WorldWideScience

Sample records for accidental gamma irradiation

  1. Dosimetric properties of textile fibers: application of electron paramagnetic resonance dosimetry to an accidental gamma irradiation

    The dosimetric properties of some twenty textile fibers have been studied in order to develop a method for determining the dose received in the case of an accidental gamma irradiation. Three textile fibers having properties most closely satisfying our needs were selected for detailed investigations: cotton, polypropylene and quartz. Electron Paramagnetic Resonance (EPR) readout techniques were used. In order to eliminate spectral anisotropy problems due to textile fiber inhomogeneities, a system has been developed to rotate samples in the resonant cavity during measurements. The structure, physical and chemical properties of cotton and polypropylene were investigated. A bibliographic study of the combined effects of light, heat and ionizing radiation on textile fibers was carried out. A linear relation exists between the EPR signal and the gamma ray dose received over a certain dose range. A method has been developed for preparing samples so as to reduce background noise not due to irradiation; in this way the detection threshold is lowered and a greater time stability obtained. Unknown doses corresponding to known spectra are determined by linear interpolation using a series of spectra obtained from the same fabric irradiated with known doses

  2. Accidental gamma dose measurement using commercial glasses.

    Narayan, Pradeep; Vaijapurkar, S G; Senwar, K R; Kumar, D; Bhatnagar, P K

    2008-01-01

    Commercial glasses have been investigated for their application in accidental gamma dose measurement using Thermoluminescent (TL) techniques. Some of the glasses have been found to be sensitive enough that they can be used as TL dating material in radiological accident situation for gamma dosimetry with lower detection limit 1 Gy (the dose significant for the onset of deterministic biological effects). The glasses behave linearly in the dose range 1-25 Gy with measurement uncertainty +/- 10%. The errors in accidental dose measurements using TL technique are estimated to be within +/- 25%. These glasses have shown TL fading in the range of 10-20% in 24 h after irradiation under room conditions; thereafter the fading becomes slower and reaches upto 50% in 15 d. TL fading of gamma-irradiated glasses follows exponential decay pattern, therefore dosimetry even after years is possible. These types of glasses can also be used as lethal dose indicator (3-4 Gy) using TL techniques, which can give valuable inputs to the medical professional for better management of radiation victims. The glasses are easy to use and do not require lengthy sample preparation before reading as in case of other building materials. TL measurement on glasses may give immediate estimation of the doses, which can help in medical triage of the radiation-exposed public. PMID:18285317

  3. Gamma irradiation devices

    The main parameters and the preparation procedures of the gamma radiation sources frequently applied for irradiation purposes are discussed. In addition to 60Co and 137Cs sources also the nuclear power plants offer further opportunities: spent fuel elements and products of certain (n,γ) reactions can serve as irradiation sources. Laboratory scale equipments, pilot plant facilities for batch or continuous operation, continuous industrial irradiators and special multipurpose, mobile and panorama type facilities are reviewed including those in Canada, USA, India, the Soviet Union, Hungary, UK, Japan and Australia. For irradiator design the source geometry dependence of the spatial distribution of dose rates can be calculated. (V.N.)

  4. Sterilization by gamma irradiation

    Since 1980 the National Institute of Nuclear Research counts with an Industrial Gamma Irradiator, for the sterilization of raw materials and finished products. Through several means has been promoted the use of this technology as alternative to conventional methods of sterilization as well as steam treatment and ethylene oxide. As a result of the made promotion this irradiator has come to its saturation limit being the sterilization irradiation one of the main services that National Institute of Nuclear Research offers to producer enterprises of disposable materials of medical use also of raw materials for the elaboration of cosmetic products and pharmaceuticals as well as dehydrated foods. It is presented the trend to the sterilization service by irradiation showed by the compilation data in a survey made by potential customers. (Author)

  5. Economics of gamma irradiation processing

    The gamma-ray irradiation business started at the Takasaki Laboratory of Japan Atomic Energy Research Institute. The irradiation facilities were constructed thereafter at various sites. The facilities must accept various types of irradiation, and must be constructed as multi-purpose facilities. The cost of irradiation consists of the cost of gamma sources, construction expense, personnel expense, management expense, and bank interest. Most of the expenses are considered to be fixed expense, and the amount of irradiation treatment decides the original costs of work. The relation between the irradiation dose and the construction expense shows the larger facility is more economical. The increase of amount of treatment reduces the original cost. The utilization efficiency becomes important when the amount of treatment and the source intensity exceed some values. The principal subjects of gamma-ray irradiation business are the sterilization of medical tools and foods for aseptic animals, the improvement of quality of plastic goods, and the irradiation of foods. Among them, the most important subject is the sterilization of medical tools. The cost of gamma irradiation per m3 in still more expensive than that by ethylene oxide gas sterilization. However, the demand of gamma-ray irradiation is increasing. For the improvement of quality of plastic goods, electron irradiation is more favourable than the gamma irradiation. In near future, the economical balance of gamma irradiation can be achieved. (Kato, T.)

  6. Biological dose estimation for accidental supra-high dose gamma-ray exposure

    Chen, Y., E-mail: yingchen29@yahoo.com.cn [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China); Yan, X.K. [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China); Department of Radiation Safety, Beijing Institute of Nuclear and Chemical Safety, 14 Guan-cun, Dongcheng District, Beijing 100077 (China); Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K. [Department of Radiation Toxicology and Oncology, Beijing Institute of Radiation Medicine, 27 Taiping Road, Haidian District, Beijing 100850 (China)

    2011-09-15

    To correctly estimate the biological dose of victims accidentally exposed to a very high dose of {sup 60}Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of {sup 60}Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0{sup -3}D{sup 2}. Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy {gamma}-irradiation from a supra-high dose {sup 60}Co gamma-ray accident.

  7. Gamma irradiators for radiation processing

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

  8. Gemstone dedicated gamma irradiation development

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  9. Gemstone dedicated gamma irradiation development

    Omi, Nelson M.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: nminoru@ipen.br; prela@ipen.br

    2007-07-01

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to its poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator constructed in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations, were performed. With the definitive optimized irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. This work presents some optimization parameters and the expected performance of the irradiator. (author)

  10. Gamma irradiators: developments in India

    A comprehensive programme for the production of 60Co sources and their applications was initiated at the Bhabha Atomic Research Centre in 1970. Initially a series of research irradiators called Gamma Chambers and Panoramic Batch Irradiators (PANBITs) was fabricated for R and D and pilot scale studies. In 1974 the first commercial scale, gamma sterilization plant ISOMED was commissioned with UNDP assistance. Subsequently two more plants were designed and built indigenously, one at Bangalore and the other at Delhi. A radiation plant for sludge hygienisation was built at Baroda and commissioned in 1992. The current interest in radiation vulcanization of natural rubber latex (NRL) prompted the development and commissioning of a pilot scale NRL, irradiator at Kottayam, Kerala in 1992. A multipurpose irradiator is built recently at Jodhpur, as an upgraded version of the vintage PANBIT. Salient feature of these plants are presented . (author). 6 figs

  11. Gamma irradiation service in Mexico

    In 1980 it was installed in Mexico, on the National Institute of Nuclear Research, an irradiator model J S-6500 of a canadian manufacture. Actually, this is the greatest plant in the Mexican Republic that offers a gamma irradiation process at commercial level to diverse industries. However, seeing that the demand for sterilize those products were not so much as the irradiation capacity it was opted by the incursion in other types of products. During 17 years had been irradiated a great variety of products grouped of the following form: dehydrated foods, disposable products for medical use, cosmetics, medicaments, various. Nowadays the capacity of the irradiator is saturated virtue of it is operated the 24 hours during the 365 days of the year and only its operation is suspended by the preventive and corrective maintenance. However, the fresh food market does not be attended since this irradiator was designed for doses greater than 10 kGy (1.0 Mrad)

  12. Gamma Irradiation of Polyesters Film

    Experimental investigations on the effects of gamma irradiation in air of aromatic polyesters are carried out, in order to evaluate the influence of aromatic density and the role of oxygen on the radiation resistance. The thermoplastic polyesters PolyEthyleneTerephthalate (PET), PolyButylene Terephthalate (PBT), PolyEthyleneNaphthalate (PEN), Poly1,4-cyclohexanedimethylen terephthalate-co-ethyleneterephthalate (PCT-co-ET) are moulded in thin films of 50 micron and irradiated at different absorbed doses, ranging from 0 to 1000 kGy, using a Co-60 gamma source. The structural changes in the polymers are studied by means of several physical-chemical and nuclear techniques. Electron Paramagnetic Resonance analyses are carried out to detect the radicals induced by irradiation and to follow their decay by oxygen permeation. Viscometric measurements show a similar trend for the different irradiated polyesters: in particular, chain scission induced by irradiation depends on the aromatic density contained in the polymer and shows a saturation effect at the highest doses. Positron Annihilation Lifetime Spectroscopy points out a decrease of the ortho-positronium signal caused by the production of oxidized species inhibiting the positronium formation. Finally, the experimental results obtained on the irradiated films are compared with previous studies carried out on the same polyesters moulded in sheets of 1-2 mm of thickness and γ-irradiated at the same adsorbed doses

  13. Gamma-irradiation of tomatoes

    The influence of gamma-ray on tomatoes picked in a pink-red ripening stage, good for consumption, is studied. For that purpose tomatoes of ''Pioneer 2'' variety packed in perforated 500 g plastic bags were irradiated on a gamma device (Cobalt-60) at a dose power of 1900 rad/min with doses 200 or 300 krad. Samples were stored after irradiation at room temperature (20 - 22sup(o)C). Microbiological studies demonstrated that 44 resp. 99.96 per cent of the initial number of microorganisms was destroyed after irradiation with 200 resp. 300 krad. The time required for the number of microorganisms to be restored was accordingly increased. Irradiation delayed tomato ripening by 4 to 6 days, demonstrable by the reduced content of the basic staining substances - carotene and licopine. Immediately after irradiation the ascorbic acid content was reduced by an average of 13 per cent. After 18 days the amount of ascorbic acid in irradiated tomatoes was increased to a higher than the starting level, this is attributed to reductone formation during irradiation. The elevated total sugar content shown to be invert sugar was due to further tomato ripening. (Ch.K.)

  14. Gamma irradiation of fruits

    At a Joint FAO/IAEA/WHO Expert Committee on Food Irradiation (JECFI) meeting held in 1976, recommendations were made to rationalize the unnecessarily elaborate wholesomeness evaluation procedures for irradiated foodstuffs. Irradiation at the commercially recommended doses did not adversely affect the constituents of mangoes, papayas, litchis and strawberries at the edible-ripe stage. These favourable radiation-chemical results justified the development of a theoretical model mango which could be used for extrapolation of wholesomeness data from an individual fruit species to all others within the same diet class. Several mathematical models of varying orders of sophistication were evolved. In all of them, it was assumed that the radiant energy entering the system reacted solely with water. The extent of the reaction of the other components of the model fruit with the primary water radicals was then determined. No matter which mathematical treatment was employed, it was concluded that the only components which would undergo significant modification would be the sugars. In order to extrapolate these data from the mango to other fruits, mathematical models of three fruits containing less sugar than the mango, viz. the strawberry, tomato and lemon, were compiled. With these models, the conclusion was reached that the theoretical degradation spectra of these fruits were qualitatively similar to the degradation pattern of the model mango. Theory was again substantiated by the practical demonstration of the protective effect of the sugars in the tomato and lemon. The decrease in radiation damage was enhanced by the mutual protection of the components of the whole synthetic fruits with ultimate protection being afforded by the biological systems of the real fruits

  15. Food irradiation: Gamma processing facilities

    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)

  16. Food irradiation: Gamma processing facilities

    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)

  17. Gamma Irradiation does not Cause Carcinogenesis of Irradiated Herbs

    Full text: Microbial contamination of medicinal herbs can be effectively reduced by gamma irradiation. Since irradiation may cause carcinogenicity of the irradiated herbs, the objective of this research is to study the effect of gamma irradiation (10 and 25 kGy) from cobalt-60 on carcinogenicity. The herbs studied were Pueraria candollei Grah., Curcuma longa Linn. Zingiber montanum, Senna alexandrina P. Miller, Eurycoma Longifolia Jack, Gymnostema pentaphylum Makino, Ginkgo biloba, Houttuynia cordata T., Andrographis paniculata, Thunbergia laurifolia L., Garcinia atroviridis G., and Cinnamomum verum J.S.Presl. The results showed that gamma irradiation at the dose of 10 and 25 kGy did not cause carcinogenicity of the irradiated herbs

  18. Radiation safety of gamma and electron irradiation facilities

    There are currently some 160 gamma irradiation facilities and over 600 electron beam facilities in operation throughout virtually all Member States of the IAEA. The most widespread uses of these facilities are for the sterilization of medical and pharmaceutical products, the preservation of foodstuffs, polymer synthesis and modification, and the eradication of insect infestation. The safety record of this industry has been very good. Nevertheless, there is a potential for accidents with serious consequences. Gamma and electron beam facilities produce very high dose rates during irradiation, so that a person accidentally present in the irradiation chamber can receive a lethal dose within minutes or seconds. Precautions against uncontrolled entry must therefore be taken. Furthermore, gamma irradiation facilities contain large amounts of radioactivity and if the mechanism for retracting the source is damaged, the source may remain exposed, inhibiting direct access to carry out remedial work. Contamination can result from corroded or damaged sources, and decontamination can be very expensive. These aspects clearly indicate the need to achieve a high degree of safety and reliability in the facilities. This can be accomplished by effective quality control together with careful design, manufacture, installation, operation and decommissioning. The guidance in this Safety Series publication is intended for competent authorities responsible for regulating the use of radiation sources as well as the manufacturers, suppliers, installers and users of gamma and electron beam facilities. 20 refs, 6 figs

  19. Radiation safety and accident experience at gamma irradiation plants

    Gamma irradiation plants for the sterilization of medical products, preservation of food grains and for various other applications employ multikilocurie 60Co sealed sources inside shielded irradiation cells. A number of interlocks are provided between the cell entry door and the source raise mechanisms, in order to prevent the entry of any person to the cell when the source is in the exposed condition. The present paper gives the general safety features and the interlocks employed in these plants along with the safety features of irradiation plants at BARC, namely 106 Ci Isomed plant for the sterilization of medical products, 105 Ci FIPLY plant for research in food preservation and 105 Ci PANBIT plant for industrial research. Over the last two decades five cases of accidental exposure have been reported in literature in which the operator gained entry to the irradiation cell when the source was in the exposed condition. Two of these cases resulted in fatalities while the remaining three cases resulted in hospitalization of the exposed individuals for six to seven weeks. A brief outline of these accidental exposure cases and the causes of the accidents are discussed in this paper. (author). 19 refs

  20. Production of modified starches by gamma irradiation

    As a new processing method for the production of modified starch, gamma irradiation and four kinds of inorganic peroxides were applied to commercial corn starch. The addition of inorganic peroxides without gamma irradiation or gamma irradiation without the addition of inorganic peroxides effectively decreased initial viscosity, but did not sufficiently keep viscosity stable. The combination of adding ammonium persulfate (APS) and gamma irradiation showed the lowest initial viscosity and the best stability out of the tested four kinds of inorganic peroxides. Among the tested mixing methods of APS, soaking was found to be more effective than dry blending or spraying. Therefore, the production of modified starch with low viscosity as well as with sufficient viscosity stability became feasible by the control of gamma irradiation dose levels and the amount of added APS to starch

  1. Clinical and biological observations on seven accidentally irradiated algerian persons

    On may 5th 1978 an Ir 192 source of 15 Curies for gammagraphy set in a pencil-like holder fell from a truck on the road from Algiers to Setif. It was found 2 or 3 days later by two young boys 3 and 7 years old (AEK and RAB). They handled this bright metallic object for some hours. Later their Grandmother (Mrs ARA, 47 years old) took the source away from them, brought it into their house and hid it in the kitchen. The Iridium source remained for 6 weeks in this room where 5 persons were irradiated depending on various conditions of time, posture and dose rate. Two young female patients DJA (22 years old) and FMA (20 years old and pregnant) regularly frequented the working area of the kitchen at a distance of between 0.80 and 1.50 meters from the source which delivered a dose rate in the range of 8 Roentgen/hour at one meter. The exposure was estimated to be 6 to 8 hours daily. Two girls, FAH (17 years old) and NOU (19 years old) usually spent several hours in the kitchen doing their homework. After 4 weeks, the pregnant woman FMA suffered a malaise and decided to leave the house and go to another house. From this time on the two younger girls replaced FMA in the kitchen and were irradiated from 6 to 8 hours daily. Moreover, Mrs ARA, the Grandmother, came frequently into the kitchen and often leaned against the shelf where the source had been hidden and was thus often very close to it. The Algerian authorities looked actively for the missing and finally located it on June 12, 38 days after it had been lost. On June 14th, the seven injured persons were evacuated from Algiers to Paris where they were taken to the Curie Foundation Hospital (Dr. Jammet)

  2. The effects of acute irradiation on a forest biogeocenosis: Experimental data, model and practical applications for accidental cases

    The effects of acute irradiations of a mixed pine and birch forest in spring and autumn with a high power point-type gamma radiation source (1180 TBq 137Cs) have been described. Radiation dose relationships for numerous response reactions of woody and herbaceous plants (growth and development of organs of woody plants, cytogenetical, physiological and biochemical changes in trees, reproductive potential of plants, damage and dying off of the forest as a biogeocenosis on the whole) have been calculated. Post-radiation recovery of the forest was investigated. Changes involving the secondary reactions related to radiation damage and death of the trees are presented. A model for radiation damage of forests has been designed. Examples are given on the usage of this model in the description of radiation effects in forests in the event of accidental releases of radionuclides into environment

  3. Therapeutic approaches of hematopoietic syndrome after serious accidental global irradiation. Ex vivo expansion interest of hematopoietic cells

    Aplasia is one of the main syndrome, appearing after one global accidental irradiation by one ionizing radiation source. The hematopoietic syndrome is characterized by a peripheric blood cell number fall; the cell marrow is reduced too

  4. Tolerance of edible flowers to gamma irradiation

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  5. Tolerance of edible flowers to gamma irradiation

    Koike, Amanda C.R.; Araujo, Michel M.; Costa, Helbert S.F.; Almeida, Mariana C.; Villavicencio, Anna Lucia C.H., E-mail: ackoike@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2011-07-01

    People have been eating flowers and using them in culinary creations for hundreds of years. Edible flowers are increasingly being used in meals as an ingredient in salads or garnish, entrees, drinks and desserts. The irradiation process is an alternative method that can be used in disinfestation of food and flowers, using doses that do not damage the product. The sensitivity of flowers to irradiation varies from species to species. In the present research was irradiated with doses up to 1 kGy some edible flowers to examine their physical tolerance to gamma-rays. Furthermore, high doses gamma irradiation causes petal withering, browning process and injury in edible flowers. (author)

  6. Regulation for the radiological safety in the design and operation of industrial Gamma irradiators in Egypt

    Large gamma irradiators present a high potential irradiation hazard since the amount of radioactivity is of the order of P Bq and a very high dose rate are produced during irradiation. Nevertheless, individuals may accidentally receive a lethal dose within minutes or seconds, due to failure of radiation control and safety systems. The competent authority (NCNSRC) is concerned with the impact of all radiation activities on workers as well as public health and safety. Radiation control of such large irradiation facilities can be achieved by means of strict regulatory procedures during construction, licensing, operation, inspection, maintenance and decommissioning

  7. Resistance of acrylic vessel to gamma irradiation

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the 222Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  8. Resistance of acrylic vessel to gamma irradiation

    Carneiro, Andre Cavalcanti; Menezes, Maria Angela de B.C.; Pereira, Marcio Tadeu; Rocha, Nirlando Antonio; Vilela, Jefferson Jose, E-mail: andreccarneiro@gmail.com, E-mail: menezes@cdtn.br, E-mail: mtp@cdtn.br, E-mail: nar@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Braga, Mario Roberto Martins S.S., E-mail: mariomartins@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares

    2013-07-01

    This paper describes the preliminary studies made in acrylic material in order to verify the effects of radiolysis in acrylic recipients in which the uranium ore standards are conditioned and check if the material is able to keep the {sup 222}Rn inside the vessel. The preliminary results after gamma irradiation of two kinds of recipients indicate no differences between the vessels irradiated and the ones no irradiated, related to color changes and tension resistance. (author)

  9. The influence of gamma irradiation in poultry

    The effect of a single whole - body gamma - irradiation of broiler chickens with a dose of 15.0 Gy on the activities of alaninaminotransferase (ALT) and aspartataminotransferase (AST) in the serum was investigated 1, 3, 5 and 7 days post irradiation. The numbers of erythrocytes and leucocytes and concentrations of haemoglobin in peripheral blood was investigated 1, 2, 4, 7, 9 and 14 days post irradiation. (authors)

  10. Preservation of potatoes by gamma irradiation

    In Algeria, potatoes are a major food item in nutrition habits. Because of lack of cold storage facilities, losses can reach up to 40% of the total output of summer harvest. This paper describes the first experiments on the application of gamma irradiation for the preservation of local varieties of potatoes. Losses are strongly reduced by inhibition sprouting effect of irradiation and reduction of sugars content has no significant influence on the acceptability of irradiated potatoes

  11. Quality of gamma irradiated California Valencia oranges

    The effects of gamma irradiation at 0.30-1.0 kGy (30-100 krad) on sensory qualities, certain biochemical components, and short-term storage life of Valencia oranges were examined. Irradiation at 0.75 kGy maintained food quality during 7°C storage for 7 weeks, while 0.50 kGy irradiation retained food quality at 21 °C. Irradiation at 0.26-0.30 kGy accomplished fruit fly disinfection while preserving market qualities of the oranges

  12. Gemstone enhancing dedicated gamma irradiator development

    The gemstones gamma irradiation process to enhance the color is widely accepted for the jewelry industry. These gems are processed in conventional industrial gamma irradiation plant which are optimized for other purposes, using underwater irradiation devices with high rejection rate due to it's poor dose uniformity. A new conception design, which states the working principles and manufacturing ways of the device, was developed in this work. The suggested device's design is based on the rotation of cylindrical baskets and their translation in circular paths inside and outside a cylindrical source rack as a planetary system. The device is meant to perform the irradiation in the bottom of the source storage pool, where the sources remain always shielded by the water layer. The irradiator matches the Category III IAEA classification. To verify the physical viability of the basic principle, tests with rotating cylindrical baskets were performed in the Multipurpose Irradiator raised in the CTR, IPEN. Also, simulations using the CADGAMMA software, adapted to simulate underwater irradiations were performed. With the definitive irradiator, the irradiation quality will be enhanced with better dose control and the production costs will be significantly lower than market prices due to the intended treatment device's optimization. (author)

  13. Development of modified starch by gamma irradiation

    The purpose of this study was to develop the production technology of modified starch. Corn starches were gamma irradiated at 0-110 kGy and the effect of irradiation dose levels on the physicochemical properties of corn starches were investigated. Blue value linearly decreased, while alkali number and solubility markedly increased as irradiation dose levels were increased. The optical transmittance increased as applied irradiation dose levels were increased in the temperature range of 65-95 deg. C. Water binding capacity and swelling power showed maximum value at 30 and 10 kGy, respectively and they tended to decrease thereafter. Gelatinization viscosity of the gamma irradiated starch considerably decreased as compared to that of the non-irradiated starch. Irradiation at 110kGy resulted in a marked reduction of peak viscosity and cooling viscosity at 30 deg. C by 100 and 300 times, respectively. The physicochemical properties of corn starch irradiated at 30 kGy were similar to those of commercial acid-modified starch, while those of corn starch irradiated at 100 kGy were similar to those if oxidized starch

  14. Analysis of gamma irradiated pepper constituents, 5

    Gamma irradiated peppers (10 krad, 100 krad, 1 Mrad) were analyzed by HPLC. The extraction method and HPLC conditions were same as the first report, that is, the extraction from pepper was performed by Automatic Air Hammer and the extracted samples were separated on a reversed phase C8 column with a concave gradient from 0.1% trifluoro aceticacid (TFA) in water to 75% acetonitrile-0.1% TFA in water for 60 minutes and detected at 210 nm, 280 nm. It is difficult to compare with irradiated and unirradiated pepper constituents by their peak height or area. And the method of multi variant statistically analysis was introduced. The 'peak n area/peak n + 1 area' ratio was calculated by computer. Each peak area was accounted by integrator. The value of these ratio were called 'parameter'. Each chromatogram has 741 parameters calculated with 39 chromatographic peaks. And these parameters were abopted to the multi variant statiscally analysis. Comparison of constituents between irradiated pepper and unirradiated pepper was done by 741 parameters. The correlation of parameters between irradiated and unirradiated was investigated by use of computer. Some parameters of irradiated case were selected as which had no correlation with unirradiated case. That is to say these parameters were thought to be changed with gamma spectrum irradiation. By this method, Coumarin was identified as a changed component with gamma irradiation. (author)

  15. Sewage Water Treatment by Gamma Irradiation

    This study indicates that Gamma irradiation could be the solution for raising the standards of disinfection in waste water of Damascus city up to the international standards, when samples of the inlet of the planet was irradiated with Gamma radiation at dose rate of 3.4 KGy./hr The radiation sensitivity of total micro-organisms, fungi, and pathogenic bacteria was 0.316, 0.318 , 0.306 KGy respectively Also the results showed the absence of Ascaris Lumbricoides ova which permit reusing the recycled waste water in irrigation safely. (authors)

  16. Storage ability of gamma irradiated mango fruits

    Extension of shelf-life have been achieved by many methods. the most modern one is using gamma irradiation as a promising technology for the developing nations. The aim of this investigation is to study the effects of gamma irradiation either alone or in combination with Alar or Benlate on 'Hindi Be Senara' mature green fruits and also to determine the optimum treatment and maximum extension in shelf - life. Mature-green 'Hindi be sinara' mango fruits were taken from trees planted in commercial orchard in 'kerdasa'Giza

  17. UTN's gamma irradiation facility: design and concept

    UTN is building a multipurpose gamma irradiation facility which compromises of research and pilot scale irradiation cells in The Fifth Malaysia Plan. The paper high-lights the basic futures of the facility in terms of its design and selection including layout sketches. Plant performances and limitations are discussed. Plants safety is briefly highlighted in block diagrams. Lastly, a typical specification brief is tabled in appendix for reference purposes. (author)

  18. Inactivation of Bacillus anthracis by Gamma irradiation

    N. Natalia

    2013-09-01

    Full Text Available The use of Bacillus anthracis as a biological weapon heighlightened awareness of the need for validated methods for the inactivation of B. anthracis spores. Ionizing radiation is capable of causing a variety of chemical changes and biological effects on bacteria which can be due both to direct interactions with critical cell components and to indirect actions on bacteria by molecular entities formed as a result of radiolysis of other molecules in the bacterial cell. This study determined the gamma irradiation dose for inactivating B. anthracis spores and its biological effects on the bacterial characteristics. Gamma irradiation was conducted at the IRKA irradiator at the National Nuclear Energy Agency, Jakarta and cobalt-60 was used as the source of ionizing radiation (capacity of ca. 134,044 Kci. Freeze dried culture of B. anthracis in glass ampoules was irradiated using variable doses of 30, 20 and 10 KGy. Viability, biochemical and protease enzyme characteristics of B. anthracis were evaluated before and after irradiation. The ability of B. anthracis to degrade gelatin, haemoglobin and bovine immunoglobulin G was also tested. The results showed that ionizing radiation was able to inactivate or kill 11,05 x 108 cfu B. anthracis by 95.37%, 99.58% and 99.99 at respective doses of 10, 20 and 30 KGy. Bacterial spores appear to be less susceptible to irradiation than the vegetative cells, because of their specific structure. The survive spores irradiated at 30kGy shows some biochemical characteristic changes. The survivors failed to degrade methyl -D-glucopyranoside and arbutine. The ability of B. anthracis protease to degrade gelatin, haemoglobin and bovine immunoglobulin G was not affected by irradiation. These findings showed that a gamma irradiation at 30 KGy effectively inactivates B. anthracis spores without changing the protease activities.

  19. Investigations on fiberoptic behaviour during gamma irradiation

    Siehs, J.

    1980-12-01

    The behavior of bulk glasses and fiber optics under gamma irradiation and two types of annealing processes (thermal and optical) were investigated. The samples were irradiated in the thermal column of the TRIGA Mark II reactor. The irradiation induced losses of transmission were measured in a dual beam spectrophotometer. The transmission was measured one hour after reactor shut-down. Thermal annealing was done at 300, 400 and 500 C. Photo bleaching was investigated with a quartz-lamp, an arc-lamp and an UV-laser light.

  20. Mobile gamma-irradiation robot

    A source container with 98 TBq of 137Cs and shielding made from depleted uranium has the total weight of 264 kg, height of 0.370 and diameter 0.272 m is described. The container is joined to accessories allowing movement of the radiation beam. The dose rate at a distance of 0.4 m in the beam axis is 50 Gy/h. Various technical means are available for manipulation and transport. The irradiation process proceeds according to a precalculated program. Safety measures have been taken to secure the possible application of the irradiation plant for the radiopreservation of cultural objects. The licence from health physics authorities has been obtained. The first irradiation process performed is described. (author)

  1. Chicken energia metabolism after single gamma irradiation

    The present study investigated changes in the concentration of cholesterol and glucose in the serum of poultry after single whole-body gamma irradiation with 4,5 Gy dose. In the experiment we used chickens of initial age 21 and 35 days at the beginning of the experiment. (authors)

  2. Microbial decontamination of spices by gamma irradiation

    The effect of gamma irradiation on the microbiological quality of spices was studied. It was found that the dose of 6 KGg decreases the cell count by a factor of 2-3 however complete decontamination is obtained at a dose of 10 KGg

  3. Effects of gamma irradiation on wheat quality

    Effect of gamma irradiation at the doses of 2.5,5.0,7.5,10.0 and 12.5 kGy on two bread wheat samples (Bezostaya and Gerek) with distinct physical and technological properties was investigated in this study.Irradiation at the levels used had no significant effect on the flour yields of both varieties.No apparent changes were observed in ash,protein and wet gluten contents of the irradiated samples and control.However,as the radiation level was increased the falling number and sedimentation values of the irradiated samples showed a steady decrease.Thiamine and riboflavin contents also decreased significantly with irradiation.Farinograph absorption increased with increasing radiation exposure.However, dough development time,stability and valorimeter values decreased as radiation levels increased.Maximum resistance to extension(Rm), resistance at constant deformation (R 5) and area(A) values of extensograms decreased in both varieties as radiation levels increased

  4. Gamma irradiation of peanut (Arachis hypogaea L.)

    This study was conducted to determine some effects of gamma radiation on peanut (Arachis hypogaea L.). The biological parameters used to evaluate these effects were: % emergence of irradiated seeds, % survival of plants, growth rate, chlorophyll mutations, morphological changes and yield potential. Seeds were irradiated with dose levels of 2.5, 5, 10, 15, 20, 25, 30 and 40 KK per hour of gamma radiation from a Co-60 source. In general, % of emergence and survival in the M1 gene ration decreased with increasing doses of gamma radiation. Morphological changes induced by gamma radiation in the M1 generation of peanut were: leaf flecks, thickened leaves, red purple seeds and red colored seed coat. Generally, frequency of these morphological changes increased with increasing doses of gamma radiation. Protein and fat contents were increased by 2.8% to 1.5% respectively, while starch content decreased with 2.6% in the M2. On the basis of the results obtained, gamma radiation is an effective mutagenic agent in inducing various morphological and genetic changes in peanut

  5. Gamma irradiation of natural dyes

    Dyes play an important role in textile industry. Synthetic dyes of various classes are normally used for dyeing fabrics. Recently, considerable attention is focussed on the use of natural dyes all over the world in the context of German ban on some of synthetic azo dye due to their allergenic or carcinogenic potential. However natural dyes and their solution in aqueous medium show microbial contamination on storage. The present study deals with effect of gamma radiation on the microbial load, tinctorial value and dye uptake of natural dyes. (author)

  6. Microbial determination of Cumin by gamma irradiation

    Cumin is one of the valuable export items of Iran, and like most of the agricultural products it is contaminated by microorganisms. Due to importance of this product, the gamma irradiation method, which has applications in microbial decontamination, has been used for the improving its quality and increasing the shelf life-time. For this purpose pak ages of 10 gr of cumin were irradiated by 2,4,6 and 8 KGy from 60Co source. With each dose, four samples were irradiated and results were compared with controlled not irradiated samples. According to the standard limitation of bacteria and molds the total optimum doses are 7.5 and 5 KGy respectively

  7. The Portuguese gamma irradiation facility

    A Gamma Radiation Facility was built up in the National Laboratory of Industrial Technology and Engineering (LNETI), Lisbon, Portugal. This plant (UTR GAMA-Pi) is a Cobalt-60 dry storage continuous facility with a nominal capacity of 1.5 x 1016 Bq. The initial activity is 1.1 x 1016 Bq and the throughput capacity 103 ton/year for product with a bulk density of 0.2 g/cm3 treated with a minimum absorbed dose of 25 kGy. Complementary control devices were installed: ventilation system, closed water refrigeration circuit, internal TV system, detection and extinction fire system and emergency power group. It must be emphasized that the best attention was given to the conception and efficiency of the interlock safety systems. This facility will be utilized mainly for radiosterilization of medical articles and decontamination of wine cork stoppers. (author)

  8. Cytotoxicity of mycotoxins after gamma irradiation

    Calado, Thalita; Verde, S. Cabo; Abrunhosa, Luís; Fernández-Cruz, M.; Venâncio, Armando

    2015-01-01

    Due to the high toxicity of mycotoxins, many methods have been used to reduce or eliminate them from food and feed. Gamma radiation is one technique that has been investigated with some promising results in the degradation of mycotoxins from food commodities. The aims of this study were (i) to clarify the effect of gamma irradiation on aflatoxin B1 (AFB1), aflatoxin B2, aflatoxin G1, aflatoxin G2 and ochratoxin A (OTA); (ii) to evaluate the effect of the presence of water du...

  9. Sensitivity of rice varieties to gamma irradiation

    R.Sasikala and R.Kalaiyarasi

    2010-01-01

    Six promising rice varieties viz., CO 43, CO 47, CO 48, CO 49, ADT 43 and Improved White Ponni were treated withgamma irradiation with doses of 100Gy, 200Gy, 250Gy, 300Gy and 350Gy of gamma rays in order to study effect of gammairradiation in seed germination of rice varieties and study the root and shoot length variation. Treated seeds were sownseparately in germination paper and nursery with the two replications. The germination percentage was decreased aftergamma irradiation. But the decre...

  10. Evaluation of gamma irradiation of teas

    There is a growing interest in the determination of non-essential traces elements in agroindustrial products. The continuous ingestion and accumulation in the organism of such elements, that may be toxic, can cause hazards to the human health in the long term. Reliable analytical techniques are necessary to monitor such products, including teas. In this work, the neutron activation technique is being employed to determine the trace elements in teas, due to its high sensibility and the possibility to perform a multi-elementary analysis. The gamma irradiation of teas is also being studied, because the shelf life can be extended and no chemical product is added to the teas. There is a concern related to the formation of free radicals in the teas, which is being accessed with electronic paramagnetic resonance. The results of the gamma irradiation up to 20 kGy of Camelia sinensis, Ilex paraguariensis, and Matricaria recutita are presented. (author)

  11. Gamma irradiation in a saturated tuff environment

    The influence of gamma irradiation on the reaction of actinide doped SRL 165 and PNL 76-68 glasses in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The reaction, and subsequent actinide release, of both glasses depends on the dynamic interaction between radiolysis effects which cause the solution pH to become more acidic and glass reaction which drives the pH more basic. The use of large gamma irradiation dose rates to accelerate reactions that would occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons are made between the present results and data obtained by reacting the same or similar glasses using MCC-1 and NNWSI rock cup procedures. 11 references, 3 figures

  12. Evaluation of gamma irradiation of teas

    Gerolis, Luanai G.L.; Lameiras, Fernando S.; Menezes, Maria A.B.C.; Leal, Alexandre S., E-mail: luanaigraz@yahoo.com.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Krambrock, Klaus, E-mail: klaus@fisica.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisica. Lab. de Ressonancia Paramagnetica Eletronica

    2013-07-01

    There is a growing interest in the determination of non-essential traces elements in agroindustrial products. The continuous ingestion and accumulation in the organism of such elements, that may be toxic, can cause hazards to the human health in the long term. Reliable analytical techniques are necessary to monitor such products, including teas. In this work, the neutron activation technique is being employed to determine the trace elements in teas, due to its high sensibility and the possibility to perform a multi-elementary analysis. The gamma irradiation of teas is also being studied, because the shelf life can be extended and no chemical product is added to the teas. There is a concern related to the formation of free radicals in the teas, which is being accessed with electronic paramagnetic resonance. The results of the gamma irradiation up to 20 kGy of Camelia sinensis, Ilex paraguariensis, and Matricaria recutita are presented. (author)

  13. Biochemical changes in ginger after gamma irradiation

    Ginger (Zingiber officinate) was irradiated with gamma rays (0.1Kgy, 1.0Kgy). Biochemical changes during storage at room temperature (23-28 degree centigrade), in sand (23-28 degree centigrade) and at cold (8 degree centigrade) temperature were observed. Changes in starch, soluble protein, fixed oil and volatile oil contents showed that treatment of ginger at 0.1Kgy radiation level was most appropriate for storage upto 45 days

  14. ESR identification of gamma-irradiated albendazole

    Çolak, Seyda

    2010-01-01

    The use of ionizing radiation for sterilization of pharmaceuticals is a well-established technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma-irradiated solid albendazole samples is investigated at different temperatures in the dose range of 3-34 kGy by electron spin resonance (ESR) spectroscopy. Irradiation with gamma radiation produced two different radical species in albendazole. They were fairly stable at room temperature but relatively unstable above room temperature, giving rise to an unresolved ESR spectrum consisting of three resonance peaks centered at g=2.0057. Decay activation energies of the contributing radical species were calculated to be 47.8 (±13.5) and 50.5 (±9.7) kJ/mol using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to best describe the experimental dose-response data. Albendazole does not present the characteristics of good dosimetric materials. However, the discrimination of irradiated albendazole from its unirradiated form was possible even 6 months after storage in normal conditions. Based on these findings, it is concluded that albendazole and albendazole-containing drugs can be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilization.

  15. Gamma spectrometrical examination of irradiated fuel

    Gamma scanning is the only non-destructive technique for quantitative measuring of fission or activation products in spent fuel. The negligence of local variation of the linear attenuation coefficient of gamma rays in the irradiated fuel remains the main source of systematic error. To eliminate it we combine the (single) emission gamma ray scanning technique with a transmission measurement. Mathematical procedure joined with the experiment is particularly convenient for fuel elements of circular cross-section. In such a manner good results are obtainable even for relatively small number of measuring data. Accomplished routines enable to esteem the finite width of the collimation slit. The experiment has been partially automated. Trial measurements were carried out, and the measured data were successfully processed

  16. Inactivation of RNA viruses by gamma irradiation

    Four kinds of RNA viruses, Bluetongue virus (BT), Bovine Virus Diarrhea-Mucosal Disease virus (BVD·MD), Bovine Respiratory Syncytial virus (RS), Vesicular Stmatitis virus (VS), were subjected to various doses of gamma irradiation to determine the lethal doses. The D10 values, which are the dose necessary to decimally reduce infectivity, ranged from 1.5 to 3.4 kGy under frozen condition at dry-ice temperature, and they increased to 2.6 to 5.0 kGy under frozen condition at dry-ice temperature. Serum neutralzing antibody titer of Infectious Bovine Rhinotracheitis (IBR) was not adversely changed by the exposure to 36 kGy of gamma-rays under frozen condition. Analysis of electrophoresis patterns of the bovine serum also reveales that the serum proteins were not remarkably affected, even when exposed to 36 kGy of gamma radiation under frozen condition. The results suggested that gamma irradiation under frozen condition is an effective means for inactivating both DNA and RNA viruses without adversely affecting serum proteins and neutralizing antibody titer. (author)

  17. Effects of gamma irradiation on deteriorated paper

    Bicchieri, Marina; Monti, Michela; Piantanida, Giovanna; Sodo, Armida

    2016-08-01

    Even though gamma radiation application, also at the minimum dosage required for disinfection, causes depolymerization and degradation of the paper substrate, recently published papers seemed, instead, to suggest that γ-rays application could be envisaged in some conditions for Cultural Heritage original documents and books. In some of the published papers, the possible application of γ-rays was evaluated mainly by using mechanical tests that scarcely reflect the chemical modifications induced in the cellulosic support. In the present article the effect of low dosage γ-irradiation on cellulosic substrates was studied and monitored applying different techniques: colorimetry, spectroscopic measurements, carbonyl content and average viscometric degree of polymerization. Two different papers were investigated, a non-sized, non-filled cotton paper, and a commercial permanent paper. To simulate a real deteriorated document, which could need γ-rays irradiation, some samples were submitted to a hydrolysis treatment. We developed a treatment based on the exposition of paper to hydrochloric acid vapors, avoiding any contact of the samples with water. This method induces a degradation similar to that observed on original documents. The samples were then irradiated with 3 kGy γ-rays at a 5258 Gy/h rate. The aforementioned analyses were performed on the samples just irradiated and after artificial ageing. All tests showed negative effects of gamma irradiation on paper. Non-irradiated paper preserves better its appearance and chemical properties both in the short term and after ageing, while the irradiated samples show appreciable color change and higher oxidation extent. Since the Istituto centrale restauro e conservazione patrimonio archivistico e librario is responsible for the choice of all restoration treatments that could be applied on library and archival materials under the protection of the Italian State (http://www.icpal.beniculturali.it/allegati/DM-7

  18. Sprouting inhibition of rhizomes by gamma irradiation

    Sprouting inhibition by gamma irradiation to prolong the storage life of 4 species of rhizomes, namely curcuma domestica, kaemferia galanga, curcuma xanthoriza and curcuma aeruginosa, has been carried out. Two groups of samples were used, freshly harvested rhizomes and fresh rhizomes which have been stored for about two weeks. The samples were packed in a plastic net bag, each contained about 100 grams of rhizomes. Irradiation was carried out at room temperature at the doses of 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.15, 0.20 and 0.25 kGy. Post irradiation storage was done at room temperature with relative humidity ranging between 85 and 95%. The results showed that irradiation doses of 0.06 to 0.08 kGy was sufficient to inhibit sprouting of freshly harvested rhizomes and prolonged its storage life for 6 weeks, while in the other group sprouting still occured at the dose of 0.25 kGy. Irradiation dose up to 0.25 kGy did not cause significant effect on moisture and volatile oil contents, as well as volatile oil characteristics of the samples. About 50% of weight losses were found either in irradiated or unirradiated samples after being stored for 8 weeks. Odour and texture were evaluated organoleptically while mould growth and insect damage were observed visually. (author)

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

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

  20. Silicon/HfO2 interface: Effects of gamma irradiation

    Maurya, Savita

    2016-05-01

    Quality of MOS devices is a strong function of substrate and oxide interface. In this work we have studied how gamma photon irradiation affects the interface of a 13 nm thick, atomic layer deposited hafnium dioxide deposited on silicon wafer. CV and GV measurements have been done for pristine and irradiated samples to quantify the effect of gamma photon irradiation. Gamma photon irradiation not only introduces positive charge in the oxide and at the interface of Si/HfO2 interface but also induce phase change of oxide layer. Maximum oxide capacitances are affected by gamma photon irradiation.

  1. Sensitivity of rice varieties to gamma irradiation

    R.Sasikala and R.Kalaiyarasi

    2010-07-01

    Full Text Available Six promising rice varieties viz., CO 43, CO 47, CO 48, CO 49, ADT 43 and Improved White Ponni were treated withgamma irradiation with doses of 100Gy, 200Gy, 250Gy, 300Gy and 350Gy of gamma rays in order to study effect of gammairradiation in seed germination of rice varieties and study the root and shoot length variation. Treated seeds were sownseparately in germination paper and nursery with the two replications. The germination percentage was decreased aftergamma irradiation. But the decrease was neither proportional to the increase in dosage nor definite pattern was found in allthe six rice varieties. At the dose of 350Gy all the six varieties exhibited the low germination percentage especially in thevariety ADT 43 is 33%. The gamma ray dose of 300Gy was causing 42-51% seedling height reductions in CO 43, CO 47,CO 48, CO 49 and ADT43. The seedling height was decreased in decreasing manner with the increase of irradiation dose inthe varieties such as CO 47 and improved white ponni. The root development in seedlings was inhibited higher in the dose of300Gy in all the six varieties. At higher dose of 350Gy root length is very much affected in the varieties viz., CO 43 with76% reduction and 70% reduction in improved white ponni. Plant height and seed fertility percentage were decreased withincrease of gamma radiation dose in linear fashion. Seed fertility decreased with increase of radiation dose was observed inCO 47, ADT 43 and improved white ponni. In ADT 43 seed fertility was reduced approximately 69% at gamma ray dose of350Gy.

  2. Effect of gamma irradiation on Korean traditional multicolored paintwork

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d’Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong. - Highlights: • Effects of gamma irradiation on the Dancheong were evaluated. • We confirmed that optical and structural properties of Dancheong were maintained. • Irradiation can contribute the decontamination for

  3. The use of chromosomic anomalies for the estimation of an accidental acute irradiation dose in man

    The induction of chromosome abnormalities (dicentrics, rings and fragments) in human blood samples subjected to cobalt 60 gamma irradiation was studied for 11 doses varying from 25 to 1800 rads. The chromosome aberrations were counted in lymphocytes after 48 hours of in vitro culture. The results obtained from the observation of 6400 cells made it possible to establish dose-effect relationships for each types of abnormality (dicentrics, dicentrics and rings, and fragments). The dose-effect relationships were used to estimate doses received by 9 workers submitted to relatively homogeneous global acute irradiation and for which an evaluation of the average absorbed dose was possible. There is in general a good agreement between the estimation of the average absorbed dose based on chromosome damage and the physical dosimeter data. The study of the time-dependent evolution of the chromosome abnormalities in the lymphocytes of irradiated subjects shows that dosimetric estimations based on lymphocyte chromosome abnormalities in human blood are valid for several weeks after irradiation

  4. Decontamination of spices by gamma irradiation

    Effect of gamma irradiation (8 kGy) on decontamination of pre packed (in polyethylene) and unpacked spices such as black pepper and chilli, was studied over a storage period of 12 months. Radiation dose of 8.0 kGyu completely decontaminated by the spices. Fungal packaged samples. Water content increased from a range values of 7.6-8.5% to 11.4 to 15.2% the increase was higher in red chilli than black pepper. Colour values significantly changed during storage, however the influence of radiation was not consistent. (author)

  5. Decontamination of spices by gamma irradiation

    Decontamination of spices (onion powder, cardamom, red pepper powder, etc.) used for special types of Bulgarian sausages was investigated. Gamma irradiation (60Co) at doses of 4, 6, 8 and 10 kGy was applied. It was found that the total count of microorganisms in spices was between 1.85.105 and 3.8.107. The largest was the amount of the coliforms and the staphylococci in the onion powder. The cardamom and onion powder were free of coliforms with dose of 4 kGy. The staphylococci were eliminated with doses of 6 kGy. The number of proteolytic microorganisms was decreased but they were isolated from spices irradiated even with 10 kGy. (author)

  6. Decontamination of spices by gamma irradiation

    Decontamination by gamma irradiation of minor spices such as coriander, fennel, cumin, aniseed, cardamom (large) and ajowan was studied. The bacterial load on these spices ranged from 102 - 105 cfu/g, while the fungal load ranged from 10-103 cfu/g. No microorganisms were detected in samples exposed to radiation and stored up to 12 mo. Though pathogens, such as coliforms, B. cereus and Staphylococci were detected in some samples of spices, their presence was not detected in spices exposed to radiation. A comparison of gas liquid chromatographic profiles indicated no significant change in the quality of volatile oils of these spices. Intra country transportation studies, in collaboration with two national laboratories and a multinational corporation, confirmed our earlier observations regarding retention of quality in several spices following irradiation, transport and storage. Similar results were evident from intercountry collaborative studies with Japan. (author). 10 refs, 6 figs, 10 tabs

  7. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS

    Clark, E.

    2011-09-22

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

  8. Mechanical performance of gamma irradiated surgical sutures

    Surgical sutures are medical devices made of natural or synthetic polymeric materials that, due to its end-use, have to be sterilized. Historically, the sterilization by heat or using ethylene oxide had presented so numerous drawbacks that today the non-pollutant radiation sterilization has become a well established sterilization process, that brings, environmental, technical, and economical advantages. The amount of irradiation doses required for sterilization of health care products is 25 kGy in most instances to achieve the necessary sterility assurance level. As high energy radiation produces modifications in the molecular structure of organic materials with changes in its mechanical properties, the aim of this work was to evaluate the mechanical behavior of surgical sutures under irradiation. Silk, polyamide and catgut sutures were gamma irradiated up to doses of 50 kGy in an industrial irradiation sterilization plant. Afterwards, these sutures were mechanical tested for tensile strength under knot following the specifications of the NBR13904 draft standard, using the CTRD-INSTRON at IPEN. The mechanical lab results show that sutures made of Silk and Polyamide do not present any change in their mechanical performance up to the dose of 50 kGy. On the other hand, Catgut present mechanical stability up to 30 kGy and afterwards, a slight decrease in its tensile strength was detected. (author)

  9. Toxoplasma gondii gamma irradiation using Co-60

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

  10. Effect of gamma irradiation on Korean traditional multicolored paintwork

    Yoon, Minchul; Kim, Dae-Woon; Choi, Jong-il; Chung, Yong-Jae; Kang, Dai-Ill; Hoon Kim, Gwang; Son, Kwang-Tae; Park, Hae-Jun; Lee, Ju-Woon

    2015-10-01

    Gamma irradiation can destroy fungi and insects involved in the bio-deterioration of organic cultural heritages. However, this irradiation procedure can alter optical and structural properties of historical pigments used in wooden cultural heritage paintings. The crystal structure and color centers of these paintings must be maintained after application of the irradiation procedure. In this study, we investigated the effects of gamma irradiation on Korean traditional multicolored paintwork (Dancheong) for the preservation of wooden cultural heritages. The main pigments in Korean traditional wooden cultural heritages, Sukganju (Hematite; Fe2O3), Jangdan (Minium; Pb3O4), Whangyun (Crocoite; PbCrO4), and Jidang (Rutile; TiO2), were irradiated by gamma radiation at doses of 1, 5, and 20 kGy. After irradiation, changes in Commision Internationale d'Eclairage (CIE) color values (L*, a*, b*) were measured using the color difference meter, and their structural changes were analyzed using X-ray diffraction (XRD) analysis. The slightly change in less than 1 dE* unit by gamma irradiation was observed, and structural changes in the Dancheong were stable after exposure to 20 kGy gamma irradiation. In addition, gamma irradiation could be applied to painted wooden cultural properties from the Korean Temple. Based on the color values, gamma irradiation of 20 kGy did not affect the Dancheong and stability was maintained for five months. In addition, the fungicidal and insecticidal effect by less than 5 kGy gamma irradiation was conformed. Therefore, the optical and structural properties of Dancheong were maintained after gamma irradiation, which suggested that gamma irradiation can be used for the preservation of wooden cultural heritages painted with Dancheong.

  11. EPR investigation of some gamma-irradiated excipients

    Aleksieva, Katerina; Yordanov, Nicola D.

    2012-09-01

    The results of electron paramagnetic resonance (EPR) studies on some excipients: lactose, microcrystalline cellulose (avicel), starch, dioxosilane (aerosil), talc and magnesium stearate before and after gamma-irradiation are reported. Before irradiation, all samples are EPR silent except talc. After gamma-irradiation, they show complex spectra except magnesium stearate, which is EPR silent. Studies show the influence of gamma-irradiation on EPR spectra and stability of gamma-induced radicals. Analysis of the EPR spectrum of gamma-irradiated talc shows that this material is radiation insensitive. Only lactose forms stable-free radicals upon gamma sterilization and can be used for identification of radiation processing for a long time period thereafter.

  12. Degradation of corn starch under the influence of gamma irradiation

    Irradiation of corn (maize) starch with different doses of gamma irradiation ranging from 1 x 105 rad to 1 x 106 rad resulted in the increase of starch acidity and reducing power. Molecular degradation was observed as a result of marked decrease in starch viscosity and intinsic viscosity as well as swelling capacity. The gelatinization time and temperature of the irradiated starch became shorter than in the control sample. Internal changes in the irradiated starch occured as a result of lowering the number of glucose unit per segment in the irradiated starch molecules. All changes were proportional to the doses of gamma irradiation used. (orig.)

  13. Gamma ray irradiation for sludge solubilization and biological nitrogen removal

    This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewage sludge. The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. The gamma ray irradiation showed effective sludge solubilization efficiencies. Both soluble chemical oxygen demand (SCOD) and biochemical oxygen demand (BOD5) increased by gamma ray irradiation. The feasibility of the solubilized sludge carbon source for a biological nitrogen removal was also investigated. A modified continuous bioreactor (MLE process) for a denitrification was operated for 20 days by using synthetic wastewater. It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal. - Research highlights: → This study was conducted to investigate the effects of gamma ray irradiation on the solubilization of waste sewagesludge. → The recovery of an organic carbon source from sewage sludge by gamma ray irradiation was also studied. → It can be concluded that the gamma ray irradiation was useful for the solubilization of sludge and the recovery of carbon source from the waste sewage sludge for biological nitrogen removal.

