WorldWideScience

Sample records for irradiated additionally unirradiated

  1. Detection of irradiated spice in blend of irradiated and un-irradiated spices using thermoluminescence method

    International Nuclear Information System (INIS)

    Goto, Michiko; Yamazaki, Masao; Sekiguchi, Masayuki; Todoriki, Setsuko; Miyahara, Makoto

    2007-01-01

    Five blended spice sample were prepared by mixing irradiated and un-irradiated black pepper and paprika at different ratios. Blended black pepper containing 2%(w/w) of 5.4 kGy-irradiated black pepper showed no maximum at glow1. Irradiated black pepper samples, mixed to 5 or 10%(w/w), were identified as 'irradiated' or 'partially irradiated' or 'un-irradiated'. All samples with un-irradiated pepper up to 20%(w/w) were identified as irradiated'. In the case 5.0 kGy-irradiated paprika were mixed with un-irradiated paprika up to 5%(w/w), all samples were identified as irradiated'. The glow1 curves of samples, including irradiated paprika at 0.2%(w/w) or higher, exhibited a maximum between 150 and 250degC. The results suggest the existence of different critical mixing ratio for the detection of irradiation among each spices. Temperature range for integration of the TL glow intensity were compared between 70-400degC and approximate 150-250degC, and revealed that the latter temperature range was determined based on the measurement of TLD100. Although TL glow ratio in 150-250degC was lower than that of 70-400degC range, identification of irradiation was not affected. Treatment of un-irradiated black pepper and paprika with ultraviolet rays had no effect on the detection of irradiation. (author)

  2. Characterization of un-irradiated and irradiated reactor graphite; Karakterizacija neozracenog i ozracenog reaktorskog grafita

    Energy Technology Data Exchange (ETDEWEB)

    Marinkovic, S [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1965-11-15

    This report contains three parts: characterization of Yugoslav nuclear graphite development of methods and obtained results, characterization of un-irradiated and irradiated domestic nuclear graphite; calculation of electrical conductivity changes due to vacancies in the graphite crystal lattice.

  3. In vivo genetic toxicity studies in Chinese hamsters fed irradiated or unirradiated foodstuffs

    International Nuclear Information System (INIS)

    Altmann, H.

    1982-01-01

    Two in vivo genetic toxicity studies were performed in Chinese hamsters fed irradiated or unirradiated diets of chicken, fish or dates in order to detect possible mutagenic effects caused by irradiating these foodstuffs. The tests selected for study were: 1. Chromosomal analysis of bone narrow cells and 2. DNA metabolism in spleen cells. Chicken, fish and dates were irradiated with doses of 7, 2.5 and 1 kGy respectively. These investigations were subsequently extended to include the effects of irradiated dried onions, pulses and cocoa beans on DNA metabolism in Chinese hamster spleen cells only. Dried onions were irradiated with doses of 0.15, 9 and 15 kGy, pulses with 10 kGy and cocoa beans with 3.2 to 5 kGy. In addition, a fumigated cocoa bean group was included. No significant differences in chromosomal aberration rate were detected between groups fed irradiated or unirradiated diets. Dried dates, whether irradiated or not, showed some evidence of genetic toxicity in their effect on DNA metabolism in the spleen cells of Chinese hamsters. Both date diets caused more strand breaks DNA than are usual for Chinese hamster spleen cells, but DNA repair was not adversely affected. Chicken, both irradiated and unirradiated, was found to enhance replicative DNA synthesis but had no effect on the DNA repair process. Irradiated fish, however, caused enhanced DNA synthesis compared to unirradiated fish, but also had no adverse effect on DNA repair. Irradiated white beans also enhanced DNA synthesis compared to controls whereas unirradiated samples inhibited synthesis. (orig./MG)

  4. Rescue Effects: Irradiated Cells Helped by Unirradiated Bystander Cells

    Science.gov (United States)

    Lam, R. K. K.; Fung, Y. K.; Han, W.; Yu, K. N.

    2015-01-01

    The rescue effect describes the phenomenon where irradiated cells or organisms derive benefits from the feedback signals sent from the bystander unirradiated cells or organisms. An example of the benefit is the mitigation of radiation-induced DNA damages in the irradiated cells. The rescue effect can compromise the efficacy of radioimmunotherapy (RIT) (and actually all radiotherapy). In this paper, the discovery and subsequent confirmation studies on the rescue effect were reviewed. The mechanisms and the chemical messengers responsible for the rescue effect studied to date were summarized. The rescue effect between irradiated and bystander unirradiated zebrafish embryos in vivo sharing the same medium was also described. In the discussion section, the mechanism proposed for the rescue effect involving activation of the nuclear factor κB (NF-κB) pathway was scrutinized. This mechanism could explain the promotion of cellular survival and correct repair of DNA damage, dependence on cyclic adenosine monophosphate (cAMP) and modulation of intracellular reactive oxygen species (ROS) level in irradiated cells. Exploitation of the NF-κB pathway to improve the effectiveness of RIT was proposed. Finally, the possibility of using zebrafish embryos as the model to study the efficacy of RIT in treating solid tumors was also discussed. PMID:25625514

  5. The influence of late-stage pupal irradiation and increased irradiated: un-irradiated male ratio on mating competitiveness of the malaria mosquito Anopheles arabiensis Patton.

    Science.gov (United States)

    Helinski, M E H; Knols, B G J

    2009-06-01

    Competitiveness of released males in genetic control programmes is of critical importance. In this paper, we explored two scenarios to compensate for the loss of mating competitiveness after pupal stage irradiation in males of the malaria mosquito Anopheles arabiensis. First, competition experiments with a higher ratio of irradiated versus un-irradiated males were performed. Second, pupae were irradiated just prior to emergence and male mating competitiveness was determined. Males were irradiated in the pupal stage with a partially or fully-sterilizing dose of 70 or 120 Gy, respectively. Pupae were irradiated aged 20-26 h (young) as routinely performed, or the pupal stage was artificially prolonged by cooling and pupae were irradiated aged 42-48 h (old). Irradiated males competed at a ratio of 3:1:1 to un-irradiated males for mates in a large cage design. At the 3:1 ratio, the number of females inseminated by males irradiated with 70 Gy as young pupae was similar to the number inseminated by un-irradiated males for the majority of the replicates. At 120 Gy, significantly fewer females were inseminated by irradiated than by un-irradiated males. The irradiation of older pupae did not result in a significantly improved male mating competitiveness compared to the irradiation of young pupae. Our findings indicate that the loss of competitiveness after pupal stage irradiation can be compensated for by a threefold increase of irradiated males, but only for the partially-sterilizing dose. In addition, cooling might be a useful tool to facilitate handling processes of large numbers of mosquitoes in genetic control programmes.

