A comparison between rad-hard float zone silicon diodes as gamma dosimeter in radiation processing

International Nuclear Information System (INIS)

Camargo, Fábio de; Gonçalves, Josemary A.C.; Bueno, Carmen C.

2017-01-01

In this work, we report on the results obtained with rad-hard Standard Float Zone (STFZ) and Diffused Oxygenated Float Zone (DOFZ) silicon diodes in radiation processing dosimetry. The dosimetric probes were designed to operate in the direct current mode, as on-line radiation dosimeter. The irradiation of the samples was performed using a 60 Co source with a dose rate of almost 2.4 kGy/h. The current response of each diode was measured as a function of the exposure time in steps from 5 kGy up to 50 kGy to achieve a total absorbed dose of 275 kGy. In this dose range it is observed a significant decrease in the photocurrent generated in both devices due to gamma radiation defects produced in their active volumes. To mitigate this effect, the samples were pre-irradiated with 60 Co gamma rays at 700 kGy. Despite of being less sensitive, these devices presented stable and reproducible current signals with a relative sensitivity decrease of about 19% within the whole range of dose studied. The dose-response curves of the pre-irradiated diodes showed quadratic behavior with correlation coefficient higher than 0.9999 for total absorbed dose up to 275 kGy. The comparison of the FZ and DOFZ responses evidenced that the latter was slightly superior to the first. However, it is important to note that all pre-irradiated diodes can be used as gamma dosimeters in radiation processing applications. (author)

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.

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-.

Virtual Gamma Ray Radiation Sources through Neutron Radiative Capture

Energy Technology Data Exchange (ETDEWEB)

Scott Wilde, Raymond Keegan

2008-07-01

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

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.

Processing of gamma-ray spectrometric logs

International Nuclear Information System (INIS)

Umiastowski, K.; Dumesnil, P.

1984-10-01

CEA (Commissariat a l'Energie Atomique) has developped a gamma-ray spectrometric tool, containing an analog-to-digital converter. This new tool permits to perform very precise uranium logs (natural gamma-ray spectrometry), neutron activation logs and litho-density logs (gamma-gamma spectrometric logs). Specific processing methods were developped to treate the particular problems of down-hole gamma-ray spectrometry. Extraction of the characteristic gamma-ray peak, even if they are superposed on the background radiation of very high intensity, is possible. This processing methode enables also to obtain geological informations contained in the continuous background of the spectrum. Computer programs are written in high level language for SIRIUS (VICTOR) and APOLLO computers. Exemples of uranium and neutron activation logs treatment are presented [fr

Study of the properties of inverted liquid sugar processed with gamma radiation and electron beam

International Nuclear Information System (INIS)

Podadera, Priscilla

2007-01-01

Brazil occupies position of prominence in the sugar market and high consumption of this ingredient in the liquid form, in special for the beverages and food industries. The liquid sugar presents advantages in relation to the bulk granulated system such as easiness of the handling and dosage, reduced space for the storage, reduction of the losses, costs and hand of workmanship, improvement of the sanitizing and great possible variation in the ratios of different mixtures of sugars. The inverted liquid sugar is a solution of sucrose, glucose and fructose in water. This ingredient receives this name because during its production it has an inversion of the optic power of rotation of the solution. In the productive process of the inverted sugar some points occur that can generate contamination by microorganisms, so its become important the development of techniques that propitiate the efficient sanitizing of this raw material. This work aims at to consider two alternative techniques of microbiologic control: gamma radiation with source of cobalto-60 and radiation with electron beam. The study was lead in the doses of 5, 10, 20, 30 and 50 kGy. Concentration of sucrose presented in syrup decreased with the radiation indicating the scission of glycosidic linkage in addition with the glucose and fructose formation, generating the increase in solids soluble. The acid compounds formation occurred, confirmed by the reduction of pH, that it was proportional with the increase of the radiation dose. The biggest doses had provoked change of color in the syrup by the long molecular chain polymers formation. Viscosity in the samples processed by gamma radiation increased in relation to the control, indicating the prevalence of polymerization of molecules, whereas in the radiation with electron beam the polymerization was only observed in the sample that received the dose of 50 kGy, In the sensorial analysis, the judges had pointed significant difference (5%) in the flavor among

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

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1997-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

Energy Technology Data Exchange (ETDEWEB)

Kunstadt, P [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

1998-12-31

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Food irradiation: Gamma processing facilities

International Nuclear Information System (INIS)

Kunstadt, P.

1997-01-01

The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

Radiation processing of horticulture produce

International Nuclear Information System (INIS)

Khandal, R.K.

2004-01-01

The present paper deals with various aspects of radiation processing of horticultural products. The risk and success factors of the radiation processing units would be discussed, based on the experiences gained from the operation of Sac over a period of more than twenty years. Emphasis would be given to gamma radiation processing

Ionization processes in the Fe 27 region of hot iron plasma in the field of hard gamma radiation

International Nuclear Information System (INIS)

Illarionov, A.F.

1989-01-01

A highly ionized hot plasma of an iron 26 56 Fe-type heavy element in the field of hard ionizing gamma-ray radiation is considered. The processes of ionization and recombination are discussed for a plasma consisting of the fully ionized Fe 27 and the hydrogen-like Fe 26 ions of iron in the case of large optical depth of the plasma with respect to the photoionization by gamma-ray quanta. The self-ionization process of a hot plasma with the temperature kT ≅ I (I being the ionization potential), due to the production of the own ionizing gamma-ray quanta, by the free-free (ff) and recombination (fb) radiation mechanisms, is investigated. It is noted that in the stationary situation the process of self-ionization of a hot plasma imposes the restriction upon the plasma temperature, kT<1.5 I. It is shown that the ionization of heavy-ion plasma by the impact of thermal electrons is dominating over the processes of ff- and fb-selfionization of plasma only by the large concentration of hydrogen-like iron at the periphery of the region of fully ionized iron Fe 27

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.)

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

International Nuclear Information System (INIS)

Santos, Paulo S.; Vasquez, Pablo A.S.

2015-01-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Two-faces stationary irradiation method and dosimetric considerations for radiation processing at the multipurpose gamma irradiation facility / IPEN-CNEN

Energy Technology Data Exchange (ETDEWEB)

Santos, Paulo S.; Vasquez, Pablo A.S., E-mail: psantos@ipen.br, E-mail: pavsalva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Over the last ten years, the Multipurpose Gamma Irradiation Facility of the Nuclear and Energy Research Institute - IPEN/CNEN located inside the Sao Paulo University campus has been providing services on radiation processing, especially for sterilization of health care and disposable medical products as well as support to research studies on modification of physical, chemical and biological properties of several materials. Placed at the same campus operates an extremely important radiopharmaceutical production facility when almost all disposable supplies used to produce medical products as the technetium-99m are continuously sterilized by gamma radiation. Many university biomedical research laboratories specially those working with equipment for cell cultures and vaccine production also make use of the gamma sterilization. Animal feed and shavings used by certified bioteries are routinely disinfected. Alternative underwater irradiation methods were developed to meet the demand of gemstone color enhancement. Human tissues including bone, skin, amniotic membranes, tendons, and cartilage belonging to National Banks are usually irradiated too. Different kind of polymers, hydrogels, foods as well native fruits, have been irradiated in this facility. Cultural heritage objects as books, paintings and furniture are disinfected routinely by gamma radiation. The success of the implementation of radiation processing in this facility is due to research and development of irradiation and dosimetry methods suitable for each condition. In this work are presented some considerations about the distribution dose and the two-faces stationary irradiation method developed and validated for this facility. (author)

Possibility of using gamma radiation from HTR reactors for the processing of food and medical products

International Nuclear Information System (INIS)

Pahladsingh, R.R.

2004-01-01

During the fission process in most of the presently operating nuclear reactors nuclear energy is converted into thermal energy and transferred to common steam cycles for power generation. As part of the fission process also α, β and neutrons particles are released from the nucleus; the release of gamma-rays is also a part of the fission process. In present nuclear reactors α, β, neutrons particles and particularly gamma-rays are not gainfully used as a result of the reactor design and of the containment. These plants are built as required by regulations and international standards for safety. The inherently safe HTR reactor, by its physics and design, does not need a special reinforced containment and it is worth looking into the possibilities of this design feature to use the by-products, such as Gamma-rays, from nuclear fission. In the HTR Pebble Bed Reactors the α, and β particles will remain in the kernels of the pebbles. This means that only the neutron particles and gamma-rays will be available outside the reactor pressure vessel. In this report a proposal is presented to use the gamma-rays of the HTR reactor for irradiation of food and agricultural produce. For neutron shielding a reflector is placed inside the reactor while outside the reactor neutron- and thermal-shielding will be accomplished with water. The high energy gamma-rays will pass through the water-shield and could be harnessed for radiation processing of food and medical products. (author)

X-Ray and Gamma-Ray Radiation Detector

DEFF Research Database (Denmark)

2015-01-01

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

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)).

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)

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)

Inactivation of bacterial spores by combination processes: ultraviolet plus gamma radiation. [Streptococcus faecium, micrococcus radiodurans, clostridium botulinum

Energy Technology Data Exchange (ETDEWEB)

Grecz, N; Durban, E

1973-01-01

Bacterial spores, viruses and some vegetative bacteria such as Streptococcus faecium and Micrococcus radiodurans are distinguished by high radiation resistance. In order to lay a theoretical basis for biomedical sterilization applications, we have investigated the combined action of uv and gamma rays. Spores of two strains of C. botulinum were selected, a highly radiation resistant strain, 33A having a D/sub 10/-value of 0.32 Mrad, and a relatively radiation sensitive strain, 51B having a D/sub 10/-value of 0.12 Mrad. Strain 33A exhibits an extensive initial ''shoulder'' in its uv as well as gamma ray survival curves; strain 51B shows only a slight shoulder. The shoulder in the gamma ray survival curve of spores of strain 33A could be reduced or completely eliminated by preirradiation with uv. Simultaneously the D/sub 10/-value for gamma inactivation of spores of 33A was reduced substantially. For example, the gamma resistance was reduced almost to half of its original D/sub 10/-value by uv-preirradiation for only one minute under an 8 watt GE germicidal lamp. The effect of uv-preirradiation on the radiation sensitive strain 51B was less pronounced. In fact, there was about seven fold higher positive interaction (synergism) between uv and gamma radiation in 33A spores than in 51B spores. The experiments suggest that interference with DNA repair enzymes in the radiation resistant strain are responsible for lethal synergism between uv and gamma radiation. A hypothesis is developed attempting to explain the combined effect of these two radiations in terms of a special summation of known DNA lesions in the cell. These observations emphasize the potential practical advantages of combining uv and gamma rays for effective sterilization of certain biomedical devices, drugs and biologicals.

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

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)

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)

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)

The gamma-ray radiation preservation technology for files and books

International Nuclear Information System (INIS)

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

1988-01-01

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

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

Directory of Open Access Journals (Sweden)

Ivanov Kirill E.

2008-01-01

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Progress in gamma processing of commercial products

International Nuclear Information System (INIS)

Fraser, F.M.

1988-01-01

In this paper the global outlook for gamma radiation processing of commercial products is discussed. Canada's contribution to the development of the industry is presented. New developments in the applications of the process and its marketing are discussed. (U.K.)

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

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

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)

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)

Growth of Radiation Processing Plant, Vashi - an overview

International Nuclear Information System (INIS)

Singh, Ranjeet

2014-01-01

Radiation Processing Plant, Vashi (RPP) is the first commercial scale Gamma Irradiator for food processing in India. The facility was commissioned on 1 st January 2000 with the mandate of showcasing commercial viability of food processing using gamma radiation. Some of the food products that are processed at RPP, Vashi include dehydrated onion powder, coriander, turmeric, black pepper, cumin, pet food and dried seafood items. RPP, Vashi is the largest radiation processor of food products in the country. More than 95% of the quantity processed is exported to various countries generating millions of foreign exchange annually

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

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

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

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

Dosimetry and process control for radiation processing

International Nuclear Information System (INIS)

Mod Ali, N.

2002-01-01

Complete text of publication follows. Accurate radiation dosimetry can provide quality assurance in radiation processing. Considerable relevant experiences in dosimetry by the SSDL-MINT has necessitate the development of methods making measurement at gamma plant traceable to the national standard. It involves the establishment of proper calibration procedure and selection of appropriate transfer system/technique to assure adequate traceability to a primary radiation standard. The effort forms the basis for irradiation process control, the legal approval of the process by the public health authorities (medical product sterilization and food preservation) and the safety and acceptance of the product

Advanced multi-dimensional imaging of gamma-ray radiation

International Nuclear Information System (INIS)

Woodring, Mitchell; Beddingfield, David; Souza, David; Entine, Gerald; Squillante, Michael; Christian, James; Kogan, Alex

2003-01-01

The tracking of radiation contamination and distribution has become a high-priority US DOE task. To support DOE needs, Radiation Monitoring Devices Inc. has been actively carrying out research and development on a gamma-radiation imager, RadCam 2000 TM . The imager is based upon a position-sensitive PMT coupled to a scintillator near a MURA coded aperture. The modulated gamma flux detected by the PSPMT is mathematically decoded to produce images that are computer displayed in near real time. Additionally, we have developed a data-manipulation scheme which allows a multi-dimensional data array, comprised of x position, y position, and energy, to be used in the imaging process. In the imager software a gate can be set on a specific isotope energy to reveal where in the field of view the gated data lies or, conversely, a gate can be set on an area in the field of view to examine what isotopes are present in that area. This process is complicated by the FFT decoding process used with the coded aperture; however, we have achieved excellent performance and results are presented here

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)

Poster - 11: Radiation barrier thickness calculations for the GammaPod

International Nuclear Information System (INIS)

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

2016-01-01

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

Poster - 11: Radiation barrier thickness calculations for the GammaPod

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-15

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

Composting of gamma-radiation disinfected sewage sludge

International Nuclear Information System (INIS)

Kawakami, W.; Hashimoto, S.; Watanabe, H.; Nishimura, K.; Watanabe, H.; Ito, H.; Takehisa, M.

1981-01-01

The composting of radiation disinfected sewage sludge has been studied since 1978, aiming to present a new process of sludge composting for agricultural uses. This process is composed of two steps: irradiation step to disinfect sludge, and composting step to remove odor and easily decomposable organics in sludge. In this paper, the gamma-irradiation effect on sludge cake and composting condition of irradiated sludge are discussed. (author)

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.

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.

Development of Quantum Devices and Algorithms for Radiation Detection and Radiation Signal Processing

International Nuclear Information System (INIS)

El Tokhy, M.E.S.M.E.S.

2012-01-01

The main functions of spectroscopy system are signal detection, filtering and amplification, pileup detection and recovery, dead time correction, amplitude analysis and energy spectrum analysis. Safeguards isotopic measurements require the best spectrometer systems with excellent resolution, stability, efficiency and throughput. However, the resolution and throughput, which depend mainly on the detector, amplifier and the analog-to-digital converter (ADC), can still be improved. These modules have been in continuous development and improvement. For this reason we are interested with both the development of quantum detectors and efficient algorithms of the digital processing measurement. Therefore, the main objective of this thesis is concentrated on both 1. Study quantum dot (QD) devices behaviors under gamma radiation 2. Development of efficient algorithms for handling problems of gamma-ray spectroscopy For gamma radiation detection, a detailed study of nanotechnology QD sources and infrared photodetectors (QDIP) for gamma radiation detection is introduced. There are two different types of quantum scintillator detectors, which dominate the area of ionizing radiation measurements. These detectors are QD scintillator detectors and QDIP scintillator detectors. By comparison with traditional systems, quantum systems have less mass, require less volume, and consume less power. These factors are increasing the need for efficient detector for gamma-ray applications such as gamma-ray spectroscopy. Consequently, the nanocomposite materials based on semiconductor quantum dots has potential for radiation detection via scintillation was demonstrated in the literature. Therefore, this thesis presents a theoretical analysis for the characteristics of QD sources and infrared photodetectors (QDIPs). A model of QD sources under incident gamma radiation detection is developed. A novel methodology is introduced to characterize the effect of gamma radiation on QD devices. The rate

RVNRL and radiation processing in Thailand

International Nuclear Information System (INIS)

Siri-Upathum, C.

