectrum of the irradiated pepper is consisted of four components a sextet centered at g=2.0, a singlet at the same g-value, a singlet at g=4.0 and side peaks near g=2.0. The first one is attributable to a signal with hyperfine (hf) interactions of Mn{sup 2+} (hf constant=7.4 mT). The second one is due to an organic free radical that is induced by the {gamma}-ray irradiation. The third one may originated from Fe{sup 3+} in the nonhem proteins. The fourth signal was found at the symmetric positions of the organic free radical, i.e., the second signal. Upon heating, the forth signals decreased monotonicaly. The ESR signal of the pepper heated for more than 10 min was essentially the same as that before the irradiation. On the other hand, the second signal increased and then leveled off at a constant value by further heating. This is indicative the occurrence of some biochemical reactions such as Maillard reaction during heating procedures. (author)

  9. Assessment of differences between X and gamma rays in order to validate a new generation of irradiators for insect sterilization

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Thiago; Walder, Julio M.M., E-mail: piaui@cena.usp.b [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil); Parker, Andrew G.; Jessup, Andrew; Orozco-Davila, Dina; Islam, Amirul; Dammalage, Thilakasiri, E-mail: A.Jessup@iaea.or [Joint FAO/IAEA-UN A-2444, Seibersdorf (Austria). Insect Pest Control Subprogramme; Pereira, Rui, E-mail: R.Cardoso-Pereira@iaea.or [Joint FAO/IAEA-UN, Vienna (Austria). Insect Pest Control Subprogramme

    2009-07-01

    Recent fears of terrorism provoked an increase in delays and denials of transboundary shipments of radioisotopes. This represents a serious constraint to sterile insect technique (SIT) programs around the world as they rely on the use of ionizing energy from radioisotopes for insect sterilization. In order to validate a novel Xray irradiator, a series of studies on Ceratitis capitata (Wiedemann) and Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) were carried out, comparing the relative biological effectiveness (RBE) between X-rays and traditional gamma radiation from {sup 60}Co. Male C. capitata pupae and pupae of both sexes of A. fraterculus, both 24 to 48 h before adult emergence, were irradiated with doses ranging from 15 to 120 Gy and 10 to 70 Gy respectively. Estimated mean doses of 91.2 Gy of X and 124.9 Gy of gamma radiation induced 99% sterility in C. capitata males. Irradiated A. fraterculus were 99% sterile at about 40-60 Gy for both radiation treatments. Standard quality control parameters were not significantly affected by the two types of radiation. There were no significant differences between X and gamma radiation regarding mating indices. The RBE did not differ significantly between the tested X and gamma radiation, and X-rays are as biologically effective for SIT purposes as gamma rays are. This work confirms the suitability of this new generation of X-ray irradiators for pest control programs in UN Member States. (author)

  10. Monte Carlo simulation of prompt gamma-ray spectra from depleted uranium under D-T neutron irradiation and electron recoil spectra in a liquid scintillator detector

    OpenAIRE

    Qin, Jianguo; Lai, Caifeng; Liu, Rong; Zhu, Tonghua; Zhang, Xinwei; Ye, BangJiao

    2015-01-01

    To overcome the problem of inefficient computing time and unreliable results in MCNP5 calculation, a two-step method is adopted to calculate the energy deposition of prompt gamma-rays in detectors for depleted uranium spherical shells under D-T neutrons irradiation. In the first step, the gamma-ray spectrum for energy below 7 MeV is calculated by MCNP5 code; secondly, the electron recoil spectrum in a BC501A liquid scintillator detector is simulated based on EGSnrc Monte Car...

  11. Culture competency and regeneration capacity of rice (oryza sativa) embryogenic callus after irradiation with 60Co gamma rays

    International Nuclear Information System (INIS)

    The aims of this investigation are to prove the applying of a combination consequence, in vitro somatic embryogenesis induction and irradiation. Three main point were focused. callus formation from irradiated mature embryos, effect of gamma radiation on the growth of embryogenic and the interaction between gamma rays effects and embryogenic calli sizes on regeneration rate. Callus size was classified in this study in three groups. The first white color (> 1.0 mm), less than normal size. The second (1-2 mm ) just reached the normal size, yellowish green color, from which fully regenerated plants were mainly derived and usually produced multiple shoots. The third group was more than normal (5 mm ) in size, yellow green to light green in color, these larger Calli did not regenerate but became rhizogenic and necrotic. The relationship between the larger callus size and plant regeneration ability could be due to that the large calluses are old, with lesser cellular activity. The highest callus induction rate from irradiated mature embryos was found at 20-40 Gy, also higher than non-irradiated embryos. Higher doses of gamma irradiation on callus induction effected a poor response, mature embryos exposited to 60 Gy and non-irradiated callus achieved the lowest callus induction. Callus forming roots ( % rhizogenic callus) was not significantly differed by increased radiation dosage. An increase in callus fresh and dry weight was materialized by an increase in dose from 20-40 Gy than non-irradiated by a decrease in callus and dry weight at 60 Gy. When embryogenic callus grew, green spots began to differentiate and green shoots started to develop respectively

  12. Formation and conversion of defect centers in low water peak single mode optical fiber induced by gamma rays irradiation

    Science.gov (United States)

    Wen, J. X.; Luo, W. Y.; Xiao, Z. Y.; Wang, T. Y.; Chen, Z. Y.; Zeng, X. L.

    2010-02-01

    The formation and conversion processes of defect centers in low water peak single mode optical (LWPSM) fiber irradiated with gamma rays were investigated at room temperature using electron spin resonance. Germanium electron center (GEC) and self-trapped hole center (STH) occur when the fibers are irradiated with 1 and 5 kGy cumulative doses, respectively. With the increase in irradiation doses, the GEC defect centers disappear, and new defect centers such as E' centers (Si and Ge) and nonbridge oxygen hole centers (NBOHCs) generate. The generation of GEC and STH is attributed to the electron transfer, which is completely balanced. This is the main reason that radiation-induced attenuation (RIA) of the LWPSM fiber is only 10 dB/km at communication window. The new defect centers come from the conversion of GEC and STH to E' centers and NBOHC, and the conversion processes cause bond cleavage, which is the root cause that the RIA of the LWPSM fiber significantly increases up to 180 dB/km at working window. Furthermore, the concentration of new defect centers is saturated easily even by increasing cumulative doses.

  13. Gas Evolution from Insulating Materials for Superconducting Coil of Iter by Gamma Ray Irradiation at Liquid Nitrogen Temperature

    Science.gov (United States)

    Idesaki, A.; Koizumi, N.; Sugimoto, M.; Morishita, N.; Ohshima, T.; Okuno, K.

    2008-03-01

    A laminated material composed of glass cloth/polyimide film/epoxy resin will be used as an insulating material for superconducting coil of International Thermonuclear Experimental Reactor (ITER). In order to keep safe and stable operation of the superconducting coil system, it is indispensable to evaluate radiation resistance of the material, because the material is exposed to severe environments such as high radiation field and low temperature of 4 K. Especially, it is important to estimate the amount of gases evolved from the insulating material by irradiation, because the gases affect on the purifying system of liquid helium in the superconducting coil system. In this work, the gas evolution from the laminated material by gamma ray irradiation at liquid nitrogen temperature (77 K) was investigated, and the difference of gas evolution behavior due to difference of composition in the epoxy resin was discussed. It was found that the main gases evolved from the laminated material by the irradiation were hydrogen, carbon monoxide and carbon dioxide, and that the amount of gases evolved from the epoxy resin containing cyanate ester was about 60% less than that from the epoxy resin containing tetraglycidyl-diaminophenylmethane (TGDDM).

  14. GAS EVOLUTION FROM INSULATING MATERIALS FOR SUPERCONDUCTING COIL OF ITER BY GAMMA RAY IRRADIATION AT LIQUID NITROGEN TEMPERATURE

    International Nuclear Information System (INIS)

    A laminated material composed of glass cloth/polyimide film/epoxy resin will be used as an insulating material for superconducting coil of International Thermonuclear Experimental Reactor (ITER). In order to keep safe and stable operation of the superconducting coil system, it is indispensable to evaluate radiation resistance of the material, because the material is exposed to severe environments such as high radiation field and low temperature of 4 K. Especially, it is important to estimate the amount of gases evolved from the insulating material by irradiation, because the gases affect on the purifying system of liquid helium in the superconducting coil system. In this work, the gas evolution from the laminated material by gamma ray irradiation at liquid nitrogen temperature (77 K) was investigated, and the difference of gas evolution behavior due to difference of composition in the epoxy resin was discussed. It was found that the main gases evolved from the laminated material by the irradiation were hydrogen, carbon monoxide and carbon dioxide, and that the amount of gases evolved from the epoxy resin containing cyanate ester was about 60% less than that from the epoxy resin containing tetraglycidyl-diaminophenylmethane (TGDDM)

  15. Gamma-ray irradiation effects of poly(ethylene-2, 6-naphthalate) and poly(ethylene-terephthalate)

    International Nuclear Information System (INIS)

    The irradiation effects and radiation resistances of poly(ethylene-2, 6-naphthalate) (PEN) and poly(ethylene-terephthalate)(PET) were investigated by the analyses of evolved gases, crosslinking and chain scission, and physical properties of thermal behavior and tensile strength after irradiation by gamma-rays under vacuum and in oxygen atmosphere. The evolved gases in both PEN and PET were mainly CO2 and small amounts of H2, CH4, and CO. The G-values of CO2 were 0.004 for PEN and 0.07 for PET by irradiation under vacuum, and were 0.26 for PEN and 0.17 for PET in oxygen. In the case of irradiation without oxidation, the crosslinking proceeded mainly for PEN, but the chain scission was the main reaction for PET. In the case of oxidative irradiation, the chain scission proceeded and no cross-linking was observed for both PEN and PET. The change of mechanical properties of PEN film irradiated under vacuum was very small by comparing with PET. The radiation resistances of PEN and PET were evaluated to be 12 MGy for PEN and 2 MGy for PET in non-oxidative conditions, and were 4.5 MGy for PEN and 1.4 MGy for PET in oxidation conditions by the measurements of tensile testing. The reason of high radiation resistance of PEN was thought that PEN molecules have a large resonance energy of napthalene in the polymer chain, and have higher probability of crosslinking comparing with PET molecules due to the molecular conformation such as crystalline structure. (author)

  16. Effect of gamma-ray irradiation on structural properties of GaAsN films grown by metal organic vapor phase epitaxy

    Science.gov (United States)

    Klangtakai, Pawinee; Sanorpim, Sakuntam; Wattanawareekul, Atiwat; Suwanyangyaun, Pattana; Srepusharawoot, Pornjuk; Onabe, Kentaro

    2015-05-01

    The effects of gamma-ray irradiation on the structural properties of GaAs1-xNx films (N concentration=1.9 and 5.1 at%) grown by metal organic vapor phase epitaxy on GaAs (001) substrates were investigated. The GaAs1-xNx films were irradiated by gamma rays with irradiation strength of 0-2.0 MGy. Scanning electron microscopy and atomic force microscopy results showed that a gamma ray with a strength of 0, 0.5, 1.0, 1.5, and 2.0 MGy formed holes with a density of 0.0, 8.8, 9.4, 11.5, and 11.9 ?m-2, respectively, on the surface of a GaAs0.981N0.019 film with low N content. On the other hand, the irradiated high-N-content GaAs0.949N0.051 film exhibited a cross-hatch pattern, which was induced by partial strain relaxation at high N levels, with a line density of 0.0, 0.21, 0.37, 0.67, and 0.26 ?m-1 corresponding to an irradiation strength of 0, 0.5, 1.0, 1.5, and 2.0 MGy, respectively. The high-resolution X-ray diffraction and Raman scattering results revealed an increase in N incorporation and strain relaxation after irradiation. In addition, the GaAs0.949N0.051 films exhibited phase separation, which took place via N out-diffusion across the interface when the irradiation strength exceeded 1.0 MGy. Based on these results, the main cause of structural change was determined to be the irradiation effects including displacement damage and gamma-ray heating.

  17. Induction of mutant resistant to alternaria blotch of apple by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Apple cultivars resistant to Alternaria blotch disease have been produced by cross-breeding, but it is difficult to produce resistance by crossing without changing the properties of cultivar because the gene composition of the cultivar tree is almost heterozygous. This study aimed to investigate the resistant mutation in Alternaria blotch susceptible and semiresistant cultivars. The resistance to Alternaria blotch pathogen or AM toxin is classified into the following three groups: 1) highly sensitive group including Indo, Redgold and Starking delicious, 2) semi-resistant group including Fuji, Orin and Golden delicious and 3) resistant group including Gala and Tsugaru. After gamma ray exposure of 80 Gy (at 5 Gy/hour), AM-toxin insensitive clones were selected in the VM6 generation. These selected mutants could be rooted and habituated under field conditions. The degree of disease resistance was assessed by AM toxin treatment and Alternaria blotch fungi spore inoculation test. The leaves of these mutants were changed to variegated at high temperature, suggesting that some mutation related to chloroplast might have occurred. Alternaria blotch resistant strains could be produced by exposing to ?ray and selecting with AM toxin in shoot-tip culture system, but the functional effects of the AM toxin in Alternaria blotch and also the mechanism in the mutant lines were still unclear. (M.N.)

  18. Change in microflora of sewage sludge by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Total bacteria of activated dewatered sludge cake of Takasaki city which amounted to 2 x 109 per gram diminished rapidly with the radiation dose, but slowly after 0.5 Mrad, and 103 per gram survived even after 10 Mrad irradiation. However, coliforms which amounted to 8 x 107 per gram were inactivated below 0.5 Mrad irradiation. The predominant bacteria in non-irradiated sludge were Pseudomonas cepacia and it mainly survived up to 2 Mrad, but Bacillus were predominant at 0.5 to 0.7 Mrad irradiation. The main residual flora from 2 to 5 Mrad was composed of Pseudomonas soranacearum, P. cepacia and P. delafieldii, and the main residual flora in more than 5 Mrad irradiated sludge was P. flava. These typical strains of Pseudomonas in phosphate buffer were radiation sensitive, and their D10 values were from 0.005 to 0.021 Mrad under aerobic irradiation conditions. (author)

  19. Effect of gamma-ray irradiation on the unloaded animal model

    Science.gov (United States)

    Choi, Jong-Il; Yoon, Min-Chul; Sung, Nak-Yoon; Kim, Jae-Hun; Jong Lee, Yun; Lee, Ki-Soo; Choi, In-Ho; Nam, Gung Uk; Lee, Ju-Woon

    During the space flight, human beings encountered the extreme conditions such as the cosmic ray irradiation and microgravity. There have been developed the animal models to simulate the microgravity condition in laboratory, but no study was carried out to investigate the combined effect of microgravity and exposure to irradiation. In this study, it was examined the effect of gamma irradiation on the suspension model. Rats were divided into four groups, Group I was loaded and not exposed to gamma irradiation, Group 2 was unloaded and not exposed, Group 3 was loaded and exposed to gamma irradiation at the dose of 50 mSV, and Group 4 was unloaded and exposed to gamma irradiation at the same dose. It was measured body, muscles and tissues weights and the biological analysis and the hematological response in blood samples were conducted. Anti-gravity tissue weight was only changed between loading and un-loading condition. However, there was no difference between irradiation exposed and not exposed unloaded groups. To know the difference of protein expression in anti-gravity tissues, 2 dimensional electrophoresis was performed. It has been found that the expression levels of several proteins were different by unloading condition and by irradiation exposed condition, respectively. These results provided the information on the combined effect of irradiation and microgravity to simulate space flight, and could be useful to search the candidate material for the countermeasure against space environment.

  20. Low temperature gamma ray irradiation effects on polymer materials (4)-gas analysis of GFRP and CFRP

    International Nuclear Information System (INIS)

    Gas analysis was carried out at RT after gamma-irradiation at room temperature and 77K for glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP) having the same epoxy resin matrix. Gas yield from CFRP was less than that from GFRP at RT, but comparable at 77 K. The yields of CO and CO2 showed a large dependence on the irradiation temperature, i.e. they were much less at 77 K. Radiation resistance of GFRP and CFRP towards 77 K irradiation is expected to be higher than that towards RT irradiation. (author)

  1. Individual variability in the yield of chromosomal aberrations after low dose gamma-ray irradiation

    International Nuclear Information System (INIS)

    Full text: Factors such as DNA repair, chromatin structure, cell cycle control and apoptosis can modify the response of mammalian cells to ionising radiation. Consequently, genetic differences underlying these phenomena may affect individual susceptibility to ionising radiation. In the present study interindividual differences in dose response of chromosomal aberrations at low doses of gamma-rays were examined. Peripheral lymphocytes from ten healthy males were isolated from a sample of whole blood. Doses of 0, 0.1, 0.25, 0.5, 0.75 and 1.0 Gy at a dose rate of 0.8 Gy/min were given using a 60Co source. The cells were incubated at +370C for 48 hours, the last 4 hours in the presence of 0.2 ?g/ml Colcemid. The cells were treated with hypotonic solution (0.075 M KCl) and fixed in methanol - acetic acid (3:1). A cocktail of biotin-labelled whole-chromosome probes for chromosomes 1, 2 and 4 and a digoxigenin-labelled pan-centromeric probe were used. Detection and amplification of the chromosome cocktail and the centromere probe were performed simultaneously by three layers of antibodies: 1) avidin-FITC and anti-digoxigenin, 2) biotin-labelled anti-avidin and AMCA anti-mouse, 3) avidin-FITC and AMCA anti-rat. Translocations, dicentrics, acentics, insertions and painted ring chromosomes were scored. The observed frequencies of painted translocations and dicentrics were converted into genomic frequencies by the formula established by Lucas et al., and using the lengths of chromosomes 1, 2 and 4 given by Morton. The results will be described in detail and the individual variability will be discussed. (author)

  2. Gamma-ray spectrometric measurements of fission rate ratios between fresh and burnt fuel following irradiation in a zero-power reactor

    International Nuclear Information System (INIS)

    The gamma-ray activity from short-lived fission products has been measured in fresh and burnt UO2 fuel samples after irradiation in a zero-power reactor. For the first time, short-lived gamma-ray activity from fresh and burnt fuel has been compared and fresh-to-burnt fuel fission rate ratios have been derived. For the measurements, well characterized fresh and burnt fuel samples, with burn-ups up to 46 GWd/t, were irradiated in the zero-power research reactor PROTEUS. Fission rate ratios were derived based on the counting of high-energy gamma-rays above 2200 keV, in order to discriminate against the high intrinsic activity of the burnt fuel. This paper presents the measured fresh-to-burnt fuel fission rate ratios based on the 142La (2542 keV), 89Rb (2570 keV), 138Cs (2640 keV) and 95Y (3576 keV) high-energy gamma-ray lines. Comparisons are made with the results of Monte Carlo modeling of the experimental configuration, carried out using the MCNPX code. The measured fission rate ratios have 1? uncertainties of 1.7–3.4%. The comparisons with calculated predictions show an agreement within 1–3?, although there appears to be a slight bias (?3%).

  3. Effects of whole body irradiation of 60Co-gamma ray on vivo primary migration of mesenteric lymph node lymphocytes in mice

    International Nuclear Information System (INIS)

    Using a cell labeling technique with 51Cr, the changes in the in vivo primary migration of mesenteric lymph node (MLN) lymphocytes were investigated in mice after whole body irradiation with 60Co-gamma rays. The results showed that after 0.5 to 4 Gy whole body irradiations with 60Co-gamma rays, there are some marked changes in the primary migration of murine MLN lymphocytes in normal syngeneic recipients. In recipients, an increased content of 51Cr in liver was observed after a 4 Gy irradiation of the donor, but no significant change in the 51Cr content was found in spleen at any dose, and the contents of 51Cr in MLN at 0.5 Gy, in lungs at 1 Gy and in small intestine at 1 Gy were significantly decreased

  4. Effect of pH on paste properties of irradiated corn starch by gamma-rays

    International Nuclear Information System (INIS)

    The degradation of starch by ?-irradiation and the effect of pH on gelatinization of starch after irradiation were investigated. Paste viscosities were markedly affected by pH on gelatinization and a decrease in the viscosity of irradiated starch was stimulated by increasing pH. On the other hand, the solubility of irradiated starch increased significantly at the high pH. The granule structure of irradiated starch easily disintegrated at alkaline pH. Remarkable dissolution from the surface of the irradiated starch granules was observed after heating at high pH only a filamentous network frame remained, but the unirradiated one collapsed and folded. It was seen that alkali treatment after irradiation reduces the required dose to obtain low viscosity starch. The required dose to produce a low viscosity starch, for example Ajinomoto Essan Sizer 600 grade, was ca. 3 Mrad at pH 11.0 and ca. 5 Mrad at pH 7.0, whereas it was ca. 7 Mrad without pH adjustment. (author)

  5. Identification of gamma ray irradiated wheat by electron spin resonance, DNA comet assay and germination test

    International Nuclear Information System (INIS)

    In several countries, there has been an increase in the use of radiation for food processing thus improving the quality and sanitary conditions, inhibiting pathogenic microorganisms, delaying the natural aging process and so extending product lifetime. The need to develop analytical methods to detect these irradiated products is also increasing. The goal of this research was to identify wheat irradiated using three different techniques: Electron spin resonance, DNA comet assay and germination test, for comparison. Wheat variety IAC 289 and husked wheat variety IAC 355 was from Instituto Agronomico de Campinas. Grains were irradiated with a gamma 60Co source (Gammacell 220 GC) in the Centro de Energia Nuclear na Agricultura and in the Instituto de Pesquisas Energeticas e Nucleares. Dose rate used were 1.6 kGy/h and 5.8 kGy/h. Applied doses were 0.0 kGy ; 0.10 kGy ; 0.25 kGy ; 0.50 kGy ; 0.75 kGy ; 1.0 kGy and 2.0 kGy. After irradiation, grains were analyzed over a 6 month period. It is possible to use E8R to identify irradiated husked wheat until 3 weeks after the date of irradiation. Comet assay was a qualitative test that we used to identify irradiated wheat at least 6 months after storage. The germination test make possible the identification and the better criteria was the shoot length. (author)

  6. Effects of gamma-ray irradiation on a cyanate ester/epoxy resin

    International Nuclear Information System (INIS)

    Effects of ?-ray irradiation on a cyanate ester/epoxy resin composed of dicyanate ester of bisphenol A (DCBA) and diglycidyl ether of bisphenol A (DGEBA) were investigated by changes in physicochemical and mechanical properties after the ?-ray irradiation with dose of 100 MGy as maximum at around 40 °C under vacuum. After the irradiation, gases of hydrogen, carbon monoxide and carbon dioxide were evolved, glass transition temperature decreased, and flexural strength also decreased. It was concluded that ether linkages bonded to cyanurate, isocyanurate and oxazolidinone structures are mainly decomposed by the irradiation. After 100 MGy irradiation, the flexural strength of DCBA/DGEBA was maintained more than 170 MPa which is 90% of initial value of 195 MPa. Flexural modulus and density slightly increased to the values of 3.9 GPa and 1.211 g/cm3 from initial values of 3.4 GPa and 1.199 g/cm3, respectively. - Highlights: • A cyanate ester/epoxy resin was irradiated by ?-rays with dose of 100 MGy in vacuum. • Viscoelastic property, structural change and gas evolution were investigated. • Ether linkages in the network structure were mainly decomposed by the irradiation. • The flexural strength of resin was maintained >170 MPa which is 90% of initial value

  7. Effectiveness of gamma-ray chronic irradiation on in vitro mutagenesis in crops

    International Nuclear Information System (INIS)

    Effects of chronic or acute irradiations were compared using in vitro culture on inducing the mutation in model crops. In chrysanthemum, combined method with irradiation and in vitro culture can solve the problem of chimera formation in induced mutants, and provided 10 times greater mutation frequency than usual plant irradiation. The chronic culture method showed the widest color spectrum, whereas, the acute culture indicated a relatively low mutation rate and a very limited flower color spectrum in chrysanthemum. Flower color mutation of the regenerators could be induced more from petals and buds than from leaves. These facts are supposed that the gene loci fully expressed on floral organs may be unstable for mutation by mutagenesis or culture. It may be likely to control a direction of desired mutation on using explants with specific gene loci activated. In sugarcane, the chronic culture method extended quantitative characteristics of regenerated clonal lines toward not only the negative but positive direction. On the other hand, the acute culture method showed lower quantitative mutation as the irradiation dose rose. In chronic irradiation, regenerated mutant lines in sugarcane indicate generally little decrease in chromosome number and wider variations with relatively less damage. In acute irradiation, regenerated mutant lines show remarkable decrease of chromosome numbers in sugarcane mutant lines as the irradiation dose rose. There is close positive correlation between chromosome number and biomass of each mutant line. The chromosome number estimation is a proper indicator to monitor damage of adopted irradiation methods. Possible reason why the chronic culture methods indicate higher frequency and wider spectrum on mutation is demonstrated. . Problems solved and prospect of chronic irradiation and in vitro techniques are discussed. (Author)

  8. Low temperature gamma ray irradiation effects on polymer materials (4)-gas analysis of GFRP and CFRP

    Science.gov (United States)

    Kudoh, H.; Kasai, N.; Sasuga, T.; Seguchi, T.

    1996-11-01

    Gas analysis was carried out at RT after gamma-irradiation at room temperature and 77K for glass fiber reinforced plastic (GFRP) and carbon fiber reinforced plastic (CFRP) having the same epoxy resin matrix. Gas yield from CFRP was less than that from GFRP at RT, but comparable at 77 K. The yields of CO and CO 2 showed a large dependence on the irradiation temperature, i.e. they were much less at 77 K. Radiation resistance of GFRP and CFRP towards 77 K irrdiation is expected to be higher than that towards RT irradiation.

  9. SAXS investigations of structural changes after gamma ray irradiation of potato starch and starch suspensions

    International Nuclear Information System (INIS)

    The products obtained after gamma irradiation with doses 9.1, 18.2, 36.3, 54.5 kGy of native starch and water suspensions of starch were investigated using small-angle X-ray scattering (SAXS). Relations between changes in the scattering curves (diminution of the intensity of the reflection related to distance d?100 A and elevation of scattering curves) connected with destruction of long-range ordering in starch granules, and the conditions of the irradiation process were observed. Iradiation influences the long-range ordering more intensively in cases of native starch as compared with water suspensions of starch irradiated. (orig.)

  10. Behavior of Random Hole Optical Fibers under Gamma Ray Irradiation and Its Potential Use in Radiation Sensing Applications

    Directory of Open Access Journals (Sweden)

    Anbo Wang

    2007-05-01

    Full Text Available Effects of radiation on sensing and data transmission components are of greatinterest in many applications including homeland security, nuclear power generation, andmilitary. A new type of microstructured optical fiber (MOF called the random hole opticalfiber (RHOF has been recently developed. The RHOFs can be made in many differentforms by varying the core size and the size and extent of porosity in the cladding region.The fibers used in this study possessed an outer diameter of 110 μm and a core ofapproximately 20 μm. The fiber structure contains thousands of air holes surrounding thecore with sizes ranging from less than 100 nm to a few μm. We present the first study ofthe behavior of RHOF under gamma irradiation. We also propose, for the first time to ourknowledge, an ionizing radiation sensor system based on scintillation light from ascintillator phosphor embedded within a holey optical fiber structure. The RHOF radiationresponse was compared to normal single mode and multimode commercial fibers(germanium doped core, pure silica cladding and to those of radiation resistant fibers (puresilica core with fluorine doped cladding fibers. The comparison was done by measuringradiation-induced absorption (RIA in all fiber samples at the 1550 nm wavelength window(1545 ± 25 nm. The study was carried out under a high-intensity gamma ray field from a 60Co source (with an exposure rate of 4x104 rad/hr at an Oak Ridge National Laboratory gamma ray irradiation facility. Linear behavior, at dose values less than 106 rad, was observed in all fiber samples except in the pure silica core fluorine doped cladding fiber which showed RIA saturation at 0.01 dB. RHOF samples demonstrated low RIA (0.02 and 0.005 dB compared to standard germanium doped core pure silica cladding (SMF and MMF fibers. Results also showed the possibility of post-fabrication treatment to improve the radiation resistance of the RHOF fibers.

  11. Effect of gamma rays on the populations of irradiated varieties and hybrids in Sesame

    International Nuclear Information System (INIS)

    Six varieties and nine hybrids of sesame were subjected to gamma irradiation. The effect of irradiation on the populations of irradiated varieties and hybrids was studied in second and third generations. In general, irradiation of hybrids and varieties produced more or less similar pattern of deviations in the population mean with negative shift for most of the characters studied. Non-alteration of population mean for plant height and 1000 seed weight was observed in the M2 and M3. In F2M2 and F3M3 generations, the 1000 seed weight remained unaltered. Most of the other characters which showed negative shift in F2M2 recorded non-alteration in F3M3. (author)

  12. Study on the changes in phyicochemical properties of seafood cooking drips by gamma ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jong Il; Kim, Yeon Joo; Kim, Jae Hun; Yoon, Yo Han; Song, Beom Seok; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Chun, Byung Soo; Ahn, Dong Hyun [Pukyong National University, Busan (Korea, Republic of); Lee, Ju Yeoun [Chonbuk National University, Jeonju (Korea, Republic of)

    2010-03-15

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lots of proteins, carbohydrates, and other functional materials. But, the seafood cooking drips are easily contaminated because of its rich nutrients, and their color are very dark. This study was conducted to investigate the effect of gamma irradiation on the quality of seafood cooking drips including Hizikia fusiformis, Enteroctopus dofleini, and Thunnus thynnus. The Hunter's color values (L, Brightness) of H. fusiformis, and T.thynnus, were increased with increasing irradiation doses, showing becoming bright. The crude protein content and crude lipid content were increased by gamma irradiation. These results indicated that gamma irradiation increased extraction efficiency of available compounds in cooking drips.

  13. Characterization of Amylopectin irradiated by gamma rays using viscosity and radius gyration technique

    International Nuclear Information System (INIS)

    Food irradiation is one of the most applicable methods that have been used in food industry especially to preserve food. Besides preservation of food, irradiation can also reduce microorganism, inhibit budding and others. However, this method can be misused by some irresponsible organization or person such as irradiate the food over the dose limit value. Therefore, the detection method is important to detect any misused in irradiation method. The objective of this research is to identify any changes in the structure of amylopectin by using radius gyration technique. Besides that, the viscosity of the sample is also determined by using Rheometer. The last objective of this research is to find a relationship between radius gyration and irradiation dose can be determined. Amylopectin and cassava powder were the sample in this research. The samples were irradiated in the gamma-cell at 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0, and 10.0 kGy doses. 0 kGy were the controlled sample. The sample were made into gel to analysed using Rheometer and Small Angle X-ray Scattering (SAXS). The viscosity of the sample were analysed by using Rheometer while the radius gyration of the sample were analysed by using SAXS. Hence, the result of this experiment is, the viscosity of amylopectin reduces as the doses increases. But, at 10 kGy, the viscosity of the cassava starch was increased significantly. For the SAXS analysis, it is shows that the graph for amylopectin were fluctuates. While, for cassava starch the radius gyration increases with doses. Hence, the rheometer technique is suitable to be develop as a detection method in food irradiation. Further research should be done to improve the detection technique in food irradiation. (author)

  14. Gamma ray irradiated goat milk: comparative sensorial analysis with pasteurized goat milk

    International Nuclear Information System (INIS)

    Goat milk consumption has increased in the last years, due to its better digestibility and for constituting a good alternative to cow milk for intolerant people. Brazil has over 10 millions goats, mainly in the Northeast area. Considering that it is very important to increase the shelf-life for this product, this work was done to test the gamma-radiation as a preservation method, evaluating acceptability by sensorial analysis compared with pasteurized milk. The goat milk was bought in the Animal Production Department/ESALQ/USP, Piracicaba, and irradiated with 3,5 kGy in the Food Irradiation Laboratory/CENA/USP, using a cobalt-60 irradiator, type Gammabeam-650, from Nordion, Canada. After irradiation, the samples were maintained under refrigeration at 5 deg C and submitted to sensorial analysis at 1st, 7th and 15th days by 30 untrained tasters. The results indicated, by Tukey test, a significant preference for the pasteurized milk in comparison to the irradiated one, because a hard caprine flavor was developed by the irradiation. (author)

  15. Measurements of potato tubers gamma-ray irradiated in nitrogen gas or carbondioxide gas

    International Nuclear Information System (INIS)

    In this report the respiration of the potato tubers irradiated in nitrogen gas or carbondioxide gas was studied. Potato tubers of common Japanese variety, ''Danshaku'' were used for the examination. Potato tubers of about 2kg were put into each of Triple-Nylon bags and the bags were sealed after replacement of air in bags with nitrogen or carbondioxide gases. More than 16 hours after sealing of bags, the ?-dose (60Co) of 150 Gy or 250 Gy were given to the potato tubers in bags at the dose rate of 104 R/h. After irradiation, all bags were opened in air and amounts of CO2 released by respiration of tubers were measured with Hitachi gas chromatograph analyser Type 023. The amounts of CO2 released from the potato tubers irradiated in open air is shown in Fig. 2. The results show that there is an initial lag period of several hours, followed by a rapid increase in the respiration, after which the CO2 release was gradually decreased. Potato tubers irradiated in nitrogen gas show a similar release of CO2 on time scale to the potato tubers irradiated in open air, but the total amounts of CO2 are approximately half of those of the potato tubers irradiated in open air (Figs. 3 and 4). (J.P.N.)

  16. Structure alteration and immunological properties of {sup 60}Co gamma rays irradiated bothropstoxin-I

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, Janaina A.; Yonamine, Camila Myiagui; Caproni, Priscila; Casare, Murilo; Spencer, Patrick Jack; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: janabap@gmail.com; Andrade Junior, Heitor Franco de; Vieira, Daniel Perez; Galisteo Junior, Andres Jimenez [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Instituto de Medicina Tropical de Sao Paulo, SP (Brazil). Lab. de Protozoologia

    2007-07-01

    About 20000 ophidic accidents are registered every year in Brazil. Serum therapy with equine antisera is the only efficient treatment. The venoms employed for immunization are fairly toxic and some venoms present low immunogenicity. Thus, the obtention of modified antigens with lower toxicity and preserved or improved immunogenicity would be useful. These toxins, when submitted to gamma radiation, in aqueous solution, present structural modifications. This occurs due to reactions with the radiolysis products of water. Some scavenger substances, such as NaNO{sub 3} and t-butanol, remove selectively the water radiolysis products. Ionizing radiation has proven to be a powerful tool to attenuate snake venoms toxicity without affecting and even increasing their immunogenic properties. However, the immune mechanisms involved in recognition, processing and presentation of irradiated antigens are yet unclear. In the present work, we investigated the immunological behavior of bothropstoxin-I (Bthx-1), before and after irradiation, in the presence of selective scavengers. Isogenic mice were immunized with either the native or the irradiated toxin, either with or without scavengers. After three immunizations, serum samples were collected and the antibody titers and isotypes were determined by Enzyme Linked Immuno Sorbent Assay. The antigenic characterization of native and irradiated bothropstoxin-I was performed by Western blot. The detection of expression of murine cytokines (IFN-{gamma} and IL-10) was analyzed by RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction). According to our data, irradiation process has promoted structural modifications in the toxin, characterized by higher molecular weight forms of the protein (aggregates and oligomers). Our data also indicate that irradiated toxins, alone or in the presence of NaNO{sub 3}, an aqueous electron scavenger, were immunogenic and the antibodies elicited by them were able to recognize the native toxin. On the other hand, when the toxin was irradiated in presence of t-butanol, a discrete reduction in antibodies levels was observed, suggesting a role of hydroxyl radicals in the modulation of immune response. Irradiated bothropstoxin-1 elicited antibodies responsive to both toxins forms, as demonstrated by Western blot. The cytokines profiles indicated that IFN-{gamma} mRNA presence appeared to be higher for mice immunized with irradiated toxin, while IL-10 mRNA presence was predominant with the antigen in its native form. These results indicate that irradiation of proteins leads to significant structural modifications, and also to a modulation of the immunological response. (author)

  17. Structure alteration and immunological properties of 60Co gamma rays irradiated bothropstoxin-I

    International Nuclear Information System (INIS)

    About 20000 ophidic accidents are registered every year in Brazil. Serum therapy with equine antisera is the only efficient treatment. The venoms employed for immunization are fairly toxic and some venoms present low immunogenicity. Thus, the obtention of modified antigens with lower toxicity and preserved or improved immunogenicity would be useful. These toxins, when submitted to gamma radiation, in aqueous solution, present structural modifications. This occurs due to reactions with the radiolysis products of water. Some scavenger substances, such as NaNO3 and t-butanol, remove selectively the water radiolysis products. Ionizing radiation has proven to be a powerful tool to attenuate snake venoms toxicity without affecting and even increasing their immunogenic properties. However, the immune mechanisms involved in recognition, processing and presentation of irradiated antigens are yet unclear. In the present work, we investigated the immunological behavior of bothropstoxin-I (Bthx-1), before and after irradiation, in the presence of selective scavengers. Isogenic mice were immunized with either the native or the irradiated toxin, either with or without scavengers. After three immunizations, serum samples were collected and the antibody titers and isotypes were determined by Enzyme Linked Immuno Sorbent Assay. The antigenic characterization of native and irradiated bothropstoxin-I was performed by Western blot. The detection of expression of murine cytokines (IFN-? and IL-10) was analyzed by RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction). According to our data, irradiation process has promoted structural modifications in the toxin, characterized by higher molecular weight forms of the protein (aggregates and oligomers). Our data also indicate that irradiated toxins, alone or in the presence of NaNO3, an aqueous electron scavenger, were immunogenic and the antibodies elicited by them were able to recognize the native toxin. On the other hand, when the toxin was irradiated in presence of t-butanol, a discrete reduction in antibodies levels was observed, suggesting a role of hydroxyl radicals in the modulation of immune response. Irradiated bothropstoxin-1 elicited antibodies responsive to both toxins forms, as demonstrated by Western blot. The cytokines profiles indicated that IFN-? mRNA presence appeared to be higher for mice immunized with irradiated toxin, while IL-10 mRNA presence was predominant with the antigen in its native form. These results indicate that irradiation of proteins leads to significant structural modifications, and also to a modulation of the immunological response. (author)

  18. Stage differences in developmental disorders in ICR mouse embryos irradiated with gamma-rays

    International Nuclear Information System (INIS)

    This study was designed to determine precisely the radiosensitive period in the development of ICR mouse embryos during which external malformations and growth retardation tend to occur. Female and male mice were placed together for only three hours to allow fairly precise identification of the time of conception. The pregnant mice were divided into 31 groups, which were irradiated in turn with 1.5 Gy gamma radiation at 6-hour intervals during the period of organogenesis. They were then observed on day 18 of gestation. Items recorded were intrauterine death, external malformations, sex ratio and fetal body weight. Death of the embryo/fetus, especially death in the early period of organogenesis, was most frequent in mice irradiated between days 6.75 and 8.25 of gestation, but there was no statistically significant difference in the frequency of early- and late-period deaths between irradiated and control groups. The types and frequencies of external malformations observed differed according to the exposure period. The most highly sensitive period for each malformation lasted no more than 12 hours. Reduction of fetal body weight was a good indicator of radiation effects, and was observed mostly in the groups irradiated between days 9.75 and 11.00 of gestation. The sex ratio was not affected by the period in which irradiation was performed. (author)

  19. Characterization of injected linear low density polyethylene (LLDPE) irradiated by gamma-ray

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana C.F.; Parra, Duclerc F.; Ferreto, Helio F.R.; Lugao, Ademar B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The aim of this paper is to investigate of gamma irradiation effects on linear low density polyethylene (LLDPE) injected. Polymers processed by gamma radiation have new physical-chemical and mechanical properties. The ionizing radiation promotes chain scission and creates free radicals which can recombine, providing their annihilation, for crosslinking or branching. The polymer was irradiated with a source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at about 5 kGy s{sup -1} rate, at room temperature. The changes in molecular structure of LLDPE were evaluated using melt flow index, gel fraction, differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FT-IR) and thermogravimetry analysis (TG). The results showed that the properties depend on dose irradiation. (author)

  20. Development and characterization of biodegradable polymer blends - PHBV/PCL irradiated with gamma rays

    International Nuclear Information System (INIS)

    This paper presents the results of a study that aimed to develop PHBV biodegradable polymer blends, in a major concentration with PCL, irradiate the pure polymers and blends in two doses of gamma radiation and to analyze the changes in chemical and mechanical properties. The blends used in this study were from natural biodegradable copolymer poly (hydroxybutyrate-valerate) (PHBV) and synthetic biodegradable polymer poly (caprolactone) (PCL 2201) with low molar mass (2,000 g/mol). Several samples were prepared in a co-rotating twin-screw extruder and afterwards, the tensile specimens were injected for the irradiation treatment with 50 kGy to 100 kGy doses and for the mechanical tests. The characterization of the samples before and after the irradiation treatments was performed through scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and mechanical tensile tests. (author)

  1. Functionalization and magnetization of carbon nanotubes using Co-60 gamma-ray irradiation

    Science.gov (United States)

    Chen, C. Y.; Fu, M. J.; Tsai, C. Y.; Lin, F. H.; Chen, K. Y.

