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Sample records for 60co gamma radiation

  1. 60Co gamma radiation effect on AlGaN/AlN/GaN HEMT devices

    Institute of Scientific and Technical Information of China (English)

    WANG Yan-Ping; LUO Yin-Hong; WANG Wei; ZHANG Ke-Ying; GUO Hong-Xia; GUO Xiao-Qiang; WANG Yuan-Ming

    2013-01-01

    The testing techniques and experimental methods of the 60Co gamma irradiation effect on AlGaN/AlN/GaN high electron mobility transistors (HEMTs) are established.The degradation of the electrical properties of the device under the actual radiation environment are analyzed theoretically,and studies of the total dose effects of gamma radiation on AlGaN/AlN/GaN HEMTs at three different radiation bias conditions are carried out.The degradation patterns of the main parameters of the AlGaN/AlN/GaN HEMTs at different doses are then investigated,and the device parameters that were sensitive to the gamma radiation induced damage and the total dose level induced device damage are obtained.

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

    Institute of Scientific and Technical Information of China (English)

    HE Sao-Ping; YAO Zhi-Bin; ZHANG Feng-Qi

    2009-01-01

    Radiation hardened CC4007RH and non-radiation hardened CC4011 devices were irradiated using 80Co gamma rays, 1 MeV electrons and 1--9 MeV protons to compare the ionizing radiation damage of the gamma rays with the charged particles. For all devices examined, with experimental uncertainty, the radiation induced threshold voltage shifts (△Vth) generated by 60Co gamma rays are equal to that of 1 MeV electron and 1-7 MeV proton radiation under 0 gate bias condition. Under 5 V gate bias condition, the distinction of threshold voltage shifts (△Vth) generated by 60Co gamma rays and 1 MeV electrons irradiation are not large, and the radiation damage for protons below 9 MeV is always less than that of 60Co gamma rays. The lower energy the proton has, the less serious the radiation damage becomes.

  3. Performance of a Roos ionization chamber in gamma radiation beams ({sup 60}Co)

    Energy Technology Data Exchange (ETDEWEB)

    Perini, Ana P.; Neves, Lucio P.; Caldas, Linda V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Among the different types of dosimetry instruments, the ionization chambers are the most practical and and important radiation measurement devices due to their high sensitivity and relatively constant response within a wide range of energies. A commercial PTW ionization chamber (Roos electron chamber) usually utilized in X-ray beams, was tested to verify the possibility of its dosimetric application in {sup 60}Co beams. The main tests in this work were: short- and long-term stability, saturation, ion collection efficiency, polarity effect, leakage current and angular dependence. The characterization tests were performed using a Gammatron {sup 60}Co irradiator and a special goniometer made of PMMA. All results were within international recommendations. The reproducibility test presented results within the recommended limit of {+-}1%, and all coefficients of variation observed in the repeatability test were lower than {+-}0.07%. The ion collection efficiency was better than 99.9% for both polarities. For all pairs of polarity evaluated during the saturation test, the polarity effect was lower than the recommended limit. The maximum variation obtained for angular dependence test was only 0.5%. The chamber tested in this work achieved the expected results in the case of all pre-operational tests realized: stability, leakage current, angular dependence, saturation, ion collection and polarity effect. Evaluating the satisfactory results obtained, it is possible to indicate the usefulness of this ionization chamber for dosimetry in {sup 60}Co gamma radiation beams. (author)

  4. Radiation quality of tritium: a comparison with 60Co gamma rays.

    Science.gov (United States)

    Chen, Jing

    2013-09-01

    In a previous study, microdosimetric simulations were performed for tritium uniformly distributed in a medium, and for tritium bound to biologically critical sites of dimensions from 10 nm to 2 µm. Results of local energy density, i.e. energy deposition in microscopic regions, are different for these two cases. Based on the spatial distribution of energy deposition, dose mean lineal energies are calculated for tritium in the forms of tritiated water (HTO) and organically bound tritium (OBT). The dose mean lineal energies of OBT are about a factor of 1.7 higher than those of HTO in a wide range of target dimensions of biological interest. The results are consistent with radiobiological findings that OBT is about twice as effective as HTO. In this study, the same calculations were performed for (60)Co gamma rays in a wide range of target dimensions of biological interest (10 nm to 2 µm). Compared with (60)Co gamma rays, the estimated relative biological effectiveness could vary from 1.3 to 3.5 for HTO, and 2.3 to 5.6 for OBT. The results are consistent with radiobiological findings for various biological endpoints in different biological systems that OBT is about twice as effective as HTO.

  5. Response of avocado genotypes to improvement through {sup 60}Co gamma radiation; Respuesta de diversos genotipos de aguacate al mejoramiento por radiacion gamma de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, E. De la; Rubi A, M.; Garcia A, J.M. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    Ten avocado genotypes were subjected to gamma radiation from 0 to 45 Gy in 1993. Vegetative and reproductive data were analysed in a factorial design. Genotypes differed significative on height and fruit number. Radiation affected significative fruit number but not tree height. ''Hass'' showed strongest interaction between genotype and doses, for fruit number. (Author)

  6. Influence of 60Co gamma radiation on fluorine plasma treated enhancement-mode highelectron-mobility transistor

    Institute of Scientific and Technical Information of China (English)

    Quan Si; Hao Yue; Ma Xiao-Hua; Yu Hui-You

    2011-01-01

    AlGaN/GaN depletion-mode high-electron-mobility transistor (D-HEMT) and fluorine (F) plasma treated enhancement-mode high-electron-mobility transistor (E-HEMT) are exposed to 60Co gamma radiation with a dose of 1.6 Mrad (Si). No degradation is observed in the performance of D-HEMT. However, the maximum transconductance of E-HEMT is increased after radiation. The 2DEG density and the mobility are calculated from the results of capacitance-voltage measurement. The electron mobility decreases after fluorine plasma treatment and recovers after radiation. Conductance measurements in a frequency range from 10 kHz to 1 MHz are used to characterize the trapping effects in the devices. A new type of trap is observed in the F plasma treated E-HEMT compared with the D-HEMT, but the density of the trap decreases by radiation. Fitting of Gp/ω data yields the trap densities DT = (1 - 3) × 1012 cm-2-·eV-1 and DT = (0.2 - 0.8) × 1012 cm-2·eV-1 before and after radiation, respectively.The time constant is 0.5 ms-6 ms. With F plasma treatment, the trap is introduced by etch damage and degrades the electronic mobility. After 60Co gamma radiation, the etch damage decreases and the electron mobility is improved. The gamma radiation can recover the etch damage caused by F plasma treatment.

  7. Study on the energy dependence of gamma radiation detectors for {sup 137}Cs and {sup 60}Co; Estudo da dependencia energetica de detectores de radiacao gama para {sup 137}Cs e {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E., E-mail: fbnonato@ipen.b, E-mail: rediniz@ipen.b, E-mail: vcsouza@ipen.b, E-mail: vivolo@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    38 Geiger-Mueller radiation detectors and 9 ionization chambers were calibrated, viewing to study the energy dependence of the monitor response for gamma radiation fields ({sup 137}Cs and {sup 60}Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  8. Use of {sup 60}Co gamma radiation in increased levels of total polyphenol extracts of bark of Schinus terebinthifolius Raddi

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo H.F.; Silva, Edvane B.; Silva, Hianna A.M.F.; Amorin, Elba L.C.; Peixoto, Tadeu J.S.; Yara, Ricardo; Lima, Claudia S.A., E-mail: santosghf@hotmail.com, E-mail: edvborges@yahoo.com, E-mail: amdemelo@hotmail.com, E-mail: claudia.salima@gmail.com, E-mail: ricardo.yara@gmail.com, E-mail: tadeu1903@yahoo.com.br, E-mail: elba@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2013-07-01

    Schinus terebinthifolius Raddi (Anacardiaceae) is well known as sources of phenolic compounds. Known as mastic pepper, red pepper tree is a plant native to midsize coast of Brazil. Some of its structures have proven antibacterial, anti-inflammatory, antifungal and healing. The aim of this study was to evaluate the difference in the phenol contents of crude extracts that were measured after irradiating the barks of S. terebinthifolius using gamma radiation from {sup 60}Co. The crude extract were divided into a control group and eight experimental groups, which were separated based on the doses of gamma radiation to which they were exposed: 2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 20.0 and 50.0 kGy (Assays were performed in triplicate). The results allow observe that gamma radiation promoted in extracts of bark of S. terebinthifolius, many percents increase (p> 0.05) of total polyphenol content between 2.5 kGy (41.93%) and 50.0 kGy (44.52%) compared to 0 kGy (30.07%), with the same gradual to 10.0 kGy, and reaching peak maximum at 10.0 kGy (68.44%). However, the study puts the process of gamma radiation from {sup 60}Co as an alternative significant increase in the percentage of some natural substances of plant material, and subsequently contribute to the augmentation of various therapeutic applications to which they are assigned. (author)

  9. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with {sup 60}Co gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Stalin, A.; Broos, K.V. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Sadiq Bukhari, A., E-mail: abjmc@yahoo.in [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Syed Mohamed, H.E. [P.G. and Research Department of Zoology, Jamal Mohamed College (Autonomous), Tiruchirappalli 620020, Tamil Nadu (India); Singhal, R.K. [Analytical Spectroscopy Section, Analytical Chemistry Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India); Venu-Babu, P. [Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Center, Trombay, Mumbai 4000085 (India)

    2013-11-15

    Graphical abstract: -- Highlights: •Analyzing the impact of {sup 60}Co gamma radiation (low doses) in M. rosenbergii. •LD{sub 50} identified in 30 Gy; Irradiated exhibits morphological changes than control. •Significantly decreased HSI and histological changes in irradiated groups. •Aberration severities increased as increased of dose level. •Biomonitoring tool in determining low dose radiation pollution in aquatic ecosystem. -- Abstract: This study was framed to investigate the {sup 60}Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD{sub 50} value of {sup 60}Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of

  10. Morphological and histological studies on freshwater prawn Macrobrachium rosenbergii (de man) irradiated with (60)Co gamma radiation.

    Science.gov (United States)

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-Babu, P

    2013-11-15

    This study was framed to investigate the (60)Co gamma radiation induced morphological and histological variations in freshwater prawn Macrobrachium rosenbergii. The LD50 value of (60)Co gamma irradiated M. rosenbergii observed (by probit analysis) at 30 Gy. Prawns were irradiated to four different dose levels (3 mGy, 30 mGy, 300 mGy and 3,000 mGy) using Theratron Phoenix TeleCobalt Unit [P-33] and one control group (without irradiation) maintained separately. Irradiated groups exhibited several morphological variations such as discoloration; damaged rostrum; opaque coloration in cephalothorax; black bands and dot formation in abdomen; deformed uropods and telson in tail regions when compared with control group. The Hepato Somatic Index reflected the severity of radiation on hepatopancreas. Histological variations in gills, hepatopancreas and muscles of irradiated groups were observed. In gills, structural changes such as swollen and fused lamellae, abnormal gill tips, hyperplasic, necrotic and clavate-globate lamellae were observed in gamma irradiated prawns. Accumulation of hemocytes in hemocoelic space, interstitial sinuses filled with abnormal infiltrated hemocytes, the tubular epithelium with ruptured basal laminae, abnormal and coagulated lumen, necrotic tubules, thickened basal laminae, tissue debris, necrotic hepatocytes were observed in irradiated prawn hepatopancreas. In muscle, shrinkage of muscular fiber and necrotic musculature were observed in irradiated prawns. These structural alterations of the organs it is felt could affect the vital physiological functions such as respiration, osmotic and ionic regulation in gills and muscles; absorption, storage and secretion of the hepatopancreas which in turn could adversely affect the growth and survival of freshwater prawn M. rosenbergii.

  11. Effect of 60Co-gamma radiation on the random walk error of interferometric fiber optic gyroscopes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two 60Co-gamma radiation experiments were launched to explore the radiation effect on optical components and interferometric fiber optic gyroscope (IFOG). In optical components radiation experiment, the result showed that polarization-maintaining (PM) fiber coil loss was the most affected parameter in all the RWC (random walk coefficient) related parameters, compared with the weak sensitivity of other components parameters. In the IFOG radiation experiment, the RWC performance degradation was found to be almost due to an increase of the PM fiber attenuation. Based on the experiment result, a RWC prediction model in radiation, which is obtained by embedding PM fiber loss expression into the RWC model, was built following a power law of dose and dose rate. An IFOG RWC in space radiation environment was predicted from radiation dose and dose rate by the RWC prediction model. This RWC value calculated from test data is fully accorded to the RWC value predicted from radiation dose.

  12. Radiolysis of D(+)-carnitine by /sup 60/Co-. gamma. -radiation and formation of L(+)-. beta. -methylcholine

    Energy Technology Data Exchange (ETDEWEB)

    Loester, Heinz; Strack, Erich; Seim, Hermann

    1986-06-01

    The radiolysis of D(+)-carnitine by /sup 60/Co-..gamma..-radiation was examined to obtain optically active ..beta..-methylcholine. It was found that the radiolysis leads to a number of trimethylammonium bases but to no other betaines. (+)-..beta..-Methylcholine and acetonyltrimethylammonium could be identified by means of common analytical methods. The amounts of methylamines formed by irradiation were very small. Racemization of the D(+)-carnitine did not occur during irradiation, L(-)-carnitine was not found when an enzymatical determination method was used. The fact that (+)-..beta..-methylcholine was formed from D(+)-carnitine is pharmacologically important, because acetyl-L(+)-..beta..-methylcholine has a strong interaction with muscarinic receptors.

  13. An investigation on the radiation sensitivity of DNA conformations to {sup 60}Co gamma rays by using Geant4 toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Semsarha, F. [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Goliaei, B., E-mail: goliaei@ibb.ut.ac.ir [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Raisali, G.; Khalafi, H. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Mirzakhanian, L. [Medical Physics Unit, McGill University, 1650 Cedar Avenue, Montreal, Quebec (Canada)

    2014-03-15

    To investigate the impact of conformational properties of genetic material of living cells on radiation-induced DNA damage, single strand breaks (SSB), double strand breaks (DSB) and some microdosimetric quantities of A, B and Z-DNA conformations caused by {sup 60}Co gamma rays, have been calculated. Based on a previous B-DNA geometrical model, models of A and Z forms have been developed. Simple 34 base pairs segments of each model repeated in high number and secondary electron spectrum of {sup 60}Co gamma rays have been simulated in a volume of a typical animal cell nucleus. All simulations in this study have been performed by using the Geant4 (GEometry ANd Tracking 4)-DNA extension of the Geant4 toolkit. The results showed that, B-DNA has the lowest yield of simple strand breaks with 2.23 × 10{sup −10} Gy{sup −1} Da{sup −1} and 1.0 × 10{sup −11} Gy{sup −1} Da{sup −1} for the SSB and DSB damage yield, respectively. The A-DNA has the highest SSB yield with 3.59 × 10{sup −10} Gy{sup −1} Da{sup −1} and the Z-DNA has the highest DSB yields with 1.8 × 10{sup −11} Gy{sup −1} Da{sup −1}. It has been concluded that there is a direct correlation between the hit probability, mean specific imparted energy and SSB yield in each model of DNA. Moreover, there is a direct correlation between the DSB yield and both the mean lineal energy and topological characteristics of each model.

  14. Supplementary comparison CCRI(I)-S2 of standards for absorbed dose to water in 60Co gamma radiation at radiation processing dose levels

    DEFF Research Database (Denmark)

    Burns, D. T.; Allisy-Roberts, P. J.; Desrosiers, M. F.

    2011-01-01

    rate effect is presented and discussed briefly. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication......Eight national standards for absorbed dose to water in 60Co gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer dosimeters. The comparison was organized...

  15. Evaluation of fruit productivity and quality in Hass avocado submitted to {sup 60}Co gamma radiation; Evaluacion de productividad y calidad de fruta en aguacate Hass sometido a radiacion gamma de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Cruz T, E. De la; Ibanez P, J.; Mijares O, P.; Garcia A, J.M. [Instituto nacional de Investigaciones Nucleares, Departamento de Biologia, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1999-07-01

    Evaluation of productivity, postharvest behavior and fruit quality was performed on four years Hass avocado trees irradiated with {sup 60} Co gamma rays in doses of 5, 10, 15, 20 and 25 Gy, established in the ''La Labor'' Experimental Center of the Centro de Investigaciones Cientificas y Tecnologias del Aguacate en el Estado de Mexico (CICTAMEX) at Temascaltepec Mexico. Productivity had a significant increase in the dose of 15 Gy being the average number of fruits nearly 400 % more than the control at fruit setting, being such difference reduced at fruit harvesting to 300 %. In regard to postharvest performance, the respiration index (mg CO{sub 2}/kg/hr) did not show significant differences among treatments. Also others variables such as physiological weight losses, texture, maturity pattern, and sensorial tests (color, flavor, aroma, texture) were not different in regard to the control. This mean that radiation has altered productivity but not the quality and postharvest behavior of fruits. (Author)

  16. Supplementary comparison CCRI(I)-S2 of standards for absorbed dose to water in {sup 60}Co gamma radiation at radiation processing dose levels

    Energy Technology Data Exchange (ETDEWEB)

    Burns, D.T.; Allisy-Roberts, P.J. [Bureau International des Poids et Mesures, Pavillon de Breteuil, F-92312 Sevres cedex (France); Desrosiers, M.F. [National Institute of Standards and Technology, Gaithersburg, MD (United States); Sharpe, P.H.G. [National Physical Laboratory, Teddington, Middlesex (United Kingdom); Pimpinella, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, Rome (Italy); Lourenco, V. [CEA Saclay, LIST, Laboratoire National Henri Becquerel, Gif-sur-Yvette (France); Zhang, Y.L. [National Institute of Metrology, Beijing (China); Miller, A. [Riso High Dose reference Laboratory, Riso DTU, Roskilde (Denmark); Generalova, V. [Institute for Physical-Technical and Radiotechnical Measurements, Moscow (Russian Federation); Sochor, V. [Czech Metrology Institute, Brno (Czech Republic)

    2011-06-15

    Eight national standards for absorbed dose to water in {sup 60}Co gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer dosimeters. The comparison was organized by the Bureau International des Poids et Mesures, who also participated at the lowest dose level using their radiotherapy-level standard for the same quantity. The national standards are in general agreement within the standard uncertainties, which are in the range from 1 to 2 parts in 10{sup 2}. Evidence of a dose rate effect is presented and discussed briefly. (authors)

  17. Measurement of 60CO gamma radiation induced attenuation in multimode step-index POF at 530 nm

    Directory of Open Access Journals (Sweden)

    Kovačević Milan S.

    2013-01-01

    Full Text Available As optical fibres are used ever more extensively in space applications, nuclear industry, medicine and high-energy physics experiments, it has become essential to investigate the influence of ionizing radiation on their characteristics. In this work, the radiation-induced attenuation at 530 nm is investigated experimentally in step-index multimode polymethyl-methacrylate plastic optical fibres exposed to low dose-rate gamma radiation. Cumulative doses ranged from 50 Gy to 500 Gy. The radiation induced attenuation has been empirically found to obey the power law RIA= aDb, where D is the total radiation dose and a and b are the constants determined by fitting.

  18. Comparison of the standards for air kerma of the NRC and the BIPM for {sup 60}Co gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, C.; Allisy, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); McCaffrey, J.P.; Ross, C.K. [National Research Council (Canada)

    2010-02-15

    An indirect comparison of the standards for air kerma of the National Research Council (NRC), Canada, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the {sup 60}Co radiation beam of the BIPM in May 2009. The comparison result, based on the calibration coefficients for two transfer standards and expressed as a ratio of the NRC and the BIPM standards for air kerma, is 1.0032 with a combined standard uncertainty of 2.8 * 10{sup -3}. The result of the previous direct comparison in {sup 60}Cogamma rays, made in 1998 and modified in 2007 was 1.0025 (27). The degrees of equivalence between the NRC and the other participants in the key comparison have been calculated and the results are presented in the form of a matrix. A graphical presentation is also given. (authors)

  19. Biochemical and pharmacological studies of native and irradiated crotamine with gamma radiation of {sup 60}Co; Estudo bioquimico e farmacologico das crotaminas nativa e irradiada com radiacao gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Mitake, Malvina Boni

    2000-07-01

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

  20. Resposta de sementes de amendoim a diferentes doses de radiação gama (60Co Response of peanut seeds to different levels of gamma radiation (60Co

    Directory of Open Access Journals (Sweden)

    Tatiana da S. Santos

    2010-10-01

    Full Text Available A radiação gama, proveniente da fonte de 60Co, é bastante utilizada para esterilização, visando a prevenção da decomposição e a toxidez de origem microbiana em diversos produtos. O grau de radiossensibilidade de um embrião vegetal depende da espécie, do estágio de seu desenvolvimento durante a radiação, da dose empregada e do critério usado para medir o efeito biológico, sendo comumente utilizado o teste de germinação. Objetivou-se, com este trabalho, estudar a sensibilidade do amendoim a radiação gama e seus efeitos na germinação, no vigor e na micoflora das sementes da cultivar BRS Havana, irradiadas com uma fonte de 60Co, tipo gammacell, com taxa de dosagem de 12,5 kGy h-1. As doses testadas em kGy foram as seguintes: 0; 0,5; 1,0; 1,5; 2,0; 2,5; 3,0; 6,0; 9,0; 12,0; 15,0; 18,0; 21,0 e 24,0. Com os resultados obtidos, concluiu-se que as doses acima de 3,0 kGy prejudicaram a viabilidade das sementes e as doses acima de 12 kGy comprometeram totalmente o vigor e a germinação das sementes de amendoim. A radiação a partir da dose 2,0 kGy eliminou os fungos Aspergillus flavus e Aspergillus niger e, a partir da dose 3,0 kGy, eliminou o Aspergillus glaucus. O Penicilium spp. permaneceu em mais de 30% das sementes em todos os tratamentos com radiação, não sendo eliminado até a dose de 24 kGy.The gamma radiation from 60Co source is widely used for sterilization aiming at preventing decomposition and toxicity from microbes in several products. The degree of radiosensitvity of a plant embryo depends on the species, the development stage during radiation, doses used and the criteria used to measure the biological effect, the germination test, being commonly used.This work aimed to study the peanut sensitivity to gamma radiation and its effects in the germination, in the vigour and seeds microflora of cultivar BRS Havana, irradiated with 60Co source, type gammacell with rate of dosage of 12.5 kGy h-1. The tested doses were the

  1. Distinctions of effects of pulsed laser radiation and /sup 60/Co gamma radiation on some microorganisms. [Escherichia coli; Saccharomyces cerevisiae

    Energy Technology Data Exchange (ETDEWEB)

    Petin, V.G.; Rusina, L.K.; Sebrant, Yu.V.; Baranov, V.Yu.; Malyuta, D.D.; Niz' ev, V.G.

    1979-03-01

    Studies were made of the sensitivity of yeast cells varying in ploidy and bacterial cells varying in genotype to the effects of pulsed laser radiation and the combined effect of laser and ionizing radiation. It was demonstrated that there is no additivity of irradiation with a train of pulses, as compared to a single pulse. The impairment of cellular reproductive capacity under the influence of lasers was irreversible.

  2. Study of gamma radiation from {sup 60}Co effects on Apis mellifera venom: biochemical, pharmacological and immunological aspects; Estudo dos efeitos da radiacao gama de {sup 60}Co na peconha de Apis mellifera: aspectos bioquimicos, farmacologicos e imunologicos

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Helena

    2001-07-01

    Africanized honeybees are very common insects in Brazil and frequently cause accidents followed by important immunological reactions and even deaths. Their venoms are composed of a complex mixture of substances of general biological actions. Ionizing radiation is able to modify molecular structures affecting the biological properties of proteins. It decreases toxic and enzymatic activities and so, it appears promising as a venom detoxification tool. The main objective of this work was to study the effects of gamma radiation on bee venom, regarding biochemical, pharmacological and immunological aspects. Africanized Apis mellifera whole venom (2 mg/ml) in 0.15 M NaCl solution was irradiated with 2 kGy in a {sup 60}Co source. Native and irradiated bee venoms were submitted to high performance size exclusion chromatography (Tosohaas G2000SW column), high performance reversed phase chromatography in a C-18 column under water/acetonitrile gradient, SDS-PAGE. For both venoms studies have been carried out in UV absorption spectrum, protein concentration, hemolytic activity, and PLA{sub 2} activity analysis, lethality assay (LD{sub 50}). Biodistribution studies was carried out after labelling native and irradiated bee venom with {sup 99m}Tc. The results showed that gamma radiation did not change the protein concentration nor its immunogenicity, although it could be observed that irradiated bee venom UV spectrum and SDS-PAGE profile presented differences when compared to native bee venom. This suggests that some structural alterations in bee venom components could have occurred after irradiation. HPLC-RP profiles showed that gamma radiation could have caused conformational changes, such as unfolding of molecule chains, changing their hydrophobic groups exposuring. The hemolytic and the PLA{sub 2} activities of irradiated bee venom were smaller than the native ones. The gamma radiation diminished the toxicity of bee venom, but did not abolish its bioactivity, like hemolysis

  3. Study about the sensibility in vitro of different strains of Vibrio cholera 01 exposed to 60 Co gamma radiation; Estudo da sensibilidade in vitro de diferentes cepas de Vibio cholerae 01 a radiacao gama de 60Co

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Ivany Rodrigues de [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Servicos de Saude; Gelli, Dilma Scala; Jakabi, Miyoko [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Microbiologia; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@net.ipen.br

    1998-07-01

    The presence of some microorganisms in food, or the metabolites originated during their own multiplication may bring several diseases to humans: intoxications and food borne infections. Among the agents that may cause those diseases, we find Vibrio cholerae 01. In this experiment, the studies are focused on the radiosensibility in vitro of four strains of V. cholerae 01, exposed to different doses of ionizing radiation of {sup 60} Co. The results are compared with other data related to bacterial food borne diseases, including water. (author)

  4. Immunizing potential of sporulated oocysts of Eimeria nieschulzi exposed to heat and /sup 60/Co gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Conder, G.A.; Duszynski, D.W.

    1977-04-01

    Sporulated oocysts of Eimeria nieschulzi Dieben 1924, a rat coccidium, were exposed to radiation, heat, or both in an effort to attenuate the parasite. Moderate levels of each treatment or combination thereof attenuated the parasite, reduced pathogenesis (as judged by oocyst discharge during primary infection), and produced immunity to challenge when the oocysts were subsequently inoculated into rats. Thus, heat- and/or radiation-treated E. nieschulzi oocysts fed to rats could reduce pathogenesis during a primary infection and yet give good homologous protection.

  5. Study of {sup 60}Co as gamma source in backscatter gamma densitometers

    Energy Technology Data Exchange (ETDEWEB)

    Gholipour Peyvandi, R.; Taheri, A.; Rahmanzadeh Tootkaleh, S.; Askari Lehdarboni, M. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Islami Rad, S.Z. [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Univ. of Qom (Iran, Islamic Republic of). Dept. of Physic

    2015-07-15

    In this work the performance of backscatter gamma densitometer is studied using {sup 60}Co as gamma source. The ability of the densitometer to determine the liquid's interfaces in multi-phase flows was assessed. The aim mainly was to investigate the possibility of using {sup 60}Co in this system. Furthermore, a comparison between {sup 60}Co and was done. The obtained results indicate that {sup 60}Co can be advantageous in this regard.

  6. Soil compaction and gamma radiation ({sup 60}Co) in the development of the cowpea beans [Vigna unguiculata, (L) Walp]; Compactacao do solo e radiacao gama ({sup 60}Co) no desenvolvimento do feijao caupi [Vigna unguiculata, (L) Walp

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Eliane Ferreira; Colaco, Waldeciro [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Radioagronomia]. E-mails: aroucha@ufpe.br; wcolaco@ufpe.br

    2005-08-15

    The objective is to investigate the effect of compaction and increased doses of gamma radiation on the development of cowpea [Vigna unguiculata, (L) Walp] var. IPA-206 cultivated in a Neossolo fluvic soil, artificially compacted. Significant differences were observed in plant height, with the increase doses in soil density (1.30 Mg.m{sup -3} - compacted soil and 1.70 Mg.m{sup -3} - non-compacted soil), and in response to increased doses of irradiation (y-rays) [ [0, 100, 200 and 300 Gy). The diameter of the stem was significantly reduced in response to the increase in soil density, however the same did not occur in relation to the doses of irradiation (y-rays) holding capacity of the soil was reduced in response to the increase in soil density. (author)

  7. Effects of {sup 60}Co radiation on bothropstoxin-1 structure

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, P.J.; Nascimento, N.; Rogero, J.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia; Byrne, M.; Smith, L.A. [United States Army Medical Research, Frederick, MD (United States). Inst. of Infectious Diseases. Toxinology Div.

    2000-07-01

    Gamma radiation is able to detoxify snake venoms and toxins without significantly affecting their immunogenic properties. This method has been successfully employed to attenuate toxins for antisera production without inducing toxic effects in animals undergoing immunization. However, the mechanism of attenuation is not fully understood and much work remains at the molecular level in order to further characterize the effects of radiation on these proteins. The present study was undertaken to evaluate structural modifications following irradiation of bothropstoxin-1 (bthTx-1), a myotoxin from Bothrops jararacussu. It is believed that the functional form of the toxin is a homodimer with the binding affinity provided by electrostatic and hydrophobic interactions. Purified BthTx-1 was irradiated with 500, 1000 and 2000 Gy of {sup 60}Co gamma radiation. The irradiated and native toxins were compared by mass spectrometry, circular dichroism (CD) and tryptophan fluorescence quenching, results suggest that the monomer-monomer interactions are hydrophobic in nature. No significant differences were observed between the two forms of the toxin by CD spectral interpretation. However, significant losses of secondary structure could be observed when the native and irradiated BthTX-1 were compared after disulfide bond reduction. Fluorescence data indicates that the solvent accessibility of Trp 77 has been modified, which may explain the differences in quaternary structure. (author)

  8. Effect of {sup 60} Co gamma radiation on trehalose level of Saccharomyces boulardii cells; Efeito da radiacao gama {sup 60} Co nos niveis de trealose de celulas de Saccharomyces boulardii

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Raquel Gouvea dos; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil). Nucleo de Radiobiologia; Duarte, Rinaldo; Nicoli, Jacques R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Microbiologia

    1996-07-01

    The medicine Floratil used for diarrhea treatment is composed by lyophilized yeast cells of Saccharomyces boulardii. The action mechanism of this product is unknown. The efficacy of S. boulardii depends on its viability. The increase in the trehalose level in S. cerevisiae cells submitted to a previous sub-lethal level heat shock results in resistance to a lethal shock. The aim of this work was to study weather the cell trehalose level is involved also in the resistance of gamma irradiation. It was noted that the yeast cells surviving to gamma irradiation had more trehalose level than control cells. Apparently there is a positive correlation between of trehalose level and gamma irradiation resistance of S.boulardii cells. (author)

  9. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the LNE-LNHB, France and the BIPM in 60Co gamma radiation

    Science.gov (United States)

    Kessler, C.; Burns, D. T.; Delaunay, F.; Donois, M.

    2013-01-01

    An indirect comparison of the standards for air kerma of the Laboratoire National de Métrologie et d'Essais-Laboratoire National Henri Becquerel (LNE-LNHB), France and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in April 2013. The comparison result, evaluated as a ratio of the LNE-LNHB and the BIPM standards for air kerma, is 0.9994 with a combined standard uncertainty of 1.8 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  10. Comparison of the standards for absorbed dose to water of the NRC and the BIPM for {sup 60}Co gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, C.; Allisy-Roberts, P.J.; Burns, D.T. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); McCaffrey, J.P.; McEwen, M.R.; Ross, C.K. [National Research Council of Canada, Ottawa (Canada)

    2010-06-15

    A comparison of the standards for absorbed dose to water of the National Research Council of Canada (NRC) and of the Bureau International des Poids et Mesures (BIPM) was carried out in the {sup 60}Co radiation beam of the BIPM in May 2009 under the auspices of the key comparison BIPM.RI(I)-K4. The comparison result, based on the calibration coefficients for two transfer standards and expressed as a ratio of the NRC and the BIPM standards for absorbed dose to water, is 0.9980(52). This result replaces the 1998 NRC value of 0.9976(51) in this key comparison. The degrees of equivalence between the NRC and the other participants in this comparison have been calculated and the results are given in the form of a matrix for the ten national metrology institutes (NMIs) with published results that have taken part in the ongoing comparison for absorbed dose to water. A graphical presentation is also given. (authors)

  11. Key comparison BIPM.RI(I)-K1 of the air-kerma standards of the SCK.CEN, Belgium and the BIPM in 60Co gamma radiation

    Science.gov (United States)

    Kessler, C.; Burns, D.; Mihailescu, L. C.; Chiriotti, S.

    2017-01-01

    A first key comparison of the standards for air kerma of the Laboratory for Nuclear Calibrations (LNK) from the Studiecentrum voor Kernenergie—Centre d'Etude de l'Energie Nucleaire (SCK.CEN), Belgium and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in September 2016. The comparison result, evaluated as a ratio of the SCK.CEN and the BIPM standards for air kerma, is 1.0021 with a combined standard uncertainty of 2.6 × 10-3. The results for an indirect comparison made at the same time are consistent with the direct results at the level of 7 parts in 104. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  12. Effect of gamma radiation of {sup 60}Co in the variability of chinese bean [Vigna unguiculata (l.) Walpers] en R{sub 4}M{sub 4}; Efecto de la radiacion gamma de {sup 60}Co en la variabilidad de frijol chino [Vigna unguiculata (l.) Walpers] en R{sub 4}M{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Salmeron E, J.; Bueno J, J.E.; Valencia E, F. [CSAEGro, Iguala, Guerrero, Tel and Fax 01 733 (33) 24328 (Mexico); Cervantes S, T. [IREGEP (Mexico); Cruz T, E. De la [ININ, Departamento de Biologia, 52750 La Marquesa, Estado de Mexico (Mexico)]. e-mail: csaegro@prodigy.net.mx

    2007-07-01

    Selection of plants of Chinese bean coming from seed irradiated with gammas of {sup 60}Co in the generation R{sub 4}M{sub 4} (fourth recurrent irradiation, fourth segregate generation) were carried out, taking as selection approaches the plant architecture, the numbers of sheaths for plant, sheath longitude, position of the sheaths, grain size and resistance to plagues and illnesses. 17 lines were selected for grain and 3 lines with fodder characteristics of black grain color were also obtained. (Author)

  13. The influence of {sup 60}Co gamma radiation on the action of phenolic compounds Anadenanthera colubrina (Vell.) Brenan in the microbiological control of crude extracts

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo Henrique F. dos; Silva, Edvane B. da, E-mail: santosghf@hotmail.co [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR); Sena, Kesia Xisto da Fonseca R. de; Silva, Bruna L., E-mail: kxfrs@bol.com.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Antibioticos; Lima, Claudia S. de A., E-mail: claudia.salima@gmail.co [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    2009-07-01

    Anadenanthera colubrina (Vell.) Brenan, known popularly as angico is a tree founded in northeastern of Brazil, and has great economic and ecological interest. These trees are characterized by high levels of tannins. To evaluate the influence of gamma radiation in plant extracts of barks and leaves of angico, we got extracts of barks and leaves in 70% ethanol, which was filtered and evaporated until dryness. It were classified in four groups (non-irradiated, 5; 7.5 and 10 kGy). The total phenols were quantified by Folin-Ciocalteau method, and the tannins, using the precipitation of casein. The antimicrobial activity of extracts was observed using the paper disk diffusion methods against Gram-positive, Gram-negative, acid-alcohol-resistant bacteria: and yeasts. The halos greater than 10 mm were considered actives. It was also performed the Minimal Inhibitory Concentration (MIC) using Gram positive and alcohol-acid resistant bacteria. The results showed that tannins of A. colubrina, were 52 to 57% of total phenols, and leaves, 58 to 60%. The percentage of total phenols and tannins in the barks and leaves of A. colubrina have not statistically significant change when compared with the irradiated control. These results suggest that A. colubrina has antimicrobial activity against the Gram-positive and alcohol-acid -resistant bacteria, confirmed by MIC. The extracts of leaves it was additionally actives against the Gram-negative and against the yeast C. albicans. These results show that the gamma radiation has not influence about the antimicrobial activity of crude extracts of barks and leaves of A. colubrina. (author)

  14. Effect of {sup 60}Co gamma radiation on the levels of phenolic compounds from crude extracts of bark of Spondias luta L

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo H.F.; Silva, Hianna A.M.F.; Melo, Mychely S., E-mail: santosghf@hotmail.com, E-mail: hiannaamfs@gmail.com, E-mail: mychely.melo@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silva, Edvane B., E-mail: edvborges@yahoo.com [Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academinco de Vitoria

    2013-07-01

    Spondias luta L. (Anacardiaceae), popularly known as cajazeira, is a plant widespread in several regions of Brazil, famous for containing phenolic compounds, which are responsible for your characteristic astringent. Ionizing radiations have the ability to cross the material, ionizing atoms and molecules, causing changes in atoms and molecules important. It is known ionizing radiation promotes quantitative and qualitative changes in plant materials, increasing, decreasing or inactivating secondary substances. The objective of this work was to evaluate the effect of gamma radiation as a modifier of the activity of the phenolic compounds of the bark extract of S. luta L. Methods: For the dosage of phenol extracts (control, irradiated with 5 kGy, 10 kGy, 15 kGy and 20 kGy) were diluted in methanol to a final concentration of 200 mg / L. In test tubes were added 50 μL of extract plus 1 ml of distilled water and 500 μl of Folin (diluted 1:10). After 10 minutes in a dark chamber was added 2.5 ml of calcium carbonate to 20% and the content of the tube was homogenized. After 20 minutes was performed with a spectrophotometer at 735 nm. The assay was performed in triplicate and calculated from a standard curve solution of gallic acid and expressed in μEAG (GAE/mg extract). Results: The control extracts, irradiated to 5 kGy, 10 kGy, 15 kGy and 20 kGy, had, respectively, 6.25, 6.70, 6.25, 6.85, 6.45 μEAG/mg of extract. Conclusion: The results showed no significant change in the amount of phenolic compounds, showing that these compounds are radioresistant extract these doses. (author)

  15. Cytotoxicity evaluation of Diethyltoluamide (DEET) in Perna perna (Linnaeus, 1758) mussels non-irradiated and irradiated with {sup 60}Co gamma radiation; Avaliacao da citotoxicidade do dietiltoluamida (DEET) em mexilhoes Perna perna (Linnaeus, 1758) irradiados e nao irradiados com radiacao gama de {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela de Assis

    2013-07-01

    Recent studies have identified the presence of several emerging pollutants in aquatic environments. The occurrence in different environmental matrices has been continuously reported, highlighting the need for toxicity studies. The DEET (N,N-diethyl-meta-toluamide) is the active ingredient used in most insect repellents, and is present in many commercially available formulations. Apart from chemical pollutants, aquatic organisms are subject to exposure of ionizing radiation from natural sources or in the vicinity of nuclear power plants. The present study evaluated the toxicity of DEET in organisms irradiated and non-irradiated with {sup 60}Co gamma radiation, and the effects that radiation causes in lysosomes of hemocytes of Perna perna mussel. For this purpose, assays were performed to identify the acute toxicity of DEET concentration and the dose of gamma radiation able to cause mortality. Subsequently, cytotoxicity assays were carried out to assess the stability of the lysosomal membrane in organisms exposed to ionizing radiation and DEET. According to the results obtained in acute toxicity tests, the concentration of DEET that causes mortality of 50% exposed organisms (LC50) is 114,27 mg L{sup -1}, and the radiation dose that causes mortality (LD50) is 1068 Gy. In the cytotoxicity assays, the concentration of the non-observed effect (NOEC) for irradiated and non-irradiated organisms 0.0001 mg L-1 and observed effect concentration (LOEC) at concentrations above this. The IC25 (72h) for non-irradiated organisms was 0.0003 mg L-1 and IC50 (72h) was 0.0008 mg L{sup -1} for irradiated and non-irradiated organisms. Despite of the concentrations of effect found in this study were higher than in the environment, both measurements are in the same order of magnitude and should be also take into account the possible synergistic effects of DEET with other contaminants in the aquatic environment. (author)

  16. Gamma ({sup 60}CO) radiation effects on arcelin protein and evaluation of bean lineages against Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae);Efeito da radiacao gama ({sup 60}CO) sobre a proteina arcelina e avaliacao de linhagens de feijoeiro a Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boh.) (Col.: Bruchidae)

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Ana Claudia Girardo

    2006-07-01

    The resistance of arcelin carrying seeds of bean lineages (Phaseolus vulgaris L.) against the bean weevils Acanthoscelides obtectus (Say, 1831) and Zabrotes subfasciatus (Bohemann, 1833) (Coleoptera: Bruchidae), and the influence of gamma radiation ({sup 60}CO) on the manifestation of arcelin resistance to Z. subfasciatus were verified. Laboratorial tests, in choice and non-choice tests, with wild specimens carrying Arc-1, Arc-2, Arc-3, Arc-4, Raz-56 and Raz-59 (with Arc-5 alleles) and commercial lineages as control IAC - Carioca and IAC - Arua were conducted. Statistical design was completely randomized, with five repetitions, with 10 g of grains from each lineage samples by portion. Attractiveness, oviposition, emergence, mortality, adults' weigh and longevity, developing period, sexual rate, seeds' weigh loss, infestation and fecundity (Z. subfasciatus) were observed. Gamma radiation doses irradiations, in general, haven't affected the resistance manifestation of lineages carrying arcelin protein variants against the Z. subfasciatus bean weevil, thus, joint application use of both control methods can be recommended. Raz-56 lineage showed high resistance of the antibiosis types and non-preference for oviposition and feeding to Z. subfasciatus, while Raz-59 showed antibiosis and non-preference for feeding, and both (Raz-56 and Raz-59) showed intermediate resistance to A. obtectus, against which lineage Arc-2 was the most harmful to its development, expressing non-preference to feeding and/or antibiosis. (author)

  17. Effects of {sup 60}Co gamma radiation on toxicity and hemorrhagic, myonecrotic, and edema-forming activities of Cerastes cerastes venom

    Energy Technology Data Exchange (ETDEWEB)

    Abib, H. [Univ. des Sciences et de la Technologie, Lab. de Biologie Cellulaire et Moleculaire, Faculte des Sciences Biologiques, Houari Boumedienne, Bab Ezzouar (Algeria); Laraba-Djebari, F. [Inst. Pasteur d' Algerie, Lab. de Recherche et de Developpement sur les Venins, Alger (Algeria)]. E-mail: flaraba@ibnsina.ands.dz

    2003-12-01

    Antisera are used as effective antidotes against the local effects of snake bites. To improve antisera production and extend the life of surrogates used to produce antibodies, the chronic effects of venom toxicity must be reduced. The present study evaluated the effectiveness of gamma irradiation to reduce the local effects associated with viperid snake bites by evaluating in NMRI mice the toxicity and edematic, hemorrhagic, and myonecrotic activities of native and irradiated Cerastes cerastes venoms. These results indicated that the toxicity of irradiated venoms (1 and 2 kGy) decreased as compared with that of native venom. The edematic and hemorrhagic activities were also reduced in the detoxified samples, particularly with the 2-kGy radiation dose. Furthermore, the creatine phosphokinase (CPK) activity was significantly increased in the serum and decreased in the myocardium after envenomation with native venom, but no significant enzymatic changes were observed in mice envenomated with irradiated venom. Histopathologic evaluation showed that native venom caused severe degenerative changes in the myocardium. In the case of 2-kGy-irradiated venom, no tissue alterations were observed. These results indicate that irradiation of venom with a 2-kGy dose may offer an effective method for reducing the chronic toxic effects of venom in immunized animals. (author)

  18. Response of the Sertoli cell and stem germ cell to /sup 60/Co. gamma. -radiation (dose and dose rate) in testes of immature rats

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, B.H.; Blend, M.J.

    1976-06-01

    Gamma-radiation effects (dose and dose rate) on the Sertoli cells and stem cells of the germinal line in immature rat testes were examined. Prior to Day 4 of postnatal development, the gonocyte or primitive germ cell was the most radiosensitive cell in the testis. From Day 4 to approximately Day 15 the Sertoli cell was the most critical element, and thereafter the stem cell was of first importance. A dose of 100 rads irreversibly reduced the number of Sertoli cells to 63 percent of control. Of the ages tested beyond Day 2, the 9-day testis was most severely affected. It was estimated that a dose of 400 rads would reduce sperm output of the 9-day testis to 21 percent of control. After Day 4 and prior to Day 20, 300 rads produced a permanent decrement in the stem-cell population. Six hundred rads are required to produce this effect in the adult. Dose rate was an important mediator of the radioresponse of both Sertoli and germ cells.

  19. 60Co contamination in recycled steel resulting in elevated civilian radiation doses: causes and challenges.

    Science.gov (United States)

    Chang, W P; Chan, C C; Wang, J D

    1997-09-01

    Since late 1992, more than 100 building complexes containing public and private schools and nearly 1,000 apartments have been identified in Taiwan with elevated levels of gamma-radiation from construction steel contaminated with 60Co. Due to improper handling of 60Co contaminated scrap steel in late 1982 and 1983, contaminated construction materials have been widely distributed throughout the country. These contaminated construction materials have generated elevated radiation exposures to members of the public in Taiwan. As of early 1996, more than 4,000 people, including young students, have been identified as receiving more than 1 mSv y(-1) above the local background for up to 12 y. This report provides a detailed discussion of the sources of the 60Co contamination in construction steel, its discovery in the building complexes, and preliminary evaluation and remediation activities.

  20. Dose-dependent and gender-related radiation-induced transcription alterations of Gadd45a and Ier5 inhuman lymphocytes exposed to gamma ray emitted by (60)Co.

    Science.gov (United States)

    Tavakoli, Hassan; Manoochehri, Mahdi; Modarres Mosalla, Sayed Mahdi; Ghafori, Mostafa; Karimi, Ali Akbar

    2013-04-01

    Growth arrest DNA damage-inducible 45a gene (Gadd45a) and immediate early response gene 5 (Ier5) have been emphasised as ideal radiation biomarkers in several reports. However, some aspects of radiation-induced transcriptional alterations of these genes are unknown. In this study, gender-dependency and dose-dependency as two factors that may affect radiation-induced transcription of Gadd45a and Ier5 genes were investigated. Human lymphocyte cells from six healthy voluntary blood donors (three women and three men) were irradiated in vitro with doses of 0.5-4.0 Gy from a (60)Co source and RNA isolated 4 h later using the High Pure RNA Isolation Kit. Dose and gender dependency of radiation-induced transcriptional alterations of Gadd45a and Ier5 genes were studied by quantitative real-time polymerase chain reaction. The results showed that as a whole, Gadd45a and Ier5 gave responses to gamma rays, while the responses were independent of radiation doses. Therefore, regardless of radiation dose, Gadd45a and Ier5 can be considered potential radiation biomarkers. Besides, although radiation-induced transcriptional alterations of Gadd45a in female and male lymphocyte samples were insignificant at 0.5 Gy, at other doses, their quantities in female samples were at a significantly higher level than in male samples. Radiation-induced transcription of Ier5 of females samples had a reduction in comparison with male samples at 1 and 2 Gy, but at doses of 0.5 and 4 Gy, females were significantly more susceptible to radiation-induced transcriptional alteration of Ier5.

  1. A comparison of the 60Co gamma radiation hardness, breakdown characteristics and the effect of SiNx capping on InAlN and AlGaN HEMTs for space applications

    Science.gov (United States)

    Smith, M. D.; O'Mahony, D.; Vitobello, F.; Muschitiello, M.; Costantino, A.; Barnes, A. R.; Parbrook, P. J.

    2016-02-01

    Electrical performance and stability of InAlN and AlGaN high electron mobility transistors (HEMTs) subjected 9.1 mrad of 60Co gamma radiation and off-state voltage step-stressing until breakdown are reported. Comparison with commercially available production-level AlGaN HEMT devices, which showed negligible drift in DC performance throughout all experiments, suggests degradation mechanisms must be managed and suppressed through development of advanced epitaxial and surface passivation techniques in order to fully exploit the robustness of the III-nitride material system. Of the research level devices without dielectric layer surface capping, InAlN HEMTs exhibited the greater stability compared with AlGaN under off-state bias stressing and gamma irradiation in terms of their DC characteristics, although AlGaN HEMTs had significantly higher breakdown voltages. The effect of plasma-enhanced chemical vapour deposition SiNx surface capping is explored, highlighting the sensitivity of InAlN HEMT performance to surface passivation techniques. InAlN-SiNx HEMTs suffered more from trap related degradation than AlGaN-SiNx devices in terms of radiation hardness and step-stress characteristics, attributed to an increased capturing of carriers in traps at the InAlN/SiNx interface.

  2. Microdosimetry of DNA conformations: relation between direct effect of (60)Co gamma rays and topology of DNA geometrical models in the calculation of A-, B- and Z-DNA radiation-induced damage yields.

    Science.gov (United States)

    Semsarha, Farid; Raisali, Gholamreza; Goliaei, Bahram; Khalafi, Hossein

    2016-05-01

    In order to obtain the energy deposition pattern of ionizing radiation in the nanometric scale of genetic material and to investigate the different sensitivities of the DNA conformations, direct effects of (60)Co gamma rays on the three A, B and Z conformations of DNA have been studied. For this purpose, single-strand breaks (SSB), double-strand breaks (DSB), base damage (BD), hit probabilities and three microdosimetry quantities (imparted energy, mean chord length and lineal energy) in the mentioned DNA conformations have been calculated and compared by using GEometry ANd Tracking 4 (Geant4) toolkit. The results show that A-, B- and Z-DNA conformations have the highest yields of DSB (1.2 Gy(-1) Gbp(-1)), SSB (25.2 Gy(-1) Gbp(-1)) and BD (4.81 Gy(-1) Gbp(-1)), respectively. Based on the investigation of direct effects of radiation, it can be concluded that the DSB yield is largely correlated to the topological characteristics of DNA models, although the SSB yield is not. Moreover, according to the comparative results of the present study, a reliable candidate parameter for describing the relationship between DNA damage yields and geometry of DNA models in the theoretical radiation biology research studies would be the mean chord length (4 V/S) of the models.

  3. Perna perna (LINNAEUS, 1758) mussels irradiated by {sup 60}CO gamma rays cytotoxicity evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela A.; Pusceddu, Fabio H.; Rogero, Sizue O.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    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 {sup 60}Co 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)

  4. Effect of gamma radiation from {sup 60}C in conservation and quality of pepper fresh and pulp; Efeito da radiacao gama do {sup 60}Co na conservacao e qualidade de pimenta in natura e em polpa

    Energy Technology Data Exchange (ETDEWEB)

    Milagres, Regina Celia Rodrigues de Miranda

    2014-07-01

    Capsicum peppers are among the most used and most valued seasoning spices in the world. They are highly susceptible to post harvest decay, therefore the use of irradiation may contribute to conservation of this fruit which has significant nutritional, economic and social value. Were evaluated the effects of gamma radiation of {sup 60}Co in increasing the shelf-life and preservation of quality of pepper 'Dedo-de-moca' (Capsicum baccatum var. Pendulum) fresh and pulp associated or not with another conservation methods. Gamma radiation doses were investigated of 0,25; 0,50; 0,75; 1,00; 1,25; 1,50; 2,00 e 3,00 kGy in fresh fruit and 1,50; 2,00; 3,00; 4,50 e 6,00 kGy in pepper pulp. The use of laboratory pasteurization (85°C/3min), the addition of citric acid (5%) and 5% NaCl were also investigated in the pepper pulp. The samples were stored at 5 °C and or 25 °C. Were performed analysis: visual (disease incidence, turgidity and color); bioactive compounds (carotenoids, capsaicinoids, antioxidant capacity and phenolic compounds); physicochemical (Weight loss, firmness, soluble solids (SS), pH, titratable acidity (TA), ratio, color and moisture); respiratory rate and ethylene production; proximate composition (moisture, soluble and insoluble fiber, ash, protein, ether extract, total and available carbohydrate); microbiological contamination (mesophilic aerobic microorganisms, coliforms at 45 °C, Salmonella spp. and yeasts and molds) and sensory (acceptance test, difference test and paired preference). Radiation doses between 0.25 and 3.00 kGy were not effective to increase shelf-life and maintain fresh pepper quality during storage. There was increased intensity of red color, of incidence of disease, decreased turgidity and changes in physical, chemical and nutritional parameters. In pulp, the doses of gamma radiation of 4.50 and 6.00 kGy and the addition of 5% NaCl no changing sensory attributes, physical-chemical and bioactive compounds. Only the

  5. 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

  6. Gamma 60Co-irradiation of organic matter in the Phosphoria Retort Shale

    Science.gov (United States)

    Lewan, M. D.; Ulmishek, G. F.; Harrison, W.; Schreiner, F.

    1991-04-01

    Irradiation experiments were conducted on a thermally immature rock sample of the Phosphoria Retort Shale and its isolated kerogen. A 60Co-source for gamma radiation was employed at dosages ranging from 81 to 885 Mrads, which are attainable by Paleozoic and Precambrian black shales with syngenetic uranium enrichments. Kerogen elemental, isotopic, and pyrolysate compositions are not affected at these dosages, but the bitumens extracted from the irradiated rock are affected. The major effects are reductions in the amounts of bitumen, acyclic isoprenoids, and high-molecular weight acyclic carboxylic acids. Natural differences in the amounts of bitumen and acyclic isoprenoid due to regional and stratigraphie variations in organic source input and depositional conditions make the radiation-induced reductions in these parameters difficult to use as indicators of natural radiation damage in black shales. However, the preferential reduction in the high-molecular weight acyclic carboxylic acids, which are ubiquitous in the living precursory organic matter, is diagnostic of experimental γ-irradiation but may not be diagnostic of natural irradiation. The overall process associated with radiation damage is polymerization by cross-linking through a free radical mechanism. As a result, irradiation of organic matter in black shales is more likely to retard rather than enhance petroleum generation.

  7. Immunohistochemical study on effects of [sup 60]Co [gamma] irradiation on salivary gland ducts of rat

    Energy Technology Data Exchange (ETDEWEB)

    Saitoh, Kazuhiko (Meikai Univ., Sakato, Saitama (Japan). School of Dentistry)

    1992-09-01

    Cytokeratin distribution in salivary glands was detected by use of polyclonal antikeratin antiserum (TK) and monoclonal antibodies (KL 1, RGE 53, and RPN 1164). The salivary glands of male rats received either 17.82 Gy or 27.97 Gy [sup 60]Co [gamma] irradiation in a single exposure and were then compared immunohistochemically with those of normal rats. Polyclonal anti-keratin antiserum (TK), which reacts with 41-65 KD keratins, stained almost all ducts in normal glands. RPN 1164 (no. 8 keratin) staining was negative in intercalated ducts of normal parotid and submandibular glands, but strongly positive in both striated and excretory ducts of these glands. Monoclonal antibody KL 1 (55-57 KD keratins) and RGE 53 (no. 18 keratin) did not bind to any ductal or acinar epithelia. Only in the sublingual gland were acini positive for TK staining, possibly indicating myoepithelial cells. No effects of [sup 60]Co [gamma] irradiation were apparent regarding keratin distribution in the intercalated in apical cytoplasm by [sup 60]Co [gamma] irradiation. Also, in the excretory duct, the basal side of the cells exhibited weakened staining following [sup 60]Co [gamma] irradiation were the most significant in the parotid and the least in the sublingual gland. Also this reaction depended upon the doses of [sup 60]Co used. The present findings suggested that negative or weakened staining at the basal and perinuclear portions of striated duct cells specifically reflects the primary or secondary cell damage produced by [sup 60]Co [gamma] irradiation. Since the distribution of cytoskeletal proteins in the cytoplasm reflects certain pathological conditions, immunohistochemical detection of these proteins seem to have a diagnostic value with respect to cellular injury. (J.P.N.) 77 refs.

  8. 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)

  9. Irradiation effect on enzymatic activity of papain with {sup 60}Co-{gamma} rays

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, Masakazu; Ohashi, Isao; Oka, Masahito; Hayashi, Toshio [Osaka Prefecture Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology

    1998-12-31

    An investigation was made on the durability of enzyme activity against {sup 60}Co-{gamma} irradiation at a dose up to 55 kGy/h using dry powder and aqueous solution of papain preparations on the market. Hybrid materials including bioactive molecules combined with biocompatible synthetic polymers are expected to have biocompatible properties and also biomimetic functions as a component of artificial organs for human body. The activity of papain in an aqueous solution was rapidly decreased at the early stage of irradiation through oxidation of SH group at its active site with active oxygen produced by the irradiation and then, partially recovered since SH group was reproduced in an anoxic state after O{sub 2} consumption in the solution irradiated at a high dose. A usual radiation method for sterilization was found applicable to decontamination of dry and frozen preparations of papain. When suitable conditions for radiation were chosen and N{sub 2} gas was purged to suppress the formation of free radicals, it was possible to keep the enzyme activity at more than 50% of the initial activity after radiation at 30 kGy. (M.N.)

  10. Manufacture of Single 60Co Source Irradiation Facility and the Measurement of Reference Radiation Filed

    Institute of Scientific and Technical Information of China (English)

    GAO; Fei; WANG; Hong-yu; NI; Ning; ZHANG; Li; HOU; Jin-bing; SONG; Ming-zhe

    2012-01-01

    <正>Reference radiation filed produced by isotope source is necessary for calibration of radiation dose meter. 60Co single source radiation facility is an important method to produce reference radiation. Collimation design of the facility is good for characteristics of the field, but there are scattered photon influences however. Scattered radiation is mainly come from collimation, source shield, floor, walls and

  11. Study of the action of {sup 60}Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp;Estudo da acao da radiacao gama de {sup 60}Co sobre Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris em polpa de manga congelada

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Marco Antonio dos Santos

    2009-07-01

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of foodborne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5 kGy in a {sup 60}Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09 kGy for E. coli ATCC 8739, 0.60 and 0.98 kGy for S. poona and 0.72 and 0.88 kGy for A. acidoterrestris respectively. The triangular test showed that a 5 kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  12. Study of the action of {sup 60}Co gamma radiation on Salmonella poona, Escherichia coli and Alicyclobacillus acidoterrestris in mango pulp; Estudo da acao da radiacao gama de {sup 60}Co sobre Salmonella poona, Escherichia coli e Alicyclobacillus acidoterrestris em polpa de manga congelada

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Marco Antonio dos Santos

    2009-07-01

    The application of non-thermal treatments has proven effective in inhibiting bacteria such as Salmonella and Escherichia coli. Mango is a fruit of national consumption with a great exportation potential. Meanwhile, outbreaks of food borne disease related to mango consumption caused mistrust on the degree of food security offered by the product. The objective of this work was to establish the radioresistance of bacteria Escherichia coli, Salmonella Poona and Alicyclobacillus acidoterrestris on the mango pulp by the calculation of the D10 values and to know the radiation effect on the sensory characteristics of the fruit pulp. The microbiological profile of frozen mango pulp available at the local market was also established using conventional methods of plating and Most Probable Number (MPN). The pulps experimentally inoculated with the bacteria listed above were irradiated with doses of 0, 1, 2, 3, 4 and 5kGy in a {sup 60}Co source. The sensory analysis was performed using a dose of 5 kGy, using the triangular test and the test of acceptance with hedonic scale. The results of this study show that the quality of mango pulp sell in the local market is not satisfactory in accordance with the standards established by the Brazilian law and the literature, showing the need of using other tools to achieve acceptable levels of quality. The D10 values obtained are in the range of 1.01 and 1.09kGy for E. coli ATCC 8739, 0.60 and 0.98kGy for S. poona and 0.72 e 0.88kGy for A. acidoterrestris respectively. The triangular test showed that a 5kGy radiation dose changed the sensory characteristics of mango pulp. Nevertheless, sensory analysis of a food product prepared with the irradiated pulp obtained good acceptance in the attributes of global appearance, flavor and aroma. (author)

  13. Effect of {sup 60}Co radiation processing in mate (Ilex paraguariensis); Efeito do processamento por radiacao de {sup 60}Co na erva-mate (llex paraguariensis)

    Energy Technology Data Exchange (ETDEWEB)

    Furgeri, Camilo

    2009-07-01

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

  14. 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)

  15. Study of irradiated toxins with {sup 60}Co gamma rays: immune system behavior

    Energy Technology Data Exchange (ETDEWEB)

    Caproni, Priscila; Baptista, Janaina A.; Almeida, Tiago Luiz de; Passos, Luiz A.C.; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: pricaproni@hotmail.com

    2007-07-01

    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 {sup 60}Co gamma rays, yielding toxoids with good immunogenicity. The achievement of modified antigens with lower toxicity and preserved or improved immunogenicity can be useful. Ionizing radiation has been proven to be a powerful tool to attenuate snake venoms 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 have investigated the immunological behavior of bothropstoxin-I, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were investigated 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 the protein (aggregates and oligomers). Our data indicate that irradiated toxins were immunogenic and the antibodies elicited by them were able to recognize the native toxin in ELISA. These results indicate that irradiation of toxic proteins can promote significant modifications in their structures, but still retain many of the original antigenic and immunological properties of native proteins. Also, our data indicate that the irradiated protein induced higher titers of IgG2a and IgG2b, suggesting that Th1 cells were predominantly involved in the immune response. (author)

  16. Determination of the correction factor for attenuation, dispersion and production of electrons (K{sub wall}) in the wall of graphite of a ionization chamber Pattern National Type CC01 in fields of gamma radiation of {sup 60}Co; Determinacion del factor de correccion por atenuacion, dispersion y produccion de electrones (K{sub wall}) en la pared de grafito de una Camara de Ionizacion Patron Nacional Tipo CC01 en campos de radiacion gamma de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez R, J.T.; Morales P, J.; Cruz E, P. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2001-12-15

    It was determined the Kwall correction factor for the wall of graphite of the chamber of the pattern national type CC01 series 133 for a radiation field Gamma of {sup 60}Co. With this end to measured the currents of ionization l(x) as function of the thickness of the wall of the chamber: X=4,8,12,16 and 20 mm.The mensurations for each thickness consisting of three groups, of sizes n = 30 or 60 data for each group; obtaining 8 complete groups of mensurations independent in eight different dates.The determinate the factor carried out using three regression models: lineal, logarithmic and quadratic, models that were tried to validate with the tests of : i) Shapiro-Wilk and {chi}{sup 2} for the normality of the entrance data ii) Tests of Bartlett for variances homogeneity among groups for each thickness iii) The tests of Duncan for the stockings among groups of each thickness, and iv) The tests of adjustment lack (LOF) for the models used. Nevertheless, alone the models of the group of corresponding mensurations at 01-03-2000 17-08-2001 they can be validated by LOF, but not for tests of normality and homogeneity of variances. Among other assignable causes of variation we have: i) The values captured by the system of mensuration of the variables of it influences: pressure, temperature and relative humidity don{sup t} belong together with the existent ones to the moment to capture the l(x). ii) The mensuration room presents flows of air, for what was suited o diminish their volume and to eliminate the flows of air. iii) A protocol settled down of taking of measures that it consisted in: - Pre-irradiation 5 minutes the chamber after the change of polarity and hood change, with a period of stabilization of 5 minutes after the pre-irradiation. - Pre-irradiation for 5 minutes before the taking of the readings, with the object of eliminating variation sources assigned to currents of escapes or due variations to transitory. iv) To realize corrections for relative humidity of

  17. Key comparison BIPM.RI(I)-K4 of the absorbed dose to water standards of the LNE-LNHB, France and the BIPM in 60Co gamma radiation

    Science.gov (United States)

    Kessler, C.; Burns, D. T.; Delaunay, F.; Donois, M.