  6. Histochemical differentiation between unirradiated and gamma-irradiated tissue in commercial use of some irradiated vegetables

    International Nuclear Information System (INIS)

    Foa, E.

    1978-01-01

    The use of gamma irradiation as a commercial method for the preservation of fruits and vegetables calls for methods of differentiation between unirradiated and irradiated products. A new approach to studying the influence of gamma irradiation on vegetable tissue at the cellular level by histochemical techniques has been developed by the authors and already applied to a number of fruits and vegetables. The possibility of evidencing radiation effects in the polysaccharide components of the cell wall suggested that these detected differences could be applied to differentiate irradiated from unirradiated tomatoes and potatoes. Some work done to determine changes in the cell wall polysaccharides of gamma-irradiated potatoes and tomatoes and to relate these changes to some other factors, such as storage time and vegetable variety, is reported here. While significant differences have been found in the optical densities of the total polysaccharides of the cell wall as a function of irradiation and of the other variables mentioned, it is not yet possible to use these values as a means of reliable differentiation. (author)

  7. Bakery products from irradiated and unirradiated eggs - detection of irradiation in a processed food

    International Nuclear Information System (INIS)

    Pfordt, J.; Grabowski, H.U. von

    1995-01-01

    The detection of radiation-specific degradation products in fat has become an established method which has successfully been applied to egg products. This study is making evident the detectability of irradiated eggs as an ingredient of specified processed foods. Tart layers were produced from both irradiated and non-irradiated liquid whole egg. When the fat components were isolated from the tart layers and investigated by GC/MS, the presence of irradiated eggs could clearly be shown. While the radiation-induced hydrocarbons and 2-alkylcyclobutanones could not be found in unirradiated samples, tart layers from irradiated eggs contained these substances. Especially for the hydrocarbons a satisfying correlation between radiation dose and concentration could be observed. The concentrations of radiation-induced compounds were generally lower in the tart layers than in the liquid egg samples they had been produced from. (orig.) [de

  8. Evaluation of staphylococcus aureus growth in unirradiated and irradiated cured meats using the Gompertz equation

    International Nuclear Information System (INIS)

    Szczawinski, J.; Szczawinska, M.

    1993-01-01

    1. Sodium nitrite, in concentration of 156 mg/kg, exerted little (from practical point of view) inhibitory effect on S. aureus in cured meat. Its addition caused lag time extension, increase of exponential growth rate, decrease of generation time and maximum population density of staphylococci in samples of cured meat stored at 20 C. 2. Growth curves of Staphylococcus aureus in unirradiated and irradiated (50 kGy) meats cured without sodium nitrite were similar. 3. Irradiation of meat cured with 156 mg/kg sodium nitrite with increasing doses of ionizing radiation (0, 10, 30, 50 kGy) progressively decreased growth rates and lag time and increased generation time and maximum population densities of Staphylococcus aureus in samples inoculated after radiation treatment and incubated at 20 C. (orig.)

  9. Functional recovery in the irradiated kidney following removal of the contralateral unirradiated kidney

    International Nuclear Information System (INIS)

    Robbins, M.E.C.; Hopewell, J.W.; Golding, S.J.

    1986-01-01

    Radiation-induced damage to one kidney in the pig causes a fall in total renal function; this would be recognised and lead to a compensatory response in the unirradiated kidney. The presence of the unirradiated contralateral kidney may effectively prevent the irradiated kidney from expressing any potential for repair and/or recovery of function. If this were true then the question would obviously arise, does the irradiated kidney retain some capacity for recovery? In order to answer this question, the contralateral unirradiated kidney was removed from pigs 26 weeks after the irradiation of the other kidney. The subsequent response of the irradiated kidney to nephrectomy was assessed in terms of the changes in renal size and haemodynamics, i.e. GFR and effective renal plasma flow (ERPF). (Auth.)

  10. Temperature dependence of magnetoresistance in neutron-irradiated and unirradiated high resistivity p-type silicon

    International Nuclear Information System (INIS)

    Yildirim, M.; Efeoglu, H.; Abay, B.; Yogurtcu, Y.K.

    1996-01-01

    The temperature dependence of the transverse magnetoresistance in irradiated and unirradiated p-type Si is studied in the range from 120 to 290 K. The magnetoresistance coefficients for the unirradiated left angle 001 right angle and left angle 1 anti 10 right angle samples increases with decreasing sample temperature in the range from 160 to 290 K, however, this behavior is reversed below 160 K. It is proposed that this reversal is due to the double injection effect. The magnetoresistance coefficient for the irradiated left angle 001 right angle sample increases with decreasing sample temperature in the range of 120 to 290 K and is greater than that for the unirradiated left angle 001 right angle sample. This result can be explained by increased scattering due to the increased number of defects produced by irradiation. On the other hand, the magnetoresistance coefficient for the unirradiated left angle 1 anti 10 right angle sample is found to be greater than that of the unirradiated left angle 001 right angle sample. (orig.)

  11. Unirradiated UO2 in irradiated zirconium alloy sheathing

    International Nuclear Information System (INIS)

    MacDonald, R.D.; Hardy, D.G.; Hunt, C.E.L.; Scoberg, J.A.

    1979-07-01

    Zircaloy-clad UO 2 fuel elements have defected in power reactors when element power outputs were raised significantly after a long irradiation at low power. We have irradiated fuel elements fabricated from fresh UO 2 pellets and zirconium alloy sheaths previously irradiated without fuel. This gave a fuel element with radiation-damaged low-ductility sheathing but with no fission products in the fuel. The elements were power boosted in-reactor to linear power outputs up to 84 kW/m for two five-day periods. No elements defected despite sheath strains of 0.82 percent at circumferential ridge postions. Half of these elements were subsequently soaked at low power to build up the fission product inventory in the fuel and then power boosted to 63 kW/m for a third time. Two elements defected on this final boost. We conclude that these defects were caused by fission product induced stress-corrosion cracking and that this mechanism plays an importent role in power reactor fuel defects. (auth)

  12. Sperm quantity and size variation in un-irradiated and irradiated males of the malaria mosquito Anopheles arabiensis Patton

    NARCIS (Netherlands)

    Helinski, M.; Knols, B.G.J.