    2014-10-01

    Functionalized magnetic carbon nanotubes (CNTs) can be used in the biological and biomedical fields as biosensors, drug delivery systems, etc., which makes research into processes for manufacturing modified CNTs quite important. In this paper, Co-60 gamma irradiation is shown to be an effective tool for fabricating functionalized and magnetized CNTs. After the Co-60 gamma irradiation, the presence of carboxylic functional groups on the CNT walls was confirmed by their Fourier transform infrared spectra, and the presence of Fe3O4 was verified by the X-ray diffraction patterns. The functionalized and magnetized CNTs produced using Co-60 gamma irradiation have excellent dispersion properties. The techniques for functionalizing and magnetizing CNTs are introduced in this paper, and applications of the modified CNTs will be reported after more data are gathered.

  2. The effect of gamma-rays on the hemoglobin of whole-body irradiated mice

    Science.gov (United States)

    Ashry, H. A.; Selim, N. S.; El-Behay, A. Z.

    1994-07-01

    Changes in the UV-visible absorption spectrum of mouse hemoglobin as a result of whole body irradiation were studied. White albino adult mice were exposed to a Cs-137 ?-source at a dose rate of 47.5 Gy/h to different absorbed dose values ranging from 1 to 8 Gy. Blood specimens were taken 24 h after irradiation. The UV-visible absorption spectra of hemoglobin of irradiated and control mice were measured in the wavelength range from 200 to 700 nm. The obtained results showed significant changes in the bands measured at 340 nm, in the Soret band measured at 410 nm, also, the ?- and ?-bands measured at 537 and 572 nm showed significant decrease in intensity with the absorbed dose increase. The absorbance measured at 630 nm showed no significant changes. The radiation effect on the animal hemoglobin was discussed on the basis of the obtained results.

  3. Chemical and physical change of packaging materials for food by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Recently, foods are often exposed to radiation under packed states with various wrapping materials. In this study, the effects of ?-ray radiation were investigated on the additives in wrapping materials on the market. 10 - 50 kGy ? radiation was irradiated to samples under sealed condition in a glass-ware. Polyethylene bag and wrapping film, polypropylene wrapping film, cup and sheet, and polystyrene cup were used as samples. And the additives in these materials were analyzed by GC/MS to evaluate the radiation effects on them. The irradiation was found to induce rapid degradation of antioxidants, especially, Irgafos 168. Some fatty acid amides used as a lubricant and a plasticizer, DBP were also reduced, but not aliphatic hydrocarbons. However, all polystyrene products used in this study included no additives. The contents of styrene dimer and trimer in those wrapping materials were not changed by ?-irradiation. (M.N.)

  4. Effect of the irradiation on Salmonella enteretidis var. typhimurium with gamma rays from 60Co

    International Nuclear Information System (INIS)

    The use of ionizinf radiation to the destruction of microrganisms responsible for food deterioration, and productive of feeding toxinfections constitute their usefulness for actually peaceful goals of nuclear energy. The feeding toxinfections are, among us, produced in their most part by Salmonella enteritidis var. typhimurim. One hundred nineteen samples of milk containing about 150.000 bacteria per ml, by means doses ranging from 100 to 1.100 gy, two samples of surviving bacteria were again irradiated by doses up to 2.5000 Gy. The bacteria not previously irradiated were throughly killed by means of doses of 1.100 Gy. Salmonella enteritidis var. typhimurium was inactivated by means of 1.200 and 1.900 Gy doses. It was concluded that 60-Cobalt gamma radiation minimal lethal dose to Salmonella enteritidis var. typhimurium is 1.200 Gy; the re-irradiation to the survivors prompts the forthcoming of more resistant germs. (author)

  5. Physico chemical and microbiological changes in nopal (Opuntia spp.) irradiated with gamma rays of cobalt 60

    International Nuclear Information System (INIS)

    The objective of this work is to study the physico-chemical and microbiological changes which take place in the nopal (Opuntia spp.) after they have been irradiated and stored at environment and refrigeration temperatures in order to determine the level of irradiation dose more adequate for getting them an increase in the storage life, as well as to determine the physico-chemical changes attributed to the irradiation doses used, comparing the obtained results with those ones of non-irradiated nopal samples, which are considered as control samples. The radiation source used was a GAMMABEAM-651 PT, property of the Nuclear Sciences Institute of UNAM. The nopals studied are of the variety (Milpa Alta, Opuntia ficus) which were cut and packed in polyethylene bags with and without nitrogen. In order to find the adequate dose level it was used a lot of 200 samples which were treated in sets of 10. They were irradiated in doses of 0.5 to 10 kGy at a dose reason of 3.7 kGy/h. The adequate doses for getting an increase in the storage life, where there was not darkness were of 1.5 and 2.0 kGy, allowed doses in the NOM-033-SSA1-1993, it was not found any change in acceptability by flavour, but so in the titled activity values and sugars. The lowest loss of weight was found in the 1.5 kGy dose without nitrogen and the highest in the 2.0 kGy with nitrogen dose. Likewise was determined that with the irradiation treatment in the recommended doses it is diminished the microorganisms growth, obtaining an improvement in the general appearance of the nopals during their storage period. (Author)

  6. Activity of lysosomal acid phosphatase in the perpheral blood lymphocytes of mice irradiated with gamma rays

    International Nuclear Information System (INIS)

    In the peripheral blood lymphocytes of Albino-Swiss mice after irradiation with 450 r an intracellular increase in the acid phophatase activity was determined with Barka and Anderson's cytochemical method. The increase in the enzyme activity was accompanied by the increase in the absolute count of enzyme-positive lymphocytes exhibiting high activity of the enzyme, i.e. containing more than five enzyme-positive lysosomal granules. The absolute count of cells of diffuse enzymatic reaction type did not increase after irradiation. (author)

  7. The effect flavobin on nucleic acids in tissues of rats irradiated with gamma rays

    International Nuclear Information System (INIS)

    Flavobion /SPOFA/ is a hepatoprotective preparation containing an effective constituent - the flavonoids, namely, silybin, silydianin and silychristin, collectively referred to as silymarin. Suspension of this preparation was given p.o. by tube in a dose of 70 mg/kg, one hour before whole-body irradiation with a 5.7 Gy dose of gamma radiation (60Co). Animals were subjected to partial hepatectomy /by 30 min. after irradiation/ and examined on hour 30 after operation. Flavobion administ6ration influenced the concentration and total content of RNA and DNA in the spleen and bone marrow. However, in a target organ, liver, changes in nucleic acids less pronounced

  8. Selection of mutants resistant to black spot disease by chronic irradiation of gamma-rays in Japanese pear 'Osanijisseiki'

    International Nuclear Information System (INIS)

    'Osanijisseiki', a self-compatible, spontaneous bud sport of the Japanese pear 'Nijisseiki' is an excellent cultivar with a smooth skin. However, this cultivar is susceptible to Japanese pear black spot disease caused by Alternaria alternata Japanese pear pathotype. To obtain resistant mutants from 'Osanijisseiki', nursery plants of 'Osanijisseiki' have been irradiated chronically with gamma-rays in the Gamma Field of the Institute of Radiation Breeding, NAR, MAFF, since 1986. Screening tests using AK toxin, a host-specific toxin produced by A. alternata Japanese pear pathotype, were performed form 1988 to 1993. Four branches of young trees planted at a distance of 40 m from the 60Co source were selected as being resistant mutants in 1991 (IRB 502-13T and IRB 502-14T) and 1993 (IRB 502-17T and IRB 502-18T). Sensitivity of the four resistant mutants to AK-toxin and susceptibility to the pathogen were compared with other of susceptible and resistant cultivars. The results showed that these four mutants possessed intermediate resistance. Furthermore, a mutant, IRB 502-13T, had the same characteristics as the original 'Osanijisseiki', except for the difference in toxin sensitivity. The characteristics of the other mutants, IRB 502 14-T, IRB 502-17T, and IRB 502-18T, care being examined. (author)

  9. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

    Energy Technology Data Exchange (ETDEWEB)

    Clark, E.

    2013-09-13

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be equivalent to about 280 days exposure to initially pure tritium gas at one atmosphere. The glass transition temperature of the tritium exposed EPDM rose about 10 ?C. over 280 days, while no glass transition temperature change was observed for gamma irradiated EPDM. This means that gamma irradiation in deuterium cannot be used as a surrogate for tritium exposure.

  10. Gamma ray irradiation induced degradation in ultra-thin silica layers

    International Nuclear Information System (INIS)

    In this paper, the influence of gamma irradiation on the electrical properties of Metal-Oxide-Semiconductor (MOS) with an ultra-thin silica layer N2O nitrided or not is investigated. Mainly electron trapping, defects generation and breakdown during electrical stress are studied. (author)

  11. Work hardening characteristics of gamma-ray irradiated Al-5356 alloy

    International Nuclear Information System (INIS)

    Effects of ?-irradiation and deformation temperatures on the hardening behavior of Al-5356 alloy have been investigated by means of stress–strain measurements. Wire samples irradiated with different doses (ranging from 500 to 2000 kGy) were strained at different deformation temperatures Tw (ranging from 303 to 523 K) and a constant strain rate of 1.5×10?3 s?1. The effect of ?-irradiation on the work-hardening parameters (WHP): yield stress ?y, fracture stress ?f, total strain ?T and work-hardening coefficient ?p of the given alloy was studied at the applied deformation temperature range. The obtained results showed that ?-irradiation exhibited an increase in the WHP of the given alloy while the increase in its deformation temperature showed a reverse effect. The mean activation energy of the deformation process was calculated using an Arrhenius-type relation, and was found to be ?80 kJ/mole, which is close to that of grain boundary diffusion in aluminum alloys

  12. Work hardening characteristics of gamma-ray irradiated Al-5356 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Saad, G. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt); Fayek, S.A. [Physics Department, National Center for Radiation Research and Technology, Nasr City, Cairo (Egypt); Fawzy, A. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt); Soliman, H.N., E-mail: dr_hany.nazmy@yahoo.com [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt); Nassr, E. [Physics Department, Faculty of Education, Ain Shams University, Cairo (Egypt)

    2014-06-01

    Effects of ?-irradiation and deformation temperatures on the hardening behavior of Al-5356 alloy have been investigated by means of stress–strain measurements. Wire samples irradiated with different doses (ranging from 500 to 2000 kGy) were strained at different deformation temperatures T{sub w} (ranging from 303 to 523 K) and a constant strain rate of 1.5×10{sup ?3} s{sup ?1}. The effect of ?-irradiation on the work-hardening parameters (WHP): yield stress ?{sub y}, fracture stress ?{sub f}, total strain ?{sub T} and work-hardening coefficient ?{sub p} of the given alloy was studied at the applied deformation temperature range. The obtained results showed that ?-irradiation exhibited an increase in the WHP of the given alloy while the increase in its deformation temperature showed a reverse effect. The mean activation energy of the deformation process was calculated using an Arrhenius-type relation, and was found to be ?80 kJ/mole, which is close to that of grain boundary diffusion in aluminum alloys.

  13. Effect of dissolved oxygen on corrosion behavior of stainless steel in gamma ray irradiation environment

    International Nuclear Information System (INIS)

    Experimental data on corrosion behavior of stainless steel in actual BWR primary environment under irradiated field are lacking in literature, because the personnel access and maintenance for the experiment are difficult. The corrosion test loop, which had two test sections set inside and outside of the irradiation test room, was used to do the work successfully. The tests were performed by control of water quality in two typical BWR corrosion environments, namely normal water chemistry (NWC) and hydrogen water chemistry (HWC). Corrosion products released from the main loop construction material, type 316 stainless steel, and corrosion potentials of test coupons, type 304 stainless steel, were measured. And the corrosion oxide films formed on the coupons were characterized. The corrosion behaviors of the austenitic stainless steels were affected by the corrosion environment, which was determined by both of the water chemistry condition, NWC or HWC, and radiolysis of water

  14. Quality assessment of coffee beans with ESR and gamma-ray irradiation

    International Nuclear Information System (INIS)

    Peroxy radical formation in raw coffee beans of different qualities and origins from all over the world has been studied with electron spin resonance (ESR) analysis. The ?-ray equivalent absorbed dose (ED) which creates the same concentration of radicals is obtained by the additive ?-ray irradiation of the coffee beans. The ED and the cup quality is somewhat inversely related suggesting that the peroxidation of the unsaturated fatty acid is somewhat indicative of the degree of the aromatic decomposition and rancidity. (author)

  15. Inclusion polymerization of vinyl chloride monomer in deoxycholic acid host via {gamma}-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chirachanchai, S.; Kumkrong, A. [The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok (Thailand); Ishida, Hatsuo [Department of Macromolecular Science, Case Western Reserve University, Cleveland, OH (United States)

    2000-03-01

    Inclusion polymerization of vinyl chloride monomer (VCM) was studied in the system of 3{alpha}, 12{alpha} -dihydroxy-5{beta}-cholan-24-oic acid (deoxycholic acid, DCA). DCA-VCM inclusion compound system was originally prepared by guest intercalation technique in DCA guest free crystal. The inclusion polymerization of DCA-VCM by {gamma}-irradiation at total dose 2 Mrad, gives a syndiotactic rich polyvinyl chloride (PVC) as can be confirmed by FT-IR and FT-NMR. (author)

  16. Effect of gamma-ray irradiation on some chemical and physical properties of buffalo milk

    International Nuclear Information System (INIS)

    Gamma irradiation of buffalo milk at low dose of 0.5 Mrad has no effect on the acidity and pH. The heat stability of milk was increased while the salt balance of milk and rennet coagulation time were decreased. Effect on ?-lact-albumin was very little. A very rear increase was observed in case of phosphorus, citric acid, and Ca + Mg content of milk. (orig.)

  17. Functionalization and magnetization of carbon nanotubes using Co-60 gamma-ray irradiation

    International Nuclear Information System (INIS)

    Functionalized magnetic carbon nanotubes (CNTs) can be used in the biological and biomedical fields as biosensors, drug delivery systems, etc., which makes research into processes for manufacturing modified CNTs quite important. In this paper, Co-60 gamma irradiation is shown to be an effective tool for fabricating functionalized and magnetized CNTs. After the Co-60 gamma irradiation, the presence of carboxylic functional groups on the CNT walls was confirmed by their Fourier transform infrared spectra, and the presence of Fe3O4 was verified by the X-ray diffraction patterns. The functionalized and magnetized CNTs produced using Co-60 gamma irradiation have excellent dispersion properties. The techniques for functionalizing and magnetizing CNTs are introduced in this paper, and applications of the modified CNTs will be reported after more data are gathered. - Highlights: Dispersion ability of carbon nanotubes (CNTs) was improved by functionalization. CNTs were easily manipulated by precipitation of magnetic nanoparticles. Our product can be used as versatile biosensor substrate for biomarker screening

  18. Functionalization and magnetization of carbon nanotubes using Co-60 gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.Y.; Fu, M.J.; Tsai, C.Y. [Division of Isotope Application, Institute of Nuclear Energy Research, Atomic Energy Council, P.O. BOX 3-27 Longtan, Taoyuan County 32546, Taiwan (R.O.C.) (China); Lin, F.H. [Institute of Biomedical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (R.O.C.) (China); Chen, K.Y., E-mail: chenky@iner.gov.tw [Division of Isotope Application, Institute of Nuclear Energy Research, Atomic Energy Council, P.O. BOX 3-27 Longtan, Taoyuan County 32546, Taiwan (R.O.C.) (China)

    2014-10-01

    Functionalized magnetic carbon nanotubes (CNTs) can be used in the biological and biomedical fields as biosensors, drug delivery systems, etc., which makes research into processes for manufacturing modified CNTs quite important. In this paper, Co-60 gamma irradiation is shown to be an effective tool for fabricating functionalized and magnetized CNTs. After the Co-60 gamma irradiation, the presence of carboxylic functional groups on the CNT walls was confirmed by their Fourier transform infrared spectra, and the presence of Fe{sub 3}O{sub 4} was verified by the X-ray diffraction patterns. The functionalized and magnetized CNTs produced using Co-60 gamma irradiation have excellent dispersion properties. The techniques for functionalizing and magnetizing CNTs are introduced in this paper, and applications of the modified CNTs will be reported after more data are gathered. - Highlights: Dispersion ability of carbon nanotubes (CNTs) was improved by functionalization. CNTs were easily manipulated by precipitation of magnetic nanoparticles. Our product can be used as versatile biosensor substrate for biomarker screening.

  19. Gamma-ray irradiation effects on interlaminar tearing strength of epoxy-based FRP

    International Nuclear Information System (INIS)

    The degradation of interlaminar tearing strength induced by ?-ray irradiation in epoxy-based FRP has been investigated. A remarkable decrease in the tearing strength of FRP was observed for higher doses (above 5 MGy). Observation of the fracture surface revealed that a local fracture propagated along the interface between resin and fiber in the lower dose region, and it took place through the resin in the higher dose region. The fracture through the resin it attributed to the degradation of the resin matrix which is typically revealed as voids in the fracture surface. (orig.)

  20. Radio protective effects of calcium channel blockers (Deltiazem) on survival of Saccharomyces cerevisiae cells irradiated with different doses of gamma rays

    International Nuclear Information System (INIS)

    Investigations of radioprotective effects of Deltiazem (as one of the commonly used calcium channel blockers, which is used in the treatment of acute and chronic angina and spasmo angina, in addition to the treatment of different types of essential hypertension) has been carried on Saccharomyces Cerevisiae cells. Cells cultures of the most famous yeast Saccharomyces Cerevisiae (bakers yeast) were irradiated with different doses of gamma rays. Results revealed that the necessary dose of gamma rays that leads to 10% of survived cellular population (D10 value) was about 256 Gy. This irradiation dose was used then in all irradiation experiments on culture of S. Cerevisiae cells in which different concentrations of Deltiazem (55, 110, 165 mg/Kg medium) were added before and after irradiation in order to study the radio protective effect of Deltiazem. Results showed that Deltiazem enhances survival percentage of irradiated S. Cerevisiae cultures in a concentration dependent manner. This study confirmed our previous works, which had demonstrated that Deltiazem protects lethally and supralethally irradiated rats, and enhances survival of pre-irradiated Deltiazem treated animals.(author)

  1. Effects of hydrazine addition and N2 atmosphere on the corrosion of reactor vessel steels in diluted seawater under gamma-rays irradiation

    International Nuclear Information System (INIS)

    Seawater was injected into the reactor cores in the Fukushima Daiichi Nuclear Power Station. Corrosion of primary containment vessel (PCV) steel and reactor pressure vessel (RPV) steel is considered to progress until the molten fuel debris is removed. To evaluate durability of the PCV and RPV steels, corrosion tests were conducted in diluted seawater at 50°C under gamma-rays irradiation of dose rates of 4.4 and 0.2 kGy/h. To evaluate the effect of hydrazine (N2H4) as an oxygen scavenger under gamma-rays irradiation, 10 and 100 mg/L N2H4 were added to the diluted seawater. Without addition of N2H4, weight loss in the PCV and RPV steels irradiated with the 0.2 kGy/h dose rate was comparable with those without irradiation and weight loss in the vessel steels irradiated with the 4.4 kGy/h dose rate was higher than those without irradiation. Under irradiation, weight loss in the PCV and RPV steels in diluted seawater containing N2H4 was comparable with that in diluted seawater without N2H4. When gas phase in the flask was replaced with N2, weight loss in the PCV and RPV steels, and O2 and H2O2 concentrations in the diluted seawater decreased. (author)

  2. Coloration of fluorophosphate glasses containing fluorescein molecules by heat treatment or gamma ray irradiation

    International Nuclear Information System (INIS)

    The 70SnF2·30P2O5 glasses containing 25-500 ppm of fluorescein exhibit change in color from light yellow to reddish orange (absorption maximum, ?=500 nm) when heated at 240degC for 120-180 min. The fluorophosphate glasses also change the color from light yellow to reddish brown (?=480 nm) when irradiated with 60Co ?-rays of 5x104 Gy. The P-F stretching mode observed in the Fourier transformed infrared (FT-IR) spectra showed an increase in peak intensity along with the coloration, suggesting a cleavage of the weak chemical bond between fluoride ions (F-) and fluorescein molecules. The coloration is ascribed to change of the molecular structure of fluorescein from non-crystalline to crystalline type. ESR spectra of ?-ray irradiated 70SnF2·30P2O5 glasses showed a poorly resolved doublet, which was ascribed to a hole-trapped PO3F- center produced by electron scattering: PO3F2- ? PO3F- + e-. (author)

  3. ESR investigations on {gamma}-ray irradiated 3-methyl nylon 3

    Energy Technology Data Exchange (ETDEWEB)

    Catiker, Efkan [Abant Izzet Baysal University, Department of Chemistry, 14280 Bolu (Turkey); Guven, Olgun [Hacettepe University, Department of Chemistry, 06532 Ankara (Turkey); Ozarslan, Ozdemir [Abant Izzet Baysal University, Department of Chemistry, 14280 Bolu (Turkey); Chipara, Mircea [University of Texas Pan American, Department of Physics and Geology, 1201 W. University Drive, Edinburg, TX 78541-2999 (United States)], E-mail: mchipara@utpa.edu

    2008-06-15

    Electron spin resonance spectroscopy investigations on {gamma} irradiated 3-methyl nylon 3 (poly-3-methyl {beta}-alanine) are reported. The resonance spectra (recorded after the irradiation in nitrogen atmosphere has been stopped) have been attributed to the parallel and perpendicular components of a triplet line assigned to the delocalization of the uncoupled electron over an effective nuclear spin 1. It was suggested that this effective spin arises from the fast tunneling/rotation of a proton between two positions. The resonance spectra have been simulated with accuracy by using a simplified spin Hamiltonian and assuming Lorentzian-like resonance line shapes and axial asymmetry of the resonance line due to the trapping of free radicals in randomly oriented crystallites. The time evolution of free radicals in nitrogen atmosphere at room temperature has been analyzed. The decay kinetics of stable free radicals in 3-methyl nylon 3 (under inert atmosphere) has been investigated. It was shown that the radiation-induced radicals in inert atmosphere decay through a unimolecular reaction.

  4. Decomposition of colored wastewater for recycling water by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Utilization of advanced treated water from wastewater treatment plants for the restoration of waterway is in progress to improve the waterside environment. However, the colored wastewater containing molasses pigments, melanoidins, is not decolorized by activated sludge process, and the water can not be applied for recycling water. We have studied the radiation treatment for decolorization of wastewater discharged from baker's yeast factory. The decolorization after decomposition of colored biorefractory organic substances in wastewater, enhancement in biodegradability and effective decrease in values of COD were observed after gammaray irradiation. Although the decrease in values of COD was observed, however chromaticity was not improved after the combined treatment of wastewater by radiation together with activated sludge. The result suggests that it is necessary to find the optimum conditions for stimulation of sludge in the combined treatment. (author)

  5. Decomposition of colored wastewater for recycling water by gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tanabe, Hiroko; Sekiguchi, Masayuki; Sawai, Teruko [Tokyo Metropolitan Isotope Research Center (Japan)

    1995-03-01

    Utilization of advanced treated water from wastewater treatment plants for the restoration of waterway is in progress to improve the waterside environment. However, the colored wastewater containing molasses pigments, melanoidins, is not decolorized by activated sludge process, and the water can not be applied for recycling water. We have studied the radiation treatment for decolorization of wastewater discharged from baker`s yeast factory. The decolorization after decomposition of colored biorefractory organic substances in wastewater, enhancement in biodegradability and effective decrease in values of COD were observed after gammaray irradiation. Although the decrease in values of COD was observed, however chromaticity was not improved after the combined treatment of wastewater by radiation together with activated sludge. The result suggests that it is necessary to find the optimum conditions for stimulation of sludge in the combined treatment. (author).

  6. Preparation of hydrogels for atopic dermatitis containing natural herbal extracts by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Atopic dermatitis (AD) is a familial and chronic inflammatory pruritic skin disease that affects a large number of children and adults in industrialized countries. It is known that one of the prominent features of AD and chronic pruritus is partially due to the histamine released from mast cell. In this work, hydrogel patches with natural herbal extracts were prepared by 'freezing and thawing', and a gamma irradiation. It showed eminent healing results as a consequence of long-term moisturizing effects and natural herbal extracts on atopic wounds. Besides its non-toxicity and human harmlessness, it can be easily attached to or detached from the skin without any trace and help patients to feel refreshment when attached. Based on this work, the hydrogel patches we made can be potentially used as an alternative remedy for not only pruritus in AD, but other dermatitis.

  7. Gamma-ray irradiation synthesis of silk fibroin-coated CdS quantum dots

    International Nuclear Information System (INIS)

    Silk fibroin coated CdS quantum dots (SF-CdS QDs) were successfully synthesized in an aqueous system at room temperature under 60Co ?-ray irradiation. The prepared QDs were characterized by transmission electron microscopy (TEM), energy dispersion spectrometry (EDS), Fourier transform infrared spectrometer(FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis) and photoluminescence (PL) spectrometry. The synthesized QDs were about 5 nm in diameter with excellent water-solubility. The QDs showed strong visible yellow-green luminescence under UV excitation, at an emission peak of around 538 nm. This method could be conveniently extended to fabricate other nanoparticles coated with silk fibroin. (authors)

  8. Preparation of hydrogels for atopic dermatitis containing natural herbal extracts by gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Youn-Mook; An, Sung-Jun; Kim, Hae-Kyoung [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong Jeongeup-si Jellabuk-do, 580-185 (Korea, Republic of); Kim, Yun-Hye [AMOTECH Co., Ltd., Kimpo-City, Kyungki-do (Korea, Republic of); Youn, Min-Ho; Gwon, Hui-Jeong; Shin, Junhwa [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong Jeongeup-si Jellabuk-do, 580-185 (Korea, Republic of); Nho, Young-Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, 1266 Sinjeong-dong Jeongeup-si Jellabuk-do, 580-185 (Korea, Republic of)], E-mail: ycnho@kaeri.re.kr

    2009-07-15

    Atopic dermatitis (AD) is a familial and chronic inflammatory pruritic skin disease that affects a large number of children and adults in industrialized countries. It is known that one of the prominent features of AD and chronic pruritus is partially due to the histamine released from mast cell. In this work, hydrogel patches with natural herbal extracts were prepared by 'freezing and thawing', and a gamma irradiation. It showed eminent healing results as a consequence of long-term moisturizing effects and natural herbal extracts on atopic wounds. Besides its non-toxicity and human harmlessness, it can be easily attached to or detached from the skin without any trace and help patients to feel refreshment when attached. Based on this work, the hydrogel patches we made can be potentially used as an alternative remedy for not only pruritus in AD, but other dermatitis.

  9. Gamma-ray irradiation resistance of silver doped GeS{sub 2}–Ga{sub 2}S{sub 3}–AgI chalcohalide glasses

    Energy Technology Data Exchange (ETDEWEB)

    Shen, W. [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); ENEA-UTT-MATIRR, Via Anguillarese 301, 00123 Rome (Italy); Baccaro, S.; Cemmi, A. [ENEA-UTT-MATIRR, Via Anguillarese 301, 00123 Rome (Italy); Ren, J. [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Z.; Zhou, Y. [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); ENEA-UTT-MATIRR, Via Anguillarese 301, 00123 Rome (Italy); Yang, Y. [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, G., E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2014-06-01

    Highlights: • The ?-ray irradiation resistance of Ag doped chalcohalide glasses (GeS{sub 2}–Ga{sub 2}S{sub 3}–AgI) has been investigated. • The introduction of silver ions plays a specific role in the modification of the gamma-ray irradiation resistance of glasses. • The sulfur exerts an important effect on the photo-sensitivity of chalcogenide glasses. - Abstract: In the present work, series of silver doped Ge–Ga–S–AgI chalcohalide glasses have been prepared and their optical transmission spectra are compared before and after ?-ray irradiation at different doses. The differential transmission spectra of the irradiated samples with and without Ag doping have been compared to characterize the ?-ray irradiation induced red-shift of electronic absorption and formation of color centers. Ag doping plays an important role in increasing ?-ray irradiation resistance of the chalcohalide glasses due to its specific effect on the valence band and the network structure of glasses.

  10. Gamma-ray irradiation resistance of silver doped GeS2–Ga2S3–AgI chalcohalide glasses

    International Nuclear Information System (INIS)

    Highlights: • The ?-ray irradiation resistance of Ag doped chalcohalide glasses (GeS2–Ga2S3–AgI) has been investigated. • The introduction of silver ions plays a specific role in the modification of the gamma-ray irradiation resistance of glasses. • The sulfur exerts an important effect on the photo-sensitivity of chalcogenide glasses. - Abstract: In the present work, series of silver doped Ge–Ga–S–AgI chalcohalide glasses have been prepared and their optical transmission spectra are compared before and after ?-ray irradiation at different doses. The differential transmission spectra of the irradiated samples with and without Ag doping have been compared to characterize the ?-ray irradiation induced red-shift of electronic absorption and formation of color centers. Ag doping plays an important role in increasing ?-ray irradiation resistance of the chalcohalide glasses due to its specific effect on the valence band and the network structure of glasses

  11. Effects of absorbed dose rate, irradiation temperature and post-irradiation temperature on the gamma ray response of red Perspex dosimeters

    International Nuclear Information System (INIS)

    The influences of irradiation temperature and gamma radiation dose rate on the response of red 4034 Perspex dosimeters have been reported in the literature to be of relatively minor consequence, particularly for irradiations at up to a temperature of 40 deg. C and at absorbed dose rates of the order of 7 kGy·h-1 (?2 Gy·s-1). The present study shows this to be true; however, if there are marked differences in the temperature (22 deg. C to 50 deg. C) during extended storage periods (up to 16 hours) after irradiation, there is a tendency to overestimate an unknown dose administered at the elevated temperature, as a result of using a calibration made at an ambient lower temperature (e.g. 22 deg. C). The present study of dose rate effects also shows that there is a pronounced tendency to overestimate an unknown gamma ray dose administered at a relatively low dose rate (3 and 7 kGy·h-1) as a result of using a calibration made at a considerably higher dose rate (e.g. 31 kGy·h-1), even when the temperature of irradiation and storage is controlled at 22 deg. C. (author). 14 refs, 13 figs

  12. Gamma-ray astronomy

    OpenAIRE

    Pohl, Martin

    2001-01-01

    This paper summarizes recents results in gamma-ray astronomy, most of which were derived with data from ground-based gamma-ray detectors. Many of the contributions presented at this conference involve multiwavelength studies which combine ground-based gamma-ray measurements with optical data or space-based X-ray and gamma-ray measurements. Besides measurements of the diffuse emission from the Galaxy, observations of blazars, gamma-ray bursts, and supernova remnants this pape...

  13. Simulation of survival curves in several bacteria irradiated with ultraviolet and gamma rays

    International Nuclear Information System (INIS)

    Although ultraviolet and gamma sterilization were routinely used, D10-values and D99.9-values have been used in actual applications. However, our preliminary results showed that UV-survival curves were sigmoidal and ?-curves were exponential having a shoulder at beginning in many strains. This study was conducted to make clear the reason of occurence of the sigmoid in UV survival curves, at first. Both survival curves of spore cells and vegetable cells in Bacillus subtilis against UV-irradiation are shown with the same sigmoidal pattern. It is clarified that the difference in sensibilities of vegetative and spore cells could not account for the presence of tails. The UV sterilized data have been simulated by adapting a multi hit theory and taking into account the decrease in UV-intensity in liquid suspensions due to Lambert's law. These also follows that the above multi-hit simulation is effective for the ? data and four hits are best fitted to the observed data in both cases of bacteria and fungi. From these results, it is demonstrated that if D10-value and L-value are used as indices for practical sterilization and if a target area and a hit number, a parameter of penetration in UV sterilization are considered, the sterilization level will become more accurate than that as determined by D10- and D99.9-values currently used. (author)

  14. Control of drug releasing from biodegradable polymer drug delivery system by gamma-ray irradiation

    International Nuclear Information System (INIS)

    In order to introduce the drug to the target organ, we developed a gel to control the drug releasing velocity by response to change of temperature by means of ?-ray irradiation to gelatin-GMA modified dextran mixture aqueous solution. A certain level of molecular weight of drug is necessary. The response to the temperature (change of drug releasing velocity) was affected by the concentration of gelatin and the modification rate of GMA. The Higuchi equation was applied to the releasing of ?-galactosidase from gelatin-dextran gel and the releasing velocity was calculated. The releasing velocity decreased with increasing GMA modification rate at 37degC and 15degC. The releasing velocity of ?-galactosidase decreased with increasing the concentration of gelatin at 15degC, but the velocity increased with increasing the concentration at 37degC. These results indicated that the good drug releasing conditions are obtained by controlling the GMA modification rate and the concentration of gelatin. (S.Y.)

  15. Grafting study of polysulfone polymeric membranes by gamma ray irradiation; Estudo da grafitizacao de membranas polimericas a base de polissulfona por irradiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Radiation-induced grafting of styrene poli sulfone films were investigated by simultaneous method in solution using gamma-ray from a radio nuclide {sup 60}Co source. The gamma-ray energy of high intensity induced breaking of chemical bonds leading to free radical formation. The radical start a conventional polymerization sequence comparable with that obtained with a chemical catalyst acting as initiator. The effects of grafting conditions such as irradiation total dose, dose rate and addition of cross linking agent, were studied by means of morphology analysis, thermal degradation and crystallinity. After the grafting reaction, the membranes were submitted to an exhaustive extraction with solvent to remove the polystyrene homopolymer formed. The degree of grafting (DOG) was analyzed by percentage of weight increase. As a result, the reaction always follows the same pattern: DOG increases rapidly initially whilst propagation is the main reaction, then more slowly as termination becomes more frequent. (author)

  16. Late effects of protracted whole-body irradiation of beagles by cobalt-60 gamma rays

    International Nuclear Information System (INIS)

    So that a stronger basis for extrapolation of low-level radiation effects to man can be provided, existing data from small laboratory animals are being supplemented by studies in a longer lived animal, the dog. Beagle dogs are exposed to continuous cobalt-60 irradiation either throughout life or until predetermined total doses are accumulated. The radiation-specific excess-mortality rate and associated causes of death will be related to both dose rate and total dose. The ongoing studies also emphasize the pathogenesis of myelogenous leukemia. At dose rates of 3.75 to 26.25 rads/day, given continuously, responses were consistent, highly dose-rate dependent, and limited primarily to the hematopoietic system. At rates as low as 0.3 rad/day, the hematopoietic system is still the limiting factor for survival, but below 3.75 rads/day present evidence suggests that the responses are independent of dose rate. Longitudinal studies of peripheral blood and bone marrow detected four preclinical phases of myelogenous leukemia. These phases were characterized by standard hematologic end points, ultrastructural features, in vitro cloning assays, and the acute radiation sensitivity of stem cells. Results suggest that an induced error-prone repair mechanism is the basis for the onset of radiation-induced myelogenous leukemia. Interim data from dogs given terminated exposures suggest that the types of tumors and times to death are different from controls but the numbers of tumors are not yet greater than in controls. 26 refs., 12 figs., 5 tabs

  17. Major soluble proteome changes in Deinococcus deserti over the earliest stages following gamma-ray irradiation

    Directory of Open Access Journals (Sweden)

    Dedieu Alain

    2013-01-01

    Full Text Available Abstract Background Deinococcus deserti VCD115 has been isolated from Sahara surface sand. This radiotolerant bacterium represents an experimental model of choice to understand adaptation to harsh conditions encountered in hot arid deserts. We analysed the soluble proteome dynamics in this environmentally relevant model after exposure to 3 kGy gamma radiation, a non-lethal dose that generates massive DNA damages. For this, cells were harvested at different time lapses after irradiation and their soluble proteome contents have been analysed by 2-DE and mass spectrometry. Results In the first stage of the time course we observed accumulation of DNA damage response protein DdrB (that shows the highest fold change ~11, SSB, and two different RecA proteins (RecAP and RecAC. Induction of DNA repair protein PprA, DNA damage response protein DdrD and the two gyrase subunits (GyrA and GyrB was also detected. A response regulator of the SarP family, a type II site-specific deoxyribonuclease and a putative N-acetyltransferase are three new proteins found to be induced. In a more delayed stage, we observed accumulation of several proteins related to central metabolism and protein turn-over, as well as helicase UvrD and novel forms of both gyrase subunits differing in terms of isoelectric point and molecular weight. Conclusions Post-translational modifications of GyrA (N-terminal methionine removal and acetylation have been evidenced and their significance discussed. We found that the Deide_02842 restriction enzyme, which is specifically found in D. deserti, is a new potential member of the radiation/desiccation response regulon, highlighting the specificities of D. deserti compared to the D. radiodurans model.

  18. Low Dose Gamma Irradiation Potentiates Secondary Exposure to Gamma Rays or Protons in Thyroid Tissue Analogs

    Energy Technology Data Exchange (ETDEWEB)

    Green, Lora M

    2006-05-25

    We have utilized our unique bioreactor model to produce three-dimensional thyroid tissue analogs that we believe better represent the effects of radiation in vivo than two-dimensional cultures. Our thyroid model has been characterized at multiple levels, including: cell-cell exchanges (bystander), signal transduction, functional changes and modulation of gene expression. We have significant preliminary data on structural, functional, signal transduction and gene expression responses from acute exposures at high doses (50-1000 rads) of gamma, protons and iron (Green et al., 2001a; 2001b; 2002a; 2002b; 2005). More recently, we used our DOE funding (ending Feb 06) to characterize the pattern of radiation modulated gene expression in rat thyroid tissue analogs using low-dose/low-dose rate radiation, plus/minus acute challenge exposures. Findings from these studies show that the low-dose/low-dose rate “priming” exposures to radiation invoked changes in gene expression profiles that varied with dose and time. The thyrocytes transitioned to a “primed” state, so that when the tissue analogs were challenged with an acute exposure to radiation they had a muted response (or an increased resistance) to cytopathological changes relative to “un-primed” cells. We measured dramatic differences in the primed tissue analogs, showing that our original hypothesis was correct: that low dose gamma irradiation will potentiate the repair/adaptation response to a secondary exposure. Implications from these findings are that risk assessments based on classical in vitro tissue culture assays will overestimate risk, and that low dose rate priming results in a reduced response in gene expression to a secondary challenge exposure, which implies that a priming dose provides enhanced protection to thyroid cells grown as tissue analogs. If we can determine that the effects of radiation on our tissue analogs more closely resemble the effects of radiation in vivo, then we can better estimate the risks and modify assign limits to radiation worker and astronauts. Additionally, confirmation that tissue analogs represent a realistic in vivo response to radiation will allow scientists to perform tissue relevant experiments without the expense of using animals. Confirmation of the in vivo approximation of our model will strengthen our findings from the recent completion of our DOE funding which is the subject of the current proposal.