    2013-01-01

    An indirect comparison has been made of the standards for absorbed dose to water in 60Co radiation of the Laboratoire National de Métrologie et d'Essais-Laboratoire National Henri Becquerel (LNE-LNHB), France and of the Bureau International des Poids et Mesures (BIPM). The measurements at the BIPM were carried out in April 2013. The comparison result, based on the calibration coefficients for two transfer standards and evaluated as a ratio of the LNE-LNHB and the BIPM standards for absorbed dose to water, is 0.9971 with a combined standard uncertainty of 3.9 × 10-3. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  18. Sensitivity to. gamma. rays of avian sarcoma and murine leukemia viruses. [/sup 60/Co, uv

    Energy Technology Data Exchange (ETDEWEB)

    Toyoshima, K. (Osaka Univ., Japan); Niwa, O.; Yutsudo, M.; Sugiyama, H.; Tahara, S.; Sugahara, T.

    1980-09-01

    The direct inactivation of avian and murine oncoviruses by ..gamma.. rays was examined using /sup 60/Co as a ..gamma..-ray source. The inactivation of murine leukemia virus (M-MuLV) followed single-hit kinetics while the subgroup D Schmidt-Ruppin strain of avian sarcoma virus (SR-RSV D) showed multihit inactivation kinetics with an extrapolation number of 5. The two viruses showed similar uv-inactivation kinetics. The genomic RNA of the SR-RSV D strain was degraded by ..gamma.. irradiation faster than its infectivity, but viral clones isolated from the foci formed after ..gamma.. irradiation had a complete genome. These results suggest that SR-RSV D has a strong repair function, possibly connected with reverse transcriptase activity.

  19. Effects of (60)Co gamma irradiation on behavior and gill histoarchitecture of giant fresh water prawn Macrobrachium rosenbergii (DE MAN).

    Science.gov (United States)

    Stalin, A; Broos, K V; Sadiq Bukhari, A; Syed Mohamed, H E; Singhal, R K; Venu-babu, P

    2013-06-01

    Present study was designed to observe the effects of (60)Co gamma radiation in behavioral and histological changes in the gills of giant fresh water prawn Macrobrachium rosenbergii. The adult prawns were irradiated with four different dose levels (3mGy, 30mGy, 300mGy and 3000mGy) and the control group (without irradiation) was maintained separately. Behavioral changes like hyperactivity, loss of balance, reduced swimming rate, slower rate of food intake and convulsions were observed in higher dose levels of 300mGy and 3000mGy. The histological alterations such as accumulated haemocytes in haemocoelic spaces, abnormal gill tips, lifted lamellar epithelium, swollen and fused lamellae, hyperplasic, necrotic, clavate-globate and complete disorganization of lamellae were observed in (60)Co gamma irradiated prawns. Significantly more considerable histological alterations were observed in the highest dose level of 3000mGy, but no mortality was evidenced. This study serves as biomonitoring tool to assess the radiation pollution in the aquatic environment.

  20. Evaluating the effect of gamma radiation ({sup 60}Co) on protein arcelin and its influence in the resistance of Zabrotes subfasciatus (Boh., 1833) (Coleoptera: Bruchidae); Avaliacao do efeito da radiacao gama ({sup 60}Co) sobre a proteina arcelina e sua influencia na resistencia a Zabrotes subsfasciatus (Boh., 1833) (Coleoptera: Bruchidae)

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Valeria Wanderley

    1998-07-01

    The objective of this research was to evaluate the effects of different gamma doses of Cobalt-60 on arcelin protein in the manifestation of resistance to Zabrotes subfasciatus (Boh., 1833). Seeds of four lines of Phaseolus vulgaris carriers of arcelin protein (Arcelin-1, Arcelin-2, Arcelin-3 and Arcelin-4) and a cultivar without this protein were used as control (IAC-Carioca Akyta) obtained from the Instituto Agronomico do Estado de Sao Paulo - Nucleo Experimental de Campinas (IAC), were irradiated in a source of Cobalt-60, of the panoramic type, from the Instituto de Pesquisas Energeticas e Nucleares/CNEN/SP. The activity was approximately 2218.79 Ci, and the dose rate 0.678 kGy/h. The doses used were 0; 0.25; 0.5; 1.0 and 2.0 kGy. The results showed that the radiation doses did not influence the parameters evaluated in the resistance because a high degree of antibiose in the Arcelin-1 and Arcelin-2 lines was maintained. The Arcelin-3 and Arcelin-4 lines also maintained their behavior less expressive of resistance by antibiose only prolonging the period from egg to adult. The electrophoretic analysis of the lines and cultivar were not changed in relation to the radiation doses. But there was a decrease in relation to the intensity of color of the bands (absorbance) with the increase of the doses. (author)

  1. Description of morphologic characters in avocado trees (Persea americana. Mill) var. Hass, submitted to gamma radiation of {sup 60} Co; Descripcion de caracteres morfologicos en arboles de aguacate (Persea americana. Mill) var. Hass, sometidos a radiacion gama de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval R, L

    2004-07-01

    It was carried out the characterization of 77 trees of avocado ''Hass'' subjected to gamma radiation of Co{sup 60}, in doses of 0, 5, 10,15, 20 and 25 Gy based on previous studies of radiosensitivity with ends of improvement located in the experimental center ''La Labor'' belonging to the foundation Salvador Sanchez Colin. CICTAMEX. S C. in Temascaltepec, Mexico. It was carried out the morphological characterization of this variety according to the nomenclature settled down by the International Office of Genetic Resources (IBPGRI), registering 27 variables for the description of the tree, 33 for description of the fruit and 14 for the characterization of the seed. Regarding the architectural characterization 10 variables were evaluated. Using gamma radiation of Co{sup 60} in the doses of 15 and 20 Gy it was detected a reduction of 22% in the portage of the tree, likewise had reduction the diameter of the trunk and of the foliage. It was found that the reduction in the behavior of the tree induces to a bigger variation of the form of the same one, in the distribution of the branches in the form of the fruit and in the form of the seed you Also detects a remarkable increment in the productivity of some hoist irradiated regarding the architecture of the tree one observes that the angle of inclination of the branches increase when being increased the radiation dose and that the longitude of the annual section of growth decreased significantly in the doses of 20 and 25 Gy. One observes a significant Increment in the I number of buds prolepticos in those hoist irradiated in the I finish mbdulo of rhythmic growth. Io that indicates a change substantial in the I inhabit of growth With the purpose of determining if the changes in morphology and architecture of the tree corresponded with the modification at level meristematico, they were carried out observations to the court microscope of having knitted apical vegetative meristematico

  2. Evaluation of the Timepix chip radiation hardness using a {sup 60}Co source

    Energy Technology Data Exchange (ETDEWEB)

    Čarná, Mária; Dučevová, Kateřina; Hejtmánek, Martin, E-mail: hejtmark@fzu.cz; Konček, Ondřej; Marčišovský, Michal

    2013-12-21

    Radiation damage is a widely studied topic for its effects on detectors and supporting electronics in various practical applications. Radiation hardness and stability of the detector properties are critical parameters in applications of semiconductor radiation detectors. The 0.25μm CMOS technology used in fabrication of the Medipix2 and Timepix chips provides high degree of inherent radiation hardness. We present the study of operational, detection and signal processing properties of the irradiated Timepix chip exposed to a high-flux {sup 60}Co source reaching the operational limits of the chip. -- Highlights: • Radiation hardness of pixel detector based on Medipix2 against {sup 60}Co has been performed. • The {sup Co} was used as a radiation source due to its usage in number of practical applications. • Systematic study of γ radiation of various energies on the detector systems is desired.

  3. Study on shelf life extension of papayas irradiated by /sup 60/Co gamma-rays

    Energy Technology Data Exchange (ETDEWEB)

    Chang, M.S.; Chen, M.D.; Lin, C.T.; Fu, Y.K.

    1984-11-01

    Papayas are one of the main fresh fruits in Taiwan area. Papaya fruits were treated with hot water to pasteurize peels followed by /sup 60/Co gamma-ray irradiation to extend the ripening time. The purpose of synergetic methods is to extend the shelf life of papaya fruits. This experiment was carried out by seven treatments, which were: (1) control group, (2) hot water treatment only, (3) hot water treatment with a 25 krad ..gamma..-irradiation, (4) hot water treatment with a 50 krad ..gamma..-irradiation, (5) hot water treatment with a 75 krad ..gamma..-irradiation, (6) 75 krad ..gamma..-irradiation only, and (7) hot water treatment with a 100 krad ..gamma..-irradiation. The items of observation were: surface yellowing, surface decaying, quality of texture, and length of period lasted after irradiation for 50% marketable papayas. The results of this study showed that a shelf-life extension of six days could be obtained for papayas subjected to hot water (50 to 55/sup 0/C) treatment and a 100 krad irradiation. 3 refs., 2 figs., 2 tabs.

  4. Modifications in structural, cation distribution and magnetic properties of {sup 60}Co gamma irradiated Li-ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Mane, Maheshkumar L. [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India); Shirsath, Sagar E., E-mail: shirsathsagar@hotmail.com [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India); Dhage, Vinod N.; Jadhav, K.M. [Department of Physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad (M.S.) 431 004 (India)

    2011-09-15

    Highlights: {yields} Gamma irradiation induced defects in lithium ferrite. {yields} Modifications in structural and magnetic properties. {yields} Fe{sup 3+} changes to Fe{sup 2+} after gamma irradiation. - Abstract: Polycrystalline samples of Li{sub 0.5}Fe{sub 2.5}O{sub 4} ferrite precursor were prepared by conventional standard double sintering ceramic technique and then irradiated with three different doses of {sup 60}Co gamma rays. The crystal structure and phase orientation of the irradiated and unirradiated samples of Li{sub 0.5}Fe{sub 2.5}O{sub 4} ferrite was done by using X-ray diffraction technique at room temperature. The lattice parameter of the studied samples increased due to the formation of Fe{sup 2+} ions under the ionizing effect of gamma radiation. The strain in the materials due to the irradiation was calculated from XRD data. Scanning electron microscope (SEM) studies indicate that the irradiation causes amorphization, especially at the grain boundaries. The cation distribution was calculated from XRD data analysis. By using cation distribution structural parameters such as theoretical lattice constant, ionic radii of available sites and the oxygen parameter 'u' have been calculated. The estimated cation distribution and other structural parameters shows strong influence of gamma rays on polycrystalline Li-ferrite. The magnetic properties of irradiated and unirradiated lithium ferrite were performed by using pulse field hysteresis loop technique at room temperature. Electrical properties such as diffusion coefficient and dielectric properties were carried out with the influence of gamma irradiation. Activation energy of diffusion process decreased after irradiation. The increase of diffusion coefficient with increasing dose rate of gamma irradiation was reinforced by the increase of Fe{sup 2+} ions and the displacement of metal ions from its original sites under the effect of gamma irradiation.

  5. Numerical simulation of 60Co-gamma irradiation effects on electrical characteristics of n-type FZ silicon X-ray detectors

    Science.gov (United States)

    Vigneshwara Raja, P.; Rao, C. V. S.; Narasimha Murty, N. V. L.

    2016-07-01

    This paper describes the gamma irradiation effects on the electrical characteristics of n-type float zone (FZ) silicon detectors by incorporating a 4-level 60Co-gamma radiation damage model in the commercial device simulator for plasma X-ray tomography diagnostics. In the simulations, a segmented n-type silicon detector (i.e. p+-n-n+ structure) is considered with varying substrate resistivity (ρ = 5.4, 2.5, and 0.3 kΩ cm). The simulation results have been validated with the reported experimental measurements carried out on similar device structures. The 60Co-gamma irradiation induced changes in the electrical characteristics of the detectors are analyzed up to the dose of 3500 Mrad. The possible gamma induced degradation in the X-ray response of the detectors is investigated from the changes in the effective doping concentration and the leakage current of the detectors. The survival of the gamma irradiated detectors is predicted from the simulation studies. The comparison between the 60Co-gamma and 14.1 MeV neutron irradiation effects (typical fusion environments) on silicon detectors is attempted.

  6. Different gamma radiation doses effects of {sup 60} Co on buds of banana plant (Nanicao-AAA) breeded in vitro; Efeito de diferentes doses de radiacao gama do {sup 60} Co em gemas de bananeira (Nanicao-AAA) desenvolvidas in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gilberto Dias [Pernambuco Univ., Recife, PE (Brazil). Dept. de Botanica; Andrade, Arnobio Goncalves de [Universidade Federal Rural de Pernambuco, Recife, PE (Brazil). Lab. de Quimica Vegetal; Kido, Laureen Michelle Houllou; Franca, Jose Geraldo Eugenio de [Empresa Pernambucasna de Pesquisa Agropecuaria (IPA), Recife, (Brazil); Colaco, Waldeciro [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear

    1999-11-01

    Buds from banana cv. Nanicao-AAA (3 mm x 3 mm) were aseptically cultured in a modified Murashige and Skoog (MS) basal medium supplement with bezylaminepurine and sucrose, and solidified with agar. Buds placed on sterile Petri dishes were irradiated with increasing gamma rays doses (10, 20, 30, and 40 Gy). The statistical design was completely randomized with 5 doses and 30 replications. After irradiation, buds were transferred to 10 ml of the same medium into test tubes, and allowed to grow in a controlled environment (25 deg C, 16 h illumination ) for 4 weeks. There were no significant differences (Tukey, 0,05) between doses in terms of oxidation: in around 20% for all treatments. On the other hand, a statistically significant decrease in the germination of new buds with increased doses of irradiation was observed. The treatment with 40 Gy reduced in 80% the germination of new buds by the end of the evaluated period (4 weeks), resulting in a mean production of 1,5 buds. Mean production in the control was 7,6 buds. no statistically significant differences were detected between treatments with 10, 20, and 30 Gy, with a mean production of 3 buds, less than half obtained in the control. (author) 9 refs., 2 figs.

  7. Effects of 2. 0 Gy of /sup 60/Co gamma rays irradiation on rat embryos

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Juing-Yi; Satow, Yukio

    1987-01-01

    Pregnant rats of Donryu strain were exposed to a whole-body /sup 60/Co ..gamma.. ray irradiation of a single dose of 2.0 Gy (Dose rate: 0.5 Gy/min) on day 7, 8, 9, 10 or 11 of gestation (sperm day = day 0). The rats were sacrificed on day 18 and the offspring were examined for external and visceral malformations. Malformed embryos occurred between days 7 and 11 with the highest incidence occurring on day 9. Dose with 2.0 Gy increased the rate of resorption or death (52.1 %), in the survivors, caused congenital malformation in a majority of embryos (86.5 %) on day 8 of gestation. There is an increase in malformation (93.3 %) and growth retardation, but no increase in mortality (42.9 %) on day 9 of gestation. Relatively few anomalies resulted from irradiation on day 7 of gestation. The peak day for cardiovascular anomalies occurred on day 9 (88.3 % of all survival embryos) with high levels also occurring on day 8 (86.5 %). Cardiovascular anomalies consisted of VSD, hypoplasia of the pulmonary trunk, coarctation of the aorta, double aortic arch, right aortic arch, riding aorta, complete transposition of the aorta, persistent atrioventricular canal, vascular ring, aberrant right subclavian artery and others. Similar anomalies, but at a lower incidence, were produced by /sup 60/Co ..gamma.. ray at dose levels of 2.0 Gy on day 10 or 11 of gestation. Cases of cleft lip and cleft palate or facial cleft were observed seventeen fetuses on day 9 of gestation (31 %). Exencephaly occurred in nine embryos treated on day 9 (16.1 %) and in one embryos treated on day 10. Tail defects appeared with treatment on day 9 with the latter predominating on day 11. The present study show that maximum resorption (52.1 %) was seen with treatment on day 8 whereas the highest rate of malformation (93.3 %) was observed with treatment on day 9. (J.P.N.).

  8. Investigation of the /sup 59/Co(n,. gamma. )/sup 60/Co reaction with unpolarized and polarized neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kopecky, J. (Stichting Energieonderzoek Centrum Nederland, Petten. Nuclear Structure Group); Delfini, M.G. (Stichting Energieonderzoek Centrum Nederland, Petten. Nuclear Structure Group; Rijksuniversiteit Utrecht (Netherlands). Fysisch Lab.); Chrien, R.E. (Brookhaven National Lab., Upton, NY (USA))

    1984-10-15

    Capture of 24 keV neutrons and polarized as well as unpolarized thermal neutrons in /sup 59/Co has been investigated. Of the 350 ..gamma..-rays observed 335 could be placed in a /sup 60/Co level scheme containing 144 levels. The reaction Q-value amounts to 7491.92(8) keV. The chi/sup 2/ analysis of the circularly polarized ..gamma..-rays results in 31 unambiguous spin assignments for /sup 60/Co levels. The fraction of the J=4/sup -/ channel in the thermal capture was determined to be (80 +- 1)%. An average ..gamma..-ray multiplicity of 2.3 gammas per neutron capture was observed. The resulting level scheme is compared to shell-model predictions. Possible reaction mechanisms are discussed.

  9. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    DEFF Research Database (Denmark)

    Wooten, H Omar; Green, Olga; Yang, Min

    2015-01-01

    PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS......: The ViewRay treatment planning system (Oakwood Village, OH) was used to create (60)Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup......% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range organs with mean doses >20 Gy. The mean doses for all (60)Co plan OARs were within...

  10. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H. Omar, E-mail: hwooten@radonc.wustl.edu; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  11. Effect of 60Co gamma irradiation on dielectric and complex impedance properties of Dy3+ substituted Ni-Zn nanoferrites

    Science.gov (United States)

    Veena, M.; Somashekarappa, A.; Shankaramurthy, G. J.; Jayanna, H. S.; Somashekarappa, H. M.

    2016-12-01

    Nanocrystalline Ni1-xZnxFe2-yDyyO4 (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0; y=0.0 and 0.1) ferrites were synthesized by combustion method. Ni-Zn-Dy nanoferrites were investigated by X-ray diffraction, scanning electron microscopy, dielectric and impedance properties, before and after γ-irradiation process by 60Co γ-radiation with a dose rate of 310 kGy. The lattice parameter of irradiated samples increased attributed to the conversion of smaller size Fe3+ ions to larger size Fe2+ ions on ionizing effect of gamma radiation. Experimental results reveal that reduction in dielectric constant (ε‧), loss tangent (tan δ), real (Z‧) and imaginary (Z‧‧) impedance and increase in ac conductivity (σac) have been increased with increasing in frequency. It was found that ε‧, tan δ, σac increase, Z‧‧ and Z‧‧ reach a maximum value and thereafter decrease with further Zn ion substitution. The values of ε‧, tan δ and σac decrease with Dy3+ substitution and enhanced after irradiation. The complex impedance analysis suggesting predominant contribution to conduction was through the grain boundary.

  12. Effects of {sup 60}Co gamma-rays, ultraviolet light, and mitomycin C on halobacterium salinarium and thiobacillus intermedius

    Energy Technology Data Exchange (ETDEWEB)

    Shahmohammadi, H.R.; Asgarani, E.; Terato, Hiroaki; Ide, Hiroshi; Yamamoto, Osamu [Hiroshima Univ. (Japan)

    1997-03-01

    Lethal effects of {sup 60}Co {gamma}-rays, UV light, and mitomycin C on two kinds of bacteria, Halobacterium salinarium which grows in highly concentrated salt media and Thiobacillus intermedius which requires reduced sulfur compounds, were studied and compared with those on Escherichia coli B/r. D{sub 37} values for H. salinarium, T. intermedius and E. coli B/r were 393, 150, and 92 Gy, respectively, by exposure to {sup 60}Co {gamma}-rays. They were 212, 38, and 10 J/m{sup 2}, respectively, by exposure to UV light and 2.36, 0.25, and 0.53 {mu}g/ml/h, respectively, by exposure to mitomycin C. Against these agents, H salinarium was much more resistant than T. intermedius and E. coli B/r. (author)

  13. Effects of 60Co gamma-rays, ultraviolet light, and mitomycin C on Halobacterium salinarium and Thiobacillus intermedius.

    Science.gov (United States)

    Shahmohammadi, H R; Asgarani, E; Terato, H; Ide, H; Yamamoto, O

    1997-03-01

    Lethal effects of 60Co gamma-rays, UV light, and mitomycin C on two kinds of bacteria, Halobacterium salinarium which grows in highly concentrated salt media and Thiobacillus intermedius which requires reduced sulfur compounds, were studied and compared with those on Escherichia coli B/r. D37 values for H. salinarium, T. intermedius and E. coli B/r were 393, 150, and 92 Gy, respectively, by exposure to 60Co gamma-rays. They were 212, 38, and 10 J/m2, respectively, by exposure to UV light and 2.36, 0.25, and 0.53 microgram/ml/h, respectively, by exposure to mitomycin C. Against these agents, H. salinarium was much more resistant than T. intermedius and E. coli B/r.

  14. Radiosensibilidad de semillas de soya a los rayos gamma 60Co

    Directory of Open Access Journals (Sweden)

    C. de la Fé

    2000-01-01

    Full Text Available El presente estudio se desarrolló en las instalaciones del Instituto Nacional de Ciencias Agrícolas, con el objetivo de evaluar la radiosensibilidad de semillas de soya a los rayos gamma 60Co. Para su ejecución, se seleccionaron e irradiaron muestras de 50 semillas de la variedad Cubasoy-23, las que fueron sembradas en condiciones semicontroladas (macetas en la campaña de primavera, 1997. Las dosis de radiación fueron desde los 50 hasta los 480 Gy, con incrementos de 50 Gy entre las dosis de 50 y 200 Gy e incrementos de 40 Gy entre esta última y la dosis de 480 Gy. Las evaluaciones realizadas consistieron en porcentaje de semillas germinadas a los tres, seis y nueve días de la siembra, altura de las plantas a los 10, 20 y 50 días y número de pares de hojas emitidas a los 10 y 20 días de la siembra. El estudio realizado evidenció la ocurrencia de un efecto fuerte de las dosis aplicadas en el porcentaje de semillas germinadas, resultando las dosis próximas a los 280 Gy las de mayor efecto radioestimulador de la germinación. Desde el punto de vista de la altura de las plantas, el efecto de las dosis aplicadas se correspondió con el descrito para otros materiales biológicos irradiados, caracterizándose este por un aumento a dosis bajas seguido por una reducción cada vez mayor a medida que las dosis aplicadas se incrementaron. Por su parte, la emisión de hojas por las plantas mantuvo un comportamiento en correspondencia con la altura de las plantas. Los resultados del estudio permiten sugerir la aplicación de dosis próximas a los 360 Gy en los trabajos dirigidos a la creación de variabilidad genética en programas de mejora por inducción de mutaciones

  15. [Effect of tonicity of the medium on the sensitivity of Escherichia coli bacteria to gamma-quantum 60Co, ultrasound and hyperthermia].

    Science.gov (United States)

    Morozov, I I; Petin, V G; Morozova, G V

    1998-01-01

    The cell lethality and permeability induced in Escherichia coli B/r and Escherichia coli BS-1 by 60Co gamma-ray irradiation, ultrasound and hyperthermia in media containing different concentrations of NaCl have been investigated. It was shown that independently from the nature of damaging factors hypotonic media increase while hypertonic media in certain range of osmolyte concentration decrease sensitivity of cells to action of this factors. It was proposed that discovered phenomenology was caused by salt modification of status of the cell osmotic homeostasis destabilizing by ionizing radiation, ultrasound or hyperthermia and was not related with the system of dark repair of DNA.

  16. Effects of /sup 60/Co-. gamma. irradiation on the cell proliferation kinetics of DMBA-induced tongue carcinoma in hamster

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Toshio

    1987-10-01

    In the vocation of the radiation therapy, it is very important to analize the cell kinetics of the normal and tumor tissues, and the radiation effects. Thus, this study analizes the effects of /sup 60/Co-..gamma.. irradiation to DMBA-induced hamster tongue carcinoma (hereafter ''the tumor'') and normal tongue epithelium (hereafter ''the normal'') by using /sup 3/H-TdR puls labeling technics and percentage labeled mitoses (PLM) method. Result : 1) Cell cycle time (Tc) of the Normal was 42.0 hours, and that of the tumor was 18.1 hours. After irradiation, Tc of the tumor was prolonged, but that of the normal was shortened by about 11 hours. 2) Initial labeling index (L.I.) of the tumor was decreased immidiately after irradiation, but on 7 and 10 days L.I. gained back to the pre-irradiation rate. 3) tumor doubling time (Td) was 6.4 +- 1.6 days, and potential doubling time (Tp) was 18.9 hours. 4) Time of pre-DNA synthetic stage (Tg/sub 1/) of the normal was 31.0 hours and that of the tumor was 8.7 hours. After irradiation, Tg/sub 1/ of the normal was shortened by about 10 hours and that of the tumor was prolonged. 5) After irradiation, time of synthetic stage (Ts) of both the normal and the tumor was slightly prolonged. 6) After irradiation, mitotic stage (Tm) of both the normal and the tumor was not changed. 7) Growth fraction (GF) of the normal was 64.5%, and that of the tumor was 79.8%. After irradiation, it was decreased, while it of the tumor was increased temporarily after irradiation. 8) The rate of cell loss facter of the tumor was 0.88.

  17. Preliminary Study on the Quantitative Value Transfer Method of Absorbed Dose to Water in 60Co γ Radiation

    Directory of Open Access Journals (Sweden)

    SONG Ming-zhe

    2015-01-01

    Full Text Available Absorbed dose to water in 60Co γ radiation is the basic physics quantity in the quantitative value system of radiation therapy, it is very necessary for radiation therapy. The study on the quantitative value transfer method of absorbed dose to water in 60Co γ Radiation could provide important technical support to the establishment of Chinese absorbed dose to water quantity system. Based on PTW-30013 ionization chamber, PMMA water phantom and 3D mobile platform, quantitative value transfer standard instrument was established, combined with the requirement of IAEA-TRS398, developed preliminary study of 60Co absorbed dose to water quantity value transfer method. After the quantity value transfer, the expanded uncertainty of absorbed dose to water calibration factor of PTW-30013 was 0.90% (k=2, the expanded uncertainty of absorbed dose to water of 60Co γ reference radiation in Radiation Metrology Center (SSDL of IAEA was 1.4% (k=2. The results showed that, this value transfer method can reduce the uncertainty of 60Co absorbed dose to water effectively in Secondary Standard Dosimetry Laboratory.

  18. Studying the Effect of Ionization Radiation of 60Co on the Spirulina

    Science.gov (United States)

    Ai, Weidang; Guo, Shuang-Sheng; Ai, Weidang; Dong, Wen-Ping; Qin, Li-Feng; Tang, Yong-Kang

    It studied the effect of ionization radiation on the Spirulina plastensis(No.6) by using the γ-rays of 60 Co. In the experiment, Spirulina were irradiated, and the dose of the ionization radiation covered 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0kGy. After irradiating, these Spirulina were cultured under the same conditions. During the course of the experiment, the growth rate, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the results, low dose of γ-rays (less than 1.5kGy) could improve the content of phycobilin and protein of Spirulina. Only small changes in the morphology of algae filament were found at dose less than 1.0kGy. But with the increase of the dose of γ-rays (more than 1.5kGy), the filaments would break up or even disintegrate. Spirulina had stronger ionization radiation proof and self-rehabilitation capacity, but the growth of Spirulina was stagnated. The LD50 (i.e. the dose resulted in 50% death of the Spirulina) of the colony was 2.0kGy. Considering the capacity of being resistant to γ-rays irradiation, Spirulina can be considered as one of the key biological components in the Controlled Ecological Life Support System (CELSS) for future long-term space missions. Keywords: Controlled Ecological Life Support System (CELSS); Spirulina; ionization radiation; biological component

  19. 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

  20. Different gamma ray ({sup 60} Co) dose effects on Sorghum genotype germination; Efeito de diferentes doses de radiacao gama do {sup 60} Co sobre a germinacao de genotipos de sorgo (Sorghum bicolor)

    Energy Technology Data Exchange (ETDEWEB)

    Tabosa, Jose Nildo; Gomes, Roberto Vicente; Reis, Odemar Vicente dos [Empresa Pernambucana de Pesquisa Agropecuaria (IPA), Recife (Brazil)]. E-mail: tabosa@ipa.br; Colaco, Waldeciro [Universidade Federal de Pernambuco, Recife, PE (Brazil). Dept. de Energia Nuclear]. E-mail: wcolaco@ufpe.br

    2004-08-15

    In agriculture, applying irradiation is a very valuable way of obtaining vegetable products for human and animal consumption. Cobalt-60, one of the main sources of gamma-rays, is considered an important tool in plant breeding programs, which have the objective of promoting genetic variability of cultivars with resistance to adverse environments. In this research, the effects of different {sup 60}Co doses on germination vigor and seed germination velocity of forage sorghum genotypes were evaluated. The study was carried out at the IPA (Empresa Pernambucana de Pesquisa Agropecuaria) in Recife, Pernambuco, Brazil. The work was installed in germination boxes, following laboratory recommendations. Thus, a experiment involving three sorghum genotypes (IPA 467-4-2, IPA 02-03-01, and Sudan 4202), five {sup 60}Co doses (Zero, 150, 300, 350, and 400 Gy), was set up. The sees were irradiated before the beginning of the experiment being exposed to gamma rays from a {sup 60}Co-source (cobalt irradiator) at DEN (Nuclear Engineering Department) of the UFPE (Pernambuco Federal University), Brazil. The work also had the objective of evaluating the sorghum genotypes x {sup 60}Co dose interaction. The main results obtained showed that the sorghum genotype IPA 02-03-01 presented the greatest values of germination and vigor percentages, and seed germination velocity, when compared to the others evaluated, on 350 and 400 Gy of {sup 60}Co doses. (author)

  1. Succinylcholine-induced hyperkalemia in the rat following radiation injury to muscle. [60Co

    Energy Technology Data Exchange (ETDEWEB)

    Cairoli, V.J.; Ivankovich, A.D.; Vucicevic, D.; Patel, K.

    1982-02-01

    During anesthetic preparation of a patient who had received routine radiation therapy of sarcoma of the leg, cardiac collapse occurred following succinylcholine (SCh) administration. Experiments were designed to test the hypothesis that radiation injury to muscle might cause increased sensitivity to SCh similar to that reported in patients with muscle trauma, severe burns, and lesions causing muscle denervation. Venous plasma potassium levels and arterial blood gas tensions were measured in rats after they were given SCh (3 mg/kg) at various times following 60Co irradiation of the hind legs. Nonirradiated rats responded to SCh with a slight but statistically significant increase in plasma K+. Rats subjected to high levels of radiation (10,000 to 20,000 R) and given SCh 4 to 7 days later responded in the same way as the control rats. Plasma K+ levels in rats exposed to a fractionated irradiated dosage (25000 R given twice with a 1-week interval) followed by SCh 1 week later were similar to those in the control group, but when SCh was given 2 weeks later (3 weeks after initial irradiation) there was a marked elevation of plasma K+, from 3.6 to 7.7 meq/L, a statistically significant increase.

  2. Microbiological analysis of peach palm in natura submitted to {sup 60}Co radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Priscila V.; Araujo, Michel M.; Nunes, Thaise C.F.; Costa, Helbert S.F.; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: priscilavsilva@gmail.com, e-mail: villavic@ipen.br; Hojeije, Khalil Y. [Floresta Industria e Comercio Ltda., Sao Paulo, SP (Brazil)

    2009-07-01

    The palm tree (Bactris gasipaes Kunth) is a species with high potential benefits, because of the nutritional value of its fruits that could be used both in human and animals feeding and mainly for peach palm extraction. It represents a great source of dietary fiber and a moderate source of magnesium and iron. Food irradiation is a worldwide technology that aims to improve the product quality, in order to eliminate diverse microorganisms that can spoil the food. Radiation processing, in the recommended doses, causes very few chemical alterations and nutritional losses in foods, being considered insignificant and/or similar to other food treatments. The objective of this study was to evaluate the effect of irradiation on microbiological counts of mesophilic aerobic in the peach palm in natura. Samples were irradiated with 1.0 and 1.5 kGy using a {sup 60}Co multipurpose irradiator. Radiation treatment appeared to be a useful alternative to reduce microbial contamination in the samples analyzed. (author)

  3. Immune response against bothropstoxin-I irradiated with {sup 60}Co gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Baptista, J.A.; Spencer, P.J.; Higa, O.Z.; Casare, M.S.; Campos, L.A.; Nascimento, N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Biologia Molecular]. E-mail: janabap@gmail.com; Andrade Junior, H.F de [Sao Paulo Univ., SP (Brazil). Inst. de Medicina Tropical de Sao Paulo. Lab. de Protozoologia]. E-mail: hfandrad@usp.br

    2005-07-01

    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 gamma rays, yielding toxoids with good immunogenicity. Ionizing radiation has proven to be a powerful tool to attenuate snake venoms 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-I, a K49 phospholipase, before and after irradiation. Structural modifications of the toxin were investigated by SDS-PAGE and mass spectrometry. Aiming to compare the toxicity between native and irradiated forms of the toxin, an in vitro cytotoxicity assay, using CHO cells, was performed. 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 the protein (aggregates and oligomers). When analyzed by mass spectrometry, the irradiated bothropstoxin appeared in several oxidized forms. The cytotoxicity assay showed that the modified toxin was 5 folds less toxic than its native counterpart. Irradiated toxins were immunogenic and the antibodies elicited by them were able to recognize the native toxin in ELISA. These results indicate that irradiation of toxic proteins can promote significant modifications in their structures, but still retain many of the original immunological properties. (author)

  4. The effect of the substitution of D{sub 2}O for H{sub 2}O on the degradation of myosin {beta} in solution by heat and by {sup 60}Co {gamma} radiation (1962); Effet de la substitution de D{sub 2}O a H{sub 2}O sur l'alteration de la Myosine B en solution par la chaleur et par les rayons {gamma} du {sup 60}CO (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Pinset-Harstrom, I.; Fritsch, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    (1) Alterations of myosin B produced by heat or irradiation are shown to be qualitatively identical as demonstrated by analytical centrifugation. (2) A considerable isotope effect was demonstrated using 75 per cent D{sub 2}O in the solvent. The sensitivity of myosin B to heat and irradiation is discussed in the light of this isotope effect. (3) Polymers appearing upon heat treatment of myosin B seem to be of a very different nature than the polymers occurring alter a similar treatment upon myosin A. Polymers obtained from myosin B can be depolymerized by ATP and they appear in a much narrower temperature range than myosin A polymers. This fact indicates a considerable difference in the activation enthalpies in the two reactions. (authors) [French] (1) Cette etude montre que les alterations de la myosine B provoquees par la chaleur et par l'irradiation aux rayons {gamma} sont - telles qu'elles apparaissent a l'ultracentrifugation analytique - qualitativement semblables. (2) Nous avons observe un effet isotopique considerable de la presence de 75 pour cent de D{sub 2}O dans le solvant sur la sensibilite de la myosine B envers ces deux agents, et nous avons presente une tentative d'explication de ce fait. (3) Les polymeres qui apparaissent apres un traitement par la chaleur de la myosine semblent etre d'une nature tres differente des polymeres que l'on voit apparaitre apres un traitement identique de la myosine A. Ceux obtenus a partir de le myosine B sont depolymerisables par l'intermediaire de l'ATP et apparaissent dans une zone de temperature beaucoup plus etroite que celles de la myosine A. Ce dernier fait indique une difference considerable de l'enthalpie d'activation des deux reactions. (auteurs)

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

    Directory of Open Access Journals (Sweden)

    Xie Chuan-Xiao

    2004-01-01

    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 low 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.

  6. Dose intercomparison studies for 60Co gamma-ray and electron beam irradiation in the year 2002

    Institute of Scientific and Technical Information of China (English)

    LIN Min; Takuji KOJIMA; Zofia PEIMEL-STUGLIK; CHEN Yun-Dong; CUI Ying; CHEN Ke-Sheng; LI Hua-Zhi; XIAO Zhen-Hong; Slawomir FABISIAK

    2004-01-01

    Dose inter-comparison studies for 60Co γ-ray and 10MeV electron beam irradiation were carried out from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosimeters made by CIAE, which will be used as transfer standard dosimetry system mainly for electron beam irradiation.The expanded uncertainty of CIAE alanine/EPR dosimetry system was 4.1% for doses not higher than 10 kGy and 5.4% for those above 10 kGy (k=2). CIAE alanine-PE film dosimeters were sent to JAERI, RISO (National Laboratory in Denmark) and INCT respectively, which were irradiated by 60Co gamma-rays or electron beams in each laboratory. The irradiated dosimeters were then sent back to CIAE for electron paramagnetic resonance (EPR) analysis.The agreements were obtained to be ±1.9% for gamma-ray dose measurement and ±4.3% for electron beam dose measurement, which were all within the combined uncertainty of the reference and CIAE alanine/EPR dosimetry system. Furthermore, the overall mean ratio was found to be 0.995 with 1.8% in the coefficient of variation (CV). The preliminary inter-comparison studies indicated that CIAE film alanine/EPR dosimetry system had the potential to be used as a transfer dosimetry system for high dose measurement.

  7. Determination of late-time Gamma-Ray (60Co) sensitivity of single diffusion Lot 2N2222A transistors.

    Energy Technology Data Exchange (ETDEWEB)

    DePriest, Kendall Russell; Kajder, Karen C.; Peters, Curtis D. (American Staff Augmentation Providers, LLC, Albuquerque, NM)

    2008-08-01

    Sandia National Laboratories (SNL) has embarked on a program to develop a methodology to use damage relations techniques (alternative experimental facilities, modeling, and simulation) to understand the time-dependent effects in transistors (and integrated circuits) caused by neutron irradiations in the Sandia Pulse Reactor-III (SPR-III) facility. The development of these damage equivalence techniques is necessary since SPR-III was shutdown in late 2006. As part of this effort, the late time {gamma}-ray sensitivity of a single diffusion lot of 2N2222A transistors has been characterized using one of the {sup 60}Co irradiation cells at the SNL Gamma Irradiation Facility (GIF). This report summarizes the results of the experiments performed at the GIF.

  8. The RBE of 3.4 MeV alpha-particles and 0.565 MeV neutrons relative to 60Co gamma-rays for neoplastic transformation of human hybrid cells and the impact of culture conditions.

    Science.gov (United States)

    Frankenberg-Schwager, M; Spieren, S; Pralle, E; Giesen, U; Brede, H J; Thiemig, M; Frankenberg, D

    2010-01-01

    The neoplastic transformation of human hybrid CGL1 cells is affected by perturbations from external influences such as serum batch and concentration, the number of medium changes during the 21-day expression period and cell seeding density. Nevertheless, for doses up to 1.5 Gy, published transformation frequencies for low linear energy transfer (LET) radiations (gamma-rays, MeV electrons or photons) are in good agreement, whereas for higher doses larger variations are reported. The (60)Co gamma-ray data here for doses up to 1.5 Gy, using a low-yield serum batch and only one medium change, are in agreement with published frequencies of neoplastic transformation of human hybrid cells. For 3.4 MeV alpha-particles (LET = 124 keV/mum) and 0.565 MeV monoenergetic neutrons relative to low doses of (60)Co gamma-rays, a maximum relative biological effectiveness (RBE(M)) of 2.8 +/- 0.2 and 1.5 +/- 0.2, respectively, was calculated. Surprisingly, at higher doses of (60)Co gamma-rays lower frequencies of neoplastic transformation were observed. This non-monotonic dose relationship for neoplastic transformation by (60)Co gamma-rays is likely due to the lack of a G2/M arrest observed at low doses resulting in higher transformation frequencies per dose, whereas the lower frequencies per dose observed for higher doses are likely related to the induction of a G2/M arrest.

  9. The effect of 60Co-gamma radio-sterilization on Boswellia carterii essential oil composition

    OpenAIRE

    P. Badr; S. Daneshamouz; A.A. Mohammadi; A.R. Akbarizadeh; Afsharypuor, S.

    2016-01-01

    Background and objectives:Gamma-irradiation is used vastly for both decontamination and sterilization of natural products; but these high-energy rays can affect heat-sensitive essential oils. Methods: The oleo-gum-resin of Boswellia carterii (Burseraceae) was sterilized by γ-irradiation at dose 30 KGy. The essential oils obtained by hydrodistillation of non-irradiated Boswellia (NIB) and irradiated Boswellia (IB) were analyzed by GC/MS and the changes were compared. The structure of octyl ace...

  10. The effect of 60Co-gamma radio-sterilization on Boswellia carterii essential oil composition

    Directory of Open Access Journals (Sweden)

    P. Badr

    2016-10-01

    Full Text Available Background and objectives:Gamma-irradiation is used vastly for both decontamination and sterilization of natural products; but these high-energy rays can affect heat-sensitive essential oils. Methods: The oleo-gum-resin of Boswellia carterii (Burseraceae was sterilized by γ-irradiation at dose 30 KGy. The essential oils obtained by hydrodistillation of non-irradiated Boswellia (NIB and irradiated Boswellia (IB were analyzed by GC/MS and the changes were compared. The structure of octyl acetate as the major component and marker of B. carterii was confirmed by MS/MS. Results: Twenty-five compounds comprising 99.55% of NIB oil and nineteen compounds comprising 98.61% of IB oil were identified. Major constituents which were common for both oils were octyl acetate (52.67 % in NIB, 76.51 % in IB, 1-octanol (6.37 % in NIB, 5.19 % in IB, duva-4, 8, 13-triene-1,3α diol (5.52 % in NIB, 3.94 % in IB, verticiol (13.63 % in NIB and verticillane type diterpene (5.4 % in IB they made up 78.19% and 91.04% of NIB and IB, respectively. Conclusion: Gamma irradiation was an efficient method for sterilization of Boswellia carterii oleo-gum resin, but it resulted in change in the essential oil composition particularly octyl acetate changed from 52.67% to 76.51%.

  11. Impaired colony-forming ability following. gamma. irradiation of skin fibroblasts from tuberous scierosis patients. [/sup 60/Co

    Energy Technology Data Exchange (ETDEWEB)

    Paterson, M.C.; Sell, B.M.; Smith, B.P.; Bech-Hansen, N.T.

    1982-05-01

    The radiosensitivity of cultured dermal fibroblasts from human subjects afflicted with tuberous sclerosis (TS), a hereditary neurocutaneous syndrome, was assessed by assaying loss of colony-forming ability in response to acute ..gamma..-ray exposure. Related to control strains from clinically normal donors, three cell lines (GM1635, GM1643, GM2333) from two affected patients displayed enhanced sensitivity to inactivation by /sup 60/Co ..gamma..-ray treatment, whether administered oxically (air-saturated) or hypoxically (N/sub 2/-gassed); a fourth strain (GM1644) from a third patient exhibited normal radiosensitivity under both treatment conditions. The post-..gamma..-irradiaton colony-forming ability of the three hypersensitive TS strains was intermediate between that of normal controls and that of strains from patients inheriting the radiotherapy-sensitive neurovascular disorder ataxia telangiectasia. The variability in the radioresponse of the TS stains (three sensitive and one normal) is not surprising, considering the widely recognized clinical heterogeneity in the disease. Our findings, aside from providing a laboratory marker for early (possible presymptomatic) detection of persons at high risk for TS, may lead to a better understanding of the origin and progressive development of this multifaceted syndrome.

  12. Characterization of {sup 60}Co and {sup 137}Cs beams from irradiator Shepherd 81 - 14D of LNMRI/IRD in radiation protection; Caracterizacao dos feixes de {sup 60}Co and {sup 137}Cs do Irradiador Shepherd 81 - 14D do LNMRI/IRD em radioprotecao

    Energy Technology Data Exchange (ETDEWEB)

    Silva, C.N.M. da; Cabral, T.S., E-mail: cosme@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The objective of this work is the characterization of {sup 60}Co beams and the {sup 137}Cs irradiator Shepherd 81-14D acquired by the National Metrology Laboratory of Ionising Radiation of the Institute of Radiation Protection and Dosimetry (LNMRI /IRD), for use in calibration of measuring instruments of gamma radiation in air kerma and ambient dose equivalent, irradiation of films and TLD's. Field homogeneity measurements were carried out, calculated input and output time of the source and commissioning of sources. (author)

  13. The effects of exposure of {sup 60}Co on the oxidant/antioxidant status among radiation victims

    Energy Technology Data Exchange (ETDEWEB)

    Demir, Mustafa E-mail: mmdemir@e-kolay.net; Konukoglu, Dildar; Kabasakal, Levent; Yelke, Hakan Kadir; Ergen, Kadir; Ahmed, Sabbir

    2002-07-01

    This retrospective study has been performed with radiation victims who were accidentally exposed to a {sup 60}Co source and its release into the environment. The aim of the study was to assess the effects of elevated radiation exposures on plasma level, on erythrocyte thio barbituric acid reactive substance (TBARS) level and on erythrocyte glutathione (GSH) levels. Patients were treated in different hospitals with different symptoms such as nausea, vomiting, dizziness, along with severe anemia in some patients. Blood samples were collected 3-5 days following the radiation accident. Increases in plasma (6.25{+-}0.90 nmol ml{sup -1}) and erythrocyte TBARS levels (330.5{+-}30.5 {mu}mol gHb{sup -1}) were found in comparison to a healthy group (3.72{+-}0.68 nmol ml{sup -1} and 150.7{+-}20.5 {mu}mol gHb{sup -1}, respectively) at a significant level (p<0.001). Erythrocyte GSH levels (5.2{+-}0.30 {mu}mol gHb{sup -1}) were found to be decreased among the victims (healthy group: 10.2{+-}0.7 {mu}mol gHb{sup -1}) at the same significance level (p<0.001). These observations confirm a significant change induced by radiation in the oxidant/antioxidant status among the victims. It is suggested here that antioxidant supplementation therapy might be effective in preventing the harmful effects of {sup 60}Co radiation among radiation victims.

  14. {sup 60}Co gamma-irradiation effects on electrical properties of a rectifying diode based on a novel macrocyclic Zn octaamide complex

    Energy Technology Data Exchange (ETDEWEB)

    Ocak, Y.S. [Department of Science, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Kilicoglu, T., E-mail: kilicoglutahsin@gmail.co [Department of Physics, Faculty of Art and Science, University of Batman, Batman (Turkey); Department of Physics, Faculty of Art and Science, University of Dicle, Diyarbakir (Turkey); Topal, G. [Department of Chemistry, Faculty of Education, University of Dicle, Diyarbakir (Turkey); Baskan, M.H. [Department of Physics, Faculty of Education, University of Dicle, Diyarbakir (Turkey)

    2010-01-01

    C{sub 36}H{sub 28}N{sub 12}O{sub 8}ZnCl{sub 2}.9/2H{sub 2}O, Zn-octaamide (ZnOA) macrocyclic compound was synthesized to be used in the fabrication of electronic and photoelectronic devices. The structure of new compound was identified by using {sup 1}H NMR, {sup 13}C NMR, IR, UV-vis and LC-MS spectroscopic methods. The Sn/ZnOA/n-Si/Au structure was engineered by forming a thin macrocyclic organic compound layer on n-Si inorganic substrate and then by evaporating Sn metal on the organic layer. It was seen that the device had a good rectifying behaviour and showed Schottky diode properties. The diode was irradiated under {sup 60}Co gamma-source at room temperature. Characteristic parameters of the diode were determined from its current-voltage (I-V) and capacitance voltage (C-V) measurements before and after irradiation. It was observed that gamma-irradiation had clear effects on I-V and C-V properties. Also, it was seen that the barrier height, the ideality factor and the series resistance values decreased after the applied radiation, while the saturation current value increased.

  15. A 60Co multipurpose radiation processing facility at Bahia Blanca, Argentina

    Science.gov (United States)

    Curzio, O. A.; Croci, C. A.

    The aim of the project is to have a multipurpose facility which will enable us to show the techno-economic viability of the irradiation process applied to regional products, important from the economic point of view. The topics will fundamentally be connected with regional themes such as food preservation and the modification of polymer structures. This project will make it possible to carry out basic and applied studies related to radiation chemistry, dosimetry and engineering irradiation processes. The facility will operate in the Universidad Nacional del Sur (UNS) with a maximum activity of 18.5 PBq of Co-60. The viability and design of the irradiation facility is supported by the Government of the Buenos Aires Province since it is interested in the socio-economic benefit of this technology at the regional level.

  16. Toxoplasma gondii gamma irradiation using Co-60; Irradiacao do Toxoplasma gondii com gama do {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Serra-Freire, Nicolau Maues [Universidade Federal Rural do Rio de Janeiro, RJ (Brazil). Dept. de Parasitologia Animal; Maliska, Carmelindo [Hospital Central do Exercito, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear; Norberg, Antonio Neres [Instituto de Biologia do Exercito (IBEx), Rio de Janeiro, RJ (Brazil)

    1996-07-01

    The use of nuclear power through radiation for the destruction of microorganisms which cause food deterioration, infections and toxicosis, is specifically for peaceful purposes. Toxoplasma gondii is a protozoa responsible for illnesses in humans and animals. One of the most common ways of transmission is through raw or poorly cooked meat. There is little information on the resistance of T. gondii to radiation. The objective of this research is to determine the Minimum Lethal Dose (MLD) of gamma radiation for those microorganisms. Suspensions of T. gondii containing approximately one million taquizoites/ml were irradiated with doses between up 0,01 up to 0,15 kGy (Kilogray) and inoculated to mice. The surviving T. gondii were re-irradiated with 0,01 up to 0,16 kGy. The irradiated protozoa were totally destroyed with a 0,15 kGy dose (MLD). Taquizoites issued from live protozoa of 0,14 kGy also were completely destroyed with dose of 0,15 kGy. No increase in resistance was observed regarding the non irradiated protozoa. (author)

  17. (60)Co in cast steel matrix: A European interlaboratory comparison for the characterisation of new activity standards for calibration of gamma-ray spectrometers in metallurgy.

    Science.gov (United States)

    Tzika, Faidra; Burda, Oleksiy; Hult, Mikael; Arnold, Dirk; Marroyo, Belén Caro; Dryák, Pavel; Fazio, Aldo; Ferreux, Laurent; García-Toraño, Eduardo; Javornik, Andrej; Klemola, Seppo; Luca, Aurelian; Moser, Hannah; Nečemer, Marijan; Peyrés, Virginia; Reis, Mario; Silva, Lidia; Šolc, Jaroslav; Svec, Anton; Tyminski, Zbigniew; Vodenik, Branko; Wätjen, Uwe

    2016-08-01

    Two series of activity standards of (60)Co in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of (60)Co in the cast steel standards were (1.077±0.019) Bqg(-1) on 1 January 2013 12h00 UT and (1.483±0.022) Bqg(-1) on 1 June 2013 12h00 UT, respectively.

  18. 白藜芦醇对60Coγ射线照射小鼠氧化损伤的防护%Radioprotective Effect of Resveratrol on Oxidative Damage in 60Co Gamma Ray Irradiated Mice

    Institute of Scientific and Technical Information of China (English)

    徐冰心; 李成林; 史煜华; 谢京波; 陈阿鑫; 高娇; 任晔; 李建忠; 刘志国

    2012-01-01

    Objective To investigate the radioprotective effect of resveratrol( RES) on gamma-irradiation-induced serum and liver oxidative damage in mice. Methods Thirty male ICR mice were randomized into 5 groups; normal control group, irradiated control group, RES 50,100 and 200 mg·kg-1 irradiated groups. RES was administered respectively to three dosage groups by gavage on 3rd day before irradiation and 7th day after irradiation. Except for normal control, all the mice were whole-body irradiated by 60Co gamma ray(a single dose of 6.0 Gy). The mice were killed on 7th day. The activities of superoxide dismutase (SOD) ,glutathione peroxidase (GSh-Px) and the amount of malondialdehyde( MDA) of the serum and liver were measured. Results Compared with normal control group,the activities of SOD and GSH-Px were significantly decreased while the amount of MDA was significantly increased in irradiated control group mice. Compared with irradiated control, the activities of SOD and GSH-Px tended to increase while the amount of MDA tended to decrease in RES 50 mg ·kg-1' irradiated group mice. The activities of SOD and GSh-Px and the amount of MDA increased with the RES dosage. Conclusion RES has radioprotective effect against oxidative damage to the serum and liver in 60Co rays irradiated mice. This effect of RES depends on the dosage.%目的 研究白藜芦醇对60Coγ射线照射小鼠氧化损伤的防护作用.方法 30只♂ ICR小鼠随机分成5组,正常对照组、照射对照组以及白藜芦醇低、中、高剂量( 50、100、200 mg·kg-1)照射组,照射前3d至照后第7天灌服给药,每天1次,共10次.除正常对照组外,所有小鼠60Coγ射线全身6 Gy辐照1次,照射后第7天小鼠取外周血和肝组织标本,测定血清和肝组织匀浆中超氧化物歧化酶(SOD)、谷胱苷肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量.结果与正常对照组比较,照射对照组小鼠血清和肝组织匀浆中SOD和GSH-Px活性显著下降,MDA含量显

  19. 49. Biological dose assessment by the analyses of chromosomal aberrations and CB micronuclei in two victims accidentally exposed to 60Co gamma-rays

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Biological doses were estimated by using the yields of dicentrics plus rings(dic+r) and cytokinesis-block micronuclei (CBMN) for two victims of the 60Co radiation source accident occurred on Mar 6,2001 in the City of Xuchang(victim A), and Jun 26,2001 in the City of Kaifeng(victim B), Henan Province, respectively. The whole blood of the victim A (male, 37 years old) and the victim B (female, 27 years old)

  20. SPRF60Coγ圃装置研制%THE ESTABLISHMENT OF SPRF COBALT-60 GAMMA FIELD

    Institute of Scientific and Technical Information of China (English)

    王家银; 张运法; 李品芳

    1984-01-01

    SPRF60Coγ圃装置由二阶围墙、帽形伞塔.半地下水井三者良好组合成为一个半封闭型γ圃.既可降低墙外散射剂量,又能在圃内达到引变剂量.对解决城郊建圃中存在的防护剂量与引变剂量关键技术问题有重要意义.

  1. Replication of simian virus 40 in simian virus 40-transformed hamster kidney cells induced by mitomycin C or /sup 60/Co. gamma. irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rakusanova, T.; Smales, W.P.; Kaplan, J.C.; Black, P.H.

    1978-07-15

    Several clones of simian virus 40 (SV40)-transformed hamster kidney cells, which are heterogeneous for induction of infectious SV40, have been studied. SV40 yields are low after induction with /sup 60/Co ..gamma.. irradiation or mitomycin C. In order to clarify the mechanism(s) by which virus is produced in induced cells, we analyzed the replication of viral DNA and production of virion (V) antigen and infectious virus after induction in various clones as well as in lytically infected permissive cells. Cells replicating SV40 DNA or synthesizing V antigen were visualized by in situ hybridization and immunofluorescence techniques, respectively. Only some cells in induced cultures were found to produce SV40 and those which did were less efficient than lytically infected monkey cells. Mitomycin C or /sup 60/Co ..gamma.. irradiation acted by inducing more cells to replicate virus rather than by increasing the amount of SV40 released from individual cells. A greater proportion of cells could be induced to replicate SV40 DNA than to synthesize V antigen in all induced clones studied. Also, SV40 DNA replication was induced at lower doses of ..gamma.. irradiation than the production of either V antigen or infectious virus suggesting that synthesis of late virus protein is more restricted in induced cells than is replication of SV40 DNA. These findings indicate that one of the effects of induction treatments on SV40-transformed hamster cells is an enhancement of the cells' capacity to support SV40 replication.

  2. INCASOY-35: PRIMERA VARIEDAD DE SOYA OBTENIDA EN CUBA A PARTIR DEL EMPLEO DE TÉCNICAS DE IRRADIACIÓN DE RAYOS GAMMA DE 60Co

    Directory of Open Access Journals (Sweden)

    R. Ortiz

    2005-01-01

    Full Text Available La variedad INCASoy-35 fue obtenida a partir de la irradiación de semillas de la variedad INCASoy-15 con dosis de 240 Gy de rayos gamma 60Co; esta variedad se adapta a siembras de primavera, verano e invierno y puede alcanzar rendimientos de 3 t.ha-1 de granos. Tolera las principales plagas y enfermedades y, en especial, resiste el ataque de nemátodos Meloidogyne incognita. En la época adversa de primavera, las semillas han mostrado tolerancia al deterioro. Tiene capacidad de garantizar altas producciones con bajos insumos, por lo que resulta factible para la agricultura cubana.

  3. Calculation of direct effects of {sup 60}Co gamma rays on the different DNA structural levels: A simulation study using the Geant4-DNA toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Tajik, Marjan; Rozatian, Amir S.H. [Department of Physics, University of Isfahan, Hezar Jarib Street, Isfahan 81746-73441 (Iran, Islamic Republic of); Semsarha, Farid, E-mail: Semsarha@ibb.ut.ac.ir [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box: 13145-1384, Tehran (Iran, Islamic Republic of)

    2015-03-01

    In this study, simple single strand breaks (SSB) and double strand breaks (DSB) due to direct effects of the secondary electron spectrum of {sup 60}Co gamma rays on different organizational levels of a volume model of the B-DNA conformation have been calculated using the Geant4-DNA toolkit. Result of this study for the direct DSB yield shows a good agreement with other theoretical and experimental results obtained by both photons and their secondary electrons; however, in the case of SSB a noticeable difference can be observed. Moreover, regarding the almost constant yields of the direct strand breaks in the different structural levels of the DNA, calculated in this work, and compared with some theoretical studies, it can be deduced that the direct strand breaks yields depend mainly on the primary double helix structure of the DNA and the higher-order structures cannot have a noticeable effect on the direct DNA damage inductions by {sup 60}Co gamma rays. In contrast, a direct dependency between the direct SSB and DSB yields and the volume of the DNA structure has been found. Also, a further study on the histone proteins showed that they can play an important role in the trapping of low energy electrons without any significant effect on the direct DNA strand breaks inductions, at least in the range of energies used in the current study.

