WorldWideScience

Sample records for high-energy beamstrahlung gamma-radiation

  1. Cosmic gamma radiation of ultra high energy of primordial origin

    International Nuclear Information System (INIS)

    Aquino Filho, F.G. de.

    1984-01-01

    The quantum mechanical effects near a collapsing black hole as shown by Stephen W.Hawking in 1974 to produce streaming particles through tunneling effect was explored in the context of cosmic gamma ray production. In this thesis, we show the possible production of gamma rays of high energies (ν approx 10 41 Hz) in the initial stages of the formation of the Universe by the explosion of primordial mini black holes. These mini black hole explosions happening at 10 -43 s to 10 -37 s after the start perhaps may account for the existing universal cosmic background radiation of 2.7 0 K. (Author) [pt

  2. Cadmium telluride gamma-radiation detectors with a high energy resolution

    International Nuclear Information System (INIS)

    Alekseeva, L.A.; Dorogov, P.G.; Ivanov, V.I.; Khusainov, A.K.

    1985-01-01

    This paper considers the possibility of improving the energy resolution of cadmium telluride gamma-radiation detectors through the choice of the geometry and size of the sensitive region of the detector. The optimum ratio of the product of the mobility and lifetime for electrons to the same product for holes from the point of view of energy resolution is greater than or equal to 10 2 for a detector of spherical geometry and should be less than or equal to 10 for a cylindrical geometry and approximately 1 for a planar geometry. The optimum values of the major and minor radii of a spherical detector are calculated

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

    Science.gov (United States)

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

    1995-05-01

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

  4. Comparative effects of exposure to high-energy electrons and gamma radiation on active avoidance behaviour

    International Nuclear Information System (INIS)

    Hunt, W.A.

    1983-01-01

    The effect of two types of ionizing radiation was examined on active avoidance behaviour. Male Sprague-Dawley rats were trained to avoid footshock by jumping onto a retractable ledge. When irradiated with high-energy electrons or gamma photons, their performance was degraded in a dose-dependent manner. However, electrons were 1.6 times as effective as gamma photons with ED50s of 62 and 102 Gy, respectively. All animals recovered within 24 min for all doses used. The data suggest that different types of ionizing radiation may not be equivalent when assessing their effect on behaviour. (author)

  5. Detection of high energy gamma radiations with liquid rare gases as scintillators; Detection des rayonnements Gamma de grande energie avec les gaz rares liquides comme scintillateurs

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Phan Xuan

    1965-11-25

    This research thesis reports the study of a sensor based on a liquid scintillator for the detection of high energy (10 to 30 MeV) gamma radiations. The scintillator is a liquefied argon or xenon rare gas. The author first studies the process of energy transfer from the particle to the sensing medium. He addresses the different involved elements and phenomena: electromagnetic radiations (Compton Effect, photoelectric effect, pair production, and total gamma absorption), charged particles (braking radiation, collisions) and application to gamma spectrometry. He describes and discusses the scintillation mechanisms (scintillation of organic and inorganic materials), the general characteristics of scintillators (impurities, converters), and then reports the practical realisation of the sensor. Results are presented and discussed [French] Dans ce travail, nous nous proposons d'etudier une technique. Il s'agit d'un detecteur a scintillateur liquide pour la detection des rayonnements gamma energiques (10 a 30 MeV). Le scintillateur utilise est un gaz rare liquefie argon ou xenon. Nous examinerons d'abord les processus de transfert de l'energie de la particule au milieu detecteur puis les mecanismes de scintillation en general pour pouvoir exploiter au mieux les phenomenes favorables. Nous presenterons ensuite la realisation pratique du detecteur. Ses qualites (et defauts) trouveront leur place dans la fin de ce memoire. Bien qu'a l'heure actuelle, par la methode de Kyropoulos, on puisse faire pousser des gros cristaux d'iodure de sodium, l'utilisation des 'gaz rares' liquefies comme scintillateurs est, grace a la brievete de la scintillation, tres utile lorsqu'on recherche un fort taux de comptage (jusqu'a 10 impulsions par seconde) ou lorsqu'on veut resoudre certains problemes de coincidence. Les cristaux NaI(Tl) de grandes dimensions sont d'un montage facile mais leur manipulation requiert beaucoup de precautions du fait qu'ils supportent tres mal les chocs thermiques

  6. Quantum beamstrahlung from gaussian bunches

    International Nuclear Information System (INIS)

    Chen, P.

    1987-08-01

    The method of Baier and Katkov is applied to calculate the correction terms to the Sokolov-Ternov radiation formula due to the variation of the magnetic field strength along the trajectory of a radiating particle. We carry the calculation up to the second order in the power expansion of B tau/B, where tau is the formation time of radiation. The expression is then used to estimate the quantum beamstrahlung average energy loss from e + e - bunches with gaussian distribution in bunch currents. We show that the effect of the field variation is to reduce the average energy loss from previous calculations based on the Sokolov-Ternov formula or its equivalent. Due to the limitation of our method, only an upper bound of the reduction is obtained. 18 refs

  7. Gamma radiation from active galaxy nuclei detected at very high energies with H.E.S.S: Multi-wavelength study and simulation of radioactive processes

    International Nuclear Information System (INIS)

    Lenain, J.P.

    2009-01-01

    Active Galactic Nuclei (AGN) are among the most energetic sources in the Universe. A subgroup of AGN possesses relativistic jets, the emission of which is purely non-thermal. In the case where the jet is aligned to the line of sight, these objects, called 'blazars', have their emission amplified by the relativistic Doppler effect. Since the advent of very high energy (VHE; E > 100 GeV) γ-ray astrophysics, Cerenkov telescopes like H.E.S.S. have observed almost thirty AGN, mainly blazars, from the ground. Cerenkov radiation from particle showers created by the interaction of γ-rays in the terrestrial atmosphere is used to derive the properties of the incident photon and thus to study these extragalactic sources. We have studied the highly variable VHE γ-ray emission from the blazar PKS 2155-304, from which 2 major outbursts were detected in July 2006, within the framework of a dynamic Synchrotron self-Compton (SSC) model. This variable emission presents properties excluding the most standard emission scenarios for blazars. We have also developed an SSC emission model for misaligned relativistic jets, to interpret the recent discovery of VHE γ-ray emission from 2 radio galaxies, M87 and Cen-A, which established the emergence of a new family of cosmic TeV emitters. We conclude with a systematic study conducted on all the AGN currently known at TeV with a stationary SSC model. We present tools for predictions of flux densities in these objects, which can be confronted with future observations by the Cerenkov Telescope Array (CTA). (author)

  8. Effect of Beamstrahlung on Bunch Length and Emittance in Future Circular e+e- Colliders

    CERN Document Server

    Valdivia Garcia, Marco Alan

    2016-01-01

    In future circular e+e− colliders, beamstrahlung may limit the beam lifetime at high energies, and increase the energy spread and bunch length at low energies. If the dispersion or slope of the dispersion is not zero at the collision point, beamstrahlung will also affect the transverse emittance. In this paper, we first examine the beamstrahlung properties, and show that for the proposed FCC-ee, the radiation is fairly well modelled by the classical formulae describing synchrotron radiation in bending magnets. We then derive a set of equations determining the equilibrium emittances in the presence of a nonzero dispersion at the collision point. An example case from FCC-ee will serve as an illustration.

  9. Beamstrahlung spectra in next generation linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.; Chen, P. (Stanford Linear Accelerator Center, Menlo Park, CA (United States)); Kozanecki, W. (DAPNIA-SPP, CEN-Saclay (France))

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  10. Beam-strahlung effects in e-p collider

    International Nuclear Information System (INIS)

    Cho, Y.

    1982-09-01

    The electromagnetic fields produced by one beam in an interaction point of a colliding-beam facility cause to the emission of synchrotron radiation by the other beam. This effect, the beam strahlung, for the e+e - colliders has been considered by several authors, and they have pointed out that the effect is very important consideration at very-high-energy e+e - colliders. At the first glance, the beam-strahlung effect can play an important role in the e-p collision due to the fact that the circulating currents in the collider are much higher than those of the e+e - machine. However the detailed study shows that is not the case because of the collision geometry involved. What follows in this note is the beam-strahlung derivations using the method previously used by Hofmann and Keil. The difference between this note and that of Hofman and Keil is that in the case of e+e - collider, equal mass particles are involved in the consideration and, in the e-p case, the electrons radiate and the protons provide the electromagnetic fields

  11. Observation of galactic gamma radiation

    International Nuclear Information System (INIS)

    Paul, J.A.

    1982-09-01

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

  12. Gamma radiation in apartments

    International Nuclear Information System (INIS)

    Grindborg, J.-E.

    1983-05-01

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

  13. Gamma radiation in dwellings

    International Nuclear Information System (INIS)

    Mjoenes, L.

    1981-08-01

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

  14. gamma. radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Curie, I

    1948-12-08

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

  15. Gamma radiation and chickens

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  16. Concrete for. gamma. radiation shielding

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-06-01

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

  17. Beamstrahlung spectra in next generation linear colliders. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Barklow, T.; Chen, P. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Kozanecki, W. [DAPNIA-SPP, CEN-Saclay (France)

    1992-04-01

    For the next generation of linear colliders, the energy loss due to beamstrahlung during the collision of the e{sup +}e{sup {minus}} beams is expected to substantially influence the effective center-of-mass energy distribution of the colliding particles. In this paper, we first derive analytical formulae for the electron and photon energy spectra under multiple beamstrahlung processes, and for the e{sup +}e{sup {minus}} and {gamma}{gamma} differential luminosities. We then apply our formulation to various classes of 500 GeV e{sup +}e{sup {minus}} linear collider designs currently under study.

  18. Gamma Radiation from Fission Fragments

    International Nuclear Information System (INIS)

    Higbie, Jack

    1969-10-01

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

  19. Gamma Radiation from Fission Fragments

    Energy Technology Data Exchange (ETDEWEB)

    Higbie, Jack

    1969-10-15

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

  20. Sewage sterilization through gamma radiation

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  1. Galactic structure and gamma radiation

    International Nuclear Information System (INIS)

    Casse, Michel; Cesarsky, Catherine; Paul Jacques

    1977-01-01

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

  2. Semiconductor scintillator detector for gamma radiation

    International Nuclear Information System (INIS)

    Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S.

    2015-01-01

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

  3. High energy irradiation of bacterial membrane vesicles

    International Nuclear Information System (INIS)

    De La Rosa, M.A.M.

    1977-01-01

    The interactions of membrane components and two well-defined transport systems in the E. coli ML 308-225 membrane vesicles with 60 Co gamma radiation were investigated. The results presented show that gamma radiation can monitor membrane components and functions of varying radiosensitivities. The possible application of high-energy radiation as a physical probe of membrane structure and functions is indeed promising

  4. Beamstrahlung and QED backgrounds at future linear colliders

    International Nuclear Information System (INIS)

    Schroeder, D.V.

    1990-10-01

    This dissertation is a detailed study of several aspects of beamstrahlung and related phenomena. The problem is formulated as the relativistic scattering of an electron from a strong but slowly varying potential. The solution is readily interpreted in terms of a classical electron trajectory, and differs from the solution of the corresponding classical problem mainly in the effect of quantum recoil due to the emission of hard photons. When the general solution is expanded for the case of an almost-uniform field, the leading term is identical to the well-known formula for quantum synchrotron radiation. The first non-leading term is negligible in all cases of interest where the expansion is valid. In applying the standard synchrotron radiation formula to the beamstrahlung problem, the effects of radiation reaction on the emission of multiple photons can be significant for some machine designs. Another interesting feature is the helicity dependence of the radiation process, which is relevant to the case where the electron beam is polarized. The inverse process of coherent electron-positron pair production by a beamstrahlung photon is a potentially serious background source at future colliders, since low-energy pairs can exit the bunch at a large angle. Pairs can also be produced incoherently by the collision of the two photons, either real or virtual. The rates, spectra, and angular distributions for both the coherent and incoherent processes are estimated here. At a 1/2 TeV machine the incoherent process will be more common, resulting in roughly 10 6 pairs per bunch crossing. One member of each pair is always pushed outward, at an angle determined by its energy, by the field of the oncoming bunch. In addition, a small number of pairs are initially produced with a comparable or larger angle

  5. The induced radioactivity danger parameter for gamma radiation

    International Nuclear Information System (INIS)

    Perry, D.R.

    1985-07-01

    Dosimetric and practical aspects of the induced radioactivity danger parameter, as used for calculating the gamma radiation dose rate near to objects that have been exposed to high energy radiation, are examined. A simplified and more generally applicable method of calculation is proposed, based on energy balance in homogeneous media. The problems of applying this in practice are discussed, and it is shown that corrections are generally small enough to be neglected in many practical applications. Examples of calculations by previous and proposed methods are given. (author)

  6. Gamma radiation from PSR B1055-52

    DEFF Research Database (Denmark)

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

    1999-01-01

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

  7. On the honeybee resistance to gamma radiation

    International Nuclear Information System (INIS)

    Courtois, G.; Lecomte, J.

    1960-01-01

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

  8. Environmental Gamma Radiation Measurements in Baskil District

    International Nuclear Information System (INIS)

    Canbazoglu, C.

    2008-01-01

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

  9. 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)

  10. Some factors affecting urokinase inactivation. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Hiroo; Iketa, Yoshito

    1985-10-01

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

  11. Effects of gamma radiation in tomato seeds

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  12. SGR-76 gamma radiation level indicator

    International Nuclear Information System (INIS)

    Chubinskij-Nadezhdin, I.V.

    1978-01-01

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

  13. Project Marna Natural Gamma Radiation MAP

    International Nuclear Information System (INIS)

    Suarez, E.; Fernandez, J.A.

    1997-01-01

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

  14. Residual water treatment for gamma radiation

    International Nuclear Information System (INIS)

    Mendez, L.

    1990-01-01

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

  15. Effects of gamma radiation in annatto seeds

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  16. Quality control of gamma radiation measuring systems

    International Nuclear Information System (INIS)

    Surma, M.J.

    2002-01-01

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

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

    African Journals Online (AJOL)

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

  18. 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)

  19. Lepton-number-charged scalars and neutrino beamstrahlung

    Science.gov (United States)

    Berryman, Jeffrey M.; de Gouvêa, André; Kelly, Kevin J.; Zhang, Yue

    2018-04-01

    Experimentally, baryon number minus lepton number, B -L , appears to be a good global symmetry of nature. We explore the consequences of the existence of gauge-singlet scalar fields charged under B -L -dubbed lepton-number-charged scalars (LeNCSs)—and postulate that these couple to the standard model degrees of freedom in such a way that B -L is conserved even at the nonrenormalizable level. In this framework, neutrinos are Dirac fermions. Including only the lowest mass-dimension effective operators, some of the LeNCSs couple predominantly to neutrinos and may be produced in terrestrial neutrino experiments. We examine several existing constraints from particle physics, astrophysics, and cosmology to the existence of a LeNCS carrying B -L charge equal to two, and discuss the emission of LeNCSs via "neutrino beamstrahlung," which occurs every once in a while when neutrinos scatter off of ordinary matter. We identify regions of the parameter space where existing and future neutrino experiments, including the Deep Underground Neutrino Experiment, are at the frontier of searches for such new phenomena.

  20. Gamma radiation sterilises bacteria-contaminated waste

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

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

  1. Automated TLD system for gamma radiation monitoring

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  2. Effects of gamma radiation on potato meristems

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Garcia Collantes, M.A.

    1976-01-01

    The development of buds in potato tubers subjected to gamma radiation at doses of 3, 6, 8 and 12 Krad is studied at histological level. The irradiation was supplied at the beguining and end of the resting period, and the irradiated buds were observed at different stages of their development. Meristem's sensitivity depends on the state of activity involved at the moment of irradiation. Different parts of the meristem present different radiosensitivity, being the most radioresistant. (author) [es

  3. Effects of gamma radiation in soybean

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  4. 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)

  5. Low doses of gamma radiation in soybean

    International Nuclear Information System (INIS)

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

    2017-01-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  6. Low doses of gamma radiation in soybean

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

    The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

  7. 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)

  8. Gamma radiation effects on peanut skin antioxidants

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  9. Ore sorting using natural gamma radiation

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  10. Sensitiveness of jasmine cuttings to gamma radiation

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  11. Gamma radiation and HZE treatment of seedlings in Arabidopsis

    Data.gov (United States)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-23

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

  13. Well logging with natural gamma radiation

    International Nuclear Information System (INIS)

    Ellis, D.V.

    1983-01-01

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

  14. Electron energy spectrum and maximum disruption angle under multi-photon beamstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Yokoya, Kaoru; Chen, Pisin

    1989-03-01

    The final electron energy spectrum under multi-photon beamstrahlung process is derived analytically in the classical and the intermediate regimes. The maximum disruption angle from the low energy tail of the spectrum is also estimated. The results are then applied to the TLC and the CLIC parameters. 6 refs., 1 fig., 1 tab.

  15. Sterilization plants equipped with the isotopic gamma radiation sources

    International Nuclear Information System (INIS)

    Mehta, K.; Chmielewski, A.G.

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-01-01

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

  17. 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)

  18. The effect of gamma-radiation on bilirubin

    International Nuclear Information System (INIS)

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

    2001-01-01

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  20. Bone densitometry in dogs using gamma radiation

    International Nuclear Information System (INIS)

    Oliveira, A.L.B.; Costa, V.E.; Rezende, M.A.; Grossklauss, D.B.B.F.; Oliveira, T.B.

    2010-01-01

    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

  1. Investigation of zones with increased ground surface gamma radiation

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  2. Portable neutron and gamma-radiation instruments

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  3. Environmental gamma radiation measurements in Bangladeshi houses

    International Nuclear Information System (INIS)

    Idrish Miah, M.

    2002-01-01

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

  4. Environmental gamma radiation measurements in Bangladeshi houses

    International Nuclear Information System (INIS)

    Miah, M.I.

    2004-01-01

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

  5. Environmental gamma radiation measurements in Bangladeshi houses

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-06-01

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

  6. Degradation of polycarbonate induced by gamma radiation

    International Nuclear Information System (INIS)

    Araujo, E.S. de; Guedes, S.M.L.

    1992-01-01

    Polycarbonate (PC) DUROLON amorphous, of molecular weight 22000 g/mol is used in medical supplies and may be sterilized by gamma radiation. The main chain scission and polymer degradation occur when this polymer is irradiated. The value G = 1.54 to DUROLON was obtained by equation: 10 6 /M v = 10 6 /M v' + 0.054 G R. The degradation without crosslinking it is not general rule to all types of polycarbonates; an comparison was realized. The infrared (FT-IR) spectra of irradiated PC by gamma rays with different doses showed the main chain scissions in carbonyl groups. The mechanism of polymeric degradation to DUROLON, observed by NMR spectra, is a recombination of phenoxy and phenyl radicals. (author)

  7. Origin of the diffuse background gamma radiation

    International Nuclear Information System (INIS)

    Stecker, F.W.; Puget, J.L.

    1974-05-01

    Recent observations have now provided evidence for diffuse background gamma radiation extending to energies beyond 100 MeV. There is some evidence of isotropy and implied cosmological origin. Significant features in the spectrum of this background radiation were observed which provide evidence for its origin in nuclear processes in the early stages of the big-band cosmology and tie in these processes with galaxy formation theory. A crucial test of the theory may lie in future observations of the background radiation in the 100 MeV to 100 GeV energy range which may be made with large orbiting spark-chamber satellite detectors. A discussion of the theoretical interpretations of present data, their connection with baryon symmetric cosmology and galaxy formation theory, and the need for future observations are given. (U.S.)

  8. Gamma radiation effects on liofilized human serum

    International Nuclear Information System (INIS)

    Padron Soler, E.; Romay Penabad, Z.; Chavez Ardanza, A.; Hernandez Gonzalez, C.; Martin Gonzalez, O.; Garcia Gonzalez, I.; Prieto Miranda, E.

    1995-01-01

    Human freeze dried serum was artificially contaminated with Flavobacterium sp. for studying the effects of gamma radiation of it. The radiobiological parameters of the contaminator were determined and the sterilization dose was set. The quality of the product irradiated at both, calculated sterilization dose (8.5 kGy) an another one about 25 kGy was determined. It was made according to: sterility testing, total proteins, pH enzymes (alanina-aminotransferase, aspartato-aminotransferase, alkaline phosphatase), protein electrophoresis, fast performance liquid chromatographic and effect on the cellular growth. From the latter was concluded that the calculated sterilization dose was adequate form keeping the biological properties and viability of the irradiated serum. Nevertheless, the dose of 25 k Gy was not adequate because of its dangerous effects on the cell culture

  9. Gamma radiation a help to archeological woods

    International Nuclear Information System (INIS)

    Balibar, F.

    1981-01-01

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

  10. Study of the gamma radiation of ionium

    Energy Technology Data Exchange (ETDEWEB)

    Curie, I

    1949-12-01

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

  11. Preservation of yams by gamma radiation

    International Nuclear Information System (INIS)

    Bansa, D.; Appiah, V.

    1999-01-01

    Loss of yam in storage due to sprouting is very high. There is the need to investigate the possibility of inhibiting the sprouting of local varieties of yams using gamma radiation. The effect of radiation on the storage yams and the functionality of the irradiated yams in the Ghanaian food system was studied. Yams were purchased from a farm in Nkwanta. Some of the yams were irradiated at an average dose of 120 Gy and a dose rate of 114 Gy/hr. The irradiated yams were stored alongside unirradiated controls in a specially constructed barn and on the ground as is traditionally done by the farmers at ambient temperature for 6 months. The stored yams were processed into some local food products, namely, boiled yam, fried yam and fufu and sensory evaluation carried out on them using the Hedonic Scale Test and analysed by Analysis of variance. Results indicated that all the unirradiated yams sprouted by the 3rd month of storage. 6.2% of the irradiated yams stored on the barn and 18.0% of those stored on the ground sprouted. 2.26% irradiated and 8.0% unirradiated yams stored on the barn compared to 22.0% and 12.0% respectively of the yams stored on the ground got rotten within the storage period. Food products made from irradiated yams were preferred to those made from the unirradiated yams in terms of texture, taste, colour and general acceptability. The results suggest that gamma radiation dose of 120 Gy effectively inhibited the sprouting of yams for 6 months under tropical ambient conditions. There was less rotting in the yams stored in the barn compared to those stored on the ground. There was also less rotting in the irradiated yams stored in the barn in comparison with the unirradiated ones. Food products made from irradiated yams were judged better in quality than those made from the unirradiated ones. (au)

  12. Mobile robot prototype detector of gamma radiation

    International Nuclear Information System (INIS)

    Vazquez C, R.M.; Duran V, M. D.; Jardon M, C. I.

    2014-10-01

    In this paper the technological development of a mobile robot prototype detector of gamma radiation is shown. This prototype has been developed for the purpose of algorithms implementation for the applications of terrestrial radiation monitoring of exposed sources, search for missing radioactive sources, identification and delineation of radioactive contamination areas and distribution maps generating of radioactive exposure. Mobile robot detector of radiation is an experimental technology development platform to operate in laboratory environment or flat floor facilities. The prototype integrates a driving section of differential configuration robot on wheels, a support mechanism and rotation of shielded detector, actuator controller cards, acquisition and processing of sensor data, detection algorithms programming and control actuators, data recording (Data Logger) and data transmission in wireless way. The robot in this first phase is remotely operated in wireless way with a range of approximately 150 m line of sight and can extend that range to 300 m or more with the use of signal repeaters. The gamma radiation detection is performed using a Geiger detector shielded. Scan detection is performed at various time sampling periods and diverse positions of discrete or continuous angular orientation on the horizon. The captured data are geographical coordinates of robot GPS (latitude and longitude), orientation angle of shield, counting by sampling time, date, hours, minutes and seconds. The data is saved in a file in the Micro Sd memory on the robot. They are also sent in wireless way by an X Bee card to a remote station that receives for their online monitoring on a laptop through an acquisition program by serial port on Mat Lab. Additionally a voice synthesizing card with a horn, both in the robot, periodically pronounced in Spanish, data length, latitude, orientation angle of shield and detected accounts. (Author)

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-05

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

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

    Science.gov (United States)

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

    2017-12-01

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

  16. Beamstrahlung Photon Load on the TESLA Extraction Septum Blade(LCC-0104)

    Energy Technology Data Exchange (ETDEWEB)

    Seryi, A

    2003-10-02

    This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design.

  17. Beamstrahlung Photon Load on the TESLA Extraction Septum Blade(LCC-0104)

    International Nuclear Information System (INIS)

    Seryi, A

    2003-01-01

    This note describes work performed in the framework of the International Linear Collider Technical Review Committee [1] to estimate the power load on the TESLA extraction septum blade due to beamstrahlung photons. It is shown, that under realistic conditions the photon load can be several orders of magnitude higher than what was estimated in the TESLA TDR [2] for the ideal Gaussian beams, potentially representing a serious limitation of the current design

  18. Sterilization of peat by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Parker, F E; Vincent, J M [New South Wales Univ., Kensington (Australia). School of Microbiology

    1981-01-01

    The effect of gamma-radiation on the survival of microorganisms has been quantified for the natural population of two types of peat. Data for several microbial types have been separately determined by regular plating and by indirect statistical probability estimates including, a wholly enclosed 'inverted-bottle' technique for higher dose levels to exclude any possibility of post-treatment contamination. The most persistent microorganisms at intermediate dosage (2.5-3.5 Mrad) were commonly a micrococcus (which closely resembled Micrococcus radiodurans) arthrobacter-like rods, myxobacteria and amoeboid forms. The persistent organisms all survived because of high resistance to ..gamma..-irradiation, not because of high initial numbers. The most numerous true bacteria (including spore-formers), actinomycetes, filamentous fungi and yeasts were all readily destroyed. Although the safety margin with the commercially recommended dose of 5 Mrad is low for some of the more resistant organisms, no change is justified at this stage since the organisms most likely to survive such a dose do not seem to seriously affect the subsequent growth and survival of rhizobia. Moreover there would be some risk of radiation-induced peat toxicity if higher doses were applied and some post-irradiation contamination will be difficult to avoid in commercial production.

  19. Effect of gamma radiation on polyvinylpyrrolidone hydrogels

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-01

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

  20. Gamma Radiation-Induced Template Polymerization Technique

    International Nuclear Information System (INIS)

    Siyam, T.

    2005-01-01

    Gamma radiation induced copolymerization of acrylamide sodiumacrylate (AM-AANa) in the presence and absence of the polymer additive was studied at low monomer concentration(1.4M/l). The results showed that the exponents of the dose rate for the polymerization rate was found to be 1.3 and 1.4 in the absence and in the presence of the polymer additive respectively. The molecular weight of the formed polymer increased by addition of the polymer to the system. In the presence of the polymer the comonomers polymerize on the added polymer. In the absence of the added polymer the comonomers polymerize according to the copolymerization process at the initial stage of the copolymerization. While at high conversion the residual comonomers polymerize on the formed macromolecular chains of the produced polymer. These studies showed that the copolymerization in the presence of added polymer is completely template copolymerization while in the absence of the polymer the copolymerization process is only template process with a high conversion

  1. Effect of gamma radiation on polyvinylpyrrolidone hydrogels

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  2. Effects of gamma radiation on rabbit lens

    International Nuclear Information System (INIS)

    Ordahl, J.N.; Gorthy, W.C.

    1982-01-01

    Eyes of young New Zealand white rabbits were irradiated with 2000 rads of gamma radiation ( 60 Co) and the eyes removed at 2, 8, 16, and 30 days post-irradiation for electron microscopic analysis. Lenses were treated histochemically for acid phosphatase localization to examine the role of lysosomal enzymes in the early development of radiation cataracts. Intercellularly located acid phosphatase reaction product, noted in the epithelium and subjacent cortex, was more prevalent after irradiation, especially in central and transitional epithelial zones. In the central zone small vesicles typically were most numerous in areas of extensive intercellular reaction product. The occurrence of discrete packets of reaction product within the vesicles and the adjoining intercellular space, plus the resemblance of the peripheral vesicles to small Golgi vesicles also containing reaction product, suggested an exocytotic release of the enzyme. These appearances suggest that lysosomal hydrolases are released extracellularly by a secretory mechanism accelerated by radiation and that these hydrolases may play a role in both physiological and pathological functions of the lens. (author)

  3. Gamma radiation sterilized amnion: use in ophthalmology

    International Nuclear Information System (INIS)

    Martinez P, M. E.; Leon T, Y.; Vazquez M, L.

    2010-10-01

    Amnion processed at the Radio sterilized Tissue Bank at the National Institute of Nuclear Research, sterilized with 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)

  4. 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)

  5. Effect of gamma radiation and ethylene oxide on neomycin sulphate

    International Nuclear Information System (INIS)

    Gopal, N.G.S.; Rajagopalan, S.

    1981-01-01

    Neomycin is affected by ethylene oxide but not by gamma radiation (2.75 Mrad). Differential refractometry is more advantageous in quantitating neomycin A, B and C than is the ninhydrin method. (Auth.)

  6. Inactivation of rabies diagnostic reagents by gamma radiation

    International Nuclear Information System (INIS)

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

    1980-01-01

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

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

    Science.gov (United States)

    dos Santos Ferreira, Eduardo; Sarango Souza, Juliana

    2017-10-01

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

  8. Mango conservation, Mangifera indica L., haden variety by gamma radiation

    International Nuclear Information System (INIS)

    Domarco, R.E.

    1989-02-01

    This paper evaluates the chemical characteristics and the mangoes sensorial quality after treatments with different doses of gamma radiation and during a period of storage, with constant conditions of temperature and relative humidity. (author)

  9. Gamma radiation shielding analysis of lead-flyash concretes

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  10. Measuring stations for gamma radiation - measured results 1982

    International Nuclear Information System (INIS)

    Kjelle, P.E.

    1983-01-01

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

  11. Leptoquark production at high energy e+e- colliders

    International Nuclear Information System (INIS)

    Bluemlein, J.; Boos, E.

    1994-08-01

    The prospects to search for scalar and vector leptoquarks at high energy e + e - colliders are reviewed. We compare production cross sections in the energy range between √s=O(200 GeV) and 1 TeV for e + e - annihilation. QED and QCD corrections and the effect of beamstrahlung in these processes are discussed. For the case of linear colliders the search potential in the different possible collider modes as e + e - annihilation, e ± γ scattering, and γγ fusion is compared. (orig.)

  12. Gamma radiation detectors for safeguards applications

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  13. Gamma radiation effects on nestling Tree Swallows

    International Nuclear Information System (INIS)

    Zach, R.; Mayoh, K.R.

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  15. 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.

  16. Gamma radiation effects on the rheological properties of high and low density polyethylenes

    International Nuclear Information System (INIS)

    Rangel-Nafaile, C.; Garcia-Rejon, A.; Garcia Leon, A.

    1986-01-01

    High energy radiation of polymeric materials is a topic of considerable interest from commercial and scientific points of view. Within an inert atmosphere, irradiation of polyethylene yields a crosslinking effect with a consequent improvement in its mechanical properties in comparison to the virgin materials. Additionally, if irradiated specimens are melted and recrystallized, the radiation-induced crosslinking hinders their crystalline growth altering dramatically their flow properties such as the elasticity. This work portrays the effects of the gamma radiation on the rheological properties of high and low density polyethylenes manufactured by PEMEX and analyzes the implications of theoretical results derived from the Acierno's model when it is implemented with the rheological properties of high energy irradiated polyethylenes. (author)

  17. Environmental gamma radiation levels around various DAE research centres

    International Nuclear Information System (INIS)

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

    2014-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-12-01

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

  19. Preparation of plastic-cellulose compounds by high energy gamma radiation

    International Nuclear Information System (INIS)

    Rosa, M.C.F.

    1978-01-01

    The use of high intensity sources of ionizing radiation for inducing polymer cross-linking was studied and the feasibility of its application in making plastic and cellulose combined compounds, particularly plates formed by paper sheets aglutinated with polyester resin, was analyzed. Several types of paper capable of being used in the plate composition were tested. It was verified that with the preparation technique used in this work the ordinary filter paper gave the best results. By different material testing techniques it was found that the chemical and mechanical properties of plates cured with radiation doses of about 1.5 Mrad are favorably compared with those exhibited by plates of equal composition, cured by the classic method (adding chemical initiator and accelerator) [pt

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  1. 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)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  3. Dosimetry and Shielding of X and Gamma Radiation

    International Nuclear Information System (INIS)

    Oncescu, M.; Panaitescu, I.

    1992-01-01

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

  4. Research progress in airborne surveys of terrestrial gamma radiation

    International Nuclear Information System (INIS)

    Burson, Z.G.

    1974-01-01

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

  5. Assembly of gamma radiation detection with directivity properties

    International Nuclear Information System (INIS)

    Stoica, M.; Talpalariu, C.

    2016-01-01

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

  6. Effect of gamma radiation on honey quality control

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  7. 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.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  10. Environmental gamma radiation monitoring at Visakhapatnam using thermoluminescence dosimeters

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  11. Gamma radiation effects on vitamin C standard solutions

    International Nuclear Information System (INIS)

    Amaro, Jose Daniel V.; Mansur Netto, Elias

    1995-01-01

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

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  13. Mathematical simulation of gamma-radiation angle distribution measurements

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  14. Dose Rate of Environmental Gamma Radiation in Java Island

    International Nuclear Information System (INIS)

    Gatot Suhariyono; Buchori; Dadong Iskandar

    2007-01-01

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

  15. Preservation of yams by gamma radiation | Bansa | Journal of the ...

    African Journals Online (AJOL)

    Loss of yam in storage due to sprouting is very high. There is the need to investigate the possibility of inhibiting the sprouting of local varieties of yams using gamma radiation. The effect of radiation on the storage yams and the functionality of the irradiated yams in the Ghanaian food system was studied. Yams were ...

  16. Computed temperature profile in materials exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ping, Tso Chin; Choong, Yap Siew; Seon, Chan Kam

    1987-06-01

    Computed temperature profiles are presented for the materials of lead, steel, concrete and water in curved shells, when they are exposed to gamma radiation. The results are based on the usual simplified theory of thermal conduction with an exponential heat source.