  19. Influence of various commercial packaging conditions on survival of Escherichia coli O157:H7 to irradiation by electron beam versus gamma rays.

    Science.gov (United States)

    López-González, V; Murano, P S; Brennan, R E; Murano, E A

    1999-01-01

    Irradiation of ground beef patties inoculated with the organism Escherichia coli O157:H7 was performed either by gamma rays from a cobalt 60 source or by electron beam generated by a linear accelerator. Patties were packaged in one of the following materials: nylon/polyethylene bags, Saran/polyester/polyethylene bags (PM2), or Saran overwrap with a Styrofoam tray inside. Bags were sealed in air or under vacuum and were irradiated at either 5 or -15 degrees C. Average D10 values (dose required to inactivate 90% of a microbial population) ranged from 0.27 to 0.63 kGy, depending on the conditions. Overall, higher D10 values (Peffect of oxygen- and water-derived radicals on microbial survival. Irradiation by gamma rays resulted in higher D10 values (P<0.047) than irradiation by electron beam, with the highest values being observed at -15 degrees C. Differences may be attributed to dose rate (1.0 kGy/h for gamma, 17 kGy/min for electron beam) since it is possible that, at low dose rates, microbial enzymes may have more time to repair damage to the cell due to irradiation, resulting in higher D10 values. PMID:9921821

  20. Physico-chemical processes in Vertical-Double-Diffused Metal-Oxide-Semiconductor Field Effect Transistors induced by gamma-ray irradiation and post-irradiation annealing

    Directory of Open Access Journals (Sweden)

    Pejovi? Mili? M.

    2015-01-01

    Full Text Available The behavior of commercial power Vertical-Double-Diffused Metal Oxide Semiconductor Field Effect Transistors (VDMOSFETs during gamma-ray irradiation and subsequent annealing at room and elevated temperature was investigated. The densities of radiation-induced fixed traps and switching traps were determined from the sub-threshold I-V curves using the midgap technique. It was shown that the creation of fixed traps dominated during irradiation. The experimental results have also proved the existence of latent switching traps buildup process during annealing at an elevated temperature. This increase correlated with the decrease in fixed trap density. Physical and chemical processes responsible for the threshold voltage shift during irradiation have been analyzed on the basis of interactions between secondary electrons released by gamma photons with covalent bonds Sio - O and Sio - Sio. H-W model has been used for the explanation of processes leading to latent switching traps buildup at an elevated temperature and its passivation at late annealing times. [Projekat Ministarstva nauke Republike Srbije, br. 171007

  1. High gamma-rays irradiation tests of critical components for ITER (International Thermonuclear Experimental Reactor) in-vessel remote handling system

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Kenjiro; Kakudate, Satoshi; Oka, Kiyoshi [Department of Fusion Engineering Research, Naka Fusion Research Establishment, Japan Atomic Energy Research Institute, Naka, Ibaraki (Japan)] [and others

    1999-02-01

    In ITER, the in-vessel remote handling is inevitably required to assemble and maintain the activated in-vessel components due to deuterium and tritium operation. Since the in-vessel remote handling system has to be operated under the intense of gamma ray irradiation, the components of the remote handling system are required to have radiation hardness so as to allow maintenance operation for a sufficient length of time under the ITER in-vessel environments. For this, the Japan, European and Russian Home Teams have extensively conducted gamma ray irradiation tests and quality improvements including optimization of material composition through ITER R and D program in order to develop radiation hard components which satisfy the doses from 10 MGy to 100 MGy at a dose rate of 1 x 10{sup 6} R/h (ITER R and D Task: T252). This report describes the latest status of radiation hard component development which has been conducted by the Japan Home Team in the ITER R and D program. The number of remote handling components tested is about seventy and these are categorized into robotics (Subtask 1), viewing system (Subtask 2) and common components (Subtask 3). The irradiation tests, including commercial base products for screening, modified products and newly developed products to improve the radiation hardness, were carried out using the gamma ray irradiation cells in Takasaki Establishment, JAERI. As a result, the development of the radiation hard components which can be tolerable for high temperature and gamma radiation has been well progressed, and many components, such as AC servo motor with ceramics insulated wire, optical periscope and CCD camera, have been newly developed. (author)

  2. High gamma-rays irradiation tests of critical components for ITER (International Thermonuclear Experimental Reactor) in-vessel remote handling system

    International Nuclear Information System (INIS)

    In ITER, the in-vessel remote handling is inevitably required to assemble and maintain the activated in-vessel components due to deuterium and tritium operation. Since the in-vessel remote handling system has to be operated under the intense of gamma ray irradiation, the components of the remote handling system are required to have radiation hardness so as to allow maintenance operation for a sufficient length of time under the ITER in-vessel environments. For this, the Japan, European and Russian Home Teams have extensively conducted gamma ray irradiation tests and quality improvements including optimization of material composition through ITER R and D program in order to develop radiation hard components which satisfy the doses from 10 MGy to 100 MGy at a dose rate of 1 x 106 R/h (ITER R and D Task: T252). This report describes the latest status of radiation hard component development which has been conducted by the Japan Home Team in the ITER R and D program. The number of remote handling components tested is about seventy and these are categorized into robotics (Subtask 1), viewing system (Subtask 2) and common components (Subtask 3). The irradiation tests, including commercial base products for screening, modified products and newly developed products to improve the radiation hardness, were carried out using the gamma ray irradiation cells in Takasaki Establishment, JAERI. As a result, the development of the radiation hard components which can be tolerable for high temperature and gamma radiation has been well progressed, and many components, such as AC servo motor with ceramics insulated wire, optical periscope and CCD camera, have been newly developed. (author)

  3. Effect of Irradiation of 60CO Gamma Rays on Growth of Garlic (Allium Sativum L) Plants Cv. Lumbu Hijau at Low Land Area

    International Nuclear Information System (INIS)

    Garlic originally come from the sub tropical area. In Indonesia, garlic is grown generally in high land area with an altitude between 1000 - 1600 m above sea level. Therefore, the area for growing and producing garlic is limited. Besides, genetic variation of garlic is very narrow since garlic belongs to vegetatively propagated crops. An effort for increasing genetic variation of garlic was done by exposing garlic cloves to gamma rays in order to obtain garlic mutant lines adapted to low land area. Garlic cloves were exposed to different doses of gamma rays 0 (untreated) 2, 4, 6, 8 and 10 Gy at the Centre for Research and Development of Isotope and Radiation Technology. Each dose consisted of 150 garlic cloves. Untreated and irradiated garlic cloves were grown at Bandar Buat Experimental Station (50 m above sea level), Padang, West Sumatera. The experiment was arranged in a randomized block design with three replication. The parameter observed were percentage of grown plants and survival harvested plants, plant height, leaf number, chlorophyll content, number of stomata, plant age, number of cloves per bulbs, fresh, dry weight and diameter of bulbs. The result indicated that the dose of gamma rays 6 Gy is an advantage dose for obtaining well adapted garlic mutant lines in the low land area. (author)

  4. The effects of gamma-ray irradiation to strawberry (Fragaria x ananassa Duch.) calli on shoot regeneration, achene formation and morphological variations of regenerants

    International Nuclear Information System (INIS)

    Strawberry (Fragaria x ananassa 'Nyoho') calli, derived from anthers, were irradiated with gamma -ray at dosages from 100 to 1,600 Gy (10 Gy · hr-1) and their effects on callus growth, plant regeneration, and somaclonal variation were analyzed. The growth of callus and percentage of plant regeneration from the callus were reduced slightly at dosages less than 200 Gy, moderately at 400 Gy, and markedly above 800 Gy. Fruit growth associated with seed fertility (>50 % ) was morphologically normal at less than 100 Gy, whereas achene formation was significantly inhibited above 200 Gy. The percentages of morphological variation in regenerants formed from the irradiated callus were:13.7 (no irradiation), 18.6 (100 Gy), 66.0 (200 Gy), 75.7 (400 Gy), and 97.0 (800 Gy). Furthermore, higher dosages yielded wider variations, e.g., thick and small leaf, light leaf color, white flesh, and long fruit. In some regenerants, more than one morphological aberrations developed, some of which were transmissible to daughter plants. These results revealed that the irradiating strawberry callus with gamma - ray resulted in a higher degree and wider spectrum of somaclonal variation than did simple callus culture. (author)

  5. Gamma Ray Bursts

    International Nuclear Information System (INIS)

    I present the observational properties of gamma-ray burst and outline the current theoretical models of these phenomena. I review the main problems in the gamma-ray burst science and sketch the prospects for the future. (author)

  6. Effect of gamma ray irradiation on the structural and electrical transport properties of PrFe{sub 1?x}Mn{sub x}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Sultan, Khalid, E-mail: ksbhat.phy@gmail.com; Ikram, M., E-mail: ksbhat.phy@gmail.com [Department of Physics, National Institute of Technology Hazratbal, Srinagar-190006, Jammu and Kashmir (India); Asokan, K. [Material Science Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi-110067 (India)

    2014-04-24

    The effect of gamma ray irradiation on the structural and transport properties of polycrystalline bulk samples of PrFe{sub 1?x}Mn{sub x}O{sub 3} (x = 0.0, 0.1, 0.5) were investigated. The samples were synthesized by solid state reaction method and exposed to {sup 60}Co gamma radiation to accumulated dose of 625 KGy. From the Raman study, the modes exhibit a blue shift with broadening of spectral features in the irradiated samples. The dielectric constant (??) was also studied as a function of frequency. The dielectric constant and ac conductivity increases with Mn doping but decrease on irradiation. Exposure to gamma radiation results in substantial modification in the physical properties of these compounds.

  7. Development of High Yielding Mutants of Brassica campestris L. cv. Toria Selection Through Gamma Rays Irradiation

    OpenAIRE

    Muhammad Aslam Javed; Muhammad Aquil Siddiqui; Muhammad Kashif Riaz Khan; Abdullah Khatri; Imtiaz Ahmed Khan; Nazir A. Dahar; Muhammad Hussain Khanzada; Raziullah Khan

    2003-01-01

    Homogeneous seeds of Brassica campestris L. cv. Toria selection were treated with different doses of gamma rays (750, 1000 and 1250 Gy) to induce genetic variability for the selection of new genotypes with improved agronomic traits. After passing through different stages of selection, two promising mutants were selected for further studies. Two selected mutants along with 5 other entries including parent variety were evaluated for yield and yield components in yield trials for two consecutive...

  8. Effect of dose-rate and age at irradiation on cancer development in Sprague-Dawley rats exposed to gamma rays

    International Nuclear Information System (INIS)

    The probability that rats develop tumors following a 3 Gy exposure to gamma rays from cobalt 60 was observed to depend on age at exposure and on dose rate. Dose rate reduction by a factor of 60 decreased the carcinogenic incidence (mainly carcinomas) by a factor of about 5. Lifetime excess of malignant neoplasia decreased by a factor of about 10 in 9 month-old rats as compared to animals irradiated in utero. The 3-month age group developed slightly fewer cancers than the group irradiated in utero, and tumor location was different. The higher incidence of tumors following in utero exposure was dependent to the high sensitivity of brain and gonads during organogenesis. (author)

  9. Biochemical and pharmacological characterization of irradiated crotamine by gamma rays of {sup 60}Co; Caracterizacao bioquimica e farmacologica da crotamina irradiada por raios gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Karina Corleto

    2014-07-01

    The serum production in Brazil, the only effective treatment in cases of snakebites, uses horses that although large size, have reduced l lifespan compared with horses not immunized. Ionizing radiation has been shown as an excellent tool in reducing the toxicity of venoms and toxins isolated, and promote the achievement of better immunogens for serum production, and contributing to the welfare of serum-producing animals. It is known, however, that the effects of ionizing radiation on protein are characterized by various chemical modifications, such as fragmentation, cross-linking due to aggregation and oxidation products generated by water radiolysis. However, the action of gamma radiation on toxins is not yet fully understood structurally and pharmacologically, a fact that prevents the application of this methodology in the serum production process. So we proposed in this paper the characterization of crotamine, an important protein from the venom of Crotalus durissus terrificus species, irradiated with {sup 60}Co gamma rays. After isolating the toxin by chromatographic techniques and testing to prove the obtaining of pure crotamine, it was irradiated with gamma rays and subjected to structural analysis, Fluorescence and Circular Dichroism. Using high hydrostatic pressure tests were also conducted in order to verify that the conformational changes caused by radiation suffer modifications under high pressures. From the pharmacological point of view, muscle contraction tests were conducted with the objective of limiting the action of crotamine in smooth muscle as well as the change in the action of toxin caused structural changes to the front. Analysis of Circular Dichroism and Fluorescence showed changes in structural conformation of crotamine when subjected to gamma radiation and that such changes possibly occurring in the secondary and tertiary structure of the protein. The observed in pharmacological tests showed that the irradiated crotamine was less effective in lowering the vas deferens twitch in rats in comparison to native crotamine. In addition, the behavior of irradiated toxin in tonic contraction, modulated by noradrenaline, was different from that observed for the native toxin. (author)

  10. The effects of 137Cs gamma-rays irradiation on upland cotton pollen and M1(F1M1)generation

    International Nuclear Information System (INIS)

    The radiation effects of upland cotton pollen irradiated by 137Cs gamma-rays were studied with Zhemian 9 and Zhe 102 as the research materials. The results are as follows: 1. There were significant negative correlation between radiation dosage and the vitality of upland cotton pollen with the correlation coefficient of -0.9545?-0.9785. The half-lethal dosage with pollen of Zhemian 9 and Zhe 102 was 5.50 Gy and 4.69 Gy, respectively. 2. The emergence and growth of seedlings of M1 and F1M1 generations from the pollen irradiated with dosage of more than 7.51 Gy were all significantly retarded. The induced-aberration effects varied with varieties. 3. All irradiation dosage inhibited yield and fiber qualities except 1.88 Gy. The inhibition effects of irradiation on yield components of M1 and F1M1 generations from irradiated pollen were greater than those on fiber qualities, especially on lint percentage and weight per boll. The protein content of cotton seed kernal of M1 and F1M1 generations increased with the rising of irradiation dosage, while the oil content decreased. 4. The radiosensitivity of F1M1 was higher than that of M1. It is suggested that the suitable dosage in cotton breeding should be less than 4.79 Gy

  11. Feasibility of applying gamma irradiation as disinfestation technique on date fruits in respect to nutritional value that is affected by disinfesting gamma ray doses

    International Nuclear Information System (INIS)

    Infested and non-infested dry date fruits (Phonex dactylifera), Abrimi variety (9.2% moisture), with Ephestia cautella Walker were irradiated for 0, 15, 20 and 40 Krad gamma ray doses emitted from Co-60 source with 1.36 x 10-rad/h. as a dose rate. Irradiated fruits were stored at room temperature, at 20-250C and 85-95% R.H., in packages to avoid reinfestation. A dose of 20 Krad is 100 percent effective in preventing the emergency of eggs, larva, and pupae in fruits as reflected by zero per cent emergency count for live adults. Also, this dose was found to be lethal for adult stage of the insect. On the other hand, 2 Krad dose does not produce significant changes in the nutritional qualities of fruits, as measured by chemical analytical means for carbohydrates, protein and amino acids, directly after irradiation as well as at 2, 4 and 6 months storage. The triangular tests show that irradiation treatments even with 4 Krad exerted no determinal effect upon the sensory qualities of stored irradiated date fruits. These results point out the feasibility of applying gamma irradiation, 20 Krad, as disinfestation technique against Ephestia cautella Walker in dry date fruits without exerting any effect on the nutritional value

  12. Comparison of base substitutions in response to nitrogen ion implantation and 60Co-gamma ray irradiation in Escherichia coli

    Scientific Electronic Library Online (English)

    Xie, Chuan-Xiao; Xu, An; Wu, Li-Jun; Yao, Jian-Min; Yang, Jian-Bo; Yu, Zeng-Liang.

    Full Text Available To identify the specificity of base substitutions, a novel experimental system was established based on rifampicin-resistant (Rif r) mutant screening and sequencing of the defined region of the rpoB gene in E. coli. We focused on comparing mutational spectra of base substitutions induced by either l [...] ow energy nitrogen ion beam implantation or 60Co-gamma rays. The most significant difference in the frequency of specific kinds of mutations induced by low energy nitrogen ion beam was that CG ®TA transitions were significantly increased from 32 to 46, AT ®TA transversions were doubled from 7 to 15 in 50 mutants, respectively. The preferential base substitutions induced by nitrogen ion beam implantation were CG ®TA transitions, AT ®GC transitions, AT ®TA transversions, which account for 92.13% (82/89) of the total. The mutations induced by 60Co-gamma rays were preferentially GC ®AT and AT ®GC transitions, which totaled 84.31% (43/51).

  13. Effects of gamma-ray irradiation on interface states and series-resistance characteristics of BiFeO{sub 3} MOS capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Kaya, Senol, E-mail: senolkaya52@gmail.com [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Nuclear Radiation Detectors Research and Development Center, 14280 Bolu (Turkey); Aktag, Aliekber [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Nuclear Radiation Detectors Research and Development Center, 14280 Bolu (Turkey); Yilmaz, Ercan [Physics Department, Abant Izzet Baysal University, 14280 Bolu (Turkey); Nuclear Radiation Detectors Research and Development Center, 14280 Bolu (Turkey); Tyndall National Institute, University College Cork, Lee Maltings, Cork (Ireland)

    2014-01-15

    The effects of radiation on the electrical-interface-state density (D{sub it}) and series resistance (R{sub s}) characteristics of BiFeO{sub 3} MOS capacitors were studied in this work. To study the response of MOS devices to gamma irradiation over a range of doses, MOS samples were irradiated using a Co-60 gamma-ray source from 0.5 to 16 grays at a dose rate of 0.0030 Gy/s. C–V and G/?–V measurements were recorded prior to and after irradiation at high (1 MHz) frequency. The effects of the radiation were determined from analysis of the C–V and G/?–V curves. A slightly decrease in the R{sub s} values with increasing irradiation dose was observed. The total interface-state density was found to decrease because of the reordering and restructuring of radiation-induced defects in the MOS capacitors. The experimental results indicate that the electrical R{sub s} and D{sub it} characteristics of BiFeO{sub 3} MOS capacitors depend on the gamma-irradiation dose, and the calculated densities of the interface states are on the order of 10{sup 11} eV{sup ?1} cm{sup ?2}. However, the calculated D{sub it} values are not high enough to pin the Fermi level of the Si substrate and thereby corrupt device operation over the given dose range.

  14. Morphogenetical studies on the M2- and M3-populations of wheat (Triticum aestivum ssp. vulgare L.) after seed irradiation with gamma rays

    International Nuclear Information System (INIS)

    This study deals with the irradiation induced variability in five quantitative traits of wheat. Various statistical parameters and genetic estimates were used herein to determine the magnitude of heritable and non-heritable components of variance in two successive generations (M2 and M3) after treating the seeds of a pure line of the Egyptian hexaploid wheat variety 'Giza 155' with different gamma ray doses. Results indicated a generalized reduction in the mean value of these characters observed in both generations as compared to the mother stock. However, great variability was obtained in both generations more apparent in M3 than M2. Phenotypical correlations, genotypical correlations, and heritability estimates of these characters exhibited high values. The results were represented and discussed. Conclusions were drawn and radiobiological concepts were used for better understanding of the basic feature of radiaton induced mutations. (orig.)

  15. An approach to reuse of PCB-contaminated transformer oil using gamma radiolysis. Basic decomposition property of PCB and 1,2,4-trichlorobenzene under gamma ray irradiation

    International Nuclear Information System (INIS)

    The radiolytic decompositions of low-concentration polychlorinated biphenyls (PCB) and 1,2,4-trichlorobenzene (TCBz) in a transformer oil have been studied using a 60Co gamma ray irradiation facility. Significant decompositions of PCB and TCBz were observed in the oil at tens of kGy absorbed dose without any additive. We derived the required dose for KC500 decomposition in transformer oil using a power function, which indicates that oil with lower PCB concentration needs less dose to treat PCB wastes. We also observed that the gamma radiolyses of PCB and TCBz did not affect each other; the decompositions of PCB and TCBz proceed independently. Both PCB concentration analysis and total chlorine mass concentration analysis indicated that most dechlorinated chlorine atoms react to generate other chlorine compounds in the oil. We found that the gamma radiolysis without additional compounds in the oil can be a useful way of reusing PCB-contaminated transformer oil. (author)

  16. The role of spermatogonia in the recovery process from temporary sterility induced by gamma-ray irradiation in the teleost Oryzias latipes

    International Nuclear Information System (INIS)

    Adult males of the fish Oryzias latipes were irradiated with 0.5 or 1 kR of 137Cs-gamma-rays (100 R/min). From the viewpoint of the cell-population shift and cell differentiation, the radiation effects on the spermatogenesis in the testis were analyzed. Among the three types of spermatogonia, the first type, the spermatogonia As, were very resistant to radiation, judging from the survival of the cells, but the other types, the spermatogonia Ad and the spermatogonia B, were sensitive to radiation. The spermatogonia As began to proliferate after the degeneration and disappearance of the spermatogonia Ad following the iradiation. During the proliferation phase of the cells, some of the spermatogonia As were morphologically transformed into the spermatogonia Ad, which contributed to the repopulation of the spermatogenetic cells in the testis following the cell loss induced by radiation damage. (auth.)

  17. Localization of the lactate dehydrogenase (LDH) and of the acid phosphatase (AP) in liver cells of embryos and chickens irradiated with gamma rays

    International Nuclear Information System (INIS)

    Using enzymatic histo- and cytochemical techniques, effects of acute 1000-rad gamma rays were studied with regard to changes occurring in the location and activity of the following embryonic or young chick hepatic enzymes: acid phosphatase (AP), indicative of lysosomes, and lactate dehydrogenase (LDH), involved in glycolytic metabolism. Exposures were given to 12-, 20-, or 21-day embryos and to 7-day-old chicks, and liver sections prepared 1, 24, or 72 days postradiation. Comparisons were made to unirradiated age-specific controls. Increases in AP and LDH activities were observed under all of the conditions tested, with extent of effect depending on both stage of development at exposure and time after exposure. Peak values were observed at 24 hours after irradiation of 12-day embryos. (A.B.)

  18. Application of the radiochemical - and the direct gamma ray spectrometry method to the burnup determination of irradiated uranium oxide

    International Nuclear Information System (INIS)

    The burn up of natural U3O8 that occurs by the action of thermal neutrons was determined, using the radioisotopes 144Ce, 137Cs, 103Ru, 106Ru and 95Zr as monitors. The determination of the burn up was made using both destructive and non-destructive methods. In the non-destructive method, the technique of direct gamma-ray spectrometry was used and the radioisotopes mentioned were simultaneously counted in a Ge-Li detector. In the radiochemical method the same radioisotopes were isolated one from the other and from all other fission products before counting. The solvent extraction technique was used for the radiochemical separation of uranium, cerium, cesium and ruthenium. To separate zirconium and niobium, adsorption in silica-gel was used. The extraction agent employed to isolate cesium was dipycrilamine and for the separation of the other radioisotopes Di-(2-Ethyl Hexyl) Phosphoric acid (HDEHP) was used. (Author)

  19. Determination of absorbed dose in a patient irradiated by beams of x or gamma rays in radiotherapy procedures

    International Nuclear Information System (INIS)

    Several important changes in the underlying physical concepts of radiotherapy are discussed. Radiotherapy with external photon beams is now carried out to a very large extent with radiation of high energy. However, medium and low energy photons still have a place and give rise to problems to which special attention has to be drawn. This report will assume the use of high energy radiation (including 60Co gamma rays) unless otherwise stated. Isocentric techniques are now fairly common and the dosimetric procedures used with these techniques are somewhat different from those used with the more traditional techniques based on a fixed source-skin distance (SSD). The digital computer is widely and increasingly used as a means of calculating dose distributions and for other procedures discussed in this report

  20. Gamma-ray sources

    International Nuclear Information System (INIS)

    Results are presented from an analysis of the celestial gamma-ray fine-scale structure based on over half of the data which may ultimately be available from the COS-B satellite. A catalogue consisting of 25 gamma-ray sources measured at energies above 100 MeV is presented. (Auth.)

  1. Permeability Properties of Commercial Sealing Elastomers to Light Gases with and Without Irradiation

    International Nuclear Information System (INIS)

    Elastomers are commonly used as sealing materials for applications at moderate vacuum levels. Use of elastomeric seals in ITER processing systems without any other path barrier is unacceptable from tritium confinement aspects and with safety operation. Alternative sealing methods make part of intense R-and-D efforts for root fore-pumping systems in ITER. A large variety of elastomer materials are available in the market. Gas permeability performance of elastomers are known to depend on composition and other basic properties. Such differences can lead to orders of magnitude for He or H-isotopes permeabilities justifying a systematic experimental study for ranges of interest (0-1 bar, T oC). Radiation rapidly induces hardening and other property modifications, hence performance in radiation degrading environments of their sealing properties requires additional research. The screening of available commercial grades of diverse elastomeric membranes have been performed tested in the gas permeation cell rig developed in CIEMAT for out-of-irradiation qualification and compared with measurements done in a permeation cell coupling the Van de Graaff 2 MeV e- beam facility under ionizing radiation. Time lag measurement through membranes are obtained with and without irradiation. Evidenced differences in transport magnitudes are discussed in terms of composition and elastomer microstructure. Permeability values, gas pressure dependencies and transport domains are made explicit and discussed. (author)

  2. Effects of gamma-ray and UV irradiation on the abnormal aggregation of proteins, and study of repair and protection mechanism

    International Nuclear Information System (INIS)

    Presented are following 7 Studies on the title subject. Abnormal Protein Aggregation and Amino Acid Racemization by Radiation and UV-ray, report the effects of artificial replacement of Asp76 in 70-88th residues of alphaA-crystallin (aA-cry) to L-alpha, L-beta, D-alpha and D-beta/aspartic acid on the properties of the peptide. The hydrophobicity, circular dichroism and insulin aggregation are greatly altered by the isomerization. Analysis of Radiation-induced Structural and Functional Changes around the Aspartic Acid Residues in a Protein, report an attempt to develop a method to prepare the protein with isomerized Asp residue at a specific site of aA-cry with protein ligation, which is unsuccessful. Radiation-induced Damage of Biomolecules and Its Protective Mechanism, report the effect of gamma-ray on linolenic acid and its modification by beta-carotene as carotenoids localize in the membrane lipid and participate in the radiation resistance of bacteria. The pigment is suggested to work protective against damages of biomolecules and to be under strict regulation for its intracellular level. Modeling of D-aspartic Acid Accumulation in a Protein and Its Mechanistic Regulation by the Degrading Enzyme of the Amino Acid, report the role of D-aspartyl endopeptidase, found by authors (DAEP) and dynamics of D-Asp containing protein in superoxide dismutase-deleted mice and in HepG2 cells exposed to H2O2. DAEP is suggested to be damaged by the oxidizing stress, which results in the accumulation of D-Asp containing protein possibly leading to acceleration of senescence. Dynamics and Working Mechanism of a Complicated and Huge Protein Complex, report the analysis of yeast 20S and 26S proteasome assembly using the diffusion, X-ray and small-angle neutron scattering. In Situ Observation and Analysis of Dynamics of Aggregation/Dissociation of Proteins, report that the subunit exchange between 1H- and 2H-double rings of each 7-aggregated ring of proteasome alpha7 subunit is measurable by small-angle neutron scattering alone. Comparison of Conformational Changes of Tryptophanase Induced by Ammonium Phosphate and Gamma-ray Irradiation, report that tryptophanase becomes active to D-tryptophan when exposed to the phosphate salt, but does not by 138-1106 Gy gamma ray despite a circular dichroism shift. (T.T.)

  3. Radionuclides release from re-irradiated fuel under high temperature and pressure conditions. Gamma-ray measurements of VEGA-5 test

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Akihide; Kudo, Tamotsu; Nakamura, Takehiko; Kanazawa, Toru; Kiuchi, Toshio; Uetsuka, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The VEGA (Verification Experiments of radionuclides Gas/Aerosol release) program is being performed at JAERI to clarify mechanisms of radionuclides release from irradiated fuel during severe accidents and to improve source term predictability. The fifth VEGA-5 test was conducted in January 2002 to confirm the reproducibility of decrease in cesium release under elevated pressure that was observed in the VEGA-2 test and to investigate the release behavior of short-life radionuclides. The PWR fuel of 47 GWd/tU after about 8.2 years of cooling was re-irradiated at Nuclear Safety Research Reactor (NSRR) for 8 hours before the heat-up test. After that, the two pellets of 10.9 g without cladding were heated up to about 2,900 K at 1.0 MPa under the inert He condition. The experiment reconfirmed the decrease in cesium release rate under the elevated pressure. The release data on short-life radionuclides such as Ru-103, Ba-140 and Xe-133 that have never been observed in the previous VEGA tests without re-irradiation was obtained using the {gamma} ray measurement. (author)

  4. Irradiation effect of 60Co gamma rays on bulk etch rate, track etch rate and activation energy of CR-39 solid state nuclear track detector

    International Nuclear Information System (INIS)

    Solid State Nuclear Track Detectors (SSNTDs) are extensively used for registering nuclear tracks (Fleischer, Price and Walker 1975. CR-39 is one of the most commonly used as SSNTDs. CR-39 is transparent in visible spectrum and combines an exceptional range of qualities which are not available in other SSNTDs. Gamma irradiation in CR-39 yields cross-linking and chain scission. Due to cross-linking, etch rate decreases. If the probability of cross-linking reaction is larger than chain scission, the material would become hardened. In chain scission process, emission of atoms and molecules (CO, CO2, and H2) occurs as a result of cut in the long chain. This process softens the material which increases etch rate. It is well known that track registration properties of latent tracks are affected by exposing such detectors to gamma rays radiation. The effect of gamma irradiation on CR-39 with and without gamma dose before and after irradiation with 241Am source, have been studied

  5. Gamma-Ray Bursts

    OpenAIRE

    Rau, Arne

    2012-01-01

    Gamma-ray bursts are the witnesses of stellar explosions at cosmological distances and among the most energetic phenomena in the Universe. Here I present a study of the population of Gamma-ray bursts from three different observational aspects. (i) The prompt gamma-ray emission was investigated based on the event sample detected with the anti-coincidence shield of the spectrometer on-board the INTEGRAL satellite. (ii) The afterglow phase and the underlying host galaxies at optical and near-inf...

  6. Study of uptake and endocytosis of gamma rays-irradiated crotoxin by mice peritoneal macrophages; Avaliacao do mecanismo de captacao e endocitose de crotoxina submetida a acao da radiacao, por macrofagos peritoneais de camundongos

    Energy Technology Data Exchange (ETDEWEB)

    Cardi, Bruno Andrade

    1999-07-01

    The purpose was to investigate the uptake and endocytosis of 2000 Gy {sup 60}Co irradiated crotoxin through mouse peritoneal macrophages, correlating with native one and another non related protein, the ovalbumin. Native (CTXN) or 2000 Gy {sup 60} Co {gamma}-rays (dose rate 540 Gy/hour) irradiated crotoxin (CTXI) or ovalbumin processed of same manner (OVAN - OVAI) were offered to mouse peritoneal macrophages and their uptake was evaluated by immunohistochemistry and quantitative in situ ELISA. The involvement of scavenger receptors (ScvR) was evaluated by using blockers drugs (Probuco-PBC or Dextran Sulfate - SD) or with nonspecific blocking using fetal calf serum (FBS). The morphology and viability of macrophages were preserved during the experiments. CTXI showed irradiation-induced aggregates and formation of oxidative changing were observed on this protein after gamma rays treatment. By immunohistochemistry we could observe heavy stained phagocytic vacuole on macrophages incubated with CTXI, as compared with CTXN. Quantitatively by in situ ELISA, the sema pattern was observed, displaying a 2-fold CTXI incorporation. In presence of PBC or SD we could find a significant decrease of CTXI uptake but not of CTXN. However the CTXN uptake was depressed by FBS, not observed with CTXI. OVA, after gamma rays treatment, underwent a high degradation suffering a potent incorporation and metabolism by macrophages, with a major uptake of OVAI in longer incubation (120 minutes). Gamma rays ({sup 60} Co) produced oxidative changes on CTX molecule, leading to a uptake by ScvR-mice peritoneal macrophages, suggesting that the relation antigen-presenting cells and gamma rays-modified proteins are responsible for the better immune response presented by irradiated antigens. (author)

  7. Comparative effect of gamma-rays and ultraviolet irradiation on sensitivities and mutation induction of escherichia coli

    International Nuclear Information System (INIS)

    Three strains of Escherichia coli, B1, B2 and B/r were irradiated with ?-rays and ultraviolet rays. E. coli B1 and B2 were isolated from E. coli B. They were inoculated on either Tryptone agar or Glucose-NH4 agar plates to observe the comparative sensitivities to the irradiations. UV irradiation was more effective for the inactivation of cells than ?-rays irradiation in all strains when compared at the same absorbed energy. The sensitivities to the irradiations were in the order of E. coli B1, B2 and B/r by both irradiations. Higher sensitivities were observed when inoculated on Glucose-NH4 agar plates than on Tryptone agar plates. Induction of mutation was also studied on lac-mutant and auxotroph. MacConkey agar plates were used to distinguish the lac-mutant from the wild type; the mutant showed whitish colonies compared to the reddish purple colonies by wild type. Auxotroph was distinguished from the wild type which formed colonies on Glucose-NH4 agar plate, while the auxotroph colonies were made after adding casamino acid onto Glucose-NH4 agar plates. Induction of lac-mutant and auxotroph by ?-irradiation was the most frequent in E. coli B/r when compared at the same survival fraction of 10-4. Induction of mutation occurred more frequently by ?-irradiation than by UV-irradiation, and more stable mutants were obtained by ?-irradiation. (J.P.N.)

  8. Gamma-ray irradiation effects on corrosion rates of stainless steel in boiling nitric acid containing ionic additives

    International Nuclear Information System (INIS)

    Irradiation effects of ?-rays on corrosion rates of type 304ULC stainless steel in 9 x 10-3 mol/m3 boiling nitric acid containing an ionic additive of multivalence elements of Ce(IV), Cr(VI) or Ru(III) were studied by measuring weight losses of specimens immersed under the 60Co ?-ray irradiation of 1 kC/(kg·h) (4 MR/h). Tests without irradiation were carried out as well to obtain reference data. All the coexisting ionic species enhanced the corrosion in comparison with those in pure nitric acid, and the ?-ray irradiation moderated the enhancement. The valence analyses of these additives and redox potential measurements before and after the immersion batch under the irradiation suggested that the reduction of Ce(IV) and Cr(VI) induced by the irradiation have moderated the corrosion environment. (author)

  9. Correlation between radiation-induced defects, and optical properties of pure fused silica-core optical fiber, under gamma-ray irradiation in air at 1273 K

    International Nuclear Information System (INIS)

    Radiation-induced effects on optical properties such as thermoluminescence and optical absorption of pure fused silica-core optical fibers were investigated in situ under gamma-ray irradiation at 0.16 mGy/s and 1273 K in air. The intensities of broad optical transmission peaks below 900 nm decreased due to appearances of non-bridging oxygen hole center (NBOHC), oxygen deficiency centers (ODCs), and optical leakage with increasing annealing time. The intensities of optical absorption and luminescence characteristics peaks at 1390 nm were enhanced by the increment of Si-OH concentration due to the reaction of water vapor or hydrogen with NBOHC, ODCs, and SiO2 glass network. In addition, high resolution-transmission electron microscopy (HR-TEM) showed that SiO2 crystals approximately 10 nm in diameter were formed in the clad and core of the irradiated optical fiber. The crystallization of the SiO2 glass network had greater influence on the optical transmission and luminescence properties.

  10. The effect of pre-heating and pre-irradiation with gamma-rays on thermal annealing in-bis-[n-benzoil-n-(o) tolylhydroxylaminate] cooper (II)

    International Nuclear Information System (INIS)

    The main purpose of this work was to make a contribution on the study of the chemical effects of the (N,?) reaction on copper chelate. The influence of some factors such as pre-heating and pre-irradiation with gama-rays on the retention and thermal annealing of bis [N-benzoyl-N-(o)tolylhydroxylaminate] copper (II) was investigated. The complex was synthesized and later characterized by means of: determination of the melting-point, elemental analysis, infra-red and visible range absortion spectrophotometry. The compound was heated and also irradiated with gamma-rays in order to verify the effect of thermolysis on the retention. It seems that heat and gamma-radiaition can produce deffects which will lower the susceptibility of the compound to thermal annealling. On the basis on the model envolving electronic species some explanation of ours results were made and a mechanism was proposed for the retention and thermal annealing assuming the capture of free electrons and also the existence of holes. (author)

  11. Correlation between radiation-induced defects, and optical properties of pure fused silica-core optical fiber, under gamma-ray irradiation in air at 1273 K

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, B., E-mail: btsuchiya@meijo-u.ac.jp [Department of General Education, Faculty of Science and Technology, Meijo University (Japan); Kondo, S.; Tsurui, T. [Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577 (Japan); Toh, K. [Tokai Research Establishment, Japan Atomic Energy Agency, Tokai-mura, Ibaraki-ken 319-1195 (Japan); Nagata, S.; Shikama, T. [Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2011-10-01

    Radiation-induced effects on optical properties such as thermoluminescence and optical absorption of pure fused silica-core optical fibers were investigated in situ under gamma-ray irradiation at 0.16 mGy/s and 1273 K in air. The intensities of broad optical transmission peaks below 900 nm decreased due to appearances of non-bridging oxygen hole center (NBOHC), oxygen deficiency centers (ODCs), and optical leakage with increasing annealing time. The intensities of optical absorption and luminescence characteristics peaks at 1390 nm were enhanced by the increment of Si-OH concentration due to the reaction of water vapor or hydrogen with NBOHC, ODCs, and SiO{sub 2} glass network. In addition, high resolution-transmission electron microscopy (HR-TEM) showed that SiO{sub 2} crystals approximately 10 nm in diameter were formed in the clad and core of the irradiated optical fiber. The crystallization of the SiO{sub 2} glass network had greater influence on the optical transmission and luminescence properties.