  4. Effects of Nitric Oxide on Growth and Sensitivity of Human Glioma A172 Cells to 60Co and X-ray Radiation

    Institute of Scientific and Technical Information of China (English)

    QiuRong; LiuBing; GuoChuanling; LiWenjian; MaQiufeng; LiSha

    2003-01-01

    Nitric oxide (NO)has been implicated both in regression and progression of tumors due to its production by both tumor cells and infiltrating lymphocytes. Ionizing radiation causes the regression of tumors, and can augment the production of NO by macrophages in vitro. The authors examined the effect of nitric oxide (NO) generating agent sodium nitroprusside (SNP) on the growth and radiosensitivity of cultured glioma A172 cells to 60Co or X-ray radiation.

  5. Effect of {sup 60}Co gamma-irradiation on two-dimensional electron gas transport and device characteristics of AlGaN/GaN HEMTs

    Energy Technology Data Exchange (ETDEWEB)

    Umana-Membreno, G.A.; Dell, J.M.; Parish, G.; Nener, B.D.; Faraone, L. [School of Electrical, Electronic and Computer Engineering, The University ofWestern Australia, Crawley WA 6009 (Australia); Ventury, R.; Mishra, U.K. [Dept. of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106 (United States)

    2005-05-01

    The effect of {sup 60}Co gamma-irradiation on Al{sub 0.33}Ga{sub 0.67}N/GaN high-electron-mobility transistors (HEMTs) has been investigated using DC and geometrical magnetoresistance measurements. The devices studied were of similar epitaxial structure, yet differed in the doping levels of the Al{sub 0.33}Ga{sub 0.67}N barrier layer: (A) nominally undoped and (B) Si-doped with SiN{sub x} passivation. Exposure to cumulative gamma-ray doses up to 20 Mrad(Si) is shown to induce significant changes in drain-current level, threshold voltage and gate leakage current level. Analysis of magnetoresistance characteristics measured at 80 K indicated that irradiation induced an increase in two-dimensional electron-gas (2DEG) density, which leads to negative threshold voltage shifts observable in the drain current versus gate voltage characteristics, attributable to the introduction of defect centers in the Al{sub 0.33}Ga{sub 0.67}N layer and/or at the gate-AlGaN interface. The 2DEG mobility-concentration profiles are shown to remain approximately unchanged for doses up to 20 Mrad(Si). Device failure, evidenced as loss of gate control over the channel and/or excessive gate leakage, occurred after exposure to 30 Mrad(Si) for device A, whereas sample B failed after 20 Mrad(Si) total dose due to failure of half of the gate contact. Degradation of gate and source/drain contacts characteristics with total dose appears to limit the tolerance of the studied HEMTs to {sup 60}Co gamma-irradiation. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Gynogenesis in carp, Cyprinus Carpio L. and tench, Tinca Tinca L. induced by 60Co radiation in highly homogeneous radiating field

    Science.gov (United States)

    Pipota, J.; Linhart, O.

    The paper deals with a method of fertility inactivation of fish spermatozoa by gamma radiation. Spermatozoa motility remained unchanged after irradiation. Irradiated sperm has been utilized to induced gynogenesis by means of retention of the second polar body and of mitotic gynogenesis, realized in carp for the first time. Homogeneity of gamma-rays field was + - 1 %.

  7. Effects of gamma irradiation of the {sup 60} Co on antimicrobial action of plant extracts of bark and leaves of Schinus terebinthifolius Raddi; Efeitos da radiacao gama do {sup 60} Co sobre a acao antimicrobiana de extratos vegetais de cascas e folhas de Schinus terebinthifolius Raddi

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edvane Borges da; Santos, Gustavo Henrique Farias dos; Amaral, Ademir de Jesus [Universidade Federal da Pernambuco (GERAR/DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia; Lima, Jeniffer Maiza de Souza [Universidade Federal da Pernambuco (CAV/UFPE), Vitoria de Santo Antao, PE (Brazil); Xisto, Kesia; Araujo, Rosilma de Oliveira [Universidade Federal da Pernambuco (DA/UFPE), Recife, PE (Brazil). Dept. de Antibioticos

    2014-07-01

    This study aimed to evaluate the potential for antimicrobial activity in vitro of extracts of bark and leaves of S. terebinthifolius treated with {sup 60}Co gamma radiation. 5,0 doses were used; 7.5 and 10 kGy, being held non-irradiated controls. To determine the antimicrobial activity was applied to the disc diffusion technique to evaluate the diameter of the inhibition zones against Gram-positive bacteria, gram-negative bacteria, alcohol-acid-resistant and yeast. Antimicrobial activity was considered significant for halos ≥ 15 mm. The results indicate an intensification of antimicrobial action of bark extracts, the 5.0 kGy, against S. aureus. Was held the micro dilution in broth to determine the minimum inhibitory concentration (MIC) and Minimum Bactericidal Concentration (MBC) of peels extracts, compared to eight clinical isolates of S. aureus. The MBC values showed that ionizing radiation did not produce the increased of anti bacteriostatic action of S. terebinthifolius, but the results indicated that S. terebinthifolius bark extracts can be used as an antimicrobial agent and ionizing radiation as an important alternative in this conservation feature.

  8. Structural and optical analysis of 60Co gamma-irradiated thin films of polycrystalline Ga10Se85Sn5

    Science.gov (United States)

    Ahmad, Shabir; Asokan, K.; Shahid Khan, Mohd.; Zulfequar, M.

    2015-12-01

    The present study focuses on the effects of gamma irradiation on structural and optical properties of polycrystalline Ga10Se85Sn5 thin films with a thickness of ∼300 nm deposited by the thermal evaporation technique on cleaned glass substrates. X-ray diffraction patterns of the investigated thin films show that crystallite growth occurs in the orthorhombic phase structure. The surface study carried out by using the scanning electron microscope (SEM) confirms that the grain size increases with gamma irradiation. The optical parameters were estimated from optical transmission spectra data measured from a UV-vis-spectrophotometer in the wavelength range of 200-1100 nm. The refractive index dispersion data of the investigated thin films follow the single oscillator model. The estimated values of static refractive index n0, oscillator strength Ed, zero frequency dielectric constant ε0, optical conductivity σoptical and the dissipation factor increases after irradiation, while the single oscillator energy Eo decreases after irradiation. It was found that the value of the optical band gap of the investigated thin films decreases and the corresponding absorption coefficient increases continuously with an increase in the dose of gamma irradiation. This post irradiation changes in the values of optical band gap and absorption coefficient were interpreted in terms of the bond distribution model.

  9. The depth-dependence of the biological effectiveness of 60Co gamma rays in a large absorber determined by dicentric chromosomes in human lymphocytes.

    Science.gov (United States)

    Schmid, Ernst; Roos, Hartmut; Kramer, Hans-Michael

    2008-01-01

    Radiobiological evidence is shown concerning a significant depth-dependence of the maximum relative biological effectiveness at limiting low doses (RBE(M)) of (60)Co gamma rays in a cubic polymethylmethacrylate (PMMA) phantom of 30 cm edge length. Using the dose-response curve for the dicentric data in human lymphocytes obtained in the present experiment at a depth of 20 cm, together with the comprehensive and consistent data set determined earlier at smaller depths of the PMMA phantom, there is an increase in the RBE(M) value by a factor of 2.18 +/- 1.25 at a depth of 20 cm relative to 1 cm in the phantom. All the dicentric data are based on identical exposure durations and irradiation temperatures as well as identical culture and evaluation conditions, with blood from the same donor.

  10. Tenth value layers for 60Co gamma rays and for 4, 6, 10, 15, and 18 MV x rays in concrete for beams of cone angles between 0 degrees and 14 degrees calculated by Monte Carlo simulation.

    Science.gov (United States)

    Jaradat, Adnan K; Biggs, Peter J

    2007-05-01

    The calculation of shielding barrier thicknesses for radiation therapy facilities according to the NCRP formalism is based on the use of broad beams (that is, the maximum possible field sizes). However, in practice, treatment fields used in radiation therapy are, on average, less than half the maximum size. Indeed, many contemporary treatment techniques call for reduced field sizes to reduce co-morbidity and the risk of second cancers. Therefore, published tenth value layers (TVLs) for shielding materials do not apply to these very small fields. There is, hence, a need to determine the TVLs for various beam modalities as a function of field size. The attenuation of (60)Co gamma rays and photons of 4, 6, 10, 15, and 18 MV bremsstrahlung x ray beams by concrete has been studied using the Monte Carlo technique (MCNP version 4C2) for beams of half-opening angles of 0 degrees , 3 degrees , 6 degrees , 9 degrees , 12 degrees , and 14 degrees . The distance between the x-ray source and the distal surface of the shielding wall was fixed at 600 cm, a distance that is typical for modern radiation therapy rooms. The maximum concrete thickness varied between 76.5 cm and 151.5 cm for (60)Co and 18 MV x rays, respectively. Detectors were placed at 630 cm, 700 cm, and 800 cm from the source. TVLs have been determined down to the third TVL. Energy spectra for 4, 6, 10, 15, and 18 MV x rays for 10 x 10 cm(2) and 40 x 40 cm(2) field sizes were used to generate depth dose curves in water that were compared with experimentally measured values.

  11. Thermal stability of formulations of PVC irradiated with {gamma} of {sup 60}; Estabilidad termica de formulaciones de PVC irradiadas con {gamma} de {sup 60} Co

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M.E.; Carrasco A, H. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: memp@nuclear.inin.mx; Castaneda F, A.; Benavides C, R.; Garcia R, S.P. [CIQA, 25100 Saltillo, Coahuila (Mexico)

    2004-07-01

    The industry of cables and wires frequently use cable isolations with base of formulations of PVC, in those that stabilizer has usually been used with the help of heavy metals, as the lead, which is toxic. To solve the problem, from the 2002 one has come studying in combined form in the National Institute of Nuclear Research ININ and the Center of Investigation in Applied Chemistry CIQA, the modifications induced by the radiation in formulations with the help of vinyl poly chloride PVC. In these formulations, prepared with cross linking agent, plastifying industrial grade, stuff and non toxic stabilizers of calcium estearate and zinc industrial grade, it is sought to replace the stabilizer of Pb. For this were irradiated it test tubes of PVC with gamma radiation of cobalt 60 to three different dose in atmospheres of air and argon. Later it was determined their thermal stability at different times of heating and it was measured the Young modulus by means of thermo mechanical analysis. Those results obtained together with other techniques of characterization suggest that the irradiated proposed formulation can substitute the one stabilized with lead. (Author)

  12. Gamma Radiation Tolerance of Magnetic Tunnel Junctions

    Science.gov (United States)

    Ren, Fanghui; Jander, Albrecht; Dhagat, Pallavi; Nordman, Cathy

    2011-10-01

    Determining the radiation tolerance of magnetic tunnel junctions (MTJ), which are the storage elements of non-volatile magnetoresistive random access memories (MRAM), is important for investigating their potential application in space. In this effort, the effect of gamma radiation on MTJs with MgO tunnel barriers was studied. Experimental and control groups of samples were characterized by ex situ measurements of the magnetoresistive hysteresis loops and I-V curves. The experimental group was exposed to gamma rays from a ^60Co source. The samples initially received a dose of 5.9 Mrad (Si) after which they were again characterized electrically and magnetically. Irradiation was then continued for a cumulative dose of 10 Mrad and the devices re-measured. The result shows no change in magnetic properties such as coercivity or exchange coupling due to irradiation. After correcting for differences in temperature at the time of testing, the tunneling magnetoresistance was also found to be unchanged. Thus, it has been determined that MgO-based MTJs are highly tolerant of gamma radiation, particularly in comparison to silicon field-effect transistors which have been shown to degrade with gamma ray exposure even as low as 100 Krad [Zhiyuan Hu. et al., IEEE trans. on Nucl. Sci., vol. 58, 2011].

  13. Cellulose destruction under successive thermal and radiation treatment. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ershov, B.G.; Komarov, V.B.

    1985-02-01

    The influence of successive thermal and radiation effect on cellulose is investigated. The samples were ..gamma.. irradiated (/sup 60/Co) with a dose rate of 20 kGy/h (the absorbed doses ranged from 0 to 80 kGy) and heated up to 190 deg C. It is shown that the attainment of the same destruction depth for the heated-up cellulose occurs at noticeably lower absorbed doses than for the cellulose which has not been subjected to thermal treatment. For successive thermal and radiation treatment of cellulose the ratio S=S therm.+Ssub(rad) where S is a number of broken bonds in a macromolecule is correct. The radiation-chemical yield of cellulose destruction is determined to be: G=7.3 +- 0.1 mol/100 eV.

  14. Optimization of process parameters for the inactivation of Lactobacillus sporogenes in tomato paste with ultrasound and {sup 60}Co-{gamma} irradiation using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ye Shengying [College of Food Science, South China Agricultural University, Wushan, Guangzhou, GD 510640 (China)], E-mail: yesy@scau.edu.cn; Qiu Yuanxin; Song Xianliang; Luo Shucan [College of Food Science, South China Agricultural University, Wushan, Guangzhou, GD 510640 (China)

    2009-03-15

    The processing parameters for ultrasound and {sup 60}Co-{gamma} irradiation were optimized for their ability to inactivate Lactobacillus sporogenes in tomato paste using a systematic experimental design based on response surface methodology. Ultrasonic power, ultrasonic processing time and irradiation dose were explored and a central composite rotation design was adopted as the experimental plan, and a least-squares regression model was obtained. The significant influential factors for the inactivation rate of L. sporogenes were obtained from the quadratic model and the t-test analyses for each process parameter. Confirmation of the experimental results indicated that the proposed model was reasonably accurate and could be used to describe the efficacy of the treatments for inactivating L. sporogenes within the limits of the factors studied. The optimized processing parameters were found to be an ultrasonic power of 120 W with a processing time of 25 min and an irradiation dose of 6.5 kGy. These were measured under the constraints of parameter limitation, based on the Monte Carlo searching method and the quadratic model of the response surface methodology, including the a/b value of the Hunter color scale of tomato paste. Nevertheless, the ultrasound treatment prior to irradiation for the inactivation of L. sporogenes in tomato paste was unsuitable for reducing the irradiation dose.

  15. Toxoplasma gondii: effects of {sup 60} Co ionizing radiation in the viability and infectivity, detected in vitro in LLC-MK2 cells and in vivo in C57BL/6J mice

    Energy Technology Data Exchange (ETDEWEB)

    Hiramoto, Roberto M.; Almeida, Beatriz S.V.; Cardoso, Roselaine P.A.; Andrade Junior, Heitor F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    1997-12-01

    Toxoplasmosis, caused by Toxoplasma gondii, promotes devasting disease in fetus and AIDS patients. The longlife immunity of natural infection is inefficient in eliminate tissue infective cysts. Few immunization programs were tested, mostly with attenuated strains. Ionizing radiation were used with successful in vaccine production, without reproductive ability with a relatively normal physiology until reproduction. Here, we tested several schedules of {sup 60} Co irradiation of tachzoites from RH strain of T. gondii, from peritoneal exudate or suspensions of LLC-MK2 infected cells, to optimize the viability and sterility of the irradiated agents. The tachzoites were exposed to 50, 100 and 200 Gy in a GammaCell 220 at 366 Gy/h. The viability was tested by motility, integrity and Trypan Blue dye exclusion. All irradiation schedules maintained a high (>90%) viability of the parasites. Dilutions were injected in C57Bl/6j mice with induction of specific antibodies, no clinical disease but uncertain sterility. Infection of LLC--MK2 cells showed that viable and reproductive parasites were often found in 50 Gy irradiated cells, rarely found in 100 Gy irradiated cells, rarely found in 100 Gy irradied cells, with no growth occuring with 200 Gy irradiated tachzoites. Our data show that 200 Gy {sup 60} Co irradiation blocks the reproductive capacity without affecting the short term viability of tachzoites of T. gondii. (author). 11 refs., 1 fig.

  16. Gamma radiation effects on peanut skin antioxidants

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  18. Resveratrol Effects on Life Span and Fertility of Caenorhabditis Elegans Subject to 60Co Gamma Ray Irradiation%白藜芦醇对60Coγ射线照射线虫寿命和生殖的影响

    Institute of Scientific and Technical Information of China (English)

    叶侃; 季晨博; 郭锡熔; 古桂雄

    2011-01-01

    Caenorhabditis elegans was used as experimental model to investigate radiation effect of resveratol on caenorhabdities elegans irradiated by 60Co γray. Treatment with resveratrol can increase average life span and spawning rate, improve the surrival rate of eggs, and protect their mitochondrion function of cacnorhabdities elegans exposure to 60Co rr ray. The results indicate that resveratrol has radiation protection effects, which might be related to its action on ROS decrease and mitochondrial defend.%以线虫作为实验模型,观察白藜芦醇(RES)对受60Coγ射线照射线虫的保护作用.结果表明,白藜芦醇能提高受照射线虫的寿命,增加产卵率,提高卵的存活率,保护其线粒体功能.其作用机制可能与白藜芦醇减轻氧自由基所致的线虫线粒体损伤有关.

  19. A Novel Animal Model of Impaired Glucose Tolerance Induced by the Interaction of Vitamin E Deficiency and 60Co Radiation

    Directory of Open Access Journals (Sweden)

    Yue Guan

    2015-01-01

    Full Text Available Impaired glucose tolerance (IGT, known as the prediabetes stage, is usually induced by habits of life or environmental factors. Established IGT animal models are mostly conducted with chemical compounds such as streptozocin or genetic modification. However, the occasion of exposure to these factors in daily life is seldom. The objective of this study was to establish a new animal model of IGT induced by VE deficiency in diet and exposure to radiation. SD rats were treated individually or in combination of these two factors. In the combination group, the calculated insulin sensitivity index decreased; then HOMA-β value increased. Oxidative damage and IGT were observed. Insulin secretion level in perfusate from pancreas response to glucose was characterized by a rapid but reduced first phase and an obviously defective second phase upon pancreas perfusion. Histopathological images demonstrated the pathological changes. Western blotting analysis showed that the insulin signaling pathway was downregulated. The interaction of VE deficiency in diet and exposure to radiation could break the equilibrium of oxidation and antioxidation and result in IGT. More importantly, a new IGT model was successfully established which may be conducive to further research into development of drugs against human IGT.

  20. Comparative effects of 60Co gamma-rays and neon and helium ions on cycle duration and division probability of EMT 6 cells. A time-lapse cinematography study.

    Science.gov (United States)

    Collyn-d'Hooghe, M; Hemon, D; Gilet, R; Curtis, S B; Valleron, A J; Malaise, E P

    1981-03-01

    Exponentially growing cultures of EMT 6 cells were irradiated in vitro with neon ions, helium ions or 60Co gamma-rays. Time-lapse cinematography allowed the determination, for individual cells, of cycle duration, success of the mitotic division and the age of the cell at the moment of irradiation. Irradiation induced a significant mitotic delay increasing proportionally with the delivered dose. Using mitotic delay as an endpoint, the r.b.e. for neon ions with respect to 60Co gamma-rays was 3.3 +/- 0.2 while for helium ions it was 1.2 +/- 0.1. Mitotic delay was greatest in those cells that had progressed furthest in their cycle at the time of irradiation. No significant mitotic delay was observed in the post-irradiation generation. Division probability was significantly reduced by irradiation both in the irradiated and in the post-irradiated generation. The reduction in division probability obtained with 3 Gy of neon ions was similar to that obtained after irradiation with 6 Gy of helium ions or 60Co gamma-rays.

  1. Inactivation effect of 60Co gamma ray on cysticerci of Taenia solium in pork%60Coγ射线对猪肉中囊尾蚴的辐照杀灭效应

    Institute of Scientific and Technical Information of China (English)

    钟凯; 高翔; 计融

    2011-01-01

    Objective revealing the relationship between irradiation dose and inactivation ratio for eysticerei of Taenia solium in pork, determining the minimal dose for totally killing cysticerci and providing scientific evidence for setting up relevant hygienic standards of radiation. Methods After Taenia solium infected pork being treated with different irradiation doses; cysticerci were separated and incubated in fresh swine bile. The adjusted inactivation ratio was calculated according to the survival rate. Results There was a linear correlation between irradiation dose and adjusted inactivation ratio, the D10 value was about 3.8 kGy, and a totally killing could be achieved by 4.5 kGy irradiation. Conclusion Irradiation at a dose of 4.5 kGy could be applied as the maximum dose to inactivate cysticerci of Taenia solium in pork processing.%目的 揭示猪肉中囊尾蚴灭活率与辐照剂量的相关关系及最小杀灭剂量,为制定相应辐照卫生规范提供科学依据.方法 以不同剂量Co γ射线处理感染囊尾蚴的猪肉,并用新鲜猪胆汁孵化剥离出的囊尾蚴,根据成活率计算校正灭活率.结果 辐照剂量与校正灭活率具有线性相关,D值约为3.8 kGy,4.5 kGy可完全杀灭囊尾蚴.结论 4.5 kGy γ射线对猪肉中囊尾蚴有很好的杀灭效果.

  2. Mortality and growth of cobalt-60 gamma-irradiated adult Pacific oyster, Crassotrea gigas%60Co-γ射线对成体长牡蛎生长的影响及致死效应

    Institute of Scientific and Technical Information of China (English)

    刘晓; 彭小明; 张国范; 赵敏; 郭希明

    2005-01-01

    Effects of ionizing irradiation of 60Co-γ ray on mortality and growth of one year-old Pacific oysters ( Crassotrea gigas ) were studied. Irradiation was conducted at 4℃ and without sea water, and the survival, shell length, shell width, whole wet weight and condition index of irradiated oysters were measured. A biphasic dose response effect of 660Co-γ irradiation on Pacific oyster with high stimulatory response dose range to 100 Gy, and strong hormesis effects had been observed. Gamma ray induced mortality happened within 90 days after irradiation, and the relation between dosage ( D ) and mortality at 90 days could be described by the equation of M90 = 0.0041D2- 0. 1816D (R2= 0. 9958) with an LD50/90 of 135 Gy, indicating that the Pacific oyster has strong resistance to 60Co-γ irradiation. Growth in shell length, shell width and whole wet weight of Pacific oyster were also enhanced by 60 Gy of 60Co-γ ray. The condition index was also enhanced by 60Co-γ irradiation in the dosage range from 40 to 100 Gy, with the maximum stimulatory response of 2.5 fold of control value at the 40 Gy dosage, suggesting that the accelerating effects of γ ray on growth of the Pacific oyster led to increase in dry meat. Results of this study showed that ionizing irradiation might be useful in the improvement of production traits in shellfish.

  3. Report on EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 (EUROMET project no. 813): Comparison of air kerma and absorbed dose to water measurements of {sup 60}Co radiation beams for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Csete, I. [National Office of Measures (OMH) - pilot laboratory and corresponding author (Hungary); Leiton, A.G. [Research Centre for Energy, Environment and Technology (CMRI-CIEMAT) (Spain); Sochor, V. [Czech Metrology Institute (CMI) (Czech Republic); Lapenas, A. [Latvian National Metrology Center (LNMC-RMTC) (Latvia); Grindborg, J.E. [Swedish Radiation Protection Authority (SSI) (Sweden); Jokelainen, I. [Radiation and Nuclear Safety Authority (STUK) (Finland); Bjerke, H. [Norwegian Radiation Protection Authority (NRPA) (Norway); Dobrovodsky, J. [Slovak Institute of Metrology (SMU) (Slovakia); Megzifene, A. [International Atomic Energy Agency, IAEA, Vienna (Austria); Hourdakis, C.J. [Hellenic Atomic Energy Committee (HAEC-HIRCL) (Greece); Ivanov, R. [National Centre of Metrology (NCM) (Bulgaria); Vekic, B. [Rudjer Boskovic Institute (IRB) (Croatia); Kokocinski, J. [Central Office of Measures (GUM) (Poland); Cardoso, J. [Institute for Nuclear Technology (ITN-LMRIR) (Portugal); Buermann, L. [Physikalisch Technische Bundesanstalt (PTB) (Germany); Tiefenboeck, W. [Bundesamt fur Eich und Vermesungswesen (BEV) (Austria); Stucki, G. [17 Bundesamt fur Metrologie (METAS) (Switzerland); Van Dijk, E. [NMi Van Swinden Laboratorium (NMi) (Netherlands); Toni, M.P. [ENEA-CR Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti (ENEA) (Italy); Minniti, R. [20 National Institute of Standards and Technology (NIST) (United States); McCaffrey, J.P. [National Research Council Canada (NRC) (Canada); Silva, C.N.M. [National Metrology Laboratory of Ionizing Radiation (LNMRI-IRD) (Brazil); Kharitonov, I. [D I Mendeleyev Institute for Metrology (VNIIM) (RU); Webb, D. [Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) (Australia); Saravi, M. [National Atomic Energy Commission (CNEA-CAE) (Argentina); Delaunay, F. [Laboratoire National Henri Becquerel (LNE-LNHB) (France)

    2010-06-15

    The results of an unprecedented international effort involving 26 countries are reported. The EUROMET.RI(I)-K1 and EUROMET.RI(I)-K4 key comparisons were conducted with the goal of supporting the relevant calibration and measurement capabilities (CMC) planned for publication by the participant laboratories. The measured quantities were the air kerma (K{sub air}) and the absorbed dose to water (Dw) in {sup 60}Co radiotherapy beams. The comparison was conducted by the pilot laboratory MKEH (Hungary), in a star-shaped arrangement from January 2005 to December 2008. The calibration coefficients of four transfer ionization chambers were measured using two electrometers. The largest deviation between any two calibration coefficients for the four chambers in terms of air kerma and absorbed dose to water was 2.7% and 3.3% respectively. An analysis of the participant uncertainty budgets enabled the calculation of degrees of equivalence (DoE), in terms of the deviations of the results and their associated uncertainties. As a result of this EUROMET project 813 comparison, the BIPM key comparison database (KCDB) will include eleven new Kair and fourteen new D{sub w} DoE values of European secondary standard dosimetry laboratories (SSDLs), and the KCDB will be updated with the new DoE values of the other participant laboratories. The pair-wise degrees of equivalence of participants were also calculated. In addition to assessing calibration techniques and uncertainty calculations of the participants, these comparisons enabled the experimental determinations of N{sub Dw}/N{sub Kair} ratios in the {sup 60}Co gamma radiation beam for the four radiotherapy transfer chambers. (authors)

  4. Decontamination of biological ferment by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sabundjian, Ingrid T.; Salum, Debora C.; Silva, Priscila V.; Furgeri, Camilo; Duarte, Renato; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: villavic@ipen.br

    2007-07-01

    Biological ferment is a product obtained from pure yeast (Saccharomyces cerevisiae) culture by a suitable technological process and employed to increase the size and porosity of the baker's products. Foods containing high microorganisms count indicate that Good Manufacturing Practices were not applied. The aim of this study was to observe the viability of Dry Biological Ferment after the radiation process using different doses of {sup 60}Co gamma rays and different storage times. Dry baker's yeast Saccharomyces cerevisiae samples were purchased from a local supermarket in Sao Paulo (Brazil) and irradiated at IPEN in a Gammacell source at 0.5, 1.0, 2.0 and 3.0 kGy doses (dose-rate of 3.51 kGy/h) at room temperature (25 deg C). The fluorescent method was performed to observe the viability of yeast cells. The viability decrease with the increase of the radiation dose, as shown: the amount of the viable cell found in the non-irradiated samples (control) at 0 day was 87.2%; 30 days 67.7%; 60 days 77.4% and 90 days 60.1%. With 1.0 kGy at 0 day was 61.4%; 30 days 22.7%; 60 days 56.9% and 90 days 24.2%. With 3.0 kGy at 0 day was 57.00%; at the next periods the most of the cells become not viable. (author)

  5. Effect of the ionizing radiation of the {sup 60}Co on the radiological properties of guar gum and carboxymethylcellulose for the food industry use; Efeito da radiacao ionizante de {sup 60}Co sobre propriedades radiologicas da goma guar e carboximetilcelulose para uso na industria alimenticia

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Fernando Fabris; Mastro, Nelida Lucia del [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    Hydrosoluble polysaccharides or gums are long chain polymers that dissolve or disperse in water. When added to foods, they change rheological characteristics, stabilize emulsions, promote particle suspension, control crystallization and inhibit sineresis of processed foods. Guar gum is an hydro soluble polysaccharide obtained from the seed of Cyamopsis tetragonolobus. Carboxy-methylcellulose (CMC) is an homopolisaccharide prepared by the treatment of alkaline cellulose with sodium monochloroacetate. This work presents the results of the study of radiation effects on the viscosity of guar gum and CMC used for the food industry when irradiated with {sup 60} Co ionizing radiation. (author)

  6. Characterization of 60 Co y-radiation induced radical products of antipyrine by means of high performance liquid chromatography, mass spectrometry, capillary zone electrophoresis, micellar electrokinetic capillary chromatography and nuclear magnetic resonance spectrometry

    NARCIS (Netherlands)

    Coolen, S.A.J.; Everaerts, F.M.; Huf, F.A.

    1997-01-01

    Monitoring the amount of oxidative damage, caused by free radicals, is a major problem in free radical and aging research. Antipyrine is proposed as an exogenous marker for the biomolecular monitoring of oxidative stress. In this paper the characterization of the 60Co γ-radiation products of antipyr

  7. Radiation-induced alterations in the distribution of lysosomal hydrolases in rat spleen homogenates. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, S.L.; Eklund, S.K.

    1978-07-01

    Whole-body exposure of rats to /sup 60/Co-..gamma.. radiation results in increases in the activities of two lysosomal hydrolases, ..beta..-glucuronidase and ..cap alpha..-fucosidase, found in the supernatant fraction of spleen homogenates. The redistribution of these enzymes from the ''particulate-bound'' to the ''free-supernatant'' fraction of spleen homogenates has been studied as a function of radiation dose. The response curves for the ratio of free/bound enzyme versus dose sigmoidal with maximum occurring at 300 to 400 rad.

  8. Comunicación corta. RADIOESTIMULACIÓN DE LA GERMINACIÓN EN Stevia rebaudiana CULTIVAR KH-IAN VC-142 (EIRETÉ, MEDIANTE EL EMPLEO DE RAYOS GAMMA 60CO

    Directory of Open Access Journals (Sweden)

    María C. González

    2015-01-01

    Full Text Available El presente trabajo tuvo como objetivo evaluar el efecto de bajas dosis de rayos gamma 60 Co en la germinación de las semillas de Stevia rebaudiana . Para ello se irradiaron semillas del cultivar KH-IAN VC-142 (Eireté, con dosis de 10 a 90 Gray (Gy. Se determinó que todas las dosis empleadas incrementaron el número de semillas germinadas pero la dosis de 10 Gy fue la que provocó la mayor estimulación en la germinación de las semillas.

  9. Obtention of zinc polymethacrylate via free radicals induced by gamma radiation; Obtencion del polimetacrilato de zinc via radicales libres inducidos por radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Urena N, F.; Flores E, J. [Departamento de Fisica, Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

    2000-07-01

    The objective of this work was to synthesise the monomer of zinc methacrylate and subsequently to carry out the polymerization reaction with the purpose to obtain the compound desired, the zinc polymethacrylate. For this it was used a gamma radiation source, {sup 60} Co, as initiator of the polymerization reaction. (Author)

  10. Gamma radiation sterilized amnion: use in ophthalmology

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Leon T, Y. [Hospital General Regional 220, IMSS, Paseo Tollocan No. 620, Col. Vertice, Toluca 50150, Estado de Mexico (Mexico); Vazquez M, L., E-mail: esther.martinez@inin.gob.m [Hospital General de Mexico, Dr. Balmis 148, Col. Doctores, 06720 Mexico D. F. (Mexico)

    2010-10-15

    Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with {sup 60}Co gamma radiation, have been used in Mexico since 2005 either as a graft to replace the damaged ocular surface, or as a patch to prevent unwanted inflammatory reactions. Patients from the Hospital General de Mexico (HGM) and Instituto Mexicano del Seguro Social (IMSS), suffering diverse pathologies such as keratoconjunctivitis; recurrent pterygium associated with symblepharon; corneal neuro trophic ulcers, chemical and thermal burns, and corneal thinning s, had been successfully treated with irradiated amnion. In the HGM, a clinical prospective study on lesions of the ocular surface of 17 eyes from 15 patients, affected with the above mentioned pathologies, was successful in 88.2%. The results have proven to be excellent as much for cosmetic purposes as for functional ones. Without the treatment, the patients could have suffered a healing after-effect or loss of sight. At IMSS, a controlled clinical randomized trial with 108 eyes from 100 patients, affected with primary nasal pterygium, was performed in 2009. These eyes were treated with radio sterilized amnion and intraoperative mitomycin C to prevent recurrence after excision of the primary pterygium. The preliminary results do not shown adverse reaction, inflammation and pain were significantly reduced radio sterilized amnion also offer security because they do no express antigens HLA-A, B or Dr and the sterile irradiated tissue do not provoke rejection or transmit an infective disease. (Author)

  11. Activity evaluation from different native or irradiated with {sup 60} Co gamma rays snake venoms and their inhibitory effect on Leishmania (Leishmania) amazonensis; Avaliacao da atividade de diferentes venenos de serpentes, nativos ou irradiados, com radiacao gama de {sup 60} Co, quanto ao poder inibitorio do crescimento de Leishmania (Leishmania) amazonensis

    Energy Technology Data Exchange (ETDEWEB)

    Lourenco, Cecilia de Oliveira

    2000-07-01

    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 LLCMK{sub 2} 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 {sup 60}Co 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)

  12. Gamma radiation-induced synthesis and characterization of Polyvinylpyrrolidone nanogels

    Science.gov (United States)

    Ges, A. A.; Viltres, H.; Borja, R.; Rapado, M.; Aguilera, Y.

    2017-01-01

    Due to the importance of bioactive peptides, proteins and drug for pharmaceutical purpose, there is a growing interest for suitable delivery systems, able to increase their bioavailability and to target them to the desired location. Some of the most studied delivery systems involve encapsulation or entrapment of drugs into biocompatible polymeric devices. A multitude of techniques have been described for the synthesis of nanomaterials from polymers, however, the use of ionizing radiation (γ, e-), to obtain nano- and microgels polymer is characterized by the possibility of obtaining products with a high degree of purity. Although, in the world, electronic radiation is used for this purpose, gamma radiation has not been utilized for these purposes. In this paper is developed the formulation the formulation of Polyvinylpyrrolidone (PVP) nanogels synthesized by gamma radiation techniques, for their evaluation as potential system of drug delivery. Experiments were performed in absence of oxygen using aqueous solutions of PVP (0.05% -1%). Crosslinking reactions were carried out at 25° C in a gamma irradiation chamber with a 60Co source (MPX-γ 30). The Viscosimetry, Light Scattering, X-Ray Diffraction and Transmission Electron Microscopy (TEM), were used as characterization techniques.

  13. [Gamma-radiation action on cells of algae Euglena gracilis].

    Science.gov (United States)

    Glinkova, E; Zhuchkina, N I; Koltovoĭ, N A; Koltovaia, N A

    2012-01-01

    Considering the potentials of algae Euglena to constitute a part of biological systems of human life support, effects of low radiation doses on algal cells and radiosensitivity dependence on their genotype were studied. In experiments with gamma-irradiation (60Co) of Euglena gracilis, the highest radioresistance was demonstrated by strain Z. OFL; the chloroplasts lacking Z-derived strain showed hypersensitivity to radiation. E. bacillaris and derived chlorophyll-lacking strains W3 and W10 had intermediate radiosensitivity. Irradiation with the doses of up to 10 Gy produced a hormetic effect in the stock strains. Cells death was observed only after irradiation by doses above 100 Gy. The stimulating effect was exerted both on radioresistance and growth rate. Dyes made possible rapid evaluation of the proportion of living and dead cells. Comparison of two survival tests showed that the classic medium inoculation overestimates cell deaths as it disregards the living non-proliferating cells.

  14. Patient-Specific Quality Assurance for the Delivery of {sup 60}Co Intensity Modulated Radiation Therapy Subject to a 0.35-T Lateral Magnetic Field

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. Harold, E-mail: hli@radonc.wustl.edu; Rodriguez, Vivian L.; Green, Olga L.; Hu, Yanle; Kashani, Rojano; Wooten, H. Omar; Yang, Deshan; Mutic, Sasa

    2015-01-01

    Purpose: This work describes a patient-specific dosimetry quality assurance (QA) program for intensity modulated radiation therapy (IMRT) using ViewRay, the first commercial magnetic resonance imaging-guided RT device. Methods and Materials: The program consisted of: (1) a 1-dimensional multipoint ionization chamber measurement using a customized 15-cm{sup 3} cube-shaped phantom; (2) 2-dimensional (2D) radiographic film measurement using a 30- × 30- × 20-cm{sup 3} phantom with multiple inserted ionization chambers; (3) quasi-3D diode array (ArcCHECK) measurement with a centrally inserted ionization chamber; (4) 2D fluence verification using machine delivery log files; and (5) 3D Monte Carlo (MC) dose reconstruction with machine delivery files and phantom CT. Results: Ionization chamber measurements agreed well with treatment planning system (TPS)-computed doses in all phantom geometries where the mean ± SD difference was 0.0% ± 1.3% (n=102; range, −3.0%-2.9%). Film measurements also showed excellent agreement with the TPS-computed 2D dose distributions where the mean passing rate using 3% relative/3 mm gamma criteria was 94.6% ± 3.4% (n=30; range, 87.4%-100%). For ArcCHECK measurements, the mean ± SD passing rate using 3% relative/3 mm gamma criteria was 98.9% ± 1.1% (n=34; range, 95.8%-100%). 2D fluence maps with a resolution of 1 × 1 mm{sup 2} showed 100% passing rates for all plan deliveries (n=34). The MC reconstructed doses to the phantom agreed well with planned 3D doses where the mean passing rate using 3% absolute/3 mm gamma criteria was 99.0% ± 1.0% (n=18; range, 97.0%-100%), demonstrating the feasibility of evaluating the QA results in the patient geometry. Conclusions: We developed a dosimetry program for ViewRay's patient-specific IMRT QA. The methodology will be useful for other ViewRay users. The QA results presented here can assist the RT community to establish appropriate tolerance and action limits for View

  15. Gamma radiation shielding and health physics characteristics of diaspore-flyash concretes.

    Science.gov (United States)

    Singh, Kanwaldeep; Singh, Sukhpal; Singh, S P; Mudahar, Gurmel S; Dhaliwal, A S

    2015-06-01

    Different gamma radiation interaction parameters has been measured experimentally for the prepared diaspore-flyash concretes at 59.54, 662, 1173 and 1332 keV using narrow-beam transmission geometry and results are found to be in good agreement with theoretical values computed with a computer programme, WinXCom. The radiation exposure rate and absorbed dose rate for the gamma radiation with and without shielding of diaspore-flyash concretes have been determined using linear attenuation results. The results show that on average, there is reduction of 95%, 53% and 40% in dose rate for gamma sources (241)Am, (137)Cs and (60)Co, respectively with diaspore-flyash concretes as shielding material. Other health physics parameters namely equivalent dose, effective dose, gamma flux and energy fluence rate have also been determined.

  16. Intra-arterial administration of carboplatin plus lower dosage radiation of {sup 60}CO as induction treatment in advanced oral cancer

    Energy Technology Data Exchange (ETDEWEB)

    Okutomi, Tadashi; Kato, Yukihiro; Ichihara, Hideki; Kusunoki, Yukihiro; Hatakeyama, Daijiro; Yokoyama, Kyoko; Tatematsu, Norichika [Gifu Univ. (Japan). School of Medicine; Liu, Jianhua

    2000-11-01

    Conventional pre-operative chemoradiotherapy often causes severe side effects, which may result in interruption of the treatment and delay of decided operation. Carboplatin (CBDCA) is one of the effective chemotherapeutants for head and neck cancer. We treated 23 patients with advanced oral cancers by a combination of intra-arterial administration of Carboplatin and {sup 60}CO radiotherapy. The dosage of Carboplatin was between 20 mg and 35 mg per square meter of body surface. The dosage of external {sup 60}CO irradiation was 2 Gy per day and 30 to 60 Gy in total. We evaluated clinical response, toxicity and survival of this therapy of all the patients. Histologic response was also evaluated in some of them. All cancers responded to the regional chemoradiotherapy and demonstrated remission. Two (8%) completed response rate (CR) and 16 (69%) partial response rate (PR) were achieved. The accumulated five-year overall survival rate by Kaplan-Meier method was 73.9%. Fourteen patients (60.8%) showed no evidence of disease (NED) within five years after the therapy. All patients had stomatitis, but most of them were not so severe. The major hematological toxicity was leukopenia, but it was from mild to moderate and reversible. Our study showed that this therapy provided low toxicity, high clinical and histological response rate. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

  18. The effects of gamma radiation on soybean isoflavones contents

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  19. Characterization of hydrothermal green quartz produced by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Enokihara, Cyro T.; Rela, Paulo R., E-mail: cteiti@ipen.br, E-mail: prela06@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Schultz-Güttler, Rainer A., E-mail: rainersgut@gmail.com [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Geociencias

    2015-07-01

    A specific variety of quartz showing a green color in nature or induced artificially by radiation gamma ({sup 60}Co) is quite rare. Only two occurrences are known today, where this type of quartz can be found: Canada, at the Thunder Bay Amethyst Mine, Ontario and Brazil, at widely scattered geode occurrences along a 600 km stretch from Quarai at Brazils southern most tip to Uberlandia in Minas Gerais. These two occurrences have been formed by strong hydrothermal activities.That way much quartz crystals showed a very fast growth history facilitating the formation of growth defects (twinning, small angle tilting, mosaic growth, striations) and the uptake of water in form of micro inclusions, molecular water, silanol (Si-OH) and OH. In the present work the material analyzed is from hydrothermal regimes found in intrusions of basaltic rocks located in the Rio Grande do Sul state. To characterize these materials, colored green by gamma rays, analyses by ICP, electron microscopy, water loss techniques and UV-VIS or NIR-FTIR spectroscopic measurements have been made. Silanol complexes are formed, which by radiation due to gamma rays form the color center NBOHC (Non-bonding Oxygen Hole Center), showing absorption between 590 to 620 nm, responsible for the green color. The water content with up to 3200 ppm by weight exceeds the amount of charge balancing cations (Fe, Al, Li). There is no correlation between water content and cations as in other color varieties. (author)

  20. Alterations induced in Escherichia Coli cells by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da [Federal University of Technology of Parana (CPGEI/UTFPR), Curitiba, PR (Brazil)]. E-mails: jaquekap@yahoo.com.br; schelin@cpgei.cefetpr.br; sergei@utfpr.edu.br; Jesus, E.F.O. de; Lopes, R.T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear]. E-mails: ricardo@lin.ufrj.br; edgar@lin.ufrj.br; Carlin, N.; Toledo, E.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica]. E-mail: nelson.carlin@dfn.if.usp.br

    2007-07-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ({sup 60}Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

  1. Gamma Radiation Reduced Toxicity of Azoxystrobin Tested on Artemia franciscana.

    Science.gov (United States)

    Dvorak, P; Zdarsky, M; Benova, K; Falis, M; Tomko, M

    2016-06-01

    Fungicide azoxystrobin toxicity was monitored by means of a 96-h biotest with Artemia franciscana nauplius stages after exposure to solutions with concentrations of 0.2, 0.4, 0.6 and 0.8 mg L(-1) irradiated with (60)Co gamma radiation with doses of 1, 2.5, 5 and 10 kGy. The effects of ionization radiation on azoxystrobin toxicity were mainly manifested by a statistically significant reduction of lethality after 72- and 96-h exposure. A maximum reduction of lethality of 72 % was achieved using doses of 1-5 kGy for an azoxystrobin initial concentration of 0.4 mg L(-1) and after 72 h of exposure. At a 96-h exposure, a difference of lethal effects reached up to 70 % for a dose of 10 kGy. The observed effect of gamma ionizing radiation on azoxystrobin toxicity suggest that this approach can be applied as an alternative for a reduction of azoxystrobin residua in food.

  2. Degradation of malathion by gamma radiation of Cobalt-60

    Energy Technology Data Exchange (ETDEWEB)

    Wiendl, F.M.; Sgrillo, R.B. (Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil))

    1982-07-01

    On biological tests with Sitophilus oryzae (L.) and Tribolium casteneum Herbest., it could be observed that malathion sup(*) is degraded by gamma radiations of /sup 60/Co, at doses of 10 and kGy. It was determined that, if utilizing Sitophilus oryzae as insect test, the degradation of the insecticide by radiations is more difficult to observe, perhaps because starvation is a main factor, allied to the stress induced by the insecticide. Using Tribolium castaneum as test insect its greater longevity under starvation conditions permit to observe more details of the letality induced by the insecticide, more or less degraded by the gamma rays. It could be also observed that concentrations of 37.5 mg/m/sup 2/ (3.5 mg/sq. foot) or more are similar in its letal action. The effects of the radiations on the insecticide are better observed on concentrations of 18.75 mg/m/sup 2/ (1.7 mg/sq. foot) or less. Even the concentration of 0.59 mg/m/sup 2/ (0.05 mg/sq. foot), if irradiated, cause almost the same mortality as concentrations of between 1,500 and 2,000 mg/m/sup 2/ (150-200 mg/sq. foot) normaly indicated on practice.

  3. Evaluation of the ionizing radiation effects of the {sup 60}Co on the physical, chemical and nutritional properties of Phaseolus vulgaris L. e Vigna unguiculata (L.) Walp beans; Avaliacao dos efeitos da radiacao ionizante de {sup 60}Co em propriedades fisicas, quimicas e nutricionais dos feijoes Phaseolus vulgaris L. e Vigna unguiculata (L.) Walp

    Energy Technology Data Exchange (ETDEWEB)

    Villavicencio, Anna Lucia Casanas Haasis

    1998-07-01

    The effects of {sup 60} Co ionizing radiations in doses of 0; 0.5; 1.5; 2.5; 5.0 and 10 kGy on beans, Phaseolus vulgaris L., of the carioca variety and Vigna unguiculata (L.) Walp, of the macacar variety stored for 6 months were studied. The cooking time was established, and then the following analyses were carried out: Sensory, vitamins B{sub 1}, B{sub 2} and B{sub 6} protein content, biological evaluation in rats (Food intake and Weight gain (in grams)), apparent Digestibility (Dapp), apparent Net Protein Utilization (NPUapp) and apparent Biological Value (BVapp), as well as the applicability of detection methods of irradiated foodstuffs through germination tests, the analysis of DNA migration, thermoluminescence and analysis of the carbohydrates formed by radiation. Changes in the cooking time were observed for all doses. In doses up to 1 kGy, the nutritional quality of the irradiated beans were not altered. The application of the proposed detection methods of the irradiated foodstuffs allowed the detection of irradiated beans with doses as low as 0.5 kGy. (author)

  4. Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

    Energy Technology Data Exchange (ETDEWEB)

    Scott Wilde, Raymond Keegan

    2008-07-01

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

  5. Efeito da irradiação (60Co na frequência fúngica de amendoim in natura em função do tempo de prateleira Gamma-irradiation effect (60Co in fungi frequency of peanut in natura and after storage

    Directory of Open Access Journals (Sweden)

    Guilherme Prado

    2006-10-01

    Full Text Available Foi verificado o efeito da irradiação gama (60Co na capacidade de destruir a microbiota fúngica, em amendoim em grão, cultivar Tatu Vermelho, da safra 2003 (segundo semestre. Os grãos de amendoim, após a irradiação, foram mantidos à temperatura ambiente em embalagem plástica comercial, durante 180 dias. Para a determinação da porcentagem fúngica foi utilizada a técnica do plaqueamento direto utilizando o meio Ágar Dicloran Rosa de Bengala Cloranfenicol (DRBC, desinfetando ou não os grãos com solução de hipoclorito de sódio. Em grãos de amendoim irradiados e desinfetados externamente, observou-se redução da infecção fúngica a 5 kGy e destruição total de fungos a 10 kGy, após 180 dias de armazenamento à temperatura ambiente. Em grãos irradiados e não desinfetados externamente foram verificados, em função do tempo de armazenamento, aumento da população de fungos com a dose de 1 kGy, redução com a dose de 5 kGy e eliminação total com a aplicação de 10 kGy. A irradiação gama, na dose de 10 kGy ou superior, demonstrou ser um processo eficaz na redução da microbiota fúngica de amendoim em grão, cultivar Tatu Vermelho.Gamma-irradiation effect was verified on the capability of destroying the mycoflora of peanuts grain, Tatu Vermelho cultivar, 2003 crop (second semester. The peanuts grains, after irradiation, were kept at room temperature in plastic bags during 180 days. To determine the percentage of fungi, the direct plating technique was used and the grains were plated out on mycological media dicholoran rose bengal chloranphenicol (DRBC, being desinfected or not with sodium hypochlorite solution. Irradiated and desinfected peanuts was observed a reduction of fungi infection at 5 kGy and total fungi destruction at 10 kGy, after 180 days in storage at room temperature. Irradiated and non desinfected grains showed a increase of fungi population with 1 kGy dose, reduction with 5 kGy dose and total

  6. Preliminary research on the establishment of non-invasive model of radiation-induced oral mucositis in rats by 60 Coγ-rays irradiation%60 Coγ射线照射大鼠建立放射性口腔黏膜炎模型的初步研究

    Institute of Scientific and Technical Information of China (English)

    刘礼; 陶人川; 雍翔智; 蒋兰岚; 曾启新

    2016-01-01

    目的:建立大鼠放射性口腔黏膜炎模型,观察并分析黏膜组织炎症变化过程。方法:选择SD大鼠45只,随机分为9组:空白对照组;实验组8组均用60 Coγ射线以35 Gy剂量单次照射口鼻部。观察大鼠口腔黏膜状况,对炎症期间拒食的大鼠进行灌注流食喂养。分别于放射后1、3、5、7、10、14、21及28 d处死1组实验组大鼠,对照组于28 d处死,取口腔黏膜组织进行HE染色和光镜下观察。结果:放射后5~6 d,大鼠口腔黏膜出现红肿伴有小面积溃疡;7~8 d小溃疡逐渐融合成大面积溃疡,并持续到9~13 d;14 d开始,溃疡逐渐缩小并愈合;21~28 d溃疡完全愈合。 HE染色显示放射后第5 d,黏膜下层出现大量炎性细胞浸润,但上皮层连续完整;第7、10 d,上皮层崩解、脱落;第14 d溃疡底部可见新生肉芽组织及新生毛细血管;第21、28 d,溃疡处有新的上皮组织出现,基底层排列紧密。结论:经60 Coγ射线照射成功建立放射性口腔黏膜炎大鼠模型,炎症从5~8 d开始,第9~13 d达到高峰,14 d左右开始缓解恢复,21~28 d恢复正常。%Objective:To establish a non-invasive model of radiation-induced oral mucositis( RTOM) in rats and ob-serve the dynamic process of the occurrence,development and healing of mucosal inflammation. Methods:After randomly di-viding 45 SD rats into 9 groups,one group was maintained as a blank control group,while each rat of the other 8 groups re-ceived an irradiation of single 35 Gy dose of 60 Coγ-rays. The condition of the oral mucosal was observed everyday. Each group of experimental rats was sacrificed at the 1 st , 3 rd , 5 th , 7 th , 10 th , 14 th , 21 st and 28 th day after the irradiation respectively. However,the control group of rats were sacrificed only on the 28th day. Oral mucosa tissues of the dead rats were harvested. The samples underwent HE staining for histological

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1989-05-01

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

  8. Development of irradiator {sup 60}Co sources

    Energy Technology Data Exchange (ETDEWEB)

    Mosca, Rodrigo C.; Moura, Eduardo S.; Zeituni, Carlos A.; Mathor, Monica B., E-mail: rcmosca@usp.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated {sup 60}Co. The development of was based on 11 sources of {sup 60}Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of {sup 60}Co is just one cause radionecrosis point (target point) of approximately 5 mm{sup 2} with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm{sup 2} in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  9. Effect of ethanolic extract of propolis on cell viability of chinese hamster ovary cells (CHO-K1) irradiated with {sup 60}CO gamma-rays using differential staining technique

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Marcos P.M. de; Castro, Renato F. de; Okazaki, Kayo; Vieira, Daniel P., E-mail: dpvieira@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    The objective of present study was to assess the effect of Brazilian propolis (AF-08) on CHO-K1 cells irradiated with {sup 60}Co, through the differential staining technique, using acridine orange and ethidium bromide. The cells were pre-incubated with different concentrations of propolis (50, 100 and 200 μg/mL) for 24h and irradiated with 5 Gy, analyzed at 24 and 48h after exposure. This technique is based on the cell capacity to incorporate fluorescent DNA dyes, where the viable (green), apoptotic (orange/yellow) and necrotic (red) cells can be identified through fluorescence microscopy. Digital high-resolution images were acquired from at least 5 visualization fields, and cells were analyzed using ImageJ and Flowing software. This approach permitted to analyze a large number of cells/sample with the time reduction, much easier and faster, proportioning more statistical power of the technique. The treatment with propolis only was not cytotoxic at 24 and 48h, except for the higher concentration of 200 μg/mL associated or not with radiation, increasing apoptotic and mainly necrotic cells (p<0.001). The data showed a promising use of propolis as well as technique used, pointing out that 200 μg/mL of propolis was cytotoxic, but at lower one (50 μg/mL) presented a radioprotective effect in irradiated CHO-K1 cells. (author)

  10. Effects of gamma radiation in tomato seeds

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  11. Modification of silicone sealant to improve gamma radiation resistance, by addition of protective agents

    Science.gov (United States)

    González-Pérez, Giovanni; Burillo, Guillermina

    2013-09-01

    Poly (dimethylsiloxane) (PDMS) sealant (SS) was modified with the addition of different protective compounds to conserve its physical-chemical properties during gamma irradiation. 2-Vinyl naphthalene (2-VN), bisphenol-A (BPA) and poly (vinyl carbazole) (PVK) were used to evaluate radiation protection through the crosslinking effect of radiation. The samples were irradiated with doses from 100 kGy to 500 kGy at room temperature in air, with a 60Co gamma source, and the changes in molecular weight, thermal behavior, elastic properties and infrared spectra (FTIR-ATR) absorbance analysis were determined. The molecular weight of unmodified silicone sealant increases with the absorbed dose because of crosslinking as predominant effect. However, the crosslinking effect was inhibited with the addition of protective agent due to the aromatic compounds present. Modified silicone sealant films present better radiation resistance than unmodified system.

  12. Study of the effect of gamma irradiation ({sup 60} Co) on the quality of sugar cane spirit and on the cask of maturation; Estudo do efeito da irradiacao gamma ({sup 60} Co) na qualidade da cachaca e no tonel de envelhecimento

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Mariana Branco de; Horii, Jorge; Alcarde, Andre Ricardo [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept.de Agroindustria, Alimentos e Nutricao]. E-mails: jhorii@esalq.usp.br; aralcard@esalq.usp.br

    2006-10-15

    The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy). Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such as volatile acidity, esters, superior alcohols and furfural throughout the 390 days. There is evidence, however, that some component parameters like aldehydes, tannin, color and copper concentration are in some way influenced resulting in partial acceleration of the ageing or maturing process. At the end of the ageing period, a sensorial analysis was made using 30 non-trained people who tasted the drink. The ageing process acceleration was confirmed by the sensorial evaluation, where the irradiated sugar cane spirit and/or barrel had higher approval regarding all parameters analyzed (scent, flavor and appearance). (author)

  13. Development of an analytical model for the determination of {sup 60}Co in aqueous samples by atomic absorption and gamma spectrometry techniques; Elaboracion de un modelo analitico para la determinacion de {sup 60}Co en muestras acuosas mediante tecnicas de absorcion atomica y espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Solis A, N. A.

    2015-07-01

    The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

  14. Mediate gamma radiation effects on some packaged food items

    Science.gov (United States)

    Inamura, Patricia Y.; Uehara, Vanessa B.; Teixeira, Christian A. H. M.; del Mastro, Nelida L.

    2012-08-01

    For most of prepackaged foods a 10 kGy radiation dose is considered the maximum dose needed; however, the commercially available and practically accepted packaging materials must be suitable for such application. This work describes the application of ionizing radiation on several packaged food items, using 5 dehydrated food items, 5 ready-to-eat meals and 5 ready-to-eat food items irradiated in a 60Co gamma source with a 3 kGy dose. The quality evaluation of the irradiated samples was performed 2 and 8 months after irradiation. Microbiological analysis (bacteria, fungus and yeast load) was performed. The sensory characteristics were established for appearance, aroma, texture and flavor attributes were also established. From these data, the acceptability of all irradiated items was obtained. All ready-to-eat food items assayed like manioc flour, some pâtés and blocks of raw brown sugar and most of ready-to-eat meals like sausages and chicken with legumes were considered acceptable for microbial and sensory characteristics. On the other hand, the dehydrated food items chosen for this study, such as dehydrated bacon potatoes or pea soups were not accepted by the sensory analysis. A careful dose choice and special irradiation conditions must be used in order to achieve sensory acceptability needed for the commercialization of specific irradiated food items.

  15. Effects of gamma radiation on bee venom: preliminary studies

    Energy Technology Data Exchange (ETDEWEB)

    Costa, H.; Boni-Mitake, M.; Souza, C.F.; Rogero, J.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia

    1999-11-01

    Africanized honeybees are very common insects in Brazil and frequently cause accidents followed by important immunological reactions and even deaths. Their venoms are composed of a complex mixture of substances of general biological actions. several works utilizing ionizing radiation showed that it is able to modify protein structures, and successfully detoxify snake venoms toxins, although maintaining its immunological properties. The main objective of this paper was to study the effects of gamma radiation on bee venom, regarding some biochemical and toxicological aspects. Africanized Apis melllifera whole venom (2 mg/ml) in 0.15 M Na Cl solution was irradiated with 2 kGy in a {sup 60} Co source. Preliminary studies has been carried out in order to identify some biochemical changes after irradiation. Concerning this, irradiated and native venom were submitted to a molecular exclusion chromatography (Sephadex G-100), UV absorption spectrum and protein concentration analysis. It could be seen that irradiated bee venom spectrum presented differences when compared to native bee venom, suggesting that some structural alterations has occurred. Protein concentration and chromatography profiles were not changes after irradiation. In order to evaluate the toxicity a lethality assay (L D{sub 50}) has been performed with both venoms, and irradiated venom showed to be less toxic than native one. (author) 23 refs., 3 figs., 1 tab.