2000-01-01

Industrial application of radiation processing in Thailand is gaining wide acceptance. The first private-owned radiation sterilization plant was established in 1984. Commercialization of protective rubber gloves from radiation vulcanized of natural rubber latex (RVNRL) started in 1993. Two new sterilization plants using electron beam accelerator and gamma irradiation were commissioned in 1997 and 1999 respectively. Another gamma sterilization plant is scheduled to operate in the year 2000. Additional electron accelerator is being installed in one operational gamma sterilization plant, for upgrading of gemstones. Research and development at Office of Atomic Energy for Peace (OAEP) and universities has been focused on RVNRL, radiation treatment of sludge, grafting of cassava starch and utilization of irradiated silk protein. Except for RVNRL which has passed to commercial scale, pilot scale of radiation treatment of sludge has achieved its goal to be utilized as new resources for animal feed and fertilizer. (author)

RVNRL and radiation processing in Thailand

Energy Technology Data Exchange (ETDEWEB)

Siri-Upathum, C. [Department of Nuclear Technology, Faculty of Engineering, Chulalongkorn University, Bangkok (Thailand)

2000-03-01

Industrial application of radiation processing in Thailand is gaining wide acceptance. The first private-owned radiation sterilization plant was established in 1984. Commercialization of protective rubber gloves from radiation vulcanized of natural rubber latex (RVNRL) started in 1993. Two new sterilization plants using electron beam accelerator and gamma irradiation were commissioned in 1997 and 1999 respectively. Another gamma sterilization plant is scheduled to operate in the year 2000. Additional electron accelerator is being installed in one operational gamma sterilization plant, for upgrading of gemstones. Research and development at Office of Atomic Energy for Peace (OAEP) and universities has been focused on RVNRL, radiation treatment of sludge, grafting of cassava starch and utilization of irradiated silk protein. Except for RVNRL which has passed to commercial scale, pilot scale of radiation treatment of sludge has achieved its goal to be utilized as new resources for animal feed and fertilizer. (author)

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/).

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

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)

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)

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)

Development of radiation safety monitoring system at gamma greenhouse gamma facility

International Nuclear Information System (INIS)

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

2009-01-01

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

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.

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.

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

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)

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)

Evaluation of the effects of gamma radiation in minimally processed vegetables of Brassica oleracea species

International Nuclear Information System (INIS)

Nunes, Thaise Cristine Fernandes

2009-01-01

The consumption of collard greens (Brassica oleracea cv. acephala) and broccoli (Brassica oleracea L. var. italica) has been inversely associated with morbidity and mortality caused by degenerative diseases. These species are highly consumed in Brazil, which enables its use as minimally processed (MP). The growing worldwide concern with the storage, nutritional quality and microbiological safety of food has led to many studies aimed at microbiological analysis, vitamin and shelf life. To improve the quality of these products, radiation processing can be effective in maintaining the quality of the product, rather compromising their nutritional values and sensory. The aim of this study was to evaluate the effectiveness of gamma radiation from 60 Co at doses of 0, 1.0 and 1.5 kGy on the reduction of microbiota in these plants, and analyze their nutritional and sensory characteristics. The methodology used in this study was microbiological analysis, colorimetric analysis, analysis of phenolic compounds, antioxidant analysis and sensory analysis. The microbiological analysis showed a decrease in the development of populations of aerobic microorganisms, psychotropic and yeast and mold with increasing doses of radiation. The sensory analysis showed no significant difference between different times of cooking analyzed. The analysis of phenolic compounds, significant differences between the samples, suggesting that with increasing dose of irradiation was an increase in the amount of phenolic compounds found in broccoli and collard greens MP. It can be observed that the sample of control collard greens showed high antioxidant activity and for the samples treated by irradiation was a decrease of percentage. In contrast the samples of broccoli show an increase in the rate of scavenging DPPH with increase of the dose of radiation. The colorimetric analysis revealed that for samples of MP collard greens and broccoli foil of no significant differences, but for samples of stems of

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.

Radiation safety for operators of gamma irradiation plants

International Nuclear Information System (INIS)

1989-01-01

These notes have been prepared by the UK Panel for Gamma and Electron Irradiation with advice from the HSE (Technology Division and Factory and Agricultural Inspectorate) to assist operators of Gamma irradiation plants to comply with the requirements of the Ionising Radiations Regulations (IRR 1985), and other relevant regulations (see below). The process is currently used for the sterilisation of medical devices and in the treatment of plastics materials etc. The Government has proposed that the process should also be permitted for the treatment of foodstuffs, and these notes will also be relevant to any irradiation plants which may be used in the UK for this purpose. (author)

Cosmic gamma-ray background radiation. Current understandings and problems

International Nuclear Information System (INIS)

Inoue, Yoshiyuki

2015-01-01

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

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)

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

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.

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)

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

CERN Document Server

Bratchenko, M I; Rozhkov, V V

2001-01-01

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

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.)

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)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-07-01

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

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

International Nuclear Information System (INIS)

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

2017-01-01

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

Radiation-induced reduction of diuron by gamma-ray irradiation

International Nuclear Information System (INIS)

Zhang Jibiao; Zheng Zheng; Zhao Tan; Zhao Yongfu; Wang Lianhong; Zhong Yun; Xu Yue

2008-01-01

Diuron degradation efficiencies and the proposed mechanism by gamma-ray irradiation were investigated. Several factors that might affect the degradation values were further examined. The UV absorbances at 200-400 nm and diuron concentration decreased with the increase of radiation dose. When diuron initial concentration was 18.5 mg L -1 and 1.0 kGy was selected as the radiation dose, diuron removal value and loss of total organic carbon were 100 and 34.1%, respectively. However, the concentration of Cl - ion increased with the increase of radiation dose. The process could be depicted by first order reaction kinetics and the reaction was mainly caused by the reaction of diuron with ·OH and e aq - . The degradation efficiency decreased with the increase of initial concentration at the same radiation dose. H 2 O 2 , HCO 3 - , NO 3 - , NO 2 - , CH 3 OH and humic acid as additives reduced the degradation efficiency. Furthermore, the increase of NO 3 - , NO 2 - , CH 3 OH and humic acid would result in the decrease of the degradation values. The pH value could affect the removal efficiency and the degradation process was enhanced in acid condition. The pH value became lower with increasing radiation dose after gamma-ray irradiation

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)

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)

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)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2004-12-16

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

Process for constructing a gamma thermometer

International Nuclear Information System (INIS)

Barbet, M.J.P.; Cohen, B.S.; Robillard, M.

1982-01-01

A process is described for constructing a gamma thermometer having a substance absorbing the radiation and a set of thermocouples for measuring the local power in a fuel assembly of a nuclear reactor. A claim is particularly made for the preparation of the tube containing it and for its filling with an inert gas [fr

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)

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

Radiation breeding researches in gamma field. Results of researches

International Nuclear Information System (INIS)

Morishita, Toshikazu

2006-01-01

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

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

International Nuclear Information System (INIS)

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

2001-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1982-12-01

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

Treatment of Municipal and Industrial Waste by Radiation Processing

International Nuclear Information System (INIS)

Abdelaziz, M.E.

1999-01-01

In recent years the effort in science and technology is shifting from conventional technologies preventing the pollution of air, water and soil, towards processing by gamma or by electron beam (EB) irradiation in order to prevent pollution, rather than curing the problems caused by production processes, which are not optimized with regard to pollution control. Radiation processing may help to improve the environmental situation in two aspects : It provides alternatives to conventional technologies for the cleaning of air, flue gases and water,...etc, and it also helps to realize clean processes for preventing pollution in the first place. This paper will outline the basic principles of radiation processing for waste streams of environmental relevance, will summarize the state-of -the-art in environmental applications of radiation processing to show both the advantages and the limitations of the radiation processing of waste streams, and to highlight the environmental and economic benefits of clean processes made possible by radiation processing applied to municipal and industrial waste. Reference is made to gamma and EB radiation sources, and description of new technologies is presented

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

International Nuclear Information System (INIS)

Nonato, Fernanda Beatrice Conceicao

2010-01-01

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

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.

Radiation-induced reduction of diuron by gamma-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Zhang Jibiao [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zheng Zheng [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)], E-mail: zzheng@nju.edu.cn; Zhao Tan [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Zhao Yongfu [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Institute of Atomic Energy, Jiangsu Academy of Agriculture Sciences, Nanjing 210014 (China); Wang Lianhong; Zhong Yun; Xu Yue [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

2008-03-01

Diuron degradation efficiencies and the proposed mechanism by gamma-ray irradiation were investigated. Several factors that might affect the degradation values were further examined. The UV absorbances at 200-400 nm and diuron concentration decreased with the increase of radiation dose. When diuron initial concentration was 18.5 mg L{sup -1} and 1.0 kGy was selected as the radiation dose, diuron removal value and loss of total organic carbon were 100 and 34.1%, respectively. However, the concentration of Cl{sup -} ion increased with the increase of radiation dose. The process could be depicted by first order reaction kinetics and the reaction was mainly caused by the reaction of diuron with {center_dot}OH and e{sub aq}{sup -}. The degradation efficiency decreased with the increase of initial concentration at the same radiation dose. H{sub 2}O{sub 2}, HCO{sub 3}{sup -}, NO{sub 3}{sup -}, NO{sub 2}{sup -}, CH{sub 3}OH and humic acid as additives reduced the degradation efficiency. Furthermore, the increase of NO{sub 3}{sup -}, NO{sub 2}{sup -}, CH{sub 3}OH and humic acid would result in the decrease of the degradation values. The pH value could affect the removal efficiency and the degradation process was enhanced in acid condition. The pH value became lower with increasing radiation dose after gamma-ray irradiation.

Evaluation of the processing of dry biological ferment for gamma radiation

International Nuclear Information System (INIS)

Sabundjian, Ingrid Traete

2007-01-01

The developed work had with objectives to demonstrate if it had alteration in the growth of UFC in plate and in the viability of yeasts and total bacteria when dry biological ferment was dealt with by different doses to gamma radiation and under different times storage, to determine the D10 dose for total bacteria and yeasts in this product and to analyzed the processing of this product it promoted some benefit without causing unfeasibility of exactly. The different samples of dry biological ferment had been irradiated at IPEN in a Gammacell - 220 source at 0.5; 1; 2 and 3 kGy doses (dose rate of 3.51 kGy/h). This procedure referring samples to each dose of radiation had been after destined to the microbiological analysis and the test of viability while excessively the samples had been stored the ambient temperature (23 degree C). The increase of the dose of radiation caused a reduction in the counting of yeasts growth, of total bacteria growth and also in the frequency of viable yeast cells, demonstrated by FDA-EB fluorescent method. Beyond of radiation the storage time also it influenced in counting reduction of total bacteria and reduction of frequency of viable cells. According with the analysis of simple linear regression, the dose of radiation necessary to eliminate 90% of the yeast population was between 1.10 and 2.23 kGy and for the bacterial population varied between 2.31 and 2.95 kGy. These results demonstrated clearly the negative points of the application of ionizing radiation in dry biological ferment; therefore the interval of D10 found for total bacteria is superior to found for yeasts. Being thus, the use of this resource for the improvement of the product quality becomes impracticable, since to reduce significantly the bacterial population necessarily we have that to diminish the population of yeasts. With yeasts reduction of we will go significantly to modify the quality and the viability of product. (author)

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.

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.

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

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)

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)

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)

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.

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

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.

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.

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.

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)

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)

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.)

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.)

The study analysis of degradation product of Tributyl Phosphate by Gamma radiation and influence in extraction process

International Nuclear Information System (INIS)

Damunir; Didiek Herhady, R; Busron-Masduki; Ashar-Waskito; Armanu

1996-01-01

The analysis study of degradation product of TBP by gamma radiation using Co-60 Irradiator Irvasena was done. The investigation stressed on analysis and the relation of degradation product of TBP and extraction process. TBP-dodecane 30 % irradiated by radiation doses 1.172x10 3 rad, 1.155x10 5 rad, 1.125x10 7 and 1.155x10 9 rad. The analysis of degradation product of TBP mainly of MBP and DBP were determined in the mixture media of 5 ml isopropyl alcohol, 5 ml ethylene glycol, 5 ml acetone and 15 ml alcohol with potentiometric titration using NaOH 0.1 N in the alcohol solution, at potential condition of 500 mV and potential derivative 500 mV. The experiment shows that the gamma radiation doses 1.125x10 7 rad result 0.125 ± 0.049 mg MBP/ml solvent and 1.556 ± 0.084 mg DBP/ml solvent and radiation doses 1.115x10 9 rad result 26.135 ± 0.114 mg MBP/ml solvent and 62.454 ± 1.107 mg DBP/ml solvent, MBP dan DBP un detectable for radiation doses 1.172x10 3 rad and 1.055x10 5 rad. The result of MBP and DBP analysis compare to Tachehiko Ishihara and Erich Zimmer, using potentiometric titration method for MBP and DBP analysis was reliable addition and none addition. The TBP-dodecane solvent was irradiation by radiation doses 10 7 rad or greater than, is suggested to treat the solvent by regeneration so that doesn't disturbance extraction

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

DEFF Research Database (Denmark)

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

2011-01-01

Eight national standards for absorbed dose to water in 60Co gamma radiation at the dose levels used in radiation processing have been compared over the range from 1 kGy to 30 kGy using the alanine dosimeters of the NIST and the NPL as the transfer dosimeters. The comparison was organized...... by the Bureau International des Poids et Mesures, who also participated at the lowest dose level using their radiotherapy-level standard for the same quantity. The national standards are in general agreement within the standard uncertainties, which are in the range from 1 to 2 parts in 102. Evidence of a dose...

Radiation processing of food and agricultural commodities

International Nuclear Information System (INIS)

Sharma, Arun

2014-01-01

Reducing post-harvest food losses is becoming increasingly important for sustaining food supplies. Appropriate post-harvest processing, handling, storage and distribution practices are as important as the efforts to increase productivity for improving food security, food safety and international trade in agricultural commodities. Preservation of food by ionizing radiation involves controlled application of energy of ionizing radiation such as gamma rays, X-rays, and accelerated electrons to agricultural commodities, food products and ingredients, for improving their storage life, hygiene and safety. The process employs either gamma rays emitted by radioisotopes such as cobalt-60 or high-energy electrons or X-rays generated from machine sources

GammaCam trademark radiation imaging system

International Nuclear Information System (INIS)

1998-02-01

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

Radiation processing in India. Current status and future program

International Nuclear Information System (INIS)

Mittal, Jai Pal

2003-01-01

Radiation processing is an alternative to conventional methods such as thermal and chemical processing in many industrial applications. In India, this technology has found extensive applications in area of healthcare, agriculture, food preservation, industry and environment. Both gamma radiation and electron beam accelerators are being utilized for this purpose. Presently, 6 commercial gamma irradiators housing about 1.5 million curie Co-60 and an annual turnover of over US$ 2 million and 3 commercial electron beam (EB) accelerators with installed capacity of 185 kW are commercially operating in India. Five demonstration plants housing a total of 0.5 million curie Co-60 have been set up to assess the techno-commercial viability of the processes such as radiation vulcanization of natural rubber latex, decontamination of spices, hygienization of sewage sludge, shelf-life extension of onions. The new areas being explored include use of electron beam treated pulp for viscose-rayon process, radiation processed 'hydrogel' burn/wound dressings and radiation processing of natural polymers. In the present paper, the current status of this program, especially the recent developments and future direction of radiation processing technology in India is reviewed. (author)

Characteristics of liver tissue for attenuate the gamma radiation; Caracteristicas del tejido hepatico para atenuar la radiacion gamma

Energy Technology Data Exchange (ETDEWEB)

Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Amador V, P.; Chacon R, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2005-07-01

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

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

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.

Radiation processing with high-energy X-rays

International Nuclear Information System (INIS)

Cleland, Marshall R.; Stichelbaut, Frederic

2009-01-01

The physical, chemical or biological characteristics of selected commercial products and materials can be improved by radiation processing. The ionizing energy can be provided by accelerated electrons with energies between 75 keV and 10 MeV, gamma rays from cobalt-60 with average energies of 1.25 MeV or X-rays with maximum energies up to 7.5 MeV. Electron beams are preferred for thin products, which are processed at high speeds. Gamma rays are used for products that are too thick for treatment with electron beams. High-energy X-rays can also be used for these purposes because their penetration in solid materials is similar to or even slightly greater than that of gamma rays. Previously, the use of X-rays had been inhibited by their slower processing rates and higher costs when compared with gamma rays. Since then, the price of cobalt-60 sources has been increased and the radiation intensity from high-energy, high-power X-ray generators has also increased. For facilities requiring at least 2 MCi of cobalt-60, the capital and operating costs of X-ray facilities with equivalent processing rates can be less than that of gamma-ray irradiators. Several high-energy electron beam facilities have been equipped with removable X-ray targets so that irradiation processes can be done with either type of ionizing energy. A new facility is now being built which will be used exclusively in the X-ray mode to sterilize medical products. Operation of this facility will show that high-energy, high-power X-ray generators are practical alternatives to large gamma-ray sources. (author)

A new radiochromic film for radiation processing

International Nuclear Information System (INIS)

Sidney, L.N.; Lynch, D.C.; Willett, P.S.; Englund, W.J.