  12. Degradation of transport critical current of Y123 and Bi(Pb)2223 HTSC ceramics under gamma-ray irradiation

    International Nuclear Information System (INIS)

    The relations of a transport critical current of high-temperature superconductors Bi(Pb)2223 and Y123 from fluence a gamma - quantum Co60 are investigated. It is established, that the reduction Jc for both materials happens in the same interval of dozes of irradiation. It can testify about unified mechanism of radiation damage in Bi(Pb)2223 and Y123 ceramics. The changes of relations of a critical current from an external magnetic field at irradiation a gamma - quantum show, that diamagnetic properties of both materials are less sensitive to irradiation, on a comparison with a critical current

  13. Radiosensitizing effect of nitric oxide in tumor cells and experimental tumors irradiated with gamma rays and proton beams

    International Nuclear Information System (INIS)

    Nitric oxide (NO) has been reported to be a radiosensitizer of mammalian cells under hypoxic conditions. In a previous study, we demonstrated an enhancement in radiation response induced by NO in mouse tumor cells under aerobic conditions, with an increasing effect as a function of malignancy. The aim of the present study was to evaluate the effect of NO in tumor cells and in experimental tumors irradiated with ? rays and proton beams. Irradiations were performed with a 137Cs ? source and with proton beams generated by the TANDAR accelerator. Tumor cells were treated with the NO donor DETA-NO and the sensitizer enhancement ratio (SER) was calculated using the ? parameter of the survival curve fitted to the linear-quadratic model. Tumor cells irradiated with protons were radio sensitized by DETA-NO only in the more malignant cells irradiated with low LET protons (2.69±0.08 keV/?m). For higher LET protons there were no radiosensitizing effect. For human tumor cells pre-treated with DETA-NO and irradiated with ? rays, a significantly greater effect was demonstrated in the malignant cells (MCF-7) as compared with the near normal cells (HBL-100). Moreover, a significant decrease in tumor growth was demonstrated in mice pre-treated with the NO donor spermine and irradiated with ? rays and low LET protons as compared with mice irradiated without pre-treatment with the NO donor. In conclusion, we demonstrated a differential effect of NO as a radiosensitizer of malignant cells, both with ? rays and low LET protons. This selectivity, coupled to the in vivo inhibition of tumor growth, is of great interest for the potential use of NO releasing agents in radiotherapy. (author)

  14. Effect of dose rate on inactivation of microorganisms in spices by electron-beams and gamma-rays irradiation

    International Nuclear Information System (INIS)

    Total aerobic bacteria in spices used in this study were determined to be 1 x 106 to 6 x 107 per gram. A study on the inactivation of microorganisms in spices showed that doses of 6-9 kGy of EB (electron-beams) or ?-irradiation were required to reduce the total aerobic bacteria to below 103 per gram. However, a little increase of resistance was observed on the inactivation of total aerobic bacteria in many spices in case of EB irradiation. These differences of radiation sensitivities between EB and ?-rays was explained by dose rate effect on oxidation damage to microorganisms from the results of radiation sensitivities of Bacillus pumilus and B. megaterium spores at dry conditions. On the other hand, these high dose rate of EB irradiation suppressed the increase of peroxide values in spices at high dose irradiation up to 80 kGy. However, components of essential oils in spices were not changed even irradiated up to 50 kGy with EB and ?-rays. (author)

  15. Effect of dose rate on inactivation of microorganisms in spices by electron-beams and gamma-rays irradiation

    Science.gov (United States)

    Ito, Hitoshi; Islam, Md. Shamsul

    1994-06-01

    Total aerobic bacteria in spices used in this study were determined to be 1 × 10 6 to 6 × 10 7 per gram. A study on the inactivation of microorganisms in spices showed that doses of 6-9kGy of EB (electron-beams) or ?-irradiation were required to reduce the total aerobic bacteria in many However, a little increase of resistance was observed on the inactivation of total aerobic bacteria in many spices in case of EB irradiation. These difference of radiation sensitivities between EB and ?-rays was explained by dose rate effect on oxidation damage to microorganisms from the results of radiation sensitivities of Bacillus pumilus and B. megaterium spores at dry conditions. On the other hand, these high dose rate of EB irradiation suppressed the increase of peroxide values in spices at high dose irradiation up to 80 kGy. However, components of essential oils in spices were not changed even irradiated up to 50 kGy with EB and ?-rays.

  16. On-line bulk analysis of raw material in a cement plant using the neutron irradiation and capture gamma ray technique

    International Nuclear Information System (INIS)

    In collaboration with Ciments Lafarge, the Laboratoire central des ponts et chaussees (LCPC) has developed a technique, involving neutron irradiation, for on-line bulk analysis of raw material quality, along the input line to a cement plant, by determining the quantities of the following elements: calcium, silicon, aluminium and iron. A system was constructed and tested in a cement plant under actual service conditions. The system consists of a sampler placed on the on-stream line supplying the plant at a rate of 1000 t/h. An analysing hopper incorporating a neutron irradiation system, consisting of a 14 MeV neutron generator tube, and a gamma ray detection system, comprising a NaI(Tl) scintillator associated with a photomultiplier, are coupled to this sampler. The system is fed continuously with the raw material to be analysed. Gamma radiation spectra supplied by the detector are analysed on two distinct measurement channels. One of these channels processes the nuclear radiation generated by neutron capture phenomena, while the other channel processes the nuclear radiation resulting from neutron activation phenomena. The data collected under the operating conditions mentioned above (i.e. in real time) allows readings to be obtained every 2 min for silicon, calcium, aluminium and iron as a result of the processing method applied to gamma capture and activation spectra. A comparison was made between these measurements and the results of an analysis of the same piles, conducted simultaneously through a sampling tower delivering at an hourly rate a sample analysed in accord with the X ray fluorescence process. Comparison of the results obtained from both analysis methods highlights the advantages of the neutron irradiation process. (author). 4 figs, 2 tabs

  17. A New Mutant for Yellow Mosaic Virus Resistance in Mungbean (Vigna radiata (L.) Wilczek) Variety SML-668 by Recurrent Gamma-ray Irradiation

    International Nuclear Information System (INIS)

    The mungbean variety SML-668 is early, high-yielding and large-seeded but susceptible to yellow mosaic virus (YMV) disease. To develop YMV resistance in SML-668, a mutation breeding programme has been undertaken. Seeds of SML-668 were irradiated with 600Gy Gamma-rays and planted in the field. Three thousand plants in M1 generation were harvested separately and planted in M2. Ninety lines showed sterility and only 10 lines showed mutants for chlorophyll, small seed size, short pod length, dwarf plant type and profuse branching, but there was no YMV-resistant mutant. All the mutants along with normal plants of the segregating lines were harvested separately in M2. In M3 generation 2,500 normal lines were planted as single plant progenies and screened for YMV resistance and did not observe any YMV resistant mutant. Hence, the normal M3 lines were made into two separate bulks and one bulk was irradiated with 500Gy as a recurrent irradiation and another was sown as it is. In M3M1 generation, a mutant showing very minor leaf symptoms for YMV, and without any pod symptoms was isolated. Th mutant was purified by growing up to M3M6 generations. All the mutant plants showed very minor leaf symptoms but no symptoms in the pod. The pods and seeds were normal and also gave normal yield as compare to highly resistant check where two recessive genes controlling resistance is reported. The susceptible plants showed leaf and pod symptoms an showed severe yield losses. This mutant was used in crossing programme to study the genetics of YMV resistance. (author)

  18. Study on the properties of blend rubber prepared with grafted rubber and irradiated rubber by Gamma Rays

    International Nuclear Information System (INIS)

    The blend rubbers were prepared by mixing ?-rays irradiated and monomer grafted rubbers. The monomers, methyl methacrylate (MMA) and styrene were used separately to prepare grafted rubber by exposure to radiation. The physico-chemical properties of the blend rubbers were evaluated. The tensile strength and elongation at break of the blend rubbers decrease whereas modulus at 500% elongation, swelling ratio and permanent set increase with the increased proportion of grafted rubber in the blend. The tear strength of the blend between irradiated and styrene grafted rubbers increases with the increased proportion of grafted rubber but that of the blend of irradiated and MMA grafted rubbers remains almost constant. The blend rubber could be used for special type of application like rubber thread, tube, catheter etc

  19. NewSUBARU polarized gamma-ray source

    International Nuclear Information System (INIS)

    Laser Compton scattering gamma-ray beam source was developed on BL01 of NewSUBARU synchrotron radiation facility. The gamma-ray beams were used for application experiments, a nuclear physics research, a nondestructive inspection of thick material, a magnet Compton scattering measurements, and nuclear transmutation research. Recently, new gamma-ray irradiation hutch was added to expand experimental area. Permission of radiation safety control for new hutch has been approved. In new hutch, gamma-ray photon energy of up to 76 MeV is available. Expected flux of quasi-monochromatic gamma-ray (16.7MeV, ?E/E?7.5%) is 6x105 ?/s using 10W Nd laser and 250 mA electron current. User application of this gamma-ray source will be started this fall. (author)

  20. Influence of irradiation with {gamma}-ray photons on the photoluminescence of Cd{sub 0.9}Zn{sub 0.1}Te crystals preliminarily subjected to the intense radiation of a neodymium laser

    Energy Technology Data Exchange (ETDEWEB)

    Glinchuk, K. D. [National Academy of Sciences of Ukraine, Lashkarev Institute of Semiconductor Physics (Ukraine); Medvid' , A. P.; Mychko, A. M. [Riga Technical University (Latvia); Naseka, Yu. M.; Prokhorovich, A. V.; Strilchuk, O. M., E-mail: strilchuk@isp.kiev.ua [National Academy of Sciences of Ukraine, Lashkarev Institute of Semiconductor Physics (Ukraine)

    2013-04-15

    The effect of the preliminary treatment of Cd{sub 0.9}Zn{sub 0.1}Te crystals with high-power pulses of neodymium laser radiation (the power density is {<=}1.8 MW/cm{sup 2}, at a wavelength of 532 nm) on the low-temperature (5 K) photoluminescence induced by {gamma}-ray radiation (the dose was {Phi}{sub {gamma}} = 5 kGy) is studied. The luminescence bands are related to radiation-stimulated donor-acceptor pairs, which include shallow neutral donors and neutral cadmium vacancies stimulated by {gamma}-ray irradiation, the transition of free electrons to neutral cadmium vacancies formed by radiation, and the annihilation of excitons bound to the above vacancies. It is shown that, in the crystals preliminarily treated with laser radiation, the intensity of the {gamma}-ray-stimulated luminescence bands is significantly lower than in crystals not subjected to laser radiation. This fact is accounted for by a decrease in the concentration of cadmium vacancies generated by the {gamma}-ray radiation as a result of their annihilation during the course of their interaction with laser-stimulated defects, in particular, as a consequence of their recombination at laser-stimulated interstitial cadmium atoms.

  1. Standard test method for determining the content of cesium-137 in irradiated nuclear fuels by high-resolution gamma-ray spectral analysis

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the determination of the number of atoms of 137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated (1). The determination of atom percent fission, uranium and plutonium concentrations, and isotopic abundances are covered in Test Methods E 267 and E 321. 1.2 137Cs is not suitable as a fission monitor for samples that may have lost cesium during reactor operation. For example, a large temperature gradient enhances 137Cs migration from the fuel region to cooler regions such as the radial fuel-clad gap, or, to a lesser extent, towards the axial fuel end. 1.3 A nonuniform 137Cs distribution should alert the analyst to the potential loss of the fission product nuclide. The 137Cs distribution may be ascertained by an axial gamma-ray scan of the fuel element to be assayed. In a mixed-oxide fu...

  2. Use of delayed gamma rays for active non-destructive assay of {sup 235}U irradiated by pulsed neutron source (plasma focus)

    Energy Technology Data Exchange (ETDEWEB)

    Andola, Sanjay; Niranjan, Ram [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kaushik, T.C., E-mail: tckk@barc.gov.in [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Rout, R.K. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kumar, Ashwani; Paranjape, D.B.; Kumar, Pradeep; Tomar, B.S.; Ramakumar, K.L. [Radioanalytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gupta, S.C. [Applied Physics Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2014-07-01

    A pulsed neutron source based on plasma focus device has been used for active interrogation and assay of {sup 235}U by monitoring its delayed high energy ?-rays. The method involves irradiation of fissile material by thermal neutrons obtained after moderation of a burst of neutrons emitted upon fusion of deuterium in plasma focus (PF) device. The delayed gamma rays emitted from the fissile material as a consequence of induced fission were detected by a large volume sodium iodide (NaI(Tl)) detector. The detector is coupled to a data acquisition system of 2k input size with 2k ADC conversion gain. Counting was carried out in pulse height analysis mode for time integrated counts up to 100 s while the temporal profile of delayed gamma has been obtained by counting in multichannel scaling mode with dwell time of 50 ms. To avoid the effect of passive (natural) and active (from surrounding materials) backgrounds, counts have been acquired for gamma energy between 3 and 10 MeV. The lower limit of detection of {sup 235}U in the oxide samples with this set-up is estimated to be 14 mg.

  3. Effects of gamma-ray irradiation on interspecific hybridization between Chamaecyparis obtusa S. et Z. and Chamaecyparis pisifera S. et Z

    International Nuclear Information System (INIS)

    C. obtusa S. et Z. is one of the most important forest trees in Japan, and possesses high wood quality. It adapts to dry or semi-dry planting sites, but when it is planted in humid and productive soil, physiological damage is often seen, and its woods are not resistant against termite harm. On the contrary, C. pisifera S. et Z. has high adaptability to humid and productive soil, and is resistant against termite harm. In order to improve the resistance of C. obtusa against diseases and insects, an attempt to obtain a hybrid between C. obtusa and C. pisifera has been made. However, it was found to be very difficult to obtain the hybrid because of low cross compatibility. Therefore, the radiosensitivity of reproductive organs and the induction of mutation in C. obtusa and C. pisifera, the cause of interspecific incompatibility between both species, and the possibility of breaking down the incompatibility were investigated. Also, the cytological screening of the hybrids between C. obtusa and C. pisifera was made. It was considered that the acute gamma-ray irradiation from 500 to 600 R on male flowers was optimum for the hybridization of the present purpose. All of the hybrids produced in this study were triploid. (Kako, I.)

  4. Cloning and molecular analysis of GA2ox1 gene mutation generated by gamma-ray 60Co irradiation in mutagenized Tamxoan - TDB06 rice cultivar

    International Nuclear Information System (INIS)

    In the present study, we have used various rice cultivars such as Nipponbare, Tamxoan Hai Hau and mutagenized TDB06 which was obtained from Tamxoan Hai Hau calli irradiated by gamma-ray 60Co with the aim of cloning, sequencing and investigating the molecular mutants of GA2ox1 gene which regulates the height of rice cultivars. Interestingly, we have found that the nucleotide sequence of GA2ox1 gene of mutagenized TDB06 is slightly changed compare to that of original Tamxoan Hai Hau and Nipponbare. The GA2ox1 gene sequence differences of mutagenized TDB06 compared to Tamxoan Hai Hau and Nipponbare are 9 and 2 nucleotides, respectively. We have also shown that the amino acid sequence of GA2ox1 protein is also different among various cultivars in which amino acids corresponding to positions 137 (Alanine), 167 (Threonine), 222 (Valine), 227 (Histidin) of mutagenized TDB06 were replaced with other amino acids Valine, Alanine, Arginine and Lysin, respectively. Nucleotide sequences of GA2ox1 gene isolated from mutagenized TDB06 and Tamxoan Hai Hau cultivars have been registered in Genbank/NCBI with accession numbers EF164903 and EF164904. Based on these initial results, we continuously isolate genes related to dwarf character, construct vectors and do transformation. This strategy can significantly contribute to improve efficiency of rice breeding in Vietnam. (author)

  5. Influence of Melatonin on The Ultrastructure of Posterior Midgut of Male Ceratitis Capitata (Wied.) Irradiated With Gamma Rays

    International Nuclear Information System (INIS)

    The basic architecture and organization of the posterior midgut epithelial cells in male med flies, Ceratitis capitata (Diptera, Tephtitidae), have been inspected after being subjected to sterilizing dose of gamma radiation (90 Gy). Their midgut cells damages were monitored by means of electron microscope. The treated cells were swollen and have slight vacuolation and increase of vesicles. The ground cytoplasm contained large vacuoles of myelinoid bodies, slight irregularity of few RER, lipid droplets and multi vesicular bodies. Some mitochondria were polymorlyphic owing to swelling of membrane or fusion together to form various shapes. Midgut epithelial cells of insects pre-treated with melatonin prior to gamma irradiation showed approximately normal structures, and preservation could be observed. The combined treatment by irradiation and melatonin could be successfully used to reduce the adverse effects of irradiation and subsequently can be used in the integrated pest management to help in the success of the sterile insect technique against the insects as well as to minimize complications of irradiation on sensitive non-target organs. This has many applications during radiotherapy for patients with cancer

  6. The early response of pineal N-acetyltransferase activity, melatonin and catecholamine levels in rats irradiated with gamma rays

    International Nuclear Information System (INIS)

    Male Wistar rats adapted to an artificial light-dark regimen were whole-body gamma-irradiated with a dose of 14.35 Gy. Irradiation, sham-irradiation and decapitation 30, 60 and 120 min after the exposure were performed between 2000 h and 0100 h in the darkness. The serotonin N-acetyltransferase activity (NAT), the concentration of melatonin and corticosterone were also determined. Ionizing radiation did not change the activity of NAT, the key enzyme of melatonin synthesis; however, it decreased the concentration of pineal melatonin. The concentration of pineal dopamine and norepinephrine decreased 30 and 120 min after exposure, while the concentration of epinephrine was elevated 30 min after irradiation, though later it was markedly decreased. The serum melatonin level was not changed but an increase in corticosterone level was observed. In the early period after exposure a decrease in pineal melatonin occurred, accompanied by a decrease in pineal catecholamines. On the contrary, in the phase of developed radiation injury the signs of increased melatonin synthesis were observed on days 3 and 4 after the exposure. (author) 6 figs., 25 refs

  7. Thermo-mechanical characteristics of UV-irradiated polyurethane elastomers extended with ?, ?-alkane diols

    International Nuclear Information System (INIS)

    A series of polyurethane elastomers were prepared by the reaction of poly ?-caprolactone and 4,4'-diphenylmethane diisocyanate. The prepolymer was extended using ?, ?-alkane diols as chain extenders having 2-10 methylene units in their structure. The synthesized samples were irradiated for 50, 100 and 200 h in an ultra violet (UV) exposure unit. Modifications in the chemical structure before and after irradiation were characterized using Fourier Transform Infrared spectroscopy. The thermal and mechanical properties were affected by the ultra violet irradiation time and the number of methylene units in the chain extenders. The experimental results indicated that the morphological structure changed during irradiation as a consequence of hard segment and soft segment degradation.

  8. Thermoluminescence, thermoluminescence emission and optical absorption of CsI:Pb2+ crystals irradiated with gamma rays

    International Nuclear Information System (INIS)

    Thermoluminescence, thermoluminescence emission and optical absorption studies have been made in lead doped cesium iodide crystal. Unirradiated crystal gives rise to optical absorption bands at 275, 230, 225 and 213 nm which are identified as the A,B,C,D, bands respectively of the lead impurity. The bands formed on irradiation at 382 nm and 331 nm are attributed to the Pb+ and Pb centres formed on irradiation. The TL glow curves show a peak at 383 K and a shoulder at 423 K. The peak at 383 K has emission at 330, 450 and 550* nm while the shoulder at 423 K has emission at 550 nm only. These peaks are attributed to Pb+ and Pb 0. (author). 15 refs., 5 figs

  9. Effect of spermidine on the survival of saccharomyces cerevisiae cells irradiated with different doses of gamma rays

    International Nuclear Information System (INIS)

    Saccharomyces cerevisiae cells were used to test the radioprotective effect of added spermidine [H3N(CH2)3NH2(CH2)4NH3]3+ as one of the natural polyamines that are essential for cell life. Spermidine plays an important role in suppressing radiation damages at certain concentration (10-5M/L), either via scavenging free radicals or via reducing the frequency of radiation - induced mutations. Spermidine increased noticeably the D10 value at concentration of 10-5 M/L compared with the other two used concentrations of 10-6 and 10-4 M/L. Applying spermidine before irradiation was more effective than applying it after irradiation. (author)

  10. Thermoluminescence characteristics of Nd-doped SiO2 optical fibers irradiated with the 60Co gamma rays

    International Nuclear Information System (INIS)

    Thermoluminescence (TL) properties (radiation sensitivity, dose response, signal fading) of Nd-doped SiO2 optical fibers irradiated with 1.25 MeV photons to 1–50 Gy were studied. The peak of the glow curve is around 190 °C regardless of the dose. The dose response is linear up to 50 Gy. The radiation sensitivity is 219 nC mg?1 Gy?1. The fiber can be a potential candidate for photon radiotherapy dosimetry due to its high radiation sensitivity, linear dose response in a wide range, slow fading, and high spatial resolution due to the small size of the fiber. - Highlights: • First study of Nd+3 doped optical fibers irradiated by 1250 keV gamma radiation. • Linear response of optical fiber doped with neodymium. • The peak intensity of TL response for 60 Gy is twice that of the 30 Gy. • A potential candidate for photon radiotherapy dosimetry

  11. Resveratrol effects on life span and fertility of caenorhabditis elegans subject to 60Co gamma ray irradiation

    International Nuclear Information System (INIS)

    Caennorhabditis elegans was used as experimental model to investigate radiation effect of resveratrol on caenorhabditis elegans irradiated by 60Co ? ray. Treatment with resveratrol can increase average life span and spawning rate, improve the survival rate of eggs, and protect their mitochondrion function of caenorhabditis elegans exposure to 60Co ? ray. The results indicate that resveratrol has radiation protection effects, which might be related to its action on ROS decrease and mitochondrial defend. (authors)

  12. Changes in the microflora of Vienna sausages after irradiation with gamma-rays and storage at 10 deg C

    International Nuclear Information System (INIS)

    The species of microorganisms which can grow on commercial viennas on the storage at 10 deg C were Lactobacillus, Streptococcus and yeasts. When the viennas specially made which did not contain preservatives in it were used for this investigation, growth of microorganisms such as Lactobacillus, Streptococcus, Micrococcus, Bacillus and yeasts were predominant on the storage at 10 deg C, and Pseudomonas and molds some time propagated. When smoked-viennas specially made for the National Project were used for preservation, growth of microorganisms consisted mainly of the species of Lactobacillus, Micrococcus, Acinetobacter, Flavobacterium, Streptococcus, Serratia, Corynebacterium and yeasts. Irradiation of viennas at 300 and 500 krad reduced the aforementioned flora to the Lactobacillus, Streptococcus, Acinetobacter and yeasts. The number of microorganisms on the viennas packed with nitrogen gas was not increased for 3 to 7 days by means of 300 krad irradiation, and extended the storage-life 2 to 3 times. When irradiated with a dose of 500 krad, the number of microorganisms was not increased for 9 to 14 days on the storage at 10 deg C. (author)

  13. Effect of condition of the water in cement paste for hydrogen gas generated by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Some low level radioactive wastes are required to be solidified with cementitious material in the package. The hydrogen gas is generated from cementitious material by the radiolysis. The irradiation experiment was made to estimate the amount of hydrogen gas generation from cement paste by classified water in cement paste into two kinds that were the free water and the chemically combined water. The G values of the hydrogen gas ranged from 0.06 to 0.12 in powdered sample and from 0.08 to 0.15 in solid sample. The free water in the cement paste was found to be the main source to generate hydrogen gas by the irradiation, and the chemically combined water in cement paste can be ignored in the hydrogen gas generation. The G value of free water in the cement paste was 0.35±0.15. As the hydrogen gas generated from cement paste is calculated, it is computable by the use of G value of free water in cement paste for the amount of free water. The amount of the hydrogen gas generation is smaller than the hydrogen gas calculated by using the G value of 0.45 and by the assumption that all water in the cement sample was decomposed by irradiation. (author)

  14. Some aspects of the behavior at different ages of Ceratitis capitata (Wiedemann, 1824) (Diptera-Tephritidae) irradiated with gamma rays

    International Nuclear Information System (INIS)

    The present work was carried out in the laboratory of the Entomology Section of the Nuclear Energy for Agriculture Center (CENA) in Piracicaba, Sao Paulo state, Brazil, to determine the effects different gamma radiation doses on the reproductive potential of males and the flight behavior of Ceratitis capitata (Wied.). For all the treatments with gamma radiation a Cobalt-60 source type Gamma beam-650 was used, with activity of approximately 13,410 x 10B Bq. (4,967 Ci.), and the dose rate of 2.000 Gy per hour. The doses used were 80 Gy, 100 Gy and 120 Gy. The three doses employed affected more the longevity of males than the females and the number of spermatozoid found lower in the irradiated insects compared with the control, with no significant differences between doses. The insects irradiated with 80 Gy showed activity similar to the control population until four days after emergence: afterwards they were more active than the unirradiated. The gamma irradiation diminished the take-off ability of the insects. (author). 59 refs., 9 figs., 9 tabs

  15. Assessment of the radioprotective effects of amifostine and melatonin on human lymphocytes irradiated with gamma-rays in vitro

    International Nuclear Information System (INIS)

    Radioprotective effects of amifostine and melatonin on human peripheral blood irradiated with g-rays were investigated using the micronucleus (MN) assay and the analysis of sister chromatid exchanges (SCE). Duplicate blood samples were pre-treated with amifostine (7.7 mM), melatonin (2 mM) and their combination for 30 minutes. Negative controls were also included. After treatment with radioprotectors, one blood sample from each experimental group was exposed to g-rays from a 60Co source. The radiation dose absorbed was 2 Gy. Pre-treated irradiated blood samples showed a decrease in the total number of MN and in the number of cells with more than one MN. Moreover, they also showed significantly lower mean SCE values. Our results indicate that amifostine, melatonin and their combination in vitro have radioprotective effects on g-irradiated human peripheral blood lymphocytes, with no significant genotoxicity. Therefore, it may be reasonable to use them in combination, adjusting the doses of amifostine to achieve the best radioprotective effect with as few side effects as possible. Before employment, this combination should be extensively tested in vitro and in vivo, using the same and other biomarkers for different radiation dose and concentration ranges of both radioprotectors.(author)

  16. Studies into the variability in the tryptophan content induced by irradiation with gamma rays for different wheat varieties

    International Nuclear Information System (INIS)

    Air dry seeds of three wheat varieties - Sadovo 1, Ludogorka and Altimir 67 were 10 and 15 krad irradiated. The crude protein and tryptophan content was determined in M2 plants and compared with non-irradiated control plants. It was established that the three varieties under study show different reaction to gamma radiation. The crude protein and tryptiphan content in the M2 plants of the Sadovo 1 and Altimir 67 varieties after 10 krad irradiation was negative compared to the average one. After 15 krad radiation the average crude protein and tryptiphan content in the Altimir 67 M2 plants was negligably different from the control ones. The M2 Altimir 67 plants average crude protein and tryptophan content after 15 krad radiation is higher than the control one e.g. it is not negative. With a view of selection the M2 plants of Sadovo 1 and Altimir 67 varieties prove more suitable taking into consideration the crude protein and tryptophan content changes. (authors)

  17. Identification of gamma ray irradiated and unirradiated foodstuffs by electron spin resonance (ESR) and thermoluminescence (TL) techniques

    International Nuclear Information System (INIS)

    In this study, the identification of irradiated food samples containing cellulose, bone and sugar was done by Electron Spin Resonance (ESR) technique. The change of ESR signal intensities using in this identification process with radiation dose and storage time was followed. The radiation induced ESR signal intensities of sugar, green tea, sage tea, lentil and shrimp samples increased with increasing dose. It was not observed any significant change on the ESR signal intensities of sugar samples with storage time at ambient temperature. But the radiation induced ESR signal intensities for the other samples decreased with time at ambient temperature. In this work, for red lentil samples, the changes of ESR spectral parameters of heat-induced free radical ESR signals with heating temperatures were also investigated. It has investigated also that whether a possible radiation treatment could be identified of red pepper samples sold in Turkish markets using Thermoluminescence method which have been adopted or proposed TS EN 1788:2007 Standard (Foodstuffs-Detection of Irradiated Food From Which Silicate Minerals Can be Isolated-Method by Thermoluminescence). Firstly, the glow curve of silicate minerals isolated from the red pepper samples has been recorded (TL1), and after a subsequent exposure of the already measured minerals to a defined radiation gamma dose (1kGy) has been recorded as a second glow curve (TL2). It has been concluded that the red pepper samples have not been irradiated evaluating the glow curve shapes and the TL glow ratios (TL1/TL2).

  18. Influence of the molecular modifications on the properties of EPDM elastomers under irradiation

    International Nuclear Information System (INIS)

    The degradation of the mechanical behaviour of EPDM elastomers used as cable insulation materials has been investigated by mechanical spectroscopy and tensile tests for different formulations: unvulcanised EPDM, vulcanised and stabilised elastomer with an antioxidant. In all cases, ?-irradiation of EPDM under oxygen leads to a reduction of the molecular mobility indicated by the shift of the glass transition relaxation temperature towards higher temperatures. Moreover, the molecular flow occurring above Tg is suppressed after irradiation for the unvulcanised EPDM providing evidence of cross-linking. The competition between cross-linking and chain scissions is shown by the decrease of the storage modulus above the crystallites melting temperature (?40 deg. C) at doses larger than 100 kGy. A strong increase of the Young modulus and reduction of the elongation at break of the non-vulcanised EPDM becoming more brittle are shown by stress/strain characterisations performed at 80 deg. C. At the opposite vulcanised EPDM exhibits higher elongation at break after crystallites melting. This evolution is interpreted by the competition between cross-linking and chain scissions, being hindered by the crystallites at room temperature. The intrinsic irradiation effects can be isolated after crystallite melting. The reduction of the molecular mobility can be explained by a chemi-crystallisation process assisted by chain scissions, leading to a more rigid phase upon irradiation

  19. Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

    Energy Technology Data Exchange (ETDEWEB)

    May, J.C. E-mail: may@cber.fda.gov; Rey, L. E-mail: louis.rey@bluewin.ch; Lee, C.-J.; Arciniega, Juan

    2004-10-01

    Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine.

  20. Evaluation of components of X-ray irradiated 7-valent pneumococcal conjugate vaccine and pneumococcal vaccine polyvalent and X-ray and gamma-ray irradiated acellular pertussis component of DTaP vaccine products

    International Nuclear Information System (INIS)

    Samples of pneumococcal vaccine polyvalent, 7-valent pneumococcal conjugate vaccine, and two different diphtheria and tetanus toxoids and acellular pertussis vaccines adsorbed were irradiated with X-rays and/or gamma-rays (Co-60). Mouse IgG and IgM antibody responses (ELISA) for types 9V, 14, 18C, and 19F pneumococcal polysaccharides and conjugates indicated that the polysaccharides were more tolerant of the radiation than the conjugates. The mouse antibody response for the detoxified pertussis toxin (PT) antigen, filamentous hemagglutinin antigen (FHA), pertactin (PRN), and fimbriae types 2 and 3 (FIM) antigens for the appropriate vaccine type indicated that the antibody response was not significantly changed in the 25 kGy X-ray irradiated vaccines frozen in liquid nitrogen compared to the control vaccine

  1. Study of the ionization of alkane-electron scavenger reactant mixtures irradiated by 60Co gamma rays

    International Nuclear Information System (INIS)

    This study deals with ionization of alkane-electron scavenger reactant mixtures, irradiated by 60Co ?-rays. It is shown that the extrapolated free-ion yields (extrapolated yield method) decrease with the reactant concentration. On the basis of ONSAGER model and theoretical treatment of MOZUMDER, the cross sections of epithermal electron attachment in hexane, cyclohexane, 2,2-dimethylbutane, cyclopentane, 2,2,4-trimethylpentane for CCl4, C7F14, C6H5Br, C6H5Cl, C6F14, (C6H5)2 are determined. A comparison between gas-phase and liquid-phase cross sections is established

  2. Mechanical properties and failure surfaces of gamma-ray irradiated systems based on thermoplastic 1,2 polybutadiene

    Science.gov (United States)

    Bhagawan, S. S.; Kuriakose, B.; De, S. K.

    The effect of 60Co gamma-radiation on the mechanical properties of clay filled and unfilled 1,2 polybutadiene (1,2 PBD) and 1,2 PBD-natural rubber (NR) blends has been investigated. In the case of blends the effects on blend ratio and filler have been studied with reference to absorbed radiation dose varying from 0.1 to 100 Mrad at room temperature. Radiation was found to transform the flexible samples to brittle and rigid materials especially at high dose levels. The stress-strain behaviour, tensile strength, elongation, tension set and crosslink density were found to be markedly affected at dose levels of 10 Mrad and above. On irradiation 1,2 PBD was found to undergo predominantly crosslinking while the blends exhibited both crosslinking and chain scission due to the presence of NR. The tensile fracture surfaces of the irradiated samples were examined by scanning electron microscope (SEM) in order to gain insight into the mechanism of failure.

  3. The Effect Of SEA On Long Tail Monkeys (Macaca Fascicularis) Lymphocyte Culture Gamma Ray-Irradiated In Vitro

    International Nuclear Information System (INIS)

    Staphylococus enteroxine (SEA) is one of toxins produced by the bacterium Staphylococus aureus. In the culture, SEA has proven as a potent stimulator of lymphocytes in man event at fg/ml concentrations. This research studied the effect of SEA compared to Phytohaemagglutinine (PHA) on the peripheral blood lymphocytes culture of the long-tail monkeys. About 5 ml blood was collected from 5 monkeys and irradiated using Gamma Cell-220 P3TIR with doses of 0 (control); 1.0; 2.0; 3.0 and 4.0 Gy. The blood samples were cultured in the appropriate growth medium based on standard procedure and added with 1.0 ml (0.5 mug/ml) SEA or 0.15 ml PHA. The cultures were then incubated for 96 hours and prepared the slides. The results showed that on the unirradiated peripheral blood lymphocytes of long-tail monkeys the mitotic indices obtained using PHA and SEA are relatively similar. On the irradiated lymphocytes with doses of 1-3 Gy, the mitotic indices using SEA are relatively higher than that of PHA. Dose responses of dicentric, ring and acentric fragment of both PHA and SEA are relatively the same

  4. Morphological variation in the 7th generation soybean mutant lines irradiated by gamma ray under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    M. Younessi Hamzehkhanlu

    2012-06-01

    Full Text Available Genetic diversity is the base of plant breeding. Hence, 33 M7 soybean mutant lines, which were evolved by ? ray from cultivar L17 irradiated with doses of 150, 200 and 250 Gray (absorbed dose, with L17 cultivar and two commercial cultivars (Clark and Williams were evaluated in view of some morphological traits (number of leaves/plant, pods/plant, seeds/pod, seeds/plant, 100-seed weight, dry weight of aerial parts, dry weight of roots, plant yield, harvest index, nodules/root and dry weight of nodules under completely randomized design with three replications in greenhouse of Agricultural, Medical and Industrial Research School, Nuclear Science and Technology Research Institute, Atomic Energy Organization of Iran, Karaj, Iran. All traits in the studied mutant lines, except number of seeds per pod, showed a significant difference at ?=1% and ?=5% in comparison with L17 and commercial cultivars. Mutant line number 13 (M13 was recognized as the top line in view of the studied traits. Seed yield per plant showed the highest correlation (0.886 with harvest index (P<0.01. Cluster analysis of the studied traits along with Ward method resulted in separation of the lines into four independent groups. It can be inferred from the results that irradiation did induce significant genetic variability with regard to majority of the studied traits, such as number of nodules per plant and harvest index.

  5. Gamma ray calibration system

    International Nuclear Information System (INIS)

    This invention is in the field of gamma ray inspection devices for tubular products and the like employing an improved calibrating block which prevents the sensing system from being overloaded when no tubular product is present, and also provides the operator with a means for visually detecting the presence of wall thicknesses which are less than a required minimum. (author)

  6. Effect of pelvic irradiation of lactose absorption. [. gamma. rays or x rays were used in gynecologic malignancy therapy

    Energy Technology Data Exchange (ETDEWEB)

    Stryker, J.A.; Mortel, R.; Hepner, G.W.

    1978-01-01

    Twenty-four patients undergoing pelvic irradiation for gynecologic malignancies had /sup 14/C-lactose breath tests performed in the first and fifth weeks of their treatment. The /sup 14/C-lactose breath test was performed by administering 2 ..mu..Ci of /sup 14/C-lactose by mouth along with 50 g of lactose. Breath samples were collected in ethanolic hyamine 1, 2, and 3 hr later; the radioactivity of the trapped /sup 14/CO/sub 2/ was determined by liquid scintillation spectroscopy. In the first week of treatment the percentage of administered /sup 14/C excreted as /sup 14/CO/sub 2/ at 1, 2, and 3 hr was 1.7 +- 0.8% (mean +- SD), 4.5 +- 1.6%, and 5.8 +- 1.4%, respectively. In the fifth week of treatment the 1-hr, 2-hr, and 3-hr values were 1.2 +- 0.9%, 3.6 +- 2.0%, and 4.7 +- 1.9%, respectively. The difference between the first week and fifth week test results at 1, 2, and 3 hr was statistically significant (t = 2.64, p < 0.02), (t = 2.24, p < 0.05), (t = 2.95, p < 0.01). There was a negative correlation between the 1-hr /sup 14/C-lactose breath test results in the fifth week and the stool frequency at that time (r = -0.44, p < 0.05). Seven of 12 patients whose 1 hr /sup 14/C-lactose breath test results in the fifth week were below normal (<1.2%) had nausea at that time. The data suggest that in some patients, lactose malabsorption as a result of the effect of radiation on small intestinal function may be etiologically related to the symptoms of nausea and diarrhea which occur commonly in patients who are undergoing pelvic irradiation. In addition, the results suggest that lactose-containing foods should be restricted in some patients who are undergoing pelvic irradiation to prevent symptoms resulting from radiation-induced lactose intolerance.

  7. Formation of radical cations and dose response of alpha-terthiophene-cellulose triacetate films irradiated by electrons and gamma rays

    CERN Document Server

    Emmi, S S; Ceroni, P; D'Angelantonio, M; Lavalle, M; Fuochi, P G; Kovács, A

    2002-01-01

    The radiation-induced UV-vis spectrum of alpha-terthiophene radical cation in solid is reported. The radical cation initiates an oligomerization in the CTA matrix producing permanently coloured conjugated polarons. The specific net absorbance at 465 nm is linearly related with dose up to 2x10 sup sup 6 sup sup G y, for electrons and gamma irradiation. The decrease of the UV typical absorption (355 nm) and of four IR bands of alpha-terthiophene is linear with dose, as well. Although sensitivity is influenced by dose rate, it turned out that a linear relationship holds between sensitivity and log dose rate, in the range from 2 to 10 sup sup 5 Gy, min. These findings suggest a potential application of the system for dosimetric purposes over a wide range of dose and dose rate.

  8. Effect of gamma-ray irradiated natural herbal extracts on NF-kB activation in HMC-1 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Soo; Lim, Youn Mook; Gwon, Hui Jeong; Choi, Bo Ram; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2009-12-15

    Recently, studies have documented various health benefits of some natural herbal extracts (NHE) such as Houttuynia cordata (H), Centella asiatica (C), Plantago asiatica (P), Morus alba L. (M), and Ulmus davidiana (U). The aim of the present study was to demonstrate the radiation effect on NF-kB activation of the NHE in the human mast cell line (HMC-1). The HMC-1 cells were stimulated with phorbol 12-myristate 13-acetate (PMA) plus A23187. Both non-and irradiated NHE also significantly inhibited the PMA plus A23187-induced nuclear factor NF-kB activation and also suppressed the expression of activation of NF-kB. These results indicated that the NHE exerted a regulatory effect on inflammatory reactions mediated by mast cells.

  9. Gamma rays from Galactic pulsars

    CERN Document Server

    Calore, Francesca; Donato, Fiorenza

    2014-01-01

    Gamma rays from young pulsars and milli-second pulsars are expected to contribute to the diffuse gamma-ray emission measured by the {\\it Fermi} Large Area Telescope (LAT) at high latitudes. We derive the contribution of the pulsars undetected counterpart by using information from radio to gamma rays and we show that they explain only a small fraction of the isotropic diffuse gamma-ray background.

  10. Poly(acrylic acid)/polyethylene glycol hygrogel prepared by using gamma-ray irradiation for mucosa adhesion

    Science.gov (United States)

    Nho, Young-Chang; Park, Jong-Seok; Shin, Jung-Woong; Lim, Youn-Mook; Jeong, Sung-In; Shin, Young-Min; Gwon, Hui-Jeong; Khil, Myung-Seob; Lee, Deok-Won; Ahn, Sung-Jun

    2015-01-01

    A buccal delivery system provides a much milder environment for drug delivery compared to an oral delivery which presents a hostile environment for drugs, especially proteins and polypeptides, owing to acid hydrolysis. Local delivery in an oral cavity has particular applications in the treatment of toothaches, periodontal disease, and bacterial infections. Poly(acrylic acid) (PAA)-based hydrogels prepared using a chemical initiator have been attempted for a mucoadhesive system owing to their flexibility and excellent bioadhesion. In this experiment, PAA and polyethylene glycol (PEG) were selected to prepare using a radiation process a bioadhesive hydrogel for adhesion to mucosal surfaces. PAA and PEG were dissolved in purified water to prepare a homogeneous PAA/PEG solution, and the solution was then irradiated using an electron beam at dose up to 70 kGy to make the hydrogels. Their physical properties, such as gel percent, swelling percent, and adhesive strength to mucosal surfaces, were investigated. In this experiment, various amounts of PEG were incorporated into the PAA to enhance the mucoadhesive property of the hydrogels. The effect of the molecular weight of PEG on the mucoadhesion was also examined.