  17. Study of local Agregate for Gamma radiation concrete shield

    International Nuclear Information System (INIS)

    Tochrul-Binowo; Endro-Kismolo; Darsono

    1996-01-01

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

  18. Treatment of tannery effluent by irradiation. [gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Roszak, W; Pekala, W

    1983-01-01

    Different samples of tannins were exposed to gamma radiation at room temperature. Some of them were aerated during irradiation.In irradiated samples the concentration of phenol and organic substances decreased and their biodegradability increased. Aerated samples had a higher decrease of phenol concentration. (E.G.M.).

  19. Observations of nesting avifauna under gamma-radiation exposure

    International Nuclear Information System (INIS)

    Buech, R.R.

    1977-01-01

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

  20. Sewage sludge pasteurization by gamma radiation: financial viability case studies

    International Nuclear Information System (INIS)

    Swinwood, J.F.; Kotler, J.

    1990-01-01

    This paper examines the financial viability of sewage sludge pasteurization by gamma radiation, by examining the following three North American scenarios: 1. Small volume sewage treatment plant experiencing high sludge disposal costs; 2. Large volume sewage treatment plant experiencing low sludge disposal costs; 3. Large volume sewage treatment plant experiencing high sludge disposal costs. (author)

  1. Sewage sludge pasteurization by gamma radiation: financial viability case studies

    Energy Technology Data Exchange (ETDEWEB)

    Swinwood, J.F.; Kotler, J. (Nordion International Inc., Kanata, Ontario (Canada))

    1990-01-01

    This paper examines the financial viability of sewage sludge pasteurization by gamma radiation, by examining the following three North American scenarios: 1. Small volume sewage treatment plant experiencing high sludge disposal costs; 2. Large volume sewage treatment plant experiencing low sludge disposal costs; 3. Large volume sewage treatment plant experiencing high sludge disposal costs. (author).

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

    Indian Academy of Sciences (India)

    Wintec

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

  3. Sewage sludge pasteurization by gamma radiation: Financial viability case studies

    Science.gov (United States)

    Swinwood, Jean F.; Kotler, Jiri

    This paper examines the financial viability of sewage sludge pasteurization by gamma radiation, by examining the following three North American scenarios: 1) Small volume sewage treatment plant experiencing high sludge disposal costs. 2) Large volume sewage treatment plant experiencing low sludge disposal costs. 3) Large volume sewage treatment plant experiencing high sludge disposal costs.

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

    International Nuclear Information System (INIS)

    Osterhuber, R.; Condreva, K.

    1998-01-01

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

  5. Cosmic very high-energy {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, R. [Max-Planck-Institut fur Physik, Muenchen (Germany)

    1998-12-31

    The article gives a brief overview, aimed at nonspecialists, about the goals and selected recent results of the detection of very-high energy {gamma}-rays (energies above 100 GeV) with ground based detectors. The stress is on the physics questions, specially the origin of Galactic Cosmic Rays and the emission of TeV {gamma}-radiation from active galaxies. Moreover some particle-physics questions which are addressed in this area are discussed.

  6. Characterization of crumb rubber modified by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  7. Characterization of crumb rubber modified by gamma radiation

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  8. Designing equipment for use in gamma radiation environments

    International Nuclear Information System (INIS)

    Vandergriff, K.U.

    1990-05-01

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

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

    International Nuclear Information System (INIS)

    Araujo, E.S. de.

    1991-02-01

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

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

    Science.gov (United States)

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

    2017-12-01

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

  11. Gamma radiation influences postharvest disease incidence of pineapple fruits

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  12. Polycrystalline Materials as a Cold Neutron and Gamma Radiation Filter

    International Nuclear Information System (INIS)

    Habib, N.

    2009-01-01

    The total neutron cross-section of polycrystalline beryllium, graphite and iron has been calculated beyond their cut-off wavelength using a general formula. The computer Cold Filter code was developed in order to provide the required calculations. The code also permits the calculation of attenuation of reactor gamma radiation, The calculated neutron transmissions through polycrystalline Be graphite and iron at different temperatures were compared with the experimental data measured at the ETRR-1 reactor using two TOF spectrometers. An overall agreement is obtained between the formula fits and experimental data at different temperatures. A feasibility study is carried on using polycrystalline Be, graphite and iron an efficient filter for cold neutrons and gamma radiation.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  14. SENSITIVITY OF THE CUMIN SEEDS ASSOCIATED FUNGI TO GAMMA RADIATION

    International Nuclear Information System (INIS)

    BOTROS, H.W.; HELAL, I.M.; EL TOBGY, K.M.K.

    2008-01-01

    The present study was carried out to investigate the sensitivity of fungi associated to cumin seeds for gamma radiation. In this regard, the isolated seed associated fungi from the cumin seeds were fifteen fungal species belonging to five genera. The fungal species concerning, Aspergillus ochraceus, Fusarium oxysporium and Aspergillus flavus were the predominant fungi in percentages of 17.8, 15.83 and 12.78 %, respectively. Aspergillus ochraceus was the most effective prevalent fungi on the seed germination causing highest percentage of seed invasion followed by Fusarium oxysporium and Aspergillus flavus. The amylolytic, proteolytic and lipolytic activity and mycotoxin production of the three predominant fungi were negatively influenced by gamma radiation when exposed to doses of 1.0 , 1.5 , 2.5 , 3.5 , 5.0 and 7.5 kGy a behaviour which was parallel to the inhibition in the amount of growth by gamma irradiation

  15. Dosimetric studies for gamma radiation validation of medical devices

    International Nuclear Information System (INIS)

    Soliman, Y.S.; Beshir, W.B.; Abdel-Fattah, A.A.; Abdel-Rehim, F.

    2013-01-01

    The delivery and validation of a specified dose to medical devices are key concerns to operators of gamma radiation facilities. The objective of the present study was to characterize the industrial gamma radiation facility and map the dose distribution inside the product-loading pattern during the validation and routine control of the sterilization process using radiochromic films. Cardboard phantoms were designed to achieve the homogeneity of absorbed doses. The uncertainty of the dose delivered during validation of the sterilization process was assessed. - Highlights: ► Using γ-rays for sterilization of hollow fiber dialyzers and blood tubing sets according to ISO 11137, 2006. ► Dosimetry studies of validations of γ-irradiation facility and sterilized medical devices. ► Places of D min and D max have been determined using FWT-60 films. ► Determining the target minimum doses required to meet the desired SAL of 10 −6 for the two products.

  16. Slaughterhouse sewage treatment using gamma radiation - economical feasibility study

    International Nuclear Information System (INIS)

    Melo, Rita; Botelho, M. Luisa; Branco, Joaquim

    2005-01-01

    This paper presents preliminary results of a financial viability study for the implementation of gamma radiation technology on a slaughterhouse wastewater treatment industry. Five scenarios were studied, including the current practice, representing different types of treatments and goals, e.g.: water reuse and/or sludge add value as agriculture fertilizers. Cost-benefit analysis, including the net present value (NPV) of each scenario, was used as a technique to compare the relative value of various strategies. Taking in account that the initial investment is amortized after 20 years, the implementation of Co-60 treatment with 20% water reuse and sludge application as agriculture fertilizers represents the most profitable project with the highest NPV. Therefore, the implementation of gamma radiation technology on a slaughterhouse wastewater treatment industry is not only technically viable as well as economically feasible. (author)

  17. Density measurement using gamma radiation - theory and application

    International Nuclear Information System (INIS)

    Springer, E.K.

    1979-01-01

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

  18. 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.

  19. Gamma radiation hazard to miners in bituminous coal mines

    International Nuclear Information System (INIS)

    Skubacz, K.

    1986-01-01

    Radiation hazard to miners working in 16 bituminous coal mines was determined by a thermoluminescence method. While the miners exposure to gamma radiation is higher than that of the general population, the yearly dose was never found to exceed 5 mSv in any investigated person. Factors contributing to the estimate of the exposure hazard and the need for individual dose monitoring in mines are discussed in more detail. 3 refs., 4 figs. (author)

  20. The role of contacts in semiconductor gamma radiation detectors

    International Nuclear Information System (INIS)

    Lachish, U.

    1998-01-01

    It is proposed that the operation of semiconductor gamma radiation detectors, equipped with ohmic contacts, which allow free electron flow between the contacts and bulk material, will not be sensitive to low hole mobility, hole collection efficiency, or hole trapping. Such fast-operating detectors may be readily integrated into monolithic arrays. The detection mechanism and various material aspects are discussed and compared to those of blocking contact detectors. Some suggestions for detector realization are presented. (orig.)

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

    African Journals Online (AJOL)

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

  2. Gamma radiation effects in vertically aligned carbon nanotubes

    OpenAIRE

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

    2011-01-01

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

  3. Gamma radiation effects on different sorts of onions

    International Nuclear Information System (INIS)

    Burov, B.A.

    1977-01-01

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

  4. Pharmaceutical aerosols. Study of their gamma radiation sterilization

    International Nuclear Information System (INIS)

    Sebert, P.

    1984-10-01

    The gamma radiation sterilization of pharmaceutical aerosols was studied. The following topics were investigated: radiosterilization of nitrogen protoxide used as a propellant; radiosterilization of packaging materials (aluminium containers, plastics valves); radio-sterilization of excipients and active ingredients. Most of the investigated materials proved to be stable to irradiation (2,5 Mrads) from pharmacopoeial aspect. Stability tests of the preparations packaged showed no change in the parameters investigated [fr

  5. The electric charge of the aerosols under gamma radiation

    International Nuclear Information System (INIS)

    Gensdarmes, F.; Cetier, P.; Boulaud, D.; Gensdarmes, F.; Renoux, A.

    2000-01-01

    During a PWR type reactor accident, the gamma radiation may create a high ionized atmosphere. In such a situation the aerosols properties knowledge is useful to simulate the particles transport and deposit in the enclosed. The aim of this study is to determine the aerosol charges distribution in a high ionized medium, in function of the ionic properties of the medium. (A.L.B.)

  6. Disinfection of sewage water and sludge using gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

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

  7. Disinfection of sewage water and sludge using gamma radiation

    International Nuclear Information System (INIS)

    Musaad, R.M.A.

    2008-04-01

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

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

    International Nuclear Information System (INIS)

    Koperski, J.; Jasinska, M.

    1980-01-01

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

  9. Resistance of Salmonella enteritidis variety typhimurium to gamma radiation

    International Nuclear Information System (INIS)

    Norberg, A.N.; Maliska, C.

    1988-01-01

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

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

    Science.gov (United States)

    Betancourt Quiles, Maritza

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

  11. Influence of gamma radiation onto polymeric matrix with papain

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  12. 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.

  13. Physiological quality of rice seed submitted to gamma radiation

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  14. Insect disinfestation of packed dates by gamma-radiation

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  15. Inactivation of bacteria in sewage sludge by gamma radiation

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  16. 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.

  17. 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.

  18. Disinfection of wastewaters: high-energy electron vs gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Farooq, S [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Civil Engineering; Kurucz, C N; Waite, T D [Miami Univ., Coral Gables, FL (United States); Cooper, W J [Florida International Univ., Miami, FL (United States). Drinking Water Research Center

    1993-07-01

    A study was undertaken to examine the sensitivity of a wastewater population of coliphage, total coliforms and total flora present in raw sewage and secondary effluent after irradiating with similar doses delivered by a high-energy electron beam and [gamma]-radiation. The electron beam study was conducted on a large scale at the Virginia Key Wastewater Treatment Plant, Miami, Florida. The facility is equipped with a 1.5 MeV, 50 mA electron accelerator, with a wastewater flow rate of 8ls[sup -1]. Concurrent [gamma]-radiation studies were conducted at laboratory scale using a 5000 Ci, [sup 60]Co [gamma]-source. Three logs reduction of all three test organisms were observed at an electron beam dose of 500 krads, while at least four logs reduction were observed at the same dose utilizing the [gamma]'source. (Author).

  19. Effect of gamma radiation on garlic storage under natural conditions

    International Nuclear Information System (INIS)

    Ayyoubi, Zouhair; Sharabi, N.E.

    1993-02-01

    Garlic cloves were exposed to 30, 60, and 100 Gy of gamma radiation using Co 60 as a sources, to study the effect of different doses on the sprout inhibition of garlic. All the doses applied were effective. No sprout occurred in any of the treatments subjected to natural storage conditions. The effect of irradiation was evident in limiting the weight decrease. It reached 12 - 19% in 1987 and 1988 experiments respectively after 320 days of storage. Irradiation had no effect on the garlic consumptive specifications compared to the control. (author). 4 refs., 2 figs., 5 tabs

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

    International Nuclear Information System (INIS)

    EI-Ahdal, M.A.

    2007-01-01

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

  1. Effect of Gamma Radiation on Quality of Imitation Crab Meat

    International Nuclear Information System (INIS)

    Charoen, Saovapong; Sajjabut, Surasak

    2007-08-01

    Full text: Irradiation at 0.5, 1.0 and 1.5 kGy of some commercial imitation crab meats with non-vacuum packaging reduced the total viable count by 1-2 log cycles, while coliform and Staphylococcus aureus were eliminated by 1.5 kGy gamma radiation. Although TBA number of 1 and 1.5 kGy irradiated samples increased significantly, but the sensory evaluation did not show any significant differences compared with the controls. Radiation dosage of 1.5 kGy appeared to be sufficient for improving bacterial quality and eliminating coliform and Staphylococcus aureus

  2. Degradation study of Durolon polycarbonate submitted to gamma radiation

    International Nuclear Information System (INIS)

    Miranda, A.; Sciani, V.

    1992-01-01

    The effect of gamma radiation from a cobalt 60 source in the 27000 Durolon polycarbonate irradiated with doses between 0,2 and 1000 kGy at 25 0 C was analyzed. For this reason the samples was submitted to the mechanical assay of tension, deformation and hardness and optical assay of transmittance. The obtained results show a good mechanical stability of the polycarbonate, when it was submitted to gamma irradiation in doses up to 20 kGy. (C.G.C.). 05 refs., 04 figs

  3. Decontamination of black pepper and red pepper by gamma radiation

    International Nuclear Information System (INIS)

    Oularbi, S.; Mansouri, B.

    1993-04-01

    In the present work, it has been studied the decontamination of two types of spices (black pepper and red pepper) by gamma radiation. The initial microbial population of spices not treated is about 10 (7) to 10 (8) per gram. The population decrease exponentially with irradiation dose. By this, it has been established that a dose of 6 kGy reduces the microbial flora low than 10 (3) per gram. A total elimination of moulds is obtained at dose of 8 kGy

  4. Sterilization of spices and vegetable seasoning by gamma radiation

    International Nuclear Information System (INIS)

    Lescano, G.; Narvaiz, P.; Kairiyama, E.

    1991-01-01

    Ginger, turmeric, Cayenne pepper, onion and garlic powders were gamma irradiated with doses of 10 and 30 kGy, and stored at room temperature for six months. Microbiological, chemical and sensory analyses were performed. Samples were sterilized with 30 kGy. The pH values of water extracts of these condiments appear practically unchanged by the applied gamma radiation doses. Spectrophotometric analysis of methyl alcohol extracted of the pigments showed no irradiation effect in turmeric and ginger. Seasoning capacity (odour, flavour and pungency) were not altered by 30 kGy irradiation. (author) 24 refs.; 2 figs.; 4 tabs

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

    International Nuclear Information System (INIS)

    Urbina P, M.C.; Casas G, L.

    1984-01-01

    Garlic preservation was studied during a period of eleveth 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 is possible to preserve garlic for a period up to ten months, with market quality. (Author)

  6. Gamma radiation inside closed volumes with thin irradiating walls

    International Nuclear Information System (INIS)

    Karpov, V.I.

    1978-01-01

    The dose rate of gamma radiation inside a parallelepiped with thin radiating walls was calculated. The calculation was based on determining the dose rate from a rectangular plate and subsequently summing the dose rates from all the parallelepiped walls. The dose rate from the rectangular plate was calculated by reducing it to an equivalent plate of infinite length and certain fixed width. When the radiators had constant surface density, the dose rate in the geometric centre of volumes having the form of a parallelepiped was shown to have the least value in the case when the parallelepiped degenerates to a cube

  7. Absolute exposure determination of cobalt-60 gamma radiation

    International Nuclear Information System (INIS)

    Ahmad, S.S.; Ali, A.; Orfi, S.D.

    1986-02-01

    The report describes the procedure for the determination of absolute exposure for Cobalt-60 gamma radiation. A graphite cavity chamber, nominal volume of 1 cm 3 , manufactured by Austrian Research Centre Seibersdorf has been used. The exposure rate at reference distance determined with the graphite chamber was compared with mean exposure rate measured with NPL-Therapy level X-ray exposure meter normalized to same date. An agreement of 0.39% was found between the two measuring systems, which seems to be very encouraging and quite satisfactory. (authors)

  8. Use of gamma radiation in preparation of Salmonella vaccine

    International Nuclear Information System (INIS)

    Govekar, L.G.; Lewis, N.F.

    1976-01-01

    The conventional method for preparation of TAB vaccine involves the addition of 0.1% formaldehyde to 18 hr. old Salmonells cultures, and incubation of formaldehyde preparations for 3 days at 35 degC. This method is however time consuming and cumbersome. A simple method which has been developed irradiates Salmonella typhirium cultures at predetermined gamma radiation doses. Cell suspensions in phosphate buffer subjected to 0.3 -0.5 Mrad were found to be detoxified but retain their antigenic properties. These irradiated cell suspensions were found to immunize mice more effectively than the commercially available vaccine. (author)

  9. Sterilization of sera and vaccines by cobalt gamma radiation

    International Nuclear Information System (INIS)

    Guidolin, R.; Morais, J.F.; Higashi, H.G.; Correa, A.; Cicarelli, R.M.B.; Previde, E.

    1988-01-01

    Diphtheria, tetanus, anti-snake venom sera and Diphtheria-Pertussis-Tetanus vaccine were submitted to different intensities of gamma radiation, in order to: verify the resistance of their specific activities to the action of gamma rays; evaluate the possibility of using this type of energy to sterilize some heterogeneous hyper immune sera and vaccines commonly utilized in Public Health. The results, according to the range employed, show the possibility of sterilizing the products tested, without any alteration to specific biological and chemical properties. (author)

  10. Cryo-gamma radiation inactivation of bovine herpesvirus type-1

    Science.gov (United States)

    Degiorgi, C. Fernández; Smolko, E. E.; Lombardo, J. H.

    1999-07-01

    The radioresistance of bovine herpesvirus-1 (BHV-1), commonly known as infectious bovine rhinotracheitis virus (IBRV), suspended in free serum Glasgow-MEM medium and frozen at -78°C was studied. The number of surviving virus at a given dose of gamma-radiation was determined by a plaque assay system. D 10 values were calculated before and after removal of cell debris. The D 10 values obtained were 4.72 kGy and 7.31 kGy before and after removal of cell debris, respectively. Our results indicate that the inactivated viral particles could be used for vaccine preparation or diagnostic reagents.

  11. Polypropylene-polyethylene blends modified by gamma radiation

    International Nuclear Information System (INIS)

    Terence, Mauro C.; Ruiz, Francisco C.

    2009-01-01

    One way to obtain a better mechanical property of polypropylene and polyethylene is to increasing the number of polymer chains cross-linked by gamma radiation. After irradiation a network is formed as a result of various chemical reactions and the radicals formed are concentrated in the amorphous phase. With the objective to improve the mechanical properties of PP, blends with PE were prepared and irradiated in doses up to 500 kGy, in atmospheric ambient. The molecular characterization of the blends was made by infrared spectroscopy and the data showed an increase in rigidity and a unique behaviour in Izod impact resistance. (author)

  12. 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.

  13. Preliminary measurements of gamma radiation in Chilean Antarctic Stations

    International Nuclear Information System (INIS)

    Stuardo B, E.

    1983-01-01

    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 μR/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. (Author)

  14. Gamma radiation effects in Sitophilus oryzae (Linne, 1763) (Coleoptera, Curculionidae)

    International Nuclear Information System (INIS)

    Pacheco, J.M.

    1973-01-01

    Lethal effects were studied for the egg, larval and pupal stages as well as sterilization of adults of Sitophilus oryzae (L.) by the application of gamma radiation. Irradiation of pupae with an estimated dosis of 7887 ± 158 rad inhibits adult emergency. Hypotheses have been suggested that the apparent density and (or) nutrient value of food substrates decisively influence the sterilizing dosis for this insect. Thus, in rice and maize which are apparently denser and (or) of higher nutrient value than maccaroni, insects are sterilized by a dosis of 7 krad, while in maccaroni the sterilizing dosis decreases to 5 krad. (author)

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  16. 77 FR 62267 - Proposed Extension of Existing Information Collection; Gamma Radiation Surveys

    Science.gov (United States)

    2012-10-12

    ... debilitating occupational diseases. Natural sources include rocks, soils, and ground water. Gamma radiation..., electronic, mechanical, or other technological collection techniques or other forms of information technology...

  17. Effect of Gamma radiation on microbial population of natural casings

    International Nuclear Information System (INIS)

    Trigo, M.J.; Fraqueza, M.J.

    1998-01-01

    The high microbial load of fresh and dry natural casings increases the risk of meat product contamination with pathogenic microorganims, agents of foodborn diseases. The aim of this work is to evaluate the killing effect of gamma radiation on the resident microbial population of pork and beef casings, to improve their hygiene and safety. Portions of fresh pork (small intestine and colon) and dry beef casings were irradiated in a Cobalt 60 source with absorbed doses of 1, 2, 5 and 10 kGy. The D 10 values of total aerobic microorganisms in the pork casings were 1.65 kGy for colon and 1.54 kGy for small intestine. The D 10 value found in beef dry casings (small intestine) was 10.17 kGy. Radurization with 5 kGy was able to reduce, at least, 6 logs the coliform bacteria in pork casings. The killing effect over faecal Streptococci was 4 logs for pork fresh casings and 2 logs for beef dry casings. Gamma radiation with 5 kGy proved to be a convenient method to reduce substantially the microbial population of pork fresh casings. Otherwise, the microbial population of beef dry casings still resisted to 10 kGy

  18. Gamma radiation treatment activates glucomoringin synthesis in Moringa oleifera

    Directory of Open Access Journals (Sweden)

    Tsifhiwa Ramabulana

    Full Text Available Abstract Plants are a very rich source of pharmacologically relevant metabolites. However, the relative concentrations of these compounds are subject to the genetic make-up, the physiological state of the plant as well as environmental effects. Recently, metabolic perturbations through the use of abiotic stressors have proven to be a valuable strategy for increasing the levels of these compounds. Oxidative stress-associated stressors, including ionizing radiation, have also been reported to induce metabolites with various biological activities in plants. Hence, the aim of the current study was to investigate the effect of gamma radiation on the induction of purported anti-cancerous metabolites, glucomoringin and its derivatives, in Moringa oleifera Lam., Moringaceae. Here, an UHPLC-qTOF-MS-based targeted metabolic fingerprinting approach was used to evaluate the effect of gamma radiation treatment on the afore-mentioned health-beneficial secondary metabolites of M. oleifera. Following radiation, an increase in glucomoringin and three acylated derivatives was noted. As such, these molecules can be regarded as components of the inducible defense mechanism of M. oleifera as opposed to being constitutive components as it has previously been assumed. This might be an indication of a possible, yet unexplored role of moringin against the effects of oxidative stress in M. oleifera plants. The results also suggest that plants undergoing photo-oxidative stress could accumulate higher amounts of glucomoringin and related molecules.

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

    International Nuclear Information System (INIS)

    Sofaan, A. H.

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Pardo, M.E. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico)], E-mail: memp@nuclear.inin.mx; Ley-Chavez, E. [ISSEMYM Toluca, Mexico DF (Mexico); Reyes-Frias, M.L. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico); Rodriguez-Ferreyra, P. [Hospital ' Dr. Nicolas San Juan' , Toluca, Mexico DF (Mexico); Vazquez-Maya, L.; Salazar, M.A. [Hospital General de Mexico, Mexico DF (Mexico)

    2007-11-15

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

  1. 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.

  2. Characteristics of liver tissue for attenuate the gamma radiation

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. Gamma radiation scanning of nuclear waste storage tile holes

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  4. Simultaneous Thermal and Gamma Radiation Aging of Electrical Cable Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Fifield, Leonard S.

    2018-04-11

    The polymers used for insulation in nuclear power plant electrical cables are susceptible to aging during long term operation. Elevated temperature is the primary contributor to changes in polymer structure that result loss of mechanical and electrical properties, but gamma radiation is also a significant source of degradation for polymers used within relevant plant locations. Despite many years of polymer degradation research, the combined effects of simultaneous exposure to thermal and radiation stress are not well understood. As nuclear operators contemplate and prepare for extended operations beyond initial license periods, a predictive understanding of exposure-based cable material degradation is becoming an increasingly important input to safety, licensing, operations and economic decisions. We are focusing on carefully-controlled simultaneous thermal and gamma radiation accelerating aging and characterization of the most common nuclear cable polymers to understand the relative contributions of temperature, time, dose and dose rate to changes in cable polymer material structure and properties. Improved understanding of cable performance in long term operation will help support continued sustainable nuclear power generation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-15

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

  6. Control device intended for a gamma radiation measuring instrument

    International Nuclear Information System (INIS)

    1976-01-01

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

  7. Gamma Radiation Assessment In Kartini Reactor And Its Vicinity

    International Nuclear Information System (INIS)

    Yazid, M.; Supriyatni, E.; Maryono; Bastianudin, Aris

    2000-01-01

    Measurement to calculate dose assesment for gamma radiation in Kartini Reactor and its vicinity has been done whether on operated or un operated condition. Measurement was performed using height pressured ionization chamber, Reuther Stokes RS-112 production. Measurement location was determined based on distance variation inwardly and outwardly of reactor building and its vicinity. The result showed that the average dose rate in the reactor building when un operated is in the range of 11.4-38.6 mu rad/hour and when the reactor operated is 166.4-1910.9 mu rad/hour. While the vicinity of the reactor on operated condition the average dose rate is 34.4-38.6 mu rad/hour in un operated condition is 6.9-7.0 mu rad/hour. This result showed that the reactor operated did not rise the radiation exposure level in its vicinity. From the personnel assesment dose rate of gamma radiation is 28.54 mrem/week on operated condition, 0.90 mrem.week on un operated condition. While dose rate outside the reactor is 0.44 and 0.27 mrem/week for operated and un operated condition consecutively. This dose rate is still below maximum permissible dose than recommended by the national regulation of radiation protection from BAPETEN No. 01/Ka.BAPETEN/V-99

  8. Gamma radiation effect on Populus nigra assimilatory pigments

    International Nuclear Information System (INIS)

    Creanga, I. A.; Tudorie, Marcela; Mocanasu, C.; Creanga, Dorina

    2002-01-01

    The influence of low intensity gamma radiation on the photosynthesis in young poplar saplings was studied. Black poplar (Populus nigra) was chosen due to its ecological importance, as fast growing tree species with many hybrids, in the frame of a polluted environment. Assimilatory pigments in the leaves of irradiated saplings were assayed using standard spectrophotometric method in acetone extract. Series of five saplings formed the experimental samples. Chlorophyll a and chlorophyll b levels appeared as diminished in exposed samples in comparison to the controls. Linear regression was established in every case, the line slope showing the higher effect in chlorophyll b. Carotene pigments presented a slight increasing tendency in the exposed samples. Assimilatory pigment sum was shown to be affected by the same decreasing tendency. Student t-test was applied (two tailed, pair type) to reveal statistical significance of observed modifications. Though not very deep, the modifications induced by exposure to gamma radiation of low intensity (comparable to the local atmospheric variations, caused by both natural and artificial sources) represent putative inhibitory factors in young plant photosynthesis. The main mechanism of radiation action seems to be water radiolysis, triggering peroxide cascade, generally producing toxic products for the cell metabolism. Nevertheless, living cell ability to repair some damages caused by external stress could be revealed in the present case by the enhancing tendency of the carotenes which sustain photosynthesis as secondary pigments. (authors)

  9. Quality assurance of environmental gamma radiation monitoring in Slovenia

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  10. Effects of 60Co gamma radiation on crotamine

    Directory of Open Access Journals (Sweden)

    Boni-Mitake M.

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-12-01

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

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

    International Nuclear Information System (INIS)

    Martinez-Pardo, M.E.; Ley-Chavez, E.; Reyes-Frias, M.L.; Rodriguez-Ferreyra, P.; Vazquez-Maya, L.; Salazar, M.A.

    2007-01-01

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

  13. Gamma radiation and the conservation of natural orange juice

    International Nuclear Information System (INIS)

    Iemma, Juliana; Alcarde, Andre Ricardo; Domarco, Rachel Elisabeth; Spoto, Marta Helena Fillet; Blumer, Lucimara; Matraia, Clarice

    1999-01-01

    The effect of gamma radiation was evaluated on the microbiological population, soluble solids content, acidity, p H and ascorbic acid content of natural orange juice. Microbial activity may cause deterioration of orange juice. Irradiation is a process of food conservation which eliminates microorganisms. nevertheless radiation may affect some characteristics of irradiated food. The experimental design was a 4 x 5 factorial scheme, including control and 3 rates of irradiation (2.0, 4.0 and 6.0 kGy) and 5 storage periods (1, 7, 14, 21 and 28 days), with 2 replicates. Samples of juice were extracted from variety Pera oranges and irradiated at a rate of 2.0 kGy/h ( 60 Cobalt) and thereafter stored at 5 +- 3 deg C. Results showed small changes in soluble solids content, acidity and p H, for all treatments. The ratio soluble solids/acidity was also determined and showed little variation for all treatments. There was a reduction on ascorbic acid content of the orange juice with increased radiation dosage and storage time. Gamma radiation was effective in reducing the microbiological population of the juice. (author)

  14. Why high energy physics

    International Nuclear Information System (INIS)

    Diddens, A.N.; Van de Walle, R.T.

    1981-01-01

    An argument is presented for high energy physics from the point of view of the practitioners. Three different angles are presented: The cultural consequence and scientific significance of practising high energy physics, the potential application of the results and the discovery of high energy physics, and the technical spin-offs from the techniques and methods used in high energy physics. (C.F.)

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  17. Study of effect of gamma radiation on molecular weight and mechanical properties of PHB and PHNV

    International Nuclear Information System (INIS)

    Fechine, Guilhermino J.M.; Terence, Mauro C.; Rabello, M.S.; Willen, Renate M.R.

    2011-01-01

    The effect of gamma radiation on molecular weight and mechanical properties (tensile and flexural) of PHB and PHBV samples was investigated. The values of stress and strain at the break point for both mechanical properties indicated that scission molecular reactions were predominant in PHB and PHBV samples submitted to gamma radiation. These results were confirmed by Size Exclusion Chromatography (SEC) analysis. (author)

  18. The annual terrestrial gamma radiation dose to the population of the urban Christchurch area

    International Nuclear Information System (INIS)

    Chapman, R.H.

    1983-01-01

    Natural terrestrial gamma radiation dose rates were measured with a high pressure ionization chamber at 70 indoor (195 site measurements) and 58 outdoor locations in the metropolitan Christchurch area. Based on these site measurements, the average gonad dose rate to the population from natural terrestrial gamma radiation was estimated to be 273+-56 microgray per annum. (auth)

  19. The influence of gamma radiation on the molecular weight and glass transition of PLLA and HAp/PLLA nanocomposite

    International Nuclear Information System (INIS)

    Milicevic, D.; Trifunovic, S.; Dojcilovic, J.; Ignjatovic, N.; Suljovrujic, E.

    2010-01-01

    The influence of gamma radiation on the molecular weight and glass transition behaviour of poly-L-lactide (PLLA) and hydroxyapatite/poly-L-lactide (HAp/PLLA) nanocomposite has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy (ΔH*) for glass transition was determined on the basis of the heating rate dependence of the glass transition temperature (T g ). Our findings support the fact that chain scission is the main reason for the decrease of T g and ΔH* with the absorbed dose. Furthermore, more intensive chain scission degradation of PLLA was observed in HAp/PLLA and can only be ascribed to the presence of HAp nanoparticles. Consequently, initial differences in the glass transition temperature and/or apparent activation energy of PLLA and HAp/PLLA became more pronounced with absorbed dose. This study reveals that radiation-induced changes in molecular weight and glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of these biomaterials.

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

    International Nuclear Information System (INIS)

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

    1991-01-01

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

    Mafra, Olga Yajgunovitch

    1969-01-01

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

  3. Alterations induced in Escherichia Coli cells by gamma radiation

    International Nuclear Information System (INIS)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da; Jesus, E.F.O. de; Lopes, R.T.; Carlin, N.; Toledo, E.S.

    2007-01-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ( 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)

  4. Effect of gamma radiation on chitin-nanosilver membranes

    International Nuclear Information System (INIS)

    Singh, Rita; Singh, Durgeshwer

    2014-01-01

    Antimicrobial wound dressings are indispensable for the effective healing of skin wounds such as burns and ulcers. Various synthetic and natural polymers with good biocompatibility have been used to develop wound dressings. Chitin possesses excellent properties that are advantageous for wound dressing namely biocompatibility, biodegradability and haemostatic activity. Chitin-nanosilver membranes were developed for use as an antimicrobial dressing for wound care. For clinical applications, the wound dressing should be assuredly free of microbial contamination. Gamma irradiation has well appreciated technological advantages and is the most suitable method for the sterilization of biomedical materials. The present study was carried out to evaluate the effect of gamma radiation on the chemical and functional characteristics of the chitin-nanosilver membranes

  5. Gamma radiation damage in crotamine (venom of Brazilian rattlesnake)

    International Nuclear Information System (INIS)

    Costa, T.A.; Rogero, J.R.

    1988-01-01

    Ionizing Radiations changes the molecular structure due to chemical bond destruction. These chemical alterations is able to change the biological properties of the macro-molecules. Crotamine was obtained from Crotalus durissus terrificus venom by molecular exclusion cromatography and irradiated in concentration of 2 mg/ml of NaCl 0,85% with gamma radiation produced by a 60 Co source. We used doses of 100 Gy, 250 Gy, 500 Gy, 1000 Gy and 2000 Gy (dose rate = 1,19.10 3 Gy/h). We performed the following experiments: presence of free SH groups, proteic concentration,SDS-PAGE and immunodifusion. Preliminary results showed an increase of the number of bands in SDS-PAGE suggesting the appearence of protein aggregates that proportional to the dose increasing. The immunodiffusion data showed no modification of the immunochemical activity against theButantan anti - sera. (author) [pt

  6. Effect of 60 Co gamma radiation on crystalline proteins

    International Nuclear Information System (INIS)

    Bernardes, D.M.L.