  14. Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

    Kim, Jae-Hun; Sung, Nak-Yun; Raghavendran, H. Balaji; Yoon, Yohan; Song, Beom-Seok; Choi, Jong-il; Yoo, Young-Choon; Byun, Myung-Woo; Hwang, Young-Jeong; Lee, Ju-Woon

    2009-07-01

    Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX ( Pstatistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

  15. The improvement of corn starch isolation process by gamma irradiation

    Gamma irradiation was applied to non-glutinous and glutinous corns for improving starch isolation process. No significant changes in proximate composition of corn grains were observed by gamma irradiation. Irradiation at 1 and 5 kGy was effective for sterilizing all contaminated microorganisms of non-glutinous and glutinous corns, respectively. The moisture-uptake rate constants were increased in proportional to the steeping temperature and applied irradiation dose level. The irradiation efficacy on water absorption properties was also recognized in the corns stored for six months at room temperature. The combined use of gamma irradiation with sulfur dioxide solution was very effective for reducing steeping time. The starch yield gradually increased as irradiation dose levels increased. At 2 kGy, the sarch yield of non-glutinous and glutinous corns increased by 38% and 27%, respectively. No significant difference in Hunter's color value was observed between the starches isolated from nonirradiated and irradiated corn grains

  16. Gamma-ray spectroscopy on irradiated fuel rods

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

  17. Modifications of Viscoelastic Properties of Polysaccharides by Gamma Irradiation

    The aim of this work was to establish the effect of gamma irradiation on the viscoelastic properties of the sodium alginate. Aqueous suspensions of sodium alginate at different concentrations (0.25 - 4%) were irradiated using a 60Co gamma-ray source (10, 25 and 50 kGy). The monitored rheological parameters showed the non-Newtonian behavior of the samples is kept by gamma irradiation. The decrease tendency of the apparent viscosity by irradiation samples and with decrease of the concentration as well has been noticed

  18. Structural Characteristics of Laminarin, Seaweed Polysaccharide, Degraded by Gamma Irradiation

    Choi, Jongil; Kim, Jaehun; Song, Beomseok; Kim, Jaekyung; Park, Jongheum; Lee, Juwoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Recently, it has been reported that low molecular weight laminarin had the enhanced biological activities. In this study, laminarin was degraded by gamma irradiation, and the changes in its structure and antioxidant property were investigated. Gel permeation chromatography data showed that the average molecular weight of the irradiation dose increased. The absorbance at 290 nm from UV spectra was increased depending on the irradiation dose resulting from the formation of carbonyl groups. The anti oxidative activity was increased in the gamma irradiated laminarin depending on the absorbed dose. It was reasoned by the formed carbonyl groups in gamma irradiated laminarin. Therefore, gamma irradiation could be a promising method for preparing low molecular weight laminarin with enhanced biological activities.

  19. Structural Characteristics of Laminarin, Seaweed Polysaccharide, Degraded by Gamma Irradiation

    Recently, it has been reported that low molecular weight laminarin had the enhanced biological activities. In this study, laminarin was degraded by gamma irradiation, and the changes in its structure and antioxidant property were investigated. Gel permeation chromatography data showed that the average molecular weight of the irradiation dose increased. The absorbance at 290 nm from UV spectra was increased depending on the irradiation dose resulting from the formation of carbonyl groups. The anti oxidative activity was increased in the gamma irradiated laminarin depending on the absorbed dose. It was reasoned by the formed carbonyl groups in gamma irradiated laminarin. Therefore, gamma irradiation could be a promising method for preparing low molecular weight laminarin with enhanced biological activities

  20. Caffeine degradation in water by gamma irradiation, ozonation and ozonation/gamma irradiation

    Torun Murat

    2014-03-01

    Full Text Available Aqueous solutions of caffeine were treated with ozone and gamma irradiation. The amounts of remaining caffeine were determined after solid phase extraction as a function of absorbed dose and ozonation time. In addition to this, some important parameters such as inorganic ions, chemical oxygen demand (COD dissolved oxygen and total acidity changes were followed. Caffeine (50 ppm is found to be completely decomposed at 3.0 kGy and 1.2 kGy doses in the absence of H2O2 and in 1.20 mM H2O2 solutions, respectively. In the case of gamma irradiation after ozonation, 50 ppm caffeine was removed at 0.2 kGy when the solution was ozonized for 100 s at a rate of 10 g O3 h-1 in 400 mL 50 ppm paracetamol solution.

  1. Application of gamma irradiation for inhibition of food allergy

    This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk β-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods

  2. Physicochemical Properties of Gamma-Irradiated Corn Starch

    Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples

  3. Application of gamma irradiation for inhibition of food allergy

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Jo, Cheorun; Kim, Hee-Yun

    2002-03-01

    This study was carried out to evaluate the application of food irradiation technology as a method for reducing food allergy. Milk β-lactoglobulin, chicken egg albumin, and shrimp tropomyosin were used as model food allergens for experiments on allergenic and molecular properties by gamma irradiation. The amount of intact allergens in an irradiated solution was reduced by gamma irradiation depending upon the dose. These results showed that epitopes on the allergens were structurally altered by radiation treatment and that the irradiation technology can be applied to reduce allergenicity of allergic foods.

  4. Study of a Case Involving Accidental Irradiation of a Human Being

    A description is given of an accident involving extremely uneven irradiation (ranging from 50 rads to 1.7 Mrads), in which a worker carried a 137Cs source belonging to an industrial gamma radiography unit in his trouser pockets for a total period of 18 hours on 3 and 4 May 1968. Low irradiation of the haematopoietic and gastrointestinal organs inhibited the occurrence of the acute syndrome. The front of the thighs, the inguinoscrotal region, and to a lesser extent the hands, were the areas most affected by lesions. The radiation doses delivered to the affected areas were estimated from biological radiation dosimetry parameters (the extent and chronological order of some of the lesions) and from experimental data on the dose as a function of distance and depth of the tissues, obtained by reconstructing the accident with a phantom and a set of thermoluminescent dosimeters. The paper describes the appearance a few days later of wet radiation dermatitis covering areas which gradually grew until they reached approximately the limit represented by the 1000 rads isodose line. Progression of the radiation dermatitis was complete towards the end of May. At the beginning of June dry epidermal desquamation extending approximately as far as the 500 rads line was observed. With the passage of time there occurred muscular atrophy of both legs and extensive oedema of the inguinoscrotal area. The appearance of extensive femoral haemorrhages in November 1968 and January 1969 made it necessary to amputate first the lower left limb, and then the right. The rate of chromosomal aberrations in the peripheral blood confirms the low doses absorbed by the blood system (about 50 rads). A summary of results of the analyses made is given, together with comments on the prognosis of the patient's development, based on the distribution of the radiation dose received. (author)

  5. Research of glycolaldehyde formed during gamma irradiation of maize starch

    During gamma irradiation of maize starch, glycolaldehyde occurs (5.6 μg/g/Mrad, in oxygen). The influence of several parameters has been determined: irradiation conditions (dose, temperature, surrounding gas), stockage temperature and starch characteristics (moisture, impurities). On the other hand, irradiation effects were compared to heat treatment effects. (orig.)

  6. Exoelectron emission studies of irradiated catalysts. [Gamma radiation; Alpha beams

    Kuzembaev, K.K.; Sokolskij, D.V.; Burtsev, A.F.; Asubaev, M.K. (AN Kazakhskoj SSR, Alma-Ata. Inst. Organicheskogo Kataliza i Ehlektrokhimii); Kortov, V.S.; Kalentiev, V.A. (Sverdlovskij Politekhnicheskij Inst., Sverdlovsk (USSR))

    1983-01-01

    Catalytic and exoemission properties of ..gamma..-irradiated Pd/SiO/sub 2/ and ..cap alpha..-irradiated Fe/Al catalysts have been found to change sympatically. The character of the active centers formed on the catalyst surface under irradiation is discussed. 9 refs.

  7. Glycoalkaloids and phenolic compounds in gamma irradiated potatoes

    Potatoes were used to study the metabolic stress effects in irradiated vegetable products. The changes of the contents of specific target compounds (glycoalkaloids, phenolic acids and coumarins) in alcoholic extracts of gamma irradiated potatoes were studied for metabolic irradiation stress. Doses of up to 3 kGy were applied to potatoes of several varieties. (Auth.)

  8. Inactive Doses and Protein Concentration of Gamma Irradiated Yersinia Enterocolitica

    Yersinia enterocolitica is one of bacteria which cause coliform mastitis in dairy cows. The bacteria could be inactivated by gamma irradiation as inactivated vaccine candidate. The experiment has been conducted to determine the inactive doses and the protein concentration of Yersinia enterocolitica Y3 which has been irradiated by gamma rays. The cells cultures were irradiated by gamma rays with doses of 0, 100, 200, 400, 600, 800, 1.000 and 1.500 Gy (doses rate was 1089,59 Gy/hours). The inactive dose was determined by the drop test method and the protein concentration of cells were determined by Lowry method. The results showed that the inactive doses occurred on 800 – 1500 Gy. The different irradiation doses of cell cultures showed the effect of gamma irradiation on the protein concentration that was random and has a significant effect on the protein concentration. (author)

  9. Effect of gamma irradiation on storability of Syrian walnut

    Walnut fruits of Baladi variety were irradiated with 0, 0.5, 1.0, 1.5 and 2.0 kGy of gamma irradiation. The irradiated and unirradiated fruits were stored at room temperature (15 to 18 Centigrade) and at a relative humidity of 50 to 70%. Fungal load, proximate composition, chemical changes and sensory properties of nuts were evaluated immediately after irradiation, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the fungal load. Used doses did not cause any significant change in proximate composition of walnuts. Immediately after irradiation, gamma irradiation increased total acidity and decreased iodine value and the volatile basic nitrogen (VBN). whereas, after 12 months of storage, gamma irradiation decreased total acidity and peroxide value and increased iodine value and (VBN). Immediately after irradiation no significant differences were observed between irradiated and non-irradiated samples in flavor and aroma. Whereas, after 12 months of storage higher doses (1.5 and 2.0 kGy) had a negative effect on sensory characteristics. (author)

  10. Therapeutic approaches of hematopoietic syndrome after serious accidental global irradiation. Ex vivo expansion interest of hematopoietic cells; Approches therapeutiques du syndrome hematopoietique apres irradiation globale accidentelle grave. Interet de l`expansion ex vivo des cellules hematopoietiques

    Thierry, D.

    1994-12-31

    Aplasia is one of the main syndrome, appearing after one global accidental irradiation by one ionizing radiation source. The hematopoietic syndrome is characterized by a peripheric blood cell number fall; the cell marrow is reduced too.

  11. Wastewater treatment using gamma irradiation: Tetouan pilot station, Morocco

    The increasing demand on limited water supplies has accelerated the wastewater reuse and reclamation. We investigated gamma irradiation effects on wastewater by measuring differences in the legislated parameters, aiming to reuse the wastewater. Effluents samples were collected at the urban wastewater treatment station of Tetouan and were irradiated at different doses ranging from 0 to 14 kGy using a Co60 gamma source. The results showed an elimination of bacterial flora, a decrease of biochemical and chemical oxygen demand, and higher conservation of nutritious elements. The results of this study indicated that gamma irradiation might be a good choice for the reuse of wastewater for agricultural activities.

  12. Biohydrogen production using waste activated sludge disintegrated by gamma irradiation

    Highlights: • The waste activated sludge could be disintegrated by gamma irradiation. • The disintegrated sludge could be used for biohydrogen production. • Combined alkali-irradiation treatment achieved the highest solubilization of sludge. - Abstract: The biohydrogen production using the disintegrated and dissolved sludge by gamma irradiation was studied. The experimental results showed that gamma irradiation and irradiation combined with alkali pretreatment could disintegrate and dissolve waste activated sludge for biohydrogen production. The alkali-irradiation treatment of the sludge at pH = 12 and 20 kGy achieved the highest disintegration and dissolution, i.e., it could destroy the cell walls and release organic matters (such as soluble COD, polysaccharides and protein) into the solution. The disintegrated sludge could be used as a low-cost substrate for biohydrogen production

  13. Effects of gamma irradiation on antioxidants of medicinal plants

    The antioxidant effect of water extracts from irradiated medicinal plants on inhibition of lipid peroxidation in human plasma was examined. The results presented herein indicate that crude extracts from 29 kinds, 31 extracts, of medicinal plants, irradiated at 10 and 25 kilo gray. showed no significant change in inhibition of lipid peroxidation in plasma induced by gamma irradiation (p<0.05). It also found that extraction yields in some irradiated plants were increased

  14. Degradation of epoxy coatings under gamma irradiation

    Epoxy networks based on Diglycidyl ether of bisphenol A (DGEBA) and cured with Jeffamine® (POPA) or polyamidoamine (PAA) were gamma irradiated at 25 °C in air. Dose rates of 50, 200 or 2000 Gy h−1 for doses up 100 kGy were used. Structural changes were monitored by IR spectrophotometry, DSC and sol–gel analysis. Both networks display some common features: for I≥200 Gy h−1, reaction products grow proportionally to time and the rate is a decreasing function of dose rate. The simplest explanation is that peroxy radicals are the main precursors of these products (in the dose rate domain under study), through a unimolecular rearrangement of which an hypothetical mechanism is proposed. DGEBA–POPA are more reactive then DGEBA–PAA networks (according to IR criteria), that can be attributed to the high reactivity of tertiary CH bands in polyoxypropylene segments. The oxidation of these sites leads to methyl ketones. A simple kinetic model in which methyl ketones result from rearrangements of tertiary peroxyls and from tertiary alkoxyls was proposed. It leads to an expression of the radiochemical yield of methyl ketones (G(MK)) of the form G(MK)=a+bI−1/2 where a and b are parameters depending of elementary rate constants. Experimental G(MK) values are reasonably well fitted by this equation. In DGEBA–PAA networks, a wide variety of oxidation products, among which amides predominate, can be observed. In these networks, chain scissions predominate over crosslinking, whereas a slight predominance of crosslinking was observed, at least for the lowest dose rate, in DGEBA–POPA. - Highlights: ► The effects of irradiation at three distinct dose rates have been studied on two epoxy networks. ► DGEBA–polyamidoamine networks appear more stable than DGEBA–polyoxypropylene diamine ones. ► A simple kinetic model involving methyl ketones is proposed.

  15. Effect of gamma irradiation on storability of strawberry (Fragaria sp)

    Despite the increased production of strawberry in Syria, the storability and marketability of fruits were not well studied. The objectives of this study were to investigate the effect of gamma irradiation on storability of Senga sengana strawberry produced in Syria and the effect of gamma irradiation on fungal sp. i.e. Botrytis; Penicillium; Rhizopus. The fruits were treated with 1 , 2 and 3 KGy of gamma rays. Treated and untreated fruits were stored at 2 to 4 centigrade and 80 to 90 % relative humidity (RH). In order to investigate their marketability, the fruits where held at room temperature (25 to 30 centigrade). Weight loss, microbial decay, and total loss, juice production, pH, total soluble solids of the juice and organoleptic qualities were evaluated throughout the different storage and marketing periods. The results indicate that gamma irradiation decreased the microbial decay and increased the storability and marketability of fruits by 50 and 100% after using 2 and 3 kGy, respectively. D10 were 1.8 and 2.4 for Botrytis and Rhizopus respectively. One day after irradiation total soluble solids and its pH values were increased. Fourteen days later, irradiated fruits produced more juice with higher pH, but total soluble solids were less. Gamma irradiation did not have an effect on aroma and colour of fruits, whereas, 3 kGy of gamma irradiation had an adverse negative effect on taste. (author)

  16. Glucose metabolism in gamma-irradiated rice seeds

    Gamma-irradiation of 30 kR in rice seeds caused marked inhibition in seedling growth, and prevented the release of reduced sugar during the period of 25 to 76hr after soaking. The C6/C1 ratio following irradiation continued to decrease up to the 76th hour of soaking; the control's ratio tended to increase with comparable soaking time. The percentage recovery of 14C in carbon dioxide from glucose -1-14C was lower in irradiated than in control seeds. These results indicate that gamma-irradiation reduces the participation of the pentose phosphate pathway in glucose catabolism during an early period of germination. (author)

  17. Economics of gamma processing in cobalt-60 irradiation facilities

    Gamma processing by cobalt-60 is well established. However, since irradiation of food is relatively new from the commercial point of view, it is important to assess costs of gamma irradiation in the context of food processing. Five different types of AECL-RCC irradiation equipment are examined in terms of their throughputs, and capital and operating costs. Using these figures, costs of irradiation of nine types of food products are presented. In general, these represent about 2-10% of the wholesale cost of these products

  18. EPR study on gamma-irradiated fruits dehydrated via osmosis

    Yordanov, N.D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)]. E-mail: ndyepr@bas.bg; Aleksieva, K. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2007-06-15

    The shape and time stability of the electron paramagnetic resonance (EPR) spectra of non- and {gamma}-irradiated papaya, melon, cherry and fig samples dehydrated via osmosis are reported. It is shown that non-irradiated samples are generally EPR silent whereas {gamma}-irradiated exhibit 'sugar-like' EPR spectra. The recorded EPR spectra are monitored for a period of 7 months after irradiation (stored at low humidity and in the dark). The results suggest longer period of unambiguous identification of the radiation processing of osmose dehydrated fruits. Therefore, the Protocol EN 13708,2001 issued by CEN is fully applicable for the studied fruit samples.

  19. Brain anomalies induced by gamma irradiation in prenatal period

    Gamma irradiation has been utilized in order to produce cortical and callosal abnormalities. We have also checked for the presence of the aberrant longitudinal bundle in the brains of mice born acallosal due to prenatal irradiation is also checked. Pregnant mice were exposed to gamma irradiation from a 60 Co source at 16, 17 and 19 days of gestational age (E 16, E 17 and E 19) with total doses of 2 Gy and 3 Gy. At 60 days postnatal the offspring of irradiated animals were intra cardiac perfused, the brains were removed from the cranio and cut into coronal or para sagittal sections. (author)

  20. Effects of neutron and continuous gamma irradiation of rats

    The effect of single neutron irradiation (2 Gy) alone and combined with continuous gamma irradiation (6 Gy accumulated during 10.5 days) was studied on the survival of rats and on nucleic acids both in the lymphoid organs and testes. After neutron irradiation alone the most profound changes in lymphoid organs and testes were found on the third and within the days 28-60, respectively. Regeneration has been undergone at a relatively fast rate. Continuous irradiation subsequent to neutron irradiation deepened only slightly the extent of the initial changes. The effect of combined irradiation manifested mainly at later times in marked slowing down of regeneration. (author)

  1. Thermal investigations on gamma irradiated honey for medicinal use

    DSC and TGA investigations were carried out on gamma irradiated honey. Honey could be sterilized at 25 kGy radiation dose. DSC studies were carried out from 35 deg C to 450 deg C in air and nitrogen atmosphere on unirradiated and irradiated honey. DSC profiles show broadening and reduction in endothermic enthalpy at 130 deg C in irradiated sample due to partial oxidation of honey during irradiation. TGA profiles recorded in air and nitrogen atmosphere indicate formation of volatile oxidation products during irradiation and heating in air. The phenolic contents in the irradiated honey were found to increase by 40% but pH did not change significantly. (author)

  2. Effect of gamma irradiation on some characteristics of shell eggs and mayonnaise prepared from irradiated eggs

    Shell eggs were irradiated at doses of 0.0, 0,5, 1.0 and 1.5 kGy of gamma irradiation. Immediately after irradiation, microbiological, physical and chemical analyses of eggs and sensory evaluation of mayonnaise prepared from irradiated eggs were done. The results indicated that all doses of gamma irradiation reduced the total counts of mesophilic bacteria and total coli form of yolk eggs. Irradiated eggs with 1.5 kGy maybe suitable microbiologically to prepare safe mayonnaise. There are no significant differences on saturated fatty acids and TBA values between yolk fat extracted from irradiated and that of non-irradiated eggs. Sensory evaluation showed no significant differences between mayonnaise prepared from irradiated and non-irradiated eggs. (Author)

  3. Introduction of gamma irradiation Center in Iran

    Industrial sterilization, and especially radiation sterilization, of single use, disposable medical supplies are contributing significantly to health standards in each country. Today there are in excess of 135 plants around the world using gamma radiation by more than 90 million curies of cobalt-60 to sterilize single use medical products. This process in far superior to other methods of sterilization, some of the advantages of this process include its basic simplicity compared with thermal or chemical methods. In the former process only a single variable of time is controlled while for the latter processes five or six parameters such as time, temperature, pressure, humidity, concentration, type of cover etc. need to be monitored. Compared with the chemical method, irradiation technique is also free from the environmental hazards associated with the exhausting of the, often carcinogenic sterilizing agent. United Nation Development Programs (UNDP) and International Atomic Energy Agency (IAEA) have, through financial and technical support, promoted the introduction of radiation sterilization in several developing countries. This centre is also being established in Iran through UNDP financial and IAEA technical assistance. Although the main task of this centre is to radiosterilize the disposable medical products, but the scope of activities also encompass investigation of processing techniques of various products as well as research and development in the related fields. (Author)

  4. Gamma irradiation versus microbial contamination of Thai medicinal herbs

    Wannipa Phianphak

    2007-03-01

    Full Text Available Seventeen species of herbs established in Thai traditional remedies were microbially decontaminated by gamma-irradiation doses of 7.7 and 8.8 kGy. The herb samples were randomly collected four times from producers in Chiangmai during a 1-year period. These were tested, qualitatively and quantitatively, for total aerobic bacteria, Staphylococcus spp., Salmonella spp., coliform bacteria, and fungi before and after gamma treatment. No microorganisms were found after gamma treatment; and the color, aroma, and texture of the herbs remained normal. The applied dose of gamma irradiation was within the regulatory limits in Thailand (<10 kGy and the main export country (USA< 30 kGy. Gamma irradiation is an effective treatment for microbial decontamination of Thai export herbs.

  5. Quality comparison between gamma-irradiated or electron beam irradiated pork patties

    This study was conducted to evaluate the microbial safety, hardness and sensory properties of pork patties irradiated with gamma ray or electron beam at the absorbed dose from 5 to 20 kGy. Minced pork was prepared in 24 hours after butchery for manufacturing of pork patties. It was produced by methods of our previous study and then packaged to vacuum condition. Gamma (430 kCi, Co-60) and electron beam (2.5 MeV, electron accelerator) were used for food irradiation, and the absorbed doses used were up to 20 kGy under room temperature. The microbiological and sitological characteristics of the samples were observed during accelerated storage at 30 deg. C for 10 d. The results of the total aerobic bacteria in pork patties during the accelerated storage showed that the sterilization effect of gamma irradiation was superior to that of electron beam irradiation. The hardness and sensory properties such as colour, chewiness, taste, and overall acceptability of pork patties were decreased depending upon irradiation dose. Gamma irradiated samples have lower hardness and sensory scores than those of electron beam irradiated samples. In conclusion, gamma irradiation on pork patties was appeared more effective than E-beam irradiation. However, further studies to reduce the quality deterioration of gamma-irradiated pork patties should be continuously conducted

  6. Pork fat peroxidation by gamma-irradiation

    In this paper, pork fat peroxidation by γ-irradiation and the possible effects of oxygen, UV-irradiation and storage after the γ-irradiation have been investigated. It has been found that the level of peroxides in irradiated pork increases linearly with the increasing absorbed dose. The chemical yield of peroxides formed in the irradiated fat is about 4.2 and independent on the sample temperature or absorbed dose rate, but dependent on storage time of sample before γ-irradiation. The irradiated pork exhibits some unusual features as following: 1) the peroxide content in irradiated pork is higher than that in unirradiated one; 2) the peroxide content in irradiated pork increases gradually on storage and is essentially constant in unirradiated one, which is very useful for the detection of irradiated pork; 3) the further peroxidation in irradiated pork is much more susceptible to UV radiation than that in unirradiated pork

  7. Gamma irradiation influence on physical properties of milk proteins

    Gamma irradiation was found to be an effective method for the improvement of both barrier and mechanical properties of the edible films and coatings based on calcium and sodium caseinates alone or combined with some globular proteins. Our current studies concern gamma irradiation influence on the physical properties of calcium caseinate-whey protein isolate-glycerol (1:1:1) solutions and gels, used for films preparation. Irradiation of solutions was carried out with Co-60 gamma rays applying 0 and 32 kGy dose. The increase in viscosity of solutions was found after irradiation connected to induced crosslinking. Lower viscosity values were detected, however, after heating of the solutions irradiated with a 32 kGy dose than after heating of the non-irradiated ones regarding differences in the structure of gels and resulting in different temperature-viscosity curves that were recorded for the irradiated and the non-irradiated samples during heating and cooling. Creation of less stiff but better ordered gels after irradiation arises probably from reorganisation of aperiodic helical phase and β-sheets, in particular from increase of β-strands, detected by FTIR. Films obtained from these gels are characterised by improved barrier properties and mechanical resistance and are more rigid than those prepared from the non-irradiated gels. The route of gel creation was investigated for the control and the irradiated samples during heating and the subsequent cooling

  8. Gamma irradiation reduces the immunological toxicity of doxorubicin, anticancer drug

    Doxorubicin (DOX) is a widely used anticancer agent, but exhibits some immunological toxicity to patients during chemotherapy. The present study was conducted to evaluate the effect of gamma irradiation on the immunological response and the inhibition activity on in vivo tumor mass of DOX. The results showed that DOX irradiated at 10 and 20 kGy reduce the inhibition of mouse peritoneal macrophage proliferation and induce the release of cytokines (TNF-α and IL-6) when compared with non-irradiated DOX. The cytotoxicity against human breast (MCF-7), murine colon adenocarcinoma (Colon 26) and human monocytic (THP-1) tumor cell were not significantly different between non-irradiated and irradiated DOX (P<0.05). In vivo study on the tumor mass inhibition, gamma-irradiated DOX showed a considerable inhibition of tumor mass and this effect was statistically non-significant as compared with non-irradiated DOX. In conclusion, gamma irradiation could be regarded as a potential method for reducing the immunological toxicity of DOX. Further researches is needed to reveal the formation and activity of radiolysis products by gamma irradiation.

  9. Application of gamma-irradiation to cereals and cereals products

    Gamma-irradiation may be used on cereals and cereal products to control insect infestation and microbiological problems. Such problems include mould growth, mycotoxin production, pathogens, spore-forming organisms and total microbial load. Deleterious effects of gamma-irradiation arise only at relatively high dose levels with consequences on germination rate, wheat flour dough properties, and cake and noodle quality. Radiation-induced changes to starch have greater impact on behaviour of cereal products than such changes to other cereal components

  10. Effect of gamma ray irradiation on sodium borate single crystals

    Kalidasan, M.; Asokan, K.; Baskar, K.; Dhanasekaran, R.

    2015-12-01

    In this work, the effects of 5 kGy, 10 kGy and 20 kGy doses of gamma ray irradiation on sodium borate, Na2[B4O5(OH)4]·(H2O)8 single crystals have been studied. Initially these crystals were grown by solution growth technique and identified as monoclinic using X-ray diffraction analysis. X-ray rocking curves confirm the formation of crystalline defects due to gamma rays in sodium borate single crystals. The electron paramagnetic resonance spectra have been recorded to identify the radicals created due to gamma ray irradiation in sodium borate single crystals. The thermoluminescence glow curves due to the defects created by gamma rays in this crystal have been observed and their kinetic parameters were calculated using Chen's peak shape method. The optical absorption increases and photoluminescence spectral intensity decreases for 5 kGy and 20 kGy doses gamma ray irradiated crystals compared to pristine and 10 kGy dose irradiated one. The effect of various doses of gamma rays on vibrational modes of the sodium borate single crystals was studied using FT-Raman and ATR-FTIR spectral analysis. The dielectric permittivity, conductance and dielectric loss versus frequency graphs of these crystals have been analyzed to know the effect of gamma ray irradiation on these parameters.

  11. Inactivation of citrus tristeza virus by gamma ray irradiation

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

  12. Catalytic properties of testicular hyaluronidase after gamma-irradiation

    Sharma, P.K.; Gupta, G.S.

    1986-08-01

    The effect of gamma-irradiation on ovine testicular hyaluronidase was studied in aqueous solution. Following irradiation, hyaluronidase is inhibited, and the kinetics of inhibition follow a pattern in which Ksub(m) and Vsub(max) decline as radiation dose is increased. It was indicated that the binding affinity of the residual activity of hyaluronidase with substrate is enhanced and depends upon radiation damage. Effects of various agents such as pH, salts, PCMB and glutathione on irradiated hyaluronidase have been compared with non-irradiated enzyme. The irradiated hyaluronidase was more sensitive to inhibition by CuSO/sub 4/ than the non-irradiated enzyme. The residual activity after irradiation is less refractory to FeCl/sub 3/ inhibition and less sensitive to NaCl stimulation compared to non-irradiated hyaluronidase. pH response curves of ovine testicular hyaluronidase show two maxima which become more evident after irradiation.

  13. Catalytic properties of testicular hyaluronidase after gamma-irradiation

    The effect of gamma-irradiation on ovine testicular hyaluronidase was studied in aqueous solution. Following irradiation, hyaluronidase is inhibited, and the kinetics of inhibition follow a pattern in which Ksub(m) and Vsub(max) decline as radiation dose is increased. It was indicated that the binding affinity of the residual activity of hyaluronidase with substrate is enhanced and depends upon radiation damage. Effects of various agents such as pH, salts, PCMB and glutathione on irradiated hyaluronidase have been compared with non-irradiated enzyme. The irradiated hyaluronidase was more sensitive to inhibition by CuSO4 than the non-irradiated enzyme. The residual activity after irradiation is less refractory to FeCl3 inhibition and less sensitive to NaCl stimulation compared to non-irradiated hyaluronidase. pH response curves of ovine testicular hyaluronidase show two maxima which become more evident after irradiation. (orig.)

  14. Gamma-ray irradiation tests of High-Tc SQUID

    Gamma-ray irradiation tests of High-Tc SQUIDs were carried out to examine their workability in nuclear reactor environments. The SQUIDs were made of a HoBa2Cu3O7-x superconductive thin film on SrTiO3 substrates. Some were encapsulated in separate cases of glass-fiber-rein-forced epoxy resin. Gamma-ray irradiation was performed with a Co-60 gamma-ray source. Irradiation dose rates were (8.1 to 12.2) x 103 Gy/h (i.e., (1.0 to 1.5) x 106 R/h), and the maximum absorption dose was about 10.4 MGy. During and after irradiation, noises of SQUIDs were measured with a power spectrum analyzer. Changes in modulation voltage were also investigated. No gamma-ray induced noise was observed during irradiation. The noise level and modulation voltage did not change until a total irradiation dose of about 3 MGy, and after that it decreased slightly. We concluded that the tested high-Tc SQUIDs are very resistant to gamma-ray irradiation, and thus the application of high-Tc SQUIDs in inspection of reactor components seems promising. (author)

  15. Keeping the quality of cows' butter by gamma-irradiation

    This investigation aims to study the use of gamma irradiation for keeping the quality of cows' butter. Fresh butter samples were exposed to gamma irradiation at doses of 0, 2.5 and 5 kGy followed by refrigerated storage and the effects of these treatments on the microbiological aspects and lipid characteristics of butter samples were studied. Moreover, fatty acid profiles and unsaponifiable matter constituents were determined by gas chromatographic analysis, while the stability of butter was determined by rancimat. The results indicated that gamma irradiation at 2.5 kGy dose reduced the counts of total bacteria, lipolytic bacteria, coliforms, molds and yeasts, however, these counts gradually increased during cold storage. Also irradiation at 5 kGy dose greatly reduced the total bacterial count which gradually increased upon storage, while completely eliminated the Other determined microorganisms. Irradiation treatments increased the acid value and peroxide value of butter, while the iodine number was not altered. Moreover, gas chromatographic analysis showed that gamma irradiation slightly increased the total volatile fatty acids, total saturated fatty acids and total hydrocarbons, while slightly decreased the total unsaturated fatty acids and total sterols. In addition, irradiation of butter decreased its stability as determined by rancimat and upon storage of both irradiated and non irradiated butter samples, the acid value gradually increased, while a flexuous changes in the peroxide value were observed. The present study proved that 2.5 and 5 kGy gamma irradiation doses could keep the quality of cows' butter and increased its shelf life at 4 +/- 1degreeC for 8 and 12 weeks as compared to 4 weeks for non irradiated butter (based on the visual appearance of mold growth on the surface of samples) without any effects on its sensory properties

  16. Disinfection of sewage sludges by gamma irradiation and alternative methods

    Sewage sludges generally maintain high concentrations of pathogens. For their safe reutilization on agriculturally used areas a disinfection treatment is necessary. Conventional methods for this purpose are e.g. heat-treatment (pasteurization), composting and lime-treatment. A new technique for sludge disinfection is the irradiation treatment by gamma-rays or by accelerated electrons. The first practical plant for gamma-irradiation of sewage sludges has been in operation since 1973 in Geiselbullach, near Munich, Federal Republic of Germany. This paper summarizes the existing and projected plants for the sewage sludge disinfection by irradiation and names the conventional alternative methods with their main advantages and disadvantages. The techniques for irradiation and sludge handling in irradiation plants are described. Broad research work in Geiselbullach with the aim of operational and economic optimization led to a combined treatment of irradiation and oxygenation: the oxiradiation-treatment. The costs for gamma-irradiation and alternative treatments for sewage sludge disinfection are given. Finally the problems with gamma irradiation plants are discussed. (author). 1 ref., 2 figs, 1 tab

  17. Manual on panoramic gamma irradiators (categories 2 and 4)

    In addition to a basic guide to the principles of production of ionizing radiation and to the methods of radiation protection and dosimetry, this document considers the procedures that should be employed when using panoramic gamma irradiators. Applications for such irradiators are described and radiation protection procedures discussed

  18. A Production Gamma Irradiation Plant for Radiation Investigations

    The paper discusses some results of work to develop typical gamma irradiation plants for biological, medical, radiation chemistry and agricultural studies. The principal demands made on pilot industrial and experimental irradiation plants are given. Various such experimental plants have been developed and are being produced in the USSR, and the technical data of some of them are described in the paper. (author)

  19. Results on Neutron and Gamma Irradiation of Electrolytic Tilmeters

    We report on irradiation studies done to a sample of high precision electrolytic tiltmeters with gamma-rays, up to a maximum dose of 150 kGy, an neutrons, up to a maximum fluence 1.5x10''14 cm''2. The effect of the irradiation on their performance is discussed. (Author) 19 refs

  20. Effect of gamma irradiation on Hom Tong banana

    This report contains research on the use of gamma irradiation to retard the ripening and extend the shelf life of bananas. The major concerns were the effects that irradiation would have on the nutritional content, the organoleptic properties and the pigment of the fruit

  1. Gamma Irradiation for the Inhibition of Shrimp (Penaeus aztecus) Allergy

    Food irradiation technology was conducted to reduce shrimp allergy. The experiment was designated in 3 portions as follows; A, the irradiation of raw shrimp; B the irradiation of shrimp and then cooking; and C, cooking the shrimp and then irradiation. Gamma irradiation was done with doses of 1, 3, 5, 7, 10 kGy. A shrimp sarcoplasmic protein solution (SSPS) and a myofibrillar protein solution (SMPS) were prepared from A portion. Cooked shrimp protein solutions were also prepared from B and C portions. The binding abilities of the shrimp allergic patients' IgE and mouse monoclonal Ab 4.9.5 (mAb 4.9.5), produced to the shrimp heat-stable protein, to each sample solution were determined by ELISA. Binding abilities of patients' IgE and mAb 4.9.5 to irradiated shrimp fractions were dose-dependently reduced. The cooking treatment after irradiation was more effective than the irradiation treatment after cooking in the reduction of the binding abilities of IgE and IgG. SDS-PAGE was performed to compare irradiated shrimp proteins with non-irradiated shrimp proteins. SDS-PAGE showed that no bands were changed by gamma irradiation. The results indicated that food irradiation with an adequate dose can be reduce allergenicity of shrimp

  2. Radiation protection in category III large gamma irradiators

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

  3. Modelling a gamma irradiation process using the Monte Carlo method

    Soares, Gabriela A.; Pereira, Marcio T., E-mail: gas@cdtn.br, E-mail: mtp@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2011-07-01

    In gamma irradiation service it is of great importance the evaluation of absorbed dose in order to guarantee the service quality. When physical structure and human resources are not available for performing dosimetry in each product irradiated, the appliance of mathematic models may be a solution. Through this, the prediction of the delivered dose in a specific product, irradiated in a specific position and during a certain period of time becomes possible, if validated with dosimetry tests. At the gamma irradiation facility of CDTN, equipped with a Cobalt-60 source, the Monte Carlo method was applied to perform simulations of products irradiations and the results were compared with Fricke dosimeters irradiated under the same conditions of the simulations. The first obtained results showed applicability of this method, with a linear relation between simulation and experimental results. (author)

  4. Gamma-irradiation of wet corn. Microbiological aspects

    In the course of a survey of several years work on microbiological decontamination and control of wet corn by gamma-irradiation the following factors are studied: inhibiting and selective effect of gamma-irradiation (100 to 500krads) on the microflora of grains; evolution of residual microflora of irradiated wet grains (moisture content about 35%), during storage experiments under ventilated or airtight conditions. Two important points emerge from those studies. The microflora which develops on irradiated sample is much less varied than that of the control sample. The microbial population of an irradiated sample rises up in a few days on a level with the initial one of the control, then goes on increasing while remaining, as a rule, slightly inferior to that of the control placed under the same conditions. This greatly lowers the practical interest of irradiation, which can only be used together with another treatment able to inhibit the quick growth of the residual microflora

  5. Effects of gamma irradiation on raw materials and perfumes

    In order to enlight the strange problem of apparent perfume stability observed in manufactured talc powders sterilized by gamma rays, investigations were made on samples of odorant substances (raw materials, essential oils, or elaborated mixtures). As a rule, no immediate adulteration of olfactive caracteristics resulted at once from gamma irradiation. In several cases, a stabilizing effect appeared immediately and remained effective after long storage in various conditions (of temperature, or light, or oxygen exposure). This unexpected effect seems to be in accordance with previous experiments on gamma or electron irradiations of mixtures of organic molecules, reported in litterature: a mutual inhibition was observed to take place

  6. Gamma-ray irradiation of a boreal forest ecosystem

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

  7. Lattice Raman scattering in gamma-irradiated tryptophan crystals

    The character of change in lattice Raman spectra of aromatic aminoacid crystals-D-tryptophan - under the effect of gamma radiation has been traced. The choice of aromatic aminoacid as object for investigation is related to assumed high sensitivity of tryptophan crystal structure to the effect of short-wave irradiation due to the presence of a great number of protons in it, which interect intensively with gamma quanta. Considerable change in lattice Raman spectrum of D-tryptophan crystals under the effect of small doses of gamma irradiation has been revealed

  8. Studies on safety and efficiency of gamma-irradiated ginseng

    Gamma irradiation was applied to the biological quality improvement and preservation of white ginseng which has problems in a hygienic quality and storage stability. The current phosphine treatment showed no influence on microorganisms contaminated even though it was very useful for disinfestation of the sample, while 5 kGy irradiation effectively controlled the biological quality of the stored sample, with minimal effects on the quality parameters of white ginseng. Thus, it is concluded that gamma irradiation at a range of 5 kGy can be an alternative method of chemical fumigants provided air-tight packaging excluding recontamination is used for the stored product. (Author)

  9. Neutron and gamma irradiation damage to organic materials.

    White, Gregory Von, II; Bernstein, Robert

    2012-04-01

    This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

  10. Post harvest changes gamma-irradiated banana Prata

    The effect of the gamma-irradiation was evaluated at 0.25 and 0.50 kGy, on the development of peel coloration, CO2 and ethylene evolution, conversion of starch to sugars, pulp-to-peel ratio, pectic solubilization and activities of enzymes of the cell wall, pectin methylesterase (PME), and polygalacturonase (PG), during maturation of 'Prata' bananas. The gamma-irradiation did not affect the normal colour development of the fruits. An increase in the ethylene peak and a decrease in the CO2 peak was observed. The gamma-irradiation did not affect the degradation of starch, while a delay in soluble sugar accumulation was noted on the 6 and 7 colour grades. The fruits subjected to 0.25 kGy had the highest increase in the pulp-to-peel relation, beginning with colour grade 5, due to a possible stress effect of that dose. An increase of pectin solubilization was observed. Higher PME activities were exhibited by irradiated fruits, although the gamma-irradiation suppressed the PG activity throughout the maturation period. The gamma-irradiation did not extend the post-harvest life of 'Prata' bananas. (author)

  11. The Financial Analysis of Gamma Irradiation Technology

    The present study discusses the guideline from the economics point of view of the commercial operation optimized for the Egyptian second irradiation facility. This study included four sections about the financial analysis, the analysis of future demand, future supply of commercial application of irradiation and the irradiation price system

  12. Study and simulation of irradiated zirconium alloys fracture under type RIA accidental loading conditions

    The thesis aims to study and simulate the mechanical behavior under Reactivity Initiated Accident loading conditions, of the Zircaloy 4 fuel claddings, irradiated or not. It also aims to characterize and simulate the behavior and the fracture under RIA loading conditions of hydrided Zircaloy 4 non irradiated. This study proposes an experimental approach and a simulation. (A.L.B.)

  13. Effect of radiation on solid paracetamol: ESR identification and dosimetric features of gamma-irradiated paracetamol

    Polat, M.; Korkmaz, M.

    2006-01-01

    In the present work, electron spin resonance (ESR) identification of gamma-irradiated paracetamol and its potential use as a normal and/or accidental dosimetric material were investigated in the dose range of 2.5-25 kGy. Both unirradiated paracetamol and mechanically ground vermidon samples exhibited a weak single resonance line at g = 2.0049 +/- 0.0006 and had Delta H-pp = 0.6 +/- 0.02 mT. Gamma irradiation produced an increase in signal intensity with a small hyperfine splitting in both paracetamol and vermidon and many weak resonance lines on both sides of a central line in the case of vermidon. Dose-response curves associated with central line of paracetamol and vermidon were found to follow polynomial and linear function, respectively. Simulation calculations based on the room temperature ESR intensity data of the paracetamol sample irradiated at 10 kGy were performed to determine the structure and spectral parameters of the radiation-induced radical species involved in the formation of the experimental ESR spectrum of paracetamol.

  14. Effect of gamma irradiation on ethylene-octene copolymers

    Two ethylene-octene copolymers (POE) were irradiated with 60Co gamma radiation and influence of irradiation atmosphere, absorbed dose and heat treatment of samples on the crosslinking were studied. Thermal properties and crystalline morphology of non-irradiated and irradiated POE were determined by using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXS), respectively. The Charlesby-Pinner equation was used to describe the relationship between absorbed dose and sol fraction. The gel fraction of irradiated POE was lower and decreased with the increase of octene content when irradiated in oxygen, compared to irradiation in nitrogen atmosphere. The gel fraction increased significantly with the increasing of absorbed dose for the two copolymers. Heat treatment of samples prohibited the crosslinking of irradiated POE. The DSC results indicated that a subtle change of thermal properties of POE was observed before and after gamma irradiation at low dose. No change was found from the WAXS spectra of non-irradiated and irradiated POE. For heat-treating samples, the Charlesby-Pinner equation can not fit perfectly with the relationship between the sol fraction and absorbed dose, but it fits well with the crosslinking reaction of POE pellets

  15. Change of microflora of two starch samples by gamma irradiation

    Starch is the basic component of a larger number of manufactured foods. The disinfection of such a powder by 60Co is studied here. Gamma irradiation of two starch samples with different degrees of contamination allows the assumption that, in most cases, good radio-pasteurization can be achieved with 300 krad. The radio-pasteurization doses (varying from 300 to 600 krad) are a function of the initial contamination. Irradiation effects are spectacular with moulds. Activation of spores of some Clostridium species leads us to recommend an irradiation level higher than 200 krad. The most resistant organisms to gamma irradiation are the aerobic and anaerobic sporulated bacteria. The thermophilic forms are the most important. Spores of Bacillus, chiefly Bacillus licheniformis and Bacillus brevis, are the most frequent bacteria. Storage of irradiated starch at room temperature has little effect upon the number of revivable survivors. (orig.)

  16. Effects of gamma-irradiation on meat proteins

    The proteins extracted from beef, pork and chicken meats were irradiated with up to 100 kGy at room temperature. The extracted proteins were evaluated on their in vitro digestibility by incubating successively with pepsin and pancreatin conjugate. Amino acid compositions and SDS-PAGE pattern were also analyzedin for these proteins. Gamma irradiation within the applied dose range (up to 100 kGy) produced negligible in in vitro digestibility and amino acid composition. Analysis of gamma-irradiated proteins by SDS-PAGE revealed radiolysis of ovalbumin to proteins or peptides with lower molecular weight. On the other hand, the proteins directly extracted from irradiated meats containing moisture were also evaluated for their in vitro digestibility, amino acid compositions and SDS-PAGE pattern. However, the results obtained from this experiment were similar to those of irradiated proteins after extraction from the meats

  17. Synthesis of polysaccharide chemical gels by gamma-irradiation

    Recently many biodegradable hydrogel systems have been developed in the area of controlled drug delivery. In previous studies, the authors prepared biodegradable hydrogels by crosslinking natural polymers, such as albumin and dextran, using gamma-irradiation. Natural polymers were functionalized by introducing double bonds through reaction with glycidyl acrylate. The functionalized polymers were then crosslinked to form chemical gels by exposure to gamma-irradiation. In this study, they examined the ability of various polysaccharides to form chemical gels by gamma-irradiation. Dextran, alginic acid, hyaluronic acid, benzyl esters of hyaluronic acid, and gellan were functionalized. The effects of the polymer concentration and the gamma-irradiation dose on the hydrogel formation were examined. All the polysaccharides used formed chemical gels, although the extent of gel formation was different. For alginic acid, hyaluronic acid, and benzyl ester of hyaluronic acid at 25% of esterification degree, the chemical gels were formed at lower polymer concentration and at lower gamma-irradiation dose, if the solution was acidified to pH 3. The ability to form chemical gels with various natural polymers would be useful in the development of controlled drug delivery systems

  18. Effect of gamma irradiation on drugs

    Several drugs (ceftazidime, vancomycin, glucagon, erythromycin and dobutamine) were studied in order to determine their radiostability. The methods used to measure the degradation of the drug were the potency and the colour change after irradiation. Electron spin resonance (ESR) is currently being used to detect irradiated foodstuffs and may be a promising technique to detect irradiated drugs. Trapped radicals in cefazolin sodium were studied and quantified by ESR for this purpose. It is proposed that the trapped radicals play an important role in the formation of the final radiolytic compounds. The potency of ceftazidime was not significantly modified after an irradiation of 25 kGy, whereas the potency of erythromycin and dobutamine decreased slightly. Glucagon was revealed to be radiosensitive with a significant decrease in its potency after irradiation. The visible spectra of glucagon and dobutamine did not change significantly after irradiation. The absorbance of erythromycin and vancomycin increased after irradiation. According to European Pharmacopoeia standards, the colour change of ceftazidime is unacceptable. The ESR spectra reveal that the trapped radicals in cefazolin sodium are characteristic of an irradiation. The radical concentration is dependent on the irradiation dose and decays over time. Radical concentration in cefazolin sodium was reduced by 99% after 100 days of storage. These radicals are responsible for about 13% of the measured final radiolytic product. Ionic reactions could also lead to final radiolytic products. (author)

  19. Agriculture Applications for Some Gamma Irradiated Bacterial Strains

    GAMMA Radiation has many peaceful applications in different fields including agriculture. In this study, gamma radiation is used to enhance the activity of eight microbial strains, Azotobacter chroococcum, Azotobacter vinelandii, Bacillus megaterium ATCC 19213, Bacillus subtilis ATCC 6051T, Bacillus subtilis ATCC 6633, Cellulomonas fimi ATCC 484, Micrococcus luteus ATCC 9341 and Pseudomonas fluorescens subsp. Cellulosa that are used intensively in agricultural practices in Egypt. Nitrogen fixing activity of A. chroococcum and A. vinelandii was decreased with increasing gamma irradiation doses. Irradiation doses equals 1 and 1.5 kGy enhanced phosphatase activity of B. megaterium ATCC 19213 and B. subtilis ATCC 6633 by nearly three and two folds respectively. HPLC analysis showed qualitative and quantitative changes in organic acid profile of phosphate-solubilising bacteria after irradiation. Gamma radiation has a significant positive effect on cellulolytic activity of Cellulomonas fimi ATCC 484, Pseudomonas fluorescens subsp. Cellulosa, Bacillus subtilis ATCC 6051T and Micrococcus luteus ATCC 9341 in bench scale experiment. By applying cellulose decomposer mixture to common compost used in Lower Egypt, there is a slight difference between compost treated with irradiated mixture and un-irradiated one. A field experiment was conducted to estimate the effect of irradiated phosphate-solubilising bacteria on planted maize.

  20. Termite feeding preference to four wood species after gamma irradiation

    The effect of gamma irradiation at 100 kGy and at lower levels on termite resistance was examined in the laboratory by no-choice and choice feeding termite tests (Coptotermes formosanus Shiraki) using four wood species: sapwood of Cryptomeria japonica D. Don, and heartwoods of Pseudotsuga menziesii (Mirbel) Franco, Larix kaempferi (Lambert) Carriere, and Chamaecyparis obtusa Endl. The wood consumption rates in C. japonica and P. menziesii specimens were likely to increase with increases in gamma-irradiation levels, whereas little effect of gamma irradiation was seen in L. kaempferi and C. obtusa. Similar results were obtained in the two-choice test. The current results indicated that in the two-choice test with C. formosanus, 100-kGy-irradiated C. japonica and P. menziesii, which are not rich in antitermite substances, were eaten more than other wood samples with or without gamma irradiation. However, only C. japonica showed significant difference in termite feeding activity. The mass loss in 100-kGy-irradiated C. japonica was significantly higher in the multichoice test

  1. Tolerance, quality and storability of gamma-irradiated Egyptian rice

    The effect of gamma irradiation on some organoleptic and physico-chemical properties and the storability of Egyptian rice was investigated. Radiation up to 50krad was chosen as an adequate dose causing non-significant changes in eating and cooking qualities. The effect of irradiation on degradation of starch and protein molecules is demonstrated on the basis of studies on the viscosity and solubility of rice paste. Irradiation at relatively low dose levels up to 50krad did not affect the chemical and nutritional qualities of rice regarding amino acids and B vitamins. It was also found that irradiation maintains better storability of rice under ambient temperature. (author)

  2. Ex vivo expansion of haematopoietic cells in the treatment of accidental irradiation-induced aplasia. Feasibility Studies

    haematopoietic cells for the treatment of accidental irradiation-induced aplasia. (author)

  3. Kraft cooking of gamma irradiated wood, (2)

    Pre-irradiation of wood in alkaline aqueous ethanol increases kraft pulp yield by up to 1.2%, as already reported. In order to clarify the mechanism of the pulp yield gain, the behaviors of lignin and carbohydrates during pre-irradiation and cooking were investigated. The results are summarized as follows: 1) γ-Irradiation of guaiacylethane in alkaline aqueous ethanol produced 5-(1-hydroxyethyl)-guaicylethane, which is formed by radical coupling between α-hydroxyethyl radical from ethanol and guaiacylethane radical having an unpaired electron at C-5. 5,5'-Dehydrodiguaiacylethane, which may be a predominant product produced by γ-irradiation in the absence of ethanol, was also detected. 2) The yield of vanillin obtained by nitrobenzene oxidation of MWL decreased with an increase of γ-ray dosage. The presence of ethanol during γ-irradiation lessened the extent of this decrease and also the degradation of cellobiose. 3) Gel filtration of the products obtained by γ-irradiation of MWL and cellobiose in the presence of 14C-ethanol showed the possible combination between ethanol and MWL or cellobiose. 4) Molecular weight distributions of kraft lignin obtained from pre-irradiated beech chips were compared with those obtained from unirradiated chips. This result shows that γ-irradiation in the presence of ethanol decreases the ability of lignin to condense during kraft cooking. (author)

  4. Effect of gamma-irradiation on ripening papaya pectin

    Papaya (Carica papaya, L., var. Sunset) at three initial ripeness stages were irradiated with 0.25, 0.50, 0.75, 1.0, or 1.5 kGy gamma-irradiation and pectin changes during ripening determined. A significant linear relationship was found between irradiation dose and firmness immediately after irradiation. Irradiation had no effect on fruit skin or flesh color of papaya fruit irradiated at the 5 to 30% yellow stage and allowed to ripen. Papaya irradiated when 5 to 30% yellow showed no significant changes in pectin methylesterase activity when ripe. Immediately after irradiation, the pectin in 10 to 30% yellow papaya showed depolymerization and demethoxylation, though no effect on pectin methylesterase activity was detected. There was an increase in water soluble pectin (WSP), while chelator soluble (CSP) and alkali soluble pectin (ASP) decreased, with a significant decline in the methanol content of the ASP fraction. After the 25 to 30% yellow ripeness stage, fruit irradiated at 0.50 to 1.0 kGy had less pectic depolymerization, and had a firmer texture than nonirradiated when ripe. A lower level of WSP and higher levels of CSP and ASP were found in ripe fruit that had been irradiated at 0.5 to 1.0 kGy when 25 to 30% yellow skin with a significant quadratic relationship between irradiation dose and the three pectin fractions. The firmness of these irradiated fruit were retained for two days longer than the nonirradiated control. (author)

  5. Thermoluminescence properties of irradiated commercial color pencils for accidental retrospective dosimetry

    Color pencils are widely used mostly in kindergartens, in schools and could be found in all houses with families having young children. Their wide spread use in modern times as well as their chemical composition, consisting mostly of Si and Al, constitute two strong motivations towards exploiting their use as accidental retrospective thermoluminescent dosimeters. The present manuscript reports on the study of colored pencils manufactured by a commercial brand in China which is very common throughout Turkey. The preliminary results discussed in the present work illustrated encouraging characteristics, such as the presence of a trapping level giving rise to natural TL in a temperature range that is sufficiently high. Specific thermoluminescence features of this peak, such as glow peak shape and analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability to low attributed doses were studied. The results suggest that the color pencils could be effectively used in the framework of retrospective thermoluminescent dosimetry with extreme caution, based on multiple aliquot protocols. - Highlights: • Thermoluminescence of the inner part of commercial colored pencils was studied. • The presence of a trapping level giving rise to natural TL at 260 °C was yielded. • Deco analysis, anomalous fading, thermal quenching, reproducibility, linearity and recovery ability of this peak were studied

  6. The effect of gamma irradiation on some corn pests

    This work is a study on the effects of gamma irradiation upon reproduction and mating competitiveness of the sugar cane stem borer Seasmia Cretica and the cotton leaf worm Spodoptera Littoralis. Six doses of gamma radiation, 10, 15, 20,30 and 35 krad were used for S. cretica, while three doses 20 , 35 and 50 krad were used for S. littoralis. These studies continued throughout two year 1981- 1983

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

    Clark, E.