  16. Estudo do efeito da irradiação gamma (60CO na qualidade da cachaça e no tonel de envelhecimento Study of the effect of gamma irradiation (60co on the quality of sugar cane spirit and on the cask of maturation

    Directory of Open Access Journals (Sweden)

    Mariana Branco de Miranda

    2006-12-01

    Full Text Available O processo de envelhecimento ou maturação das bebidas proporciona uma melhora nas características sensoriais da cachaça, tornando-a de qualidade superior e de maior valor econômico. O método tradicional de maturação de bebidas é sua interação com madeiras, sendo que a irradiação pode acelerar este processo de envelhecimento. A cachaça e os tonéis de carvalho de 20 L de capacidade foram submetidos à irradiação gama (150 Gy. Análises físico-químicas e cromatográficas foram realizadas periodicamente ao longo de 390 dias do período de envelhecimento da bebida. A irradiação da cachaça e do tonel não alterou a maioria dos componentes voláteis do coeficiente de congêneres como acidez volátil, ésteres, álcoois superiores e furfural durante os 390 dias. Há evidências, entretanto, de que os parâmetros de alguns componentes como aldeídos, taninos, cor e teor de cobre são de alguma forma influenciados, resultando em aceleração parcial do processo de maturação ou envelhecimento. Ao final do período de envelhecimento, foi feita uma análise sensorial com 30 provadores não treinados. A aceleração do processo de envelhecimento foi confirmada pela avaliação sensorial, e a cachaça e/ou tonel irradiados receberam maior indicação de aprovação em todos os parâmetros analisados (aroma, sabor e aparência.The ageing or maturing process of drink improves the sensorial characteristics of the product making it a qualified drink with higher economical value. The traditional maturing method of drinks involves their interaction with wood and irradiation can accelerate this ageing process. Sugar cane spirit and oak barrels with a 20 L capacity were treated using gamma irradiation (150 Gy. Physical-chemical and chromatographic analyses were constantly performed for 390 days during the drink ageing period. The sugar cane spirit and barrel irradiation did not change most volatile components of the same type coefficient such

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

    Science.gov (United States)

    Srivastava, Saurabh; Aggarwal, Bharti; Singh, Arvind; Kumar, A. Vinod; Topkar, Anita

    2016-05-01

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

  18. Influence of gamma radiation on grapes color during storage period

    Energy Technology Data Exchange (ETDEWEB)

    Santillo, Amanda G.; Rogovschi, Vladimir D.; Araujo, Michel M.; Silva, Priscila V.; Silveira, Ana P.M.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: agsantillo@gmail.com, e-mail: villavic@ipen.br

    2009-07-01

    In general food contains some components that are very sensible to irradiation processing and if radiation dose is higher, can cause some harmful transformation in taste, odor and flavor in these foods, present in very lower concentrations, regulating their appearance and nutritious value. The ionizing radiation application in order to preserve and disinfect food is used for the reduction of pathogenic microorganisms, extending the shelf life and reducing the loss of crops during storage of the product. The genus Vitis is the main representative of the Vitaceae family due to the nutritional importance of the grape (Vitis vinifera L.), widely consumed 'in natura'. The V. vinifera produces a fruit of great nutritional value to humans. The quality and acceptance of products are associated with sensory parameters such as color, which is the primary criterion for acceptance by the consumer. Anthocyanins are generally unstable when exposed to sources of ionizing radiation. The flavonoids are largely distributed in nature and are responsible for most of blue, purple and all shades of red colors. In vines, these compounds are responsible for the color of the grape skin and are also found in the flesh of some varieties of grapes. The objective of this study is to analyze the effects of gamma radiation on color of grapes at different days of storage. The irradiation will be in {sup 60}Co source at doses of 0 and 4.5 kGy. The samples will be stored at room and refrigerated temperature for 21 days. The evaluation of color will be analyzed through 'L', 'a' and 'b' parameters. (author)

  19. Gamma-Gamma Absorption in the Broad Line Region Radiation Fields of Gamma-Ray Blazars

    CERN Document Server

    Boettcher, Markus

    2016-01-01

    The expected level of gamma-gamma absorption in the Broad Line Region (BLR) radiation field of gamma-ray loud Flat Spectrum Radio Quasars (FSRQs)is evaluated as a function of the location of the gamma-ray emission region. This is done self-consistently with parameters inferred from the shape of the spectral energy distribution (SED) in a single-zone leptonic EC-BLR model scenario. We take into account all geometrical effects both in the calculation of the gamma-gamma opacity and the normalization of the BLR radiation energy density. As specific examples, we study the FSRQs 3C279 and PKS 1510-089, keeping the BLR radiation energy density at the location of the emission region fixed at the values inferred from the SED. We confirm previous findings that the optical depth due to $\\gamma\\gamma$ absorption in the BLR radiation field exceeds unity for both 3C279 and PKS 1510-089 for locations of the gamma-ray emission region inside the inner boundary of the BLR. It decreases monotonically, with distance from the cen...

  20. Effects of gamma radiation in annatto seeds

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  1. Gamma Radiation Effects on Peanut Skin Antioxidants

    Directory of Open Access Journals (Sweden)

    Adriano Costa de Camargo

    2012-03-01

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

  2. Gamma radiation effects on peanut skin antioxidants.

    Science.gov (United States)

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

    2012-01-01

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

  3. Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Cantinha, Rebeca S.; Nakano, Eliana [Instituto Butantan, Sao Paulo, SP (Brazil). Lab. de Parasitologia], e-mail: rebecanuclear@gmail.com, e-mail: eliananakano@butantan.gov.br; Borrely, Sueli I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes], e-mail: sborrely@ipen.br; Amaral, Ademir; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR)], e-mail: amaral@ufpe.br; Silva, Luanna R.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia], e-mail: amdemelo@hotmail.com, e-mail: luannaribeiro_lua@hotmail.com

    2009-07-01

    Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of {sup 60}Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD{sub 50} obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

  4. On-line {sup 60}Co monitor for reactor recirculation system piping in primary containment vessel during reactor operation

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Katsunori, E-mail: katsunori.ueno.pa@hitachi.com [Hitachi Research Laboratory, Hitachi, Ltd., Hitachi 319-1224, Ibaraki (Japan); Tadokoro, Takahiro [Hitachi Research Laboratory, Hitachi, Ltd., Hitachi 319-1224, Ibaraki (Japan); Tsuyuki, Mizuho; Matsubara, Hirofumi; Ota, Nobuyuki; Nagase, Makoto [Hitachi-GE Nuclear Energy, Ltd., Hitachi 317-0073, Ibaraki (Japan)

    2014-10-15

    Highlights: • We developed an on-line {sup 60}Co monitor for reactor recirculation system piping during reactor operation. • Energy resolution at 1.4 × 10{sup 6} cps is 33 keV at 1332 keV using a pulse integral method. • A coincidence method is applied to reduce an effect of background gamma rays. • The coincidence counting of {sup 60}Co cascade gamma rays could be detected for a background dose rate of 4.8 mSv/h. - Abstract: Water chemistry control during reactor operation and installation of temporary radiation shielding prior to scheduled outages are carried out in order to reduce workers’ dose exposure caused by {sup 60}Co which is the main radiation source during scheduled outages of boiling water reactor (BWR) power plants. It is necessary to monitor the deposited {sup 60}Co on inner surfaces of reactor recirculation system (RRS) piping to evaluate effects of water chemistry control. We have developed an on-line {sup 60}Co monitor (OLCM) for this purpose. The OLCM applies a pulse integral method as a new method to measure gamma-ray counts of more than 1.0 × 10{sup 6} counts per second (cps) and a coincidence counting method to reduce an effect of background gamma rays caused by {sup 16}N in the measurement of {sup 60}Co cascade gamma rays. Energy resolution at 1.4 × 10{sup 6} cps is 33 keV using the pulse integral method and single LaBr{sub 3}:Ce scintillation detector. The energy resolutions of this detector using the fast response photo multiplier tube (PMT) are 50 keV at 1.5 × 10{sup 6} cps and 59 keV at 2.1 × 10{sup 6} cps. Furthermore, we measured the energy spectra using the pulse integral method, the coincidence counting method and two LaBr{sub 3}:Ce scintillation detectors and examined the transition of coincidence counting for {sup 60}Co detection under high dose rate during reactor operation at the Kyoto University Research Reactor (KUR). The coincidence counting of {sup 60}Co cascade gamma rays could be detected, and the result was

  5. 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)

  6. Effects of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  7. Effect of gamma radiation on PA 6,12 in argon atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Menchaca C, C. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, Cuernavaca 62209, Morelos (Mexico); Martinez B, G. [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados, Facultad de Quimica, Universidad Autonoma del Estado de Mexico, Km. 12 Carretera Toluca-Atlacomulco, San Cayetano 50200, Estado de Mexico (Mexico); Alvarez C, A. [Departamento de Ingenieria Quimica y Bioquimica, Intituto Tecnologico de Zacatepec, Av. Tecnologico 27, Zacatepec 62780, Morelos (Mexico); Lara, V. H. [Departamento de Quimica, Universidad Autonoma Metropolitana, Unidad Iztapalapa, Apdo. Postal 55-534, Mexico 09340, D. F. (Mexico); Lopez V, H.; Carrasco A, H. [Departamento de Fisica de Radiaciones, ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico)], e-mail: gonzomartinez02@yahoo.com.mx

    2009-07-01

    Radiation effects on crystalline fibers of PA 6,12 (nylon 6,12) gamma irradiated with {sup 6}0Co under argon atmosphere at 15 kGy, 50 kGy, 100 kGy, 200 kGy and 300 kGy were studied, covering chemical structure, morphology and surface pattern. Characterization techniques show the effect of the different doses of gamma radiation. As the doses increase, amazing behavior had been found. From thermal analysis (TGA and DTA) it is evident the decrease in melting point and in the decomposition temperatures, but the heat of fusion has a different answer to the gamma irradiation, increasing or at least remaining in the same value. These results can be related to those obtained by X-rays, which shows a an unseen behavior, with no significant differences between the spectra with the crystal size being the same for each radiation doses. Finally, , the surface pattern given by AFM and SEM confirms the physical damaged caused by the radiation doses applied. All of these changes can be attributed to the chain scission mechanism provoked by the interaction radiation-matter, which is the main cause of the oligomer formation and crystal reorganization. (Author)

  8. Effect of 60 Co-γradiation on some growth and nutrition indexes of Medicago sativa L.%60Co-γ辐射对紫花苜蓿部分生长及营养指标的影响

    Institute of Scientific and Technical Information of China (English)

    刘胜洪; 周玲艳; 杨妙贤; 刘文

    2015-01-01

    将紫花苜蓿( Medicago sativa L.)10个品种种子经2000 Gy剂量的60 Co-γ射线辐射处理,并就辐射处理对其部分生长和营养指标的影响进行了比较分析.结果显示,经60 Co-γ射线处理后,10种紫花苜蓿种子的萌发率、株高和营养指标等都发生了不同程度的变化.辐射处理对先行者、 WL525、 WL903和Adrenalian等紫花苜蓿品种种子萌发率的影响较小,而明显降低了其余大富豪、阿尔冈金、费纳尔、苜蓿王、标杆和WL2321等6个品种的种子萌发率;辐射处理对部分紫花苜蓿品种的生长速度有促进作用,而对部分品种的生长速度有抑制作用;辐射处理对大部分品种的粗蛋白、总糖、总氨基酸浓度有显著增高或降低作用,但对全部品种的干/鲜质量比无显著影响.%Ten Medicago sativa L.varieties were radiated by 2 000 Gy 60 Co-γray, and some growth and nutrition indexes were analyzed.The results showed that the germination rate, plant height and nutritional quality changed at different degrees after the radiation.The germination rates of six varieties, Million-aire, Algonguin, Fnal, Alfaking, Beraga and WL2321, were decreased by the radiation with no effect on those of four varieties, Xianxingzhe, WL525, WL903 and Adrenalian.Growth speed of partial varieties increased and that of partial varieties decreased after the radiation.Crude protein, total sugar and total a-mino acid contents of most varieties increased or decreased significantly but dry/fresh weight ratio of all changed with no significant difference after the radiation.

  9. Gamma Radiation Effects on Peanut Skin Antioxidants

    OpenAIRE

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

    2012-01-01

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

  10. Interaction of gamma radiation on the functionality of the molluscicidal extract of Anacardium occidentale Linn

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo Henrique Farias dos [Grupo de Estudos em Radioprotecao e Radioecologia (GERAR) . Departamento de Energia Nuclear. Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Silva, Edvane Borges da [Centro Academico de Vitoria. Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil); Amorim, Elba Lucia C.; Peixoto Sobrinho, Tadeu J.S., E-mail: elba@ufpe.br [Departamento de Ciencias Farmaceuticas. Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Melo, Ana Maria Mendonca de Albuquerque; Lima, Claudia Sampaio de Andrade [Departamento de Biofisica e Radiobiologia. Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2011-07-01

    Biological control of Biomphalaria glabrata that is the intermediate host of Schistosoma mansoni, through molluscicides has been an alternative against schistosomiasis. Many studies have been developed to obtain molluscicide products, from plants. Anacardium occidentale L. (cashew), a plant rich in phenolic compounds shows molluscicidal activity in earlier assays. However there is an interest of enhancing the action of bioactive substances in order to use it in small concentrations, reducing costs in their utilization. This study were conducted using ethanolic extracts of bark and leaves of A. occidentale, before and after exposure to gamma radiation from {sup 60}Co, checking their secondary metabolites, their biological activity against Biomphalaria glabrata and environmental toxicity. The extracts of A. occidentale were obtained by cold maceration in 70% ethanol, filtered, dried and divided into two experimental groups: control (0 kGy) and irradiated at a dose of 10 kGy. The quantification of metabolites was performed in six replicates for the determination of total phenols by Folin-Ciocalteau method and tannins, the precipitation of casein. Tests for biological control of embryos and adults of B. glabrata snails and assessment of environmental toxicity (using Artemia salina larvae) were performed in triplicate, following a period of 24 hours of exposure to extracts at a concentration of 100 mg/L and its respective controls. Data were expressed as percentages of means and standard deviations. The results showed that the gamma radiation from {sup 60}Co resulted in leaf extracts, increased levels of total phenols and tannins, which enhanced the lethality for embryos and adults of B. glabrata. There was a reduction of the toxicity of leaf extracts after irradiation in the Artemia salina. Since in extracts of bark, gamma radiation did not alter the levels of total phenols and tannins, however, it was noted potentiation of lethality of adult snails of B. glabrata. The

  11. Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Roman L, J.; Cruz Z, E. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Pina L, Y. I. [UNAM, Facultad de Ciencias, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Marcazzo, J., E-mail: jesus.roman@nucleares.unam.mx [Instituto de Fisica Arroyo Seco - UNICEN, Pinto 399, 7000 Tandil (Argentina)

    2016-10-15

    Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of {sup 60}Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

  12. Unruh gamma radiation at RHIC?

    CERN Document Server

    Biro, T S; Schram, Z

    2011-01-01

    Varying the proposition that acceleration itself would simulate a thermal environment, we investigate the semiclassical photon radiation as a possible telemetric thermometer of accelerated charges. Based on the classical Jackson formula we obtain the equivalent photon intensity spectrum stemming from a constantly accelerated charge and demonstrate its resemblances to a thermal distribution for high transverse momenta. The inverse transverse slope differs from the famous Unruh temperature: it is larger by a factor of pi. We compare the resulting direct photon spectrum with experimental data for AuAu collisions at RHIC and speculate about further, analytically solvable acceleration histories.

  13. Evaluation of fungal burden and aflatoxin presence in packed medicinal plants treated by gamma radiation.

    Science.gov (United States)

    Aquino, Simone; Gonçalez, Edlayne; Rossi, Maria Helena; Nogueira, Juliana Hellmeister de Campos; Reis, Tatiana Alves Dos; Corrêa, Benedito

    2010-05-01

    This study was developed to evaluate the fungal burden, toxigenic molds, and mycotoxin contamination and to verify the effects of gamma radiation in four kinds of medicinal plants stored before and after 30 days of irradiation treatment. Eighty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia, and Cassia angustifolia) purchased from drugstores, wholesale, and open-air markets in São Paulo city, Brazil, were analyzed. The samples were treated using a (60)Co gamma ray source (Gammacell) with doses of 5 and 10 kGy. Nonirradiated samples were used as controls of fungal isolates. For enumeration of fungi on medicinal plants, serial dilutions of the samples were plated in duplicate onto dichloran 18% glycerol agar. The control samples revealed a high burden of molds, including toxigenic fungi. The process of gamma radiation was effective in reducing the number of CFU per gram in all irradiated samples of medicinal plants after 30 days of storage, using a dose of 10 kGy and maintaining samples in a protective package. No aflatoxins were detected. Gamma radiation treatment can be used as an effective method for preventing fungal deterioration of medicinal plants subject to long-term storage.

  14. Analysis of adhesion of radiation curable compositions to polyester substrate. [. gamma. rays or electrons

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, W.K.; Barbery, J.; Gupta, B.S.

    1977-07-01

    Properties of bonds produced by radiation curing of adhesives on polyester film were studied. Investigation of bonding in polyester non-wovens had revealed that adhesion of binders to fibers was weak, which resulted in interfacial failures, judged from electron micrographs. If a binder droplet surrounds a cluster of fibers, tearing of binder took place but fibers still peeled out of droplets with interfacial separation. In order to understand the failure mechanism, a study was carried out on Mylar film bonded with adhesives cured by electron beam or gamma-rays from /sup 60/Co. Mixtures of isodecyl acrylate and methyl methacrylate were copolymerized between Mylar films to produce adhesives with a wide range of glass transition temperatures. Hexanediol diacrylate was added in various amounts to produce different degrees of cross-linking. Small amounts of fumed silica (Cab-O-Sil) were added to thicken the monomers used in the /sup 60/Co experiments. By varying rheological properties in this fashion, a maximum peel force of 3.5 lb/in. was obtained. This value is in line with peel strengths from polyester using commercial, prepolymerized adhesives with solubility parameters similar to those used here delta = 8.3 to 9.3). These results show that the primary reason for the poor adhesion of radiation curable adhesives to polyester is their high degree of cross-linking and that radiation curable adhesives are not basically different from other types, except in cases where their unique properties could be utilized with advantage.

  15. Manufacture of Single ~(60)Co Source Irradiation Facility

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Reference radiation filed produced by isotope source is necessary for calibration of radiation dose meter. According to the GB/T 12162.1-2002 "X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  17. Composition and apparatus for detecting gamma radiation

    Science.gov (United States)

    Hofstetter, K.J.

    1994-08-09

    A gamma radiation detector and a radioluminescent composition for use therein. The detector includes a radioluminescent composition that emits light in a characteristic wavelength region when exposed to gamma radiation, and means for detecting said radiation. The composition contains a scintillant such as anglesite (PbSO[sub 4]) or cerussite (PbCO[sub 3]) incorporated into an inert, porous glass matrix via a sol-gel process. Particles of radiation-sensitive scintillant are added to, a sol solution. The mixture is polymerized to form a gel, then dried under conditions that preserve the structural integrity and radiation sensitivity of the scintillant. The final product is a composition containing the uniformly-dispersed scintillant in an inert, optically transparent and highly porous matrix. The composition is chemically inert and substantially impervious to environmental conditions including changes in temperature, air pressure, and so forth. It can be fabricated in cylinders, blocks with holes therethrough for flow of fluid, sheets, surface coatings, pellets or other convenient shapes. 3 figs.

  18. 60Co-γ射线辐照处理对天竺葵、观赏椒种子发芽率及幼苗的影响%The Effect of 60Co-γRay Radiation on the Germination Rate of Seed and Growth of Seeding of Pelargonium and Capsioum annuum L.

    Institute of Scientific and Technical Information of China (English)

    强继业; 夏更寿; 王海棠; 尹瑞新; 王元军

    2005-01-01

    60Co-γ射线辐照处理天竺葵、观赏椒种子,观察其发芽率和幼苗生长情况.结果表明:γ射线辐射对这2种观赏植物的发芽率和幼苗生长发育具有不同的影响.对天竺葵的发芽率有促进作用,但抑制幼苗生长;对观赏椒发芽率作用不显著,对幼苗前期生长有抑制作用.

  19. MCz diode response as a high-dose gamma radiation dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, F. [Instituto de Pesquisas Energeticas e Nucleares-IPEN-CNEN/SP, Caixa Postal 11049 - 05422 970 Sao Paulo/SP (Brazil); Goncalves, J.A.C. [Instituto de Pesquisas Energeticas e Nucleares-IPEN-CNEN/SP, Caixa Postal 11049 - 05422 970 Sao Paulo/SP (Brazil); Depto. de Fisica, Pontificia Universidade Catolica de Sao Paulo-PUC/SP, Rua Marques de Paranagua no 111-01303 050 Sao Paulo/SP (Brazil); Khoury, H.J. [Nuclear Energy Department, Universidade Federal de Pernambuco-UFPE, Av. Prof. Luiz Freire no 1000-50740 540 Recife/PE (Brazil); Napolitano, C.M. [Instituto de Pesquisas Energeticas e Nucleares-IPEN-CNEN/SP, Caixa Postal 11049 - 05422 970 Sao Paulo/SP (Brazil); Haerkoenen, J. [Helsinki Institute of Physics-HIP, University of Helsinki, 00014 Helsinki (Finland); Bueno, C.C. [Instituto de Pesquisas Energeticas e Nucleares-IPEN-CNEN/SP, Caixa Postal 11049 - 05422 970 Sao Paulo/SP (Brazil); Depto. de Fisica, Pontificia Universidade Catolica de Sao Paulo-PUC/SP, Rua Marques de Paranagua no 111-01303 050 Sao Paulo/SP (Brazil)], E-mail: ccbueno@ipen.br

    2008-02-15

    This work presents the preliminary results obtained with a high-resistivity magnetic Czochralski (MCz) silicon diode processed at the Helsinki Institute of Physics as a high-dose gamma dosimeter in radiation processing. The irradiation was performed using a {sup 60}Co source (Gammacell 220, MDS Nordion) within total doses from 100 Gy up to 3 kGy at a dose rate of 3 kGy/h. In this interval, the dosimetric response of the diode is linear with a correlation coefficient (r{sup 2}) higher than 0.993. However, without any irradiation procedure, the device showed a small sensitivity dependence on the accumulated dose. For total dose of 3 kGy, the observed decrease was about 2%. To clarify the origin of this possible radiation damage effect, some studies are under way.

  20. 60Coγ射线对生理盐水和玉米中黄曲霉孢子的辐照效应研究%Irradiation effect of 60Co gamma ray on Aspergillus flavus spores in normal saline and maize

    Institute of Scientific and Technical Information of China (English)

    钟凯; 高翔; 计融

    2011-01-01

    目的 研究γ射线对黄曲霉孢子辐照效应.方法 两种介质中不同浓度黄曲霉孢子经不同剂量辐照后进行菌落计数,计算D值和理论最小杀灭剂量,并实验验证实际最小杀灭剂量.结果 生理盐水中高浓度孢子D值0.39kGy,最低杀灭剂量2.5kGy,低浓度孢子D值0.47kGy,最低杀灭剂量1.5kGy;玉米中高浓度孢子D值为0.67kGy,最低杀灭剂量3.0kGy,低浓度孢子D值为0.72kGy,最低杀灭剂量2.0kGy.结论 3.0kGy可用于粮食中黄曲霉的杀灭.%Objective To observe irradiation effect of gamma ray on Aspergillus flavus spores.Methods Aspergillus flavus spores of different concentration were prepared on two media and were exposed to gamma ray.D10 values and theoretical minimal sterilizing doses were calculated by colony counting results.Actual minimal sterilizing doses were verified according to theoretical dose.Results D10 value and minimal sterilizing dose of high concentration spore in normal saline were 0.39kGy and 2.5kGy.Those of low concentration spore in normal saline were 0.47kGy and 1.5kGy.D10 value and minimal sterilizing dose of high concentration spore in maize were 0.67kGy and 3.0kGy.Those of low concentration spore in maize were 0.72kGy and 2.0kGy.Conclusion 3.0kGy may be suitable for grain processing to sterilize Aspergillus flavus.

  1. 60Co-γ射线照射大鼠损伤作用中硫辛酸对谷胱甘肽的调节与再生%Modulation of lipoic acid and regeneration of glutathion in rats injured by radiation with 60Co-γ ray

    Institute of Scientific and Technical Information of China (English)

    赵康涛; 海春旭; 梁欣; 张晓迪; 秦绪军; 刘瑞; 陈宏莉; 谷小刚

    2003-01-01

    目的: 以60Co-γ射线照射大鼠损伤为模型,研究硫辛酸对大鼠谷胱甘肽(glutathione, GSH)的调节和再生作用. 方法: 二级SD大鼠40只,雌雄各半,随机分为4组,为阴性对照组、阳性对照组、低剂量组(硫辛酸0.2 g*L-1),高剂量组(硫辛酸0.4 g*L-1),60Co-γ射线照射剂量为4 Gy. 对阳性组、低剂量组、高剂量组动物进行照射后,低剂量组和高剂量组动物分别给予硫辛酸油溶液灌胃(5 mL*kg-1). 阴性组和阳性组分别给予处理精炼油灌胃作为对照;连续灌胃给药2 d后断头处死,收集全血静置、析出血清,用荧光分光法及分光光度法测定GSH,MDA和谷胱甘肽过氧化物酶(glutathione peroxidase, GPx)等指标. 结果: 辐射损伤引起还原型谷胱甘肽含量的降低而氧化型谷胱甘肽(oxidized glutathione, GSSG)的含量增高(P<0.05);补充了硫辛酸能增加还原型谷胱甘肽的含量,且随着给药剂量的增加而升高(P<0.05),GSSG则呈相反趋势;硫辛酸能降低辐射损伤造成的GPx的活性的应激性增高(P<0.05). 结论: 硫辛酸对辐射损伤造成的氧化损伤具有保护作用,并能调节抗氧化剂GSH的含量,提高机体的抗氧化能力.

  2. Afterglow Radiation from Gamma Ray Bursts

    Energy Technology Data Exchange (ETDEWEB)

    Desmond, Hugh; /Leuven U. /SLAC

    2006-08-28

    Gamma-ray bursts (GRB) are huge fluxes of gamma rays that appear randomly in the sky about once a day. It is now commonly accepted that GRBs are caused by a stellar object shooting off a powerful plasma jet along its rotation axis. After the initial outburst of gamma rays, a lower intensity radiation remains, called the afterglow. Using the data from a hydrodynamical numerical simulation that models the dynamics of the jet, we calculated the expected light curve of the afterglow radiation that would be observed on earth. We calculated the light curve and spectrum and compared them to the light curves and spectra predicted by two analytical models of the expansion of the jet (which are based on the Blandford and McKee solution of a relativistic isotropic expansion; see Sari's model [1] and Granot's model [2]). We found that the light curve did not decay as fast as predicted by Sari; the predictions by Granot were largely corroborated. Some results, however, did not match Granot's predictions, and more research is needed to explain these discrepancies.

  3. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with {sup 60}Co gamma rays, in Leishmania spp; Acao do veneno de Bothrops moojeni e sua fracao L-aminoacido oxidase, submetida ao tratamento com raios gama de {sup 60}Co, em Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Andre Gustavo Tempone

    1999-07-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 {mu}g/ml (EC{sub 50}), L.(V.) panamensis (0.78 |{mu}g/ml) and L.(L.) chagasi (0.63 ({mu}g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC{sub 50} of 11|{mu}g/ml. Irradiation of LAO with 6{sup 0C}o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC{sub 50} of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  4. Propagation speed of gamma radiation in brass

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  5. Damage correlations in semiconductor devices exposed to gamma and high energy swift heavy ions

    Science.gov (United States)

    Pushpa, N.; Prakash, A. P. Gnana

    2015-05-01

    NPN rf power transistors and N-channel depletion MOSFETs are irradiated by different high energy swift heavy ions and 60Co gamma radiation in the dose range of 100 krad to 100 Mrad. The damage created by different heavy ions and 60Co gamma radiation in NPN rf power transistors and N-channel depletion MOSFETs have been correlated and studied in the same dose range. The recoveries in the electrical characteristics of different swift heavy ions and 60Co gamma irradiated devices have been studied after annihilation.

  6. Disinfection of domestic effluents by gamma radiation: effects on the inactivation of Ascaris lumbricoides eggs.

    Science.gov (United States)

    de Souza, Gloria S M B; Rodrigues, Ludmila A; de Oliveira, Warllem J; Chernicharo, Carlos A L; Guimarães, Marcos P; Massara, Cristiano L; Grossi, Pablo A

    2011-11-01

    This work investigated the inactivation of Ascaris lumbricoides eggs in domestic effluents by gamma radiation from a (60)Co source. Domestic wastewater was treated in a compact demo-scale system consisting of a UASB reactor and a trickling filter; treatment was carried out at the Center for Research and Training on Sanitation (CePTS), Federal University of Minas Gerais, in Belo Horizonte-MG, Brazil. One-liter of treated wastewater samples was artificially contaminated with an average of 1000 non-embryonated Ascaris lumbricoides eggs from human feces; samples were then irradiated in a multiple-purpose irradiator at different doses (0.5-5 kGy). Eggs were recovered from the wastewater and the viability of these irradiated eggs was evaluated; the description of the egg developmental phases with each dose of gamma radiation was recorded. Radiation doses of 3.5 kGy effectively disinfected effluents with lower concentrations of A. lumbricoides eggs; higher radiation doses of 5 kGy were necessary to disinfect effluents with higher eggs concentrations.

  7. Inhaled /sup 239/PuO/sub 2/ and/or total-body gamma radiation: Early mortality and morbidity in rats and dogs

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-08-01

    Rats and beagle dogs were given doses of /sup 60/Co gamma radiation and/or body burdens of /sup 239/PuO/sub 2/ within lethal ranges in an experiment to determine and compare morbidity and mortality responses of both species within 1 year after exposure. Radiation-induced morbidity was assessed by measuring changes in body weights, hematologic parameters, and pulmonary-function parameters. Gamma radiation caused transient morbidity, reflected by immediately depressed blood cell concentrations and by long-term loss of body weight and diminished pulmonary function in animals of both species that survived the acute gamma radiation syndrome. Inhaled plutonium caused a loss of body weight and diminished pulmonary function in both species, but its only effect on blood cell concentrations was lymphocytopenia in dogs. Combined gamma irradiation and plutonium lung burdens were synergistic, in that animals receiving both radiation insults had higher morbidity and mortality rates than would be predicted based on the effect of either kind of radiation alone. Plutonium lung burdens enhanced the effect of gamma radiation in rats within the first 30 days of exposure, and gamma radiation enhanced the long-term effect of plutonium lung burdens in both species. Rats were less sensitive to both kinds of radiation, whether administered alone or in combination. 71 refs., 105 figs., 48 tabs.

  8. Study of radiation detectors response in standard X, gamma and beta radiation standard beams; Estudo da resposta de monitores de radioprotecao em feixes padronizados de radiacao X, gama e beta

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda Beatrice Conceicao

    2010-07-01

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

  9. Near ground gamma radiation associated with lightning

    Science.gov (United States)

    Sakuma, K.; Greenfield, M. B.; Ikeda, Y.; Kubo, K.

    2004-03-01

    Increases in the atmospheric gamma radiation of 22 to 82above normal background have been observed after the onset of lightning fifteen times since March 2001[1]. Gamma rays have been observed with up to four 12.9 cm3 NaI detectors and recently with a high resolution Ge detector positioned 6-21 m and 15 m above ground, respectively. The tail of the observed background subtracted gamma ray rates GRR were fitted with exponential decay curves yielding typical correlation coefficients of 0.95 to 0.99 and half-lives of 52.7 +/-4.81 min and 52.8+/-10.95 min, without and with precipitation, respectively. The GRR above 300 KeV from radon progeny due to precipitation were subtracted [2]. The 3x3 Ge detector with 2 KeV resolution positioned about 2 m from one of the NaI detectors observed increases in GRR minutes after the onset of lightning with a delayed 50 min exponential decay which was concurrently observed in the NaI detector. [1] M. B. Greenfield et al., Journal of Applied Physics 93 no. 3 (2003) pp 1839-1844. [2] M. B. Greenfield et al., Journal of Applied Physics 93 no. 9 (2003) pp 5733-5741.

  10. Determination of {sup 60}Co sorption in natural clinoptilolite; Determinacion de la sorcion de {sup 60}Co en clinoptilolita natural

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez B, E.; Granados C, F. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1997-07-01

    It was studied the clinoptilolite behavior coming from a deposit in Taxco, Guerrero in hydration and stabilization conditions with sodium for determining its sorption properties. The ion exchange process was carried out through gamma spectrometry using a CoCl{sub 2} solution marked with {sup 60} Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co{sup +2}/g mineral, from 0.314 m eq Co{sup +2}/g mineral correspond at ion exchange. (Author)

  11. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Energy Technology Data Exchange (ETDEWEB)

    Lucas de Oliveira, P.C.; Madruga, R.A.; Barbosa, N.P.U. [Uberaba School of Veterinary Medicine (UNIUBE), MG (Brazil)]. E-mail: pedrolucaso@uol.com.br; Sakate, M. [UNESP, Botucatu, SP (Brazil). School of Veterinary Medicine and Animal Husbandry

    2007-07-01

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from {sup 60}Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a {sup 60}Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  12. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Directory of Open Access Journals (Sweden)

    P. C. Lucas de Oliveira

    2007-01-01

    Full Text Available Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from 60Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca venom, natural and irradiated from a 60Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5mg/kg of natural venom; and GIIV, inoculated with 0.5mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase (CK, aspartate amino-transferase (AST and alanine amino-transferase (ALT; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom.

  13. A comparison of drought resistance of three zoysiagrasses and their new strains induced by 60Coradiation%3种结缕草及其60Co-γ辐射诱变新品系抗旱性比较

    Institute of Scientific and Technical Information of China (English)

    宋华伟; 刘颖; 曹荣祥; 张巨明

    2015-01-01

    [目的]探究3种结缕草Zoysia japonica及其60Co-γ辐射诱变选育的6种新品系间抗旱性的差异.[方法]以兰引Ⅲ号(LY)、ZS-1 (ZS)和ZS-SJZ (ZSS)3种结缕草及其6种新品系为材料,在盆栽条件下进行干旱胁迫处理,在干旱胁迫处理后第3、9、15天测定叶片相对含水量、相对电导率、脯氨酸含量、可溶性总糖含量,同时观测草坪草盖度和颜色变化;干旱胁迫处理后复水,观测草坪草盖度和颜色变化.[结果和结论]随着干旱胁迫的加剧,结缕草叶片相对含水量不断下降,脯氨酸含量、可溶性总糖含量和相对电导率呈上升趋势,草坪盖度和颜色评分降低.通过隶属函数标准差系数赋予权重法对9份材料的抗旱性进行综合评价,抗旱性从强到弱依次为ZSS-5> ZS-3> LY> LY-2> ZS> ZS-4> LY-1> ZSS-6> ZSS,新品系ZSS-5、ZSS-6、ZS-3抗旱性优于其亲本,说明结缕草可以通过辐射育种选育抗旱品种.

  14. Evaluation of soluble solids content and pH of ice cream treated with gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rogovschi, V.D.; Nunes, T.C.F.; Fabbri, A.D.T.; Sagretti, J.M.; Sabato, S.F. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The ice cream is considered an aerated suspension of fat and ice crystals in a concentrated sugar solution containing hydrocolloids, proteins and casein micelles. Only in Brazil, in the year 2010, it was produced 1120 million liter of ice cream and due to high demand by the consumers, this is considered the most important product of the dairy industry. The objective of this work is to evaluate the soluble solids content (SSC) and the hydrogenionic potential (pH) of vanilla ice cream conditioned in isothermal boxes irradiated with 3.0 and 5.0 kGy in the Multipurpose Irradiator of {sup 60}Co located at IPEN - CNEN/SP. It can be concluded that the treatment of ice cream with gamma radiation did not cause changes in the analyzed parameters. . (author)

  15. Gold nanoparticles synthesized by gamma radiation and stabilized by bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Leal, Jessica; Silva, Andressa A.; Geraldes, Adriana N.; Lugao, Ademar B., E-mail: jessicaleal@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Grasselli, Mariano, E-mail: mariano.grasselli@gmail.com [Departamento de Ciencia y Tecnologia, Universidad Nacional de Quilmes, Bernal (Argentina)

    2015-07-01

    Gold nanoparticles (AuNPs) are a new option for pharmaceutical and cosmetic industries due to their interesting chemical, electrical and catalytic properties. Research for cancer treatments have been developed using this promising radiotherapy agent. The challenge of gold nanoparticles is to keep them stable, due to metallic behavior. It is know that surface plasma resonance promotes agglomeration of metallic nanoparticles, but they are not stable. Stabilizers have been used to reduce agglomeration. The aim of this work is reduction of HAuCl{sub 4} salt to AuNPs performed by gamma radiation {sup 60}Co source and the stabilization of gold nanoparticles using bovine serum albumin (BSA) fraction V as stabilizer agent. AuNPs were characterized by UV-visible to verify the nanoparticles formation. Samples containing BSA and samples obtained by the conventional method (without stabilizer) were monitored for two weeks and analyzed. Results were compared. (author)

  16. Statistical uncertainty in educational experiment on the attenuation of gamma radiation

    CERN Document Server

    Pilakouta, Mirofora

    2011-01-01

    Due to time and financial restrictions in an educational laboratory, we are making compromises, using experimental setups in which limitations and uncertainties are important. In these cases we should pay particular attention to the role of different factors that affect our experiment, in order to achieve the best possible educational outcome and to avoid misconceptions. In this paper problems related to the use of very low activity source 60Co in the experiment of measuring the linear attenuation coefficient of gamma rays through matter, will be presented. The role of background radiation in measurements and in the relative statistical uncertainty as well as the role of statistical uncertainty in the choice of representative measurements is discussed. Moreover students' difficulties and misconceptions related mainly to the statistical uncertainty and its connection to measurements overlapping are recorded. An explanation for the possible reasons of these misunderstandings is attempted in order to improve the...

  17. Gamma radiation shielding analysis of lead-flyash concretes.

    Science.gov (United States)

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

    2014-11-04

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

  18. Angular and energy dependence of radiation protection monitors to the quantity ambient dose equivalent for gamma radiation;Dependencia angular e energetica de monitores de radioprotecao para medidas de equivalente de dose ambiental para radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Nonato, Fernanda B.C.; Carvalho, Valdir S.; Diniz, Raphael E.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    In Brazil, most of the equipment used for monitoring area is just used in the quantities exposure and absorbed dose, with the need of adjustment to the ambient dose equivalent, H{sup *}(10). In this work, 19 Geiger-Mueller detectors and 7 ionization chambers were calibrated in the Calibration Laboratory of the Instituto de Pesquisas Energeticas Nucleares, IPEN. The energy dependence of these radiation detectors was studied for gamma radiation ({sup 137}Cs e {sup 60}Co) and the angular dependence, for {sup 137}Cs radiation. (author)

  19. Gamma radiation effects on mechanical properties and morphology of a polyurethane derivate from castor oil

    Science.gov (United States)

    Azevedo, Elaine Cristina; Orivaldo Chierice, Gilberto; Claro Neto, Salvador; Scheidegger Soboll, Daniel; Mauro Nascimento, Eduardo; Lepienski, Carlos Mauricio

    2011-03-01

    In this study, an adhesive of a polyurethane derivate from castor oil was irradiated with gamma radiation from a 60Co source, at doses from 0.2 to 25 kGy. This adhesive polyurethane is considered for use in hospital furniture because it does not liberate dangerous solvents. Hardness and elastic modulus were measured by instrumented indentation with a pyramidal Berkovich indenter, using loads from 0.08-40 mN with a nanoindenter XP. The instrumented indentation hardness was 110 MPa for an untreated sample, increasing to 124 MPa after irradiation with 25 kGy, at penetration depths of about 5 μm. The increases in elastic modulus induced by radiation were less pronounced. This polyurethane is naturally cross-linked and the relative modifications in the hardness are attributed to an additional cross-linking process induced by radiation. X-ray diffraction indicates a slight increase in crystallinity. The roughness measured by atomic force microscopy increases after gamma irradiation.

  20. Gamma radiation measurements in Brazilian commercial granites

    Energy Technology Data Exchange (ETDEWEB)

    Anjos, R.M.; Veiga, R.; Mosquera, B.; Carvalho, C.; Macario, K. [Universidade Federal Fluminense, Niteroi (Brazil)

    2006-07-01

    Full text of publication follows: Gamma radiation from radionuclides which are characterized by half lives comparable to the age of the earth, such as 40 K and the radionuclides from the 238 U and 232 Th series, and their decay products, represent the main terrestrial source of irradiation to the human body. Their concentrations vary for different types of rocks, where high radiation levels are associated with igneous rocks such as granite. Thorium, uranium and potassium concentrations of granitic rocks are intimately related to their mineral compositions and general petrologic features. Then, these features associated with effects of weathering and metamorphism produce expressive alterations in the relationship between the natural radionuclides (Th, U, K, Th/U and Th/K). Consequently, the measurements of thorium, uranium, and potassium concentrations of different granite samples result on individual differentiation sequences. From the 232 Th, 238 U and 40 K activity concentrations obtained for each sample, it is possible to evaluate their respective dose rates in air, when these stones are used as tiling rocks. These results are of great interest in the environmental radiological protection study, since granites are widely used as building and ornamental materials, including as indoor covering. In this way, the Laboratory of Radioecology (L.A.R.A.) of the Physics Institute of the Universidade Federal Fluminense (I.F. -U.F.F.) has been performing analyzes on more than one hundred differ ent types of the main Brazilian commercial granites in last two years [1]. Using NaI and HP Ge gamma-ray spectrometers to determine the concentration of natural radionuclides in these samples, the annual effective dose rates and the gamma activity concentration index have been evaluated and compared to the limits proposed by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) and European Commission (E.C.). In addition, the correlations between thorium

  1. Bone densitometry in dogs using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, A.L.B.; Costa, V.E.; Rezende, M.A.; Grossklauss, D.B.B.F.; Oliveira, T.B. [UNESP, Botucatu, SP (Brazil)

    2010-07-01

    Full text. The purpose of this work came from the possibility of joining similar methodologies for determination of density, used in different areas, and provide more precise values of bone density by analyzing the mass attenuation coefficient. For over 20 years, The Applied Physics Laboratory, Department of Physics and Biophysics, IBB- UNESP, Botucatu campus, has been working in the determination of density in different areas, using the methods of immersion and gamma radiation attenuation. The results presented have excellent precision, due to the facility in obtaining and preparing samples, coupled to the large experience in the area. This study aims to determine the bone density of samples of mongrel dogs (dogs without defined breed) by the immersion method; to determine the mass attenuation coefficient of bones samples of mongrel dogs with a gamma radiation source; to discuss and to evaluate the methodological aspects involved in the optic densitometry used nowadays, presenting its advantages and disadvantages and, finally, to examine the effect of animal weight, age and sex on bone densitometry of medium-sized dogs. For this study, we use upper limbs samples, at the joint region humerus-radio-ulnar of after death mongrel dogs, assigned by the Department of Pathology, Faculty of Animal Science and Veterinary Medicine (UNESP-Botucatu) and by the Kennel of the city of Araras, Sao Paulo. This work is performed in three stages. In the first step is determined the density by the method of immersion in water, in the second step, is obtained the mass coefficient attenuation and, finally, in the third step are discussed the implemented methods and evaluate the density bone samples to establish correlations with the age, weight and sex parameters of each group of animals. Based on this methodology , we can find the average value for the mass attenuation coefficient of gamma radiation with energy 59,6, find variations in the values of bone densitometry in the same bone

  2. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    Energy Technology Data Exchange (ETDEWEB)

    Kulisek, J.A., E-mail: Jonathan.Kulisek@pnnl.gov; Schweppe, J.E.; Stave, S.C.; Bernacki, B.E.; Jordan, D.V.; Stewart, T.N.; Seifert, C.E.; Kernan, W.J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, {sup 60}Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

  3. Real-time airborne gamma-ray background estimation using NASVD with MLE and radiation transport for calibration

    Science.gov (United States)

    Kulisek, J. A.; Schweppe, J. E.; Stave, S. C.; Bernacki, B. E.; Jordan, D. V.; Stewart, T. N.; Seifert, C. E.; Kernan, W. J.

    2015-06-01

    Helicopter-mounted gamma-ray detectors can provide law enforcement officials the means to quickly and accurately detect, identify, and locate radiological threats over a wide geographical area. The ability to accurately distinguish radiological threat-generated gamma-ray signatures from background gamma radiation in real time is essential in order to realize this potential. This problem is non-trivial, especially in urban environments for which the background may change very rapidly during flight. This exacerbates the challenge of estimating background due to the poor counting statistics inherent in real-time airborne gamma-ray spectroscopy measurements. To address this challenge, we have developed a new technique for real-time estimation of background gamma radiation from aerial measurements without the need for human analyst intervention. The method can be calibrated using radiation transport simulations along with data from previous flights over areas for which the isotopic composition need not be known. Over the examined measured and simulated data sets, the method generated accurate background estimates even in the presence of a strong, 60Co source. The potential to track large and abrupt changes in background spectral shape and magnitude was demonstrated. The method can be implemented fairly easily in most modern computing languages and environments.

  4. Effects of temperature and gamma radiation on the stability of 125{sub -}19-Iodo cholesterol; Efectos de la temperatura y la radiacion gamma sobre la estabilidad dle 19-Yodocolestero. 125 I

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L.; Rebollo, D. V.; Ruiz, J. M.

    1986-07-01

    He have studied the effect of the temperature and the gamma radiations on the I25I-19-iodocholesterol synthesized in our laboratory; the time of caducity (t 90) have been fixed from the rate constants of decomposition (k) (20,9) 32,1 y 144 . 10-3 h''-1) for different temperatures (35, 50 y 75degree centigree), and the value of Go(-M) (1,52) by radiation of samples of 19-Iodocholesterol-I25 I (0,94 mg/ml) with 60co (0,177 Hrad/h) . (Author) 8 refs.

  5. Carbohydrate based materials for gamma radiation shielding

    Science.gov (United States)

    Tabbakh, F.; Babaee, V.; Naghsh-Nezhad, Z.

    2015-05-01

    Due to the limitation in using lead as a shielding material for its toxic properties and limitation in abundance, price or non-flexibility of other commonly used materials, finding new shielding materials and compounds is strongly required. In this conceptual study carbohydrate based compounds were considered as new shielding materials. The simulation of radiation attenuation is performed using MCNP and Geant4 with a good agreement in the results. It is found that, the thickness of 2 mm of the proposed compound may reduce up to 5% and 50% of 1 MeV and 35 keV gamma-rays respectively in comparison with 15% and 100% for the same thickness of lead.

  6. Orchid flowers tolerance to gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Olivia Kimiko E-mail: okikuchi@net.ipen.br

    2000-03-01

    Cut flowers are fresh goods that may be treated with fumigants such as methyl bromide to meet the needs of the quarantine requirements of importing countries. Irradiation is a non-chemical alternative to substitute the methyl bromide treatment of fresh products. In this research, different cut orchids were irradiated to examine their tolerance to gamma-rays. A 200 Gy dose did inhibit the Dendrobium palenopsis buds from opening, but did not cause visible damage to opened flowers. Doses of 800 and 1000 Gy were damaging because they provoked the flowers to drop from the stem. Cattleya irradiated with 750 Gy did not show any damage, and were therefore eligible for the radiation treatment. Cymbidium tolerated up to 300 Gy and above this dose dropped prematurely. On the other hand, Oncydium did not tolerate doses above 150 Gy.(author)

  7. Orchid flowers tolerance to gamma-radiation

    Science.gov (United States)

    Kikuchi, Olivia Kimiko

    2000-03-01

    Cut flowers are fresh goods that may be treated with fumigants such as methyl bromide to meet the needs of the quarantine requirements of importing countries. Irradiation is a non-chemical alternative to substitute the methyl bromide treatment of fresh products. In this research, different cut orchids were irradiated to examine their tolerance to gamma-rays. A 200 Gy dose did inhibit the Dendrobium palenopsis buds from opening, but did not cause visible damage to opened flowers. Doses of 800 and 1000 Gy were damaging because they provoked the flowers to drop from the stem. Cattleya irradiated with 750 Gy did not show any damage, and were therefore eligible for the radiation treatment. Cymbidium tolerated up to 300 Gy and above this dose dropped prematurely. On the other hand, Oncydium did not tolerate doses above 150 Gy.

  8. Measurement of the radiative decay width \\Gamma[\\Lambda(1520) --> \\Lambda \\gamma] with the SPHINX spectrometer

    CERN Document Server

    Antipov, Y M; Batarin, V A; Vavilov, D V; Victorov, V A; Eroshin, O V; Golovkin, S V; Gorin, Yu P; Kolganov, V Z; Kozhevnikov, A P; Konstantinov, A S; Kubarovskii, V P; Kurshetsov, V F; Landsberg, L G; Leontiev, V M; Lomkatsi, G S; Molchanov, V V; Mukhin, V A; Nilov, A F; Patalakha, D I; Petrenko, S V; Smolyankin, V T; Antipov, Yu.M.; Gorin, Yu.P.

    2004-01-01

    The radiative decay \\Lambda(1520) --> \\Lambda \\gamma was measured directly in the study of exclusive diffractive-like reaction p + N --> \\Lambda(1520) K^+ + N, \\Lambda(1520) --> \\Lambda \\gamma with the SPHINX spectrometer. The values of the branching and partial width of this radiative decay were obtained: BR[\\Lambda(1520) --> \\Lambda \\gamma] = (1.02+/-0.21)x10^{-2} and \\Gamma[\\Lambda(1520) \\to \\Lambda \\gamma] = 159+/-35 keV (statistical uncertainty). The systematic uncertainty is estimated to be below 15%.

  9. LiCaAlF6 scintillators in neutron and gamma radiation fields

    Science.gov (United States)

    Viererbl, L.; Klupák, V.; Vinš, M.; Koleška, M.; Šoltés, J.; Yoshikawa, A.; Nikl, M.

    2016-09-01

    Intentionally doped LiCaAlF6 (LiCAF) single crystals are prospective scintillators, especially for thermal neutron detection through the 6Li(n,t)4He nuclear reaction. Four different LiCAF scintillator samples were tested in various neutron and gamma fields. Two of the tested samples were LiCAF:Eu and LiCAF:Eu,Na single crystals, and another two samples were made of LiCAF:Eu micro crystals dispersed in transparent rubber, with different rubber dimensions. All LiCAF samples contain lithium enriched to6Li. A plutonium-beryllium source was used as a neutron source. The neutron spectrum was modified by moderator and filter to get different ratios between thermal, epithermal and fast neutron fluence rates. The MCNP code was used for calculations of the fluence rates for different configurations. Radionuclides 137Cs and 60Co were applied as gamma radiation sources. The light signal from the scintillator was evaluated with a photomultiplier and a multichannel analyzer. The purpose of this work was to study the characteristics of LiCAF scintillators, especially the ability to discriminate signals from neutron and gamma radiation, which is the basic scintillator condition for neutron detection in mixed neutron-gamma radiation fields. Generally, the discrimination can be done by the pulse height and/or the pulse shape of the evaluated signals. Both methods can be used for a LiCAF scintillator. However, only the pulse height discrimination method is discussed in this paper. The possibility of fast neutron detection with LiCAF scintillators was also tested.

  10. Detection and thermoluminescence of coriander (Coriandrum sativum L.) irradiated with {sup 60}Co; Deteccion y termoluminiscencia del cilantro (Coriandrum sativum L.) irradiado con {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz G, B. [Departamento de Agricultura y Ganaderia, Universidad de Sonora, 083190 Hermosillo, Sonora (Mexico); Cruz Z, E. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, UNAM, A. P. 70-543, 04510 Mexico D. F. (Mexico); Barboza F, M. [Centro de Investigacion en Fisica, Universidad de Sonora, A. P. 5-088, 083190 Hermosillo, Sonora (Mexico)

    2009-10-15

    The fresh and dried coriander (Coriandrum sativum L.) is a spice of high commercial value as food for consumption in Mexico. Their hygienic quality is often poor due to some factors: contaminants present in irrigation water and the cultivation atmosphere, harvesting and post harvest handling, mainly. The process by radiation is an alternative to achieve the sterilization to adequate dose for the hygienic quality for its consumption. However, irradiation also involves food detection exposed to radiation. This paper presents detected results on the dried coriander that was obtained from fresh samples and thermoluminescent properties such as glow curves structure from low doses (0.5 Gy) to high (15 kGy), the dose response, thermoluminescent signal decay, in order to determine the loss of stability during the storage of the poly mineral fraction. We obtained the inorganic fraction separation of the organic part of particle sizes of 10 {mu}m by the Zimmerman method. The samples were exposed at two dose ranges; 0.5-400 Gy and 0.5-15 kGy of gamma radiation with {sup 60}Co. The limit of thermoluminescent detection of the irradiated coriander samples was from 1 Gy. The glow curves were at a broad band of 35-400 C, with a maximum thermoluminescence around 182-196 C, and run at 164 C for high doses of 15 kGy. The range of linear response to dose was 4-25 Gy, whereas higher doses than the kGy order the response increase with the dose. The thermoluminescent properties of the coriander poly mineral fraction, show it can be used to identify irradiated food at gamma doses relatively low and even in doses of commercial interest due to the high stability of thermoluminescent signals. (Author)

  11. Aflatoxins and ochratoxin a reduction in black and white pepper by gamma radiation

    Science.gov (United States)

    Jalili, M.; Jinap, S.; Noranizan, M. A.

    2012-11-01

    Irradiation is an important means of decontamination of food commodities, especially spices. The aim of the current study was to investigate the efficacy of gamma radiation (60Co) for decontaminating ochratoxin A (OTA) and aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) residues in artificially contaminated black and white pepper samples. The moisture content of the pepper samples was set at 12% or 18%, and the applied gamma dose ranged from 5 to 30 kGy. Mycotoxin levels were determined by high-performance liquid chromatography (HPLC) after immunoaffinity column (IAC) chromatography. Both the gamma irradiation dose and moisture content showed significant effects (P<0.05) on mycotoxin reduction. The maximum toxin reductions, found at 18% moisture content and 30 kGy, were 55.2%, 50.6%, 39.2%, 47.7% and 42.9% for OTA, AFB1, AFB2, AFG1 and AFG2, respectively.

  12. Gamma Radiation Effects on Physical, Optical, and Structural Properties of Binary As-S glasses

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, S. K.; McCloy, John S.; Riley, Brian J.; Murphy, Mark K.; Qiao, Hong (Amy); Windisch, Charles F.; Walter, Eric D.; Crum, Jarrod V.; Golovchak, Roman; Shpotyuk, O.

    2012-03-01

    Gamma radiation induces changes in physical, optical, and structural properties in chalcogenide glasses., Previous research has focused on As{sub 2}S{sub 3} and families of glasses containing Ge. For the first time, we present composition and dose dependent data on the As-S binary glass series. Binary As{sub x}S{sub 100-x} (x = 30, 33, 36, 40, and 42) glasses were irradiated with gamma radiation using a {sup 60}Co source at 2.8 Gy/s to accumulated doses of 1, 2, 3, and 4 MGy. The irradiated samples were characterized at each dose level for density, refractive index, x-ray diffraction, and Raman spectrum. These results are compared to those of as-made and 1 year aged samples. We report an initial increase in density followed by a decrease as a function of dose that contradicts the expected compositional dependence of molar volume of these glasses. This unusual behavior is explained based on microvoid formation and nanoscale phase-separation induced by the irradiation in these glasses. XRD, Raman, and EPR data provide supporting evidence, underscoring the importance of optimally- or overly-constrained structures for stability under aging or irradiation.

  13. Evaluation of the ionizing radiation {sup 60}Co effect on the physical, chemical and nutritional properties of different cultivars of soybean grains (Glycine max (L.));Avaliacao dos efeitos da radiacao ionizante de {sup 60}Co em propriedades fisicas, quimicas e nutricionais de diferentes cultivares de graos de soja Glycine max (L.)

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Tais Carolina Franqueira de

    2006-07-01

    With the increase of the world population, creative strategies will be necessary to control food production. To achieve this challenge, new cultivars have been development, though different techniques and characteristics. To improve food conservation, a plant of methods can be used. The use of Cobalto-60 radiation is a secure and useful method to increase the life time of foods. Due to the commercial and nutritional importance of soybean, some alterations must be studied. This study has the objective to determinate this alterations caused by irradiation (with doses of 2, 4 and 8 kGy) in raw and cooked grain of five different cultivars of soybean (BRS 212, BRS 213, BRS 214, 231 BRS and E48), this study includes analysis of time cooking and hydratation, and chemical analysis of proximate composition, in vitro digestibility of proteins, percentage of deamidation , phenolics compounds, trypsin inhibitors and tannins. The amount of water absorbed by each grain varied from 14.00 to 16.66mL, and the time cooking varied from 119.67 to 291.33 minutes. The values found for ash were 4.90 to 6.08%, for protein from 21.23 to 36.99%, for fat from 19.22 to 24.84%, soluble staple fibres from 1.37 to 4.03% and insoluble staple fibres from 15.97 to 18.87%. The deamidation percentage in the different samples varied of 17,34 to 57.79% and the digestibility in vitro from 84.45 to 89.11%. Inside of the anti nutritional factors, the total compounds phenolics varied from 3.9 to 9.7 mg/g, the units of trypsin inhibited from 24.75 to 57.53 UTI/g and the tannins from 0.02 to 0.32 mg/g. For the physical analyses it showed differences in the time of hydratation among them and the irradiation promoted reduction in the time, but not in the amount of absorbed water; in the cooking time it had reduction with the increase of the doses of radiation; the differences found in the proximate composition did not have influence with the irradiation, but with the different cultivars; for the digestibility

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-15

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

  15. Sorption of {sup 60} Co on inorganic solids; Sorcion de {sup 60} Co en solidos inorganicos

    Energy Technology Data Exchange (ETDEWEB)

    Granados C, F.; Bulbulian G, S. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Mardel V, B. [UAM-I, 09340 Mexico D.F. (Mexico)

    2003-07-01

    The behavior of sorption of the {sup 60} Co in aqueous solution under static conditions to different values of pH of the aqueous solution (1, 3, 5, 7, and 10) on MgO, MnO{sub 2}, SnO, TiO{sub 2}, activated carbon and calcinate hydrotalcite was investigated. It was found that the best sorbents of the {sup 60} Co was the MnO{sub 2}, activated carbon and TiO{sub 2} whose sorption was incremented when increasing the pH value of the aqueous solutions, in the one case of the hydrated oxides, the {sup 60} Co interacted with the electrically charged surface of the sorbents that depends on the pH of the solution and of the point of zero charge (zpc) of the sorbent. (Author)

  16. Q{sub {gamma}-H2AX}, an analysis method for partial-body radiation exposure using {gamma}-H2AX in non-human primate lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Redon, Christophe E., E-mail: redonc@mail.nih.gov [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Nakamura, Asako J.; Gouliaeva, Ksenia [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States); Rahman, Arifur; Blakely, William F. [Armed Forces Radiobiology Research Institute, Uniformed Services University, Bethesda, MD 20889-5603 (United States); Bonner, William M. [NIH, NCI, CCR, Laboratory of Molecular Pharmacology, Bethesda, MD 20892 (United States)

    2011-09-15

    We previously used the {gamma}-H2AX assay as a biodosimeter for total-body irradiation (TBI) exposure ({gamma}-rays) in a rhesus macaque (Macaca mulatta) model. Utilizing peripheral blood lymphocytes and plucked hairs, we obtained statistically significant {gamma}-H2AX responses days after total-body exposure to 1-8.5 Gy ({sup 60}Co {gamma}-rays at 55 cGy min{sup -1}). Here, we introduce a partial-body exposure analysis method, Q{sub {gamma}-H2AX}, which is based on the number of {gamma}-H2AX foci per damaged cells as evident by having one or more {gamma}-H2AX foci per cell. Results from the rhesus monkey - TBI study were used to establish Q{sub {gamma}-H2AX} dose-response calibration curves to assess acute partial-body exposures. {gamma}-H2AX foci were detected in plucked hairs for several days after in vivo irradiation demonstrating this assay's utility for dose assessment in various body regions. The quantitation of {gamma}-H2AX may provide a robust biodosimeter for analyzing partial-body exposures to ionizing radiation in humans.

  17. Natural Gamma Radiation in Primary Schools of Zanjan Province

    Directory of Open Access Journals (Sweden)

    Faranak Saghatchi

    2016-06-01

    Full Text Available Background: Environmental gamma ray refers to the gamma radiation from terrestrial sources and building materials. In enclosed spaces radiation can become a health hazard leading to potential increase in the rates of lung cancer. The goal of this study is to assess the exposure to natural gamma radiation of children in the schools of Zanjan province. Method: The natural gamma radiation was assessed in 46 primary schools of Zanjan province. A total number of 75 classrooms were studied. The measurements were performed in classrooms and schoolyards using a Geiger–Muller detector (RDS-110. Alongside radiation measurements, all the data corresponding to the characteristics of each school building were collected. Results: The results showed that the outdoor dose rate ranged from 82 to 106nSv h-1 while gamma dose rate due to inside classrooms ranged from 106 to 137nSvh-1. The findings represented that the highest indoor gamma dose rate belonged to the buildings of more than 30 years and metal frame and brick (P<0.05. Conclusion: We concluded that the effective dose due to gamma radiation from terrestrial sources and building materials for students of primary schools in Zanjan province (0.83 mSv was higher than worldwide average of the annual effective dose (0.48 mSv.