    1991-01-01

    In order to study the effects of 6 0 Co gamma radiation on crystalline proteins an in vitro system was set up. For that, aqueous solutions from bovine crystalline were used irradiated with 0, 5.000, 10.000, 15.000, 20.000 and 25.000 Gy. The treatment led to protein alterations determined by different methods. By turbidimetry the formation of aggregates that increased with the radiation dose was revealed. The same observation was done from viscosity data and from the UV spectrum of the samples. From amino acid analysis and fluorimetry determinations, tryptophan appeared as the most sensitive amino acid. An increase in the free-S H-groups was also observed. After the standardization of the method, the radio modifier capability of glutathione, amino ethyl thiourea, mercapto ethyl alanine and dimethyl sulfoxide was tested. The results showed that in the presence of those substances the radiation effect was diminished. (author)

  7. 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)

  8. Effect of gamma radiation on the poly(vinyl alcohol)

    International Nuclear Information System (INIS)

    Terence, M.C.; Guedes, S.M.L.

    2000-01-01

    The poly(vinyl alcohol) (PVAL) is a polymer used as bio material. The PVAL was used as ocular insert and may be used as a drug delivery system (DDS) for pair PVAL/gancyclovir, where the last one is used for treatment of people with retinitis caused by cytomegalovirus. These inserts are crosslinked systems. The crosslink was induced by gamma radiation applied in polymer. The samples of PVAL was irradiated by gamma rays with doses in the range 0 to 100 kGy. On irradiated PVAL samples was observed a low yellowness, attributed to the formation of polymeric radicals that are stable in the structure of the polymer, from radiolysis of PVAL. (author)

  9. Spectral measurements of gamma radiation streaming through ducts

    International Nuclear Information System (INIS)

    Meenakshisundaram, P.K.; Bhatnagar, V.M.; Raghunath, V.M.; Gopinath, D.V.

    1979-01-01

    The paper presents the spectral measurements of gamma radiation streaming through multi-legged rectangular concrete ducts for cesium-137 and cobald-60 sources. Effect of lead lining the inner surface of the duct on the streaming radiation spectrum and optimization of liner thickness for minimum streaming radiation dose have been studied. For three-legged ducts, a comparative analysis of lead lining the entire duct as against lining any one or both the corners of the duct is reported. It is seen that lead lining any one of the corners would reduce the streaming radiation dose by a factor of 5 to 12. Lining both the corners which is nearly as effective as lining the entire duct reduces the dose by a factor of 16 to 60 depending on the soruce energy and duct dimensions. (orig.)

  10. Neutron and/or gamma radiation detecting system

    International Nuclear Information System (INIS)

    Cerff, K.

    1985-01-01

    A large reception surface for the radiation to be detected is formed on a body of scintillation material (ZnS-AG with B matrix) which is adapted to convert neutron or gamma radiation into light energy. A large number of fiber light conductors is embedded in the body of scintillation material such that the fibers extend essentially parallel and fully across the reception surface of the body of scintillation material. The light energy, upon propagation along the fiber light conductors, is coupled into the conductors along the surface of the fibers which are unisotropic. This arrangement permits the use of unisotropic light conductor systems which provide for a separation of light collecting and light transmitting functions which results in a substantial reduction of light absorption losses during light transmission so that most of the light energy coupled into the fiber light conductors reaches the optoelectronic amplifier coupled to the end of the light conductors. (orig./HP) [de

  11. Perception of gamma radiation by adults of Sitophilus zeamais mots

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Walder, J.M.M.

    1975-05-01

    Perception of gamma radiation by living organisms has been evidenced only a few times. The occurence of such perception with maize weevil, Sitophilus zeamais Motschulsky is presented. Tubes containing maize weevil were placed in a radial position to a gamma source. Counting of the insects inside the tubes at different distances from the source was made immediately after irradiation. It was noticed that the insects submitted to irradiation had been driven away from the source as compared with those not submitted (control). A possible relationship exists between this effect and the Cerenkov effect which affects directly the visual organs of the insect. This is probably due to the fact that the insects have a large quantity of water in the occular cells

  12. Attenuate Eimeria Tenella parasite by gamma radiation in chicken vaccination

    International Nuclear Information System (INIS)

    El-atar, M.A.

    1998-01-01

    Mature occysts of eimeria tenella were attenuated by different doses of gamma radiation. The vitality, pathogenicity and immunogenicity of these occysts were examined by infecting one day old broiler chicks. The study revealed that the irradiated occysts lost pathogenicity by increasing radiation dose. To examine the immunogenicity of irradiated occysts, chickens were challenged 28 days post immunogenic infection. It was shown that the irradiated occycts kept their immunogenicity but this ability decreased when the irradiation dose was increased. Also, the number of vaccination doses as well as the level of irradiation were studied. Occysts irradiated with 15, 18, 20 Krad were used to vaccinate one-day old broiler chicks for one or two times, and seven-day old chicks for three times. High level of protection was observed as shown by disappeaeance of clinical signs or mortality in most vaccinated groups

  13. Gamma radiation effect on sisal / polyurethane composites without coupling agents

    Directory of Open Access Journals (Sweden)

    Marina Cardoso Vasco

    Full Text Available Abstract Natural fibers and polyurethane based composites may present chemical bonding between the components of the polymer and the lignin of the fiber. The incidence of radiation can cause degradation of the polymeric material and alter its mechanical properties. The objective of this study was to obtain and characterize cold pressed composites from polyurethane derived from castor oil and sisal fibers, without coupling agents, through thermogravimetric and mechanical tests, before and after the incidence of 25 kGy dose of gamma radiation. Woven composites that were not irradiated had maximum values of 4.40 GPa for flexural elastic modulus on three point flexural test and dispersed fiber composite that were not irradiated had maximum values of 2.25 GPa. These materials are adequate for use in non-structural applications in radiotherapy and radiodiagnostic rooms.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-07-01

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

  15. System of message for gamma-radiation monitor

    International Nuclear Information System (INIS)

    Bolic, M.D.; Koturovic, A.M.

    2001-01-01

    Paper describes a system of voice messages for gamma-radiation monitor based on PC. The systems reproduces recorded messages that is simpler than the process of their synthesis. Message choice is based on combination of recorded digital results and/or received reference messages or warnings. The system of generation of voice messages applies the Windows based software. The total memory array required to create independent voice system is maximum 1.7 mbyte. The monitor may be used for continuous monitoring of radioactivity level with 5-8 s period of message repetition. Another option of the system operation is based on monitor application for the environment monitoring. Period of messages in this case is equal to 5-30 min [ru

  16. Gamma radiation effect on sisal / polyurethane composites without coupling agents

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, Marina Cardoso; Claro Neto, Salvador; Nascimento, Eduardo Mauro; Azevedo, Elaine, E-mail: marina.mcv@gmail.com [University of Patras (Greece); Universidade de Sao Paulo (USP) Sao Carlos, SP (Brazil); Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2017-04-15

    Natural fibers and polyurethane based composites may present chemical bonding between the components of the polymer and the lignin of the fiber. The incidence of radiation can cause degradation of the polymeric material and alter its mechanical properties. The objective of this study was to obtain and characterize cold pressed composites from polyurethane derived from castor oil and sisal fibers, without coupling agents, through thermogravimetric and mechanical tests, before and after the incidence of 25 kGy dose of gamma radiation. Woven composites that were not irradiated had maximum values of 4.40 GPa for flexural elastic modulus on three point flexural test and dispersed fiber composite that were not irradiated had maximum values of 2.25 GPa. These materials are adequate for use in non-structural applications in radiotherapy and radiodiagnostic rooms. (author)

  17. Improvement of PVC floor tiles by gamma radiation

    International Nuclear Information System (INIS)

    Plessis, T.A. du; Badenhorst, F.

    1988-01-01

    Gamma radiation presents a unique method of transforming highly plasticized PVC floor tiles, manufactured at high speed through injection moulding, into a high quality floor covering at a cost at least 30% less than similarly rated rubber tiles. A specially formulated PVC compound was developed in collaboration with a leading manufacturer of floor tiles. These tiles are gamma crosslinked in its shipping cartons to form a dimensionally stable product which is highly fire resistant and inert to most chemicals and solvents. These crosslinked tiles are more flexible than the highly filled conventional PVC floor tiles, scratch resistant and have a longer lifespan and increased colour fastness. These tiles are also less expensive to install than conventional rubber tiles. (author)

  18. Production of radioisotopic gamma radiation sources in JAERI

    International Nuclear Information System (INIS)

    Katoh, Hisashi; Kogure, Hiroto; Suzuki, Kyohei

    1980-04-01

    The present state of production of gamma radiation sources in Japan Atomic Energy Research Institute (JAERI) is described. Sources of 192 Ir, 60 Co and 170 Tm for industrial and 198 Au and 192 Ir for medical applications are produced and delivered routinely by JAERI. Prefabricated assembly targets are irradiated in JRR-2, JRR-3, JRR-4 or JMTR. The irradiated targets are disassembled in a heavy density concrete cave or a lead-shielded cell, depending on the level of radioactivity. The yield of radioactivity in each target is measured with the aid of an ionization chamber. Where necessary, irradiated targets are encapsulated hermetically in capsules of aluminium, stainless steel or other material. The yield of radioactivity is estimated in relation with the burn-up of target nuclide and product nuclide. (author)

  19. 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.

  20. Continuous monitoring system for environmental {gamma} radiation near nuclear facility

    Energy Technology Data Exchange (ETDEWEB)

    Hua, Jin; Qingyu, Yue; Wenhai, Wang [Academia Sinica, Beijing, BJ (China). Inst. of Atomic Energy

    1996-06-01

    The continuous monitoring system which is used for the environmental routine and accident emergency {gamma} radiation monitoring near nuclear facility is described. The continuous monitoring system consists of a high pressurized ionization chamber, integrated weak current amplifier, V/F converter and intelligent data recorder. The data gained by recorder can be transmitted to a PC through a standard RS-232-C interface for the data handling and graph plotting. This continuous monitoring system has the functions of alarm over threshold and recorded output signal of detector and temperature. The measuring range is from 10 nGy{center_dot}h{sup -1} to 10 mGy{center_dot}h{sup -1} because a high insulation switch atomically changed measuring ranges is used. The monitoring system has been operating continuously for a long time with high stability and reliability. (5 figs., 2 tabs.).

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

    International Nuclear Information System (INIS)

    Santos, Marcio Ramatiz L.; Arthur, Valter; Salgado, Jocelem M.; Spoto, Marta H. Fillet; Canniatti-Brazaca, Solange G.

    2009-01-01

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

  2. Bacterial growth on Mueller Hinton medium sterilized by. gamma. -radiation

    Energy Technology Data Exchange (ETDEWEB)

    Eisenberg, E. (Israel Atomic Energy Commission, Yavne. Soreq Nuclear Research Center); Bogokowsky, B.; Altmann, G. (Sheba Medical Center, Tel Hashomer (Israel); Tel Aviv Univ. (Israel). Medical School)

    1981-12-01

    The possibility of radiosterilization of culture media for the cultivation of bacteria was investigated. Mueller Hinton agar, a medium widely used for the propagation of some fastidious pathogenic bacteria, was sterilized with 1.0 and 1.5 Mrad doses of ..gamma..-radiation. Bacteria belonging to seven different species grew as well on the radiosterilized medium as on medium sterilized by heat in a conventional way. Reduction in colony size was observed on the radiosterilized medium with Staphylococcus aureus and Shigella boydii. Neisseria meningitidis, the most fastidious bacterium tested, did not grow at all. The addition of small amounts of catalase corrected the deleterious radiation effect and all bacteria tested could be successfully grown on irradiated Mueller Hinton agar supplemented with up to 11 Keil units catalase per liter medium.

  3. Dosimetry of electron and gamma radiation with DL-alanine

    International Nuclear Information System (INIS)

    Costa, Z.M. da; Campos, L.L.

    1996-01-01

    A dosimetric method based on the quantitative determination of stabilised free radicals in irradiated crystalline DL-alanine by electron spin resonance (ESR) spectroscopy was proposed as early in 1962. Since then, alanine dosemeters owing to their unique properties have been investigated by many authors and used in dosimetry of various types of radiation, namely gamma rays, electron and neutrons. Alanine is a simple aminoacid, on irradiation at room temperature predominantly free paramagnetic radicals of the type CH 3 -CH-COOH are produced. This paper reports the application of powder DL-alanine/ESR dosemeter for measurement of absorbed dose of gamma radiation from 60 Co sources and reactor nucleus and electron beams from accelerator. The obtained results give useful information about the instrumental care necessary to obtain the needed overall accuracy in determination of absorbed dose. (author)

  4. Gamma radiation-polymerized methacrylates used as heavy metals adsorbents

    International Nuclear Information System (INIS)

    Barrera D, C.; Roa M, G.; Balderas H, P.; Bilyeu, B.; Urena N, F.

    2009-01-01

    Heavy metal removal from aqueous solution is a priority research area since the actual methods are costly and a major drawback is the large amounts of sludge generated when applying traditional techniques. Adsorption is a physiochemical wastewater treatment process, which is gaining prominence as a means of producing high quality effluents, which are low in metal ion concentrations. The development of inexpensive adsorbents for the treatment of wastewater is an important area in environmental sciences. In this work we describe some of the physical and chemical phenomena that take place in the polymerization of methacrylates when gamma radiation is used. We explain how polymeric material characterization equipment are used for obtaining information regarding the material properties. Then we explain how the new polymeric material obtained can be use for the wastewater treatment. Finally, a comparison in the heavy metal removal from aqueous solution with other sorbent materials is presented. (Author)

  5. Gamma radiation for the decontamination of soil containing dioxin

    International Nuclear Information System (INIS)

    Chhor, M.P.; Wethington, J.A. Jr.

    1986-01-01

    Dioxin-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contamination poses an environmental danger. Different methods for the cleanup of contaminated sites have been proposed. The G value for dioxin dispersed in soil wetted with ethanol is much greater than G values for typical aromatic hydrocarbons. Doses > 6.24 x 10 23 eV/kg lead to decreasing rates of destruction of TCDD, and doses > 24.97 x 10 23 eV/kg are not very effective. Gamma irradiation of contaminated soil apparently will not result in large (powers of 10) decontamination factor. The concept of using gamma radiation for the degradation of TCDD in contaminated soil is about as good or as bad as other methods being tested

  6. Gamma radiation induced and natural variability for nodulation in legumes

    Energy Technology Data Exchange (ETDEWEB)

    Maherchandani, N; Rana, O P.S. [Haryana Agricultural Univ., Hissar (India). Dept. of Genetics

    1977-09-01

    Gamma radiation induced variability for nodulation was studied in 112 M4 mutant lines of cowpea variety C-15-2. Ten lines superior in nodulation to the original variety have been identified. Natural variability for nodulation and plant growth was investigated in 75 genotypes of chickpea. A number of genotype were found to be superior to cultivated variety C-235 for nodulation characters. Nodule characters were found to be related to dry matter accumulation but not to grain yield. Another experiment on 10 varieties of chick pea conducted under aseptic conditions revealed that host genotypes showed specificity for Rhizobial strains and different Rhizobial strains differed in their effectiveness on different host genotypes. H 551 and H 355 were the most responsive varieties.

  7. Degradation studies on plasticised PVC films submitted to gamma radiation

    International Nuclear Information System (INIS)

    Vinhas, Gloria Maria; Souto-Maior, Rosa Maria; Lapa, Camila Maria; Almeida, Yeda Medeiros Bastos de

    2003-01-01

    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 among 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 plasticised films the one which presented the larger degradation index due to chain scission was the DEHP plasticised PVC. (author)

  8. Monitoring system for gamma radiation of porch type for vehicles

    International Nuclear Information System (INIS)

    Vazquez C, R.M.; Molina, G.; Gutierrez O, E.; Ramirez J, F.J.; Garcia H, J.M.; Aguilar B, M.A.; Vilchis P, A.E.; Cruz E, P.; Torres B, M.A.

    2005-01-01

    A monitoring system of gamma radiation for vehicles of the porch type developed in the ININ is presented. This system carries out the radiological monitoring of the vehicles in continuous form, detecting the bottom radiological environment and the presence of nuclear material transported in vehicles. The vehicles are monitored while they pass to low speed through the porch. The detectors are plastic scintillators of great volume that allow high sensibility detection. The arrangement of detecting is interconnected in net, and the data are concentrated on a personal computer whose interface man-machine can be accessed from any personal computer connected to Internet. The system monitoring in real time with options of sampling times from 50 ms configurable up to 500 ms. (Author)

  9. Thermoluminescence of sulfated zircon exposed to gamma radiation

    International Nuclear Information System (INIS)

    Rubio, E.; Castano, V.M.; Mendoza A, E.; Gonzalez, P.R.

    2003-01-01

    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 2 SO 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)

  10. Gamma radiation processing dosimetry with commercial silicon diodes

    International Nuclear Information System (INIS)

    Ferreira, Danilo Cardenuto

    2009-01-01

    This work envisages the development of dosimeters based on Si diodes for gamma radiation dosimetry from 1 Gy up to 100 Gy. This dose range is frequently utilized in radiation processing of crystal modifications, polymers crosslinking and biological studies carried out in the Radiation Technology Center at IPEN-CNEN/SP. The dosimeter was constructed by a commercial SFH00206 (Siemens) Si diode, operating in a photovoltaic mode, whose electrical characteristics are suitable for this application. The current generated in the device by the Cobalt-60 gamma radiation from the Irradiators types I and II was registered with a digital electrometer and stored during the exposure time. In all measurements, the current signals of the diode registered as a function of the exposure time were very stable. Furthermore, the device photocurrent was linearly dependent on the dose rate within a range of 6.1x10 -2 Gy/min up to 1.9x10 2 Gy/min. The calibration curves of the dosimeters, e.g., the average charge registered as a function of the absorbed dose were obtained by the integration of the current signals as a function of the exposure time. The results showed a linear response of the dosimeter with a correlation coefficient better than 0.998 for total absorbed dose up to 120 Gy. Finally, due to the small experimental errors 5 % it was also possible to measure the transit dose due to the movement of the Cobalto- 60 radioactive sources in irradiation facilities used in this work. (author)

  11. Gamma radiation influence on technological characteristics of wheat flour

    International Nuclear Information System (INIS)

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

    2012-01-01

    This study aimed at determining the influence of gamma radiation on technological characteristics of wheat (Triticum sativum) flour and physical properties of pan breads made with this flour. The bread formulation included wheat flour, water, milk, salt, sugar, yeast and butter. The α-amylase activity of wheat flour irradiated with 1, 3 and 9 kGy in a Gammacell 220 (AECL), one day, five days and one month after irradiation was evaluated. Deformation force, height and weight of breads prepared with the irradiated flour were also determined. The enzymatic activity increased—reduction of falling number time—as radiation dose increased, their values being 397 s (0 kGy), 388 s (1 kGy), 343 s (3 kGy) and 293 s (9 kGy) respectively, remaining almost constant over the period of one month. Pan breads prepared with irradiated wheat flour showed increased weight. Texture analysis showed that bread made of irradiated flour presented an increase in maximum deformation force. The results indicate that wheat flour ionizing radiation processing may confer increased enzymatic activity on bread making and depending on the irradiation dose, an increase in weight, height and deformation force parameters of pan breads made of it. - Highlights: ► We study the influence of gamma radiation on wheat flour and properties of breads. ► Falling number decreased with radiation remaining almost constant up to one month. ► Ionizing radiation may confer an increase in texture parameters, weight and height on the bread.

  12. Utilization of Gamma Radiation for Disinfecting Domestic Wastewater

    International Nuclear Information System (INIS)

    Aldehmani, K.; Abokhabta, S.; Rahil, E.; Elammari, M.; Aboudeeb, F.

    2004-01-01

    Wastewater treatment by Gamma radiation is an effective, economic and environmentally friendly as the water produced has the specification to be reused for watering trees, gardens, football fields and golf courses instead of using fresh water that can be saved for drinking purposes as we suffer a severe shortage of fresh water. Sewage water samples were brought from Elhadba Elkhadra wastewater treatment plant which is located in the City of Tripoli. Samples were taken from two places: the inlet of the plant and from the stream coming out from the biological treatment, they are taken in sterile plastic bottles to ensure that cross contamination does not take place. Samples were irradiated at Tajura Research Centre with different doses ranged between 0.5 and 2 kGy with a dose rate of 10 Gy/min. These samples were investigated chemically and microbiologically. A study was carried out on the effect of gamma radiation on pathogenic organisms, and the total suspended solids in the raw and treated samples. Results showed that the doses 2.0 kGy and 1.5 kGy were enough to terminate the total microbial count and Enterobacter ease respectively but only a dose of 1.0 kGy was needed to eliminate total coliform, fecal coliform and spore forming bacteria. There were also higher BOD, pH and E.C. values in raw sewage than the sewage that was subjected to biological treatment which gave a good indication for the efficiency of the biological treatment. (authors)

  13. 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)

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  15. Semiconductor scintillator detector for gamma radiation; Detector cintilador semicondutor para radiacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Laan, F.T.V. der; Borges, V.; Zabadal, J.R.S., E-mail: ftvdl@ufrgs.br, E-mail: borges@ufrgs.br, E-mail: jorge.zabadal@ufrgs.br [Universidade Federal do Rio Grande do Sul (GENUC/DEMEC/UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares. Departamento de Engenharia Mecanica

    2015-07-01

    Nowadays the devices employed to evaluate individual radiation exposition are based on dosimetric films and thermoluminescent crystals, whose measurements must be processed in specific transductors. Hence, these devices carry out indirect measurements. Although a new generation of detectors based on semiconductors which are employed in EPD's (Electronic Personal Dosemeters) being yet available, it high producing costs and large dimensions prevents the application in personal dosimetry. Recent research works reports the development of new detection devices based on photovoltaic PIN diodes, which were successfully employed for detecting and monitoring exposition to X rays. In this work, we step forward by coupling a 2mm anthracene scintillator NE1, which converts the high energy radiation in visible light, generating a Strong signal which allows dispensing the use of photomultipliers. A low gain high performance amplifier and a digital acquisition device are employed to measure instantaneous and cumulative doses for energies ranging from X rays to Gamma radiation up to 2 MeV. One of the most important features of the PIN diode relies in the fact that it can be employed as a detector for ionization radiation, since it requires a small energy amount for releasing electrons. Since the photodiode does not amplify the corresponding photon current, it must be coupled to a low gain amplifier. Therefore, the new sensor works as a scintillator coupled with a photodiode PIN. Preliminary experiments are being performed with this sensor, showing good results for a wide range of energy spectrum. (author)

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

    Science.gov (United States)

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

    2016-10-14

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

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

    International Nuclear Information System (INIS)

    Fernandez Gonzalez, J.; Martin Moreno, C.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

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

    1987-08-01

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

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

    International Nuclear Information System (INIS)

    Martin Moreno, C.; Fernandez Gonzalez, J.

    1983-01-01

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

  20. 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

  1. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Riou, M

    1949-02-21

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

  3. Field Deployable Gamma Radiation Detectors for DHS Use

    International Nuclear Information System (INIS)

    Sanjoy Mukhopadhyay

    2007-01-01

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

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

    International Nuclear Information System (INIS)

    Rossi, Paolo; Collibus, M. Ferri de; Florean, M.; Monti, C.; Mugnaini, G.; Neri, C.; Pillon, M.; Pollastrone, F.; Baccaro, S.; Piegari, A.; Damiani, C.; Dubus, G.

    2013-01-01

    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

  5. 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)

  6. Gamma radiation use on the aging of sugar cane spirit

    International Nuclear Information System (INIS)

    Walder, Julio M. M.; Spoto, Marta H. F.; Novaes, Fernando V.; Alcarde, Andre R.

    2002-01-01

    The objective of this work was to verify the influence of gamma radiation on the aging of sugarcane spirit. Samples of sugarcane spirit (cachaca ) were irradiated in a Gammabeam Cobalt-60 source with doses between 0 (control) and 300 Gy, with 50 Gy increasing. The irradiated samples were offered to 5 expert judges for sensorial tests using the comparison: irradiated versus control. The chemical volatile components of the irradiated spirit were determined using a gas chromatograph. Sensorial tests elected the dose of 150 Gy as the best for sugarcane spirit irradiation based on its flavour and bouquet. These sensorial characteristics were due to the chemical changes observed in esters, aldehydes and higher alcohol's concentrations. The samples irradiated with 250 and 300 Gy developed a bitter taste and an 'oxidized' flavour. A second experiment was carried out using single and twice-distilled sugarcane spirit, normal aged in oak barrels or not, or added with oak extract. Samples were irradiated with the dose of 150 Gy and scored by the same sensorial analysis methodology. All irradiated samples had their flavour improved. The irradiation of the non-maturated twice-distilled sugarcane spirit produced a flavour compared to spirits maturated during one year of normal aging. (author)

  7. UV- and gamma-radiation sensitive mutants of Arabidopsis thaliana

    International Nuclear Information System (INIS)

    Jiang, C.Z.; Yen, C.N.; Cronin, K.; Mitchell, D.; Britt, A.B.

    1997-01-01

    Arabidopsis seedlings repair UV-induced DNA damage via light-dependent and -independent pathways. The mechanism of the ''dark repair'' pathway is still unknown. To determine the number of genes required for dark repair and to investigate the substrate-specificity of this process we isolated mutants with enhanced sensitivity to UV radiation in the absence of photoreactivating light. Seven independently derived UV sensitive mutants were isolated from an EMS-mutagenized population. These fell into six complementation groups, two of which (UVR1 and UVH1) have previously been defined. Four of these mutants are defective in the dark repair of UV-induced pyrimidine [6-4] pyrimidinone dimers. These four mutant lines are sensitive to the growth-inhibitory effects of gamma radiation, suggesting that this repair pathway is also involved in the repair of some type of gamma-induced DNA damage product. The requirement for the coordinate action of several different gene products for effective repair of pyrimidine dimers, as well as the nonspecific nature of the repair activity, is consistent with nucleotide excision repair mechanisms previously described in Saccharomyces cerevisiae and nonplant higher eukaryotes and inconsistent with substrate-specific base excision repair mechanisms found in some bacteria, bacteriophage, and fungi. (author)

  8. 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.

  9. Corrosion of copper-based materials in gamma radiation

    International Nuclear Information System (INIS)

    Yunker, W.H.

    1986-06-01

    The corrosion behaviors of pure copper (CDA 101), 7% aluminum-copper bronze (CDA 613) and 30% nickel-copper (CDA 715) are being studied in a gamma radiation field of 1 x 10 5 R/h. These studies are in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) Project, by Lawrence Livermore National Laboratory (LLNL), of copper-based materials for possible use in container systems for the permanent geologic burial of nuclear waste. Weight loss, tear drop (stressed), and crevice specimens of the three materials were exposed to water vapor-air atmospheres at 95 0 C and 150 0 C and to liquid water at 95 0 C for periods of one, three, and six months. Longer exposures are in progress. Measurements include: changes in the chemical composition of the gas and water, specimen weight changes, oxide film weights, evidence of microcracking and crevice corrosion, and chemical composition of the oxide films by Auger electron spectroscopy and x-ray diffraction. Interim results show considerable pit and under-film corrosion of alloys CDA 613 and CDA 715. Uniform corrosion rates range from 0.012 mil/yr (0.30 μm/yr) to 0.22 mil/yr (5.6 μm/yr), based on specimen weight losses during six- and seven-month exposures. The time dependencies will be determined as more data become available

  10. Comparative study of Si diodes for gamma radiation dosimetry

    International Nuclear Information System (INIS)

    Pascoalino, Kelly Cristina da Silva

    2010-01-01

    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 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)

  11. Gamma radiation shielding materials improved with burning resistance

    International Nuclear Information System (INIS)

    Nakamura, Michio; Nakamura, Ken-ichi; Yukawa, Katsunori.

    1985-01-01

    Purpose: To obtain gamma irradiation shielding materials excellent in workability and resistant to burning by using a two component type room temperature vulcanizing silicon rubber composition as the base material. Method: Silicon rubber comprising a diorganopolysiloxane polymer, an alkyl silicate as a crosslinker and a suitable sulfurdizing catalyst, for example, a carboxylate is mixed with iron powder and silicon oxide powder as reinforcing and flame retardant material and applied with molding. The iron powder and the silica rocks powder have grain size of 50 - 150 μm and 1 - 70 μm and charged by the amount of from 55 to 60 % by weight and from 20 to 25 % by weight respectively. The fluidizing property is impaired if the particle size of the silica rocks powder is less than 1 μm and, while on the other hand, no desired specific gravity of a predetermined value can be obtained for the molding product if the filled amount of the iron powder is less than 55 %. The oxygen index of the molding product is 45 to improve the burning resistance. The materials are excellent in the air-tightness, gamma radiation shielding performance, elasticity and workability required for the cable penetrations in a nuclear power plant and they generate noxious gases neither. (Kawakami, Y.)

  12. 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.

  13. An experimental search for gamma radiation associated with thunderstorm activity

    International Nuclear Information System (INIS)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and > 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source

  14. Gamma radiation damage in pixelated detector based on carbon nanotubes

    International Nuclear Information System (INIS)

    Leyva, A.; Pinnera, I.; Leyva, D.; Abreu, Y.; Cruz, C. M.

    2013-01-01

    The aim of this paper is to evaluate the possible gamma radiation damage in high pixelated based on multi-walled carbon nanotubes detectors, grown on two different substrata, when it is operating in aggressive radiational environments. The radiation damage in displacements per atom (dpa) terms were calculated using the MCCM algorithm, which takes into account the McKinley-Feshbach approach with the Kinchin-Pease approximation for the damage function. Was observed that with increasing of the gamma energy the displacement total number grows monotonically reaching values of 0.39 displacements for a 10 MeV incident photon. The profiles of point defects distributions inside the carbon nanotube pixel linearly rise with depth, increasing its slope with photon energy. In the 0.1 MeV - 10 MeV studied energy interval the electron contribution to the total displacement number become higher than the positron ones, reaching this last one a maximum value of 12% for the 10 MeV incident photons. Differences between the calculation results for the two used different substrata were not observed. (Author)

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

    Science.gov (United States)

    de Jong, Peter; van Dijk, Willem

    2008-01-01

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

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

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  17. Internal conversion theory of gamma radiation in unfilled atomic shells

    International Nuclear Information System (INIS)

    Anderson, Eh.M.; Trusov, V.F.; Ehglajs, M.O.

    1980-01-01

    The internal conversion theory of gamma radiation in unfilled shells, when the atom is in a state with certain energy and momentum, is considered. A formula for the conversion coefficient between the atom and ion levels is obtained. This coefficient turns to be dependent on genealogic characteristics of the atom. It is discussed when the conversion coefficients are proportional to the numbers of filling subshells in the atom. Exact calculations have been carried out in the multiconfigurational approximation taking into account intermediate coupling for the d-shell of the Fe atom Single-electron radial wave functions have been calculated on the basis of the relativistic method of the Hartree-Fock-Dirak self-consistent field. Conversion coefficients on certain subshells as well as submatrix elements of the production operator are calculated. The electric coefficient of internal conversion (CIC) in the calculation for one electron does not depend on spin orientation. That is why the electric CIC from the level will not depend on filling number distribution by subshells. For magnetic CIC the dependence on the atom state is significant. Using multiconfiguration basis for calculating energy matrix and its succeeding diagonalization means the account of the intermediate coupling type, which takes place for the unfilled shells

  18. Use of HgI2 as gamma radiation detector

    International Nuclear Information System (INIS)

    Perez Morales, J.M.

    1993-01-01

    The Mercuric Iodide (HgI 2 ) has become one of the most promising room temperature semiconductors for the construction of X and gamma radiation detectors. The classical methods of spectroscopy have not demonstrated to achieve optimum results with HgI 2 detectors, mainly due to its particular carrier transport properties. Several alternative spectroscopic methods developed in the last ten years are presented and commented, selecting for a complete study one of them: 'The Partial Charge Collection Method'. The transport properties of the carriers generated by the radiation in the detector is specially important for understanding the spectroscopic behaviour of the HgI 2 detectors. For a rigorous characterization of this transport, it has been studied a digital technique for the analysis of the electric pulses produced by the radiation. Theoretically, it has been developed a Monte Carlo simulation of the radiation detection and the electronic signal treatment processes with these detectors in the energy range of 60-1300 KeV. These codes are applied to the study of the The Partial Charge Collection Method and its comparison with gaussian methods. Experimentally, this digital techniques is used for the study of the transport properties of thin HgI 2 detectors. Special interest is given to the contribution of the slower carriers, the holes, obtaining some consequent of spectroscopic interest. Finally, it is presented the results obtained with the first detectors grown and mounted in CIEMAT with own technology. (author). 129 ref

  19. Calibration of extremity dosemeters for gamma radiation fields

    International Nuclear Information System (INIS)

    Papadopulos, S.B.; Gregori, B.N.; Cruzate, J.A.

    1998-01-01

    In this work the kerma conversion factor are free in air, dose equivalent H(d,0 ) are presented, they were obtained theoretical and experimentally in finger and arm for gamma radiation fields. Extremity dosemeters put on surface finger and arm phantom have been irradiated. The finger phantom is a solid cylinder of PMMA polymethylmethacrylate 19 mm diameter and 300 mm height. The arm phantom is a 73 mm external diameter cylinder with PMMA walls 2.5 mm thick fill with water and 300 mm height. The radiation sources were cobalt 60 and cesium 137 from the Regional Center of Reference (CRR) of the National Commission of Atomic Energy (CNEA) and the Nuclear Regulatory Authority (ARN). Also in ISO wide X ray spectra W60, W110 and W200 have been irradiated. The results obtained show a good correlation with those published, they have a difference less than 7%. The factors will be applied to the evaluation of the equivalent doses coming from workers whose main irradiated zone is in the hands. (author)

  20. A new extremity dosemeter for beta and gamma radiation

    International Nuclear Information System (INIS)

    Heinzelmann, M.; Pagenkamper, M.