  11. Age and sex dependence in tumorigenesis in mice by continuous low-dose-rate gamma-ray whole-body irradiation

    International Nuclear Information System (INIS)

    We investigated the dependency of sex and age in mice in the induction of neoplasms by gamma-rays from cesium-137 at a low dose rate of 0.375Gy/22h/day. Thymic lymphomas occurred significantly at the same incidence in both sexes, and more frequently when younger mice were exposed to radiation. Strain C57BL/6J mice were divided into 8 groups, which were whole-body irradiated with a total dose of 39Gy for 105 days each. The exposure was begun at 28 days of age (male:AM1, female:AF1), and then stepwise increasing the starting age by 105 days, i.e., from 133 days (AM2 and AF2), from 238 days (AM3 and AF3), and from 343 days (AM4 and AF4), respectively. Unirradiated mice served as control (UM and UF). The incidence of thymic lymphomas was about 60 % in AM1, AM2, AF1 and AF2, 40 % in AM3 and AF3 and 20 % in AF4 and AF4, demonstrating no sex dependency, but a distinct age dependency, for lymphomogenesis. It was proven that mice showed a tendency to become less susceptible to radiation induced thymic lymphoma with increasing age. Concomitantly, life-shortening also was caused, and the greater the degree of life-shortening was, the younger the mice were the start of exposure. Life-shortening was attributed to thymic lymphoma, and hemorrhage and infectious diseases due to the depletion of bone marrow cells. (author)

  12. Cellular response to low Gamma-ray doses

    Energy Technology Data Exchange (ETDEWEB)

    Manzanares A, E.; Vega C, H.R.; Leon, L.C. de [Unidades Academicas de Estudios Nucleares, Universidad Autonoma de Zacatecas, A.P. 336, 98000 Zacatecas (Mexico)]. E-mail: emanz@cantera.reduaz.mx; Rebolledo D, O.; Radillo J, F. [Facultad de Ciencias Biologicas y Agropecuarias de la Universidad de Colima, Colima (Mexico)

    2002-07-01

    Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

  13. Cellular response to low Gamma-ray doses

    International Nuclear Information System (INIS)

    Lymphocytes, obtained from healthy donors, were exposed to a low strength gamma-ray field to determine heat shock protein expression in function of radiation dose. Protein identification was carried out using mAb raised against Hsp70 and Hsc70.Hsp70 protein was detected after lymphocyte irradiation. In all cases, an increasing trend of relative amounts of Hsp70 in function to irradiation time was observed. After 1.25 c Gy gamma-ray dose, lymphocytes expressed Hsp70 protein, indicating a threshold response to gamma rays. (Author)

  14. Gamma ray camera

    International Nuclear Information System (INIS)

    An Anger gamma ray camera is improved by the substitution of a gamma ray sensitive, proximity type image intensifier tube for the scintillator screen in the Anger camera. The image intensifier tube has a negatively charged flat scintillator screen, a flat photocathode layer, and a grounded, flat output phosphor display screen, all of which have the same dimension to maintain unit image magnification; all components are contained within a grounded metallic tube, with a metallic, inwardly curved input window between the scintillator screen and a collimator. The display screen can be viewed by an array of photomultipliers or solid state detectors. There are two photocathodes and two phosphor screens to give a two stage intensification, the two stages being optically coupled by a light guide. (author)

  15. Gamma ray beam transmutation

    International Nuclear Information System (INIS)

    We have proposed a new approach to nuclear transmutation by a gamma ray beam of Compton scattered laser photon. We obtained 20 MeV gamma ray in this way to obtain transmutation rates with the giant resonance of 197Au and 129Iodine. The rate of the transmutation agreed with the theoretical calculation. Experiments on energy spectrum of positron, electron and neutron from targets were performed for the energy balance and design of the system scheme. The reaction rate was about 1.5?4% for appropriate photon energies and neutron production rate was up to 4% in the measurements. We had stored laser photon more than 5000 times in a small cavity which implied for a significant improvement of system efficiency. Using these technologies, we have designed an actual transmutation system for 129Iodine which has a 16 million year's activity. In my presentation, I will address the properties of this scheme, experiments results and transmutation system for iodine transmutation

  16. Gamma-Ray Localization of Terrestrial Gamma-Ray Flashes

    International Nuclear Information System (INIS)

    Terrestrial gamma-ray flashes (TGFs) are very short bursts of high-energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of ?5-10 deg. at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the subsatellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

  17. Surface characteristics of UV-irradiated polyurethane elastomers extended with ?, ?-alkane diols

    International Nuclear Information System (INIS)

    Polyurethane elastomers (PUEs) based on 4,4'-diphenylmethane diisocyanate (MDI), poly (?-caprolactone) (PCL) and extended with series of chain extender (CE) were synthesized via two step polymerization technique. The synthesized samples were irradiated for 50, 100 and 200 h in an UV exposure unit as such the spectral distribution of the light is good match for terrestrial solar radiation. The modifications in the chemical structures of the PU before and after irradiation were characterized using Fourier transform infrared (FT-IR) technique. The effect of irradiation time and chain extenders length on surface properties were studied and investigated. Photo-oxidation of PU surface leads to fast increase in surface free energy and its polar component. Simultaneously, the work of water adhesion to polymer increases significantly during UV-irradiation. The higher changes in surface properties, observed by water absorption (%), equilibrium degree of swelling, as well as monitored by ATR-FT-IR and contact angle measurement, were found for the PU samples extended with higher number of methylene unit and irradiation time

  18. Surface characteristics of UV-irradiated polyurethane elastomers extended with {alpha}, {omega}-alkane diols

    Energy Technology Data Exchange (ETDEWEB)

    Zia, Khalid Mahmood [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Bhatti, Ijaz Ahmad [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan)], E-mail: ijazchem@yahoo.com; Barikani, Mehdi [Iran Polymers and Petrochemicals Institute, P.O. Box 14965/115, Tehran (Iran, Islamic Republic of); Zuber, Mohammad [Department of Textile Chemistry, National Textile University Faisalabad (Pakistan); Islam-ud-Din [Department of Mathematics and Statistics, University of Agriculture, Faisalabad 38040 (Pakistan)

    2008-08-30

    Polyurethane elastomers (PUEs) based on 4,4'-diphenylmethane diisocyanate (MDI), poly ({epsilon}-caprolactone) (PCL) and extended with series of chain extender (CE) were synthesized via two step polymerization technique. The synthesized samples were irradiated for 50, 100 and 200 h in an UV exposure unit as such the spectral distribution of the light is good match for terrestrial solar radiation. The modifications in the chemical structures of the PU before and after irradiation were characterized using Fourier transform infrared (FT-IR) technique. The effect of irradiation time and chain extenders length on surface properties were studied and investigated. Photo-oxidation of PU surface leads to fast increase in surface free energy and its polar component. Simultaneously, the work of water adhesion to polymer increases significantly during UV-irradiation. The higher changes in surface properties, observed by water absorption (%), equilibrium degree of swelling, as well as monitored by ATR-FT-IR and contact angle measurement, were found for the PU samples extended with higher number of methylene unit and irradiation time.

  19. Gamma-Ray Burst Lines

    OpenAIRE

    Briggs, Michael S.

    1999-01-01

    The evidence for spectral features in gamma-ray bursts is summarized. As a guide for evaluating the evidence, the properties of gamma-ray detectors and the methods of analyzing gamma-ray spectra are reviewed. In the 1980's, observations indicated that absorption features below 100 keV were present in a large fraction of bright gamma-ray bursts. There were also reports of emission features around 400 keV. During the 1990's the situation has become much less clear. A small fra...

  20. An Elementary Treatment of Gamma-Ray Heating and Gamma-Ray Dosage in Inhomogeneous Reactors

    International Nuclear Information System (INIS)

    An analysis is made of the heat produced by the absorption of gamma rays in a sample placed into a reactor. It is clearly shown that enormous local (space) variations in gamma flux exist in current reactors. An application to the Hanford reactors is treated in some detail. Although the estimates obtained may be good to but a factor of two, it is clearly shown that in most cases the major portion of the heating is due to (n, ?) reactions within the sample itself, and in some cases to the gamma rays generated in liners and cans, and not from the gamma rays generated in fission, nor from the moderator. Some implications of these results are discussed, among the most important being their application to radiation chemistry in reactors. Several mathematical results for absorption and generation of gamma rays in various bodies which should be useful in estimating dosage rates for samples irradiated in reactors are given (Appendix II). A method for making the calculations for an arbitrary absorption law are given (Appendix III). This method may be used with the true absorption law for gamma rays or even for the calculation of the absorption of the energy of particles possessing a range law of absorption, e.g., ?-rays or protons.

  1. Surface treatment of poly(ethylene terephthalate) by gamma-ray induced graft copolymerization of methyl acrylate and its toughening effect on poly(ethylene terephthalate)/elastomer blend

    International Nuclear Information System (INIS)

    To improve the compatibility between ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (E-MA-GMA) elastomer and poly(ethylene terephthalate) (PET), thereby enhance the toughening effect of E-MA-GMA on PET, ?-radiation-induced graft copolymerization technique was used to graft methyl acrylate (MA) monomer onto PET. The produced PET-g-PMA copolymer can be used as a self-compatibilizer in PET/E-MA-GMA blend since the copolymer contains the same segments, respectively, with PET and E-MA-GMA. The impact strength of PET/E-MA-GMA blend increased nearly by 30% in the presence of less than 0.1 wt% PET-g-PMA compared with that of the neat PET/elastomer blend, without loss of the tensile strength of the blends. This work proposed a potential application of radiation-induced grafting copolymerization technique on the in-situ compatibilization of PET/elastomer blends so as to improve the integral mechanical properties of PET based engineering plastic. - Highlights: • PMA was grafted onto PET resins by ?-ray radiation-induced copolymerization. • The obtained PET-g-PMA can improve the compatibility between PET and E-MA-GMA. • A small amount of PET-g-PMA can enhance the impact strength of PET/E-MA-GMA blend

  2. Experimental investigations into the effects of irradiation with neutron and gamma rays on the immune system, as demonstrated at the model of immunity of Salmonella typhimurium on the mouse

    International Nuclear Information System (INIS)

    Mice were irradiated with neutron and gamma rays (with a dose of 200 rad respectively 300 rad). Either 24 hours before or after the irradiation the mice were vaccinated and revaccinated with a Salmonella typhimurium vaccine. By ELISA, IHA and BTZD-test specific antibodies against Salmonella typhimurium could be found. The 200 rad irradiated animals had a lower increase in the formation of antibodies compared with mice not irradiated, if the irradiation was applied before the immunisation. On the 300 rad irradiated animals a reduction of the formation of the antibodies could be observed, too. The antibody titres, however, were higher and an earlier increase of the number of the antibodies was found in comparison with the 200 rad irradiated animals. A second antigene application after 7 days and an irradiation after the first respectively the second immunisation gave no noticeable proof of immune suppression. In our tests it was found out, that for the definition of the antibody titres of the sera the ELISA and the IHA had been more sensitive than the BTZD-test. (orig./MG)

  3. Microstructural study of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x}/Ag samples irradiated with {sup 60}Co {gamma} rays at high doses

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, R. [Programa de Postgrado en Fisica de Materiales, Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Apartado Postal 2681, CP 22800, Ensenada, BC (Mexico); Galvan, D.H. [CECIMAC-UNAM, Apartado Postal 2681, CP 22800, Ensenada, BC (Mexico); Adem, E. [Instituto de Fisica-UNAM, Apartado Postal 20-364, CP 01000, Mexico DF (Mexico); Bartolo-Perez, P. [CINVESTAV-IPN Unidad Merida, Departamento de Fisica Aplicada, Merida, Yucatan (Mexico); Maple, M.B. [Physics Department and Institute for Pure and Applied Physical Sciences, La Jolla, CA (United States)

    1998-06-01

    We have investigated the damage induced by irradiation in Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x} silver added samples. The samples were prepared with 0 and 6.5 wt% of silver and irradiated by high-energy {gamma} irradiation (50-150 Mrad). The roles of silver and dosage irradiation are discussed in terms of their effects on microstructure, crystallinity, critical temperature (T{sub c}) and zero-resistance temperature (T{sub 0}). After irradiation, T{sub c} decreased while the room-temperature electrical resistance increased by a factor of 8 for some of the samples. The difference in T{sub 0} between irradiated and non-irradiated YBCO samples was of the order of 10 K. We have found that the difference is bigger for silver-added samples. We have also observed several changes in diffraction patterns of YBCO and YBCO-silver samples. SEM images, EDS and XPS analysis showed that silver resided inside the grains as single atoms and as metallic clusters. The relative concentrations of the elements in samples were quantified by Auger electron spectroscopy. The values showed a gradual increase for radiation doses ranging between 0 and 100 Mrad. For doses up to 100 Mrad, J{sub c} decreased because of the weak-link breakage induced by high doses of {gamma} rays. (author)

  4. Estimating. gamma. -rays dose using computer

    Energy Technology Data Exchange (ETDEWEB)

    Al-Rawi, A.M.; Muslih, R.M.; Al-Harithy, R.S. (Baghdad Univ. (Iraq). Coll. of Education for Women)

    1990-01-01

    When gum arabic is exposed to {gamma}-rays, a change in its reflection and absorption ability for the different wave lengths is obtained. This change is used for estimating the absorbed {gamma}-rays directly. In the present work we are not concerned with the type of components that are chemically formed as emphasis will only be put on the physical changes. The physical state is taken as a potential chemical change since a molecular damage is accumulated as a result of the dose absorbed. The fortran IV data General (Nova 3) designed for estimating colour measurements was connected to a spectrophotometer that enables measuring the changes in both absorbing and reflecting or even diffusing of light through irradiated materials. (author).

  5. Biodegradation polyurethane derived from vegetable oil irradiated with gamma rays 25 kGy and 100 kGy; Biodegradacao de poliuretano derivado de oleo vegetal irradiado com raios gama 25 kGy e 100 kGy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Antonia M. dos, E-mail: amsantos@rc.unesp.br [Universidade Estadual Paulista - Unesp, Rio Claro, SP (Brazil); Claro Neto, Salvador [Universidade de Sao Paulo - USP, Campus de Sao Carlos, SP (Brazil); Azevedo, Elaine C. de [Universidade Federal do Parana, Campus de Curitiba, PR (Brazil)

    2011-07-01

    The environment requires polymers that can be degraded by the action of microorganisms. In this work was studied the biodegradation of polyurethane samples derived from vegetable oil (castor oil), which were irradiated with gamma rays 25 kGy and 100 kGy compared with the same polyurethane without being irradiated. Biodegradation of polyurethane was carried out in culture medium containing the fungus Aspergillus niger by 146 days and the result was evaluated using the technique of thermogravimetric analysis, where there was a change of behavior of the curves TGA / DTG occurred indicating that chemical modifications of molecules present in the structure of the polymer chain, thus confirming that the material has undergone the action of microorganisms. (author)

  6. Planetary gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    The chemical composition of a planet can be inferred from the gamma rays escaping from its surface and can be used to study its origin and evolution. The measured intensities of certain gamma rays of specific energies can be used to determine the abundances of a number of elements. The major sources of these gamma-ray lines are the decay of natural radionuclides, reactions induced by energetic galactic-cosmic-ray particles, capture of low energy neutrons, and solar-proton-induced radioactivities. The fluxes of the more intense gamma-ray lines emitted from 30 elements were calculated using current nuclear data and existing models. The source strengths for neutron-capture reactions were modified from those previously used. The fluxes emitted from a surface of average lunar composition are reported for 288 gamma-ray lines. These theoretical fluxes have been used elsewhere to convert the data from the Apollo gamma-ray spectrometers to elemental abundances and can be used with results from future missions to map the concentrations of a number of elements over a planet's surface. Detection sensitivities for these elements are examined and applications of gamma-ray spectroscopy for future orbiters to Mars and other solar-system objects are discussed

  7. Applied gamma-ray spectrometry

    CERN Document Server

    Dams, R; Crouthamel, Carl E

    1970-01-01

    Applied Gamma-Ray Spectrometry covers real life application of the gamma-ray and the devices used in their experimental studies. This book is organized into 9 chapters, and starts with discussions of the various decay processes, the possible interaction mechanisms of gamma radiation with matter, and the intrinsic and extrinsic variables, which affect the observed gamma-ray and X-ray spectra. The subsequent chapters deal with the properties and fabrication of scintillation detectors, semiconductor detectors, and proportional gas counters. These chapters present some of the most widely utilized

  8. Gamma ray induced chromophore modification of softwood thermomechanical pulp

    International Nuclear Information System (INIS)

    This study focuses on bleaching a softwood (black spruce, balsam fur) thermomechanical pulp with gamma rays. Gamma rays are known for their enormous penetrating power, along with their ionizing properties. They can generate highly energetic radicals capable of oxidizing lignin chromophores. The authors studied the influence of isopropyl alcohol, sodium borohydride, oxygen, hydrogen peroxide, nitrogen dioxide and water along with gamma ray irradiation of the pulps. The authors measured the optimal dose and dose rate, along with the influence of the radical scavengers like oxygen on the bleaching effect of gamma irradiated pulps. They observe various degrees of bleaching of these pulps. Evidence relates this bleaching to the generation of perhydroxyl anions upon irradiation of water. Also, they were able to pinpoint the influence of the dose rate on the rate of formation and disappearance of these perhydroxyl anions and their influence on bleaching kinetics. Stability toward photoyellowing, and photoyellowing's kinetic of papers from these pulps was also studied

  9. Combination effect of gamma rays, EMS and the storage before irradiation on some characteristics of M1 and M2 plants of bread wheat triticum aestivum L.(Cv. ajeeba)

    International Nuclear Information System (INIS)

    Three samples of bread-wheat CV.Ajeeba stored under baghdad prevailing room conditions since 1988,1978 and 1983 wereirradiation with gamma rays (15 Krad).They were then treated with the chemical mutagen(EMS).Seeds were sown in the field during the cultivation seasons of 1983-1985.The effects of gamma radiation,EMS,the storage periods and their interaction on some developmental stages of M1 plants were statistically significant.However,no differences were observed among M2 plants.The greatest number of variants were found among M2 plants that had originated from seeds stored since 1968,irradiated and treated with EMS.(3 tabs., 18 refs.)

  10. Chromosomal mutations and chromosome loss measured in a new human-hamster hybrid cell line, ALC: studies with colcemid, ultraviolet irradiation, and 137Cs gamma-rays

    Science.gov (United States)

    Kraemer, S. M.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

    1997-01-01

    Small mutations, megabase deletions, and aneuploidy are involved in carcinogenesis and genetic defects, so it is important to be able to quantify these mutations and understand mechanisms of their creation. We have previously quantified a spectrum of mutations, including megabase deletions, in human chromosome 11, the sole human chromosome in a hamster-human hybrid cell line AL. S1- mutants have lost expression of a human cell surface antigen, S1, which is encoded by the M1C1 gene at 11p13 so that mutants can be detected via a complement-mediated cytotoxicity assay in which S1+ cells are killed and S1- cells survive. But loss of genes located on the tip of the short arm of 11 (11p15.5) is lethal to the AL hybrid, so that mutants that have lost the entire chromosome 11 die and escape detection. To circumvent this, we fused AL with Chinese hamster ovary (CHO) cells to produce a new hybrid, ALC, in which the requirement for maintaining 11p15.5 is relieved, allowing us to detect mutations events involving loss of 11p15.5. We evaluated the usefulness of this hybrid by conducting mutagenesis studies with colcemid, 137Cs gamma-radiation and UV 254 nm light. Colcemid induced 1000 more S1- mutants per unit dose in ALC than in AL; the increase for UV 254 nm light was only two-fold; and the increase for 137Cs gamma-rays was 12-fold. The increase in S1- mutant fraction in ALC cells treated with colcemid and 137Cs gamma-rays were largely due to chromosome loss and 11p deletions often containing a breakpoint within the centromeric region.

  11. The Gamma-ray Sky with Fermi

    OpenAIRE

    Thompson, D. J.

    2013-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent lim...

  12. Thermo-mechanical characteristics of UV-irradiated polyurethane elastomers extended with {alpha}, {omega}-alkane diols

    Energy Technology Data Exchange (ETDEWEB)

    Zia, Khalid Mahmood [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan)], E-mail: ziakmpkpolym@yahoo.com; Bhatti, Ijaz Ahmad [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Barikani, Mehdi [Iran Polymers and Petrochemicals Institute, P.O Box 14965/115, Tehran (Iran, Islamic Republic of); Zuber, Mohammad [Department of Industrial Chemistry, G.C. University, Faisalabad (Pakistan); Sheikh, Munir Ahmad [Department of Chemistry, University of Agriculture, Faisalabad 38040 (Pakistan)

    2009-05-15

    A series of polyurethane elastomers were prepared by the reaction of poly {epsilon}-caprolactone and 4,4'-diphenylmethane diisocyanate. The prepolymer was extended using {alpha}, {omega}-alkane diols as chain extenders having 2-10 methylene units in their structure. The synthesized samples were irradiated for 50, 100 and 200 h in an ultra violet (UV) exposure unit. Modifications in the chemical structure before and after irradiation were characterized using Fourier Transform Infrared spectroscopy. The thermal and mechanical properties were affected by the ultra violet irradiation time and the number of methylene units in the chain extenders. The experimental results indicated that the morphological structure changed during irradiation as a consequence of hard segment and soft segment degradation.

  13. Compton Gamma-Ray Observatory

    Science.gov (United States)

    1991-01-01

    This photograph shows the Compton Gamma-Ray Observatory being released from the Remote Manipulator System (RMS) arm aboard the Space Shuttle Atlantis during the STS-35 mission in April 1991. The GRO reentered the Earth's atmosphere and ended its successful mission in June 2000. For nearly 9 years, GRO's Burst and Transient Source Experiment (BATSE), designed and built by the Marshall Space Flight Center, kept an unblinking watch on the universe to alert scientist to the invisible, mysterious gamma-ray bursts that had puzzled them for decades. By studying gamma-rays from objects like black holes, pulsars, quasars, neutron stars, and other exotic objects, scientists could discover clues to the birth, evolution, and death of star, galaxies, and the universe. The gamma-ray instrument was one of four major science instruments aboard the Compton. It consisted of eight detectors, or modules, located at each corner of the rectangular satellite to simultaneously scan the entire universe for bursts of gamma-rays ranging in duration from fractions of a second to minutes. In January 1999, the instrument, via the Internet, cued a computer-controlled telescope at Las Alamos National Laboratory in Los Alamos, New Mexico, within 20 seconds of registering a burst. With this capability, the gamma-ray experiment came to serve as a gamma-ray burst alert for the Hubble Space Telescope, the Chandra X-Ray Observatory, and major gound-based observatories around the world. Thirty-seven universities, observatories, and NASA centers in 19 states, and 11 more institutions in Europe and Russia, participated in BATSE's science program.

  14. Fillers influence on mechanical properties of elastomers during their ageing by irradiation; Influence des charges sur les proprietes mecaniques des elastomeres lors de leur vieillissement par irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Planes, E.; Chazeau, L.; Vigier, G. [Institut National des Sciences Appliquees (INSA), MATEIS, UMR CNRS 5510, 69 - Villeurbanne (France); Planes, E. [NEXANS Research Center, 69 - Lyon (France); Stevenson, I. [Laboratoire des Materiaux Polymeres et Biomateriaux (IMP/LMPB) UMR CNRS 5627, UCBL, 69 - Villeurbanne (France)

    2008-07-01

    This paper presents the study of ageing under irradiation of filled elastomers, particularly aluminium tri-hydrate ATH or nano-scopic silica filled EPDM. The materials have been physico-chemically, micro-structurally and mechanically characterised at various levels of ageing: here only results for physical and mechanical properties (at small (DMA) and large deformations) have been presented. From these analyses, the competition between crosslinking and chains scissions during irradiation was highlighted. Moreover, a strong influence of fillers on mechanical properties during ageing was observed. (authors)

  15. Neutron interrogation system using high gamma ray signature to detect contraband special nuclear materials in cargo

    Science.gov (United States)

    Slaughter, Dennis R. (Oakland, CA); Pohl, Bertram A. (Berkeley, CA); Dougan, Arden D. (San Ramon, CA); Bernstein, Adam (Palo Alto, CA); Prussin, Stanley G. (Kensington, CA); Norman, Eric B. (Oakland, CA)

    2008-04-15

    A system for inspecting cargo for the presence of special nuclear material. The cargo is irradiated with neutrons. The neutrons produce fission products in the special nuclear material which generate gamma rays. The gamma rays are detecting indicating the presence of the special nuclear material.

  16. Study of stability of humic acids from soil and peat irradiated by gamma rays; Estudo da estabilidade de acidos humicos extraidos de solo e turfa, frente a radiacao ionizante gama

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Wilson Tadeu Lopes da

    1995-07-01

    Humic acids samples (one deriving from a sedimentary soil and other from a peat), in aqueous media, were irradiated with gamma rays, in doses of 10, 50 and 100 kGy, in order to understand their chemical behavior after the irradiation. The material, before and after irradiation, was analyzed by Elemental Analysis, Functional Groups (carboxylic acids and phenols), UV/Vis Spectroscopy (E{sub 4}/E{sub 6} ratio), IR spectroscopy, CO{sub 2} content and Gel permeation Chromatography (GPC) ). The Elemental Analysis showed the humic acid derived from a peat had a most percentage quantity of Carbon and Hydrogen than the material from a sedimentary soil. From the UV/Vis Spectroscopy, it was observed a decrease of E{sub 4}/E{sub 6} ratio with an increase of the applied dose. The data from GPC are in agreement with this. The results showed that the molecular weight of the material increased by exposing it to a larger radiolitical dose. The peat material was less affected by the gamma radiation than the soil material. The carboxylic groups were responsible by radiochemical behavior of the material. (author)

  17. Terrestrial gamma-ray flashes

    International Nuclear Information System (INIS)

    Lightning and thunderstorm systems in general have been recently recognized as powerful particle accelerators, capable of producing electrons, positrons, gamma-rays and neutrons with energies as high as several tens of MeV. In fact, these natural systems turn out to be the highest energy and most efficient natural particle accelerators on Earth. Terrestrial Gamma-ray Flashes (TGFs) are millisecond long, very intense bursts of gamma-rays and are one of the most intriguing manifestation of these natural accelerators. Only three currently operative missions are capable of detecting TGFs from space: the RHESSI, Fermi and AGILE satellites. In this paper we review the characteristics of TGFs, including energy spectrum, timing structure, beam geometry and correlation with lightning, and the basic principles of the associated production models. Then we focus on the recent AGILE discoveries concerning the high energy extension of the TGF spectrum up to 100 MeV, which is difficult to reconcile with current theoretical models

  18. Gamma rays for Ephestia Kuehniella control

    International Nuclear Information System (INIS)

    Trials were undertaken to establish gamma irradiation action on the various developmental stages of Ephestia Kuehniella. It was found that its eggs perished 100% when irradiated with a dose of 6 krad. Mortality of young larvae irradiated with gamma ray dose of 4-22 krad accounted for 23.91-43.64% during the first 10 days, and for 53.9-95% after 50 days. Irradiation with 20-22 krad intensity resulted in 100% mortality 60 days post irradiation. In the case of adult larvae, 8.8-40.57% were killed 10 days post irradiation and 53.98-100% - after 50 days. Some larvae could survive for 90 days post 8-12 krad irradiation. A dose of 20 krad required 70 days to produce 100% mortality and 22 krad - 50 days. Pupae mortality ranged from 28.4 to 30.72%, depending on the dose but their moths lived only 2 days and could not be fertilized. The inference is that gamma irradiation may be used to control Ephestia Kuehniella

  19. Gamma-ray Imaging Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

    2006-10-05

    In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

  20. Interaction of hyperthermia with gamma rays in Allium cepa cells

    International Nuclear Information System (INIS)

    Hyperthermia treatments(40 and 50degC) applied prior to gamma ray irradiation (500 R) reduce the chromosomal damage caused by the latter significantly in Allium test. This protection has been ascribed to clastogenic adoptation and/or formation of heat shock proteins. (author). 13 refs., 2 tabs

  1. Activation of wine bentonite with gamma rays

    International Nuclear Information System (INIS)

    The action of gamma rays on wine bentonite as well as influence of its adsorption and technologic qualities on the composition and stability of wines against protein darkening and precipitation has been studied. The experiments were carried out with wine bentonite produced in the firm Bentonite and irradiated with doses of 0.4, 0.6, 0.8 and 1.0 MR. White and red wines have been treated with irradiated bentonite under laboratory conditions at 1.0 g/dm3. All samples are treated at the same conditions. The flocculation rate of the sediment was determined visually. Samples have been taken 24 h later from the cleared wine layers. The following parameters have been determined: clarification, filtration rate, phenolic compounds, calcium, colour intensity, total extracted substances, etc. The volume of the sediment has been determined also. The control samples have been taken from the same unirradiated wines. The results showed better and faster clarification in on the third, the 20th and the 24th hours with using of gamma-irradiated at doses 0.8 and 1.0 MR. The sediment was the most compact and its volume - the smallest compared to the samples treated with bentonite irradiated with doses of 0.6 and 0.4 MR. This ensures a faster clarification and better filtration of treated wines. The bentonite activated with doses of 0.8 and 1.0 MR adsorbs the phenolic compounds and the complex protein-phenolic molecules better. In the same time it adsorbs less extracted substances compared to untreated bentonite and so preserves all organoleptic properties of wine. The irradiated bentonite adsorbs less the monomers of anthocyan compounds which ensures brighter natural colour of wine. The gamma-rays activation consolidates calcium in the crystal lattice of bentonite particles and in this way eliminates the formation of crystal precipitates

  2. Direct irradiation of LaMn?Si? and LaMn?Ge? compounds with thermal neutrons to produce ¹??La(¹??Ce) probe nuclei for PAC Spectroscopy: analysis of possible interferences from ??Mn and ??’??Ge gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Bosch-Santos, Brianna; Cabrera-Pasca, Gabriel A.; Carbonari, Artur W.; Saiki, Mitiko; Saxena, Rajendra N., E-mail: brianna@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this paper we describe a method to introduce radioactive ¹??La nuclei with a half-life of ~40 h, into samples of intermetallic compounds LaMn?X? (X=Si,Ge) to carry out Perturbed gamma-gamma angular correlation (PAC) spectroscopy measurements using ¹??La (¹??Ce) as probe nuclei. While there are several methods to introduce this probe nucleus in a variety of samples, an alternate method is described which produces ¹??La (¹??Ce) probe in LaMn?Ge? and LaMn?Si? compounds by directly irradiating for a short time with thermal neutrons in the IEA-R1 nuclear reactor at IPEN/CNEN-SP. This method could be used because La is a component of the samples. Natural La contains (99.9%) as ¹³?La isotope which, when irradiated with neutrons produces ¹??La, the parent radioisotope of ¹??Ce used for PAC measurements. However, other elements present in the compounds are also activated during neutron irradiation to produce gamma emitting radioisotopes in particular ??Mn and ??’??Ge. In order to verify if these would interfere in the PAC measurements, we have measured the gamma spectrum of these isotopes in the samples at different time intervals after the end of irradiation using a high resolution HPGe spectrometer PAC spectra at room temperature were measured for both LaMn?Si? and LaMn?Ge? compounds using ¹??La (¹??Ce) as probe nuclei and showed that interference from other gamma-rays is negligible if PAC measurements started 24 hs after the end of irradiation of the sample. (author)

  3. Low-dose gamma-ray irradiation induces translocation of Nrf2 into nuclear in mouse macrophage RAW264.7 cells

    International Nuclear Information System (INIS)

    The transcription factor nuclear erythroid-derived 2-related factor 2 (Nrf2) regulates expression of genes encoding antioxidant proteins involved in cellular redox homeostasis, while ?-ray irradiation is known to induce reactive oxygen species in vivo. Although activation of Nrf2 by various stresses has been studied, it has not yet been determined whether ionizing irradiation induces activation of Nrf2. Therefore, we investigated activation of Nrf2 in response to ?-irradiation in mouse macrophage RAW264.7 cells. Irradiation of cells with ?-rays induced an increase of Nrf2 expression. Even 0.1 Gy of ?-irradiation induced a translocation of Nrf2 from cytoplasm to the nucleus, indicating the activation of Nrf2 by low-dose irradiation. Expression of heme oxygenase-1, which is regulated by Nrf2, was also increased at 24 h after irradiation with more than 0.1 Gy of ?-rays. Furthermore, the activation of Nrf2 was suppressed by U0126, which is an inhibitor of the extracellular signal regulated protein kinase 1/2 (ERK1/2) pathway, suggesting involvement of ERK1/2-dependent pathway in the irradiation-induced activation of Nrf2. Our results indicate that low-dose ?-irradiation induces activation of Nrf2 through ERK1/2-dependent pathways. (author)

  4. Gamma ray assisted fabrication of fluorescent oligographene nanoribbons

    International Nuclear Information System (INIS)

    Graphical abstract: Facile low cost method for production of oligographene nanoribbons is presented. Highlights: ? Gamma ray assisted fabrication of oligographene nanoribbons. ? Facile, large scale and low cost method of graphene nanoribbon fabrication. ? Produced nanoribbons are fluorescent in the blue region of visible spectrum. -- Abstract: In this paper, facile low cost method for production of oligographene nanoribbons is presented. Nanoribbons are produced by gamma ray assisted cutting of oligographene dispersed in cyclopentanone. Width and height of the smallest nanoribbons are 30 and 1 nm, respectively. Due to the presence of a small number of defects introduced by gamma irradiation, nanoribbons are photoluminescent in the UV and blue region of the visible spectrum.

  5. Gamma ray induced mutant of a mutant of chrysanthemum

    International Nuclear Information System (INIS)

    Rooted cuttings of small flowered chrysanthemum mutant Himani were irradiated with 1.5, 2.0 and 2.5 Krad of gamma rays. Reduction of survival, plant height, leaf and pollen grain size, various abnormalities in leaf and flower-heads, delay in flower bud initiation, colour showing and full bloom and increase in pollen grain sterility were recorded after exposure to gamma rays. TLC and UV spectrophotometric analysis showed quantitative differences in pigments in the control and its induced Canary Yellow mutant. (author)

  6. Organ doses of adults and children from environmental gamma rays

    International Nuclear Information System (INIS)

    Organ doses from environmental gamma-rays were calculated using Monte Carlo methods for infinite plane sources in the ground, semi-infinite volume sources in the air and volume source in the ground. The results of the simulations of the gamma-ray transport in the air over ground geometry were used as sources irradiating four different anthropomorphic phantoms representing different ages and sexes; in this way, the effect of body and organ size on organ doses could be examined. Dose conversion factors normalised to air kerma and to source intensity were obtained. (orig.)

  7. Co-expression of antioxidant enzymes with expression of p53, DNA repair, and heat shock protein genes in the gamma ray-irradiated hermaphroditic fish Kryptolebias marmoratus larvae

    International Nuclear Information System (INIS)

    Highlights: •Novel identification of DNA repair-related genes in fish. •Investigation of whole expression profiling of DNA repair genes upon gamma radiation. •Analysis of effects of gamma radiation on antioxidant system and cell stress proteins. •Usefulness of verification of pathway-based profiling for mechanistic understanding. -- Abstract: To investigate effects of gamma ray irradiation in the hermaphroditic fish, Kryptolebias marmoratus larvae, we checked expression of p53, DNA repair, and heat shock protein genes with several antioxidant enzyme activities by quantitative real-time RT-PCR and biochemical methods in response to different doses of gamma radiation. As a result, the level of gamma radiation-induced DNA damage was initiated after 4 Gy of radiation, and biochemical and molecular damage became substantial from 8 Gy. In particular, several DNA repair mechanism-related genes were significantly modulated in the 6 Gy gamma radiation-exposed fish larvae, suggesting that upregulation of such DNA repair genes was closely associated with cell survival after gamma irradiation. The mRNA expression of p53 and most hsps was also significantly upregulated at high doses of gamma radiation related to cellular damage. This finding indicates that gamma radiation can induce oxidative stress with associated antioxidant enzyme activities, and linked to modulation of the expression of DNA repair-related genes as one of the defense mechanisms against radiation damage. This study provides a better understanding of the molecular mode of action of defense mechanisms upon gamma radiation in fish larvae

  8. Co-expression of antioxidant enzymes with expression of p53, DNA repair, and heat shock protein genes in the gamma ray-irradiated hermaphroditic fish Kryptolebias marmoratus larvae

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, Jae-Sung [Research Institute for Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Bo-Mi; Kim, Ryeo-Ok [Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Seo, Jung Soo [Pathology Team, National Fisheries Research and Development Institute, Busan 619-902 (Korea, Republic of); Kim, Il-Chan [Division of Life Sciences, Korea Polar Research Institute, Korea Institute of Ocean Science and Technology, Incheon 406-840 (Korea, Republic of); Lee, Young-Mi, E-mail: ymlee70@smu.ac.kr [Department of Green Life Science, College of Convergence, Sangmyung University, Seoul 110-743 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@hanyang.ac.kr [Research Institute for Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Chemistry, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2013-09-15

    Highlights: •Novel identification of DNA repair-related genes in fish. •Investigation of whole expression profiling of DNA repair genes upon gamma radiation. •Analysis of effects of gamma radiation on antioxidant system and cell stress proteins. •Usefulness of verification of pathway-based profiling for mechanistic understanding. -- Abstract: To investigate effects of gamma ray irradiation in the hermaphroditic fish, Kryptolebias marmoratus larvae, we checked expression of p53, DNA repair, and heat shock protein genes with several antioxidant enzyme activities by quantitative real-time RT-PCR and biochemical methods in response to different doses of gamma radiation. As a result, the level of gamma radiation-induced DNA damage was initiated after 4 Gy of radiation, and biochemical and molecular damage became substantial from 8 Gy. In particular, several DNA repair mechanism-related genes were significantly modulated in the 6 Gy gamma radiation-exposed fish larvae, suggesting that upregulation of such DNA repair genes was closely associated with cell survival after gamma irradiation. The mRNA expression of p53 and most hsps was also significantly upregulated at high doses of gamma radiation related to cellular damage. This finding indicates that gamma radiation can induce oxidative stress with associated antioxidant enzyme activities, and linked to modulation of the expression of DNA repair-related genes as one of the defense mechanisms against radiation damage. This study provides a better understanding of the molecular mode of action of defense mechanisms upon gamma radiation in fish larvae.

  9. Short duration gamma ray bursts

    Indian Academy of Sciences (India)

    Patrick Das Gupta

    2004-10-01

    After a short review of gamma ray bursts (GRBs), we discuss the physical implications of strong statistical correlations seen among some of the parameters of short duration bursts ($T_{90}$ < 2 s). Finally, we conclude with a brief sketch of a new unified model for long and short GRBs.

  10. Novae in gamma-rays

    CERN Document Server

    Hernanz, M

    2013-01-01

    Classical novae produce radioactive nuclei which are emitters of gamma-rays in the MeV range. Some examples are the lines at 478 and 1275 keV (from 7Be and 22Na) and the positron-electron annihilation emission (511 keV line and a continuum below this energy, with a cut-off at 20-30 keV). The analysis of gamma-ray spectra and light curves is a potential unique and powerful tool both to trace the corresponding isotopes and to give insights on the properties of the expanding envelope determining its transparency. Another possible origin of gamma-rays is the acceleration of particles up to very high energies, so that either neutral pions or inverse Compton processes produce gamma-rays of energies larger than 100 MeV. MeV photons during nova explosions have not been detected yet, although several attempts have been made in the last decades; on the other hand, GeV photons from novae have been detected in some particular novae, in symbiotic binaries, where the companion is a red giant with a wind, instead of a main ...