    2009-01-01

    Anopheles mosquitoes are important candidates for genetic control strategies. However, little is known about sperm quality and quantity as determinants of male reproductive success. In this study, sperm quantity and length variation were assessed in testes of un-irradiated and irradiated Anopheles

  13. High Temperature Tensile Properties of Unirradiated and Neutron Irradiated 20 Cr-35 Ni Austenitic Steel

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R B; Solly, B

    1966-12-15

    The tensile properties of an unirradiated and neutron irradiated (at 40 deg C) 20 % Cr, 35 % Ni austenitic steel have been studied at 650 deg C, 750 deg C and 820 deg C. The tensile elongation and mode of fracture (transgranular) of unirradiated specimens tested at room temperature and 650 deg C are almost identical. At 750 deg C and 820 deg C the elongation decreases considerably and a large part of the total elongation is non-uniform. Furthermore, the mode of fracture at these temperatures is intergranular and microscopic evidence suggests that fracture is caused by formation and linkup of grain boundary cavities. YS and UTS decrease monotonically with temperature. Irradiated specimens show a further decrease in ductility and an increase in the tendency to grain boundary cracking. Irradiation has no significant effect on the YS, but the UTS are reduced. The embrittlement of the irradiated specimens is attributed to the presence of He and Li atoms produced during irradiation and the possible mechanisms are discussed. Prolonged annealing of irradiated and unirradiated specimens at 650 deg C appears to have no significant effect on tensile properties.

  14. A study of the behaviour of irradiated or unirradiated grafts in the camera aquosa of irradiated and unirradiated animals

    International Nuclear Information System (INIS)

    Djalali-Behzad, G.

    1969-06-01

    Following grafts of new born mice spinal ganglia in the 'camera aquosa' of adult mice, the authors tried hematopoietic tissue grafts in the same conditions. The growth of iso-logous and hetero-logous bone marrow in the 'camera aquosa' showed that this tissue, even after exposure to supralethal doses, was capable of survival and growth. A counter-experiment with non irradiated bone marrow grafts in the 'camera aquosa' of rats delivered 700 rads led to the conclusion that the environment, intoxicated by exposure, acted on the graft so that after vascularization it became unable to grow. (author) [fr

  15. Molecular dynamics study on interfacial thermal conductance of unirradiated and irradiated SiC/C

    International Nuclear Information System (INIS)

    Wang, Qingyu; Wang, Chenglong; Zhang, Yue; Li, Taosheng

    2014-01-01

    SiC f /SiC composite materials have been considered as candidate structural materials for several types of advanced nuclear reactors. Both experimental and computer simulations studies have revealed the degradation of thermal conductivity for this material after irradiation. The objective of this study is to investigate the effect of SiC/graphite interface structure and irradiation on the interfacial thermal conductance by using molecular dynamics simulation. Five SiC/graphite composite models were created with different interface structures, and irradiation was introduced near the interfaces. Thermal conductance was calculated by means of reverse-NEMD method. Results show that there is a positive correlation between the interfacial energy and interfacial C–Si bond quantity, and irradiated models showed higher interfacial energy compared with their unirradiated counterparts. Except the model with graphite atom plane parallel to the interface, the interfacial thermal conductance of unirradiated and irradiated (1000 eV) models, increases as the increase of interfacial energy, respectively. For all irradiated models, lattice defects are of importance in impacting the interfacial thermal conductance depending on the interface structure. For the model with graphite layer parallel to the interface, the interfacial thermal conductance increased after irradiation, for the other models the interfacial thermal conductance decreased. The vibrational density of states of atoms in the interfacial region was calculated to analyze the phonon mismatch at the interface

  16. Thermal studies on unirradiated and γ-irradiated polymer of allyl diglycol carbonate

    International Nuclear Information System (INIS)

    Kalsi, P.C.; Pandey, A.K.; Iyer, R.H.; Singh Mudher, K.D.

    1995-01-01

    The thermal decomposition of unirradiated and γ-irradiated (5.93-15.5 MRad dose range) allyl diglycol carbonate polymer (trade name, CR-39) was studied by thermogravimetry (TG) and differential thermal analysis (DTA). These studies indicate four main decomposition steps in CR-39 polymer in air. Assessment of the influence of radiation dose on the above range shows that while the 5.93 MRad γ-irradiated polymer CR-39 degrades in three steps, the 15.5 MRad γ-irradiated polymer degrades in only two steps. The kinetics of the different stages of degradation were also evaluated from the TG curves. Irradiation enhances the decomposition rate and the effect increases further with increasing radiation dose. The activation energy values calculated for all the decomposition stages decrease on irradiation

  17. Interaction of spermine with DNA, vitamin C and bovine serum albumin in the unirradiated and gamma irradiated states

    International Nuclear Information System (INIS)

    Upadhyay, S.N.; Lal, C.; Bhardwaj, R.; Chaturvedi, S.; Chaudhury, N.K.

    2006-01-01

    Structural deformability of spermine with radiation dose (maximum 10 Gy) has been proved. Complex formation of spermine with DNA, vitamin C and BSA took place. Calibration and radiation-induced absorption changes in spermine by ninhydrin reagent has been followed quantitatively. Interaction of vitamin C with DNA and their radiation-induced changes have been reported. Interaction of spermine with DNA in the unirradiated and gamma irradiated states in 10 -3 M phosphate buffer and water have been compared. Addition of spermine and vitamin C to DNA makes DNA structure more condensed. Bovine serum albumin also binds with spermine and protects it from radiation-induced degradation. (author)

  18. The effect of compressive stress on the Young's modulus of unirradiated and irradiated nuclear graphites

    International Nuclear Information System (INIS)

    Oku, T.; Usui, T.; Ero, M.; Fukuda, Y.

    1977-01-01

    The Young's moduli of unirradiated and high temperature (800 to 1000 0 C) irradiated graphites for HTGR were measured by the ultrasonic method in the direction of applied compressive stress during and after stressing. The Young's moduli of all the tested graphites decreased with increasing compressive stress both during and after stressing. In order to investigate the reason for the decrease in Young's modulus by applying compressive stress, the mercury pore diameter distributions of a part of the unirradiated and irradiated specimens were measured. The change in pore distribution is believed to be associated with structural changes produced by irradiation and compressive stressing. The residual strain, after removing the compressive stress, showed a good correlation with the decrease in Young's modulus caused by the compressive stress. The decrease in Young's modulus by applying compressive stress was considered to be due to the increase in the mobile dislocation density and the growth or formation of cracks. The results suggest, however, that the mechanism giving the larger contribution depends on the brand of graphite, and in anisotropic graphite it depends on the direction of applied stress and the irradiation conditions. (author)

  19. Damage and failure of unirradiated and irradiated fuel rods tested under film boiling conditions

    International Nuclear Information System (INIS)

    Mehner, A.S.; Hobbins, R.R.; Seiffert, S.L.; MacDonald, P.E.; McCardell, R.K.

    1979-01-01

    Power-cooling-mismatch experiments are being conducted as part of the Thermal Fuels Behavior Program in the Power Burst Facility at the Idaho National Engineering Laboratory to evaluate the behavior of unirradiated and previously irradiated light water reactor fuel rods tested under stable film boiling conditions. The observed damage that occurs to the fuel rod cladding and the fuel as a result of film boiling operation is reported. Analyses performed as a part of the study on the effects of operating failed fuel rods in film boiling, and rod failure mechanisms due to cladding embrittlement and cladding melting upon being contacted by molten fuel are summarized

  20. Thermogravimetric studies of the thermo-oxidative stability of irradiated and unirradiated polyethylene

    International Nuclear Information System (INIS)

    Novakovic, L.; Gal, O.; Markovic, V.; Stannett, V.T.