    1988-01-01

    An extremity dosemeter developed at the Juelich Nuclear Research Centre is very well suited for the precise and energy-independent measurement of the skin dose generated by beta or gamma radiation. This is also confirmed by the results of this intercomparison programme. The dosemeter contains three TLDs of LiF in Teflon mounted behind a window of 0.9 mg/cm 2 . The great advantage of this dosemeter is three TLD's enabling statements about the radiation quality. However, the dosemeter has two disadvantages The dosemeter is complicated to manufacture. A very thin plastic foil of 0.9 mg/cm 2 must be attached to a support. This work is difficult and time-consuming and cannot be automated. The window in front of the TLD is not sturdy enough and is occasionally destroyed when the dosemeter is being worn. These two disadvantages prevent this extremity dosemeter from being used more frequently. For this reason, work was begun on developing a new extremity dosemeter without these two disadvantages. The great advantage of the previous dosemeter of obtaining statements about the type of radiation with the aid of readings from three TLD's was to be retained. The improved extremity dosemeter has a more sturdy and thicker window with a similar response as the previous dosemeter with a thinner window

  1. Current trends in gamma radiation detection for radiological emergency response

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Guss, Paul; Maurer, Richard

    2011-09-01

    Passive and active detection of gamma rays from shielded radioactive materials, including special nuclear materials, is an important task for any radiological emergency response organization. This article reports on the current trends and status of gamma radiation detection objectives and measurement techniques as applied to nonproliferation and radiological emergencies. In recent years, since the establishment of the Domestic Nuclear Detection Office by the Department of Homeland Security, a tremendous amount of progress has been made in detection materials (scintillators, semiconductors), imaging techniques (Compton imaging, use of active masking and hybrid imaging), data acquisition systems with digital signal processing, field programmable gate arrays and embedded isotopic analysis software (viz. gamma detector response and analysis software [GADRAS]1), fast template matching, and data fusion (merging radiological data with geo-referenced maps, digital imagery to provide better situational awareness). In this stride to progress, a significant amount of inter-disciplinary research and development has taken place-techniques and spin-offs from medical science (such as x-ray radiography and tomography), materials engineering (systematic planned studies on scintillators to optimize several qualities of a good scintillator, nanoparticle applications, quantum dots, and photonic crystals, just to name a few). No trend analysis of radiation detection systems would be complete without mentioning the unprecedented strategic position taken by the National Nuclear Security Administration (NNSA) to deter, detect, and interdict illicit trafficking in nuclear and other radioactive materials across international borders and through the global maritime transportation-the so-called second line of defense.

  2. The effects of gamma radiation on scenedesmus quaricauda (Turp.) Breb

    International Nuclear Information System (INIS)

    Aranez, A.T.; Antonio, B.A.

    1983-01-01

    Scenedesmus quadricauda (Turp) Breb. were exposed to 0.5 kr, 3 kr, 6 kr, 9 kr, and 12 kr of gamma radiation. The low dose of 0.5 increased the growth rate of 3.12% during the first week and by 15.27% and 20.48% during the third and fourth weeks respectively. The stimulating effect was observed up to the fourth week only. The growth rate of the algae treated with 3 kr and that of the control were almost the same. Those treated with 6 kr, 9 kr and 12 kr gamma rays had growth rates of 86.33%, 70.70%, and 58.20% of control respectively during the first week after which their growth rates surpassed that of the control. Mutant cells twice the size of the normal ones, occurred as single cells, in coenobia of 2 cells, or in coenobia of 4 cells. These mutants have been successfully propagated. Coenobia with enlarged cells, with cells of abnormal shape, with cells of unequal sizes, and with unusual arrangement of cells were noted. There were also coenobia containing cells with kidney-shaped chloroplast. (Auth.)

  3. Study of the Gamma Radiation Effect on Tannins Samples

    International Nuclear Information System (INIS)

    Coto Hernandez, I.; Barroso Solares, S.; Martinez Luzardo, F.; Guzman Martinez, F.; Diaz Rizo, O.; Arado Lopez, J.O.; Santana Romero, J.L.; Baeza Fonte, A.; Rapado Paneque, M.; Garcia, F.

    2011-01-01

    Vegetable tannins are polyphenolic substances of different chemical mixtures, in correspondence with the characteristics of groups of polyphenols. Taking into consideration its composition, we can find different types of flavonoids, mainly in the so-called condensed tannins. In general, many applications have been explored, including the medical ones, due to their proven biological activity as antiviral, antibacterial and others characteristics derived from their reactions with metal ions and amino acids of the protein components. Therefore it is promising to examine the effects of gamma radiation on the structure of tannin, looking for the possible modification of its biological activity. To this end, samples of tannins are irradiated at different doses (maximum dose 35 kGy) with the use of a Cobalt-60 irradiator. Scanning Electron Microscopy (SEM) permitted to characterize the samples in morphology and composition. The changes were analyzed by using infrared spectroscopy Fourier transform (FT-IR) and High Resolution Liquid Chromatography (HPLC). At the end we discuss the implication of the results for a dosage range above 5 kGy. (Author)

  4. Indoor gamma radiation monitoring In Rawalpindi, Pakistan using TLD100

    International Nuclear Information System (INIS)

    Azam, Sana; Tufail, Muhammad; Sohail, Muhammad

    2008-01-01

    Full text: Natural radioactivity originates from extraterrestrial sources as well as from radioactive elements in earth's crust. The amount of radioactivity varies from place to place and with altitude. The aim of this study was to observe the indoor radiation level in Rawalpindi using TLD. For this purpose LiF:Mg:Ti (TLD100) chips were used. Chips were annealed and then calibrated using different sources and the calibration factor obtained by using Cs137 source was selected for dose estimation. Its value was 0.1403 μGy/TL response. Rawalpindi categorized into six regions. In each region, 5 cemented houses were selected and TLD 100 chips were placed at a distance of 0.5 m from ground the level. Chips were properly covered to protect them from ultraviolet light and moisture and were placed for three months. The average annual indoor dose rate for Rawalpindi was estimated to be 392.105μGy/yr and average dose to be 97.65μGy. Therefore, the effective dose for population of Rawalpindi from indoor gamma radiation was estimated to be 313.68μSv/yr using an indoor occupancy factor of 80%. (author)

  5. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A., E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com, E-mail: edvborges@yahoo.com, E-mail: luannaribeiro_lua@hotmail.com, E-mail: williams.wns@gmail.com, E-mail: ricardolclf@hotmail.com, E-mail: dewson.rocha@gmail.com, E-mail: s, E-mail: amdemelo@hotmail.com, E-mail: ricielleaugusto@gmail.com, E-mail: williams.wns@gmail.com, E-mail: ejfranca@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-11-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- {sup 60}Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

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

    International Nuclear Information System (INIS)

    Costa, H.; Boni-Mitake, M.; Souza, C.F.; Rogero, J.R.

    1999-01-01

    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 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 50 ) has been performed with both venoms, and irradiated venom showed to be less toxic than native one. (author)

  7. The use of gamma radiation in fluid flow measurements

    International Nuclear Information System (INIS)

    Tjugum, S.A.; Johansen, G.A.

    2000-01-01

    The use of gamma radiation in densitometry measurements is a well known principle. These measurements are often used in the oil industry where there is a need for finding the gas fraction of an oil/water/gas flow. The traditional gamma densitometer has a simple construction, where the measured parameter is the attenuation of a single gamma beam. High reliability, robustness and the clamp-on possibility are advantages that this type of instruments offer. More information can be found by studying how radiation is scattered and absorbed by matter. This information is needed in new multiphase flow meters. Problems to be solved in these instruments are how to find volume fractions of more than two components, how to handle different flow regimes in non-homogeneous flow, and how to do measurements independent of the salinity of the water. The new technology involves multi-energy, multi-mode and multi-sensor systems. At the University of Bergen the focus has been on how to do flow regime and salinity independent measurements by using multi-sensor and multi-mode systems. This paper gives an overview of the different techniques, and presents the latest results within this field of research at the University of Bergen. (author)

  8. Oxidative stress in mollusks Biomphalaria Glabrata exposed to gamma radiation

    International Nuclear Information System (INIS)

    Silva, Luanna R.S.; Augusto, Ricielle L.; Siqueira, Williams N.; Luna Filho, Ricardo L.C.; Pereira, Dewson R.; França, Elvis J.; Silva, Edvane B.; Melo, Ana M.M.A.

    2017-01-01

    Ionizing radiation can cause biological changes in different organisms such as mollusks from Biomphalaria glabrata species, in which alterations could be observed in the reproductive system of the specimens, prejudicing fertility and fecundity. As the changes may occur due to the lipid peroxidation caused by the action of free radicals on the gonads, the objective of this work was to evaluate the oxidative damage caused by the exposure of B. glabrata mollusks to different doses of gamma radiation. In addition, efforts were carried out to standardize a sensitive and low-cost technique for detecting negative effects caused by high doses of ionizing radiation. For this, each mollusk group (n = 10) was submitted to 0 (control), 10, 15, 20 and 25 Gy (Gammacell- "6"0Co, dose rate 3.532 kGy/h). The TBARS method was applied for the quantification of lipid peroxidation of the gonads of the mollusks after 24 and 48 h. ANOVA, followed by the mean comparison (Tukey) at the 5% of significance level, indicated high concentrations of TBARS in the gonads after 24 h. Otherwise, after 48 h, differences for TBARS concentrations were not significant at the 95% confidence level, determining that the action of free radicals from ionizing radiation on cell membranes mainly occurred within 24 h after irradiation. (author)

  9. Effects of gamma radiation on fruit fly, Dacus zonatus (Saunders)

    International Nuclear Information System (INIS)

    Sutantawong, M.

    1990-01-01

    The effects of gamma radiation on egg, larval and pupal stages of fruit fly, Dacus zonatus (Saunders) were studied. The 24-hour-old eggs, 1-2, 1-4, 7-8-day-old larvae and 8-day-old pupae were irradiated at 10-600 Gy with a cobalt-60 source and maintained at 26+1 0 C, 60-80% RH. The results showed that the LD 50 for 24-hour-old eggs at 2 days after irradiation was 302 Gy. The dose of 600 Gy caused 100% mortality of eggs and larvae hatching from eggs irradiated at 100 Gy were unable to develop to pupae. The 1-2-day-old larvae irradiated at 150 Gy were unable to form pupae. The dose of 50 Gy prevented adult emergence from irradiated 1-2, 4-5, 7-8-day-old larvae. Probit analyses indicated that radiation dose at 58.35 Gy sterilized 99% D. zonatus (Saunders) male emerged from pupae. In addition, female emerged from pupae irradiated at 30 Gy was unable to lay eggs

  10. Influences of the GAMMA radiation on useful life of strawberry

    International Nuclear Information System (INIS)

    Bonilla B, Ligia M.; Sepulveda P, Claudia M.

    1993-01-01

    The present investigation was carried out with the purpose of prolonging the useful life of strawberry (bird variety) by means of gamma radiation, eliminating the causing microorganisms of the deterioration of the fruit partially: aerobic mesophyll, psicrotrophos, molds and yeasts, effect that was controlled by means of the recount of the same ones. In the same way, it was carried out a quantitative analysis of some parameters such organolitics as flavor, color and hardness, to observe the behavior of the strawberry with the different applied treatments. The irradiation process was made with a source of Co-60, provided by the INEA with an activity of 82 kilo curios. The used radiation doses were 0, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy, which were quantified by means of chemical dosimeter : Sulfate cupric ferrous-sulfate. Strawberries were storage under refrigeration with controlled conditions of temperature between 1 and 2 C and relative humidity of 85-90, and periodically, samples were removed for different analyses

  11. 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.

  12. Gamma radiation in the conservation Cucurbita moschata processed minimally

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Lucia C.A.S.; Franco, Suely S.H.; Arthur, Valter, E-mail: lcasilva@cena.usp.br, E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil). Laboratório de Radiobiologia e Ambiente; Harder, Márcia N.C., E-mail: marcia.harder@fatec.sp.gov.br [Faculdade de Tecnologia de Piracicaba (FATEC), Piracicaba, SP (Brazil). Dep. Roque Trevisan; Arthur, Paula B.; Pires, Juliana; Filho, Jorge C., E-mail: paula.arthur@hotmail.com, E-mail: gilmita@uol.com.br, E-mail: juliana.angelo@gmail.com [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    The objective of the work was to evaluate the effect of gamma radiation on (Cucurbita moschata) processed minimally. The zucchinis were acquired in of Horticulture Department of the ESALQ/ USP, Piracicaba, SP. Brazil, and taken to the laboratory of Food Irradiation of CENA/USP, where they were washed in running water, peeled and cut in cubes. The squash cubes were dipped in a solution of sodium hypochlorite 15ml/L for 4 minutes and kept in plastic box (polypropylene). They were irradiated with doses of: 0 (control), 1.0 and 2.0 kGy, in a source of Cobalt-60, type Gammacell-220 with a dose rate of 0.666 kGy/h, and stored in temperature of 5°C. After 1, 3 and 7 days of irradiation were realized analyses of: color (factors L, a, b), pH, Brix and acidity. By obtained results conclude that there is not statistics difference between the treatments processed by irradiation and the control. Therefore the dose of 2.0 kGy can be used to reduce the level of microbial load without affects the physical chemical characteristics of minimally processed zucchini. (author)

  13. 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)

  14. Terrestrial Gamma Radiation Dose Rate of West Sarawak

    Science.gov (United States)

    Izham, A.; Ramli, A. T.; Saridan Wan Hassan, W. M.; Idris, H. N.; Basri, N. A.

    2017-10-01

    A study of terrestrial gamma radiation (TGR) dose rate was conducted in west of Sarawak, covering Kuching, Samarahan, Serian, Sri Aman, and Betong divisions to construct a baseline TGR dose rate level data of the areas. The total area covered was 20,259.2 km2, where in-situ measurements of TGR dose rate were taken using NaI(Tl) scintillation detector Ludlum 19 micro R meter NaI(Tl) approximately 1 meter above ground level. Twenty-nine soil samples were taken across the 5 divisions covering 26 pairings of 9 geological formations and 7 soil types. A hyperpure Germanium detector was then used to find the samples' 238U, 232Th, and 40K radionuclides concentrations producing a correction factor Cf = 0.544. A total of239 measured data were corrected with Cf resulting in a mean Dm of 47 ± 1 nGy h-1, with a range between 5 nGy h-1 - 103 nGy h-1. A multiple regression analysis was conducted between geological means and soil types means against the corrected TGR dose rate Dm, generating Dg,s= 0.847Dg+ 0.637Ds- 22.313 prediction model with a normalized Beta equation of Dg,s= 0.605Dg+ 0.395Ds. The model has an 84.6% acceptance of Whitney- Mann test null hypothesis when tested against the corrected TGR dose rates.

  15. Gamma radiation in the control of insects in animal feed

    International Nuclear Information System (INIS)

    Arthur, Paula B.; Arthur, Valter; Silva, Lucia C.A.S.; Franco, Suely S.H.; Franco, Jose G.; Villavicencio, Anna Lucia; Harder, Marcia N.C.

    2015-01-01

    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)

  16. Gamma radiation in the conservation Cucurbita moschata processed minimally

    International Nuclear Information System (INIS)

    Silva, Lucia C.A.S.; Franco, Suely S.H.; Arthur, Valter

    2017-01-01

    The objective of the work was to evaluate the effect of gamma radiation on (Cucurbita moschata) processed minimally. The zucchinis were acquired in of Horticulture Department of the ESALQ/ USP, Piracicaba, SP. Brazil, and taken to the laboratory of Food Irradiation of CENA/USP, where they were washed in running water, peeled and cut in cubes. The squash cubes were dipped in a solution of sodium hypochlorite 15ml/L for 4 minutes and kept in plastic box (polypropylene). They were irradiated with doses of: 0 (control), 1.0 and 2.0 kGy, in a source of Cobalt-60, type Gammacell-220 with a dose rate of 0.666 kGy/h, and stored in temperature of 5°C. After 1, 3 and 7 days of irradiation were realized analyses of: color (factors L, a, b), pH, Brix and acidity. By obtained results conclude that there is not statistics difference between the treatments processed by irradiation and the control. Therefore the dose of 2.0 kGy can be used to reduce the level of microbial load without affects the physical chemical characteristics of minimally processed zucchini. (author)

  17. Removal of trihalomethane from chlorinated seawater using gamma radiation.

    Science.gov (United States)

    Rajamohan, R; Natesan, Usha; Venugopalan, V P; Rajesh, Puspalata; Rangarajan, S

    2015-12-01

    Chlorine addition as a biocide in seawater results in the formation of chlorination by-products such as trihalomethanes (THMs). Removal of THMs is of importance as they are potential mutagenic and carcinogenic agents. In this context, a study was conducted that used ionizing radiation to remove THMs from chlorinated (1, 3, and 5 mg/L) seawater by applying various dosages (0.4-5.0 kGy) of gamma radiation. Bromoform (BF) showed a faster rate of degradation as compared to other halocarbons such as bromodichloromethane (BDCM) and dibromochloromethane (DBCM). In chlorine-dosed seawater, total irradiation dose of 0.4 to 5 kGy caused percentage reduction in the range of 6.9 to 76.7%, 2.3 to 99.6%, and 45.7 to 98.3% for BDCM, DBCM, and BF, respectively. During the irradiation process, pH of the chlorinated seawater decreased with increase in the absorbed dose; however, no change in total organic carbon (TOC) was observed. The results show that gamma dose of 2.5 kGy was adequate for maximum degradation of THM; but for complete mineralization, higher dose would be required.

  18. Effects of gamma radiation on commercial operational amplifiers

    International Nuclear Information System (INIS)

    Claro, Luiz H.; Santos, Jose A. dos

    2009-01-01

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

  19. Shelf life of ground beef patties treated by gamma radiation.

    Science.gov (United States)

    Roberts, W T; Weese, J O

    1998-10-01

    The effects of irradiation on microbial populations in ground beef patties vacuum package and irradiated frozen at target doses of 0.0, 1.0, 3.0, 5.0, and 7.0 kGy were determined. Irradiated samples were stored at 4 or -18 degrees C for 42 days, and mesophilic aerobic plate counts (APCs) were periodically determined. Fresh ground beef (initial APC of 10(2) CFU/g) treated with 3.0, 5.0, and 7.0 kGy was acceptable ( 10(7) CFU/g) by day 14 and 21, respectively, whereas patties treated at 5.0 kGy did not spoil until 42 days. The nonirradiated control samples for both batches of ground beef spoiled within 7 days. Microbial counts in ground beef patties stored at -18 degrees C did not change over the 42-day period. Shelf life of ground beef patties stored at 4 degrees C may be extended with gamma radiation, especially at 5.0 and 7.0 kGy. Initial microbial load in ground beef samples was an important shelf life factor.

  20. 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.

  1. 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.

  2. High energy neutron radiography

    International Nuclear Information System (INIS)

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-01-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

  3. Effect of gamma radiation on electrical and optical properties of (TeO2)

    Indian Academy of Sciences (India)

    Employing dose dependence of the current, some real-time gamma radiation dosimeters have been prepared, which ... are on world over to investigate the influence of gamma radi- ... Employing thermal evaporation in a vacuum, thin films of.

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

    International Nuclear Information System (INIS)

    Jahn, W.; Piesch, E.

    1975-01-01

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

  5. Influence of gamma radiation on microbiological parameters of the ethanolic fermentation of sugar-cane must

    International Nuclear Information System (INIS)

    Alcarde, A.R.; Walder, J.M.M.; Horii, J.

    2003-01-01

    The influence of gamma radiation on reducing the population of some bacteria Bacillus and Lactobacillus that usually contaminate the sugar-cane must and its effects on acidity of the medium and viability of the yeast during fermentation were evaluated. The treatment with gamma radiation reduced the bacterial load of the sugar-cane must. Consequently, the volatile acidity produced during the fermentation of the must decreased and the viability of the yeast afterwards added increased

  6. Measurements of Small Exposures of Gamma Radiation with CaSO{sub 4}:Mn Radiothermoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Bjaerngard, Bengt

    1963-08-15

    A system for measurements of small exposures of gamma radiation using CaSO{sub 4}:Mn thermoluminescence has been developed. The construction and performance of a read-out apparatus is described as well as the construction and characteristics of a simple dosimeter. The reproducibility of the method at various exposures is estimated. 20 {mu}R of 1 MeV gamma radiation can be measured with a reproducibility within {+-} 50 % (standard deviation)

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

    International Nuclear Information System (INIS)

    Ahmed, M.S.H.

    1981-01-01

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

  8. Detection of the strange bodies on the conveyor belt using gamma radiation technique

    International Nuclear Information System (INIS)

    Barna, A.; Ochiana, G.; Oncescu, M.

    1990-01-01

    The aim of this paper is to present a method for the computation of the activity of a gamma radiation source used in a radiometric assembly designed to detect the strange bodies (iron, stone or wood-made granules) within the textile material on the conveyor belt. The mathematical modelling method based on the Monte Carlo procedure has been used, with different values of the errors of types I and II; the investigation method is the transmission of gamma radiations. (Author)

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-15

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

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

    International Nuclear Information System (INIS)

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

    2017-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  13. High energy hadron scattering

    International Nuclear Information System (INIS)

    Johnson, R.C.

    1980-01-01

    High energy and small momentum transfer 2 'yields' 2 hadronic scattering processes are described in the physical framework of particle exchange. Particle production in high energy collisions is considered with emphasis on the features of inclusive reactions though with some remarks on exclusive processes. (U.K.)

  14. The high energy galaxy

    International Nuclear Information System (INIS)

    Cesarsky, C.J.

    1986-08-01

    The galaxy is host to a wide variety of high energy events. I review here recent results on large scale galactic phenomena: cosmic-ray origin and confinement, the connexion to ultra high energy gamma-ray emission from X-ray binaries, gamma ray and synchrotron emission in interstellar space, galactic soft and hard X-ray emission

  15. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1986-03-01

    The luminosity and energy requirements are considered for both proton colliders and electron-positron colliders. Some of the basic design equations for high energy linear electron colliders are summarized, as well as design constraints. A few examples are given of parameters for very high energy machines. 4 refs., 6 figs

  16. Bacteriological evaluation of fresh chicken sausage submitted to gamma radiation

    International Nuclear Information System (INIS)

    Borges, Alexandre

    2002-01-01

    Many developed countries have established a goal of self-sufficiency in food production, while many other obtain their principal foreign exchange through food exports. For these reasons, it is essential to eliminate losses in food products. It is no less important to prevent or combat food-transmitted diseases, principally across poultry and poultry derivatives, which play a major role in certain infections and is the focus of national public health goals in order to increase the international commerce. In tropical countries, perishable products represent the largest markets. The population lives in a constant battle against the deterioration of these foods. Such loss is enormous where the climate favors the proliferation of agents of decomposition and acceleration of putrification. Increasing the useful life of these perishable products will provide producers the option of commercializing them in low harvest season, thus achieving higher prices, and providing sensible growth to the agro-industrial market. Treatment of perishables with gamma radiation presently constitutes one of the most modern, safe, and efficient methods for increasing food preservation. The irradiation of foods can offer various special advantages such as: kill or sterilize pathogenic organisms in food, improving their quality and duration, reducing the level of toxics, slow or stop the aging of roots and tubers, disinfect products of animal and vegetable origin thus slowing their decomposition, increasing their shelf-life, and prolonging their conservation refrigeration. The practice of irradiating foods for the treatment of microorganisms has begun to gain momentum in Brazil, where roughly 25% of all food produced annually is lost to disease and insects activity, increased by lack of adequate storage treatments. Various countries have already adopted the method that, when practiced properly by qualified professionals, does not cause side effects other than the extension of useful life. In

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  18. Process for hardening an alkyd resin composition using ionizing radiation. [electron beams, gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, T; Murata, K; Maruyama, T

    1969-11-27

    In an alkyd resin composition having free hydroxide radicals and containing a conjugated unsaturated fatty acid and/or oil as a component thereof, a process for hardening an alkyd resin composition comprises the steps of dissolving into a vinyl monomer, the product obtained by the semi-esterification reaction of said hydroxide radicals with acid anhydrides having polymerizable radicals and hardening by ionizing radiation to provide a coating with a high degree of cross-linking, with favorable properties such as toughness, hardness, chemical resistance and resistance to weather and with the feasibility of being applied as the ground and finish coat on metals, wood, paper, outdoor construction or the like. Any kind of ionization radiation, particularly accelerated electron beams, ..gamma.. radiation can be used at 50/sup 0/C to -5/sup 0/C for a few seconds or minutes, permitting continuous operation. In one example, 384 parts of phthalic anhydride, 115 parts of pentaerythritol, 233 parts of trimethylol ethane, 288 parts of tung fatty acid and 49 parts of para-tertiary-butyl benzoic acid are mixed and heated with 60 parts of xylene to an acid value of 12. In addition, 271 parts of maleic anhydride and 0.6 parts of hydroquinone are admixed with the content and heated to terminate the reaction. 100 parts of a 50% stylene solution of this alkyd resin are mixed with 1 part of a 60% toluene solution of cobalt naphthenate, and then coated on a glass plate and irradiated with high energy electron beams of 300 kV with a dose of 5 Mrad for 1 sec.

  19. Development of aerial gamma radiation survey system, 1

    International Nuclear Information System (INIS)

    Tsutsumi, Masahiro; Saito, Komei; Sakamoto, Ryuichi; Nagaoka, Toshi; Moriuchi, Shigeru

    1986-05-01

    JAERI has started to develop an aerial gamma radiation survey system by a helicopter in 1980. The development of measuring instruments, the experiments in the field of natural and artificial radiation sources, and the imaginary emergency survey at a real site, were executed. This report describes mainly about the hardware and software of this system. The system consists of gamma-ray measuring instruments with NaI(Tl) scintillation detectors, microwave positioning instruments, and a data processing system for postflight data. A foreign-made geological survey system is improved on for radiation measurements. For covering the wide radiation range, detectors of various shapes and sizes are prepared, from a large volume detector, DET-1024 - four 4'' x 4'' x 16'' crystals assembly - to a 2'' diameter x 2'' NaI(Tl) crystal. Radiation and position data are recorded on a magnetic tape, and computer-processed afterwards. Moreover, scene below flight courses and internal communication are recorded on video tape with the information of clock and position superimposed. In consequence of field experiments carried out five times, basic radiation data for evaluating airborne acquired data are accumulated, and flight survey procedures are established. As more practical use, a system has been produced more compactly and functionally. Exposure rates (> 1 mR/h), energy distribution spectra, and energy window counts are obtained for radiation data. Using the Spectrum-Dose Conversion Method, the accurate exposure rates are directly calculated from pulse height spectra. Numerical tables of G(E) function converting pulse height spectra into exposures are shown in this report. As regards the analysis of survey data, process codes have been completed with either large-computer or mini-computer. (author)

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

    International Nuclear Information System (INIS)

    Santillo, Amanda G.; Rogovschi, Vladimir D.; Araujo, Michel M.; Silva, Priscila V.; Silveira, Ana P.M.; Villavicencio, Anna L.C.H.

    2009-01-01

    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 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)

  1. 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)

  2. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Elbarbary, Ahmed M.; Ghobashy, Mohamed Mohamady [Atomic Energy Authority, Nasr City (Egypt). National Center for Radiation Research and Technology (NCRTT)

    2017-07-01

    Superabsorbent hydrogels (PVP/CMC) based on polyvinylpyrrolidone (PVP)/carboxylmethyl cellulose (CMC) of different copolymer compositions were prepared by gamma radiation. Factors affecting the gel content (%) and the swelling ratio (g/g) of hydrogel such as irradiation dose as well as copolymer composition were investigated. With increasing the CMC content in PVP/CMC hydrogels, increases the swelling and improves the water retention capability. The high swelling ratio was observed at copolymer composition of PVP/CMC (60/40). Fast swelling of the hydrogels was obtained after 20 min. The effect of different fertilizers and buffers of different pH's on equilibrium swelling of hydrogels was investigated. Fertilizers such as urea, monopotassium-phosphate (MPK), and nitrogen-phosphate-potassium (NPK) were loaded onto the hydrogel to supply nitrogen, potassium and phosphorous nutrients. PVP/CMC hydrogels retained 28-36% after 72 h and slow retention was noticed up to 9 days. The swelling of hydrogel in fertilizer solutions is lower than that in water. The hydrogels showed adsorption desorption of fertilizers which governs by slow release property. The release rate of urea is much higher 10 times than that of phosphate. After 3 days, urea released 60%, while phosphate released 10-12%. The applicability of PVP/CMC hydrogels in the agricultural fields shows greater growth effect on zea maize plants. The growth of zea maize plant in soil mixed with PVP/CMC hydrogels loaded fertilizers is greater than untreated soil. The slow release fertilize, the high swelling and the slow water retention behaviors of PVP/CMC hydrogels encourage their use as safer release systems for fertilizers and as soil conditioner in agricultural applications.

  3. External gamma radiation survey for oil wellheads in Saudi Arabia

    International Nuclear Information System (INIS)

    Nassar, Rafat M.; Mously, Khalid A.; Cowie, Michael I.

    2008-01-01

    Naturally occurring radioactive material (NORM) is known to be associated with oil and gas extraction. As part of a comprehensive NORM management strategy, Saudi Aramco needed to determine the extent of NORM contamination associated with their oil and gas operations. As part of that strategy, this study focused on external gamma survey of oil producing wellheads at various locations. The study aimed to: 1-) Identify wellheads with elevated gamma radiation dose rate; 2-) Specify the exact locations of the high dose rates on the wellheads; 3-) Identify the radioisotopes responsible for the high dose rates; and 4-) Propose worker protection requirements during maintenance. The majority (∼92%) of the surveyed wellheads showed no enhanced gamma dose-rate above background level. From the remaining ∼8%, only a few wellheads showed dose rates between 1,000-3,700 n Sv/h. The study revealed that NORM contamination tends to accumulate at turns of the pipes, around pipe diameter changes, the joints, the back of valves, and at the base of the wellhead. Also, for a given location, NORM build up on the interior of pipework varies over time and continues to migrate down stream until it reaches the Gas and Oil Separation Plants (GOSP). There NORM is expected to accumulate and reside in the form of sludge. Gamma spectroscopy analysis revealed that 226 Ra and its progeny are responsible for the high radiation dose rates detected. It was concluded that NORM will not pose significant radiation hazards to workers as long as the tubing and piping are not opened. (author)

  4. 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)

  5. Effects of gamma radiation on Sporothrix schenckii yeast cells

    International Nuclear Information System (INIS)

    Lacerda, Camila M. de Sousa; Martins, Estefania Mara Nascimento; Andrade, Antero S.R.; Resende, Maria Aparecida de

    2009-01-01

    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 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)

  6. Controlled release fertilizers using superabsorbent hydrogel prepared by gamma radiation

    International Nuclear Information System (INIS)

    Elbarbary, Ahmed M.; Ghobashy, Mohamed Mohamady

    2017-01-01

    Superabsorbent hydrogels (PVP/CMC) based on polyvinylpyrrolidone (PVP)/carboxylmethyl cellulose (CMC) of different copolymer compositions were prepared by gamma radiation. Factors affecting the gel content (%) and the swelling ratio (g/g) of hydrogel such as irradiation dose as well as copolymer composition were investigated. With increasing the CMC content in PVP/CMC hydrogels, increases the swelling and improves the water retention capability. The high swelling ratio was observed at copolymer composition of PVP/CMC (60/40). Fast swelling of the hydrogels was obtained after 20 min. The effect of different fertilizers and buffers of different pH's on equilibrium swelling of hydrogels was investigated. Fertilizers such as urea, monopotassium-phosphate (MPK), and nitrogen-phosphate-potassium (NPK) were loaded onto the hydrogel to supply nitrogen, potassium and phosphorous nutrients. PVP/CMC hydrogels retained 28-36% after 72 h and slow retention was noticed up to 9 days. The swelling of hydrogel in fertilizer solutions is lower than that in water. The hydrogels showed adsorption desorption of fertilizers which governs by slow release property. The release rate of urea is much higher 10 times than that of phosphate. After 3 days, urea released 60%, while phosphate released 10-12%. The applicability of PVP/CMC hydrogels in the agricultural fields shows greater growth effect on zea maize plants. The growth of zea maize plant in soil mixed with PVP/CMC hydrogels loaded fertilizers is greater than untreated soil. The slow release fertilize, the high swelling and the slow water retention behaviors of PVP/CMC hydrogels encourage their use as safer release systems for fertilizers and as soil conditioner in agricultural applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    Banjanac, R.; Maletić, D.; Joković, D., E-mail: yokovic@ipb.ac.rs; 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/(m{sup 2}s·2π·srad) in the ground level laboratory, and to about 5000 photons/(m{sup 2}s·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. - Highlights: • We studied the low-energy part of continuous background spectra of germanium detectors. • The study was performed at the ground level and at the shallow underground sites. • The instrumental spectrum is due to radiations of the similar continuous spectrum. • The low-energy radiation is of both terrestrial and cosmic-ray origin. • In our study, we find that this radiation is of predominantly terrestrial origin.

  8. Effects of gamma radiation on melon read-to-eat

    International Nuclear Information System (INIS)

    Pires, Juliana A.; Polizel, Francine Fernanda; Harder, Marcia N.C.; Silva, Lucia C.A.S.; Arthur, Paula B.; Arthur, Valter

    2013-01-01

    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 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)

  9. Curcumin Attenuates Gamma Radiation Induced Intestinal Damage in Rats

    International Nuclear Information System (INIS)

    EI-Tahawy, N.A.