    2013-09-13

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

  8. Effects of aeration on gamma irradiation of sewage sludge

    In this paper the effect of aeration on gamma irradiation of sewage sludge was investigated to examine the potential solubilization of solids in sewage sludge to ultimately reduce the solids volume for disposal. Results showed that aeration increased the effectiveness of gamma radiation. The efficiency of sludge solubilization with aeration was increased by around 25% compared to that without aeration at an irradiation dose of 2.5-9 kGy. The soluble protein, polysaccharide and humic (like) substance concentrations were higher under aerated conditions. With aeration the overall reaction appears to be oxidative as evidenced by the higher nitrate and nitrite ion concentrations in solution.

  9. Gamma-irradiation sterilization of lipases for cheese making

    The possibility of sterilizing the enzyme compounds of lipases from Oospora fragrans strains by gamma irradiation was studied. The enzyme compounds were exposed to gamma irradiation at the doses from 0.1 to 0.8 Mrad with the discreteness of 0.1 Mrad and at the dose of 2.0 Mrad. After the radiation treatment the lipases were investigated for bacterial invasion by the cultivation method and for the lipolytic activity by the titrometrical method. It is shown that the sterilization effect is achieved without losses of lipase activity and the radiation dose necessary for sterilization depends on initial invasion levels in the enzyme compounds

  10. Effects of aeration on gamma irradiation of sewage sludge

    Chu, Libing; Wang, Jianlong; Wang, Bo

    2010-08-01

    In this paper the effect of aeration on gamma irradiation of sewage sludge was investigated to examine the potential solubilization of solids in sewage sludge to ultimately reduce the solids volume for disposal. Results showed that aeration increased the effectiveness of gamma radiation. The efficiency of sludge solubilization with aeration was increased by around 25% compared to that without aeration at an irradiation dose of 2.5-9 kGy. The soluble protein, polysaccharide and humic (like) substance concentrations were higher under aerated conditions. With aeration the overall reaction appears to be oxidative as evidenced by the higher nitrate and nitrite ion concentrations in solution.

  11. Performance evaluation of gamma irradiated SiR-EPDM blends

    Deepalaxmi, R., E-mail: deepalaxmivaithi@gmail.com; Rajini, V.

    2014-07-01

    Highlights: • The effects of gamma irradiation on SiR-EPDM blend are examined. • Cross-linking reaction is dominant in blends C, D and E, due to higher EPDM content. • The tensile strength and hardness of blend E is improved by gamma irradiation. • The blend C and EPDM rich blends (D, E) are found to have superior performance. • Among C, D and E, suitable blend can be selected for a particular NPP application. - Abstract: Cable insulation materials (CIM) should perform their safety functions throughout their installed life in nuclear power plants (NPP). The CIM will be exposed to gamma irradiation at the installed locations. In order to forecast long-term performance of CIM, the short time accelerated testing was carried out. Due to its good mechanical strength, ethylene propylene diene monomer (EPDM) is widely used as CIM. Silicone rubber (SiR) is used in high temperature environments, due to its good di-electric properties/hydrophobicity. The blending of these two polymers may result in the improvement in their specific properties. This paper analyses the effects of gamma irradiation on the five different compositions (90-10; 70-30; 50-50; 30-70; 10-90) of SiR-EPDM blends. The blends were exposed to four different doses (25 Mrad, 100 Mrad, 200 Mrad and 250 Mrad) of gamma irradiation. The electrical and mechanical parameters like volume resistivity (VRY), surface resistivity (SRY), tensile strength (TS), elongation at break (EB), hardness (H) of the virgin and gamma irradiated blends were determined as per ASTM/IEC standards. The nature of degradation was investigated using Fourier transform infrared spectroscopy (FTIR). The simultaneous occurrence of cross-linking and chain scission is found to be the mechanism for ageing in SiR-EPDM blends. The electrical parameters such as volume resistivity and surface resistivity of all the blends are found to improve for all doses of gamma irradiation. To validate the influence of cross-linking reaction of the Si

  12. Effects of low-dose. gamma. -irradiation on grapefruit products

    Moshonas, M.G.; Shaw, P.E.

    Products obtained from Florida grapefruit irradiated with low-dosage ..gamma..-rays as a possible treatment for infestation by larvae of the Caribbean fruit fly were evaluated to determine effects on flavor and composition. Seven tests were run in which twenty-two lots of fruit were exposed to 7.5, 15, 30, 60 or 90 krd of ..gamma..-irradiation covering the 1981-1982 and early 1982-1983 harvesting season. There were few significant adverse flavor effects on products from irradiated fruit with the exception of the first test run on early-season fruit. In some cases, particularly at the lower doses of radiation, there was a significant improvement of flavor in grapefruit sections. There were no marked differences in vitamin C, sugar or acid levels in juice nor on essential peel oil composition of volatile constituents from irradiated fruit when compared with those from untreated fruit. 18 references, 2 tables.

  13. Processing and utilization of gamma irradiated oil seeds

    To provide safe and nutritious food in adequate quantity to the rapidly expanding population is a challenging task for many countries in the world. One way of bridging this gap is by conserving what is produced by preventing or reducing post harvest losses. Oil seeds are second major agricultural crops next to food grains. The present investigation deals with the effect of low dose gamma irradiation on the storage life of oil seeds. Seeds chosen for the present study were ground nut, sesame and cottonseed. In view of the above the proposed study focuses on the effect of low dose gamma irradiation on the processing parameters of the oil extracted from irradiated as well as non irradiated oil seeds. Also the oil obtained was analysed for the various chemical and physical characteristics including the chemical composition (fatty acid composition) of the oil

  14. Gamma irradiation induced variation in carrots (Daucus Carota L.)

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue culture, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by > 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type [reducing vs. non reducing sugars]. Induced variation in root color and rot shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment (Author)

  15. Gamma irradiation-induced variation in carrots (Daucus carota L.)

    Carrot tissue cultures, germinating seed, and dry seed were exposed to gamma radiation. Irradiation accelerated germination of carrot seed in the M1 generation at low doses (0.5 and 1 krad), whereas higher doses delayed germination. A high negative correlation was observed between dose and survival of plants after seed irradiation. Plant size and root weight were 20% to 35% greater than control plants after seeds, but not tissue cultures, were exposed to low doses of gamma irradiation. Higher doses reduced M1 plant size by 50% in germinating seed and tissue culture treatments but less for the dry seed treatment. Seed production decreased while phenotypic variation of M1 plants increased with increasing gamma ray dosage. Root weight and total dissolved solids were highly variable in M2 families. Less variation was observed in total carotene content and none was seen in sugar type (reducing vs. non reducing sugars). Induced variation in root color and root shape was also observed. Irradiation of germinating seed and tissue cultures yielded more M2 variation than irradiation of dry seed. Putative point mutations were not observed. Unirradiated carrot tissue cultures did not yield significant M2 somaclonal variation. Average root weight of M2 plants increased with increasing gamma ray dosage, especially for the dry seed treatment

  16. Lipid profile of gamma irradiated nutmeg - a detailed investigation

    Effect of gamma irradiation on the lipid profile of nutmeg (Myristica fragranes) irradiated to doses of 2.5, 5.0,7.5 and 10kGy was examined using chromatographic techniques such as TLC and GLC. A dose dependent decrease in triacylglycerol content and a concomitant increase in free fatty acid upon irradiation characterized TLC profile of the total lipid. Interestingly, free fatty acids are almost absent in the non-irradiated samples. Fatty acid composition of triacylglycerol, the major lipid class was found to be made of myristic (90%), palmitic (6%), lauric (3%), petroselinic (0.13%) and stearic acid (0.5%) as determined by GC/MS. The relative composition of the free fatty acids liberated during irradiation was also similar. This suggests a breakdown of acylglycerols during irradiation resulting in release of free fatty acids. The impact of these changes on the flavor of the spice is discussed. (author)

  17. Quality comparison between gamma-irradiated and E-beam irradiated pork patties

    This study compared the effects of gamma and electron beam (e-beam) irradiation on the quality of pork patties. Pork patties (diameter: 100 mm, thickness: 10 mm) were vacuum-packaged and irradiated by gamma ray (60Co with a 490 kCi source) and e-beam (2.5 MeV) at five, ten, 15, and 20 kGy at room temperature. During accelerated storage at 30 deg C for 10 d, determination of total bacterial populations, hardness, and sensory evaluation was conducted at appropriate sampling intervals. The results of total bacterial populations showed that the gamma-irradiated (GR) samples had lower (P < 0.05) total bacterial counts than e-beam-irradiated (EB) samples during storage at 30 deg C for 10 d, regardless of irradiation dose. The hardness and sensory properties such as colour, chewiness, taste, and overall acceptability of pork patties were decreased depending upon irradiation dose. GR samples had lower hardness and sensory scores than those of EB samples. In conclusion, gamma irradiation on pork patties should be useful in decreasing bacterial populations when compared with e-beam irradiation. However, further studies should be conducted to reduce the quality deterioration of GR pork patties. (author)

  18. Effects of gamma irradiation on solid and lyophilised phospholipids

    Stensrud, G.; Redford, K.; Smistad, G.; Karlsen, J.

    1999-11-01

    The effects of gamma irradiation (25 kGy) as a sterilisation method for phospholipids (distearoylphosphatidylcholine and distearoylphosphatidylglycerol) were investigated. 31P-NMR revealed minor chemical degradation of the phospholipids but lower dynamic viscosity and pseudoplasticity, lower turbidity, higher diffusion constant, smaller size, more negative zeta potential and changes in the phase transition behaviour of the subsequently produced liposomes were observed. The observed changes could to some extent be explained by the irradiation-induced degradation products (distearoylphosphatidic acid, fatty acids, lysophospholipids).

  19. Responses of gamma irradiated mice to {alpha}-tocopherol

    Eliosoff, N.M.; Dubner, D.; Gisone, P. [Comision Nacional de Energia Atomica, Gerencia de Seguridad Radiologica y Nuclear, Buenos Aires (Argentina)

    1992-07-01

    CB57 female mice whole body gamma irradiated were orally administered with acetato DL-{alpha}-tocopherol. It was observed a higher survival in {alpha}-tocopherol treated groups up to 14th and 10th days with doses of 8.5 and 10 Gy respectively and a greater bone marrow cellularity at day 10 in {alpha}-tocopherol treated group irradiated with 10 Gy. (author)

  20. Preservation of crab meat by gamma irradiation

    Fresh crab meat from swimming crab (Portunus pelagicus, Linn.) was irradiated at doses of 0.075, 0.15 and 0.25 Mrad and held at 30C. The storage life of non-irradiated crab meat was approximately 7 days compared with 14 days for crab meat irradiated at 0.075 Mrad and 28 days for samples receiving 0.15 or 0.25 Mrad treatment. Total aerobic count, trimethylamine nitrogen, total volatile basic nitrogen, and ammonia contents were used as objective indices of freshness in comparison with sensory evaluation of the crab meat. All objective indices correlated well with the sensory judgement of the samples. The crab meat used in the study was heavily contaminated with microorganisms. Irradiation at 0.15 and 0.25 Mrad reduced approximately 2 log cycles in the total count. Acinetobacter (Achromobacter) was predominated in irradiated crab meat, especially after prolonged storage. High coagulase positive staphylococci count was detected in only non-irradiated crab meat

  1. Apoptosis and necrosis in testes irradiated with gamma rays

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

  2. Biosolubilization gamma irradiate ion result coal by mould trichoderma sp

    Biosolubilization of coal is process of converting solid coal to liquid fuel/chemicals by mean of microorganism. The aim of this research was to study the effect of gamma rays irradiation with varian doses of irradiation into solubilization of subbituminous coal by Trichoderma sp. The dosage used was 5, 10, and 20 kGy and unirradiated coal as control. The method was submerged culture in MSS+ medium and incubated at room temperature and agitated at 150 rpm for 21th days. The parameters observed were colonization, pH and biosolubilization product based on absorbance value at λ250nm and λ450nm and GC/MS analysis for the best treatment. The results showed that coal biosolubilization could be increased by gamma irradiation. The mould could growth well in medium containing irradiated coal and the medium of pH was decreased after incubation. The biosolubilization was increased but the irradiation dosage of coal didn't affect significantly. The best dose was 20 kGy with product biosolubilization similar to gasoline and solar. Based on the result, the pre-treatment of gamma irradiation on coal has potency to increased biosolubilization. (author)

  3. Microbiological and chemical characteristics of gamma irradiated roasted Veal Meat

    This investigation aims 10 study the possibility of using gamma irradiation at doses of 1,3 and 5 KGy for microbial decontamination of roasted veal meat (kebab). The samples were purchased from local market and examined for the counts of Staphylococcus aureus, Bacillus cereus, presence of Salmonella spp and the counts of total bacterial, molds and yeasts and Enterobacteriaceae. The results illustrated that all samples were positive for Staphylococcus aureus, Bacillus cereus, while Salmonella spp was detected in only 3 samples. Therefore, these product samples were gamma irradiated at doses of 0,1,3 and 5 kGy, then stored at cold storage (4±1 degree C). The effects of these treatments on the microbiological, chemical and sensory characteristics were studied post treatment and during cold storage. Irradiation at 1 kGy reduced the counts of total bacterial, molds and yeasts, Enterobacteriaceae, Staphylococcus aureus and Bacillus cereus as well as eliminating Salmonella spp. On the other hand, irradiation at 3 and 5 kGy doses completely eliminated the present Enterobacteriaceae, S. aureus, B, cereus and Salmonella spp. Irradiation of samples increased their amounts of thiobarbituric acid reactive substances (TBARS) but it did not affect the sensory characteristics of samples and it had no effects on their total volatile nitrogen (TVN) contents, while storage increased the TBARS and TVN for irradiated and non-irradiated samples. Gamma irradiation treatments had no effects on the sensory characteristics for appearance, odor and taste of all kebab samples and extended their time of sensory preference. However, doses of 1, 3 and 5 kGy reduced the counts of total bacteria and extended of the refrigerated shelf-life of samples to 11, 23 and 29 days, respectively, compared to 5 days for non-irradiated controls

  4. Gamma irradiation treatment of cereal grains for chick diets

    Wheat (W), triticale (T), hulled barley (HB), hull-less barley (HLB), hulled oats (HO), and hull-less oats (HLO) were gamma irradiated (60Co) at 0, 3, 6 and 9 Mrad to study the effect of irradiation on the nutritional value of cereal grains for chicks. A significant curvilinear relationship between radiation dose and 3-wk body weight of chicks fed irradiated cereals was noted for T, HB, HLB, HO and HLO. Chicks fed W or T showed no effect or lower body weight, respectively, while body weights of chicks fed barley or oat samples were higher with irradiation. The improvement tended to be maximal at the 6 Mrad level. Irradiation significantly improved the gain-to-feed ratio for chicks fed either HO or HLO. Apparent fat retention and tibia ash were higher in chicks fed irradiated HLO than in those fed untreated HLO. In a second experiment chick body weight, apparent amino acid and fat retention, tibia ash, and gain-to-feed ratios were lower in chicks fed autoclaved (121 degrees C for 20 min) barley than in those fed untreated barley. Irradiation (6 Mrad) subsequent to autoclaving barley samples eliminated these effects. Irradiation appears to benefit cereals containing soluble or mucilagenous fiber types as typified by beta-glucan of barley and oats. These fibers appear prone to irradiation-induced depolymerization, as suggested by increased beta-glucan solubility and reduced extract viscosity for irradiated barley and oat samples

  5. Immobilization of cobalt in collapsed non-irradiated and {gamma}-irradiated X zeolites

    Lima, Enrique [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D.F. (Mexico) and Universidad Autonoma Metropolitana, Iztapalapa, Av. San Rafael Atlixco No. 186 Col. Vicentina, 09340 Mexico D.F. (Mexico)]. E-mail: lima@xanum.uam.mx; Bosch, Pedro [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D.F. (Mexico); Bulbulian, Silvia [Instituto Nacional de Investigaciones Nucleares, Col. Escandon, Delegacion Miguel Hidalgo, 11801 Mexico D.F. (Mexico)

    2007-02-15

    Cobalt exchanged X zeolites were gamma irradiated and heated until the zeolite structure collapsed. Heating destroys the zeolite network as found by X-ray-diffraction and {sup 29}Si, {sup 27}Al MAS NMR spectroscopy. Gamma irradiation treatment diminished the collapsing temperature of zeolite. Cobalt leaching from crystalline and amorphized zeolites was verified by ion exchange with NaCl solution. Results show that cobalt is not released from the amorphous materials. Furthermore adsorption of xenon and {sup 129}Xe NMR spectroscopy reveal that cobalt ions are heterogeneously distributed in the non irradiated amorphous materials. Gamma irradiation causes the mobility of cobalt in the amorphous materials resulting then in a more homogeneous distribution. Cobalt is, thus, retained safely in the amorphous materials.

  6. Studies on apple preservation by 60 -gamma irradiation

    Studies on '60'Co-gamma irradiation of Golden Delicious apple have been carried out. The results showed that the optimum irradiation dosage for stored apple was ranged from 0.3-0.5 k Gy, with this dosage, the contents of vitamin c and titratalbe acidity in these apples had no significant change compared with unirradiated apples. The respiratory rate and the amount of ethylene release were decreased after irradiation. The mortality of the verticillate pathogenic fungi was 97% at the dose of 0.5 k Gy

  7. Gamma irradiation study on barbituric acid and its phosphorus trimer

    Phosphorus tri barbiturate was synthesized from barbituric acid and structure was substantiated on the basis of microanalytical and spectroscopic techniques. The reactant and product were irradiated by gamma-rays and the ultraviolet measurements taken before and after irradiation were discussed. The effect of dose rate on UV absorption was found to be insignificant. The PH values were also measured before and after irradiation and the variation was correlated with the UV shifts at various concentrations of the aqueous solution of the compound. The results suggested, that the possible radiolysis decomposition site in the product is the carbon-phosphorus bond. The thermal analysis results were also studied

  8. The effect of gamma irradiation on bacteria in stored rice

    The effect of gamma irradiation on bacteria was studied for reducing the total microbial numbers that contaminating raw product under storage. Different storage packages of rice samples were irradiated at various levels of dosage. The results of bacterial isolation, total bacterial count and the isolation of bacterial food pathogenus were discussed. It was observed that the presence of bacteria colonies was suppressed by the presence of yeast and moulds eventhough the number of them decreased as the irradiation dosage levels were increased. (A.J.)

  9. Conservation of garlic bulbs (Allium sativum L. ) by gamma irradiation

    Fernandez, J.; Arranz, T.

    1979-01-01

    The effect of different doses of gamma radiation (from 5 to 30 krad) on the conservation of garlic bulbs during a 12 months period is studied. Irradiations were made at three different times and the best results were obtained with the treatment given during the two months following harvest. During this period, 5 krad are enough to inhibit garlic bulbs sprouting.

  10. Thermal decomposition of ammonium perchlorate during gamma-ray irradiation

    To assess radiation damage effects in propellants, pyrotechnics, and similar materials, thermal decomposition measurements were made on ammonium perchlorate powders and crystals during gamma-ray irradiation. Gas evolution studies were made on single crystals and powders of ammonium perchlorate, both at room temperature and at 2270C. The results are discussed. (U.S.)

  11. Dosimetry computer module of the gamma irradiator of ININ

    This work present the technical specifications for the upgrade of the dosimetry module of the computer system of the gamma irradiator of the Instituto Nacional de Investigaciones Nucleares (ININ) whose result allows the integration and consultation of information in industrial dosimetry subject under an outline client-server. (Author)

  12. Gamma irradiation for food preservation and sterilization of medical supplies

    A new technology in food preservation by using gamma irradiation was introduced and its advantages over a number of conventional processes were discussed. The new technique is also applicable in the sterilization of medical supplies. It is relatively simple and does not require very highly skilled manpower

  13. Conservation of garlic bulbs (allium sativum L.) by gamma irradiation

    The effect of different doses of gamma radiation (from 5 to 30 krad) on the conservation of garlic bulbs during a 12 months period is studied. Irradiations were made at three different times and the best results were obtained with the treatment given during the two months following harvest. During this period, 5krad are enough to inhibit garlic bulbs sprouting. (author)

  14. Thermoluminescence response of gamma-irradiated sesame with mineral dust

    The thermoluminescence (Tl) emission of minerals isolated from Mexican and Indian sesame seeds appear as a good tool to discern between irradiated and non-irradiated samples. According to the X-ray diffraction and environmental scanning microscope, the adhered dust in both samples is mainly composed by different amounts of quartz and feldspars. These mineral phases exhibit (i) enough sensitivity to ionizing radiation inducing good Tl intensity, (ii) high stability of the Tl signal during the storage of the material (i.e. low fading) and (iii) are thermally and chemically stable. Blind tests performed under laboratory conditions, but simulating industrial preservation processes (similar temperature and moisture, and presence of white light), allows to distinguish between 1 KGy gamma-irradiated and non-irradiated samples even 11000 hours (15 months) after the irradiation proceeding. (Author)

  15. Gamma irradiation for insect deinfestation damages native Australian cut flowers

    Gamma irradiation doses above 0.05 kGy for Geraldton wax, 0.1 kGy for banksia and 1.0 kGy for kangaroo paw caused significant (P <0.05) reductions in flower and foliage vase lives. Doses of greater than 2 kGy and up to 10 kGy were required for immediate 100% kill of the bioassay insects (adult flour beetle, Mediterranean fruit fly adults and larvae, and spotted moth larvae). Pretreating Geraldton wax shoots by cooling them or pulsing them with sugar lessened the detrimental effect of irradiation (0.1 kGy) on vase life. Pretreatment with silver thiosulphate had no positive effect. Irradiation of Geraldton wax shoots in an inert atmosphere (nitrogen) exacerbated irradiation, induced reduction in vase life and increased flower abscission. None of the postharvest treatments tested were sufficiently ameliorative for irradiation to be considered a viable deinfestation treatment for Geraldton wax. (author)

  16. A simple and efficient gamma irradiator for RVNRL

    This work describes a new design of a gamma irradiator for RVNRL which obeys a reliable operation and an efficient economical equation. Our irradiator is of a nobel design according to present requirements of latex industries and to the state of the art of radiation technology. The irradiator is of a wet storage type, where the radioactive sources are fixed in the reactor vessel, permanently submerged in deionized water. Preformulated latex is pumped from a deposited vessel into the reactor vessel and it is recirculated during the irradiation cycle avoiding turbulences and dose inhomogeneities. The irradiation time per one ton batch with a Co-60 charge of 3.5E15 Bq (100 kCi) is of approximately 4 hours

  17. Thermoluminescence response of gamma-irradiated sesame with mineral dust

    Rodriguez L, Y. [CSIC, Instituto de Estructura de la Materia, Calle Serrano 121, 28006 Madrid (Spain); Correcher, V. [CIEMAT, Av. Complutense 22, 28040 Madrid (Spain); Garcia G, J. [CSIC, Museo Nacional de Ciencias Naturales, Calle Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Cruz Z, E., E-mail: y.r.l@csic.es [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior s/n, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2011-10-15

    The thermoluminescence (Tl) emission of minerals isolated from Mexican and Indian sesame seeds appear as a good tool to discern between irradiated and non-irradiated samples. According to the X-ray diffraction and environmental scanning microscope, the adhered dust in both samples is mainly composed by different amounts of quartz and feldspars. These mineral phases exhibit (i) enough sensitivity to ionizing radiation inducing good Tl intensity, (ii) high stability of the Tl signal during the storage of the material (i.e. low fading) and (iii) are thermally and chemically stable. Blind tests performed under laboratory conditions, but simulating industrial preservation processes (similar temperature and moisture, and presence of white light), allows to distinguish between 1 KGy gamma-irradiated and non-irradiated samples even 11000 hours (15 months) after the irradiation proceeding. (Author)

  18. Gamma irradiation effects on dexamethasone and triamcinolone acetonide

    The effects of cobalt-60 gamma rays on dexamethasone and triamcinolone acetonide were examined by physico-chemical determination. Irradiation dose used were 0, 20 and 49 kGy while storage time were 0 and 6 months at about 30 ± 2oC. The results showed that irradiation up to a dose of 40 kGy and 6 months storage time do not give any change on the UV spectra, DSC thermograms, and infrared spectra of the powder and also do not give any significant effect on acid value, pH and viscosity of the eye ointments (p<0.05). There were significant changes in iodine value after irradiation and storage treatment. The HPLC chromatograms of triamcinolone acetonide powder and eye ointment showed that some degradation caused by irradiation have taken place but there was no change on the HPLC chromatogram of dexamethasone after irradiation. (author). 24 refs

  19. Sucrose synthesis in gamma irradiated sweet potato

    Effect of α-irradiation carbohydrate metabolism was examined to elucidate mechanism of sucrose accumulation in sweet potato (SP). Enzymes examined were: β-amylase, phosphorylase, phosphoglucomutase, phosphoglucose isomerase, sucrose phosphate synthetase and sucrose synthetase. Irradiated SP (Red Jewell) sucrose was synthesized to yield 10.7% after 4 d PI. Activities of sugar synthesizing enzymes in irradiated SP were enhanced to different degrees using 100-200 Krad and 3 d PI at 240C. Phosphorylase and phosphoglucomutases specific activities reached 2.4 and 1.8 folds, respectively compared to control SP. β-amylase, phosphoglucose isomerase, sucrose synthetase and sucrose phosphate synthetase were also affected to yield 1.2, 1.3, 1.3 and 1.2 folds, respectively compared to controls. It is believed that amylase hydrolyzed starch to glucose which is converted to fructose by phosphoglucose isomerase. Sucrose is then formed by sucrose phosphate synthetase and/or sucrose synthetase leading to its accumulation. The irradiated SP was used for alcohol fermentation leading to 500 gal. of 200 proof ethanol/acre (from 500-600 bushels tuber/acre)

  20. Using gamma irradiation to improve sterile turf and forage bermudagrasses

    The widely-used Tif-series of turf bermudagrasses - Tifgreen, Tifway, and Tifdwarf - are vegetatively propagated sterile triploids that cannot be improved by conventional breeding methods. Dormant stolons, washed free of soil and cut into one-or two-node sections were treated with varying dosages of EMS (ethyl methane sulfonate) and gamma irradiation ranging from 7 to 12 kR. EMS failed to produce noticeable variants but gamma irradiation from a Cobalt 60 source created 158 mutants. These mutants differed in many characters such as leaf size, hairiness, stem diameter, internode length, basic plant color, herbicide tolerance, spreading rate, and nematode resistance. Attempts to improve the winterhardiness of tetraploid sterile Coastcross-1 forage bermudagrass by exposing over 1,400,000 sprigs (vegetative stems) to 7 kR of gamma rays gave chlorophyll deficient mutants but progress in increasing winterhardiness has not been established. (author)

  1. Evaluation of average molecular weight of gamma-irradiated polytetrafluoroethylene

    Statistical treatment of the decrease in the number-average molecular weight of gamma-irradiated polytetrafluoroethylene (PTFE) sample was carried out by considering the random degradation of main chains, difference in the susceptibility to radiation damage between the crystalline and amorphous regions, and the evolution of low molecular weight gases. A specimen which consists of n chains was considered. The fracture density P was treated as the probability of fracture of main chains occurring per bond. The number of chain fractions was given. The monomer unit of the number-average molecule after evolution during gamma-irradiation was deduced. The fracture of main chains caused by radiation is dominant in the amorphous region. The dependence of amorphous fraction on radiation dose can be expressed. The calculated number-average molecular weight of irradiated PTFE was compared with the experimental results obtained from the viscoelastic method. (J.P.N.)

  2. Mutagenicity studies on alcohol extracts from gamma-irradiated potatoes

    The alcohol extracts freshly prepared from gamma-irradiated potatoes were examined for their mutagenic activity in bacterial and mammalian cell systems. Negative results were obtained from all following test systems: Mutation assays with Salmonella typhimurium His- strains such as TA 100, TA 98, TA 1535, TA 1537, and streptomycin-dependent mutant (SM sup(d)) strain, TA 100 - 10, inductests with Escherichia coli strains, K 12 GY 5027 and K 12 C600, chromosomal aberration tests with Chinese hamster cells in culture, as well as micronucleus tests in mice. In addition, no difference in the mutagenic activities was found between extracts prepared from the irradiated and the unirradiated potatoes, suggesting that no mutagenic substance was produced in potatoes following gamma-irradiation. (author)

  3. Stability of Grafted Polymer Nanoscale Films toward Gamma Irradiation.

    Borodinov, Nikolay; Giammarco, James; Patel, Neil; Agarwal, Anuradha; O'Donnell, Katie R; Kucera, Courtney J; Jacobsohn, Luiz G; Luzinov, Igor

    2015-09-01

    The present article focuses on the influence of gamma irradiation on nanoscale polymer grafted films and explores avenues for improvements in their stability toward the ionizing radiation. In terms of applications, we concentrate on enrichment polymer layers (EPLs), which are polymer thin films employed in sensor devices for the detection of chemical and biological substances. Specifically, we have studied the influence of gamma irradiation on nanoscale poly(glycidyl methacrylate) (PGMA) grafted EPL films. First, it was determined that a significant level of cross-linking was caused by irradiation in pure PGMA films. The cross-linking is accompanied by the formation of conjugated ester, carbon double bonds, hydroxyl groups, ketone carbonyls, and the elimination of epoxy groups as determined by FTIR. Polystyrene, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, dimethylphenylsilanol, BaF2, and gold nanoparticles were incorporated into the films and were found to mitigate different aspects of the radiation damage. PMID:26259102

  4. Effect of neutron and gamma irradiation on magnetic bubble memories

    Many years of research preceeded the introduction of magnetic bubble memories (M.B.M.) into the memory components market. They are used as bulk storage memories principally for their non volatile characteristics under irradiation. A physical and technological description of MBM is given in the first part of the text together with the results of work on their vulnerability when subjected to irradiation. Permanent damage caused by neutrons and gamma radiation on thin magnetic layers is then studied. A theoretical analysis on the stability of bubbles based on the results of pulsed laser experiments is given. The stability of the information stored in a commercially available MBM subjected to neutron and gamma irradiation (MBM - TIB 203 of 92 kBits, Texas) is described in the last part of the text. The vulnerability thresholds determined for the MBM are too high for them to be used in a radioactive environment with an improved electronic control system

  5. EPR structure of the gamma irradiated alanine spectrum

    In this study is shown that the broadened five-line EPR pattern of the gamma irradiated alanine possibly decomposes into a more complex pattern when the recorded spectrum is subject to an operation of deconvolution. The EPR powder spectra of gamma irradiated DL- and L-alanine with and without binders are analysed. In all recorded spectra, each observed line is resolved into an asymmetrical triplet when a Gaussian distribution of 8.2 gauss width is removed, by deconvolution, from the observed spectrum. On the other hand, from a simple fitting analysis carried out on the original data, one encounters that some calculated relations between characteristic parameters, such as intensity ratios, deviate consistently from assumed height ratios. Both, from deconvolution and fitting results, a different structure is suggested for the observed broadened five-line EPR pattern of γ-irradiated powder DL- and L-alanine. (Author)

  6. Gamma Irradiation Induces DNA Double-Strand Breaks in Fibroblasts: A Model Study for the Development of Biodosimetry

    Accidental exposure to ionizing radiation can immediately induce double-strand breaks (DSBs) of DNAs which later pose detrimental damage on organisms including genetic instability and cell death. The aim of this study is to simulate such incident by exposing a cell model to gamma radiation and the resulting DNA DSBs were immunofluorescently labeled and quantified to establish a dose response relationship. Human dermal fibroblasts were grown into monolayers before irradiated by gamma rays from a Co-60 source at doses 0, 0.2, 1, 2 and 4 Gy and a dose rate of 0.21 Gy/min. DNA DSBs, which appeared as foci inside the cells' nuclei, were evaluated by flow cytometry and confocal microscopy. Data showed that the foci intensity increased linearly in relation to the increase in irradiation dose within 1 h post exposure. These findings can be further developed to serve as a personal biodosimetry to assess the immediate extent and potential health risks of accidental exposure to ionizing radiation in individuals.

  7. Application of gamma irradiation for the enhanced physiological properties of polysaccharides from seaweeds

    Choi, Jong-il; Kim, Hyun-Joo; Kim, Jae-Hun; Byun, Myung-Woo [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580185 (Korea, Republic of); Soo Chun, Byeong; Hyun Ahn, Dong [Department of Food Science and Biotechnology, Pukyong National University, Busan 608737 (Korea, Republic of); Hwang, Young-Jeong [Division of Food Science, Jinju International University, Jinju 660759 (Korea, Republic of); Kim, Duk-Jin [Division of Food Engineering and Nutrition, Daegu University, Daegu 712714 (Korea, Republic of); Kim, Gwang Hoon [Department of Biology, Kongju National University, Chungnam 314701 (Korea, Republic of); Lee, Ju-Woon [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2009-07-15

    Polysaccharides from seaweeds, fucoidan and laminarin, were irradiated with gamma rays, and their structural changes and anti-oxidative activities were investigated. The gamma irradiation decreased the average molecular weights of polysaccharides, and UV spectra of irradiated polysaccharides showed increases in the numbers of carboxyl and carbonyl groups and double bonds. DPPH radical scavenging ability and reducing power of the gamma irradiated polysaccharides were significantly higher than those non-irradiated.

  8. Application of gamma irradiation for the enhanced physiological properties of polysaccharides from seaweeds

    Polysaccharides from seaweeds, fucoidan and laminarin, were irradiated with gamma rays, and their structural changes and anti-oxidative activities were investigated. The gamma irradiation decreased the average molecular weights of polysaccharides, and UV spectra of irradiated polysaccharides showed increases in the numbers of carboxyl and carbonyl groups and double bonds. DPPH radical scavenging ability and reducing power of the gamma irradiated polysaccharides were significantly higher than those non-irradiated.

  9. The resistance of salmonella typhirium on gamma irradiation

    This research intended to investigate the registance of S. typhimurium on the gamma irradiation, temperature and pH in the cell suspension of 10 exp. 8 and homogenants sludge medium. The resistance of bacteria S. typhimurium in cells suspension of 10 exp. 8 was irradiated with gamma ray (60-Co) at the doses of 0; 0.15; 0.30; and 0.45 kGy. The dose rate was 1.00 kGy/h, in the gamma cell 220 irradiator and then the suspension was plated on the media, which have pH from 6, 7, and 8. Then incubated at temperature of 30, 37 and 42 Celcius centigrade for 2 x 24 hours. The resistance of bacteria S. typhimorium in 10% sludge homogenate in TGY broth was iradiated with gamma ray at doses of 0; 0.5; 1.0; 1.5; 2.0; and 2.5 kGy with dose rate of 0.95 kGy/h. After irradiation the bacteria was incubated for 24 hours at room temperature (28 +/- 2) Celcius centigrade then innoculate on SS, Mac Conkey, and XLD media. After 2 x 24 hours grows on petri dishes, the growth of colonies were observed and total bacterial counts per ml was calculated. The results showed irradiation and pH media gave significant decrease in the total bacterial count. Irradiation doses of 0.45 kGy reduced the total number of bacterial counts by 5 log cycles with the pH variation from 6 - 8 while the results in the sludge homogenete showed that the media give no significant effect on the ground capabilities of S. typhimorium. (author). 7 refs, 4 figs, 4 tabs

  10. Rapid differentiation between gamma-irradiated and non irradiated potato tubers

    Jona, Roberto; Fronda, Anna

    The use of gamma irradiation as commercial method for the preservation of fruits and vegetables calls for methods of differentiation between irradiated and non-irradiated foodstuffs. In a previous research, the polysaccharidic content of cell walls of irradiated tissue has been investigated, but it required rather long time to reach the result. A method devised to ascertain the vitality of cells has been applied to distinguish irradiated from non-irradiated potato tubers. 500 mg of tissue excised from tubers have been infiltrated with tetrazolium chloride 0.6% in phosphate buffer, pH 7.4. After 15 hrs of incubation at 30°C the treated tissues have been extracted with 95% ethanol whose O.D. has been measured at 530 mμ wavelength. The colour intensity of the alcohol allowed a very clearcut recognition of the irradiated tubers.

  11. Rapid differentiation between gamma-irradiated and non irradiated potato tubers

    The use of gamma irradiation as commercial method for the preservation of fruits and vegetables calls for methods of differentiation between irradiated and non-irradiated foodstuffs. In a previous research, the polysaccharidic content of cell walls of irradiated tissue has been investigated, but it required rather long time to reach the result. A method devised to ascertain the vitality of cells has been applied to distinguish irradiated from non-irradiated potato tubers. 500 mg of tissue excised from tubers have been infiltrated with tetrazolium chloride 0.6% in phosphate buffer, pH 7.4. After 15 hrs of incubation at 300C the treated tissues have been extracted with 95% ethanol whose O.D. has been measured at 530 mμ wavelength. The colour intensity of the alcohol allowed a very clearcut recognition of the irradiated tubers. (author)

  12. Effect of gamma irradiation on wear characteristics of UHMWPE for joint prostheses

    Ultra-high molecular weight polyethylene (UHMWPE) is widely used as a rubbing material for clinical applications in total prostheses. Generally, total joint prostheses are sterilized by gamma irradiation. Gamma ray ordinarily does not change the properties of ceramic and metal material, but it is well known that UHMWPE has high sensitivities to gamma irradiation. Gamma irradiation causes crosslinking of UHMWPE, which changes its property from original one. This work shows that gamma irradiation has remarkable effects on the reduction of UHMWPE wear. Gamma irradiation is very useful for reduction of UHMWPE wear. In this experiment, medium gamma irradiation is enough to reduce UHMWPE wear. However, gamma irradiation causes reduction in tensile strength and elongation of UHMWPE. Therefore, we found that optimum point of dose to prevent reduction of mechanical properties and reduce wear. Additionally, we also indicate the wear reduction mechanism of crosslinked UHMWPE. (author)

  13. Experimental qualification of a code for optimizing gamma irradiation facilities

    Dose computation codes are a prerequisite for the design of gamma irradiation facilities. Code quality is a basic factor in the achievement of sound economic and technical performance by the facility. This paper covers the validation of a code by reference dosimetry experiments. Developed by the ''Societe Generale pour les Techniques Nouvelles'' (SGN), supplier of irradiation facilities and member of the CEA Group, the code is currently used by that company. Experimental data were obtained under conditions representative of those prevailing in the gamma irradiation of foodstuffs. Irradiation was performed in POSEIDON, a Cobalt 60 cell of ORIS-I. Several Cobalt 60 rods of known activity are arranged in a planar array typical of industrial irradiation facilities. Pallet density is uniform, ranging from 0 (air) to 0.6. Reference dosimetry measurements were performed by the ''Laboratoire de Metrologie des Rayonnements Ionisants (LMRI) of the Bureau National de Metrologie'' (BNM). The procedure is based on the positioning of more than 300 ESR/alanine dosemeters throughout the various target volumes used. The reference quality was the absorbed dose in water. The code was validated by a comparison of experimental and computed data. It has proved to be an effective tool for the design of facilities meeting the specific requirements applicable to foodstuff irradiation, which are frequently found difficult to meet. (author)

  14. Thermoluminescence of Simulated Interstellar Matter after Gamma-ray Irradiation

    Koike, K; Koike, C; Okada, M; Chihara, H

    2002-01-01

    Interstellar matter is known to be strongly irradiated by radiation and several types of cosmic ray particles. Simulated interstellar matter, such as forsterite $\\rm Mg_{2}SiO_{4}$, enstatite $\\rm MgSiO_{3}$ and magnesite $\\rm MgCO_{3}$ has been irradiated with the $\\rm ^{60}Co$ gamma-rays in liquid nitrogen, and also irradiated with fast neutrons at 10 K and 70 K by making use of the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL. Maximum fast neutron dose is $10^{17}n_f{\\rm /cm^{2}}$). After irradiation, samples are stored in liquid nitrogen for several months to allow the decay of induced radioactivity. We measured the luminescence spectra of the gamma ray irradiated samples during warming to 370K using a spectrophotometer. For the forsterite and magnesite, the spectra exhibit a rather intense peak at about 645 -- 655 nm and 660 nm respectively, whereas luminescence scarcely appeared in olivine sample. The spectra of forsterite is very similar to the ERE of the Red Rectangle.

  15. Experimental qualification of a code for optimizing gamma irradiation facilities

    Mosse, D. C.; Leizier, J. J. M.; Keraron, Y.; Lallemant, T. F.; Perdriau, P. D. M.

    Dose computation codes are a prerequisite for the design of gamma irradiation facilities. Code quality is a basic factor in the achievement of sound economic and technical performance by the facility. This paper covers the validation of a code by reference dosimetry experiments. Developed by the "Société Générale pour les Techniques Nouvelles" (SGN), a supplier of irradiation facilities and member of the CEA Group, the code is currently used by that company. (ERHART, KERARON, 1986) Experimental data were obtained under conditions representative of those prevailing in the gamma irradiation of foodstuffs. Irradiation was performed in POSEIDON, a Cobalt 60 cell of ORIS-I. Several Cobalt 60 rods of known activity are arranged in a planar array typical of industrial irradiation facilities. Pallet density is uniform, ranging from 0 (air) to 0.6. Reference dosimetry measurements were performed by the "Laboratoire de Métrologie des Rayonnements Ionisants" (LMRI) of the "Bureau National de Métrologie" (BNM). The procedure is based on the positioning of more than 300 ESR/alanine dosemeters throughout the various target volumes used. The reference quantity was the absorbed dose in water. The code was validated by a comparison of experimental and computed data. It has proved to be an effective tool for the design of facilities meeting the specific requirements applicable to foodstuff irradiation, which are frequently found difficult to meet.

  16. Protein denaturation of banana prawns (Penaeus marquensis) after gamma irradiation

    The aim of this investigation was to determine the irradiation dose limit for maintaining shrimps freshness, based on the existence of protein denaturation of shrimps caused by gamma irradiation at radurization dose range. Protein denaturatio was studied using tryptic digestibility, solubility, and Ca ATPas actomyosin activity as the criterions. Electrophoretic studies were done to detect structural changes in protein that probably occured after irradiation at the applied doses. It was proved that tryptic digestibility, solubility, and Ca ATPase actomyosin activity of control and samples irradiated at 3, 4, and 5 kGy were significantly different (P<0.01) which indicated the existence of protein denaturation. Protein patterns of samples irradiated at 4 and 5 kGy were also distinctly different with those of the control. The 7th. band was broken into two bands. It could be concluded that for maintaining the freshness of shrimps, gamma irradiation dose used should not exceed 3 kGy. (authors). 8 refs, 1 fig 4 tabs

  17. On enzyme kinetic parameters modification of gamma irradiation

    To elucidate the molecular mechanisms of gamma-ray action on biomolecules there were investigated the modifications in activity and other kinetic parameters for some enzymes irradiated in pure dry state at relative high doses. There were considered bacterial and fungal α-amylases, glucoamylase and Mucor sp. protease irradiated by a 60 Co gamma-ray source in the dose range 1.0-30.0 kGy, at different dose-rates between 0.5-2.0 kGy/h, at room temperature. Considering the enzyme inactivation in this dose range, the dose-effect relationships have an expected form and depend on the irradiation conditions but not significantly on the dose rate. The catalytic properties of enzymes were modified by irradiation. By usual methods it is evidenced a direct correlation between the enzymatic activities, Michaelis-Menten constant, Km, reaction velocities, v, and the irradiation dose. These experimental findings can support a self-consistent theoretical approach on biophysical radiation action on biological active molecules like enzymes. At the same time, some enzyme behaviour to irradiation could be considered like a good biological indicator of radiation response. (Author) 4 Figs., 19 Refs

  18. New developments in design of gamma irradiation plants

    Symec Engineers (I) Pvt. Ltd is an ISO 9001:2008 certified company which is among the leading manufacturers of gamma irradiation plants in India and abroad. The company's long history of achievements begins from the building of India's first indigenous irradiation plant in 1990 to the successful commissioning of India's first and only batch irradiation plant in 2005, to the completion of India's largest irradiation plant of 5 million curies capacity in 2012. Symec has recently added two more feathers in its cap by commissioning a 3 Mci multi-purpose facility in Biyagama, Sri Lanka and another 100Kci batch type blood irradiation facility in Addis Ababa, Ethiopia for the IAEA. In all Symec has successfully completed 10 gamma irradiation plants in India and abroad, and is involved in three more projects in this sector. Based on the years of experience in the international and domestic market, Symec has evolved several interesting design features and developments in its plants. Some of these features are described below. (author)

  19. Isolation of Enterobacter cowanii in tomatoes after gamma irradiation

    The tomato is one of the most consumed fruit in the world. Bacteria of the family Enterobacteriaceae are responsible for large outbreaks of gastroenteritis. Irradiation is a physical method which reduces waste by eliminating spoilage organisms in foods. The objective of this study was to identify and determine the resistance profile of micro-organisms of the family Enterobacteriaceae from irradiated tomatoes. Were used three batches each containing 80 tomatoes, and divided in control and irradiated. The samples were individually properly identified as the irradiation dose applied. The material was subjected to irradiation with gamma rays, for irradiating with a cobalt-60 source, using doses: 1.0, 1.5 and 2 kGy (6,060 kGy/h). For microbiological analysis tomatoes were cut out, and removing the shells to obtain samples weighing 25g. Each sample was transferred to an Erlenmeyer containing sterilized water, stirring the assembly mechanically. Aliquots of the wash waters were sown in differential and selective media. After reisolation, the colonies were subjected to Gram staining then performed biochemical tests for identification. The antibiotic susceptibility tests were performed according to CLSI (Clinical Laboratory Standard Institute). It was isolated three strains of Enterobacter cowanii in tomato samples irradiated with a dose of 1.0 kGy, without isolating the other doses. As for the resistance profile, the strains were resistant to Ampicillin identified. Gamma irradiation at a dose of 1.5 and 2 kGy was effective in tomatoes as well as the micro-organism isolated after irradiation showed no profile of multidrug resistance. (author)

  20. Genetic Changes in Stevia rebaudiana after Gamma Irradiation

    In vitro propagated plantlets of Stevia rebaudiana Bertoni J.were irradiated with doses 0, 5, 10 and 20 Gy. Irradiated plantlets exhibited changes in electrophoretic profile of proteins, there were some new bands induced with molecular weight of 100, 45, 32, and 30 kDa. In some treatments and some other bands disappeared such as the 205 and 100 kDa bands form plantlets treated with 10 Gy. Isoenzyme were also examined, esterase isozyme, isopolyphenol oxidase, alkaline phosphatase, catalse, acid phosphatase and peroxidase isozyme also altered by treatments. RAPD analysis was performed to determine the effect of gamma-irradiation on DNA changes. Polymorphisms between regenerates from non-irradiated and irradiated plantlets were found. The scope of variation spectrum by gamma-irradiation was larger than that by tissue culture. All the primers used produced polymorphic bands. Six primers generated 129.0 RAPD markers, among which 49.0 (37.98%) were polymorphic, with a mean of 8.17 pol morphisms per primer. The results showed that gamma-irradiation induced changes in plantlets that can be detected by molecular and biochemical markers. Stevia rebaudiana Bertoni. Stevia is a member of the Compositae family and native to the valley of the Rio Monday in the highlands of Paraguay, where it has been used by aboriginal people as a sweetener for centuries. It is one of 154 members of the genus Stevia and one of only two that produce sweet steviol glycosides. Stevioside has a sweetening potency of 200-300 times that of sucrose and it is stable to heat (Soejarto et a/., 1982 and 1983 and Lewis, 1992). The leaves were used either to sweeten mate or as a general sweetening agent. Currently Stevia production is centred in China and there is a major market in Japan (Kinghorn and Soejarto 1985)

  1. Gamma irradiation service in Mexico; Servicio de Irradiacion Gamma en Mexico

    Liceaga C, G.; Martinez A, L.; Mendez T, D.; Ortiz A, G.; Olvera G, R. [Departamento del Irradiador Gamma. Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, Col. Escandon, 11801 Mexico D.F. (Mexico)

    1997-12-31

    In 1980 it was installed in Mexico, on the National Institute of Nuclear Research, an irradiator model J S-6500 of a canadian manufacture. Actually, this is the greatest plant in the Mexican Republic that offers a gamma irradiation process at commercial level to diverse industries. However, seeing that the demand for sterilize those products were not so much as the irradiation capacity it was opted by the incursion in other types of products. During 17 years had been irradiated a great variety of products grouped of the following form: dehydrated foods, disposable products for medical use, cosmetics, medicaments, various. Nowadays the capacity of the irradiator is saturated virtue of it is operated the 24 hours during the 365 days of the year and only its operation is suspended by the preventive and corrective maintenance. However, the fresh food market does not be attended since this irradiator was designed for doses greater than 10 kGy (1.0 Mrad)

  2. Effect of gamma irradiation on antinutritional factors in broad bean

    The effect of gamma irradiation on the level of antinutritional factors (trypsin inhibitor (TI), phytic acid and oligosaccharides) of broad bean was investigated. The seeds were subjected to gamma irradiation at 0, 2.5, 5, 7.5 and 10 kGy, respectively using cobalt-60 gamma radiation with a dose rate 2.37 kGy/h. TI activity was reduced by 4.5%, 6.7%, 8.5% and 9.2% at 2.5, 5, 7.5 and 10 kGy, respectively. Meanwhile, irradiation at 10.2, 12.3, 15.4 and 18.2 kGy reduced the phytic acid content. The flatulence causing oligosaccharides were decreased as the radiation dose increased. The chemical composition (protein, oil, ash and total carbohydrates) of the tested seeds was determined. Gamma radiation seems to be a good procedure to improve the quality of broad bean from the nutritional point of view

  3. Effect of gamma irradiation on antinutritional factors in broad bean

    Al-Kaisey, Mahdi T.; Alwan, Abdul-Kader H.; Mohammad, Manal H.; Saeed, Amjed H.

    2003-06-01

    The effect of gamma irradiation on the level of antinutritional factors (trypsin inhibitor (TI), phytic acid and oligosaccharides) of broad bean was investigated. The seeds were subjected to gamma irradiation at 0, 2.5, 5, 7.5 and 10 kGy, respectively using cobalt-60 gamma radiation with a dose rate 2.37 kGy/h. TI activity was reduced by 4.5%, 6.7%, 8.5% and 9.2% at 2.5, 5, 7.5 and 10 kGy, respectively. Meanwhile, irradiation at 10.2, 12.3, 15.4 and 18.2 kGy reduced the phytic acid content. The flatulence causing oligosaccharides were decreased as the radiation dose increased. The chemical composition (protein, oil, ash and total carbohydrates) of the tested seeds was determined. Gamma radiation seems to be a good procedure to improve the quality of broad bean from the nutritional point of view.

  4. Continuous induction of unscheduled DNA synthesis by gamma irradiation

    The induction of DNA-synthesis in non-S-phase cells is a very sensitive measure of a preceding damage of the DNA. Usually, in an in vivo -in vitro test (treatment of an animal, incorporation of H3-thymidine in a cell suspension) the damaging of DNA takes place hours to days before the evaluation. In this case, the time course of the UDS-induction after a single dose of 1 Gy gamma irradiation should be observed for a long time (21 months). C57 black mice served as test animals. In an age of about 80 days they were irradiated and the induction of unscheduled DNA synthesis was measured at ten points of time during the whole life-span of the animals. Although the repair in this gamma radiation damage in DNA is a very quick process - with centrifugation in alkaline sucrose you find a half time of some minutes - an induction of unscheduled DNA synthesis could be seen at the irradiated animals until the end of their life (640 days). The reason for this could be permanent disorders in cellular regulation caused by the gamma irradiation. 4 figs. (Author)

  5. Cell death induced by gamma irradiation of developing skeletal muscle

    Newborn Sprague-Dawley rats were exposed to a single dose of 2 Gy gamma rays and killed from 6 h to 5 d later. Increased numbers of dying cells, characterised by their extreme chromatin condensation and often nuclear fragmentation were seen in skeletal muscle 6 h after irradiation. Dying cells decreased to nearly normal values 48 h later. In situ labelling of nuclear DNA fragmentation identified individual cells bearing fragmented DNA. The effects of gamma rays were suppressed following cycloheximide i.p. at a dose of 1 μg/g body weight given at the time of irradiation. Taken together, the present morphological and pharmacological results suggest that gamma ray induced cell death in skeletal muscle is apoptotic, and that the process is associated with protein synthesis. Finally, proliferating cell nuclear antigen-immunoreactive cells, which were abundant in control rats, decreased in number 48 h after irradiation. However, a marked increase significantly above normal age values was observed at the 5th day, thus suggesting that regeneration occurs following irradiation-induced cell death in developing muscle. (author)

  6. Variation in electrical properties of gamma irradiated cadmium selenate nanowires

    Chauhan, R. P.; Rana, Pallavi; Narula, Chetna; Panchal, Suresh; Choudhary, Ritika

    2016-07-01

    Preparation of low-dimensional materials attracts more and more interest in the last few years, mainly due to the wide field of potential commercial applications ranging from life sciences, medicine and biotechnology to communication and electronics. One-dimensional systems are the smallest dimension structures that can be used for efficient transport of electrons and thus expected to be critical to the function and integration of nanoscale devices. Nanowires with well controlled morphology and extremely high aspect ratio can be obtained by replicating a nanoporous polymer ion-track membrane with cylindrical pores of controlled dimensions. With this technique, materials can be deposited within the pores of the membrane by electrochemical reduction of the desired ion. In the present study, cadmium selenate nanowires were synthesized potentiostatically via template method. These synthesized nanowires were then exposed to gamma rays by using a 60Co source at the Inter University Accelerator Centre, New Delhi, India. Structural, morphological, electrical and elemental characterizations were made in order to analyze the effect of gamma irradiation on the synthesized nanowires. I-V measurements of cadmium selenate nanowires, before and after irradiation were made with the help of Keithley 2400 source meter and Ecopia probe station. A significant change in the electrical conductivity of cadmium selenate nanowires was found after gamma irradiation. The crystallography of the synthesized nanowires was also studied using a Rigaku X-ray diffractrometer equipped with Cu-Kα radiation. XRD patterns of irradiated samples showed no variation in the peak positions or phase change.