1990-01-01

Acid-sensitive leuco dyes in combination with a chlorine-containing polymer have been used to make a new kind of radiochromic film for radiation processing. When exposed to gamma, electron beam, or high intensity ultraviolet radiation, these films undergo a color change from colorless to royal blue, fuschia, or black, depending on the dye. The dose response for gamma and electron beam radiation has been characterized using reflection and transmission spectrophotometry over an adsorbed dose range of 1 to 100 kGy. The primary features of the films include improved color stability before and after irradiation and improved moisture resistance. The response and stability of the films make them useful for indicator (qualitative) or dosimeter (quantitative) films or labels for sterilization of medical products, food (especially meat, poultry, and spices), pharmaceuticals, and cosmetics, and the crosslinking of plastics, and the curing of polymer coatings. Large pieces of the film could be used in dose mapping when setting up and validating radiation processes and medical treatments

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.

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.

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.

Directory of gamma processing facilities in Member States

International Nuclear Information System (INIS)

2004-02-01

Ionizing radiation can modify physical, chemical and biological properties of materials. This characteristic of radiation was recognised very soon after the discovery of radioactivity. At present, the principal applications concern sterilisation of health care products, food irradiation and materials modification for polymers. Besides naturally occurring radioactive isotopes, artificial ones were produced using cyclotrons. A significant impetus, however, was given to the radiation processing industry with the advent of nuclear reactors, which were used to produce radioisotopes. Gamma ray emitters like cobalt-60 became popular radiation sources for medical and industrial applications. Many gamma ray irradiators have been built and it is estimated that less than 200 are currently in operation all over the world. In recent times, the use of electron accelerators as a radiation source (sometimes equipped with X ray converter) is increasing. However, gamma irradiators are difficult to replace, especially in the case of non-uniform and high-density products. The International Atomic Energy Agency (IAEA) has several programmes related to industrial irradiation applications for processing of various products including those related to health care, pharmaceuticals, food and polymers, and applications associated with plant design, dosimetry and safety. Through the technical co-operation programme, the IAEA supports these activities in developing countries and helps them to build local capacity to implement various industrial applications of radiation processing. The IAEA also organises and conducts training courses and workshops, provides individual training to personnel, and sends experts to the radiation facilities in Member States where help is needed. All these activities can be carried out much more efficiently and effectively if there were a comprehensive directory of radiation facilities operating in Member States. Also, such a compilation would be a valuable tool for

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.

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)

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)

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)

Radiation processing of food to ensure food safety and security

International Nuclear Information System (INIS)

Gautam, Satyendra

2016-01-01

Radiation processing of food utilizes the controlled application of energy from ionizing radiations such as γ-rays , electrons and X-rays on food. Gamma-rays and X-rays are short wavelength radiations of the electromagnetic spectrum. The approved sources of gamma radiation for food processing are radioisotopes (Cobalt-60 and Caesium-137), electron beam (up to 10 MeV) and X-rays (up to 5 MeV) wherein the latter two are generated by machines using electricity. γ-radiation can penetrate deep into the food materials causing the desired effects. Irradiation works by disrupting the biological processes that lead to decay. While interacting with water and other biomolecules that constitute the food and living organisms, radiation energy is absorbed by these molecules. The interactions of radiation and radiolytic products of water with DNA impair the reproduction of microorganism and insects, and thus help in achieving the desired objectives pertaining to food safety and security

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

The characterization of wound dressing poly (vinyl pyrrolidone) hydrogels using gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Rezende, Talita C.; Pinheiro, Christiano J.G., E-mail: talitacolombi@yahoo.com, E-mail: christrieste@yahoo.it [Universidade Federal do Espirito Santo (CCA/UFES), Alegre, ES (Brazil). Programa de Pós-Graduação em Engenharia Química; Paula, Heberth D., E-mail: hdpaula@gmail.com [Universidade Federal do Espirito Santo, Alegre (UFES), ES (Brazil). Departamento de Farmácia; Morais, Pedro A.B., E-mail: pedmora2005@gmail.com [Universidade Federal do Espirito Santo (UFES), Alegre, ES (Brazil). Departamento de Química

2017-07-01

The first hydrogel for wound dressing processed by radiation was developed in Poland in 1986 by the inventor Janusz M. Rosiak and reached the local market in 1992. Laboratories of developing countries, which face all kinds of restrictions, were seduced by the simplicity of the process and low cost of its raw materials. It was a technological breakthrough due to its painless product characteristics and having improved healing properties such as absorbing a high water capacity, attached to healthy skin, and being easy to remove, plus its intelligent production process combining sterilization and crosslinking in a simultaneous operation. The use of hydrogels as biomaterials has increased recently. Hydrogel wound dressings were prepared using the gamma ray irradiation technique. Radiation was applied as a tool for crosslinking and sterilization of these materials. The hydrogels are composed of poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG) and agar at radiation doses of 15, 20, 25, 30 kGy. The influence of some process parameters on their properties was investigated by: sterilization, gel fraction, swelling measures and mechanical properties. Hydrogels with less than 20 kGy of radiation were not properly sterilized. The gel fraction and swelling increased with increasing radiation dose due to increased crosslinking density, and at 25kGy, obtained optimum swelling. No significant differences were found for the test of mechanical properties but hydrogel matrices of different doses of gamma radiation. (author)

The characterization of wound dressing poly (vinyl pyrrolidone) hydrogels using gamma radiation

International Nuclear Information System (INIS)

Rezende, Talita C.; Pinheiro, Christiano J.G.; Paula, Heberth D.; Morais, Pedro A.B.

2017-01-01

The first hydrogel for wound dressing processed by radiation was developed in Poland in 1986 by the inventor Janusz M. Rosiak and reached the local market in 1992. Laboratories of developing countries, which face all kinds of restrictions, were seduced by the simplicity of the process and low cost of its raw materials. It was a technological breakthrough due to its painless product characteristics and having improved healing properties such as absorbing a high water capacity, attached to healthy skin, and being easy to remove, plus its intelligent production process combining sterilization and crosslinking in a simultaneous operation. The use of hydrogels as biomaterials has increased recently. Hydrogel wound dressings were prepared using the gamma ray irradiation technique. Radiation was applied as a tool for crosslinking and sterilization of these materials. The hydrogels are composed of poly (N-vinyl-2-pyrrolidone) (PVP), poly (ethylene glycol) (PEG) and agar at radiation doses of 15, 20, 25, 30 kGy. The influence of some process parameters on their properties was investigated by: sterilization, gel fraction, swelling measures and mechanical properties. Hydrogels with less than 20 kGy of radiation were not properly sterilized. The gel fraction and swelling increased with increasing radiation dose due to increased crosslinking density, and at 25kGy, obtained optimum swelling. No significant differences were found for the test of mechanical properties but hydrogel matrices of different doses of gamma radiation. (author)

Radiation processing of liquid with low energy electron accelerator

Energy Technology Data Exchange (ETDEWEB)

Makuuchi, Keizo [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2003-02-01

Radiation induced emulsion polymerization, radiation vulcanization of NR latex (RVNRL) and radiation degradation of natural polymers were selected and reviewed as the radiation processing of liquid. The characteristic of high dose rate emulsion polymerization is the occurrence of cationic polymerization. Thus, it can be used for the production of new materials that cannot be obtained by radical polymerization. A potential application will be production of polymer emulsion that can be used as water-borne UV/EB curing resins. The technology of RVNRL by {gamma}-ray has been commercialized. RVNRL with low energy electron accelerator is under development for further vulcanization cost reduction. Vessel type irradiator will be favorable for industrial application. Radiation degradation of polysaccharides is an emerging and promising area of radiation processing. However, strict cost comparison between liquid irradiation with low energy EB and state irradiation with {gamma}-ray should be carried out. (author)

The utilize of gamma radiation on the examination of mechanical properties of polymeric materials

Directory of Open Access Journals (Sweden)

F. Greškovič

2012-04-01

Full Text Available The article deals about the application area of radiation crosslinking of plastics, which follows after the injection moulding. The main objective of the presented article is the research of influence irradiation dosage on mechanical properties of materials: PP filled by 15 % of mineral filler – talc. Mechanical properties - tensile strength and impact strength by Charpy were examined in dependence on absorbed dose of the gamma rays on various conditions and were compared with non-irradiated samples. Radiation processing involves mainly the use of either electron beams from electron accelerators or gamma radiation from Cobalt-60 sources.

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.

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

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

Impact of Gamma Radiation Processing to Improve the Hygienic Quality of some Chicken Products

International Nuclear Information System (INIS)

Mohamed, W.S.; El-Mossalami, I.I.; Nosier, S.M.

2009-01-01

For food to be entirely safe from the microbiological viewpoint, it must need to contain the least possible counts of microorganisms of hygienic importance. This investigation aims to study the possible use of gamma radiation for bacterial decontamination of chicken products which are produced in Egypt. One hundred and twenty samples of frozen chicken kofta and burgers (60 each) were purchased from retail markets at Cairo Governorate. They were surveyed for the hygienic quality as well as the effect of gamma radiation (dose levels of 1, 2 and 3 kGy) on the bacterial population, chemical and sensory quality of these products. The results indicated that the total aerobic bacterial counts (APC) ranged from 106 to 107 cfu/g in the examined samples. Moreover, some samples were contaminated with food borne pathogens such as Listeria species and Salmonella species. Gamma irradiation greatly reduced the microbial density of the studied food samples. The microbial reduction increased as the dose level of irradiation increase, whereas irradiation of chicken products at 3 kGy dose reduced aerobic counts and eliminated Salmonella and Listeria species, also it proved to be of great importance in increasing the safety and acceptability of ready to eat frozen chicken products with no adverse effect on their chemical or sensory quality

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.

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.

Sources of gamma radiation in a reactor core

Energy Technology Data Exchange (ETDEWEB)

Roos, Matts

1959-05-15

In a thermal reactor the gamma ray sources of importance for shielding calculations and related aspects are 1) fission, 2) decay of fission products, 3) capture processes in fuel, poison and other materials, 4) inelastic scattering in the fuel and 5) decay of capture products. The energy release and the gamma ray spectra of these sources have been compiled or estimated from the latest information available, and the results are presented in a general way to permit application to any thermal reactor, fueled with a mixture of {sup 235}U and {sup 238}U. As an example the total spectrum and the spectrum of radiation escaping from a fuel rod in the Swedish R3-reactor are presented.

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)

Evaluation of the effects of gamma radiation on physicochemical characteristics of kiwi (Actinidia deliciosa) cv. Hayward minimally processed

International Nuclear Information System (INIS)

Oliveira, Ana Claudia Sampaio

2011-01-01

The search for a healthy life has led consumers to rethink their eating habits, consuming fruits and vegetables in place of manufactured products, therefore, the demand for minimally processed products has evolved rapidly. The kiwi fruit (Actinidia deliciosa) has high nutritional value, being rich in C vitamin especially, which has wide acceptance in consumer markets. Thus, along with papaya, passion fruit and pineapple, kiwi can be considered as an additional feature of C vitamin in the diet, or as a substitute for traditional citrus. The aim of this study was to assess the effects of gamma radiation on physical and chemical characteristics of kiwis minimally processed and stored under refrigeration, since this technology increases the shelf life of fruits and vegetables. The Kiwis was stripped, processed and cut into slices, stored in polyethylene bags of 10 cm squared and irradiated at doses of 0 (control), 1 and 2 kGy. A source of 60 Co Gammacell 220, dose rate of 0.429 kGy/hour, in which each treatment had 5 replicates with 15 slices of kiwifruit per replicate. After irradiation the samples were stored in a climatic chamber at 6 degree C (near the temperature of commercial refrigerators). The following criteria were physical chemical analysis: pH, color, chlorophyll content, loss of weight, moisture, acidity and Brix. The analysis were done on 1 st , 7 th and 14 th days after irradiation. The results indicated that gamma radiation did not induce deleterious changes in the physicochemical properties of the kiwi may be used for preservation of minimally processed kiwifruit. (author)

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

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

International Nuclear Information System (INIS)

Aquino, Simone; Araujo, Michel M.; Villavicencio, A.L.C.H.; Goncalez, Edlayne; Reis, Tatiana A. dos; Correa, Benedito

2007-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2007-07-01

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

Status of radiation processing: Indian scenario

International Nuclear Information System (INIS)

Niyogi, U.K.

2013-01-01

Radiation processing is a technique to process different types of materials by way of providing radiations of different energies for various applications. Depending upon the changes, one needs to select the radiations of appropriate energy. The well established mechanism behind the changes occurring in the material is the excitation of electrons in the molecules and atoms. It is a proven technology for more than five decades which results in the modification in materials, both at the bulk and surface levels. While radiations such as IR and UV have low energy and hence affect the surface of the material only, highly energetic radiations such as gamma and e-beam are useful to modify the material at the bulk level. Radiation processing is the most efficient technique for polymerization, sterilization, disinfestations, etc. which are applied in industries such as wires and cables, healthcare, food processing, pet/animal feed, herbal and ayurvedic, artificial jewellery, etc.

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

EPR-dosimetry for radiation processing of food

International Nuclear Information System (INIS)

Peimel-Stuglik, Z.; Fabisiak, S.

2002-01-01

The usefulness of two, easy accessible alanine-polymer dosimeters to low (D ≤ 10 kGy) ionizing radiation dose measurements, were investigated. In both cases (ALANPOL from IChTJ and foil dosemeters from Gamma Service, Radeberg, Germany) the results were positive. EPR-alanine method based on the described dosimeters meets the requirements to use it in radiation processing of food. Thin foil dosemeters from Gamma Service are recommended mainly for dose distribution measurements. ALANPOL - for routine use. The advantage of ALANPOL is lower price, higher sensitivity and high resistance to unfavourable environmental conditions, including water. (author)

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)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-06-15

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

A biotechnological project with a gamma radiation source of 100,000 Ci

International Nuclear Information System (INIS)

Lombardo, J.H.; Smolko, E.E.

1990-01-01

A project for the production of radiovaccines and other bio-medical products is presented which includes a radiation facility provided with a gamma ray source equivalent to 100,000 Ci of Co-60. The whole process incorporates novel basic features in virus production and inactivation steps. The former is carried out in animals previously subjected to immunodepression through electromagnetic radiation. The latter is obtained at low temperatures by using either electromagnetic or particle radiations. A vaccine manufacture process is shown to illustrate the utilization of ionizing radiations to obtain a foot and mouth disease virus (FMDV) vaccine with good antigenic quality and low cost. (author)

Gamma radiation and its role in bio prosthetic aortic valves implanted in rat hearts

International Nuclear Information System (INIS)

Lamas, Gloria I.; Kairiyama, Eulogia; Navia, Jose

2000-01-01

Porcine heart valves glutaraldehyde fixed are implanted in patients with valvular deterioration. Mineralization may be the major factor in the long-term failure of tissue bio prosthesis. Gamma radiation randomly breaks some glutaraldehyde cross-links. As a consequence of irradiation, the polymeric fibers belonging to the valvular tissue are broken too, leading to sites of collagen fiber disorganisation. It is well known that the collagen fibers may act as a passive nucleator of salts where the calcium phosphate salts precipitate. This salt concentration has been described in association with disintegrated sites of protein fiber, which may favour new sites where the calcium salts would be deposit. The irradiation process is a technique used for sterilization of porcine heart valve. The main objective of this work was to study the effect of different doses of gamma radiation on the calcification process of subcutaneously implanted valves in rats. Small pieces from glutaraldehyde fixed valves, irradiated to different doses with a 60 Co sources were implanted subcutaneously in rats. The calcium was measured by X-ray and atomic absorption spectrophotometry. In our experimental conditions and at the radiation doses used in these tests, the calcium measurements on control and irradiated material were not significantly different. We conclude that, at the employed doses, the gamma radiation does not alter the process. (author) [es

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)

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.

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

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)

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

Radiation dosimetry for commissioning Egypt's 'ega-gamma I' facility for radiation processing

International Nuclear Information System (INIS)

El-Behay, A.Z.; Rageh, S.I.; El-Assy, N.B.; Roushdy, H.

1981-01-01

The use of ionizing radiation for sterilization of medical products and biological tissues has become an alternative to autoclaving or gas treatment by ethylene oxide. Moreover, large radiation facilities are now increasing for processing many industrial products, such as rubber, textiles, plastics, coatings, films, wire and cable. For quality control of irradiated products released to the public, greater consideration is now being given to the use of physical radiation dosimetry, since it is simple, reliable, and reproducible. This work describes dosimetry for the new 60 Co irradiation plant, located at the National Center for Radiation Research and Technology of Egypt. Detailed measurements of absorbed dose extremes in product boxes processed in the plant were made using commercially supplied dyed plastic dosimeters (Red Acrylic and Red Perspex). These physical dosimeters were calibrated against the yield of cerous ion due to γ-ray irradiation of ceric sulphate solution as a standard chemical dosimeter. (author)

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.

Radiation processing. Current status and future possibilities

International Nuclear Information System (INIS)

Woods, R.J.

2000-01-01

Radiation processing developed following the Second World War and employees gamma- or electron-irradiation to process polymers, cure alkene-based inks and coatings, sterilize medical supplies, irradiate food, and manage wastes. The current status of these applications is described with the probable direction of future developments. (author)

Thermal effects in radiation processing

International Nuclear Information System (INIS)

Zagorski, Z.P.