    2009-01-01

    Small Intestine exhibits numerous morphological and functional alterations during radiation exposure. Oxidative stress, a factor implicated in the intestinal injury may contribute towards some of these alterations. The present work was designed to evaluate the efficacy of curcumin, a yellow pigment of turmeric on y-radiation-induced oxidative damage in the small intestine by measuring alterations in the level of thiobarbituric acid reactive substances (TSARS), serotonin metabolism, catecholamine levels, and monoamine oxidase (MAO) activity in parallel to changes in the architecture of intestinal tissues. In addition, monoamine level, MAO activity and TSARS level were determined in the serum. Curcumin was supplemented orally via gavages, to rats at a dose of (45 mg/ Kg body wt/ day) for 2 weeks pre-irradiation and the last supplementation was 30 min pre exposure to 6.5 Gy gamma radiations (applied as one shot dose). Animals were sacrificed on the 7th day after irradiation. The results demonstrated that, whole body exposure of rats to ionizing radiation has induced oxidative damage in small intestine obvious by significant increases of TSARS content, MAO activity and 5-hydroxy indole acetic acid (5-HIAA) and by significant decreases of serotonin (5-HT), dopamine (DA), norepinephrine (NE) and epinephrine (EPI) levels. In parallel histopathological studies of the small intestine of irradiated rats through light microscopic showed significant decrease in the number of villi, villus height, mixed sub mucosa layer with more fibres and fibroblasts. Intestinal damage was in parallel to significant alterations of serum MAO activity, TBARS, 5-HT, DA, NE and EPI levels. Administration of curcumin before irradiation has significantly improved the levels of monoamines in small intestine and serum of irradiated rats, which was associated with significant amelioration in MAO activity and TBARS contents

  10. Networked gamma radiation detection system for tactical deployment

    Science.gov (United States)

    Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Smith, Ethan; Guss, Paul; Mitchell, Stephen

    2015-08-01

    A networked gamma radiation detection system with directional sensitivity and energy spectral data acquisition capability is being developed by the National Security Technologies, LLC, Remote Sensing Laboratory to support the close and intense tactical engagement of law enforcement who carry out counterterrorism missions. In the proposed design, three clusters of 2″ × 4″ × 16″ sodium iodide crystals (4 each) with digiBASE-E (for list mode data collection) would be placed on the passenger side of a minivan. To enhance localization and facilitate rapid identification of isotopes, advanced smart real-time localization and radioisotope identification algorithms like WAVRAD (wavelet-assisted variance reduction for anomaly detection) and NSCRAD (nuisance-rejection spectral comparison ratio anomaly detection) will be incorporated. We will test a collection of algorithms and analysis that centers on the problem of radiation detection with a distributed sensor network. We will study the basic characteristics of a radiation sensor network and focus on the trade-offs between false positive alarm rates, true positive alarm rates, and time to detect multiple radiation sources in a large area. Empirical and simulation analyses of critical system parameters, such as number of sensors, sensor placement, and sensor response functions, will be examined. This networked system will provide an integrated radiation detection architecture and framework with (i) a large nationally recognized search database equivalent that would help generate a common operational picture in a major radiological crisis; (ii) a robust reach back connectivity for search data to be evaluated by home teams; and, finally, (iii) a possibility of integrating search data from multi-agency responders.

  11. Mediate gamma radiation effects on some packaged food items

    International Nuclear Information System (INIS)

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

    2012-01-01

    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 60 Co 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. - Highlights: ► We applied gamma radiation on several kinds of packaged food items. ► Microbiological and sensory analyses were performed 2 and 8 months after irradiation. ► All ready-to-eat food items assayed were approved for microbial and sensory characteristics. ► Most ready-to-eat meals like sausages and chicken with legumes were also acceptable. ► Dehydrated bacon potatoes or pea soups were considered not acceptable.

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

    Science.gov (United States)

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

    2017-02-01

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

  13. High energy astrophysics

    International Nuclear Information System (INIS)

    Engel, A.R.

    1979-01-01

    High energy astrophysical research carried out at the Blackett Laboratory, Imperial College, London is reviewed. Work considered includes cosmic ray particle detection, x-ray astronomy, gamma-ray astronomy, gamma and x-ray bursts. (U.K.)

  14. High energy positron imaging

    International Nuclear Information System (INIS)

    Chen Shengzu

    2003-01-01

    The technique of High Energy Positron Imaging (HEPI) is the new development and extension of Positron Emission Tomography (PET). It consists of High Energy Collimation Imaging (HECI), Dual Head Coincidence Detection Imaging (DHCDI) and Positron Emission Tomography (PET). We describe the history of the development and the basic principle of the imaging methods of HEPI in details in this paper. Finally, the new technique of the imaging fusion, which combined the anatomical image and the functional image together are also introduced briefly

  15. Studies on Decontamination of Cosmetic Creams by Gamma Radiation

    International Nuclear Information System (INIS)

    Taher, D.A.

    2011-01-01

    In the present study, 50 cosmetic cream samples were purchased from the market in Egypt. Cream samples were found to be contaminated with bacteria and fungi in the range of 1.0 x10 5 to 1.0 x 10 8 and 1.3 x 10 3 to 2.1 x 10 6 respectively. The contaminating organisms were gram positive cocci, gram positive rods, gram negative cocci, gram negative rods, gram negative cocci, Aspergillus species and penicillium species. The effect of consumer handling and time on the microbial levels of the tested cream samples which showed, in the present investigations, no microbial contamination were used. The results reveal that the level of contamination was found to increase with time and during use. The contamination were identified as gram positive rods, gram positive cocci. Aspergillus species and Penicillium species. Samples were subjected to gamma radiation, bacterial sublethal dose levels ranged between 1.5 and 20 kGy, 5 and 7 kGy, 3 and 5 kGy, while the fungal sublethal dose levels ranged between 3 and 5 kGy, 3 and 5 kGy also 3 and 5 kGy for foundation creams, foundation moisturizing and moisturizing creams, respectively. Bacteria survived sublethal dose levels were identified as Staphylococcus haemolyticus, Micrococcus sp. Bacillus brevis, Staphylococcus hominis-novo, Bacillus spharicus, Bacillus-pantothenticus and Bacillus Alvei in foundation cream. While, Acenatobacter baumann / haem, Bacillus sphaericus and Bacillus pumilus are the bacteria that survived the sublethal dose levels in foundation-moisturizing cream. Bacillus pantothenticus, Staphylococcus haemolyticus and Micrococcus. sp. were recorded in moisturizing cream samples. The surviving fungi were identified as Aspergillus niger, Aspergillus fumigatus in foundation cream, and Aspergillus niger, Aspergillus tamari and Penicillium chrysogenum in foundation-moisturizing cream, while the fungi surviving is Aspergillus niger in moisturizing cream. For foundation cream, the sterilizing doses were calculated to be (6

  16. Gamma radiation effect on allergen protein of laying hen eggs

    International Nuclear Information System (INIS)

    Harder, Marcia Nalesso Costa

    2009-01-01

    The egg is the most complete natural food; it has all the necessary nutrients such as vitamins, aminoacids and essential minerals to maintain a life. However, although, has several proteins that promote allergies in considerable part of the world population. To determine allergenic food proteins, one of the most used tests is the immunoassays such as ELISA (enzyme linked immunosorbent assay), where the antibody recognizes the antigen and this connection is showed by an enzymatic system, in other words, optical density. The aim of this study was to determine the polyclonal antibody efficiency, produced in laboratory, to identify the presence the ovo mucoid antigen in treated eggs by gamma irradiation for its inactivation. To evaluate the treatments, polyclonal antibody was produced in four New Zealand female rabbits, at 45 days old, immunized with bio conjugated ovo mucoid. Was used Freund Complete Adjuvant at first immunization and PBS Buffer at four subsequently immunizations every fifteen days, plus a booster 48 hours before the blood retreated. The blood serum was tittered by PTA ELISA (Plate trapped antigen). All procedures were approved by Institute of Animal Science and Pastures (IZ)'s Committee of Ethical and Animal Experimentation and preceded according to European Norms for ethical and animal welfare. It was used, in nature, commercial laying eggs, from the Genetic Department of Agricultural University Luiz de Queiroz ESALQ/USP. So the samples were submitted to the gamma radiation coming from a source of 60 Co, type Multipurpose at the Energetically Researches and Nuclear Institute (IPEN), under a dose rate of 19.4 and 31.8Gy/hour, in the doses: 0 (control); 10KGy; 20KGy and 30KGy, in all rates. By the ELISA s test we can find the egg allergen ovo mucoid and the radiation treatment do not showed considerable changes. So we can concluded that the antibody produced is capable of identify the ovo mucoid allergenic protein and the gamma irradiation in such

  17. Effects of gamma radiation on raspberries: safety and quality issues.

    Science.gov (United States)

    Verde, S Cabo; Trigo, M J; Sousa, M B; Ferreira, A; Ramos, A C; Nunes, I; Junqueira, C; Melo, R; Santos, P M P; Botelho, M L

    2013-01-01

    There is an ever-increasing global demand from consumers for high-quality foods with major emphasis placed on quality and safety attributes. One of the main demands that consumers display is for minimally processed, high-nutrition/low-energy natural foods with no or minimal chemical preservatives. The nutritional value of raspberry fruit is widely recognized. In particular, red raspberries are known to demonstrate a strong antioxidant capacity that might prove beneficial to human health by preventing free radical-induced oxidative stress. However, food products that are consumed raw, are increasingly being recognized as important vehicles for transmission of human pathogens. Food irradiation is one of the few technologies that address both food quality and safety by virtue of its ability to control spoilage and foodborne pathogenic microorganisms without significantly affecting sensory or other organoleptic attributes of the food. Food irradiation is well established as a physical, nonthermal treatment (cold pasteurization) that processes foods at or nearly at ambient temperature in the final packaging, reducing the possibility of cross contamination until the food is actually used by the consumer. The aim of this study was to evaluate effects of gamma radiation on raspberries in order to assess consequences of irradiation. Freshly packed raspberries (Rubus idaeus L.) were irradiated in a (60)Co source at several doses (0.5, 1, or 1.5 kGy). Bioburden, total phenolic content, antioxidant activity, physicochemical properties such as texture, color, pH, soluble solids content, and acidity, and sensorial parameters were assessed before and after irradiation and during storage time up to 14 d at 4°C. Characterization of raspberries microbiota showed an average bioburden value of 10(4) colony-forming units (CFU)/g and a diverse microbial population predominantly composed of two morphological types (gram-negative, oxidase-negative rods, 35%, and filamentous fungi, 41

  18. Gamma radiation field extremity personal dosimeter. Calibration and implementation

    International Nuclear Information System (INIS)

    Papadopulos, S.B.; Gregori, B.N.; Cruzate, J.A.

    2000-01-01

    The purpose of this paper is to show the extremity dose equivalent-kerma conversion factors obtained theoretical and experimentally in arm and finger for normally incident gamma radiation. Extremity dosemeters, based on termoluminescent dosimeters (TLD) LiF 7 (TLD-700, Harshaw), have been irradiated on designed as finger and arm phantoms. The finger phantom is been characterised as a solid cylinder made of polymethylmethacrylate (PMMA) 19mm diameter and 300mm height. The arm phantom is a cylinder 73mm external diameter with PMMA walls 2.5mm thick filled with water and 300mm height. There were used several radiation sources like Co-60 and Cs-137 from the Regional Reference Dosimetry Centre (CRR) of the National Atomic Energy Commission (CNEA) and from the Nuclear Regulatory Authority (ARN) of Argentina. In the same way RX wide spectrum irradiations were made in the ISO-4037 qualities W60, W110 and W200. At the same time the conversion factors have been theoretically obtained. In order to achieve this, the finger and arm phantoms have been modelled and the photon and electron transport have been done with the Monte Carlo code MCNP-4B. There was a good agreement between the theoretical and experimental results, showing a difference less than 8%. Also the experimental results have been compared with the published data available giving a difference less than 7%. In this work is shown the performance of the extremity dosimeter usually used by the exposed workers of the ARN. It has got a similar energy response in the range of W110-Co-60 (not more than 7%) with respect to the experimental results obtained. The dose equivalent-kerma conversion factors are going to be used in the dose equivalent evaluation of workers mainly hands exposed. Related with the incident energy several applied recommendations have been made. An application is presented in nuclear medicine experiences. In the case of a thyroid treatment with 131 I, the external dose workers have been evaluated

  19. Effect of gamma-radiation on sugar cane spirit

    International Nuclear Information System (INIS)

    Souza, Maria Djiliah Camargo Alvarenga de

    2000-01-01

    Irradiation has appeared as an alternative technique in food preservation. Besides cold decontamination irradiation can increase the quality of the food through the improvement of technological properties. For alcoholic beverages ionizing radiation has been applied to wines, whiskeys and beers in countries such as Thailand and China. In those cases, the purpose of the technique was to accelerate aging, to improve the sensory characteristics and as sterilization treatment. The aim of this work was to study the effect of gamma radiation on the quality of sugar cane spirit by gas chromatography analysis of volatile compounds and sensory analysis. The sugar cane spirit newly distilled samples and commercial samples from different states (SP, CE and RJ) were irradiated either in glass or oak cask (Quercus alba sp) in a 60 Co Gammacell 220 at dose rate of 7.7 kGy/h and total doses of 0; 0.1; 2; 5 and 10 kGy. The analytical determination of esters, acetaldehyde and higher alcohols were performed in a gas chromatograph with flame ionization detector employing a Megabore CG-745 column. The alcoholic graduation was measured in a Gay-Lussac alcohometer and the pH was determined using an Analyser 300 pHmeter. The color change was measured by the absorbance at 420 nm in a Shimadzu UV 1601 spectrophotometer. The acceptance tests related to odor, taste, global impression and color were analyzed using Tukey average tests (p ≤0,05), ANOVA and histograms of panelists' scores frequency. A correlation between acetaldeyde, esters, higher alcohols levels and radiation dose was found in the sugar cane spirit newly distilled samples irradiated in oak cask and commercial samples. An increase in methanol concentration was verified, although remaining enough below the permissible limit accepted by the Brazilian Legislation. A decrease in the alcoholic graduation and pH in the irradiated samples was observed. A slight discoloration in the irradiated samples was verified. According to ANOVA

  20. Applications og gamma radiation to the forestry industry

    International Nuclear Information System (INIS)

    Sotomayor, Patricia

    1999-01-01

    together with some universities, resulting in the presentation of a R and D project to Fondef. Together with the Universidad Austral de Chile, phytosanitary applications for gamma radiation are being explored, such as, irradiation as a quarantine treatment for export timbers, which is in the R and D stage internationally. This work presents the state-of-the-art for these applications and a preliminary estimate of the economic feasibility of introducing the commercial production of wood-plastic compounds into Chile, including the installation of a commercial multipurpose gamma irradiation plant (AU)

  1. Design of gamma radiation equipment for studying a bubbling gas fluidized bed. Determination of a radial void fraction profile and bubble velocities in a 0.40 m column

    Energy Technology Data Exchange (ETDEWEB)

    Hoogeveen, M O [Technische Univ. Delft (Netherlands). Lab. voor Fysische Technologie

    1993-12-01

    In this work the possibility of the use of gamma radiation in investigating bubbles in a large three dimensional gas-fluidised bed was examined. A measuring system was designed based upon the absorption of gamma radiation. As high energy (>100 keV) gamma radiation penetrates deeply into matter, it can be used to scan through a gas-solid fluidised bed. The attenuation of a beam of mono-energetic photons is related to the amount of solid particles in the path of the beam. With the gamma absorption technique two parameters can be determined: The void fraction and the bubble velocity. With one narrow beam of gamma radiation a chordal void fraction can be measured in the homogeneous part of the bed. An optimalisation procedure for the void fraction determination led to the choice of Cs-137 as radiation source. This optimalisation procedure concerned minimizing of the standard deviation in the determined chordal void fraction as a function of the energy of gamma radiation. With two narrow parallel beams placed at a distance of 12 cm above each other a bubble velocity can be obtained. A cross-correlation between the two detector responses gives the time shift between the two responses. The system was designed for velocity measurements in the non-homogeneous part of the column. A simulation of the two beam measurement method for an air fluidized bed, 0.40 m in diameter, of polystyrene particles led to the choice of 100 mCi for the source strength for each of the two Cs-137 sources. For a 100 mCi Cs-137 source a shielding of 8 cm of lead is necessary to comply with safety regulations, concerning the use of radioactive materials. A source holder was designed, containing two encapsulated 100 mCi Cs-137 sources, in accordance with the regulations in the licence of the Delft University of Technology for the use of encapsulated sources. (orig.).

  2. Design of gamma radiation equipment for studying a bubbling gas fluidized bed. Determination of a radial void fraction profile and bubble velocities in a 0.40 m column

    International Nuclear Information System (INIS)

    Hoogeveen, M.O.

    1993-12-01

    In this work the possibility of the use of gamma radiation in investigating bubbles in a large three dimensional gas-fluidised bed was examined. A measuring system was designed based upon the absorption of gamma radiation. As high energy (>100 keV) gamma radiation penetrates deeply into matter, it can be used to scan through a gas-solid fluidised bed. The attenuation of a beam of mono-energetic photons is related to the amount of solid particles in the path of the beam. With the gamma absorption technique two parameters can be determined: The void fraction and the bubble velocity. With one narrow beam of gamma radiation a chordal void fraction can be measured in the homogeneous part of the bed. An optimalisation procedure for the void fraction determination led to the choice of Cs-137 as radiation source. This optimalisation procedure concerned minimizing of the standard deviation in the determined chordal void fraction as a function of the energy of gamma radiation. With two narrow parallel beams placed at a distance of 12 cm above each other a bubble velocity can be obtained. A cross-correlation between the two detector responses gives the time shift between the two responses. The system was designed for velocity measurements in the non-homogeneous part of the column. A simulation of the two beam measurement method for an air fluidized bed, 0.40 m in diameter, of polystyrene particles led to the choice of 100 mCi for the source strength for each of the two Cs-137 sources. For a 100 mCi Cs-137 source a shielding of 8 cm of lead is necessary to comply with safety regulations, concerning the use of radioactive materials. A source holder was designed, containing two encapsulated 100 mCi Cs-137 sources, in accordance with the regulations in the licence of the Delft University of Technology for the use of encapsulated sources. (orig.)

  3. Effects of gamma radiation and irradiated bean seeds on the dry bean weevil, Acanthoscelides obtectus say (Coleoptera: Bruchidae)

    International Nuclear Information System (INIS)

    Ignatowicz, S.; Brzostek, G.

    1988-01-01

    Low dosages of gamma radiation affected the development of immature stages of the bean weevil, Acanthoscelides obtectus Say. Radiosensitivity of the bean weevils decreased during their development, and adults seemed to be the most resistant stage for gamma radiation. There were no significant differences in mortality of immature stages of the pest during their development in beans treated with gamma radiation at dosages up to 1.06 kGy. Moreover, the females showed no ovipositional preference for untreated or irradiated beans

  4. Analysis of the gamma radiation effects in the composite of polyurethane derived from castor oil and natural fibers

    International Nuclear Information System (INIS)

    Kienen, Victor D.; Todt, Matheus L.; Capellari, Giovanni S.; Azevedo, Elaine C.; Neto, Salvador C.

    2015-01-01

    Composite of Polyurethane derived from castor oil and natural fibers are obtained from renewable raw material, low cost, and for not assaulting nature. This paper analyzes the effects of gamma radiation on composite polyurethane derived from castor with sawdust irradiated with gamma radiation of 25 kGy . It was held from 3 tips bending tests and micrograph by scanning electron microscopy. The results indicate that gamma radiation decreases the breakdown voltage and the micrograph of the fracture indicates brittle fracture occurred. (author)

  5. Effect of different doses of gamma radiation on shelf life of mango (Mangifera indica L.) fruits cv. Dashehari

    International Nuclear Information System (INIS)

    Baghel, B.S.; Gupta, N.; Tiwari, R.

    2005-01-01

    The mango fruits cv. Dashehari irradiated with different doses of gamma radiation for extending their shelf life and for stabilizing the market demand, revealed that irradiation of mango fruits with 200 Gy gamma radiation increase the post harvest life of 93.75 percent mango fruits by 12 days over control (46.66 percent) and proved superior to maintain the considerable physico-chemical composition of mango fruits as compared to control and higher doses of gamma radiation. (author)

  6. An experimental high energy physics program

    International Nuclear Information System (INIS)

    Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.

    1989-01-01

    The CLEO detector accumulated, (∼480,000 B-mesons) the world's largest sample of B decays, before being shutdown in May 1988 for the installation of CLEO II. This data sample came from 335 pb -1 accumulated at the Υ(4S). The Cornell Electron Storage Ring set new luminosity records, reaching 3.5 pb -1 in a single day. These data are being intensively analyzed and 21 papers were given at the Baltimore APS meeting. Among the highlights are: confirmation of B 0 bar B 0 mixing; discovery of the charm-strange baryon Ξ c 0 ; limits on b → u decay; and non-observation of B → p bar pπ(π), which was reported by the ARGUS collaboration. The construction of CLEO II is proceeding on schedule. The new 1.5 T superconducting magnet has passed all tests and all of the detector elements have been installed. This includes a 7800 CsI crystals electromagnetic shower calorimeter. The data from the Gamma Ray Astrophysics experiment show a significant signal for high energy gamma ray emission from Cygnus X-3 and also confirm the previously reported anomalous period from Her X-1. Meanwhile, the old 6 mirror telescope has been refitted with 26 high resolution mirrors and improved fast electronics. GRANDE, the next generation detector based on the water Cherenkov technique, has been formally proposed to HEPAP. The detector will search for neutrino emission in the southern hemisphere and gamma radiation in the northern hemisphere

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

    International Nuclear Information System (INIS)

    Kawano, T.

    1982-01-01

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

  8. High energy radiation detector

    International Nuclear Information System (INIS)

    Vosburgh, K.G.

    1975-01-01

    The high energy radiation detector described comprises a set of closely spaced wedge reflectors. Each wedge reflector is composed of three sides forming identical isoceles triangles with a common apex and an open base forming an equilateral triangle. The length of one side of the base is less than the thickness of the coat of material sensitive to high energy radiation. The wedge reflectors reflect the light photons spreading to the rear of the coat in such a way that each reflected track is parallel to the incident track of the light photon spreading rearwards. The angle of the three isosceles triangles with a common apex is between 85 and 95 deg. The first main surface of the coat of high energy radiation sensitive material is in contact with the projecting edges of the surface of the wedge reflectors of the reflecting element [fr

  9. High-energy detector

    Science.gov (United States)

    Bolotnikov, Aleksey E [South Setauket, NY; Camarda, Giuseppe [Farmingville, NY; Cui, Yonggang [Upton, NY; James, Ralph B [Ridge, NY

    2011-11-22

    The preferred embodiments are directed to a high-energy detector that is electrically shielded using an anode, a cathode, and a conducting shield to substantially reduce or eliminate electrically unshielded area. The anode and the cathode are disposed at opposite ends of the detector and the conducting shield substantially surrounds at least a portion of the longitudinal surface of the detector. The conducting shield extends longitudinally to the anode end of the detector and substantially surrounds at least a portion of the detector. Signals read from one or more of the anode, cathode, and conducting shield can be used to determine the number of electrons that are liberated as a result of high-energy particles impinge on the detector. A correction technique can be implemented to correct for liberated electron that become trapped to improve the energy resolution of the high-energy detectors disclosed herein.

  10. The Theory of High Energy Collision Processes - Final Report DOE/ER/40158-1

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tai, T.

    2011-09-15

    In 1984, DOE awarded Harvard University a new Grant DE-FG02-84ER40158 to continue their support of Tai Tsun Wu as Principal Investigator of research on the theory of high energy collision processes. This Grant was renewed and remained active continuously from June 1, 1984 through November 30, 2007. Topics of interest during the 23-year duration of this Grant include: the theory and phenomenology of collision and production processes at ever higher energies; helicity methods of QED and QCD; neutrino oscillations and masses; Yang-Mills gauge theory; Beamstrahlung; Fermi pseudopotentials; magnetic monopoles and dyons; cosmology; classical confinement; mass relations; Bose-Einstein condensation; and large-momentum-transfer scattering processes. This Final Report describes the research carried out on Grant DE-FG02-84ER40158 for the period June 1, 1984 through November 30, 2007. Two books resulted from this project and a total of 125 publications.

  11. Theoretical high energy physics

    International Nuclear Information System (INIS)

    Lee, T.D.

    1991-01-01

    This report discusses theoretical research in high energy physics at Columbia University. Some of the research topics discussed are: quantum chromodynamics with dynamical fermions; lattice gauge theory; scattering of neutrinos by photons; atomic physics constraints on the properties of ultralight-ultraweak gauge bosons; black holes; Chern- Simons physics; S-channel theory of superconductivity; charged boson system; gluon-gluon interactions; high energy scattering in the presence of instantons; anyon physics; causality constraints on primordial magnetic manopoles; charged black holes with scalar hair; properties of Chern-Aimona-Higgs solitons; and extended inflationary universe

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

    Directory of Open Access Journals (Sweden)

    DANIJELA R. SEKULIĆ

    2009-09-01

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

  13. Effect of gamma radiation on the titrable acidity and vitamin c content of citrus fruits

    Directory of Open Access Journals (Sweden)

    Iftekhar Ahmad

    2012-06-01

    Full Text Available The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora and Citrus assamensis (Ginger lime. Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased with increase of radiation does as well as storage time and this changes of vitamin C and titrable acidity content with gamma radiation and increasing storage period have found statistically significant.

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

    International Nuclear Information System (INIS)

    Arthur, Valter; Arthur, Paula Bergamin

    2001-01-01

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

  15. Gene conversion and reversion events in Saccharomyces cerevisiae. Model for study of gamma radiation damage

    International Nuclear Information System (INIS)

    Moreno, Damaris; Fuentes, Jorge L.; Prieto Miranda, Enrique F.; Sanchez Lamar, Angel; Baluja, Ligia

    2004-01-01

    Radiosensitivity and kinetics of induction of gene conversion and reversion events in Saccharomyces cerevisiae strain D7 to gamma radiation at dose ranges from 100 to 800 Gy and 50 to 300 Gy respectively were studied. A source of 60Co PX- -30 at a dose rate of 49,43 GY/min was utilized. The cell survival curve showed DL50 of 150 Gy. Cell death kinetics was linear and adjusted over 98 %. The induction of gene conversion events was significant in relation to control from 50 Gy on. However, gene reversion was significant only at 200 Gy. Generally speaking, gene conversion event frequencies were higher than those of reversion, which indicates that gamma radiation preferably induces recombinogenic events. Both the conversion and reversion events showed exponential dependence on gamma radiation dose. The relative benefits of this test for mutagenesis and anti-mutagenesis studies were debated in this paper

  16. Analysis of waste compounds of Gauzama Crinita and high density PET reinforced by gamma radiation

    International Nuclear Information System (INIS)

    Gago, Javier; Ramos, Victor; Hernandez, Yuri; Montoya, Eduardo; Lopez, Alcides; Universidad Nacional de Ingenieria, Lima; Acevedo, Moises

    2013-01-01

    The reinforcing effects of gamma radiation in a high density polyethylene and wood waste white Bolaina (Guazuma crinita) compounds from Pucallpa region are presented. Samples were mixed with maleic anhydride and extruded at a temperature between 170 and 200 °C, yielding small cylindrical pellets; were subsequently pressed through thermic process between 180 and 200 °C, in a time range between 15 to 20 minutes. The produced samples were exposed to gamma radiation between 50 and 300 kGy, and then subjected to mechanical testing of hardness and roughness. It was observed that the hardness and the roughness increases in direct proportion to the increase of the dose of gamma radiation, but the samples subjected to doses in the range of 100 to 150 kGy, had a slight inverse behavior. (authors).

  17. The First Step in Studying the Ability of Destroying the Antibiotics by Gamma Radiation

    International Nuclear Information System (INIS)

    Nguyen Mong Giao; Tran Hung Manh; Nguyen Thi Ai Thu; Nguyen Quoc Thai; Tran, Khac An; Tran, Van Hung

    2010-12-01

    This paper presents the research results of the possibility to destroy the antibiotics in the form of liquid by gamma radiation to break the molecular bond of antibiotics. The 60 Co gamma radiation with the doses of 4.7 kGy to 29.3 kGy was irradiated on chloramphehicol and flumequine solution to define the content of antibiotics by the high performance liquid chromotography method. After irradiating, concentration of antibiotics is reduced from 30.26% to 98.89%. Based on the results, we can draw the conclusion that, with appropriate doses, the gamma radiation can destroy antibiotics. This result can be used to destroy after-content of antibiotics in seafood products. (author)

  18. Effect of gamma radiation dose and sensitizer on the physical properties of irradiated natural rubber latex

    International Nuclear Information System (INIS)

    Komgrit, R.; Thawat, C.; B, Tripob; Wirach, T.

    2009-07-01

    Full text: The vulcanization of natural rubber latex can be induced by gamma radiation, which enhances cross-linking within the rubber matrix. The purpose of this research is to investigate the effect of gamma radiation dose and sensitizers on the physical properties of irradiated natural rubber. Three sensitizers n-butyl acrylate (n-B A), tetrachloroethylene (C 2 Cl 4 ) and trichloromethane (CHCl 3 ) were mixed with natural rubber latex before irradiation with gamma ray dose varied from 14 to 22 kGy. Results showed that the mixture of three sensitizers with specific ratios effectively induced the cross-linking of natural rubber latex. The cross-linking ratio and improved physical properties increased with increasing gamma dose. Therefore, the mixture ratios of n-B A, C 2 Cl 4 and CHCl 3 have shown to be a critical parameter in the vulcanization of natural rubber latex by gamma radiation

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-05-01

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

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

    International Nuclear Information System (INIS)

    Herron, V.J.

    1979-01-01

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

  1. Assessment of background gamma radiation levels around Tummalapalle uranium mining and processing facility, Andhra Pradesh

    International Nuclear Information System (INIS)

    Rana, B.K.; Dhumale, M.R.; Molla, Samim; Rao, K.B.; Jha, S.K.; Tripathi, R.M.; Sahu, S.K.

    2018-01-01

    Natural environmental radioactivity and the associated external exposure due to gamma radiation depend primarily on the geological and geographical conditions, and appear at different levels in the soil of each region in the world. The dose received by the population in a region comprises of (i) external gamma radiation dose due to cosmic rays and primordial radionuclides; (ii) inhalation dose due to radon, thoron and their progeny, and (iii) ingestion dose due to the intake of radionuclides through the consumption of food, milk, water, etc. In this study, background gamma radiation level around Tummalapalle uranium mining and processing site was estimated by using radiation survey meter and deploying environmental TLDs. The generated data can be served as baseline for this area for future comparison for prolonged operation of the plant, for the upcoming adjacent projects and during decommissioning phase of the mine, mill and tailings pond

  2. A national-wide survey of radon and gamma radiation levels in Australian homes

    International Nuclear Information System (INIS)

    Langaroo, M.K.; Wise, K.N.; Duggleby, J.K.; Kotler, L.H.

    1990-04-01

    A nation-wide survey of Australian homes has been conducted to determine the average annual doses to the Australian population from exposure to radon and gamma radiation. The exposure to radon was measured using solid state track detectors (SSTD) whilst the gamma radiation dose was concurrently determined using thermoluminescent dosimetry. Dosemeters were placed in approximately 3400 randomly distributed homes (representing about 1 in 1400 occupied dwellings) for twelve months. The measured annual average radon concentration in Australian homes is 12 Bq m -3 . Using appropriate conversion factors, the annual average effective dose equivalents to the Australian population were determined to be 0.6 mSv and 0.9 mSv for radon and gamma radiation respectively. 20 refs., 3 tabs., 7 figs

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

    Science.gov (United States)

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

    2017-04-01

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

  4. Theoretical high energy physics

    International Nuclear Information System (INIS)

    Lee, T.D.

    1992-01-01

    This progress report discusses research by Columbia University staff in high energy physics. Some of the topics discussed are as follows: lattice gauge theory; quantum chromodynamics; parity doublets; solitons; baryon number violation; black holes; magnetic monopoles; gluon plasma; Chern-Simons theory; and the inflationary universe

  5. High energy astrophysics

    International Nuclear Information System (INIS)

    Shklorsky, I.S.

    1979-01-01

    A selected list of articles of accessible recent review articles and conference reports, wherein up-to-date summaries of various topics in the field of high energy astrophysics can be found, is presented. A special report outlines work done in the Soviet Union in this area. (Auth.)

  6. High energy battery. Hochenergiebatterie

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, H.; Beyermann, G.; Bulling, M.

    1992-03-26

    In a high energy battery with a large number of individual cells in a housing with a cooling medium flowing through it, it is proposed that the cooling medium should be guided so that it only affects one or both sides of the cells thermally.

  7. High energy beam cooling

    International Nuclear Information System (INIS)

    Berger, H.; Herr, H.; Linnecar, T.; Millich, A.; Milss, F.; Rubbia, C.; Taylor, C.S.; Meer, S. van der; Zotter, B.

    1980-01-01

    The group concerned itself with the analysis of cooling systems whose purpose is to maintain the quality of the high energy beams in the SPS in spite of gas scattering, RF noise, magnet ripple and beam-beam interactions. Three types of systems were discussed. The status of these activities is discussed below. (orig.)

  8. High energy colliders

    International Nuclear Information System (INIS)

    Palmer, R.B.; Gallardo, J.C.

    1997-02-01

    The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e + e - , μ + μ - ) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

  9. High Energy Physics

    Science.gov (United States)

    Untitled Document [Argonne Logo] [DOE Logo] High Energy Physics Home Division ES&H Personnel Collider Physics Cosmic Frontier Cosmic Frontier Theory & Computing Detector R&D Electronic Design Mechanical Design Neutrino Physics Theoretical Physics Seminars HEP Division Seminar HEP Lunch Seminar HEP

  10. A study on the effect of low doses gamma radiation on mushroom spawn

    International Nuclear Information System (INIS)

    Ajlouni, Said

    1993-03-01

    Mushroom spawn (Hybrid-521) was irradiated at room temperature using low doses of gamma radiation (50-600 rad). The spawn was then planted at two stages; first, after 24 hours of irradiation, and second after storage for three weeks at refrigeration temperature. Results of this study showed that the applied doses of gamma radiation did not have any stimulatory effect on mushroom growth or productivity. It was also noticed that mushroom production rate decreased when irradiated spawn was stored for three weeks prior to planting, as compared with spawn planted 24 hours after irradiation. (author). 18 refs., 2 figs., 2 tabs

  11. Effect of gamma radiation on the titrable acidity and vitamin c content of citrus fruits

    OpenAIRE

    Iftekhar Ahmad

    2012-01-01

    The study was carried out to assess effect of gamma radiation on the acidity and vitamin C content of the Citrus macroptera (Satkora) and Citrus assamensis (Ginger lime). Irradiation with doses 0.5, 1.0, 2.0, 3.0 kGy were applied to assess the effect on the titrable acidity and vitamin C contents every one week interval for total five weeks. Both titrable acidity and vitamin C content of C. macroptera, and C. assamensis are sensitive to both gamma radiation and storage time; have decreased wi...