  7. Radioprotective Effect Of Green Tea Extract On GAMMA Irradiated Mice

    This study aimed to evaluate the possible radioprotective role of green tea extract (GTE) in mice exposed to gamma radiation. Eighty male mice were divided into four groups; group (A) was considered the control, group (B) received 1.5% GTE for 14 days, group (C) exposed to 4 Gy gamma radiation and group (D) received GTE and exposed to 4 Gy gamma radiation. Blood and liver tissue were collected from these groups 24 hours, 3 days and 5 days post-irradiation to measure the levels of hepatic malondialdehyde (MDA) and superoxide dismutase (SOD), serum aminotransferases (ALT and AST), Hb concentration, RBCs, WBCs and platelets counts, in addition to ultra-structure examination of the liver. The results revealed that GTE supplementation prior to irradiation significantly decreased hepatic MDA, increased hepatic antioxidant enzyme (SOD) and decreased serum ALT and AST compared to irradiated mice. Also, supplementation of mice with GTE led to regeneration and protection of hepatocytes and the levels of the hematological parameters were significantly increased in the GTE pre-treated group as compared to irradiated animals. It could be conclude that the GTE may be a good agent to attenuate radiation-induced damage to the liver and hematopoietic system.

  8. Investigation of thermoluminescence characteristics of gamma irradiated phlogopite mica

    The present paper investigates the thermoluminescence (TL) characteristics of phlogopite mica irradiated with gamma rays in the dose ranges from 5 kGy to 40 kGy. It has been found that at all gamma doses, TL glow curve of phlogopite mica shows a simple glow curve structure with one broad peak around 400 K temperature. There is no shift in peak temperature with increase in gamma dose which clearly indicates that TL glow peaks are of first order kinetics. The TL intensity increases linearly up to 30 kGy and then shows saturation up to 40 kGy which have been explained using TIM and UNIM model. The effect of different heating rates on the TL intensity, TL glow peak temperature and total glow curve area for 10 kGy irradiated phlogopite mica has also been studied. Theoretical analysis of TL glow curves of gamma irradiated phlogopite mica has been done by glow curve deconvolution procedure using computerized Glow Fit software and the trapping parameters of isolated TL glow peaks have also been determined. The simple glow curve structure and the linear TL response to a wide range of gamma doses of phlogopite mica confirm its suitability as an effective thermoluminescent material and explore its potential for tremendous applications in radiation dosimetry. - Highlights: ► The present paper reports the thermoluminescence characteristics of phlogopite mica. ► This investigation focuses on the TL response of phlogopite mica to gamma rays. ► Different kinetic parameters have also been studied for the better understanding of the TL phenomenon

  9. Characterization of Gamma-Irradiated Egyptian Wheat Flour

    Physical, rheological and baking properties of bread Shamy, prepared from gamma-irradiated Egyptian wheat flour up to 25 KGy as one of common types of bread in Egypt, were studied and the acceptability of bread was evaluated by sensory tests. All amylo-, farino-, and extensograph characteristics and also sample ph showed significant decrease as irradiation dose increased. Such results could be explained in terms of loss of unique elastic and cohesive properties of wheat gluten and starch damage upon increment of radiation dose. The improvement in properties of bread, baked from flour irradiated up to 7.5 KGy, could be explained on the basis of a simulation in gas production during dough fermentation due to increase in starch degradation products. However, bread, prepared from wheat samples irradiated above 7.5 KGy, exhibited significantly lower values of acceptance because of physico-chemical changes in both starch and gluten

  10. Low temperature gamma-ray irradiation effects on polymer materials

    The gamma radiation induced degradation of glass fiber reinforced plastic (GFRP) and polymethylmethacrylate (PMMA) at 77K was examined by flexural test and gas analysis after irradiation and compared by the irradiation at room temperature. The decrease in flexural strength at break was much less at 77K than at RT. The evolution of CH4, CO and CO2 was also depressed at 77K. The temperature dependence of the degradation closely relates to the local molecular motion of matrix resin during irradiation. Polytetrafluoroethylene (PTFE) was also studied by irradiation at RT, 77K and 4K in terms of tensile elongation and molecular weight. The degradation was much less at 77K and 4K than at RT, and the same between 77K and 4K. (author)

  11. Aversive conditioning in prenatally gamma-irradiated rats

    To examine how intrauterine exposure to gamma rays would exert on four kinds of aversive conditioning, rat fetuses were irradiated with 0.27, 0.48, or 1.46 Gy at Day 15 post conception. When ordinary avoidance conditioning was given to the groups with 0.27 and 0.48 Gy, there was no significant difference between the irradiated groups and the control group in the rate of positive avoidance response. Nor was this different in the irradiated groups and the control group, when the rate of baseline response was examined in avoidance conditioning. In positive avoidance conditioning to two kinds of anticipatory electric stimuli, the acquisition of avoidance was significantly inferior in all irradiated groups to that in the control group. When giving succesive discrimination learning, the group with 1.46 Gy tended to have higher rate of positive avoidance response and remarkably lower rate of passive avoidance response than the control group. (Namekawa, K.)

  12. The decontamination effects of gamma irradiation on the edible gelatin

    The decontamination effects of gamma irradiation on the edible gelatin were studied. The results indicated that the bacterium and mold in the gelatin decreased significantly with the dose of 5 kGy treatment. However, the content of crude protein, microelement, amino acid in the gelatin remained unchanged under the irradiation of 4 and 8 kGy. The viscosity of the gelatin decreased with the increase of the irradiation dose, but the gelatin with a dose of 5 kGy treatment still accorded with the standard of the second-order class. These results suggested that the optimum irradiation dose for edible gelatin for the purpose of decontamination was in the range 3-5 kGy. (author)

  13. Effect of Gamma Irradiation on Natural and Synthetic Latexes

    As compared with bulk rubber, rubber particles in latexes vulcanized by irradiation possess specific properties. The properties of synthetic latex particles (SKS-30A and SKN-40) vulcanized by gamma irradiation, and of the films obtained from them, differ in properties they acquire by other vulcanization techniques. Changes in the properties of latex (pH-value, surface tension, viscosity, etc.) as a colloidal system under irradiation depend to a considerable extent upon the chemical nature of the rubber and on its derivation. Yields differ according to whether the vulcanization is carried out by particle or by bulk irradiation. Ageing processes for such latexes and the films obtained from them differ from ageing processes for non-vulcanized or sulphur-vulcanized latexes. The radiation vulcanized products have increased stability. The properties of the vulcanized rubber in the latex are confirmed by data indicating high resolution nuclear magnetic resonance spectra. (author)

  14. Shrubs of the Field Irradiator - Gamma area in eastern Manitoba

    Detailed descriptions and line drawings are given of over 100 shrub taxa (including semi-woody shrubs and vines) which are common in Manitoba; most of them are found within the Field Irradiator - Gamma (FIG) area or its immediate surroundings. Ecological and morphological notes are included along with a few general remarks on the effects of exposure to long-term gamma radiation. Keys are given for certain genera, small family groups or other critical species groups. This document is intended to facilitate identification of shrubs for experimental purposes in the FIG projects, and it should also be useful to those who are generally interested in the shrubs of Manitoba. (auth)

  15. Color centers aggregation kinetics in lithium fluoride after gamma irradiation

    Lithium fluoride crystals are irradiated at various doses by gamma rays at 77 K. The time evolution of photoluminescence signals from aggregated F2+, F2, F3+ and F3 color centers, and of the absorption intensity of primary F centers are measured at various annealing temperatures. The lifetimes of anionic vacancies υa and F2+ centers, the characteristic times of concentration growth of F2, F3+ and F3 centers, and also the activation energies of diffusion of vacancies and F2+ centers together with various processes of aggregation are determined. It is found that lifetime decreases for vacancies while increases for F2+ centers by increasing the irradiation dose. It is also shown that, after irradiation during annealing, vacancies are formed as a result of the reaction F2++H→υa+Fl−, where Fl− is a fluorine ion in a lattice site and H is a fluorine interstitial atom. Then these vacancies participate in color centers aggregation kinetics. The presence of F− centers in the irradiated crystal is established, and the processes which lead to the formation of F2, F3+ and F3 centers after irradiation, are unveiled. -- Highlights: • Experimental investigation of color centers in LiF crystals after gamma irradiation. • Study of formation kinetics for F, F2, F3 and F3+ centers after irradiation at 77 K. • Lifetimes of anionic vacancies and F2+ centers at few irradiation doses. • Aggregation rates of F2, F3 and F3+ centers and their reciprocal influence. • Estimates of activation energies for color center diffusion

  16. Gamma greenhouse for chronic irradiation in plant mutation breeding

    The gamma greenhouse makes use of chronic irradiation from a 137Cs source (double encapsulated 800 Ci caesium-137 pencil) producing a low dose rate, which is considered to be more effective in recovering and producing useful mutants in comparison to acute irradiation. The irradiation facility comprises an open topped irradiation area 30 m in diameter, protected by a partial concrete wall with entry maze and site topography. For safety, the facility is protected by a sophisticated interlock system, which only allows the source to be exposed when all the prerequisite safety conditions are met, and automatically returns the source to the safe storage position if any safety device is compromised. The main irradiation area is further protected by a 300 m diameter exclusion zone that is also protected by the safety interlock circuit. The facility can accommodate a wide range of plant materials such as seeds, seedlings in pots, cuttings, callus, somatic embryos and suspension cell cultures. Plant samples will be exposed to low dose gamma radiation over long periods of time (hours, weeks, months), depending on their nature and sensitivity. There was evidence whereby exposure of tissue culture materials to continuous low dose gamma irradiation resulting in considerably elevated somaclonal variation frequency without negative effects on culture response. It is not surprising that in vitro culture generating somaclonal variation together with in vitro mutagenesis inducing mutation lead to a higher variation frequency due to possible addition of mutagenic effect by in vitro mutagenesis to somaclonal variability arising from in vitro culture as well as the interaction between them. (Author)

  17. Gamma-ray Irradiation Induces Useful Morphological Variation in Bermudagrass

    Songul SEVER MUTLU

    2015-12-01

    Full Text Available Bermudagrass, Cynodon dactylon (L. Pers. is a widely used warm-season turfgrass species in warmer regions of the world. Gammairradiation has been used to generate useful variations in turfgrass breeding for various morphological traits. The objective of the present study was to measure and determine variations in morphology and turfgrass characteristics of a native drought resistant bermudagrass germplasm irradiated with 70, 90 or 110 Gy using a 60Co source. The stolons containing a single node were irradiated and immediately planted for regeneration in a greenhouse at the Akdeniz University, Antalya, Turkey. Selected mutants regenerated from the irradiated stolons were clonally propagated and transplanted into plastic pots for further observations of turfgrass characteristics.  Survival rates of stolons exposed to 70, 90 and 110 Gy were 76%, 43% and 17% respectively, 6 weeks after treatment. Dosages of 85 and 57 Gy were determined as LD50 and LD20 for the cuttings, respectively. The linear reduction of survival rate with increasing gamma-rays was highly correlated (r2=0.99. A total of four mutant lines (0.3 % of the irradiated plants showed a distinct dwarfed growth habit. Three of these lines were originated from 70 Gy and one from 110 Gy. These mutant lines exhibited more dwarf growth habit, higher shoot density, finer leaf texture than parental genotype. Mutant lines developed in this study can be used for the development of improved bermudagrass cultivars for landscaping and sports turf.

  18. EPR study on tomatoes before and after gamma-irradiation

    The results from the EPR studies on fresh, air-dried and lyophilized tomato samples before and after gamma-irradiation are reported. Before irradiation fresh and air-dried tomatoes exhibit one singlet EPR line characterized with common g-factor of 2.0048±0.0005, whereas freeze-dried tomato does not show any EPR spectrum. After irradiation, a typical 'cellulose-like' triplet EPR spectrum appears in all samples, attributed to cellulose free radicals, generated by gamma-irradiation. It consists of intense central line with g=2.0048±0.0005 and two weak satellite lines separated ca. 3 mT left and right of it. In air-dried and lyophilized tomatoes the 'cellulose-like' EPR spectrum is superimposed by an additional partly resolved carbohydrate spectrum. Fading measurements of the radiation-induced EPR signals indicate that the intensity of the EPR spectra of air-dried and freeze-dried tomato are reduced to about 50% after 50 days, whereas those of fresh irradiated tomatoes kept at 4 oC fade completely in 15 days. The reported results unambiguously show that the presence of two satellite lines in the EPR 'cellulose-like' spectra of tomato samples can be used for identification of radiation processing.

  19. Inactivation of Salmonellae in Frozen Catfish by Gamma Irradiation

    The effect of gamma irradiation on salmonellae viability in frozen catfish was investigated using fresh cut of catfish artificially contaminated with stationary phase cells of salmonellae, frozen at-18 οC and irradiated with does ranging from 0.0 to 2.4 kGy. The D10 values for ten serovars of salmonellae ranged from 0.47 to 0.77 kGy. Salmonella Enteritidis was the most resistant serovars found in frozen catfish. Dosage at 2.5 kGy would be sufficient to kill 103.2 Salmonella Enteritidis that may occasionally present in frozen catfish

  20. Dosimetry in air in the product 1 gamma irradiator

    In this paper are presented the results of the dosimetry in air in the product-1 gamma irradiator of the Research Institute of the Food Industry. The dose was measured with the Fricke system. This dosemeter was used for the determination of the dose distribution in the irradiator container. It was obtained the minimum, maximum and overall average value of the dose. The calibration functions of the plant well time, evaluated using linear regression analysis, present very good adjustment for these parameters when it was chosen four different settings for the well time. The dose uniformity ratio is 1.3. 11 refs

  1. Bacterial use of biofilms cross-linked by gamma irradiation

    Gamma-irradiation was used to produce sterile free-standing biodegradable caseinate films. The effect of irradiation doses (i.e. number of cross-links) on the bacterial use of these films using a strain of Pseudomonas aeruginosa was investigated. Results showed that the main difference in overall utilisation for both films (4 or 64 kGy) was observed in terms of period of utilisation which was delayed 8 days for the film containing the highest number of cross-links (64 kGy)

  2. Effect of gamma irradiation on fungi in stored rice

    The objective of this study is to examine the effect of different doses of gamma irradiation on fungi infecting rice stored in various packaging materials. The agar plate test method was used. It was observed that the percentage of fungi did not appear to decrease with the increase of irradiation up to 2 kGy and also no indication of any significant reduction in percentage of fungi isolated with increasing time of storage at all levels of radiation treatment. The majority of the fungi isolated were Aspergillus and Penicillium species. (A.J.)

  3. The ripening of gamma irradiated fruits of jujube

    Mature green jujube fruits of cv. Zaytoni were subjected to gamma radiation doses of 0, 10, 30 and 50 krad. The irradiated and unirradiated fruits were then kept at 20°C and 85–90% r.h., and changes in weight loss, total soluble solids, titratable acidity and ascorbic acid content were determined. Fruits subjected to 30 krad were firmer and greener than unirradiated control fruits after six days of storage, and this treatment delayed ripening by three days. There was no significant loss in the nutritive value of the fruit due to irradiation

  4. Effect of gamma irradiation on mortality of tribolium castaneum (HERBST)

    An investigation was made to assess the susceptibility of larvae and adults of Tribolium castaneum to gamma irradiation. The larvae were more susceptible to irradiation than the adults. A dose of 0.05 kGy killed all the larvae but higher dose of 0.15 kGy was required to kill all the adults. Therefore, a dose of 0.15 kGy was found to be the effective dose to kill both the larvae and the adults of T. castaneum. (author)

  5. Conversion of lignocellulosic waste by gamma irradiation and fungal fermentation

    Effects of microbial elimination (initially contaminated bacteria and fungi) were confirmed at wide range of irradiation doses (15-30 kGy) with gamma rays of Co-60 for substrates with sawdusts, sugar cane baggasse, rice straw, oil palm fibre and others. Some changes of main components of basic polysaccharides and nitrogen sources in substrates under irradiation and fermentations have been examined to confirm effective conversions and assimilations of inorganic nitrogen into protein, particularly using N-15 tracer techniques. Biomass obtained by fungal fermentations would be used for animal feed and spent compots were useful for biofertilizer production. (author)

  6. X-ray versus gamma irradiation effects on polymers

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to 60Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties

  7. Cadmium leaching from thermal treated and gamma irradiated Mexican aluminosilicates

    Thermal and radiation effects on the leaching of cadmium from two cadmium exchanged zeolitic tuffs and one clay were determined. The cadmium exchanged aluminosilicates were heated at different temperatures (500, 700, 900 and 1100 oC), and the materials were then treated with NaCl (1 M and 5 M) and HNO3 (0.001 M and 1 M) solutions to determine the leaching behaviour of cadmium from the materials. The stability of cadmium in the materials increased as the heating temperature was increased. Cadmium leaching from gamma irradiated and heated materials at 1100 oC was higher than leaching from non-irradiated samples

  8. Physiological response of wheat, maize and cotton to gamma irradiation

    Grains of wheat triticum aestivum vulgare cv. Giza 155, maize Zea mays cv. double hybrid strain 17 S and cotton seeds Gossypium barbadence cv. Giza 67 were irradiated with successive doses of gamma rays from 0 to 64 Krad. Irradiating wheat grains with 1 Krad, maize grains with 0.5 Krad and cotton seeds with 4 Krad stimulated their germination and enhanced the growth of seedlings and their chlorophyll content. Also, these doses activated Alpha- and Beta-Amylase in the seeds. Higher doses had suppression effects. Peroxidase value in the seedlings of the three species was accelerated progressively in concomitant with the increase in the dosage

  9. X-ray versus gamma irradiation effects on polymers

    Croonenborghs, B. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium); Smith, M.A. [Sterigenics International, 10811 Withers Cove Park Drive, Charlotte, NC 28278 (United States); Strain, P. [Sterigenics EMEAA, Remylaan 4c box 4, 3018 Leuven (Belgium)], E-mail: pstrain@eu.sterigenics.com

    2007-11-15

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to {sup 60}Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  10. X-ray versus gamma irradiation effects on polymers

    Croonenborghs, B.; Smith, M. A.; Strain, P.

    2007-11-01

    Today, the most common methods used for medical device sterilisation are by gaseous ethylene oxide and by electron beam or gamma irradiation. With X-ray sterilisation about to enter the market, its material compatibility needs to be assessed at doses typically encountered during a sterilisation process. This paper reports on a study that compares the effects of exposing different types of plastics that are commonly used in medical devices to 60Co or to 5 MeV X-rays. The dose rate for both irradiation modalities was of the same order of magnitude. Under these conditions, both types of radiation are found to have similar effects on polymer properties.

  11. Reduction of nitrogen oxides by gamma-irradiated hemoproteins. Pt. 1. Nitrite reducing activity of gamma-irradiated hemoproteins

    In nature, nitrite reductases located in microorganisms as well as in plants convert nitrite (NO2-) into ammonium ion (NH4+). It is rather difficult to isolate nitrite reductase because of very low content in microorganisms and plants. Bovine blood hemoglobin (Hb), horse cardiac muscle myoglobin (Mb) and horse cardiac muscle cytochrome c (Cyt c) in 50μM aqueous solution were treated by gamma-irradiation at doses of 10-30 kGy in the presence of air. The present study shows that NO2- is connected into NH4+ by gamma-irradiated hemoprotein in the presence of sodium hydrosulfite as a reducing agent and methyl viologen as an electron carrier. The concentration of NO2- and NH4+ after reaction were determined by using diazo-reaction and ninhydrin reaction, respectively, after separation by HPLC. NO2- remained and NH4+ formed by 10 kGy irradiated Cyt c, Hb and Mb at pH4 at 60 min were, 0% and 46%, 17% and 31%, 31% and 24%, respectively. Formation of hydroxylamine by reaction of NO2- was not recognized in this reaction. The process of conversion of NO2- to NH4+ is a net 6 electrons, 8-proton reaction. These results suggest that gamma-irradiated Hb, Mb and Cyt c can be used as a substituent of nitrite reductase. (J.P.N.)

  12. Degradation of poly(carbonate urethane) by gamma irradiation

    Özdemir, T.; Usanmaz, A.

    2007-06-01

    Poly(carbonate urethane) (PCU), is a valuable commercial engineering polymer. In order to understand the possible use of PCU in radioactive waste management as a solidifying agent or as a disposal container, radiation stability of the PCU is studied by Co-60 gamma irradiations at two different dose rates of 1540 and 82.8 Gy/h. The total dose of irradiation was up to 6.24 MGy. Degradation nature was tested by studying the changes in mechanical and thermal properties with rate and total dose of irradiation. Ultimate tensile strength and toughness first increased and then decreased with the irradiation dose. Half value dose (HVD) for elongation was 4010 kGy and for tensile strength 6010 kGy at the dose rate of 1540 Gy/h. The non-irradiated PCU transparent color changed to yellow and then brown with increased irradiation dose. The FTIR spectral analysis showed a random scission of polymer with irradiation. From the experimental observation, it was shown that PCU can be used for embedding radioactive waste for about 300 years.

  13. The effect of gamma irradiation on Nematospiroides dubius

    Mice were infected with gamma irradiated larvae of Nematospiroides dubius and autopsied 5 weeks later for worm counts. It was found that male worms were more susceptible to irradiation than female worms. In both instances, however the survival curve on a semi logarithmic plot was characterised by a shoulder at low doses and an exponential component at the higher levels of exposure. No male worms were recovered from mice infected with larvae given more than 12 krad but some female worms were capable of surviving 20 krad. The fecundity of female worms was reduced by 61% at 4 krad and totally ablated at 8 krad. Further experiments demonstrated that the survival of irradiated N. dubius in vivo was related to the extent of the damage caused at the time of irradiation and was not dependent on additional host parameters. Thus neither the number of irradiated worms inoculated nor the sex of the host radically altered the sex ratio or proportion of the worms lost as a result of irradiating the larvae. Furthermore, treatment with cortisone or sublethal irradiation of the host did not increase the proportion of surviving worms. It was therefore, concluded that a host immune response was not involved. (author)

  14. Qualities of Patin Fishball Irradiated by Gamma Rays (60Co)

    An experiment on patin fishball quality using gamma irradiation (60Co) has been conducted. Samples were irradiated at 0, 1, 3 and 5 kGy and stored in refrigerator at temperature 10 oC for sixty days. Samples were analysed every fifteen days, except content of fat and protein that analysed only at the beginning and the end of storage. The purpose of this experiment is to know the quality changes of patin fishball irradiated during storage, by measuring of chemical (content of fat, protein, water, TVB value, pH value) and microbiology (TPC aerobic and anaerobic bacteria) changes. The results showed that irradiation did not affect macro nutrient contents (content of fat, protein and water) of patin fishball during storage but irradiation can affect TVB and pH values. Irradiation at 1 kGy can reduce one logarithmic cycle of total aerobic and anaerobic bacteria. The storage life of irradiated patin fishball treated at 1, 3 and 5 kGy could be extended up to 15, 30 and 60 days, respectively. Control samples the storage life could be extended less than 15 days. (author)

  15. Identification of gamma-irradiated fruit juices by EPR spectroscopy

    The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60 min at 40 °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to “cellulose-like” EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical “sugar-like“ spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation. - Highlights: • The EPR analysis of juices, nectars and syrups proves that the sample has been irradiated. • Two sample preparation procedures were used. • The stability of the radiation induced EPR signals was studied over 2 months. • Application of European standards can be extended for irradiated juices and syrups

  16. Effect of gamma irradiation on milled rice quality

    Gamma irradiation as a technique for preserving cereal grains and other foodstuff is now gaining prominence. It has been proven to reduce post-harvest losses from insect infestation and microbial action. To validate its effects on storage, physicochemical, cooking, and sensory qualities of milled rice, this study was then conducted. Batches of milled rice stored in three different packaging materials (polypropylene sack, polythylene bag, and polypropylene sack lined with polyethylene bag) were irradiated with 0, 0.5, and 1.0 kilogray of Co60. Treated samples were stored at room temperature and their grain qualities were evaluated monthly for a period of nine months. Irradiation decreased grain whiteness, gel consistency, water uptake ratio during cooking, and sensory ratings. It increased iodine blue value and percent soluble solids. The magnitude of change was influenced by the dose of irradiation. The effect was more apparent with 1.0 kGy. dose. Differences in sensory quality between irradiated and non-irradiated samples became less evident with time. Irradiated rice stored in a polypropylene sack lined with a polyethylene bag was more organoleptically acceptable than those packed in polypropylene sacks and polyethylene bags. (Author)

  17. A commercial gamma-ray irradiation plant in Japan

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

  18. Genetic repairing through storage of gamma irradiated seeds in inbred maize (Zea mays L.)

    Kumar, Girjesh; Rai, Prashant Kumar

    2009-01-01

    Gamma irradiation can induce beneficial as well as deleterious impacts on chromosome behavior in crop plants. The cytogenetic changes occurring due to the storage of inbred seeds after gamma irradiation in the somatic and gametic cells of Zea mays L. were investigated in this study. A wide spectrum of chromosomal anomalies was encountered in somatic and gametic cells of maize that are gamma irradiated, stored (aged), and treated with a combination of both of these treatments. Gamma rays and a...

  19. Gamma-irradiation of malic acid in aqueous solutions

    Negron-Mendoza, A.; Graff, R.L.; Ponnamperuma, C.

    1980-12-01

    The gamma-irradiation of malic acid in aqueous solutions was studied under initially oxygenated and oxygen-free conditions in an attempt to determine the possible interconversion of malic acid into other carboxylic acids, specifically those associated with Krebs cycle. The effect of dose on product formation of the system was investigated. Gas-liquid chromatography combined with mass spectrometry was used as the principal means of identification of the nonvolatile products. Thin layer chromatography and direct probe mass spectroscopy were also employed. The findings show that a variety of carboxylic acids are formed, with malonic and succinic acids in greatest abundance. These products have all been identified as being formed in the gamma-irradiation of acetic acid, suggesting a common intermediary. Since these molecules fit into a metabolic cycle, it is strongly suggestive that prebiotic pathways provided the basis for biological systems.

  20. Physical properties of gamma irradiated poly (vinyl alcohol) hydrogel preparations

    Complete text of publication follows. Poly (vinyl alcohol) films from 15% w/w aqueous solutions and a thickness of 0.2 mm were selected for this study. The films were first humidified and then acetalized and/or gamma irradiated. Then, their physical properties were tested. Tensile strength of the hydrogel films reached its maximum value in samples irradiated with a 80 kGy dose but in the case of previously acetalized films the dose necessary for maximum tensile strength was only 40 kGy. In each case tests of stability in boiling water and autoclave heating to 121 deg C were done. The combination of processes of acetalization with formaldehyde and gamma radiation produced an elastic hydrogel with good tackiness and excellent mechanical and thermal strength, with an important reduction of the absorbed radiation dose

  1. Induced mutations in mungbean by gamma irradiation

    Uthong-1 is the recommended mungbean variety in Thailand. A study in the greenhouse showed that lethal dose 50 of gamma rays at 28 days for Uthong-1 was about 70 krad. In field experiments the selection method of plant progeny rows was used until the M4 generation. Forty mutant lines showed early maturity and 32 mutants showed high yield. In the M6 generation, seven early maturing and five high yielding mutant lines were selected for preliminary yield trials. The results of these trials showed the mutant line Hy-3-60-8 had the highest yield in the dry and late rainy seasons. Its seed size was also bigger than that of the control by about 5%. The results of subsequent standard yield trials showed that Hy-3-60-8 could do well in the early rainy season and E-3-60-37 was suitable for the dry season. Mutant lines E-3-60-34, E-3-60-30 and E-3-60-37 were superior in seed size to the control in every season. (author). 1 ref, 4 figs, 7 tabs

  2. Increased sensitivity to gamma irradiation in bacteria lacking protein HU.

    Boubrik, F; Rouviere-Yaniv, J.

    1995-01-01

    The heterodimeric HU protein, isolated from Escherichia coli, is associated with the bacterial nucleoid and shares some properties with both histones and HMG proteins. It is the prototype of small bacterial DNA binding proteins with a pleiotropic role in the cell. HU participates in several biological processes like cell division, initiation of DNA replication, transposition, and other biochemical functions. We show here that bacteria lacking HU are extremely sensitive to gamma irradiation. E...

  3. Effect of gamma irradiation on some plant oils

    The aim of this work was to study the possibility of using different sage doses of γ -rays (up to 1000 K. rad) for destroying or minimizing trypsin inhibitors for soybean seeds and detect their effect on the main constituents of seeds. Attention was focussed on changes occured in physiochemical properties, fatty acids composition and unsaponifiable matter components of soybean oil due to both gamma irradiation and storage treatments. In addition, the changes in the main constituents of soybean meals were also studied

  4. Effect of gamma irradiation on stability of sheep tall fat

    The main objective of this investigation was to find out the effect of gamma irradiation on the physicochemical and storage characteristics of sheep tail fat results of irradiatied samples showed a signi ficaut (P0.01)increase in peroxide value, free fatty acids, carbonyl compounds (saturated and unsaturated), viscosity, and a significant decrease (P0.01)in melting point, smoking point, specific gravity and refractive index and no Iodine value

  5. Investigations on starch from gamma irradiated rye and wheat

    Wheat and rye and the flours derived from them were gamma irradiated with 50, 500 and 5000 krad. Changes in the amount and the chemical structure of starch were detected. A degradation of starch could be seen at the highest radiation dose in all samples. Flour is more sensitive to radiation then the respective corn. The lower radiation doses gave effects which were near or below the detection limit of the used methods. 76 refs., 16 figs., 29 tabs

  6. Mutation induction in oil palm cultures using gamma irradiation

    Induced mutations have played an important role in the improvement of wide range of food crops, ornamental plants and oil crops such as sesame and sunflower. Based on these successes an attempt was made to employ the mutagenesis techniques to broaden the genetic variation in breeding materials of oil palm. Traits of interest are high yield, dwarfness and disease resistance. Embryogenic callus initiated from several high yielding clones were exposed to gamma irradiation for optimum dose determination. (Author)

  7. Resistance of some common fungi to gamma irradiation.

    Saleh, Y G; Mayo, M S; Ahearn, D G

    1988-01-01

    Ten species of fungi representing the genera Alternaria, Aspergillus, Caldosporium, Curvularia, Fusarium, and Penicillium were examined for their relative resistance to gamma irradiation from a 137Cs source. Inactivation doses for dematiaceous fungi in agar medium ranged from 0.6 to greater than 1.7 megarads, whereas those for moniliaceous fungi were less than 0.3 megarad. D10 values (the dose required to reduce the inoculum by 1 log) for Curvularia geniculata (greater than 0.29 megarad) exce...

  8. Development of an irradiation system for a small size continuous run multipurpose gamma irradiator

    The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is a product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 PBq. The performed qualification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process qualification. The initial load of the multipurpose irradiator was 3.4 PBq with 13 cobalt-60 sources model C-188, supplied by MDS Nordion - Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The polymethylmetacrylate (PMMA) dosimeter system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning with dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma irradiators available on the market. (authors)

  9. Development of an irradiation system for a small size continuous run multipurpose gamma irradiator

    The Radiation Technology Center from Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil, developed with a revolutionary design and national technology, a small size continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotate door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m2 of floor area, the irradiator design is product overlap sources and the maximum capacity of cobalt-60 wet sources is 37 P Bq (1 MCi). The performed quantification program of this multipurpose irradiator was based on AAMI/ISO 11137 standard, which recommends the inclusion of the following elements: installation and process quantification. The initial load of the multipurpose irradiator was 3.4 P Bq (92.1 k Ci) with 13 cobalt-60 sources model C-188, supplied by MDS Nordion Ion Technologies - Canada. For irradiator dose optimization, the source distribution was done using the software Cadgamma developed by IPEN-CNEN/SP. The poly-methylmethacrylate (PMMA) dosimeters system, certified by the International Dose Assurance Service (IDAS) of the International Atomic Energy Agency (IAEA) was used for irradiator dose mapping. The economic analysis, performance concerning to dose uniformity and cobalt-60 utilization efficiency were calculated and compared with other commercial gamma

  10. Effects of gamma irradiation on durum wheats and spaghetti quality

    The efficient control of insects in cereal grains has long been the main objective of processors who are always looking for safer and more economical methods. Gamma irradiation is a physical technique of food preservation that seems to have a potential to protect grains from insect infestation and microbial contamination during storage. It has been reported that gamma irradiation doses in the range of 0.2-1.0 kGy are effective in controlling insect infestation in cereals (IAEA 1991). Increasing the dose to 5 kGy totally kills the spores of many fungi surviving the lower doses (Murray 1990). Besides its protective role from insects and microorganisms, gamma irradiation also has important effects on various quality criteria of cereal grains. Experiments have been performed to study the effects of gamma irradiation on various aspects of wheat quality such as milling characteristics, dough properties, and baking quality (Lai et al 1959, Lee 1959, Fifield et al 1967, Rao et al 1975, Paredes-Lopez and Covarrubias-Alvarez 1984, MacArthur and D'Appolonia 1983, Ng et al 1989). It was reported that amylograph peak viscosity and falling number values of the flour decreased significantly as radiation levels increased (MacArthur and D'Appolonia 1983, Ng et al 1989). Rao et al (1975) showed that as radiation dose increased, amylograph peak height and dough stability decreased. At 10 kGy, loaf volume and crumb grain were impaired. Paredes-Lopez and Covarrubias-Alvarez (1984) found that the overall bread quality of wheat was greatly reduced at medium doses of radiation (1-10 kGy). At doses >5 kGy, irrespective of the baking formula used, loaf volume and baking quality deteriorated (Lai et al 1959). Irradiation of grain has also caused problems in noodle quality. Japanese noodles (udon) show increased cooking losses and inferior scores in sensory analysis when the bread wheats have been irradiated in the range of 0.2-1.0 kGy (Shibata et al 1974, Urbain 1986). However, no detailed

  11. Gamma background irradiation. Standards and reality

    The systematic deviation of the results of measuring the power of air dose absorbed from the natural gamma background radiation in Bulgaria is inadmissibly large and variable. This in turn augments the dispersion of results as well as the mean value relative to worldwide data, to an implausible level, hardly attributable to the variegated geographical relief of the country. Thus in practice local anthropogenic increases hardly lend themselves to detection and demonstration. In the Radiation Protection Standards (RPS-92) in effect in Bulgaria, and in other documents concerning the same radiation factors as well, the maximum allowable limits for the population as a whole are clearly specified on the basis of worldwide expertise along this line. As a rule these limits are being exceeded by the actually measured values, and for this reason the cited documents contain a clause stipulating that these limits do not refer to the natural radiation background and therefore the latter may be virtually ignored. Thus the basic risk factor for the population goes beyond control at levels commensurable with the officially established limits, its twofold increase inclusive. The maximum allowable limit becomes undefinable. Bearing in mind the fact that in compliance with the cited RPS-92 elimination of the technogenic ionizing radiation sources incorporated in the environment prior to 1992 is 'freezed', it is evident that exposure of the population to anthropogenic radiation becomes legally allowable in a much wider range than the one specified by world legislators. One may anticipate radiation induced health noxae for the population directly or by anthropogenic radiation stress on biocenosis. A relatively large part of the population is susceptible to the effect of low radiation doses. Presumably this contingent will augment as a result of eventual fluctuations. The casual relationship which is difficult to establish should be given due consideration in the analysis of the causes

  12. Effects of gamma irradiation on the colour of pigments

    Negut, D. C.; Ponta, C. C.; Georgescu, Rodica M.; Moise, I. V.; Niculescu, Gh.; Lupu, A. I. M.

    2007-07-01

    The aim of this paper is to investigate the influence of gamma irradiation process on the colour of painted wood panels. Insects and micro-organisms are frequently identified enemies of cultural objects from museums and archives. Based on its biocide effect, gamma radiation could be used for decontamination and conservation purposes. Important advantages can be mentioned in its favour: no toxic or radioactive residues remained in the treated item; large amount of objects can be treated quickly; excellent reliability; attractive cost. In case of emergency radiation treatment in industrial facilities is probably the only method that can be used. There is also a potential side-effect. Interaction of gamma rays with any substance may change its chemical and physical properties. The change is proportional with the irradiation dose. In the case of paintings, eventually colour changes have to be evaluated. Such an approach actually establishes irradiation treatment limitations. A portable integrating sphere spectrophotometer was used for colour measurements. The results of colour analysis before and after the radiation treatment of the painted wood panels are reported and discussed.

  13. Evaluation of artemisia mutant lines conducted from gamma irradiation treatment

    Cases of Malaria diseases attack in Indonesia has been increasing. Plasmodium falciparum the cause of malaria disease is now resistant to the usual medicine. One of malaria medicine which recommended by WHO is artemisinine compound extracted from Artemisia annua L plant. Low artemisinine content is one problem of Artemisia development in Indonesia. Increasing genetic variation using gamma irradiation is one alternative method to improve artemisinin content. In 2007, induce mutation had been done to artemisia seeds using gamma irradiation at dosage of 10-100 Gy. The good rooting planlet was regenerated and acclimatized in the green house, and then the seedling (M0 generation) was planted in the field at 1545 m asl. Plants derived from seeds without gamma irradiation treatment and cultured in vitro (in vitro control) were used as control. The result showed there were some morphological variations between the mutant lines (plant height, shape of the leaves and time of flowering). Ten mutant lines were selected based on biomass yield and analyzed for the artemisinine content.The result showed that artemisinine content of the mutant lines ranged from 0.44 - 1.41%, and it was significantly higher than that of in vitro control (0.43%). (author)

  14. Improved performance of Tectona grandis seeds with gamma irradiation

    Tectona grandis Linn., commonly known as 'Teak' is grown in gardens and parks for the leaf shape and size. However, the major problem in cultivation of this plant is poor seed germination. Therefore, investigations on the effect of gamma irradiation in the seeds of Teak were undertaken. Genetically pure seeds were treated with 10, 20, 30, 40 and 50 kR in a 60Co-Gamma Cell administered at 1.2 kR/min. Irradiation with lower doses improved seed germination. Similarly, 20 and 30 kR influenced the seedling growth to a significant extent and different degrees of stimulation was observed in almost all the treated plant population. As a result of better seed establishment, the number of leaves and branches were considerably higher. Girth of the stem at different levels of growth varied, maximum being in 10 kR plants. In these treatments, a plant type was obtained which had altered leaf shape and prolonged leaf bearing phase. The photosynthetic area in this plant was significantly more than control and had its reflection on growth. The data obtained indicate considerable improvement in the overall performance of seeds irradiated with gamma rays. (author)

  15. Microbial decontamination of some chicken meat products by gamma irradiation

    This investigation aims to study the possibility of using gamma irradiation for microbial decontamination of some chicken meat products (Luncheon, Burger and debonded minced chicken) which are produced by three companies (Halwany Bros.(H)-Faragalla (F) and Egypco (E)). The samples were purchased from local supermarkets and examined for the presence of Salmonella spp. and Staphylococcus aureus. The examination illustrated that all examined samples were positive for Staphylococcus aureus. While Luncheon (F), Burger (H) and debonded minced chicken (E) were only positive for Salmonella spp. Therefore, these product samples were gamma irradiated at 0, 3, 6 and 9 kGy. The effects of radiation treatments and cold storage (5+,-1 degree) on the total volatile basic nitrogen (T.V.B.N.), microbiological quality and sensory properties of samples under investigation were studied. The results indicated that 3kGy dose of gamma irradiation completely destroyed Staphylococcus aureus and Salmonella spp. and caused slight increase in (T.V.B.N.) content for all samples. A gradual increase in total bacteria, molds and yeast and T. V. B. N. during storage were observed, while 6 kGy dose was also sufficient for destroying Salmonella spp. and Staphylococcus aureus in all chicken meat products under investigation without any detectable effects on the sensory properties of these products and increased the shelf-life of luncheon, burger and minced for 8, 4 and 3 weeks respectively as compared with 4, 2 and 1 weeks for control samples

  16. Gamma knife treatment of rat glioma Influences of irradiation dose on apoptosis and necrosis

    Peng Wang; Mianshun Pan; Xinggen Fang

    2008-01-01

    BACKGROUND: Apoptosis and necrosis are cellular death mechanisms that are induced in glioma cells following gamma knife irradiation. Increased apoptosis is essential for maintaining and enhancing treatment efficacy.OBJECTIVE: To observe apoptotic and necrotic mechanisms of rat glioma models induced by gamma knife treatment and to analyze the influences of irradiation doses on apoptosis and necrosis. DESIGN: Controlled animal experiment. SETTING: Cancer Hospital of Tianjin Medical University and Gamma Knife Center of Hefei Brain Hospital.MATERIALS: Eighteen female specific pathogen free Sprague Dawley rats, weighing 180-210 g and 5-6 weeks old, were purchased from the Experimental Animal Center, Medical College of Suzhou University. Rat C6 glioma cells were purchased from the cell bank of Chinese Academy of Sciences. Annexin V-FITC Reagent Kit (Bender Med System. Company, USA) and a flow cytometer (Becton Dickinson FACSCalibur) were provided.METHODS: The experiment was conducted at the Cancer Hospital of Tianjin Medical University and Gamma Knife Center of Hefei Brain Hospital from December 2006 to May 2007. All rats were inoculated with C6 glioma cells, i.e., 4 μL of a C6 glioma cell suspension was injected 5 mm deep in the cortex. All rats were divided randomly into a model group, 9-Gy treatment group, and 12-Gy treatment group. There were six rats in each group.MAIN OUTCOME MEASURES: Apoptosis and necrosis of normal brain tissue and glioma were observed by Flow Cytometry one week after irradiation, and pathological changes to tumor tissue were identified by HE staining.RESULTS: Eighteen rats were initially selected for the study: two rats from the model and 12-Gy treatment groups died from accidental anesthesia. The remaining 16 rats were included in the final result analysis. Cellular apoptosis and necrosis: apoptosis and necrosis were significantly increased in the treatment groups after gamma knife irradiation, compared to the model group (P < 0

  17. Gamma Rays Irradiation Effects on Polysulfones at Elevated Temperature

    Polysulfone has excellent mechanical and thermal properties. Its application covers a wide rage such as nuclear facilities and space environment. The radiation chemical scheme on polysulfone is not well established as it undergoes both scission and cross-linking. In this study, the temperature dependence of the irradiation effect on polysulfone was studied by measuring glass transition temperature, gel fraction, molecular weight and gas evolution. Polysulfone film of 50 micrometer thickness was irradiated with gamma rays at dose rate of 5-7 kGy/h to absorbed dose of 0.1-4 MGy under vacuum in glass ampoules at room temperature, 100, 150, 180, 210 degree. Glass transition temperature (Tg) measured with differential scanning calorimeter lowered with dose upon irradiation at room temperature and 100 centigrade, though Tg rose upon irradiation above 180 centigrade, respectively. Gel fraction in chloroform at room temperature was measured. Pristine polysulfone is soluble to chloroform but after irradiation it formed gel. The decrease of gel dose, and the increase of gel fraction were observed with elevation of irradiation temperature. The number average molecular weight measured with gel permeation chromatography decreased with dose at irradiation temperatures except for 210 degree, where slight increase was observed. On the other hand, weight average molecular weight increased at all temperatures. The molecular weight distribution changed towards lower direction and became broad at all cases examined. These results indicate that the predominant scheme is scission but simultaneous cross-linking occurs, especially at elevated temperature. The probability of the cross-linking was increased by irradiation at elevated temperature above 180 degree, though the probability of main chain scission was not changed very much. The yield of evolution of total gas, CO, CO2 and SO2 gases increased at elevated temperature, while yield of evolved H2 was independent of irradiation

  18. Comparative sensitivity of tribolium SPP to gamma irradiation throughout ontogeny

    Storage losses from insect attack are often as great as those sustained by the growing crops. Moreover, losses in growing crops are frequently obvious, whereas losses in stored grain are likely to be insidious. Estimates of losses to the world's supply of stored grain from insect damage range from 5 to 10 percent of the world's production (Burkholder, 1990). In certain tropical and subtropical countries as well as Bangladesh, estimates are much higher (FAO, 1977). These problems encouraged the search for other means of control, including the use of physical measures. In this respect, two methods that show promise for controlling insects without leaving harmful chemical residues are the use of gamma radiation or microwave radiation (Cornwell, 1966; Hamid et al., 1968). Of the two, irradiation of insects has attracted wide attention in various fields from development to genetics, and through its possible application to insect pest eradication programmes (Knipling, 1955). However, the control of insects in foodstuffs by irradiation depends on acquiring the necessary basic radiobiological knowledge, on advances in irradiation, and on health and safety considerations. This research is into the possible use of gamma irradiation in controlling stored product pests as an alternative to other control methods. (author)

  19. Effect of gamma irradiation on sulfur-cured chlorobutyl rubber

    Scagliusi, Sandra R.; Cardoso, Elisabeth E.L.; Ono, Lilian S.; Lugao, Ademar B., E-mail: srscagliusi@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Chlorobutyl rubber (CIIR) is similarly manufactured to butyl rubber (IIR). The insertion of chlorine atom in isoprene group represents an improvement in its properties, such as: high vulcanizing speed, low permanent stress and compatibility with other types of rubber. The presence of reactive chlorine in butyl chlorate allows a variety of vulcanizing techniques, being the cure via sulfur, the most conventional. In these compounds carbon-halogen bonds are weaker than carbon-carbon and carbon-hydrogen bonds, and the main effect of radiation is to break the carbon-halogen bond to give an organic free radical. Irradiations of certain alkyl chlorides can bring about isomerism in which the location of the halogen atom is changed, the carbon skeleton of molecule remaining unaltered. Irradiation of n-butyl chlorides gives high yields of tertiary carbon. The major effect of high energy photon, such as gamma rays, in organic polymers is the generation of free radicals, along changes in mechanical properties. This work aims to the study of irradiation effect on mechanical properties of a sulfur cured chlorobutyl rubber compound, gamma irradiated within 25, 50, 100, 150 e 200 kGy doses range. The techniques used in their characterization were: strength - stress analysis and elasticity modulus. Results obtained were investigated, demonstrated and discussed. (author)

  20. Germination test for identification of gamma-irradiated bean seeds

    The feasibility of germination test for the practical detection of irradiated beans has not been investigated. The objective of this study was to determine if the relationship between the root growth rate and radiation dose could be used to produce a rapid analytical method for identification of irradiated beans. Such detection method could be potentially used for both (a) identification of irradiated food, and (b) for quarantine inspection (to certify that the agricultural product has been irradiated, and the pests present in it do not pose a quarantine risk). Results presented in this paper indicate that the germination test is not always capable of discriminating satisfactorily between irradiated and unirradiated samples of bean seeds, because the sensitivity of the test is often higher than the low doses which are suggested for disinfestation purposes. However, using the germination test, an unexperienced person can easily discriminate untreated bean seeds from those irradiated with 0.3-1.5 kGy doses of gamma radiation. (orig./vhe)

  1. Operation and maintenance of land-based stationary gamma irradiators

    The high intensity gamma irradiators designed and built in accordance with Atomic Energy Regulatory Board (AERB) Standard Specification (AERB-SS-6, 1993) provide adequate protection to the operating personnel and members of the public. In the event of any malfunction or failure of a component or a subsystem, radiological mishaps could occur. Such malfunction or failure shall be minimized by prompt servicing/maintenance. Further, the irradiator systems may malfunction or deteriorate if they are not operated strictly within the technical specifications and as per the prescribed procedures. Improper or inadequate servicing and maintenance coupled with incorrect operation of irradiator have in the past, led to serious accidents in some countries. These incidents highlight the importance of strict compliance with operating procedures, servicing/maintenance schedule as well as quality assurance in these. The safety requirements stipulated in this code have to be compiled with by operating organisation, servicing/maintenance personnel and operators for irradiators operated on commercial scale or for research and development. This code is applicable to class II, III and IV type of irradiators specified in the AERB Standard Specification AERB-SS-6, 1993. Safety practices to be adopted in operation, servicing/maintenance, decommissioning and emergency situations are specified in this code. These requirements pertain only to the radiological safety aspects of the irradiator. (author). 3 refs., 4 appendixes

  2. Development of shelf-stable meat sausages using gamma irradiation

    Irradiation techniques have been applied in development of ready to eat or shelf stable sausages. These sausages can be eaten directly without the need for prior heating or cooking procedure and displayed in the room temperature on the shelves of the retailers without frozen facilities. This study was designed to investigate the acceptability and microbial status of packed ready to eat sausages that had been sterilized using gamma irradiation at MINTec-Sinagama. Packed pre-cooked sausage samples (sealed in plastic-polyethylene individually) were irradiated with different doses of 2.5 kGy, 3.5 kGy and 5.5 kGy. Acceptability of the sausages was determined through sensory evaluation by 30 members of untrained panelists comprising of staffs of MINT. A 5 points hedonic rating scale was used. The attributes evaluated were rancidity, texture, chewiness, juiciness, aroma, colour, shape and overall acceptance. Samples irradiated with doses 3.5 kGy were the most acceptable followed by samples irradiated with doses 2.5 kGy and 5.5 kGy respectively. Irradiation with doses up to 2.5 kGy will virtually eliminate disease-causing microorganisms and pathogens. The total microbial count, detection of Salmonella, Escherichia coli, Staphylococcus aureus and fungi in these samples were determined and discussed. (Author)

  3. Degradation of poly(bisphenol-a-epichlorohydrin) by gamma irradiation

    In this study, radiation stability of poly(bisphenol-a-epichlorohydrin) (PBEH) was studied via gamma irradiations at two different dose rates of 1540 and 82.8 Gy/h, in order to understand the possible use of PBEH in radioactive waste management as a solidifying agent. The total dose of irradiation was up to 2150 kGy. Degradation nature was tested by studying the changes in mechanical and thermal properties with the change of dose rate and total dose of irradiation. Tensile strength at yield was increased first then decreased when irradiated, while toughness decreased. The half value dose (HVD) of elongation was found as 29 kGy at dose rate of 1540 Gy/h. The non-irradiated PBEH was transparent, and the color changed to yellow with irradiation. Mechanical tests showed that PBEH has high radiation stability although there were some structural changes. It was seen that PBEH is a candidate polymer to be used in the immobilization of radioactive waste regarding radiation stability

  4. Sulfur-containing components of gamma-irradiated garlic bulbs

    Joongho Kwon (Korea Advanced Energy Research Inst., Daeduk (Republic of Korea)); Jonguck Choi; Hyungsik Yoon (Kyungpook National Univ., Taegu (Republic of Korea))

    1989-01-01

    Sulfur-containing components associated with garlic flavors were investigated to determine the effect of {gamma}-irradiation at 0.1Gy on the quality of garlic bulbs (Allium sativum L.) during storage at 3{plus minus}1{sup 0}C and 80{plus minus}5% RH for 10 months. Irradiation treatment had no influence on the amount of total sulfur and thiosulfinate of stored garlic for 10 months, while the storage period brought about a significant reduction (P < 0.05) in the content of both components after the 6-8th month of storage compared with that at the beginning of storage period. The identity of irradiated alliin (S-allyl-L-cysteine sulfoxide) at sprout-inhibition dose was confirmed according to thin-layer chromatography, i.r. and NMR spectroscopy data. (author).