    1985-01-01

    In part one of this series the effects of a phenolic, an amine and a thioester antioxidant on the thermo-oxidative stability of irradiated and unirradiated low-density polyethylene was reported. In this paper the effects of combined phenolic and thioester stabilizers are described. Isothermal thermogravimetric analysis was used to study the systems. Pronounced synergism was observed with the induction periods, the time when the initial weight loss begins and the 5% weight loss. At about 50% of each stabilizer increases greater than twofold were observed both with the unirradiated and irradiated polymers. The rate constants for oxygen uptake were decreased. However, the rates of degradation at 5% weight loss fell between the values of the two pure stabilizers with no pronounced synergism in either case. In the absence of oxygen little effect of either antioxidant or their mixtures was observed. The corresponding activation energies were somewhat higher, however, with the irradiated samples containing antioxidants. Dynamic thermogravimetry was used for this study. A kinetic analysis indicated that there were somewhat different modes of degradation at lower- and higher-temperature ranges. (author)

  1. Thermogravimetric studies of the thermo-oxidative stability of irradiated and unirradiated polyethylene. 2. Combined antioxidants

    Energy Technology Data Exchange (ETDEWEB)

    Novakovic, L; Gal, O; Markovic, V; Stannett, V T

    1985-01-01

    In part one of this series the effects of a phenolic, an amine and a thioester antioxidant on the thermo-oxidative stability of irradiated and unirradiated low-density polyethylene was reported. In this paper the effects of combined phenolic and thioester stabilizers are described. Isothermal thermogravimetric analysis was used to study the systems. Pronounced synergism was observed with the induction periods, the time when the initial weight loss begins and the 5% weight loss. At about 50% of each stabilizer increases greater than twofold were observed both with the unirradiated and irradiated polymers. The rate constants for oxygen uptake were decreased. However, the rates of degradation at 5% weight loss fell between the values of the two pure stabilizers with no pronounced synergism in either case. In the absence of oxygen little effect of either antioxidant or their mixtures was observed. The corresponding activation energies were somewhat higher, however, with the irradiated samples containing antioxidants. Dynamic thermogravimetry was used for this study. A kinetic analysis indicated that there were somewhat different modes of degradation at lower- and higher-temperature ranges. (author).

  2. Reactor Materials Program electrochemical potential measurements by ORNL with unirradiated and irradiated stainless steel specimens

    International Nuclear Information System (INIS)

    Baumann, E.W.; Caskey, G.R. Jr.

    1993-07-01

    Effect of irradiation of stainless steel on electrochemical potential (ECP) was investigated by measurements in dilute HNO 3 and H 2 O 2 solutions, conditions simulating reactor moderator. The electrodes were made from unirradiated/irradiated, unsensitized/sensitized specimens from R-reactor piping. Results were inconclusive because of budgetary restrictions. The dose rate may have been too small to produce a significant radiolytic effect. Neither the earlier CERT corrosion susceptibility tests nor the present ECP measurements showed a pronounced effect of irradiation on susceptibility of the stainless steel to IGSCC; this is confirmed by the absence in the stainless steel of the SRS reactor tanks (except for the C Reactor tank knuckle area)

  3. Reactor Materials Program electrochemical potential measurements by ORNL with unirradiated and irradiated stainless steel specimens

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, E.W.; Caskey, G.R. Jr.

    1993-07-01

    Effect of irradiation of stainless steel on electrochemical potential (ECP) was investigated by measurements in dilute HNO{sub 3} and H{sub 2}O{sub 2} solutions, conditions simulating reactor moderator. The electrodes were made from unirradiated/irradiated, unsensitized/sensitized specimens from R-reactor piping. Results were inconclusive because of budgetary restrictions. The dose rate may have been too small to produce a significant radiolytic effect. Neither the earlier CERT corrosion susceptibility tests nor the present ECP measurements showed a pronounced effect of irradiation on susceptibility of the stainless steel to IGSCC; this is confirmed by the absence in the stainless steel of the SRS reactor tanks (except for the C Reactor tank knuckle area).

  4. Characterization of un-irradiated MIMAS MOX fuel by Raman spectroscopy and EPMA

    Science.gov (United States)

    Talip, Zeynep; Peuget, Sylvain; Magnin, Magali; Tribet, Magaly; Valot, Christophe; Vauchy, Romain; Jégou, Christophe

    2018-02-01

    In this study, Raman spectroscopy technique was implemented to characterize un-irradiated MIMAS (MIcronized - MASter blend) MOX fuel samples with average 7 wt.% Pu content and different damage levels, 13 years after fabrication, one year after thermal recovery and soon after annealing, respectively. The impacts of local Pu content, deviation from stoichiometry and self-radiation damage on Raman spectrum of the studied MIMAS MOX samples were assessed. MIMAS MOX fuel has three different phases Pu-rich agglomerate, coating phase and uranium matrix. In order to distinguish these phases, Raman results were associated with Pu content measurements performed by Electron Microprobe Analysis. Raman results show that T2g frequency significantly shifts from 445 to 453 cm-1 for Pu contents increasing from 0.2 to 25 wt.%. These data are satisfactorily consistent with the calculations obtained with Gruneisen parameters. It was concluded that the position of the T2g band is mainly controlled by Pu content and self-radiation damage. Deviation from stoichiometry does not have a significant influence on T2g band position. Self-radiation damage leads to a shift of T2g band towards lower frequency (∼1-2 cm-1 for the UO2 matrix of damaged sample). However, this shift is difficult to quantify for the coating phase and Pu agglomerates given the dispersion of high Pu concentrations. In addition, 525 cm-1 band, which was attributed to sub-stoichiometric structural defects, is presented for the first time for the self-radiation damaged MOX sample. Thanks to the different oxidation resistance of each phase, it was shown that laser induced oxidation could be alternatively used to identify the phases. It is demonstrated that micro-Raman spectroscopy is an efficient technique for the characterization of heterogeneous MOX samples, due to its low spatial resolution.

  5. Kinetics of thermal decomposition of γ-irradiated and unirradiated complexes of mandelhydroxamic acid

    International Nuclear Information System (INIS)

    Hassan, R.M.; Farid, T.; El-Bellihi, A.A.