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

    International Nuclear Information System (INIS)

    Su Zongdi; Zhang Limin; Zhou Chunmei; Sun Zhengjun

    1994-01-01

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

  13. Growth, physiological, biochemical and productive changes in peas due to gamma radiation effect

    International Nuclear Information System (INIS)

    Stajkov, G.; Ivanov, K.; Antonov, M.

    1985-01-01

    Investigations concerning the mechanism of the stimulating effect of low doses of gamma radiation on peas were made in 1971-1983. Results showed that: a) gamma radiation with 1000 R enhanced the level and activity of indolyl auxines gibberellins and in the seeds, causing specific changes in catalase and peroxidase activity; b) the content of crude protein and essential aminoacids was raised; c) grain yield increased by 16% as compared to the control; d) the dose 1000 R proved to be the optimal one

  14. Influence of gamma radiation on antibodies fixation on polystyrene. Application to ELISA enzyme immunoassay

    International Nuclear Information System (INIS)

    Esterlin, S.

    1986-01-01

    This thesis is divided into two parts: the first part includes a description of the ELISA test, a comparative analysis of the main supports (polystyrene microtitration trays) used for this technique and an evaluation of gamma radiation effects on the quality of the supports. The study was carried out with the following antigens: Spiroplasma citri R8A2, a tymovirus and Tristeza virus. The second part dealt with the effects of gamma radiations on antibodies and antibody-support system (interaction immobilized immunoglobulins-plastic support) [fr

  15. Production of plastified wood with stronger static bending strength means of polymerization induced by gamma radiation

    International Nuclear Information System (INIS)

    Silva Filho, Elias

    1999-01-01

    The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

  16. Combination treatment of gamma radiation and paraben in controlling spoilage of poultry meat

    International Nuclear Information System (INIS)

    Shiralkar, N.D.; Rege, D.V.

    1977-01-01

    With a view of controlling spoilage, combination treatment of poultry meat with gamma radiation and a chemical preservative has been investigated. Raw poultry pieces of about 25 g. weight were dipped in 0.1% propyl-paraben solution for two hours and were given a 0.1 Mrad dose from 60 Co gamma radiation. It was found that paraben was not affected by irradiation. The flavour evaluation scores indicated the shelf-life of poultry meat was prolonged by a couple of days as compared to untreated controls in refrigerated storage. (M.G.B.)

  17. biostudy on vigna sinensis beetle, callosobruchus chinensis l.and its control by gamma radiation

    International Nuclear Information System (INIS)

    Hasan, A.I.A.

    2005-01-01

    the present study carried out to determine: 1.the effects of the separate and combined effect of bacillus thuringiensis and gamma radiation on some biological aspects of callosobruchus chinensis. 2. the weight loss in infected seeds and total population of the pest after store it for different on adult beetles to determine the proteins, lipids and carbohydrates contents. 4. some analysis in the cowpea vigna anguiculata seeds to investigate the nutritive value after different treatments with bacillus thuringiensis (b.t) and gamma radiation

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-07-01

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

  19. Study of mechanical behavior of PMMA in bending and after UV irradiation and gamma radiation

    International Nuclear Information System (INIS)

    Todt, M.L.; Kienen, V.D.; Azevedo, E.C.

    2014-01-01

    PMMA is a polymer that has density similar to water and refractive index alike to glass. It has been used in the substitution to roofing tiles and coverages, affording to be exposed to UV radiation and gamma radiation. This paper had the objective to study the effect in the flexural proprieties of the PMMA exposed to these types of radiations and the evaluation of the wettability through a contact angle measurer. The PMMA specimens have been submitted to 1500 h of UVA radiation, 1500 h of UVC radiation and to 25kGy of gamma radiation. The results show that the PMMA. (author)

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

    International Nuclear Information System (INIS)

    Garlick, D.R.

    1984-09-01

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

  1. Virtual photon impulse of bunch, beampipe response, coherent RF Beamstrahlung; and BEPC bunch length, BES jam, virtual acceleration

    International Nuclear Information System (INIS)

    Jing Shen

    1993-01-01

    A brief EEE view of signal QED is presented. The research has been concentrated on the virtual photon modes of ultra relativistic shock wave in a bunch-beampipe system, and real photon modes of Coherent RF Beamstrahlung CRFB. Physically, the virtual photons emitted by a bunch were treated as a travelling pseudo wave packet in a flight coaxial cavity constructed by bunch-wakefield core and beampipe. Mathematically, it is a boundary solution of shock wave excited by ultra relativistic impulse of bunch. The new modes of solution: VTA, VTEM, VTM, VLE are virtual photon packets and RTE, RTM, RTEM are real photon modes of CRFB. By these results the author measured and corrected BEPC bunch length from signals of : (1) TOF reference of BES, (2) BPM of BEPC, (3) Colliding CRFB of BEPC - BES coupling signal, as well as (4) the ordinary method of Synchrotron Radiation. All results of the measured bunch lengths are in accordance with the design length of BEPC, and were verified by the BES data of vertex reconstruction of hadron events. The author also found that CRFB is the unknown jam source of BES electronics. VLE virtual photons can accelerate particles

  2. High energy nuclear physics

    International Nuclear Information System (INIS)

    Meyer, J.

    1988-01-01

    The 1988 progress report of the High Energy Nuclear Physics laboratory (Polytechnic School, France), is presented. The Laboratory research program is focused on the fundamental physics of interactions, on the new techniques for the acceleration of charged particles and on the nuclei double beta decay. The experiments are performed on the following topics: the measurement of the π 0 inclusive production and the photons production in very high energy nuclei-nuclei interactions and the nucleon stability. Concerning the experiments under construction, a new detector for LEP, the study and simulation of the hadronic showers in a calorimeter and the H1 experiment (HERA), are described. The future research programs and the published papers are listed [fr

  3. High energy medical accelerators

    International Nuclear Information System (INIS)

    Mandrillon, P.

    1990-01-01

    The treatment of tumours with charged particles, ranging from protons to 'light ions' (carbon, oxygen, neon), has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. These high energy medical accelerators are presented in this paper. (author) 15 refs.; 14 figs.; 8 tabs

  4. Theoretical high energy physics

    International Nuclear Information System (INIS)

    Lee, T.D.

    1990-05-01

    This report discusses progress on theoretical high energy physics at Columbia University in New York City. Some of the topics covered are: Chern-Simons gauge field theories; dynamical fermion QCD calculations; lattice gauge theory; the standard model of weak and electromagnetic interactions; Boson-fermion model of cuprate superconductors; S-channel theory of superconductivity and axial anomaly and its relation to spin in the parton model

  5. High energy nuclear excitations

    International Nuclear Information System (INIS)

    Gogny, D.; Decharge, J.

    1983-09-01

    The main purpose of this talk is to see whether a simple description of the nuclear excitations permits one to characterize some of the high energy structures recently observed. The discussion is based on the linear response to different external fields calculated using the Random Phase Approximation. For those structure in heavy ion collisions at excitation energies above 50 MeV which cannot be explained with such a simple approach, we discuss a possible mechanism for this heavy ion scattering

  6. High energy dosimetry

    International Nuclear Information System (INIS)

    Ruhm, W.

    2010-01-01

    Full text: Currently, quantification of doses from high-energy radiation fields is a topical issue. This is so because high-energy neutrons play an important role for radiation exposure of air crew members and personnel outside the shielding of ion therapy facilities. In an effort to study air crew exposure from cosmic radiation in detail, two Bonner Sphere Spectrometers (BSSs) have recently been installed to measure secondary neutrons from cosmic radiation, one at the environmental research station 'Schneefernerhaus' at an altitude of 2650 m on the Zugspitze mountain, Germany, the other at the Koldewey station close to the North Pole on Spitsbergen. Based on the measured neutron fluence distributions and on fluence-to-dose conversion coefficients, mean ambient dose equivalent rate values of 75.0 ± 2.9 nSv/h and 8.7 ± 0.6 nSv/h were obtained for October 2008, respectively. Neutrons with energies above about 20 MeV contribute about 50% to dose, at 2650 m. Ambient dose equivalent rates measured by means of a standard rem counter and an extended rem counter at the Schneefernerhaus confirm this result. In order to study the response of state-of-the-art radiation instrumentation in such a high-energy radiation field, a benchmark exercise that included both measurements in and simulation of the stray neutron radiation field at the high-energy particle accelerator at GSI, Germany, were performed. This CONRAD (COordinated Network for RAdiation Dosimetry) project was funded by the European Commission, and the organizational framework was provided by the European Radiation Dosimetry Group, EURADOS. The Monte Carlo simulations of the radiation field and the experimental determination of the neutron spectra with various Bonner Sphere Spectrometers suggest the neutron fluence distributions to be very similar to those of secondary neutrons from cosmic radiation. The results of this intercomparison exercise in terms of ambient dose equivalent are also discussed

  7. Effect of the gamma radiation of cobalt 60 on the beta carotids present in the carrot

    International Nuclear Information System (INIS)

    Perez Lopez, Sergio Victor Hugo

    1997-01-01

    In the present work it was investigated the effect of the gamma radiation of cobalt 60 on the beta carotid's in the carrot (daucus carota), using for it three different radiation dose (100, 150 and 200 kilo-rad) and analyzing them by means of the liquid chromatography technique of high resolution (HPLC)

  8. Electron equilibrium for parallel plate ionization chambers in gamma radiation fields

    International Nuclear Information System (INIS)

    Caldas, L.; Albuquerque, M. da P.P.

    1989-08-01

    Parallel plate ionization chambers, designed and constructed for use in low energy X-radiation fields, were tested in gamma radiation beams ( 6 Co and 137 Cs) of two different Calibration Laboratories, in order to study the electron equilibrium occurrence and to verify the possibility of their use for the detection of the kind of radiation too. (author) [pt

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

    International Nuclear Information System (INIS)

    Albinsson, H.; Lindow, L.

    1970-06-01

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

  10. Study on the energy dependence of gamma radiation detectors for 137Cs and 60Co

    International Nuclear Information System (INIS)

    Nonato, Fernanda B.C.; Diniz, Raphael E.; Carvalho, Valdir S.; Vivolo, Vitor; Caldas, Linda V.E.

    2009-01-01

    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 ( 137 Cs and 60 Co). The results were considered satisfactory only for ionization chambers and for some Geiger-Mueller detectors

  11. Effect of gamma radiation on properties of a composite rocket propellant

    International Nuclear Information System (INIS)

    Dedgaonkar, V.G.; Pol, V.G.; Navle, P.B.; Ghorpade, V.G.; Wani, V.S.

    2000-01-01

    Gamma radiation was employed for modifying the properties of a composite rocket propellant prepared in a standard way. It was observed that when the same gamma dose was imparted to hydroxy terminated polybutadiene (HTPB) then converted into propellant, the enhancement in the properties was much larger than the irradiated propellant samples. (author)

  12. Hematologic status of mice submitted to sublethal total body irradiation with mixed neutron-gamma radiation

    International Nuclear Information System (INIS)

    Herodin, F.; Court, L.

    1989-01-01

    The hematologic status of mice exposed to sublethal whole body irradiation with mixed neutron-gamma radiation (mainly neutrons) is studied. A slight decrease of the blood cell count is still observed below 1 Gy. The recovery of bone marrow granulocyte-macrophage progenitors seems to require more time than after pure gamma irradiation [fr

  13. The effect of Low-dose Gamma Radiation on the Bio-chemical ...

    African Journals Online (AJOL)

    Low-dose gamma radiation has been applied to intravenous fluids to enhance the sterility assurance levels. This study was undertaken to determine the stability of gamma irradiated 2.5 % dextrose, 2.5 % dextrose in saline, Ringers lactate and Gastrointestinal replacement fluid at doses of 0, 2, 4, 6, 8, 10 and 20 kGy.

  14. An evaluation of the use of gamma radiation in sewage treatment

    International Nuclear Information System (INIS)

    Bonhote, P.A.; Clouston, J.G.; Ford, G.W.K.; Gregory, J.N.

    1974-12-01

    Literature evaluating the potential use of gamma radiation for the treatment of sewage is critically reviewed. It is concluded that irradiation treatment cannot contribute significantly to the improvement of conventional processes for sewage water recovery. Irradiation methods at present have no cost or technical advantage, and no proven biological advantage over known treatment systems. (author)

  15. Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

    International Nuclear Information System (INIS)

    Passos, B.F.T.

    1985-01-01

    The behaviour of coordinated compound obtained from the copper (II) and the L-(+)- alanine to gamma radiation was determined. A study of synthesis and characterization of this complex was made with elementary analysis, ultraviolet and visible electronic spectroscopy, infrared vibrational spectroscopy, proton magnetic resonance spectroscopy and thermo-gravimetric analysis. (C.G.C.)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  18. Biological changes in Musca domestica L., 1758 (Diptera:Muscidae), induced by gamma radiation (60 Co)

    International Nuclear Information System (INIS)

    Grecchi, M.A.

    1989-01-01

    This work was carried out in the Entomology Section of the Centre of Nuclear Energy in Agriculture (CENA), University of Sao Paulo, Piracicaba, Sao Paulo, Brazil. The objective of the present research work was to investigate some effects of gamma radiation on the various stages of M. domestica life cycle. (author)

  19. Gamma radiation effect on the anatomical structure of soybean (Glycine max. Merr)

    International Nuclear Information System (INIS)

    Bhikuningputra, W.

    1976-01-01

    Gamma radiation effects on soybean plant (Glycine max. Merr) have been studied by using radiation doses of 0, 20, 25, 30, and 35 Krad. Investigation is carried out after each treatment. It proves that each treatment causes different morphological changes on leaves, stems, roots, and fibres of the treated plants. (SMN)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1970-06-15

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

  1. Response of avocado genotypes to improvement through 60Co gamma radiation

    International Nuclear Information System (INIS)

    Cruz, E. De la; Rubi A, M.; Garcia A, J.M.

    1997-01-01

    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)

  2. ESR and microbiological studies on gamma radiation processed dehydrated onion powder

    International Nuclear Information System (INIS)

    Khedkar, K.C.; Kumbhare, M.N.; Sharma, G.; Lavale, D.S.; Kadam, R.M.; Bhide, M.K.; Sastry, M.D.

    2001-01-01

    Paper describes the potential of ESR technique for detection of free radicals produced in the irradiated onion powder. Experiments were carried out to evaluate the effect of light, moisture and time on the stability of free radicals produced by gamma radiation. Some microbiological studies were also carried out on unprocessed and radiation-processed product. (author)

  3. Some observations of the variations in natural gamma radiation due to rainfall

    International Nuclear Information System (INIS)

    Minato, S.

    1980-01-01

    Results of observations of variations in natural gamma-radiation flux densities due to rainfall are presented and discussed in relation to rate of rainfall. Variations of fluences with amounts of rainfall are also described. It is concluded that the frequency distribution of the ratio of the fluence to the amount of rainfall has a trend to be lognormal

  4. Antibody Level Upon Newcastle Disease Virus In Chicken After Exposure To GAMMA Radiation

    International Nuclear Information System (INIS)

    Pejakovic-Hlede, J.; Dotur, J.; Pasic, S.; Gottstein, Z.; Majer, M.; Vilic, M.

    2015-01-01

    The aim of this study was to investigate the effect of gamma radiation upon Newcastle disease virus antibody level after acute exposure with dose of 0.05 Gy and 0.8 Gy gamma radiation. The experiment was made on light chicken breeds irradiated with dose of 0.05 Gy and 0.8 Gy gamma radiation with dose rate of 0.0117 Gy/s on the first and on the third day after hatching. Chicken were vaccinated by nebulization on the first day after hatching. Antibody level upon Newcastle disease in blood serum of chicken was quantified by hemagglutination inhibition assay on 1th, 7th, 14th and 28th day after vaccination. Results demonstrate that antibody titre against Newcastle disease in blood serum of chicken irradiated with dose of 0.05 Gy and 0.8 Gy gamma radiation on the first and on the third day after hatching was not statistically significant. Therefore, these results suggest that irradiation of light chicken breeds on the first and third day after vaccination with dose of 0.05 Gy and 0.8 Gy does not change antibody titre upon Newcastle disease. (author).

  5. Obtention of zinc polymethacrylate via free radicals induced by gamma radiation

    International Nuclear Information System (INIS)

    Urena N, F.; Flores E, J.

    2000-01-01

    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, 60 Co, as initiator of the polymerization reaction. (Author)

  6. Effect of gamma-radiation on cercariae of Schistosoma incognitum and S. spindale

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskara Rao, T; Rao, B V; Hafeez, Md [College of Veterinary Sciences, Tirupati (India). Dept. of Parasitology

    1989-06-01

    In the present study an attempt has been made to study the effect of gamma radiation on cercariae of Schistosoma incognitum and S. spindale in mice at different dose levels of radiation, so as to note differences in their developmental patterns, compared with non-irradiated controls. (author). 10 refs.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  8. Geological influence on terrestrial gamma radiation dose rate in the Malaysian State of Johore

    International Nuclear Information System (INIS)

    Ramli, A.T.; Hussein, A.W.M.A.; Lee, M.H.

    2001-01-01

    Measurements of environmental terrestrial gamma radiation dose-rate (TGRD) have been made in Johore, Malaysia. The focus is on determining a relationship between geological type and TGRD levels. Data were compared using the one way analysis of variance (ANOVA), in some instances revealing significant differences between TGRD measurements and the underlying geological structure

  9. Principle and methods for measurement of snow water equivalent by detection of natural gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Endrestoel, G O [Institutt for Atomenergi, Kjeller (Norway)

    1979-01-01

    The underlying principles for snow cover determination by use of terrestrial gamma radiation are presented. Several of the methods that have been proposed to exploit the effect are discussed, and some of the more important error sources for the different methods are listed. In conclusion an estimate of the precision that can be obtained by these methods is given.

  10. Principle and methods for measurement of snow water equivalent by detection of natural gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Endrestol, G O

    1979-01-01

    The underlying principles for snow cover determination by use of terrestrial gamma radiation are presented. Several of the methods that have been proposed to exploit the effect are discussed, and some of the more important error sources for the different methods are listed. In conclusion estimates of the precision that can be obtained by these methods are given.

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  12. Cobalt-60 gamma radiation effects on degradation of pesticides used in stored rice and beans

    International Nuclear Information System (INIS)

    Groppo, Gerson A.

    1988-02-01

    The present work, carried out at CENA, an agriculture nuclear energy center - University of Sao Paulo - Brazil, investigates the Cobalt-60 gamma radiation effects on insecticides applied to stored rice and beans. The radiation dose applied - 200 Gy - to the stored rice and beans treated with insecticides was not sufficient to cause a noticeable chemical degradation through insect mortality. (author). 31 refs., 23 tabs

  13. Mutagenic effectiveness and efficiency of EMS, sodium azide and gamma radiation in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Barshile, J.D.; Apparao, B.J.

    2006-01-01

    Mutagenic effectiveness and efficiency of Ethyl Methane Sulphonate (EMS), Sodium Azide (SA) and gamma radiation on two cultivars of chickpea (Cicer arietinum L), Vijay and Vishwas were evaluated by the biological damages caused by them in M 1 generation and on the basis of frequency of chlorophyll mutations produced in the M 2 generation. All mutagenic treatments of EMS, SA and gamma radiation decreased germination, seedling height, plant survival and pollen fertility in both the cultivars. The extent of effect was dose dependent. LD 50 values of mutagen were found to be helpful for planning experimental mutagenesis in chickpea. Frequency of chlorophyll mutations in M 2 generation was less in Vijay as compared to Vishwas. Mutagenic effectiveness is inversely proportional to the increasing concentrations/doses of mutagens in both the cultivars, except for gamma radiation treatments in the cultivar Vishwas. All three mutagens (except EMS in the Vijay and gamma radiation in the cultivar Vishwas) exhibited gradual decrease in mutagenic efficiency, with an increase in their concentration/dose. (author)

  14. Modification of low density polyethylene, isostatic polypropylene and their blends by gamma radiation

    International Nuclear Information System (INIS)

    Santos Rosa, D. dos

    1991-01-01

    The effects of the gamma radiation (of a 60 Co source), over low density polyethylene, isostatic polypropylene and their blends of low density polyethylene / polypropylene were studied. The structures modifications were attended by infrared spectrometry (IV), differential scanning calorimeter (DSC), strain-strain measurement, density measurement and scanning electron microscope (SEM). (author)

  15. Isodose mapping of terrestrial gamma radiation dose rate of Selangor state, Kuala Lumpur and Putrajaya, Malaysia

    International Nuclear Information System (INIS)

    Sanusi, M.S.M.; Ramli, A.T.; Gabdo, H.T.; Garba, N.N.; Heryanshah, A.; Wagiran, H.; Said, M.N.

    2014-01-01

    A terrestrial gamma radiation survey for the state of Selangor, Kuala Lumpur and Putrajaya was conducted to obtain baseline data for environmental radiological health practices. Based on soil type, geological background and information from airborne survey maps, 95 survey points statistically representing the study area were determined. The measured doses varied according to geological background and soil types. They ranged from 17 nGy h −1 to 500 nGy h −1 . The mean terrestrial gamma dose rate in air above the ground was 182 ± 81 nGy h −1 . This is two times higher than the average dose rate of terrestrial gamma radiation in Malaysia which is 92 nGy h −1 (UNSCEAR 2000). An isodose map was produced to represent exposure rate from natural sources of terrestrial gamma radiation. - Highlights: • A methodology is presented to reduce terrestrial gamma dose rate field survey. • Geological background of acid intrusive of granitic type has the highest dose rates. • The mean dose rate is 2 times higher than the world average. • Isodose map of terrestrial gamma radiation for Selangor, Kuala Lumpur and Putrajaya was produced

  16. Synthesis, characterization and behaviour of trans-bis (argininate) copper (II) to gamma radiation

    International Nuclear Information System (INIS)

    Pereira, A.B.

    1984-01-01

    The synthesis, the characterization and the behaviour to gamma radiation of trans-bis (argininate) copper (II) are presented. The synthesis is made from copper sulfate, sodium hydroxide and hydrochloride of L (+) arginine, in aqueous medium, and the characterization by infrared spectroscopy, visible and ultraviolet spectroscopy and elementary analysis. (C.G.C.)

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  18. High energy radiation in cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-10-15

    Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

  19. High energy radiation in cancer treatment

    International Nuclear Information System (INIS)

    1959-01-01

    Certain basic recommendations on the use of supervoltage radiation and radioisotope teletherapy in the treatment of malignant growths have been made by an expert study group which met in Vienna in August this y ear. The group, convened jointly by the International Atomic Energy Agency and the World Health Organization, was composed of 20 radiotherapists and radiation physicists from 12 countries. High energy radiation, used in the treatment of malignant tumours, can be either in the form of gamma- or X-rays or in the form of beams of accelerated electrons. The source of radiation is kept at a certain distance from the patient. The study group was agreed on the value of supervoltage radiotherapy, including gamma-ray and high voltage x-ray therapy as well as electron beam therapy. The required gamma radiation can be obtained from large sources of radioactive materials like cobalt 60 or caesium 137, while electron beams are produced by high voltage accelerators. The experts considered the sources in four broad categories: large supervoltage units, intermediate units, small isotope units and units of electron beams or very high energy x-rays. Each group of source was described including its usage. The experts made it clear that while supervoltage radiation should be a part of an organized radiotherapy department, the radiation facilities at any particular establishment should not be of the supervoltage type alone. The high energy facilities could be fruitfully used only when there was a background of general radiotherapy. The group emphasized that supervoltage radiotherapy, in common with other forms of radiotherapy, should be conducted only by adequately trained and qualified personnel, including radiation physicists, and specified the training and qualifications required of such personnel. It was felt that specialized training was one of the main requirements at the present stage and the training programmes of IAEA and WHO should be utilized extensively for this

  20. Direct Effects Of Chronic Gamma Radiation On Musa Acuminata Var. Berangan, A Local Malaysia Banana Cultivar

    International Nuclear Information System (INIS)

    Maimum Tahir; Azhar Mohamad; Rozeita Laboh; Umikalsum Mohd Bahari

    2014-01-01

    Musa acuminata var. Berangan, is a popular variety of our local banana known as Pisang Berangan. The variety is a triploid banana, use mainly for dessert and has a great value for commodity fruit crops. However, production of PisangBerangan has been threatened by diseases such as Fusarium wilt, black sigatoka, Fusarium wilt, burrowing nematodes and viral diseases like Banana streak virus, Banana bunch top virus and Banana bract mosaic virus. The scenario becoming worst as Musa has a narrow genetic background for breeding and/or selection program. The banana breeding program of edible bananas is hampered by high sterility, and very limited amounts of seeds. Mutation induction via chronic gamma radiation is an alternative ways in creating more variants for selections towards a better quality and disease tolerance. A total number of 75 samples at nursery stage (1 month) were exposed to chronic gamma radiation in Gamma Greenhouse at Malaysian Nuclear Agency for 28 weeks. The samples were accordingly arranged with distance ranging from 1 m to 15 m from gamma source (Cesium-137). Plant height and new buds were used as measurement parameters in evaluating the direct effects of the chronic gamma radiation. Results showed effective dose of chronic gamma radiation in Pisang Berangan was 20 Gy. Number of new emerging sucker was ranging from 1-3 pieces with the highest at ring-4 and ring-5. Plant height was observed ranging from 22.1 to 110.5 cm. Effects of chronic radiation were observed after 3-4 months in the GGH. The samples revealed as striking leaves, short inter node and new emergence of suckers. The objective of this work is to get a dose response for chronic gamma radiation in Pisang Berangan. As for selection of potential mutant variants, new emerging suckers were tissue cultured in segregating chimeras and to get required numbers of samples for further field evaluation. (author)

  1. High energy ion implantation

    International Nuclear Information System (INIS)

    Ziegler, J.F.

    1985-01-01

    High energy ion implantation offers the oppertunity for unique structures in semiconductor processing. The unusual physical properties of such implantations are discussed as well as the special problems in masking and damage annealing. A review is made of proposed circuit structures which involve deep implantation. Examples are: deep buried bipolar collectors fabricated without epitaxy, barrier layers to reduce FET memory sensitivity to soft-fails, CMOS isolation well structures, MeV implantation for customization and correction of completed circuits, and graded reach-throughs to deep active device components. (orig.)

  2. Theoretical High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Norman H.; Weinberg, Erick J.

    2014-07-14

    we provide reports from each of the six faculty supported by the Department of Energy High Energy Physics Theory grant at Columbia University. Each is followed by a bibliography of the references cited. A complete list of all of the publications in the 12/1/2010-04/30/2014 period resulting from research supported by this grant is provided in the following section. The final section lists the Ph.D. dissertations based on research supported by the grant that were submitted during this period.

  3. High energy physics

    International Nuclear Information System (INIS)

    Fortney, L.R.; Goshaw, A.T.; Walker, W.D.

    1991-01-01

    This progress report presents a review of research done over the past five years by the Duke High Energy Physics Group. This research has been centered at Fermilab where we have had a continuing involvement with both the Tevatron collider and fixed-target programs. In 1988 we began extensive detector R ampersand D for the SSC through its Major Subsystem Program. Duke has been an active member of the Solenoidal Detector Collaboration (SDC) since its formation. These last five years has also been used to finish the analysis of data from a series of hybrid bubble chamber experiments which formed the core of Duke's research program in the early 1980's

  4. High energy cosmic rays

    CERN Document Server

    Stanev, Todor

    2010-01-01

    Offers an accessible text and reference (a cosmic-ray manual) for graduate students entering the field and high-energy astrophysicists will find this an accessible cosmic-ray manual Easy to read for the general astronomer, the first part describes the standard model of cosmic rays based on our understanding of modern particle physics. Presents the acceleration scenario in some detail in supernovae explosions as well as in the passage of cosmic rays through the Galaxy. Compares experimental data in the atmosphere as well as underground are compared with theoretical models

  5. Measurement and Calculation of Gamma Radiation from HWZPR Reactor

    International Nuclear Information System (INIS)

    Jalali, Majid

    2006-01-01

    HWZPR is a research reactor with natural uranium fuel, D 2 O moderator and graphite reflector with maximum power of 100 W. It is a suitable means for theoretical research and heavy water reactor experiments. Neutrons from the core participate in different nuclear reactions by interactions with fuel, moderator, graphite and the concrete around the reactor. The results of these interactions are the production of prompt gammas in the environment. Useful information is gained by the reactor gamma spectrum measurement from point of view of relative quantity and energy distribution of direct and scattered radiations. Reactor gamma ray spectrum has been gathered in different places around the reactor by HPGe detector. In analysis of these spectra, 1 H(n,γ) 2 H, 16 O(n,n'γ) 16 O, 2 H(n,γ) 3 H and 238 U(n,γ) 239 U reactions occurring in reactor moderator and fuel, are important. The measured spectrum has been primarily estimated by the MCNP code. There is agreement between the code and the experiments in some points. The scattered gamma rays from 27 Al (n,γ) 28 Al reaction in the reactor tank, are the most among the gammas scattered in the reactor environment. Also the dose calculations by MCNP code show that 72% of gamma dose belongs to the energy range 3-11 MeV from reactor gamma spectrum and the danger of exposure from the reactor high-energy photons is serious. (author)

  6. Theoretical high energy physics

    International Nuclear Information System (INIS)

    Lee, T.D.

    1993-01-01

    Brief reports are given on the work of several professors. The following areas are included: quantum chromodynamics calculations using numerical lattice gauge theory and a high-speed parallel computer; the ''spin wave'' description of bosonic particles moving on a lattice with same-site exclusion; a high-temperature expansion to 13th order for the O(4)-symmetric φ 4 model on a four-dimensional F 4 lattice; spin waves and lattice bosons; superconductivity of C 60 ; meson-meson interferometry in heavy-ion collisions; baryon number violation in the Standard Model in high-energy collisions; hard thermal loops in QCD; electromagnetic interactions of anyons; the relation between Bose-Einstein and BCS condensations; Euclidean wormholes with topology S 1 x S 2 x R; vacuum decay and symmetry breaking by radiative corrections; inflationary solutions to the cosmological horizon and flatness problems; and magnetically charged black holes

  7. High energy astrophysical techniques

    CERN Document Server

    Poggiani, Rosa

    2017-01-01

    This textbook presents ultraviolet and X-ray astronomy, gamma-ray astronomy, cosmic ray astronomy, neutrino astronomy, and gravitational wave astronomy as distinct research areas, focusing on the astrophysics targets and the requirements with respect to instrumentation and observation methods. The purpose of the book is to bridge the gap between the reference books and the specialized literature. For each type of astronomy, the discussion proceeds from the orders of magnitude for observable quantities. The physical principles of photon and particle detectors are then addressed, and the specific telescopes and combinations of detectors, presented. Finally the instruments and their limits are discussed with a view to assisting readers in the planning and execution of observations. Astronomical observations with high-energy photons and particles represent the newest additions to multimessenger astronomy and this book will be of value to all with an interest in the field.

  8. Prospects at high energies

    International Nuclear Information System (INIS)

    Quigg, C.

    1988-11-01

    I discuss some possibilities for neutrino experiments in the fixed-target environment of the SPS, Tevatron, and UNK, with their primary proton beams of 0.4, 0.9, and 3.0 TeV. The emphasis is on unfinished business: issues that have been recognized for some time, but not yet resolved. Then I turn to prospects for proton-proton colliders to explore the 1-TeV scale. I review the motivation for new physics in the neighborhood of 1 TeV and mention some discovery possibilities for high-energy, high-luminosity hadron colliders and the implications they would have for neutrino physics. I raise the possibility of the direct study of neutrino interactions in hadron colliders. I close with a report on the status of the SSC project. 38 refs., 17 figs

  9. High energy physics problems

    International Nuclear Information System (INIS)

    Arbuzov, B.A.

    1977-01-01

    Described are modern views on the particle structure and particle interactions at high energies. According to the latest data recieved, all particles can be classified in three groups: 1) strong interacting hadrons; 2) leptons, having no strong interactions; 3) photon. The particle structure is described in a quark model, and with the use of gluons. The elementary particle theory is based on the quantum field theory. The energy increase of interacting particles enables to check the main theory principles, such as conventions for causality, relativistic invariance and unitarity. Investigations of weak interactions are of great importance. The progress in this field is connected with unified gauge theories of weak and electromagnetic interactions. For weak interactions promissing are the experiments with colliding electron-proton rings. The new data, especially at higher energies, will lead to a further refinement of the nature of particles and their interactions

  10. Effect of gamma radiation on the growth of botryodiplodia theobromae and on rot development in banana fruits

    International Nuclear Information System (INIS)

    Mostafa, I.Y.; El-Ashmawi, A.M.; Fahim, M.M.; Kararah, M.A.