  18. 60Coγ射线2.0 Gy剂量诱导大鼠淋巴细胞基因表达的改变%Study of Differential Gene Expression Profiling in Peripheral Blood Lymphocyte of Rat with 2 .0 Gy Gamma Ray Irradiation

    Institute of Scientific and Technical Information of China (English)

    李建国; 尹晶晶; 秦秀军; 张伟; 周晋源; 闻建华

    2013-01-01

    利用Agilent Rat全基因组芯片技术和实时荧光定量PCR技术,采用60 Coγ射线对SD大鼠全身照射,照射剂量为2.0 Gy ,分析照后6、12、24小时大鼠外周血淋巴细胞的差异表达基因谱和通路,同时对基因芯片结果进行验证。结果表明:(1)照后6小时,差异表达基因有1084个,其中上调的736个,下调的348个;照后12小时,差异表达基因有2590个,其中上调的1621个,下调的969个;照后24小时,差异表达基因有3938个,其中上调的2278个,下调的1660个;3个时间点共同差异表达基因有446个,其中上调的274个,下调的172个。(2)照后6小时,差异表达基因涉及到的通路有18个;照后12小时,差异表达基因涉及到的通路有35个;照后24小时,差异表达基因涉及到的通路有38个。其中通路Cell adhesion molecules、Toxoplasmosis、B cell receptor signaling、Intestinal immune network for IgA Production等在照后3个时间点均有出现。(3)差异表达基因Trmt61a和Enc1的相对定量结果与基因芯片检验结果表达趋势一致。%The study analyzed the differential expression profile and pathway of peripheral blood lymphocyte in SD rats 6 ,12 and 24 hours after irradiation to 2 .0 Gy gamma ray .The results showed that at 6 hours after ir-radiation there were 1084 differentially expressed genes of which 736 genes were up-regulated and 348 genes down-regulated .12 hours after irradiation there were 2590 differentially expressed genes of which 1621 genes were up-regulated and 969 genes down-regulated .24 hours after irradiation there were 3938 differentially ex-pressed genes of which 2278 genes were up-regulated and 1660 genes down-regulated .There were 446 co-ex-pressed differential genes at three time points ,of which 274 genes were up-regulated and 172 genes down-regu-lated .The KEGG analysis revealed that 6h point 18 pathways ,12 hours point 35 pathways ,and 24 hours point

  19. Use of {sup 60}Co panoramic source in the induction of oral mucositis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Maira F.; Benetti, Carolina; Zezell, Denise M., E-mail: mairandrade@yahoo.com, E-mail: zezell@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Correa, Luciana, E-mail: lcorrea@usp.br [Universidade de Sao Paulo (FO/USP), Sao Paulo, SP (Brazil). Fac. de Odontologia

    2013-07-01

    Oral Mucositis is a well-known side effect of chemo-radiotherapy in cancer patients or transplant recipients that could induce hospitalization or impairs therapy in different levels of severity. This study is devoted to define the first steps in the research of low level laser treatments in oral mucositis, proposing a {sup 60}Co radiation to experimentally induce oral mucositis in rats using Panoramic gamma irradiator, simulating usual radiotherapy of head and neck cancer. Fifteen male Wistar rats, above 250g, were irradiated at Centro de Tecnologia das Radiacoes (IPEN - CNEN/SP) and divided in three experimental groups, with different single doses of radiation (30 Gy, 25 Gy and 20 Gy). The animals were observed for a 20 days period. Animals that received 30 Gy and 25 Gy developed greater severity of mucositis and premature euthanasia was performed in these groups on the 7th and 11th day after the irradiation, respectively. The 20 Gy group developed oral mucositis grading from moderated to severe between the days 7 and 11 after irradiation, with progressive body mass loss and decrease in the intake of food and water. These animals recovered from oral mucositis around the 18th day and clinical remission at the 20th day. The single dose of 20 Gy Gamma radiation proved to be efficient way for inducing oral mucositis in rats, allowing the establishment of an experimental model for oral mucositis in rats for future use on interventions of this serious aspect of radiation therapy, such as laser therapy using different wave lengths and power densities. (author)

  20. Gamma radiation from PSR B1055-52

    DEFF Research Database (Denmark)

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

    1999-01-01

    The telescopes on the Compton Gamma Ray Observatory (CGRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics that distinguish this pulsar: the light...

  1. DNA Damage in Melania Snail (Semisulcospira libertine) Irradiated with Gamma Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Tae Ho; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute, Jeongeup (Korea, Republic of); An, Kwang Guk [Chungnam National University, Daejeon (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2010-10-15

    Generally radiological protection has focused on human. But International Commission on Radiological Protection (ICRP) requires the effect data of ionizing radiation on nonhuman biota for the radiological protection of the environment. The choice of a melania snail as a model for environmental biomonitoring of radiation genotoxicity took into account that invertebrates represent one of aquatic species. The comet assay or single cell gel electrophoresis (SCGE) assay, first introduced by Ostling and Johanson, was used to detect DNA single strand breaks and to investigate the application of this technique as a tool for aquatic biomonitoring. Comet assay offers considerable advantages over some other assays used in DNA damage detection, such as chromosomal aberrations, sister chromatid Exchange and the micronucleus test, since there is no need for cells to be in a dividing state. Other advantages are its rapidity, relatively low coast, and wide applicability to virtually any nucleated cell type. In this study, we evaluated DNA damage in cells of Semisulcospira libertina after irradiation with {sup 60}Co gamma radiation by using the comet assay

  2. Micronuclei as biomarkers of genotoxicity of gamma radiation in aquatic environments

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luanna R.S.; Silva, Edvane B.; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (GERAR/DEN/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia; Silva, Ronaldo C. da [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Genetica; Amancio, Francisco F. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia

    2011-07-01

    Ionizing radiation is a genotoxic agent, inducing gene mutations and cellular death. Several efforts have been defendants in the development of techniques for measurement of radiation damage in biological systems. Among these techniques, micronuclei test has been showing as a great bio marker of DNA damage, being used in environmental monitoring to detect genotoxic agents in the environment. Additionally, organisms as Biomphalaria glabrata, freshwater molluscs, presents itself as an excellent model to assess damage caused by physical and chemical agents, due their biological and environmental characteristics. The snails were divided into groups of 5 individuals exposed to doses of 0 (control), 25, 35, 45 and 55 Gy of {sup 60}Co. After 48 hours of irradiation, the hemo lymph was collected and prepared the slides, which were stained with Giemsa and analyzed the cellular changes in haemocytes Statistical analysis was accomplished through chi-square test, ANOVA and Tukey test (p< 0,05). The results indicated that B. glabrata showed to be sensitive to gamma radiation. The snails irradiated with 35 Gy showed a decrease of haemocytes, while that of 55 Gy increased. Cellular and morphological changes were observed at doses of 35, 45 and 55 Gy and the dose of 55 Gy, the most radiotoxic. (author)

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

    Science.gov (United States)

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

    2016-08-05

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

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

    Science.gov (United States)

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

    2016-06-21

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

  5. The application of gamma radiation to control tobacco beetles (Lasioderma serricorne F. )

    Energy Technology Data Exchange (ETDEWEB)

    Chang, M.S.; Chen, C.C.; Fu, Y.K.

    1981-03-01

    Tobacco beetle (Lasioderma serricorne F.) is the most serious pest of stored tobaccos in Taiwan. The aim of this study is to use /sup 60/Co ..gamma..-ray irradiation to control tobacco beetles of stored tobaccos. The results are: (1) the sterility dose of adults irradiated by /sup 60/Co ..gamma..-rays is 9.6 krad, with an immediate lethal dose of 500 krad and a total death 18 days post irradiation of 200 krad; (2) the immediate lethal dose of larvae is 400 krad, with a non-emerging dose of 200 krad; (3) adults could not emerge from the pupae irradiated by /sup 60/Co ..gamma..-rays at 200 krad; (4) larvae could not be hatched from the oval stage irradiated by 25 krad. In conclusion, /sup 60/Co ..gamma..-ray irradiation of 200 krad could be applied to stored tobaccos to control tobacco beetles with total disinfestation of larvae and adults and complete non-appearence of F/sub 1/ generation 18 days post irradiation.

  6. Gamma radiation effects in coriander (coriandrum sativum L) for consumption in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Cruz Z, E. [UNAM, Instituto de Ciencias Nucleares, Unidad de Irradiacion y Seguridad Radiologica, Apdo. Postal 70-543, 04510 Mexico D. F. (Mexico); Ruiz G, B. [Universidad de Sonora, Departmento de Agricultura y Ganaderia, Apdo. Postal 305, 83190 Hermosillo, Sonora (Mexico); Flores E, T. [UNAM, Facultad de Quimica, Departamento de Alimentos y Biotecnologia, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Barboza F, M. [Universidad de Sonora, Centro de Investigacion en Fisica, Apdo. Postal 5-088, 83190 Hermosillo, Sonora (Mexico)

    2011-02-15

    Ionizing radiation is an effective process for disinfecting and prolonging the shelf-life of several food products. Food irradiation may be one of the most significant contributions to public health in the developing countries. Following the irradiation it is necessary to analyze the radiation dose effects in foodstuffs. Thermally stimulated luminescence (Tl) properties and microbiological load as a function of the gamma doses were analyzed in fresh commercial Coriander (Coriandrum sativum L.) samples. For Tl analyses the poly mineral fraction was separated from a coriander and 10 {mu}m size particles were selected. The poly mineral samples were exposed to a 0.5-15,000 Gy dose from gamma radiation using a {sup 60}Co facility, Gamma beam 651PT, semi-industrial irradiator with 98.4 Gy/min dose rate. The glow curves were broad bands and characteristic of quartz that is present in the sample as detected by XRD. The main Tl characteristics were determined, including the structure of the glow curves, Tl response, reproducibility of Tl signals over 12 cycles of subsequent irradiations, and the fading effect during the storage during 30 days. The Tl method was found useful for detection of irradiated coriander. In order to analyze the effect of gamma radiation on the bacterial load in the fresh food coriander, several coriander samples were exposed to 0-10 kGy dose. It was observed that at 0.5 kGy dose the aerobic mesophilic count was reduced to 99.9%, while the initial total coliform bacteria decreased from 871,000 cfu/g to less than 100. The microbiological results are lower than the limit indicated by the Mexican regulatory authority; 150,000 cfu/g for mesophiles and 100 cfu/g for total coliforms. The aim of this work is to investigate the Tl properties of the poly mineral fraction obtained from coriander and to measure the microbiological load as a function of the gamma irradiation dose also. (Author)

  7. Evaluation of fungal burden of medicinal plants submitted to gamma radiation process after 30 days

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Simone; Araujo, Michel M.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes]. E-mail: siaq06@hotmail.com; Goncalez, Edlayne; Reis, Tatiana A. dos; Correa, Benedito [Universidade de Sao Paulo, SP (Brazil). Inst. de Ciencias Biomedicas. Dept. de Microbiologia]. E-mail: correabe@usp.br

    2007-07-01

    Forty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia and Cassia angustifolia), purchased from pharmacies and street market in the five cities of Sao Paulo State, were irradiated using a {sup 60}Co gamma ray source (Gammacell) with a dose of 10.0 kGy, delivered at dose rate of 3.0 kGy/h. Nonirradiated samples were used as controls of fungal isolates. For fungal counts and identification in medicinal plants a serial dilutions from 10{sup -1} to 10{sup -6} of the samples were seeded in duplicates and plated using the method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25 deg C. Mycological analysis of control samples revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi. The process of gamma radiation was effective in reducing the number of colony forming units (cfu/g) in all irradiated samples of medicinal plants after 30 days, using the dose of 10.0 kGy and kept of veiled conditions. (author)

  8. Influence of dose on particle size of colloidal silver nanoparticles synthesized by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Naghavi, Kazem, E-mail: Kazem.naghavi@gmail.co [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia); Saion, Elias [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia); Rezaee, Khadijeh [Department of Nuclear Engineering, Faculty of Modern Sciences and Technologies, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Yunus, Wan Mahmood Mat [Universiti Putra Malaysia, Physics Department, 43400 UPM SERDANG, Selangor (Malaysia)

    2010-12-15

    Colloidal silver nanoparticles were synthesized by {gamma}-irradiation-induced reduction method of an aqueous solution containing silver nitrate as a precursor in various concentrations between 7.40x10{sup -4} and 1.84x10{sup -3} M, polyvinyl pyrrolidone for capping colloidal nanoparticles, isopropanol as radical scavenger of hydroxyl radicals and deionised water as a solvent. The irradiations were carried out in a {sup 60}Co {gamma} source chamber at doses up to 70 kGy. The optical absorption spectra were measured using UV-vis spectrophotometer and used to study the particle distribution and electronic structure of silver nanoparticles. As the radiation dose increases from 10 to 70 kGy, the absorption intensity increases with increasing dose. The absorption peak {lambda}{sub max} blue shifted from 410 to 403 nm correspond to the increase of absorption conduction electron energy from 3.02 to 3.08 eV, indicating the particle size decreases with increasing dose. The particle size was determined by photon cross correlation spectroscopy and the results showed that the particle diameter decreases exponentially with the increase of dose. The transmission electron microscopy images were taken at doses of 20 and 60 kGy and the results confirmed that as the dose increases the diameter of colloidal silver nanoparticle decreases and the particle distribution increases.

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

    OpenAIRE

    Ivanov Kirill E.; Ponomaryev-Stepnoi Nikolai N.; Stepennov Boris S.; Teterin Yury A.; Teterin Anton Y.; Kharitonov Vladimir V.

    2008-01-01

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

  10. Shielding for beta-gamma radiation.

    Science.gov (United States)

    Fletcher, J J

    1993-06-01

    The build-up factor, B, for lead was expressed as a polynominal cubic function of the relaxation length, mu x, and incorporated in a "general beta-gamma shielding equation." A computer program was written to determine shielding thickness for polyenergetic beta-gamma sources without resorting to the conventional "add-one-HVL" method.

  11. Development of a Small-Sized, Flexible, and Insertable Fiber-Optic Radiation Sensor for Gamma-Ray Spectroscopy

    Directory of Open Access Journals (Sweden)

    Wook Jae Yoo

    2015-08-01

    Full Text Available We fabricated a small-sized, flexible, and insertable fiber-optic radiation sensor (FORS that is composed of a sensing probe, a plastic optical fiber (POF, a photomultiplier tube (PMT-amplifier system, and a multichannel analyzer (MCA to obtain the energy spectra of radioactive isotopes. As an inorganic scintillator for gamma-ray spectroscopy, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce crystal was used and two solid-disc type radioactive isotopes with the same dimensions, cesium-137 (Cs-137 and cobalt-60 (Co-60, were used as gamma-ray emitters. We first determined the length of the LYSO:Ce crystal considering the absorption of charged particle energy and measured the gamma-ray energy spectra using the FORS. The experimental results demonstrated that the proposed FORS can be used to discriminate species of radioactive isotopes by measuring their inherent energy spectra, even when gamma-ray emitters are mixed. The relationship between the measured photon counts of the FORS and the radioactivity of Cs-137 was subsequently obtained. The amount of scintillating light generated from the FORS increased by increasing the radioactivity of Cs-137. Finally, the performance of the fabricated FORS according to the length and diameter of the POF was also evaluated. Based on the results of this study, it is anticipated that a novel FORS can be developed to accurately measure the gamma-ray energy spectrum in inaccessible locations such as narrow areas and holes.

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

    Science.gov (United States)

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

    2016-01-01

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

  13. Effect of the {gamma}-radiation on phenol fractions obtained from the leaves of Echinodorus macrophyllus Mich

    Energy Technology Data Exchange (ETDEWEB)

    Silva, T.M., E-mail: silvatm@ufmg.br [Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Presidente Antonio Carlos, 6627 Pampulha, 31.270-901 Belo Horizonte, MG (Brazil); Dias, M.D. [Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Presidente Antonio Carlos, 6627 Pampulha, 31.270-901 Belo Horizonte, MG (Brazil); Pereira, M.T. [Centro de Desenvolvimento da Tecnologia Nuclear-CDTN, Av. Presidente Antonio Carlos, 6627 Pampulha, 31.270-901 Belo Horizonte, MG (Brazil); Takahashi, J.A.; Ferraz, V.P.; Pilo-Veloso, D.; Alcantara, A.F.C. [Departamento de Quimica, ICEx, Universidade Federal de Minas Gerais, Av. Presidente Antonio Carlos, 6627 Pampulha, 31.270-901 Belo Horizonte, MG (Brazil)

    2012-01-15

    Echinodorus macrophyllus Mich. (Chapeu-de-couro) is popularly used as diuretic, anti-arrhythmic, anti-inflammatory, and anti-rheumatic agents. Leaves of this species are largely commercialized and show high level of microbiological contamination (bacteria and fungi). This work describes the effect of the {sup 60}Co {gamma}-radiation on the phenol fractions obtained from the leaves of E. macrophyllus. trans-Ferulic acid, (E)-caffeoyltartronic acid, 6-C-(1-hexitol)-apigenin, and 6-C-(1-hexitol)-luteolin were isolated by preparative HPLC. HPLC chromatograms showed concentration changes of some phenolic constituents, suggesting the formation of radiolytic products. The phenol fractions were active against Bacillus subitilis and Staphylococcus aureus and showed high antioxidant activity. However, the antibacterial and antioxidant activities reduced when the absorbed dose was increased. - Highlights: > Effects of the {gamma}-radiation on the chemical constituents of the leaves of E. macrophyllus. > To determine the conditions, which are sufficient for microbiological decontamination. > Analysis by HPLC of the phenol fractions obtained from the leaves of E. macrophyllys. > Effects of the {gamma}-radiation in the antioxidant and antimicrobial activities of E. macrophyllus.

  14. Physiological quality of rice seed submitted to gamma radiation; Qualidade fisiologica de sementes de arroz submetidas a radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Helen Lucia da Cruz; Tillmann, Maria Angela Andre; Meneghello, Geri Eduardo, E-mail: helenllc@gmail.co [Universidade Federal de Pelotas (UFPel), RS (Brazil). Programa de Pos-graduacao em Ciencia e Tecnologia de Sementes; Bobrowski, Vera Lucia [Universidade Federal de Pelotas (UFPel), RS (Brazil). Dept. de Genetica; Dode, Luciana Bicca [Universidade Catolica de Pelotas (UCPel), RS (Brazil)

    2009-08-15

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

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

    Directory of Open Access Journals (Sweden)

    Ivanov Kirill E.

    2008-01-01

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

  16. 30 CFR 57.5047 - Gamma radiation surveys.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Gamma radiation surveys. 57.5047 Section 57.5047 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL...) Standard N13.8-1973, entitled “Radiation Protection in Uranium Mines”, section 14.1 page 12, which...

  17. A localized excess of diffuse gamma radiation

    Science.gov (United States)

    Chen, A.; Dwyer, J.; Kaaret, P.

    1995-01-01

    Using archival Energetic Gamma Ray Experiment Telescope (EGRET) gamma-ray data and atomic hydrogen (H I) column densities derived from 21 cm radio observations, we have found a large irregular region in the northern Galactic hemisphere extending from (l approximately 90 deg, b approximately 52 deg) to (l approximately 45 deg, b approximately 77 deg) with a significant enhancement in the gamma-ray emissivity compared to the surrounding sky. The region contains no previously identified gamma-ray point sources. The emission may arise from a localized enhancement in cosmic-ray density or from the presence of matter other than H I. If the emission is due to unseen matter, a column density enhancement equivalent to approximately 2 x 10(exp 20) H-atoms/sq cm is required.

  18. Development and Performance Characteristics of Personal Gamma Spectrometer for Radiation Monitoring Applications.

    Science.gov (United States)

    Park, Hye Min; Joo, Koan Sik

    2016-06-21

    In this study, a personal gamma (γ) spectrometer was developed for use in applications in various fields, such as homeland security and environmental radiation monitoring systems. The prototype consisted of a 3 × 3 × 20 mm³ Ce-doped Gd-Al-Ga-garnet (Ce:GAGG) crystal that was coupled to a Si photomultiplier (SiPM) to measure γ radiation. The γ spectrometer could be accessed remotely via a mobile device. At room temperature, the implemented Ce:GAGG-SiPM spectrometer achieved energy resolutions of 13.5%, 6.9%, 5.8%, and 2.3% for (133)Ba at 0.356 MeV, (22)Na at 0.511 MeV, (137)Cs at 0.662 MeV, and (60)Co at 1.33 MeV, respectively. It consumed only about 2.7 W of power, had a mass of just 340 g (including the battery), and measured only 5.0 × 7.0 cm².

  19. Development and Performance Characteristics of Personal Gamma Spectrometer for Radiation Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Hye Min Park

    2016-06-01

    Full Text Available In this study, a personal gamma (γ spectrometer was developed for use in applications in various fields, such as homeland security and environmental radiation monitoring systems. The prototype consisted of a 3 × 3 × 20 mm3 Ce-doped Gd–Al–Ga–garnet (Ce:GAGG crystal that was coupled to a Si photomultiplier (SiPM to measure γ radiation. The γ spectrometer could be accessed remotely via a mobile device. At room temperature, the implemented Ce:GAGG-SiPM spectrometer achieved energy resolutions of 13.5%, 6.9%, 5.8%, and 2.3% for 133Ba at 0.356 MeV, 22Na at 0.511 MeV, 137Cs at 0.662 MeV, and 60Co at 1.33 MeV, respectively. It consumed only about 2.7 W of power, had a mass of just 340 g (including the battery, and measured only 5.0 × 7.0 cm2.

  20. Designing Equipment for Use in Gamma Radiation Environments

    Energy Technology Data Exchange (ETDEWEB)

    Vandergriff, K.U.

    1990-01-01

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

  1. Study of Neutron and Gamma Radiation Protective Shield

    OpenAIRE

    Eskandar Asadi Amirabadi; Marzieh Salimi; Nima Ghal-Eh; Gholam Reza Etaati; Hossien Asadi

    2013-01-01

    Due to the development of nuclear technology and use of these technologies in various fields of industry, medicine, research and etc, protection against radioactive rays is one of the most important topics in this field .The purpose of this is to reduce the dose rate from radioactive sources. The sources in terms of components are emitted various types of nuclear radiation with different energies. These radiations are involving of alpha particles, beta, and neutron and gamma radiation. Given ...

  2. Analysis of the frequency of unstable chromosome aberrations in human lymphocytes irradiated with {sup 60}Co; Analise da frequencia de alteracoes cromossomicas instaveis em linfocitos humanos irradiados com {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Lima, Fabiana F., E-mail: july_cgm@hotmail.com, E-mail: mendes_sb@hotmail.com [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: santos_neide@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2013-07-01

    The aim of this study was to analyze the frequency of unstable chromosomal aberrations induced by gamma radiation from a {sup 60}Co source at two different doses. Samples were obtained from a healthy donor and exposed to {sup 60}Co source (Gammacel 220 ) located in the Department of Nuclear Energy of Pernambuco Federal University (DEN/UFPe/Brazil) with a rate of air Kerma to 3,277 Gy/h. Exposures resulted in absorbed dose 0.51 Gy and 0.77 Gy. Mitotic metaphases were obtained by culturing lymphocytes for chromosome analysis and the slides were stained with 5% Giemsa. Among the unstable chromosomal aberrations the dicentric chromosomes, ring chromosomes and acentric fragments were analyzed. To calculate the significance level the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. To calculate the significance level of the chi - square test was used, considering relevant differences between the frequencies when the value of p < 0.05. The results showed that there was significant difference of the frequencies of dicentric chromosomes (from 0.18 to 0.51 to 0.37 Gy to 0.77 Gy), however there was no statistically significant difference between the frequencies of acentric fragments ( 0.054 to 0, 51 Gy to 0.063 to 0.77 Gy) and ring chromosomes (0.001 to 0.51 Gy to 0.003 to 0.77 Gy). The low number of rings is found justified, considering that in irradiated human lymphocytes, its appearance is rare relative to dicentrics. The results confirm that dicentrics are the most reliable biomarkers in estimating dose after exposure to gamma radiation. These two points will make the calibration curve dose-response being built for Biological Dosimetry Laboratory of CRCN-NE/CNEN.

  3. Search for the Radiative Decay B --> phi gamma

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schröder, T; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Zhang, L; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De, R; Sangro; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Thompson, J; Vavra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martínez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Pan, Y; Prepost, R; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2003-01-01

    We perform a search for the exclusive radiative decay B0 --> phi gamma, which is dominated by b d annihilation, in a sample of 124 million BB events collected with the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring at SLAC. No significant signal is seen. We set an upper limit on the branching fraction BR(B0 --> phi gamma < 8.5x10-7) at the 90% confidence level.

  4. Gamma-radiation monitoring network at sea

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, Ch.; Schilling, G.; Gruettmueller, M.; Becker, K

    1999-04-01

    A stationary monitoring network to observe the sea for radioactive contaminations, using a newly constructed NaI-detector system, is described. The monitoring efficiency for total-{gamma} counting and {gamma}-spectrometry as well as a method suppressing the registration of natural radioactivity are discussed. On the basis of three accident scenarios with releases of radioactivity into the sea it is demonstrated that under sea conditions the limit of detection of this 'in situ' method is comparable to the regularly performed monitoring by radiochemical {sup 137}Cs analysis of seawater samples.

  5. Humoral immune response against native or {sup 60}Co irradiated venom and mucus from stingray Paratrygon aiereba

    Energy Technology Data Exchange (ETDEWEB)

    Thomazi, Gabriela Ortega Coelho; Alves, Glaucie Jussilane; Aires, Raquel da Silva; Turibio, Thompson de Oliveira; Rocha, Andre Moreira; Spencer, Patrick Jack; Nascimento, Nanci do, E-mail: 0916@prof.itpacporto.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Seibert, Carla Simone, E-mail: carlaseibert@yahoo.com [Universidade Federal do Tocantins (UFT), Porto Nacional, TO (Brazil)

    2015-07-01

    Poisonings and traumas caused by poisonous freshwater fish such as rays are considered a major public health problem and draw attention because of accidents involving these animals cause serious local symptoms and are disabling, keeping the victim away from work. The therapy of these cases is based only on the symptoms of patients, which implies in its low efficiency, causing suffering for the victims. This study aims to evaluate and compare the humoral immune response in animals inoculated with native or {sup 60}Co irradiated Paratrygon aiereba venom and mucus. Ionizing radiation has proven to be an excellent tool to decrease the toxicity of venoms and isolated toxins. The mucus and venom samples of P. aiereba were irradiated using gamma rays from a {sup 60}Co source. Animals models were immunized with the native or irradiated mucus or venom. The assays were conducted to assess the production of antibodies by the immunized animals using enzyme immunoassay and western blotting. Preliminary results show the production of antibodies by the immunized animals. The resulting sera were also checked for antigenic cross- reactivity between venom and mucus, demonstrating the potential of mucus as an antigen for serum production for the specific treatment for accidents by stingrays. However, it is essential to carry out further tests in order to verify the neutralization of the toxin by antibodies formed by animals. (author)

  6. Reusable shielding material for neutron- and gamma-radiation

    Science.gov (United States)

    Calzada, Elbio; Grünauer, Florian; Schillinger, Burkhard; Türck, Harald

    2011-09-01

    At neutron research facilities all around the world radiation shieldings are applied to reduce the background of neutron and gamma radiation as far as possible in order to perform high quality measurements and to fulfill the radiation protection requirements. The current approach with cement-based compounds has a number of shortcomings: "Heavy concrete" contains a high amount of elements, which are not desired to obtain a high attenuation of neutron and/or gamma radiation (e.g. calcium, carbon, oxygen, silicon and aluminum). A shielding material with a high density of desired nuclei such as iron, hydrogen and boron was developed for the redesign of the neutron radiography facility ANTARES at beam tube 4 (located at a cold neutron source) of FRM-II. The composition of the material was optimized by help of the Monte Carlo code MCNP5. With this shielding material a considerable higher attenuation of background radiation can be obtained compared to usual heavy concretes.

  7. Effect of gamma radiation on honey quality control

    Science.gov (United States)

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

    2009-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  9. Effect of gamma radiation on honey quality control

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-15

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

  10. Disinfection of sewage sludge with gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Melmed, L.N.; Comninos, D.K.

    1979-10-01

    Disinfection of sewage sludge by ionizing radiation, thermoradiation, and radiation combined with oxygenation was investigated in experimentation in Johannesburg, South Africa. Inactivation of Ascaris lumbricoides ova was used as the criterion of disinfection. Experimentation and methodology are explained. Complete inactivation could be obtained when 0.5 kGy radiation was applied at 50..cap alpha..C to a sludge containing 3% solids and when 0.4 kGy radiation was applied at 55..cap alpha..C to a sludge with 20% solids. (1 drawing, 5 graphs, 4 photos, 4 tables)

  11. Cytotoxic effects of gamma radiation and DEET on Perna perna mussels

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Gisela A.; Rogero, Sizue O.; Silva, Marina V.; Rogero, Jose Roberto, E-mail: gisela.martini@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Aiming at the protection of aquatic biota becomes desirable progress in identifying and quantifying the presence of chemical contaminants to an evaluation of its bioavailability and harmful effects to the aquatic ecosystem. Diethyltoluamide (DEET) is one of the most commonly used active ingredients in insect repellents and is considered an emergent contaminant. In addition the environment in regions near nuclear facilities (mostly coastal) and in regions with higher level of background radiation, many aquatic organisms could be exposed to radiation, becoming more susceptible to other contaminants. Therefore, the purpose of this study was the investigation of the biological effects of ionizing radiation in combination with the exposure of Perna perna mussels to DEET. Previously it was determined the doses of {sup 60}Co gamma radiation (3 and 107 Gy) and the DEET concentrations (0.02 and 0.001mg L-1) which causes cytotoxicity in lysosomes of Perna perna mussels hemocytes. The effects were evaluated by the neutral red retention time assay in irradiated and non-irradiated organisms. The assays were performed in 72 hours, with readings on each 24 hours. The endpoint was the lysosome membrane disruption causing the decrease of the neutral red retention time observed . The results showed that was no statistic difference of irradiated organisms with 3 Gy and exposed to different concentrations of DEET in comparison with non-irradiated organisms, the mean neutral red retention time in assays was around 40 minutes. The organisms that were exposed to DEET after 107 Gy irradiation dose showed cell lysis and neutral red retention time less than 30 minutes, this suggests that synergistic effect can be observed depending on the irradiated dose and the DEET concentration. (author)

  12. Effect of gamma-radiation and microwave heating on endosperm microstructure in relation to some technological properties of wheat grain.

    Science.gov (United States)

    Błaszczak, W; Gralik, J; Klockiewicz-Kamińska, E; Fornal, J; Warchalewski, J R

    2002-04-01

    Grains of the Polish winter wheat variety Begra were subject to gamma-radiation (60Co) within the dose range of 0.05-10 kGy and microwave treatment from 15 to 180 s, the latter resulting in a bulk grain temperature ranging from 28 to 98 degrees C. Both processes were responsible for marked structural changes of wheat kernel endosperm and were pronounced with increasing dose of ionizing radiation or with prolonged time of microwave treatment. Endosperm microstructures of wheat kernels treated with gamma-radiation ranging from 0.05 to 0.5 kGy did not differ from that of untreated ones. Only some changes in the structure of starch granules and proteins were observed at doses of 1, 5 and 10 kGy. Simultaneously at the doses of 5 and 10 kGy a statistically significant decrease of falling number, sodium dodecyl sulfate (SDS) sedimentation values, dough stability and energy were observed, while dough weakening progressed. Microwave treatment longer than 90 s caused marked changes in kernel endosperm structure. Some changes of proteins caused by denaturation created visible fibrils as well as high swelling and deformation of starch granules. This was followed by an increase in the falling number value, decrease in the estimated results of SDS sedimentation test, lowering of the percent of gluten washed out and of the dough energy, respectively. Also a significant decrease in bread quality expressed by volume and score was observed with increasing time of exposure to microwave.

  13. Gamma radiation effects on the viscosity of green banana flour

    Energy Technology Data Exchange (ETDEWEB)

    Uehara, Vanessa B.; Inamura, Patricia Y.; Mastro, Nelida L. Del [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: vanessa.uehara@usp.br, e-mail: patyoko@yahoo.com, e-mail: nlmastro@ipen.br

    2009-07-01

    Banana (Musa sp) is a tropical fruits with great acceptability among consumers and produced in Brazil in a large scale. Bananas are not being as exploited as they could be in prepared food, and research could stimulate greater interest from industry. The viscosity characteristics and a product consistency can determine its acceptance by the consumer. Particularly the starch obtained from green banana had been studied from the nutritional point of view since the concept of Resistant Starch was introduced. Powder RS with high content of amylose was included in an approved food list with alleged functional properties in Brazilian legislation. Ionizing radiation can be used as a public health intervention measure for the control of food-borne diseases. Radiation is also a very convenient tool for polymer materials modification through degradation, grafting and crosslinking. In this work the influence of ionizing radiation on the rheological behavior of green banana pulp was investigated. Samples of green banana pulp flour were irradiated in a {sup 60}Co Gammacell 220 (AECL) with doses of 0 kGy,1 kGy, 3 kGy, 5 kGy and 10 kGy in glass recipients. After irradiation 3% and 5% aqueous dilution were prepared and viscosity measurements performed in a Brooksfield, model DVIII viscometer using spindle SC4-18 and SC4-31. There was a reduction of the initial viscosity of the samples as a consequence of radiation processing, being the reduction inversely proportional to the flour concentration. The polysaccharide content of the banana starch seems to be degraded by radiation in solid state as shown by the reduction of viscosity as a function of radiation dose. (author)

  14. Behavior of the sorption of {sup 60} Co in aqueous solution on inorganic materials as function of p H; Comportamiento de la sorcion del {sup 60} Co en solucion acuosa sobre materiales inorganicos como una funcion del pH

    Energy Technology Data Exchange (ETDEWEB)

    Granados, F.; Bulbulian, S.; Solache R, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Bertin, V. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    The sorption of the {sup 60} Co is evaluated in aqueous solution on Mg O, MnO{sub 2}, TiO{sub 2}, Sn O, activated carbon and hydrotalcite calcined as a function of the p H, using the method for lots and quantifying at the {sup 60} Co for gamma spectrometry. Likewise it was explained the one behavior of the sorption of the {sup 60} Co in the materials with base in the chemical species of this radioactive isotope in aqueous solution. The chemical species of the {sup 60} Co in solution were identified by electrophoresis of high voltage for the different p H values. It was found that under the experimental conditions, the {sup 60} Co showed a significant sorption on MnO{sup 2}, TiO{sup 2} and activated carbon. On the other hand, in Mg O, Sn O and calcined hydrotalcite also was observed a sorption, although in smaller quantities. The studied hydrated metallic oxides retained the {sup 60} Co for ion exchange via. It was found that the {sup 60} Co was present as a cationic specie to p H 1, 3, 5 and 7 and like a neutral specie to alkaline p H. (Author)

  15. Effect of gamma radiation on Campylobacter jejuni

    Energy Technology Data Exchange (ETDEWEB)

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

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

  16. Use of gamma radiation for preparation of nutrient culture media

    Energy Technology Data Exchange (ETDEWEB)

    Speranskaya, I.D.; Tumanyan, M.A.; Mironova, L.L.

    1977-01-01

    A technique was developed for sterilization of nutrient culture media using ..gamma..-radiation. For this purpose, dry preparations were exposed to 3 to 6 Mrad radiation, then dissolved in sterile distilled water. The quality of media and solutions thus obtained is as good as that of preparations sterilized by filtration. The advantage of the proposed sterilization method is that liquid media can be rapidly prepared and dry sterile media can be stored at room temperature for long periods of time.

  17. Evidence for successful acceptance of irradiated free gingival allografts in dogs. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rubenstein, H.S.; Ruben, M.P.; Levy, C.; Peiser, S.

    1975-04-01

    Free graft samples were excised and frozen to -55/sup 0/C. Subsequently the grafts were exposed to 2.5 x 10/sup 6/ rads of /sup 60/Co ..gamma..-radiation. The irradiated allogeneic grafts were later reconstituted and surgically transferred to four recipient subjects. Three autogenous nonirradiated grafts were also placed as controls. The animals were killed so as to furnish healing data at 0, 3, 7, 10, and 40 days postoperatively. Fourteen allografts were evaluated. They were judged to be nonantigenic, immunologically incompetent and nonviable. However, retention of an essentially unaltered connective tissue corium may have been instrumental in supporting subsequent epithelial regeneration from adjacent host tissue, while being passively incorporated into a very dynamic receptor zone. The graft thus served as a scaffolding for connective tissue deposition and attachment. It appears that the experimental regime obviated the immunologic interference usually encountered in allografting procedures. Thus, high intensity irradiation of the graft tissue may have rendered the tissue to be immunologically tolerable. Further studies are required to ascertain the duration of the host's immunologic unresponsiveness to the alien tissue, as well as ultimate structural and biologic fate of the transplanted tissues. Experiments are now in progress which have been designed to test the extent of immunologic sensitization induced by the grafted tissue.

  18. Gamma radiation synthesis of colloidal AgNPs for its potential application in antimicrobial fabrics

    Science.gov (United States)

    Bera, Anuradha; Garai, Purabi; Singh, Rita; Prakash Gupta, P.; Malav, Shatrughan; Singh, Durgeshwer; Kumar, Devendra; Tiwari, B. L.; Vaijapurkar, S. G.

    2015-10-01

    Highly stable colloidal solution of silver nanoparticles in a water-isopropanol-polyvinyl alcohol system was prepared through 60Co-gamma radiation at total dose of 35 kGy at dose rate of 5.67 kGy/h under nitrogen atmosphere. Ultraviolet-visible (UV-vis), X-ray diffraction (XRD), Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) of the obtained colloidal solution indicated the formation of spherical shaped well mono dispersed silver nanoparticles with average diameter about 30 nm having very narrow size distribution. The radiolytically obtained nanosilver colloid was coated onto cotton fabrics by a simple industrial screen printing method and its adhesion with the fabric was found out by leaching studies using Atomic Absorption Spectrophotometry (AAS). Good adhesion was achieved by the adopted method wherein 89.5% of the coated nanosilver was retained in the fabric even after keeping the fabrics soaked in water for more than 60 h. Antimicrobial efficacy tests of the nanosilver coated cotton fabric showed that nanosilver coating is effective in killing both bacterial and fungal strains even at very low nanosilver loading (21.81 μgm/cm2). Nanosilver coating on the cotton fabric did not allow microbes (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Candida albicans) to adhere and proliferate on fabric surface. Staphylococci (Staphylococcus aureus) and Yeast (Candida albicans) showed inhibition zones in presence of these nanosilver coated fabrics while no inhibition zone was observed with the uncoated control fabric.

  19. Growth changes induced by gamma radiation on Biomphalaria straminea (Dunker, 1848

    Directory of Open Access Journals (Sweden)

    Motta Mauricy A da

    1999-01-01

    Full Text Available Doses of 60Co gamma radiation with 2.5; 5; 7.5; 10; 15; 20; 25; 30; 35; 40; 45; 50; 55; 60; 80; 160; 320 and 640 Gy were applied to 1,080 snails Biomphalaria straminea, an intermediate host of Schistosoma mansoni, divided in groups containing 30 mollusks. In addition, 60 non irradiated snails were kept as control. Fifty percent of the population was kept in colonies (allowing cross fertilization while the other half was maintained in sexual isolation (allowing self fertilization and during one month their growth was observed through the daily measurement of the shell diameter. Results showed that after 20 Gy doses the growth in shell diameter of irradiated snails was greater than that of the control group after 30 days. At this dose the snail size was the greatest, among all isolated groups. The 80 Gy doses also induced the final shell diameter of isolated snails to be greater then that observed in the control groups. As this effect was most evident among the isolated snails, a possible hormonal role may have been involved in the observed phenomena, which is under investigation with the objective of identifying any future applications that this could have to schistosomiasis control.

  20. Approximation of Sums of Experimental Radiative Strength Functions of Dipole Gamma-Transitions in the Region $E_\\gamma \\approx B_n$ for the Atomic Masses $40 \\leq a \\leq 200$

    CERN Document Server

    Sukhovoj, A M; Khitrov, V A

    2008-01-01

    The sums k(E1)+k(M1) of radiative strength functions of dipole primary gamma-transitions were approximated with high precision in the energy region of $0.5 < E_1 < B_n-0.5$ MeV for nuclei: 40K, 60Co, 71,74Ge, 80Br, 114Cd, 118Sn, 124,125Te, 128I, 137,138,139Ba, 140La, 150Sm, 156,158Gd, 160Tb, 163,164,165Dy, 166Ho, 168Er, 170Tm, 174Yb, 176,177Lu, 181Hf, 182Ta, 183,184,185,187W, 188,190,191,193Os, 192Ir, 196Pt, 198Au, 200Hg by sum of two independent functions. It has been shown that this parameter of gamma-decay are determined by the structure of the decaying and excited levels, at least, up to the neutron binding energy.

  1. Carbon Nanotubes Synthesis Through Gamma Radiation

    Science.gov (United States)

    Tirado, Pablo; Garcia, Rafael; Montes, Jorge; Melendrez, Rodrigo; Barboza, Marcelino; Contreras, Oscar

    2015-03-01

    Carbon nanotubes show a great potential of applications since there discovery by Iijima in 1991[1] due to their numerous physical-chemical properties such as their high weight to strength relationship, which make them ideal to use in high resistance compound materials, and in many other applications[2] In this work, a novel method for the synthesis of carbon nanotubes is presented, starting from an ultra-thin sheet of graphite synthesized by the chemical vapor decomposition technique (CVD), using ultra high purity methane and hydrogen at 1200°C in a horizontal quartz reactor. For the synthesis of carbon nanotubes, the graphite sheets were exposed to different doses of radiation, with the objective of breaking the graphite bonds and form carbon nanotubes; a Gammacell equipment model 220 Excel was used for the purpose, which counts with a radiation source of cobalt 60, and a current radiation rate of 0.9 Gy/seconds. The time of exposure to radiation was varied in each sample, according to the desired dose of radiation in each case, afterwards the samples were characterized using the Raman spectroscopy and TEM microscopy techniques with the objective of observing the kind of nanotubes formed, their morphology and their number of defects. Results will be shown during the poster session.

  2. Synthesis of graphene using gamma radiations

    Indian Academy of Sciences (India)

    Leila Shahriary; Anjali A Athawale

    2015-06-01

    Considering the advantages of radiolytic synthesis such as the absence of toxic chemical as a reducing agent, uniform distribution of reducing agent and high purity of product, the synthesis of graphene (rGO) from graphene oxide (GO) by the gamma irradiation technique using a relatively low dose rate of 0.24 kGy h−1 has been described. Structural and physicochemical properties of GO and rGO were investigated with the help of various characterization techniques. The presence of peak at 271 nm in ultraviolet–visible spectrum, C= C aromatic stretching vibrations between 1450 and 1600 cm−1 in the Fourier transform infrared spectrum and significant decrease in photoluminescence peak intensity at 470 and 567 nm wavelengths represent the reduction of GO to graphene by gamma irradiation. The decrease in stacking height from 7.71 nm in GO to 3.52 nm in rGO as observed from the X-ray powder diffraction analysis further confirms the same. Raman spectra show significantly lower D to G band ratio for rGO compared with GO. Also, the cyclic voltammograms obtained using GO- and rGO-modified electrodes (working electrode) in standard redox system show enhanced peak intensities together with decrease in potential difference between oxidation and reduction peaks in case of graphene.

  3. Measurements of 60Co in spoons activated by neutrons during the JCO criticality accident at Tokai-mura in 1999.

    Science.gov (United States)

    Gasparro, J; Hult, M; Komura, K; Arnold, D; Holmes, L; Johnston, P N; Laubenstein, M; Neumaier, S; Reyss, J-L; Schillebeeckx, P; Tagziria, H; Van Britsom, G; Vasselli, R

    2004-01-01

    Neutron activated items from the vicinity of the place where the JCO criticality accident occurred have been used to determine the fluence of neutrons around the facility and in nearby residential areas. By using underground laboratories for measuring the activation products, it is possible to extend the study to also cover radionuclides with very low activities from long-lived radionuclides. The present study describes gamma-ray spectrometry measurements undertaken in a range of underground laboratories for the purpose of measuring (60)Co more than 2 years after the criticality event. The measurements show that neutron fluence determined from (60)Co activity is in agreement with previous measurements using the short-lived radionuclides (51)Cr and (59)Fe. Limits on contamination of the samples with (60)Co are evaluated and shown to not greatly affect the utility of neutron fluence determinations using (60)Co activation.

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

    Directory of Open Access Journals (Sweden)

    Sudhanshu Saxena

    2014-01-01

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

  5. Evaluation of {gamma}-radiation on green tea odor volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, G.B., E-mail: gbfanaro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Duarte, R.C., E-mail: renatocduarte@yahoo.com.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Araujo, M.M., E-mail: mmozeika@yahoo.co [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil); Purgatto, E., E-mail: epurgatt@usp.b [Universidade de Sao Paulo-Faculdade de Ciencias Farmaceuticas, FCF/USP, Departamento de Alimentos e Nutricao Experimental, Av. Prof. Lineu Prestes, 580 Bloco 14, 05508-900, Sao Paulo, SP (Brazil); Villavicencio, A.L.C.H., E-mail: villavic@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN)-Centro de Tecnologia das Radiacoes, Av. Professor Lineu Prestes, 2242, 05508-000 Sao Paulo, SP (Brazil)

    2011-01-15

    The aim of this study was to evaluate the gamma radiation effects on green tea odor volatiles in green tea at doses of 0, 5, 10, 15 and 20 kGy. The volatile organic compounds were extracted by hydrodistillation and analyzed by GC/MS. The green tea had a large influence on radiation effects, increasing the identified volatiles in relation to control samples. The dose of 10 kGy was responsible to form the majority of new odor compounds following by 5 and 20 kGy. However, the dose of 5 kGy was the dose that degraded the majority of volatiles in non-irradiated samples, following by 20 kGy. The dose of 15 kGy showed has no effect on odor volatiles. The gamma radiation, at dose up to 20 kGy, showed statistically no difference between irradiated and non irradiated green tea on odors compounds.

  6. Design and development of a portable gamma radiation monitor

    Energy Technology Data Exchange (ETDEWEB)

    Munir, M.; Khalid, M. [Health Physics Division, Directorate of Systems and Services, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore, Islamabad 45650 (Pakistan); Ahmad, N.; Sohail, S.; Naveed, R. A.; Rafiq, M. Q. [Pakistan Institute of Engineering and Applied Sciences (PIEAS), P. O. Nilore, Islamabad 45650 (Pakistan)

    2009-07-15

    A portable gamma radiation monitor has been designed and developed. The monitor can be used effectively in the dose range from 0.07 to 500 mGy/h due to gamma rays of energy greater than 65 keV. The monitor overestimated radiation doses and the uncertainty in the measured dose rate has been found to be {<=}30%. The response of the monitor can be considered isotropic within an acceptable error of {+-}30%. Provision has also been added to use the monitor as an installed radiation monitor. In installed mode, it can be operated from a remote location up to 1 km and the timing history can be stored on a personal computer.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  8. Managing NIF safety equipment in a high neutron and gamma radiation environment.

    Science.gov (United States)

    Datte, Philip; Eckart, Mark; Jackson, Mark; Khater, Hesham; Manuel, Stacie; Newton, Mark

    2013-06-01

    The National Ignition Facility (NIF) is a 192 laser beam facility that supports the Inertial Confinement Fusion program. During the ignition experimental campaign, the NIF is expected to perform shots with varying fusion yield producing 14 MeV neutrons up to 20 MJ or 7.1 × 10(18) neutrons per shot and a maximum annual yield of 1,200 MJ. Several infrastructure support systems will be exposed to varying high yield shots over the facility's 30-y life span. In response to this potential exposure, analysis and testing of several facility safety systems have been conducted. A detailed MCNP (Monte Carlo N-Particle Transport Code) model has been developed for the NIF facility, and it includes most of the major structures inside the Target Bay. The model has been used in the simulation of expected neutron and gamma fluences throughout the Target Bay. Radiation susceptible components were identified and tested to fluences greater than 10(13) (n cm(-2)) for 14 MeV neutrons and γ-ray equivalent. The testing includes component irradiation using a 60Co gamma source and accelerator-based irradiation using 4- and 14- MeV neutron sources. The subsystem implementation in the facility is based on the fluence estimates after shielding and survivability guidelines derived from the dose maps and component tests results. This paper reports on the evaluation and implementation of mitigations for several infrastructure safety support systems, including video, oxygen monitoring, pressure monitors, water sensing systems, and access control interfaces found at the NIF.

  9. Viabilidade e micoflora de sementes de amendoim irradiadas com cobalto (60Co Viability and mycoflora of irradiated seeds of peanut with cobalt (60Co

    Directory of Open Access Journals (Sweden)

    Niédja M. C. Alves

    2011-03-01

    Full Text Available Estudou-se o efeito de diferentes doses da irradiação gama na germinação e percentagem de infecção fúngica em sementes de amendoim cultivar BR1. Inicialmente, as sementes foram avaliadas quanto à micoflora, utilizando-se o método de papel de filtro umedecido, a germinação em substrato de papel germitest e determinação do teor de umidade em estufa, a 105 ± 2 ºC. Posteriormente, as sementes foram submetidas à irradiação com uma fonte de 60Co, tipo gammacell, onde se estudou o efeito de 8 doses de irradiação na micoflora e germinação das sementes acondicionadas em embalagem de PET e polietileno trançado durante 60 dias de armazenamento, sem controle de temperatura e umidade relativa do ar. Os fatores estudados (doses em kGy, embalagens e tempo de armazenamento foram analisados em um delineamento inteiramente casualizado, dispostos em fatorial. Com base nos resultados, observou-se que a irradiação gama afetou negativamente a germinação das sementes de amendoim e que doses acima de 3,0 kGy comprometem a germinação das sementes. A radiação a partir da dose 1,5 kGy eliminou os fungos Aspergillus niger e, Penicillium a partir da dose de 2,5 kGy.The effect of different doses of the gamma irradiation was studied on germination and percentage of fungal infection in peanut seeds cultivar BR1. Initially the seeds were evaluated for the mycoflora using the method of humidified filter paper, the germination in paper substratum germitest and determination of the moisture content in oven at 105 ± 2 ºC. Later on the seeds were submitted to irradiation with a source of 60Co, type gammacell, where the effect was studied of 8 doses of irradiation in the mycoflora and germination of the seeds conditioned in PET packing and polyethylene tressed during 60 days of storage, without control of temperature and relative humidity of the air. The studied factors (doses in kGy, packing and time of storage were analyzed in a completely

  10. Validation of dose-response curve of CRCN-NE - Regional Center for Nuclear Sciences from Northeast Brazil for {sup 60}Co: preliminary results; Validacao da curva dose-resposta do CRCN-NE para {sup 60}Co: resultados preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Mendonca, Julyanne C.G.; Mendes, Mariana E.; Hwang, Suy F.; Lima, Fabiana F. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Santos, Neide, E-mail: july_cgm@yahoo.com.br [Universidade Federal de Pernambuco (CCB/UFPE), Recife, PE (Brazil). Departamento de Genetica

    2014-07-01

    The cytogenetic study has the chromosomal alterations as biomarkers in absorbed dose estimation by the body of individuals involved in exposure to ionizing radiation by interpreting a dose response calibration curve. Since the development of the technique to the analysis of data, you can see protocol characteristics, leading the International Atomic Energy Agency indicate that any laboratory with intention to carry out biological dosimetry establish their own calibration curves. The Biological Dosimetry Laboratory of the Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN), Brazil, recently established the calibration curve related to gamma radiation ({sup 60}Co). Thus, this work aimed to start the validation of this calibration curve from samples of three different blood donors which were irradiated with an absorbed known single dose of 1 Gy. Samples were exposed to {sup 60}Co source (Glaucoma 220) located in the Department of Nuclear Energy (DEN/UFPE). After fixation with methanol and acetic acid and 5% Giemsa staining, the frequency of chromosomal alterations (dicentric chromosomes, acentric rings and fragments) were established from reading of 500 metaphases per sample and doses were estimated using Dose Estimate program. The results showed that, using the dose-response curve calibration for dicentrics, the dose absorbed estimated for the three individuals ranged from 0.891 - 1,089Gy, taking into account the range of confidence of 95%. By using the dose-response curve for dicentrics added to rings and for the same interval of confidence the doses ranged from 0,849 - 1,081Gy. Thus, the estimative encompassed known absorbed dose the three individuals in confidence interval of 95%. These preliminary results seems to demonstrate that dicentric dose-response curves and dicentrics plus rings established by CRCN-NE / CNEN are valid for dose estimation in exposed individuals. This validation will continue with samples from different individuals at different doses.

  11. Phenols and tannins contents of Anacardium occidentale Linn and Anadenanthera colubrina (Vell.) Brenan exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Gustavo Henrique Farias dos [Universidade Federal de Pernambuco (GERAR/UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia; Silva, Edvane Borges da [Universidade Federal de Pernambuco (UFPE), Vitoria de Santo Antao, PE (Brazil). Centro Academico de Vitoria; Amorim, Elba Lucia Cavalcanti de; Peixoto Sobrinho, Tadeu, E-mail: elba@ufpe.b [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Ciencias Farmaceuticas; Lima, Claudia Sampaio de Andrade [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    2011-07-01

    Anacardium occidentale Linn (cajueiro) and Anadenanthera colubrina (Vell.) Brenan (angico) are very know as a source of phenolic compounds, mainly tannins. The aim of this study was to evaluate the difference of phenols and tannins contents of crude extracts were measured after irradiation of barks and leaves of each plant source, using a source of {sup 60}Co. The crude extracts were divided into control group and three groups which were separately after exposition to gamma radiation, in doses of 5; 7.5 and 10 kGy. From each group, the total phenols were quantified by the Folin-Ciocalteau method, while the contents of tannins were assessed using precipitation of the casein technique. For all doses, the total phenol and tannin percentages from 'cajueiro' barks presented no significant statistical alteration. However, for the leaves of 'cajueiro', their chemical composite levels significantly changed with the radiation absorbed dose. On the other hand, the gamma irradiation did not cause alterations in total phenols and tannins content of extracts from 'angico'. (author)

  12. ONE CASE OF LEUKEMIA INDUCED BY 60Co ACCIDENT

    Institute of Scientific and Technical Information of China (English)

    邵松生; 冯嘉林; 等

    1995-01-01

    The peripheral blood lymphocyte chromosomes in a case of 60Co γ rays accident were examined at 2.5h after exposure.The frequency of the dicentrics plus centric rings was 89% and exposure dose was estimated to be 4.78 (4.53-4.88)GY.The examinations of lymphocyte chromosome aberration within follow-up 12a showed that the incidence of Dic+R reduced with lg regrssion(r=-0.9895).While the number of ceels with stable aberration remained unchanged and showed a tendency to increase.During the period of leukemia,bone marrow cell chromosome aberrations were studied by method of G-banding.Of 13 cells observed,4 cells belonged to normal karyotypes.Among 9 aberration cells,12 aberrations were detected.The majority of which were classified as translocation,deletion and inversion,Numeric aberrations were-9,12,20-,22,-y.This case suggested that acute lymphocytic leukemia was induced after radiation accident.

  13. Field Deployable Gamma Radiation Detectors for DHS Use

    Energy Technology Data Exchange (ETDEWEB)

    Sanjoy Mukhopadhyay

    2007-08-01

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

  14. Field-deployable gamma-radiation detectors for DHS use

    Science.gov (United States)

    Mukhopadhyay, Sanjoy

    2007-09-01

    Recently, the Department of Homeland Security (DHS) has integrated all nuclear detection research, development, testing, evaluation, acquisition, and operational support into a single office: the Domestic Nuclear Detection Office (DNDO). The DNDO has specific requirements set for all commercial off-the-shelf and government off-the-shelf radiation detection equipment and data acquisition systems. This article would investigate several recent developments in field deployable gamma radiation detectors that are attempting to meet the DNDO specifications. Commercially available, transportable, handheld radio isotope identification devices (RIID) are inadequate for DHS' requirements in terms of sensitivity, resolution, response time, and reach-back capability. The leading commercial vendor manufacturing handheld gamma spectrometer in the United States is Thermo Electron Corporation. Thermo Electron's identiFINDER TM, which primarily uses sodium iodide crystals (3.18 x 2.54cm cylinders) as gamma detectors, has a Full-Width-at-Half-Maximum energy resolution of 7 percent at 662 keV. Thermo Electron has just recently come up with a reach-back capability patented as RadReachBack TM that enables emergency personnel to obtain real-time technical analysis of radiation samples they find in the field1. The current project has the goal to build a prototype handheld gamma spectrometer, equipped with a digital camera and an embedded cell phone to be used as an RIID with higher sensitivity, better resolution, and faster response time (able to detect the presence of gamma-emitting radio isotopes within 5 seconds of approach), which will make it useful as a field deployable tool. The handheld equipment continuously monitors the ambient gamma radiation, and, if it comes across any radiation anomalies with higher than normal gamma gross counts, it sets an alarm condition. When a substantial alarm level is reached, the system automatically triggers the saving of relevant spectral data and

  15. Effect of kappa-carrageenan on the properties of poly(N-vinyl pyrrolidone)/kappa-carrageenan blend hydrogel synthesized by {gamma}-radiation technology

    Energy Technology Data Exchange (ETDEWEB)

    Zhai Maolin E-mail: zkkf@pku.edu.cn; Ha Hongfei; Yoshii, F.; Makuuchi, K

    2000-03-01

    A series of hydrogels in the form of rods were prepared from kappa-carrageenan (KC) and poly (N-vinyl pyrrolidone) (PVP) by gamma radiation with {sup 60}Co {gamma} source at room temperature. The properties of the prepared hydrogels, such as the gel strength, gel fraction and swelling behavior were investigated. Incorporation of KC into the PVP/water system increased obviously the gel strength and equilibrium degree of swelling (EDS) of PVP hydrogel. The experimental analyses showed that the crosslinking reaction of PVP was quicker than the degradation of KC at a low dose (less than 30 kGy), and the degradation of KC was inhibited in the PVP/KC mixture system. So an interpenetrating polymer network (IPN) hydrogel composed of PVP (a chemical crosslinking network) and KC (a physical crosslinking network) was proposed here. The existence of different classes of water in this IPN system was shown by water melting curves using DCS. (author)

  16. Quality assurance of environmental gamma radiation monitoring in Slovenia.

    Science.gov (United States)

    Stuhec, M; Zorko, B; Mitić, D; Miljanić, S; Ranogajec-Komor, M

    2006-01-01

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

  17. Search for Charmonium States Decaying to J/psi gamma gamma Using Initial-State Radiation Events

    CERN Document Server

    Aubert, B; Bóna, M; Boutigny, D; Couderc, F; Karyotakis, Yu; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Graugès-Pous, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo-Sánchez, P; Barrett, M; Ford, K E; Hart, A J; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schröder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Çuhadar-Dönszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, Y K; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, C; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro-Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F R; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flächer, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Stängle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Mclachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, Gallieno; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; LoSecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonian, R; Wong, Q K; Blount, N L; Brau, J E; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; La Vaissière, C de; Hamon, O; Hartfiel, B L; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai-Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; Vasseur, G; Yéche, C; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W M; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Lüth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Vavra, J; Van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martínez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R V; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihályi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H; al, et

    2006-01-01

    We study the processes e+e- -> (J/psi gamma gamma) gamma and e+e- -> (J/psi pi- pi+) gamma where the hard photon radiated from an initial e+e- collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/psi gamma gamma we consider J/psi pi0, J/psi eta, chi_{c1} gamma, and chi_{c2} gamma candidates. The invariant mass of the hadronic final state defines the effective e+e- CM energy in each event, so these data can be compared with direct e+e- measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/psi gamma gamma channels in the Y(4260) mass region.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-12-16

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

  19. Gamma-radiation induced damage of proteins in the thick fraction of egg white

    Directory of Open Access Journals (Sweden)

    MARIJA VUCKOVIC

    2005-11-01

    Full Text Available The thick fraction of egg white saturated with either N2O or Ar was irradiated in the dose range 1.5–45 kGy at 60Co gamma source. The gel structure decomposition and other processes accompanied with changes in protein molecular mass were followed by Sephadex G-200 exclusion chromatography, denaturing SDS-polyacrylamide gel electrophoresis, viscosity and turbidity measurements. The complex behaviour of viscosity was observed in the N2O saturated sample (where the hydrated electron was converted into the OH radical; the initial abrupt decrease that radually slows down reaching the minimum at 12 kGy (hmin = 2.7 mPa s followed by the slow rise was measured. The Ar saturated sample ([eaq-] ~ [OH] showed both the significantly faster initial decrease and lower viscosity minimum (hmin = 2.2 mPa s. The combined Sephadex G-200 exclusion chromatography and denaturing SDS-polyacrylamide gel electrophoresis data revealed that the three-dimensional egg white (hydrated gel structure was (efficiently decomposed even in the N2O saturated sample. The protein scission was detected in the entire dose range studied, while the protein agglomeration is not noticed at low doses (around 1.5 kGy; however, it dominates at higher doses. In the highest dose region studied, the loss of structure in SDS-PAGE chromatograms indicates that the agglomerates are formed from protein fragments rather than from intact proteins. The continuous linear increase in turbidity was measured. The results obtained indicate that ionizing radiation causes the breakdown of the protein network of the thick fraction of egg white via the reduction of S–S bridges by the hydrated electron and the protein fragmentation due to the direct action of ionizing radiation. The protein agglomeration is initiated by the reaction of the OH radical; its inefficiency at low doses is attributed to the glucose antioxidant properties and radical immobility.