    1992-01-01

    The thermal decomposition of γ-irradiated and unirradiated complexes of mandelhydroxamic acid (HMA), Co (HMA) 2 .1/2H 2 O, Mn (HMA) 2 .2H 2 O, Ba (HMA) 2 .2H 2 O and Cd (HMA) 2 .2H 2 O have been studied thermogravimetrically (under isothermal conditions). The thermal dehydration of each complex occured in one step, while the decomposition of dehydrated complexes occured in two steps. The kinetic parameters for dehydration were computed by different models. The thermal dehydration is regulated by random nucleation A 3 for Co-, Mn-, and Cd-complexes and by phase-boundary (R 3 ) for Ba-complex. The effect of γ-irradiation on the kinetic parameters of thermal decomposition is discussed. Radiation did not modify the mechanism of the reaction but accelarated the dehydration steps in the case of Mn- and Co-complexes. (author) 7 refs.; 1 fig.; 4 tabs

  6. Oxidation kinetic changes of UO2 by additive addition and irradiation

    International Nuclear Information System (INIS)

    You, Gil-Sung; Kim, Keon-Sik; Min, Duck-Kee; Ro, Seung-Gy

    2000-01-01

    The kinetic changes of air-oxidation of UO 2 by additive addition and irradiation were investigated. Several kinds of specimens, such as unirradiated-UO 2 , simulated-UO 2 for spent PWR fuel (SIMFUEL), unirradiated-Gd-doped UO 2 , irradiated-UO 2 and -Gd-doped UO 2 , were used for these experiments. The oxidation results represented that the kinetic patterns among those samples are remarkably different. It was also revealed that the oxidation kinetics of irradiated-UO 2 seems to be more similar to that of unirradiated-Gd-doped UO 2 than that of SIMFUEL

  7. Fusarium growth on culture media made of tissue juice from irradiated and unirradiated potato tubers

    International Nuclear Information System (INIS)

    Taczanowski, M.

    1994-01-01

    Fusarium Sulphureum Schlecht is one of the tuber pathogens causing potato storage disease knowing as dry rot. Because irradiation can disturb the tissue defence mechanism against the pathogen, it was decided to carry out experiments on influence of the treatment on subsequent tuber tissue reaction to a maceration process. The maceration as a physical stress was a substitute for the pathogen activity. Tubers of two potato varieties were tested: Mila -a resistant variety to Fusarium and Atol - susceptible one. Tubers of both varieties were irradiated with a dose of 105 kGy. Unirradiated tubers were taken as a control. A day after irradiation the cortex tissue was macerated using an ordinary rasper and the resulted tissue pulp was strained through medical gauze to obtain crude juice. The juice was clarified by centrifugation and then added to dissolved PDA. The volume ratio of juice to PDA was 1:1. The prepared media were dispensed into Petri dishes. Small pieces of the Fusarium culture were put on the surface of the medium at the centre of each Petri dish. Subsequent growth of the fungus was assessed by measurement of culture diameters every 24 hours. Linear functions of the Fusarium growth were obtained for Mila control and Atol control. In the case of Mila, the Fusarium found more favourable conditions for its growth in the presence of juice from irradiated tubers than from the control ones. Making the same comparison for Atol, no difference was detected. (author)

  8. The reaction of unirradiated and irradiated nuclear graphites with water vapor in helium

    International Nuclear Information System (INIS)

    Imai, Hisashi; Nomura, Shinzo; Kurosawa, Takeshi; Fujii, Kimio; Sasaki, Yasuichi

    1980-10-01

    Nuclear graphites more than 10 brands were oxidized with water vapor in helium and then some selected graphites were irradiated with fast neutron in the Japan Materials Testing Reactor to clarify the effect of radiation damage of graphite on their reaction behaviors. The reaction was carried out under a well defined condition in the temperature range 800 -- 1000 0 C at concentrations of water vapor 0.38 -- 1.30 volume percent in helium flow of total pressure of 1 atm. The chemical reactivity of graphite irradiated at 1000 +- 50 0 C increased linearly with neutron fluence until irradiation of 3.2 x 10 21 n/cm 2 . The activation energy for the reaction was found to decrease with neutron fluence for almost all the graphites, except for a few ones. The order of reaction increased from 0.5 for the unirradiated graphite to 1.0 for the graphite irradiated up to 6.0 x 10 20 n/cm 2 . Experiment was also performed to study a superposed effect between the influence of radiation damage of graphite and the catalytic action of barium on the reaction rate, as well as the effect of catalyser of barium. It was shown that these effects were not superposed upon each other, although barium had a strong catalytic action on the reaction. (author)

  9. Overview and Critical Assessment of the Tensile Properties of unirradiated and irradiated EUROFER97

    Energy Technology Data Exchange (ETDEWEB)

    Lucon, E.; Vandermeulen, W.

    2007-10-15

    Material research represents a crucial issue for the assessment of fusion as a future viable source of energy. Structural materials, in particular, need to show a superior mechanical and chemical behaviour to guarantee the safe operation of the reactor during its whole lifetime, while retaining low activation characteristics to minimise the environmental impact of the produced waste. In this context, specific efforts have been focused for the last twenty years in Europe, Japan and the US, on developing suitable Reduced Activation Ferritic Martensitic (RAFM) steels as candidate structural materials. EUROFER97 has recently emerged in Europe as the reference material for the DEMO design. In the framework of the Long-Term Programme of EFDA (European Fusion Development Agreement), a coordinated effort has been launched aimed at providing a critical assessment of the mechanical and microstructural properties of EUROFER97 in the unirradiated and irradiated conditions, based on the results accumulated since the late 90ies within numerous EFDA tasks.

  10. An analysis of facial nerve function in irradiated and unirradiated facial nerve grafts

    International Nuclear Information System (INIS)

    Brown, Paul D.; Eshleman, Jeffrey S.; Foote, Robert L.; Strome, Scott E.

    2000-01-01

    Purpose: The effect of high-dose radiation therapy on facial nerve grafts is controversial. Some authors believe radiotherapy is so detrimental to the outcome of facial nerve graft function that dynamic or static slings should be performed instead of facial nerve grafts in all patients who are to receive postoperative radiation therapy. Unfortunately, the facial function achieved with dynamic and static slings is almost always inferior to that after facial nerve grafts. In this retrospective study, we compared facial nerve function in irradiated and unirradiated nerve grafts. Methods and Materials: The medical records of 818 patients with neoplasms involving the parotid gland who received treatment between 1974 and 1997 were reviewed, of whom 66 underwent facial nerve grafting. Fourteen patients who died or had a recurrence less than a year after their facial nerve graft were excluded. The median follow-up for the remaining 52 patients was 10.6 years. Cable nerve grafts were performed in 50 patients and direct anastomoses of the facial nerve in two. Facial nerve function was scored by means of the House-Brackmann (H-B) facial grading system. Twenty-eight of the 52 patients received postoperative radiotherapy. The median time from nerve grafting to start of radiotherapy was 5.1 weeks. The median and mean doses of radiation were 6000 and 6033 cGy, respectively, for the irradiated grafts. One patient received preoperative radiotherapy to a total dose of 5000 cGy in 25 fractions and underwent surgery 1 month after the completion of radiotherapy. This patient was placed, by convention, in the irradiated facial nerve graft cohort. Results: Potential prognostic factors for facial nerve function such as age, gender, extent of surgery at the time of nerve grafting, preoperative facial nerve palsy, duration of preoperative palsy if present, or number of previous operations in the parotid bed were relatively well balanced between irradiated and unirradiated patients. However

  11. Response of unirradiated and irradiated PWR fuel rods tested under power-cooling-mismatch conditions

    International Nuclear Information System (INIS)

    MacDonald, P.E.; Quapp, W.J.; Martinson, Z.R.; McCardell, R.K.; Mehner, A.S.