  5. Study on gamma irradiation of snail slime for cosmetic applications

    Snail slime is a product used by the cosmetic industry for skin regeneration. Due to its origin and obtaining method, prior to be commercialized, it requires to be exposed to a decontaminated procedure. Samples of snail slime were provided by the manufacturer and were treated with gamma irradiation doses of 2, 3 and 5 kGy. Microbiological, physico-chemical and organoleptic tests, indicated by the product specifications, were performed to the irradiated and control samples in order to determine the optimal decontamination dose. IR spectra of the irradiated samples and control were also obtained. It was determined that the minimum dose of 3 kGy was enough to achieve decontamination of the product without significant changes of the physico-chemical properties. Likewise, at 3 kGy, appearance, color and odour of snail slime remained almost unchanged. (author)

  6. Is Vitamin E Life Supporter for Gamma Irradiated Galleria Mollenella?

    This study conducted to determine the effect of vitamin E separate or combined with gamma ray in semi artificial diets on some biological aspects of the Greater wax moth, Galleria mellonella L. (Pyralidae : Lepidoptera). The increase in the average number of eggs per mated female for more than 70 % of the control in both treated male and female. Also, through the F1 generation (descendant of P1 progeny fed on artificial diet plus vitamin E) in either irradiated male or female at 100 and 300 Gy dose levels. The life supporter of vitamin E clearly demonstrates throughout F1 whose offspring fed on artificial diet plus Vitamin E, also more pronounced during the first generation treated with gamma irradiation (100 and 300 Gray) which descendant from the offspring were fed on the artificial diet containing Vitamin E (0.02%) than that treatments which treated with gamma irradiation only. The average weight of larvae and pupae significantly increase by using petroleum ether only or this may be abnormal. The average weight of larvae and pupae at the concentration 0.02% was 105.07 and 121.87 % from the control treatment, respectively then decreased to 67.86 and 75.12%, respectively from the control treatment at the concentration 0.04% and then increase at the two concentrations 0.06 and 0.08 %. The increase in weight gain in the case combined ( 100 Gy or 300 Gy with Vitamin E) more than in case using a single dose of gamma irradiation , the increase in case 300 Gy only or combined with Vitamin E more than the control treatment. The best result in case of Vitamin (E) only then when treated the pest with gamma radiation after Vitamin (E) and the effect at 100 Gy better than in case 300 Gy. The combined effect of sub sterilizing dose (300 Gy) and sterilizing doses (400 and 500 Gy) of gamma radiation and vitamin E on the mating competitiveness of F1 males G. Mellenella shows that the competitiveness values more than 1.0 at the combined VE and the two dose levels 400 and 500 Gy

  7. Improvement of saccharification process for bioethanol production from Undaria sp. by gamma irradiation

    Yoon, Minchul; Choi, Jong-il; Lee, Ju-Woon; Park, Don-Hee

    2012-08-01

    Recently, many research works have reported on improvements to the saccharification process that increase bioethanol production from cellulosic materials. Gamma irradiation has been studied as an effective method for the depolymerization of complex polysaccharides. In this study, the effect of gamma irradiation on saccharification of Undaria biomass for bioethanol production was investigated. The Undaria biomass was irradiated at doses of 0, 10, 50, 100, 200 and 500 kGy and then hydrolyzed using sulfuric acid. The effects of gamma irradiation were measured through microscopic analysis to determine morphological changes and concentration of the reducing sugar of hydrolysates. Microscopic images show that gamma irradiation causes structure breakage of the Undaria cell wall. The concentration of reducing sugar of hydrolysates significantly increased as a result of gamma irradiation, with or without acid hydrolysis. These results indicate that the combined method of gamma irradiation with acid hydrolysis can significantly improve the saccharification process for bioethanol production from marine algae materials.

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

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

  9. Effects of Gamma Irradiation on Antioxidant, Antimicrobial Activities and Physical Characteristics of Sargassum thunbergii Extract

    This study was carried out to determine the effect of gamma irradiation (3-20 kGy) on the antioxidant, antimicrobial activities and physical characteristics of Sargassum thunbergii (ST) extracts. When ST powder was treated by gamma irradiation, the yields and total phenolic compounds (TPC) of water extracts were increased, but radical scavenging activities were not changed. When ST extract was irradiated, the TPC and DPPH radical scavenging activities were increased. In addition, gamma irradiation of ST extract decreased viscosity and removed color. These results suggest that gamma irradiation would be a useful method for improving the physical characteristics of ST extract while maintaining native biological activities

  10. Influence of gamma irradiation on carbon nanotube-reinforced polypropylene.

    Castell, P; Medel, F J; Martinez, M T; Puértolas, J A

    2009-10-01

    Single walled carbon nanotubes (SWNT) have been incorporated into a polypropylene (PP) matrix in different concentrations (range: 0.25-2.5 wt%). The nanotubes were blended with PP particles (approximately 500 microm in size) before mixing in an extruder. Finally, rectangular plates were obtained by compression moulding. PP-SWNT composites were gamma irradiated at different doses, 10 and 20 kGy, to promote crosslinking in the matrix and potentially enhance the interaction between nanotubes and PP. Extensive thermal, structural and mechanical characterization was conducted by means of DSC, X-ray diffraction, Raman spectroscopy, uniaxial tensile tests and dynamic mechanical thermal (DMTA) techniques. DSC thermograms reflected higher crystallinity with increasing nanotube concentration. XRD analysis confirmed the only presence of a monoclinic crystals and proved unambiguously that CNTs generated a preferred orientation. Raman spectroscopy confirmed that the intercalation of the polymer between bundles is favored at low CNTs contents. Elastic modulus results confirmed the reinforcement of the polypropylene matrix with increasing SWNT concentration, although stiffness saturation was observed at the highest concentration. Loss tangent DMTA curves showed three transitions for raw polypropylene. While gamma relaxation remained practically unchanged in all the samples, beta relaxation temperatures showed an increase with increasing CNT content due to the reduced mobility of the system. Gamma-irradiated PP exhibited an increase in the beta relaxation temperature, associated with changes in glass transition due to radiation-induced crosslinking. On the contrary, gamma-irradiated nanocomposites did not show this effect probably due to the reaction of radiative free radicals with CNTs. PMID:19908494

  11. EPR investigations of gamma-irradiated ground black pepper

    Polovka, Martin [Department of Chemical Technology of Wood, Pulp and Paper, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava (Slovakia); Brezova, Vlasta [Department of Physical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava (Slovakia)]. E-mail: vlasta.brezova@stuba.sk; Stasko, Andrej [Department of Physical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava (Slovakia); Mazur, Milan [Department of Physical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Radlinskeho 9, SK-812 37 Bratislava (Slovakia); Suhaj, Milan [Food Research Institute, Priemyselna 4, P.O. Box 25, SK-824 75 Bratislava (Slovakia); Simko, Peter [Food Research Institute, Priemyselna 4, P.O. Box 25, SK-824 75 Bratislava (Slovakia)

    2006-02-15

    The {gamma}-radiation treatment of ground black pepper samples resulted in the production of three paramagnetic species (GI-GIII) which arise from a different origin and have different thermal behavior and stability. The axially symmetric spectra can be characterized by the spin Hamiltonian parameters: GI (g{sub -}bar =2.0060, g{sub -}bar =2.0032; A{sub -}bar =0.85mT, A{sub -}bar =0.70mT) and GII (g{sub -}bar =2.0060, g{sub -}bar =2.0050; A{sub -}bar =0.50mT, A{sub -}bar =0.40mT) assigned to carbohydrate radical structures. The parameters of EPR signal GIII (g{sub -}bar =2.0029, g{sub -}bar =2.0014; A{sub -}bar =3.00mT, A{sub -}bar =1.80mT) possessed features characteristic of cellulose radical species. The activation energies, evaluated by Arrhenius analysis, are in order E{sub a}(GI)gamma}-irradiated samples ({approx}40%), compared to the reference (non-irradiated) ground black pepper, where a decrease of {approx}13% was found. The influence of {gamma}-radiation treatment on the radical-scavenging activities of aqueous and ethanol extracts of black pepper were investigated by both an EPR spin trapping technique and DPPH assay. No changes were detected in either the water or ethanol extracts for a {gamma}-irradiation dose of 10kGy.

  12. Effect of gamma irradiation on olive leaves and application on meat products

    The gamma irradiation is a high technology in the treatment of food product, for this reason we have been interested to study the effect of gamma irradiation on microbial charge (Bioburden), the phenolics compounds and their antioxidant activities on the olive leaves. The irradiated olive leaves are added as an antimicrobial and antioxidant compound on minced meat for preservation.

  13. Physiological characteristics of cucumber seed production plants by presowing laser and gamma irradiation

    Seeds from G-3 maternal line of hybrid cucumber cultivar Pobeda F1 were treated with helium-neon 632.8 nm laser-exit power 20 mW and gamma-rays (60Co) in a field experiment under conditions suitable for hybrid seed production. The irradiation was carried out a week before sowing and the following variants were investigated: 1. sevenfold laser irradiation; 2. 10 Gy gamma irradiation; 3. combined laser + gamma rays irradiation. Seeds from the parent line were not irradiated. A positive effect of irradiation on the photosynthetic intensity, content of plastid pigments in leaves and activity of catalase and peroxidase has been observed. (author)

  14. Effect of gamma irradiation on proteins of some agricultural products

    Soybean and broad bean were exposed to gamma rays at dose levels of 10 ,30 and 50 KGy. Some chemical changes were studied in beans such as chemical composition, total amino acids, protein electrophoresis and trypsin inhibitor. Also irradiated beans were used as a sole source of protein in feeding rats. Some parameters were studied such as, true growth rate, food intake, protein efficiency ratio, true protein digestibility, biological value, serum total protein and serum albumin . The results indicated that irradiation treatments, did n't cause any obvious effects on the chemical composition . Also, no changes were shown in the number of protein bands. A little difference was observed in the bands density. Irradiation doses caused variable results with the majority of the amino acids, but they led to a gradual reduction in the activity of trypsin inhibitor. Moreover, the irradiation treatments caused an increased food intake. The rats growth rates, protein efficiency ratio, true protein digestibility and protein biological values were increased as the irradiation dose increased, but serum total protein and serum albumin were not affected

  15. Effect of gamma irradiation on textile waste water

    This paper studies the use of gamma irradiation for textile waste water treatment. Prior to irradiation, the raw wastewater was diluted to using tap water to targeted concentration of COD 400 mg/ l. The sample was irradiated at selected dose between the ranges of 2 kGy to 100 kGy. The results showed that Irradiation was effective in removing the highly colored refractory organic pollutants. The degree of removal influenced by the dose introduced during the treatment process. As the dose increased, higher removal of organic pollutant was recorded. The COD removal at lowest dose, 2 kGy is about 310 mg/ l. Meanwhile, at highest dose, 100 kGy the COD reduced to 100 mg/ l. On the other hand, other properties of the wastewater such as pH, turbidity, suspended solid, BOD and color shows tremendous changes as the dose increases. This showed the concentration of pollutants and dose of irradiation applied are directly proportional to each other. (author)

  16. Reduction of pathogenic bacteria in organic compost using gamma irradiation

    Organic compost is a useful fertilizer for organic farming. However, it poses a microbiological hazard to the farm products because most of the composts are originated from excremental matters of domestic animals. In this study, the radiation treatment was performed to improve microbiological safety of organic compost and the effectiveness of gamma irradiation for inactivating Salmonella Typhimurium and Escherichia coli was investigated. The total aerobic and coliform bacteria in the 16 commercial composts were ranged from 105 to 107 CFU/ml and 0 to 103 CFU/ml, respectively. All coliform bacteria in the composts were eliminated by irradiation at a dose of 3 kGy, while about 102 CFU/ml of the total aerobic bacteria were survived up to 10 kGy. In the artificial inoculation test, the test organisms (inoculated at 107 CFU/g) were eliminated by irradiation at 3 kGy. Approximate D10 values of Salmonella Typhimurium and E. coli in the compost were 0.40 and 0.25 kGy, respectively. In the cultivation test, the test organisms of the compost had transfer a lettuce leaves. The growth pattern of lettuce was not different between irradiated and non-irradiated composts

  17. Effect of gamma irradiation on textile waste water

    This paper studies the use of gamma irradiation for textile waste water treatment. Prior to irradiation, the raw waste water was diluted using tap water to targeted concentration of COD 400 mg/l. The sample was irradiated at selected dose between the ranges of 2 kGy to 100 kGy. The results showed that Irradiation was effective in removing the highly colored refractory organic pollutants. The COD removal at lowest dose, 2 kGy is about 310 mg/l. Meanwhile, at highest dose, 100 kGy the COD reduced to 100 mg/l. The degree of removal influenced by the dose introduced during the treatment process. As the dose increased, higher removal of organic pollutant was recorded. On the other hand, other properties of the wastewater such as pH, turbidity, suspended solid, BOD and color shows tremendous changes as the dose increases. This shows the concentration of pollutants and dose of irradiation applied are directly proportional to each other. (Author)

  18. Color changes of vienna sausage by gamma irradiation

    Color change of vienna sausage induced by gamma irradiation was investigated. Discoloration of irradiated vienna sausage was evaluated by use of the color difference meter and sensory test. The discoloration by irradiation was influenced by oxygen contents in packing pouches. In the case of commercial vienna sausage, significant difference from unirradiated control by 99% of probability was recognized at the doses of 1.0 Mrad in nitrogen, 0.5 Mrad in air and 0.3 Mrad in oxygen, respectively. The color change of the specially prepared vienna sausage (40% pork, 40% mutton, 20% beef, and no additional preservatives) was less than that of the commercial one. The absorbance at 540 nm of extracts from vienna sausages with 80% acetone decreased with increasing irradiation dose and oxygen content. While, change in absorbance at 340 nm was practically unaffected by the oxygen concentration. These results suggest that the degradation of nitroso-heme complex by irradiation causes mainly the discoloration of vienna sausage. (auth.)

  19. Elimination of salmonella from fermented pork by gamma irradiation

    A fermented pork product, locally known as ''Nham'', is usually contaminated with salmonella and occasionally with Trichinella spiralis and Taenea solium. This product is always eaten raw as cooking destroys its delicate flavour. A survey made on the MPN of salmonella revealed that much less than 100 salmonella was found in one gram of the product. Nham was inoculated with S. derby, S. anatum, S. newport, or S. paratyphi B, the most common serotypes of salmonella found in this product, at 106, 104, or 102 per gram. The inoculated product was irradiated by the gamma beam-650 Co-60 irradiator at 0, 0.1, 0.2, 0.3 or 0.4 Mrad. Dosage at 0.4 Mrad eliminated salmonella as much as 106 per g; 0.3 Mrad eliminated 106/g of S. newport and S. paratyphi B and 104/g of S. derby and S. anatum; and 0.2 Mrad eliminated 102/g of all serotypes of salmonella in the product. No changes in the organoleptic properties of irradiated Nham was found when irradiated at 0.3 Mrad or less. Dosage at 0.2 Mrad appeared to be sufficient for commercial irradiation of Nham for the elimination of salmonella

  20. Effect of gamma irradiation on the behavioral properties of crotoxin

    E.G. Moreira

    1997-02-01

    Full Text Available Crotoxin has been detoxified with gamma radiation in order to improve crotalic antiserum production. Nevertheless, present knowledge of the biological characteristics of irradiated crotoxin is insufficient to propose it as an immunizing agent. Crotoxin is known to increase the emotional state of rats and to decrease their exploratory behavior (Moreira EG, Nascimento N, Rosa GJM, Rogero JR and Vassilieff VS (1996 Brazilian Journal of Medical and Biological Research, 29: 629-632. Therefore, we decided 1 to evaluate the effects of crotoxin in the social interaction test, which has been widely used for the evaluation of anxiogenic drugs, and 2 to determine if irradiated crotoxin induces behavioral alterations similar to those of crotoxin in the social interaction, open-field and hole-board tests. Male Wistar rats (180-220 g were used. Crotoxin (100, 250, and 500 µg/kg was injected intraperitoneally 2 h before the social interaction test. Similarly, irradiated crotoxin (2000 Gy gamma radiation from a 60Co source was administered at the doses of 100, 250, and 500 µg/kg for the hole-board test, and at the doses of 1000 and 2500 µg/kg for the open-field and social interaction tests. ANOVA complemented with the Dunnett test was used for statistical analysis (P<0.05. Crotoxin decreased the social interaction time (s at the doses of 100, 250 and 500 µg/kg (means ± SEM from 51.6 ± 4.4 to 32.6 ± 3.7, 28.0 ± 3.6 and 31.6 ± 4.4, respectively. Irradiated crotoxin did not induce behavioral alterations. These results indicate that 1 crotoxin may be an anxiogenic compound, and 2 in contrast to crotoxin, irradiated crotoxin was unable to induce behavioral alterations, which makes it a promising compound for the production of crotalic antiserum

  1. Sensory evaluation of gamma irradiated coconut cream powder

    A study was conducted to determine the effect of gamma irradiation (5, 10 and 15kGy) and storage on the sensory quality of coconut cream powder. Ageing process was achieved using GEER oven at 60 degree C for seven days, which is equivalent to one-year storage at room temperature. The sensory evaluation was conducted to determine the level of acceptance on four parameters, namely odour, colour, creamy taste and overall acceptance. Twenty (20) taste panelists gave their score from scale] (least acceptable) to 5 (most acceptable). The results showed that there was a significant different (P 0. 05) in all the sensory properties. The sensory evaluation of stored samples showed that there was significant different (P>0.05) in odour, creamy taste, colour and overall acceptance compared to the control. Based on the overall acceptance, gamma irradiation as low as 5 kGy could affect the sensory quality of coconut cream powder. The possibility of using doses lower than 5 kGy for decontamination of coconut cream powder could be considered in the future study. The irradiated product was not acceptable after one-year storage. (Author)

  2. Effect of gamma-irradiation and subsequent recovery in vitro

    The callus cells of Vicia faba L. were irradiated with gamma ray up to 8 kR, and the effect on the calli immediately after the irradiation and during recovery was investigated. The studies were done on the growth, cytology, morphology and rhizogenetic behavior of the calli. Recovery was possible up to 4 kR, and whereas the effect seemed to depend on dose in all cases, the recovery appeared to be independent of dosage up to the limit of 4 kR. Significant difference was not observed among regenerated roots. The change in the structure of chromosomes was observed in older calli. Though chemical mutagens are more extensively used for inducing mutation in the plant tissues in culture, physical mutagens have certain advantages over chemical mutagens, and can provide information on cell growth behavior, its radio-sensitivity and the induction of mutation. Vicia faba is a suitable material to both in vivo and in vitro tests, and its large chromosomes seem to be very suitable to cytological studies. Therefore in this study, the nature of growth, the morphological variation and behavior of the chromosomes of the callus cells of Vicia fabe L. immediately after gamma irradiation and during recovery were examined. (Kako, I.)

  3. The effects of gamma irradiation on blood and its components

    Although people belonging to the high-risk categories for infectious diseases have been asked not to donate blood, and donor blood is being tested by the most sensitive methods before distribution, viral hepatitis and acquired immuno deficiency syndrome (AIDS) transmissions by blood transfusion continue to be documented. Transmission may occur by false negative tests and the so-called ''window period'' of AIDS. The objective of this study was to determine the feasibility of application of gamma radiation sterilization to blood and its components by investigating possible alterations of important components of blood after irradiation. With the doses of 2.5-25 kGray, whole blood (WB) and freeze-dried plasma (FDP) were irradiated at 4 C and fresh frozen plasma (FFP) was irradiated at dry-ice temperature (-78.5C). There was no significant difference in the amount of sugar, protein, albumin and pH in WB, FDP, FFP and sodium, potassium in plasma between non-irradiated and irradiated samples (p>0.05). No appreciable difference of coagulation factors in FDP and FFP was noted before and after irradiation. In whole blood, the amount of plasma hemoglobin increased and blood cells decreased. There was an obvious decrease of sodium and increase of potassium in plasma from irradiated whole blood even with 2.5 kGy. The data of this study indicates that application of radiation sterilization to plasma, both freeze-dried and frozen, is possible when the proper conditions are applied. Whole blood, however, needs more data to evaluate this possibility

  4. Degradation of dibutyl phthalate in water by the aid of metals under {gamma}-ray irradiation

    Yoshida, Tomoko; Tanabe, Tetsuo [Nagoya Univ., Center for Integrated Research in Science and Engineering, Nagoya, Aichi (Japan); Miyashita, Yoshinori; Yoshida, Hisao; Hattori, Tadashi [Nagoya Univ., Department of Applied Chemistry, Nagoya, Aichi (Japan)

    2001-09-01

    The degradation of dibutyl phthalate (DBP), one of endocrine disrupters, by {gamma}-ray irradiation was enhanced by the effective energy conversion of {gamma}-ray through the interaction with some kind of metal materials. (author)

  5. Radiative accidental matter

    Sierra, D Aristizabal; Wegman, D

    2016-01-01

    Accidental matter models are scenarios where the beyond-the-standard model physics preserves all the standard model accidental and approximate symmetries up to a cutoff scale related with lepton number violation. We study such scenarios assuming that the new physics plays an active role in neutrino mass generation, and show that this unavoidably leads to radiatively induced neutrino masses. We systematically classify all possible models and determine their viability by studying electroweak precision data, big bang nucleosynthesis and electroweak perturbativity, finding that the latter places the most stringent constraints on the mass spectra. These results allow the identification of minimal radiative accidental matter models for which perturbativity is lost at high scales. We calculate radiative charged-lepton flavor violating processes in these setups, and show that $\\mu\\to e \\gamma$ has a rate well within MEG sensitivity provided the lepton-number violating scale is at or below $10^6\\,$ GeV, a value (natur...

  6. Effect of gamma-irradiation defects on ferroelectric phase transitions of TGSe and DTGSs crystals

    Song, Y W

    1999-01-01

    The influence of gamma-irradiation defects upon the second-order phase transition in TGSe and the first-order phase transition in DTGSe crystals was studied by means of specific-heat measurements. gamma-irradiation defects changed the behavior of the thermodynamic properties, and the order of the phase transition was changed from the first to the second in the DTGSe crystal. The kinetics of gamma-irradiation defects was studied.

  7. Effect of gamma irradiation on antioxidant activity of Amoora rohitaka

    The effect of a medium dose of gamma radiation on antioxidant activity of Amoora rohitaka was studied. Radiation doses were 0, 1, 3 and 5 kGy. Antioxidant activity was screened by using different assay. With increasing dose the formation of Maillard reaction products (MRPs) contributes to the increase in the antioxidant activity. MRPs are formed as a result of Maillard reaction. In ABTS [2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid di-ammonium salt] assay, ethanol extract showed increase in scavenging activity. It also showed a marked increase in polyphenolic contents. The present study reveals that gamma irradiation can be an efficient process to increase antioxidant activity of Amoora rohitaka. (author)

  8. Optical fiber sensor for low dose gamma irradiation monitoring

    de Andrés, Ana I.; Esteban, Ã.`scar; Embid, Miguel

    2016-05-01

    An optical fiber gamma ray detector is presented in this work. It is based on a Terbium doped Gadolinium Oxysulfide (Gd2O2S:Tb) scintillating powder which cover a chemically etched polymer fiber tip. This etching improves the fluorescence gathering by the optical fiber. The final diameter has been selected to fulfill the trade-off between light gathering and mechanical strength. Powder has been encapsulated inside a microtube where the fiber tip is immersed. The sensor has been irradiated with different air Kerma doses up to 2 Gy/h with a 137Cs source, and the spectral distribution of the fluorescence intensity has been recorded in a commercial grade CCD spectrometer. The obtained signal-to-noise ratio is good enough even for low doses, which has allowed to reduce the integration time in the spectrometer. The presented results show the feasibility for using low cost equipment to detect/measure ionizing radiation as gamma rays are.

  9. Gamma and neutron irradiation tests on commercial IC op amps

    Experimental results of gamma and neutron irradiation tests on 30 types of integrated-circuit operational amplifiers from 11 manufacturers are presented. All units were low-cost, commercial-grade devices. Op amps were evaluated for changes in offset voltage, input bias current, power supply current, open-loop gain, gain-bandwidth product, slew rate, power-supply and common-mode rejection ratios. Bipolar transistor op amps with resistive collector load resistors for the input stage indicated the best radiation hardness

  10. EPR studies of gamma-irradiated taurine single crystals

    Bulut, A. E-mail: abulut@samsun.omu.edu.tr; Karabulut, B.; Tapramaz, R.; Koeksal, F

    2000-04-01

    An EPR study of gamma-irradiated taurine [C{sub 2}H{sub 7}NO{sub 3}S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of {sup 32}SO{sup -}{sub 2} and {sup 33}SO{sup -}{sub 2} radicals. The hyperfine values of {sup 33}SO{sup -}{sub 2} radical were used to obtain O-S-O bond angle for both sites.

  11. EPR studies of gamma-irradiated taurine single crystals

    Bulut, A.; Karabulut, B.; Tapramaz, R.; Köksal, F.

    2000-04-01

    An EPR study of gamma-irradiated taurine [C 2H 7NO 3S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of 32ṠO -2 and 33ṠO -2 radicals. The hyperfine values of 33ṠO -2 radical were used to obtain O-S-O bond angle for both sites.

  12. EPR studies of gamma-irradiated taurine single crystals

    An EPR study of gamma-irradiated taurine [C2H7NO3S] single crystal was carried out at room temperature. The EPR spectra were recorded in the three at mutually perpendicular planes. There are two magnetically distinct sites in monoclinic lattice. The principle values of g and hyperfine constants for both sites were calculated. The results have indicated the presence of 32SO-2 and 33SO-2 radicals. The hyperfine values of 33SO-2 radical were used to obtain O-S-O bond angle for both sites

  13. Resistance of some common fungi to gamma irradiation

    Ten species of fungi representing the genera Alternaria, Aspergillus, Caldosporium, Curvularia, Fusarium, and Penicillium were examined for their relative resistance to gamma irradiation from a 137Cs source. Inactivation doses for dematiaceous fungi in agar medium ranged from 0.6 to greater than 1.7 megarads, whereas those for moniliaceous fungi were less than 0.3 megarad. D10 values (the dose required to reduce the inoculum by 1 log) for Curvularia geniculata (greater than 0.29 megarad) exceeded those for control spores of Bacillus pumilus (0.15 megarad)

  14. Synthesis of copper polyacrylate nanocomposites by gamma irradiation

    This research involves the synthesis of copper nanoparticles with controlled size by the application of gamma radiation with varying polyacrylic acid (PAA) and CuSO4 concentration. An alternative and convenient method was done which employs Co60 irradiation of solutions of copper salt and PAA with irradiation dose of 1.6, 3.6, 6.4, and 9.2 MRad. The effect of polymer and copper sulfate's initial concentrations as well as the effect of the presence of alcohol as radical scavenger and the presence of ethylenediaminetetraacetic acid as stabilizer were evaluated. Characterization of nanocomposite properties such as plasmon resonance band, fluorescence, and particle morphology and size were determined. Layer-by-layer assembly of Cu-PAA nanocomposites and polydiallyl dimethyl ammonium chloride (PDDA) was also constructed. Stability of the synthesized copper-PAA nanocomposites in terms of the disappearance of plasmon band with time was evaluated. (Author)

  15. Gamma irradiation of starch samples contaminated with anaerobic germs

    Starch samples were mixed with spores of Clostridium botulinum and Clostridium perfringens and irradiated with 60Co γ-rays of different intensities. The radiosensitivity and the survival rates of the spores were determined. Of the starch samples examined only a small part contained spores of mesophilic Clostridia. None of the samples showed signs of presence of rigidly thermophilic varieties and of Clostridium botulinum or Clostridium perfringens. 14 groups of germs were isolated from the dry products of starch industry. At least one germ group showed an activation phenomenon and a probable survival rate of 300% at 75 krad. This is true for the germ group which appears most frequently with starch and can be identified as Clostridium sporogenes. Gamma irradiation does not neutralize lysozyme dependence of the Clostridium perfringens germ which has this property. With a few reservations the standards for germ content which have been set for Bacillus spores can be also used for Clostridium spores. (orig./AJ)

  16. Gamma irradiation of unsaturated hydrocarbons in presence of hydrogen

    Only small increases in yield (G values) of saturated products are observed in the irradiation with 60Co gamma radiation, of ethylene and 1-butene. The values obtained are: G(C2H6)=0,3-0,4 (for ethylene/H2) and G(n-C4H10)=2,1 (for 1-butene/H2), with total dose of 8 to 9.1019 eV. In a similar irradiation of acetylene in presence of hydrogen, ethylene was obtained with relatively high G-values: G=5,4 for a dose of 2.1018 eV G=17,5 for 2,5x1019 eV and G=8,4 for 2,3.1020 eV. Benzene yield shows some increases (G=6,6-9,1) in relation to values in absence of hydrogen. (author)

  17. Chemical constituents of Panax ginseng exposed to. gamma. irradiation

    Kwon, Joongho; Belanger, J.M.R.; Sigouin, M.; Lanthier, J.; Willemot, C.; Pare, J.R.J. (Agriculture Canada, Saint-Hyacinthe, Quebec (Canada))

    1990-03-01

    Chemical constituents were monitored to assess the biochemical and nutritional safety of Panax ginseng powders that were irradiated at doses of 1-10 kGy. Quantitative analysis has shown that the main effective components - saponins - are not altered by {sup 60}Co {gamma} irradiation. Ginsenoside-Rg{sub 1} was not affected by the treatment. Negligible changes were observed in the free carbohydrate contents. Doses of more than 5 kGy caused significant decreases in sulfur-containing amino acids and in tyrosine. At doses of 10 kGy, free amino acids, such as proline and lysine, showed an appreciable increase. The composition in minerals was not altered irrespective of the applied doses.

  18. Effect of gamma irradiation on khapra beetle Trogoderma granarium everts

    The effect of gamma irradiation on all developmental stages of khapra beetle was examined. The results showed that when higher doses were applied and immature stages were treated the developmental time, larval and pupal mortality and adults' deformation were increased. Whereas, the fecundity and fertility of the emerged adults resulted from the treatment of immature stages, were increased when old eggs, larvae and pupae were treated with low doses. When newly emerged adults were irradiated the longevity of the male and the female was not affected, while the fecundity and fertility were declined especially when high doses were applied. The female of khapra beetle was more radiosensitive than the male, regardless of the applied dose or/and the treated developmental stage. (author)

  19. Gamma irradiation studies on Gladiolus cv. White Friendship

    Dormant corms of Gladiolus cv. White Friendship were irradiated with 250, 500, 750, 1000 and 1250 Gy of gamma rays. Reduction in survival, plant height, number of leaves and floret, spike length, leaf and corm size and delayed flowering were recorded after irradiation. Morphological abnormalities in foliage and florets and chromosomal aberration during root tip mitosis increased with increase in exposure. Flowering was ceased cent per cent in highest dose of 1250 Gy. LD50 on survival basis was found in 750 Gy exposure. MV2 and MV3 also followed the similar pattern of results as exhibited by MV1 plants. Pink flower colour mutation was detected in few plants as sectorial chimeric form in MV2 in treated population. In MV3 one plant produced spike with lighter pink florets in 750 Gy treatment. This mutant has been isolated in pure form. (author). 10 refs., 2 figs., 2 tabs

  20. Gamma-irradiated cationic starches: Paper surface-sizing agents

    Cationic starches, precisely depolymerized by gamma-irradiation (60Co), were dispersed in mild alkali and evaluated as surface sizes for bond paper on a pilot paper machine. The irradiated products had excellent dispersion properties, were well retained on fibers when sized wastepaper (broke) was repulped and had an ability to enhance paper properties that was comparable to that of starch-based materials used commercially. A yellow corn flour, cationized by an essentially dry reaction process recently developed at this Center, was also radiolyzed and evaluated as a size. This latter product was unique in that all drying steps were eliminated in the preparation of a cationic ceral product of reduced viscosity. (orig.)

  1. Modification of ethylene-norbornene copolymer by Gamma irradiation

    Kačarević-Popović Zorica M.

    2006-01-01

    Full Text Available The possibility of modifying polyethylene and many other polymers with high energy radiation has led to many useful applications. Due to their new combination of properties and the shortage of experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC, polymerised from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and the physics of polymeric systems. Ethylenenorbornene copolymer, pristine and containing an antioxidant were subjected to gamma irradiation in the presence of air and in water. The irradiated copolymer was studied using IR and UV-vis spectrophotometric analysis. The radiation-induced changes in the molecular structure were correlated to changes in the glass transition temperature measured by the DSC method.

  2. Gamma irradiation in developing consumer friendly lip balm

    Main base ingredients of lip balm such as petroleum jelly and coloring materials are harmful to customers. Side effects from impurities in petroleum jelly in the manufacturing process have been implicated at causing cancer and long term damage to health. Artificial colours have been found to cause cancer in animals and many people experienced allergic reactions i.e. skin irritation and contact dermatitis. Therefore 'friendly' lip balm was formulated by substituting the base ingredient, i.e. petroleum jelly, with vegetable fats and incorporated with anthocyanin pigments from Hibiscus sabdariffa L. (roselle) and Brassica oleracea var. capitata f. rubra (red cabbage) as natural colorants. Anthocyanins are considered secondary metabolites, allowed as food additives and act as powerful antioxidants. The herbal lip balm samples were gamma irradiated (2.5, 5.0 and 10 kGy) at Mintec SINAGAMA, Malaysian Nuclear Agency, Bangi. The samples were tested for microbiology quality i.e. total microbial count and presence of yeast and mold. The results showed that there were no microbial and yeast/mold colonies were detected in non-irradiated samples (control) and after irradiation. The essential oils from herbs and spices included in the herbal lip balms not only improve the taste and aroma but also had potential as natural preservatives due to their antibacterial properties. Gamma irradiation at dose 2.5 kGy was suitable as minimum dose to decontaminate the herbal lip balm without affecting the colour and texture. From market survey, friendly lip balm is considered as a safe and attractive product, with multifunctional uses i.e. to prevent chapped lips, freshen the breath, reduces mouth odour and contributes to improving general health quality. (Author)

  3. Irradiated Microsphere Gamma Analyzer for Examination of Particle Fuel

    Paul A. Demkowicz; Various

    2014-06-01

    Fabrication of the first series of fuel compacts for the current US tristructural isotropic (TRISO) coated particle fuel development and qualification effort was completed at Oak Ridge National Laboratory (ORNL) in 2006. In November of 2009, after almost 3 years and 620 effective full power days of irradiation in the Advanced Test Reactor at Idaho National Laboratory (INL), the first Advanced Gas Reactor irradiation test (AGR-1) was concluded. Compacts were irradiated at a calculated timeaveraged, volume-averaged temperature of 955–1136°C to a burnup ranging from 11.2–19.5% fissions per initial metal atom and a total fast fluence of 2.2–4.3·1025 n/m2 [1]. No indication of fission product release from TRISO coating failure was observed during the irradiation test, based on real-time monitoring of gaseous fission products. Post-irradiation examination (PIE) and hightemperature safety testing of the compacts has been in progress at both ORNL and INL since 2010, and have revealed small releases of a limited subset of fission products (such as silver, cesium, and europium). Past experience has shown that some elements can be released from TRISO particles when a defect forms in the SiC layer, even when one or more pyrocarbon layers remain intact and retain the gaseous fission products. Some volatile elements can also be released by diffusion through an intact SiC layer during safety testing if temperatures are high enough and the duration is long enough. In order to understand and quantify the release of certain radioactive fission products, it is sometimes necessary to individually examine each of the more than 4000 coated particles in a given compact. The Advanced Irradiated Microsphere Gamma Analyzer (Advanced- IMGA) was designed to perform this task in a remote hot cell environment. This paper describes the Advanced- IMGA equipment and examination process and gives results for a typical full compact evaluation.

  4. The Use Of GAMMA Irradiation To Produce Drought Resistant Rices

    Rice is one of the most important food crops for human. Among factors such as climate, soil, weed and pest, drought is a major constraint to the rice production. Therefore, besides the production of high yield, the development of drought resistant rice for upland is a practical sense requirement. C71 is the blast resistant cultivar having good quality and has been widely grown in Northern provinces. However, its drought resistance is at intermediate level. In this paper, we present the results on the use of gamma irradiation in production of drought resistant mutants in C71 rice cultivar with an attempt to develop this cultivar for water-limited prone. The dry seeds of C71 were irradiated with the doses of 10, 15, 20, 25, 30, 35 and 40 krad. After irradiation, the seeds were germinated, and 10 days-old seedlings were treated with PEG 6000 for artificial drought screening. The results on PEG treatments, showed that the survival percentages of irradiated lines were increased comparing to the control lines. The molecular analysis indicated that there were alterations in the genome of the obtained rice lines. The lines could be useful material for development of drought resistant rice. (author)

  5. EPR study on non- and gamma-irradiated herbal pills

    Aleksieva, K.; Lagunov, O.; Dimov, K.; Yordanov, N. D.

    2011-06-01

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  6. Concomitant Effects of Caffeine and Gamma Irradiation in Female Rats

    The present study was undertaken to evaluate the protective potential of caffeine as an antioxidant (80 mg/kg b.w.) i.p. injected 1 hr before exposure to a dose of (7 Gy) gamma irradiation in female rats. Alterations in serum lipids, cholesterol, triacylglycerol and fatty acids as well as total proteins, urea and uric acid have been investigated 1, 3 and 7 days post irradiation and /or caffeine treatment. Histological and histochemical changes of the dorsal aorta have been studied 7 days post treatment. Results revealed elevated total lipids, cholesterol, triacylglycerol, beside distortion in fatty acids throughout the whole experimentation period by caffeine pre injection, irradiation application and by dual treatment. Protein and urea were elevated by caffeine or irradiation, while both treatments dropped their levels, whereas uric was decreased by all treatments. Histopathological changes and deposition of sudanophilic material in the dorsal aorta wall were detected by either one or both treatments, which point out a limitation in the protective potential of caffeine

  7. Thermoluminescence in gamma irradiated iPP-VGVGCNF

    Nanocomposites have been obtained by dispersing various amounts of vapor grown carbon nanofibers within isotactic polypropylene via melt mixing. The as obtained nanocomposites were gamma irradiated at various integral doses by using a 60Co source. The irradiation was performed in air, at room temperature, and at a dose rate of about 1 kGy/h up to an integral dose of 28 kGy. Thermoluminescence investigations revealed the role of carbon nanotubes in the radiation-induced modification of polymer-based nanocomposites. Almost all samples (pristine polymer and polymer-based nanocomposites irradiated and not irradiated) showed two overlapping thermoluminescence signals. It is concluded that the dispersion of carbon nanotubes decreases the amount of trapped electrons improving eventually the radiation stability of the polymeric matrix. The low temperature thermoluminescence peak was tentatively associated to melting phenomena. The origin of the high temperature thermoluminescence peak is more complex. Nevertheless, the experimental data suggests that this peak is sensitive to the polymer-filler interface.

  8. Thermoluminescence in gamma irradiated iPP-VGVGCNF

    Cherestes, Margareta [S. C. Dozimed SRL, Bucharest (Romania); Constantinescu, Livia Maria [University of Bucharest, Faculty of Physics, Magurele, Bucharest (Romania); Chipara, Dorina Magdalena, E-mail: dchipara@utpa.edu [The University of Texas Pan-American, Department of Physics and Geology, Edinburg, TX 78539 (United States); Cherestes, Codrut [S. C. Dozimed SRL, Bucharest (Romania); Chipara, Mircea [The University of Texas Pan-American, Department of Physics and Geology, Edinburg, TX 78539 (United States)

    2013-06-15

    Nanocomposites have been obtained by dispersing various amounts of vapor grown carbon nanofibers within isotactic polypropylene via melt mixing. The as obtained nanocomposites were gamma irradiated at various integral doses by using a {sup 60}Co source. The irradiation was performed in air, at room temperature, and at a dose rate of about 1 kGy/h up to an integral dose of 28 kGy. Thermoluminescence investigations revealed the role of carbon nanotubes in the radiation-induced modification of polymer-based nanocomposites. Almost all samples (pristine polymer and polymer-based nanocomposites irradiated and not irradiated) showed two overlapping thermoluminescence signals. It is concluded that the dispersion of carbon nanotubes decreases the amount of trapped electrons improving eventually the radiation stability of the polymeric matrix. The low temperature thermoluminescence peak was tentatively associated to melting phenomena. The origin of the high temperature thermoluminescence peak is more complex. Nevertheless, the experimental data suggests that this peak is sensitive to the polymer-filler interface.

  9. Dose measurements at the Philippine multipurpose gamma irradiation facility

    The Philippine Nuclear Research Institute has recently set up a pilot scale multipurpose gamma irradiation facility. In January 1989, the irradiator was initially loaded with 1 PBq 60Co. Dosimetry measurements made during the commissioning and routine operation of the facility are described. Different dosimeter systems such as ethanol monochlorobenzene, red 4034 Perspex, potassium dichromate, GAMMACHROME YR and FWT-60 radiochromic film were used. The dosimeters were calibrated against a Fricke dosimeter. To determine the dose distribution in air, dosimeters were placed on polystyrene sheets, which were positioned at different distances from the source. The dose distribution and dose uniformity ratio in dummy products of different bulk densities, irradiated at different distances from the source, were determined. Two types of cardboard boxes, one for mangoes and the other for medical products, were utilized. Newspaper was used as dummy product to fill the boxes. The effect of vertical turning on dose uniformity ratio was also investigated. The dose distribution and uniformity ratio were also determined during the routine irradiation of onions and mangoes. (author). 7 refs, 4 figs, 6 tabs

  10. Effect of gamma irradiation on the properties of tyre cords

    Gamma irradiation of high tenacity Nylon 6.6 (Ny 66) and polyester (PET) tyre cords was investigated. The untreated and treated tyre cords with different twist levels were irradiated at different dose rates in air. The effects of irradiation on both Ny 66 and PET cords were not found to be depending on the twist levels of the cords. The changes in the mechanical and thermal properties with absorbed dose at two different dose rates were measured. The mechanical properties were observed to deteriorate with increasing dose for Ny 66 cords, whereas remained almost unchanged for PET cords both in greige and dipped forms. Hot shrinkage value for the greige Ny 66 cords was found to be improved, i.e. decreased. This decrease was much lower for greige PET than Ny 66 cords. It is concluded that PET cord has higher radiation resistance than Ny 66 cord and the effects of high energy irradiation on tyre cords have to be taken into consideration during tyre design if pre-vulcanization with high energy radiation is to be applied

  11. Water radiolysis in a crack tip under gamma ray irradiation

    Under a non-irradiation condition, oxidant, e.g., O2 and H2O2, in a crack tip is supplied from the bulk water. But under irradiation conditions, even if the diffusion of radiolytic species is not sufficient, direct radiolysis in the crack tip causes high concentrations of radiolytic species. As a result of measurements and Monte Carlo calculation of gamma ray energy deposition, it has been confirmed that the energy deposition rate in the gap water is larger than that in the bulk water. The energy absorption rate increases as the gap width decreases and reaches 1.3 times that in the bulk water. In order to evaluate crack propagation rate for irradiation assisted stress corrosion cracking (IASCC) of stainless steel, a water radiolysis model in a crevice is proposed. A larger energy deposition rate in the crevice water produces many more radiolytic species, which causes high oxidant concentrations in spite of enhanced recombination of the species at the crevice inner surface. So, for IASCC evaluation, crevice water chemistry plays an important role to determine the crack propagation rate under irradiation. (authors)

  12. EPR study on non- and gamma-irradiated herbal pills

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  13. EPR study on non- and gamma-irradiated herbal pills

    Aleksieva, K., E-mail: katerina_bas@abv.b [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Lagunov, O. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Dimov, K. [Institute of Cryobiology and Food Technologies, 1162 Sofia (Bulgaria); Yordanov, N.D. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2011-06-15

    The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048{+-}0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show 'cellulose-like' EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation.

  14. Enhanced release of bone morphogenetic proteins from demineralized bone matrix by gamma irradiation

    Gamma irradiation is a useful method for sterilizing demineralized bone matrix (DBM), but its effect on the osteoinductivity of DBM is still controversial. In this study, the osteoinductive activity of gamma-irradiated DBM was examined using a mouse myoblastic cell line (C2C12). DBM was extracted from adult bovine bone and was irradiated at a dose of 25 kGy using a 60cobalt gamma-irradiator. Cell proliferation with DBM was not affected by gamma-irradiation, but alkaline phosphatase and osteocalcin productions were significantly increased in C2C12 cell groups treated with gamma-irradiated DBM. It was reasoned that bone morphogenetic proteins were more efficiently released from gamma-irradiated DBM than from the non-irradiated control. This result suggests the effectiveness of radiation sterilization of bone implants - Highlights: • Demineralized bone matrix (DBM) was gamma-irradiated for sterilization. • Irradiated DBM had higher alkaline phosphatase and osteocalcin production. • It was reasoned the more released bone morphogenetic proteins by irradiation. • This result supports the application of radiation sterilization for bone implants

  15. Evaluation of the physicochemical stability of liquid soy lecithin after decontamination by gamma irradiation

    Commercial samples of liquid soy lecithin were irradiated with different gamma doses up to 5 kGy. Several physicochemical properties were determined every 2 months for a period of 8 months after the irradiation and were compared to those of blank samples. No significant differences were found between the physicochemical properties of irradiated and non-irradiated soy lecithin samples. (author)

  16. Effect of gamma irradiation on structure and properties of polysulfone

    The structure and properties of polysulfone under irradiation by gamma rays were investigated by mechanical testing, fourier transform infrared spectroscopy, scanning electronic micrograph, differential scanning calorimeter, gel permeation chromatography and X-ray photoelectron spectroscopy respectively. The results show that tensile strength, flexural strength, impact strength, number averaged molecular weight, peak molecular weight, glass transition temperatures and number averaged polymerization degree of polysulfone decrease with the absorbed dose. The chemical structure of polysulfone keeps unchanged. The embrittlement of material and the smoothness of the fracture surface increase with the absorbed dose. The ascending part of the aging curves of flexural strength, impact strength and weight averaged molecular weight of polysulfone reveale that the cross-linking mechanism dominates at lower absorbed doses, and descending part of the curves shows that degradation mechanism dominates at higher doses. Radiation degradation kinetics of polysulfone under gamma irradiation can be described as random event. It may be indirectly proved that cross-linking mechanism dominates at low absorbed doses, and degradation mechanism dominates at higher absorbed doses. (authors)

  17. Response of reptilian live to external gamma irradiation

    Adult healthy specimens of Uromastix hardwickii were exposed to three doses (i.e. 2.25, 4.50 and 9.00 Gy) of gamma radiation from a 60Co source (experimental group). Five animals were sacrificed at each post-irradiation intervals of 1, 2, 3, 7 and 14 days. The liver was fixed in Bouin's fluid and after processing in a routine way, it was examined histologically. Five sham-irradiated animals (control group) were also sacrificed to compare the results. Low dose (i.e. 2.25 Gy) did not produce any apparent radiolesions in the liver. Changes in the form of cytoplasmic degranulation, swollen hepatocytes, pycnosis, increases in bile pigmentation were noticed after 4.50 and 9.00 Gy gamma ray exposure. Hyperaemia, widening of sinusoids and cytoplasmic vacuolation were also noticed in 9.00 Gy group. The liver exhibited normal picture on day 14 after exposure to both the doses. The radiolesions were found dose dependent. (author)

  18. Selection of Novel Cowpea Genotypes Derived Through Gamma Irradiation

    Lydia eHorn

    2016-03-01

    Full Text Available Cowpea (Vigna unguiculata [L.] Walp. yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985, Shindimba (IT89KD-245-1 and Bira (IT87D-453-2 were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colours and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants’ lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding.

  19. Biosolubilization of raw and gamma irradiated lignite by trichoderma asperellum

    Biosolubilization is a promising technology for converting solid coal to liquid oil by addition of microorganism. Aim of this research is to compare between gamma irradiated lignite (10 kGy) with raw lignite in biosolubilization by selected fungi Trichoderma asperellum. Treatments were A (MSS + gamma irradiated lignite 5% + T. asperellum) and B (MSS + raw lignite 5% + T. asperellum) with sub-merged culture. There were two parameters observed i.e. biosolubilization product based on absorbance value at λ250nm and λ450nm and metal analysis by neutron activation analysis (NAA). The highest biosolubilization will be analyzed by FTIR and GCMS. The results showed that biosolubilization of raw lignite (B) was higher than sterilized lignite (A) based on absorbance value at λ250nm and λ450nm. The metal of lignite was decreased after incubation. FTIR analysis showed that both of treatment had similar spectra on biosolubilization products. GCMS analysis showed that both of treatment had different number of hydrocarbon, i.e. C6 - C35 (A) and C10 - C35 (B) and dominated by aromatic acids, aliphatic and phenylethers. Both of treatment product had the potency as oil substituted but its recommended to deoxygenate for higher quality. (author)

  20. Selection of Novel Cowpea Genotypes Derived through Gamma Irradiation.

    Horn, Lydia N; Ghebrehiwot, Habteab M; Shimelis, Hussein A

    2016-01-01

    Cowpea (Vigna unguiculata [L.] Walp.) yields are considerably low in Namibia due to lack of improved varieties and biotic and abiotic stresses, notably, recurrent drought. Thus, genetic improvement in cowpea aims to develop cultivars with improved grain yield and tolerance to abiotic and biotic stress factors. The objective of this study was to identify agronomically desirable cowpea genotypes after mutagenesis using gamma irradiation. Seeds of three traditional cowpea varieties widely grown in Namibia including Nakare (IT81D-985), Shindimba (IT89KD-245-1), and Bira (IT87D-453-2) were gamma irradiated with varied doses and desirable mutants were selected from M2 through M6 generations. Substantial genetic variability was detected among cowpea genotypes after mutagenesis across generations including in flowering ability, maturity, flower and seed colors and grain yields. Ten phenotypically and agronomically stable novel mutants were isolated at the M6 each from the genetic background of the above three varieties. The selected promising mutants' lines are recommended for adaptability and stability tests across representative agro-ecologies for large-scale production or breeding in Namibia or similar environments. The novel cowpea genotypes selected through the study are valuable genetic resources for genetic enhancement and breeding. PMID:27148275

  1. Decay prevention in waterlogged archaeological wood using gamma irradiation

    Gamma irradiation is evaluated as a novel decay prevention treatment for waterlogged archaeological wood. A dose of 15 kGy was found to be sufficient to inactivate a large number of wood biodeteriogens, including fungi, bacteria and invertebrates, at various stages of development. For timbers excavated from polluted sites, a dose of 25 kGy is suggested to inactivate human pathogens. The dose spread required for such treatments are 1.33:1 and 1.2:1, respectively, in timbers up to 150 mm thickness and density not exceeding 1590 kg/m3. No adverse effects on the physical properties of slightly or heavily degraded waterlogged archaeological wood were detected at doses of up to 100 kGy. This is the maximum recommended single or cumulative lifetime dose for any timber. Gamma irradiation offers far greater efficacy over currently used decay prevention treatments and, a step-wise procedure for evaluating timbers for treatment and dosimetry is presented. (author)

  2. Gamma irradiation of quartz from Pannier basin, South America

    Enokihara, Cyro T.; Rela, Paulo R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], E-mail: cteiti@ipen.br, E-mail: prela@ipen.br; Guttler, Rainer A.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias

    2007-07-01

    The use of gamma radiation to induce or enhance color centers in gemstones is a widespread technique and applied worldwide on a industrial scale since at least 1970. The presence of defects and defect structures in quartz from a border region of southern Brazil and Uruguay are the reason for the creation of a new color variety of quartz called 'Prasiolite' in the gem trade. This quartz has a pleasant green color produced by gamma irradiation. The procedures of irradiation at IPEN show that the activation of these color producing defects can be monitored by detailed chemical and spectroscopic analysis. For the first time UV-VIS-NIR spectra of this new color variety of quartz are shown. They revealed special features of these quartz crystals coming from basaltic terranes of the Parana Basin. Contrary to most specimen of quartz from other parts of Brazil, they have such a high water and OH content that they resemble more chalcedony or opal, but not highly crystalline quartz specimens. The cause of the color are broken bonds of Si-OH defining the so-called dangling bonds. (author)

  3. Stability of vitamin E content of {gamma}-irradiated biscuits

    Taipina, Magda S.; Mastro, Nelida L. del [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: nlmastro@ipen.br; magtaipina@ig.com.br; Lamardo, Leda C.A. [Instituto Adolfo Lutz, Sao Paulo, SP (Brazil). Secao de Quimica Biologica]. E-mail: llamardo@ial.sp.gov.br

    2007-07-01

    The technology of food irradiation is seen by the industry as a means of ensuring food safety, since it exposes foods to ionizing radiation that kills insects, moulds and bacteria. The need to eliminate bacterial pathogens from read-to-eat food products must always be balanced with the maintenance of product quality. In addition to determining the effective ionizing radiation doses required for pathogen elimination the effects of irradiation on product chemistry, nutritional value and quality must also been determined. Vitamin E ({alpha}-tocopherol) is one of the most potent natural lipophilic antioxidants commonly present in the human diet. As it is considered a free radical scavenger there is a growing concern that irradiation might reduce the vitamin E content of food products prepared with ingredients rich in any of the dietary source of the vitamin. This work describes the effects of ionizing radiation on the vitamin E content of some biscuits commercially found in the market. Three lots of biscuits were used. Irradiation was performed in a {sup 60}Co Gammacell 220 source, dose rate of about 3.5 kGy/h at doses of 1 kGy and 3 kGy. For vitamin E determination samples were saponified with ethanolic potassium hydroxide in the presence of pyrogallol, and the tocopherols were extracted with petroleum ether. The absorbance was measured at 520 nm. From the obtained results it is possible to conclude that there was a notorious stability of the vitamin content of the biscuits submitted to gamma-irradiation at the assayed doses. (author)

  4. Effect of gamma irradiation on refrigerator storage of peach fruits

    Peach fruits of cvs. Halle and Elberta were gamma irradiated by 0, 2.0, 2.5 and 3.0 kGy and stored in the usual way (20-25 grad C) or in refrigerator (5 and 0 grad C). The rate of mould decay, reduction in market quality and complex evaluation of the fruits at the time of storage were investigated. Linear regression correlations between the percentage of decay and the time of storage were estimated by probit-logarithmic transformation of the percentage of the decayed fruits. On that basis were assess the probable terms to reach 5% decay (permissible period of storage) and 10% decay. The criteria of quality and taste evaluation of the fruits for these periods were determined. The irradiation of peach fruits with 2.5 and 3.0 kGy prolonged 3 to 5 times the period free of decay (up to 5%) in the case of normal storage conditions as compared to the control (no irradiation). The sharp reduction in quality and the sensorial evaluation for these periods did not justify irradiation in case of usual storage conditions. Irradiation with the same rates in case of refrigeration storage proved a useful supplementary factor prolonging the periods before appearance of decay up to 17 days (i.e. 42% as compared to the control) and the permissible period of storage up to 25 days (25% more than the control). These results were obtained at a dose of 2.5 kGy for cv. Halle fruits, at dose 3.0 kGy for cv. Elberta fruits and at storage temperature of 0 grad C. For the periods up to 5% decay (25 to 26 days) the criteria of quality and the complex evaluation remained above the permissible level. Longer storage was not advisable because physiological damage of the fruit was evident

  5. Rheological properties of blood after whole body gamma-irradiation

    The study of rheological properties of blood has special interest; since it is a circulating fluid exposed to shear rates during its life time. This work aims to investigate the influence of whole body gamma irradiation on the rheological properties of rat's blood. The applied shear rate was from 12 to 375 s-1. Low shear viscosity (up to 100 s-1) depends mainly on the erythrocytes aggregation while the high shear viscosity depends on the erythrocytes deformability. Materials and Methods: Adult male rats were exposed to 1, 2.5, 3.5, 5, 7 and 9 Gy single doses. The consistency index, apparent viscosity, yield stress and aggregation index were increased after exposure to gamma radiation. The dielectric properties of the erythrocytes, in the low frequency range (60 Hz to 40 k Hz), were measured in order to investigate the changes in the membrane surface charge. Results: The results obtained indicate that the viscosity, consistency index and yield stress increased after the exposure to the lowest dose taken; 1 Gy, and continued to increase as the exposure dose increased up to dose 7 Gy and then decrease after exposure to 9 Gy. The relative permittivity and relaxation time showed significant decrease after exposure to the lowest dose and continue to decrease as the dose increased. Conclusion: The obtained results can be attributed to the decrease of membrane surface charge after exposure to gamma radiation. The decrease in the membrane surface charge is known to decrease the repulsion between the cells and increase blood viscosity.