  20. Projection of needs for gamma radiation sources and other radioisotopes and assessment of alternatives for providing radiation sources

    Energy Technology Data Exchange (ETDEWEB)

    Ross, W.A.; Jensen, G.A.; Clark, L.L.; Eakin, D.E.; Jarrett, J.H.; Katayama, Y.B.; McKee, R.W.; Morgan, L.G.; Nealey, S.M.; Platt, A.M.; Tingey, G.L.

    1989-06-01

    Pacific Northwest Laboratory reviewed the projected uses and demands for a variety of nuclear byproducts. Because the major large-scale near-term demand is for gamma irradiation sources, this report concentrates on the needs for gamma sources and evaluates the options for providing the needed material. Projections of possible growth in the irradiation treatment industry indicate that there will be a need for 180 to 320 MCi of /sup 60/Co (including /sup 137/Cs equivalent) in service in the year 2000. The largest current and projected use of gamma irradiation is for the sterilization of medical devices and disposable medical supplies. Currently, 40% of US disposable medical products are treated by irradiation, and within 10 years it is expected that 90% will be treated in this manner. Irradiation treatment of food for destruction of pathogens or parasites, disinfestation, or extension of allowable storage periods is estimated to require an active inventory of 75 MCi of /sup 60/Co-equivalent gamma source in about a decade. 90 refs., 7 figs., 25 tabs.

  1. Oxidation of naringenin by gamma-radiation

    Science.gov (United States)

    Nagy, Tristan O.; Ledolter, Karin; Solar, Sonja

    2008-06-01

    The reaction of rad OH with naringenin (4',5,7-trihydroxyflavanone) in the presence of air induced the formation of the hydroxylation product eriodictyol (3',4',5,7-tetrahydroxyflavanone). Its yield was dependent on pH. The initial degradation yield of naringenin was Gi(-Nar)=(2.5±0.2)×10 -7 mol dm -3 J -1. For the reaction with rad OH, a rate constant k ( rad OH+naringenin)=(7.2±0.7)×10 9 M -1 s -1 was determined. In the presence of N 2O and NaN 3/N 2O, no eriodyctiol was formed. Apigenin (4',5,7-trihydroxyflavon) was detected as decay product of the naringenin phenoxyl radicals. In Ar-saturated solutions, naringenin exhibited a pronounced radiation resistance, G(-naringenin) ˜0.3×10 -7 mol dm -3 J -1.

  2. Effects of gamma radiation on snake venoms

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, N.; Spencer, P.J.; Andrade, H.F.; Guarnieri, M.C.; Rogero, J.R

    1998-06-01

    Ionizing radiation is able to detoxify several venoms, including snake venoms, without affecting significantly their immunogenic properties. In order to elucidate this phenomena, we conceived a comparative pharmacological study between native and irradiated (2,000 Gy) crotoxin, the main toxin of the South American rattlesnake Crotalus durissus terrificus. Crotoxin was isolated and purified by molecular exclusion chromatography, pI precipitation and, subsequently submitted to irradiation. Gel filtration of the irradiated toxin resulted in some high molecular weight aggregates formation. Crotoxin toxicity decreased two folds after irradiation, as determined by LD{sub 50} in mice. Native and irradiated crotoxin biodistribution ocurred in the same general manner, with renal elimination. However, in contrast to irradiated crotoxin, the native form was initially retained in kidneys. A later concentration (2-3 hr) appeared in phagocytic mononuclear cells rich organs (liver and spleen) and neural junction rich organs (muscle and brain)

  3. 60Co-γ辐照高产低植酸小麦新品系的鉴定筛选%Screening and Identification of New High-Yielding Wheat Lines with Low Phytic Acid Induced by 60Co-γRadiation

    Institute of Scientific and Technical Information of China (English)

    郎淑平; 马燕欣

    2016-01-01

    通过辐射诱变手段获得种子低植酸(low phytic acid)突变系,进而选育低植酸作物品系,是可行的技术路径。本研究利用60 Co-γ辐照小麦种子,从其后代中筛选到熟期与辐射亲本相仿或早熟、高产且籽粒植酸含量明显低于辐射亲本的小麦新品系10份,为小麦育种提供新的种质资源。%In recent years,it has emerged as a research hotspot that crop mutant lines with low phytic acid (LPA)are induced by radia-tion mutagenesis,which are subsequently used as materials to breed LPA varieties.In this study,by screening a large number of 60 Co-γradiated wheat seeds,we obtained 10 new wheat lines.Compared to their parental variety,the new wheat lines attained higher yield and had lower phytic acid content while having similar or earlier maturity time.These new wheat lines can be used as a new source of wheat germplasm for breeding LPA varieties in the future.

  4. X-Ray and Gamma-Ray Radiation Detector

    DEFF Research Database (Denmark)

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  6. Shielding of gamma radiation by typical European houses

    Science.gov (United States)

    Meckbach, Reinhard; Jacob, Peter; Paretzke, Herwig G.

    1987-03-01

    The shielding of gamma radiation by typical European houses has been investigated using a Monte Carlo photon transport code. Sources of the gamma radiation are activity deposited on the building and its surroundings and air-borne radionuclides in an semi-infinite cloud. Results are given for different source energies and at various locations inside and outside of the buildings. The effects of deposition on nearby trees and of shielding by neighbouring buildings was investigated. A comparison has been made with results obtained for the same buildings by the point kernel buildup factor method. More than an order of magnitude underestimations by the point kernel method are shown to arise in certain cases.

  7. Titanium-Water Thermosyphon Gamma Radiation Effects and Results

    Science.gov (United States)

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

    2012-01-01

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

  8. Titanium-Water Thermosyphon Gamma Radiation Exposure and Results

    Science.gov (United States)

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

    2012-01-01

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

  9. Gamma radiation induced effects on slaughterhouse wastewater treatment

    Science.gov (United States)

    Melo, Rita; Cabo Verde, Sandra; Branco, Joaquim; Botelho, M. Luisa

    2008-01-01

    A preliminary study using gamma radiation on slaughterhouse wastewater samples was carried out. Chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) results were obtained at a dose rate of 0.9 kGy h -1. A decrease of COD, BOD and colour was observed after irradiation at high absorbed doses. The microbiological results, following irradiation in the same conditions, correlated with the BOD results. The results obtained highlight the potential of this technology for wastewater treatment.

  10. Oxidation of naringenin by gamma-radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Tristan O. [Department of Nutritional Sciences, Section Radiation Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria); Ledolter, Karin [Department of Biomolecular Structural Chemistry, University of Vienna, Campus-Vienna-Biocenter 5, A-1030 Vienna (Austria); Solar, Sonja [Department of Nutritional Sciences, Section Radiation Biology, University of Vienna, Althanstrasse 14, A-1090 Vienna (Austria)], E-mail: sonja.solar@univie.ac.at

    2008-06-15

    The reaction of {sup {center_dot}}OH with naringenin (4',5,7-trihydroxyflavanone) in the presence of air induced the formation of the hydroxylation product eriodictyol (3',4',5,7-tetrahydroxyflavanone). Its yield was dependent on pH. The initial degradation yield of naringenin was G{sub i}(-Nar)=(2.5{+-}0.2)x10{sup -7} mol dm{sup -3} J{sup -1}. For the reaction with {sup {center_dot}}OH, a rate constant k ({sup {center_dot}}OH+naringenin)=(7.2{+-}0.7)x10{sup 9} M{sup -1} s{sup -1} was determined. In the presence of N{sub 2}O and NaN{sub 3}/N{sub 2}O, no eriodyctiol was formed. Apigenin (4',5,7-trihydroxyflavon) was detected as decay product of the naringenin phenoxyl radicals. In Ar-saturated solutions, naringenin exhibited a pronounced radiation resistance, G(-naringenin) {approx}0.3x10{sup -7} mol dm{sup -3} J{sup -1}.

  11. Influence of gamma radiation onto polymeric matrix with papain

    Science.gov (United States)

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

    2010-03-01

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

  12. Inactivation of bacteria in sewage sludge by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-01-01

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

  13. Influence of gamma radiation onto polymeric matrix with papain

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-15

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

  14. Sensory evaluation of black beans submitted to gamma radiation from Cobalt-60; Avaliacao sensorial de feijao preto submetido a radiacao de Cobalto-60

    Energy Technology Data Exchange (ETDEWEB)

    Moura, Neila Camargo de; Canniatti-Brazaca, Solange Guidolin; Spoto, Marta Helena Fillet, E-mail: sgcbraza@esalq.usp.b [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Agroindustria, Alimentos e Nutricao; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Secao de Entomologia e Irradiacao de Alimentos

    2005-04-15

    The objective of this research was to evaluate the sensory aspects of black beans submitted to gamma radiation from {sup 60}Co. The study involved eight panelists, between 17 to 23 years old, who were selected and trained for the descriptive analysis of appearance, aroma, flavor and texture. The panelists analyzed alterations of appearance, aroma, flavor and texture of non-irradiated and irradiated black beans with doses 2, 4, 6, 8 and 10kGy. The results were analyzed by test F, ANOVA and the Tukey test (5%), with the use of computers and the sensory analysis software Compusense Five and SAS. The results showed that irradiated samples decreased the bitter flavor, accentuated color and brightness and samples non-irradiated dry texture. The radiation treatment is a good method for conservation of black beans in doses evaluated in this study.(author)

  15. Tolerance to Gamma Radiation in the Marine Heterotardigrade, Echiniscoides sigismundi

    Science.gov (United States)

    Hygum, Thomas L.; Andersen, Kasper N.; Clausen, Lykke K. B.; Møbjerg, Nadja

    2016-01-01

    Tardigrades belong to the most radiation tolerant animals on Earth, as documented by a number of studies using both low-LET and high-LET ionizing radiation. Previous studies have focused on semi-terrestrial species, which are also very tolerant to desiccation. The predominant view on the reason for the high radiation tolerance among these semi-terrestrial species is that it relies on molecular mechanisms that evolved as adaptations for surviving dehydration. In this study we report the first study on radiation tolerance in a marine tardigrade, Echiniscoides sigismundi. Adult specimens in the hydrated active state were exposed to doses of gamma radiation from 100 to 5000 Gy. The results showed little effect of radiation at 100 and 500 Gy but a clear decline in activity at 1000 Gy and higher. The highest dose survived was 4000 Gy, at which ca. 8% of the tardigrades were active 7 days after irradiation. LD50 in the first 7 days after irradiation was in the range of 1100–1600 Gy. Compared to previous studies on radiation tolerance in semi-terrestrial and limnic tardigrades, Echiniscoides sigismundi seems to have a lower tolerance. However, the species still fits into the category of tardigrades that have high tolerance to both desiccation and radiation, supporting the hypothesis that radiation tolerance is a by-product of adaptive mechanisms to survive desiccation. More studies on radiation tolerance in tardigrade species adapted to permanently wet conditions, both marine and freshwater, are needed to obtain a more comprehensive picture of the patterns of radiation tolerance. PMID:27997621

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

    Science.gov (United States)

    Gandolph, Jacob; Mauer, Lisa; Perchonok, Michele

    2006-01-01

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

  17. On the omnipresent background gamma radiation of the continuous spectrum

    Science.gov (United States)

    Banjanac, R.; Maletić, D.; Joković, D.; Veselinović, N.; Dragić, A.; Udovičić, V.; Aničin, I.

    2014-05-01

    The background spectrum of a germanium detector, shielded from the radiations arriving from the lower and open for the radiations arriving from the upper hemisphere, is studied by means of absorption measurements, both in a ground level and in an underground laboratory. The low-energy continuous portion of this background spectrum that peaks at around 100 keV, which is its most intense component, is found to be of very similar shape at the two locations. It is established that it is mostly due to the radiations of the real continuous spectrum, which is quite similar to the instrumental one. The intensity of this radiation is in our cases estimated to about 8000 photons/(m2s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m2s·2π·srad) in the underground laboratory, at the depth of 25 m.w.e. Simulations by GEANT4 and CORSIKA demonstrate that this radiation is predominantly of terrestrial origin, due to environmental gamma radiations scattered off the materials that surround the detector (the "skyshine radiation"), and to a far less extent to cosmic rays of degraded energy.

  18. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy.

    Directory of Open Access Journals (Sweden)

    Luciana Tourinho Campos

    Full Text Available The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®; it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86, which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21, which is also from BEBIG.The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the photoelectric effect, pair

  19. Monte Carlo Dosimetry of the 60Co BEBIG High Dose Rate for Brachytherapy

    Science.gov (United States)

    Campos, Luciana Tourinho; de Almeida, Carlos Eduardo Veloso

    2015-01-01

    Introduction The use of high-dose-rate brachytherapy is currently a widespread practice worldwide. The most common isotope source is 192Ir, but 60Co is also becoming available for HDR. One of main advantages of 60Co compared to 192Ir is the economic and practical benefit because of its longer half-live, which is 5.27 years. Recently, Eckert & Ziegler BEBIG, Germany, introduced a new afterloading brachytherapy machine (MultiSource®); it has the option to use either the 60Co or 192Ir HDR source. The source for the Monte Carlo calculations is the new 60Co source (model Co0.A86), which is referred to as the new BEBIG 60Co HDR source and is a modified version of the 60Co source (model GK60M21), which is also from BEBIG. Objective and Methods The purpose of this work is to obtain the dosimetry parameters in accordance with the AAPM TG-43U1 formalism with Monte Carlo calculations regarding the BEBIG 60Co high-dose-rate brachytherapy to investigate the required treatment-planning parameters. The geometric design and material details of the source was provided by the manufacturer and was used to define the Monte Carlo geometry. To validate the source geometry, a few dosimetry parameters had to be calculated according to the AAPM TG-43U1 formalism. The dosimetry studies included the calculation of the air kerma strength Sk, collision kerma in water along the transverse axis with an unbounded phantom, dose rate constant and radial dose function. The Monte Carlo code system that was used was EGSnrc with a new cavity code, which is a part of EGS++ that allows calculating the radial dose function around the source. The spectrum to simulate 60Co was composed of two photon energies, 1.17 and 1.33 MeV. Only the gamma part of the spectrum was used; the contribution of the electrons to the dose is negligible because of the full absorption by the stainless-steel wall around the metallic 60Co. The XCOM photon cross-section library was used in subsequent simulations, and the

  20. Evaluation by EPR of potential antioxidant components of {sup 60}Co-irradiated varieties of soybean; Avaliacao por RPE de componentes com potencial antioxidante de variedades de soja irradiadas com {sup 60}CO

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcos Ronaldo Ramos de

    2009-07-01

    Brazil is today the second main producer of soybean in the world with a planted ground of about 21 million hectares and an annual production of 60 million tons in 2008, being slight more than a fourth of the annual production. The presence of flavonoids, particularly isoflavones in soybean products has been related as important for human health. It has been suggested that flavonoids play a role in the protection of plants by screening vital cellular components from damaging UV radiation. Electron paramagnetic resonance (EPR) spectroscopy can measure free radicals produced by dissociation molecules resulting from irradiation. It has been successfully employed for the detection of some irradiated food products. Twenty one Brazilian soybean cultivars from two crops were gamma-irradiated with a {sup 60}Co source and evaluated by EPR. Correlation coefficients were made among the central EPR signal (g = 2.0039) and the total and partial isoflavones contents. There was no correlation with total contents, though glicitein and acetyl-daidzin showed a negative correlation. Even 7 months after irradiation the intensity of central EPR signal were high enough to distinguish the irradiated samples. EPR measurements of separated parts of the grain were more efficient for that purpose, particularly from hilum and coat. The radiation did not change substantially the total isoflavone contents, although there were some evidences suggesting some conversion of glycosides to aglycones. (author)

  1. IVVS actuating system compatibility test to ITER gamma radiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Paolo, E-mail: paolo.rossi@enea.it [Associazione EURATOM-ENEA sulla Fusione, 45 Via Enrico Fermi, 00044 Frascati, Rome (Italy); Collibus, M. Ferri de; Florean, M.; Monti, C.; Mugnaini, G.; Neri, C.; Pillon, M.; Pollastrone, F. [Associazione EURATOM-ENEA sulla Fusione, 45 Via Enrico Fermi, 00044 Frascati, Rome (Italy); Baccaro, S.; Piegari, A. [ENEA CR Casaccia, 301 Via Anguillarese, 00123 Santa Maria di Galeria, Rome (Italy); Damiani, C.; Dubus, G. [Fusion For Energy c/Josep Pla, n° 2 Torres Diagonal Litoral, 08019 Barcelona (Spain)

    2013-10-15

    Highlights: • ENEA developed and tested a prototype of a laser In Vessel Viewing and ranging System (IVVS) for ITER. • One piezo-motor prototype has been tested on the ENEA Calliope gamma irradiation facility to verify its compatibility to ITER gamma radiation conditions. • After a total dose of more than 4 MGy the piezo-motor maintained almost the same working parameters monitored before test without any evident and significant degradation of functionality. • After the full gamma irradiation test, the same piezo-motor assembly will be tested with 14 MeV neutrons irradiation using ENEA FNG facility. -- Abstract: The In Vessel Viewing System (IVVS) is a fundamental remote handling equipment, which will be used to make a survey of the status of the blanket first wall and divertor plasma facing components. A design and testing activity is ongoing, in the framework of a Fusion for Energy (F4E) grant agreement, to make the IVVS probe design compatible with ITER operating conditions and in particular, but not only, with attention to neutrons and gammas fluxes and both space constraints and interfaces. The paper describes the testing activity performed on the customized piezoelectric motors and the main components of the actuating system of the IVVS probe with reference to ITER gamma radiation conditions. In particular the test is performed on the piezoelectric motor, optical encoder and small scale optical samples .The test is carried out on the ENEA Calliope gamma irradiation facility at ITER relevant gamma fields at rate of about 2.5 kGy/h and doses of 4 MGy. The paper reports in detail the setup arrangement of the test campaign in order to verify significant working capability of the IVVS actuating components and the results are shown in terms of functional performances and parameters. The overall test campaign on IVVS actuating system will be completed on other ENEA testing facilities in order to verify compatibility to Magnetic field, neutrons and thermal

  2. Novel comb-type hydrogels of net-[PP-g-AAc]-g-4VP synthesized by gamma radiation, with possible application on Cu{sup 2+} immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Lazo, L.M. [Facultad de Quimica, Departamento de Ingenieria Quimica, Universidad Nacional Autonoma de Mexico (Mexico); Burillo, G., E-mail: burillo@nucleares.unam.m [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico 04510 D.F. (Mexico)

    2010-01-15

    A novel comb-type grafted hydrogel system of net-[PP-g-AAc]-g-4VP was synthesized by gamma radiation in three steps. In the first step a pH sensitive graft copolymer of AAc onto PP film was obtained by radiation grafting of acrylic acid (AAc) onto polypropylene (PP) films in aqueous solution at radiation doses of 10 kGy with a {sup 60}Co source. The grafted side chains of poly (acrylic acid) (PAAc) were then cross-linked with gamma radiation at different radiation doses to give net-[PP-g-AAc]. Finally, 4-vinylpyridine (4VP) was grafted into the net-[PP-g-AAc]. The comb-type grafted hydrogel obtained, net-[PP-g-AAc]-g-4VP, has been studied through determination of graft yield and swelling behavior at room temperature. Two critical pH values were found for net-[PP-g-AAc]-g-4VP at 4.5 and 7.2. Initial studies on the immobilization of Cu{sup 2+} ions from solution into net-[PP-g-AAc]-g-4VP films were performed. The comb-type grafted hydrogel, grafted onto PP was also characterized by differential scanning calorimetry (DSC), scanning electronic microscopy (SEM) and FTIR-ATR.

  3. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Science.gov (United States)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  4. Gamma radiation induced changes in nuclear waste glass containing Eu

    Science.gov (United States)

    Mohapatra, M.; Kadam, R. M.; Mishra, R. K.; Kaushik, C. P.; Tomar, B. S.; Godbole, S. V.

    2011-10-01

    Gamma radiation induced changes were investigated in sodium-barium borosilicate glasses containing Eu. The glass composition was similar to that of nuclear waste glasses used for vitrifying Trombay research reactor nuclear waste at Bhabha Atomic Research Centre, India. Photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques were used to study the speciation of the rare earth (RE) ion in the matrix before and after gamma irradiation. Judd-Ofelt ( J- O) analyses of the emission spectra were done before and after irradiation. The spin counting technique was employed to quantify the number of defect centres formed in the glass at the highest gamma dose studied. PL data suggested the stabilisation of the trivalent RE ion in the borosilicate glass matrix both before and after irradiation. It was also observed that, the RE ion distributes itself in two different environments in the irradiated glass. From the EPR data it was observed that, boron oxygen hole centre based radicals are the predominant defect centres produced in the glass after irradiation along with small amount of E’ centres. From the spin counting studies the concentration of defect centres in the glass was calculated to be 350 ppm at 900 kGy. This indicated the fact that bulk of the glass remained unaffected after gamma irradiation up to 900 kGy.

  5. Synthesis and radiation degradation of vinyl polymers with fluorine: search for improved lithographic resists. [Gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Pittman, C.U. Jr. (Univ. of Alabama, University); Chen, C.Y.; Ueda, M.; Helbert, J.N.; Kwiatkowski, J.H.

    1980-12-01

    Homopolymers of methyl ..cap alpha..-fluoroacrylate (MFA), trifluoroethyl methacrylate (TFEM), and hexafluoroisopropyl methacrylate (HFIM) were prepared, as were their methyl methacrylate (MMA) copolymers. Copolymers of vinylidene fluoride (VDF) and chlorotrifluoroethylene (CTFE) with MMA were also prepared. The radiation susceptibilities of these polymers were measured by the /sup 60/Co ..gamma..-irradiation method, in which molecular weights were measured by membrane osmometry and gel permeation chromatography (GPC). All the copolymers degraded by predominant chain scission except poly(methyl ..cap alpha..-fluoroacrylate), (PMFA), which crosslinks even at low doses (ca. 1 Mrad). The G/sub s/-G/sub x/ and G/sub s/ values of the chain scissioning polymers and copolymers are higher than those of poly(methyl methacrylate) PMMA reference. The high susceptibility of PMFA homopolymer to crosslinking is in contrast to that of poly(methyl ..cap alpha..-chloroacrylate), as we reported earlier. This effect is interpreted as resulting from extensive hydrogen fluoride and polyenyl radical formation, which leads to facile crosslinking. However, incorporation of the MFA monomer unit causes the (22/78) MFA/MMA copolymer to degrade with a larger value of G/sub s/ that PMMA. Apparently a second-order process leads to crosslinking in PMFA and this is retarded in the copolymer. In the homopolymers of HFIM and TFEM and in the HFIM-MMA and TFEM-MMA copolymers the HFIM and TFEM components facilitate degradation with negligible crosslinking. The increased degradation susceptibility of VDF and CTFE copolymers with MMA over that of PMMA is attributed to processes at the VDF or CTFE components (present in smaller concentrations (3 to 5 mole %) than the threshold levels (25 to 50% necessary for significant crosslinking).

  6. Study of effects gamma radiation linear low density polyethylene (LLDPE) injected; Estudo dos efeitos da radiacao gama no polietileno linear de baixa densidade (PEBLD) injetado

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ana Claudia Feitoza de

    2014-09-01

    The use of package sterilization through gamma radiation aim to reduce the microbiological contamination. The linear low density polyethylene (LLDPE) can be obtained by a process in solution, suspension or gaseous phase, depending on the type of the catalyzer used, that can be heterogeneous, or homogeneous, or metallocenes Ziegler-Natta. According to the literature, the gamma radiation presents a high penetration at polymeric materials causing the appearing of scissions, reticulation, and degradation when oxygen presence. This paper were irradiated with {sup 60}Co with 2000 kCi of activity, in presence of air, samples of LLDPE injected. Utilized doses of 5, 10, 20, 50 or 100 kGy, and about 5 kGy.h{sup -1} dose rates, at room temperature. After irradiation, the samples were heated for 60 min at 100 deg C to promote recombination and annihilation of residual radicals. For characterization of PEBLD were used methods; Melt flow index, swelling, gel fraction, Fourier Transform Infrared (FTIR), Differential Scanning Calorimetry (DSC), X-Ray Diffraction (DRX), Thermogravimetric Analysis (TG), Dynamic Mechanical Analysis (DMA), rheological measurements, Scanning Electronic Microscopy and mechanical tests to identify the effects or gamma radiation in polyethylene. (author)

  7. Use of MCNP to compare the response of dose deposited in the TLD 100, TLD 600 and TLD 700 in radiation fields due to {sup 60}Co and {sup 241}AmBe source; Uso do MCNP para comparacao das respostas de dose depositada nos TLD 100, TLD 600 e TLD 700 em campos de irradiacao devido a fontes de {sup 60}Co e {sup 241}AmBe

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, Tassio A.; Castro, Vinicius A.; Siqueira, Paulo T.D., E-mail: tassio.cavalieri@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2012-08-15

    The successes of Boron Neutron Capture Therapy (BNCT) depend on the ability to deliver an adequate irradiation field to the target cells. Neutron beams used in BNCT are mostly driven from reactors and therefore, not only have a neutron energy range which far exceeds the thermal region but also do have a great gamma component. Beam characterization and dosimetry are consequently one of the essential procedures to be overcome to properly apply this technique. One of the methods currently used in mixed field (field containing both neutron and gamma) characterization, lies on the use of a pair of detectors with distinct responses to each beam component. But this technique needs to be better understood of how each thermoluminescent dosimeter (TLD) behaves in a mixed field or in a pure field. This work presents the results of a set of simulations performed in order to analyze the response of three ordinary types of TLDs - TLD 100, TLD 600 and TLD 700 - submitted to different irradiation fields from a Cobalt source and an Americium-Beryllium source inside a paraffin disk. And is also a possible method for performing the selection and calibration of theses TLDs. (author)

  8. Gamma radiation effects on siloxane-based additive manufactured structures

    Science.gov (United States)

    Schmalzer, Andrew M.; Cady, Carl M.; Geller, Drew; Ortiz-Acosta, Denisse; Zocco, Adam T.; Stull, Jamie; Labouriau, Andrea

    2017-01-01

    Siloxane-basedadditive manufactured structures prepared by the direct ink write (DIW) technology were exposed to ionizing irradiation in order to gauge radiolysis effects on structure-property relationships. These well-defined 3-D structures were subjected to moderate doses of gamma irradiation in an inert atmosphere and characterized by a suite of experimental methods. Changes in thermal, chemical, microstructure, and mechanical properties were evaluated by DSC, TGA, FT-IR, mass spectroscopy, EPR, solvent swelling, SEM, and uniaxial compressive load techniques. Our results demonstrated that 3-D structures made from aromatic-free siloxane resins exhibited hardening after being exposed to gamma radiation. This effect was accompanied by gas evolution, decreasing in crystallization levels, decreasing in solvent swelling and damage to the microstructure. Furthermore, long-lived radiation-induced radicals were not detected by EPR methods. Our results are consistent with cross-link formation being the dominant degradation mechanism over chain scission reactions. On the other hand, 3-D structures made from high phenyl content siloxane resins showed little radiation damage as evidenced by low off gassing.

  9. Influence of age and gender in response to {gamma}-radiation in Portuguese individuals using chromosomal aberration assay - Preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Martins, V.; Antunes, A.C. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Cardoso, J.; Santos, L. [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Metrology Laboratory of Ionizing Radiation, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal); Gil, O. Monteiro, E-mail: octavia.gil@itn.pt [Instituto Tecnologico e Nuclear, Unidade de Proteccao e Seguranca Radiologica, Dosimetry and Radiobiology Group, E.N. 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2011-09-15

    Cytogenetic indicators are widely used in radiobiology to evaluate effects of ionizing radiation since dicentric chromosomes (Dic) are almost exclusively induced by ionizing radiation, and spontaneous frequency of Dic is very low in the healthy general population (about one Dic per 1000 cells). A particular interest of biodosimetry has been not only to obtain absorbed dose estimates using adequate calibration curves, under the assumption that all individuals respond equally to radiation-induced chromosome aberrations, but also to find a way to demonstrate inter-individual radiosensitivity and a possible correlation with age and gender. Thus, the objective of this preliminary work was the evaluation of the influence of age and gender on the outcome of cytogenetic biomarkers after {gamma}-irradiation. Samples of peripheral blood lymphocytes from six healthy, non-smoker, donors from both genders (three men and three women), in the range of 20 to 49 years, were irradiated with doses from 0 Gy to 3 Gy air kerma, using a {sup 60}Co gamma rays source with a dose rate from 170-180 mGy/min. A clear dose-dependent increase in terms of aberrant cells excluding gaps (ACEG) and Dic was observed for all donors. Our preliminary results suggest, in the higher dose level evaluated (3 Gy), a larger intervariability among individuals for Dic, with females apparently more sensitive than males (P<0.05). Considering the different age groups, male donors showed a decrease, with age, for Dic and ACEG at the higher dose and also, for the background level, in case of ACEG. Future work will consider the study of more individuals, from both genders and different ages, in order to verify if this tendency persists and to enable the implementation of a dose-response calibration curve at Instituto Tecnologico e Nuclear for the Portuguese population, to quantify the biological dose in case of a radiological accident or emergency.

  10. Effects of gamma radiation on antinutritional factors of soybean

    Energy Technology Data Exchange (ETDEWEB)

    Toledo, Tais C.F. de; Arthur, Valter [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos e Radioentomologia]. E-mail: tcftoled@cena.usp.br; arthur@cena.usp.br; Brazaca, Solange G.C. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz. Dept. de Agroindustria, Alimentos e Nutricao]. E-maik: sgcbraza@esalq.usp.br; Piedade, Sonia M. de S. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Dept. de Ciencias Exatas]. E-mail: piedade@esalq.usp.br

    2007-07-01

    The soybean is one of the most important legume cultivated in the world. Some leguminous, particularly soybeans, contain significant amounts of bioactive compounds that may change the utilization of nutrients by the organism, when consumed. The main protein responsible for the low nutritional value of raw soybean grains and the trypsin and lectin inhibitors. Some methods can be used to minimize lost during storage, and the ionizing radiation with Cobalto-60 constitutes a safe and efficient method for the increase in the time of useful life of foods. The sum of observations exposed in previous chapters leads to the proposal of determining the possible alterations promoted by the use of gamma radiation (with doses of 2, 4 and 8 kGy) in the alteration of antinutrients (total phenolic, trypsin inhibitor and tannins) in soybean (cultivars BRS 212, BRS 213, BRS 214, BRS 231 and EMBRAPA 48). Total phenolic ranged from 2.46 to 10.83 mg/g, and the dose of 8 kGy promoted an increase on the content of total phenolic compounds in all raw samples and in cooked samples from some cultivars. The trypsin inhibited ranged from 18.19 to 71.64 UTI/g, and all cultivars presented the same behavior in relation to radiation for inhibited trypsin units both for raw and cooked samples, with significant differences (p{<=}0.05) between all doses used. For tannins, ranged from 0.01 to 0.39 mg/g, and the gamma radiation promoted reduction on the tannin contents as the radiation dose increased until a limited dose. All the antinutrients studied underwent reduction with increases on the doses. (author)

  11. Development and characterization of a new graphite ionization chamber for dosimetry of {sup 60}Co beams

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio Pereira; Perini, Ana Paula; Santos, William de Souza; Caldas, Linda V.E., E-mail: lpneves@ipen.br, E-mail: aperini@ipen.br, E-mail: wssantos@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    Ionization chambers are the most employed dosimeters for precise measurements, as those required in radiotherapy. In this work, a new graphite ionization chamber was developed and characterized in order to compose a primary standard system for the beam dosimetry of the {sup 60}Co sources. This dosimeter is a cylindrical type ionization chamber, with walls and collecting electrode made of high-purity graphite, and the insulators and stem made of Teflon®. The walls are 3.0 mm thick, and it has a sensitive volume of 1.40 cm{sup 3}. The characterization was divided in two steps: experimental and Monte Carlo evaluations. This new dosimeter was evaluated in relation to its saturation curve, ion collection efficiency, polarity effect, short- and medium-term stabilities, leakage current, stabilization time, linearity of response and angular dependence. All results presented values within the established limits. The second part of the characterization process involved the determination of the correction factors, obtained by Monte Carlo simulations. Comparing these correction factors values with those from other primary standard laboratories, the highest differences were those for the wall and stem correction factors. The air-kerma rate of the {sup 60}Co source was determined with this new dosimeter and with the IPEN standard system, presenting a difference of 1.7%. These results indicate that this new dosimeter may be used as a primary standard system for {sup 60}Co gamma beams. (author)

  12. Decoloration Kinetics of Waste Cooking Oil by 60Co γ-ray/H2O2

    Science.gov (United States)

    Xiang, Yulin; Xiang, Yuxiu; Wang, Lipeng

    2016-03-01

    In order to decolorize, waste cooking oil, a dark red close to black solution from homes and restaurants, was subjected to 60Co γ-ray/H2O2 treatment. By virtue of UV/Vis spectrophotometric method, the influence of Gamma irradiation to decoloration kinetics and rate constants of the waste cooking oil in the presence of H2O2 was researched. In addition, the influence of different factors such as H2O2 concentration and irradiation dose on the decoloration rate of waste cooking oil was investigated. Results indicated that the decoloration kinetics of waste cooking oil conformed to the first-order reaction. The decoloration rate increased with the increase of irradiation dose and H2O2 concentration. Saponification analysis and sensory evaluation showed that the sample by 60Co γ-ray/H2O2 treatment presented better saponification performance and sensory score. Furthermore, according to cost estimate, the cost of the 60Co γ-ray/H2O2 was lower and more feasible than the H2O2 alone for decoloration of waste cooking oil.

  13. SAS 2 observations of the earth albedo gamma radiation above 35 MeV

    Science.gov (United States)

    Thompson, D. J.; Simpson, G. A.; Ozel, M. E.

    1981-01-01

    The earth albedo gamma radiation above 35 MeV in the equatorial region is investigated using observations from the second Small Astronomy Satellite. The zenith angle distribution of the gamma radiation has a peak toward the horizon which is about an order of magnitude more intense than the radiation coming from the nadir, and nearly two orders of magnitude more intense than the gamma radiation from most parts of the sky. The gamma radiation originating from the western horizon is a factor of four more intense than the radiation from the eastern horizon and a factor of three more intense than that from the northern and southern directions. This reflects the geomagnetic effects on the incident cosmic rays whose interactions produce the albedo gamma rays. The variation of the upcoming gamma ray intensity with vertical cutoff rigidity is consistent with the empirical relationship found by Gur'yan et al. (1979).

  14. Gamma radiation induced effects on slaughterhouse wastewater treatment

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Rita [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal)], E-mail: ritamelo@itn.pt; Cabo Verde, Sandra [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal); Branco, Joaquim [Departamento de Quimica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal); Botelho, M. Luisa [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2008-01-15

    A preliminary study using gamma radiation on slaughterhouse wastewater samples was carried out. Chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) results were obtained at a dose rate of 0.9 kGy h{sup -1}. A decrease of COD, BOD and colour was observed after irradiation at high absorbed doses. The microbiological results, following irradiation in the same conditions, correlated with the BOD results. The results obtained highlight the potential of this technology for wastewater treatment.

  15. Preliminary measurements of gamma radiation in Chilean Antarctic Stations

    Energy Technology Data Exchange (ETDEWEB)

    Stuardo B, E. (Comision Chilena de Energia Nuclear, Santiago. Dept. de Aplicaciones Nucleares)

    1983-11-01

    Natural and artificial gamma radiation, 1 m above the soil, is being investigated in 4 Chilean Antartic Stations. The measurements are performed with different types of TLD detectors. Preliminary results in the Tte. Marsh Station are reported and discussed. An average exposition of 3,5 ..mu..R/h was found during a 108 days period. This exposition corresponds to an annual dose of about 40 mrad, 8% of the annual dose limit for individual of the public. The presence of low energy artificial radioisotopes was not found.

  16. Garlic (Alium sativum) preservation by application of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Urbina P, M.C.; Casas G, L. (Comision Chilena de Energia Nuclear, Santiago. Dept. de Aplicaciones de los Isotopos y Radiaciones)

    1984-04-01

    Garlic preservation was studied during a period of eleven months using doses of gamma radiation of 0,06 and 0,12 kGy. The product was stored in netted mesh bags, at room temperature and relative humidity. Sprouting, weight losses, microbiological damages, decoloration and emaciation were controlled periodically. The results of this study permit to conclude that with a dose of 0,06 kGy it is possible to preserve garlic for a period up to ten months, with market quality.

  17. Simultaneous Thermal and Gamma Radiation Aging of Cable Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S.; Liu, Shuaishuai; Bowler, Nicola

    2016-12-19

    Polymers used in nuclear power plant electrical cable systems experience aging and degradation over time due to environmental stress including heat and gamma irradiation. Prediction of long-term cable performance has been based on results of short-term accelerated laboratory aging studies, but questions remain regarding the correlation of accelerated aging to long-term, in-plant aging. This work seeks to increase understanding of the combined effects of heat and radiation on cable polymer material aging toward addressing these questions.

  18. Gamma radiation effects on the reproductive capacity of Tribolium castaneum

    Energy Technology Data Exchange (ETDEWEB)

    Hu, T.; Tsai, L.T.; Fu, Y.K.

    1984-10-01

    Unmated pairs of Tribolium castaneum (Hbst.) were treated with gamma radiation from 8.2 to 65.6 Gy at 8.2-Gy increment and allowed to mate and oviposit. The number of larva per fertile pair and the percentage of sterility at each dosage were determined. The regression line for logarithm of average number of larva progeny per pair and a probit sterility curve were calculated. The average number of progeny per pair was reduced 10% by a dosage of 28.99 Gy. The probit sterility line indicated that 107 Gy in the sterilizing dosage for this species. 9 refs., 2 figs., 1 tab.

  19. New detectors of neutron, gamma- and X-radiations

    CERN Document Server

    Lobanov, N S

    2002-01-01

    Paper presents new detectors to record absorbed doses of neutron, gamma- and X-ray radiations within 0-1500 Mrad range. DBF dosimeter is based on dibutyl phthalate. EDS dosimeter is based on epoxy (epoxide) resin, while SD 5-40 detector is based on a mixture of dibutyl phthalate and epoxy resin. Paper describes experimental techniques to calibrate and interprets the measurement results of absorbed doses for all detectors. All three detectors cover 0-30000 Mrad measured does range. The accuracy of measurements is +- 10% independent (practically) of irradiation dose rates within 20-2000 rad/s limits under 20-80 deg C temperature

  20. Ceramic Matrix Composites Performances Under High Gamma Radiation Doses

    Science.gov (United States)

    Cemmi, A.; Baccaro, S.; Fiore, S.; Gislon, P.; Serra, E.; Fassina, S.; Ferrari, E.; Ghisolfi, E.

    2014-06-01

    Ceramic matrix composites reinforced by continuous ceramic fibers (CMCs) represent a class of advanced materials developed for applications in automotive, aerospace, nuclear fusion reactors and in other specific systems for harsh environments. In the present work, the silicon carbide/silicon carbide (SiCf/SiC) composites, manufactured by Chemical Vapour Infiltration process at FN S.p.A. plant, have been evaluated in term of gamma radiation hardness at three different absorbed doses (up to around 3MGy). Samples behavior has been investigated before and after irradiation by means of mechanical tests (flexural strength) and by surface and structural analyses (X-ray diffraction, SEM, FTIR-ATR, EPR).

  1. Radiative striped wind model for gamma-ray bursts

    Science.gov (United States)

    Bégué, D.; Pe'er, A.; Lyubarsky, Y.

    2017-01-01

    In this paper we revisit the striped wind model in which the wind is accelerated by magnetic reconnection. In our treatment, radiation is included as an independent component, and two scenarios are considered. In the first one, radiation cannot stream efficiently through the reconnection layer, while the second scenario assumes that radiation is homogeneous in the striped wind. We show how these two assumptions affect the dynamics. In particular, we find that the asymptotic radial evolution of the Lorentz factor is not strongly modified whether radiation can stream through the reconnection layer or not. On the other hand, we show that the width, density and temperature of the reconnection layer are strongly dependent on these assumptions. We then apply the model to the gamma-ray burst context and find that photons cannot diffuse efficiently through the reconnection layer below radius r_D^{Δ } ˜ 10^{10.5} cm, which is about an order of magnitude below the photospheric radius. Above r_D^{Δ }, the dynamics asymptotes to the solution of the scenario in which radiation can stream through the reconnection layer. As a result, the density of the current sheet increases sharply, providing efficient photon production by the Bremsstrahlung process which could have profound influence on the emerging spectrum. This effect might provide a solution to the soft photon problem in GRBs.

  2. Dosimetric evaluation of Radiotherapy units wit {sup 60}Co; Evaluacion dosimetrica de unidades de radioterapia con {sup 60}Co

    Energy Technology Data Exchange (ETDEWEB)

    Leon, B. Salinas de; Tovar M, V.; Becerril V, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services ({sup 60} Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of {sup 60} Co radiotherapy units. (Author)

  3. Long-term follow-up study on reproductive and endocrine function in six victims accidentally exposed to 60 Co radiation%6名钴-60源辐射事故受照者生殖及内分泌功能远期效应随访

    Institute of Scientific and Technical Information of China (English)

    赵凤玲; 傅宝华; 吕玉民; 吴艳延; 邢志伟; 姜恩海; 姜梅玲; 于程程

    2014-01-01

    目的:了解钴-60(60Co)源辐射事故对受照者生殖及内分泌功能的远期效应。方法对河南省1999年4月26日60 Co源辐射事故6名受照者进行为期15年的生殖及内分泌功能远期效应医学观察。重点询问受照者婚育史及女性月经史;采用彩色多普勒超声诊断仪(以下简称“彩超”)检查受照者子宫、卵巢和甲状腺;检测其周围血血清生殖激素和甲状腺功能指标,并检测男性受照者精液常规。结果成年女性“梅”受照后出现放射性闭经,受照后2年子宫和卵巢明显缩小,生殖激素雌二醇和孕酮水平下降,卵泡刺激素( FSH)和黄体生成素( LH)水平升高。8岁男童“旺”受照后随访期间生殖器官发育正常,精液常规和生殖激素水平正常,婚后生育1健康男孩。成年男性“天”、“勇”、“民”和“义”受照后性欲无明显改变,受照后3个月精子均明显减少或缺乏,精子活动率下降,受照后6个月和1年精子均为0,受照后2年开始恢复;受照后1年“天”、“民”、“义”FSH均出现一过性升高,“民”LH出现一过性升高,但该时间点上述4名成年男性受照者睾酮均正常。有5名受照者于受照后15年进行彩超检查,其中“梅”、“天”和“民”检出甲状腺结节,“旺”和“义”甲状腺正常。“梅”受照后11、13和15年促甲状腺素水平升高,三碘甲状腺原氨酸和甲状腺素水平正常;其他5名受照者甲状腺功能正常。结论60 Co源电离辐射可损害受照者生殖能力,导致其甲状腺功能改变。性腺和甲状腺急性放射病患者远期随访观察应重点关注的靶器官。%Objective To explore the long-term effects of radiation on reproductive and endocrine function in persons exposed to 60 Co in the radiation source accident .Methods Fifteen-year-long long-term medical follow-up observation on the reproductive

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-07-01

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

  5. Gamma radiation effects on commercial Mexican bread making wheat flour

    Energy Technology Data Exchange (ETDEWEB)

    Agundez-Arvizu, Z. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Fernandez-Ramirez, M.V. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Arce-Corrales, M.E. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Cruz-Zaragoza, E. [Instituto de Ciencias Nucleares-UNAM, A.P. 70-543, Mexico 04510 DF (Mexico); Melendrez, R. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico); Chernov, V. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico); Barboza-Flores, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico)]. E-mail: mbarboza@cajeme.cifus.uson.mx

    2006-04-15

    Gamma irradiation is considered to be an alternative method for food preservation to prevent food spoilage, insect infestation and capable of reducing the microbial load. In the present investigation, commercial Mexican bread making wheat flour was irradiated at 1.0 kGy using a {sup 6}C Gammabeam 651 PT irradiator facility. No changes were detected in moisture, protein and ashes in gamma irradiated samples as compared to those of non-irradiated samples. Slight radiation effects were observed in the alveogram values and farinograph properties; the falling number decreased 11%, the absorption as well as the mixing tolerance were practically unchanged by irradiation. An increase of 15% in the stability value and a 29% in the dough development time were observed. Also the deformation energy decreased 7% with no change at all in the tenacity/extensibility factor. Total aerobic, yeast and mold counts were reduced 96%, 25% and 75%; respectively by the irradiation process. The obtained results confirm that gamma irradiation is effective in reducing the microbial load in bread making wheat flour without a significant change in the physicochemical and baking properties.

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

    CERN Document Server

    Bratchenko, M I; Rozhkov, V V

    2001-01-01

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

  7. Radiative striped wind model for gamma-ray bursts

    CERN Document Server

    Bégué, D; Lyubarski, Y

    2016-01-01

    In this paper we revisit the striped wind model in which the wind is accelerated by magnetic reconnection. In our treatment, radiation is included as an independent component, and two scenarios are considered. In the first one, radiation cannot stream efficiently through the reconnection layer, while the second scenario assumes that radiation is homogeneous in the striped wind. We show how these two assumptions affect the dynamics. In particular, we find that the asymptotic radial evolution of the Lorentz factor is not strongly modified whether radiation can stream through the reconnection layer or not. On the other hand, we show that the width, density and temperature of the reconnection layer are strongly dependent on these assumptions. We then apply the model to the gamma-ray burst context and find that photons cannot diffuse efficiently through the reconnection layer below radius $r_{\\rm D}^{\\Delta} \\sim 10^{10.5}$ cm, which is about an order of magnitude below the photospheric radius. Above $r_{\\rm D}^{\\...

  8. Seed germination of peanuts irradiated with cobalt ({sup 60}CO); Germinacao de sementes de amendoim irradiadas com cobalto ({sup 60}Co)

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B., E-mail: niedjamarizze@yahoo.com.b, E-mail: josivanda@deag.ufcg.edu.b, E-mail: elvirabe@gmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia Agricola; Leal, Artur S. Cavalcanti, E-mail: arturcleal@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    This work was realized to evaluate the effect of gamma irradiation ({sup 60}Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  9. Mobile robot prototype detector of gamma radiation; Prototipo de robot movil detector de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez C, R.M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Duran V, M. D.; Jardon M, C. I., E-mail: raulmario.vazquez@inin.gob.mx [Tecnologico de Estudios Superiores de Villa Guerrero, Carretera Federal Toluca-Ixtapan de la Sal Km. 64.5, La Finca Villa Guerrero, Estado de Mexico (Mexico)

    2014-10-15

    In this paper the technological development of a mobile robot prototype detector of gamma radiation is shown. This prototype has been developed for the purpose of algorithms implementation for the applications of terrestrial radiation monitoring of exposed sources, search for missing radioactive sources, identification and delineation of radioactive contamination areas and distribution maps generating of radioactive exposure. Mobile robot detector of radiation is an experimental technology development platform to operate in laboratory environment or flat floor facilities. The prototype integrates a driving section of differential configuration robot on wheels, a support mechanism and rotation of shielded detector, actuator controller cards, acquisition and processing of sensor data, detection algorithms programming and control actuators, data recording (Data Logger) and data transmission in wireless way. The robot in this first phase is remotely operated in wireless way with a range of approximately 150 m line of sight and can extend that range to 300 m or more with the use of signal repeaters. The gamma radiation detection is performed using a Geiger detector shielded. Scan detection is performed at various time sampling periods and diverse positions of discrete or continuous angular orientation on the horizon. The captured data are geographical coordinates of robot GPS (latitude and longitude), orientation angle of shield, counting by sampling time, date, hours, minutes and seconds. The data is saved in a file in the Micro Sd memory on the robot. They are also sent in wireless way by an X Bee card to a remote station that receives for their online monitoring on a laptop through an acquisition program by serial port on Mat Lab. Additionally a voice synthesizing card with a horn, both in the robot, periodically pronounced in Spanish, data length, latitude, orientation angle of shield and detected accounts. (Author)

  10. Method for imaging quantum dots during exposure to gamma radiation

    Science.gov (United States)

    Immucci, Andrea N.; Chamson-Reig, Astrid; Yu, Kui; Wilkinson, Diana; Li, Chunsheng; Stodilka, Robert Z.; Carson, Jeffrey J. L.

    2011-03-01

    Quantum dots have been used in a wide variety of biomedical applications. A key advantage of these particles is that their optical properties depend predictably on size, which enables tuning of the emission wavelength. Recently, it was found that CdSe/ZnS quantum dots lose their ability to photoluminescence after exposure to gamma radiation (J. Phys. Chem. C., 113: 2580-2585 (2009). A method for readout of the loss of quantum dot photoluminescence during exposure to radiation could enable a multitude of real-time dosimetry applications. Here, we report on a method to image photoluminescence from quantum dots from a distance and under ambient lighting conditions. The approach was to construct and test a time-gated imaging system that incorporated pulsed illumination. The system was constructed from a pulsed green laser (Nd:YAG, 20 pulses/s, 5 ns pulse duration, ~5 mJ/pulse), a time-gated camera (LaVision Picostar, 2 ns gate width), and optical components to enable coaxial illumination and imaging. Using the system to image samples of equivalent concentration to the previous end-point work, quantum dot photoluminescence was measureable under ambient room lighting at a distance of 25 cm from the sample with a signal to background of 7.5:1. Continuous exposure of samples to pulsed laser produced no measureable loss of photoluminescence over a time period of one hour. With improvements to the light collection optics the range of the system is expected to increase to several metres, which will enable imaging of samples during exposure to a gamma radiation source.

  11. Use of gamma radiation to sterilize Ceratitis capitata (Wied., 1824), tsl VIENNA 8 strain, for application of sterile insect technique in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Mastrangelo, Thiago de A.; Costa, Maria de L.Z.; Paesman, Leandro; Walder, Julio M.M. [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)]. E-mails: piaui@cena.usp.br; jmwalder@cena.usp.br; Mascarin, Gabriel M. [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ)]. E-mail: gmmascar@esalq.usp.br

    2007-07-01

    The Sterile insect technique is a method of pest control allowed in integrated pest management programs in fruit growing, where sterile insects released compete in mate process against fertile wild ones, generating a gradual population reduction. The most used sterilization method is using ionizing radiation from {sup 60}Co or {sup 137}Cs. For efficient application of SIT, an important item is the sterilizing dose. This must be as lower as possible in order to preserve insect behavior. In this work, it was studied the reproductive potential of fruit fly Ceratitis capitata, tsl VIENNA 8 strain, irradiated with different doses of gamma radiation. This strain shall be used in population suppression programs at fruit-growing areas from Northeast of Brazil, through a partnership between CENA and Biofactory MOSCAMED Brazil, intending only sterile male releases. Radiation source used was a {sup 60}Co irradiator, with 17.2 .1012 Bq. Individualized couples were distributed in a randomized delineament with 10 replicates for each treatment and eggs were collected for fifteen days. With 9 and 10 days old, pupae were irradiated with doses ranging from 30 to 120 Gy. All means of emerged adult's percentages were higher than 90%. In regards to fecundity, different doses didn't affect the number of eggs laid, being the overall mean around 30 eggs/couple/day. Fertility data showed that as radiation dose increases, sterility increases. It was concluded that the dose of 90 Gy could be used in Brazil, since to SIT programs a dose is chosen witch prevents an egg hatch higher than 1%. (author)

  12. Differential gene expression in human fibroblasts after alpha-particle emitter (211)At compared with (60)Co irradiation

    DEFF Research Database (Denmark)

    Danielsson, Anna; Claesson, Kristina; Parris, Toshima Z;

    2013-01-01

    trastuzumab monoclonal antibody (0.25, 0.5, and 1 Gy) and (60)Co (1, 2, and 3 Gy). Results: We report gene expression profiles that distinguish the effect different radiation qualities and absorbed doses have on cellular functions in human fibroblasts. In addition, we identified commonly expressed transcripts...

  13. 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.

  14. Comparative study of Si diodes for gamma radiation dosimetry; Estudo comparativo das respostas de diodos de Si para dosimetria de radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Pascoalino, Kelly Cristina da Silva

    2010-07-01

    In this work it is presented the comparative study of Si diodes response for gamma radiation dosimetry. The diodes investigated, grown by float zone (Fz) and magnetic Czochralski (MCz) techniques, were processed at the Physics Institute of Helsinki University in the framework of the research and development of rad-hard silicon devices. To study the dosimetric response of these diodes they were connected in the photovoltaic mode to the input of a digital electrometer to measure the photocurrent signal due to the incidence of gamma-rays from a {sup 60}Co source (Gammacell 220). The dosimetric parameter utilized to study the response of these devices was the charge, obtained trough the integration of the current signals, as a function of the absorbed dose. Studies of the influence of the pre-irradiation procedures on both sensitivity and stability of these diodes showed that the sensitivity decreased with the total absorbed dose but after a preirradiation of about 873 kGy they became more stable. Radiation damage effects eventually produced in the devices were monitored trough dynamic current and capacitance measurements after each irradiation step. Both samples also exhibited good response reproducibility, 2,21% (Fz) and 2,94% (MCz), obtained with 13 consecutive measurements of 15 kGy compared with the equivalent 195 kGy absorbed dose in one step of irradiation. It is important to note that these results are better than those obtained with routine polymethylmethacrylate (PMMA) dosimeters used in radiation processing dosimetry. (author)

  15. Gamma radiation influence on technological characteristics of wheat flour

    Science.gov (United States)

    Teixeira, Christian A. H. M.; Inamura, Patricia Y.; Uehara, Vanessa B.; Mastro, Nelida L. d.

    2012-08-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it.

  16. Neutron and gamma radiation shielding material, structure, and process of making structure

    Energy Technology Data Exchange (ETDEWEB)

    Hondorp, H.L.

    1981-07-06

    The present invention is directed to a novel neutron and gamma radiation shielding material consisting of 95 to 97% by weight SiO/sub 2/ and 5 to 3% by weight sodium silicate. In addition, the method of using this composition to provide a continuous neutron and gamma radiation shielding structure is disclosed.

  17. Effect of gamma radiation on optical and electrical properties of tellurium dioxide thin films

    Indian Academy of Sciences (India)

    T K Maity; S L Sharma

    2008-11-01

    Gamma radiation induced changes in the optical and electrical properties of tellurium dioxide (TeO2) thin films, prepared by thermal evaporation, have been studied in detail. The optical characterization of the as-deposited thin films and that of the thin films exposed to various levels of gamma radiation dose clearly show that the optical bandgap decreases with increase in the gamma radiation dose up to a certain dose. At gamma radiation doses above this value, however, the optical bandgap has been found to increase. On the other hand, the current vs voltage plots for the as-deposited thin films and those for the thin films exposed to various levels of gamma radiation dose show that the current increases with the gamma radiation dose up to a certain dose and that the value of this particular dose depends upon the thickness of the film. The current has, however, been found to decrease with further increase in gamma radiation dose. The observed changes in both the optical and electrical properties indicate that TeO2 thin films can be used as the real time gamma radiation dosimeter up to a certain dose, a quantity that depends upon the thickness of the film.

  18. Differential interpretation of the results of well logging with scattered gamma radiation of radioactive ores

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, Yu.B.; Kuzin, V.F.

    1979-01-01

    Studied are the possibilities of quantitative interpretation of the results of logging of scattered gamma radiation. Recording of the scattered gamma radiation of radioactive ores makes it possible in a number of cases to solve the questions of lithological separation of rocks and the identification of their substantive composition. The effectiveness of exploration of radioactive raw materials is increased.

  19. Development of polyaniline thin films for gamma radiation dosimetry; Desenvolvimento de filmes finos de polianilina para dosimetria da radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Ana Paula; Araujo, Elmo S. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear; Azevedo, Walter M. de [Pernambuco Univ., Recife, PE (Brazil). Dept. de Quimica Fundamental

    2001-07-01

    The increasing applications of the ionizing radiation added to the difficulty on operation of some dosimeters have became necessary the development of news materials and news dosimetry techniques. On the other hand, the study of the properties of conducts polymers are quite recent as well as its research in the dosimetry field is still superficial. The utilization of polyaniline (PANI) as a dosimetric material is of great relevancy, because this polymer has got good quality in the dosimetry. It is easy to operation, the devices may be fabricated in different geometry, it is a low cost material, and the electrical properties variation measurement system is simple. In addition, it does not exist previously study that characterizes this polymer as a dosimeter. Some early results have showed that doped PANI when irradiated with gamma rays ({sup 60} Co), dose range from 0 to 10kGy, responds proportionally to the doses above 1kGy. Thus, it is possible the utilization this polymer in high-energy dosimetry. Studies much more detailed are being made in order to complete the evidence of PANI as a dosimetric material. (author)

  20. Search for Charmonium States Decaying to J/\\psi\\gamma \\gamma $ Using Initial-State Radiation Events

    Energy Technology Data Exchange (ETDEWEB)

    Aubert, B.; Barate, R.; Bona, M.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; /Barcelona U., ECM; Palano,; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B.; /Bergen U.; Abrams, G.S.; /LBL,

    2006-11-30

    We study the processes e{sup +}e{sup -} {yields} (J/{psi}{gamma}{gamma}){gamma} and e{sup +}e{sup -} {yields} (J/{psi}{pi}{sup -}{pi}{sup +}){gamma} where the hard photon radiated from an initial e{sup +}e{sup -} collision with center-of-mass (CM) energy near 10.58 GeV is detected. In the final state J/{psi}{gamma}{gamma} we consider J/{psi}{pi}{sup 0}, J/{psi}{eta}, {chi}{sub c1}{gamma}, and {chi}c{sub 2}{gamma} candidates. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} CM energy in each event, so these data can be compared with direct e{sup +}e{sup -} measurements. We report 90% CL upper limits for the integrated cross section times branching fractions of the J/{psi}{gamma}{gamma} channels in the Y (4260) mass region.

  1. Degradation studies on plasticized PVC films submited to gamma radiation

    Directory of Open Access Journals (Sweden)

    Vinhas Glória Maria

    2003-01-01

    Full Text Available Poly (vinyl chloride, PVC, is a rigid polymer and for several of its applications must be compounded with plasticizing agents. The plasticizers minimize the dipolar interactions, which exist between the polymer's chains, promoting their mobility. In this work we studied the properties of PVC/plasticizer systems submitted to different doses of gamma radiation. We have used four commercial plasticizers amongt them di(2-ethylhexyl phthalate, DEHP, which is present in a great number of commercial applications. The PVC/plasticizer systems have been studied as films made by the solvent evaporation technique. Irradiated and non-irradiated films have been characterized by viscosimetric analysis, mechanical essays and infrared spectroscopy. The results have shown that the rigid, non plasticized, PVC film presented the greatest degradation index, while among the plasticized films the one which presented the larger degradation index due to chain scission was the DEHP plasticized PVC.