1985-01-01

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

Thermal effects in radiation processing

International Nuclear Information System (INIS)

Zagorski, Z.P.

1984-01-01

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

Recent developments in the field of radiation processing

International Nuclear Information System (INIS)

Andrzej, G. Chmielewski

2006-01-01

Full text: Radiation has been discovered more than one hundred years ago. Since than, properties of radiation to modify physico-chemical properties of materials have found many applications. Radiation technologies applying gamma sources and electron accelerators for material processing are well established processes. There are over 160 gamma industrial irradiators and 1300 electron industrial accelerators in operation worldwide. They are being widely used for sterilization, food irradiation and polymer processing. New developments in the field of radiation sources engineering are compact size gamma irradiators, high power electron accelerators (medium energy range) for environmental applications and other types (high energy range) for materials' processing, with direct e-/X conversion. Future applications of low energy, inexpensive EB processing systems are foreseen. Electron beam lithography for microelectronics is a well-established technique. The already tested e-/X system equipped in an accelerator of 700 kW power opens new horizons for this kind of application. The developments described above need introduction of new computational methods that facilitate prediction of dose distribution, even in containers filled with complex products of varying densities. This technique provides good solutions for homeland security applications which may be complemented by mobile system applications. Technologies to be developed besides environmental applications could be nano materials, structure engineered materials (sorbents, the composites, ordered polymers, etc.) and natural polymers' processing. New products based on radiation processed polysaccharides have already been commercialized in many countries of the East Asia and Pacific Region, especially in those being rich in natural polymers. Very important and promising applications concern environment protection - radiation technology being a clean and environment friendly process, helps to curb pollutants' emission as

Use of ionising radiation for food processing applications

International Nuclear Information System (INIS)

Ninjoor, V.

1989-01-01

Food irradiation is a recently developed technique used to sterilize and preserve food. Food products are exposed to ionising radiations such as X-rays, gamma rays or high energy electrons which destroy food borne pathogens and parasites and inhibit sprouting. Shelf life of food is extended. The following aspects of radiation processing of food are discussed in the monograph: radiation sources, choice of dose for specific results, safety and nutritional quality of radiation processed food, international status of acceptance of food irradiation, and cost. (M.G.B.). 6 tabs

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).

Development of a novel gamma probe for detecting radiation direction

Science.gov (United States)

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

2016-01-01

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

Development of a novel gamma probe for detecting radiation direction

International Nuclear Information System (INIS)

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

2016-01-01

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

Application of Gamma Radiation for Removal of Organic Pollutants from Wastewater

Energy Technology Data Exchange (ETDEWEB)

Meguenni, H.; Mahlous, M.; Mansouri, B. [Centre de Recherche Nucléaire d' Alger, 2Bd Frantz Fanon BP-399 Alger (Algeria); Bouchfer, S. [ONA Office National de l’Assainissement, Alger (Algeria)

2012-07-01

The study of this research is focused on the possibility of using gamma radiation in order to decrease the concentration of polycyclic aromatic hydrocarbon (PAH) in effluents. The research was initiated with a concentration of 100ppm of synthetic naphthalene aqueous solution submitted to different absorbed doses. The HPLC analysis has shown that the dose of 30kGy degraded 99.96% of the naphthalene molecule. The identification program of NIST library has identified the by-products formed during the radiation process. Concerning the industrial effluent wastewater sample, we opted for analysis by GC-MS before and after gamma irradiation, to monitor the degradation of PAH and other pollutants from the refinery. The results show that in global view, gamma radiation decreases significantly the contaminated level, with the increase of the absorbed dose. In detailed view, the relative content of the naphthalene, 2,7 dimethyl in the effluent sample decreased with the increase of the absorbed dose. At the dose of 6 kGy the molecule was completely degraded. The COD of effluent sample presented a reduction of 58%, when 10 kGy dose was applied. After irradiation a secondary treatment, based on adsorption using a natural adsorbent, has to be applied in order to remove the by-products of radiation degradation, to get a better quality of effluent and consequently improve the environmental condition. (author)

Application of Gamma Radiation for Removal of Organic Pollutants from Wastewater

International Nuclear Information System (INIS)

Meguenni, H.; Mahlous, M.; Mansouri, B.; Bouchfer, S.

2012-01-01

The study of this research is focused on the possibility of using gamma radiation in order to decrease the concentration of polycyclic aromatic hydrocarbon (PAH) in effluents. The research was initiated with a concentration of 100ppm of synthetic naphthalene aqueous solution submitted to different absorbed doses. The HPLC analysis has shown that the dose of 30kGy degraded 99.96% of the naphthalene molecule. The identification program of NIST library has identified the by-products formed during the radiation process. Concerning the industrial effluent wastewater sample, we opted for analysis by GC-MS before and after gamma irradiation, to monitor the degradation of PAH and other pollutants from the refinery. The results show that in global view, gamma radiation decreases significantly the contaminated level, with the increase of the absorbed dose. In detailed view, the relative content of the naphthalene, 2,7 dimethyl in the effluent sample decreased with the increase of the absorbed dose. At the dose of 6 kGy the molecule was completely degraded. The COD of effluent sample presented a reduction of 58%, when 10 kGy dose was applied. After irradiation a secondary treatment, based on adsorption using a natural adsorbent, has to be applied in order to remove the by-products of radiation degradation, to get a better quality of effluent and consequently improve the environmental condition. (author)

Radiation-Induced Graft Polymerization: Gamma Radiation and Electron Beam Technology for Materials Development

International Nuclear Information System (INIS)

Madrid, Jordan F.; Cabalar, Patrick Jay; Lopez, Girlie Eunice; Abad, Lucille V.

2015-01-01

The formation of functional hybrid materials by attaching polymer chains with advantageous tailored properties to the surface of a base polymer with desirable bulk character is an attractive application of graft copolymerization. Radiation-induced graft polymerization (RIGP) has been a popular approach for surface modification of polymers because of its merits over conventional chemical processes. RIGP, which proceeds primarily via free radical polymerization process, has the advantages such as simplicity, low cost, control over process and adjustment of the materials composition and structure. RIGP can be performed using either electron beam or gamma radiation and it can be applied to both synthetic and natural polymers. These merits make RIGP a popular research topic worldwide. Moreover, the materials synthesized and produced via RIGP has found applications, and were proposed to produce continuous impact, in the fields of medicine, agriculture, pollution remediation, rare earth and valuable metals recovery, fuel cell membrane synthesis and catalysis to name a few. From 2012 our group has performed electron beam and gamma radiation-induced graft polymerization of various monomers onto polymers of natural and synthetic origins (e.g. monomers - glycidyl methacrylate, styrene, acrylonitrile, N,N-dimethylaminoethyl methacrylate; base polymers – polyethylene/polypropylene nonwoven fabric, polypropylene nonwoven fabric pineapple fibers, cellulose nonwoven fabric microcrystalline cellulose). We tested these grafted materials for heavy metals (Pb, Ni, Cu) and organic molecule removal from aqueous solutions and E. coli activity (using reversible addition fragmentation chain transfer RAFT mediated grafting). The results clearly showed the success of materials modified via FIGP in these applications. Currently, we are studying the applications of grafted materials on treatment of waste waters from tanning industry, value addition to abaca nonwoven fabrics cell sheet

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

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

Scintillation characteristics of phosphich-detector for detection of beta- and gamma-radiations

CERN Document Server

Ananenko, A A; Gavrilyuk, V

2002-01-01

The results of the study on the influence of individual peculiarities of the compound scintillation detector structure on the value and stability of the light yield by the gamma- and beta-radiation combined registration are presented. The phosphich detector is manufactured from the sodium iodide monocrystal, activated by thallium, and the scintillation plastic on the polystyrol basis. The comparison of the experimental results with the mathematical modeling data revealed certain regularities of the process of forming the phosphich detector light signal. The recommendations are worked out by means whereof the following characteristics of the scintillation unit: the light yield and its stability, amplitude resolution and the peak-to-valley ratio by the gamma- and beta-radiation registration were improved

Optimization of radiolytic degradation of sulfadiazine by combining Fenton and gamma irradiation processes

International Nuclear Information System (INIS)

Rivas-Ortiz, Iram Barbaro; Cruz-Gonzalez, German; Manduca-Artiles, Michel; Jauregui-Haza, U.J.

2017-01-01

Gamma radiation (GR) is a promising technique, among known advanced oxidation processes, degrading water contaminants. Nevertheless, few authors report the degradation of sulfonamides by GR, and limited information exists concerning the use of GR in the case of sulfadiazine (SDZ). The objectives of this work are (1) evaluating GR as an alternative method for treating wastewater contaminated with SDZ and examinating the intensification of GR with oxidants (H 2 O 2 or Fenton reagent). GR was performed with a high-activity 60 Co source. The gamma radiation/Fenton process gave the best result, leading to total SDZ removal and high (74.13%) pollutant mineralization. (author)

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)

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.

Investigation of radiation gamma-sterilization effect on sodium alginate hydrogels

International Nuclear Information System (INIS)

Valueva, M.I.; Oltarzhevskaya, N.D.; Maksimova, Yu.S.; Fenin, A.A.

2012-01-01

The effect of gamma-radiation in doses ensuring materials sterility (6-15 kGy) on alginate hydrogels is studied. For conservation of polymer solutions viscosity after sterilization it is necessary to introduce in polymer matrix different additives inhibiting the radiolysis process. Substances-antioxidants (aqueous extracts of sea-buckthorn and blueberry), polyvinylpyrrolidone, pectin, polyethylene oxides with molecular mass from 400 to 40000 have been studied as the additives. The additives selected have the positive effect on the result of alginate hydrogels sterilization. It is established, that the problem of human tissue radiation protection is closely connected with the problem of biopolymer hydrogels radiation protection [ru

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)

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...

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

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

Effect of gamma radiation on the stability of UV replicated composite mirrors

Science.gov (United States)

Zaldivar, Rafael J.; Kim, Hyun I.; Ferrelli, Geena L.

2018-04-01

Composite replicated mirrors are gaining increasing attention for space-based applications due to their lower density, tailorable mechanical properties, and rapid manufacturing times over state-of-the-art glass mirrors. Ultraviolet (UV)-cured mirrors provide a route by which high-quality mirrors can be manufactured at relatively low processing temperatures that minimize residual stresses. The successful utilization of these mirrors requires nanometer scale dimensional stability after both thermal cycling and hygrothermal exposure. We investigate the effect of gamma irradiation as a process to improve the stability of UV replicated mirrors. Gamma radiation exposure was shown to increase the cure state of these mirrors as evidenced by an increase in modulus, glass transition temperature, and the thermal degradation behavior with dosage. Gas chromatography-mass spectroscopy also showed evidence of consumption of the primary monomers and initiation of the photosensitive agent with gamma exposure. The gamma-exposed mirrors exhibited significant improvement in stability even after multiple thermal cycling in comparison with nonirradiated composite mirrors. Though improvements in the cure state contribute to the overall stability, the radiation dosage was also shown to reduce the film stress of the mirror by over 80% as evidenced using Stoney replicated specimens. This reduction in residual stress is encouraging considering the utilization of these structures for space applications. This paper shows that replicated composite mirrors are a viable alternative to conventional optical structures.

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)

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.

The study of polymeric hydro-gels with unique properties obtained by polymerization with gamma radiation processing

International Nuclear Information System (INIS)

Dragusin, M.

1995-01-01

This thesis presents the work carried out on polymeric hydro-gels obtained by radiation processing using 60 Co gamma rays from the irradiation facility IETI-10.000 (10 k Ci), and on the polymeric hydro-gels obtained by irradiation with the electron beams from a linear accelerator (6 MeV). The aim of the study was to determine the effect of the rate dose and total dose absorbed in the materials. There are presented the preparation methods of homo- and co-polymer hydro-gels (acrylics, namely anionic and neutral monomers (acrylamide, acrylic acid, vinyl acetate) and cationic monomers (di-methyl di-allyl ammonium chloride)) such as floculants, additives, absorbers, etc. Concerning with these we have analysed the preparation methods, the mechanical, thermal, diffusivity, and swelling properties of polymeric hydro-gels in a large variety of gels of type I or II. The technological aspects and end use were studied in connection with the characteristics of the radiation processing of these hydro-gels as a function of chemical composition rate and absorbed dose, swelling degree (low and very high hydro-soluble), mechanical and diffusional properties. (author) 33 figs., 12 tabs., 101 refs

Gamma radiation on the conservation of the pupunha (Bactris gasipaes HBK) minimally processed

International Nuclear Information System (INIS)

Spoto, Marta H. F.

2002-01-01

The aim of this work was to evaluate the influence of gamma radiation on microorganisms and enzymatic darkness reaction of the minimally processed hart of palm pupunha (Bactris gasipaes HBK). The pupunha stalks came from Piraju county, State of Sao Paulo and at CENA/USP laboratory they were peeled and cut in small stalks into a solution of sodium chloride (2.5%) plus citric acid (0.8%). After packing in polyethylene bags the samples were irradiated with doses of 6, 8 and 10 kGy. The samples were storage for 14 days period under refrigeration (5 deg C), with analysis at the 1 st , 7 th and 14 th day. No microorganism (bacteria, fungi or yeast) were detect in the irradiated samples during the the storage period. Through the a * e b * values the control sample showed a yellow-greenish color and the irradiated samples presented almost white. The pH values kept stable and the ratio values diminished for all treatments during the storage period. (author)

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)

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

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)

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Development and implementation of an automated system for antiquated of the process of gamma radiation monitors calibration; Desenvolvimento e implantacao de um sistema automatizado para adequacao do processo de calibracao de monitores de radiacao gama

Energy Technology Data Exchange (ETDEWEB)

Silva Junior, Iremar Alves

2012-07-01

In this study it was carried out the development and implementation of a system for the appropriate process of gamma radiation monitors calibration, constituted by a pneumatic dispositive to exchange the attenuators and a positioning table, both actuated through a control panel. We also implemented a System of Caesa-Gammatron Irradiator, which increased the range of the air kerma rates, due to its higher activity comparing with the current system of gamma radiation in use in the calibration laboratory of gamma irradiation. Hence, it was necessary the installation of an attenuator dispositive remotely controlled in this irradiator system. Lastly, it was carried out an evaluation of the reduction in the rates of the occupational dose. This dissertation was developed with the aim of improving the quality of the services of calibration and tests of gamma radiation monitors - provided by the IPEN Laboratory of Instrument Calibration - as well as decreasing the occupational dose of the technicians involved in the process of calibration, following thus the principles of radiation protection. (author)

Role of activated carbon on micropollutans degradation by different radiation processes

Directory of Open Access Journals (Sweden)

Inmaculada Velo Gala

2015-04-01

Full Text Available The objective of this study was to analyse the influence of the presence of activated carbon on radiation processes. The triiodinated contrast medium diatrizoate was chosen as the contaminant model. We selected four commercial activated carbons and sixteen gamma radiation-modified carbons derived from these. The different advanced oxidation/reduction processes that have been studied were improved through the addition of activated carbon in the UV light and gamma radiating processes. In the UV/activated carbon process, the synergic activity of the activated carbon is enhanced in the samples with higher percentages of surface oxygen, ester/anhydride groups and carbon atoms with sp2 hybridization. Band gap determination of activated carbons revealed that they behave as semiconductor materials and, therefore, as photoactive materials in the presence of UV radiation, given that all band gap values are <4 eV. We also observed that the gamma radiation treatment reduces the band gap values of the activated carbons and that, in a single series of commercial carbons, lower band gap values correspond to higher contaminant removal rate values. We observed that the activity of the reutilized activated carbons is similar to that of the original carbons. Based on these results, we proposed that the activated carbon acts as a photocatalyst, promoting electrons of the valence band to the conduction band and increasing the generation of HO• radicals in the medium. Similarly, there was a synergic effect made by the presence of activated carbon in gamma radiation system, which favours pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent

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

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.)

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.

Radiation damage of light guide fibers in gamma radiation field - on-line monitoring of absorption centers formation

International Nuclear Information System (INIS)

Blaha, J.; Simane, C.; Finger, M.; Slunecka, M.; Finger, M. Jr.; Sluneckova, V.; Janata, A.; Vognar, M.; Sulc, M.

2004-01-01

The kinetics of radiation-induced changes of absorption coefficient was studied by online transmission spectra measurement for two different Kuraray light guide fibers. The samples were irradiated by bremsstrahlung gamma radiation, dose rates were from 2 Gy/s to 25 Gy/s. The kinetic coefficients both for absorption centers formation and for recovery processes were calculated. Good agreement of experimental data and simple one-short-lived absorption center model were received for radiation-hard light guide Kuraray (KFC). The more complicated process was observed on Kuraray (PSM) clear fiber. It was caused by the reaction of the oxygen dissolved in fiber and created radicals. The results are very useful for prediction of an optical fibers response in conditions of new nuclear and particle physics experiments. (author)

Damage to plasmid DNA produced by 60Co-gamma radiation and subsequent repair processes in E. coli with and without SOS induction

International Nuclear Information System (INIS)

Bien, M.