  11. High energy gamma ray observations

    Science.gov (United States)

    Fichtel, Carl E.

    1992-01-01

    Since the trajectories of astrophysical charged particles are bent by magnetic fields and normally curl many times before their detection, their origin may not be inferred from their directions as is the case with photons. Fortunately, charged particles reveal their presence through interactions in many instances leading to high-energy gamma rays. Bremsstrahlung, Compton, synchrotron, and curvature radiation all generally have a monotonically decreasing energy spectra reflecting that of the parent particles, whereas nucleon-nucleon radiation has a maximum at about 70 MeV reflecting the nature of the interaction process. Gamma radiation has been seen coming from neutron stars in pulses with the same period as the radio pulsar. Solar gamma rays also have been seen, as have short bursts of gamma rays whose origin remain a mystery. Galactic diffuse gamma radiation reveals the distribution of cosmic rays in our Galaxy. Beyond our Galaxy, active galaxies are seen in gamma rays implying a huge energy in the form of cosmic rays to be present there. The Optically Violent Variable quasar 3C 279 is particularly astounding. During an active state 3C 279 was seen to be emitting approximately 10 exp 48 erg/s if its radiation is isotropic.

  12. The Gamma-ray Universe through Fermi

    Science.gov (United States)

    Thompson, David J.

    2012-01-01

    Gamma rays, the most powerful form of light, reveal extreme conditions in the Universe. The Fermi Gamma-ray Space Telescope and its smaller cousin AGILE have been exploring the gamma-ray sky for several years, enabling a search for powerful transients like gamma-ray bursts, novae, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as dark matter annihilation. Some results include a stringent limit on Lorentz invariance derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge ga.nuna-ray structure associated with the center of our galaxy, surprising behavior from some gamma-ray binary systems, and a possible constraint on some WIMP models for dark matter.

  13. Cosmic Rays: What Gamma Rays Can Say

    CERN Document Server

    Aloisio, Roberto

    2014-01-01

    We will review the main channels of gamma ray emission due to the acceleration and propagation of cosmic rays, discussing the cases of both galactic and extra-galactic cosmic rays and their connection with gamma rays observations.

  14. The Gamma-ray Sky with Fermi

    CERN Document Server

    Thompson, D J

    2013-01-01

    Gamma rays reveal extreme, nonthermal conditions in the Universe. The Fermi Gamma-ray Space Telescope has been exploring the gamma-ray sky for more than four years, enabling a search for powerful transients like gamma-ray bursts, solar flares, and flaring active galactic nuclei, as well as long-term studies including pulsars, binary systems, supernova remnants, and searches for predicted sources of gamma rays such as clusters of galaxies. Some results include a stringent limit on Lorentz invariance violation derived from a gamma-ray burst, unexpected gamma-ray variability from the Crab Nebula, a huge gamma-ray structure in the direction of the center of our Galaxy, and strong constraints on some Weakly Interacting Massive Particle (WIMP) models for dark matter.

  15. Obtainment of a drug delivery system from PVAL irradiated by gamma rays; Obtencao de um sistema de liberacao controlada de drogas a partir do PVAL irradiado com radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Terence, Mauro Cesar

    2002-07-01

    The poly(vinyl alcohol) (PVAL) is a polymer used as biomaterial. In this work the PVAL was irradiated by gamma rays from {sup 60}Co source with doses up to 200 kGy. The PVAL was used to prepare hydrogels that may be used as a drug delivery system in ocular implant, for pair PVAL/dihidroxypropoximethyl guanine, where the last one is used for treatment of people with retinite caused by cytomegalovirus. The dose effect was studied on various properties of PVAL: the molecular weight by viscosity, the crosslink degree (G{sub cross}-l{sub ink}= 8,5) calculated from gel dose (Dg = 7,8 kGy), the average molecular weight between crosslinks, crosslinking density, tensile strength at break and the degree of crystallinity by differential scanning calorimetry. Formation and thermal decay radical were studied by electronic paramagnetic resonance. It was used the technique of superposition and subtraction of spectra obtained at various temperatures (77 K, 125 K, 170 K, 230 K and 280 K). The radicals formed were identified on irradiated PVAL on vacuum and air at 77K with 20 kGy. The thermal decay showed that air caused polymer oxidation, even after end the irradiation, because the {center_dot}OH, RO{center_dot} and ROO {center_dot} radicals were formed. The dose effect on molecular structure of PVAL was studied by transmission spectroscopy on infrared region and nuclear magnetic resonance of proton. The PVAL structural alteration was not observed up to 200kGy, although crosslink occurred on PVAL. The PVAL hydrogel formation occurred at doses upper 70 kGy and drug controlled released occurred with zero order kinetic on PVAL hydrogel irradiated with 80 kGy. (author)

  16. Studies on the sensitivity of guinea pigs and golden hamsters irradiated with different doses of gamma rays to infections with R and S forms of Pseudomonas pseudomallei

    International Nuclear Information System (INIS)

    Whole-body gamma irradiation was carried out on guinea pigs of both sexes with 2 Gy (sublethal dose), 2 Gy fractionated (4 x 0.5 Gy a day) and 0.5 Gy, and on golden hamsters with 6 Gy (sublethal dose) and 0.5 Gy. The animals were injected i.p. 24 h after irradiation with bacterial suspensions of P. pseudomallei R7 and R15. The results showed a great increase of sensitivity to infection in the animals irradiated with sublethal dose, both as regards the R and S forms. Susceptibility rose appreciably also in guinea pigs irradiated fractionally with a dose of 2 Gy and to a relatively lower degree upon irradiation with 0.5 Gy. For the golden hamsters the sensitivity toward both investigated strains was extremely high and it remained unchanged upon irradiation with 6 Gy and 0.5 Gy. The data obtained provided grounds for the existence of a certain correlation between the different radioresistance of guinea pigs and golden hamsters and the changes established in their sensitivity to infections with R and S forms of Ps. pseudomallei after whole-body gamma irradiation

  17. Gamma-ray signatures of classical novae

    CERN Document Server

    Hernanz, M; José, J

    2001-01-01

    The role of classical novae as potential gamma-ray emitters is reviewed, on the basis of theoretical models of the gamma-ray emission from different nova types. The interpretation of the up to now negative results of the gamma-ray observations of novae, as well as the prospects for detectability with future instruments (specially onboard INTEGRAL) are also discussed.

  18. Gamma-ray irradiation effect on corrosion rates of stainless steel, Ti and Ti-5Ta in boiling 9N nitric acid

    International Nuclear Information System (INIS)

    Irradiation effect of ?-rays on corrosion rates of stainless steel (type 304L), titanium and a titanium-tantalum alloy (Ti-5Ta) in 9N boiling nitric acid was investigated by measuring weight losses of specimens leached under a 60Co ?-ray environment of 1 kC kg-1/h (4 MR/h). Tests without irradiation were as well performed to obtain reference data. Plots of the weight loss normalized to specimen's surface area against total leaching time exhibited linear relations when the first leaching batch is neglected. The corrosion rates calculated from the gradients indicated slight, though significant, irradiation effects, an enhancement in stainless steel while suppressions in Ti and Ti-5Ta. Corrosion modes were found to be insensitive to the irradiation. (orig.)

  19. Leakage of potassium from red blood cells following gamma ray irradiation in the presence of dipyridamole, trolox, human plasma or mannitol

    International Nuclear Information System (INIS)

    Transfusion-associated graft-versus-host disease (TA-GVHD) is a fatal complication of blood transfusion resulting from the contamination of blood products by leukocytes. In order to prevent this disease, gamma or X-ray irradiation of blood components, which can inactivate leukocytes, is currently used. However, the minimal doses needed to destroy lymphocytes promote the leakage of potassium from red blood cells (RBCs), which can induce other side effects, such as hyperpotassemia and cardiac arrest. The reactive oxygen species (ROS) generated by the irradiation of aqueous solutions may accelerate the leakage through oxidation of the RBC membrane. Here we studied the effect of dipyridamole, Trolox, human plasma or mannitol on the leakage of potassium from RBCs following irradiation. RBC preparations (hematocrit; 30%) containing antioxidants were irradiated at 30 Gy and stored at 4 deg C for 7 d. The leakage of potassium from the RBCs caused by the irradiation was significantly suppressed by dipyridamole (more than 50 ?M), Trolox (more than 5 mM) or human plasma (50%). Mannitol (80 mM) is used to inhibit hemolysis as a constituent of MAP solution, which is a solution used for the storage of RBC products in Japan. Here it was clarified that the leakage of potassium from not only irradiated but also non-irradiated RBCs was unexpectedly promoted by mannitol. The amount of mannitol in MAP solution may have to be reconsidered. The osmotic pressure of the RBC preparation increased in a manner dependent on the concentration of mannitol. The elevated osmotic pressure may promote the leakage. In conclusion, although antioxidants have the potential to suppress the leakage of potassium ascribed to the irradiation, the extent of the supression (10-20%) by dipyridamole (DPM), Trolox or human plasma seems insufficient for the clinical use of these agents as an additive for MAP solution. (author)

  20. High dose gamma-ray standard

    International Nuclear Information System (INIS)

    The high gamma-ray doses produced in a gamma irradiator are used, mainly, for radiation processing, i.e. sterilization of medical products, processing of food, modifications of polymers, irradiation of electronic devices, a.s.o. The used absorbed doses are depending on the application and are covering the range between 10 Gy and 100 MGy. The regulations in our country require that the response of the dosimetry systems, used for the irradiation of food and medical products, be calibrated and traceable to the national standards. In order to be sure that the products receive the desired absorbed dose, appropriate dosimetric measurements must be performed, including the calibration of the dosemeters and their traceability to the national standards. The high dose gamma-ray measurements are predominantly based on the use of reference radiochemical dosemeters. Among them the ferrous sulfate can be used as reference dosemeter for low doses (up to 400 Gy) but due to its characteristics it deserves to be considered a standard dosemeter and to be used for transferring the conventional absorbed dose to other chemical dosemeters used for absorbed doses up to 100 MGy. The study of the ferrous sulfate dosemeter consisted in preparing many batches of solution by different operators in quality assurance conditions and in determining for all batches the linearity, the relative intrinsic error, the repeatability and the reproducibility. The principal results are the following: the linear regression coefficient - 0.999, the relative intrinsic error - max.6%, the repeatability (for P*=95%) - max.3%, the reproducibility (P*=95%) - max.5%

  1. Induction and repair of strand breaks and 3'-hydroxy terminals in the DNA of mammalian cells in culture following gamma-ray irradiation

    International Nuclear Information System (INIS)

    DNA was isolated in a fairly pure and intact state from cultured mouse leukaemia cells (L5178Y) after ?-ray irradiation using a hydroxyapatite column chromatography method, and analysed further by sucrose gradient centrifugation or DNA polymerase (EC 2.7.7.7, enzyme A of Klenow from Escherichia coli) assay. Irradiation of the cells induced single- and double-strand breaks in the DNA with an efficiency of 100 eV/break and 1300 eV/break, respectively. Approximately 50% of the single-strand breaks were estimated to be those arising from alkali-labile lesions. A linear, dose-dependent increase was found in the template activity of the DNA, indicating the induction of 3'-OH terminals by ?-irradiation. Post-irradiation incubation of the cells in serum-free medium allowed the majority of the breaks to rejoin within a few hours. Repair of the alkali-labile lesions was, however, found to be much slower than that of 'actual' single-strand breaks. A slight increase of the DNA template activity was found during the period of post-irradiation incubation. The reason for the increase is discussed

  2. Effect of multiple irradiation with low doses of gamma-rays on morphological transformation and growth ability of human embryo cells in vitro

    International Nuclear Information System (INIS)

    The authors measured expression of transformed phenotypes in human embryo (HE) cells repeatedly irradiated with a dose of 7.5 cGy per week throughout the life span of these cells in vitro. Irradiation was repeated until the cells had accumulated 195 cGy when the cells had reached the equivalent of their 26th passage and samples of cells at several passages were assayed for cell survival by colony formation, for mutation at hypoxanthin guanine phosphoribosyl transferase (HGPRT) locus and for transformation by focus formation. The lifespan (mean population doublings) of multiple irradiated cultures with a total dose of 97.5 cGy was slightly, but significantly, prolonged over that of controls. Although transformed foci were not observed with cells until cells had accumulated 97.5 cGy, it increased with increasing accumulated dose. No cells, however, showed unlimited life span in vitro and also expressed tumorigenicity. (author)

  3. Prompt Gamma Ray Measurement Facilities at Japan Research Reactor-3 (JRR-3)

    International Nuclear Information System (INIS)

    This paper briefly describes the present status of the two prompt gamma ray measurement facilities, PGA and MPGA, installed on neutron beam lines attached to Japan Research Reactor-3 (JRR-3). The description includes those on the configuration of the beam line as well as the supporting system of the irradiation sample, neutron intensity at the irradiation position, and detectors used for the prompt gamma ray measurement, for each of the facilities. (author)

  4. Comparison study of DNA synthesis, single strand breaks and repair in T and B lymphocytes after 60Co gamma-rays irradiation

    International Nuclear Information System (INIS)

    The synthesis of DNA in T, B lymphocytes was investigated by the determination of 3H-TdR incorporation after Gamma-irradiation. The DNA ssb (single strand breaks) and repair in lymphocytes were measured by alkaline elution. The DNA synthesis in B lymphocytes was much lower than that in T lymphocytes. No significant difference in DNA ssb was found between T and B lymphocytes. But a less effecient process of repair was observed in B lymphocytes, So it was conceived that B lymphocytes were more sensitive to Gamma-irradiation than T lymphocytes and DNA synthesis might be related with the repair of DNA ssb

  5. A gamma ray burst model

    International Nuclear Information System (INIS)

    We present a model for gamma ray bursts based on the compression of neutron stars in close binary systems. Our general relativistic hydrodynamiccomputer simulations of close neutron star binaries have found that as the orbit shrinks the density of the neutron stars rises. This compressional effect has been estimated to produce thermal energies in the neutron stars of the order of magnitude 1052to 1053 ergs on a timescale of a few seconds.This is a possible source of energy for gamma-ray bursts. The hot neutron stars will emit neutrino pairs which will partially recombine to form an electron positron pair plasma. The pair plasma will recombine after expansion to produce photons which closely mimic the characteristics of gamma-raybursts

  6. Airborne gamma ray spectrometer surveying

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency (IAEA) in its role as collector and disseminator of information on nuclear techniques has long had an interest in gamma ray spectrometer methods and has published a number of Technical Reports on various aspects of the subject. At an Advisory Group Meeting held in Vienna in November 1986 to review appropriate activities the IAEA could take following the Chernobyl accident, it was recommended that preparation begin on a new Technical Report on airborne gamma ray spectrometer surveying, taking into account the use of the technique for environmental monitoring as well as for nuclear emergency response requirements. Shortly thereafter the IAEA became the lead organization in the Radioelement Geochemical Mapping section of the International Geological Correlation Programme/United Nations Educational, Scientific and Cultural Organization (UNESCO) Project on International Geochemical Mapping. These two factors led to the preparation of the present Technical Report. 18 figs, 4 tabs

  7. Expressed sequence tags isolated from mouse bone marrow cells irradiated with high-dose gamma rays by suppression subtractive hybridization (SSH)

    International Nuclear Information System (INIS)

    Objective: To explore the molecular mechanism of bone marrow injury caused by irradiation, gene expression of bone marrow cells in mice after whole body irradiation was studied. Methods: Total RNA extracted from bone marrow cells in mice at 4 h after whole body irradiation with 7 Gy ?-rays was taken as the tester and the total RNA from control mice as the driver cDNA subtraction was performed using the protocols described in the Clontech SMART PCR cDNA Sythesis Kit and PCR-select cDNA Subtraction Kit. The subtracted cDNA was then inserted into T vector to generate subtracted cDNA library. Clones of the subtracted cDNA library were screened by hybridization and the insert sequence of the positive clones was compared with the sequence in the GenBank. Results: A total of 800 clones selected from the subtracted cDNA library were PCR-amplified and about 86% had inserts. Fourteen differential cDNA fragments were acquired after two round hybridization screening, 7 of them showed high similarity to the expressed sequence tags (ESTs) in the mouse EST database and the other 7 cDNA fragments were possibly new ESTs. Conclusion: The successfully constructed subtracted cDNA library of bone marrow cells in mice after whole body high-dose irradiation and the validation of some differential ESTs establish the basis for further research of radiation-related genes

  8. Effect of gamma rays and combined treatment between irradiation and other factors to quality of dried cuttle fish and ready-to eat cuttle fish

    International Nuclear Information System (INIS)

    The paper showed that the microbial contamination on dried cuttle fish produced from different sources was rather high: 106 - 108/g of sample. E.Coli, Cl.perfringens, Staphylococcus and fungi were found in all samples. Irradiation dose of 3 kGy combined with NaCl (10%) and benzoate natri 0.2% or NaCl (10%) and sorbate kali (2%) reduced total bacterial counts to 104/g. Microbial contamination on ready-to eat dried cuttle fish was 103/g. The pathogenic bacteria were still found in some cases. Fungi contamination was 102 - 105/g in all tested samples. Samples with initial moisture of 21 -26% irradiated at 2 kGy or without irradiation have been attacked by mould after 1 - 1.5 months of storage while there was no mould growth on samples of 19% moisture treated with 2 kGy or on samples of higher moisture but irradiated at 3 kGy, after 9 months of storage. There was not difference in enumeration of microorganisms in dried cuttle fish at 20 - 24 oC and 30 - 32 oC, as well as for two kinds of packaging. (author). 4 refs, 4 tabs

  9. On Gamma-Ray Bursts

    OpenAIRE

    Ruffini, Remo; Bernardini, Maria Grazia; Bianco, Carlo Luciano; Caito, Letizia; Chardonnet, Pascal; Cherubini, Christian; Dainotti, Maria Giovanna; Fraschetti, Federico; Geralico, Andrea; Guida, Roberto; Patricelli, Barbara; Rotondo, Michael; Hernandez, Jorge Armando Rueda; Vereshchagin, Gregory; Xue, She-Sheng(ICRANet, P.zza della Repubblica 10, I-65122 Pescara, Italy)

    2008-01-01

    (Shortened) We show by example how the uncoding of Gamma-Ray Bursts (GRBs) offers unprecedented possibilities to foster new knowledge in fundamental physics and in astrophysics. After recalling some of the classic work on vacuum polarization in uniform electric fields by Klein, Sauter, Heisenberg, Euler and Schwinger, we summarize some of the efforts to observe these effects in heavy ions and high energy ion collisions. We then turn to the theory of vacuum polarization aroun...

  10. Process for producing a collagen web for a transparent artificial cornea and a contact lens by irradiation with ultraviolet or gamma rays

    International Nuclear Information System (INIS)

    A process for producing a collagen web for use as an artificial cornea and a contact lens is provided by irradiating an acid soluble collagen web or a swelled collagen web with ultraviolet rays or gamma radiation. Cross-linking is introduced into the molecules forming a noncrystalline portion of the collagen to minimize nonuniformity of construction. In embodiments, the collagen, dissolved in a diluted hydrochloric acid or acetic acid aqueous solution at a concentration of about 0.5% to 1%(pH 2-4), is poured into a suitable container for producing and drying a web. The obtained web is neutralized with ammoniac water or vapor and is washed completely. The web is dipped in a dilute hydrochloric acid or acetic acid aqueous solution (pH 2-4) to well and then irradiated. Cross-linking is introduced, followed by further neutralization with ammoniac vapor. Finally the web is washed, air-dried or kept in water. Alternately, the above 0.5%-1% collagen solution is irradiated to gelatinize it after the oxygen dissolved in the solution is substituted with nitrogen. The irradiated web is neutralized with ammoniac water or vapor, and then washed, air-dried or kept in water. In one example, 0.58% collagen hydrochloric acid solution was poured into a methylmethacrylate box and was air-dried to form a web 0.03mm in thickness. The web was neutralized with ammoniac vapor for 24 hours and dipped to swell in a 0.01N HCl solution for 1 minute. The opposite sides of the web were irradiated with UV-rays at 15W. (Iwakiri, K.)

  11. Ion-induced gamma-ray detection of fast ions escaping from fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Nishiura, M., E-mail: nishiura@ppl.k.u-tokyo.ac.jp; Mushiake, T. [Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8561 (Japan); Doi, K.; Wada, M. [Graduate School of Science and Engineering, Doshisha University, Kyotanabe 610-0321 (Japan); Taniike, A.; Matsuki, T. [Graduate School of Maritime Sciences, Kobe University, Kobe 658-0022 (Japan); Shimazoe, K. [Graduate School of Engineering, The University of Tokyo, Tokyo 113-8654 (Japan); Yoshino, M. [Furukawa Co. Ltd., Tsukuba, Ibaraki 305-0856 (Japan); Nagasaka, T.; Tanaka, T.; Kisaki, M. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Fujimoto, Y.; Fujioka, K. [Institute of Laser Engineering, Osaka University, Osaka 565-0871 (Japan); Yamaoka, H. [RIKEN SPring-8 center, RIKEN, Sayo, Hyogo 679-5148 (Japan); Matsumoto, Y. [Tokushima Bunri University, Tokushima 770-8514 (Japan)

    2014-11-15

    A 12 × 12 pixel detector has been developed and used in a laboratory experiment for lost fast-ion diagnostics. With gamma rays in the MeV range originating from nuclear reactions {sup 9}Be(?, n?){sup 12}C, {sup 9}Be(d, n?){sup 12}C, and {sup 12}C(d, p?){sup 13}C, a high purity germanium (HPGe) detector measured a fine-energy-resolved spectrum of gamma rays. The HPGe detector enables the survey of background-gamma rays and Doppler-shifted photo peak shapes. In the experiments, the pixel detector produces a gamma-ray image reconstructed from the energy spectrum obtained from total photon counts of irradiation passing through the detector's lead collimator. From gamma-ray image, diagnostics are able to produce an analysis of the fast ion loss onto the first wall in principle.

  12. Activity evaluation from different native or irradiated with 60 Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis

    International Nuclear Information System (INIS)

    Cutaneous leishmaniasis is a disease, caused by Leishmania parasites, that occurs frequently in tropical and sub-tropical regions of the world. Skin lesions that could results in disfiguring aspect characterize it. The treatment is based on few drugs as antimony salts or pentamidine that are toxic with increasing resistance by the parasite. Alternative forms of disease treatment are in constant search, including natural components as snake venoms. Previous studies demonstrate that some components of snake venoms have an inhibitory effect against those parasites, including Leishmania species. Although snake venoms presented high toxicity, several methods have been described to detoxify most or some of their toxic components, with favorable results by the use of gamma irradiation. In this report we tested several native and irradiated snake venoms for inhibitory effect against Leishmania (Leishmania) amazonensis parasite and LLCMK2 mammalian cells, with enzymatic tests and electrophoresis. There are significant activity in Acanthophis antarcticus, Agkistrodon bilineatus, Bothrops moojeni, Bothrops jararaca, Hoplocephalus stephensi, Naja melanoleuca, Naja mossambica, Pseudechis australis, Pseudechis colletti, Pseudechis guttatus and Pseudechis porphyriacus, venom being inactive Pseudonaja textilis, Notechis ater niger, Notechis scutatus. Oxyuranus microlepidotus and Oxyuranus scutellatus venoms. After 2 KGy of 60Co irradiation most venom loses significantly their activity. Venoms with antileishmanial activity presented L-amino acid oxidase (L-AO) activity and showed common protein with a molecular weight about 60kDa in SDS-PAGE. These results indicate that L-AO activity in those venoms are probably related with antileishmanial effect. (author)

  13. Study of alteration in the mechanical properties in hybrid nanocomposite of polypropylene/sisal fibers/mineral clay irradiated with gamma rays

    International Nuclear Information System (INIS)

    A new material class formed with reinforced filler, hybrid of organic and inorganic materials provides the technological development of materials with modified properties. And among great numbers of properties that can be modified by presence of hybrid filler to stand out the tension resistance. Polymer shows behavior of tensions and deformation that are not related of simple form. The answer of this material at mechanicals solicitations depends of structural factors and externals variables. As structural factors can be, for example, molecular weight, ramifications and crosslink. As external variables can be, for example, temperature, time or velocity of deformation, kind of solicitation and others. This work was possible to verify as nanostructures materials behavior, mechanically, after were submitted gamma radiation. This work utilized as polymeric matrix, recycled polypropylene, and as hybrid filler, a mixture of montimorillonite mineral clay with natural sisal fibers. It is known that form to magnify the tensile resistance is increase the number of crosslink of principal chain for gamma radiation. After irradiation the polypropylene was crosslinked structures that are result recombination of radicals formed during process of irradiation. It.s known that radicals formed occur preferentially in the amorphous region of polymer. Considering that polymeric matrix polypropylene, without addition fillers suffer strong structural influence when irradiated, was possible verify change in the extension, tensile strength and also maxim tensile in rupture, when this matrix was incorporated with fillers hybrids. (author)

  14. Effect of different doses of gamma rays and fast neutrons on growth of carrot cellus tissue

    International Nuclear Information System (INIS)

    Callus tissue lines of four carrot cultivars, grown on three nutrient media, were irradiated with doses of gamma rays from 260 to 44700 R and fast neutrons from 180 - 21000 rad. Effects similar to those of gamma rays were obtained at lower doses of fast neutrons. The response of callus tissues to irradiation was influenced both by genetic factors and the nutrient medium. Two of the irradiated lines exhibited growth stimulation at low doses and a lower sensitivity to irradiation than did the two other ones. Tissues grown on a medium without kinetin showed the highest stimulation at low doses and the lowest growth depression at higher doses of irradiation. (author)

  15. Mitosis delay in cells of the root meristem of pea seedlings in S and G2-phases when irradiated with gamma-rays

    International Nuclear Information System (INIS)

    Irradiation (800 rads) of pea seedlings, synchronized by a 24-hr treatment with 0.03% hydroxyurea, at the stage of G1?S, induced a 12-hr delay of mitosis peak; an 8-hr delay, in the early S-phase; a 4-hr delay, in the middle of S-phase; a 10-hr delay in the late S- and a 14-16-hr delay, in G2-phase. The number of cells having chromosome aberrations at the mitosis peak was similar in all the phases under study

  16. Nuclear protein and DNA content of myocardial myocytes during adaptation of the irradiated heart to an increased hemodynamic load. [. gamma. rays; rats

    Energy Technology Data Exchange (ETDEWEB)

    Stepanov, R.P.

    1979-10-01

    The enlargement of cardiomyocyte nuclei in rats following local exposure to ..gamma.. radiation (2400 R) and in the presence of compensatory hypertrophy is related to accumulation of nuclear proteins, with prevalence of non-histone fractions. There is a decrease in number of polyploid nuclei after irradiation and an increase in number of small nuclei with reduced DNA and protein content (with an excess of histones). The combined effect of radiation and a hemodynamic load enhances these radiation effects and attenuates the nuclear changes that are inherent in development of hypertrophy.

  17. The quality study of Medicago sativa. L. var Longmu803 irradiated by the mixed high-energy particle field and 60Co-gamma ray respectively

    International Nuclear Information System (INIS)

    Ten respective group dry seeds of LongMu803 alfalfa were irradiated by mixed high-energy particle field(CR) and 60Co ? ray with five doses(109.4Gy, 144.5Gy, 194.7Gy, 284Gy, 559.6Gy).100 seeds of each group were planted in 2006 Apr, cut on 2006 Sep 27th, when the second batch of bud appeared. All the alfalfa plants were separately reaped in 2006 Sep 27th, airing in shade immediately. The dry plants were triturated by Foss CyclotecTM 1093 Mill, finenessTM 2045 Extraction System and Crude fiber (CF) with Foss FibertecTM 2010 Fiber Analysis System (Weende Method) The result shows although CR irradiated alfalfa dry seeds have better result than the 60Co ? ray in the plant height and weight, but 60Co ? ray did better in change the alfalfa plant quality. Higher dosage (284?559.8Gy) had better effect on change the CP's content than lower dosage. But high dosage's ? ray will restrain the EE's content. (author)

  18. Induction of rhodanese, a detoxification enzyme, in livers from mice after long-term irradiation with low-dose-rate gamma-rays

    International Nuclear Information System (INIS)

    The health effects of low-dose radiation exposure are of public concern. Although molecular events in the cellular response to high-dose-rate radiation exposure have been fully investigated, effects of long-term exposure to extremely low-dose-rate radiation remain unclear. Protein expression was analyzed by two-dimensional electrophoresis in livers from mice irradiated for 485 days (22 hr/day) at low-dose-rates of 0.032 ?Gy/min, 0.65 ?Gy/min and 13 ?Gy/min (total doses of 21 mGy, 420 mGy and 8000 mGy, respectively). One of the proteins that showed marked changes in expression was identified as rhodanese (thiosulfate sulfurtransferase). Rhodanese expression was increased after irradiation at 0.65 ?Gy/min and 13 ?Gy/min, while its expression was not changed at 0.032 ?Gy/min. Rhodanese is a detoxification enzyme, probably related to the regulation of antioxidative function. However, antioxidative proteins, such as superoxide dismutase (SOD)1 (also known as Cu, Zn-SOD) and SOD2 (also known as Mn-SOD), which can be induced by high-dose-rate radiation, were not induced at any low-dose-rates tested. These findings indicate that rhodanese is a novel protein induced by low-dose-rate radiation, and further analysis could provide insight into the effects of extremely low-dose-rate radiation exposure. (author)

  19. Effects of gamma rays on rat vascular smooth muscle fibers

    International Nuclear Information System (INIS)

    Modifications of the Vasomotoricity induced by gamma rays have been investigated. Vascular smooth muscle fibres (VSMF) of rat portal vein have been used in this study. Irradiation procedures using a 60 Co source have been carried out as follows: - Whole body irradiation. - Irradiation of isolated portal vein and isolated VSMF. Our results show that : 1-irradiation reduces the functional competition between Mg2+ and Ca2+, thus hyper magnetic Krebs solutions have a negligible effect on irradiated VSMF. 2- irradiation activates Ca2+ influx into the VSMF. Thus the effect of hypocalcemic solutions on irradiated VSMF is minor compared with control. 3- Hyperpotassic solutions provoke titanic contractions with high amplitude on the irradiated VSMF compared with control. 5 figs

  20. Gamma-ray co-irradiation induced graft polymerization of NVP and SSS onto polypropylene non-woven fabric and its blood compatibility

    Science.gov (United States)

    Li, Rong; Wang, Hengdong; Wang, Wenfeng; Ye, Yin

    2013-10-01

    Sodium styrenesulfonate was grafted onto PPNWF via ?-ray co-irradiation method with the existence of N-vinyl-2-pyrrolidone. The effect of absorbed dose, dose rate and concentration of binary monomer on the degree of grafting was investigated. The surface chemical change was characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The wettability was characterized through the measurement of adsorption percentage of water and phosphate buffer solution (PBS). The result demonstrated that the grafted poly(NVP-co-SSS) chains can improve the hydrophilicity of PPNWF. Furthermore, the modified PPNWF has good blood compatibility, such as low hemolysis rate, low platelet adhesion and effectively extending the blood coagulation times. Consequently, hydrophilicity and hemocompatibility of PPNWF were greatly enhanced by the immobilization of poly(NVP-co-SSS) chains.

  1. Comparison between four mutant lines of barley (Hordium Vulgare. L) resulted from California mariut irradiated with gamma rays and mother variety in different salinity

    International Nuclear Information System (INIS)

    This study was carried out for four mutants lines of barley and there mother variety for salt tolerance. These mutant lines are (1.9.3, 1.9.16, 1.10.4, 1.10.2 5 and mother variety) resulted from m5, (cobalt 60 was used as irradiation source) all these lines were planted in pots with different degree of salinity (3.8, 5.8. and 9.3 m mhos/cm). All these pots maintained at field capacity, after 8 weeks the pots were harvested and plant length, wet weight and dry weight were determined and statistically calculated. The results were shown that the mutant line (1.9.16) significantly different for salt tolerance comparison with other mutant lines and control (mother variety).(author)

  2. Gamma-ray effect on sweet potato

    International Nuclear Information System (INIS)

    The paper presents the results on modification occurred in biochemical properties of sweet potato (Ipomea batatus L.) after gamma irradiation. Two varieties, named Victoria Ianb (a white variety) and Portocaliu (a red variety), were selected and acclimatized for the agrometeorological conditions of Romania. The samples consist of roots from both usual and experimental crops. They were irradiated in batch, one week after harvesting, with a ICPR Co-60 gamma-ray source by approx. 370 TBq, dose range 100-500 Gy, dose rate 100±5 Gy/hour, dose uniformity ±5%, temperature 10oC, 80±5% relative humidity (rh). The irradiation doses received were checked using the Fricke ferrous sulphate dosimeter procedure. The roots were kept two months at relative darkness, 6-11oC, 60-75% rh and analyzed from time to time (initial, 5, 7, 14, 30 and 60 days). The following parameters are analyzed by conventional methods: total and reducing sugars (in De equivalent, %, on dry weight basis), starch content and the activities of sugar metabolizing enzymes. The red variety had a better behaviour towards irradiation that the white one. The sugar contents (both total and reducing), as well as starch, varied more in the white variety. The sugar metabolizing enzyme activities were influenced by both irradiation and storage conditions. Their activities were maximal at 200 and 300 Gy, and decreased significantly at higher doses. The activities also decreased in time, their variations being higher at lower doses (100 and 200 Gy). The results showed no significant influence of gamma irradiation on storage life. The modifications induced in sugar contents and enzyme activities had maximal effects at 200-300 Gy. (author)

  3. Flares in Gamma Ray Bursts

    OpenAIRE

    Chincarini, G.; Mao, J.; Pasotti, F.; Margutti, R.; Guidorzi, G.; Bernardini, M. G.; team, Swift Italian

    2008-01-01

    The flare activity that is observed in GRBs soon after the prompt emission with the XRT (0.3-10 KeV) instrument on board of the Swift satellite is leading to important clues in relation to the physical characteristics of the mechanism generating the emission of energy in Gamma Ray Bursts. We will briefly refer to the results obtained with the recent analysis and and discuss the preliminary results we obtained with a new larger sample of GRBs [limited to early flares] based o...

  4. Gamma Ray Burst Central Engines

    CERN Document Server

    Thompson, Todd A

    2008-01-01

    I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the flow, and both the association and the non-association with bright supernovae. I compare and contrast the collapsar and millisecond proto-magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ~100 while simultaneously maintaining a kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.

  5. Gamma-ray burst reprocessing

    Science.gov (United States)

    Melia, Fulvio

    1988-01-01

    A review of three theoretical models for the generation of transient optical emission thought to accompany the gamma-ray bursts is presented. The physics of reprocessing by Compton-heated electrons in the magnetosphere of a highly magnetized neutron star, the surface layers of a companion star, and an accretion disk are discussed. The spectral shapes, time scales, and arrival time delays between low and high energy photons predicted by the models are compared. These predictions are so different that broad band monitoring could be used to indicate which of the three scenarios (if any) is correct.

  6. Gamma-Ray Astronomy Technology Needs

    Science.gov (United States)

    Gehrels, N.; Cannizzo, J. K.

    2012-01-01

    In recent decades gamma-ray observations have become a valuable tool for studying the universe. Progress made in diverse 8re1lS such as gamma-ray bursts (GRBs), nucleosynthesis, and active galactic nuclei (AGNs) has complimented and enriched our astrophysical understanding in many ways. We present an overview of current and future planned space y-ray missions and discussion technology needs for- the next generation of space gamma-ray instruments.

  7. Understanding Doppler Broadening of Gamma Rays

    Energy Technology Data Exchange (ETDEWEB)

    Rawool-Sullivan, Mohini [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sullivan, John P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-07-03

    Doppler-broadened gamma ray peaks are observed routinely in the collection and analysis of gamma-ray spectra. If not recognized and understood, the appearance of Doppler broadening can complicate the interpretation of a spectrum and the correct identification of the gamma ray-emitting material. We have conducted a study using a simulation code to demonstrate how Doppler broadening arises and provide a real-world example in which Doppler broadening is found. This report describes that study and its results.

  8. Very High Energy Gamma-Ray Astronomy

    OpenAIRE

    Catanese, Michael; Weekes, Trevor C.

    1999-01-01

    We present a review of the current status of very high energy gamma-ray astronomy. The development of the atmospheric Cherenkov imaging technique for ground-based gamma-ray astronomy has led to a rapid growth in the number of observatories. The detection of TeV gamma rays from Active Galactic Nuclei was unexpected and is providing new insights into the emission mechanisms in the jets. Next generation telescopes are under construction and will increase dramatically the knowle...

  9. Gamma-Ray Pulsar Studies with GLAST

    Science.gov (United States)

    Thompson, David J.

    2007-01-01

    This viewgraph presentation reviews the prospects of extending the understanding of gamma ray pulsars, and answering the open questions left from the limited observations that are available from current observatories. There are 2 new gamma ray observatories that are either on orbit or will be shortly launched: (1) Astro-rivelatore Gamma a Immagini LEggero (AGILE), and Gamma-ray Large Area Space Telescope (GLAST). On board GLAST there will be two instruments Large Area Telescope (LAT), and GLAST Burst Monitor (GBM).

  10. Gamma-Ray Pulsar Studies with GLAST

    OpenAIRE

    Thompson, D. J.

    2007-01-01

    Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based o...