  2. Admixtures in Spent Plutonium Sources and Gamma-Radiation

    Directory of Open Access Journals (Sweden)

    Inga Pelanytė

    2011-04-01

    Full Text Available The isotopic composition of several spent smoke detectors containing plutonium has been investigated. The article also presents the calculated results of 241Am and 241Pu activities in smoke detectors. The received values vary from (0.934±0.028 MBq to (91.2±4.6 MBq. The eguivalent dose rate of the established gamma radiation vary from 220 nSv/h to 500 nSv/h. A dose caused by artificial radionuclides in spent smoke detectors was evaluated and compared in the article. It has been found out that due to smoke detectors, an annual dose varies from 0.06 mSv to 0.31 mSv. Article in Lithuanian

  3. Gamma radiation in papaya harvested at three stages of maturation

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel, Rodrigo Meirelles de Azevedo; Walder, Julio Marcos Melges [Centro de Energia Nuclear na Agricultura, Piracicaba, SP (Brazil). Lab. de Irradiacao de Alimentos]. E-mail: jmwalder@cena.usp.br

    2004-04-01

    Papaya is a fragile, perishable fruit, highly accepted worldwide. To keep the quality of papaya from harvest to the consumers, conservation techniques are often used; among them is the application of gamma irradiation. The objective of this work was to evaluate gamma irradiation in papayas harvested at three degrees of maturation, in order to increase shelf life. Papayas were harvested in perfect quality conditions and selected by skin coloration into three distinct degrees of maturation: maturation 0, or beginning of yellow coloration; maturation 1, yellow stripes more developed, and maturation 2, one third yellow. Half of them were irradiated with 0.75 kGy, while the other half became control treatment. They were analyzed in four periods of conservation, which were 1 DAI (days after irradiation refrigerated at 11 {+-} 1 deg C), 14 DAI, 14 DAI + 3 DRT (room temperature at 24 deg C {+-} 2 deg C) and 14 DAI + 6 DRT. The papaya maturation degree at harvest did not influence the radiation effect. Irradiation maintained firmness of papaya and, therefore, delayed ripening; modified the green color of papaya to a lighter, more intense tone, which determined more homogeneity in the development of the skin's yellow color (greater values of L{sup *} and chroma). There was no effect of irradiation in papaya weight loss, occurrence of diseases, chroma of flesh color, p H and total soluble solids contents. (author)

  4. Comparison of treatment in soybean grains between {sup 60}Co and e-beans applications

    Energy Technology Data Exchange (ETDEWEB)

    Fanaro, Gustavo B.; Araujo, Michel M.; Thomaz, Fernanda S.; Duarte, Renato C.; Villavicencio, Anna Lucia C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: gbfanaro@ipen.br; villavic@ipen.br

    2007-07-01

    Soybean is the most important oleaginous cultivated in Brazil, who is the second largest exported in the world, and generates high incomes, direct and indirectly, its oils could be used since to cook even to machine's fuel and the nutrients become basic for the feeding human being, beyond its by-products, that offer great diversities of products for the nourishing industry. Between the main factors that limit the attainment of high incomes, are the illnesses caused by microorganism like fungi, bacteria, and viruses that, in general, are difficult to control and cause damages on harvest of billions of dollar every year. An alternative to minimize the losses is preserving the grains through the irradiation that can come today from two different main sources: e-beam and {sup 60}Co. Beyond power to be off when it will not be in use, the source of e-beams machines does not need to be recharged, is easily available, possess high tax of dose and low energy. However the {sup 60}Co have low dose rate, high energy and the photons emission is continuous. This work aims to compare the effects of the radiation through viscosimetry, DNA Comet Assay and Cooking time techniques in soybean grains at doses 0, 1.0, 3.0 and 5.0kGy irradiated in ambient temperature at {sup 60}Co source Gammacell 220 (A.E.C. Ltda) and in e-beam accelerator - Radiation Dynamics (Radiation Dynamics Co. model JOB, New York, USA), 1.5 MeV- 25mA with the lower dose. (author)

  5. Gamma irradiation effects in W films

    Energy Technology Data Exchange (ETDEWEB)

    Claro, Luiz H. [Instituto de Estudos Avancados - IEAv, Rod. dos Tamoios, km 5,5, CEP: 12228-840, Sao Jose dos Campos, SP (Brazil) and Faculdade de Tecnologia Sao Francisco - FATESF, Av. Siqueira Campos, 1174, CEP: 12207-000, Jacarei (Brazil); Santos, Ingrid A. [Instituto de Estudos Avancados - IEAv, Rod. dos Tamoios, km 5,5, CEP: 12228-840, Sao Jose dos Campos, SP (Brazil); Silva, Cassia F. [Faculdade de Tecnologia Sao Francisco - FATESF, Av. Siqueira Campos, 1174, CEP: 12207-000, Jacarei, SP (Brazil)

    2013-05-06

    Using the van Der Pauw methodology, the surface resistivity of irradiated tungsten films deposited on Silicon substrate was measured. The films were exposed to {gamma} radiation using a isotopic {sup 60}Co source in three irradiation stages attaining 40.35 kGy in total dose. The obtained results for superficial resistivity display a time annealing features and their values are proportional to the total dose.

  6. Thermoluminescence of sulfated zircon exposed to gamma radiation; Termoluminiscencia de circonia sulfatada expuesta a radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, E.; Castano, V.M. [Centro de Fisica Aplicada y Tecnologia Avanzada, UNAM, A.P. 1-1010, 76000 Queretaro (Mexico); Mendoza A, E.; Gonzalez, P.R. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2003-07-01

    In this work, the thermoluminescent (Tl) signal induced by gamma radiation in zirconia and sulfated zirconia samples embedded in Ptfe pellets is reported and discussed. In this case, samples were obtained through sol-gel method using zirconium n-propoxide and H{sub 2}SO{sub 4} as precursors, and later were subjected to thermal treatment at 600 C to obtain, the tetragonal phase accordingly to X-ray diffraction analysis. Experimental results show that the thermoluminescent glow peak depends on both, the crystalline structure and sulfate concentration. Two maximum peaks were observed located at 147 C and 274 C arising from the electronic transitions. Tl response as a function of the absorbed dose shows a linear increase for a wide of range exposure as well as good stability in time. The high sensitivity, dose linearity and signal stability of this material open the potential possibility to be used for the dosimetry applications. (Author)

  7. JITTER RADIATION MODEL OF THE CRAB GAMMA-RAY FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Teraki, Yuto; Takahara, Fumio, E-mail: teraki@vega.ess.sci.osaka-u.ac.jp [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

    2013-02-15

    The gamma-ray flares of the Crab nebula detected by the Fermi and AGILE satellites challenge our understanding of the physics of pulsars and their nebulae. The central problem is that the peak energy of the flares exceeds the maximum energy E {sub c} determined by synchrotron radiation loss. However, when turbulent magnetic fields exist with scales {lambda}{sub B} smaller than 2{pi}mc {sup 2}/eB, jitter radiation can emit photons with energies higher than E {sub c}. The scale required for the Crab flares is about two orders of magnitude less than the wavelength of the striped wind. We discuss a model in which the flares are triggered by plunging the high-density blobs into the termination shock. The observed hard spectral shape may be explained by the jitter mechanism. We make three observational predictions: first, the polarization degree will become lower in flares; second, no counterpart will be seen in TeV-PeV range; and third, the flare spectrum will not be harder than {nu}F {sub {nu}}{proportional_to}{nu}{sup 1}.

  8. Observation of a Structure in $pp \\to pp\\gamma\\gamma$ near the $\\pi\\pi$ Threshold and its Possible Interpretation by $\\gamma\\gamma$ Radiation from Chiral Loops in the Mesonic $\\sigma$ Channel

    CERN Document Server

    Bashkanov, M; Calén, H; Cappellaro, F; Clement, H; Demiroers, L; Doroshkevich, E; Ekström, C; Fransson, K; Greiff, J; Gustafsson, L; Höistad, Bo; Ivanov, G; Jacewicz, M; Jiganov, E; Johansson, T; Kaskulov, M M; Keleta, S; Koch, I; Kullander, Sven; Kupsc, A; Kuznetsov, A; Marciniewski, P; Meier, R; Morosov, B; Oelert, W; Pauly, C; Petukhov, Yu P; Povtorejko, A; Ruber, Roger J M Y; Scobel, W; Shwartz, B; Skorodko, T Yu; Sopov, V; Stepaniak, J; Chernyshov, V; Thörngren-Engblom, P; Tikhomirov, V; Turowiecki, A; Wagner, G J; Wiedner, U; Wolke, M; Yamamoto, A; Zabierowski, J; Zlomanczuk, Yu

    2004-01-01

    The $pp \\to pp\\gamma\\gamma$ reaction has been measured at CELSIUS using the WASA $4\\pi$-detector with hydrogen pellet target. At $T_p = 1.20$ and 1.36 GeV, where most of the statistics has been accumulated, the $\\gamma\\gamma$ invariant mass spectrum exhibits a narrow structure around the $\\pi\\pi$ threshold, which possibly may be associated with two-photon radiation of $\\pi^+\\pi^-$ loops in the mesonic $\\sigma$ channel.

  9. Marine environmental radioactivity monitoring by ''in-situ'' {gamma}-radiation detection

    Energy Technology Data Exchange (ETDEWEB)

    Wedekind, C.; Becker, K. [Bundesamt fuer Seeschiffahrt und Hydrographie, Hamburg (Germany); Schilling, G.; Gruettmueller, M. [Bundesamt fuer Seeschiffahrt und Hydrographie, Rostock (Germany)

    2000-08-01

    A monitoring system to observe continuously the artificial part of {gamma}-radiation in the sea by valuation of the {gamma}-energy measured is described. By discrimination against the natural part of {gamma}-radiation, a limit of detection is obtained for contaminations originating from nuclear accidents which is comparable to the detection limit of common chemical analysis methods for tracer nuclides. In addition, the type of radioactive source involved can be identified by {gamma}-spectra taken simultaneously. The measuring system and its application in practice are described. (orig.)

  10. Effects of gamma radiation on melon read-to-eat

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Juliana A.; Polizel, Francine Fernanda, E-mail: jujuba_angelo@yahoo.com.br, E-mail: fran_sininho@hotmail.com [Faculdade de Tecnologia em Piracicaba (FATEP), Piracicaba, SP (Brazil); Harder, Marcia N.C.; Silva, Lucia C.A.S.; Arthur, Paula B.; Arthur, Valter, E-mail: mnharder@terra.com.br, E-mail: lcasilva@cena.usp.br, E-mail: paula.arthur@hotmail.com, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil)

    2013-07-01

    This work comes from the irradiation of Cantaloupe melons (Cucumis melo L.), with the aid of gamma irradiation (Co60) to physical and chemical changes to assess their conservation. The research aimed to evaluate the effects of irradiation on melons, including the possibility of conservation, through pH, acidity, soluble solids and fresh squash. The samples were minimally processed and submitted to gamma radiation Co{sup 60} at doses of 0 (control); 1kGy and 2kGy. Physicochemical analyzes were made in periods of 1, 7 and 14 days after irradiation treatment. On day 1 and day 7, pH levels in irradiated samples had increased compared to control. Since the 14th day, the dose decreased 1kGy equaling the control. Soluble solids showed a statistical gradual decrease according to the increase of dose. The 14th had no significant difference while the 7th the dose was increased. The 1kGy sample decreased in another dose compared to the control. In fresh squash, absent statistics were observed for all samples in the three periods. And for the analysis of titratable acidity, there was observed no significant difference at day 1. There was observed a decrease in the 2kGy and 1kGy dose to 7 days compared to the control. On 14th day, a reduction in the dose of 2kGy and deterioration of 1kGy dose of the sample. Therefore, it demonstrates the irradiation doses of 2kGy, 1kGy physic-chemically alters the Cantaloupe melon pH, soluble solids content and acidity. And the dose of 2kGy is the one that longer preserves samples based on acidity values, greater and smaller values of soluble solids. (author)

  11. Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation. [Paramecium tetraurelia; Synechococcus lividus

    Energy Technology Data Exchange (ETDEWEB)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

    1987-05-01

    Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y.

  12. Radiation damage studies performed at the Calliope gamma irradiation plant at ENEA, Italy)

    Science.gov (United States)

    Baccaro, S.; Cemmi, A.

    2011-09-01

    The Calliope plant, a pool-type irradiation facility located at the Research Centre ENEA-Casaccia (Rome), is equipped with the 60Co γ source in a high-volume shielded cell. Calliope facility is involved in radiation processing research on materials (polymers and optical components) and on devices to be used in hostile radiation environment such as nuclear plants, aerospace experiments and High Energy Physics experiments. The aim of this work is to give an overall picture of the activity we are carrying on at our laboratories with a mention to the possible applications in the field of scintillators and glasses, like doping effect to induce radiation resistance in scintillators, glasses for safe nuclear fuel disposal, suitable substitute oxides which can replace PbO in the preparation of lead-free glasses complying environmental regulations.

  13. Search for the Radiative Penguin Decays B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    CERN Document Server

    Aubert, B; Boutigny, D; Couderc, F; Gaillard, J M; Hicheur, A; Karyotakis, Yu; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, Michael T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Çuhadar-Dönszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M A; Mommsen, R K; Röthel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S M; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, Klaus R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, C; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; De Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F R; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, Erwin; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Mohanty, G B; Cowan, G; Flack, R L; Flächer, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Stängle, H; Willocq, S; Cowan, R; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L M; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; LoSecco, J M; Allmendinger, T; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonian, R; Wong, Q K; Brau, J E; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; La Vaissière, C de; Del Buono, L; Hamon, O; John, M J J; Leruste, P; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martínez-Vidal, F; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lü, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai-Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B J; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, Roy; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P F; Hamel de Monchenault, G; Kozanecki, Witold; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yéche, C; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmüller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, Gallieno; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W M; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hrynóva, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Lüth, V; Lynch, H L; Marsiske, H; Messner, R; Müller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Vavra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, Patricia R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bóna, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R V; Roney, J M; Sobie, R J; Band, H R; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihályi, A; Mohapatra, A K; Pan, Y; Prepost, R; Tan, P; Von Wimmersperg-Töller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2004-01-01

    A search for the decays B --> rho(770) gamma and B0 --> omega(782)gamma is performed on a sample of 211 million Y(4S)->BBbar events collected by the BABAR detector at the PEP-II asymmetric-energy e+e- storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions BF(B --> rho+ gamma) rho0 gamma) omega gamma) (rho/omega) gamma]<1.2 x 10^-6 and constrain V_td/V_ts< 0.19 at the 90% C.L.

  14. Gamma radiation effects on phases of evolutional cycle of Plodia interpunctella (Huebner, 1813) (Lepidoptera, Pyralidae) on artificial diet; Efeitos da radiacao gama nas fases do ciclo evolutivo da Plodia interpunctella (Huebner, 1813) (Lepidoptera - Pyralidae) em dieta artificial

    Energy Technology Data Exchange (ETDEWEB)

    Tamborlin, Maria Julia

    1988-10-01

    The effects of increased gamma radiation ({sup 60} Co) doses on different phases of the evolutional cycle of Plodia interpunctella (Hubner,1813) (Lepidoptera, Pyralidae) have bean studied under laboratory conditions in the Laboratory of Radioentomology of the Nuclear Energy for Agriculture Center (CENA) in Piracicaba, Sao Paulo State, Brazil. For all treatments with gamma radiation a Cobalt-60 source type Gamma bean-650 has been used and the activity was of approximately 2.93 x 10{sup 14} Bq (7,925 Ci), with a dose rate of 2.80 KGy per hour and the insects were kept in a climatic chamber with the temperature adjusted to 27 {+-} 2{sup 0} C and a relative humidity of 70 {+-} 10%. The LD{sub 50} and LD{sub 100} of gamma radiation for eggs of in artificial diet were respectively 51 Gy and 125 Gy. The sterilizing doses in adults which were irradiated at immature phases (larvae and pupae) were 160 Gy and 250 Gy respectively. The sterilizing doses for adults females and males were respectively 250 Gy and 300 Gy. The LD{sub 100} for adult males was 4,750 Gy, 4,500 Gy for females and 4,750 Gy for insects at random. (author). 70 refs., 10 figs., 19 tabs.

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

    Science.gov (United States)

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

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

  16. Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto, E-mail: isaiasfilhojr@yahoo.com.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica

    2009-07-01

    The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the {sup 60}Co 1332.46 KeV line. The radioactive activity of the radionuclides {sup 40}K, {sup 137}Cs, {sup 238}U, {sup 232}Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The {sup 238}U series activities were calculated through {sup 214}Pb and {sup 214}Bi activities, and the {sup 232}Th series' activity was calculated through the {sup 228}Ac, {sup 212}Pb, {sup 212}Bi and {sup 208}Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest {sup 40}K and {sup 228}Ra activities were found in the ration sample for milk cattle, 402 +- 14 and 1.71 +- 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for {sup 226}Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the {sup 238}U, {sup 40}K and {sup 232}Th were respectively 83 +- 26; 46.6 +- 2.8 and 7.79 +- 0.70 Bq/kg. The MDA values for {sup 137}Cs varied from 0.037 to 0.29 Bq/kg. (author)

  17. Optimization of radiation protection in gamma radiography facilities; Otimizacao do sistema de radioprotecao nas instalacoes radiograficas de gamagrafia

    Energy Technology Data Exchange (ETDEWEB)

    Antonio Filho, Joao

    1999-07-01

    To determine optimized dose limits for workers, a study of optimization of radiation protection was undertaken in gamma radiography facilities closed, using the Technique Multiple Attributes Utility Analysis. A total of 217 protection options, distributed in 34 irradiation scenarios for tree facility types ( fixed open, moveable and closed (bunker) were analyzed. In the determination of the optimized limit dose, the following attributes were considered; costs of the protection barriers, costs attributed to the biological detriment for different alpha (the reference value of unit collective dose), size of the isolation area, constrained limits dose of annual individual equivalent doses and collective dose. The variables studied in the evaluation included: effective work load, type and activity of the sources of radiation ({sup 192}Ir and {sup 60}Co), source-operator distance related to the characteristic of the length of the command cable and the guide tube, type and thickness of the materials used in the protection barriers (concrete, barite, ceramic, lead, steel alloy and tungsten). The optimal analytic solutions obtained in the optimization process that resulted in the indication of the optimized dose limit were determined by means of a sensitivity analysis and by direct and logic evaluations, thus, independent of the values of the monetary coefficient attributed to the biological detriment, of the annual interest rate applied to the protection cost and of the type of installation studied, it was concluded that the primary limit of annual equivalent dose for workers (now 50 mSv) can be easily reduced to an optimized annual dose limit of 5 mSv. (author)

  18. Gamma radiation in the control of insects in animal feed

    Energy Technology Data Exchange (ETDEWEB)

    Arthur, Paula B.; Arthur, Valter; Silva, Lucia C.A.S.; Franco, Suely S.H., E-mail: paula.arthur@hotmail.com, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Jose G.; Villavicencio, Anna Lucia, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Harder, Marcia N.C., E-mail: marcia.harder@fatec.sp.gov.br [Centro Paula Souza, Curso Superior de Tecnologia em Biocombustiveis (FATEC), Piracicaba, SP (Brazil)

    2015-07-01

    The pests as beetles, acarids, moths and mushrooms among other, usually infest products stored as: grains, crumbs, flours, coffee, tobacco, dried fruits, animal feeds, spices and dehydrated plants, causing the visual depreciation and promoting the deterioration of the products. The objective of this study was to use gamma radiation of Cobalt-60 in the disinfestation of some types of commercial feeds used for animals of small size. In the experiment, packages measuring 10 cm x 15 cm, with capacity of 30 grams of substrate with 4 types of trademarks were irradiated with doses of: 0 (control) 0.5; 1.0 and 2.0 kGy. Each treatment had 10 repetitions, infested with 10 insects for each package with the following species: Lasioderma serricorne, Plodia interpuctella, Sitophilus zeamais and S. oryzae. After the irradiation, all the packages were maintained at acclimatized room with 27 ± 2ºC and relative humidity of 70 ± 5%. The number of insects and holes in all packages were assessed after 60 days. The results showed that the dose of 0.5 kGy was sufficient to control all the species of insects in the tested feeds. (author)

  19. Application of Jitter Radiation: Gamma-ray Burst Prompt Polarization

    CERN Document Server

    Mao, J

    2013-01-01

    A high-degree of polarization of gamma-ray burst (GRB) prompt emission has been confirmed in recent years. In this paper, we apply jitter radiation to study the polarization feature of GRB prompt emission. In our framework, relativistic electrons are accelerated by turbulent acceleration. Random and small-scale magnetic fields are generated by turbulence. We further determine that the polarization property of GRB prompt emission is governed by the configuration of the random and small-scale magnetic fields. A two-dimensional compressed slab, which contains stochastic magnetic fields, is applied in our model. If the jitter condition is satisfied, the electron deflection angle in the magnetic field is very small and the electron trajectory can be treated as a straight line. A high-degree of polarization can be achieved when the angle between the line of sight and the slab plane is small. Moreover, micro-emitters with mini-jet structure are considered to be within a bulk GRB jet. The jet "off-axis" effect is int...

  20. Hydrogel membranes of PVAl/ clay by gamma radiation

    Science.gov (United States)

    de Oliveira, M. J. A.; Parra, D. F.; Amato, V. S.; Lugão, A. B.

    2013-03-01

    In the last decades several studies concerning the new methods for drug delivery system have been investigated. A new field known as "smart therapy" involves devices and drug delivery systems to detect, identify and treat the site affected by the disease, not interfering with the biological system. Cutaneous Leishmaniasis is an endemic disease that is characterized by the development of single or multiple localized lesions on exposed areas of skin and one coetaneous treatment could be a potential solution. The aim of this study was to obtain polymeric hydrogel matrices of poly(vinylalcohol)(PVAl) and chitosan with inorganic nanoparticles, which can release a drug according to the need of the treatment of injury caused by leishmania on the skin. The hydrogels matrices were obtained with PVAl/ chitosan and PVAl/ chitosan 0.5; 1.0 and 1.5% laponite RD clay, crosslinked by ionizing gamma radiation with dose of 25 kGy. The techniques used for characterization were swelling, gel fraction, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). After synthesis, the samples were immersed in distilled water and weighed in periods of time until 60 h for the swelling determination. The obtained results have indicated that the swelling of the membranes increases with clay concentration, in consequence of ionic groups present in the clay.

  1. Attosecond gamma-ray pulses via nonlinear Compton scattering in the radiation dominated regime

    CERN Document Server

    Li, Jian-Xing; Galow, Benjamin J; Keitel, Christoph H

    2015-01-01

    The interaction of a relativistic electron bunch with a counter-propagating tightly-focused laser beam is investigated for intensities when the dynamics is strongly affected by its own radiation. The Compton scattering spectra of gamma-radiation are evaluated employing a semiclassical description for the laser-driven electron dynamics and a quantum electrodynamical description for the photon emissions. We show for laser facilities under construction that gamma-ray bursts of few hundred attoseconds and dozens of megaelectronvolt photon energies may be detected in the near-backwards direction of the initial electron motion. Tight focussing of the laser beam and radiation reaction are demonstrated to be jointly responsible for such short gamma-ray bursts which are independent of both duration of electron bunch and laser pulse. Furthermore, the stochastic nature of the gamma-photon emission features signatures in the resulting gamma-ray comb in the case of the application of a multi-cycle laser pulse.

  2. High-Speed, Low Power 256 Channel Gamma Radiation Array Detector ASIC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Building on prior success in detector electronics, we propose to design and fabricate a 256 channel readout ASIC for solid state gamma radiation array detectors...

  3. Principles of medical rehabilitation of survivors of acute radiation sickness induced by gamma and beta and gumma and neutron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nedejina, N.M.; Galstian, I.A.; Savitsky, A.A.; Sachkov, A.V.; Rtisheva, J.N.; Uvatcheva, I.V.; Filin, S.V. [State Research Center of Russia, Moscow (Russian Federation). Inst. of Biophysics

    2000-05-01

    The purpose of this study is to reveal the principles of medical rehabilitation different degree acute radiation syndrome (ARS) survivors, who exposed {gamma}{beta}- and {gamma}{eta}-irradiation in different radiation accidents. The main reasons of working disability in the late consequences of ARS period are consequences of local radiation injures (LRI) and joining somatic diseases. Its revealing and treatment considerably improves quality of life of the patients. The heaviest consequence of LRI of a skin at {gamma}{beta}- radiation exposure is the development of late radiation ulcers and radiation fibrosis, which require repeated plastic surgery. LRI at {gamma}{eta}-radiation exposure differ by the greater depth of destruction of a underlying tissues and similar defects require the early amputations. Last 10 years microsurgery methods of plastic surgery allow to save more large segments of extremities and to decrease expression of the late consequences (radiation fibrosis and late radiation ulcers) LRI severe and extremely severe degrees. Medical rehabilitation of radiation cataract (development at doses more than 2.0 Gy) includes its extraction and artificial lens implantation, if acuity of vision is considerably decreased. Changes of peripheral blood, observed at the period of the long consequences, as a rule, different, moderate, transient and not requiring treatment. Only one ARS survivor dead from chronic myeloid leukemia. Thyroid nodes, not requiring operative intervention, are found out in Chernobyl survivors. Within the time course the concurrent somatic disease become the major importance for patients disability growth, which concurrent diseases seem to be unrelated to radiation dose and their structure does not differ from that found in general public of Russia. The rehabilitation of the persons who have transferred ARS as a result of radiating failure, should be directed on restoration of functions critical for ionizing of radiation of bodies and

  4. Registration of the Atmospheric Gamma Radiation on Board the Russian Segment of the International Space Station

    Science.gov (United States)

    Andreevsky, S. E.; Kuznetsov, V. D.; Sinelnikov, V. M.

    2017-03-01

    The paper describes the complex of scientific instruments and the algorithm of the "Molniya-Gamma" experiment on measuring gamma-ray fluxes in the energy range of 32-750 keV carried out in 2011 on board the Russian Segment (RS) of the International Space Station (ISS). About 500 thousand energy spectra with a time resolution of 1 min were obtained in 512 energy channels during 232 days. One-second variations in the number of gamma quanta in four energy channels and the triggered fluxes of gamma quanta lasting less than 100 ms were recorded simultaneously. The data obtained allow us to study temporal and spatial variation of gamma-ray radiation to detect terrestrial gamma flashes (TGFs). Data on very large number of gamma-ray spikes were acquired through a trigger data mode with a low threshold.

  5. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Tempone, A.G.; Lourenco, C.O.; Spencer, P.J.; Rogero, J.R.; Nascimento, N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Radiobiologia; Andrade Junior, H.F. [Sao Paulo Univ., SP (Brazil). Faculdade de Medicina. Inst. de Medicina Tropical

    1999-11-01

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a {sup 60} Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author) 13 refs., 3 figs.

  6. Definition of the radiation fields for the JET gamma-ray spectrometer diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zoita, Vasile, E-mail: Vasile.Zoita@jet.efda.org [EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania); Soare, Sorin [Association EURATOM-MEdC, National Institute for Cryogenics and Isotope Technologies, Rm. Valcea (Romania); Craciunescu, Teddy [Association EURATOM-MEdC, National Institute for Laser, Plasma and Radiation Physics, Bucharest (Romania); Curuia, Marian [Association EURATOM-MEdC, National Institute for Cryogenics and Isotope Technologies, Rm. Valcea (Romania); Kiptily, Vasily; Balshaw, Nick [Association EURATOM-CCFE, Culham Science Centre, Abingdon (United Kingdom); Blanchard, Patrick [EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Association EURATOM-CRPP-EPFL, Lausanne (Switzerland); Croft, David [Association EURATOM-CCFE, Culham Science Centre, Abingdon (United Kingdom); Murari, Andrea [EFDA-JET CSU Culham, Culham Science Centre, Abingdon (United Kingdom); Association EURATOM-ENEA, RFX, Padova (Italy); Syme, Brian [Association EURATOM-CCFE, Culham Science Centre, Abingdon (United Kingdom)

    2013-10-15

    The JET gamma-ray diagnostics system provides information on the behaviour of fast particles within the tokamak plasma. Information on the spatial distribution of the interacting fast particles is obtained from the gamma-ray cameras, while energy distribution information is provided by gamma-ray spectrometers. These techniques have been successfully applied so far in fast particle simulation experiments at JET. The extension of these diagnostics to high performance discharges with high neutron yields is not straightforward due to the background gamma-ray emission induced by neutrons. Two gamma-ray diagnostics upgrade projects at JET addressed this issue by developing neutron/gamma radiation filters (“neutron attenuators”) and collimators for a proper definition of the radiation (neutron and gamma) fields along the diagnostics line-of-sight. A pair of neutron/gamma collimators working in a tandem configuration have been designed and constructed for the JET quasi-tangential gamma-ray spectrometer. The tandem collimators were designed to provide shielding factors of about 5 × 10{sup 2} for 2.45 MeV neutrons and about 10{sup 3} for 9 MeV gamma-rays. The devices have been installed on the JET machine and the paper presents the first experimental results. A similar tandem collimator system was designed for deuterium-tritium experiments on JET. The results of neutron-photon transport calculations for 14.1 MeV neutrons are also presented.

  7. Gamma greenhouse: A chronic facility for crops improvement and agrobiotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Azhar, M., E-mail: azhar-m@nuclearmalaysia.gov.my; Ahsanulkhaliqin, A. W., E-mail: azhar-m@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, 43000 KAJANG, Selangor (Malaysia)

    2014-02-12

    Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, {sup 60}Co and {sup 137}Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for {sup 60}Co and 30.1 years for {sup 137}Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the

  8. Gamma greenhouse: A chronic facility for crops improvement and agrobiotechnology

    Science.gov (United States)

    Azhar, M.; Ahsanulkhaliqin, A. W.

    2014-02-01

    Gamma irradiation is one of the most common procedures in plant mutagenesis and agrobiotechnology activities. The procedures consist of chronic and acute gamma radiation. Generally, 60Co and 137Cs are gamma radiation sources for radiation processing with relatively high energy (half-life 5.27 years for 60Co and 30.1 years for 137Cs). The energy associated with gamma radiation is high enough to break the molecular bonds and ionize atoms without affecting structure of the atomic nucleus (avoiding induction of radioactivity). The Gamma Green House (GGH) is the only chronic irradiation facility in Malaysia, located at Malaysian Nuclear Agency (Nuclear Malaysia). GGH is used for induction of mutation in plants and other biological samples at low dose radiation over period of time depending on the nature and sensitivity of the plant species. The GGH consist of circular green house with 30 meters radius, control room and irradiator with interlock system. The irradiator produces low dose gamma radiation derived from Caesium-137 radioactive source. The biological samples can be exposed to low dose radiation in days, weeks, months or years. The current irradiation rate for GGH is 2.67 Gy/hr at 1 meter from the source. Chronic gamma irradiation produces a wider mutation spectrum and useful for minimizing radiation damages towards obtaining new improved traits for research and commercial values. The prospect of the gamma greenhouse is its uses in research, educations and services on induced mutation techniques for the improvement of plant varieties and microbes. In generating awareness and attract users to the facility, Nuclear Malaysia provides wide range of irradiation services for plant species and mutagenesis consultancies to academicians, students scientists, and plant breeders, from local universities, other research institutes, and growers. Charges for irradiation and consultancy services are at nominal rates. The utilization activities of the gamma greenhouse mainly

  9. Shelf life extension of fresh turmeric ( Curcuma longa L.) using gamma radiation

    Science.gov (United States)

    Dhanya, R.; Mishra, B. B.; Khaleel, K. M.; Cheruth, Abdul Jaleel

    2009-09-01

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 °C storage temperature was found to keep peeled turmeric samples microbe free and acceptable until 60 days of storage. The control sample without radiation treatment spoiled within a week of storage. The changes in color, texture and moisture content of fresh turmeric due to radiation treatment were found to be statistically insignificant.

  10. Shelf life extension of fresh turmeric (Curcuma longa L.) using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dhanya, R. [P.G. Department and Research Centre in Botany, Sir Syed College, Taliparamba 670142, Kerala (India); Mishra, B.B. [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Khaleel, K.M. [P.G. Department and Research Centre in Botany, Sir Syed College, Taliparamba 670142, Kerala (India)], E-mail: khaleelchovva@yahoo.co.in; Cheruth, Abdul Jaleel [DMJM International (Cansult Maunsell/AECOM Ltd.), Consultant of Gardens Sector Projects, Alain Municipality and Eastern Emirates, P.O. Box 1419, Al-Ain, Abu Dhabi (United Arab Emirates)], E-mail: abdul79jaleel@yahoo.co.in

    2009-09-15

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 {sup o}C storage temperature was found to keep peeled turmeric samples microbe free and acceptable until 60 days of storage. The control sample without radiation treatment spoiled within a week of storage. The changes in color, texture and moisture content of fresh turmeric due to radiation treatment were found to be statistically insignificant.

  11. Sensorial effects of gamma radiation processing on cinnamon (Laurus cinnamomum) and nut meg (Myristica fragans)

    Energy Technology Data Exchange (ETDEWEB)

    Salum, Debora C.; Sabundjian, Ingrid T.; Silva, Priscila V.; Furgeri, Camilo; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares IPEN/CNEN-SP, Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes. Lab. de Deteccao de Alimentos Irradiados]. E-mails: villavic@ipen.br; dcsalum@ipen.br; Purgatto, Eduardo [Universidade de Sao Paulo, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Alimentos e Nutricao Experimental]. E-mail: epurgatt@usp.br

    2007-07-01

    Food irradiation is the processing of food products by ionizing radiation in order, among other things, to control food borne pathogens, reduce microbial load and insect infestation, inhibit the germination of root crops, and extend the durable life of perishable products. Irradiation of dried food ingredients, particularly herbs and spices, has a great application potential, and has already been implemented in many countries. Spice irradiation is performed to increase the hygienic quality and used as decontamination processes instead of fumigation methods. European Community approves irradiation processing as an effective residue-free alternative. The present paper evaluates the effect of ionizing radiation on sensorial properties of cinnamon (Laurus cinnamomum) and nut meg (Myristica fragans). The samples have been irradiated in multipurpose irradiator of {sup 60}Co in the doses: 0, 5, 10, 15, 20 e 25 kGy. (author)

  12. Shock acceleration and gamma radiation in the intracluster medium

    CERN Document Server

    Gabici, S

    2004-01-01

    Particle acceleration is expected to take place at shocks that form during the process of large scale structure formation. Electrons accelerated at such shocks can upscatter a small fraction of the photons in the cosmic microwave background up to the gamma ray band. Here we make predictions about the detectability of the $\\gamma$--ray emission from forming clusters of galaxies with future GeV and TeV gamma ray telescopes. We also estimate the contribution of these sources to the extragalactic diffuse gamma ray background.

  13. Comparison between a commercial and homemade ionization chamber for dosimetry of {sup 60}Co beams

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P.; Perini, Ana P.; Caldas, Linda V.E., E-mail: lpneves@ipen.b, E-mail: aperini@ipen.b, E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The Calibration Laboratory at IPEN/CNEN (LCI) has developed several ionization detectors for dosimetry in diagnostic radiology, radiation protection and radiotherapy. Recently, a cylindrical ionization chamber, with a sensitive volume of 1.06cm{sup 3}, was developed, and several tests were performed to characterize this ionization chamber for radiotherapy level. The results showed that its performance was within the recommended international limits. In order to complement the studies regarding the response of this ionization chamber, in this work, the chamber response was compared with that of a commercial ionization chamber Farmer PTW, model TN30011-1. The ionization chamber produced at LCI is made of PVC and PMMA. A special build-up cap for {sup 60}Co beams was made of acrylic, with 4.00 mm thickness. All tests of both ionization chambers were performed under the same conditions, allowing good geometrical reproducibility. The performed tests were: saturation, ion collection efficiency, polarity effect and chamber tilt. The results obtained in this comparison program were all within the international recommendations, and demonstrate a good agreement of the performance of the commercial and the homemade ionization chambers. From this comparison results and from previous data, it is possible to conclude that the ionization chamber produced at IPEN presents usefulness for dosimetric applications at radiotherapy level in {sup 60}Co beams.(author)

  14. Effects of gamma radiation on Sporothrix schenckii yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Camila M. de Sousa; Martins, Estefania Mara Nascimento; Andrade, Antero S.R. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: cmsl@cdtn.br, e-mail: estefaniabio@yahoo.com.br, e-mail: antero@cdtn.br; Resende, Maria Aparecida de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: maressend@mono.icb.ufmg.br

    2009-07-01

    Sporotrichosis is a subacute or chronic infection caused by the fungus Sporothrix schenckii. Zoonotic transmission can occur after scratches or bites of animals, mainly cats, rodents, and armadillos. Up to the moment, no approved vaccine was reported for S. schenckii or to any important pathogenic fungi infection in humans, indicating the need to expand the research in this field and to explore new alternatives. The aim of this study was to evaluate the effects of gamma radiation in the viability, metabolic activity and reproductive ability of S. schenckii yeast cells for further studies on the development of a vaccine for immunization of cats and dogs. The culture of S. schenckii, in solid medium, was irradiated at doses ranging from 1.0 to 9.0 kGy. After each dose the reproductive capacity, viability and protein synthesis were estimated. The results showed that a reduction of 6 log{sub 10} cycles in the number of colonies was achieved at 6.0 kGy and after 8.0 kGy no colonies could be recovered. The viability analysis indicated that yeast cells remained viable up to 9.0 kGy. The results of protein synthesis analysis showed that the yeast cells, irradiated up to 9.0 kGy, were able to synthesize proteins. Our preliminary results indicated that for the yeast cells of S. schenckii, it is possible to find an absorbed dose in which the pathogen loses its reproductive ability, while retaining its viability, a necessary condition for the development of a radioattenuated yeast vaccine. (author)

  15. Gamma scattering in condensed matter with high intensity Moessbauer radiation

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    We give a progress report for the work which has been carried out in the last three years with DOE support. A facility for high-intensity Moessbauer scattering is now fully operational at the University of Missouri Research Reactor (MURR) as well as a facility at Purdue, using special isotopes produced at MURR. High precision, fundamental Moessbauer effect studies have been carried out using scattering to filter the unwanted radiation. These have led to a new Fourier transform method for describing Moessbauer effect (ME) lineshape and a direct method of fitting ME data to the convolution integral. These methods allow complete correction for source resonance self absorption (SRSA) and the accurate representation of interference effects that add an asymmetric component to the ME lines. We have begun applying these techniques to attenuated ME sources whose central peak has been attenuated by stationary resonant absorbers, to more precisely determine interference parameters and line-shape behavior in the resonance asymptotic region. This analysis is important to both the fundamental ME studies and to scattering studies for which a deconvolution is essential for extracting the correct recoilless fractions and interference parameters. A number of scattering studies have been successfully carried out including a study of the thermal diffuse scattering in Si, which led to an analysis of the resolution function for gamma-ray scattering. Also studied was the anharmonic motion in Na and the satellite reflection Debye-Waller factor in TaS{sub 2}, which indicate phason rather than phonon behavior. We have begun quasielastic diffusion studies in viscous liquids and current results are summarized. These advances, coupled to our improvements in MIcrofoil Conversion Electron spectroscopy lay the foundation for the proposed research outlined in this request for a three-year renewal of DOE support.

  16. Effect of the gamma radiation in the metabolic activity of the apical meristem of asparagus (Asparagus officinalis); Efecto de la radiacion gamma en la actividad metabolica del meristemo apical de esparrago (Asparagus officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez E, A.; Orozco A, J.A.; Troncoso R, R.; Ojeda C, A.J.; Mercado R, J.N.; Gardea B, A.; Tiznado H, M.E. [Centro de Investigacion en Alimentacion y Desarrollo, A.C. Carretera a la Victoria km. 0.6, A.P. 1735, Hermosillo, Sonora (Mexico); Melendrez A, R. [Universidad de Sonora, A.P. 5-088, Hermosillo, Sonora (Mexico)]. e-mail: aestrada@cascabel.ciad.mx

    2007-07-01

    The asparagus (Asparagus officinalis) is an agricultural product whose production generates a great quantity of wages as well as foreign currencies for the country because a great part of its production is exported to international markets. In direct reason to the high metabolic activity of the apical meristem, this product it possesses a short shelf life under good conditions of commercialization. Due to the above mentioned, the present work had as objective to evaluate the effect of the gamma radiation in the metabolic activity of the apical meristem of turions of asparagus during the postharvest. Turions of asparagus variety Brock of standard quality was treated with gamma radiation to absorbed dose of 1.0, 1.5, 2.0, 2.5 and 3.0 kGy using an irradiator of {sup 60}Co and stored in one controlled temperature camera maintained at 2 C during 8 days. During the experiment, the camera stayed in darkness and under conditions of high relative humidity by means of the water aspersion. Immediately before the one treatment and after 1, 2, 4 and 8 days of storage, the asparagus were sampled to evaluate the breathing speed (VRCG) by means of gas chromatography and scanning differential calorimetry (VRCDB), ethylene production (PE) by means of gas chromatography and production of metabolic heat of the apical meristem of the asparagus by means of scanning differential calorimetry (Q). Its were not found effects due to the gamma radiation in the variables of VRCG, VRCDB and Q. However, for the PE case, it was found that the doses of 1.5 and 2.5 reduced the PE from the first day of storage, while the 3 kGy dose achievement to eliminate completely the ethylene production from the first day of storage. It was concluded that the gamma radiation at the used levels in the present experiment doesn't reduce the metabolic activity of the apical meristem of the turion of asparagus although it can to improve the postharvest quality from the asparagus when reducing the ethylene

  17. Study of recombination processes for 'electron-hole' pairs in germanium irradiated by {gamma} rays from {sup 60}Co using the photovoltaic effect in P-N junctions; Etude du processus de recombinaison des paires ''electron-trou'' dans le germanium irradie par les rayons {gamma} du cobalt 60 a l'aide de l'effet photovoltaique dans les jonctions P-N

    Energy Technology Data Exchange (ETDEWEB)

    Zahedi-Mochadam, A.A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-10-01

    Using the photo-voltaic effect in p-n junctions, we have studied, during bombardment, the mechanism of the recombination of 'electron-hole' pairs in the presence of structure defects produced in germanium of the N and P types by {gamma} rays from a Co{sup 60} source. At 310 K the level of the recombination centres is situated 0.25 eV above the conduction band and the capture cross-sections of the holes and of the electrons have the respective values of: {sigma}{sub p} = 4 X 10{sup -15} cm{sup 2} and {sigma}{sub n} = 3 X 10{sup -15} cm{sup 2}. The value of {sigma}{sub n} appears to be under-estimated because the number of defects in P-type samples appears to be lower than that in N-type samples. These results lead to the conclusion that the interstitials are responsible for the recombination. At 80 K it has been found that in N-type samples, a shallow level exists at O.05 eV below the conduction band with a capture cross-section for the holes of {sigma}{sub p} {>=} 10{sup -14} cm{sup 2}. We believe that in this case the recombination of charge carriers is controlled by the neighbouring 'defect-interstitial' pairs. In P-type samples at low temperature, the life-time is practically constant during irradiation. This fact is attributed to a spontaneous annealing of defects ol purely electrical origin. In the last part of the work the study of the photo-voltaic effect applied to the problem of gamma radiation dosimetry is considered. It is shown that such dosimeters, based on this principle, make it possible to measure the intensity of gamma rays over a very wide range. (author) [French] En utilisant l'effet photovoltaique dans les jonctions p-n, nous avons etudie au cours du bombardement le mecanisme de recombinaison des paires 'electron-trou' en presence des defauts de structure introduits dans le germanium de type N et de type P par les rayons gamma d'une source de Co{sup 60}. A 310 K, le niveau des centres de recombinaison se

  18. Accuracy of soil water content estimates from gamma radiation monitoring data

    Science.gov (United States)

    Mao, Jie; Huisman, Johan Alexander; Reemt Bogena, Heye; Vereecken, Harry

    2016-04-01

    Terrestrial gamma radiation is known to be sensitive to soil water content, and could be promising for soil water content determination because of the availability of continental-scale gamma radiation monitoring networks. However, the accuracy of soil water content estimates that can be obtained from this type of data is currently unknown. Therefore, the aim of this study is to assess the accuracy of soil water content estimates from measured time series of gamma radiation. For this, four gamma radiation monitoring stations were each equipped with four soil water content sensors at 5 and 15 cm depth to provide reference soil water content measurements. The contributions of terrestrial radiation and secondary cosmic radiation were separated from the total amount of measured gamma radiation by assuming that the long-term contribution of secondary cosmic radiation was constant, and that variations were related to changes in air pressure and incoming neutrons. In addition, precipitation effects related to atmospheric washout of radon progenies to the ground that cause an increase of gamma radiation were considered by excluding time periods with precipitation and time periods less than three hours after precipitation. The estimated terrestrial gamma radiation was related to soil water content using an exponential function with two fit parameters. For daily soil water content estimates, the goodness of fit ranged from R2= 0.21 to 0.48 and the RMSE ranged from 0.048 to 0.117 m3m-3. The accuracy of the soil water content estimates improved considerably when a weekly resolution was used (RMSE ranged from 0.029 to 0.084 m3m-3). Overall, these results indicate that gamma radiation monitoring data can be used to obtain useful soil water content information. The remaining differences between measured and estimated soil water content can at least partly be explained by the fact that the terrestrial gamma radiation is strongly determined by the upper few centimeters of the soil

  19. Radiative processes (tau -> mu gamma, mu -> e gamma and muon g-2) as probes of ESSM/SO(10)

    CERN Document Server

    Babu, K S; Pati, Jogesh C.

    2003-01-01

    The Extended Supersymmetric Standard Model (ESSM), motivated on several grounds, introduces two vectorlike families (16 + 16-bar) of SO(10)) with masses of order one TeV. It is noted that the successful predictions of prior work on fermion masses and mixings, based on MSSM embedded in SO(10), can be retained rather simply within the ESSM extension. These include an understanding of the smallness of V_{cb} ~ 0.04 and the largeness of nu_mu - nu_tau oscillation angle, sin^2 2 theta_{nu_mu nu_tau}^{osc} ~ 1. We analyze the new contributions arising through the exchange of the vectorlike families of ESSM to radiative processes including tau -> mu gamma, mu -> e gamma, b -> s gamma, EDM of the muon and the muon (g-2). We show that ESSM makes significant contributions especially to the decays tau -> mu gamma and mu -> e gamma and simultaneously to muon (g-2). For a large and plausible range of relevant parameters, we obtain: a_mu^{ESSM} ~ +(10-40) times 10^{-10}, with a correlated prediction that tau -> mu gamma sh...

  20. Search for the radiative transitions $\\psi(3770)\\to\\gamma\\eta_c$ and $\\gamma\\eta_c(2S)$

    CERN Document Server

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bian, J M; Boger, E; Bondarenko, O; Boyko, I; Braun, S; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Chu, Y P; Cronin-Hennessy, D; Dai, H L; Dai, J P; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; Ding, W M; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Du, S X; Fan, J Z; Fang, J; Fang, S S; Fang, Y; Fava, L; Feng, C Q; Fu, C D; Fuks, O; Gao, Q; Gao, Y; Geng, C; Goetzen, K; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, L B; Guo, T; Guo, Y P; Haddadi, Z; Han, S; Han, Y L; Harris, F A; He, K L; He, M; He, Z Y; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Huang, G M; Huang, G S; Huang, H P; Huang, J S; Huang, L; Huang, X T; Huang, Y; Hussain, T; Ji, C S; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L L; Jiang, L W; Jiang, X S; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Kloss, B; Kopf, B; Kornicer, M; Kuehn, W; Kupsc, A; Lai, W; Lange, J S; Lara, M; Larin, P; Leyhe, M; Li, C H; Li, Cheng; Li, Cui; Li, D; Li, D M; Li, F; Li, G; Li, H B; Li, J C; Li, Jin; Li, K; Li, P R; Li, Q J; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Lin, D X; Liu, B J; Liu, C L; Liu, C X; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H M; Liu, J; Liu, J P; Liu, K; Liu, K Y; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, G R; Lu, H J; Lu, H L; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lv, M; Lyu, X R; Ma, F C; Ma, H L; Ma, Q M; Ma, S; Ma, T; Ma, X Y; Maas, F E; Maggiora, M; Malik, Q A; Mao, Y J; Mao, Z P; Messchendorp, J G; Min, J; Min, T J; Mitchell, R E; Mo, X H; Mo, Y J; Moeini, H; Morales, C Morales; Moriya, K; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pelizaeus, M; Peng, H P; Peters, K; Ping, J L; Ping, R G; Poling, R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Y; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Ruan, X D; Sarantsev, A; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, X Y; Sheng, H Y; Shepherd, M R; Song, W M; Song, X Y; Spataro, S; Spruck, B; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Toth, D; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, Q J; Wang, S G; Wang, W; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Werner, M; Wiedner, U; Wolke, M; Wu, L H; Wu, N; Wu, Z; Xia, L G; Xia, Y; Xiao, D; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Xue, Z; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H X; Yang, L; Yang, Y; Yang, Y X; Ye, H; Ye, M; Ye, M H; Yu, B X; Yu, C X; Yu, H W; Yu, J S; Yu, S P; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zang, S L; Zeng, Y; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C B; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J J; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, S H; Zhang, X J; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, X H; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, Y H; Zhong, B; Zhou, L; Zhou, Li; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zou, B S; Zou, J H

    2014-01-01

    By using a 2.92 fb$^{-1}$ data sample taken at $\\sqrt{s} = 3.773$ GeV with the BESIII detector operating at the BEPCII collider, we search for the radiative transitions $\\psi(3770)\\to\\gamma\\eta_c$ and $\\gamma\\eta_c(2S)$ through the hadronic decays $\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp$. No significant excess of signal events above background is observed. We set upper limits at a 90% confidence level for the product branching fractions to be $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c)\\times \\mathcal{B}(\\eta_c\\to K^0_SK^\\pm\\pi^\\mp) < 1.6\\times10^{-5}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S))\\times \\mathcal{B}(\\eta_c(2S)\\to K^0_SK^\\pm\\pi^\\mp) < 5.6\\times10^{-6}$. Combining our result with world-average values of $\\mathcal{B}(\\eta_c(\\eta_c(2S))\\to K^0_SK^\\pm\\pi^\\mp)$, we find the branching fractions $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c) < 6.8\\times10^{-4}$ and $\\mathcal{B}(\\psi(3770)\\to\\gamma\\eta_c(2S)) < 2.0\\times10^{-3}$ at a 90% confidence level.

  1. Investigation of gamma-ray fingerprint identifying mechanism for the types of radiation sources

    CERN Document Server

    Liu Su Ping; Gu Dang Chang; Gong-Jian; Hao Fan Hua; Hu Guang Chun

    2002-01-01

    Radiation fingerprints sometimes can be used to label and identify the radiation resources. For instance, in a future nuclear reduction treaty that requires verification of irreversible dismantling of reduced nuclear warheads, the radiation fingerprints of nuclear warheads are expected to play a key role in labelling and identifying the reduced warheads. It would promote the development of nuclear warheads deep-cuts verification technologies if authors start right now some investigations on the issues related to the radiation fingerprints. The author dedicated to the investigation of gamma-ray fingerprint identifying mechanism for the types of radiation resources. The purpose of the identifying mechanism investigation is to find a credible way to tell whether any two gamma-ray spectral fingerprints that are under comparison are radiated from the same resource. The authors created the spectrum pattern comparison (SPC) to study the comparability of the two radiation fingerprints. Guided by the principle of SPC,...

  2. Isodose mapping of terrestrial gamma radiation dose rate of Selangor state, Kuala Lumpur and Putrajaya, Malaysia.

    Science.gov (United States)

    Sanusi, M S M; Ramli, A T; Gabdo, H T; Garba, N N; Heryanshah, A; Wagiran, H; Said, M N

    2014-09-01

    A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h(-1) to 500 nGy h(-1). The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h(-1). This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h(-1) (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation.

  3. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae

    Directory of Open Access Journals (Sweden)

    Ke Zhang

    2014-05-01

    Full Text Available Radio-(60Co, which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD, catalase (CAT, peroxidase (POD, phenoloxidase (PO and acetylocholinesterase (AchE were investigated. POD and CAT activities, as well as SOD were higher in the irradiated mites. We found that exposure to 60Coradiation resulted in increased activities of SOD, CAT, POD and decreased AchE activity. When the recovery time lasted till the 5th day, the activities of POD and PO were significantly lower than the control, whereas the SOD, CAT and AchE activities returned to control levels. Cells possess protein repair pathways to rescue oxidized proteins and restore their functions, but if these repair processes fail, oxidized proteins may become cytotoxic. Our results confirm the hypothesis that low dosages of 60Co-γ irradiation increase the level of oxidative stress in P. citri adults in a short time, causing meanwhile damage and sterility. The results of this study also indicate that stress caused by exposure to irradiation could inhibit the cholinergic system in P. citri.

  4. Shielding Factors for Gamma Radiation from Activity Deposited on Structures and Ground Surfaces

    DEFF Research Database (Denmark)

    Jensen, Per Hedemann

    1985-01-01

    A computer model DEPSHIELD for the calculation of shielding factors for gamma radiation at indoor residences in multistorey and single-family houses has been developed. The model is based on the exponential point kernel that links the radiation flux density at a given detector point to a point...

  5. Preparation, Characterization and Utilization of Electrodes Coated with Polymeric Networks Formed by Gamma Radiation Crosslinking.

    Science.gov (United States)

    1987-04-01

    CHARACTERIZATION, AND UTILIZATION OF ELECTRODES COATED WITH POLYMERIC NETWORKS FORMED BY GAMMA RADIATION CROSSLINKING FINAL REPORT Accession For NTIS GRA... radiation crosslinking . The polymers and their structures are shown in Table I. All of these have been found to form cross-linked networks when exposed

  6. Establishment of Testing Device for Shielding Performance of X and Gamma Ray Radiation Protection Materials

    Institute of Scientific and Technical Information of China (English)

    SONG; Ming-zhe; WEI; Ke-xin; HOU; Jin-bing; WANG; Hong-yu; GAO; Fei; NI; Ning

    2015-01-01

    X and gamma ray radiation protective material shielding performance testing device was built based on the international standard IEC61331.1-2014.The device can be used to test attenuation ratio,attenuation equivalent and lead equivalent of radiation protective material in"narrow beam condition","broad beam condition"and"inverse

  7. Shock acceleration and gamma radiation in the intracluster medium

    OpenAIRE

    2004-01-01

    Particle acceleration is expected to take place at shocks that form during the process of large scale structure formation. Electrons accelerated at such shocks can upscatter a small fraction of the photons in the cosmic microwave background up to the gamma ray band. Here we make predictions about the detectability of the $\\gamma$--ray emission from forming clusters of galaxies with future GeV and TeV gamma ray telescopes. We also estimate the contribution of these sources to the extragalactic...

  8. Toxoplasma gondii vs ionizing radiation: cell and humoral immunity in spleen and gut of isogenic mice immunized with {sup 60}Co irradiated tachyzoites; Toxoplasma gondii vs radiacao ionizante: imunidade humoral e celular em baco e intestino de camundongos isogenicos imunizados com taquizoitos irradiados por cobalto 60

    Energy Technology Data Exchange (ETDEWEB)

    Galisteo Junior, Andres Jimenez

    2008-07-01

    We are developing a vaccine for toxoplasmosis, using ionizing radiation as a tool. Here we analyzed the production of systemic and intestinal immunity, with protection studies, in several strains of inbred mice, by oral or parenteral route, using 255 Gy irradiated tachyzoites of T. gondii RH strain, with challenge with cysts of ME- 49 strain. C57Bl/6j, BALB/c and C57Bl/6j IFN-{gamma}{sup -/-} mice were immunized with 10{sup 7} irradiated tachyzoites, be parenteral or oral route. Those preparations, both by parenteral or oral routes, induced the production of specific IgG, mainly of the lgG2b subclass, and IgA immunoglobulins in serum, , as determined by ELISA. IgM production was negligible. Parenteral immunized mice showed higher IgG avidity maturation, as compared to oral immunized mice. Fecal excretion of IgG, IgA and IgM was detected in stools of immunized animals, more intense in oral immunized mice. In cellular immunity studies, induced by antigen, with detection of cytokine production by quantitative real-time PCR, there are a great production of IFN-y by spleen cells, with lower levels in Peyer patches cells, where there are a greater IL-2 production. Challenge studies in immunized mice demonstrated protection to infection in all used schedules, greater in BALB/c mice. C57Bl/6j IFN-{gamma} -{sup /-} mice, when immunized, showed no signs of disease and produced similar or greater levels of antibodies than wild type mice. They also excreted S-lgA and S-IgM in stools, but with low numbers of brain cysts in parenteral immunized mice, despite similar mortality. Our data points to a fair possibility of use of those irradiated parasites as an oral vaccine, devised to use for veterinary or wild felines vaccination, reducing the production of oocysts by those hosts and interrupting the chain transmission of human toxoplasmosis. (author)

  9. The utilize of gamma radiation on the examination of mechanical properties of polymeric materials

    Directory of Open Access Journals (Sweden)

    F. Greškovič

    2012-04-01

    Full Text Available The article deals about the application area of radiation crosslinking of plastics, which follows after the injection moulding. The main objective of the presented article is the research of influence irradiation dosage on mechanical properties of materials: PP filled by 15 % of mineral filler – talc. Mechanical properties - tensile strength and impact strength by Charpy were examined in dependence on absorbed dose of the gamma rays on various conditions and were compared with non-irradiated samples. Radiation processing involves mainly the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources.

  10. Gamma radiation monitoring at the Eastern North Atlantic (ENA), Graciosa Island ARM facility

    Science.gov (United States)

    Barbosa, Susana; Miranda, Pedro; Azevedo, Eduardo B.; Nitschke, Kim

    2016-04-01

    Continuous monitoring of gamma radiation is often performed in nuclear facilities and industrial environments as a way to control the ambient radioactivity and give warning of potential accidents. However, gamma radiation is also ubiquitous in the natural environment. The main sources are i) cosmic radiation from space, including secondary radiation from the interaction with atoms in the atmosphere, ii) terrestrial sources from mineral grains in soils and rocks, particularly Potassium (K-40), Uranium (U-238) and Thorium (Th-232) and their decay products (e.g. Radium, Ra-226) , and iii) airborne Radon gas (Rn-222), which is the dominant source of natural environmental radioactivity. The temporal variability of this natural radiation background needs to be well understood and quantified in order to discriminate non-natural sources of radiation in the environment and artificial radionuclides contamination. To this end, continuous gamma radiation monitoring is being performed at the Eastern North Atlantic (ENA) facility located in the Graciosa island (Azores, 39N; 28W), a fixed site of the Atmospheric Radiation Measurement programme (ARM), established and supported by the Department of Energy (DOE) of the United States of America with the collaboration of the local government and University of the Azores. The site is unique for the study of the natural radioactivity background on one hand due to the remote oceanic geographical location, in the middle of the North Atlantic Ocean and clear of direct continental influence, and on the other hand because of the comprehensive dataset of atmospheric parameters that is available for enhancing the interpretation of the radiation measurements, as a result of the vast array of very detailed and high-quality atmospheric measurements performed at the ARM-ENA facility. Gamma radiation in the range 475 KeV to 3000 KeV is measured continuously with a 3" x 3" NaI(Tl) scintillator. The campaign started started in May 2015, with gamma

  11. Grafting of HEMA onto dopamine coated stainless steel by 60Co-γ irradiation method

    Science.gov (United States)

    Jin, Wanqin; Yang, Liming; Yang, Wei; Chen, Bin; Chen, Jie

    2014-12-01

    A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Co-γ irradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay.

  12. Recent results on celestial gamma radiation from SMM

    Science.gov (United States)

    Share, Gerald H.

    1991-01-01

    Observations made by the Gamma Ray Spectrometer on board the SMM are described. Recent results reported include observations and analyses of gamma-ray lines from Co-56 produced in supernovae, observations of the temporal variation of the 511 keV line observed during Galactic center transits, and measurements of the diffuse Galactic spectrum from 0.3 to 8.5 MeV. The work in progress includes measurements of the distribution of Galactic Al-26, observations to place limits on Galactic Ti-44 and Fe-60 and on Be-7 produced in novae, and searches for a characteristic gamma-ray emission from pair plasmas, a 2.223 MeV line emission, limits on deexcitation lines from interstellar C and O, and gamma-ray bursts.

  13. Radiation chemistry of salt-mine brines and hydrates. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jenks, G.H.; Walton, J.R.; Bronstein, H.R.; Baes, C.F. Jr.