1986-01-01

This study was carried out to provide information on the question as to whether radiation-induced separation of double-stranded DNA in E. coli is followed by repair processes leading to the formation of replicable material. For the detection of those double-strand breaks, E. coli was first transformed using enzymatically linearised dBR 322-DNA. This served as a reference standard to compare the transformations using radiated DNA. DNA was either exposed to increasing doses of 60 Co-gamma radiation or separated into one oc-fraction and one lin-fraction following exposure to 30 Gy. The DNA samples thus obtained were then used to transform three different strains of E. coli (wild strain, SFX, SFXrecA - ). In order to improve the repair yield, the cells were additionally SOS-induced using ultraviolet radiation. The mutation rates were a measure of the number of errors occurring during the various repair processes. Restriction analysis was carried out to characterise the resulting mutants in greater detail. (orig./MG) [de

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)

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)

Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

Science.gov (United States)

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

2013-07-01

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

Gamma radiation effects on polydimethylsiloxane rubber foams under different radiation conditions

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-15

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

Gamma teletopography

International Nuclear Information System (INIS)

Simonet, G.

1987-06-01

The mapping of gamma sources radiation emission in a nuclear plant is an important safety point. A remote gamma ray mapping process was developed in SPS/CEA/SACLAY. It uses the ''pinhole camera'' principle, precursor of photography. It mainly consists of a radiation proof box, with a small orifice, containing sensitive emulsions at the opposite. A first conventional photographic type emulsion photographs the area. A second photographic emulsion shows up the gamma radiations. The superim position of the two shots gives immediate informations of the precise location of each source of radiation in the observed area. To make easier the presentation and to improve the accuracy of the results for radiation levels mapping, the obtained films are digitally processed. The processing assigns a colours scale to the various levels of observed radiations. Taking account physical data and standard parameters, it gets possible to estimate the dose rate. The device is portable. Its compactness and fully independent nature make it suitable for use anywhere. It can be adapted to a remote automatic handling system, robot... so as to avoid all operator exposure when the local dose rate is too high [fr

Recent status and progress of radiation processing in the world

International Nuclear Information System (INIS)

Lee, Yun Jong; Lee, Byoung Hun; Im, Don Sun; Kim, Jae Ho; Nho, Young Chang

2008-01-01

Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications

Recent status and progress of radiation processing in the world

Energy Technology Data Exchange (ETDEWEB)

Lee, Yun Jong; Lee, Byoung Hun; Im, Don Sun; Kim, Jae Ho; Nho, Young Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup(Korea, Republic of)

2008-01-15

Radiation technology is currently used in a number of industrial processes such as sterilization, cross linking of polymer, food irradiation, rubber vulcanization in the tire manufacturing, contaminated medical waste, etc. Gamma ray and electron beam are the key examples of well-established economical applications of radiation processes. The purpose of this paper is to review the recent technological trends and activities for radiation processes in order for the industrial end users to better understand, and obtain useful information about the technology. It is clear that the radiation processing technology has potential for a variety of the industrial applications.

Development of FPGA-based digital signal processing system for radiation spectroscopy

International Nuclear Information System (INIS)

Lee, Pil Soo; Lee, Chun Sik; Lee, Ju Hahn

2013-01-01

We have developed an FPGA-based digital signal processing system that performs both online digital signal filtering and pulse-shape analysis for both particle and gamma-ray spectroscopy. Such functionalities were made possible by a state-of-the-art programmable logic device and system architectures employed. The system performance as measured, for example, in the system dead time and accuracy for pulse-height and rise-time determination, was evaluated with standard alpha- and gamma-ray sources using a CsI(Tl) scintillation detector. It is resulted that the present system has shown its potential application to various radiation-related fields such as particle identification, radiography, and radiation imaging. - Highlights: ► An FPGA-based digital processing system was developed for radiation spectroscopy. ► Our digital system has a 14-bit resolution and a 100-MHz sampling rate. ► The FPGA implements the online digital filtering and pulse-shape analysis. ► The pileup rejection is implemented in trigger logic before digital filtering process. ► Our digital system was verified in alpha-gamma measurements using a CsI detector

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

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

International Nuclear Information System (INIS)

Boclet, D.

1967-01-01

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

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)

Seeds of Camargue rice (Oryza Sativa L. Var Cigalon) and their responses to exposure to 60-Co gamma radiations. Study of the natural phenomenon of radiation protection

International Nuclear Information System (INIS)

Bayonove-Barthelemy, Jacqueline

1978-01-01

Within the frame of a project aiming at improving a technique of experimental mutagenesis (seed processing by cobalt-60 gamma rays), this research thesis reports the radiobiological characterization of Cigalon rice seeds, the adjustment of techniques of radiation protection, and the definition of processing and irradiation conditions which could reduce the undesirable physiological effects of cobalt-60 gamma radiation on rice seeds. The author reports the study of variations of physiological radio-sensitivity. Damages are assessed by comparing the growth of irradiated seeds with that of non-irradiated seeds. The mechanism of radiation natural protection is studied by comparing an inhibition in distilled water at two temperatures (5 and 24 C) with that obtained with cysteamine (an efficient radiation protection compound)

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

Development of aerial gamma radiation survey system III

International Nuclear Information System (INIS)

Nagaoka, Toshi; Sakamoto, Ryuichi; Saito, Kimiaki; Tsutsumi, Masahiro; Moriuchi, Shigeru; Miyasaka, Satoshi.

1985-01-01

An aerial gamma-ray survey system using a helicopter has been developed since 1980 in order to perform quick gamma-ray survey covering a wide area. To form a line in the chain of the development, a series of flight measurements were conducted in Watarase reservoir, Tochigi prefecture, in which artificial gamma-ray fields were realized using 60 Co (100 and 400 mCi) and 137 Cs (100 and 300 mCi) point sources located on the ground. For the purpose of obtaining gamma-ray pulse height spectra in the field, 6 sets of NaI(Tl) scientillation detectors were prepared. These sets of detectors consist of ones for evaluation with high accuracy as the standard, for intercomparison with other authors' results, and for practical use. Two sets of them were boarded for each flight considering the exposure rate level and detector's sensitivity. The flight measurements were performed in a space of 20 m to 500 m in altitude, and 0 m to 500 m in horizontal distance from the source. The experimental results of the spatial gamma-ray distribution for each gamma-ray field satisfactorily agreed with calculational results by Monte Carlo method. Throughout this experiment, characteristics of this survey system and detectors were clarified, and versatile data processing and analysis code was completed. Also, a method for subtraction of background exposure rate in a field including artificial radiation component was discussed using energy band information, and the coefficients for this method were determined. These data obtained are expected to be used as widely applicable data not only for the interpretation of measured value, but also for analysis of environmental gamma-ray field. (author)

Radiation Monitoring System in Advanced Spent Fuel Conditioning Process Facility

Energy Technology Data Exchange (ETDEWEB)

You, Gil Sung; Kook, D. H.; Choung, W. M.; Ku, J. H.; Cho, I. J.; You, G. S.; Kwon, K. C.; Lee, W. K.; Lee, E. P

2006-09-15

The Advanced spent fuel Conditioning Process is under development for effective management of spent fuel by converting UO{sub 2} into U-metal. For demonstration of this process, {alpha}-{gamma} type new hot cell was built in the IMEF basement . To secure against radiation hazard, this facility needs radiation monitoring system which will observe the entire operating area before the hot cell and service area at back of it. This system consists of 7 parts; Area Monitor for {gamma}-ray, Room Air Monitor for particulate and iodine in both area, Hot cell Monitor for hot cell inside high radiation and rear door interlock, Duct Monitor for particulate of outlet ventilation, Iodine Monitor for iodine of outlet duct, CCTV for watching workers and material movement, Server for management of whole monitoring system. After installation and test of this, radiation monitoring system will be expected to assist the successful ACP demonstration.

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

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

Effect of degree of order of silicon dioxide on localization processes of non-equilibrium charge carriers under the influence of gamma-radiation

CERN Document Server

Garibov, A A; Agaev, T N

1999-01-01

The effect of the degree of order of SiO sub 2 on the localization process of non-equilibrium charge carriers (NCC) when exposed to gamma-quanta at 77 K has been investigated. It has been found that with decreasing SiO sub 2 structure degree of order, a localization probability of NCC increases. A contribution of surface defect states in SiO sub 2 to localization, migration and recombination annihilation processes of NCC induced by ionizing radiation has been determined.

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

Studies On Sterilization Process For Some Traditional Products Of Herbal Medicine By Gamma Radiation

International Nuclear Information System (INIS)

Hoang Phuong Thao; Nguyen Van Binh; Tran Bang Diep; Hoang Dang Sang; Nguyen Thuy Huong Trang; Pham Duy Duong; Tran Minh Quynh

2014-01-01

Herbal eyebright products and their raw materials have been irradiated with 1, 2, 3 and 5 kGy by Co-60 gamma radiation source at Hanoi Irradiation Center (VINATOM) for sterilization. Initial bioburdens were under the limitation levels established for the traditional medicines according to the decree of 16/2011/TT-BYT issued by Vietnam Health Ministry. These values for both bacteria and fungus slightly increased during storage to three months, reach to about 10 3 and 10 2 CFU/g for bacteria and mold, respectively. However, there are no microbial colony could be observed in the samples irradiated with dose higher than 3 kGy, suggested that the radiation dose of 3 kGy was enough for sterilization of eyebright raw powders and products. At higher radiation dose of 5 kGy, the moisture and vitamin A content of the samples were insignificantly changed. These mean the radiation treatment with lower dose did not influenced on the quality of eyebright products, and radiation treatment can be applied to prolong the storage of not only eyebright, but also other traditional medicines. (author)

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1971-07-01

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

The effects of gamma radiation on soybean isoflavones contents

International Nuclear Information System (INIS)

Oliveira, Marcos R.R. de; Mastro, Nelida L. del; Mandarino, Jose M.G.

2009-01-01

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

The effects of gamma radiation on soybean isoflavones contents

Energy Technology Data Exchange (ETDEWEB)

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

2009-07-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2012-03-15

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

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.

Present status and expected progress in radiation processing dosimetry

DEFF Research Database (Denmark)

Kovács, A.; Miller, A.

2004-01-01

The paper describes the present status of radiation processing dosimetry including the methods used most widely in gamma- and electron processing as well as the new methods under development or introduction. The recent trends with respect to calibrationof routine dosimetry systems as well...

Radiation processing of minimally processed fruits and vegetables to ensure microbiological safety

International Nuclear Information System (INIS)

Bandekar, J.R.; Saroj, S.D.; Shashidhar, R.; Dhokane, V.S.; Hajare, S.N.; Nagar, V.; Sharma, A.

2009-01-01

Minimally processed fruits and vegetables are in demand as they offer ready rich source of nutrients and convenience to consumers. However, these products are often unsafe due to contamination with harmful pathogens. Therefore, a study was carried out to analyze microbiological quality of minimally processed fruits, vegetables and sprouts and to optimize radiation dose necessary to ensure safety of these commodities. Microbiological quality of these products was found to be poor. Decimal reduction dose (D 10 ) for Salmonella Typhimurium and Listeria monocytogenes in these minimally processed foods (MPF) were in the range of 164 to 588 Gy. Radiation processing with 2 kGy dose of gamma radiation resulted in 5 log reduction of S. Typhimurium and 4 log reduction of L. monocytogenes. The treatment did not significantly affect nutritional, organoleptic and textural properties. These results suggest that radiation processing can ensure safety of these products. (author)

Manual of radiation processing of cassava starch hydrogel

International Nuclear Information System (INIS)

Sonsuk, Manit

2007-01-01

The radiation processing of natural cassava starch (CS) is described for the improvement of its properties. A series of hydrogels were prepared from gelatinized CS and vinylpyrrolidone by radiation-induced graft copolymerization. Hydrogels were also synthesized from radiation-induced crosslinking of carboxymethyl CS. The optimum condition for the swelling ratio and gel fraction of the obtained hydrogels is irradiation at low dose. The polymeric chelating resins containing the hydroxamic acid groups were synthesized from the polymethyl acrylate (PMA)-grafted CS via gamma radiation. (M.H.)

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

International Nuclear Information System (INIS)

Ferreto, Helio F.R.; Oliveira, Ana C.F. de; Parra, Duclerc F.; Lugao, Ademar B.

2013-01-01

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

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)

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)

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

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

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)

Physicochemical effects of gamma radiation in peanuts and the utilization of their peanut skins as natural antioxidant

International Nuclear Information System (INIS)

Camargo, Adriano Costa de

2012-01-01

Peanuts are among the most popular oilseed in the world, their lipid content is about 50%, on average. Their fatty acid composition is characterized by high percentage of unsaturated fatty acids. Peanuts are a source of dietary tocopherol and polyphenols, antioxidants that play benefits to human health. However, the presence of potential mycotoxic fungi is a concern of this oilseed production chain. Gamma radiation, in addition to good agricultural practices, has been identified as an effective treatment for disinfecting peanuts of fungi and has been identified as a potential tool for reducing their allergenicity. However, the physicochemical quality of the peanuts deserves attention due to its high lipid percentage. The irradiation process can promote the formation of free radicals, increase lipid oxidation and induce molecular changes that may reflect changes in the antioxidant properties. In the present study samples of peanut from IAC Runner 886 cultivar, peeled, in shell and blanched as well as their peanut skins were subjected to gamma radiation in doses of 0.0, 5.0, 7.5 or 10.0 kGy with dose rate of 7.5 kGy.h -1 using a cobalt-60 source. The samples were stored for six months at room temperature and analysis were performed at the beginning of the study and after each three month storage on peanuts and just at the beginning of the study on peanut skins. Few changes noticed in the physical parameters of color seem to be more related to storage than the irradiation process Chemical parameters related to the antioxidant properties showed moderate change due to the irradiation process, while storage was determinant on the reduction of bioactive compounds as well as the antioxidant activity in the samples. No correlation was found between gamma radiation and fatty acid changes of peanuts. Tocopherol content and the induction period of the crude peanut oil were negatively correlated with gamma radiation doses. Peanut skin, which is removed in the peanut blanching

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.

Packaging materials for use in radiation processing of foods

International Nuclear Information System (INIS)

Dragusin, M.; Rotaru, P.R.

1999-01-01

In radiation processing of food, the product often has to be prepackaged to prevent microbial recontamination during and after irradiation. The packaging material is exposed to radiation during radiation processing and radiation stability is a key consideration in the selection of packaging materials. The effects of ionizing radiation on many food packaging materials at the dose levels recommended for food precessing can be minimized by selecting appropriate radiation resistant materials. It is important to select materials in which chemicals formed as a result of the radiation treatment do not migrate and interact with the food, affecting its organoleptic and toxicological aspects. It is also important to select materials in which the physical properties are not altered to the extent they cannot resist damage during commercial production, shipment and storage. Radiation treatment of food may be classified broadly into two categories: 1. Processes requiring doses less than 10 kGy; 2. Processes requiring doses from 25 to 40 kGy for production of commercial sterility. In radiation processing of foods, gamma radiation from radioisotopes Co-60 and Cs-137 is most widely used because of its high penetrating power. Electron beam irradiation (E<10 MeV) and X-rays (E<5 MeV) can also be used for certain speciality food and packaging to the food. Because the public acceptance of irradiated foods is a major problem in marketing such products, we have developed in our laboratory an alternative techniques. These techniques are based on applying films on the surfaces of foods. The films are edible, i.e. they are an aqueous solution based on caseine, glycerine, poly-etilene-glycol (PEG), crosslinked by radiation processing. So, our techniques implies no longer the food irradiation but instead its isolation from the environmental biological attacks by means of edible films obtained by irradiation. The protective properties of films, as special humidity, oxygen and fat barriers, are

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.

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)

Image processing techniques for thermal, x-rays and nuclear radiations

International Nuclear Information System (INIS)

Chadda, V.K.

1998-01-01

The paper describes image acquisition techniques for the non-visible range of electromagnetic spectrum especially thermal, x-rays and nuclear radiations. Thermal imaging systems are valuable tools used for applications ranging from PCB inspection, hot spot studies, fire identification, satellite imaging to defense applications. Penetrating radiations like x-rays and gamma rays are used in NDT, baggage inspection, CAT scan, cardiology, radiography, nuclear medicine etc. Neutron radiography compliments conventional x-rays and gamma radiography. For these applications, image processing and computed tomography are employed for 2-D and 3-D image interpretation respectively. The paper also covers main features of image processing systems for quantitative evaluation of gray level and binary images. (author)

Applications of Radiation Processing in Industry

International Nuclear Information System (INIS)

Abad, Lucille V.