    1978-01-01

    This report summarizes the results from the single-rod power-cooling-mismatch (PCM) and irradiation effects (IE) tests conducted to date in the Power Burst Facility (PBF) at the U.S. DOE Idaho National Engineering Laboratory. This work was performed for the U.S. NRC under contact to the Department of Energy. These tests are part of the NRC Fuel Behavior Program, which is designed to provide data for the development and verification of analytical fuel behavior models that are used to predict fuel response to abnormal or postulated accident conditions in commercial LWRs. The mechanical, chemical and thermal response of both previously unirradiated and previously irradiated LWR-type fuel rods tested under power-cooling-mismatch condition is discussed. A brief description of the test designs is presented. The results of the PCM thermal-hydraulic studies are summarized. Primary emphasis is placed on the behavior of the fuel and cladding during and after stable film boiling. (orig.) [de

  12. Induction of lethal mutations in the x-chromosome of unirradiated Drosophila oocytes after fertilization by irradiated spermatozoa

    International Nuclear Information System (INIS)

    Shaposhnikov, M.V.; Zainullin, V.G.

    2003-01-01

    Full text: In primary study on Drosophila it was found that irradiated male X-chromosomes induce recessive lethals in unirradiated female homologues (Abeleva et al., 1961, Radiobiologya. 1:123-126). The same effects were obtained in Drosophila in some recent investigations. The mechanisms of these effects is unknown. However it may be responsible for low-dose radiation effects as it induce mutations in unirradiated DNA. We assume that this effect may be a result of activation of error prone repair in response to preliminary DNA lesions in irradiated chromosome. In this research we analyse the frequencies of the recessive lethal mutations in the X-chromosome of Drosophila females mated with irradiated Basc males. We used acute irradiation with a dose rate of 10 Gy. For testing our hypothesis we use the mus209 and mei-41 mutant females. Mus209 is a PCNA gene homologue and mei-41 is a homologue of ATM gene. These genes are involved in post-replication DNA repair which may be error prone repair in Drosophila. It was obtained the tendency to decreasing the mutation rate at the mei-41[D5] background and decreasing mutation rate in mus209[B1] background in comparison with wild type strains CS (p<0.05). The obtained results demonstrate the possible role of mus209[B1] and mei-41[D5] genes in the inducing of mutations in the unirradiated X-chromosome in the presence of irradiated homologue

  13. Oxide particle size distribution from shearing irradiated and unirradiated LWR fuels in Zircaloy and stainless steel cladding: significance for risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W. Jr.; West, G.A.; Stacy, R.G.

    1979-03-22

    Sieve fractionation was performed with oxide particles dislodged during shearing of unirradiated or irradiated fuel bundles or single rods of UO/sub 2/ or 96 to 97% ThO/sub 2/--3 to 4% UO/sub 2/. Analyses of these data by nonlinear least-squares techniques demonstrated that the particle size distribution is lognormal. Variables involved in the numerical analyses include lognormal median size, lognormal standard deviation, and shear cut length. Sieve-fractionation data are presented for unirradiated bundles of stainless-steel-clad or Zircaloy-2-clad UO/sub 2/ or ThO/sub 2/--UO/sub 2/ sheared into lengths from 0.5 to 2.0 in. Data are also presented for irradiated single rods (sheared into lengths of 0.25 to 2.0 in.) of Zircaloy-2-clad UO/sub 2/ from BWRs and of Zircaloy-4-clad UO/sub 2/ from PWRs. Median particle sizes of UO/sub 2/ from shearing irradiated stainless-steel-clad fuel ranged from 103 to 182 ..mu..m; particle sizes of ThO/sub 2/--UO/sub 2/, under these same conditions, ranged from 137 to 202 ..mu..m. Similarly, median particle sizes of UO/sub 2/ from shearing unirradiated Zircaloy-2-clad fuel ranged from 230 to 957 ..mu..m. Irradiation levels of fuels from reactors ranged from 9,000 to 28,000 MWd/MTU. In general, particle sizes from shearing these irradiated fuels are larger than those from the unirradiated fuels; however, unirradiated fuel from vendors was not available for performing comparative shearing experiments. In addition, variations in particle size parameters pertaining to samples of a single vendor varied as much as those between different vendors. The fraction of fuel dislodged from the cladding is nearly proportional to the reciprocal of the shear cut length, until the cut length attains some minimum value below which all fuel is dislodged. Particles of fuel are generally elongated with a long-to-short axis ratio usually less than 3. Using parameters of the lognormal distribution estimates can be made of fractions of dislodged fuel having

  14. Oxide particle size distribution from shearing irradiated and unirradiated LWR fuels in Zircaloy and stainless steel cladding: significance for risk assessment

    International Nuclear Information System (INIS)

    Davis, W. Jr.; West, G.A.; Stacy, R.G.

    1979-01-01

    Sieve fractionation was performed with oxide particles dislodged during shearing of unirradiated or irradiated fuel bundles or single rods of UO 2 or 96 to 97% ThO 2 --3 to 4% UO 2 . Analyses of these data by nonlinear least-squares techniques demonstrated that the particle size distribution is lognormal. Variables involved in the numerical analyses include lognormal median size, lognormal standard deviation, and shear cut length. Sieve-fractionation data are presented for unirradiated bundles of stainless-steel-clad or Zircaloy-2-clad UO 2 or ThO 2 --UO 2 sheared into lengths from 0.5 to 2.0 in. Data are also presented for irradiated single rods (sheared into lengths of 0.25 to 2.0 in.) of Zircaloy-2-clad UO 2 from BWRs and of Zircaloy-4-clad UO 2 from PWRs. Median particle sizes of UO 2 from shearing irradiated stainless-steel-clad fuel ranged from 103 to 182 μm; particle sizes of ThO 2 --UO 2 , under these same conditions, ranged from 137 to 202 μm. Similarly, median particle sizes of UO 2 from shearing unirradiated Zircaloy-2-clad fuel ranged from 230 to 957 μm. Irradiation levels of fuels from reactors ranged from 9,000 to 28,000 MWd/MTU. In general, particle sizes from shearing these irradiated fuels are larger than those from the unirradiated fuels. In addition, variations in particle size parameters pertaining to samples of a single vendor varied as much as those between different vendors. The fraction of fuel dislodged from the cladding is nearly proportional to the reciprocal of the shear cut length, until the cut length attains some minimum value below which all fuel is dislodged. Particles of fuel are generally elongated with a long-to-short axis ratio usually less than 3. Using parameters of the lognormal distribution deduced from experimental data, realistic estimates can be made of fractions of dislodged fuel having dimensions less than specified values

  15. Chromosome dosimetry: the influence of culture media on the proliferation of irradiated and unirradiated human lymphocytes

    International Nuclear Information System (INIS)

    Purrott, R.J.; Lloyd, D.C.; Vulpis, N.