  6. Polyclonal antibody to ovomucoid determination in gamma irradiated laying eggs

    Harder, Marcia N.C.; Arthur, Valter; Silva, Lucia C.A.S.; Lopes, Tatiana G.G. [Centro de Energia Nuclear na Agricultura (CENA/USP, Piracicaba, SP. Dept. de Radiobiologia e Ambiente) (Brazil)], e-mail: mnharder@cena.usp.br, e-mail: arthur@cena.usp.br, e-mail: tgglopes@cena.usp.br; Duarte, Keila M.R. [Instituto de Zootecnia (IZ . Nova Odessa), Nova Odessa, SP (Brazil)], e-mail: keila@iz.sp.gov.br; Canniatti-Brazaca, Solange G.; Savino, Vicente J.M.; Coelho, Antonio A.D. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil)], e-mail: sgcbraza@esalq.usp.br, e-mail: vjmsavin@esalq.usp.br, e-mail: aadcoelh@esalq.usp.br

    2009-07-01

    To determine allergenic food proteins, one of the most used tests is the immunoassays such as ELISA (enzyme linked immunosorbent assay), where the antibody recognizes the antigen and this connection is showed by an enzymatic system, in other words, optical density. The aim of this study was to determine the polyclonal antibody efficiency, produced in laboratory, to identify the presence the ovomucoid antigen in treated eggs by gamma irradiation for its inactivation. To evaluate the treatments, polyclonal antibody was produced in female rabbits immunized with bioconjugated ovomucoid. Was used Freund Complete Adjuvant at first immunization and PBS Buffer at four subsequently immunizations every fifteen days, plus a booster 48 hours before the blood retreated. The blood serum was tittered by PTA-ELISA (Plate trapped antigen). All procedures were according to European Norms for ethical and animal welfare. It was used, in nature, commercial laying eggs. So the samples were submitted to the gamma radiation coming from a source of Co{sup 60}, type Multipurpose, under a dose rate of 19.4 and 31.8 Gy/hour, in the doses: 0 (control); 10 KGy; 20 KGy and 30 KGy, in all rates. By the ELISA.s test we can find the egg allergen ovomucoid and the radiation treatment do not showed considerable changes. So we can concluded that the antibody produced is capable of identify the ovomucoid allergenic protein and the gamma irradiation in such rates does not shows changes in that protein, therefore showed some changes in the color and visual viscosity of the egg samples. (author)

  7. Polyclonal antibody to ovomucoid determination in gamma irradiated laying eggs

    To determine allergenic food proteins, one of the most used tests is the immunoassays such as ELISA (enzyme linked immunosorbent assay), where the antibody recognizes the antigen and this connection is showed by an enzymatic system, in other words, optical density. The aim of this study was to determine the polyclonal antibody efficiency, produced in laboratory, to identify the presence the ovomucoid antigen in treated eggs by gamma irradiation for its inactivation. To evaluate the treatments, polyclonal antibody was produced in female rabbits immunized with bioconjugated ovomucoid. Was used Freund Complete Adjuvant at first immunization and PBS Buffer at four subsequently immunizations every fifteen days, plus a booster 48 hours before the blood retreated. The blood serum was tittered by PTA-ELISA (Plate trapped antigen). All procedures were according to European Norms for ethical and animal welfare. It was used, in nature, commercial laying eggs. So the samples were submitted to the gamma radiation coming from a source of Co60, type Multipurpose, under a dose rate of 19.4 and 31.8 Gy/hour, in the doses: 0 (control); 10 KGy; 20 KGy and 30 KGy, in all rates. By the ELISA.s test we can find the egg allergen ovomucoid and the radiation treatment do not showed considerable changes. So we can concluded that the antibody produced is capable of identify the ovomucoid allergenic protein and the gamma irradiation in such rates does not shows changes in that protein, therefore showed some changes in the color and visual viscosity of the egg samples. (author)

  8. Effect of gamma irradiation on the microbial load and quality characteristics of Baladi cheese

    Baladi cheese (manufactured from raw milk) were treated with 0, 1, 2, and 3 kGy of gamma irradiation. Microbial load, moisture, protein, lipid, free fatty acids, total volatile basic nitrogen, lipid oxidation, firmness, taste, flavour and color were determined immediately after irradiation and after 12 months of storage. The results showed that, all used doses of gamma irradiation reduced significantly the microbial load. Gamma irradiation decreased moisture, K+, Ca+, Na+, ash and free fatty acids, and increased protein contents of Baladi cheese. Volatile basic nitrogen and firmness of irradiated cheese were increased after irradiation and decreased after 12 months of storage. Gamma irradiation had no effect on sensory characteristics of Baladi cheese. (authors)

  9. Effect of Gamma Irradiation on the Sugar and Protein Composition of Iraqi Dates

    Completely ripened date fruits of several Iraqi varieties were irradiated with 30, 70, 100, 270 and 500 krad of gamma irradiation and stored at a temperature of 25-35°C in wooden boxes or in plastic bags. At various intervals samples were taken and analysed by paperchromatography, gas-chromatography and spectrophotometry for quantitative and qualitative changes in carbohydrates. The results showed no effect of gamma irradiation on reducing sugar and major carbohydrate components. The formation of malonaldehyde under gamma irradiation of dates and solid standard sugars was also studied up to 500 krad. The results showed no formation of malonaldehyde in irradiated date samples as well as standard sugars. Gamma irradiation showed no effect on the protein content of dates. However, storage showed some reduction in the protein content of both unirradiated and irradiated samples. (author)

  10. Effect of gamma irradiation on the microbial load and quality characteristics of Baladi cheese

    Baladi cheese (manufactured from raw milk) were treated with 0, 1, 2, and 3 kGy of gamma irradiation. Microbial load, moisture, protein, lipid, free fatty acids, total volatile basic nitrogen, lipid oxidation, firmness, taste, flavour and color were determined immediately after irradiation and after 12 months of storage. The results showed that, all used doses of gamma irradiation reduced significantly the microbial load. Gamma irradiation decreased moisture, K+, Ca2+, Na+, ash and free fatty acids, and increased protein contents of Baladi cheese. Volatile basic nitrogen and firmness of irradiated cheese were increased after irradiation and decreased after 12 months of storage. Gamma irradiation had no effect on sensory characteristics of Baladi cheese. (authors)

  11. Effect of Gamma Irradiation on The Microbial Load and Quality Characteristics of Baladi Cheese

    Baladi cheese (manufactured from raw milk) was treated with 0, 1, 2 and 3 kGy of gamma irradiation. Microbial load, moisture, protein, lipid, free fatty acids, total volatile basic nitrogen, lipid oxidation, firmness, taste, flavour and color were determined Immediately after irradiation and after 12 months of cold storage in brine. The results showed that, all used doses of gamma irradiation reduced significantly the microbial load. Gamma irradiation decreased the the moisture content, Ca++, Na+ , K+, ash and free fatty acids, and increased the protein contents of Baladi cheese. Volatile basic nitrogen and firmness of irradiated cheese were increased after irradiation and decreased after 12 months of storage. Gamma irradiation had no effect on the sensory characteristics of Baladi cheese. (authors)

  12. Modification of LDPE molecular structure by gamma irradiation for bioapplications

    The surface properties of low-density polyethylene (LDPE) can be modified by the grafting of 2-hydroxyethyl methacrylate (HEMA). This was done aiming at the production of new materials suitable for bioapplications. Samples with different monomer concentrations were prepared from LDPE particles by gamma irradiation, following different irradiation protocols, including irradiation in presence and absence of air. The samples were characterized by thermal analysis techniques (DSC and TGA) and by Fourier transform infrared spectroscopy (FTIR). The results obtained show a decrease in the crystallinity of the supporting matrix for copolymers with high yields of grafting. However, the new materials prepared maintain good structural order resulting from the protective effect of polyHEMA grafted onto LDPE backbone. These effects can improve the diffusion of other species deeper inside the matrix and increase the material hydrophilicity. The studies performed made possible the selection of experimental protocols adequate for the production of new copolymeric materials with high grafting yield. These were used in the production of new LDPE films with enhanced hydrophilic properties

  13. Preparation of silica-based hybrid materials by gamma irradiation

    Gamma-ray irradiation is well known to promote the crosslinking of polymer chains. The method is now used by the authors to prepare hybrid materials from a mixture of polymer and metallic alkoxides of silicium and zirconium that are usually obtained via the sol-gel process. Macroscopically homogeneous and transparent hybrid materials have been obtained by γ-irradiation of polydimethylsiloxane (PDMS), tetraethylorthosilicate (TEOS) and zirconium propoxide (PrZr). The influence of several parameters has been studied. The dose rate was found to have no significant impact in the prepared material. The polymer molecular weight was also observed not to play any special role. It was found that all irradiated samples consist of a polymer gel matrix. In the case where both alkoxides are present there are inorganic oxide regions linked to the PDMS network. However when one of the alkoxides is absent there is no formation of inorganic oxide regions linked to the polymer matrix, there being only a few individual derived molecules of the other alkoxide linked to the polymer

  14. Gamma irradiation of corn starches with different amylose-to-amylopectin ratio

    Corn starches with different amylose-to-amylopectin ratio (waxy, normal, Hylon V, and Hylon VII) were treated with five doses of gamma irradiation (1, 5, 10, 25, and 50 kGy). The effects of gamma irradiation on the physico-chemical properties of starch samples were investigated. Waxy samples showed an increase of amylose-like fractions when irradiated at 10 kGy. The reduction in apparent amylose content increased with amylose content when underwent irradiation at 25 and 50 kGy. Low amylose starches lost their pasting ability when irradiated at 25 and 50 kGy. Results from thermal behavior and pasting profile suggested that low level of cross-linking occurred in Hylon VII samples irradiated at 5 kGy. Severe reduction in pasting properties, gelatinization temperatures and relative crystallinity with increasing irradiation intensity revealed that waxy samples were affected more by gamma irradiation; this also indicated amylopectin was the starch fraction most affected by gamma irradiation. Alteration level was portrayed differently when different kind of physico-chemical properties were investigated, in which the pasting properties and crystallinity of starches were more immensely influenced by gamma irradiation while thermal behavior was less affected. Despite the irradiation level, the morphology and crystal pattern of starch granules were found remain unchanged by irradiation. (author)

  15. Radiation Safety of Gamma, Electron and X Ray Irradiation Facilities. Specific Safety Guide (Spanish Edition)

    The objective of this Safety Guide is to provide recommendations on how to meet the requirements of the BSS with regard to irradiation facilities. This Safety Guide provides specific, practical recommendations on the safe design and operation of gamma, electron and X ray irradiators for use by operating organizations and the designers of these facilities, and by regulatory bodies. SCOPE. The facilities considered in this publication include five types of irradiator, whether operated on a commercial basis or for research and development purposes. This publication is concerned with radiation safety issues and not with the uses of irradiators, nor does it cover the irradiation of product or its quality management. The five types of irradiator are: - Panoramic dry source storage irradiators; - Underwater irradiators, in which both the source and the product being irradiated are under water; - Panoramic wet source storage irradiators; - Electron beam irradiation facilities, in which irradiation is performed in an area that is potentially accessible to personnel, but that is kept inaccessible during the irradiation process; - X ray irradiation facilities, in which irradiation is performed in an area that is potentially accessible to personnel, but that is kept inaccessible during the irradiation process. Consideration of non-radiation-related risks and of the benefits resulting from the operation of irradiators is outside the scope of this Safety Guide. The practices of radiotherapy and radiography are also outside the scope of this Safety Guide. Category I gamma irradiators (i.e. 'self-shielded' irradiators) are outside the scope of this Safety Guide

  16. Chromatographic study of gamma-ray irradiated degradation of chlorinated hydrocarbon in water

    Degradation of chlorinated hydrocarbon in gamma ray irradiation was examined in order to get information on treatment of groundwater. Water chloroform was sealed into a vial irradiated with gamma ray. Both gas chromatography and ion chromatography were applied for determination of degradation products. Carbon dioxide, carbon monoxide, methane, ethane and chloride ion were detected in the irradiated system. Effect of radiation dose on the gamma ray induced chloroform degradation was investigated. The elimination of chloride ion and the degradation of chloroform were promoted by gamma irradiation in a dose-dependent manner. The G(CHCl3), which was defined as the number of degraded chloroform molecules when absorbed 100eV, was inferred to be 3.1. The degradation mechanism of chloroform irradiated with gamma ray seemed to involve that chloroform reacted with electron from radiolysis of water and the elimination of chloride ion occurred. (author)

  17. Decoloration and degradation of some textile dyes by gamma irradiation

    Şolpan, Dilek; Güven, Olgun

    2002-11-01

    The textile industry has long been one of the largest water users and polluters. Wastewater released by textile industries contains toxic refractory dye stuff at high concentration. Most of the dyes in the textile industry are non-degradable, therefore, effective treatment of dye waste effluent has not been achieved by ordinary processes. Ionizing radiation has been considered a promising process for the treatment of textile dye waste effluents. In this study, the possibility of using gamma rays to degrade or decolorize reactive dyes in water was investigated. Two different reactive dyes (Reactive Blue 15 and Reactive Black 5) in aqueous solutions were irradiated at doses of 0.1-15 kGy, at 2.87 and 0.14 kGy/h dose rates. The change of absorption spectra, pH, chemical oxygen demand (COD), and the degree of decoloration (percent reduction in optical density) were examined in the presence of air and H 2O 2. The absorption bands at 664, 640, 340, 260 nm and 596, 392, 312 nm for RB15 and RB5 decreased rapidly with increasing irradiation dose. The degree of decoloration of each dye solution with irradiation dose appeared to be 100 percent for the lower concentration (50 ppm) dye solutions. The complete decoloration was observed after 1 and 15 kGy doses for RB5 and RB15, respectively. pH of RB5 and RB15 solutions was decreased from 6.15 and 6.98 to 3.40 and 3.68 with the irradiation dose. The COD reduction for all the dye solutions was approximately 76-80% at 1 and 15 kGy for RB5 and RB15. The COD reduction and the change of pH for all the dye solutions were examined similar to each other.

  18. Simulation of gamma irradiation system for a ballast water treatment

    Invasion by different kinds of ballast the water microorganisms is one of the most important marine environment problems around the world therefore preventing the invasion of these unwanted and harmful stowaways is one of the main strategies of responsible agencies. Some of these methods such as ocean exchange, heating, filtration, hydro cyclones, UV irradiation and chemical treatment, have various problems such as technical deficiency, high costs, lack of safety and environmental side effects. Materials and Methods: A novel system of treatment by Gamma irradiation is designed to irradiate the blast water uniformly and effectively. To determine the dose distribution as a function of distance from the irradiation source, the MCNP code was used. The systems used for source implant in this simulation were Paterson-Parker, Paris and Network systems. In each system, Sivert-integral and inverse square law were used in MATLAB program to determine the dose distribution. Results: Results of initial laboratory tests on offshore water samples of Siri Island indicated that the appropriate dose for deactivation of organisms of water samples is approximately one kGy. It has been demonstrated that the dose can be provided by twenty five 100,000 Ci line sources of '60Co in a triangle implant arranged in a 1*1*1 m3 cubic shape water pipe. In order to increase efficiency and radiation safety, water passed from two other coaxial and bigger cubes, after passing from the first cube. A one meter thick wall of concrete around the cubes was adequate to shield the system completely. Conclusion: The main advantages of this system such as high efficiency, safety, reliability, minimum environmental adverse effects, proves that this novel method not only can be used for ballast water treatment, but is also effective for drinking water purification

  19. Decoloration and degradation of some textile dyes by gamma irradiation

    The textile industry has long been one of the largest water users and polluters. Wastewater released by textile industries contains toxic refractory dye stuff at high concentration. Most of the dyes in the textile industry are non-degradable, therefore, effective treatment of dye waste effluent has not been achieved by ordinary processes. Ionizing radiation has been considered a promising process for the treatment of textile dye waste effluents. In this study, the possibility of using gamma rays to degrade or decolorize reactive dyes in water was investigated. Two different reactive dyes (Reactive Blue 15 and Reactive Black 5) in aqueous solutions were irradiated at doses of 0.1-15 kGy, at 2.87 and 0.14 kGy/h dose rates. The change of absorption spectra, pH, chemical oxygen demand (COD), and the degree of decoloration (percent reduction in optical density) were examined in the presence of air and H2O2. The absorption bands at 664, 640, 340, 260 nm and 596, 392, 312 nm for RB15 and RB5 decreased rapidly with increasing irradiation dose. The degree of decoloration of each dye solution with irradiation dose appeared to be 100 percent for the lower concentration (50 ppm) dye solutions. The complete decoloration was observed after 1 and 15 kGy doses for RB5 and RB15, respectively. pH of RB5 and RB15 solutions was decreased from 6.15 and 6.98 to 3.40 and 3.68 with the irradiation dose. The COD reduction for all the dye solutions was approximately 76-80% at 1 and 15 kGy for RB5 and RB15. The COD reduction and the change of pH for all the dye solutions were examined similar to each other

  20. Application of gamma irradiation technique for the preservation of propolis

    Irradiation has been recognized as an efficient method for the reduction of deteriorating and pathogenic microorganisms in foods. Propolis is a resinous product made by bees from material processed by the bee's own metabolism and resins from plants. The aim of this work was the application of gamma irradiation technique for the preservation of propolis, because of its efficiency in the reduction of the microbial load. The changes on the total flavonoids content, phenolic compounds and other characteristics required for the qualification and characterization of Brazilian propolis were also analysed. Propolis samples from Juiz de Fora region, Minas Gerais, were irradiated in a 60Co source, with doses from 0 to 10kGy for the microbiological analyses and 5.0, 7.0 and 10.0kGy for the physico-chemical analyses. The physico-chemical that have been made were: determination of total flavonoids content, semi-quantitative determination of phenolic compounds (artepelin-C, kempferol, chrysin, galangin and quercetin), dry matter analysis, humidity, ash content, mechanical mass and waxes. The ionizing radiation has shown to be efficient in the reduction of the microbial load. Total coliforms determination showed a great reduction with the dose of 3kGy and concerning mesophile aerobic bacteria a systematic reduction was observed, achieving values <10 UFC/g for the dose of 10kGy; similar results was obtained for molds and yeasts. Salmonella assays were negative for all samples. There was no significant alteration on total flavonoids contents nor on the composition of phenolic compounds as a consequence of radiation application at the assayed conditions. The complementary analyses of dry matter and humidity contents, ashes, mechanical mass and waxes did not shown changes after irradiation even with the maximum dose of 10kGy, remaining the results within the standards required by the Brazilian legislation. (author)

  1. Effects of. gamma. -irradiation on. beta. -pinene content and germination in grapefruit

    Uchiyama, Sadao; Kawamura, Yoko; Saito, Yukio; Nagashima, Kimiyo.

    1988-12-01

    Effects of ..gamma..-irradiation on ..beta..-pinene content and germination in grapefruit were investigated in order to develop a method to identify ..gamma..-irradiated grapefruit. ..beta..-Pinene is a component of essential oil in grapefruit and was reported to be susceptible to ..gamma..-irradiation. However, it was not degraded by irradiation (30 to 200 krad) in this experiment. When grapefruit irradiated at 50 krad were stored at 10degC for 2 months, no change of ..beta..-pinene content was found. ..beta..-Pinene itself was also stable to ..gamma..-irradiation at 1 Mrad. Thus, identification of irradiated grapefruit from the amount of ..beta..-pinene was impossible. On the other hand, the effect of ..gamma..-irradiation on radicle elongation was small but that on plumule expansion was so large as to prevent shooting in grapefruit irradiated even at 30 krad. Therefore it should be possible to identify ..gamma..-irradiated grapefruit by a germination method.

  2. Irradiation dose and effect on germination and growth of desert shrub Nitraria tangutorum Bobr. with two gamma irradiation modes

    The seeds of Nitraria tangutorum were exposed to different doses of gamma radiation from 60Co gamma rays based on the two irradiation modes of without dose rate and with dose rate of 25Gy/hr. The effects of different irradiation modes and irradiation dose on the seed germination rate, emerged seedling rate and phenotypic characters of seedling have been studied. The semi-lethal dose and critical dose were determined for different irradiation mode. It has been found that there were the differences of irradiation effects between the two irradiation modes. Promotion effect on the seed germination rate, emerged seedling rate, seedling height and ground diameter in lower dose treatment were observed, while inhibition in higher dose. As compared to control, the irradiation effects on the seed germination rate and seedling height and ground diameter present the very remarkable differences at above 15000y dose without dose rate mode, while above 2400Gy with dose rate mode. The negative relativity exists between the relative emerged seedling rate and irradiation dose, the emerged seedling rate decreased with increasing dose. The semi-lethal dose based on the emerged seedling rate was 985Gy and 1363Gy for the irradiation without dose rate and with 25Gy/hr dose rate, respectively. The Appropriate 60Co gamma irradiation dose for the Nitraria tangutorum seeds was ranging from 950Gy to 1500Gy without dose rate irradiation mode, while 1300Gy to 2400Gy with 25Gy/hr dose rate mode

  3. Comparison of structural properties of pristine and gamma irradiated single-wall carbon nanotubes: Effects of medium and irradiation dose

    A systematic study of the gamma irradiation effects on single wall carbon nanotube (SWCNT) structure was conducted. Nanotubes were exposed to different doses of gamma irradiation in three media. Irradiation was carried out in air, water and aqueous ammonia. Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and Raman spectroscopy confirmed the changes in the SWCNT structure. TGA measurements showed the highest percentage of introduced groups for the SWCNTs irradiated with 100 kGy. FTIR spectroscopy provided evidence for the attachment of hydroxyl, carboxyl and nitrile functional groups to the SWCNT sidewalls. Those groups were confirmed by EA. All irradiated SWCNTs had hydroxyl and carboxyl groups irrelevant to media used for irradiation, but nitrile functional groups were only identified in SWCNTs irradiated in aqueous ammonia. Raman spectroscopy indicated that the degree of disorder in the carbon nanotube structure correlates with the irradiation dose. For the nanotubes irradiated with the dose of 100 kGy, the Raman ID/IG ratio was three times higher than for the pristine ones. Atomic force microscopy showed a 50% decrease in nanotube length at a radiation dose of 100 kGy. Scanning and transmission electron microscopies showed significant changes in the morphology and structure of gamma irradiated SWCNTs. - Highlights: ► Gamma irradiation causes SWCNT covalent functionalization. ► Type of covalently attached groups to SWCNT surface depends on irradiation medium. ► The SWCNT shortening level increases with applied irradiation dose. ► The average length of carbon nanotubes decreased by 50% at the highest dose. ► The diameter of SWCNT bundles becomes small as irradiation dose rises.

  4. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products-

    Cho, Han Ok; Byun, Myung Woo; Cho, Sung Kee; Kand, Il Joon; Yook, Hong Sun [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-02-01

    Gamma irradiation was applied to red ginseng powder for improving microbiological and physicochemical quality. Irradiation at 5-10 kGy was effective for sterilizing all contaminated microorganisms of red ginseng powder. At the dose levels, major physicochemical properties (saponin, amino acids, sugars, proximate composition, color, pH, acidity, hydrogen donating activity, fatty acids and minerals) were not changed by gamma irradiation upto 10 kGy. Based upon the results, it is concluded that gamma irradiation can effectively improve the microbiological quality of red ginseng powders without significant unfavorable changes. Therefore, it is suggested that irradiation technology is a viable alternative method to other sanitary process containing chemical fumigant and will be useful for the improvement of the quality of red ginseng powders and their products. 5 figs, 18 tabs, 92 refs. (Author).

  5. Studies on safety and efficacy of gamma-irradiated ginseng -Development of irradiation techniques for quality improvement of ginseng products-

    Gamma irradiation was applied to red ginseng powder for improving microbiological and physicochemical quality. Irradiation at 5-10 kGy was effective for sterilizing all contaminated microorganisms of red ginseng powder. At the dose levels, major physicochemical properties (saponin, amino acids, sugars, proximate composition, color, pH, acidity, hydrogen donating activity, fatty acids and minerals) were not changed by gamma irradiation upto 10 kGy. Based upon the results, it is concluded that gamma irradiation can effectively improve the microbiological quality of red ginseng powders without significant unfavorable changes. Therefore, it is suggested that irradiation technology is a viable alternative method to other sanitary process containing chemical fumigant and will be useful for the improvement of the quality of red ginseng powders and their products. 5 figs, 18 tabs, 92 refs. (Author)

  6. Effect of gamma irradiation in sterilization of dry dextran as plasma substitute and sodium chloride

    The exposure of dry dextran, sodium chloride and polyethylene packing to 0,3-2 Mrad of gamma irradiation decreased their contamination by 60 to 96%. The sterilization effect of irradiation increased with gamma-ray dose. Spores of Bacillus subtilis and Aspergillus niger were shown to be the most resistant to gamma-ray treatment. In some samples the resistant Micrococcus was also detected

  7. Inactivation of fungal contaminants on Korean traditional cashbox by gamma irradiation

    Choi, Jong-il; Lim, Sangyong

    2016-01-01

    In this study, gamma irradiation was applied to decontaminate a Korean cultural artifact, a wooden cashbox stored in local museum. Fungi isolated from the wooden cashbox were identified by 18S rDNA sequencing methods. It was observed that the isolated fungi exhibited high similarity to Aspergillus niger, Penicillium verruculosum, and Trichoderma viride. Each strain was tested for sensitivity to gamma irradiation, and was inactivated by the irradiation at a dose of 5 kGy. The wooden cashbox was thus gamma-irradiated at this dose (5 kGy), and consequently decontaminated. Two months after the irradiation, when the wooden cashbox was retested to detect biological contamination, no fungi were found. Therefore, these results suggest that gamma irradiation at a low dose of 5 kGy can be applied for successful decontamination of wooden artifacts.

  8. Effect of gamma-irradiation on the whitening activity of β-glucan

    This study evaluated the change in whitening activity of β-glucan by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 10 kGy irradiated β-glucan. Melanin synthesis of irradiated β-glucan was measured from B16BL6 melanoma cell line treated with α-melanin stimulating hormone. Melanin synthesis was increased in the α-melanin stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated β-glucan treated with α-melanin stimulating hormone. These results indicate that gamma irradiated β-glucan may elevate the whitening activity. Therefore, gamma-irradiated β-glucan could be used for nutraceutical foods in cosmetic industry

  9. Effect of gamma-irradiation on the whitening activity of {beta}-glucan

    Kim, Jae Hun; Sung, Nak Yun; Jung, Pil Moon; Choi, Jong Il; Kim, Jin Kyu; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Byun, Eui Hong [Chungnam Naitonal University, Daejeon (Korea, Republic of)

    2010-09-15

    This study evaluated the change in whitening activity of {beta}-glucan by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 10 kGy irradiated {beta}-glucan. Melanin synthesis of irradiated {beta}-glucan was measured from B16BL6 melanoma cell line treated with {alpha}-melanin stimulating hormone. Melanin synthesis was increased in the {alpha}-melanin stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated {beta}-glucan treated with {alpha}-melanin stimulating hormone. These results indicate that gamma irradiated {beta}-glucan may elevate the whitening activity. Therefore, gamma-irradiated {beta}-glucan could be used for nutraceutical foods in cosmetic industry.

  10. Effect of gamma irradiation on microbial load and quality characteristics of minced camel meat

    The effect of gamma irradiation on microbial load, chemical and sensory characteristics of camel meat has been evaluated. Camel meat was irradiated at doses of 0, 2, 4 and 6 kGy of gamma irradiation. Irradiated and non-irradiated meat was kept in a refrigerator (1-4 C). General composition and sensory evaluation of camel meat was done two days after irradiation, whereas, microbiological and chemical analysis was done immediately after irradiation and throughout the storage periods. The results indicated that all doses of gamma irradiation reduced the total mesophilic aerobic plate counts (TPCs) and total coliforms of camel meat. Thus, the microbiological shelf-life of camel meat was significantly extended from less than 2 weeks (control) to more than 6 weeks (samples irradiated with 2, 4 or 6 kGy). No significant differences in moisture, protein, fat, thiobarbituric acid (TBA) values, total acidity and fatty acids of camel meat were observed due to irradiation. There were slight effects of gamma irradiation in both total volatile basic nitrogen (VBN) and lipid oxidation values in camel meat. Sensory evaluation showed no significant differences between irradiated and non-irradiated camel meats. (author)

  11. Therapeutic potential of ex vivo expansion of haematopoietic precursors for the treatment of accidental irradiation-induced aplasia

    After whole body overexposure, the key issue is the therapeutic decision, i.e. the choice between bone marrow transplantation and other strategies. The indications of bone marrow transplantation cover only a short range of doses, provided the exposure is distributed uniformly within the body; a rare event in accidental settings. The results of the clinical trials for Granulocyte-Colony Stimulating Factor: G-CSF, Granulocyte/Macrophage Colony Stimulating Factor: GM-CSF or Interleukin 3: IL-3, in vivo and in vitro radiobiology experiments suggest that growth factor therapy could be of use after most accidental overexposures to evidence and to stimulate the remaining haematopoietic stem cells in order to shorten the duration of aplasia, although questions have been raised about growth factor infusion real clinical efficiency. Ex vivo expansion of haematopoietic precursor, stem cells and differentiated cells is a new approach of growth factor therapy, which may be of interest for the treatment of patients with accidental radiation-induced aplasia. These studies aim to expand the pool of progenitors and stem cells for transplantation or to expand differentiated cells (mainly granulocytes but also megakaryocytes) for transfusion. This is made possible due to the development of techniques allowing the selection of a population of haematopoietic progenitors and stem cells from the blood (with stimulation by growth factors prior stem cell harvesting) or bone marrow using immature cell positive selection. The next step consisting in their culture with combination of growth factors or additional stroma cells is also under development. Autologous progenitor cells generated ex vivo has been recently used with some success for reconstitution of haematopoiesis after high-dose chemotherapy. (author)

  12. Disinfestation of whole and ground spices by gamma-irradiation

    Number of insect species were identified in chilli (Capsicum annum Linn), turmeric (Curcuma longa Linn), ginger (Zingiber officinale Roscoe), pepper (Piper nigrum Linn) and coriander (Coriandrum sativum) and also in two commercial brands of prepacked ground spices. Lasioderma serricorne (Cigarette beetle), Oryzaephilus surinamensis (Saw toothed grain beetle), Rhizopertha dominica (Lesser grain borer), Sitotroga cerealella (Angoumois grain moth) and Tribolium castaneum (Red flour beetle) were the predominant pest species found in these spices. Exposure of spices to Co60 gamma irradiation at 1 kGy dose level did not show adult emergence of insects in these species during storage at ambient temperature (28-30degC) indicating that the radiation dose (10 kGy) that has been shown to be effective for microbial decontamination of spices destroys insect pests as well. (author). 8 refs

  13. Decontamination of toxigenic moulds in stored grains by gamma irradiation

    Samples of wheat, cow peas, and rice, collected from different stores, were found to be highly infested by some of the well known insects. The fungal genera, aspergillus, penicillium, fusarium and alternaria also predominated in all these samples. As the insect infection increases, the stored grains become heavily contaminated by aspergilli and penicilii. Aspergillus flavus that was isolated from all stored grains and insects is characterized by its ability to produce aflatoxins. When stored grains and insects were exposed to gamma irradiation dose of 0.4 - 0.6 kGy and 2 - 4 kGy, the insect and mould growth were greatly suppressed. The growth of A.flavus was inhibited completely at 4 kGy and the stored grains became totally free from the toxigenic moulds. 1 fig., 2 tab

  14. Design of device for testing in the gamma irradiator

    In eves of the recharge of the Gamma Irradiator, JS-6500 it was detected, that there was contamination in the container that housed the pencils of Co-60, coming from Argentina, country to which the ININ buys it recharges. It was determined that the contamination in the container was it interns and after discussing several solution options it was determined to manufacture a device to make a washing of the pencils. It was touch to the Management of Radiological Safety to determine the conceptual design of the device to make the washing and the way of operation of the same one. The Management of Prototypes and Models was responsibility of the mechanical design and its production. (Author)

  15. Quality of apples following gamma irradiation and cold storage

    The physico-chemical and organoleptic quality changes in apple cvs ‘Golden Delicious’, ‘Royal Delicious’, ‘Red Delicious’ and ‘Rich-A-Red’ exposed to gamma radiation doses of 0.1, 0.2, 0.4 and 0.6 kGy for quarantine and preservation purposes, were studied up to 6 months of storage at 2–4°C. Among the four cvs, ‘Rich-A-Red’ treated with 0.1 kGy dose showed better retention of sensory attributes and minimal changes in texture, total soluble solids, acidity and vitamin C content during storage. Results indicate that irradiation has commercial potential for apples as an alternative quarantine treatment for export requirements

  16. Economic effectiveness of irradiation with gamma rays on maize grains

    Gamma irradiation of maize grains before sowing increses the yield and improves the quality of agricultural produce. The positive results consist in the net income from silage maize from 45 to 85 per ha and from the grain maize from 85 to 109,9 per ha; the level of raw protein from the silage maize with 11,30% and from the grain maize with 6 to 12%; the level of feed units from the silage maize with 5 to 13% and from grain maize with 6 to 12%. Such direct effect in the same time is a stimulating one and raises the effectiveness of the animal production due to the better feeding of animals

  17. Media effects on radiochemical corrosion at high-output gamma irradiation facilities

    Gamma irradiation of metals at high dose rate conditions may induce or accelerate a wide variety of electrochemical corrosion processes. Examination of failures encountered in irradiation facilities due to corrosion indicated that, above a threshold value for atmospheric humidity, the electrode reactions are chiefly controlled by the action of radiolytic products arising from the electrolyte during gamma irradiation. Thus, the nature of the corrosive medium provides the decisive variable factor influencing the overall effect of radiochemical corrosion. (author)

  18. Defect formation in spinel crystals under electron and gamma beam irradiation

    There were investigated the optical absorption centers formation in magnesium aluminate spinel crystals at the action of high energy gamma or electron beams. It was revealed that at gamma irradiation the most probably the hole centers are formed to compare with that in electron irradiation. At electron beam irradiation the temperature of sample was raised which leads to thermal annealing of unstable radiation-induced centers

  19. Irradiation with low-dose gamma ray enhances tolerance to heat stress in Arabidopsis seedlings.

    Zhang, Liang; Zheng, Fengxia; Qi, Wencai; Wang, Tianqi; Ma, Lingyu; Qiu, Zongbo; Li, Jingyuan

    2016-06-01

    Gamma irradiation at low doses can stimulate the tolerance to environmental stress in plants. However, the knowledge regarding the mechanisms underlying the enhanced tolerance induced by low-dose gamma irradiation is far from fully understood. In this study, to investigate the physiological and molecular mechanisms of heat stress alleviated by low-dose gamma irradiation, the Arabidopsis seeds were exposed to a range of doses before subjected to heat treatment. Our results showed that 50-Gy gamma irradiation maximally promoted seedling growth in response to heat stress. The production rate of superoxide radical and contents of hydrogen peroxide and malondialdehyde in the seedlings irradiated with 50-Gy dose under heat stress were significantly lower than those of controls. The activities of antioxidant enzymes, glutathione (GSH) content and proline level in the gamma-irradiated seedlings were significantly increased compared with the controls. Furthermore, transcriptional expression analysis of selected genes revealed that some components related to heat tolerance were stimulated by low-dose gamma irradiation under heat shock. Our results suggest that low-dose gamma irradiation can modulate the physiological responses as well as gene expression related to heat tolerance, thus alleviating the stress damage in Arabidopsis seedlings. PMID:26945467

  20. Investigation of solid phase upon {gamma}-irradiation of ferrihydrite-ethanol suspension

    Jurkin, Tanja [Division of Materials Chemistry, Ruder Boskovic Institute, Bijenicka 54, HR-10002 Zagreb (Croatia); Zadro, Kreso [Department of Physics, Faculty of Science, University of Zagreb, Bijenicka 32, 10000 Zagreb (Croatia); Gotic, Marijan, E-mail: gotic@irb.h [Division of Materials Chemistry, Ruder Boskovic Institute, Bijenicka 54, HR-10002 Zagreb (Croatia); Music, Svetozar [Division of Materials Chemistry, Ruder Boskovic Institute, Bijenicka 54, HR-10002 Zagreb (Croatia)

    2011-07-15

    Ferrihydrite (FH) nanoparticles were synthesised and subjected to {gamma}-irradiation in the form of FH-ethanol suspension. The dose rate of {gamma}-radiation was {approx}16 kGy/h and the samples were irradiated to doses of up to 2590 kGy. {gamma}-irradiation of FH-ethanol suspensions did not cause the transformation of FH to any of the other iron oxide phases. Likewise, neither the Moessbauer and FT-IR spectroscopy nor the quantitative analysis using Energy Dispersive X-ray Spectroscopy gave any evidence of structural changes of FH upon {gamma}-irradiation. C, H analysis showed that the C concentration in FH gradually increased with dose and was higher in {gamma}-irradiated FH samples than in non-irradiated FH sample. This finding suggested that carbon in FH originated from ethanol degradation. The H concentration in FH gradually increased to the dose of up to 340 kGy and then slightly decreased. Magnetic measurements showed a progressive decrease in magnetisation with an increase in {gamma}-irradiation. The results of magnetic measurements and C, H analysis suggested the carbonisation of FH surface. It was supposed that {gamma}-irradiation of FH-ethanol suspension reductively decomposed ethanol thus generating unsaturated hydrocarbons and acetylides, which in turn formed a conjugate iron complex, thus carbonating the FH surface. The carbonisation of the FH surface prevented FH transformation to other iron oxide phases.

  1. Effect of Gamma Irradiation on Structural and Biological Properties of a PLGA-PEG-Hydroxyapatite Composite

    Sima Shahabi

    2014-01-01

    Full Text Available Gamma irradiation is able to affect various structural and biological properties of biomaterials In this study, a composite of Hap/PLGA-PEG and their ingredients were submitted to gamma irradiation doses of 25 and 50 KGy. Various properties such as molecular weight (GPC, thermal behavior (DSC, wettability (contact angle, cell viability (MTT assay, and alkaline phosphatase activity were studied for the composites and each of their ingredients. The results showed a decrease in molecular weight of copolymer with no change in the glass transition and melting temperatures after gamma irradiation. In general gamma irradiation can increase the activation energy ΔH of the composites and their ingredients. While gamma irradiation had no effect on the wettability of copolymer samples, there was a significant decrease in contact angle of hydroxyapatite and composites with increase in gamma irradiation dose. This study showed an increase in biocompatibility of hydroxyapatite with gamma irradiation with no significant effect on cell viability in copolymer and composite samples. In spite of the fact that no change occurred in alkaline phosphatase activity of composite samples, results indicated a decrease in alkaline phosphatase activity in irradiated hydroxyapatites. These effects on the properties of PLGA-PEG-hydroxyapatite can enhance the composite application as a biomaterial.

  2. Enhancement of refrigerated storage of fishery products using gamma irradiation

    A processe combining gamma radiation treatment with refrigeration has been suggested for better utilization of sea-foods of which large quantities will be available for processing after the implementation of the expansion programme of the fishing industry in India and the present capacity of refrigeration industry may be found to be inadequate to meet the demands of the expanded fishing industry. Gamma irradiation in the range of 0.1-0.25 Mrad enhances 2-3 fold storage life of refrigerated sea-foods. Low dose radiation treatment inactivates the gram-negative bacteria, the main source of sea-food spoilage, but not C. botulinum the growth of which is inhibited by the gram-negative bacteria in unirradiated sea-foods. Care has, therefore, to be taken to use a radiation dose which does not totally eliminate these bacteria so that a small percentage which survives leads to terminal spoilage and rejection of sea-foods even before C. botulinum produces toxins thus avoiding food poisoning. (M.G.B.)

  3. Rheological properties of blood after whole body gamma-irradiation

    This work aims to investigate the influence of whole body gamma irradiation on the rheological properties of rat's blood . The applied shear rate was from 12 to 375 s-1. low shear viscosity (up to 100 s-1) depends mainly on the erythrocytes aggregation while the high shear viscosity depends on the erythrocytes deformability. Adult male rats were exposed to 1, 2.5, 3.5,5,7 and 9 Gy single doses. The consistency index, apparent viscosity, yield stress and aggregation index were increased after exposure to gamma radiation . The dielectric properties of the erythrocytes, in the low frequency range (60 hz to 40 khz), were measured in order to investigate the changes in the membrane surface charge . The relative permittivity and relaxation time showed significant decrease after exposure to the lowest dose and continue to decrease as the dose increased. The obtained results showed that increase in the blood viscosity and aggregation index can be attributed to the decrease in the erythrocyte surface charges

  4. Synthesis of Copper nanoparticles through vesicle template using gamma irradiation

    Nano technology has gained attention for its application in life. This study was conducted to produce copper (Cu) nanoparticles using gamma ray irradiation through template vesicles. Cu nanoparticle has a variety of applications such as capacitor materials, catalyst, conductive coating, high thermal conductivity materials as well as lubricant additives. this study used gamma radiation compared to other methods because the use of gamma rays in producing nanoparticle is safer and environmental friendly. The purpose of this study was to see the effects of radiation on the formation of Cu nanoparticles. The radiation dose used was 80 kGy and 100 kGy. The vesicles were formed by mixing water, sodium n-lauroyl sarcosinat hydrated, 1-decanol and polyethylene glycol with certain ratio (85 %: 5 %: 7 %: 3 %). Analysis from the transmission electron microscopy (TEM) showed the production of multilammelar vesicles in size between 30 nm-80 nm. The formation of nanoparticles was analyzed using UV-Vis absorption spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). Analysis of UV-Vis absorption spectroscopy showed no resonance peak around 600 nm. XRD analysis confirmed the presence of Cu, Cu2O and CuO. Analysis and characterisation using transmission electron microscopy (TEM) also confirmed that nanoparticles were produced with different sizes according to the radiation dose. At the radiation dose of 80 kGy, nanoparticles size is found vary between 30 nm to 90 nm. While at the radiation dose of 100 kGy, nanoparticles size is found vary between 3 nm to 7 nm. From this study it can be concluded that higher radiation dse will produce smaller nanoparticles. (author)

  5. Identification of gamma irradiated pulse seed (Lens sp.) based on germination test

    The germination test of pulse seed provided a reliable method for the identification of lentil seeds that had been subjected to irradiation. Root and shoot lengths were found more sensitive to the gamma irradiation than the germination percentages. The critical dose that prevented the root elongation varied from 0.1 kGy to 0.5 kGy. Germination percentage was reduced drastically above 0.2 kGy. Above 1.0 kGy dose, the lentil seeds did not germinate. The sensitivity of lentil seeds to gamma irradiation was inversely proportional to moisture content of the seeds. In addition, storage period up to 12 months had little effect on irradiation the induced reduction of root and shoot lengths. Thus, this test can determine the difference between irradiated and non-irradiated lentil seeds even 12 months after gamma irradiation. (author)

  6. Effects of gamma irradiation on food contact polyethylene, polypropylene and polystyrene: additives and other chemicals

    The effects of gamma irradiation on additives, oligomers, and other chemicals in food contact polyethylene, polypropylene and polystyrene were investigated. Polyethylene and polypropylene products contained several antioxidants, lubricants and plasticizers. After gamma irradiation, the contents of all the antioxidants significantly decreased. Irgafos 168 disappeared the fastest. Lubricants and plasticizers decreased to some extent or not at all. 2,4-Di-tert-butylphenol was detected not only after irradiation but also before irradiation, and 1,3-di-tert-butylbenzene and 2,6-di-tert-butyl-1,4-benzoquinone were detected only after irradiation. They were presumed to be degradation products of the irradiation, though the former should be also a degradation product of the manufacturing process. On the other hand, the polystyrene products contained styrene dimers and trimers and their contents did not change after the gamma irradiation. (author)

  7. Nutritional, physiological, physicochemical and sensory stability of gamma irradiated Kimchi (Korean fermented vegetables)

    Effects of gamma irradiation on nutritional, physiological, physicochemical and sensory properties of the Korean lactic acid fermented vegetable, Kimchi, were investigated. The composition of amino acids and organic acids in Kimchi were not influenced by gamma irradiation less than 10 kGy. Angiotensine converting enzyme inhibitory, xanthin oxidase inhibitory, electron donating and antimicrobial activity of Kimchi extract were stable up to 10 kGy. There were no significant changes in pH and texture at less than 10 kGy. Color values were influenced at 10 kGy of gamma irradiation, and resulted in the increase of L*- and reduction of a*-value. About 90% of panelists identified a sensory difference between non-irradiated and 10 kGy-irradiated sample, and Kimchi irradiated at 10 kGy had lower scores in acceptability than those of the control or irradiated at 2.5 and 5 kGy

  8. Microbiological, sensorial and chemical quality of gamma irradiated pistachio nut (Pistacia vera l.)

    Mahfouz AL-BACHIR

    2014-01-01

    The present study investigated the effect of gamma irradiation and storage period on quality retention of raw pistachio nut. Var. Halebi. Kernel of the pistachio nuts were exposed to 1, 2 and 3 kGy of gamma irradiation. Irradiated and unirradiated nuts were kept at room temperature for 12 months. Used doses of irradiation significantly reduced the total bacterial plate counts (TBPCs) and total fungal counts up to undetectable level (less than 10 CFU g-1). Irradiation doses of 1, 2 and 3 kGy o...

  9. Kinetic analysis of the thermal decomposition of gamma-irradiated nickel oxalate

    Mahfouz, R.M.; Abd-El-Wahab, M.M.M. (Assiut Univ. (Egypt))

    1994-03-01

    The isothermal decomposition of un-irradiated and pre-[gamma]-irradiated dehydrated nickel oxalate has been studied in the temperature range 250-365[sup o]C. Irradiation appears to increase the number of potential nuclei-forming sites without modification of the mechanism of the thermal decomposition, which has been shown to proceed by a nucleation and growth mechanism both for un-irradiated and pre-[gamma]-irradiated samples of nickel oxalate. Application of Vand-Primak method for analysis of the decomposition data and calculation of activation energies of the decomposition process gives a good fit with that calculated using Arrhenious equation. (author).

  10. High irradiation and ageing properties of resistive Micromegas detectors at the new CERN Gamma Irradiation Facility

    Andreou, Dimitra

    2016-01-01

    Resistive Micromegas have been developed in recent years with the aim of making this technology usable in HEP experiments where the high sparking rate of classical Micromegas is not tolerable. A resistive Micromegas with four layers and an active surface of 0.5 m2 each, has been designed and built at CERN as prototype of the detectors to be used for the upgrade of the ATLAS experiment. The detector has been exposed to an intense gamma source of 16 TBq in order to study the effects of ageing and evaluate the detector behavior under high irradiation.

  11. Characterization of color centers in quartz induced by gamma irradiation

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  12. The effect of gamma irradiation on piophila casei (Linnae)

    In a study on insects infesting sun-dried salted mackerell, samples were collected from six markets in South Jakarta. It was found that piophila casei was the only insect infesting the sun-dried salted mackerell. The eggs, larvae and pupae of the flies were generally found in the head cavity and in the stomach of the fish. For the determination of disinfestation dose, the larvae and the pupae were irradiated by gamma rays. It was found that the larvae was more sensitive to irradiation than the pupae. The LD99 of pupae was 0.366 kGy. Various combinations of salting and drying processes have been done for the preservation of mackerell. It could be concluded that the growth of piophila casei was influenced more by water content than by salt content. Other aspects such as the occurence of mold and yeast, have to be considered in the preservation of fish. It was also found that ten and twenty hours salting time and thirty hours drying are the best treatments. Piophila casei did not infest on the surface of fish. (author)

  13. Investigation of Thermoluminescence Properties of Gamma- Irradiated Synthetic TL -Compound

    Calcium sulphate doped by dysprosium (CaSO4:Dy) has been locally prepared under laboratory controlled condition. Two standard techniques were used during the course of this work to achieve the optimum concentration of the activator (Dy). The obtained samples were thermally treated to improve its sensitivity as well as its stability. The glow curves of the prepared CaSO4:Dy have been taken after gamma irradiation and show three glow peaks at about 140, 225 and 350 degree C. The main dosimetric glow peak is located at 225 degree C. . It is observed also that the dosimetry peak is shifted to lower direction by increasing the dopant concentration from 0.5% up to 3% by about 15 degree C. The experimental results show that the optimum concentration of Dy in CaSO4 could be achieved when 2% by Wt. of the dopant is added to the host lattice. Also maximum sensitization is obtained when the samples are thermally annealed at 600 degree C for 100 minutes. The prepared samples are also sensitized by high dose ?-irradiation (7 kGy) from 60Co source. The rate of fading of these TL detectors is 11% after storage for three months in ambient temperature. These results have been discussed in greater details

  14. Characterization of color centers in quartz induced by gamma irradiation

    Guttler, Rainer A.S., E-mail: rainersg@usp.b [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Geociencias; Enokihara, Cyro T.; Rela, Paulo R., E-mail: prela@ipen.b, E-mail: cteiti@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    The availability of gamma ray irradiators in Brazil increased the possibilities of treatments of gemstones for color enhancements. One of the minerals with a very high potential of these treatments is quartz, a very widespread mineral with much colored commercial varieties. Quartz occurs in Brazil mainly in two geological environments, called pegmatitic and hydrothermal. The detailed mechanism of color center formation of these two types of quartz will be investigated by spectroscopic and chemical analysis. Until yet, it can be shown that due to chemical differences of the nature of mineral forming fluids, the two types behave differently. All quartzes contain mainly traces of Iron, Aluminum, Lithium and some amounts of Water. The quartz of hydrothermal origin incorporated much structurally bound water, and despite some similarities with the chemical composition of pegmatitic quartz, this high water content is the reason for the formation of Silanol radicals, giving the green color to the quartz. The main difference in chemical composition of pegmatitic quartz is the presence of higher amounts of Al and Li , responsible for the brownish and yellowish colors formed by irradiation. Since each pegmatite is different, the quartz will behave differently. This explains the formation of the famous 'Green Gold' of quartz from Sao Jose da Safira , and the more yellowish, Citrine type, color of quartz from the Coluna deposit, near Itamarandiba, Minas Gerais. (author)

  15. Microbial decontamination of cosmetic products by gamma irradiation

    The microbiological quality of cosmetic products (skin creams, massage gels and hair lotion) and the effect of gamma irradiation on this quality were investigated.The effectiveness of these cosmetic products with the tested pathogenic microorganisms was also examined. Total bacterial counts (TBC) of examined cosmetic products ranged between 5 cfu/g or ml. Most cosmetic products evaluated were free from mold and yeast. Spore forming bacteria (SFB) were low and ranged between 2 cfu/g or ml. The enterobacteriaceae (Ent) group was generally absent from the examined cosmetic products except for one sample (varic, skin cream) which contained 7x103 cfu/g. All cosmetic products studied were free from Pseudomonas species, Aeromonas hydrophila; Bacillus cereus; Listeria monocytogenes and Salmonella species. Only one sample (varic, skin cream) contained E. coli (2x102 cfu/g). Enterococcus faecalis was found in three samples of cosmetic products tested (maxi care, panol and varic creams) and the counts were 7x102, 2x102 and 5x104 cfu/g, respectively. Also Staphylococcus aureus was found in the same three samples and the counts were in the range of 2-3x102 cfu/g. The effectiveness of cosmetic products with the tested pathogenic bacteria differs according to the type of cosmetic products examined . The irradiation dose of 6 kGy was very effective in microbial decontamination and elimination of pathogenic bacteria in cosmetic products for enhancing health quality and ensuring safety of these products.