2015-01-01

Radiation processing has long been known as commercially viable technology that can be beneficially used to enhance the characteristics of many materials. Several gamma irradiators and electron beam accelerators are operating worldwide which are utilized for various established industrial applications. These could be used for the following processes: a) radiation crosslinking e.g. crosslinking of wires and cables, heat shrinkable film and tube productions, manufacture of plastic bags and tubings for medical products, pre-curing of automobile tire components, curing of polymeric coatings, etc. b) radiation degradation e.g. Scrap Teflon (Polytetraflouroethylene) to form powders, disinfestations and pasteurization of agricultural products, sterilization of medical products, etc.; and c) radiation grafting e.g. grafted non-woven fabrics for metal adsorbent. Emerging applications for radiation processing include grafted membranes for fuel cell, electrodes, cell sheet for tissue engineering, nanoparticle production, polymer composite synthesis, and fibrous catalyst for biodiesel production. Current researches at the Philippine Nuclear Research Institute consist of crosslinking of natural and synthetic polymers for medical application e.g. wound dressing, hemostats, and bioimplants for vesicouretal reflux (VUR); grafting of natural and synthetic fabrics for metal adsorbents; and radiation degradation of carrageenan as plant growth promoter. (author)

Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)

International Nuclear Information System (INIS)

Martins, C.G.; Behrens, J.H.; Destro, M.T.; Franco, B.D.G.M.; Vizeu, D.M.; Hutzler, B.; Landgraf, M.

2004-01-01

Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37 deg. C/24 h. D 10 values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log 10 . The shelf-life was increased by 1 1/2 day when the product was exposed to 1 kGy

Investigation of the effect of gamma radiation on lincomycin

International Nuclear Information System (INIS)

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

2001-01-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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).

Monitoring of low level environmental gamma exposure by the centralized radiation monitoring system

International Nuclear Information System (INIS)

Katagiri, Hiroshi; Kobayashi, Hideo; Obata, Kazuichi; Kokubu, Morinobu; Itoh, Naoji

1981-07-01

In the Japan Atomic Energy Research Institute (JAERI), a centralized automatic radiation monitoring system developed 20 years ago has recently been improved to monitor low level gamma radiation more accurately in normal operation of the nuclear facilities and to detect abnormal radioactive releases more effectively. The present state of the system is described. This system puts together environmental monitoring data such as gamma exposure rate (20 points), radioactive concentration in the air (4 points) and in water (2 drains), and meteorological items (14 including wind directions, wind speeds, solar radiation and air temperatures at a observation tower of 40 m height). Environmental monitoring around the JAERI site is carried out effectively using the system. Data processing system consists of a central processing unit, a magnetic disk, a magnetic tape, a line printer and a console typewriter. The data at respective monitoring points are transmitted to the central monitoring room by wireless or telephone line. All data are printed out and field in magnetic disk and magnetic tape every 10 minutes. When the emergency levels are exceeded, however, the data are automatically output on a line printer every 2 minute. This system can distinguish very low gamma exposure due to gaseous effluents, about 1 mR/y, from the background. Even in monthly exposures, calculated values based on the data of release amount and meteorology are in good agreement with the measured ones. (author)

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.

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

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

International Nuclear Information System (INIS)

Brehm, E.H.; Holst, T.

1975-01-01

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

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)

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

International Nuclear Information System (INIS)

Cruz Z, E.; Ruiz G, B.; Flores E, T.; Barboza F, M.

2011-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2011-02-15

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

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

Combined effect of head down tilt (HDT) and gamma radiation on the higher nervous activity of the rats

International Nuclear Information System (INIS)

Shtemberg, A.S.

1992-01-01

The paper deals with a combined effect of 30-day head down tilt (HDT) and gamma-radiation at a dose of 3 Gy on the higher nervous activity of the rats. The 30-day HDT disturbs the process of forming the motor-drinking differentiated conditioned reflex coming to a reduction of internal inhibition, generalization and sluggishness of a stimulation process. Functionally, these processes are reflected by a behavioral pattern shifting to stable stereotype impeding the formation of differentiated inhibition. Against HDT the unidirectional gamma-radiation exposure increases this effects. In some cases, it leads to blocking the adaptational procesess showing in the development of neurotic responses or deep, beyond the limits, inhibition

Degradation of phenylethylamine and tyramine by gamma radiation process and docking studies of its radiolytes

Energy Technology Data Exchange (ETDEWEB)

Cardozo, Monique; Souza, Stefânia Priscila de; Lima, Keila dos Santos Cople; França, Tanos Celmar Costa; Lima, Antonio Luis dos Santos, E-mail: santoslima@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Departamanto de Engenharia Quimica; Oliveira, Aline Alves [Universidade de Sao Paulo (USP), São Carlos, SP (Brazil). Instituto de Quimica; Rezende, Cláudia Moraes [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica

2014-07-01

Biogenic amines (BA) are toxic low molecular weight organic bases with aliphatic or heterocyclic structures that can be found in several foods. The consumption of food containing large amounts of BA can result in allergic reactions, rash, vomiting, and hypertension. Besides, BA are also known as possible precursors of carcinogens. In the present study we evaluated the effect of different gamma irradiation doses on methanol and water solutions of the BA phenylethylamine and tyramine. Our best results showed that, at a dose of 5 kGy (SI unit used for measurement of absorbed dose of ionizing radiation), it was possible to reduce the content of these two BA up to 85 and 60%, respectively, suggesting that the use of the irradiation process can be an efficient tool for its degradation. Further docking studies also suggested that the radiolytes produced in the irradiation process have more affinity for the human detoxifying enzymes monoaminoxidases type A and B (MAO-A and MAO-B) being, therefore, less toxic than its precursors. (author)

Gamma radiation, an aid to geologic mapping on the Arabian shield, Kingdom of Saudi Arabia

International Nuclear Information System (INIS)

Flanigan, V.J.

1972-01-01

Aerial gamma-radiation measurements in the Jabal Al Qarah quadrangle, Saudi Arabia, correlate with and complement magnetic data in distinguishing common Precambrian rock types. Areas of lower total-count gamma radiation correlate with areas of more intense magnetic patterns, which in turn correlate with areas of mafic rocks, as suggested from the study of the geophysical and geologic data of the Jabal Ishmas and Jabal Yafikh quadrangles adjacent to the north. In contrast, areas that reflect a lower magnetic intensity tend to show considerable variation in the radiation intensity and can be interpreted as being underlain by granitic rocks. On the basis of extrapolation of geophysical-geologic relationships established previously, selected radiation levels may be used to identify mappable rock units. Thus, radioactivity levels of 2,000 to 4,000 cpM suggest mafic rocks, levels of 4,000 to 6,000 cpM represent metavolcanic and metasedimentary rocks, levels of 7,000 to 10,000 cpM are representative of granodiorite gneiss, and levels of more than 11,000 cpM typify granitic rocks. The spectral gamma-radiation data are used to evaluate total-count anomalies and indicators of geologic processes of enrichment, and estimating the amount of isotopes of U, Th, and K within each of the lithologic units. (U.S.)

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

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.

Radiation-induced processes in the metallic powders after electron and gamma-radiation

International Nuclear Information System (INIS)

Zajkin, Yu.A.; Aliev, B.A.

2001-01-01

In the work the quantitative assessments for conditions both healing and growth of micropores in metal volume and surface layers have been made. Taking into account of these rules is important at a choice of radiation processing conditions for fine-disperse powders characterizing with increased porosity. Numerical evaluation shows, that under irradiation of a metals by electrons with energy 2 MeV and electron current density about 1 μA/cm 2 within 300-400 K temperature range the optimal doses for the micropores healing make up a several Mrad. Further increase of dose could lead to formation of pores in the crystal volume. Principal conclusions about radiation porosity development character of metallic particles surface layers one can make from analysis of the point defects distribution near surface and computing of radiation-induced diffusion coefficients

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)

Development of a sealed source radiation detector system for gamma ray scanning of petroleum distillation columns

International Nuclear Information System (INIS)

Vasquez Salvador, Pablo Antonio

2004-01-01

Gamma Ray Scanning is an online technique to 'view' the hydraulic performance of an operating column, with no disruption to operating processes conditions (pressure and temperature), as a cost-effective solution. The principle of this methodology consists of a small suitably sealed gamma radiation source and a radiation detector experimentally positioned to the column, moving concurrently in small increments on opposite sides and the quantity of gamma transmitted. The source-detector system consists of: a sealed ''6 0 Co radioactive source in a panoramic lead radiator, a scintillator detector coupled to a ratemeter / analyzer and a mobile system. In this work, a gamma scanning sealed source-detector system for distillation columns, was developed, comparing two scintillator detectors: NaI(Tl) (commercial) and CsI(Tl) (IPEN). In order to project the system, a simulated model of a tray-type distillation column was used. The equipment developed was tested in an industrial column for water treatment (6.5 m diameter and 40 m height). The required activities of 6 ''0Co, laboratory (11.1 MBq) and industrial works (1.48 TBq) were calculated by simulation software. Both, the NaI(Tl) and the CsI(Tl) detectors showed good proprieties for gamma scanning applications, determining the position and presence or absence of trays. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

1989-05-01

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

Influence of gamma radiation on mechanical and thermal properties of Cedrella fissilis and Ocotea porosa used in works of art

International Nuclear Information System (INIS)

Severiano, Lucio C.; Bardi, Marcelo A.G.; Machado, Luci D.B.; Lahr, Francisco A.R.

2009-01-01

Woods, as other materials, are susceptible to alterations in their internal structure because of physical, chemical or biological agents. Wood can be considered a natural composite with high strength capacity provided by cellulose and hemicellulose agglutinated by lignin, substances with very distinct structures. In several applications, the use of radiation can be interesting, once it turns wood more resistant to biological demand. The application of gamma radiation in work of arts and archaeological artifacts preservation began in 1970, in France. By other side, no changes in wood properties and no remaining radioactive waste were desirable. Gamma radiation from a cobalt-60 source usually is applied as a tool to the decontamination of insects and microorganisms, as well as to provide resins cure in impregnated wood. In this way, the aim of this paper is to evaluate gamma radiation effects on some physical, thermal and resistance mechanical of Brazilian wood species used in carving, as Cedro Rosa (Cedrella fissilis) and Imbuia (Ocotea porosa). Gamma radiation process considered different doses (25 kGy, 50 kGy and 100 kGy). Results showed that no gamma radiation influences were detected in the studied wood properties in the dose range applied. This is a relevant conclusion that will improve safety on arts conservation around the world. (author)

Influence of gamma radiation on mechanical and thermal properties of Cedrella fissilis and Ocotea porosa used in works of art

Energy Technology Data Exchange (ETDEWEB)

Severiano, Lucio C.; Bardi, Marcelo A.G.; Machado, Luci D.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)], e-mail: lucioseveriano@usp.br; Lahr, Francisco A.R. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia. Dept. de Engenharia de Estruturas de Madeira

2009-07-01

Woods, as other materials, are susceptible to alterations in their internal structure because of physical, chemical or biological agents. Wood can be considered a natural composite with high strength capacity provided by cellulose and hemicellulose agglutinated by lignin, substances with very distinct structures. In several applications, the use of radiation can be interesting, once it turns wood more resistant to biological demand. The application of gamma radiation in work of arts and archaeological artifacts preservation began in 1970, in France. By other side, no changes in wood properties and no remaining radioactive waste were desirable. Gamma radiation from a cobalt-60 source usually is applied as a tool to the decontamination of insects and microorganisms, as well as to provide resins cure in impregnated wood. In this way, the aim of this paper is to evaluate gamma radiation effects on some physical, thermal and resistance mechanical of Brazilian wood species used in carving, as Cedro Rosa (Cedrella fissilis) and Imbuia (Ocotea porosa). Gamma radiation process considered different doses (25 kGy, 50 kGy and 100 kGy). Results showed that no gamma radiation influences were detected in the studied wood properties in the dose range applied. This is a relevant conclusion that will improve safety on arts conservation around the world. (author)

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

Science.gov (United States)

Vurm, Indrek; Metzger, Brian D.

2018-01-01

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

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)

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)

Standard Guide for Absorbed-Dose Mapping in Radiation Processing Facilities

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This document provides guidance in determining absorbed-dose distributions in products, materials or substances irradiated in gamma, X-ray (bremsstrahlung) and electron beam facilities. Note 1—For irradiation of food and the radiation sterilization of health care products, other specific ISO and ISO/ASTM standards containing dose mapping requirements exist. For food irradiation, see ISO/ASTM 51204, Practice for Dosimetry in Gamma Irradiation Facilities for Food Processing and ISO/ASTM 51431, Practice for Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing. For the radiation sterilization of health care products, see ISO 11137: 1995, Sterilization of Health Care Products Requirements for Validation and Routine Control Radiation Sterilization. In those areas covered by ISO 11137, that standard takes precedence. ISO/ASTM Practice 51608, ISO/ASTM Practice 51649, and ISO/ASTM Practice 51702 also contain dose mapping requirements. 1.2 Methods of analyzing the dose map data ar...

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

Radiation anomaly detection algorithms for field-acquired gamma energy spectra

Science.gov (United States)

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

2015-08-01

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

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

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)

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

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

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

Radiation activities and application of ionizing radiation on cultural heritage at ENEA Calliope gamma facility (Casaccia R.C., Rome, Italy

Directory of Open Access Journals (Sweden)

Baccaro Stefania

2017-12-01

Full Text Available Since the 1980s, research and qualification activities are being carried out at the 60Co gamma Calliope plant, a pool-type irradiation facility located at the Research Centre ENEA-Casaccia (Rome, Italy. The Calliope facility is deeply involved in radiation processing research and on the evaluation and characterization of the effects induced by gamma radiation on materials for different applications (crystals, glasses, optical fibres, polymers and biological systems and on devices to be used in hostile radiation environment such as nuclear plants, aerospace and high energy physics experiments. All the activities are carried out in the framework of international projects and collaboration with industries and research institutions. In the present work, particular attention will be paid to the cultural heritage activities performed at the Calliope facility, focused on two different aspects: (a conservation and preservation by bio-deteriogen eradication in archived materials, and (b consolidation and protection by degraded wooden and stone porous artefacts consolidation.

Tomographic imaging of matter using primary and secondary X-and gamma-radiation

International Nuclear Information System (INIS)

Holloway, I.E.

1991-04-01

Gamma rays may interact with matter by a variety of processes, many of which give rise to secondary radiations. This thesis examines the possibility of performing tomographic imaging by means of these secondary photons using low-cost apparatus. The techniques are compared with each other and with transmission tomography, which plays such an important role in modern diagnostic imaging. The progress of industrial tomography is reviewed as are techniques of investigation using gamma ray scattering in both industry and medicine. Some new applications of a simple gamma ray computerized tomography (CT) scanner have been performed. A method of determining the spatial distribution of pure beta emitters in matter by performing tomographic imaging using the bremsstrahlung radiation produced by the beta particles has been demonstrated. This technique has been shown to permit imaging at depths in material greatly exceeding the range of beta particles in matter. All the imaging techniques using secondary radiation have displayed two principal limitations: long scanning times and poor quantitative accuracy. The low scanning rate results from the small number of secondary photons that are detected. The major contributing factors to poor accuracy are attenuation and the noise produced by unwanted in-scattering. The possible applications for secondary photon imaging have been briefly outlined and some suggestions for future work are included. Although techniques based upon imaging using secondary radiation will not be able to compete with transmission CT in the vast majority of applications, they may prove valuable in a range of specialised fields. (author)

Gamma hazards and risk associated with NORM in sediment from amang processing recycling ponds

International Nuclear Information System (INIS)

Nasirian Mohesen; Ismail Bahari; Pauzi Abdullah; Azizah JAafar

2007-01-01

Amang processing is an important downstream activity of tin mining noted for technologically enhancing naturally occurring radioactive materials. A study was carried out to determine the gamma radiation hazards associated with amang processing with special reference to the sediment accumulated in amang processing ponds. Twenty eight sediment samples from two amang processing plants employing the recycling close water management system were collected and analyzed. The activity concentrations of 226 Ra, 232 Th and 40 K in sediments were measured using gamma spectrometry analysis, with a Hyper Pure Ge-Li detector coupled to a Multi Channel Analyzer detector system. The range of mean activity concentrations of 226 Ra, 232 Th and 40 K were between 40.94 - 189.58 Bq kg -1 , 104.90 - 516.17 Bq kg -1 and 74.8-848.0 Bq/ kg respectively. The maximum activity concentrations of 226 Ra, 232 Th and 40 K recorded were higher than Malaysia average and the worlds natural highest. Gamma Radiation Representative Level Index, I γr associated with these levels of activity concentrations of radionuclide in sediments, warrants an immediate attention from the regulatory authorities. The contribution of amang processing and the use of recycling close water management system in enhancing potential environmental radiological risk are discussed. (author)

Investigation of Electricity Generation by Using Gamma Radiation from Spent Fuels

International Nuclear Information System (INIS)

Lee, Haneol; Yim, Man-Sung Yim

2015-01-01

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

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

Gamma radiation in the reduction of Salmonella spp. inoculated on minimally processed watercress (Nasturtium officinalis)

Energy Technology Data Exchange (ETDEWEB)

Martins, C.G.; Behrens, J.H.; Destro, M.T.; Franco, B.D.G.M.; Vizeu, D.M.; Hutzler, B.; Landgraf, M. E-mail: landgraf@usp.br

2004-10-01

Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37 deg. C/24 h. D{sub 10} values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log{sub 10}. The shelf-life was increased by 1 1/2 day when the product was exposed to 1 kGy.