    1984-01-01

    Radiosensitivity of Botryodiplodia theobromae Pat. increased with the increase in doses of gamma radiation. Young cultures (7 days old) were less sensitive to radiation than old ones (48 days); lethal doses being 800 and 600 Krad respectively. Rot development was greatly reduced when inoculated banana fruits were exposed to 300 Krad. Disease development was checked for 10 days in inoculated fruits exposed to 400 Krad. The combined treatment of 200 p.p.m. T B Z and 100 or 200 Krad gamma radiation was more effective in reducing disease incidence than either treatments alone. No deleterious effects occurred in banana fruits that were irradiated with the low doses of gamma radiation

  11. FSU High Energy Physics

    Energy Technology Data Exchange (ETDEWEB)

    Prosper, Harrison B. [Florida State Univ., Tallahassee, FL (United States); Adams, Todd [Florida State Univ., Tallahassee, FL (United States); Askew, Andrew [Florida State Univ., Tallahassee, FL (United States); Berg, Bernd [Florida State Univ., Tallahassee, FL (United States); Blessing, Susan K. [Florida State Univ., Tallahassee, FL (United States); Okui, Takemichi [Florida State Univ., Tallahassee, FL (United States); Owens, Joseph F. [Florida State Univ., Tallahassee, FL (United States); Reina, Laura [Florida State Univ., Tallahassee, FL (United States); Wahl, Horst D. [Florida State Univ., Tallahassee, FL (United States)

    2014-12-01

    The High Energy Physics group at Florida State University (FSU), which was established in 1958, is engaged in the study of the fundamental constituents of matter and the laws by which they interact. The group comprises theoretical and experimental physicists, who sometimes collaborate on projects of mutual interest. The report highlights the main recent achievements of the group. Significant, recent, achievements of the group’s theoretical physicists include progress in making precise predictions in the theory of the Higgs boson and its associated processes, and in the theoretical understanding of mathematical quantities called parton distribution functions that are related to the structure of composite particles such as the proton. These functions are needed to compare data from particle collisions, such as the proton-proton collisions at the CERN Large Hadron Collider (LHC), with theoretical predictions. The report also describes the progress in providing analogous functions for heavy nuclei, which find application in neutrino physics. The report highlights progress in understanding quantum field theory on a lattice of points in space and time (an area of study called lattice field theory), the progress in constructing several theories of potential new physics that can be tested at the LHC, and interesting new ideas in the theory of the inflationary expansion of the very early universe. The focus of the experimental physicists is the Compact Muon Solenoid (CMS) experiment at CERN. The report, however, also includes results from the D0 experiment at Fermilab to which the group made numerous contributions over a period of many years. The experimental group is particularly interested in looking for new physics at the LHC that may provide the necessary insight to extend the standard model (SM) of particle physics. Indeed, the search for new physics is the primary task of contemporary particle physics, one motivated by the need to explain certain facts, such as the

  12. The influence of geology on terrestrial gamma radiation dose rate in Pahang state, Malaysia

    International Nuclear Information System (INIS)

    Gabdo, H.T.; Ramli, A.T.; Sanusi, M.S.; Garba, N.N.; Saleh, M.A.

    2015-01-01

    Terrestrial gamma radiation dose (TGRD) rate measurements have been made in Pahang state, Malaysia. Significant variations were found between TGRD measurements and the underlying geological formations. In some cases revealing significant elevations of TGRD. The acid-intrusive geological formation has the highest mean TGRD measurement of 367 nGy/h -1 . This is more than six times the world average value of 59 nGy/h -1 , while the quaternary geological formation has the lowest mean gamma radiation dose rate of 99 nGy h -1 . The annual effective dose equivalent outdoor to the population was 0.216 mSv. The lifetime equivalent dose and relative lifetime cancer risks for an individual living in Pahang state were 81 mSv and 4.7 x 10 -3 respectively. These values are more than two times the world average of 34 mSv and 1.95 x 10 -3 respectively. (author)

  13. Gamma radiation (Co60) effects on active substances and microbe burden of medicinal plants

    International Nuclear Information System (INIS)

    Dall'Agnol, L.

    2001-01-01

    In order to evaluate the effects of radioactivity on active vegetal substances, samples of Fennel (Foeniculum vulgare Miller., fructus), Guarana (Paulinia cupana, Kunth, semen), Gingko (gingko biloba, L., folium), and Kawa-Kawa (Piper methysticum G. Forst, rhizoma), were treated with scaling doses (0 to 25 KGy) of gamma radiation (Co 60 ). The 'blind test' methodology was used. The active substances from each sample were analysed by qualitative and quantitative methods after radiation. There were no significant differences seen between the control sample (0 KGy) and the irradiated samples. Microbe contamination was significantly reduced, about 10000 CFU/g, with the initial 5 KGy dose. It was concluded that gamma radiation can be used as an alternative procedure to reduce microbiologic contamination in medicinal plants. Before this procedure can be extended to other medicinal plants, more specific analytical methods are recommended to verify possible structural alterations in active vegetal molecules. (author)

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

    International Nuclear Information System (INIS)

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

    1992-01-01

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

  15. The analogy research study on gamma radiation dose rate of radioisotopes 131Ba and 131I

    International Nuclear Information System (INIS)

    Hu Youhua; Feng Guangwen

    2013-01-01

    Analogy is a inference method ,according some properties of a class of things to inferring the similar things should also have the similar properties. The analogy of same radionuclides is widely used in radioisotope logging environment impact assessment so far. This paper is to provide fFor future providing a theoretical calculation method and analogy method between different radionuclides in radioisotope logging environment impact assessment. In this paper, using the latest decay scheme, through theoretical modeling, the aim is the the establishment of 131 Ba and 131 I radioisotopes gamma radiation dose rate calculation method, and try to carry out analogy research on gamma radiation dose rate of different radioisotopes with the same activity. The results show that the analogy of different radionuclides is feasible, which provides the new method reference for carrying out such radiation environmental impact assessment in future. (authors)

  16. Chemical modification of high molecular weight polyethylene through gamma radiation for biomaterials applications

    International Nuclear Information System (INIS)

    Raposo, Matheus P.; Rocha, Marisa C.G.

    2015-01-01

    Ultra high molecular weight polyethylene has been used in the medical field due to its high mechanical properties compared to the other polymers. Its main application is in the development of orthopedic implants, which requires high resistance to abrasion. One of the most used methods is the introduction of crosslinks in the polymer through gamma irradiation. In order to prevent oxidation reactions, studies have been developed using tacoferol (vitamin E) as an antioxidant for the material. The ascorbic acid (vitamin C), however, has been appointed as a viable alternative for vitamin E. In this work, a high molecular weight polyethylene grade (HMWPE) and polyethylene samples formulated with vitamin C were submitted to gamma radiation. Thermodynamic-mechanical methods and gel content determinations were used to characterize the samples obtained. The sample containing 1% of vitamin C and irradiated with 50 KGy of gamma radiation presented the highest content of crosslinks. (author)

  17. Effect of gamma radiation on egg hatchability of bruchids developing in three pulses

    International Nuclear Information System (INIS)

    Nagrare, V.S.; Bhatia, Parvathy

    2000-01-01

    One day old adults of Callosobruchus chinensis (Linn.) and Callosobruchus maculatus (Fab.) irradiated at 5, 10, 15, 20, 25, 30, 35 Gy dose of gamma radiation were bred on three pulses. Percent egg hatchability was inversely related with gamma radiation dose in both the species on three pulses and it was comparatively low in C. maculatus (Fab.). The mean percent hatchability was 70.66, 68.94, 65.41 on green gram, chickpea and cowpea, respectively in C. chinensis (Linn.) while in C. maculatus (Fab.) it was 66.52, 64.12, 61.27 on green gram, cowpea, chickpea, respectively. Both bruchids tolerated in the radiation doses when bred on green gram whereas they were susceptible on cowpea and chickpea. (author)

  18. Recent results on the effect of gamma radiation on the durability and microstructure of DWPF glass

    International Nuclear Information System (INIS)

    Bibler, N.E.; Tosten, M.H.; Beam, D.C.

    1989-01-01

    The effect of gamma radiation on the durability and microstructure of a simulated nuclear waste glass from the Savannah River Site has been carefully investigated. Three large pieces of glass were irradiated with a Co-60 source to three doses up to a maximum dose of 3.1 x 10 10 rad. Internal samples of the large pieces of irradiated and unirradiated glass were leached in deionized water to investigate durability changes and were examined by transmission electron microscopy (TEM) to investigate microstructure changes. Leach tests were performed in triplicate at 90 degree C with crushed glass samples in deionized water. A statistical analysis of the results indicated to the 95% confidence level that the radiation did not affect the glass durability. Careful examination by TEM indicated no effect of gamma radiation on the microstructure of the glass although severe damage could be induced by the electron beam from the microscope. 19 refs., 2 figs., 3 tabs

  19. Effect of gamma radiation and formulated essential oils on stored potato tubers

    International Nuclear Information System (INIS)

    Abo-El Seoud, M.A.; Helal, I.M.M.; Sarhan, M.M.; Galal, A. M.

    2010-01-01

    Potato tubers were irradiated with gamma radiation at doses of 0, 0.5, 0.15, 0.3 and 0.6 K-Gy. Irradiated and non-irradiated tubers were soaked in biocides formulated from essential oils of fennel, peppermint and caraway oil. All treated and non-treated tubers were stored at room temperature (20 ±1 degree C) for period of 150 days. Samples were taken every 30 days for different quality determinations. Results showed that non-treated tubers were decayed and appear to be sprouted continuously alongside the different storage periods. However, exposing the studied tubers to gamma radiation induced a promising effect for retarding this decay and sprouting. Moreover, soaking potato tubers in the formulated biocides induced further interruption for tubers decay and sprouting. In addition, the applied treatment exhibited other positive effects for keeping the good quality of the studied tubers during storage.

  20. Effect of gamma radiation on lipids by the TBARS and NMR

    International Nuclear Information System (INIS)

    Silva, Adriana Cristina de Oliveira; Cortez, Marco Antonio Sloboda; Marsico, Eliane Teixeira; Guimaraes, Carlos Frederico; Jesus, Edgar Francisco Oliveira de

    2011-01-01

    The aim of this work was to study the effect of gamma radiation on lipids by TBARS and NMR. The samples of raw whole milk were subjected to gamma radiation from Co 60 in doses of 1, 2 and 3 kGy and the production of rancidity was studied through Nuclear Magnetic Resonance (NMR) and Thiobarbituric Acid Test (2-TBARS). The TBARS values increased according to the intensity of the radiation dose applied at the samples, demonstrating correlation between the radiation dose and the production of lipid oxidation. This was confirmed by NMR with the formation of peaks of aldehydes and ketones that were small and similar in the doses of 1 and 2 kGy. In the dose of 3 kGy, the total degradation of milk fat was observed. A correlation between the NMR and 2-TBA was detected. (author)

  1. 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)

  2. The split-sting trait in Apis mellifera induced by cobalt 60 gamma radiation

    International Nuclear Information System (INIS)

    Silva, Vera Lucia Maciel

    1993-01-01

    The Split-Sting (SS) trait in honey bees, induced by gamma radiation, was discovered by Soares (1975). Bees with this trait are unable to sting, because the parts that compose the sting are separated. Many studies have been done in order to understand this new mutation. We studied the effect of gamma radiation on induction of the SS trait in feral bee strains. The doses were applied to the phase of larvae of queens with 5 days old. The following results were obtained: all doses of radiation induced the SS trait. There was an increase in the percentage of queens with SS with an increase in radiation dose; the SS trait induced by radiation is probably phenocopy; SS bees were observed in nature; increase of the rate mortality and malformation with an increase in radiation dose. (author)

  3. Spectrometric gamma radiation of shale cores applied to sweet spot discrimination in Eastern Pomerania, Poland

    Science.gov (United States)

    Skupio, Rafal; de Alemar Barberes, Gabriel

    2017-12-01

    This paper describes the application and calculation of hydrocarbon anomalies in two different boreholes located in Eastern Pomerania (northern Poland). Spectrometric data from borehole geophysical probe (borehole 1) and portable gamma logger (borehole 2) were used to analyze shale formations. The results from borehole 1 presented a statistically significant, moderate correlation between calculated hydrocarbon anomalies and hydrocarbon saturation data obtained from well log interpretation. Borehole 2 has been analyzed focusing on the gamma radiation of the core samples, and the positive results of borehole 1. Hydrocarbon anomalies calculated from spectral gamma radiation are reliable indicators of sweet spots, based solely on a cursory evaluation of core measurements. These preliminary information acquired from gamma-ray measurements could help increase sampling precision of further geochemical analysis.

  4. Quality Of Starking Apples After Exposure To Gamma Radiation As A Quarantine Treatment

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F.; Al-Bachir, M.

    2004-01-01

    Starking apples approaching physiological maturity were exposed, immediately after harvest, to gamma radiation doses ranging from 100 to 400 Gy. The irradiated fruit were stored for six months in a cold storage facility at 1±1 deg. C and 90±5 % RH. Effects of gamma radiation on weight loss, fruit firmness, pH of fruit juice, fruit taste, color and visible injuries were evaluated. The results showed that gamma irradiation increased weight loss, particularly in the first 45 days of storage. Doses higher than 200 Gy, on the other hand, reduced apple firmness after 45 days of storage while a 400 Gy dose decreased fruit pH immediately after irradiation. (Authors)

  5. The effect of gamma radiation on the peroxides activity, colour and ascorbic acid content of papaya

    International Nuclear Information System (INIS)

    Asmah, R.; Nitisewojo, P.

    1977-01-01

    The activity of peroxidase enzyme increases during ripening with external colour used as a maturity index. An experiment indicated that 200 Krad dose level was most effective in inhibiting any increase in peroxidase activity when papaya was stored at room temperature. The doses of 25, 50 and 100 Krad level at least double the shelf life of fruit with 100 Krad was the most effective when kept in the cold. The development of yellow colour and synthesis of vitamin C is not effected. So, this preliminary study indicates that gamma radiation prolongs the shelf life of papaya when stored at cold or room temperature due to the inhibiting of the ripening process. It is also suggested that treatment of fungicides combined with gamma radiation might have an additive effect on shelf life

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

    International Nuclear Information System (INIS)

    Tawfik, Z.S.

    1985-01-01

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

  7. Effects of gamma radiation on stem diameter growth, carbon gain and biomass partitioning in Helianthus annuus

    International Nuclear Information System (INIS)

    Thiede, M.E.; Link, S.O.; Fellows, R.J.; Beedlow, P.A.

    1995-01-01

    To determine the effects of gamma radiation on stem diameter growth, carbon gain, and biomass partitioning, 19-day-old dwarf sunflower plants (Helianthus annuus, variety NK894) were given variable doses (0–40 Gy) from a 60Co gamma source. Exposure of plants to gamma radiation caused a significant reduction in stem growth and root biomass. Doses as low as 5 Gy resulted in a significant increase in leaf density, suggesting that very low doses of radiation could induce morphological growth changes. Carbohydrate analysis of plants exposed to 40 Gy demonstrated significantly more starch content in leaves and significantly less in stems 18 days after exposure compared with control plants. In contrast, the carbohydrate content of the roots of plants exposed to 40 Gy was not significantly different from non-irradiated plants 18 days after exposure. (author)

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

    International Nuclear Information System (INIS)

    Erbisch, F.H.

    1977-06-01

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

  9. Evaluation of phenolic compounds in mate (Ilex paraguariensis) processed by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Furgeri, C.; Nunes, T.C.F.; Fanaro, G.B. [Instituto de Pesquisas Energeticas Nucleares, IPEN-CNEN/SP, Centro de Tecnologia das Radiacoes-Laboratory de Deteccao de Alimentos Irradiados, Av. Professor Lineu Prestes, 2242, Cidade Universitaria, CEP: 05508-900 Sao Paulo (Brazil); Souza, M.F.F.; Bastos, D.H.M. [Faculdade de Saude Publica, FSP/USP, Departamento de Nutricao-Av. Dr. Arnaldo, 715, CEP: 01246-904 Sao Paulo (Brazil); Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas Nucleares, IPEN-CNEN/SP, Centro de Tecnologia das Radiacoes-Laboratory de Deteccao de Alimentos Irradiados, Av. Professor Lineu Prestes, 2242, Cidade Universitaria, CEP: 05508-900 Sao Paulo (Brazil)], E-mail: villavic@ipen.br

    2009-07-15

    The radiation food processing has been demonstrating great effectiveness in the attack of pathogenic agents, while little compromising nutritional value and sensorial properties of foods. The mate (Ilex paraguariensis), widely consumed product in South America, generally in the form of infusions with hot or cold water, calls of chimarrao or terere, it is cited in literature as one of the best sources phenolic compounds. The antioxidants action of these constituent has been related to the protection of the organism against the free radicals, generated in alive, currently responsible for the sprouting of some degenerative illness as cancer, arteriosclerosis, rheumatic arthritis and cardiovascular clutters among others. The objective of that work was to evaluate the action of the processing for gamma radiation in phenolic compounds of terere beverage in the doses of 0, 3, 5, 7 and 10 kGy. The observed results do not demonstrate significant alterations in phenolic compounds of terere beverage processed by gamma radiation.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Erbisch, F.H.

    1977-01-01

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

  12. 60Co gamma radiation effect on AlGaN//AlN/GaN HEMT devices

    International Nuclear Information System (INIS)

    Wang Yanping; Luo Yinhong; Wang Wei; Zhang Keying; Guo Hongxia; Guo Xiaoqiang; Wang Yuanming

    2013-01-01

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

  13. A superhydrophobic EP/PDMS nanocomposite coating with high gamma radiation stability

    Science.gov (United States)

    Zhang, Yan; Ren, Fule; Liu, Yujian

    2018-04-01

    The superhydrophobic coatings with high gamma radiation stability were prepared by using epoxy/polydimethylsiloxane (EP/PDMS) resins as the matrix and silica nanoparticles as the fillers. The nanocomposite coatings exhibit superhydrophobicity with a high water contact angle (WCA) of 154° and a low sliding angle of 7°. With the amount of SiO2 increasing from 0 to 30%, the surface shows the hierarchically structure gradually and its roughness raised from 4 nm to 278 nm. And little change in the WCA of the coatings (from 155° to 149°) was observed when the pH of the droplets varied from 2 to 14. In addition, the coatings also show good adhesion grade (5B), high hardness (6H) and outstanding stability for high dose gamma radiation.

  14. Disinfestation of Averrhoa carambola infested with Anastrepha obliqua (Macquart, 1835) (Diptera - Tephritidae) using gamma radiation

    International Nuclear Information System (INIS)

    Arthur, V.; Wiendl, F.M.

    1994-01-01

    The disinfestation dose of gamma radiation in Averrhoa carambola infested with larvae of Anastrepha obliqua was determined. Fruits were collected in the field, each having about 11 larvae in the last instar. Fruits were irradiated with the following ganna radiation doses: 0 (control), 50, 150, 300, 600 and 900 Gy. Each treatment consisted of 9 fruits (3 replications) giving the amount of 99 larvae for each treatment. After irradiation the fruits were kept in a climatic chamber with the temperature adjusted to 25± 5 0 C and relative humidity of 70± 5 0 C, until larvae left the fruit and became transformed into pupae and adults. The lethal dose (LD 100 ) of gamma radiation for larvae in the fuits was 600 Gy and the dose of 50 Gy inhibited completely the total emergency of adults. (author). 19 refs, 1 figs, 1 tab

  15. Evaluation of phenolic compounds in mate (Ilex paraguariensis) processed by gamma radiation

    International Nuclear Information System (INIS)

    Furgeri, C.; Nunes, T.C.F.; Fanaro, G.B.; Souza, M.F.F.; Bastos, D.H.M.; Villavicencio, A.L.C.H.

    2009-01-01

    The radiation food processing has been demonstrating great effectiveness in the attack of pathogenic agents, while little compromising nutritional value and sensorial properties of foods. The mate (Ilex paraguariensis), widely consumed product in South America, generally in the form of infusions with hot or cold water, calls of chimarrao or terere, it is cited in literature as one of the best sources phenolic compounds. The antioxidants action of these constituent has been related to the protection of the organism against the free radicals, generated in alive, currently responsible for the sprouting of some degenerative illness as cancer, arteriosclerosis, rheumatic arthritis and cardiovascular clutters among others. The objective of that work was to evaluate the action of the processing for gamma radiation in phenolic compounds of terere beverage in the doses of 0, 3, 5, 7 and 10 kGy. The observed results do not demonstrate significant alterations in phenolic compounds of terere beverage processed by gamma radiation.

  16. Computing in high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Watase, Yoshiyuki

    1991-09-15

    The increasingly important role played by computing and computers in high energy physics is displayed in the 'Computing in High Energy Physics' series of conferences, bringing together experts in different aspects of computing - physicists, computer scientists, and vendors.

  17. Search for continuous and single day emission from ultra-high-energy sources

    International Nuclear Information System (INIS)

    Chen, Mei-Li.

    1993-01-01

    Data from the CYGNUS experiment has been used to search the northern sky for point sources of continuous ultra-high-energy gamma radiation and to examine 51 candidate sources on a daily basis to search for episodic emission. In this paper, we make use of our most recent data to update our previously published results from these searches. The data sample is approximately twice as large as the published data set for continuous emission, and contains an additional year for the daily search. The latest results, up to the time of the conference, will be presented at the meeting

  18. Soil biological shield exposed to high energy neutrons; Zemlja kao bioloski stit od neutrona visokih energija

    Energy Technology Data Exchange (ETDEWEB)

    Simovic, R; Marinkovic, N [Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

    1993-04-15

    Shielding efficiency of soil biological shield exposed to high energy neutrons was investigated. Dose rate equivalents for neutrons, secondary gamma and gamma radiation were computed on the surface of soil slabs having different thicknesses. Yields of primary and secondary nuclear radiation in the total dose were evaluated. Influence of the incident neutron spectrum, water content and chemical composition of the material on its shielding efficiency was examined. It was found that the soil density and the water content determine the quality of biological shield, the influence of other factors being less important. Comparison of shielding efficiencies for soil with sand, brick and ordinary concrete shields was done.

  19. Search for emission of ultra high energy radiation from active galactic nuclei

    International Nuclear Information System (INIS)

    1993-01-01

    A search for emission of ultra-high energy gamma radiation from 13 active galactic nuclei that were detected by EGRET, using the CYGNUS extensive air-shower array, is described. The data set has been searched for continuous emission, emission on the time scale of one week, and for on the time scale of out day. No evidence for emission from any of the AGN on any of the time scales examined was found. The 90% C.L. upper limit to the continuous flux from Mrk 421 above 50 TeV is 7.5 x 10 -14 cm -2 s -1

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

    Science.gov (United States)

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

    2008-06-27

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

  1. Clostridia and sterilization of sludges from processing stations with gamma radiation

    International Nuclear Information System (INIS)

    Anselme, P.; Brakel, J.; Paul, R.; Lacroix, J.P.

    1981-01-01

    Considering the economical aspect of sludge irradiation, the dosis of 300 Krad of gamma radiation seems quite satisfactory, at least for unsporulated bacteria. But, at this level, sporulating bacteria such as Clostridia do not disappear: more than 60 percent of the spores escaped treatment. In order to improve the results, the synergistic effect of gamma rays and calcium peroxide was tested. In definite conditions, the results were promising. (Auth.)

  2. Effect of gamma radiation on the meristematic activity of garlic (allium sativum L.) bulbs

    International Nuclear Information System (INIS)

    Fernandez, J.; Aparicio, C.

    1979-01-01

    The effect of 10 krad of gamma radiation on the sprouting and meristematic activity of garlic bulbs is studied. Results show that the irradiation inhibits the meristematic activity of the bulbs independently of the epoch of treatment. When the treatment is applied several months after harvest (five or more), some apparent sprouting could be detected. This is due to a cellular elongation process rather than to cellular divisions. (author)

  3. Calibration curve to establish the exposure dose at Co60 gamma radiation

    International Nuclear Information System (INIS)

    Guerrero C, C.; Brena V, M.

    2000-01-01

    The biological dosimetry is an adequate method for the dose determination in cases of overexposure to ionizing radiation or doubt of the dose obtained by physical methods. It is based in the aberrations analysis produced in the chromosomes. The behavior of leisure in chromosomes is of dose-response type and it has been generated curves in distinct laboratories. Next is presented the curve for gamma radiation produced in the National Institute of Nuclear Research (ININ) laboratory. (Author)

  4. Effect of gamma radiation on the meristematic activity of garlic (Allium sativum L. ) bulbs

    International Nuclear Information System (INIS)

    Fernandez, J.; Aparicio, C.

    1979-01-01

    The effect of 10 krad of gamma radiation on the sprouting and mieristematic activity of garlic bulbs is studied. Results show that the Irradiation inhibits the meristematic activity of the bulbs independently of the epoch of treatment. When the treatment is applied several months after harvest (five or more), some apparent sprouting could be detected. This is due to a cellular elongation process rather than to cellular divisions. (Author) 47 refs

  5. Effects of gamma radiation on faba bean seed beetle Bruchus Dentipes Bande

    International Nuclear Information System (INIS)

    Mansour, Mohammed; Al-Bachir, Mahfouz

    1993-04-01

    Faba bean, Vivia bata, is one of the most important agricultural legume plants in Syria. Like any other crop, it is attacked by several insect pests. The most important of these is the faba bean seed beetle, Bruchus Dentipes Baudi. Infestation occurs only in the field and the major source of infestation is infested seed used for planting. The average infestation rate is about 45% and this reduces the economic value of the seeds to less than 50%. Chemical control in the field is effective but too expensive. Treating seeds in storage with fumigants is not as effective as it used to be, probably because of the pest developing resistance. Biological control has been investigated but their is no practically acceptable biological control agent at present. The lack of an effective biological control agent and/or economically acceptable and environmentally sound chemical control has led us to investigate the possibility of using gamma radiation to disinfest faba bean seeds as soon as possible after harvest when the insect is still in its early development stages. Infested faba bean seeds were treated immediately after harvest with 4 levels of gamma radiation ranged from 30 to 120 Gy with 30 Gy intervals. Treatment was repeated 15 and 30 days later and the effect of gamma radiation on larval survival was evaluated. The results showed that 90 Gy was sufficient to stop larval development and cause a 100% mortality. This dose, however, affected negatively seed germination. These results indicate that it is possible to disinfest faba bean seeds stored for human consumption with 90 Gy of gamma radiation. However, seeds destined for planting can not be treated with this dose. (author). 35 refs., 6 tabs., 2 figs

  6. The primary exposure standard for Co-60 gamma radiation: characteristics and measurements procedures

    International Nuclear Information System (INIS)

    Laitano, R.F.; Toni, M.P.

    1983-01-01

    A description is given of a cavity ionization chamber used, as a primary exposure standard, at the Laboratorio di Metrologia delle Radiazioni Ionizzanti of the ENEA in Italy. The primary standard is designed to make absolute measurements of exposure due to the Co-60 gamma radiation. The procedures for the realizationof the exposure unit are also described. Finally results of some international comparisons are reported

  7. Degradation of the insecticide ethyl parathion in different environmental matrices by gamma radiation from Cobalt-60

    International Nuclear Information System (INIS)

    Luchini, Luiz Carlos

    1995-01-01

    This work studies the use of gamma radiation from cobalt-60 to induce parathion degradation in different matrices, as well as, quantified GC-NPD and identified by GC-MS, the radiolysis resulting products. Results show that the insecticide was completely degraded in aqueous solution after treatment with 1.0 kGy dosis in a dosis rate of 3.12 kGy h -1 . In methanol, parathion was completely degraded only with 30 kGy at 3.12 kGy h -1 . The metabolites detected after radiolysis were the same formed by biological degradation, i.e, p-nitrophenol, p-aminophenol, paraoxon and aminoparathion. The gamma radiation also degraded paraoxon which is the most toxic metabolite of parathion. It was verified that, not only the total radiation, but also the dosis rate supplied to the aqueous solution had a significant effect on the insecticide degradation, and the formation of metabolites occurred in a selective way respecting the dosis and dosis rate. Otherwise, the gamma radiation did almost not degraded the parathion adsorbed in solid matrices as rice, moist and dry soil, even using dosis of 5,30 and 50 kGy, respectively. The parathion yield and the dosis of gamma radiation needed for 50% reduction of the insecticide initial concentration in aqueous solution were also calculated and presented. Thus, it was verified that irradiation of parathion besides to be an important instrument for environmental decontamination of this pesticide in aqueous matrix, it allows the production of parathion metabolites for ecotoxicological studies. (author)

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

    International Nuclear Information System (INIS)

    Singh, Durgeshwer; Singh, Rita

    2012-01-01

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

  9. Influence of gamma radiation on the immunological and immunochemical properties of cholera

    International Nuclear Information System (INIS)

    Nedugova, G.I.; Rubtsov, I.V.; Samojlenko, I.I.

    1984-01-01

    Results of studying the effect of gamma-radiation on immunochemical properties and serologic activity of unpurified cholera exotoxin are presented. It is found that in irradiated toxin preparations physico-chemical alterations take place as the dose of ionizing radiation increases, which brings about the increase in electrophoretic mobility, aggregation of protein components. It is shown that serologic activity contained in antigene toxin preparations retains within the limits of radiation doses studied

  10. Chicken Meat Submitted to Gamma Radiation and Packed with or without Oxygen

    OpenAIRE

    Pelicia, K; Garcia, EA; Molino, AB; Santos, GC; Vieira Filho, JA; Santos, TA; Berto, DA

    2015-01-01

    The objective of this study was to evaluate the effects on gamma radiation levels on the physical and microbiological characteristics of chicken breast meat. A completely randomized experimental design in a 4x2x3 factorial arrangement was adopted. Treatments consisted of four radiation concentrations (0, 2, 4, or 8kGy), two package sealing methods (with or without vacuum), and three storage times (01, 07, or 14 days), with ten replicates each, totaling 240 chicken breast fillets. Packaging an...

  11. Radon flux maps for the Netherlands and Europe using terrestrial gamma radiation derived from soil radionuclides

    Science.gov (United States)

    Manohar, S. N.; Meijer, H. A. J.; Herber, M. A.

    2013-12-01

    Naturally occurring radioactive noble gas, radon (222Rn) is a valuable tracer to study atmospheric processes and to validate global chemical transport models. However, the use of radon as a proxy in atmospheric and climate research is limited by the uncertainties in the magnitude and distribution of the radon flux density over the Earth's surface. Terrestrial gamma radiation is a useful proxy for generating radon flux maps. A previously reported radon flux map of Europe used terrestrial gamma radiation extracted from automated radiation monitoring networks. This approach failed to account for the influence of local artificial radiation sources around the detector, leading to under/over estimation of the reported radon flux values at different locations. We present an alternative approach based on soil radionuclides which enables us to generate accurate radon flux maps with good confidence. Firstly, we present a detailed comparison between the terrestrial gamma radiation obtained from the National Radiation Monitoring network of the Netherlands and the terrestrial gamma radiation calculated from soil radionuclides. Extending further, we generated radon flux maps of the Netherlands and Europe using our proposed approach. The modelled flux values for the Netherlands agree reasonably well with the two observed direct radon flux measurements (within 2σ level). On the European scale, we find that the observed radon flux values are higher than our modelled values and we introduce a correction factor to account for this difference. Our approach discussed in this paper enables us to develop reliable and accurate radon flux maps in countries with little or no information on radon flux values.

  12. Research program to study the gamma radiation effects in Spanish bentonites

    International Nuclear Information System (INIS)

    Dies, J.; Tarrasa, F.; Cuevas de las, C.; Miralles, L.; Pueyo, J. J.

    2000-01-01

    The engineering barrier of a radioactive waste underground disposal facility, placed in a granitic host rock, will consist of a backfill of compacted bentonite blocks. At first, this material will be subjected to a gamma radiation field, from the waste canister, and heat from the spent fuel inside the canister. Moreover, any groundwater that reaches the repository will saturate the bentonite. For these reasons the performance of the engineered barrier must be carefully assessed in laboratory experiments. (Author)

  13. Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation

    International Nuclear Information System (INIS)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Richoilley, G.; Conter, A.; Croute, F.; Caratero, C.; Gaubin, Y.

    1987-01-01

    Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y

  14. Mutagenic effect of gamma radiation on Arabidopsis thaliana. Effect of low temperature and cytokinin

    International Nuclear Information System (INIS)

    Pesina, K.

    1975-01-01

    The effect was studied of low temperature and cytokinin (6-benzyl aminopurine) on sterility and mutation frequency in A r a b i d o ps i s t h a l i a n a irradiatied with gamma radiation. Liquid nitrogen temperature was found to modify the radiation effect in that that it reduced sterility and mutation frequency. Cytokinin applied to seed prior to and after irradiation increased mutation frequency. (L.O.)

  15. Determining lethal dose of gamma radiation on different stages of Tribolium Cosmonauts H b s t

    International Nuclear Information System (INIS)

    Zolfagharieh, H.R.; Majd, F.; Torshyzie, M.; Babaie, M.

    1992-10-01

    Pest infestation causes great losses to stored grain through out the world. This is specially true in developing countries where the technology is less advanced, and climatic conditions are extremely favourable for the development of pests. Irradiation is on approved method of direct control for stored-product insect in wheat and wheat flour in many countries, and in dictation are that it will soon be approved for all grain, grain products and other dry food commodities. Radiation doses required to kill or sterilized the most important storage pests in all stages are known. However irradiation is very effective in preventing insect development and in producing sterility. A detailed analysis of the radiosensitivity of stored-product insects shows the different groups of pests have very different sensitivities and quarantine doses can be tailored to kill or sterilize the species of quarantine concern. The effect of irradiation on insects are many, and varied, depending primarily on the species, stage, age and physical factors. The aim is to survey the effect of gamma radiation on stored pest, which can categorized under following classes: 1-The effect of gamma radiation on different stages grow of tribolium castaneum (H B S T); 2-Determination of lethal doses.; 3-The study of gamma radiation on products. In summary these information indicated that fairly low dosages of gamma radiation could be used on commodities such as bulk grain in which some infestation by insect stages of irradiation would be required on products such package foods where hundred percent mortality must be obtain. (author)

  16. Effect of gamma radiation on seed germination and seedling vigour in cowpea [Vigna unguiculata (L.) Walp.

    International Nuclear Information System (INIS)

    Thimmaiah, S.K.; Mahadevu, P; Srinivasappa, K.N.; Shankara, A.N.

    1998-01-01

    Cowpea [Vigna unguiculata (L.) Walp.) is regarded as hardy and one of the important tropical legumes. The plants respond differently to mutagenic treatments. Ionizing radiations affect a wide range of physiological and biochemical activities of plants. The purpose of this paper is to report the effect of gamma radiation on seed germination and seedling vigour of two important cowpea varieties viz., KBC-1 and TVX-994-02E in M 1 generation under laboratory conditions. (author)

  17. Effects of CO-60 gamma radiation on the embryonary development of Biomphalaria Glabrata (Say, 1818)

    International Nuclear Information System (INIS)

    Okazaki, K.

    1988-01-01

    Some aspects of the effects of the ionizing radiation on the embryo and on the genetical material of Biomphalaria glabrata (Mollusca: Gastropoda) are presented. The embryos weresubmitted at various stages of development to doses of 5,10,15,20 and 25 Gy of Co-60 gamma radiation. As a criteia of evaluation of the embryos radiosensitivity, four biological parameters were used: mortality, malformation, hatching and chromossomal aberrations. (M.A.C.) [pt

  18. Nanoclay filled hydrogels of poly (2-hydroxyethyl methacrylate-co-acrylamide) copolymers prepared by gamma radiation

    International Nuclear Information System (INIS)

    Rapado Paneque, M.; Matos Cause, W.; Barreras Gonzalez, G.; Griffith Perez, J.; Amalvy, J. I.; Van Espen, P.; Peniche, C.