  11. Effects of gamma-ray radiation on activity and apoptosis of rat cardiomyocytes in vitro

    International Nuclear Information System (INIS)

    Objective: It is reported that radiation-induced myocardial degeneration in the rat is preceded by changes in capillary structure and function. The aim of the present study is to investigate direct effect of gamma ray radiation on activity and apoptosis of cultured rat cardiomyocytes in vitro. Methods: The study was performed using primary cell cultures of cardiomyocytes isolated from hearts of now-born rats. After being cultured for 72h in vitro, cardiomyocytes were irradiated with single dose of 5 Gy, 10 Gy, 20 Gy of gamma ray respectively. At 48h post-irradiation, the concentration of LDH in the supernatant of cell culture was tested using methods introduced by International Federation of clinical chemistry (IFCC), and apoptosis was determined with flow cytometry. The viability of myocytes was determined with crystal violet test and MTT test at 48h and 120h post-irradiation respectively. Results: LDH concentration in the supernatant of cell culture of cardiomyocytes were increased significantly with the irradiation dose augment. Flow cytometry confirmed the induction of apoptosis in response to different gamma ray doses irradiation at 48h after irradiation. The viable cardiomyocytes irradiated by gamma ray were significantly declined at 120h after irradiation compared to un-irradiated cells, however there were no significant difference between two groups at 48h post-irradiation. Dose-effect relationship was demonstrated between cardiomyocyte apoptosis, viability and irradiation dose in the study. Conclusion: The study demonstrates gamma ray radiation can cause direct damage to cultured cardiomyocytes, including inhibiting activity and inducing apoptosis of cardiomyocytes in vitro, which shows dose effect relationship. The mechanism of gamma ray irradiation induced injury to cardiomyocytes should be investigated further. (authors)

  12. Effects of gamma rays and colchicine on mutagenesis in somaclones of Lilium davidii var willmottiae

    International Nuclear Information System (INIS)

    Bulb-scales of Lilium davidii var. willmottiae were irradiated with gamma-rays (500 - 2000 R) and their sections were cultured on MS medium supplemented with colchicine (1 - 4 mg/l), NAA and BA. The regenerated plantlets were also treated with gamma-rays (100 - 500 R) and colchicine (1 - 4 mg/l). Treatments of scales with colchicine and irradiation of various dosages all showed significant inhibition on the regeneration of plantlets from the cultures. Proliferation of regenerated plantlets which were treated with colchicine was also inhibited, especially when colchicine concentration increased to 2.0 mg/l or more. The proliferation was somewhat enhanced when regenerated plantlets were irradiated with gamma-rays of 300 R or less, while it was inhibited in the case of 400 R or more. The LD50 of gamma-rays for the plantlets was 400 - 500 R. The combined inhibiting effect of colchicine and gamma-rays on the proliferation of plantlets was greater than their separate impact. Variations in leaf thickness, leaf colour, bulb size, etc. occurred in plantlets treated with colchicine alone or in combination with irradiation. The variations were stable in subculture of the plantlets. The optimal treatment for induction of variations was 200 - 400 R gamma-rays plus 2.0 mg/l colchicine. The variations kept stable when the plantlets were transplanted into the field, and some of them are being used in breeding programs

  13. Determination of protein content in grains by radioactive thermal neutron capture prompt gamma rays analysis

    International Nuclear Information System (INIS)

    The radioactive thermal neutron capture prompt gamma rays technique can be used to determinate the nitrogen content in grains without chemical destruction, with good precision and relative rapidity. This determination is based on the detection of prompt gamma rays emitted by the 14N(n,?) 15N reaction product. The samples has been irradiated the tanGencial tube of the IEA-R1 research reator and a pair spectrometer has been used for the detection of the prompt gamma rays. The nitrogen content is determinated in several samples of soybean, commonbean, peas and rice, and the results is compared with typical nitrogen content for each grain. (Autor)

  14. Leukemic risk from neutrons and gamma rays

    International Nuclear Information System (INIS)

    Some of the most useful data for evaluating the latent effect of radiation exposure on humans comes from the medical and epidemiological studies of the Japanese atomic-bomb survivors. These survivors comprise a large population (over 100,000) exposed at all ages to a wide range of radiation doses. Estimates of radiation dose are available for most of the survivors and are designated in the literature as T65D estimates. Although each survivor's location at the time of exposure and the shielding provided by structures and terrain were taken into account in their T65D assignments of dose, these dose assignments predict only a survivor's radiation exposure in terms of tissue kerma in air. The body shielding of internal organs for gamma rays and neutrons from monoenergetic and fission sources has been investigated in detail at Oak Ridge National Laboratory within the past several years, and the results of these investigations have shown that the absorbed doses to the internal organs of the atomic-bomb survivors vary markedly from their T65D assignments of tissue kerma in air. Our calculations will be reviewed and compared with relevant calculations and measurements published by others. The emphasis in these comparisons will be on estimates of the body shielding of active bone marrow for radiation fields from a fission source. New data from age-specific calculations of self-shielding of active bone marrow by the body will be discussed and used with data from studies of the atomic-bomb survivors to investigate the age dependency of leukemic risk from neutrons and gamma rays. These results will be compared with other relevant estimates of leukemic risk derived from studies of the atomic-bomb survivors and medically irradiated groups such as the ankylosing spondylitis and tinea capitis patients. (author)

  15. Gamma ray induced somatic mutations in rose

    International Nuclear Information System (INIS)

    Budwood of 32 rose cultivars (Rosa spp.) was exposed to 3-4 krad of gamma rays and eyes were grafted on Rosa indica var. odorata root stock. Radiosensitivity with respect to sprouting, survival and plant height, and mutation frequency varied with the cultivar and dose of gamma rays. Somatic mutations in flower colour/shape were detected as chimera in 21 cultivars. The size of the mutant sector varied from a narrow streak on a petal to a whole flower and from a portion of a branch to an entire branch. 14 mutants were detected in M1V1, four in M1V2 and three in M1V3. Maximum number of mutations was detected following 3 krad treatment. Eyes from mutant branches were grafted again on root stock and non-chimeric mutants were aimed at by vegetative propagation. Mutants from 11 cultivars only could be isolated in pure form. Isolation of non-chimeric mutants sometimes is difficult due to weak growth of a mutant branch. In such a case, all normal looking branches are removed to force a better growth of the mutant branch. It is advisable to maintain irradiated plants at least for four years with drastic pruning in each year. Nine mutants viz. 'Sharada', 'Sukumari', 'Tangerine Contempo', 'Yellow Contempo', 'Pink Contempo', 'Striped Contempo', 'Twinkle', 'Curio' and 'Light Pink Prize' have already been released as new cultivars for commercialization [ref. MBNL No. 23 and 31] and others are being multiplied and assessed. The mutation spectrum appears to be wider for the cultivars 'Contempo' and 'Imperator'. Pigment composition of the original variety is relevant for the kind of flower colour mutations that can be induced

  16. Radio counterparts of gamma-ray pulsars

    OpenAIRE

    Guillemot, L.; collaboration, for the FERMI LAT; Consortium, for the Fermi Pulsar Search; Consortium, for the Fermi Pulsar Timing

    2012-01-01

    Observations of pulsars with the Large Area Telescope (LAT) on the Fermi satellite have revolutionized our view of the gamma-ray pulsar population. For the first time, a large number of young gamma-ray pulsars have been discovered in blind searches of the LAT data. More generally, the LAT has discovered many new gamma-ray sources whose properties suggest that they are powered by unknown pulsars. Radio observations of gamma-ray sources have been key to the success of pulsar s...

  17. Caracterización del peuapm irradiado con rayos gamma, almacenado en vitamina e y tratado térmicamente / CHARACTERIZATION OF UHMWPE IRRADIATED WITH GAMMA RAYS, STORED IN E VITAMIN AND THERMALLY TREATED

    Scientific Electronic Library Online (English)

    Ernesto, Davidson; Jacobo, Reyes-Romero; Delfín, Moronta; Gema, González; Othman, Falcón.

    2011-03-01

    Full Text Available La presente investigación tiene como propósito caracterizar el polietileno de ultra alto peso molecular (PEUAPM-Gur- 1050) irradiado a 100 y 50 kGy en atmosfera de argón a 25ºC a una velocidad de 4,8 kGy/h, almacenado en vitamina E a la concentración de 0,1wt% y posterior tratamiento térmico (la mue [...] stra que fue irradiada a 100kGy es la que fue recocida a 120ºC y la que fue irradiada a 50kGy es la que fue refundida a 140ºC), con el fin de mejorar las propiedades para su utilización en ortopedia. Las reacciones de entrecruzamiento fueron las que ocurrieron en mayor grado, siendo este efecto más pronunciado en la muestra que fue refundida a 140ºC. También esta muestra evidenció mayor dureza y resistencia al desgaste, no presentó cambios significativos en los valores de la resistencia a la compresión; en cambio, exhibió una disminución del 10% en el módulo de Young. El análisis mediante FTIR muestra una menor relación de grupos carbonilos en relación con grupos transvinilenos. No se evidenció la presencia de ninguna especie oxidante a través de las espectroscopias de UV cercano y RES. De estos resultados se infiere que el PEUAPM refundida a 140ºC, resultaría el más apropiado para el diseño y fabricación de las prótesis porque contribuiría a que el implante tenga una mayor duración Abstract in english The present investigation has the purpose of characterize the ultra high molecular weight polyethylene (UHMWPE-Gur- 1050), irradiated at 100 and 50 kGy in argon atmosphere at 25ºC, and at a rate of 4.8 kGy/h; After that, they were stored in vitamin E at a concentration of 0.1 wt%. In order to obtain [...] better properties for the use in orthopedics, the samples irradiated at 100 kGy where annealing at 120ºC and the ones at 50 kGy at 140ºC. The crosslinking predominant reactions, in the case of 140ºC remelting temperature, has a greater effect than at 120ºC, showing also greater hardness and resistance to compression, In spite of that they showed a 10% decreasing in the Young module. The FTIR analysis shows a lesser relation of carbonyl groups, related to the transvilidenes groups. It was not found the presence of oxidant species by means of UV and ESR spectroscopy. From the results, can be inferred that the UHMWPE, remelted at 140ºC is more appropriated for the design and manufacturing of prosthesis due to its longer lifespan

  18. Investigation of rheological properties of the irradiated isoprene-nitrile elastomers

    International Nuclear Information System (INIS)

    Full text : The aim of this work was the investigation of flow regularities both rubbers and the irradiated blends on the basis of these rubbers in dependence of following factors : different tensions and deformation shift rate, irradiation and low-molecular product degree. The flow regularities of irradiated blends with flow of non-irradiated blends were correlated

  19. Gamma-ray burst models.

    Science.gov (United States)

    King, Andrew

    2007-05-15

    I consider various possibilities for making gamma-ray bursts, particularly from close binaries. In addition to the much-studied neutron star+neutron star and black hole+neutron star cases usually considered good candidates for short-duration bursts, there are also other possibilities. In particular, neutron star+massive white dwarf has several desirable features. These systems are likely to produce long-duration gamma-ray bursts (GRBs), in some cases definitely without an accompanying supernova, as observed recently. This class of burst would have a strong correlation with star formation and occur close to the host galaxy. However, rare members of the class need not be near star-forming regions and could have any type of host galaxy. Thus, a long-duration burst far from any star-forming region would also be a signature of this class. Estimates based on the existence of a known progenitor suggest that this type of GRB may be quite common, in agreement with the fact that the absence of a supernova can only be established in nearby bursts. PMID:17293332

  20. Modulating effect of dimethylbenzanthracene on gamma-ray mutagenesis in the soybean test system

    International Nuclear Information System (INIS)

    Dimethylbenzanthracene (DMBA), a strong tumor initiator, did not show mutagenic activity in the soybean test system either alone or in combination with tumor promoter, TPA. In combination treatments with DMBA and gamma-rays, the mutagenicity of gamma-rays was not affected by post-treatment with DMBA. However, DMBA pre-treatment clearly reduced gammaray-ray induced spotting frequency, suggesting that DMBA affects mutagenesis in gamma-irradiated soybean cells

  1. Experimental Measurements and Computer Simulation of Fission Product Gamma-Ray Spectra

    OpenAIRE

    Sanderson, D.C.W.; Cresswell, A.; Allyson, J.D.; McConville, P.

    1997-01-01

    Airborne gamma ray spectrometry using high volume scintillation detectors, optionally in conjunction with Ge detectors, has potential for making rapid environmental measurements in response to nuclear accidents. An experimental investigation and computer simulation have been used to characterise the response of such detectors to short lived fission products. Small samples of 235U were irradiated in a research reactor for short periods, to generate fission product sources. Gamma ray spectra w...

  2. Selección para contenido de proteína del grano en trigo irradiado con rayos gamma de 60Co / Selection for grain protein content in wheat irradiated with 60Co gamma rays

    Scientific Electronic Library Online (English)

    L, Partida-Ruvalcaba; & #932; , Cervantes-Santana; A, Salazar-Zazueta; TJ, Velázquez-Alcaraz.

    2009-12-01

    Full Text Available Esta investigación fue realizada por la necesidad de mejorar las variedades de trigo (Triticum aestivum L.) con alta calidad nutritiva. En compuestos irradiados seleccionados en seis ciclos por mayor tamaño y densidad de grano, se efectuó selección para mayor contenido de proteína. Siete compuestos [...] tuvieron dos niveles de irradiación, difirieron en cinco generaciones de irradiación y 74 kr de dosis acumulada, excepto uno cuya diferencia fue de 73 kr, y procedieron de la variedad 'Salamanca' irradiada con rayos gamma de cobalto sesenta (60Co). La selección fue hecha en plantas M6 y M11, y las líneas seleccionadas fueron evaluadas durante dos ciclos en Montecillo, Estado de México. El contenido de proteína tendió a la normal, con media, intervalo y varianza de 13.1%, 11.6 a 15.8% y 0.45, respectivamente, y 'Salamanca' tuvo 11.5%. Con el segundo nivel de irradiación, la media (13.1%), valor máximo (15.8%), varianza (0.51) y número de líneas (9) con más de 14.6% de proteína, superaron a los del primer nivel, cuyos valores fueron 12.9%, 15.0%, 0.41 y 3. Las tres líneas superiores fueron del segundo nivel de irradiación, con proteína de 14.9 a 15.3%, cuyos mínimo y máximo superaron al contenido de proteína de 'Salamanca' en 19.2 y 22.4%, respectivamente. La correlación de proteína y rendimiento de grano fue negativa (r = -0.59) y altamente significativa; las líneas de alta proteína rindieron menos que 'Salamanca'. Las líneas tuvieron mayor volumen y peso de grano que 'Salamanca', pero casi la misma densidad. Abstract in english This study was conducted in response to the need to improve wheat (Triticum aestivum L.) varieties with a high nutritional quality. A selection for greatest protein content was carried out on irradiated composites selected during six seasons considering a greater grain size and grain density. Seven [...] composites were subjected to two irradiation levels. They differed in five irradiation generations and 74 kr of accumulated doses, except for one with a difference of 73 kr. They came from the Salamanca variety irradiated with gamma rays of cobalt sixty (60Co). The selection was made from M6 and M11 plants, and the selected lines were evaluated over two seasons at Montecillo, State of Mexico. The protein content tended to be normal, with a mean, interval and variance of 13.1%, 11.6 to 15.8% and 0.45, respectively. The 'Salamanca' had 11.5%. With the second irradiation level, the mean (13.1%), maximum value (15.8%), variance (0.51) and number of lines (9) with more than 14.6% protein, exceeded those of the first level, of which the values were 12.9 %, 15.0 %, 0.41 and 3. The three high lines corresponded to the second irradiation level, with protein from 14.9 to 15.3 % and with minimum and maximum values exceeding the protein content of 'Salamanca' by 19.2 and 22.4%, respectively. The protein and grain yield correlation was negative (r = -0.59) and highly significant; the high protein content lines yielded less than 'Salamanca'. The lines had a greater grain volume and weight than 'Salamanca', but almost the same density.

  3. Prompt gamma-ray activation analysis (PGAA)

    Energy Technology Data Exchange (ETDEWEB)

    Kern, J. [Fribourg Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The paper deals with a brief description of the principles of prompt gamma-ray activation analysis (PGAA), with the detection of gamma-rays, the PGAA project at SINQ and with the expected performances. 8 figs., 3 tabs., 10 refs.

  4. Processing of complex gamma ray spectra

    International Nuclear Information System (INIS)

    In this paper a general review on analysis of gamma ray spectra is reported. At the same time, practical recommendations on the improvements for general-purpose gamma ray spectrum analysis software as well as for particular applications, are given. The present work at the BARC in this field is presented. (author)

  5. Gamma ray observation with emulsion hybrid telescope

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, S. [Kobe University, Kobe, Hyogo 657-850 (Japan); Kodam, K. [Aichi University of Education, Kariya, Aichi 448-8542 (Japan); Kawada, J.; Nonaka, N. [Institute of Space and Aeronautical Science, JAXA, Sagamihara Kanagawa 229-8510 (Japan); Suzuki, A.; Hara, T.; Watanabe, Y.; Rokujyo, H. [Kobe University, Kobe, Hyogo 657-850 (Japan); Ariga, A.; Kazuyama, M.; Kubota, H.; Komatsu, M.; Sako, T.; Sato, O.; Taira, Y.; Takahashi, S.; Naganawa, N.; Nakano, T.; Nakamura, M.; Niwa, K. [Dept. of Physics, Nagoya University, Nagoya, Aichi 464-01 (Japan)

    2009-12-15

    A new gamma ray observation project with balloon borne emulsion chambers is presented. A new technique based on the accelerator emulsion experiments was implemented for studying high energy stellar objects with cosmic gamma rays. This paper provides the aim and concept of this project as well as some results of test experiments.

  6. Gamma-Ray Pulsar Candidates for GLAST

    Science.gov (United States)

    Thompson, D. J.

    2008-01-01

    The Gamma-ray Large Area Space Telescope (GLAST) will be launched this year, and its Large Area Telescope (LAT) is expected to discover scores to hundreds of gamma-ray pulsars. This poster discusses which of the over 1700 known pulsars, mostly visible only at radio frequencies, are likely to emit greater than 100 MeV gamma rays with intensities detectable by the LAT. The main figure of merit used to select gamma-ray pulsar candidates is sqrt(E-dot)/d2, where E-dot is the energy loss due to rotational spin-down, and d is the distance to the pulsar. The figure of merit incorporates spin-down flux at earth (proportional to E-dot/d2) times efficiency, assumed proportional to l/sqrt(E-dot). A few individual objects are cited to illustrate the issues. Since large E-dot pulsars also tend to have large timing noise and occasional glitches, their ephemerides can become inaccurate in weeks to months. To detect and study the gamma-ray emission the photons must be accurately tagged with the pulse phase. With hours to days between gamma-ray photon arrival times from a pulsar and months to years of LAT exposure needed for good detections, GLAST will rely on radio and X-ray timing measurements throughout the continuous gamma-ray observations. The poster will describe efforts to coordinate pulsar timing of the candidate gamma-ray pulsars.

  7. GAMMA-400 gamma-ray observatory

    CERN Document Server

    Topchiev, N P; Bonvicini, V; Adriani, O; Aptekar, R L; Arkhangelskaja, I V; Arkhangelskiy, A I; Bakaldin, A V; Bergstrom, L; Berti, E; Bigongiari, G; Bobkov, S G; Boezio, M; Bogomolov, E A; Bonechi, L; Bongi, M; Bottai, S; Castellini, G; Cattaneo, P W; Cumani, P; Dalkarov, O D; Dedenko, G L; De Donato, C; Dogiel, V A; Finetti, N; Gascon, D; Gorbunov, M S; Gusakov, Yu V; Hnatyk, B I; Kadilin, V V; Kaplin, V A; Kaplun, A A; Kheymits, M D; Korepanov, V E; Larsson, J; Leonov, A A; Loginov, V A; Longo, F; Maestro, P; Marrocchesi, P S; Martinez, M; Menshenin, A L; Mikhailov, V V; Mocchiutti, E; Moiseev, A A; Mori, N; Moskalenko, I V; Naumov, P Yu; Papini, P; Paredes, J M; Pearce, M; Picozza, P; Rappoldi, A; Ricciarini, S; Runtso, M F; Ryde, F; Serdin, O V; Sparvoli, R; Spillantini, P; Stozhkov, Yu I; Suchkov, S I; Taraskin, A A; Tavani, M; Tiberio, A; Tyurin, E M; Ulanov, M V; Vacchi, A; Vannuccini, E; Vasilyev, G I; Ward, J E; Yurkin, Yu T; Zampa, N; Zirakashvili, V N; Zverev, V G

    2015-01-01

    The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The energy range of GAMMA-400 is expected to be from ~20 MeV up to TeV energies for gamma rays, up to 20 TeV for electrons + positrons, and up to 10E15 eV for cosmic-ray nuclei. For high-energy gamma rays with energy from 10 to 100 GeV, the GAMMA-400 angular resolution improves from 0.1{\\deg} to ~0.01{\\deg} and energy resolution from 3% to ~1%; the proton rejection factor is ~5x10E5. GAMMA-400 will be installed onboard the Russian space observatory.

  8. Intercomparison of gamma ray analysis software packages

    International Nuclear Information System (INIS)

    The IAEA undertook an intercomparison exercise to review available software for gamma ray spectra analysis. This document describes the methods used in the intercomparison exercise, characterizes the software packages reviewed and presents the results obtained. Only direct results are given without any recommendation for a particular software or method for gamma ray spectra analysis

  9. Calibration of TLDs using 137Cs and 60Co gamma ray sources

    International Nuclear Information System (INIS)

    Various reports in the literature indicated that response of TLDs (especially LiF TLD 100) to 137Cs gamma rays is several percent greater than the response to 60Co gamma rays. A question on this was also raised in the workshop on TLD personnel monitoring that the response of TLD badge based on CaSO4:Dy Teflon TLD discs is significantly different for 137Cs and 60Co gamma rays. Since these two sources are routinely used for calibration of dosimeters, a study was undertaken to compare the response of LiF and CaSO4:Dy Teflon TLD discs by using reference beams of 137Cs and 60Co gamma rays at a standard laboratory and to evaluate the response for CaSO4:Dy Teflon TLD discs TLD cards being used for personnel monitoring in India. CaSO4:Dy Teflon TLD discs were found to exhibit a small over-response (1-4%) to 137Cs gamma rays as compared to 60Co gamma rays. However, no observable over-response was noticed for TLD cards held in the badge cassette. The discrepancy in the response of TLDs to 137Cs and 60Co gamma rays has therefore been attributed to experimental errors caused by the use of inappropriate irradiation geometry and the uncertainty in the primary dosimetry. (author)

  10. $\\gamma$ Ray Bursts and Bursters

    CERN Document Server

    Mészáros, P

    2000-01-01

    Major advances have been made in the field of gamma-ray bursts in the last two years. The successful discovery of X-ray, optical and radio afterglows, which were predicted by theory, has made possible the identification of host galaxies at cosmological distances. The energy release inferred in these outbursts place them among the most energetic and violent events in the Universe. Current models envisage this to be the outcome of a cataclysmic event leading to a relativistically expanding fireball, in which particles are accelerated at shocks and produce nonthermal radiation. The substantial agreement between observations and the theoretical predictions of the standard fireball shock model provide confirmation of the basic aspects of this scenario. The continued observations show a diversity of behavior, providing valuable constraints for more detailed, post-standard models which incorporate more realistic physical features. Crucial questions being now addressed are the beaming at different energies and its im...

  11. Modulated gamma ray beam absorptiometer

    International Nuclear Information System (INIS)

    The purpose of this paper is to describe the study and operating of a heavy elements content measuring instrument. This apparatus (French patent n0 2184533, December 16, 1974) uses the absorption of a modulated gamma ray beam to measure the concentration of 5 to 500 g per litre uranium of plutonium solutions with an over 1% accuracy. The activity of the fission products present in the solution may rise to 60 Ci/l. An automatic device suppresses all daily checkings and adjustements. The tension obtained is proportional to the content of the heavy element being measured. The influence of the nitric acid content is twenty times as weak as in the case of a conventional densimeter. This apparatus is particularly adapted to fuel reprocessing plants

  12. Gamma-ray pulsars: a gold mine

    CERN Document Server

    Grenier, Isabelle A

    2015-01-01

    The most energetic neutron stars, powered by their rotation, are capable of producing pulsed radiation from the radio up to gamma rays with nearly TeV energies. These pulsars are part of the universe of energetic and powerful particle accelerators, using their uniquely fast rotation and formidable magnetic fields to accelerate particles to ultra-relativistic speed. The extreme properties of these stars provide an excellent testing ground, beyond Earth experience, for nuclear, gravitational, and quantum-electrodynamical physics. A wealth of gamma-ray pulsars has recently been discovered with the Fermi Gamma-Ray Space Telescope. The energetic gamma rays enable us to probe the magnetospheres of neutron stars and particle acceleration in this exotic environment. We review the latest developments in this field, beginning with a brief overview of the properties and mysteries of rotation-powered pulsars, and then discussing gamma-ray observations and magnetospheric models in more detail.

  13. Unveiling the Secrets of Gamma Ray Bursts

    CERN Document Server

    Gomboc, A

    2012-01-01

    Gamma Ray Bursts (GRBs) are unpredictable and brief flashes of gamma rays that occur about once a day in random locations in the sky. Since gamma rays do not penetrate the Earth's atmosphere, they are detected by satellites, which automatically trigger ground-based telescopes for follow-up observations at longer wavelengths. In this introduction to Gamma Ray Bursts we review how building a multi-wavelength picture of these events has revealed that they are the most energetic explosions since the Big Bang and are connected with stellar deaths in other galaxies. However, in spite of exceptional observational and theoretical progress in the last 15 years, recent observations raise many questions which challenge our understanding of these elusive phenomena. Gamma Ray Bursts therefore remain one of the hottest topics in modern astrophysics.

  14. Interaction between gamma rays and colchicine solution rice variety bengawan

    International Nuclear Information System (INIS)

    Seeds of rice variety Bengawan were radiated by gamma rays of different dosages (from 2.5 to 35 krad with interval of 2.5 krad). Half of each group of irradiated seeds were then treated with a 0.5% of colchicine solution for about 3 hours, 3 days after germination in petridishes. After being washed with distilled water the seedlings were planted in a nursery. One month old plants were then transplanted into polyethylene containers in the greenhouse. The seeds from the M-1 and M-2 plants were then cultivated in the field. Results of statis-tical calculation indicate that there is an interaction bet-ween gamma rays and colchicine solution treatments which affect the plant at dose level of 35 krad. The plant grows more erect, shorter, thicker, and resistent to lodging. (author)

  15. Cosmic Rays from Gamma Ray Bursts in the Galaxy

    CERN Document Server

    Dermer, C D; Hunter, Geoffrey; Kowalski, Marian; Alexandrescu, Camil; Dermer, Charles D.; Holmes, Jeremy M.

    2005-01-01

    The rate of terrestrial irradiation events by galactic gamma-ray bursts (GRBs) is estimated using recent standard-energy results. We assume that GRBs accelerate high-energy cosmic rays, and present results of three-dimensional simulations of cosmic rays moving in the Galactic magnetic field and diffusing through pitch-angle scattering. An on-axis GRB extinction event begins with a powerful prompt gamma-ray and neutron pulse, followed by a longer-lived phase from cosmic-ray protons and neutron-decay protons that diffuse towards Earth. Our results force a reinterpretation of reported ~ 10^{18} eV cosmic-ray anisotropies and offer a rigorous test of the model where high-energy cosmic rays originate from GRBs, which will soon be tested with the Auger Observatory.

  16. Gamma ray induced flower shape mutation in Chrysanthemum cv 'Jaya'

    International Nuclear Information System (INIS)

    Rooted cuttings of Chrysanthemum cv 'Jaya' were irradiated with 1.5, 2.0 and 2.5 Krad of gamma rays. Reduction in survival, growth, plant height, number of branches and leaves per plant and leaf and flower size and increased morphological, floral and chromosomal abnormalities were recorded after irradiation. Per cent mutation in ray floret shape (tubular) could be induced and established in pure form. Comparative cytomorphological and anatomical analysis of original and mutant was carried out to understand the nature of mutation. (author). 26 refs., 3 tabs., 4 figs

  17. The measurement of gamma ray induced heating in a mixed neutron and gamma ray environment

    International Nuclear Information System (INIS)

    The problem of measuring the gamma heating in a mixed DT neutron and gamma ray environment was explored. A new detector technique was developed to make this measurement. Gamma heating measurements were made in a low-Z assembly irradiated with 14-Mev neutrons and (n, n') gammas produced by a Texas Nuclear Model 9400 neutron generator. Heating measurements were made in the mid-line of the lattice using a proportional counter operating in the Continuously-varied Bias-voltage Acquisition mode. The neutron-induced signal was separated from the gamma-induced signal by exploiting the signal rise-time differences inherent to radiations of different linear energy transfer coefficient, which are observable in a proportional counter. The operating limits of this measurement technique were explored by varying the counter position in the low-Z lattice, hence changing the irradiation spectrum observed. The experiment was modelled numerically to help interpret the measured results. The transport of neutrons and gamma rays in the assembly was modelled using the one- dimensional radiation transport code ANISN/PC. The cross-section set used for these calculations was derived from the ENDF/B-V library using the code MC2-2 for the case of DT neutrons slowing down in a low-Z material. The calculated neutron and gamma spectra in the slab and the relevant mass-stopping powers were used to construct weighting factors which relate the energy deposition in the counter fill-gas to that in the counter wall and in the surrounding material. The gamma energy deposition at various positions in the lattice is estimated by applying these weighting factors to the measured gamma energy deposition in the counter at those locations

  18. The measurement of gamma ray induced heating in a mixed neutron and gamma ray environment

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, H.K.

    1991-10-01

    The problem of measuring the gamma heating in a mixed DT neutron and gamma ray environment was explored. A new detector technique was developed to make this measurement. Gamma heating measurements were made in a low-Z assembly irradiated with 14-Mev neutrons and (n, n{prime}) gammas produced by a Texas Nuclear Model 9400 neutron generator. Heating measurements were made in the mid-line of the lattice using a proportional counter operating in the Continuously-varied Bias-voltage Acquisition mode. The neutron-induced signal was separated from the gamma-induced signal by exploiting the signal rise-time differences inherent to radiations of different linear energy transfer coefficient, which are observable in a proportional counter. The operating limits of this measurement technique were explored by varying the counter position in the low-Z lattice, hence changing the irradiation spectrum observed. The experiment was modelled numerically to help interpret the measured results. The transport of neutrons and gamma rays in the assembly was modelled using the one- dimensional radiation transport code ANISN/PC. The cross-section set used for these calculations was derived from the ENDF/B-V library using the code MC{sup 2}-2 for the case of DT neutrons slowing down in a low-Z material. The calculated neutron and gamma spectra in the slab and the relevant mass-stopping powers were used to construct weighting factors which relate the energy deposition in the counter fill-gas to that in the counter wall and in the surrounding material. The gamma energy deposition at various positions in the lattice is estimated by applying these weighting factors to the measured gamma energy deposition in the counter at those locations.

  19. Determination of nitrogen in pork meat using in-vivo prompt gamma-ray activation technique

    International Nuclear Information System (INIS)

    The concentration of nitrogen in pork meat is determined by in-vivo prompt gamma-ray activation analysis using the reactor neutron beam and a high purity germanium gamma-ray spectrometer. The photopeak area of the 10827 keV high energy prompt gamma-ray, originated from 14N(n,?) reaction on the pork medium, is analyzed to determine the concentration of nitrogen. Urea solutions with various concentration of nitrogen are used to calibrate the absolute efficiency of the gamma-ray spectrometer. In 9000 s irradiation and counting period, the minimum detectable concentration is 1.7 g of N/100 g of meat using the in-vivo technique. The result is also compared to data obtained by another analytical method. This nondestructive, in-vivo technique, with nominal radiation dose, is a reliable and promising method to determine the nitrogen concentration in living body. (author) 25 refs.; 2 figs

  20. Gamma-ray Astronomy and GLAST

    Science.gov (United States)

    McEnery, Julie

    2007-01-01

    The high energy gamma-ray (30 MeV to 100 GeV) sky has been relatively poorly studied. Most of our current knowledge comes from observations made by the Energetic Gamma Ray Experiment Telescope (EGRET) detector on the Compton Gamma Ray Observatory (CGRO), which revealed that the GeV gamma-ray sky is rich and vibrant. Studies of astrophysical objects at GeV energies are interesting for several reasons: The high energy gamma-rays are often produced by a different physical process than the better studied X-ray and optical emission, thus providing a unique information for understanding these sources. Production of such high-energy photons requires that charged particles are accelerated to equally high energies, or much greater. Thus gamma-ray astronomy is the study of extreme environments, with natural and fundamental connections to cosmic-ray and neutrino astrophysics. The launch of GLAST in 2008 will herald a watershed in our understanding of the high energy gamma-ray sky, providing dramatic improvements in sensitivity, angular resolution and energy range. GLAST will open a new avenue to study our Universe as well as to answer scientific questions EGRET observations have raised. In this talk, I will describe the GLAST instruments and capabilities and highlight some of the science we expect to address.

  1. Gamma ray induced mutants in Gladiolus

    International Nuclear Information System (INIS)

    Effects of gamma rays from 60Co was studied in three varieties of gladiolus, namely, 'Little Giant', 'Mansoer' and 'Wild Rose' irradiated at 1, 2.5, 5, 10 and 15 Krad doses at the Indian Institute of Horticultural Research, Bangalore. Percentage of sprouting was affected significantly at 10 and 15 Krad. LD50 was found to be between 10 and 15 Krad. Doses of 10 Krad and above proved to be detrimental for vegetative and floral traits. Plants treated with 10 Krad did not produce flower spikes, whereas the plants in 15 Krad treatment although sprouted but died afterwards. When treated with 10 Krad, plant height, leaf number and leaf-size were reduced significantly and leaves became narrow and leathery. Flowering was delayed significantly at 5 Krad. Radiation treatments caused decrease in spike length, number of florets per spike and floret size. A desirable and stable mutant with Shell Pink floret colour was isolated from the variety 'Wild Rose' in 1 Krad treament and it has been released as 'Shobha'. (author). 14 refs

  2. Gamma-ray perimeter security system

    International Nuclear Information System (INIS)

    A prototype perimeter security system using a beam of gamma rays from 137Cs is extremely sensitive to interruptions of the beam. Monte Carlo calculations indicate that a 1-Ci source is adequate to protect an interval of 93 m. A gamma-ray source can easily be made bidirectional, which would allow approximately 200 m of perimeter to be guarded. A system using a gamma ray having an energy in the range of 500 to 1000 keV would result in a minimum number of false alarms per year

  3. Atmospheric Cherenkov Gamma-ray Telescopes

    CERN Document Server

    Holder, Jamie

    2015-01-01

    The stereoscopic imaging atmospheric Cherenkov technique, developed in the 1980s and 1990s, is now used by a number of existing and planned gamma-ray observatories around the world. It provides the most sensitive view of the very high energy gamma-ray sky (above 30 GeV), coupled with relatively good angular and spectral resolution over a wide field-of-view. This Chapter summarizes the details of the technique, including descriptions of the telescope optical systems and cameras, as well as the most common approaches to data analysis and gamma-ray reconstruction.

  4. Gamma-Ray Bursts: A Centauro's Cry?

    International Nuclear Information System (INIS)

    Gamma-ray bursts are enigmatic flashes of gamma-rays at cosmological distances, so bright that the implied energetics is astounding: energies of order of about solar rest-energy are liberated in a time scale of the order of seconds in space regions only a few kilometres in size. Central engines capable to produce such enormous explosions, leading to a highly relativistic expending fireballs, remain a mystery. Here we propose a new candidate for the gamma-ray bursts central engine. (author)

  5. Neutron capture gamma-ray experiment facility

    International Nuclear Information System (INIS)

    Study of the gamma-rays following neutron capture has started with the 20 m flight path of a neutron TOF spectrometer at the JAERI linac. Capture gamma-rays are detected with a 55 cc Ge(Li) detector and the capture events are recorded on a magnetic tape using an on-line program of USC-3 computer (20 bits, 16 k core memory) with a gain stabilizer. Performance of the facility, effects of gamma-flash and RF noise from the linac, and energy resolution and relative efficiency of the Ge(Li) detector were examined, and preliminary measurements of the gamma-ray spectra were conducted. (auth.)

  6. The TIGRE gamma-ray telescope

    International Nuclear Information System (INIS)

    TIGRE is an advanced telescope for gamma-ray astronomy. From 0.3 to 10 MeV it is a Compton telescope. Above 1 MeV, its multi-layers of double sided silicon strip detectors allow for Compton recoil electron tracking and the unique determination for incident photon direction. From 10 to 100 MeV the tracking feature is utilized for gamma-ray pair event reconstruction. The acceptance of large scattered gamma-rays also makes TIGRE a good polarimeter below 2 MeV. Here we present the status of the TIGRE Instrument

  7. Material efficiency studies for a Compton camera designed to measure characteristic prompt gamma rays emitted during proton beam radiotherapy

    OpenAIRE

    Robertson, Daniel; Polf, Jerimy C; Peterson, Steve W; Gillin, Michael T; Beddar, Sam

    2011-01-01

    Prompt gamma rays emitted from biological tissues during proton irradiation carry dosimetric and spectroscopic information that can assist with treatment verification and provide an indication of the biological response of the irradiated tissues. Compton cameras are capable of determining the origin and energy of gamma rays. However, prompt gamma monitoring during proton therapy requires new Compton camera designs that perform well at the high gamma energies produced when tissues are bombarde...

  8. Flares in Gamma Ray Bursts

    CERN Document Server

    Chincarini, G; Pasotti, F; Margutti, R; Guidorzi, G; Bernardini, M G

    2008-01-01

    The flare activity that is observed in GRBs soon after the prompt emission with the XRT (0.3-10 KeV) instrument on board of the Swift satellite is leading to important clues in relation to the physical characteristics of the mechanism generating the emission of energy in Gamma Ray Bursts. We will briefly refer to the results obtained with the recent analysis and and discuss the preliminary results we obtained with a new larger sample of GRBs [limited to early flares] based on fitting of the flares using the Norris 2005 profile. We find, in agreement with previous results, that XRT flares follow the main characteristics observed in Norris 2005 for the prompt emission spikes. The estimate of the flare energy for the subsample with redshift is rather robust and an attempt is made, using the redshisft sample, to estimate how the energy emitted in flares depends on time. We used a $H_0=70 km/s/Mpc$, $\\Omega_\\Lambda=0.7$, $\\Omega_m=0.3$ cosmology.

  9. Gamma-ray Burst Cosmology

    CERN Document Server

    Wang, F Y; Liang, E W

    2015-01-01

    Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to $8.8\\times10^{54}$ erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the largest distances yet explored in the Universe. GRBs, as bright beacons in the deep Universe, would be the ideal tool to probe the properties of high-redshift universe: including the cosmic expansion and dark energy, star formation rate, the reionization epoch and the metal enrichment history of the Universe. In this article, we review the luminosity correlations of GRBs, and implications for constraining the cosmological parameters and dark energy. Observations show that the progenitors of long GRBs are massive stars. So it is expected that long GRBs are tracers of star formation rate. We also review the high-redshift star formation rate derived from GRBs, and implications for the cosmic reionization history. The afterglows of GRBs generally have broken power-law spectra, so it...

  10. Effects of neutrons and gamma-rays on polymethylmethacrylate plastic optical fiber

    International Nuclear Information System (INIS)

    The effects of neutron and gamma-ray irradiation on a polymethylmethacrylate (PMMA) plastic optical fiber (POF) were investigated. An improvement in the optical transmission was observed at the beginning of irradiation, but radiation damage (radiation-induced transmission loss in the visible wavelength range) increased as the irradiation continued. To determine the effects of neutrons and gamma-rays, the amount of energy absorbed in the PMMA POF was calculated using the PHITS codes. Energy deposition in the fiber was calculated considering nuclear reactions listed in the nuclear data file used for the Monte Carlo N-particle transport code. The effects of neutron and gamma radiation were observed to be similar with absorbed energy less than 1.2 kGy. However, the transmission loss induced by neutrons was larger than that induced by gamma-rays when higher energy was deposited.

  11. Effects of neutrons and gamma-rays on polymethylmethacrylate plastic optical fiber

    Energy Technology Data Exchange (ETDEWEB)

    Toh, K., E-mail: toh.kentaro@jaea.go.jp [J-PARC Center, Japan Atomic Energy Agency, Tokai 319-1195 (Japan); Sakasai, K.; Nakamura, T.; Soyama, K. [J-PARC Center, Japan Atomic Energy Agency, Tokai 319-1195 (Japan); Shikama, T. [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2011-10-01

    The effects of neutron and gamma-ray irradiation on a polymethylmethacrylate (PMMA) plastic optical fiber (POF) were investigated. An improvement in the optical transmission was observed at the beginning of irradiation, but radiation damage (radiation-induced transmission loss in the visible wavelength range) increased as the irradiation continued. To determine the effects of neutrons and gamma-rays, the amount of energy absorbed in the PMMA POF was calculated using the PHITS codes. Energy deposition in the fiber was calculated considering nuclear reactions listed in the nuclear data file used for the Monte Carlo N-particle transport code. The effects of neutron and gamma radiation were observed to be similar with absorbed energy less than 1.2 kGy. However, the transmission loss induced by neutrons was larger than that induced by gamma-rays when higher energy was deposited.

  12. Fine structure of polyoxymethylene obtained through gamma-ray induced polymerization in solid state

    International Nuclear Information System (INIS)

    The correlation of the infrared spectra for polytrioxane (PTOX) with its polymerization conditions and the gamma-ray irradiation was examined. The infrared spectra were recarded on a EPI-G2 spectrometer in the range from 600 to 1300/cm. The samples were measured in the nujol suspension of polymer powder, which was held between two KBr discs. The total dose of gamma-ray post-irradiation was about 1.4 MR. The spectra taken before and after the gamma-ray irradiation showed strong absorption bands associated with the skeletal vibration of the PTOX chains. The correlation of the superheating with the reduction of the ratio of optical density D-903/D-938 suggests that the long chains associated with the superheating were conformationally distorted in crystallites. (J.P.N.)