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

Dye film dosimetry for radiation processing

International Nuclear Information System (INIS)

Humphreys, J.C.; McLaughlin, W.L.

1981-01-01

Commercially available plastic films containing dyes or dye precursors are convenient dosimeters and imaging media for electron beams or photons used for industrial radiation processing. As ''grainless'' imaging systems having thicknesses down to a few micrometers, they provide high spatial resolution for determining detailed absorbed dose distributions through microdensitometric analysis. The radiation absorption properties of these systems are adjusted by changing film composition so that the dosimeter materials can be made to simulate the material of interest undergoing irradiation. Other advantages include long-term stability, dose-rate independence, and ease of use and calibration. Radiochromic dye films with thicknesses varying from 0.005 to 1 mm are presently used to monitor electron-beam or gamma-ray doses from 10 to 10 5 Gy (10 3 to 10 7 rad), typical of those encountered in medical applications, radiation curing of polymeric composites, wire and cable insulation, shrinkable plastic tubing and film, as well as sterilization of medical supplies and treatment of municipal and industrial wastes. An NBS calibration service to industry involves the traceability of standard 60 Co gamma ray absorbed dose measurements by means of these films employed as transfer standards

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.

Towards a new thickness-independent gamma radiation plastic film dosimeter

International Nuclear Information System (INIS)

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

2013-01-01

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

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

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)

Acceleration of aging processes of cognac alcohol under the action of gamma radiation

International Nuclear Information System (INIS)

Lichev, V.; Goranov, N.; Dimov, S.

1974-01-01

The paper reports results of studies aimed at speeding up the aging of brandy alcohol by means of gamma radiation. In the course of the studies, the optimal doses for irradiating brandy alcohols obtained from oak extracts and wood were established, and their effects on the composition and taste of alcohols in different experimental treatments were examined. Also, schemes for separate and combined irradiation of brandy alcohols and other materials were developed, and the effects of irradiated wood and oak extracts on the composition and taste of separately irradiated young brandy alcohols were studied. (E.T.)

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

Influence of the temperature in the measurement of the gamma automatic probe Gamma Tracer; Influencia de la temperatura en la medicion de la sonda gamma automatica Gamma Tracer

Energy Technology Data Exchange (ETDEWEB)

Caveda R, C.A.; Dominguez L, O.; Alonso A, D. [CPHR, Calle 20 No. 4113 e/41 y 47, Playa, C.P. 11300, A.P. 6195, C.P. 10600 La Habana (Cuba); Montalvan E, A.; Fabelo B, O. [CIAC, Ave. Finlay Km 2 1/2, Rpto. Puerto Principe, Camaguey 70800 (Cuba)]. e-mail: caveda@cphr.edu.cu

2006-07-01

In the following work an analysis of the existent relationship among the measurement of the absorbed dose rate in air due to the environmental gamma radiation and the temperature, magnitudes measured to intervals of 10 minutes by the gamma probe Gamma Tracer located in the post of occident of the National Net of Environmental Radiological Surveillance (RNVRA), in the Center of Protection and Hygiene of the Radiations (CPHR) is made. For it its were analyzed near 100,000 measurements corresponding to the period 2004-2005. For a better processing and interpretation of the data, these were analyzed with one frequency time zone and monthly using the Gamma Red software to which was necessary to add it some options. Finally it was submitted the probe to a heating process inside a stove. The results of the carried out experiments confirmed that the absorbed dose rate in air due to the environmental gamma radiation depends potentially of the probe temperature in the range of environmental temperature to which is subjected daily the same one. (Author)

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

Gamma radiation in pest control at the storehouses

International Nuclear Information System (INIS)

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

1974-01-01

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

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

International Nuclear Information System (INIS)

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

1985-01-01

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

Research of pulse gamma ray radiation effect on microcontroller system

International Nuclear Information System (INIS)

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

2012-01-01

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

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...

Application of the Sunna dosimeter film in gamma and electron beam radiation processing

DEFF Research Database (Denmark)

Kovács, A.; Baranyai, M.; Wojnárovits, L.

2000-01-01

The OSL (optically stimulated luminescence) based Sunna film containing a microcrystalline dispersion of LIF in a polymer matrix has been recently introduced for high-dose dosimetry. Our previous investigations revealed the applicability of the system in the dose range of 0.01-100 kGy, but irradi...... significant in the case of OSL analysis for doses above 5 kGy. The applicability of two types of Sunna films in electron and gamma radiation processing is discussed in the paper. (C) 2000 Elsevier Science Ltd. All rights reserved.......The OSL (optically stimulated luminescence) based Sunna film containing a microcrystalline dispersion of LIF in a polymer matrix has been recently introduced for high-dose dosimetry. Our previous investigations revealed the applicability of the system in the dose range of 0.01-100 k......Gy, but irradiation temperature and dose rate effects above 5 kGy reduced its usefulness. The recent discovery of the use of spectrophotometric analysis in the UV range for measuring doses above 5 kGy is a suitable option, while the OSL analysis can be applied for measuring lower doses due to the lack of temperature...

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

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)

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

Gamma radiation in the reduction of S almonella spp. inoculated on minimally processed watercress ( Nasturtium officinalis)

Science.gov (United States)

Martins, C. G.; Behrens, J. H.; Destro, M. T.; Franco, B. D. G. M.; Vizeu, D. M.; Hutzler, B.; Landgraf, M.

2004-09-01

Consumer attitudes towards foods have changed in the last two decades increasing requirements for freshlike products. Consequently, less extreme treatments or additives are being required. Minimally processed foods have freshlike characteristics and satisfy this new consumer demand. Besides freshness, the minimally processing also provide convenience required by the market. Salad vegetables can be source of pathogen such as Salmonella, Escherichia coli O157:H7, Shigella spp. The minimal processing does not reduce the levels of pathogenic microorganisms to safe levels. Therefore, this study was carried out in order to improve the microbiological safety and the shelf-life of minimally processed vegetables using gamma radiation. Minimally processed watercress inoculated with a cocktail of Salmonella spp was exposed to 0.0, 0.2, 0.5, 0.7, 1.0, 1.2 and 1.5 kGy. Irradiated samples were diluted 1:10 in saline peptone water and plated onto tryptic soy agar that were incubated at 37°C/24 h. D 10 values for Salmonella spp. inoculated in watercress varied from 0.29 to 0.43 kGy. Therefore, a dose of 1.7 kGy will reduce Salmonella population in watercress by 4 log 10. The shelf-life was increased by 1 {1}/{2} day when the product was exposed to 1 kGy.

Progress in radiation processing of polymers

Science.gov (United States)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

2005-07-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R&D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

Progress in radiation processing of polymers

Energy Technology Data Exchange (ETDEWEB)

Chmielewski, Andrzej G. [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria) and Department of Process and Chemical Engineering, Warsaw University of Technology, Warsaw (Poland)]. E-mail: a-g.chmielewski@iaea.org; Haji-Saeid, Mohammad [International Atomic Energy Agency, Industrial Applications and Chemistry Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, Wagramer Street 5, Vienna 1400 (Austria); Ahmed, Shamshad [Applied Chemistry Laboratories, Pakistan Institute of Nuclear Science and Technology, P.O. Box Nilore, Islamabad (Pakistan)

2005-07-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described.

Progress in radiation processing of polymers

International Nuclear Information System (INIS)

Chmielewski, Andrzej G.; Haji-Saeid, Mohammad; Ahmed, Shamshad

2005-01-01

Modification in polymeric structure of plastic material can be brought either by conventional chemical means or by exposure to ionization radiation from ether radioactive sources or highly accelerated electrons. The prominent drawbacks of chemical cross-linking typically involve the generation of noxious fumes and by products of peroxide degradation. Both the irradiation sources have their merits and limitations. Increased utilization of electron beams for modification and enhancement of polymer materials has been in particular witnessed over the past 40 years. The paper highlights several recent cases of EB utilization to improve key properties of selected plastic products. In paper is provided a survey of radiation processing methods of industrial interest, encompassing technologies which are already commercially well established, through developments in the active R and D stage which show pronounced promise for future commercial use. Radiation cross-linking technologies discussed include: application in cable and wire, application in rubber tyres, radiation vulcanization of rubber latex, development of radiation crosslinked SiC fiber, polymer recycling, development of gamma compatible pp, hydrogels etc. Over the years, remarkable advancement has been achieved in radiation processing of natural polymers. Role of radiation in improving the processing of temperature of PCL for use as biodegradable polymer, in accelerated breakdown of cellulose into viscose and enhancement in yields of chitin/chitosan from sea-food waste, is described

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)

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

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)

Gamma radiation utilization for polymers synthesis

International Nuclear Information System (INIS)

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

1990-01-01

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

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)

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

International Nuclear Information System (INIS)

Yuliati, Helfi; Akhadi, Mukhlis

2000-01-01

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

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

Quality control through dosimetry at a contract radiation processing facility

International Nuclear Information System (INIS)

Du Plessis, T.A.; Roediger, A.H.A.

1985-01-01

Reliable dosimetry procedures constitute a very important part of process control and quality assurance at a contract gamma radiation processing facility that caters for a large variety of different radiation applications. The choice, calibration and routine intercalibration of the dosimetry systems employed form the basis of a sound dosimetry policy in radiation processing. With the dosimetric procedures established, detailed dosimetric mapping of the irradiator upon commissioning (and whenever source modifications take place) is carried out to determine the radiation processing characteristics and peformance of the plant. Having established the irradiator parameters, routine dosimetry procedures, being part of the overall quality control measures, are employed. In addition to routine dosimetry, independent monitoring of routine dosimetry is performed on a bi-monthly basis and the results indicate a variation of better than 3%. On an annaul basis the dosimetry systems are intercalibrated through at least one primary standard dosimetry laboratory and to date a variation of better than 5% has been experienced. The company also participates in the Pilot Dose Assurance Service of the International Atomic Energy Agency, using the alanine/ESR dosimetry system. Routine calibration of the instrumentation employed is carried out on a regular basis. Detailed permanent records are compiled on all dosimetric and instrumentation calibrations, and the routine dosimetry employed at the plant. Certificates indicating the measured absorbed radiation doses are issued on request and in many cases are used for the dosimetric release of sterilized medical and pharmaceutical products. These procedures, used by Iso-Ster at its industrial gamma radiation facility, as well as the experience built up over a number of years using radiation dosimetry for process control and quality assurance are discussed. (author)

Gamma-ray lines from radiative dark matter decay

International Nuclear Information System (INIS)

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

2011-01-01

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

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

International Nuclear Information System (INIS)

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

1990-01-01

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

Inactivation and stability of viral diagnostic reagents treated by gamma radiation

Energy Technology Data Exchange (ETDEWEB)

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

1990-10-01

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

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)

Analysis of portable gamma flaw detectors concerning radiation hygiene

International Nuclear Information System (INIS)

Makarova, T.V.

1982-01-01

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

Dosimetric aspects of radiation processing of food and allied products

International Nuclear Information System (INIS)

Sharma, G.; Bhat, R.M.; Bhatt, B.C.

2010-01-01

Full text: Gamma radiation processing in the last 4-5 decades is continuously gaining importance in processing of a wide variety of products, as it can modify physical, chemical and biological properties of the materials, including food and allied products on industrial scale due its inherent qualities like ease of processing in finally packaged form, eco-friendly nature and other obvious reasons over conventional means of processing. Food and allied products are either from agricultural produce or animal origin; they get easily contaminated from soil during harvesting, handling, processing, environment conditions, storage and transport from various types of micro-organisms including pathogens. In many countries it is mandatory to bring down the population of micro-organisms to an acceptable level and complete elimination of pathogens before such products are accepted for human or animal consumption. Processing of food and allied products by radiation has its own challenges due to wider public acceptance of irradiated food, a wide range, 0.25-50kGy, of absorbed dose requirements for different category of such products and purposes, use of a variety of packaging materials in different shapes and sizes and because of its perishable nature. More than 50 countries including India in the world have accepted radiation processing of food and allied products by radiation. Dosimetry is an important aspect of radiation processing, whether it is food or allied product. Uniformity in dose delivered to these products depends on several factors such as product carrier to source frame alignment, product carrier and product/tote box design, product loading pattern, attenuation due to product thickness, product bulk density that varies from 0.1-1.0 kg/l and the plant design whether during processing product overlaps the source or otherwise. In this presentation dosimetric aspects of radiation processing of food and allied products and problems associated with dosimetry of such

Developments and potential of radiation processing in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Singson, C; Carmona, C [Philippine Atomic Energy Commission, Diliman, Quezon City

1981-01-01

This paper describes the research and development activities in three areas of radiation processing, namely: food irradiation, medical product sterilization and wood plastic combination. Plans and efforts exerted to acquire a larger gamma source to augment our present 5,000 curie source are discussed. Cost estimates for a radiation facility are presented on the basis of the market potential of food irradiation and medical product sterilization. Existing local industries that can benefit from the adaptation of irradiation technology in their processing requirements are described.

Effect of neutron and gamma radiations on zeolite and zeotype materials

International Nuclear Information System (INIS)

Durrani, S.K.

1994-01-01

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

Decontamination of used pesticide packaging using advanced oxidation process by ionizing radiation

International Nuclear Information System (INIS)

Mori, Manoel Nunes

2006-01-01

The discharge of empty plastic packaging of pesticides can be an environmental concern causing problems to human health, animals and plants if done without inspection and monitoring. Among the commercial pesticides, chloropyrifos has significant importance because of its wide distribution and extensive use and persistence. The hydroxyl OH attack is the most efficient process of chemical oxidation. The radiation-induced degradation of chloropyrifos in liquid samples and in polyethylene pack was studied by gamma-radiolysis. Packaging of high density polyethylene tree layer co extruded, named COEX, and water samples contaminated with chloropyrifos, were irradiated using both, a multipurpose Co-60 gamma irradiator and a gamma source with 5,000 Ci total activity, Gamma cell type. The chemical analysis of the chloropyrifos and by-products were made using a gas chromatography associated to the mass spectrometry. Gamma radiation was efficient for removing chloropyrifos from the plastic packaging in all studied cases. (author)

A broadband gamma-ray spectrometry using novel unfolding algorithms for characterization of laser wakefield-generated betatron radiation

Energy Technology Data Exchange (ETDEWEB)

Jeon, Jong Ho, E-mail: jhjeon07@ibs.re.kr; Nakajima, Kazuhisa, E-mail: naka115@dia-net.ne.jp; Pathak, Vishwa Bandhu; Cho, Myung Hoon; Yoo, Byung Ju; Shin, Kang Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Kim, Hyung Taek; Sung, Jae Hee; Lee, Seung Ku; Choi, Il Woo [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Rhee, Yong Joo [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Shin, Jung Hun; Jo, Sung Ha [Advanced Photonics Research Institute, GIST, Gwangju 500-712 (Korea, Republic of); Hojbota, Calin; Cho, Byeoung Ick; Nam, Chang Hee [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of)

2015-12-15

We present a high-flux, broadband gamma-ray spectrometry capable of characterizing the betatron radiation spectrum over the photon energy range from 10 keV to 20 MeV with respect to the peak photon energy, spectral bandwidth, and unique discrimination from background radiations, using a differential filtering spectrometer and the unfolding procedure based on the Monte Carlo code GEANT4. These properties are experimentally verified by measuring betatron radiation from a cm-scale laser wakefield accelerator (LWFA) driven by a 1-PW laser, using a differential filtering spectrometer consisting of a 15-filter and image plate stack. The gamma-ray spectra were derived by unfolding the photostimulated luminescence (PSL) values recorded on the image plates, using the spectrometer response matrix modeled with the Monte Carlo code GEANT4. The accuracy of unfolded betatron radiation spectra was assessed by unfolding the test PSL data simulated with GEANT4, showing an ambiguity of less than 20% and clear discrimination from the background radiation with less than 10%. The spectral analysis of betatron radiation from laser wakefield-accelerated electron beams with energies up to 3 GeV revealed radiation spectra characterized by synchrotron radiation with the critical photon energy up to 7 MeV. The gamma-ray spectrometer and unfolding method presented here facilitate an in-depth understanding of betatron radiation from LWFA process and a novel radiation source of high-quality photon beams in the MeV regime.