    2011-01-01

    Hydrogels are polymers characterized by their ability to absorb a considerable amount of water. Hydrogels consist of polymer molecules physically or chemically crosslinked, forming a molecular network, so that in water they swell to an equilibrium value, preserving their shape [1]. The aim of this work was to prepare by gamma radiation poly (2-hydroxyethyl methacrylate-co-acrylamide) hydrogels, p(HEMA-co-AAm), doped with Nanoclay (laponite XLG). (Author)

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

  20. Morphological changes about Artemia Salina by the effect of gamma radiation

    International Nuclear Information System (INIS)

    Dvorak, P.; Kunova, V; Kratochvil, B.; Salplachta, J.; Benova, K.

    2004-01-01

    Direction Council of Europe require restriction of laboratory vertebrae in biological experiments. Once by possibilities is using biological test II. generation among which belongs to and test for Artemia salina. Still this time published test however value only lethality in dependence on dose, exposition and time survival. This work document possibility watch of expressive morphological changes, which consist in retardation development brine shrimps stage in dependence on dose gamma radiation 60 Co. (authors)

  1. Gene expression in Catla catla (Hamilton) subjected to acute and protracted doses of gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Anbumani, S., E-mail: aquatox1982@gmail.com; Mohankumar, Mary N., E-mail: marynmk@gmail.com

    2016-09-15

    Highlights: • Gamma radiation induced up- and down- regulation of cell cycle genes. • Protracted dose-rate induced gene up-regulation to facilitate cell survival. • bcl-2 gene facilitates repair at protracted dose and cell death at acute exposures. • gadd45α, cdk1 and bcl-2 genes work in concert to promote ‘repair’ and ‘death’ circuitries in fish blood cells. - Abstract: Studies on transcriptional modulation after gamma radiation exposure in fish are limited. Cell cycle perturbations and expression of apoptotic genes were investigated in the fish, Catla catla after acute and protracted exposures to gamma radiation over a 90 day period. Significant changes in gene expression were observed between day 1 and 90 post-exposure. Gamma radiation induced a significant down-regulation of target genes gadd45α, cdk1 and bcl-2 from day 1 to day 3 after protracted exposure, whereas it persists till day 6 upon acute exposure. From day 12 onwards, Gadd45α, cdk1 and bcl-2 genes were up-regulated following protracted exposure, indicating DNA repair, cell-cycle arrest and apoptosis. There exists a linear correlation between these genes (gadd45α – r = 0.85, p = 0.0073; cdk1 – r = 0.86, p = 0.0053; bcl-2 – r = 0.89, p = 0.0026) at protracted exposures. This is the first report on the dual role of bcl-2 gene in fish exposed to acute and protracted radiation and correlation among the aforementioned genes that work in concert to promote ‘repair’ and ‘death’ circuitries in fish blood cells.

  2. Gene expression in Catla catla (Hamilton) subjected to acute and protracted doses of gamma radiation

    International Nuclear Information System (INIS)

    Anbumani, S.; Mohankumar, Mary N.

    2016-01-01

    Highlights: • Gamma radiation induced up- and down- regulation of cell cycle genes. • Protracted dose-rate induced gene up-regulation to facilitate cell survival. • bcl-2 gene facilitates repair at protracted dose and cell death at acute exposures. • gadd45α, cdk1 and bcl-2 genes work in concert to promote ‘repair’ and ‘death’ circuitries in fish blood cells. - Abstract: Studies on transcriptional modulation after gamma radiation exposure in fish are limited. Cell cycle perturbations and expression of apoptotic genes were investigated in the fish, Catla catla after acute and protracted exposures to gamma radiation over a 90 day period. Significant changes in gene expression were observed between day 1 and 90 post-exposure. Gamma radiation induced a significant down-regulation of target genes gadd45α, cdk1 and bcl-2 from day 1 to day 3 after protracted exposure, whereas it persists till day 6 upon acute exposure. From day 12 onwards, Gadd45α, cdk1 and bcl-2 genes were up-regulated following protracted exposure, indicating DNA repair, cell-cycle arrest and apoptosis. There exists a linear correlation between these genes (gadd45α – r = 0.85, p = 0.0073; cdk1 – r = 0.86, p = 0.0053; bcl-2 – r = 0.89, p = 0.0026) at protracted exposures. This is the first report on the dual role of bcl-2 gene in fish exposed to acute and protracted radiation and correlation among the aforementioned genes that work in concert to promote ‘repair’ and ‘death’ circuitries in fish blood cells.

  3. Evaluation of mathematical methods for predicting optimum dose of gamma radiation in sugarcane (Saccharum sp.)

    International Nuclear Information System (INIS)

    Wu, K.K.; Siddiqui, S.H.; Heinz, D.J.; Ladd, S.L.

    1978-01-01

    Two mathematical methods - the reversed logarithmic method and the regression method - were used to compare the predicted and the observed optimum gamma radiation dose (OD 50 ) in vegetative propagules of sugarcane. The reversed logarithmic method, usually used in sexually propagated crops, showed the largest difference between the predicted and observed optimum dose. The regression method resulted in a better prediction of the observed values and is suggested as a better method for the prediction of optimum dose for vegetatively propagated crops. (author)

  4. Nicotinic and iso nicotinic acids: interactions with gamma radiation and acid-base equilibrium

    International Nuclear Information System (INIS)

    Ribeiro, Z.A.

    1984-01-01

    The values of pKa 1 and pKa 2 for nicotinic and iso nicotinic acids in aqueous medium were determined. The effects of gamma radiation about these acids by infrared and ultraviolet spectrophotometry and thermal gravimetric analysis were also studied. It was verified that the radiolysis of acids occurred by the two process of first order, determining the degradation constant and the degradation factors for each one of the solutions. (C.G.C.)

  5. 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.

  6. 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.

  7. Shelf life extension of fresh turmeric (Curcuma longa L.) using gamma radiation

    International Nuclear Information System (INIS)

    Dhanya, R.; Mishra, B.B.; Khaleel, K.M.; Cheruth, Abdul Jaleel

    2009-01-01

    Gamma radiation processing was found to extend shelf life of fresh turmeric. A 5 kGy radiation dose and 10 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.

  8. Scope for utilizing gamma radiation for microbiological control of sewage waste-water in India

    International Nuclear Information System (INIS)

    Lewis, N.F.

    1975-01-01

    Conventional methods, including the activated sludge process, the trickling filter process and oxidation pond process, of treating sewage waste in India, do not adequately ensure safe utilization of the secondary effluent for land irrigation purposes. Preliminary findings indicate that gamma radiation in the range of 0.1-0.3 Mrad effectively destroys pathogens in the secondary effluent, thereby making available very large quantities of water for land irrigation and industrial purposes. (author)

  9. Sewage sludge pasteurization by gamma radiation: A Canadian demonstration project — 1988-91

    Science.gov (United States)

    Swinwood, Jean F.; Wilson, Bruce K.

    Nordion International Inc. and a Canadian city, in cooperation with the Federal & Provincial Ministries of the Environment, began a project in 1988 to construct and operate a commercial-scale sewage sludge pasteurization facility using gamma radiation technology. The facility is scheduled to begin operations in 1991. This paper discusses the objectives and scope of the project, the design of the irradiation system, and the plans to market the pasteurized sludge as a high-value, organic soil conditioner and fertilizer.

  10. Effects of gamma radiations on some aspects of the biology of salmonella

    International Nuclear Information System (INIS)

    Ben Miloud, Najla

    2007-01-01

    This work aimed at the study of the effect of gamma radiation on certain aspects of the biology of Salmonella, few works joined this type and gamma radiations. The lethal effect of ionizing radiations was associated at other bacterial types, to an oxidative stress due to the presence of reactive spices of oxygen and leading to deteriorations of membrane cells, proteins and nucleic acids.Thus, we proceeded to an analysis of the viability of four Salmonella serovars subject to different radiation doses going from 0.5 to 2 KGy. The results showed a viability reduction dose dependent with a differential behavior, statistically significant. In order to detect possible radio induced changes at the restriction site of the enzymes XbaI and BlnI usually used for the typing of Salmonella, we carried out a DNA restriction profile analyse of the four serovars by pulsed filed gel electrophoresis. The results showed that no change appeared on the level of these restriction sites for the used enzymes following an irradiation of 2KGy. The study of the sensitivity of Salmonella to antibiotics after a gamma radiation showed that gamma radiation has increased the sensitivity of Salmonella isolates to porin associated antibiotics. Statistical analyses showed that the effect of different irradiation dose treatment on the antibiotic sensitivity is increasingly significant. The irradiation didn't induce modifications of the sensitivity to other antibiotics, probably because of their nature, of their penetration mode inside the cell or their action way. To tray to explain the differential behavior of different serovars to irradiation. We analyzed by Quantitative real time PCR (RT- PCR), the expression level of the ARNm of the genes KATN (catalase non-hemique), DNAK (protein of thermal shock), RNA polymerase as well as of the 16S rRNA. The results showed either a repression or an induction of certain genes under the effect of an irradiation of 2 KGy. (Author)

  11. High energy physics

    International Nuclear Information System (INIS)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-01-01

    This proposal is for the continuation of the High Energy Physics program at the University of California at Riverside. In hadron collider physics the authors will complete their transition from experiment UA1 at CERN to the DZERO experiment at Fermilab. On experiment UA1 their effort will concentrate on data analysis at Riverside. At Fermilab they will coordinate the high voltage system for all detector elements. They will also carry out hardware/software development for the D0 muon detector. The TPC/Two-Gamma experiment has completed its present phase of data-taking after accumulating 160 pb - 1 of luminosity. The UC Riverside group will continue data and physics analysis and make minor hardware improvement for the high luminosity run. The UC Riverside group is participating in design and implementation of the data acquisition system for the OPAL experiment at LEP. Mechanical and electronics construction of the OPAL hadron calorimeter strip readout system is proceeding on schedule. Data analysis and Monte Carlo detector simulation efforts are proceeding in preparation for the first physics run when IEP operation comenses in fall 1989

  12. High energy physics

    International Nuclear Information System (INIS)

    Kernan, A.; Shen, B.C.; Ma, E.

    1997-01-01

    This proposal is for the continuation of the High Energy Physics Program at the University of California, Riverside. In 1990, we will concentrate on analysis of LEP data from the OPAL detector. We expect to record 10 5 Z's by the end of 1989 and 10 6 in 1990. This data will be used to measure the number of quark-lepton families in the universe. In the second half of 1990 we will also be occupied with the installation of the D-Zero detector in the Tevatron Collider and the preparation of software for the 1991 run. A new initiative made possible by generous university support is a laboratory for detector development at UCR. The focus will be on silicon strip tracking detectors both for the D-Zero upgrade and for SSC physics. The theory program will pursue further various mass-generating radiative mechanisms for understanding small quark and lepton masses as well as some novel phenomenological aspects of supersymmetry

  13. High energy plasma accelerators

    International Nuclear Information System (INIS)

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ω 0 , kappa 0 and ω 1 , kappa 1 shone on a plasma with frequency separation equal to the electron plasma frequency ω/sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ω/sub pe//e of the order of 1GeV/cm for a plasma density of 10 18 cm -3 through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed

  14. Very high energy colliders

    International Nuclear Information System (INIS)

    Richter, B.

    1985-05-01

    The conclusions are relatively simple, but represent a considerable challenge to the machine builder. High luminosity is essential. We may in the future discover some new kind of high cross section physics, but all we know now indicates that the luminosity has to increase as the square of the center of mass energy. A reasonable luminosity to scale from for electron machines would be 10 33 cm -2 s -1 at a center of mass energy of 3 TeV. The required emittances in very high energy machines are small. It will be a real challenge to produce these small emittances and to maintain them during acceleration. The small emittances probably make acceleration by laser techniques easier, if such techniques will be practical at all. The beam spot sizes are very small indeed. It will be a challenge to design beam transport systems with the necessary freedom from aberration required for these small spot sizes. It would of course help if the beta functions at the collision points could be reduced. Beam power will be large - to paraphrase the old saying, ''power is money'' - and efficient acceleration systems will be required

  15. Comparison Study On Sunlight Or Gamma Radiation Aging Resistance Of Poly (Vinyl Pyrrolidone) Aqueous Solution With PVP Nanogel

    International Nuclear Information System (INIS)

    Doan Binh; Pham Thu Hong; Nguyen Nguyet Dieu; Nguyen Thanh Duoc

    2011-01-01

    Comparison study on sunlight or gamma-radiation aging resistance of poly (vinyl pyrrolidone) (PVP) aqueous solution with PVP nanogel at 0.5% was carried out. Sunlight or gamma- radiation aging resistance of PVP aqueous solution and nanogel was evaluated on the basis of their intrinsic viscosity, UV-VIS absorbance, weight averaged molecular weight (M w ). The PVP aqueous solution and nanogel exposed to sunlight in the storage duration of 3 months and to gamma radiation at absorbed doses of 0, 15, 30, 50 kGy were used for this study. Furthermore, the stability of PVP nanogel and of PVP aqueous solution was also studied on the change of their intrinsic viscosity, UV-VIS absorbance, weight averaged molecular weight, particle size distribution and coil size. The experimental results were shown that the aging resistance of PVP nanogel was higher than that of PVP aqueous solution when exposed to gamma radiation or sunlight. (author)

  16. Ex-situ and in-situ observations of the effects of gamma radiation on lithium ion battery performance

    Science.gov (United States)

    Tan, Chuting; Bashian, Nicholas H.; Hemmelgarn, Chase W.; Thio, Wesley J.; Lyons, Daniel J.; Zheng, Yuan F.; Cao, Lei R.; Co, Anne C.

    2017-07-01

    Radiation effects induced by gamma rays on battery performance were investigated by measuring the capacity and resistance of a series of battery coin cells in-situ directly under gamma radiation and ex-situ. An experimental setup was developed to charge and discharge batteries directly under gamma radiation, equipped with precise temperature control, at The Ohio State University Nuclear Reactor Lab. Latent effects induced by gamma radiation on battery components directly influence their performance. Charge and discharge capacity and overall resistance throughout a time span of several weeks post irradiation were monitored and compared to control groups. It was found that exposure to gamma radiation does not significantly alter the available capacity and the overall cell resistance immediately, however, battery performance significantly decreases with time post irradiation. Also, batteries exposed to a higher cumulative dose showed close-to-zero capacity at two-week post irradiation.

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

    International Nuclear Information System (INIS)

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

    1976-01-01

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

  18. Protective Effect of Vitamin E against Gamma Radiation Injury in Mice Histological and Ultrastructural Studies

    International Nuclear Information System (INIS)

    Abu Nour, S.M.; Abd EI Azeem, M.G.

    2009-01-01

    Vitamin E has been shown to ameliorate the effect of ionising radiation. The present study was designed to study the effect of high dose of gamma-radiation on the intestinal tissue of mice and the protective effect of the natural antioxidant vitamin E; a slow acting free radical scavenger. 24 adult albino male mice were divided into 4 groups (6 animals each). The first group represents the control group. The second experimental group received orally daily doses of vitamin E (100 mg/ kg body wt for 15 days). The third experimental group were exposed to 7 Gy gamma-rays as a single dose, while the fourth experimental group received vitamin E in the same dose before being irradiated. All animals were scarified and jejunal specimens were processed and prepared for histological and ultrastructural study after one day post irradiation. The results suggested that gamma-radiation induced different histological changes in the intestine of irradiated animals. Degeneration of the intestinal cells and microvilli were seen by light microscopic examination. SEM electron microscope (SEM) revealed haemorrhagic ulcerating tissues. In addition, the mitochondria were markedly swollen and loss of cristae, thickness of the terminal web zone was seen by transmission electron microscope. On the contrary, in animals treated with vitamin E, the intestinal tissues revealed structure almost similar to the control group. We conclude that vitamin E had protective effects against gamma-radiation induced oxidative stress

  19. Dose Response for Monokaryon mycelium of Pleurotus pulmonarius After Acute Gamma Radiation

    International Nuclear Information System (INIS)

    Wan Safina Wan Abdul Razak; Azhar Mohamad; Nie, H.J.

    2016-01-01

    Pleurotus pulmonarius is locally known as Grey oyster. The species is popular and widely cultivated throughout the world mostly in Asia Europe as their simple and low cost production technology and higher biological efficiency. Mutation induction is an alternative ways for improving available commercial strain for better quality traits. Dose response is important in evaluating effects of mutagenesis via acute gamma radiation. Monokaryon mycelium of Pleurotus pulmonarius was exposed to acute gamma radiation ranged from 0 Gy, 0.1 kGy, 0.2 kGy, 0.3 kGy, 0.4 kGy, 0.5 kGy, 0.6 kGy, 0.7 kGy, 0.8 kGy, 0.9 kGy, 1.0 kGy, 1.5 Gy, 2.0 kGy, 3.0 kGy and 4.0 kGy at dose rate 0.013 kGy/ min. growth performance was measured at 2 days interval to get the LD_5_0. Increasing of the irradiation dose found to decrease the growth performance of the monokaryon mycelium. LD_5_0 was revealed at 1.56 kGy for mono karyon mycelium. Discoveries of the works are important for the improvement of Pleurotus species via acute gamma radiation and benefiting to growers and mushroom industries. (author)

  20. Definition of priority areas for monitoring of gamma radiation on the surroundings of the CDTN installations

    International Nuclear Information System (INIS)

    Chagas, Claudio Jose; Carvalho Filho, Carlos A.; Peixoto, Claudia Marques; Rodrigues, Paulo C. Horta; Augustin, Cristina Helena R. Rocha

    2013-01-01

    To demonstrate compliance with regulations and legal requirements, the Environmental Monitoring Program of the - Development Center of Nuclear Technology - PMA/CDTN was created in 1985. However, at that time, no data was available to represent the background - the natural level for the pre operational period in terms of Gamma radiation. Thus, the lowest value obtained among the sentinel point sites from the early period of the environmental monitoring was adopted as benchmark. As these measurements were performed by procedures and conditions other than that currently in use, this reference value may not correspond to reality. Therefore, it may not be appropriate to use it as background in assessing the possible environmental impact generated by the activities of the facilities. The goal of this study is to propose an area of geographic distribution for 12 monitoring points, outside the CDTN facilities, so that the real natural Gamma radiation levels can be accurately measured without the interference of the radioactivity levels originating from the institution, enabling the determination of the most representative values of the natural gamma radiation in the area. This survey of the natural radiation determination in the study area, with the use of modern equipment and the application of methodology taking into account historical data, as well the geological, geomorphological and geographical studies of the region, pointed to an average background value of 0.095μSv/h. This result, together with other studies, indicated a maximum range of 25m beyond the CDTN boundaries to distribute the monitoring points. (author)

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

    International Nuclear Information System (INIS)

    Cantinha, Rebeca S.; Nakano, Eliana; Silva, Luanna R.S.

    2009-01-01

    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 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 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)

  2. Application of gamma radiation on disinfestation feed grain based food for domestic animals

    International Nuclear Information System (INIS)

    Ramos, Amanda Cristina Oliveira

    2009-01-01

    This study aimed to realize a survey to identify the associated insects to feed the city Sao Paulo / SP and also to assess the effect of gamma radiation on food ration for domestic animals infested by pests. Samples of 20 stores, 'Pet Shop' in different regions in Sao Paulo / SP were subjected to trials of 1 and 45 days for collection of insects with the aid of plastic tray and screens of different sizes. The species Sitophilus zeamais, Cryptolestes ferrugineus, Lasioderma serricorne and Oryzaephilus sp. showed a higher frequency. In assessing the effects of gamma radiation we used samples of maize, sunflower seeds and mix for rodents infested with adults of the species Sitophilus zeamais, Lasioderma serricorne and Plodia interpunctella, after the period of 7 to 10 days the insects were removed and samples subjected to increasing doses of gamma radiation. The species Sitophilus zeamais and Lasioderma serricorne subjected doses from 0,25 to 1,50 kGy and species Plodia interpunctella doses from 0,10 to 2,0 kGy. After 40 days of irradiation was evaluated the number of insects emerged. The results of bioassays with Sitophilus zeamais and with Lasioderma serricorne demonstrated that doses starting at 0,5 kGy was sufficient to cause mortality of eggs and newly emerged larvae. The results with Plodia interpunctella from the 1,5 kGy, hasn't emerged adult insects, concluding that these doses were sufficient to cause mortality of eggs and larvae. (author)

  3. 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.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  5. Response of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), eggs to gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, W.D., E-mail: weliton.silva@usp.b [Department of Entomology and Acarology, Laboratory of Chemical Ecology and Insect Behavior, University of Sao Paulo, ' Luiz de Queiroz' College of Agriculture, Padua Dias Avenue, 11, 13418-900 Piracicaba (Brazil); Arthur, V.; Mastrangelo, T. [Food Irradiation and Radioentomology Laboratory, Center for Nuclear Energy in Agriculture (CENA/USP), Centenario Avenue 303, 13400-970 Piracicaba (Brazil)

    2010-10-15

    As insects increase in radiotolerance as they develop and usually several developmental stages of the pest may be present in the fresh shipped commodity, it is important to know the radiation susceptibility of the stages of the target insect before the establishment of ionizing radiation quarantine treatments. This study was performed to determine the radiotolerance of eggs of the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), to gamma radiation. This species is considered as one of the most serious worldwide pests for temperate fruits, especially peaches. Eggs (12 h old) were exposed to 0 (control), 25, 35, 50, 75, 100, 125 and 150 Gy of gamma radiation. Surviving larvae were allowed to feed on an artificial diet. Three days after irradiation, it was verified that larvae's cephalic capsules were significantly affected by gamma radiation, and the estimated mean LD{sub 90} and LD{sub 99} were 66.3 Gy and 125.8 Gy, respectively. Oriental fruit moth eggs revealed to be quite radiosensitive and very low doses as 50 Gy were sufficient to disrupt G. molesta embryogenesis. At 25 Gy, only male adults originated from the surviving larvae and, after mating with untreated fertile females, shown to be sterile.

  6. Some gamma radiation (60Co) effects on Chrysomya megacephala (Fabricius, 1794) (Diptira-Calliphoridae)

    International Nuclear Information System (INIS)

    Garcia, C.R.

    1987-03-01

    The effect of different gama radiation ( 60 Co) doses on Chrysomya megcephala (Fabricius) have been studied under laboratory conditions, in the Entomology Section of Centro de Energia Nuclear na Agricultura (CENA-USP), Piracicaba, SP, Brasil. The insects were collected close to sucking animals brooding areas, identified and reared on artificial diet, being kept in a temperature (26 +- 2 0 C) and humidity (66 +- 9%) controlled room, with 12L:12D photopheriod. A Gammabeam type 650 Cobalt-60 gamma irradiation source was used, with 28, 196x10 10 Bq activity at the beginning of the experiment. The pupae were submitted to increasing gamma radiation doses. To determine lethal doses, treatments were carried out at four different ages and to determine the sterilizing doses two-three day pupae were used. It was noted pupae radiosensitivity decreased with age, LD 50 varying from 14 - 513 Gy. The sterilizing dose for males was 40 Gy and for females 30 Gy. During the individuals life cycle, it was noted that there was a decrease in life expectancy (e x o ) of adults when the gamma radiation dose was increased. Treated males were more sensitive than females (Crossed with ''normals''), there occurring a marked reduction in the number of eggs and their viability when the used gamma radiation dose was increased. (author) [pt

  7. Effect of low-dose gamma radiation on HIV replication in human peripheral blood mononuclear cells

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y. [British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada); Conway, B. [British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada)]|[British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada). Dept. of Medicine; Montaner, J.S.G. [British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada)]|[British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada). Dept. of Medicine]|[Canadian HIV Trials Network, Vancouver (Canada); O`Shaughnessy, M.V. [British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada)]|[British Columbia Centre for Excellence in HIV/AIDS, British Columbia (Canada). Faculty of Medicine]|[Canadian HIV Trials Network, Vancouver (Canada); Greenstock, C.L. [AECL Research, Chalk River, Ontario (Canada). Radiation Biology and Health Physics Branch

    1996-08-01

    Recent studies have demonstrated that UV light and x-irradiation enhance human immunodeficiency virus (HIV) gene expression. There are few published data on related effects of {gamma}-radiation. This may be of clinical relevance, as radiotherapy has been used extensively for the treatment of acquired immunodeficiency syndrome associated conditions. We have studied the effects of {gamma}-radiation on HIV replication in mono-nuclear cells (MC). These cells were obtained from five seronegative healthy donors, exposed to 0-200 cGy {gamma}-radiation, stimulated with phytohemagglutinin-P (PHA-P) for 24 h, infected with a laboratory strain of HIV (HTLV-IIIB, multiplicity of infection = 0.001), then carried in culture for 14 days. Overall, when considering p24 antigen levels on days 7 and 11 in cultures established from cells exposed to 50 cGy, the maximal levels were significantly higher than those measured in the parallel control cultures taken as a whole (P < 0.05), with viral replication enhanced as much as 1000-fold in one case. No significant cytotoxicity was observed following exposure to doses up to 50 cGy. The mechanism of the observed effect remains unknown but may relate to direct gene activation and/or free radical generation, leading to such activation. To date, there is no evidence that viral stimulation occurs following therapeutic radiation in a clinical setting. (author).

  8. Stimulating effect of gamma radiation on haploid wheat production through microscope over co-culture system

    International Nuclear Information System (INIS)

    Naseri, M.; Rahimi, M.; Faramarz, M.

    2004-01-01

    Haploid production focuses on low plant regeneration in some wheat genotypes. Haploid application gamma ray as an electromagnetic ray has ionizing properties which can produce ions when passing through biological matter. It can produce genetic variation therefore, is applied in crop and ornamental improvement to enhance agronomic traits. The most important changes caused by gamma radiation is in DNA structure existing in the nucleus of cell. The desirable agronomic changes then will be passed on through generations. Another property of gamma ray can be it's stimulating effect which is the aim in this investigation. Microspore-overy co-culture of wheat along with application of low doses of gamma radiation 2,3 and 4 Gy as absorbing doses were implemented with the aim to evaluate wheat haploid production. Modified Morashig and Skoog medium was used as induction medium and 190-2 medium for regeneration. Two winter and two spring wheat cultivars were used as genetic material. Low doses of gamma radiation simulated microspore cell division and produced more calli relative to non-irradiated microspores only in winter type wheats. In microspore overy co-culture, filtered microspores were centrifuged and then plated in Petri dishes containing MMS+500 mg/I glutamine with 25 overies

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

    International Nuclear Information System (INIS)

    1985-01-01

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

  10. Ultraviolet and gamma-radiation effect on the zymotic characteristics of turnip moth's granules

    Energy Technology Data Exchange (ETDEWEB)

    Khakimova, M A

    1975-01-01

    Virus granules of the winter cutworm (Agrotis segetum Schiff) were used as agents for biological control of this pest of field and vegetable crops. The authors first studied the effect of uv and gamma radiation on granules of the cutworm. A purified suspension of winter moth granules, 0.5 mg of granules per mm/sup 3/, was irradiated with a BUV-15 lamp at a distance of 9 cm from the radiation source. The dose rate was 6.6x10/sup 3/ ergs/cm/sup 2/.sec. The results showed that a uv dose of 71.1x10/sup 6/ ergs/cm/sup 2/ decreased the virulence of the granules by a factor of 3 compared to the original suspension (larval mortality of 27.5%) and a dose of 95x10/sup 6/ ergs/cm/sup 2/ completely inactivated the granules. With gamma radiation (/sup 60/Co or /sup 137/Cs) the inactivating dose was only 21.6x10/sup 5/ rads. The work indicated that cutworm granules are very resistant to uv and gamma radiation.

  11. Effects of gamma radiation on the kola nut weevil, Balanogastris kolae (Desbr. ) (Coleopera: Curculionidae)

    Energy Technology Data Exchange (ETDEWEB)

    Ivbijaro, M F [Ibadan Univ. (Nigeria)

    1977-09-01

    Studies on the kola nut weevil, Balanogastris kolae (Desbr.) with gamma radiation showed that 20 krad effectively caused high larval mortality and prevented pupation. Dead larvae became soft and bluishblack and, occasionally, dry and brown. Percentage adult emergence from irradiated pupae, longevity and fecundity of emerging adults provided the basis for evaluating the effectiveness of the ionizing radiation. Mean survival and adult emergence from young pupae irradiated with 20 krad was 6 and 2 percent, respectively, in contrast to 86 and 8 percent, respectively, in old pupae given the same dosage. Old pupae (3-5 days old) showed some tolerance to gamma radiation and over 20 krad was required to prevent adult emergence. Gamma radiation seriously reduced longevity to an average of 6 and 15 days, respectively, in pre- and post-emergence irradiated adults in contrast to 44 days in the control. Distortion of the membranous hind wings were some of the adverse effects observed in adults that emerged from irradiated pupae. Reproduction and oviposition was seriously impaired by irradiation before or immediately after emergence. The opinion of a panel of experienced kola nut testers was that gamma irradiation did not alter the taste or flavour of the kola nuts and no change was observed in the colour or texture of the irradiated nuts.

  12. Effects of gamma radiation on codling moth, Cydia pomonella (L.), eggs

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F

    2005-01-01

    The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1-24 to 97-120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1-24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25-48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation. (Author)

  13. Effects of gamma radiation on codling moth, Cydia pomonella (L.), eggs

    International Nuclear Information System (INIS)

    Mansour, M.; Mohamad, F.

    2004-01-01

    The radiosensitivity of codling moth, Cydia pomonella (L.), eggs in different stages of development was studied. Eggs ranging in age from 1-24 to 97-120 h were exposed, at 24 h intervals, to gamma radiation doses ranging from 10 to 350 Gy. The effects of gamma radiation on egg hatch, pupation and adult emergence was examined. Results showed that the radiosensitivity of codling moth eggs decreased with increasing age. Egg hatch in 1-24 h old eggs was significantly affected at 20 Gy dose and at 60 Gy dose, egg hatch decreased to about 1%. At the age of 25-48 h, however, egg hatch at 60 Gy dose was about 10%, and egg sensitivity to gamma irradiation decreased significantly in the 49-72 h age group; 60 Gy dose had no significant effect on egg hatch. Eggs irradiated few hours before hatch (at the blackhead stage), were the most resistant ones; 100 Gy had no significant effect on egg hatch and at 350 Gy dose over 56% of the eggs hatched. When adult emergence was used as a criterion for measuring effectiveness, however, the effect of gamma radiation was very sever. A dose of 60 Gy completely prevented adult emergence and at 100 Gy dose all resulted larvae died before pupation

  14. 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)

  15. Effect of gamma radiation on the survival of fungal and actinomycetal florae contaminating medicinal plants

    International Nuclear Information System (INIS)

    Aziz, N.H.; El-Fouly, M.Z.; Moussa, L.A.A.; Abu-Shady, M.R.

    1997-01-01

    This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to be increased by increasing the radio-resistance of microorganisms, and hence there is a relationship between the radio-sensitivity of microorganisms and the total lipid mass of flora mycelia. (Author)

  16. Effect of gamma radiation on the survival of fungal and actinomycetal florae contaminating medicinal plants

    Energy Technology Data Exchange (ETDEWEB)

    Aziz, N.H.; El-Fouly, M.Z.; Moussa, L.A.A. [National Center for Radiation Research and Technology, Cairo (Egypt); Abu-Shady, M.R. [Ain Shams Univ., Cairo (Egypt). Faculty of Science

    1997-01-01

    This study evaluates the effect of gamma radiation on the viability of fungi and actinomycetes that contaminate medicinal plants. The relationship between the total lipids of some fungi and actinomycetes and their sensitivity to gamma radiation is also investigated. The data reveal that the viable counts of these florae decrease approximately exponentially with the radiation dose, the effective dose for the elimination of these microorganisms being about 5 kGy for all the medicinal plants under study. Response of pure cultures of fungi and actinomycetes isolated from medicinal plants to increasing absorbed doses of gamma radiation indicate that an increase in radioresistance is in the following order: Streptomyces rimosus, Fusarium solani, Nocardia kuroishii. F. oxysporum, A. fumigatus, A. flavus, A. parasiticus and A. ochraceus. The total lipid contents of molds and actinomycetes have been reported to be increased by increasing the radio-resistance of microorganisms, and hence there is a relationship between the radio-sensitivity of microorganisms and the total lipid mass of flora mycelia. (Author).

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

    International Nuclear Information System (INIS)

    Prokic, M.

    1974-01-01

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

  18. Study of effects gamma radiation linear low density polyethylene (LLDPE) injected

    International Nuclear Information System (INIS)

    Oliveira, Ana Claudia Feitoza de

    2014-01-01

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

  19. Combined effect of gamma radiation and some plant extracts on spodoptera littoralis

    International Nuclear Information System (INIS)

    Ibrahim, R.S.H.

    2012-01-01

    The present investigation was carried out to study the effects of exposure of male full-grown pupae of the cotton leaf worm Spodoptera littoralis to sub sterilizing doses of gamma radiation (100,150 or 300 Gy), treating larval diet with different concentrations of Terminalia arjuna , Erythrine caffra, Taxodium distichum or Melaleuca cajuputi plant extracts on certain biological aspects of the parental (P 1 ),F 1 generation and combined effect of Taxodium distichum(1.25 ethanol , 2.5% water extracts) and 100 Gy of gamma radiation on also, the certain biological aspects of the parental (P 1 ) and first filial (F 1 ) generations. The biological aspects included the effect on fecundity, egg hatchability, mating ability, and malformation, beside larval survival until adult emergence and sex ratio of the produced adult at different mating crosses between treated and untreated or treated other sex. Special attention was given to inherited sterility of treated male. In addition, the studies also explained the effect of gamma radiation and different concentration of plant extracts of Taxodium disticum and combined effect of both on three tested enzymes (TOC,TAC and Cytochrom p 450 ) . In addition the effect of them on the free testosterone .Using radiation in combination with Taxodium disticum gave synergistic effect by decreasing the activity of these enzymes among F 1 adult male.This means that these treatments also interfered in the functions of these enzymes and hormone.

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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