    1981-07-01

    Certain aspects of the radiation chemistry of NaCl-saturated MgCl/sub 2/ solutions and MgCl/sub 2/ hydrates at temperatures in the range of 30 to 180/sup 0/C were investigated through experiments. A principal objective was to establish the values for the yields of H/sub 2/ (G(H/sub 2/)) and accompanying oxidants in the gamma-ray radiolysis of concentrated brines that might occur in waste repositories in salt. We concluded that G(H/sub 2/) from gamma-irradiated brine solution into a simultaneously irradiated, deaerated atmosphere above the solution is between 0.48 and 0.49 over most of the range 30 to 143/sup 0/C. The yield is probably somewhat lower at the lower end of this range, averaging 0.44 at 30 to 45/sup 0/C. Changes in the relative amounts of MgCl/sub 2/ and NaCl in the NaCl-saturated solutions have negligible effects on the yield. The yield of O/sub 2/ into the same atmosphere averages 0.13, independent of the temperature and brine composition, showing that only about 50% of the radiolytic oxidant that was formed along with the H/sub 2/ was present as O/sub 2/. We did not identify the species that compose the remainder of the oxidant. We concluded that the yield of H/sub 2/ from a gamma-irradiated brine solution into a simultaneously irradiated atmosphere containing 5 to 8% air in He may be greater than the yield in deaerated systems by amounts ranging from 0% for temperatures of 73 to 85/sup 0/C, to about 30 and 40% for temperatures in the ranges 100 to 143/sup 0/C and 30 to 45/sup 0/C, respectively. We did not establish the mechanism whereby the air affected the yields of H/sub 2/ and O/sub 2/. The values found in this work for G(H/sub 2/) in deaerated systems are in approximate agreement with the value of 0.44 for the gamma-irradiation yield of H/sub 2/ in pure H/sub 2/O at room temperature. They are also in agreement with the values predicted by extrapolation from the findings of previous researchers for the value for G(H/sub 2/) in 2 M NaCl solutions

  14. A standard Fricke dosimeter compared to an ionization chamber used for dosimetric characterization of 60Co photon beam

    Science.gov (United States)

    Moussous, Ouiza; Medjadj, Toufik

    2016-06-01

    The main objective of this study was to investigate the Fricke dosimeter water equivalent system for measurement of dosimetric parameters for photon beam. The parameters measured with the Fricke dosimeter were compared to those obtained with an ionization chamber. In this work characteristics for 60Co γ-rays of field sizes ranging from 5 × 5 cm2 to 20 × 20 cm2 are reported. The measurements were carried out in the secondary standard dosimetry laboratory using a collimated 60Co gamma source therapy unit. The 60Co beam output in terms of absorbed dose to water was obtained as per IAEA TRS 398 recommendations using cylindrical ionization chamber, whose ND,w has been supplied by the IAEA's reference laboratory. Specific quantities measured include: output factors, peak scatter factor, lateral beam profiles and percentage depth dose. The Fricke dosimeters were irradiated in a water phantom using the suitable poly (methyl methacrylate), PMMA stand. Our results demonstrate that Fricke dosimeter and ionization chamber agree with each other.

  15. Lower Bound on the Cosmic TeV Gamma-ray Background Radiation

    CERN Document Server

    Inoue, Yoshiyuki

    2015-01-01

    The Fermi gamma-ray space telescope has revolutionized our understanding of the cosmic gamma-ray background radiation in the GeV band. However, investigation on the cosmic TeV gamma-ray background radiation still remains sparse. Here, we report the lower bound on the cosmic TeV gamma-ray background spectrum placed by the cumulative flux of individual detected extragalactic TeV sources including blazars, radio galaxies, and starburst galaxies. The current limit on the cosmic TeV gamma-ray background above 0.1 TeV is obtained as $3\\times10^{-8} (E/100~{\\rm GeV})^{-0.6} \\exp(-E/2000~{\\rm GeV})~{\\rm [GeV/cm^2/s/sr]} < E^2dN/dE < 1\\times10^{-7} (E/100~{\\rm GeV})^{-0.5}~{\\rm [GeV/cm^2/s/sr]}$, where the upper bound is set by requirement that the cascade flux from the cosmic TeV gamma-ray background radiation can not exceed the measured cosmic GeV gamma-ray background spectrum (Inoue & Ioka 2012). Two nearby blazars, Mrk 421 and Mrk 501, explain ~70% of the cumulative flux at 0.8-4 TeV, while extreme blaza...

  16. Assessment of Environmental Gamma Radiation Dose Rate in Ardabil and Sarein in 2009

    Directory of Open Access Journals (Sweden)

    M Alighadri

    2011-10-01

    Full Text Available Background and Objectives: Gamma rays, the most energetic photons within the any other wave in the electromagnetic spectrum, pose enough energy to form charged particles and adversely affect human health. Provided that the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, environmental gamma dose rate and corresponding annual effective dose were determined in the cities of Ardabil and Sar Ein.Materials and Methods: Outdoor environmental gamma dose rates were measured using an Ion Chamber Survey Meter in 48 selected locations (one in city center and the remaining in cardinal and ordinal directions in Ardabil and Sar Ein. Ten more locations were monitored along the hot springs effluent in Sar Ein. Measurements of gamma radiation dose rate were performed at 20 and 100 cm above the ground for a period of one hour.Results: Average outdoor environmental gamma dose rate were determined as 265, 219, and 208  for Ardabil, Sar Ein, and along the hot spring effluent, respectively. The annual affective dose for Ardabil and Sar Ein residents were estimated to be 1.45 and 1.39 mSv, respectively.Conclusion: Calculated annual effective dose of 1.49 and 1.35 are appreciably higher than the population weighted average exposure to environmental gamma radiation worldwide and that analysis of soil content to different radionuclide is suggested.

  17. Characteristics of liver tissue for attenuate the gamma radiation; Caracteristicas del tejido hepatico para atenuar la radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2005-07-01

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

  18. Radiation-induced enzyme efflux from rat heart: sedentary animals. [Gamma radiation, lactate dehydrogenase, creative kinase, glutamate oxaloacetate transaminase

    Energy Technology Data Exchange (ETDEWEB)

    MacWilliam, L.D.; Bhakthan, N.M.G.

    1976-01-01

    Serum levels of lactate dehydrogenase, creatine kinase, and glutamate oxaloacetate transaminase show initial elevations within 12 hr of exposure to 2,000 rads of ..gamma..-radiation to the thoracic region of rats. Significant decreases in heart muscle homogenate levels of these enzymes parallel initial elevations in the serum and may suggest that enhanced leakage of enzymes is a consequence of radiation injury to heart muscle. Insignificant alterations in mitochondrial glutamate oxaloacetate transaminase levels after exposure indicate that in vivo injury to the mitochondria from therapeutic levels of ..gamma..-radiation is questionable. The results support the contention that ionizing radiation instigates alterations in the dynamic permeability of membranes, allowing leakage of biologically active material out of the injured cell.

  19. Extract of Xylopia aethiopica (Annonaceae) protects against gamma-radiation induced testicular damage in Wistar rats.

    Science.gov (United States)

    Adaramoye, Oluwatosin Adekunle; Adedara, Isaac Adegboyega; Popoola, Bosede; Farombi, Ebenezer Olatunde

    2010-01-01

    Ionizing radiation is an important environmental risk factor and, a major therapeutic agent for cancer treatment. This study was designed to evaluate the protective effect of extract of Xylopia aethiopica (XA) on gamma-radiation-induced testicular damage in rats. Vitamin C (VC) served as the reference antioxidant during the study. The study consists of 4 groups of 11 rats each. Group I received corn oil (vehicle), groups II and IV were pretreated with XA (250 mg/kg) and VC (250mg/kg) for 6 weeks before and 8 weeks after exposure to gamma-radiation; group III was exposed to a single dose of gamma-radiation (5 Gy). Biochemical analysis revealed that gamma-irradiation caused a significant increase (p testicular lipid peroxidation (LPO) levels by 217% and 221%, respectively. Irradiated rats had markedly decreased testicular catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and reduced glutathione (GSH) levels. Irradiation resulted in 59% and 40% decreases in spermatozoa motility and live/dead sperm count, respectively, and a 161% increase in total sperm abnormalities. Histologically, testes of the irradiated rats showed extensive degenerative changes in the seminiferous tubules and defoliation of spermatocytes. Supplementation of XA and VC reversed the adverse effects of gamma-radiation on biochemical and histological indices of the rats. These findings demonstrated that Xylopia aethiopica has a protective effect by inhibiting oxidative damage in testes of irradiated rats.

  20. Construction of a {gamma}-{gamma} and {beta}-{gamma} coincidence measurement system for precise determination of nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Furutaka, Kazuyoshi; Nakamura, Shoji; Harada, Hideo; Katoh, Toshio [Japan Nuclear Cycle Development Institute, Tokai Works, Tokai, Ibaraki (Japan)

    1999-03-01

    A {gamma}-{gamma} and {beta}-{gamma} coincidence measurement system was constructed for the precise determination of nuclear data, such as thermal neutron capture cross sections and {gamma}-ray emission probabilities. The validity of the system was tested by a {gamma}-{gamma} coincidence measurement with a {sup 60}Co standard source. (author)

  1. Gamma radiation induced degradation in PE-PP block copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, H. R.; Sreepad, H. R.; Ahmed, Khaleel; Govindaiah, T. N. [P.G. Department of Physics, Government College (Autonomous), Mandya - 571401, Karnataka State (India)

    2012-06-05

    In the present investigation, effect of gamma irradiation on the PP-PE block copolymer has been studied. The polymer has been subjected to gamma irradiation from 100 to 500 Mrad dosages. Characterization of the polymer using XRD and FTIR was done both before irradiation and after irradiation in each step. Effect of irradiation on the electrical properties of the material has also been studied. FTIR study shows that the sample loses C - C stretching mode of vibration but gains C=C stretching mode of vibration after irradiation. Present investigation clearly indicates that though the electrical conductivity increases in the material, it undergoes degradation and shows brittleness due to irradiation.

  2. Pulsed mixed n, {gamma} radiation fields for electronic testing

    Energy Technology Data Exchange (ETDEWEB)

    Nurdin, G.; Becret, C.; Jaureguy, J.C. [Etablissement Technique Central de l`Armement (ETCA), 94 - Arcueil (France); Vie, M.; Baboulet, J.P.; Lapeyre, P.; Ramisse, D. [D.G.A., 46 - Gramat (France)

    1994-12-31

    For combined n, {gamma} TREE testing we have modified the CALIBAN Fast Burst Reactor Field with CdO/Epoxy converters to cover the range [10{sup 11} -10{sup 12}] n.cm{sup -2} (1 MeV Si), [10{sup 7} - 10{sup 8}] cGy(Si).s{sup -1}. Activation and fission {sigma} {phi}vector, 1 MeV(Si) fluences, neutron spectra, total exposures and dose rates were predicted with good agreement by n, {gamma} photon transport codes. (author). 12 refs., 2 figs., 1 tab.

  3. SAS-2 observations of the high energy gamma radiation from the Vela region

    Science.gov (United States)

    Thompson, D. J.; Bignami, G. F.; Fichtel, C. E.; Kniffen, D. A.

    1974-01-01

    Data from a scan of the galactic plane by the SAS-B high energy gamma ray experiment in the region 250 deg smaller than 12 smaller than 290 deg show a statistically significant excess over the general radiation from the galactic plane for gamma radiation of energy larger than 100 MeV. If the enhanced gamma radiation results from interactions of cosmic rays with galactic matter, as the energy spectrum suggests, it seems reasonable to associate the enhancement with large scale galactic features, such as spiral arm segments in that direction, or with the region surrounding the Vela supernova remnant with which PSR 0833-45 is associated. If the excess is attributed to cosmic rays released from the supernova interacting with the interstellar matter in that region, than on the order of 3 x 10 to the 50th power ergs would have been released by that supernova in the form of cosmic rays.

  4. Gamma radiation exposure of accompanying persons due to Lu-177 patients

    Science.gov (United States)

    Kovan, Bilal; Demir, Bayram; Tuncman, Duygu; Capali, Veli; Turkmen, Cuneyt

    2015-07-01

    Neuroendocrine tumours (NET) are cancers usually observed and arisen in the stomach, intestine, pancreas and breathing system. Recently, radionuclide therapy applications with Lu-177 peptide compound are rapidly growing; especially effective clinical results are obtained in the treatment of well-differentiated and metastatic NET. In this treatment, Lu-177-DOTA, a beta emitter radioisotope in the radiopharmaceutical form, is given to the patient by intravenous way. Lu-177 has also gamma rays apart from beta rays. Gamma rays have 175 keV average energy and these gamma rays should be under the control in terms of radiation protection. In this study, we measured the exposure dose from the Lu-177 patient.

  5. Effect of gamma radiation on growth, productivity and protein content of Chlorella Pyrenoidosa; Efecto de la radiacion gamma sobre el crecimiento, productividad y contenido proteico de Chlorella Pyrenoidosa

    Energy Technology Data Exchange (ETDEWEB)

    Martin, C.; Fernandez, J.

    1983-07-01

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

  6. Lunar radiation environment: a study by using Kaguya gamma-ray spectrometer and Monte Carlo simulation

    Science.gov (United States)

    Kobayashi, Shingo; Hayatsu, Kanako; Uchihori, Yukio; Hareyama, Makoto; Hasebe, Nobuyuki; Fujibayashi, Yukari

    2012-07-01

    We have continued to improve the estimation of radiation dose on the Moon based on observation by remote sensing and calculation of the transportation of cosmic-ray particles in the lunar materials in order to provide basic data for a future manned lunar exploration. On the lunar surface, the dose of primary galactic cosmic rays (pGCR) is the most significant and the contributions of neutrons and gamma rays are relatively small and are approximately 10% and 1% of that of pGCR, respectively. However, these percentages are changed by use of thick shieldings and also geographical feature of the lunar surface, such as margin of a huge boulder, bottom of a pit, inside of a possible lava tube. In this case, the dose by pGCRs is moderated and the contributions of neutrons and gamma rays relatively increase. Here, we show the recent estimation of spatial variation of the lunar dose due to gamma ray and neutrons measured by Kaguya gamma-ray spectrometer. The energy spectrum of gamma rays from the lunar surface are precisely measured by a germanium (Ge) gamma-ray spectrometer onboard the Japanese lunar orbiter (Kaguya/SELENE). The flux of fast neutrons from the lunar surface was also measured by detecting the characteristic gamma rays due to the neutron inelastic reaction with the Ge of the spectrometer, that is 72Ge(n, n'g)72Ge. The estimation of radiation dose on the Moon based on Monte Carlo simulation will also be presented.

  7. 100 Gy 60Co γ-Ray Induced Novel Mutations in Tetraploid Wheat

    Directory of Open Access Journals (Sweden)

    Chuntao Yang

    2014-01-01

    Full Text Available 10 accessions of tetraploid wheat were radiated with 100 Gy 60Co γ-ray. The germination energy, germination rate, special characters (secondary tillering, stalk with wax powder, and dwarf, meiotic process, and high-molecular-weight glutenin subunits (HMW-GSs were observed. Different species has different radiation sensibility. With 1 seed germinated (5%, T. dicoccum (PI434999 is the most sensitive to this dose of radiation. With a seed germination rate of 35% and 40%, this dose also affected T. polonicum (As304 and T. carthlicum (As293. Two mutant dwarf plants, T. turgidum (As2255 253-10 and T. polonicum (As302 224-14, were detected. Abnormal chromosome pairings were observed in pollen mother cells of both T. dicoccoides (As835 237-9 and T. dicoccoides (As838 239-8 with HMW-GS 1Ax silent in seeds from them. Compared with the unirradiated seed of T. polonicum (As304 CK, a novel HMW-GS was detected in seed of T. polonicum (As304 230-7 and its electrophoretic mobility was between 1By8 and 1Dy12 which were the HMW-GSs of Chinese Spring. These mutant materials would be resources for wheat breeding.

  8. Bioremediation of {sup 60}Co from simulated spent decontamination solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

    2004-07-26

    Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

  9. Gadolinium-doped water cerenkov-based neutron and high energy gamma-ray detector and radiation portal monitoring system

    Science.gov (United States)

    Dazeley, Steven A; Svoboda, Robert C; Bernstein, Adam; Bowden, Nathaniel

    2013-02-12

    A water Cerenkov-based neutron and high energy gamma ray detector and radiation portal monitoring system using water doped with a Gadolinium (Gd)-based compound as the Cerenkov radiator. An optically opaque enclosure is provided surrounding a detection chamber filled with the Cerenkov radiator, and photomultipliers are optically connected to the detect Cerenkov radiation generated by the Cerenkov radiator from incident high energy gamma rays or gamma rays induced by neutron capture on the Gd of incident neutrons from a fission source. The PMT signals are then used to determine time correlations indicative of neutron multiplicity events characteristic of a fission source.

  10. Laser flow microphotometry for rapid analysis and sorting of mammalian cells. [X and gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mullaney, P.F.; Steinkamp, J.A.; Crissman, H.A.; Cram, L.S.; Crowell, J.M.; Salzman, G.C.; Martin, J.C.; Price, B.

    1976-01-01

    Quantitative precision measurements can be made of the optical properties of individual mammalian cells using flow microphotometry. Suspended cells pass through a special flow chamber where they are lined up for exposure to blue light from an argon-ion laser. As each cell crosses the laser beam, it produces one or more optical pulses of a duration equal to cell transit time across the beam. These pulses are detected, amplified, and analyzed using the techniques of gamma ray spectroscopy. Quantitative DNA distributions made it possible to distinguish tumor cells from normal cells as well as to assay for radiation effects on tumor cells subjected to x and gamma radiation. (HLW)

  11. A biotechnological project with a gamma radiation source of 100,000 Ci

    Energy Technology Data Exchange (ETDEWEB)

    Lombardo, J.H.; Smolko, E.E. (Comision Nacional de Energia Atomica, Buenos Aires (Argentina))

    1990-01-01

    A project for the production of radiovaccines and other bio-medical products is presented which includes a radiation facility provided with a gamma ray source equivalent to 100,000 Ci of Co-60. The whole process incorporates novel basic features in virus production and inactivation steps. The former is carried out in animals previously subjected to immunodepression through electromagnetic radiation. The latter is obtained at low temperatures by using either electromagnetic or particle radiations. A vaccine manufacture process is shown to illustrate the utilization of ionizing radiations to obtain a foot and mouth disease virus (FMDV) vaccine with good antigenic quality and low cost. (author).

  12. Measurement of the branching fraction and $CP$ asymmetry in radiative $D^0 \\to V \\gamma$ decays

    CERN Document Server

    Abdesselam, A; Adamczyk, K; Aihara, H; Said, S Al; Arinstein, K; Arita, Y; Asner, D M; Aso, T; Atmacan, H; Aulchenko, V; Aushev, T; Ayad, R; Aziz, T; Babu, V; Badhrees, I; Bahinipati, S; Bakich, A M; Bala, A; Ban, Y; Bansal, V; Barberio, E; Barrett, M; Bartel, W; Bay, A; Bedny, I; Behera, P; Belhorn, M; Belous, K; Besson, D; Bhardwaj, V; Bhuyan, B; Bischofberger, M; Biswal, J; Bloomfield, T; Blyth, S; Bobrov, A; Bondar, A; Bonvicini, G; Bookwalter, C; Boulahouache, C; Bozek, A; Bračko, M; Breibeck, F; Brodzicka, J; Browder, T E; Červenkov, D; Chang, M -C; Chang, P; Chao, Y; Chekelian, V; Chen, A; Chen, K -F; Chen, P; Cheon, B G; Chilikin, K; Chistov, R; Cho, K; Chobanova, V; Choi, S -K; Choi, Y; Cinabro, D; Crnkovic, J; Dalseno, J; Danilov, M; Dash, N; Di Carlo, S; Dingfelder, J; Doležal, Z; Drásal, Z; Drutskoy, A; Dubey, S; Dutta, D; Dutta, K; Eidelman, S; Epifanov, D; Esen, S; Farhat, H; Fast, J E; Feindt, M; Ferber, T; Frey, A; Frost, O; Fujikawa, M; Fulsom, B G; Gaur, V; Gabyshev, N; Ganguly, S; Garmash, A; Getzkow, D; Gillard, R; Giordano, F; Glattauer, R; Goh, Y M; Goldenzweig, P; Golob, B; Greenwald, D; Perdekamp, M Grosse; Grygier, J; Grzymkowska, O; Guo, H; Haba, J; Hamer, P; Han, Y L; Hara, K; Hara, T; Hasegawa, Y; Hasenbusch, J; Hayasaka, K; Hayashii, H; He, X H; Heck, M; Hedges, M T; Heffernan, D; Heider, M; Heller, A; Higuchi, T; Himori, S; Hirose, S; Horiguchi, T; Hoshi, Y; Hoshina, K; Hou, W -S; Hsiung, Y B; Hsu, C -L; Huschle, M; Hyun, H J; Igarashi, Y; Iijima, T; Imamura, M; Inami, K; Inguglia, G; Ishikawa, A; Itagaki, K; Itoh, R; Iwabuchi, M; Iwasaki, M; Iwasaki, Y; Iwata, S; Jacobs, W W; Jaegle, I; Jeon, H B; Joffe, D; Jones, M; Joo, K K; Julius, T; Kakuno, H; Kang, J H; Kang, K H; Kapusta, P; Kataoka, S U; Kato, E; Kato, Y; Katrenko, P; Kawai, H; Kawasaki, T; Keck, T; Kichimi, H; Kiesling, C; Kim, B H; Kim, D Y; Kim, H J; Kim, H -J; Kim, J B; Kim, J H; Kim, K T; Kim, M J; Kim, S H; Kim, S K; Kim, Y J; Kinoshita, K; Kleinwort, C; Klucar, J; Ko, B R; Kobayashi, N; Koblitz, S; Kodyš, P; Koga, Y; Korpar, S; Kotchetkov, D; Kouzes, R T; Križan, P; Krokovny, P; Kronenbitter, B; Kuhr, T; Kumar, R; Kumita, T; Kurihara, E; Kuroki, Y; Kuzmin, A; Kvasnička, P; Kwon, Y -J; Lai, Y -T; Lange, J S; Lee, D H; Lee, I S; Lee, S -H; Leitgab, M; Leitner, R; Levit, D; Lewis, P; Li, C H; Li, H; Li, J; Li, L; Li, X; Li, Y; Gioi, L Li; Libby, J; Limosani, A; Liu, C; Liu, Y; Liu, Z Q; Liventsev, D; Loos, A; Louvot, R; Lubej, M; Lukin, P; Luo, T; MacNaughton, J; Masuda, M; Matsuda, T; Matvienko, D; Matyja, A; McOnie, S; Mikami, Y; Miyabayashi, K; Miyachi, Y; Miyake, H; Miyata, H; Miyazaki, Y; Mizuk, R; Mohanty, G B; Mohanty, S; Mohapatra, D; Moll, A; Moon, H K; Mori, T; Morii, T; Moser, H -G; Müller, T; Muramatsu, N; Mussa, R; Nagamine, T; Nagasaka, Y; Nakahama, Y; Nakamura, I; Nakamura, K R; Nakano, E; Nakano, H; Nakano, T; Nakao, M; Nakayama, H; Nakazawa, H; Nanut, T; Nath, K J; Natkaniec, Z; Nayak, M; Nedelkovska, E; Negishi, K; Neichi, K; Ng, C; Niebuhr, C; Niiyama, M; Nisar, N K; Nishida, S; Nishimura, K; Nitoh, O; Nozaki, T; Ogawa, A; Ogawa, S; Ohshima, T; Okuno, S; Olsen, S L; Ono, Y; Onuki, Y; Ostrowicz, W; Oswald, C; Ozaki, H; Pakhlov, P; Pakhlova, G; Pal, B; Palka, H; Panzenböck, E; Park, C -S; Park, C W; Park, H; Park, K S; Paul, S; Peak, L S; Pedlar, T K; Peng, T; Pesántez, L; Pestotnik, R; Peters, M; Petrič, M; Piilonen, L E; Poluektov, A; Prasanth, K; Prim, M; Prothmann, K; Pulvermacher, C; Purohit, M V; Rauch, J; Reisert, B; Ribežl, E; Ritter, M; Röhrken, M; Rorie, J; Rostomyan, A; Rozanska, M; Rummel, S; Ryu, S; Sahoo, H; Saito, T; Sakai, K; Sakai, Y; Sandilya, S; Santel, D; Santelj, L; Sanuki, T; Sasao, N; Sato, Y; Savinov, V; Schlüter, T; Schneider, O; Schnell, G; Schönmeier, P; Schram, M; Schwanda, C; Schwartz, A J; Schwenker, B; Seidl, R; Seino, Y; Sekiya, A; Semmler, D; Senyo, K; Seon, O; Seong, I S; Sevior, M E; Shang, L; Shapkin, M; Shebalin, V; Shen, C P; Shibata, T -A; Shibuya, H; Shinomiya, S; Shiu, J -G; Shwartz, B; Sibidanov, A; Simon, F; Singh, J B; Sinha, R; Smerkol, P; Sohn, Y -S; Sokolov, A; Soloviev, Y; Solovieva, E; Stanič, S; Starič, M; Steder, M; Strube, J F; Stypula, J; Sugihara, S; Sugiyama, A; Sumihama, M; Sumisawa, K; Sumiyoshi, T; Suzuki, K; Suzuki, S; Suzuki, S Y; Suzuki, Z; Takeichi, H; Takizawa, M; Tamponi, U; Tanaka, M; Tanaka, S; Tanida, K; Taniguchi, N; Taylor, G N; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Trusov, V; Tse, Y F; Tsuboyama, T; Uchida, M; Uchida, T; Uehara, S; Ueno, K; Uglov, T; Unno, Y; Uno, S; Uozumi, S; Urquijo, P; Ushiroda, Y; Usov, Y; Vahsen, S E; Van Hulse, C; Vanhoefer, P; Varner, G; Varvell, K E; Vervink, K; Vinokurova, A; Vorobyev, V; Vossen, A; Wagner, M N; Wang, C H; Wang, J; Wang, M -Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Wedd, R; Wehle, S; White, E; Wiechczynski, J; Williams, K M; Won, E; Yabsley, B D; Yamada, S; Yamamoto, H; Yamaoka, J; Yamashita, Y; Yamauchi, M; Yashchenko, S; Ye, H; Yelton, J; Yook, Y; Yuan, C Z; Yusa, Y; Zhang, C C; Zhang, L M; Zhang, Z P; Zhao, L; Zhilich, V; Zhukova, V; Zhulanov, V; Ziegler, M; Zivko, T; Zupanc, A; Zwahlen, N; Zyukova, O

    2016-01-01

    We report a measurement of the branching fractions of the radiative decays $D^0 \\to V \\gamma$, where $V=\\phi,~\\overline{K}{}^{*0}$ or $\\rho^0$. This is the first observation of the decay $D^0 \\to \\rho^0 \\gamma$. We measure preliminary branching fractions $\\mathcal{B}(D^0 \\to \\phi \\gamma)=(2.76 \\pm 0.20 \\pm 0.08) \\times 10^{-5}$, $\\mathcal{B}(D^0 \\to \\overline{K}{}^{*0} \\gamma)=(4.66 \\pm 0.21 \\pm 0.18) \\times 10^{-4} $ and $\\mathcal{B}(D^0 \\to \\rho^0 \\gamma)=(1.77 \\pm 0.30 \\pm 0.08) \\times 10^{-5}$, where the first uncertainty is statistical and the second systematic. We also present the first measurement of $CP$ asymmetry in these decays. The preliminary values are $\\mathcal{A}_{CP}(D^0 \\to \\phi \\gamma)=-(0.094 \\pm 0.066 \\pm 0.001)$, $\\mathcal{A}_{CP}(D^0 \\to \\overline{K}{}^{*0} \\gamma)=-(0.003 \\pm 0.020 \\pm 0.000)$ and $\\mathcal{A}_{CP}(D^0 \\to \\rho^0 \\gamma)=0.056 \\pm 0.151 \\pm 0.006$. The analysis was conducted using 943 fb$^{-1}$ of data collected by the Belle detector at the KEKB $e^+e^-$ collider.

  13. Measurement of gamma and neutron radiations inside spent fuel assemblies with passive detectors

    Energy Technology Data Exchange (ETDEWEB)

    Viererbl, L., E-mail: vie@ujv.cz [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Research Centre Rez Ltd. (Czech Republic); Lahodova, Z.; Voljanskij, A.; Klupak, V.; Koleska, M. [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Research Centre Rez Ltd. (Czech Republic); Cabalka, M. [Nuclear Research Institute Rez plc, 250 68 Husinec-Rez 130 (Czech Republic); Turek, K. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic (Czech Republic)

    2011-10-01

    During operation of a fission nuclear reactor, many radionuclides are generated in fuel by fission and activation of {sup 235}U, {sup 238}U and other nuclides present in the assembly. After removal of a fuel assembly from the core, these radionuclides are sources of different types of radiation. Gamma and neutron radiation emitted from an assembly can be non-destructively detected with different types of detectors. In this paper, a new method of measurement of radiation from a spent fuel assembly is presented. It is based on usage of passive detectors, such as alanine dosimeters for gamma radiation and track detectors for neutron radiation. Measurements are made on the IRT-2M spent fuel assemblies used in the LVR-15 research reactor. During irradiation of detectors, the fuel assembly is located in a water storage pool at a depth of 6 m. Detectors are inserted into central hole of the assembly, irradiated for a defined time interval, and after the detectors removed from the assembly, gamma dose or neutron fluence are evaluated. Measured profiles of gamma dose rate and neutron fluence rate inside of the spent fuel assembly are presented. This measurement can be used to evaluate relative fuel burn-up.

  14. Measurement of gamma and neutron radiations inside spent fuel assemblies with passive detectors

    Science.gov (United States)

    Viererbl, L.; Lahodová, Z.; Voljanskij, A.; Klupák, V.; Koleška, M.; Cabalka, M.; Turek, K.

    2011-10-01

    During operation of a fission nuclear reactor, many radionuclides are generated in fuel by fission and activation of 235U, 238U and other nuclides present in the assembly. After removal of a fuel assembly from the core, these radionuclides are sources of different types of radiation. Gamma and neutron radiation emitted from an assembly can be non-destructively detected with different types of detectors. In this paper, a new method of measurement of radiation from a spent fuel assembly is presented. It is based on usage of passive detectors, such as alanine dosimeters for gamma radiation and track detectors for neutron radiation. Measurements are made on the IRT-2M spent fuel assemblies used in the LVR-15 research reactor. During irradiation of detectors, the fuel assembly is located in a water storage pool at a depth of 6 m. Detectors are inserted into central hole of the assembly, irradiated for a defined time interval, and after the detectors removed from the assembly, gamma dose or neutron fluence are evaluated. Measured profiles of gamma dose rate and neutron fluence rate inside of the spent fuel assembly are presented. This measurement can be used to evaluate relative fuel burn-up.

  15. Gamma evaluation combined with isocenter optimal matching in intensity modulated radiation therapy quality assurance

    Science.gov (United States)

    Bak, Jino; Choi, Jin Hwa; Park, Suk Won; Park, Kwangwoo; Park, Sungho

    2015-12-01

    Two-dimensional (2D) dose comparisons are widely performed by using a gamma evaluation with patient-specific intensity modulated radiation therapy quality assurance (IMRT QA) or dose delivery quality assurance (DQA). In this way, a pass/fail determination is made for a particular treatment plan. When gamma evaluation results are close to the failure criterion, the pass/fail decision may change applying a small shift to the center of the 2D dose distribution. In this study, we quantitatively evaluated the meaning of such a small relative shift in a 2D dose distribution comparison. In addition, we propose the use of a small shift for a pass/fail criterion in gamma analysis, where the concept of isocenter optimal matching (IOM) is applied to IMRT QA of 20 patients. Gamma evaluations were performed to compare two dose distributions, one with and the other without IOM. In-house software was developed in C++ in order to find IOM values including both translational and rotational shifts. Upon gamma evaluation failure, further investigation was initiated using IOM. In this way, three groups were categorized: group 1 for `pass' on gamma evaluation, group 21 for `fail' on the gamma evaluation and `pass' on the gamma the evaluation with IOM, and group 22 for `fail' on the both gamma evaluations and the IOM calculation. IOM results revealed that some failures could be considered as a `pass'. In group 21, 88.98% (fail) of the averaged gamma pass rate changed to 90.45% (pass) when IOM was applied. On average, a ratio of γ ≥ 1 was reduced by 11.06% in 20 patients. We propose that gamma evaluations that do not pass with a rate of 85% to 90% may be augmented with IOM to reveal a potential pass result.

  16. Degradation of 4-Chloro phenol by gamma radiation of {sup 137}Cs and X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez J, J. C. [Instituto Tecnologico de Toluca, Av. Tecnologico s/n, Ex-Rancho La Virgen, 52140 Metepec, Estado de Mexico (Mexico); Jimenez B, J.; Cejudo A, J., E-mail: jaime.jimenez@inin.gob.m [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2010-07-01

    This paper presents results of radiolytic degradation of 4-chloro phenol in the presence of TiO{sub 2}, Al{sub 2}O{sub 3} and SiO{sub 2}, using different radiation sources than {sup 60}Co, which is so common in this type of experiment. The radiation sources used were X-rays with energy of 100 keV and radiation from {sup 137}Cs (662 keV). After irradiation with a dose of 50 c Gy X-ray and TiO{sub 2} obtained a degradation of about 5%, no degradation was obtained with {sup 137}Cs source and other oxides. This may be due to the fact that X-rays have a linear energy transfer greater value, and in the case of TiO{sub 2} present a crystalline structure, whereas the other two oxides are amorphous. Both characteristics result in better formation of a reactive species that allows the degradation of the compound. (Author)

  17. Gamma radiation in the decay of 67Ga

    NARCIS (Netherlands)

    Rietjens, L.H.Th.; Bold, H.J. van den

    1955-01-01

    The level scheme of 67Zn has been investigated by scintillation coincidence spectrometry. Angular correlation measurements of the 206 keV – 182 keV and 485 keV − 296 keV gamma cascades result in anisotropies of − 0.216 ± 0.008 and +0.27 ± 0.05. The following spins have been allocated to the levels

  18. Poly (DADMAC) encapsulation in PES microcapsules utilizing gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Francis, Sanju [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)], E-mail: sanju@barc.gov.in; Varshney, Lalit [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Tirumalesh, Keesari [Isotope Application Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Sabharwal, Sunil [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2009-01-15

    In this communication, a method for encapsulation of a polymeric resin using radiation technology is reported. The quaternary ammonium resin, polydiallyldimethylammonium chloride (PDADMAC) was incorporated in the core of a preformed hollow polyethersulfone microcapsule, using radiation technology, for the extraction of anions from aqueous solutions. The idea was to introduce the monomer into the porous microcapsules and initiate polymerization by radiation to trap the polymer formed inside the capsule. The resultant capsule was able to take up and exchange some anions (F{sup -}, Cl{sup -}, Br{sup -}, NO{sub 3}{sup 2-} and SO{sub 4}{sup 2-}) at relatively low concentrations.

  19. Poly (DADMAC) encapsulation in PES microcapsules utilizing gamma radiation

    Science.gov (United States)

    Francis, Sanju; Varshney, Lalit; Tirumalesh, Keesari; Sabharwal, Sunil

    2009-01-01

    In this communication, a method for encapsulation of a polymeric resin using radiation technology is reported. The quaternary ammonium resin, polydiallyldimethylammonium chloride (PDADMAC) was incorporated in the core of a preformed hollow polyethersulfone microcapsule, using radiation technology, for the extraction of anions from aqueous solutions. The idea was to introduce the monomer into the porous microcapsules and initiate polymerization by radiation to trap the polymer formed inside the capsule. The resultant capsule was able to take up and exchange some anions (F -, Cl -, Br -, NO 32- and SO 42-) at relatively low concentrations.

  20. Gamma radiation effects on polymeric materials and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Barrera D, C. E. (ed.); Martinez B, G. (ed.) [Universidad Autonoma del Estado de Mexico, Paseo Colon Interseccion Paseo Tollocan, Toluca 50120, Estado de Mexico (Mexico)

    2009-07-01

    This book provides a comprehensive study of the effects of gamma irradiation on polymeric materials and the principal applications. The eight chapters cover a broad range of synthesis and modification applications, from polymerization of metal methacrylates, copolymer films, and organometallic catalysts to the modification of nylons, functionalism of polyethylene, and improvement of polymer concrete, as well as a thorough explanation of the principles. The nature of gamma-initiated polymerization makes it a good method for polymers, as well as graft and block copolymers. Metal methacrylates have been made for use as metal sorbents in wastewater remediation and water treatment. Likewise, metal polyethylene copolymers have been synthesized for use as catalytic surfaces. The synthesis of stimuli-response graft copolymers for sensitive coatings can be well controlled. Gamma irradiation is also used for modification of bonds through functionalism and crosslinking. In polymer-reinforced concrete, irradiation both crosslinks the polymer and enhances bonding between the resin and mineral components. It improves compatibility and bonding in polyethylene rubber composites. It can be used to increase crosslinks in a polymer or polymer matrix to improve strength or hardness. In view of these considerations, this book would be a very useful source of information to scientists, engineers and postgraduate students alike. (Author)

  1. Attenuation of VHE gamma rays by the Milky Way interstellar radiation field

    CERN Document Server

    Moskalenko, I V; Strong, A W

    2006-01-01

    The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with multi-wavelength observations by DIRBE and FIRAS indicates that the Galactic interstellar radiation field is intense. We have made a calculation of the attenuation of very high energy gamma rays in the Galaxy using this new interstellar radiation field which takes into account its nonuniform spatial and angular distributions. We find that the maximum attenuation occurs around 100 TeV at the level of about 25% for sources located at the Galactic center, within the energy range of the HESS instrument, and is important for both Galactic and extragalactic sources.

  2. Effect of gamma radiation on lipids by the TBARS and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Adriana Cristina de Oliveira; Cortez, Marco Antonio Sloboda, E-mail: vetdri@gmail.com [Lab. de Inspecao e Tecnologia de Leite e Derivados Lacteos, Faculdade de Medicina Veterinaria, Universidade Federal Fluminense, Niteroi - RJ (Brazil); Marsico, Eliane Teixeira; Guimaraes, Carlos Frederico [Laboratorio de Controle Fisico-Quimico de Produtos de Origem Animal, Faculdade de Medicina Veterinaria, Universidade Federal Fluminense, Niteroi - RJ (Brazil); Jesus, Edgar Francisco Oliveira de [Laboratorio de Instrumentacao Nuclear, Instituto Alberto Luiz Coimbra de Pos-graduacao e Pesquisa de Engenharia, Universidade Federal do Rio de Janeiro, Rio de Janeiro - RJ (Brazil)

    2011-11-15

    The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co{sup 60} in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR) and Thiobarbituric Acid Test (2-TBARS). The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected. (author)

  3. Reduction of phorbol ester content in jatropha cake using high energy gamma radiation

    Directory of Open Access Journals (Sweden)

    Runumi Gogoi

    2014-07-01

    Full Text Available In this paper, an attempt has been made to remove phorbol ester present in jatropha cake by exposing it to gamma radiation. A sensitizer was also used to accelerate the degradation of phorbol esters. The phorbol ester content in the cake was estimated by high performance liquid chromatography (HPLC. It was observed that gamma irradiation of the jatropha seed cake was effective in reducing the phorbol ester content. Originally, the phorbol ester content in the cake was found as 0.29 mg/g, which on exposure to radiation was reduced by 33.4% and 96% with radiation dose of 30 and 125 kGy respectively. The presence of a sensitizer was found to enhances the susceptibility of phorbol esters degradation by oxidative degradation on exposure to ionizing radiation.

  4. Effect of gamma radiation on lipids by the TBARS and NMR

    Directory of Open Access Journals (Sweden)

    Adriana Cristina de Oliveira Silva

    2011-12-01

    Full Text Available The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co60 in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR and Thiobarbituric Acid Test (2-TBARS. The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected.

  5. Radiation safety issues in the water treatment plant - Indoor radon and gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jantsikene, A.; Kiisk, M.; Suursoo, S.; Koch, R. [University of Tartu, Institute of Physics (Estonia); Lumiste, L. [Tallinn University of Technology, Department of Chemical Engineering (Estonia)

    2014-07-01

    In order to reduce the indicative dose from drinking water consumption in Viimsi parish, Estonia, a new water treatment plant was launched in 2012 serving about 15 000 consumers. The promising new technology for groundwater purification consists of air injector, oxidation tank, patented venturi-type centrifugal degassing separation unit GDT and two-stage filtration in open filter columns. In each of the five parallel lines, approximately 95 tons of catalytic (FMH and sand) and 45 tons of non-catalytic (zeolite) filter materials were used. These filter materials proved to be very effective adsorbents of incoming radium isotopes. As a result, the columns emit direct gamma radiation. Moreover, columns' exposure to indoor air makes them radon generators that affect all rooms in the building. During the study period of two years the filter materials were not replaced and their lifespan has not been estimated yet. In order to minimize radiation risks for the workers inside the water treatment plant, a complex study and a long-term monitoring is needed. For the measurements of {sup 226}Ra and {sup 228}Ra concentrations in water and in solid filter materials gamma-ray spectroscopy was used. According to the results, the annual input of {sup 226}Ra and {sup 228}Ra is 325 MBq and 420 MBq, respectively. The average incoming concentration of {sup 226}Ra and {sup 228}Ra isotopes is 0.5 Bq/L and 0.6 Bq/L, respectively, and the radium content in the output water is below the limit of detection (about 10-15 mBq/L). This means strong accumulation of radium isotopes in the filter materials, thus causing an increase of {sup 222}Rn concentrations in the outgoing treated water. External dose rates throughout the length of the filter columns were measured with the portable dosimeter to estimate the {sup 226}Ra and {sup 228}Ra depth distribution. The results showed that distribution of these radionuclides is uneven with the maximum of 0.5 μSv/h for the first stage and 3 μSv/h for

  6. Influence of gamma radiation on the levels of polyphenols and lethality of ethanol extracts of Anacardium occidentale Linn., against Biomphalaria glabrata; Influencia da radiacao gama na acao moluscicida de extratos de cajueiro em Biomphalaria glabrata

    Energy Technology Data Exchange (ETDEWEB)

    Santos, G.H.F.; Silva, E.B., E-mail: santosghf@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear. Grupo de Radioprotecao e Radioecologia; Melo, A.M.M.A.; Lima, C.S.A [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica; Amorim, E.L.C.; Peixoto Sobrinho, T.J.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Farmacia

    2013-08-15

    Plant materials rich in phenolic compounds, such as Anacardium occidentale Linn., Have been used as alternatives to synthetic pesticides in Biomphalaria glabrata control programs, intermediate host of Schistosoma mansoni. Studies show that ionizing radiation can influence the content of phenolic compounds and thus their biological actions. The aim of this study was to evaluate the influence of gamma radiation of {sup 60}Co in polyphenol composition of hydroalcoholic extracts of bark and leaves of A. occidentale and evaluate the toxicity of these extracts to embryos and adults of B. glabrata. To achieve this goal this, the extracts were irradiated at 10 kGy, the controls being maintained from 0 kGy and positive (CaCO{sub 3}) and negative (H{sub 2}O). We quantified the total phenols by the Folin-Ciocalteau and tannins by precipitation of casein. Extracts were used at a concentration of 100 mg/L. The results showed that the radiation caused the changes to the leaves, the percentage of polyphenols and tannins, and the percentage of lethality in embryos and adults Biomphalaria glabrata, these percentages being: 13 ± 5 (0 kGy) and 27 ± 2.5 (10 kGy), and 36.67 ± 5.77 (0 kGy), and 56.67 ± 5.77 (10 kGy), respectively. Gamma radiation caused significant changes in the levels of polyphenols in the extracts of leaves of Anacardium ocidentale Linn., translated by the increased toxicity of this extract against embryos and adults of Biomphalaria glabrata. This indicates that gamma radiation can be used as an agent potentiating the toxicity of plant extracts on the alternate use of these materials as molluscicides. (author)

  7. Effects of gamma radiation on development of Brugia pahangi in a susceptible strain of Aedes aegypti

    Energy Technology Data Exchange (ETDEWEB)

    Richey, T.J.; Rodriguez, P.H.

    1976-08-01

    Female mosquitoes were fed on an infected jird having a microfilarial density of 201 per mm/sup 3/ of blood. Mosquitoes were exposed to doses of 3,000 and 5,000 rads of gamma radiation before and after infection. Mosquitoes were dissected 8 to 10 days later and the number of active larvae was recorded. Results indicated that postinfection radiation affected the development of Brugia pahangi. (HLW)

  8. Surface characterization of poly(vinyl chloride) urinary catheters functionalized with acrylic acid and poly(ethylene glycol) methacrylate using gamma-radiation

    Science.gov (United States)

    Islas, Luisa; Ruiz, Juan-Carlos; Muñoz-Muñoz, Franklin; Isoshima, Takashi; Burillo, Guillermina

    2016-10-01

    Poly(vinyl chloride) (PVC) urinary catheters were modified with either a single or binary graft of acrylic acid (AAc) and/or poly(ethylene glycol) methacrylate (PEGMA) using gamma-radiation from 60Co to obtain PVC-g-AAc, PVC-g-PEGMA, [PVC-g-AAc]-g-PEGMA, and [PVC-g-PEGMA]-g-AAc copolymers. The outer and inner surfaces of the modified catheters were characterized using scanning electron microscopy (SEM), confocal laser microscopy (CLM) and X-ray photoelectron spectroscopy (XPS). The XPS analyses, by examining the correlation between the variation of the C1s and O1s content at the catheter's surface, revealed that the catheter's surfaces were successfully grafted with the chosen compounds, with those that were binary grafted showing a slightly more covered surface as was evidenced by the disappearance of PVC's Cl peak. The SEM and CLM analyses revealed that catheters that had been grafted with PEGMA had a rougher outer surface as compared to those that had only been grafted with AAc. In addition, these imaging techniques showed that the inner surface of the singly grafted catheters, whether they had been grafted with AAc or PEGMA, retained some smoothness at the analyzed grafting percentages, while the binary grafted catheters showed many protuberances and greater roughness on both outer and inner surfaces.

  9. Influence of gamma-radiation on the nutritional and functional qualities of lotus seed flour.

    Science.gov (United States)

    Bhat, Rajeev; Sridhar, Kandikere Ramaiah; Karim, Alias A; Young, Chiu C; Arun, Ananthapadmanabha B

    2009-10-28

    In the present study, we investigated the physicochemical and functional properties of lotus seed flour exposed to low and high doses of gamma-radiation (0-30 kGy; the dose recommended for quarantine and hygienic purposes). The results indicated raw seed flour to be rich in nutrients with minimal quantities of antinutritional factors. Irradiation resulted in a dose-dependent increase in some of the proximal constituents. The raw and gamma-irradiated seeds meet the Food and Agricultural Organization-World Health Organization recommended pattern of essential amino acids. Some of the antinutritional factors (phytic acid, total phenolics, and tannins) were lowered with gamma-irradiation, while the seed flours were devoid of lectins, L-3,4-dihydroxyphenylalanine, and polonium-210. The functional properties of the seed flour were significantly improved with gamma-radiation. gamma-radiation selectively preserved or improved the desired nutritional and functional traits of lotus seeds, thus ensuring a safe production of appropriate nutraceutically valued products.

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

    Directory of Open Access Journals (Sweden)

    M CANTOR

    2003-04-01

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

  11. Low-dose radiation modifies skin response to acute gamma-rays and protons.

    Science.gov (United States)

    Mao, Xiao Wen; Pecaut, Michael J; Cao, Jeffrey D; Moldovan, Maria; Gridley, Daila S

    2013-01-01

    The goal of the present study was to obtain pilot data on the effects of protracted low-dose/low-dose-rate (LDR) γ-rays on the skin, both with and without acute gamma or proton irradiation (IR). Six groups of C57BL/6 mice were examined: a) 0 Gy control, b) LDR, c) Gamma, d) LDR+Gamma, e) Proton, and f) LDR+Proton. LDR radiation was delivered to a total dose of 0.01 Gy (0.03 cGy/h), whereas the Gamma and Proton groups received 2 Gy (0.9 Gy/min and 1.0 Gy/min, respectively). Assays were performed 56 days after exposure. Skin samples from all irradiated groups had activated caspase-3, indicative of apoptosis. The significant (pGamma and Proton groups were not present when LDR pre-exposure was included. However, the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay for DNA fragmentation and histological examination of hematoxylin and eosin-stained sections revealed no significant differences among groups, regardless of radiation regimen. The data demonstrate that caspase-3 activation initially triggered by both forms of acute radiation was greatly elevated in the skin nearly two months after whole-body exposure. In addition, LDR γ-ray priming ameliorated this response.

  12. Primary Observations on the Influence of 60Co Local Irradiation on Free Skin Flaps

    Institute of Scientific and Technical Information of China (English)

    杨建荣; 张园

    2002-01-01

    Objective To study the effect of postoperative radiation on free skin flaps.Methods Twenty-nine patients with free skin flaps applied to the plerosis of the postoperative defectwere followed up. Twenty-eight out of 29 patients received forearm free flaps while 1 had anterolater-al femoris skin flaps in a size ranging from 14 cm× 6 cm to 8 cm× 4 cm. These flaps were exposedto 60Co radiation ranging 40-69 Gy. Results Observation during irradiation: no visible changes ofskin flaps and oral mucous membrane were detected when irradiation dose was within 40 Gy; somechanges may be detected over 40 Gy. Observation 1 - 4 months after irradiation: pigmentations werefound in areas of erosion epidermis; skin flaps got dark but without evidence of necrosis. Observation2 years after irradiation: no necrosis happened in 29 skin flaps. Hairs were found on 15 of 29flaps. Sensation occurred within the margin of 1 cm. Conclusion Free skin flap can endure irradi-ation at the dose of 60 Gy.

  13. Thermal analysis evaluation of mechanical properties changes promoted by gamma radiation on surgical polymeric textiles

    Science.gov (United States)

    Ferreira, L. M.; Casimiro, M. H.; Oliveira, C.; Cabeço Silva, M. E.; Marques Abreu, M. J.; Coelho, A.

    2002-05-01

    The large number of surgical operations with post-operative infection problems and the appearing of new infectious diseases, contribute to the development of new materials in order to answer the needs of health care services. This development must take into account the modifications promoted by sterilisation methods in materials, namely by gamma radiation. The differential scanning calorimetry (DSC) and thermogravimetry (TGA) techniques show that a nonwoven and a laminate textiles maintain a good molecular cohesion, do not showing high levels of degradation, for gamma radiation dose values lower than 100 kGy in nonwoven and 200 kGy in laminate materials. The tensile strength and the elongation decrease slowly for the nonwoven textile and decrease faster for the laminate textile for 25 and 80 kGy absorbed dose. This paper shows that the DSC and TGA techniques can be helpful for the prevision of mechanical changes occurred in the materials as a consequence of the gamma irradiation.

  14. Influence of gamma radiation on secondary metabolism in lichens Cladonia substellata and Cladonia verticillaris

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Helena P.B.; Melo, Patryk; Primo, Dario; Vicalvi, Maria Claudia V. [Federal University of Pernambuco (CTG/DEN/UFPE), Recife, PE (Brazil). Graduate Program in Energy Technologies and Nuclear; Maciel, Leonardo N.Q. [First Space Seed, Recife, PE (Brazil); Pereira, Eugenia, E-mail: Eugenia.pereira@cnpq.pq.com.b [Federal University of Pernambuco (CFCH/UFPE), Recife, PE (Brazil). Dept. of Geographic Sciences; Silva, Nicacio [Federal University of Pernambuco (CCB/UFPE), Recife, PE (Brazil). Dept. of Biochemistry; Colaco, Waldeciro, E-mail: wcolaco@ufpe.com.b [Federal University of Pernambuco (CTG/DEN/UFPE), Recife, PE (Brazil). Dept. Nuclear Energy

    2011-07-01

    Lichens are organisms formed from a symbiotic relationship between a fungus and an alga. These when submitted to different doses and types of radiation are encouraged to produce their substances in quantities different from those that would produce without the intervention of radiation. The objective of this research was to determine the influence of gamma rays on the production of usnic acid from Cladonia substellata and on the production of fumarprocetraric acid from Cladonia verticillaris. Lichens samples were submitted to gamma irradiation Co-60 source, receiving different doses (0, 5, 10, 50 and 100 Gy) of gamma irradiator. After six months samples were collected and submitted to the extraction of its phenols. The extracts were subjected to thin-layer chromatography, and read from Biochrom Libra S22 spectrophotometer. The qualitative assessment of the chemical composition of lichens stalks irradiated or not, revealed by thin layer chromatography production of usnic acid and fumarprocetraric throughout the experiment. Regarding the quantification of fumarprocetraric acid was observed a production significantly higher in extracts obtained from irradiated lichens, the largest production obtained by the dose of 50 Gy. As for the production of usnic acid, the highlight was the dose of 10 Gy. Thus we can conclude that the lichens Cladonia verticillaris and Cladonia substellata when submitted to gamma radiation in the laboratory, produce fumarprocetraric acid and usnic acid , respectively, but the radiation dose influences the metabolism and its subsequent biosynthesis. (author)

  15. Gamma radiation technological feasibility of increasing shelf-life of table grapes

    Energy Technology Data Exchange (ETDEWEB)

    Shirzad, B.M.; Langerak, D.I. (International Facility for Food Irradiation Technology, Wageningen (Netherlands))

    1984-01-01

    Gamma radiation (1 and 2 kGy) and different sources of sulfur dioxide (0.25% SO/sub 2/, 4 g K/sub 2/S/sub 2/O/sub 5/ + 4 g C/sub 6/H/sub 8/O/sub 7/ per kg grape) and moist air heat (55 deg. C for 15 minutes) were used to increase shelf-life of Black Alicante table grapes stored at 10 deg. C and 95% relative humidity. The grape clusters were placed on foam polystyrene trays and packed with polyvinyl-chloride film. Gamma radiation at 2 kGy completely prevented decay of Black Alicante table grapes stored for 40 days at 10 deg. C without any discernible change in the organoleptic attributes of the berries. Moist air heat, 0.25% SO/sub 2/ and 1 kGy gamma radiation used alone neither prevented nor delayed moulding, whereas potassium meta-bisulfite mixed or not mixed with citric acid delayed moulding for 15 and 35 days, respectively. 1 kGy gamma radiation dose in combination with 0.25% SO/sub 2/ controlled moulding for the entire storage period of 40 days. Potassium meta-bisulfite mixed with citric acid or in combination with 2 kGy induced adverse organoleptic changes in the berries. 19 refs.

  16. Polarographic methods of investigation of radiochemical transformations of phenol compounds induced by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Norbaev, N.

    1977-01-01

    Electron polarography was used for studies on radiochemical changes in phenol compounds following exposure to gamma radiation. The amount of quinones 3 to 4 h after irradiation increased in chlorogenic acid, pyrocatechol, and quercetin; the amount of quinones decreased 24 h after irradiation. (HLW)

  17. Role of gauge invariance in B -> V gamma radiative weak decays

    CERN Document Server

    Riazuddin, M

    2002-01-01

    The role of gauge invariance in calculating B -> V gamma radiative weak decays is clarified. It is shown that the gauge invariance severely restricts the contributions mediated by the usual weak non-leptonic Hamiltonian dominated by u and c quaks with one photon attachment. Such contributions are found to be almost negligible.

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

    Science.gov (United States)

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

    1990-10-01

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

  19. Annihilation type rare radiative $B_{(s)}\\to V\\gamma$ decays

    CERN Document Server

    Kozachuk, Anastasiya; Nikitin, Nikolai

    2016-01-01

    We obtain predictions for a number of radiative decays $B_{(s)}\\to V\\gamma$, $V$ the vector meson, which proceed through the weak-annihilation mechanism. Within the factorization approximation, we take into account the photon emission from the $B$-meson loop and from the vector-meson loop; the latter subprocesses were not considered in the previous analyses but are found to have sizeable impact on the $B_{(s)}\\to V\\gamma$ decay rate. The highest branching ratios for the weak-annihilation reactions reported here are ${\\cal B}(\\bar B^0_s\\to J/\\psi\\gamma)=1.5\\cdot 10^{-7}$ and ${\\cal B}(B^-\\to \\bar D_s^{*-}\\gamma)=1.7\\cdot 10^{-7}$, the estimated accuracy of these predictions being at the level of 20\\%.

  20. Monte Carlo Calculations for Neutron and Gamma Radiation Fields on a Fast Neutron Irradiation Device

    Science.gov (United States)

    Vieira, A.; Ramalho, A.; Gonçalves, I. C.; Fernandes, A.; Barradas, N.; Marques, J. G.; Prata, J.; Chaussy, Ch.

    We used the Monte Carlo program MCNP to calculate the neutron and gamma fluxes on a fast neutron irradiation facility being installed on the Portuguese Research Reactor (RPI). The purpose of this facility is to provide a fast neutron beam for irradiation of electronic circuits. The gamma dose should be minimized. This is achieved by placing a lead shield preceded by a thin layer of boral. A fast neutron flux of the order of 109 n/cm2s is expected at the exit of the tube, while the gamma radiation is kept below 20 Gy/h. We will present results of the neutron and gamma doses for several locations along the tube and different thickness of the lead shield. We found that the neutron beam is very collimated at the end of the tube with a dominant component on the fast region.

  1. The effect of electrons, neutron and gamma radiation on nitrocellulose; Effet des radiations gamma, des electrons et des neutrons sur la nitrocellulose

    Energy Technology Data Exchange (ETDEWEB)

    Heppell-Masys, K.M. [College Militaire Royal du Canada, Dept. de chimie et genie chimique, Kingston, Ontario (Canada)

    2001-07-01

    High nitrogen content nitrocellulose is mostly used as an explosive component in the fabrication of propellant. Slow evaporation of the stabiliser agents deteriorate the safe properties of these materials throughout the years, making them hazardous to handle well beyond their shelf lives. The irradiation may neutralize and convert the stocks of aged and unstable nitrocellulose explosives into less nitrated hence non-explosive substance. The effects of electrons, thermal neutrons and gamma radiation on the nitrogen content of wet nitrocellulose using the SLOWPOKE-2 nuclear reactor were investigated. Four nitrocellulose grades containing 30% water were used:12.11% N,12.60% N, 13.11% N and 13.22% N. These samples of about 0.3g each contained in sealed polyethylene vials were exposed to thermal neutrons, gamma and electron radiation in the SLOWPOKE-2 reactor pool for various times ranging from 15 minutes to 10 hours. In order to assess the extent of change in the nitrogen content, solutions of nitrocellulose in tetrahydrofuran were analyzed using Gel Permeation Chromatography (GPC) and Fourier Transform Infrared Spectroscopy (FTIR). A decrease of molecular weights and numbers was observed from GPC results as well as an increase of polydispersity indicating chain scission of the nitrocellulose backbone. The G value indicated that scission yield was predominant over the crosslinking yield. Nitrocellulose exposure to thermal neutrons, gamma rays and electrons is indeed effective in reducing average molecular weight and number, as well as in decreasing nitrogen content.

  2. Effect of gamma radiation on micromechanical hardness of lead-free solder joint

    Energy Technology Data Exchange (ETDEWEB)

    Paulus, Wilfred [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Rahman, Irman Abdul; Jalar, Azman; Kamil, Insan; Bakar, Maria Abu [Universiti Kebangsaan Malaysia, Bangi, 43600 Kajang, Selangor (Malaysia); Yusoff, Wan Yusmawati Wan [Universiti Pertahanan Nasional Malaysia, Kem Sg. Besi, 57000 Kuala Lumpur (Malaysia)

    2015-09-25

    Lead-free solders are important material in nano and microelectronic surface mounting technology for various applications in bio medicine, environmental monitoring, spacecraft and satellite instrumentation. Nevertheless solder joint in radiation environment needs higher reliability and resistance to any damage caused by ionizing radiations. In this study a lead-free 99.0Sn0.3Ag0.7Cu wt.% (SAC) solder joint was developed and subjected to various doses of gamma radiation to investigate the effects of the ionizing radiation to micromechanical hardness of the solder. Averaged hardness of the SAC joint was obtained from nanoindentation test. The results show a relationship between hardness values of indentations and the increment of radiation dose. Highest mean hardness, 0.2290 ± 0.0270 GPa was calculated on solder joint which was exposed to 5 Gray dose of gamma radiation. This value indicates possible radiation hardening effect on irradiated solder. The hardness gradually decreased to 0.1933 ± 0.0210 GPa and 0.1631 ± 0.0173 GPa when exposed to doses 50 and 500 gray respectively. These values are also lower than the hardness of non irradiated sample which was calculated as 0.2084 ± 0.0.3633 GPa indicating possible radiation damage and needs further related atomic dislocation study.

  3. Tolerance to gamma radiation in the marine heterotardigrade, Echiniscoides sigismundi

    DEFF Research Database (Denmark)

    Jönsson, K. Ingemar; Hygum, Thomas Lunde; Andersen, Kasper Nørgaard;

    2016-01-01

    Tardigrades belong to the most radiation tolerant animals on Earth, as documented by a number of studies using both low-LET and high-LET ionizing radiation. Previous studies have focused on semi-terrestrial species, which are also very tolerant to desiccation. The predominant view on the reason...... for the high radiation tolerance among these semi-terrestrial species is that it relies on molecular mechanisms that evolved as adaptations for surviving dehydration. In this study we report the first study on radiation tolerance in a marine tardigrade, Echini