    1981-01-01

    The proliferation of phytohaemagglutinin stimulated human lymphocytes in four types of synthetic culture medium has been studied using the fluorescence plus Giemsa staining technique to determine cell cycle status. 48 hour cultures of unirradiated cells containing Ham's F10 or RPMI 1640 media yielded significant numbers of second cycle metaphases. Cultures containing Eagle's MEM or TC 199 media, however, required longer incubation times to produce appreciable numbers of second division cells. Intrinsic differences between donors in the rate of proliferation had little effect on the relative ranking of the media. Radiation induced mitotic delay of about 1 hour per Gray was observed for each medium. The relevance of these results to the accuracy of radiation dose estimation by chromosome aberration analysis is discussed. (author)

  16. Radiation induced synthesis of In{sub 2}O{sub 3} nanoparticles - Part II: Synthesis of In{sub 2}O{sub 3} nanoparticles by thermal decomposition of un-irradiated and γ-irradiated indium acetylacetonate

    Energy Technology Data Exchange (ETDEWEB)

    Al-Resheedi, Ajayb Saud; Alhokbany, Norah Saad [Department of Chemistry, College of Science, King Saud University, KSU, (Saudi Arabia); Mahfouz, Refaat Mohammed, E-mail: rmhfouz@science.au.edu.eg [Chemistry Department, Faculty of Science, Assiut University, AUN, (Egypt)

    2015-09-15

    Pure cubic phase, In{sub 2}O{sub 3} nanoparticles with porous structure were synthesized by solid state thermal oxidation of un-irradiated and γ-irradiated indium acetyl acetonate in presence and absence of sodium dodecyl sulphate as surfactant. The as- synthesized In{sub 2}O{sub 3} nanoparticles were characterized by X-ray diffraction (XRD), fourier transformation infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transition electron microscopy (TEM) and thermogravimetry (TG). The shapes and morphologies of as- synthesized In{sub 2}O{sub 3} nanoparticles were highly affected by γ-irradiation of indium acetyl acetonate precursor and by addition of sodium dodecyl sulphate as surfactant. Calcination of un-irradiated indium acetyl acetonate precursor to 4 hours of 600 °C leads to the formation of spherical- shaped accumulative and merged In{sub 2}O{sub 3} nanoparticles with porous structure, whereas irregular porous architectures composed of pure In{sub 2}O{sub 3} nanoparticles were obtained by using γ-irradiated indium acetylacetonate precursor. The as- prepared In{sub 2}O{sub 3} nano products exhibit photoluminescence emission (PL) property and display thermal stability in a wide range of temperature (25-800 °C) which suggest possible applications in nanoscale optoelectronic devices. (author)

  17. Comparison of the growth of Listeria monocytogenes in unirradiated and irradiated cook-chill roast beef and gravy at refrigeration temperatures

    International Nuclear Information System (INIS)

    Grant, I.R.; Nixon, C.R.; Patterson, M.F.

    1993-01-01

    Specific growth rates of two strains of Listeria monocytogenes in unirradiated and irradiated (2 kGy) roast beef and gravy stored at 5° and 10°C were found to be similar. However, exponential growth of L. monocytogenes after irradiation was preceded by an extended lag period of 6–9 d at 5°C and 3–4 d at 10°C, compared with lag periods of 1–2 d and <0.1 d in unirradiated beef and gravy stored similarly

  18. Tensile and electrical properties of unirradiated and irradiated Hycon 3HP{trademark} CuNiBe

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Eatherly, W.S. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    The unirradiated tensile properties of two different heats of Hycon 3HP{trademark} CuNiBe (HT Temper) have been measured over the temperature range of 20-500{degrees}C for longitudinal and long transverse orientations. The room temperature electrical conductivity has also been measured for both heats. Both heats exhibited a very good combination of strength and conductivity at room temperature. The strength remained relatively high at all test temperatures, with a yield strength of 420-520 MPa at 500{degrees}C. However, low levels of ductility (<5% uniform elongation) were observed at test temperatures above 200-250{degrees}C, due to flow localization adjacent to grain boundaries. Fission neutron irradiation to a dose of {approximately}0.7 dpa at temperatures between 100 and 240{degrees}C produced a slight increase in strength and a significant decrease in ductility. The measured tensile elongation increased with increasing irradiation temperature, with a uniform elongation of {approximately}3.3% observed at 240{degrees}C. The electrical conductivity decreased slightly following irradiation, due to the presence of defect clusters and Ni, Zn, Co transmutation products. The data indicate that CuNiBe alloys have irradiated tensile and electrical properties comparable or superior to CuCrZr and oxide dispersion strengthened copper at temperatures <250{degrees}C, and may be suitable for certain fusion energy structural applications.

  19. Radiation quality-dependence of bystander effect in unirradiated fibroblasts is associated with TGF-β1-Smad2 pathway and miR-21 in irradiated keratinocytes

    Science.gov (United States)

    Yin, Xiaoming; Tian, Wenqian; Wang, Longxiao; Wang, Jingdong; Zhang, Shuyu; Cao, Jianping; Yang, Hongying

    2015-01-01

    Traditional radiation biology states that radiation causes damage only in cells traversed by ionizing radiation. But radiation-induced bystander effect (RIBE), which refers to the biological responses in unirradiated cells when the neighboring cells are exposed to radiation, challenged this old dogma and has become a new paradigm of this field. By nature, RIBEs are the consequences of intercellular communication between irradiated and unirradiated cells. However, there are still some important questions remain unanswered such as whether RIBE is dependent on radiation quality, what are the determining factors if so, etc. Using a transwell co-culture system, we found that HaCaT keratinocytes irradiated with α-particles but not X-rays could induce bystander micronucleus formation in unirradiated WS1 fibroblasts after co-culture. More importantly, the activation of TGF-β1-Smad2 pathway and the consistent decrease of miR-21 level in α-irradiated HaCaT cells were essential to the micronucleus induction in bystander WS1 cells. On the other hand, X-irradiation did not induce bystander effect in unirradiated WS1 cells, accompanied by lack of Smad2 activation and consistent decrease of miR-21 in X-irradiated HaCaT cells. Taken together, these results suggest that the radiation quality-dependence of bystander effect may be associated with the TGF-β1-Smad2 pathway and miR-21 in irradiated cells. PMID:26080011

  20. Bioregulation of aflatoxin biosynthesis by unirradiated and irradiated conidia of Aspergillus flavus

    International Nuclear Information System (INIS)

    Aziz, N.H.; Abu-Shady, M.R.; El-Fouly, M.Z.; Moussa, L.A.