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-01-15

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1966-07-01

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

Analysis of texture in baby carrot (Daucus carota) subjected to the process of ionizing radiation

International Nuclear Information System (INIS)

Nunes, Thaise C.F.; Rogovschi, Vladimir D.; Fabbri, Adriana D.T.; Sagretti, Juliana M.A.; Sabato, Susy F.

2011-01-01

The carrot is a vegetable of great economic value due to its versatility in the food industry and can be used as raw or minimally processed vegetable or aggregating value to the product, transforming the fresh carrots in baby carrots. It is well known that the application of gamma radiation in food may help in maintaining the quality of food. The aim of this study was to analyze the effects of the low doses of ionizing radiation on texture of minimally processed baby carrot after the processing in a Multipurpose 60 Co irradiator. It can be concluded that the treatment with low doses of gamma radiation keep the quality of fresh-cut baby carrot. (author)

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1960-07-01

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

Influence of UV and Gamma radiations on the induced birefringence of stretched poly(vinyl) alcohol foils

Science.gov (United States)

Nechifor, Cristina-Delia; Zelinschi, Carmen Beatrice; Dorohoi, Dana-Ortansa

2014-03-01

The aim of our paper is to evidence the influence of Gamma and UV radiations on the induced birefringence of poly(vinyl alcohol) stretched foils. Thin foils of PVA were prepared and dried without modifying their surfaces. The polymeric foils were irradiated from 15 min to 6 h using UV and Gamma radiations. The induced by stretching under heating birefringence of PVA films was measured at λ = 589.3 nm with a Babinet Compensator. Physico-chemical processes (photo stabilization, photo degradation, oxidation) induced by irradiation of polymer matrix influence both the stretching degree and the anisotropy of etired foils. An increase of birefringence versus the stretching ratio of the PVA foils was evidenced for all studied samples. The dependence of the birefringence on the exposure time, stretching ratio and nature of radiation was also confirmed.

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

Energy Technology Data Exchange (ETDEWEB)

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

1984-08-01

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

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.

Dosimetry systems for radiation processing in Japan

International Nuclear Information System (INIS)

Tamura, Naoyuki

1995-01-01

The present situation of dosimetry systems for radiation processing industry in Japan is reviewed. For gamma-rays irradiation the parallel-plate ionization chamber in TRCRE, JAERI has been placed as a reference standard dosimeter for processing-level dose. Various solid and liquid chemical dosimeters are used as routine dosimeters for gamma processing industries. Alanine dosimeters is used for the irradiation purpose which needs precise dosimetry. For electron-beam irradiation the electron current density meter and the total absorption calorimeter of TRCRE are used for the calibration of routine dosimeters. Plastic film dosimeters, such as cellulose triacetate and radiochromic dye are used as routine dosimeters for electron processing industries. When the official traceability systems for processing-level dosimetry now under investigation is completed, the ionization chamber of TRCRE is expected to have a role of the primary standard dosimeter and the specified alanine dosimeter will be nominated for the secondary or reference standard dosimeter. (author)

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)

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.)

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.

Gamma radiation effects on commercial Mexican bread making wheat flour

Science.gov (United States)

Agúndez-Arvizu, Z.; Fernández-Ramírez, M. V.; Arce-Corrales, M. E.; Cruz-Zaragoza, E.; Meléndrez, R.; Chernov, V.; Barboza-Flores, M.

2006-04-01

Gamma irradiation is considered to be an alternative method for food preservation to prevent food spoilage, insect infestation and capable of reducing the microbial load. In the present investigation, commercial Mexican bread making wheat flour was irradiated at 1.0 kGy using a 60C Gammabeam 651 PT irradiator facility. No changes were detected in moisture, protein and ashes in gamma irradiated samples as compared to those of non-irradiated samples. Slight radiation effects were observed in the alveogram values and farinograph properties; the falling number decreased 11%, the absorption as well as the mixing tolerance were practically unchanged by irradiation. An increase of 15% in the stability value and a 29% in the dough development time were observed. Also the deformation energy decreased 7% with no change at all in the tenacity/extensibility factor. Total aerobic, yeast and mold counts were reduced 96%, 25% and 75%; respectively by the irradiation process. The obtained results confirm that gamma irradiation is effective in reducing the microbial load in bread making wheat flour without a significant change in the physicochemical and baking properties.

Gamma radiation effects on commercial Mexican bread making wheat flour

Energy Technology Data Exchange (ETDEWEB)

Agundez-Arvizu, Z. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Fernandez-Ramirez, M.V. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Arce-Corrales, M.E. [Departamento de Ciencias Quimico Biologicas, Universidad de Sonora, Hermosillo, Sonora 83000 (Mexico); Cruz-Zaragoza, E. [Instituto de Ciencias Nucleares-UNAM, A.P. 70-543, Mexico 04510 DF (Mexico); Melendrez, R. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico); Chernov, V. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico); Barboza-Flores, M. [Centro de Investigacion en Fisica, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190 (Mexico)]. E-mail: mbarboza@cajeme.cifus.uson.mx

2006-04-15

Gamma irradiation is considered to be an alternative method for food preservation to prevent food spoilage, insect infestation and capable of reducing the microbial load. In the present investigation, commercial Mexican bread making wheat flour was irradiated at 1.0 kGy using a {sup 6}C Gammabeam 651 PT irradiator facility. No changes were detected in moisture, protein and ashes in gamma irradiated samples as compared to those of non-irradiated samples. Slight radiation effects were observed in the alveogram values and farinograph properties; the falling number decreased 11%, the absorption as well as the mixing tolerance were practically unchanged by irradiation. An increase of 15% in the stability value and a 29% in the dough development time were observed. Also the deformation energy decreased 7% with no change at all in the tenacity/extensibility factor. Total aerobic, yeast and mold counts were reduced 96%, 25% and 75%; respectively by the irradiation process. The obtained results confirm that gamma irradiation is effective in reducing the microbial load in bread making wheat flour without a significant change in the physicochemical and baking properties.

Gamma radiation effects on commercial Mexican bread making wheat flour

International Nuclear Information System (INIS)

Agundez-Arvizu, Z.; Fernandez-Ramirez, M.V.; Arce-Corrales, M.E.; Cruz-Zaragoza, E.; Melendrez, R.; Chernov, V.; Barboza-Flores, M.

2006-01-01

Gamma irradiation is considered to be an alternative method for food preservation to prevent food spoilage, insect infestation and capable of reducing the microbial load. In the present investigation, commercial Mexican bread making wheat flour was irradiated at 1.0 kGy using a 6 C Gammabeam 651 PT irradiator facility. No changes were detected in moisture, protein and ashes in gamma irradiated samples as compared to those of non-irradiated samples. Slight radiation effects were observed in the alveogram values and farinograph properties; the falling number decreased 11%, the absorption as well as the mixing tolerance were practically unchanged by irradiation. An increase of 15% in the stability value and a 29% in the dough development time were observed. Also the deformation energy decreased 7% with no change at all in the tenacity/extensibility factor. Total aerobic, yeast and mold counts were reduced 96%, 25% and 75%; respectively by the irradiation process. The obtained results confirm that gamma irradiation is effective in reducing the microbial load in bread making wheat flour without a significant change in the physicochemical and baking properties

Directional gamma sensing from covariance processing of inter-detector Compton crosstalk energy asymmetries

Energy Technology Data Exchange (ETDEWEB)

Trainham, R., E-mail: trainhcp@nv.doe.gov; Tinsley, J. [Special Technologies Laboratory of National Security Technologies, LLC, 5520 Ekwill Street, Santa Barbara, California 93111 (United States)

2014-06-15

Energy asymmetry of inter-detector crosstalk from Compton scattering can be exploited to infer the direction to a gamma source. A covariance approach extracts the correlated crosstalk from data streams to estimate matched signals from Compton gammas split over two detectors. On a covariance map the signal appears as an asymmetric cross diagonal band with axes intercepts at the full photo-peak energy of the original gamma. The asymmetry of the crosstalk band can be processed to determine the direction to the radiation source. The technique does not require detector shadowing, masking, or coded apertures, thus sensitivity is not sacrificed to obtain the directional information. An angular precision of better than 1° of arc is possible, and processing of data streams can be done in real time with very modest computing hardware.

Mobile robot prototype detector of gamma radiation; Prototipo de robot movil detector de radiacion gamma

Energy Technology Data Exchange (ETDEWEB)

Vazquez C, R.M. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Duran V, M. D.; Jardon M, C. I., E-mail: raulmario.vazquez@inin.gob.mx [Tecnologico de Estudios Superiores de Villa Guerrero, Carretera Federal Toluca-Ixtapan de la Sal Km. 64.5, La Finca Villa Guerrero, Estado de Mexico (Mexico)

2014-10-15

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

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

Cobalt 60 availability for radiation processing

International Nuclear Information System (INIS)

Fraser, F.M.

1986-01-01

In the last 20 years, the steady and significant growth in the application of radiation processing to industrial sterilization has been seen. The principal application of this technology is the sterilization of disposable medical products, food irradiation, the irradiation of personal care goods and so on. At present, more than 70 million curies of cobalt-60 supplied by Atomic Energy of Canada Ltd. have been used for gamma processing in these applications. This is estimated to be more than 80 % of the total cobalt-60 in service in the world. Commercial food irradiation has an exciting future, and as to the impact of food irradiation on the availability of cobalt-60 over the next ten years, two principal factors must be examined, namely, the anticipated demand for cobalt-60 in all radiation processing applications, and the supply of cobalt-60 to reliably meet the expected demand. As for the cobalt-60 in service today, 90 % is used for the sterilization of disposable medical products, 5 % for food irradiation, and 5 % for other application. The demand for up to 30 million curies of cobalt-60 is expected over the next 10 years. Today, it is estimated that over 150,000 tons of spices, fruit and fish are irradiated. The potential cobalt-60 production could exceed 110 million curies per year. Gamma processing application will demand nearly 50 million curies in 1990. (Kako, I.)

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.

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-12-01

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

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

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

Directory of Open Access Journals (Sweden)

Tuncbilek Aydin S.

2012-01-01

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

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)

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.)

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.

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.

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

International Nuclear Information System (INIS)

He Baoping; Yao Zhibin; Zhang Fengqi

2009-01-01

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

One of the great conundrums of the 20th century science - ionizing radiation: Radiation processing and applications in the Czech Lands

International Nuclear Information System (INIS)

Janovsky, I.

2007-01-01

The article deals with the following topics: Milestones in the early history of radiation and radiation sources (1895-1954); Radiation effects - early observations and further development; Scope of radiation processing; Radiation processing in the Czech Lands (i.e. Bohemia + Moravia = the Czech part of Czechoslovakia or Austria-Hungary till 1918) (radiation sterilization of medical items; radiation processing of cable insulations; radiation preservation of objects of art and historical monuments; radiation modification of semiconductors; radiation synthesis of organic compounds; food irradiation; application of ionizing radiation in agriculture and gardening; radiation regeneration of water wells; radiation degradation of chlorinated biphenyls; radiation coloration of glass for decorative purposes; some other applications; and problems associated with practical radiation processing). An overview of 60 Co gamma irradiators and electron accelerators installed at Czech institutions is presented in the tabular form. (P.A.)

Effect of low-dose gamma-radiation upon hatchability and weight of chickens

International Nuclear Information System (INIS)

Vilic, M.; Kraljevic, P.; Simpraga, M.; Miljanic, S.

2006-01-01

hatchability. Namely, hatchability of eggs of Avian-line 34 was improved by 0.83% over that of control eggs by the dose of 0.15 Gy before incubation (1 st experiment) and 1.37% by the same dose on seventh day of incubation. The hatchability of commercial broiler Ross 308 eggs was reduced by 2.5% by exposing the eggs to 0.30 Gy of gamma radiation before incubation. The weight of chickens was increased in all three experiments on the first day, however it was not significantly different when compared to control chickens. Treatment with 0.15 Gy gamma irradiation before incubation significantly increases body mass on the forty second day (P<0.05) when compared to the control group. Chickens that received 0.15 Gy on the seventh day of incubation did not differ in the weight from the controls at the end of fattening period (1 -42 days) while chickens that received 0.30 Gy before incubation had a significant reduction (P<0.01) in body weight on the 42. day of the(P<0.05). These results suggest that the stimulatory radiation effect is limited to the dose such as a 0.15 Gy. However, increasing the dose to 0.30 Gy eliminated the radiation-induced effect. The fact that only chickens irradiated with 0.15 Gy obtained a higher weight on first day may be due to stimulatory effects on embryonal development processes. (authors)

Study the Effect of Gamma Radiation on some Solid and Polymeric Materials and Its Possible Applications in Radiation Dosimetry

International Nuclear Information System (INIS)

El-Shawadfy, E.R.

2015-01-01

Dyed solid materials (films and gels) and dyed solutions dosimeters have wide-spread applications in radiation processing for installation process qualification and routine dose control for both gamma rays and electron beam irradiation. These film dosimeters have been introduced for low- and high-dose monitoring. The introduction of new types of dosimeters is due to the effort of seeking for more reliable, more stable, simpler and cheaper systems as routine dosimeters and/or label dosimeters. The main objective of this work is to study the possibility of preparing dyed solid polymeric materials (dyed films- dyed gels) and dyed solutions, and study the dosimetric studies for the prepared materials. The results obtained in this work can be summarized in the following: Section (1): Deals with the investigation of prepared three dosimetry systems based on Toludine Blue O (TBO) dye, to make them readily usable in high and low-radiation dosimetry applications (e.g. sterilization of medical products, sterilization of pharmaceutical products and polymer modification). This section is divided into three parts: Part I: This part includes the preparation and development of polymeric films for high-dose dosimetry applications, these films are based on poly (vinyl alcohol) dyed with TBO. These flexible plastic film dosimeters are bleached when exposed to gamma-ray photons (i.e. from blue to colorless) at λmax=633 nm. The radiation chemical yield (G-Value) for different concentrations of the dye as well as the dye with additive substances (chloral hydrate) was calculated. It was found that these films are highly stable for long time before and after irradiation under different storage conditions. The response of these films is not affected by humidity change in the range of relative humidity (0-56%). PVA films dyed with TBO are suitable in the dose range from 1-150 kGy. These properties suggest them to be useful for routine and dose mapping in sterilization range of radiation

PHYTOTHERAPEUTIC EFFECT OF AVOCADOS AND SOYA AS DRUG ON HEART OF RATS EXPOSED TO GAMMA RADIATION

International Nuclear Information System (INIS)

OMRAN, M.F.; IBRAHIM, N.K.; ABU-ZIED, N.M.

2008-01-01

This study was planed to determine the role of single oral dose of avocados and soya in irradiated rats exposed to gamma radiation. the experimental animals were randomly divided into four groups; 12 rats for each. Group 1: kept as control. Group 2: rats received piascledine for 14 consecutive days. Group 3: rats submitted to whole body gamma rays (4 Gy). Group 4: rats received the same piascledine 14 days post-exposure to 4 Gy gamma radiation. The animals were weighed then dissected after one and fourteen days post-administration and the cardiac tissue and plasma were stored at 12 oC till used for biochemical analysis and kept in ice. The following parameters were determined: plasma total cholesterol, triacylglycerol, high density lipoprotein-cholesterol, low density lipoprotein-cholesterol, LDH, phospholipids, ALT, CPK and TBARS. In cardiac tissue, determinations of total cholesterol, triacylglycerol, phospholipids and TBARS were conducted.It can be concluded that administration of avocados and soy as natural drug (piascledine) post-irradiation in rats is a favorable modificator against the impaired physiological processes in animal body due to gamma irradiation

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

International Nuclear Information System (INIS)

Fehlau, P.E.

1983-01-01

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

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

Effects of gamma radiation induced forced formation of free radicals on the strength of concrete for use in nuclear power plants

Directory of Open Access Journals (Sweden)

Burnham Steven

2017-01-01

Full Text Available In this paper, we present a summary of preliminary experiments and numerical assessments of the effects of gamma radiation induced formation of free radicals in the curing stage of concrete on its characteristics. Substantial literature reports on the damaging effects of long-term and high-dose gamma and neutron exposure on concrete. However, we show that short-term exposure of concrete to gamma radiation can be beneficial in increasing its compressive strength. The effects of exposing to 630 MBq 137Cs the 56 cubes each made of 125 cm3 concrete during the first seven days of curing are compared to another 56 cubes cured by the conventional process. The average compressive strength of the gamma cured cubes is around 8.500 psi, while conventionally cured cubes show the lower average strength of around 6.700 psi. The microstructure of the gamma and conventionally cured concrete cubes is analyzed using a scanning electron microscope. The radiolysis within the microstructure of the concrete cubes is assessed with computational modeling based on Geant4. The production of free radicals from radiolysis is shown to increase with increasing source strength and increasing the time of exposure to gamma radiation. This research shows in general that curing concrete in gamma radiation field provides observable trends toward its increased strength.

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.)

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.

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...

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.

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)

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.