  16. Changes of selected secondary metabolites in potatoes and buckwheat caused by UV, gamma- and microwave irradiation

    Changes of total polyphenols, phenolcarboxylic acids and ascorbic acid in potato tubers cv. Kordoba and Rosella and three buckwheat samples (seeds, seedlings and plants: F. esculentum, cv. Pyra and Emka and tartarian buckwheat F. tataricum) induced by UV-C irradiation, gamma-irradiation and microwave irradiation were investigated

  17. Effect of a whole-body gamma irradiation on glycemia and ATP blood level in rats

    An attempt was made to establish possible correlations, during gamma irradiation, between glucose and ATP. The variations in their blood levels were studied, using specific enzymatic methods. The results obtained after a low dose irradiation (150 roentgens) demonstrated an increase of glycemia during the hours following the irradiation and a parallel decrease of ATP blood level

  18. Effect of gamma irradiation on viscosity of aqueous solutions of some natural polymers

    Effect of gamma irradiation on viscosity of aqueous solution of alginate and carbon xylmethyl cellulose (CMC) irradiated in solid state has been carried out. the viscosity of aqueous solution of alginate and CMC decreased remarkably with increasing dose and the viscosity of 2% solution of above polymers irradiated at 50 kGy was about 100 times lower than the original one. (author)

  19. The aging process of optical couplers by gamma irradiation

    Bednarek, Lukas; Marcinka, Ondrej; Perecar, Frantisek; Papes, Martin; Hajek, Lukas; Nedoma, Jan; Vasinek, Vladimir

    2015-08-01

    Scientists have recently discovered that the ageing process of optical elements is faster than it was originally anticipated. It is mostly due to the multiple increases of the optical power in optical components, the introduction of wavelength division multiplexers and, overall, the increased flow of traffic in optical communications. This article examines the ageing process of optical couplers and it focuses on their performance parameters. It describes the measurement procedure followed by the evaluation of the measurement results. To accelerate the ageing process, gamma irradiation from 60Co was used. The results of the measurements of the optical coupler with one input and eight outputs (1:8) were summarized. The results gained by measuring of the optical coupler with one input and four outputs (1:4) as well as of the optical couplers with one input and two outputs (1:2) with different split ratios were also processed. The optical powers were measured on the input and the outputs of each branch of each optical coupler at the wavelengths of 1310 nm and 1550 nm. The parameters of the optical couplers were subsequently calculated according to the appropriate formulas. These parameters were the insertion loss of the individual branches, split ratio, total losses, homogeneity of the losses and directionalities alias cross-talk between the individual output branches. The gathered data were summarized before and after the first irradiation when the configuration of the couplers was 1:8 and 1:4. The data were summarized after the third irradiation when the configuration of the couplers was 1:2.

  20. Extending the Shelf-life of Pear Fruits by Using Gamma Irradiation

    The effects of gamma irradiation on lesion diameters of grey mold disease of pear and some physico-chemical parameters of pear fruits were studied in this investigation as a pre storage treatment for extend shelf life of pear fruits. Pear fruits (Pyrus Communis, L.) were exposed to different gamma irradiation doses 0, 0.5, 1, 1.5, 2, 2.5 and 3 KGy and stored for 10, 20 and 30 days in 0 degree C and 85-90% RH. The increment of irradiant dose caused decrement of lesion diameters of grey mold disease of pear. The narrowest diameters were recorded with 3.0 KGy irradiation dose. The low dose of gamma irradiation 0.5 KGy gave a relatively high value of firmness although in higher doses firmness of pear fruits decreased. The highest loss weight was found in unirradiated fruits while the loss of weight in all irradiated fruits was still lower than those of unirradiated ones and low radiation doses decreased the loss of weight. Total soluble solid increased with increasing in storage periods with respect to gamma irradiation effect there was fluctuation in total soluble solid values. There was a decreasing in acidity during storage of irradiated and un-irradiated fruits. Free amino acid and soluble protein show a slight increasing at 0.5 KGy such increasing was followed by a gradual decrease in higher gamma irradiation doses

  1. Stability study of human serum albumin freeze dried kits: Non-Irradiated and Gamma-irradiated kits

    This study involves the time stability of the human serum albumin (HSA) freeze dried kits and the effect of gamma-irradiation on these kits and their stability. The Sn(II) Cl2 and Sn(II) citrate HSA kits have similar stability, labelling percentage and biological distribution in mice. The data obtained for the gamma-irradiation kits shows that both the Sn(II) Cl2 and Sn(II) citrate kits do show any physical, chemical or biological change of the kit constituents after their irradiation with 2.5 M rad dose

  2. Effect of Gamma Irradiation on Botrytis cinerea Causing Gray Mold and Cut Chrysanthemum Flowers

    Eun-Hee Chu

    2015-09-01

    Full Text Available Gray mold caused by Botrytis cinerea is one of the most important postharvest fungal pathogens of cut flowers. Here, gamma irradiation, an alternative for phytosanitary purposes, and sodium dichloroisocyanurate (NaDCC were used to control B. cinerea in a cut chrysanthemum (Chrysanthemum morifolium Ramat. cultivar, ‘Baekma’, one of the cultivars susceptible to B. cinerea. Spore germination and mycelium growth of B. cinerea were inhibited by gamma irradiation in an inversely dose-dependent manner. A dose of 4 kGy completely inhibited the mycelium growth of B. cinerea. A significant change in flower quality (physical properties on chrysanthemum was shown from gamma irradiation at over 0.2 kGy (p<0.05. Therefore, in this study, the integration of gamma ray (below 0.2 kGy and NaDCC, an eco-friendly form of chlorine, was investigated to control the disease with low dose of gamma irradiation dose. Interestingly, the gamma irradiated flowers showed more disease severity than the non-irradiated flowers. The combined treatment of gamma irradiation and NaDCC does not affect the severity of the fungal disease, whereas only 70 ppm of NaDCC treatment showed a significantly reduced severity. These results suggest that only chlorination treatment can be applied to control B. cinerea in cut chrysanthemum flowers.

  3. Influence of gamma-irradiation and microwaves on the antioxidant property of some essential oils

    The antioxidant property of anise, caraway, cumin and fennel essential oils extracted from untreated, gamma-irradiated and microwaved fruits against sunflower oil oxidative rancidity was evaluated. The fruits were exposed to gamma-irradiation at 10 KGy and to microwaves at low oven power setting for 1 min. The essential oils were added individually (200 ppm) to sunflower oil and the rate of oil oxidation was followed by determining the peroxide value during storage at room temperature. The irradiated and microwaved essential oils exhibited an antioxidant activity and was superior to that of sunflower oil catalysed by a mixture of BHT + BHA (200 ppm) in most cases. The present data show that gamma-irradiation and microwave treatments did not affect the antioxidant property of the essential oils under study. In addition the essential oils extracted from the gamma-irradiated fruits were more effective as an antioxidant in sunflower oil than those produced from microwaved fruits

  4. Effect of presowing laser and gamma irradiation upon the yield quality of cucumber seeds

    Cucumber seeds from cultivar Gergana were irradiated with helium-neon 632.8 nm lasers-exit power 20 MWt and gamma-rays from radioactive cobalt (Co60). The following variants were tested: sevenfold laser irradiation, 10 Gy gamma irradiation and combined laser+gamma irradiation. Untreated seeds were used as a control. As a result of radiation processing the yield of reproductional seeds has been increased by 11.1-20.0%, the germination energy - by 2.3-3.8% and the weight of 1000 air-dry seeds - by 2.3-4.2%. The increase of seed yield was connected mainly with the higher yield of ripe fruits (3.1-11.6%) and less (6.0-8.0%) - with the larger seeds quantity formed into one fruit. The higher radiobiological effect was obtained by irradiation with the combined laser+gamma radiation. (author)

  5. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a 60Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 deg. C. Additionally, the m-RNA levels of β-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

  6. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    Todoriki, Setsuko; Bari, Latiful; Kitta, Kazumi; Ohba, Mika; Ito, Yasuhiro; Tsujimoto, Yuka; Kanamori, Norihito; Yano, Erika; Moriyama, Tatsuya; Kawamura, Yukio; Kawamoto, Shinichi

    2009-07-01

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a 60Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 °C. Additionally, the m-RNA levels of β-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

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

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

    2010-03-15

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

  8. Gamma irradiation improves the antioxidant activity of Aloe vera (Aloe barbadensis miller) extracts

    Aloe has been widely used in food products, pharmaceuticals, and cosmetics because of its aromatic and therapeutic properties. In the present study, the ethanolic extracts of aloe gel were gamma-irradiated from 10 to 100 kGy. After gamma irradiation, the color of the ethanolic extracts of aloe gel changed to red; this color persisted up to 40 kGy but disappeared above 50 kGy. Liquid chromatography/mass spectrometry analysis demonstrated the production of a new, unknown compound (m/z=132) after gamma irradiation of the ethanolic extracts of aloe gel. The amount of this unknown compound increased with increasing irradiation up to 80 kGy, and it was degraded at 100 kGy. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by the 1,1-diphenyl-2-picrylhydrazyl-radical scavenging capacity. The antioxidant activity of aloe extract was dramatically increased from 53.9% in the non-irradiated sample to 92.8% in the sample irradiated at 40 kGy. This strong antioxidant activity was retained even at 100 kGy. These results indicate that gamma irradiation of aloe extract can enhance its antioxidant activity through the formation of a new compound. Based on these results, increased antioxidant activity of aloe extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  9. Improvement of color and physiological properties of tuna-processing by-product by gamma irradiation

    Although the by-products from fishery industry had many nutrients, it is being wasted or only used as bacteria media. In this study, the effect of a gamma irradiation on the cooking drips of Thunnus thynnus (CDT) was investigated to examine the possible use of the cooking drips as a functional material for food and cosmetic composition. Total aerobic bacteria, and yeasts/molds from CDT were detected at the level of 2.79 and 2.58 Log CFU/mL, respectively. But, CDT was efficiently sterilized by a gamma irradiation at a low dose of 1 kGy. The Hunter L* value of the gamma-irradiated ethanol extract of CDT was increased, and the a* and b* values were decreased compared to the non-irradiated extract, showing color improvement. Antioxidant activity of the ethanol extract of CDT was increased by a gamma irradiation depending on the irradiation dose. The increased contents of polyphenolic compounds and proteins in CDT extract by gamma irradiation may be the reason of the increased biological activity. These results suggested that the wasted cooking drips can be successfully used as functional components with gamma irradiation treatment.

  10. Effect of gamma-irradiation on the survival of Listeria monocytogenes and allergenicity of cherry tomatoes

    Todoriki, Setsuko [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan)], E-mail: setsuko@affrc.go.jp; Bari, Latiful; Kitta, Kazumi; Ohba, Mika; Ito, Yasuhiro; Tsujimoto, Yuka [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan); Kanamori, Norihito [Japan International Research Center for Agricultural Science, Tsukuba, Ibaraki 305-8686 (Japan); Yano, Erika; Moriyama, Tatsuya; Kawamura, Yukio [School of Agriculture, Kinki University, Nara-city, Nara 631-8505 (Japan); Kawamoto, Shinichi [National Food Research Institute, Tsukuba, Ibaraki 305-8642 (Japan)

    2009-07-15

    The presence of Listeria monocytogenes in fresh produce is a growing concern because of the possibility of food-borne illness. Ionizing radiation is an effective non-thermal means of eliminating pathogenic bacteria in fresh produce; however, the effect of ionizing irradiation on the allergenic properties of the host commodities remains unknown. This study aimed (i) to determine the effective dose of gamma-irradiation in eliminating L. monocytogenes on whole cherry tomatoes and (ii) to evaluate the effect of gamma-irradiation on the allergenic properties of tomato proteins. Cherry tomatoes that were inoculated with a mixture of five L. monocytogenes strains were treated with gamma-rays from a {sup 60}Co source. A 1.25 kGy dose of gamma-irradiation was found to be sufficient to eliminate L. monocytogenes on whole cherry tomatoes. The immunoblot profile of serum samples obtained from two patients with tomato allergy revealed that gamma-irradiation did not affect the allergenicity of tomato proteins for up to 7 days after irradiation when the tomatoes were stored at 20 deg. C. Additionally, the m-RNA levels of {beta}-fructofuranosidase, polygalacturonase, pectin esterase, and superoxide dismutase, the main allergenic proteins in tomato, were not affected by the applied irradiation dose. Thus, this study demonstrated that a 1.25 kGy dose of gamma-irradiation effectively eliminates L. monocytogenes on cherry tomatoes without affecting the expression of allergenic proteins in the fruits.

  11. Improvement of color and physiological properties of tuna-processing by-product by gamma irradiation

    Choi, Jong-il; Kim, Hyun-Joo; Kim, Jae-Hun; Song, Beom-Seok; Chun, Byeong-Soo; Ahn, Dong-Hyun; Byun, Myung-Woo; Lee, Ju-Woon

    2009-07-01

    Although the by-products from fishery industry had many nutrients, it is being wasted or only used as bacteria media. In this study, the effect of a gamma irradiation on the cooking drips of Thunnus thynnus (CDT) was investigated to examine the possible use of the cooking drips as a functional material for food and cosmetic composition. Total aerobic bacteria, and yeasts/molds from CDT were detected at the level of 2.79 and 2.58 Log CFU/mL, respectively. But, CDT was efficiently sterilized by a gamma irradiation at a low dose of 1 kGy. The Hunter L* value of the gamma-irradiated ethanol extract of CDT was increased, and the a* and b* values were decreased compared to the non-irradiated extract, showing color improvement. Antioxidant activity of the ethanol extract of CDT was increased by a gamma irradiation depending on the irradiation dose. The increased contents of polyphenolic compounds and proteins in CDT extract by gamma irradiation may be the reason of the increased biological activity. These results suggested that the wasted cooking drips can be successfully used as functional components with gamma irradiation treatment.

  12. Gamma irradiation improves the antioxidant activity of Aloe vera (Aloe barbadensis miller) extracts

    Mi Lee, Eun; Bai, Hyoung-Woo; Sik Lee, Seung; Hyun Hong, Sung; Cho, Jae-Young; Yeoup Chung, Byung

    2012-08-01

    Aloe has been widely used in food products, pharmaceuticals, and cosmetics because of its aromatic and therapeutic properties. In the present study, the ethanolic extracts of aloe gel were gamma-irradiated from 10 to 100 kGy. After gamma irradiation, the color of the ethanolic extracts of aloe gel changed to red; this color persisted up to 40 kGy but disappeared above 50 kGy. Liquid chromatography/mass spectrometry analysis demonstrated the production of a new, unknown compound (m/z=132) after gamma irradiation of the ethanolic extracts of aloe gel. The amount of this unknown compound increased with increasing irradiation up to 80 kGy, and it was degraded at 100 kGy. Interestingly, it was found that gamma irradiation significantly increased the antioxidant activity, as measured by the 1,1-diphenyl-2-picrylhydrazyl-radical scavenging capacity. The antioxidant activity of aloe extract was dramatically increased from 53.9% in the non-irradiated sample to 92.8% in the sample irradiated at 40 kGy. This strong antioxidant activity was retained even at 100 kGy. These results indicate that gamma irradiation of aloe extract can enhance its antioxidant activity through the formation of a new compound. Based on these results, increased antioxidant activity of aloe extracts by gamma rays can be applied to various industries, especially cosmetics, foodstuffs, and pharmaceuticals.

  13. Effect of gamma irradiation on microbial load and quality characteristics of minced camel meat

    The effect of gamma irradiation on microbial load, chemical and sensory characteristics of camel meat has been evaluated. Camel meat were irradiated at doses of 0, 2, 4 and 6 kGy of gamma irradiation. Irradiated and unirradiated meat were kept in a refrigerator (1-4 Centigrade). Immediately after irradiation, general composition and sensory evaluation of camel meat were done. Microbiological and chemical analyses of camel meat were evaluated at 0, 2, 4 and 6 weeks of storage. The results indicated that all doses of gamma irradiation reduced the total counts of mesophilic aerobic bacteria and total coli form of camel meat. Thus the microbiological shelf-life of camel meat was significantly extended from less than 2 weeks (control) to more than 6 weeks (samples irradiated with 2, 4 or 6 kGy). No significant differences in moisture, protein, fat, Thiobarbituric acid (TBA) value, total acidity, pH vale and fatty acids (C14: 0; C16: 0; C18:0) of camel meat were observed due to irradiation. Both total volatile basic nitrogen (VBN) and lipid oxidation value in camel meat were effected by gamma irradiation. Immediately after treatment, VBN of irradiated camel meat increased and lipid oxidation values decreased. Sensory evaluation showed no significant differences between irradiated and unirradiated camel meats. (author)

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

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

  15. Effect of gamma irradiation on storability of apples (Malus domestica L.)

    The effects of gamma irradiation on storability of two main apple varieties in Syria, Golden Delicious and Starking, were investigated. Fruits were irradiated with 0, 0.5, 1, and 1.5 kGy and combined irradiation with 1 kGy after packaging the fruits with polyethylene or paper bags. Irradiated and unirradiated fruits were stored at 1 to 2 C deg and 80 to 90% Rh. Weight loss and spoilage were evaluated throughout the different storage periods. Firmness, coloration and pH values were estimated immediately after irradiation. The results showed that in both varieties, gamma irradiation increased the weight loss after 45 days of storage in the 1995, but not in the 1996 season. After 180 days of storage gamma irradiation had different effects on weight loss depending on the season and variety, and increased the fungal spoilage. Application of gamma irradiation prevented the growth of Aspergillus niger and the formation of skin scald in Golden Delicious fruits. Immediately after treatment, gamma irradiation increased the softening of fruits, changed their colour from green to yellow and decreased the pH value of the juice. Combined treatments decreased the rate of weight loss and skin scald in Golden Delicious fruits and increased the fungal spoilage. (author)

  16. Induction of microspore embryogenesis in Brassica napus L. by gamma irradiation and ethanol stress

    Summary Gamma irradiation and ethanol stress treatments redirected pollen development to an embryo formation pathway in Brassica napus. Less than 0.01% of microspores developed into embryos at 25°C compared to approximately 2% at 32°C. However, subsequent to gamma irradiation and ethanol treatments up to 1% and 0.7% of microspores formed embryos at 25°C, respectively. Gamma irradiation also enhanced embryogenesis at 32°C. The possible importance of these findings is discussed in relation to microspore embryogenesis

  17. Changes in microbial community during biohydrogen production using gamma irradiated sludge as inoculum.

    Yin, Yanan; Wang, Jianlong

    2016-01-01

    The changes in microbial community structures during fermentative hydrogen production process were investigated by analyzing 16S rDNA gene sequences using gamma irradiated sludge as inoculum. The experimental results showed that the microbial community structure of untreated sludge was very rich in diversity. After gamma irradiation, lots of species were inhibited, and species with high survival rates under radiation conditions became dominant. After fermentation, Clostridium butyrium and a sequence closely related to Clostridium perfringens ATCC 13124(T) (CP000246) became predominant, which were all common hydrogen producers. Microbial distribution analysis indicated that gamma irradiation was a good pretreatment method for enriching hydrogen-producing strains from digested sludge. PMID:26492174

  18. Effect of the gamma irradiation on the bio-sorption of Cr (Vi) by orange peel

    The orange peel (Citrus sp.) is a bioadsorbent that contains functional groups able to remove Cr (Vi). To study the effect of gamma irradiation in the sorption capacity, the Nn materials were irradiated with gamma rays using a Co60 source to dose from 10 to 3500 KGy (Nlγ). The biomass irradiation with gamma rays was successful since it increased the hexavalent chromium removal obtaining a maximum removal percentage of 100%. Sorption isotherms were realized to determine the concentration effect of initial Cr (Vi), the ph effect of the solution and the relationship m/v. (Author)

  19. Studies on the effect of gamma irradiation on shelf life of Kagzi lime (Citrus aurantifolia swingle)

    Influence of irradiation on shelf life of Kagzi lime fruits were studied. The results revealed that most of the physical and chemical parameters of fruits were significantly influenced by 100 Gy gamma radiation up to 22 days without affecting fruit quality. Higher doses of gamma irradiation (> 200 Gy) deteriorated the fruit quality and organoleptic parameters of the fruit. Thus, irradiation of lime fruits with 100 Gy gamma radiation extended shelf life of lime fruits and also helps in maintaining the chemical constituents viz., T.S.S. Acidity, Vitamin C, pH and juice content. (author)

  20. Conceptual design of gamma irradiator (ISG-500) for preservation of farming product

    A conceptual design of gamma irradiator ISG-500 for a preservation of farming product has been done. The design of gamma irradiator are multi purpose with the activity of radiation source used at 2x250 kCi cobalt-60. This gamma irradiator will be built by using local materials, like as for the building structure construction, the mechanical and electrical systems and for the instrumentation and control systems. The sources of radiation that will be used is Co60 pencil types (C 188 - Nordion), concrete structured building according to BAPETEN rule and the numbers of carriers that will be used are 15 carriers. (author)

  1. H2 production through oxide irradiation: Comparison of gamma rays and vacuum ultraviolet excitation

    The production of molecular hydrogen by gamma radiolysis and vacuum ultra violet photolysis of dried and hydrated nano-porous titania and zirconia nanoparticles has been studied. The nanoparticles were prepared as free standing films using a surface sol-gel process on cellulose. A significant hydrogen production was observed for both TiO2 and ZrO2 in vacuum ultra violet or gamma irradiation. This production could be optimized by controlling the amount of water and by introducing hydroxyl radical scavengers in the irradiated systems. The mechanism underlying hydrogen production seems qualitatively different in gamma and in vacuum ultra violet (VUV) irradiation. (authors)

  2. Effect of gamma irradiation on DC electrical conductivity of ZnO nanoparticles

    The temperature dependent dc electrical conductivity of gamma irradiated Zinc oxide (ZnO) nanoparticles is presented in this paper. The X-ray diffraction (XRD) pattern shows hexagonal wurtzite structure of ZnO. Fourier Transform Infrared Spectroscopy (FTIR) confirms Zn-O stretching vibrations. UV-Visible spectroscopy studies show that the energy band gap (Eg) of the prepared ZnO nanoparticles increases with respect to gamma irradiation dose, which can be related to room temperature dc electrical conductivity. The result shows significant variation in the high temperature dc electrical conductivity of ZnO nanoparticles due to gamma irradiation

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

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

  4. Effect of gamma irradiation on curcuminoids and volatile oils of fresh turmeric ( Curcuma longa)

    Dhanya, R.; Mishra, B. B.; Khaleel, K. M.

    2011-11-01

    In our earlier study a radiation dose of 5 kGy was reported to be suitable for microbial decontamination and shelf life extension of fresh turmeric ( Curcuma longa), while maintaining its quality attributes. In continuation of that work, the effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric was studied. Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. Curcuminoid content and volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. The curcuminoid content was slightly increased by gamma irradiation. No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents.

  5. The effects of. gamma. -irradiation on Ti-Ni shape-memory alloy

    Zhang Guilin; Xu Feng; Liu Wenhong; Hu Wenxiang; Yu Fanghua; Zhang Yiping (Academia Sinica, Shanghai, SH (China). Shanghai Inst. of Nuclear Research); Wang Jingcheng; Shao Zichang (Shanghai Iron and Steel Research Inst, SH (China))

    1992-04-01

    Because gamma irradiation provides a means of introducing lattice defects into crystalline solids in a controlled fashion, it can be used to study the influence of lattice defects on the physical properties of solids such as shape-memory alloys (SMAs). The study described here shows that gamma irradiation can be used to ameliorate the performance of SMAs and to understand the mechanism of the shape memory further in these alloys. In particular it shows the effect of gamma irradiation on the martensitic transformation temperatures of Ti-Ni alloys. (UK).

  6. Measurement of Dose Distributions for Useful Utilization of BioBeam 8000 Gamma Irradiation Device

    Gamma irradiation device using Cs-137 have been widely utilized to the irradiation of cell, blood, and animal, and the dose measurement and education. Radiation irradiators for cell and blood irradiation used in numerous research institutions has demerits to perform the experiment of large volume objects like as 96 Multiwell Plate. Therefore, KIRAMS (Korea Institute of Radiological and Medical Sciences) introduced Gamma irradiation device having large volume capacity (BioBeam 8000, STS Steuerungstechnik and. Strahlenschutz GmbH, Braunschweig, Germany, Cs137, 3.35 Gy/min). In this study, dose the distribution of newly implemented BioBeam 8000 Gamma irradiation device was measured using glass dosimeter and Gafchromic EBT film dosimetry. In addition, an user guideline for useful utilization of the device based on measurement results are presented

  7. Application of positron annihilation lifetime technique for {gamma}-irradiation stresses study in chalcogenide vitreous semiconductors

    Shpotyuk, O.; Golovchak, R.; Kovalskiy, A. [Scientific Research Company ' ' Carat' ' , Stryjska str. 20279031 Lviv (Ukraine); Filipecki, J.; Hyla, M. [Physics Institute, Pedagogical University, Al. Armii Krajowej 13/1542201 Czestochowa (Poland)

    2002-08-01

    The influence of {gamma}-irradiation on the positron annihilation lifetime spectra in chalcogenide vitreous semiconductors of As-Ge-S system has been analysed. The correlations between lifetime data, structural features and chemical compositions of glasses have been discussed. The observed lifetime components are connected with bulk positron annihilation and positron annihilation on various native and {gamma}-induced open volume defects. It is concluded that after {gamma}-irradiation of investigated materials the {gamma}-induced microvoids based on S{sub 1}{sup -}, As{sub 2}{sup -}, and Ge{sub 3}{sup -} coordination defects play the major role in positron annihilation processes. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  8. Effect of gamma ray irradiation on seed germination of Ardisia crenata

    The seeds of Ardisia crenata were used as experimental material and treated with gamma ray under the irradiative doses ranging from 50∼500 Gy. The results showed that the seed germination rates were not affected under the irradiative dose of 150 Gy and below. The germination potentiality turned to reduce while the irradiative dose was higher than 250 Gy. And in the range of 300∼500 Gy the germination rates were decreased with the increase of the irradiative dose. (authors)

  9. Texture, color, lipid oxidation and sensory acceptability of gamma-irradiated marinated anchovy fillets

    The effect of gamma irradiation (0, 2, 3 and 4 kGy) on vacuum-packed marinated anchovy fillets was analyzed for their texture, color, lipid oxidation and sensory acceptability after 10 months under refrigeration. Marinated (3% acetic acid, 10% sodium chloride and 0.2% citric acid) Engraulis anchoita fillets were vacuum-packed and irradiated with a cobalt-60 source at a semi-industrial irradiation facility. The irradiation caused a slight increase in hardness values regardless of the applied dose but maintained a consistent texture over the 10 months, even though the control samples softened, most likely due to degradation. This hardness increase did not affect the textural sensory acceptability. Irradiation did not modify the color but still reduced color changes during storage, benefitting the product's quality. TBARS was increased in every sample throughout storage, but irradiation decreased these values. Sensory acceptability was not affected by gamma irradiation. Therefore, gamma irradiation could be successfully applied to this type of product for the purpose of shelf-life extension. - Highlights: • Marinated anchovies were γ-irradiated at 2, 3 and 4 kGy and stored at 4 °C (10 months). • Irradiation slightly hardened the texture and reduced its softening during storage. • Irradiated marinades had good sensory acceptability without differences with controls. • Irradiation improved the quality by reducing texture softening and color changes

  10. DNA damage response signaling in lung adenocarcinoma A549 cells following gamma and carbon beam irradiation

    Ghosh, Somnath [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Narang, Himanshi, E-mail: himinarang@gmail.com [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Sarma, Asitikantha [Radiation Biology Laboratory, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Krishna, Malini [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

    2011-11-01

    Carbon beams (5.16 MeV/u, LET = 290 keV/{mu}m) are high linear energy transfer (LET) radiation characterized by higher relative biological effectiveness than low LET radiation. The aim of the current study was to determine the signaling differences between {gamma}-rays and carbon ion-irradiation. A549 cells were irradiated with 1 Gy carbon or {gamma}-rays. Carbon beam was found to be three times more cytotoxic than {gamma}-rays despite the fact that the numbers of {gamma}-H2AX foci were same. Percentage of cells showing ATM/ATR foci were more with {gamma}-rays however number of foci per cell were more in case of carbon irradiation. Large BRCA1 foci were found in all carbon irradiated cells unlike {gamma}-rays irradiated cells and prosurvival ERK pathway was activated after {gamma}-rays irradiation but not carbon. The noteworthy finding of this study is the early phase apoptosis induction by carbon ions. In the present study in A549 lung adenocarcinoma, authors conclude that despite activation of same repair molecules such as ATM and BRCA1, differences in low and high LET damage responses might be due to their distinct macromolecular complexes rather than their individual activation and the activation of cytoplasmic pathways such as ERK, whether it applies to all the cell lines need to be further explored.

  11. Sterilization of Carriers by using Gamma Irradiation for Bio fertilizer Inoculum Production

    Full text: Gamma irradiation has been widely used in sterilization process, which leads to improvement in the quality of the products. In the case of bio fertilizer inoculum, the sterilized carrier is also needed for producing high quality bio fertilizer. This study aimed at determining the factors, such as carrier materials, moistures, and packing sizes including packaging materials that may affect the sterilization efficiency by using gamma irradiation. All carrier materials, peat and compost, could be efficiently sterilized by irradiation. The carriers that have moisture content lower than 20% could be sterilized by irradiation at 15 kGy, while carrier with 30% moisture content must be sterilized by irradiation at 25 kGy. Higher irradiation dose was also necessary for sterilization of bigger carrier packing sizes. For, packaging materials, polyethylene bag appeared most durable after gamma irradiation even at high doses. However, contaminants could be detected in irradiated carrier after storage at room temperature for two months. It was hypothesized that these contaminants are spore forming microorganisms, which resist gamma irradiation. This hypothesis, as well as the quality of bio fertilizer produced from irradiated carrier, will be further evaluated

  12. The Feasibility of Gamma Irradiation for Developing Malaria Vaccine

    Malaria, a plasmodial disease, causes more than one million deaths per year and has a significant public health impact. Improved access to prompt treatment with effective antimalarial drugs need to be conducted for prevention of infection in high risk groups. However, the parasite as causal agent has exhibited a potential danger of wide-spread resistances. This warning has directed attention to the study of alternative methods of protection against the disease, among them is to do the immunization. A deeper understanding of the nature and regulation of protective immune mechanisms against this parasite will facilitate the development of much needed vaccines. Developing a malaria vaccine remains an enormous scientific, technical, and financial challenge. Currently a vaccine is not fully available. Among the practical applications of radiobiological techniques that may be of considerable interest for public health is the use of ionizing radiation in the preparation of vaccines. Convincing data were reported that sporozoites of Plasmodium berghei irradiated with X- or gamma-rays, provide an antigenic stimulus effective to induce a protective immune response in mice and rats against subsequent sporozoite infection. Irradiated parasites are better immunogens than killed ones and although non-infective they are still metabolically active, as shown by continued protein and nucleic acid synthesis. There is a substantial number of data from human studies demonstrating that sporozoites attenuated by radiation are potent inducer of protective immunity and that they are safe and do not give rise to the asexual erythrocytic infections that cause malaria. This vaccine is relatively inexpensive to produce, easy to store, and transportable without refrigeration. A long-term effort and commitment to providing resources must be maintained and increased to achieve the goal of a malaria vaccine candidate where ionizing radiation as a tool to prepare is seemingly feasible. (author)

  13. The Feasibility of Gamma Irradiation for Developing Malaria Vaccine

    M. Syaifudin

    2011-12-01

    Full Text Available Malaria, a plasmodial disease, causes more than one million deaths per year and has a significant public health impact. Improved access to prompt treatment with effective antimalarial drugs need to be conducted for prevention of infection in high risk groups. However, the parasite as causal agent has exhibited a potential danger of wide-spread resistances. This warning has directed attention to the study of alternative methods of protection against the disease, among them is to do the immunization. A deeper understanding of the nature and regulation of protective immune mechanisms against this parasite will facilitate the development of much needed vaccines. Developing a malaria vaccine remains an enormous scientific, technical, and financial challenge. Currently a vaccine is not fully available. Among the practical applications of radiobiological techniques that may be of considerable interest for public health is the use of ionizing radiation in the preparation of vaccines. Convincing data were reported that sporozoites of Plasmodium berghei irradiated with X- or gamma-rays, provide an antigenic stimulus effective to induce a protective immune response in mice and rats against subsequent sporozoite infection. Irradiated parasites are better immunogens than killed ones and although non-infective they are still metabolically active, as shown by continued protein and nucleic acid synthesis. There is a substantial number of data from human studies demonstrating that sporozoites attenuated by radiation are potent inducers of protective immunity and that they are safe and do not give rise to the asexual erythrocytic infections that cause malaria. This vaccine is relatively inexpensive to produce, easy to store, and transportable without refrigeration. A long-term effort and commitment to providing resources must be maintained and increased to achieve the goal of a malaria vaccine candidate where ionizing radiation as a tool to prepare is seemingly

  14. Control of Postharvest Bacterial Soft Rot by Gamma Irradiation and its Potential Modes of Action.

    Jeong, Rae-Dong; Chu, Eun-Hee; Park, Duck Hwan; Park, Hae-Jun

    2016-04-01

    Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika. PMID:27147935

  15. Chemical composition and lipoxygenase activity in soybeans (Glycine max L. Merr.) submitted to gamma irradiation

    Soybeans are an important food due to their functional and nutritional characteristics. However, consumption by western populations is limited by the astringent taste of soybeans and their derivatives which results from the action of lipoxygenase, an enzyme activated during product processing. The aim of this study was to evaluate the effect of gamma irradiation on the chemical composition and specific activity of lipoxygenase in different soybean cultivars. Soybeans were stored in plastic bags and irradiated with doses of 2.5, 5 and 10 kGy. The chemical composition (moisture, protein, lipids, ashes, crude fiber, and carbohydrates) and lipoxygenase specific activity were determined for each sample. Gamma irradiation induced a small increase of protein and lipid content in some soybean cultivars, which did not exceed the highest content of 5% and 26%, respectively, when compared to control. Lipoxygenase specific activity decreased in the three cultivars with increasing gamma irradiation dose. In conclusion, the gamma irradiation doses used are suitable to inactivate part of lipoxygenase while not causing expressive changes in the chemical composition of the cultivars studied. - Highlights: • The gamma irradiation treatment reduces lipoxygenases activity of soybean. • Independently of soybean cultivar, treatment 10 kGy exhibited higher percentages of reduction of lipoxygenase. • Gamma irradiation interfered few in the chemical composition of soybean. • The lipid and protein content remained stable regardless of radiation dose applied to the soybean

  16. Control of Postharvest Bacterial Soft Rot by Gamma Irradiation and its Potential Modes of Action

    Jeong, Rae-Dong; Chu, Eun-Hee; Park, Duck Hwan; Park, Hae-Jun

    2016-01-01

    Gamma irradiation was evaluated for its in vitro and in vivo antibacterial activity against a postharvest bacterial pathogen, Erwinia carotovora subsp. carotovora (Ecc). Gamma irradiation in a bacteria cell suspension resulted in a dramatic reduction of the viable counts as well as an increase in the amounts of DNA and protein released from the cells. Gamma irradiation showed complete inactivation of Ecc, especially at a dose of 0.6 kGy. In addition, scanning electron microscopy of irradiated cells revealed severe damage on the surface of most bacterial cells. Along with the morphological changes of cells by gamma irradiation, it also affected the membrane integrity in a dose-dependent manner. The mechanisms by which the gamma irradiation decreased the bacterial soft rot can be directly associated with the disruption of the cell membrane of the bacterial pathogen, along with DNA fragmentation, results in dose-dependent cell inactivation. These findings suggest that gamma irradiation has potential as an antibacterial approach to reduce the severity of the soft rot of paprika. PMID:27147935

  17. Use of gamma irradiation to prevent aflatoxin B/sub 1/ production in smoked dried fish

    Ogbadu, G.H.

    1988-01-01

    Smoked dried fish bought from the Nigerian market was inoculated with spores of Aspergillus flavus (U.I. 81) and irradiated with doses of 0.625, 1.25, 2.50 and 5.00 kGy gamma irradiation. The effect on aflatoxin B/sub 1/ production on subsequent incubation for 8 days as stationary cultures was measured. The amount of aflatoxin B/sub 1/ produced was found to decrease with increased gamma irradiation dose levels. The non-irradiated control produced significantly (at 1% level) greater amounts of aflatoxin B/sub 1/ as compared to the treated cultures

  18. Effects of gamma irradiation on the mid-gut of Hyphantria Cunea

    In this paper, the author studied the histological changes of the midgut cells of fall webworms (Hyphantria cunea Drury) through 1.75-7 krad of the whole body gamma irradiation according to their metamorphosis by comparing the control group with the irradiated one through an optical microscope. Here the results were as follows: The epithelium of midgut was composed of columnar, goblet and regenerative cells. The effects of gamma irradiation were varied with the dosages and the stages during the metamorphosis. The degree of histological change mode by irradiation was increased with the dosages. Radiosensitivity was the highest in both last-stage larva and 8-day-old pupae. (Author)

  19. Use of gamma irradiation to prevent aflatoxin B1 production in smoked dried fish

    Smoked dried fish bought from the Nigerian market was inoculated with spores of Aspergillus flavus (U.I. 81) and irradiated with doses of 0.625, 1.25, 2.50 and 5.00 kGy gamma irradiation. The effect on aflatoxin B1 production on subsequent incubation for 8 days as stationary cultures was measured. The amount of aflatoxin B1 produced was found to decrease with increased gamma irradiation dose levels. The non-irradiated control produced significantly (at 1% level) greater amounts of aflatoxin B1 as compared to the treated cultures. (author)

  20. Variation in viscosity and ion conductivity of a polymer–salt complex exposed to gamma irradiation

    Sujata Tarafdar; S K De; Sujit Manna; Udayan De; Pradyot Nanda

    2010-02-01

    We study changes in microstructure and resulting changes in the properties of PEO(1 − )–NH4 ClO4 () samples where = 0.18, when irradiated with gamma doses varying up to 50 kGy. Viscosities of aqueous solutions of the irradiated samples give an idea of the change in molecular weight and show correlation with ion conductivity. On the whole, there is a chain scission on irradiation, though there is evidence of some cross-linking at higher doses. The ion conductivity shows a strong increase for an irradiation of 35 kGy. DSC studies indicate a decrease in crystallinity with gamma dose.

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

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

  2. Effects of gamma irradiation on the volatile compounds of ginger rhizome (Zingiber officinale Roscoe)

    Gingers were irradiated at a dose of 0.05 kGy to inhibit sprouting and conserve quality. Effects of gamma irradiation on the flavor compounds of ginger were studied. After 3 months of storage after irradiation, the quantities of some major volatile compounds such as alpha-zingiberene, alpha-bergamotene, neral, geranial, and alpha-curcumene were significantly lower in irradiated than in unirradiated ginger, although no difference was found immediately after irradiation. A triangle test showed no difference between irradiated and unirradiated gingers stored for 1 month at ambient temperature but showed significant difference after 5 months of storage

  3. Effect of gamma irradiation on storability of apples (Malus Domestica L.)

    The aim of this study was to investigate the effect of gamma irradiation on storability of the two main apple varieties, Golden Delicious and Starking, in Syria. The experiments were performed in 1995 and 1996. Fruits were irradiated with 0, 0.5, 1.0 and 1,5 kGy. Irradiated and unirradiated fruits were stored at 1 to 2 Centigrade and 80 to 90% Rh. Weight loss and spoilage due to physiological disorders and fungal diseases were evaluated throughout the different storage periods. firmness, coloration and Ph values were estimated immediately after irradiation. The results showed that, in both varieties, gamma irradiation increased the weight loss after 45 days of storage in apples gathered in 1995 but not in the 1996 season. After 180 days of storage, gamma irradiation had different effects on weight loss depending on the growing year and variety, and increased fungal spoilage. Application of gamma irradiation prevented the growth of Aspergillus niger and the formation of skin scald in 'Golden Delicious' fruits. Immediately after treatment, gamma irradiation increased the softening of fruits, changed their color from green to yellow and decreased the Ph value of the juice. (author)

  4. Suppressing effect of low-dose gamma-ray irradiation on collagen-induced arthritis

    We previously reported attenuation of autoimmune disease by low-dose gamma-ray irradiation in MRL-lpr/lpr mice. Here, we studied the effect of low-dose gamma-ray irradiation on collagen-induced arthritis (CIA) in DBA/1J mice. Mice were immunized with type II collagen, and exposed to low-dose gamma-rays (0.5 Gy per week for 5 weeks). Paw swelling, redness, and bone degradation were suppressed by irradiation, which also delayed the onset of pathological change and reduced the severity of the arthritis. Production of tumor necrosis factor-alpha, interferon-gamma, and interleukin-6, which play important roles in the onset of CIA, was suppressed by the irradiation. The level of anti-type II collagen antibody, which is essential for the onset of CIA, was also lower in irradiated CIA mice. The population of plasma cells was increased in CIA mice, but irradiation blocked this increase. Since regulatory T cells are known to be involved in suppression of autoimmune disease, the population of CD4+CD25+Foxp3+ regulatory T cells was measured. Intriguingly, a significant increase of these regulatory T cells was found in irradiated CIA mice. Overall, our data suggest that low-dose gamma-ray irradiation could attenuate CIA through suppression of pro-inflammatory cytokines and autoantibody production, and induction of regulatory T cells. (author)

  5. Effect of gamma and electron beam irradiation on textile waste water

    In this studies gamma and electron beam irradiation was used to treat textile waste water. Comparisons between both types of irradiation in terms of effectiveness to degrade the pollutants present in textile waste water were done. Prior to irradiation, the raw wastewater was diluted using distilled water to a target concentration of COD 400 mg/ l. The sample was irradiated at selected doses between the ranges of 10 kGy to 100 kGy. The results showed that irradiation has significantly contributed in the reduction of the highly colored refractory organic pollutants. The COD removal at the lowest dose, 10 kGy was reduced to 390 mg/ l for gamma and 400 mg/ l for electron beam. Meanwhile, at the highest dose, 100 kGy, the COD was reduced to 125 mg/ l for gamma and 144 mg/ l for electron beam. The degree of removal is influenced by the dose introduced during the treatment process. As the dose increased, the higher the removal of organic pollutant was recorded. However, gamma irradiation is more effective although the differences are not significant between gamma and electron beam irradiation. On the other hand, other properties of the wastewater such as pH, turbidity, suspended solid, BOD and color also shows a gradual decrease as the dose increases for both types of irradiation. (author)

  6. Effect of Gamma and Electron Beam Irradiation on Textile Waste Water

    In this studies gamma and electron beam irradiation was used to treat textile waste water. Comparisons between both types of irradiation in terms of effectiveness to degrade the pollutants present in textile waste water was done. Prior to irradiation, the raw wastewater was diluted using distilled water to a target concentration of COD 400 mg/l. The sample was irradiated at selected doses between the ranges of 10 kGy to 100 kGy. The results showed that irradiation has significantly contributed in the reduction of the highly colored refractory organic pollutants. The COD removal at the lowest dose, 10 kGy, was reduced to 390 mg/l for gamma and 400 mg/l for electron beam. Meanwhile, at the highest dose, 100 kGy, the COD was reduced to 125 mg/l for gamma and 144 mg/l for electron beam. The degree of removal is influenced by the dose introduced during the treatment process. As the dose increased, the higher the removal of organic pollutant was recorded. However, gamma irradiation is more effective although the differences are not significant between gamma and electron beam irradiation. On the other hand, other properties of the wastewater such as pH, turbidity, suspended solid, BOD and color also shows a gradual decrease as the dose increases for both types of irradiation. (author)

  7. Study on 99Mo production by solution irradiation method (2). Characterization of aqueous molybdate solutions under gamma-ray irradiation

    The solution irradiation method is proposed as a new production technique for 99Mo, which is the parent nuclide of 99mTc used as a radiopharmaceutical. In this new method, an aqueous molybdenum solution is irradiated with neutrons in a nuclear reactor, and more efficient and lower-cost 99Mo production than conventional 99Mo production can be realized by using the 98Mo (n,γ) 99Mo reaction and the molybdenum adsorbent of PZC. Aiming at the practical application of this method, unirradiation tests, gamma-ray irradiation tests, and neutron irradiation tests should be needed in order to characterize the aqueous molybdenum solution as the irradiation target. In the present study, using two kinds of aqueous molybdate solutions (an aqueous ammonium molybdate solution and an aqueous potassium molybdate solution) selected as candidates for the irradiation target of the new method, the compatibility between the solutions and structural materials, the chemical stability, the circulation characteristics, the radiolysis, and the gamma heating of the solutions were investigated under gamma-ray irradiation. In addition, the integrity of PZC was investigated under gamma-ray irradiation. As a result, the following were found: 1) the compatibility between the solutions and stainless steel is very well, 2) the solutions are chemically stable and have a smooth circulation, 3) the ratios of hydrogen in the gases generated by the radiolysis of the solutions are higher than that of pure water, 4) the effect of gamma heating on the solutions is the same level as that on pure water, and 5) the integrity of PZC is maintained. (author)

  8. Virus inactivation studies using ion beams, electron and gamma irradiation

    Smolko, Eduardo E. [Laboratorio de Polimeros, Grupo Aplicaciones Industriales, Unidad de Aplicaciones Tecnologicas y Agropecuarias, Centro Atomico Ezeiza, Comision Nacional de Energia Atomica, Pbro. Juan Gonzalez y Aragon 15, C.P. B1802AYA Ezeiza, Buenos Aires (Argentina)]. E-mail: smolko@cae.cnea.gov.ar; Lombardo, Jorge H. [Biotech S.A., C.P. 1754 Buenos Aires (Argentina)

    2005-07-01

    Known methods of virus inactivation are based on the chemical action of some substances such as acetylethylenimine, betapropiolactone, glycidalaldehyde, formaldehyde, etc. In such a process, the viral suspension should be kept at room or higher temperatures for 24-48 h. Under these conditions, physical and chemical agents act to degrade the virus antigenic proteins. On the contrary with ionizing radiations at low temperatures, the treatment does not cause such degradation allowing the study of different viral functions. In this work, particle ({alpha}, d and ss) and {gamma} irradiations were used for partial and total inactivation of Foot and Mouth Disease Virus (FMDV), Rauscher Leukemia Virus (RLV) and Herpes Simplex Virus (HSV). Obtention of the D{sub 37} dose from survival curves and the application of the target theory, permitted the determination of molecular weight of the nucleic acid genomes, EBR values and useful information for vaccine preparation. For RLV virus, a two target model of the RNA genome was deduced in accordance with biological information while from data from the literature and our own work on the structure of the scrapie prion, considering the molecular weight obtained by application of the theory, a new model for prion replication is presented, based on a trimer molecule.

  9. The cotton bolloworms Helicoverpa armigera (Huebner) control by gamma irradiation

    The cotton bollworms, Helicoverpa armigera (Huebner) were reared on an artificial medium consisting of mungbeans, brewer's yeast, vitamins, water, preservatives and antibiotic (Tetracycline hydrochloride) at 26 +- 1 deg C, 70-75% R.H., and 8-hr light duration. The development of this species were not significantly different (p = 0.05) in percent egg hatch, pupal recovery, adult eclosion, and pupal weight in each of 4 successive generations. Effects of gamma irradiation, obtained from Cesium-137 source, on eggs, larvae, pupae and adults of the cotton bollworm were also studied. All sterilizing doses, for various stages of the cotton bollworm, did not reduce the longevity both sexes of the insect. However, sterilized males emerged from eggs, larvae, pupae appeared to mate less frequently than normal males did. In contrast, males sterilized as adults mated as frequently as normal males. The sperms of sterilized males emerged from various stages were probably less motile and possibly less numerous than sperms from normal males. The results of this experiment can be concluded that, it is more effective to control this insect by sterilization in both pupal and adult stages with 150 and 200 gray respectively

  10. Promising mutant variety of rice evolved through gamma irradiation

    Rice occupies a major share in crop production in the Chotanagpur plateau of Bihar State. Uplands are roughly 40% in area where traditional low yielding rice, known as ''gora'' is cultivated as directly sown crop. Despite introduction of high yielding rice varieties, gora group of rices continue to prevail. It is therefore desired to increase the productivity level of the gora rice by mutation breeding. One such mutant known as ''gora mutant'' was obtained through gamma irradiation (10 kR) of variety Brown gora. The maturity of both parent and mutant remaining constant (ie. 100 days), there is some improvement in other characteristics like plant height, tillering capacity and kernel character. The parent being tall, shy in tillering and red bold kernel, the mutant has dwarfish characteristics, profuse tillering habit and white kernel with fine grains. The yielding capacity of mutant derivative is 30-40% higher than the parent Brown gora. This variety is in pre-release stage, and the farmers have taken great liking for it. (author)

  11. Impairment of liver and kidney functions in gamma irradiated rats suffering from pesticide toxicity

    The effect of exposure to a single whole body gamma irradiation dose at 6.5 Gy and/or either oral administration of 50 or 100 mg kelthane/kg body weight/day for 3 consecutive days, or daily feeding with 200 mg kelthane/kg body weight for 3, 6, and 12 weeks has been studied on relative liver and kidney weights, serum and liver enzymes, creatinine and inorganic phosphorous clearance, as well as percentage tubular phosphorous reabsorption in male animals. The data obtained revealed that exposure to gamma irradiation alone or combined with kelthane treatment caused significant increase in the relative liver weight besides significant decrease in serum and liver alkaline phosphatase and serum cholinesterase. Exposure to gamma irradiation after oral administration of 100 mg or feeding dietary kelthane kelthane caused significant decrease in liver glucose-6- phosphatase. Non-significant changes in aspartic and alanine transaminases could be recorded due to gamma irradiation and/or kelthane treatment

  12. Various radicals structures in gamma irradiated monoclinic and rhombic monocrystals of hydrated testosterone

    Two kinds of radicals structures in gamma irradiated monoclinal and rhombic monocrystals of hydrated testosterone are investigated by electron paramagnetic resonance. Molecular and spectroscopic properties of these radicals are discussed. (B.C.)

  13. Effect of 60Co-gamma whole-body irradiation on serum amylase level

    Changes of serum amylase activity in rats, after several doses of acut 60Co-gamma irradiation as a function of time were investigated. These changes proved to be of no diagnostic value in early radiation damage. (author)

  14. Anisotropy in CNT composite fabricated by combining directional freezing and gamma irradiation of acrylic acid

    Osička, J.; Ilčíková, M.; Mrlík, M.; Ali S. A. Al-Maadeed, M.; Šlouf, Miroslav; Tkac, J.; Kasák, P.

    2016-01-01

    Roč. 97, 5 May (2016), s. 300-306. ISSN 0264-1275 Institutional support: RVO:61389013 Keywords : directional freezing * gamma irradiation * carbon nanotubes Subject RIV: CD - Macromolecular Chemistry

  15. Effect of gamma irradiation on nutrient digestibility in SPF mini-pig

    This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 oC for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher (p<0.05) than those of autoclaved diets regardless of diet type. Digestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

  16. Comparative effects of gamma irradiation and ozone treatment on hygienic quality of Korean red ginseng powder

    Byun, Myung-Woo; Yook, Hong-Sun; Kang, Il-Jun; Chung, Cha-Kwon; Kwon, Joong-Ho; Choi, Kang-Ju

    1998-06-01

    For the purpose of improving hygienic quality of Korean red ginseng powder, the comparative effects of gamma irradiation and ozone treatment on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the microorganisms of the red ginseng powder. Physicochemical properties including compositions of the red ginseng saponin (ginsenosides) and fatty acids, pH and hydrogen donating activity were not significantly changed by gamma irradiation, whereas, ozone treatment caused significant changes in fatty acid compositions, TBA value, pH, acidity and hydrogen donating activity. The results from this study led us to conclude that gamma irradiation was more effective than ozone treatment both for the improvement of hygienic quality and for the maintenance of physicochemical quality of red ginseng powder.

  17. Effect of gamma irradiation on HPMC/ZnO nanocomposite films

    Rao, B. Lakshmeesha; Asha, S.; Madhukumar, R.; Latha, S.; Gowda, Mahadeva; Shivananda, C. S.; Harish, K. V.; Sangappa, E-mail: syhalabhavi@yahoo.co.in [Department of Studies in Physics, Mangalore University, Mangalagangotri, Mangalore – 574199 (India); Shetty, G. Rajesha [Department of Physics, Government First Grade College, Hiriadka, Udupi – 576113 (India)

    2015-06-24

    The present work looks into the structural and mechanical properties modification in ZnO nanoparticle incorporated Hydroxypropyl methylcellulose (HPMC) polymer films, induced by gamma irradiation. The irradiation process was performed in gamma chamber at room temperature by use of Cobalt-60 source (Average energy of 1.25MeV) at different doses: 0, 50, 100, 150 and 200 kGy respectively. The changes in structural parameters and mechanical properties in pure and gamma irradiated HPMC/ZnO nanocomposite films have been studied using X-ray scattering (XRD) data and universal testing machine (UTM). It is found that gamma irradiation decreases the structural parameters and improves the mechanical properties of nanocomposite films.