  13. Gamma ray induced mutation in double bracted Bougainvillea cv. 'Los Banos Beauty'

    International Nuclear Information System (INIS)

    The present investigation was carried out to study the effects of different doses of gamma rays with particular reference to induction of somatic mutation. Cuttings of Bougainvillea cv. 'Los Banos Beauty' were irradiated with 0, 0.75 and 1.00 Krad of gamma rays from 60Co and planted in pots along with equal number of control cuttings. Each treatment consisted of 48 cuttings. There was reduction in sprouting, plant height, growth, leaf number and size after gamma irradiation with increasing exposure to gamma rays. The survival was 83.33, 47.92 and 45.03 per cent in control and at 0.75 and 1.00 Krad, respectively. Different types of morphological abnormalities like faciation in stem, fission and fusion of leaf, unequal development of lamina, leathery texture, notching and obtuse apex increased after gamma irradiation. (author)

  14. Comparison of gamma-ray coincidence and low-background gamma-ray singles spectrometry

    International Nuclear Information System (INIS)

    Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma–gamma coincidence approach in elevated background conditions. However, measurement of gamma–gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma–gamma coincidence spectrometry. - Highlights: ? We compare shielded singles gamma-ray spectrometry to unshielded gamma-ray coincidence method. ? We focus on the limits of detection of radionuclides and measurement of aerosol particulate filters. ? Using gamma-ray coincidences lowers detection limits and improves identification of nuclides. ? Coincidences could shorten measurement times and enhance in-situ measurements at accident sites.

  15. Mining Gamma-Ray Burst Data

    CERN Document Server

    Hakkila, J; Haglin, D J; Mallozzi, R S; Pendleton, G N; Meegan, C A; Hakkila, Jon; Roiger, Richard J.; Haglin, David J.; Mallozzi, Robert S.; Pendleton, Geoffrey N.; Meegan, Charles A.

    2000-01-01

    Gamma-ray bursts provide what is probably one of the messiest of all astrophysical data sets. Burst class properties are indistinct, as overlapping characteristics of individual bursts are convolved with effects of instrumental and sampling biases. Despite these complexities, data mining techniques have allowed new insights to be made about gamma-ray burst data. We demonstrate how data mining techniques have simultaneously allowed us to learn about gamma-ray burst detectors and data collection, cosmological effects in burst data, and properties of burst subclasses. We discuss the exciting future of this field, and the web-based tool we are developing (with support from the NASA AISR Program). We invite others to join us in AI-guided gamma-ray burst classification (http://grb.mnsu.edu/grb/).

  16. Gamma-Ray Pulsar Studies With GLAST

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, D.J.; /NASA, Goddard

    2011-11-23

    Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

  17. Gamma-rays from decaying dark matter

    International Nuclear Information System (INIS)

    We study the prospects for detecting gamma-rays from decaying Dark Matter (DM), focusing in particular on gravitino DM in R-parity breaking vacua. Given the substantially different angular distribution of the predicted gamma-ray signal with respect to the case of annihilating DM, and the relatively poor (of order 0.1 ) angular resolution of gamma-ray detectors, the best strategy for detection is in this case to look for an exotic contribution to the gamma-ray flux at high galactic latitudes, where the decaying DM contribution would resemble an astrophysical extragalactic component, similar to the one inferred by EGRET observations. Upcoming experiments such as GLAST and AMS-02 may identify this exotic contribution and discriminate it from astrophysical sources, or place significant constraints on the mass and lifetime of DM particles. (orig.)

  18. Gamma-ray emission from thunderstorm discharges

    Science.gov (United States)

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

    2011-04-01

    Fine features of gamma-ray radiation registered during a thunderstorm at Tien-Shan Mountain Cosmic Ray Station are presented. Long duration (100-600 ms) gamma-ray bursts are found. They are for the first time identified with atmospheric discharges (lighting). Gamma-ray emission lasts all the time of the discharge and is extremely non-uniform consisting of numerous flashes. Its peak intensity in the flashes exceeds the gamma-ray background up to two orders of magnitude. Exclusively strong altitude dependence of gamma radiation is found. The observation of gamma radiation at the height 4-8 km could serve as a new important method of atmospheric discharge processes investigation.

  19. Combined Neutron and Gamma-Ray Monitor

    International Science & Technology Center (ISTC)

    A Radiation Monitor on the Basis of CdZnTe and NaI(Tl) Gamma-Ray Detectors and Neutron Detectors on Scintillating Fibers for Determining the Characteristics of Radioactive Materials with Localization of Irregularities throughout the Volume

  20. Gamma-Ray Astrophysics NSSTC Fermi GBM

    Data.gov (United States)

    National Aeronautics and Space Administration — The Fermi Gamma-Ray Burst Monitor (GBM) is not a pointed or imaging instrument. To determine fluxes for known sources, we measure the change in the count rate...

  1. Gamma rays from the Magellanic Clouds

    International Nuclear Information System (INIS)

    Predicted gamma ray fluxes from the Magellanic Clouds, obtained by using updated parameters, are significantly above the values previously determined, and well within the capabilities of observation from COS-B satellite. Concepts relating galactic gamma ray production and other Population 1 phenomena in the Milky Way were used to postulate a factor of four increase in predicted flux, based on the galactic origin hypothesis. The values obtained provide a possible test of two interpretations of gamma ray emission: enhancement in the inner galaxy from gas and cosmic ray sources alone, or increases produced by the trapping of cosmic rays in spiral arms. Because spiral structure is absent in the small cloud, and questionable in the large cloud, and both clouds are classed as irregular galaxies, the predicted enhancement in gamma ray flux may not be as great in the absence of clear spiral structure

  2. Gamma rays from clusters of galaxies

    CERN Document Server

    Blasi, P; Brunetti, G; Blasi, Pasquale; Gabici, Stefano; Brunetti, Gianfranco

    2007-01-01

    Clusters of galaxies and the large scale filaments that connect neighboring clusters are expected to be sites of acceleration of charged particles and sources of non-thermal radiation from radio frequencies to gamma rays. Gamma rays are particularly interesting targets of investigation, since they may provide precious information on the nature and efficiency of the processes of acceleration and magnetic confinement of hadrons within clusters of galaxies. Here we review the status of viable scenarios that lead to the production of gamma rays from large scale structures and are compatible with the multifrequency observations that are already available. We also discuss the possibility of detection of gamma rays with space-borne telescopes such as GLAST and ground based Cherenkov telescopes, and the physical information that may be gathered from such observations.

  3. Optical reprocessing of gamma-ray bursts

    Science.gov (United States)

    Melia, F.; Rappaport, S.; Joss, P. C.

    1986-01-01

    One model for the optical flashes associated with three cosmic gamma-ray burst sources invokes the reprocessing of some of the gamma-radiation emitted by a hypothesized collapsed object in the surface layers of a nearby companion star. This model was investigated by carrying out detail, fully hydrodynamical calculations of such reprocessing in the surface layers of very low mass stars. It is found that, at most, 7 percent of the gamma-ray fluence incident on the companion star is reprocessed into the blue band; the time scale for this reprocessing is typically 100 s, which is long compared to the duration of the gamma-ray burst itself. Using this result, it is shown that there is marginal agreement between the observed and calculated ratios of gamma-ray fluence to optical fluence at earth.

  4. Gamma-Ray Pulsar Studies with GLAST

    International Nuclear Information System (INIS)

    Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies

  5. Gamma-Ray Pulsar Studies With GLAST

    International Nuclear Information System (INIS)

    Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

  6. Thermal neutron capture gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Tuli, J.K.

    1983-01-01

    The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.

  7. Fermi LAT Discovery of Extended Gamma-Ray Emissions in the Vicinity of the HB3 Supernova Remnant

    CERN Document Server

    Katagiri, H; Ballet, J; Grondin, M H; Hanabata, Y; Hewitt, J W; Kubo, H; Lemoine-Goumard, M

    2016-01-01

    We report the discovery of extended gamma-ray emission measured by the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope in the region of the supernova remnant (SNR) HB3 (G132.7+1.3) and the W3 HII complex adjacent to the southeast of the remnant. W3 is spatially associated with bright 12CO (J=1-0) emission. The gamma-ray emission is spatially correlated with this gas and the SNR. We discuss the possibility that gamma rays originate in interactions between particles accelerated in the SNR and interstellar gas or radiation fields. The decay of neutral pions produced in nucleon-nucleon interactions between accelerated hadrons and interstellar gas provides a reasonable explanation for the gamma-ray emission. The emission from W3 is consistent with irradiation of the CO clouds by the cosmic rays accelerated in HB3.

  8. Unidentified Gamma-Ray Sources and Microquasars

    CERN Document Server

    Romero, G E; Bernado, M M K; Mirabel, I F; Torres, D F

    2004-01-01

    Some phenomenological properties of the unidentified EGRET detections suggest that there are two distinct groups of galactic gamma-ray sources that might be associated with compact objects endowed with relativistic jets. We discuss different models for gamma-ray production in both microquasars with low- and high-mass stellar companions. We conclude that the parent population of low-latitude and halo variable sources might be formed by yet undetected microquasars and microblazars.

  9. Model cosmic gamma-ray burst

    International Nuclear Information System (INIS)

    Observational facts relating to cosmic gamma-ray bursts are briefly summarized and classified into two rough categories: (1) well-established facts and (2) less-well-established facts. Most of the models proposed to explain the phenomena of cosmic gamma-ray bursts are found to be in conflict with the first category and only a few classes of explanation are compatible with both. (U.S.)

  10. VHE Gamma-ray supernova remnants

    OpenAIRE

    Funk, S

    2007-01-01

    Increasing observational evidence gathered especially in X-rays and gamma-rays during the course of the last few years support the notion that Supernova remnants (SNRs) are Galactic particle accelerators up to energies close to the ``knee'' in the energy spectrum of Cosmic rays. This review summarises the current status of VHE gamma-ray observations of SNRs. Shell-type as well as plerionic type SNRs are addressed and prospect for observations of these two source classes with...

  11. Gamma-ray bursts - A critical review

    International Nuclear Information System (INIS)

    We present a short general introduction into the field of gamma -ray bursts (GRBs) research, summarizing the past and the present status. We give an ensemble view of the GRBs observations to date, both in the prompt emission phase as well as in the afterglow phase, and a brief primer into the theory, mainly in the framework of the fireball model. Key words: gamma ray bursts. (authors)

  12. Gamma ray astronomy and baryonic dark matter

    OpenAIRE

    de Paolis, F.; Ingrosso, G.; Jetzer, Ph; Roncadelli, M.

    1999-01-01

    Recently, Dixon et al. have re-analyzed the EGRET data, finding a statistically significant diffuse $\\gamma$-ray emission from the galactic halo. We show that this emission can naturally be explained within a previously-proposed model for baryonic dark matter, in which $\\gamma$-rays are produced through the interaction of high-energy cosmic-ray protons with cold $H_2$ clouds clumped into dark clusters - these dark clusters supposedly populate the outer galactic halo and can ...

  13. Unidentified Gamma-Ray Sources and Microquasars

    OpenAIRE

    Romero, G. E.; Grenier, I. A.; Bernado, M. M. Kaufman; Mirabel, I. F.; Torres, D.F.(Institut de Ciències de l'Espai (IEEC-CSIC), E-08193 Bellaterra, Spain)

    2004-01-01

    Some phenomenological properties of the unidentified EGRET detections suggest that there are two distinct groups of galactic gamma-ray sources that might be associated with compact objects endowed with relativistic jets. We discuss different models for gamma-ray production in both microquasars with low- and high-mass stellar companions. We conclude that the parent population of low-latitude and halo variable sources might be formed by yet undetected microquasars and microbla...

  14. The HAWC Gamma-Ray Observatory: Sensitivity to Steady and Transient Sources of Gamma Rays

    CERN Document Server

    Abeysekara, A U; Alvarez, C; Álvarez, J D; Arceo, R; Arteaga-Velázquez, J C; Solares, H A Ayala; Barber, A S; Baughman, B M; Bautista-Elivar, N; Belmont, E; BenZvi, S Y; Berley, D; Rosales, M Bonilla; Braun, J; Caballero-Lopez, R A; Caballero-Mora, K S; Carramiñana, A; Castillo, M; Cotti, U; Cotzomi, J; de la Fuente, E; De León, C; DeYoung, T; Hernandez, R Diaz; Díaz-Vélez, J C; Dingus, B L; DuVernois, M A; Ellsworth, R W; Fernandez, A; Fiorino, D W; Fraija, N; Galindo, A; Garfias, F; González, L X; González, M M; Goodman, J A; Grabski, V; Gussert, M; Hampel-Arias, Z; Hui, C M; Hüntemeyer, P; Imran, A; Iriarte, A; Karn, P; Kieda, D; Kunde, G J; Lara, A; Lauer, R J; Lee, W H; Lennarz, D; Vargas, H León; Linares, E C; Linnemann, J T; Longo, M; Luna-GarcIa, R; Marinelli, A; Martinez, H; Martinez, O; Martínez-Castro, J; Matthews, J A J; Miranda-Romagnoli, P; Moreno, E; Mostafá, M; Nava, J; Nellen, L; Newbold, M; Noriega-Papaqui, R; Oceguera-Becerra, T; Patricelli, B; Pelayo, R; Pérez-Pérez, E G; Pretz, J; Rivière, C; Rosa-González, D; Salazar, H; Salesa, F; Sanchez, F E; Sandoval, A; Santos, E; Schneider, M; Silich, S; Sinnis, G; Smith, A J; Sparks, K; Springer, R W; Taboada, I; Toale, P A; Tollefson, K; Torres, I; Ukwatta, T N; Villaseñor, L; Weisgarber, T; Westerhoff, S; Wisher, I G; Wood, J; Yodh, G B; Younk, P W; Zaborov, D; Zepeda, A; Zhou, H

    2013-01-01

    The High-Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory is designed to record air showers produced by cosmic rays and gamma rays between 100 GeV and 100 TeV. Because of its large field of view and high livetime, HAWC is well-suited to measure gamma rays from extended sources, diffuse emission, and transient sources. We describe the sensitivity of HAWC to emission from the extended Cygnus region as well as other types of galactic diffuse emission; searches for flares from gamma-ray bursts and active galactic nuclei; and the first measurement of the Crab Nebula with HAWC-30.

  15. Application of Laser Compton Scattered gamma-ray beams to nondestructive detection and assay of nuclear material

    International Nuclear Information System (INIS)

    Generation of energy-tunable gamma-rays via Laser Compton Scattering (LCS) is of great interest for scientific studies and applications of MeV photons which interact with nuclei. One of the promising applications of such energy-tunable gamma-rays is the non-destructive detection and assay of nuclides which are necessary for nuclear security and safeguards. Utilizing this LCS gamma-ray beam in combination with nuclear resonant fluorescence (NRF), we can make non-destructive measurement of arbitrary nuclides. The principle of LCS-NRF is as follows. When a nucleus is irradiated by a gamma-ray and when the energy of the gamma ray is identical to the transition energy from the ground state of the nucleus, the incident gamma-ray is absorbed by the nucleus, and subsequently the nucleus de-excites by gamma-ray emission. Since the energies of the state excited by NRF are inherent in the atomic number and mass of the nucleus of interest, detection and assay of nuclides are possible by NRF measurement. The ability of gamma-ray beams to penetrate a sample enables us to detect or assay specific nuclides even inside a sample. We are developing a high-flux and a high-brightness gamma-ray source based on an energy-recovery linac and a laser enhancement cavity to produce a gamma-ray beam of 1013 ph/s. Gamma-ray measurement methods optimized for highly radioactive samples are also under development. (A.C.)

  16. Gamma-ray- and fission-neutron-induced micronuclei in PHA-stimulated and unstimulated human lymphocytes

    International Nuclear Information System (INIS)

    Two groups of normal human an blood cells, one stimulated with phytohaemagglutinin (PHA) for 24 hr (G1-S phase of the cell cycle) and one unstimulated (G0 phase), were irradiated with 60Co gamma rays or 252Cf radiation. A comparison of radiation-induced micronucleus frequencies showed that the high-dose-rate gamma rays were more effective in inducing micronuclei than were low-dose-rate gamma rays. In the cells exposed to low-dose-rate irradiation, there was little difference between the frequency of micronuclei in the G0 phase and the G1-S phase. However, cells in the G1-S phase were more sensitive than G0-phase cells to high-dose-rate gamma rays. The relative biological effectiveness of 252Cf neutron irradiation measured in micronucleus assays was consistent with the value obtained for the lethal effect of 252Cf on cultured cells. (author)

  17. Influence of the irradiation by the {gamma} rays on various factors of immunity; Influence de l'irradiation par les rayons {gamma} sur divers facteurs d'immunite

    Energy Technology Data Exchange (ETDEWEB)

    Gaude, G.; Coursaget, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Exposed animals often present, in the days or weeks following the irradiation, heavy infectious lesions. The goal of this survey was to search the influence of the total irradiation by the gamma radiation from cobalt-60, on the organism, on the phagocytic power of the leukocytes and on the biogenesis of antibodies. The experiences were done on hundred animals, rabbits and guinea pigs. All irradiations have been achieved with eight sources of Cobalt 60 of 10 curies each, disposed on a sphere of 1 m, the animal living the region neighboring of the center. The intensity of the radiation, in these conditions, is about 100 roentgens per hour. (authors) [French] Les animaux irradies presentent souvent, dans les jours ou les semaines qui suivent l'irradiation, de graves lesions infectieuses. Le but de cette etude etait de rechercher l'influence de l'irradiation totale de l'organisme par le rayonnement gamma du cobalt 60 sur le pouvoir phagocytaire des leucocytes et sur la biogenese des anticorps. Les experiences portent sur une centaine d'animaux, lapins et cobayes. Toutes les irradiations ont ete realisees avec huit sources de Cobalt 60 de 10 curies chacune, disposees sur une sphere de 1 m de rayon, les animaux ocoupant la region voisine du centre. L'intensite du rayonnement est, dans ces conditions, d'environ 100 roentgens par heure. (auteurs)

  18. Phytonutrient analysis of gamma rays mutated tomato

    International Nuclear Information System (INIS)

    Full text: With increasing of world population and reducing land resources, good quality food production has become even more important. Mutant breeding is an inevitable way for producing of vegetable crops which are sustainable under varied agro-climatic conditions and have high nutrient capacity. The use of nuclear techniques in plant breeding has been mostly directed for inducing mutations. Since the use of ionizing radiation, such as X-rays, gamma rays, e-beam and neutrons for inducing variation, has become an established technology. Induced mutations have been used in the economic value improvement of major crops such as cereals and solanaceae, which are seed propagated. The economic value of a new variety can be assessed from several parameters. From these not only area planted to the variety and percentage of the area under the crop in the region, increased yield and savings in water but also increased nutritive value, and enhanced quality are also very important parameters which should have taken into consideration. Often, induced mutations lead to more advantages than a simple desired phenotypic change.In this study, tomato seeds were irradiated at the dose of 150 Gy by using 60Co gamma rays irradiator at a fixed dose rate of 0.654 kGy/h. These seeds were planted and M4 stage mutant lines were analysed for phytonutrient capacity by using HPLC system with different types of detectors depending on the analytes to be determined (vitamin C, carotenoids and vitamin E). Accelerated Solvent Extraction technique was used for the extraction of vitamin C from the samples under high pressure of nitrogen gas. For carotenoids and tocopherols extractions, liquid-liquid partition technique was used. Photodiode Array, UV and Fluorescence detectors were used for the determination of vitamin C (L-ascorbic acid), some carotenoids (lutein, ?-carotene, lycopene) and vitamin E ( ?-, ?-, ? tocopherols), respectively. Results obtained from these analysis were found as follows; vitamin C 10.80-159.30 mg/100g of samples whereas 35,30 mg/100g of standard control sample; lutein 0.20-0.59 mg/100 g of samples whereas 0.33 mg/100 g of standard control sample; ?-carotene 0.28-2.10 mg/100 g of samples whereas 1.00 mg/100 g of standard control sample, lycopene 6.00-40.10 mg/100 g of samples whereas 16.00 mg/100 g of standard control sample; ?-tocopherol 3.19 - 99.23 mg/100g of samples whereas 3.6 mg/100g of standard control sample; ?-tocopherol 0.08 - 36.18 mg/100g of samples whereas 13.74 mg/100g of standard control sample; ?-tocopherol 0-3 mg/100g of samples whereas 2.22 of standard control sample. According to these findings, it can be clearly understood that irradiation of tomato seeds at the dose of 150 Gy by using 60Co gamma source resulted in some variations in the phytonutrient capacity of M4 stage of mutant lines tomato samples. Average of nutrient capacity is rather above the standard control samples. (author)

  19. Neutron-induced gamma-ray spectroscopy: simulations for chemical mapping of planetary surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Brueckner, J.; Waenke, H.; Reedy, R.C.

    1986-01-01

    Cosmic rays interact with the surface of a planetary body and produce a cascade of secondary particles, such as neutrons. Neutron-induced scattering and capture reactions play an important role in the production of discrete gamma-ray lines that can be measured by a gamma-ray spectrometer on board of an orbiting spacecraft. These data can be used to determine the concentration of many elements in the surface of a planetary body, which provides clues to its bulk composition and in turn to its origin and evolution. To investigate the gamma rays made by neutron interactions, thin targets were irradiated with neutrons having energies from 14 MeV to 0.025 eV. By means of foil activation technique the ratio of epithermal to thermal neutrons was determined to be similar to that in the Moon. Gamma rays emitted by the targets and the surrounding material were detected by a high-resolution germanium detector in the energy range of 0.1 to 8 MeV. Most of the gamma-ray lines that are expected to be used for planetary gamma-ray spectroscopy were found in the recorded spectra and the principal lines in these spectra are presented. 58 refs., 7 figs., 9 tabs.

  20. Effect of gamma-ray on olive fruits quality, enzyme activities and issued oil

    International Nuclear Information System (INIS)

    The results described in the present work concern the study of changes in gamma ray irradiated olive fruit (Tunisian variety: Chemlali) quality along the storage time processing and the quality of olive oil issued. The study focused on the changes related to the microbiological, physico-chemical properties, as well as pectinase activities in olive after irradiation. We also have been interested in the final product quality after oil extraction. The results of non irradiated olives were presented for comparative purposes. Mature olive fruits were treated with 0.5, 1 and 1.5 kGy gamma ray radiation. Olive fruits were then stored for one month. Irradiation at 1.5 kGy allows the almost total destruction of the total aerobic germs, yeasts and moulds. Concerning physico-chemical parameters, the increase of the dose level generated an improvement in water retention capacity and decreased the rate of polysaccharides hydrolyzes olives. Moreover, the irradiation dose of 0.5 kGy induced the increase in pectinase activities thanks to the improvement of the protein extraction yield. The gamma ray irradiation of olive fruit seems to not decrease olive oil oxidative stability in the studied samples. Finally, gamma ray radiation was able to improve the yield of extraction of the oil and insaponifiable fraction as polyphenols and beta carotenes. (Author)

  1. Possible Distance Indicators in Gamma-ray Pulsars

    OpenAIRE

    Wang, W.

    2011-01-01

    Distance measurements of gamma-ray pulsars are challenging questions in present pulsar studies. The Large Area Telescope (LAT) aboard the Fermi gamma-ray observatory discovered more than 70 gamma-ray pulsars including 24 new gamma-selected pulsars which nearly have no distance information. We study the relation between gamma-ray emission efficiency ($\\eta=L_\\gamma/\\dot E$) and pulsar parameters for young radio-selected gamma-ray pulsars with known distance information in the...

  2. Effect of gamma rays on fibre of sida rhombifolia Linn

    International Nuclear Information System (INIS)

    It was reported long back that the stem fibre of Sida rhombifolia might be advantageously employed for many purposes. A study was, therefore, undertaken to study the effect of gamma rays on plants of this species raised from irradiated seeds to assess its value with reference to its fibre and as a substitute for jute. The fibres were extracted from stems of Sida rhombifolia and their characters were compared with those obtained from the plants raised from seeds irradiated at different doses of gamma rays ranging from 5,000 R to 35,000 R. The physical tests such as length and diameter of ultimate cells, intrinsic strength, elongation percentage at break were applied while the chemical tests were based on the estimation of ash, cellulose, lignin, fat and wax contents of fibres. The results indicate that the fibres of plants raised from seeds irradiated at 20,000 R, are stronger than those of control. Their strength reaches the value of those of Corchorus species and their cellulose content is more than that in Corchorus. (author)

  3. Effect of Gamma Rays on Fast Neutron Registration in CR-39

    CERN Document Server

    Kobzev, A P; El-Halem, A A; Abdul-Ghaphar, U S; Salama, T A

    2002-01-01

    A set of CR-39 plastic detectors with front PE radiator was exposed to Am-Be neutron source, which has an emission rate of 0.86\\cdot 10^{7} sec^{-1}, and the neutron dose equivalent rate 1 m apart from the source is equal to 11 mrem/hr. Another set of samples was irradiated by a neutron dose of 4 rem, then exposed to different gamma-ray doses using ^{60}Co source. It was found that the track density grows with the increase of neutron dose and etching time. It was also found that the bulk etching rate V_{B}, the track diameter and the sensitivity of the CR-39 plastic detector with respect to the neutron irradiation increased with increasing gamma-ray dose in the range 1?10 Mrad. These results show that CR-39 can be considered as a promising fast neutron dosimeter and gamma-ray dosimeter.

  4. Autoradiographic study of gamma-ray induced unscheduled DNA synthesis in bean root meristem cells

    International Nuclear Information System (INIS)

    The gamma-ray induced unscheduled DNA synthesis in root meristem cells of Vica faba was studied autoradiographically by calculating the number of cells with different 3H-thymidine labelling degree. It was found that the level of unscheduled synthesis in cells with intermediate dose (500 R) irradiation was higher than that in cells with lower dose (250 R) irradiation; however, higher dose (1000 R) irradiation would inhibit the reparative replication

  5. Gamma-ray binaries and related systems

    CERN Document Server

    Dubus, Guillaume

    2013-01-01

    After initial claims and a long hiatus, it is now established that several binary stars emit high (0.1-100 GeV) and very high energy (>100 GeV) gamma rays. A new class has emerged called 'gamma-ray binaries', since most of their radiated power is emitted beyond 1 MeV. Accreting X-ray binaries, novae and a colliding wind binary (eta Car) have also been detected - 'related systems' that confirm the ubiquity of particle acceleration in astrophysical sources. Do these systems have anything in common ? What drives their high-energy emission ? How do the processes involved compare to those in other sources of gamma rays: pulsars, active galactic nuclei, supernova remnants ? I review the wealth of observational and theoretical work that have followed these detections, with an emphasis on gamma-ray binaries. I present the current evidence that gamma-ray binaries are driven by rotation-powered pulsars. Binaries are laboratories giving access to different vantage points or physical conditions on a regular timescale as ...

  6. Origin of diffuse galactic gamma-rays

    International Nuclear Information System (INIS)

    Theoretical interpretations of the diffuse component of galactic gamma-rays with energies around 100 MeV are reviewed, on account of that these gamma-rays are generated by three mechanisms, the 2?-decay of neutral pions produced by the collision of the nuclear component of cosmic rays with interstellar matter, the bremsstrahlung of cosmic-ray electrons, and the Compton scattering of cosmic-ray electrons by cosmic microwaves and starlight. Correlations of the gamma-ray intensity with various astronomical objects indicate that the gamma-ray emissivity is roughly proportional to the square of the interstellar gas density and also to the infrared emissivity. The energy spectrum of gamma-rays does not show the turn-over expected from the pion decay, suggesting a large contribution of the bremsstrahlung and/or Compton scattering electrons. The contribution of the latter is estimated by reference to the starlight density which is found large through infrared observation. The contribution of localized sources to the diffuse component is discussed in connection with the star formation in dense molecular clouds. (author)

  7. Uncertainties in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    High resolution gamma-ray spectrometry is a well-established metrological technique that can be applied to a large number of photon-emitting radionuclides, activity levels and sample shapes and compositions. Three kinds of quantitative information can be derived using this technique: detection efficiency calibration, radionuclide activity and photon emission intensities. In contrast to other radionuclide measurement techniques gamma-ray spectrometry provides unambiguous identification of gamma-ray emitting radionuclides in addition to activity values. This extra information comes at a cost of increased complexity and inherently higher uncertainties when compared with other secondary techniques. The relative combined standard uncertainty associated with any result obtained by gamma-ray spectrometry depends not only on the uncertainties of the main input parameters but also on different correction factors. To reduce the uncertainties, the experimental conditions must be optimized in terms of the signal processing electronics and the physical parameters of the measured sample should be accurately characterized. Measurement results and detailed examination of the associated uncertainties are presented with a specific focus on the efficiency calibration, peak area determination and correction factors. It must be noted that some of the input values used in quantitative analysis calculation can be correlated, which should be taken into account in fitting procedures or calculation of the uncertainties associated with quantitative results. It is shown that relative combined standard uncertainties are rarely lower than 1% in gamma-ray spectrometry measurements. (authors)

  8. Stellar Photon Archaeology with Gamma-Rays

    Science.gov (United States)

    Stecker, Floyd W.

    2009-01-01

    Ongoing deep surveys of galaxy luminosity distribution functions, spectral energy distributions and backwards evolution models of star formation rates can be used to calculate the past history of intergalactic photon densities and, from them, the present and past optical depth of the Universe to gamma-rays from pair production interactions with these photons. The energy-redshift dependence of the optical depth of the Universe to gamma-rays has become known as the Fazio-Stecker relation (Fazio & Stecker 1970). Stecker, Malkan & Scully have calculated the densities of intergalactic background light (IBL) photons of energies from 0.03 eV to the Lyman limit at 13.6 eV and for 0$ < z < $6, using deep survey galaxy observations from Spitzer, Hubble and GALEX and have consequently predicted spectral absorption features for extragalactic gamma-ray sources. This procedure can also be reversed. Determining the cutoff energies of gamma-ray sources with known redshifts using the recently launched Fermi gamma-ray space telescope may enable a more precise determination of the IBL photon densities in the past, i.e., the "archaeo-IBL.", and therefore allow a better measure of the past history of the total star formation rate, including that from galaxies too faint to be observed.

  9. Short gamma-ray bursts: A review

    Science.gov (United States)

    D'Avanzo, P.

    2015-09-01

    Gamma-Ray Bursts (GRBs) are rapid, bright flashes of radiation peaking in the gamma-ray band occurring at an average rate of one event per day at cosmological distances. They are characterized by a collimated relativistic outflow pushing through the interstellar medium shining in gamma-rays powered by a central engine. This prompt phase is followed by a fading afterglow emission at longer wavelength, powered in part by the expanding outflow, and in part by continuous energy injection by the central engine. The observed evidences of supernovae associated to long GRBs (those with a duration of the gamma-ray emission > 2 s) brought to a general consensus on indicating the core collapse of massive stars as the progenitor of these events. Following the most accredited model, short GRBs (the events with a duration of the gamma-ray emission ? 2 s) originate from the coalescence of compact binary systems (two neutron stars or neutron star-black hole systems). This paper presents a review of the observational properties of short GRBs and shows how the study of these properties can be used as a tool to unveil their elusive progenitors and provide information on the nature of the central engine powering the observed emission. The increasing evidence for compact object binary progenitors makes short GRBs one of the most promising sources of gravitational waves for the forthcoming Advanced LIGO/Virgo experiments.

  10. Ground-based gamma ray astronomy

    International Nuclear Information System (INIS)

    This paper is the write-up of a rapporteur talk given by the author at the 33rd International Cosmic Ray Conference in Rio de Janeiro, Brazil, in 2013. It attempts to summarize results and developments in ground-based gamma-ray observations and instrumentation from among the ? 300 submissions to the gamma-ray sessions of the meeting. Satellite observations and theoretical developments were covered by a companion rapporteur (Stawarz, L., 33rd ICRC, Rio de Janeiro, Brazil, Rapporteur talk: Space-based Gamma-Ray Astronomy, 2013). Any review of this nature is unavoidably subjective and incomplete. Nevertheless, the article should provide a useful status report for those seeking an overview of this exciting and fast-moving field. (author)

  11. Technology Needs for Gamma Ray Astronomy

    Science.gov (United States)

    Gehrels, Neil

    2011-01-01

    Gamma ray astronomy is currently in an exciting period of multiple missions and a wealth of data. Results from INTEGRAL, Fermi, AGILE, Suzaku and Swift are making large contributions to our knowledge of high energy processes in the universe. The advances are due to new detector and imaging technologies. The steps to date have been from scintillators to solid state detectors for sensors and from light buckets to coded aperture masks and pair telescopes for imagers. A key direction for the future is toward focusing telescopes pushing into the hard X-ray regime and Compton telescopes and pair telescopes with fine spatial resolution for medium and high energy gamma rays. These technologies will provide finer imaging of gamma-ray sources. Importantly, they will also enable large steps forward in sensitivity by reducing background.

  12. The Diffuse Galactic $\\gamma$-Ray Gradient

    CERN Document Server

    Breitschwerdt, D; Völk, H J

    1999-01-01

    One of the unsolved problems in cosmic ray (CR) physics is the small radial gradient of the gamma-ray intensity compared to the inferred CR source distribution in the Galactic disk. In diffusive CR propagation models the most natural explanation is very efficient spatial mixing due to MHD turbulence in the interstellar medium. However, even in the most favorable case of a very large diffusive CR halo the gamma-ray gradient is still larger than observed. In our view such a small gradient could be the result of strong advection by a Galactic wind. We show that a small gamma-ray gradient can be obtained, if the diffusion region does NOT extend far above the Galactic plane. Important ingredients of our model are: (i) anisotropic CR diffusion, (ii) strong radial and vertical gradients of the advection velocity (due to faster winds above higher CR source density regions).

  13. Heliospheric Origin of $\\gamma$-Ray Bursts

    CERN Document Server

    Li Ti Pei

    1997-01-01

    Systematic variations of average observational characteristics and correlation properties between different parameters of gamma-ray bursts (GRBs) with time from 1991 April to 1994 September are revealed. It is hard to explain the observed long-term variability by variations of experimental conditions. The variability of GRB properties with the time scale of months to years, together with the similarity between GRBs, solar hard X-ray flares and terrestrial gamma-ray flashes, may indicate an origin of GRBs, at least partly, within the heliosphere. Large-voltage and high-temperature pinch plasma columns produced by disruptive electrical discharges in the outer heliosphere can generate hard X-ray and gamma-ray flashes with energy spectra and spectral evolution characters consistent with that observed in GRBs.

  14. Evaluation of gamma-ray intensities

    International Nuclear Information System (INIS)

    Relative intensities and intensities per decay of gamma rays were evaluated for 16 nuclides, 22Na, 24Na, 46Sc, 54Mn, 60Co, 85Sr, 88Y, 95Nb, sup(108m)Ag, 134Cs, 133Ba, 139Ce, sup(180m)Hf, 198Au, 203Hg and 207Bi. For most of these nuclides disintegration rates can be determined by means of ?-? or X-? coincidence method. Since decay schemes of these nuclides are established, intensities per decay of strong gamma rays were accurately evaluated by using weak beta-ray branching ratios, relative gamma-ray intensities and internal conversion coefficients. Half-lives of the nuclides were also evaluated. Use of the nuclides, therefore, are recommended for precision intensity calibration of the detectors. (author)

  15. Solution To The Gamma Ray Burst Mystery?

    CERN Document Server

    Dar, Arnon

    1996-01-01

    Photoexcitation and ionization of partially ionized heavy atoms in highly relativistic flows by interstellar photons, followed by their reemission in radiative recombination and decay, boost star-light into beamed $\\gamma$ rays along the flow direction. Repeated excitation/decay of highly relativistic baryonic ejecta from merger or accretion induced collapse of neutron stars in dense stellar regions (DSRs), like galactic cores, globular clusters and super star-clusters, can convert enough kinetic energy in such events in distant galaxies into cosmological gamma ray bursts (GRBs). The model predicts remarkably well all the main observed temporal and spectral properties of GRBs. Its success strongly suggests that GRBs are $\\gamma$ ray tomography pictures of DSRs in galaxies at cosmological distances with unprecedented resolution: A time resolution of $dt\\sim 1~ms$ in a GRB can resolve stars at a Hubble distance which are separated by only $D\\sim 10^{10}cm$. This is equivalent to the resolving power of an optica...

  16. Method and apparatus for nuclear logging making use of lithium detectors and equipment for gamma ray stripping

    International Nuclear Information System (INIS)

    The patent deals with a borehole logging tool where a pair of spaced-apart lithium detectors is lowered into a borehole traversing a sursurface formation. The formation is irradiated with bursts of neutrons, and the neutrons returning to the borehole are detected by thermal neutron detectors. The dieaway gamma ray spectra provide information on the formation porosity. A MWD system includes a programmable gain amplifier and gamma ray stripping means. 30 figs

  17. The possibility of gamma ray sterilization by using ITU TRIGA Mark II reactor

    International Nuclear Information System (INIS)

    Gamma rays are one of the effective method for sterilization which is preferred for a long time. Generally Co-60 radioisotope sources betatrons or accelerators are used for the sterilization. In this work, it was aimed to find the possibilities of the sterilization by gamma rays obtained in ITU TRIGA Mark-II radial tube. Radiation dosages are measured in the radial tube and several medical products are irradiated. Irradiation is arranged according to the desired dosages. Irradiated sterilized goods (mainly medical products) tested and checked at the Governmental Medical Health Center and results compared with literature. It can be seen that this kind of irradiation is a good tool for sterilization. Unfortunately, because of the stability of the radial tube and impracticality of the system it is rather difficult to compete with industrial system using Co-60 and accelerators. Nevertheless, this type of irradiation is also applicable for the purpose of the sterilization by using ITU TRIGA Mark II. (author)

  18. Study on the viability of peach and apple pollen treated with gamma rays 60Co

    International Nuclear Information System (INIS)

    Pollen from Marygold peach and from Golden Delicious apple varieties was treated with gamma-rays at rates of 0.5, 1.5, 10.0, 50.0, 100, 200, 300, 400 and 500 kR, the irradiation intensity being 1350 r/min. Results point to a different influence of gamma-rays irradiation on the pollen germination. Apple pollen proved more radiosensitive. Least dose of o.5 kR exerted a stimulative effect in the pollen germination. As the irradiation dose rcse, the germination percentage declined. Doses of over 400 kR destroyed completely pollen viability in both fruit species. A linear semi-logarithmical dependence was ascertained between the irradiation rate and pollen germination. 5 and 10 kR proved most suitable for the purposes of the experimental mutagenesis at peach and apple pollen irradiation. (author)

  19. Prompt and Delayed Gamma-Rays from Fission

    International Nuclear Information System (INIS)

    The following data about gamma-rays from fission are reported and discussed; Total prompt gamma-ray spectrum, and average number and energy of gamma-rays; X-rays in prompt fission, and excitation of X-rays in matter; gamma-ray spectra as a function of the mass ratio in fission, gamma-lines in those spectra, and Doppler effect-, anisotropy in gamma-emission relative to the direction of fragments; average gamma-energy and gamma-spectra as a function of mass of the fission products; delayed gamma-rays; delayed gamma-rays as a function of fission product mass. (author)

  20. Gamma-Ray Bursts: the Four Crises

    OpenAIRE

    Tavani, Marco

    1998-01-01

    We discuss some open problems concerning the origin and the emission mechanism of gamma-ray bursts (GRBs) in light of recent developments. If GRBs originate at extragalactic distances, we are facing four crises: (1) an energy crisis, models have to account for more than 10^{53} ergs of energy emitted in the gamma-ray energy band; (2) a spectral crisis, emission models have to account for the surprising `smoothness' of GRB broad-band spectra, with no indication of the predict...