  18. The development of 3-D tomography method based on gamma-scanning of irradiated fuel rods

    Dobrin, R. [RENEL, Nuclear Power Group, Inst. for Nuclear Research (INR), Post-Irradiation Examination Lab., Pitesti (Romania); Craciunescu, T. [National Inst. of Nuclear Physics and Engineering, Horia Hulubei (IFIN-HH) Lab., Bucharest, Magurele (Romania)

    1999-07-01

    The tomographic method, consisting in the reconstruction of the images from their projections, is a relatively new nondestructive method, used in the post-irradiation examination of the nuclear fuel. The purpose of the method is to determine the distribution of gamma radioactive fission products in a cross-section of an irradiated nuclear fuel rods. More than 40 fuel rods were investigated at the INR hot cell facility, using this nondestructive technique. The method is used in conjunction with the gamma scanning method and the equipment used for tomographic investigation of the irradiated nuclear fuel is the same to that usually used for gamma scanning investigation. The paper presents the principles of the Gamma Emission Computed Tomography (GECT), as well as the results and performance of this method, when applied to the investigation of some types of fuel rods, irradiated in the TRIGA 14 MW{sub th} materials testing reactor. (author)

  19. Effect of gamma irradiation on nutrient digestibility in SPF mini-pig

    Lee, Jun-Yeob; Cho, Sung-Back; Kim, Yoo-Yong; Ohh, Sang-Jip

    2011-01-01

    This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 °C for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher ( pdiets regardless of diet type. Digestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

  20. Photo-annealing effect of gamma-irradiated erbium-doped fibre by femtosecond pulsed laser

    In this work, a photo-annealing effect of gamma-irradiated erbium-doped glass fibre is investigated. Two commercial erbium-doped fibres (EDFs) with different doping concentrations were sealed inside a chamber with a cobalt-60 gamma source for 6 h to give an accumulated dose of 3.18 kGy. A tunable femtosecond pulsed laser with a repetition rate of 80 MHz was then used to pump EDF to generate 1550 nm fluorescence and green up-conversion emission, resulting in the annealing effect of the gamma-irradiated EDF. The fluorescence power of gamma-irradiated EDF with a moderate level of doping was almost returned to the initial state by photo-annealing, unlike that of a heavily doped EDF. This finding may facilitate the development of anti-irradiated superfluorescence fibre source for space navigation. (paper)

  1. fluctuation in hematology values in gamma irradiated rats subjected to pesticide ingestion

    Male albino rats were exposed to gamma irradiation alone or after either oral daily administration of 50 or 100 mg kelthane for 3 successive days; or daily administration of 200 mg kelthane mixed with food per kg body weight for 3,6 and 12 weeks. Relative spleen weight and certain hematological values were determined. Significant decrease could be estimated in relative spleen weight due to exposure only to gamma irradiation significant increase was recorded due to treatment with 50 and 100 mg kelthane. The data obtained on hematological levels revealed insignificant changes in erythrocyte counts and hemoglobin concentration due to exposure to gamma irradiation and/.or kelthane treatment. Significant decrease was recorded in hematocrit value either for successive 30 days or due exposure to gamma irradiation after treatment with kelthane for short and long term periods. Leucocyte counts showed significant decrease for all animals groups. 2 tabs

  2. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose

  3. The effect of gamma ray irradiation on PAN-based intermediate modulus carbon fibers

    Li, Bin [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Feng, Yi, E-mail: fyhfut@163.com [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Gang; Zhang, Jingcheng [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China); Zhuang, Zhong; Wang, Xianping [Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-11-15

    Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were conducted on PAN-based intermediate modulus carbon fibers to investigate the structure and surface hydrophilicity of the carbon fibers before and after gamma irradiation. Two methods were used to determine Young’s modulus of the carbon fibers. The results show that gamma ray irradiation improved the degree of graphitization and introduced compressive stress into carbon fiber surface. Gamma ray also improved the carbon fiber surface hydrophilicity through increasing the value of O/C and enhancing the quantity of oxygen functional groups on carbon fibers. No distinct morphology change was observed after gamma ray irradiation. The Young’s modulus of the fibers increased with increasing irradiation dose.

  4. Comparative effects of gamma irradiation and ozone treatment on hygienic quality of Korean red ginseng powder

    For the purpose of improving hygienic quality of Korean red ginseng powder, the comparative effects of gamma irradiation and ozone treatment on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the microorganisms of the red ginseng powder. Physicochemical properties including compositions of the red ginseng saponin (ginsenosides) and fatty acids, pH and hydrogen donating activity were not significantly changed by gamma irradiation, whereas, ozone treatment caused significant changes in fatty acid compositions, TBA value, pH, acidity and hydrogen donating activity. The results from this study led us to conclude that gamma irradiation was more effective than ozone treatment both for the improvement of hygienic quality and for the maintenance of physicochemical quality of red ginseng powder

  5. Combined effect of gamma irradiation and plant oils on the potato tuber moth, Phthorimaea operculella (Z)

    1- Susceptibility of Phthorimaea operculella to plant oil and gamma- irradiation. 2- Susceptibility of Phthorimaea operculella to powder of some plants and gamma irradiation.-selection of the suitable concentration of plant oils. - effect on male fertility. -effect on female fecundity. -effect on adult survival. 3- Separate and combined effects of radiation and plant oil on the male mating competitiveness using the sterile dose. 4- Separate and combined effects of radiation and plant oil on the male mating competitiveness using the sub sterile dose. 5- The effects of gamma- irradiation and plant oil on the pest when the potato tubers store for different periods. 6- Some biochemical studies. o Determine the adult total protein content of treated pupae. Determine the effect of plant oils and gamma- irradiation on the activity of some enzymes as proteinase, ATPase, keitenase cholinesterase.

  6. Combined effect of formaldehyde and gamma-irradiation. Vitamin complex effect

    Combined inhalation effect of formaldehyde and gamma-irradiation on the activities of alcohol and aldehyde dehydrogenases in rat lung tissue was studied. The possibility of fitting the parameters studied by the vitamin PP, A and E and complex was shown. At investigation of white rats in conditions of formaldehyde inhalation in concentration 10 mg/m3 and gamma-irradiation by dose 0.25 Gy the changes of activities of alcohol and aldehyde dehydrogenases in the rat lung tissue were detected. An injection of PP, A and E vitamin complex after combined effect of formaldehyde and gamma-irradiation contributes to normalization of studied parameters. The K(C-1) constant is reduced. On this basis it is proposed that in such conditions formaldehyde stabilizes membranes and protects important metabolic processes against damages. Thus, vitamin complex is capable to level a toxic combined effect of formaldehyde and gamma-irradiation. 9 refs., 1 tab

  7. The Analysis of RSG-GAS Spent Fuel Elements Utilization as a Gamma Irradiator

    A gamma irradiator using RSG-GAS spent fuels was analyzed. The cylindrical geometry of the irradiator was designed using spent fuels placed in the cylindrical periphery. The analysis especially was focused to evaluate the feasibilities of the irradiator for foods and non-foods which need not too high dose rates. While the spent fuels activities were calculated by ORIGEN2 code, the dose rates at the irradiation positions were determined by linear attenuation model with transport coefficient. The evaluated results showed that the cylindrical geometry of the irradiator with diameter around 1-1.5 m gave the effective dose rate for irradiation needs the dose rate about 2 kGy/hr. Regarding this work, it can be concluded that one can use the unutilized spent fuels effectively as a gamma irradiator for certain applications. (author)

  8. Role of gamma irradiation on the natural antioxidants in cumin seeds

    Antioxidants quench oxidation by transferring hydrogen atoms to free radicals. In the present investigation, the effect of gamma irradiation on the natural antioxidants of irradiated cumin was studied. Cumin samples were purchased from retailers and then irradiated in a cobalt-60 irradiator to 0, 1, 3, 5 and 10 kGy at ambient temperature. The effect of irradiation on the antioxidant properties of the cumin seed were investigated by evaluating the radical-scavenging effect on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, determination of ferric reducing antioxidant power (FRAP), total polyphenol content (TPC) and the antioxidant index by β-carotene/linoleic acid co-oxidation. Electron spin resonance (ESR) was performed to assess ionization of cumin seeds by gamma irradiation. Irradiation was found to nonsignificantly increase and/or maintain all antioxidant parameters, TPC and the ESR signal intensity was found to be increased in cumin seeds

  9. Structural Investigation of The Effect of Gamma Irradiation in CR-39 and Makrofol Nuclear Track Detectors

    The effect of gamma irradiation on the structural properties of poly-allyl-diglycol-carbonate CR-39 and Makrofol polycarbonates solid state nuclear track detectors was investigated. Samples from CR-39 and Makrofol detectors were irradiated with gamma doses in the range 100-2000 Gy. The structural modifications in the gamma irradiated CR-39 and Makrofol samples have been studied as a function of gamma dose using X-ray diffraction and FTIR spectroscopy characterization techniques. The results indicated that the degree of ordering in both CR-39 and Makrofol detectors was greatly affected by the gamma doses. This could be correlated with the changes induced in bonds associated with the functioning groups present in the two detectors as revealed from FTIR spectroscopy

  10. Effects of neutron-gamma or gamma irradiations on plasma clotting factors. Effect of a treatment by substituted factors

    Neutron-gamma irradiation of the baboon at lethal dose altered the plasma clotting factors and induced a fibrinoformation alteration which occurred shortly before death. These disturbances, which were not found after gamma irradiation, could explain the importance of the haemorrhagic syndrome. Treatment by P.P.S.B. (factors II, VII, X and IX) counteracted the alterations of the plasma clotting factors, but had no influence on the lethality nor on the fibrinoformation alteration which seems to be an important cause of death

  11. Effect of gamma irradiation dose on the fabrication of α-elastin nanoparticles by gamma-ray crosslinking

    Nanoparticles were prepared utilizing the thermosensitive aggregation of α-elastin and gamma-ray crosslinking. We investigated the effect of the α-elastin irradiation doses to verify the yield of crosslinked nanoparticles. Aqueous solution of α-elastin (10 mg/ml) was used for the aggregation on raising temperature above its cloudy point (CP), followed by gamma-ray crosslinking. A slow heating process (1.9 oC/min) effectively led to aggregation of polypeptide and irradiation with more than 15 kGy yielded stable crosslinked nanoparticles with diameters less than ca. 200 nm and a narrow size distribution.

  12. Comparison of the efficacy of gamma and UV irradiation in sanitization of fresh carrot juice

    As there is no pasteurization procedure for the manufacture of fresh vegetable juice, both industry and consumers have sought a method for improving the storage stability and shelf-life of this category of products. In this study, the effects of commercially available, non-thermal pasteurization processes, such as gamma and UV irradiation, were compared for their efficacy in sanitizing fresh carrot juice (FCJ). FCJ was manufactured, packaged, and gamma irradiated with doses of 0, 1, 3, and 5 kGy. The manufactured FCJ was also passed through 4 UV light lamps at doses of 3.67, 4.69, and 6.50 kGy. The total aerobic bacterial count of the FCJ approached the legal limit (105 CFU/mL) after manufacturing. Both treatments were effective in reducing the number of total aerobic bacteria, and the reduced number was maintained during storage for 7 days. Gamma irradiation was more effective in suppressing microbial growth during storage. When the doses for UV treatment and gamma irradiation were higher, the inactivation effects were higher. The reduction of ascorbic acid content was greater upon gamma irradiation than UV treatment. No difference was found in the contents of flavonoids and polyphenols in FCJ after either treatment. After 3 days of refrigerated storage, the sensory scores of gamma- or UV-irradiated FCJ were superior to those of the control. The results indicate that both non-thermal treatments were effective in improving storage stability and extending shelf-life, but gamma irradiation was slightly better in suppressing microbial growth after treatment. - Highlights: ► Gamma irradiation and UV treatment were compared for their efficacy in sanitizing fresh carrot juice. ► Both treatments were effective in reducing the number of total aerobic bacteria but gamma irradiation was more effective. ► Reduction of ascorbic acid content was greater by gamma irradiation than by UV treatment. ► Sensory scores of gamma irradiated or UV-treated carrot juice were

  13. Research on the use of microwave thermography in the case of an acute irradiation of pig; the interest of this experimental model for the diagnosis and assessment of an accidental irradiation of man. Final report for the period 1 March 1984 - 30 September 1989

    Thermography, x-ray tomography and NMR imaging, and scintigraphy have been used for the early diagnosis of an acute localized irradiation of a pig. The combination of these methods allows the evaluation of the radiation injury and its possible evolution. The methods could be applied to detect an accidental irradiation of man. 2 refs

  14. Effect of gamma irradiation on biopolymer composite films of poly(vinyl alcohol) and bacterial cellulose

    Jipa, Iuliana Mihaela; Stroescu, Marta [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Stoica-Guzun, Anicuta, E-mail: stoica.anicuta@gmail.com [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Dobre, Tanase; Jinga, Sorin [University Politehnica of Bucharest, Department of Chemical Engineering, 313 Splaiul Independentei, Polizu 1-3, 060042 Bucharest (Romania); Zaharescu, Traian [Advanced Research Institute for Electrical Engineering, 313 Splaiul Unirii, 030138 Bucharest (Romania)

    2012-05-01

    Highlights: Black-Right-Pointing-Pointer The paper reports the obtaining of composite materials between PVA and BC. Black-Right-Pointing-Pointer The composite films were {gamma}-irradiated at doses up to 50 kGy. Black-Right-Pointing-Pointer The films have a good resistance, being suitable as food packaging materials. - Abstract: Composite materials containing in different ratios poly(vinyl alcohol) (PVA), bacterial cellulose (BC) and glycerol (G) as plasticizer were obtained and exposed to different {gamma} radiation doses using an irradiator GAMMATOR provided with {sup 137}Cs source. These films successively received up to 50 kGy absorbed doses at a dose rate of 0.4 kGy/h at room temperature. In order to study the chemical and structural changes during {gamma} irradiation, Fourier-transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV-Vis spectroscopy were used. Water vapour permeability (WVP), Hunter colour parameters and hardness were also measured for the irradiated samples. Investigation revealed that WVP was not significantly affected by the irradiation. Colour measurements indicated a slight decrease of pure PVA films transparency and it made clear that all samples became more reddish and yellowish after irradiation. The samples hardness was not affected by the irradiation doses used. However, the results showed no drastic structural or chemical changes of the irradiated samples, which prove, in consequence, a good durability. These composite materials could be used as packaging materials for {gamma} irradiated products.

  15. Developmental inhibition of gamma irradiation on the peach fruit moth Carposina sasakii (Lepidoptera: Carposinidae)

    Ionizing irradiation is a useful technique for disinfestation under plant quarantine as well as post-harvest management. Effects of gamma irradiation treatment were tested on different developmental events of Carposina sasakii, which is a serious pest of various orchard crops. Apple fruits infested by C. sasakii were irradiated by gamma rays ranging from 0 to 300 Gy. Inhibition rates were determined on behavioral events related to development, including larval exit from apples, cocoon formation, adult eclosion, and oviposition. Failure rates of all these developmental events increased with increasing doses of irradiation. Rates of larval exit from apples and cocoon formation decreased to 13.2% and 1.7%, respectively, at 300 Gy. However, the adult eclosion rate decreased to 5.4% at 100 Gy and was completely inhibited at doses greater than 150 Gy. LD99 values for the inhibition of cocoon formation and adult emergence was estimated into 313.4 and 191.0 Gy. Furthermore, adults developed from irradiated larvae completely failed to lay eggs. Thus, irradiation of infested apples at doses of 200 Gy and higher completely inhibited the next generation of C. sasakii. Our results suggest that gamma irradiation treatment would be a promising technique for the control of C. sasakii. - Highlights: • Effects of gamma irradiation were tested on Carposina sasakii. • LD99 values for the inhibition of adult emergence was 191.0 Gy. • Irradiation of infested apples at 150 Gy completely inhibited the emergence of next generation

  16. The influence of irradiation of gamma-rays on the pulping and paper making, (4)

    The influence of gamma-irradiation on the beating properties of unbleached kraft pulps was studied, and the changes of the mechanical and chemical properties of the sheet made from those pulps were also investigated. The results obtained were as follows: (1) When the unbeaten pulp was treated with gamma-ray, the degree of polymerization of cellulose was decreased rapidly and the formation of aldehyde and carboxyl groups in pulp was observed in addition to that the beating time of irradiated pulps was reduced comparing with non-irradiated pulp. These effects increased roughly in proportion to the radiation dose. (2) Gamma-irradiation was more effective in wet state (moisture content = 70 - 80%) than air dry state. This may be due to the degradation products of water by gamma-irradiation. (3) The mechanical properties (breaking length, tear and burst factors) of the sheets made from irradiated pulps were considerably deteriorated at 107R, but there was a slight deterioration up to 106R. (4) Comparing the result of the mechanical properties, the strengths of the various sheets were shown in the following order: the sheet irradiated after paper making gt the sheet irradiated before beating (air dry state) gt the sheet irradiated before beating (wet state). (author)

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

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

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

  18. Development of hardened PVF : PMMA polyblend: effect of gamma and electron irradiation

    R Bajpai; N B Dhagat; R Katare; Pragyesh Agrawal; S C Datt

    2003-06-01

    Specimens of poly(vinyl formal) (PVF) : poly(methyl methacrylate) (PMMA) polyblends with different weight percentage ratios were subjected to gamma irradiation (1 to 50 Mrad) and electron irradiation (1 to 20 Mrad). The effect of irradiation on the strength of the blend specimens was studied by measuring the surface microhardness using a Vickers microhardness tester attached to a Carl Zeiss NU 2 Universal research microscope. Significant changes were observed in the Vickers microhardness number, $H_v$. The $H_v$ values of gamma irradiated specimens are found to be higher than the unirradiated specimens indicating an occurrence of radiational crosslinking. The maximum value of $H_v$ is obtained at the gamma radiation dose of 15 Mrad. In case of electron irradiation the radiational crosslinking is found to take place for the blend specimens having lower wt% content of PMMA (0 and 1 wt%) in PVF matrix. On the other hand degradation of polymeric system is observed for the blends having PMMA content more than 1 wt%. The maximum value of $H_v$ is obtained for all the blend specimens at the electron irradiation dose of 8 Mrad. The degree of crosslinking in polyblends due to gamma irradiation is found to be more than electron irradiation. The scissioning mechanism is found to predominate in the polyblend system in case of electron irradiation.

  19. Mechanical and thermal properties of castor oil polyurethane bone cement after gamma irradiation

    Polyurethanes from castor oil are being employed as bone cement in medical applications. In this work the thermal and mechanical properties of gamma irradiated polyurethanes derivative from castor oil were investigated by instrumented indentation, thermogravimetry and scanning electron microscopy. A slightly increase in hardness is observed only for doses as high as 100 kGy. Thermal analysis indicates stability at human body temperature. The glass transition temperature has small changes after gamma irradiation. (author)

  20. Gamma-irradiation of food contact plastics: the rapid destruction of an arylphosphite antioxidant in polypropylene

    In view of the proposed use of gamma irradiation to sterilise foodstuffs a preliminary report is presented of a study of the effects of gamma irradiation on polypropylene containing the food antioxidant arylphosphite (Irgafos) present on its own or with the phenolic antioxidant Irganox. Irgafos is destroyed more rapidly than the phenolic antioxidant and its destruction is greater in the presence of Irganox. (U.K.)

  1. Effects of Gamma Irradiation and Silver Nano Particles on Microbiological Characteristics of Saffron, Using Hurdle Technology

    Hamid Sales, E.; Motamedi Sedeh, F.; Rajabifar, S.

    2011-01-01

    Saffron, a plant from the Iridaceae family, is the world’s most expensive spice. Gamma irradiation and silver nano particles whose uses are gradually increasing worldwide, have positive effects on preventing decay by sterilizing the microorganisms and by improving the safety without compromising the nutritional properties and sensory quality of the foods. In the present study combination effects of gamma irradiation and silver nano particles packaging on the microbial contamination of saffron...

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

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

    2014-01-01

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

  3. Effect of Gamma Irradiation on Botrytis cinerea Causing Gray Mold and Cut Chrysanthemum Flowers

    Eun-Hee Chu; Eun-Jung Shin; Hae-Jun Park; Rae-Dong Jeong

    2015-01-01

    Gray mold caused by Botrytis cinerea is one of the most important postharvest fungal pathogens of cut flowers. Here, gamma irradiation, an alternative for phytosanitary purposes, and sodium dichloroisocyanurate (NaDCC) were used to control B. cinerea in a cut chrysanthemum (Chrysanthemum morifolium Ramat.) cultivar, ‘Baekma’, one of the cultivars susceptible to B. cinerea. Spore germination and mycelium growth of B. cinerea were inhibited by gamma irradiation in an inversely dose-dependent ma...

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

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

  5. Evaluating the Effects of Gamma-Irradiation for Decontamination of Medicinal Cannabis

    Hazekamp, Arno

    2016-01-01

    In several countries with a National medicinal cannabis program, pharmaceutical regulations specify that herbal cannabis products must adhere to strict safety standards regarding microbial contamination. Treatment by gamma irradiation currently seems the only method available to meet these requirements. We evaluated the effects of irradiation treatment of four different cannabis varieties covering different chemical compositions. Samples were compared before and after standard gamma-irradiati...

  6. Gamma-irradiation improves the color and antioxidant properties of Chaga mushroom (Inonotus obliquus) extract.

    Kim, Jae-Hun; Sung, Nak-Yun; Kwon, Sun-Kyu; Srinivasan, Periasamy; Song, Beom-Seok; Choi, Jong-Il; Yoon, Yohan; Kim, Jin Kyu; Byun, Myung-Woo; Kim, Mee-Ree; Lee, Ju-Woon

    2009-12-01

    The objective of this study was to evaluate the effect of ionizing radiation on color and antioxidative properties of Chaga mushroom (Inonotus obliquus) extract (CME). CME (10 mg/mL) was gamma-irradiated at 0, 3, 5, 7, and 10 kGy, and color, antioxidant activity, and total phenolic compound levels were then determined. The lightness and yellowness were increased (P < .05), and the redness was decreased (P < .05), as irradiation dose increased. The antioxidant parameters such as the 2-diphenyl-1-picrylhydrazyl, superoxide, and hydroxyl radical scavenging activities, ferric reducing/antioxidant power, and inhibition of lipid peroxidation increased as the irradiation dose increased. Also, the total phenolic compound levels of CME were increased (P < .05) by gamma-irradiation. These results suggest that gamma-irradiation could be considered a means for improving the antioxidant properties and the color of CME. PMID:20041791

  7. Technical evaluation of gamma-irradiation pretreatment on quality preservation for fresh fish

    A comprehensive review and evaluation on the use of gamma-irradiation for preserving fresh fish quality has been made. The advantages and limitations of using gamma-irradiation of less than 1 M rad have been re-evaluated and compared with previous tests at the Halifax laboratory in terms of physical, organoleptic and some post process quality assessments. Cod, mackerel, and scallop were chosen as the models for lean, fatty and shell fish respectively. The irradiation process can prevent bacterial spoilage in fish, particularly when chilling and/or handling practices are inadequate, but the potential catalytic influences on enzymatic and chemical deterioration during the post-mortem period should also be considered. Some considerations and reservations concerning the changes in overall quality for irradiated fish are discussed. Before more research is completed, the gamma-irradiation process should not be used for shellfish, fatty fish and various prepared and frozen fish products made from Canadian Atlantic species

  8. Study on the physiological activities of gamma-irradiated seafood cooking drips

    Jo, Eu Ri; Kim, Yeon Joo; Choi, Jong Il; Sung, Nak Yun; Jung, Pil Moon; Kim, Jae Hun; Song, Beom Seok; Yoon, Yo Han; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Lee, Ju Yeoun [Chonbuk National University, Jeonju (Korea, Republic of)

    2010-03-15

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment.

  9. Study on the physiological activities of gamma-irradiated seafood cooking drips

    Cooking drips which were obtained as by-product after seafood processing in the food industries, still contain lost of proteins, carbohydrates, and other functional materials. This study was conducted to investigate the effect of gamma irradiation on the biological activities of seafood cooking drips. When the cooking drips of Hizikia fusiformis, Enteroctopus dofleini and Thunnus thynnus were irradiated, the antioxidant activities, whitening effect, and angiotensin I converting enzyme inhibition activity of the ethanol extract from seafood cooking drips were all increased by gamma irradiation. This was because of the increased extraction efficiency of available compounds by irradiation. These results suggested that the seafood cooking drips, wasted as by-products, can be used as functional compounds with gamma irradiation treatment

  10. Improvement of shelf stability and processing properties of meat products by gamma irradiation

    To evaluate the effects of gamma irradiation on the processing properties of meat products, emulsion-type sausage, beef patties and pork loin ham were manufactured. Most contaminated bacteria were killed by 3 kGy-irradiation to raw ground beef, and sausage can be manufactured with desirable flavor, a reduction of NaCl and phosphate, and extension of shelf life using gamma irradiation on the raw meat. The beef patties were manufactured with the addition of antioxidants (200 ppm), BHA, ascorbyl palmitate, α-tocopherol, or β-carotene, and gamma-irradiation. Retardation of lipid oxidation appeared at the patties with an antioxidant. A dose of 5 kGy was observed to be as effective as the use of 200 ppm NaNO2 to provide and maintain the desired color of the product during storage. After curing, irradiation, heating and smoking could extensively prolong the shelf life of the hams

  11. Improvement of shelf stability and processing properties of meat products by gamma irradiation

    Byun, Myung-Woo; Lee, Ju-Woon; Yook, Hong-Sun; Lee, Kyong-Haeng; Kim, Hee-Yun

    2002-03-01

    To evaluate the effects of gamma irradiation on the processing properties of meat products, emulsion-type sausage, beef patties and pork loin ham were manufactured. Most contaminated bacteria were killed by 3 kGy-irradiation to raw ground beef, and sausage can be manufactured with desirable flavor, a reduction of NaCl and phosphate, and extension of shelf life using gamma irradiation on the raw meat. The beef patties were manufactured with the addition of antioxidants (200 ppm), BHA, ascorbyl palmitate, α-tocopherol, or β-carotene, and gamma-irradiation. Retardation of lipid oxidation appeared at the patties with an antioxidant. A dose of 5 kGy was observed to be as effective as the use of 200 ppm NaNO 2 to provide and maintain the desired color of the product during storage. After curing, irradiation, heating and smoking could extensively prolong the shelf life of the hams.

  12. Improvement of shelf stability and processing properties of meat products by gamma irradiation

    Byun, M.-W. E-mail: mwbyun@kaeri.re.kr; Lee, J.-W.; Yook, H.-S.; Lee, K.-H.; Kim, H.-Y

    2002-03-01

    To evaluate the effects of gamma irradiation on the processing properties of meat products, emulsion-type sausage, beef patties and pork loin ham were manufactured. Most contaminated bacteria were killed by 3 kGy-irradiation to raw ground beef, and sausage can be manufactured with desirable flavor, a reduction of NaCl and phosphate, and extension of shelf life using gamma irradiation on the raw meat. The beef patties were manufactured with the addition of antioxidants (200 ppm), BHA, ascorbyl palmitate, {alpha}-tocopherol, or {beta}-carotene, and gamma-irradiation. Retardation of lipid oxidation appeared at the patties with an antioxidant. A dose of 5 kGy was observed to be as effective as the use of 200 ppm NaNO{sub 2} to provide and maintain the desired color of the product during storage. After curing, irradiation, heating and smoking could extensively prolong the shelf life of the hams.

  13. Immune response of mice and sheep to bluetongue virus inactivated by gamma irradiation

    Gamma irradiation is being tested as a means of inactivating bluetongue virus (BTV) for use in vaccines. Exposure of BTV 17 to various levels of irradiation revealed that a dose of approximately 0.6 megarad was required to reduce the virus titer by one log10, or 90%. To test the immunogenicity of irradiated BTV, mouse brain passaged virus and concentrated cell culture passaged virus were inactivated by 6 megarads of gamma irradiation, and vaccines were prepared by emulsifying the virus preparations in equal volumes of a modified incomplete Freund's adjuvant. These vaccines stimulated the production of neutralizing antibodies in mice and sheep, a cell mediated immune response in mice, and a protective immune response in sheep. The results suggest that gamma irradiation would be an effective means of inactivating BTV for the preparation of vaccines

  14. Field irradiator gamma: pre-irradiation occurrence of breeding birds in three boreal habitats

    A trail census was conducted of the breeding birds found in three major habitats in the Field Irradiator Gamma area at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba. The area sampled was about 10.50 ha in size, and included 4.25 ha of upland forest, 4.75 ha of lowland conifers, and 1.50 ha of black spruce-tamarack bog. Forty-four species of birds were identified, of which 24 were considered to be resident in the study area. The highest population density was observed in the bog, followed by upland forest and lowland conifer respectively. In contrast, species diversity was greatest in the upland forest, while it decreased markedly in the relatively monotypic lowland conifer and bog habitats. (author)

  15. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of aniseed (anisum vulgare)

    Seeds of ansium were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator, Irradiated and unirradiated samples were stored at room temperature. Microbial population on seeds, dissolved organic and inorganic solids in extract and sensory properties of extract were evaluated after 0, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the aerobic plate counts. Immediately after irradiation, the dissolved organic solids in extract of irradiated seeds were higher than those of non-irradiated ones. The dissolved organic matter in extract of irradiated and un-irradiated ansium seeds increased. After 6 and 12 months of storage. There were no significant differences in dissolved solids between the extract of irradiated and non-irradiated ansium seeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of ansium seed extract tested immediately after irradiation; however, after 12 months of storage, no significant differences (P>0.05) were found in color, taste or odor between extract of irradiated and unirradiated ansium seeds. (author)

  16. Effect of gamma irradiation on the physicochemical properties of alkali-extracted rice starch

    Starches isolated from two newly released rice varieties (K-322 and K-448) were subject to irradiation at 0, 5, 10, and 20 kGy doses. Comparative study between native (not irradiated) and irradiated starch samples was carried out to evaluate the changes in physicochemical, morphological and pasting properties due to gamma irradiation. Significant decrease was found in apparent amylose content, pH, swelling power, syneresis, and pasting properties, whereas carboxyl content, water absorption capacity, and transmittance were found to increase with the increase in irradiation dose. Granule morphology of native and irradiated starches under scanning electron microscope revealed that granules were polygonal or irregular in shape. The starch granules were somewhat deformed by gamma irradiation. X-ray diffraction pattern showed A type of pattern in native as well as irradiated starches. - Highlights: • Irradiation significantly decreased swelling power, syneresis and pasting properties of starch. • Increase in water absorption capacity, carboxyl content and light transmittance took place with irradiation. • SEM images revealed surface cracking of starch granules with increasing irradiation dose. • No significant difference was observed in the X-ray diffraction pattern of irradiated starches when compared with non-irradiated starches

  17. Application of gamma irradiation for preservation of tobacco leaf

    Irradiation of tobacco material up to 6 kGy could not change nicotine compound, total protein, soluble glucide, reducing compound. Irradiation inhibited oxidation of polyphenols. Organoleptic properties of irradiated tobacco leaf were better than control one. Mould growth in tobacco material were inhibited after irradiation. (author). 3 refs, 3 tabs

  18. Effect of gamma irradiation on curcuminoids and volatile oils of fresh turmeric (Curcuma longa)

    In our earlier study a radiation dose of 5 kGy was reported to be suitable for microbial decontamination and shelf life extension of fresh turmeric (Curcuma longa), while maintaining its quality attributes. In continuation of that work, the effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric was studied. Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. Curcuminoid content and volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. The curcuminoid content was slightly increased by gamma irradiation. No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents. - Highlights: → Effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric (Curcuma longa) was studied. → Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. → Curcuminoid content and the volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. → Curcuminoid content was slightly increased by gamma irradiation. → No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents.

  19. Effect of gamma irradiation on curcuminoids and volatile oils of fresh turmeric (Curcuma longa)

    Dhanya, R. [P.G. Department of Botany and Research Centre, Sir Syed College, Taliparamba 670142, Kerala (India); Mishra, B.B. [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Khaleel, K.M., E-mail: khaleelchovva@yahoo.co.in [P.G. Department of Botany and Research Centre, Sir Syed College, Taliparamba 670142, Kerala (India)

    2011-11-15

    In our earlier study a radiation dose of 5 kGy was reported to be suitable for microbial decontamination and shelf life extension of fresh turmeric (Curcuma longa), while maintaining its quality attributes. In continuation of that work, the effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric was studied. Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. Curcuminoid content and volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. The curcuminoid content was slightly increased by gamma irradiation. No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents. - Highlights: > Effect of gamma radiation on curcuminoids and volatile oil constituents in fresh turmeric (Curcuma longa) was studied. > Fresh peeled turmeric rhizomes were gamma irradiated at doses of 1, 3 and 5 kGy. > Curcuminoid content and the volatile oils were analyzed by reverse phase HPLC and GC-MS, respectively. > Curcuminoid content was slightly increased by gamma irradiation. > No statistically significant changes were observed due to irradiation in majority of the volatile oil constituents.

  20. Gamma-irradiated carboxymethyl kappa-carrageenan nano gels as potential drug delivery system

    This study aims to produce, characterize and assess the potential of gamma-irradiated carboxymethyl kappa-carrageenan nano gels for drug delivery system. The carboxy methylation of κ-carrageenan was carried out in 2 propanol, activated with appropriate amount of 16N sodium hydroxide and reacted with monochloroacetic acid as etherifying agent. The carboxymethyl κ-carrageenan was further subjected to gamma-irradiation followed by the formation of nano gels. In this study, nano gels were prepared from gamma irradiated carboxymethyl κ-carrageenan encapsulating a model redox indicator (methylene blue, neutral, with a pH range of 6.0-7.6), using reverse microemulsions combined with thermally induced gelation. Nano gels were characterized through Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Differential Thermal Analysis. In vitro drug loading and in vitro drug release studies were done. It was found that gamma-irradiated carboxymethyl κ-carrageenan has the potential for drug delivery system, prolonged release in particular. Furthermore, it was proven that the loading capacity,as well as the amount of drug release, increases with the dose of gamma-irradiated carboxymethyl κ-carrageenan nano gels. No significant interaction effect was seen among the different dose of gamma-irradiated carboxymethyl κ-carrageenan nano gels; a significant increase in the methylene blue release was observed with time. (author)

  1. Comparison of the effects of gamma ray and e-beam irradiation on the quality of minced beef during storage

    This study was conducted to compare the microbiological and physicochemical qualities of minced beef irradiated with gamma ray of e-beam at the absorbed doses from 5 to 20 kGy. The total bacterial counts of minced beef were decreased depending upon the irradiation doses, but sterilizing effect of gamma irradiation was higher than that of e-beam irradiation. The contents of malondialdegyde of minced beef were increased depending upon irradiation doses as well as storage periods (p< 0.05). Volatile basic nitrogen in minced beef was constantly increased during storage, but the increasing rate were retarded by irradiation. The hunter's color values(L*, a* and b*) of gamma or e-beam irradiated minced beef were decreased as irradiation dose increasing. Meanwhile, the quality changes of gamma irradiated samples were faster than e-beam irradiated samples

  2. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice root product

    Licorice root products were irradiated at doses of 0, 5, 10, 15 and 20 kGy in a 60Co package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on product, chemical changes and sensory properties of produced solution of licorice root products were evaluated after 0 and 12 months of storage. The results indicated that gamma irradiation reduced the counts of microorganisms on licorice root products. D10 of total count and klebsiella spp. were about 1.4 and 0.7 kGy, respectively. The mineral ions (Na, Ca and K) concentration in solution produced from irradiated products were lower than non-irradiated ones. Glycyrrhezinic acid and maltose concentration in solution produced from irradiated products were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences (P<0.05) were found between solution produced from irradiated and unirradiated products in color, flavor, texture, or taste

  3. Investigating the embryo/larval toxic and genotoxic effects of {gamma} irradiation on zebrafish eggs

    Simon, O., E-mail: olivier.simon@irsn.fr [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Massarin, S. [Laboratoire de Modelisation Environnementale, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Coppin, F. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Hinton, T.G. [Service d' Etude du Comportement des Radionucleides dans les Ecosystemes, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 159, BP3, 13115 Saint-Paul-lez-Durance Cedex (France); Gilbin, R. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire, Cadarache, Bat 186, BP3, 13115 Saint-Paul-lez-Durance Cedex (France)

    2011-11-15

    Eggs/larval of freshwater fish (Danio rerio) were exposed to low dose rates of external gamma radiation (from 1 to 1000 mGy d{sup -1}) over a 20-day period, with the objective of testing the appropriateness of the 10 mGy d{sup -1} guideline suggested by the IAEA. The present study examines different endpoints, mortality and hatching time and success of embryos as well as the genotoxicity of {gamma}-irradiations (after 48 h). The 20-day embryo-larval bioassay showed an enhanced larval resistance to starvation after chronic exposure to {gamma} irradiation (from low 1 mGy d{sup -1} to high dose rate 1000 mGy d{sup -1}) and an acceleration in hatching time. Gamma irradiation led to increased genotoxic damage Ito zebrafish egg (40-50% DNA in tail in Comet assay) from the lowest dose rate (1 mGy d{sup -1}). Possible mechanisms of {gamma} radiotoxicity and implications for radioprotection are discussed. - Highlights: > Relevant information on the {gamma} radiation impact on early life stage biota is scarce. > The eggs of zebrafish Danio rerio were selected as biological model. > We test the appropriateness of the 10 mGy d{sup -1} guideline (IAEA). > We observed effects measured at individual levels (starvation, hatching time). > Chronic gamma irradiation led to increased genotoxic damage to zebrafish egg. > {gamma} radiotoxicity mechanisms and implications for radioprotection are discussed.

  4. Accidental Innovation

    Austin, Robert D.; Devin, Lee; Sullivan, Erin E.

    2012-01-01

    Historical accounts of human achievement suggest that accidents can play an important role in innovation. In this paper, we seek to contribute to an understanding of how digital systems might support valuable unpredictability in innovation processes by examining how innovators who obtain value from...... they incorporate accidents into their deliberate processes and arranged surroundings. By comparing makers working in varied conditions, we identify specific factors (e.g., technologies, characteristics of technologies) that appear to support accidental innovation. We show that makers in certain specified...... conditions not only remain open to accident but also intentionally design their processes and surroundings to invite and exploit valuable accidents. Based on these findings, we offer advice for the design of digital systems to support innovation processes that can access valuable unpredictability....

  5. Physicochemical, functional and pasting properties of flour produced from gamma irradiated tiger nut (Cyperus esculentus L.)

    Tiger nut (Cyperus esculentus L.) has been recognised as one of the best nutritional crops that can be used to augment the Ghanaian diet. The application of gamma irradiation as means of preserving tiger nut could modify the characteristics of resultant flour. The purpose of this study was to determine the physicochemical, functional and pasting characteristics of flour from gamma irradiated tiger nut. The yellow and black types of tiger nut were sorted, washed and dried in an air-oven at 60 oC for 24 h. The dried tiger nut samples were irradiated at 0.0, 2.5, 5.0 and 10.0 kGy and then flours produced from them. Moisture, ash, pH, titratable acidity, water and oil absorption capacities, swelling power, solubility, bulk density and pasting properties of the flours were determined using appropriate analytical methods. Results showed that irradiation did not significantly (P>0.05) affect the moisture and ash contents of the resultant flours. Gamma irradiation significantly (P≤0.05) increased titratable acidity with concomitant decrease in pH of the flours. No significant differences were observed for water and oil absorption capacities, swelling power as well as bulk density. Solubility significantly (P≤0.05) increased generally with irradiation dose. Peak viscosity, viscosities at 92 °C and 55 °C, breakdown and setback viscosities decreased significantly with irradiation dose. Flour produced from irradiated tiger nut has a potential in complementary food formulations due to its low viscosity and increased solubility values. - Highlights: • Physicochemical, functional and pasting characteristics of flour from gamma irradiated tiger nut were studied. • Irradiation did not affect the moisture and ash contents of the resultant flours. • Titratable acidity increased with decrease in pH of the flours from the irradiated tiger nut. • Solubility increased whereas peak viscosity decreased with irradiation dose. • Flour produced from irradiated tiger nut has a

  6. Characterization of blends of PP and SBS vulcanized with gamma irradiation

    The present work has the objective of analyzing blends of PP with 30 wt% SBS vulcanized with gamma irradiation. In order to do so, SBS was irradiated at 10, 25 and 50 kGy with gamma rays. Results indicate that the gel fraction increases with irradiation dose, varying from 0.3% to 13.0% for the doses employed. Concerning tensile properties, it can be seen that the incorporation of SBS non-irradiated or irradiated decreases Young's modulus, while increasing elongation at break. Respect to thermal studies, it was detected that SBS decreases melting enthalpy of blends, fact that implies a decrease on crystallinity degree, being this effect more noticeable when SBS is irradiated at doses higher than 10 kGy. On the other hand, melting temperature diminishes slightly when adding SBS to PP, but does not show significant variations when SBS is irradiated. PPs MFI decreased with the addition of SBS, being the effect more notorious with irradiation dose. Finally, it can be concluded that SBS can be vulcanized by gamma irradiation, and that the crosslinking degree increases with irradiation dose

  7. Effects of Gamma Irradiation on Quality Characteristic and Microbiological Safety of Rape (Brassica napus) Pollen

    This study is carried out to sanitize rape (Brassica napus) pollen by gamma irradiation. Rape pollens were treated with 0, 5, 10 and 15 kGy gamma irradiations, and then analyzed for the following: general composition, microbial population, reducing sugar, Hunter color values, TBARS (2-thiobarbituric acid reactive substances) values, and VBN (volatile basic nitrogen). Mold and coliform bacteria were not detected in the samples irradiated at 5 kGy or more. Yeasts and total aerobic bacteria were not detected in the samples irradiated at 10 kGy or more (102 CFU/g). Moisture, ash, crude protein, crude fat, carbohydrate, reducing sugar and the contents of volatile basic nitrogen in the irradiated pollen did not show any significant changes by irradiation. Hunter color values, L, a and b values were decreased with increment of irradiation dose. TBARS values were increased with an increment of irradiation dose. In conclusion, gamma irradiation at 5 kGy was considered to be an effective treatment to control for mycotoxin producing fungi in rape pollen to minimize changes of general composition and physicochemical properties. Further studies should be investigated to reduce the detrimental effects induced by irradiation

  8. Effect of gamma irradiation on bitter pit of apple fruits (Malus Domestica Borkh)

    Tow varieties of apple fruits Golden and Starking were irradiated with 0, 0.5, 1.0, 1.5 kGy and with 0, 1.0, 1.5 kGy respectively. Irradiated and unirradiated fruits were stored at 1 to 2 centigrade and relative humidity of 80 to 90%. Fruit quality (firmness, skin thickness and bitter pit) and juice characteristics (moisture, ash, carbohydrates, organic acids, Ph, and viscosity), were determined during storage periods (0, 3 and 6 months). The used doses of gamma irradiation significantly decreased the percentage and intensity of bitter pit. Irradiated fruits were softer immediately after irradiation and through storage periods, there were no differences in firmness between irradiated and unirradiated fruits. Gamma irradiation increased the thickness of skin in Golden fruits and decreased it in Starking. Juice production from both varieties immediately after irradiation was not affected by gamma irradiation. However the juice produced from irradiated fruits had higher organic acids (citric and malic acids), viscosity and Ph values than the control. (author)

  9. Characterization of blends of PP and SBS vulcanized with gamma irradiation

    Gonzalez, J. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela)]. E-mail: jjgonza@usb.ve; Albano, C. [Centro de Quimica, Laboratorio de Polimeros, Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas (Venezuela) and Universidad Central de Venezuela, Facultad de Ingenieria, Escuela de Ingenieria Quimica, Caracas (Venezuela)]. E-mail: calbano@ivic.ve; Candal, M.V. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela); Ichazo, M.N. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela); Hernandez, M. [Departamento de Mecanica, Universidad Simon Bolivar, Caracas (Venezuela)

    2005-07-01

    The present work has the objective of analyzing blends of PP with 30 wt% SBS vulcanized with gamma irradiation. In order to do so, SBS was irradiated at 10, 25 and 50 kGy with gamma rays. Results indicate that the gel fraction increases with irradiation dose, varying from 0.3% to 13.0% for the doses employed. Concerning tensile properties, it can be seen that the incorporation of SBS non-irradiated or irradiated decreases Young's modulus, while increasing elongation at break. Respect to thermal studies, it was detected that SBS decreases melting enthalpy of blends, fact that implies a decrease on crystallinity degree, being this effect more noticeable when SBS is irradiated at doses higher than 10 kGy. On the other hand, melting temperature diminishes slightly when adding SBS to PP, but does not show significant variations when SBS is irradiated. PPs MFI decreased with the addition of SBS, being the effect more notorious with irradiation dose. Finally, it can be concluded that SBS can be vulcanized by gamma irradiation, and that the crosslinking degree increases with irradiation dose.

  10. Increase of radiation resistance of a soil microflora exposed to long-term gamma irradiation

    Soil microflora were exposed to long-term (18 months) gamma irradiation in an open-air facility at three different doses, 15, 150, and 1500 krads/18 months. The radiation resistance increased at all doses when compared with the radiation resistance of the microflora from soil shielded from the irradiation with a lead wall

  11. Manual on self-contained gamma irradiators (categories 1 and 3)

    In addition to a basic guide to the principles of production of ionizing radiation and to the methods of radiation protection and dosimetry, this document considers the procedures that should be employed when using self-constrained gamma irradiators. Applications for such irradiators are described and radiation protection procedures discussed

  12. Using gamma irradiation for the recovery of anthocyanins from grape pomace

    Ayed, N.; Yu, H.-L.; Lacroix, M. E-mail: Monique_Lacroix@iaf.uquebec.ca

    2000-03-01

    This research investigated the effect of gamma irradiation from 0 to 9 kGy, packaging in air or under vacuum, or in combination with other treatments for enhancing anthocyanin extraction from grape pomace. Results indicate that the irradiation at 6 kGy and packaging in the presence of a low concentration of sodium metabisulfite yielded the highest value of anthocyanin extraction. (author)

  13. Using gamma irradiation for the recovery of anthocyanins from grape pomace

    This research investigated the effect of gamma irradiation from 0 to 9 kGy, packaging in air or under vacuum, or in combination with other treatments for enhancing anthocyanin extraction from grape pomace. Results indicate that the irradiation at 6 kGy and packaging in the presence of a low concentration of sodium metabisulfite yielded the highest value of anthocyanin extraction. (author)

  14. Improved calculation of displacements per atom cross section in solids by gamma and electron irradiation

    Piñera, Ibrahin, E-mail: ipinera@ceaden.edu.cu [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Cruz, Carlos M.; Leyva, Antonio; Abreu, Yamiel; Cabal, Ana E. [Centro de Aplicaciones Tecnológicas y Desarrollo Nuclear, CEADEN, 30 St. 502, Playa 11300, Havana (Cuba); Espen, Piet Van; Remortel, Nick Van [University of Antwerp, CGB, Groenenborgerlaan 171, 2020 Antwerpen (Belgium)

    2014-11-15

    Highlights: • We present a calculation procedure for dpa cross section in solids under irradiation. • Improvement about 10–90% for the gamma irradiation induced dpa cross section. • Improvement about 5–50% for the electron irradiation induced dpa cross section. • More precise results (20–70%) for thin samples irradiated with electrons. - Abstract: Several authors had estimated the displacements per atom cross sections under different approximations and models, including most of the main gamma- and electron-material interaction processes. These previous works used numerical approximation formulas which are applicable for limited energy ranges. We proposed the Monte Carlo assisted Classical Method (MCCM), which relates the established theories about atom displacements to the electron and positron secondary fluence distributions calculated from the Monte Carlo simulation. In this study the MCCM procedure is adapted in order to estimate the displacements per atom cross sections for gamma and electron irradiation. The results obtained through this procedure are compared with previous theoretical calculations. An improvement in about 10–90% for the gamma irradiation induced dpa cross section is observed in our results on regard to the previous evaluations for the studied incident energies. On the other hand, the dpa cross section values produced by irradiation with electrons are improved by our calculations in about 5–50% when compared with the theoretical approximations. When thin samples are irradiated with electrons, more precise results are obtained through the MCCM (in about 20–70%) with respect to the previous studies.

  15. Improved calculation of displacements per atom cross section in solids by gamma and electron irradiation

    Highlights: • We present a calculation procedure for dpa cross section in solids under irradiation. • Improvement about 10–90% for the gamma irradiation induced dpa cross section. • Improvement about 5–50% for the electron irradiation induced dpa cross section. • More precise results (20–70%) for thin samples irradiated with electrons. - Abstract: Several authors had estimated the displacements per atom cross sections under different approximations and models, including most of the main gamma- and electron-material interaction processes. These previous works used numerical approximation formulas which are applicable for limited energy ranges. We proposed the Monte Carlo assisted Classical Method (MCCM), which relates the established theories about atom displacements to the electron and positron secondary fluence distributions calculated from the Monte Carlo simulation. In this study the MCCM procedure is adapted in order to estimate the displacements per atom cross sections for gamma and electron irradiation. The results obtained through this procedure are compared with previous theoretical calculations. An improvement in about 10–90% for the gamma irradiation induced dpa cross section is observed in our results on regard to the previous evaluations for the studied incident energies. On the other hand, the dpa cross section values produced by irradiation with electrons are improved by our calculations in about 5–50% when compared with the theoretical approximations. When thin samples are irradiated with electrons, more precise results are obtained through the MCCM (in about 20–70%) with respect to the previous studies

  16. Application of gamma irradiation in ginseng for both photodegradation of pesticide pentachloronitrobenzene and microbial decontamination

    This study investigates the feasibility of using gamma irradiation for photodegradation of a common residual fungicide, pentachloronitrobenzene (PCNB), in ginseng, and for microbial decontamination. American ginseng, Panax quinquefolius, was subjected to gamma irradiation. PCNB residues were analyzed by gas chromatography with electron capture detection and mass spectrometry. Eighty percent of PCNB (100 ppm) in a methanol aqueous solution was degraded by 5 kGy irradiation, and the primary degradation product was pentachloroaniline. Furthermore, contaminated PCNB (3.7 ppm) in ginseng were reduced to 0.2 ppm after 20 kGy irradiation. The IC50 for treatment of Sclerotium rolfsii with 20 kGy irradiated PCNB was about 2.7 times higher than that for treatment with unirradiated PCNB. The survival rate of mouse fibroblast L929 cells treated with 20 kGy irradiated PCNB was about 12.9% higher than that of L929 cells treated with unirradiated PCNB. Additionally, after 20 kGy irradiation, less than 5% reduction of contents of ginsenoside Rb1 and Re were observed, and amounts of ginsenosides Rc, Rd, and Rg1 were not reduced significantly. The minimal gamma dose for microbial decontamination was 10 kGy. Therefore, gamma irradiation can be used for both PCNB photodegradation and microbial decontamination of ginseng without obvious loses of ginsenoside contents.

  17. Using gamma irradiation for the recovery of anthocyanins from grape pomace

    Ayed, N.; Yu, H.-L.; Lacroix, M.

    2000-03-01

    This research investigated the effect of gamma irradiation from 0 to 9 kGy, packaging in air or under vacuum, or in combination with other treatments for enhancing anthocyanin extraction from grape pomace. Results indicate that the irradiation at 6 kGy and packaging in the presence of a low concentration of sodium metabisulfite yielded the highest value of anthocyanin extraction.

  18. Radioprotective effects of kojic acid against mortality induced by gamma irradiation in mice

    To evaluate the protective effects of kojic acid on mortality induced by gamma irradiation in mice. The efficacy was compared with amifostine as a reference radioprotector. This experimental study was conducted in the Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari and Babolsar Radiotherapy Hospital, Babolsar, Iran, between October 2006 and January 2008. Kojic acid was administrated subcutaneously as single doses of 142, 175, 232, and 350 mg/kg, one hour prior to a lethal dose of gamma irradiation (8 Gy). Amifostine was injected subcutaneously at a dose of 200 mg/kg at a similar irradiation dose. The mortality was recorded 30 days after irradiation. The antioxidant activity of the kojic acid was assessed using the 1, 1-diphenyl-2-picrylhydrazyl free stable radical (DPPH) method. One hundred and twenty NMRI mice were divided into 6 groups with 20 mice in each group. At 30 days after treatment, the percentage of survival in each group was: control, 5%; 142 mg/kg, 5%; 175 mg/kg, 0%; 232 mg/kg, 30%; 350 mg/kg, 40%; and amifostine, 40% one hour treatment prior gamma irradiation. The survival rate was statistically increased in animals treated with kojic acid (350 mg/kg), one hour prior irradiation, as compared with the irradiated control group. Kojic acid exhibited concentration-dependent scavenging activity on DPPH possessing strong antioxidant activity. Kojic acid with antioxidant activity reduced the mortality induced by gamma irradiation. (author)

  19. Effect of gamma irradiation on the protoscoleces of Echinococcus granulosus of sheep origin

    In vitro and in vivo effects of varying levels of gamma irradiation on protoscoleces of Echinococcus granulosus of sheep origin were studied. Radiation doses of 100 Gy onwards caused a decrease in the viability of protoscoleces in vitro. However, infectivity of protoscoleces was not affected at radiation doses of 300 Gy in golden hamsters and 200 Gy in mice although number and size of cysts developing from infections with irradiated protoscoleces in these animals was small in comparison to cysts developing from infections with normal protoscoleces. Four hundred E. granulosus protoscoleces, normal or 100 Gy irradiated, proved fatal for mice. A significant progressive decline in worm establishment was observed in pups given an infection of E. granulosus protoscoleces exposed to increasing levels of gamma irradiation from 100 to 600 Gy. No worms established in pups infected with protoscoleces irradiated at 400 and 600 Gy, respectively. Worms developing from irradiated infections in pups were stunted and showed developmental abnormalities. (author)

  20. Effect of gamma irradiation on storability and chemical properties of different depth samples of luncheon

    To investigate the effect of gamma irradiation on shelf-life of luncheon, meat packs were exposed to doses of 0, 1, 2 and 3 kGy in a 60Co package irradiator, and the irradiated and unirradiated samples were stored at refrigeration temperature (1-3 centigrade). Microbial population and chemical changes were evaluated through storage periods (2, 4, 6 weeks) on the surface and depth in the of meat packs. The results indicated that gamma irradiation reduced the counts of microorganisms inside the samples more than the surfaces. Also the shelf-life of luncheon meat increased from two weeks for the control to 5 weeks for irradiated samples (2 and 3 kGy). Total acidity, lipid oxidation and the volatile basic nitrogen (VBN) increased during the first stage of storage up to 2 weeks of irradiation, furthermore these values were significantly higher (P> 0.05) on the surface than inside the meat packs. (author)