    1996-01-01

    A sequential technique involving the transfer of mycelia from peptone-based, aflatoxin-non-supporting medium to glucose based, aflatoxin-supporting medium was used to study the effect of γ-irradiation on the regulation of aflatoxin biosynthesis by Aspergillus flavus. Analysis indicated that irradiation at a dose of 1.00 kGy produced enhancement of aflatoxin biosynthesis in peptone-glucose mineral salt cultures with an increase of adenine nucleotide levels and fatty acid patterns of microsomes and mitochondria. The results suggest that aflatoxin synthesis is not regulated by the overall energy status of the fungal cell but that lipoperoxidation by γ-irradiation plays a role in aflatoxin biosynthesis

  1. Semi-conservative deoxyribonucleic acid synthesis in unirradiated and ultraviolet-irradiated xeroderma pigmentosum and normal human skin fibroblasts

    International Nuclear Information System (INIS)

    Rude, J.M.; Friedberg, E.C.

    1977-01-01

    Rates of semiconservative DNA synthesis have been investigated in asynchronous xeroderma pigmentosum (XP), XP variant, and normal human skin fibroblasts using the technique of cellular autoradiography. In unirradiated cells, no differences in DNA synthesis rates were detected among the three cell strains. Exposure to UV radiation caused the rate of DNA synthesis to decrease for at least three hours in all three cell strains. In the normal cell strain, recovery of the DNA synthetic rate occurred at later times following a UV fluence of 5 J/m 2 . At this same UV fluence, recovery was absent in classical XP cells during a 24 h post-irradiation period while it was slower than normal in XP variant cells. When the UV fluence to classical XP and XP variant cells was reduced so that survival in all three cell strains was approximately the same (25%), recovery of the DNA synthetic rate was similar in all three cell strains. These results are discussed in terms of current models of DNA replication in UV-irradiated cells and indicate: (1) that pyrimidine dimers are very effective blocks to DNA synthesis and (2) that there is no inherent defect in semiconservative DNA synthesis in either classical XP or XP variant cells which is independent of a defect in DNA repair capacity

  2. Semi-conservative deoxyribonucleic acid synthesis in unirradiated and ultraviolet-irradiated xeroderma pigmentosum and normal human skin fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Rude' e, J.M.; Friedberg, E.C.

    1977-03-01

    Rates of semiconservative DNA synthesis have been investigated in asynchronous xeroderma pigmentosum (XP), XP variant, and normal human skin fibroblasts using the technique of cellular autoradiography. In unirradiated cells, no differences in DNA synthesis rates were detected among the three cell strains. Exposure to uv radiation caused the rate of DNA synthesis to decrease for at least three hours in all three cell strains. In the normal cell strain, recovery of the DNA synthetic rate occurred at later times following a uv fluence of 5 J/m2. At this same uv fluence, recovery was absent in classical XP cells during a 24 h post-irradiation period while it was slower than normal in XP variant cells. When the uv fluence to classical XP and XP variant cells was reduced so that survival in all three cell strains was approximately the same (25%), recovery of the DNA synthetic rate was similar in all three cell strains. These results are discussed in terms of current models of DNA replication in uv-irradiated cells and indicate: (1) that pyrimidine dimers are very effective blocks to DNA synthesis and (2) that there is no inherent defect in semi-conservative DNA synthesis in either classical XP or XP variant cells which is independent of a defect in DNA repair capacity.

  3. Comparison of toxin production by clostridium botulinum type E in irradiated and unirradiated vacuum-packed trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Hussain, M.; Ehlermann, D.; Diehl, J.F.

    1977-01-01

    Trouts obtained from a nearby Fish farm were slaughtered, gutted, cut into 100g samples and inoculated with 10 1 , 10 3 and 10 5 spores per g of Clostridium botulinum type E. The vacuum-packed samples were stored under melting ice (0 0 C) and at temperatures of 5 0 and 10 0 C for periods of up to 8 weeks. At weekly intervals, occurrence of spoilage and toxin production were determined. Only at 10 0 C storage, the irradiated samples showed toxin production before spoilage was observed. When the fishes were stored at 5 0 C, no toxicity occured before spoilage was observed even in samples treated with doses as high as 200 krad. Samples stored under melting ice, irradiated or unirradiated, never showed toxin production. It is concluded that the radurization of fish at doses of about 100 or 200 krad and at storage temperatures of melting ice or up to 5 0 C is safe with regard to a possible botulism risk. (orig.) [de

  4. Comparison of toxin production by clostridium botulinum type E in irradiated and unirradiated vacuum-packed trout (Salmo gairdneri)

    International Nuclear Information System (INIS)

    Hussain, A.M.; Ehlermann, D.; Diehl, J.F.

    1977-01-01

    Trouts obtained from a nearby fish farm were slaughtered, gutted, cut into 100 g samples and inoculated with 10 1 , 10 3 and 10 5 spores per g of Clostridium botulinum type E. The vacuum-packed samples were stored under melting ice (0 0 C) and at temperatures of 5 0 and 10 0 C for periods of up to 8 weeks. At weekly intervals, occurrence of spoilage and toxin production were determined. Only at 10 0 C storage, the irradiated samples showed toxin production before spoilage was observed. When the fishes were stored at 5 0 C, no toxicity occurred before spoilage was observed even in samples treated with doses as high as 200 krad. Samples stored under melting ice, irradiated or unirradiated, never showed toxin production. It is concluded that the radurization of fish at doses of about 100 or 200 krad and at storage temperatures of melting ice or up to 5 0 C is safe with regard to a possible botulism risk. (orig.) [de

  5. Time of flight measurements of unirradiated and irradiated nuclear graphite under cyclic compressive load

    Energy Technology Data Exchange (ETDEWEB)

    Bodel, W., E-mail: william.bodel@hotmail.com [Nuclear Graphite Research Group, The University of Manchester (United Kingdom); Atkin, C. [Health and Safety Laboratory, Buxton (United Kingdom); Marsden, B.J. [Nuclear Graphite Research Group, The University of Manchester (United Kingdom)

    2017-04-15

    The time-of-flight technique has been used to investigate the stiffness of nuclear graphite with respect to the grade and grain direction. A loading rig was developed to collect time-of-flight measurements during cycled compressive loading up to 80% of the material's compressive strength and subsequent unloading of specimens along the axis of the applied stress. The transmission velocity (related to Young's modulus), decreased with increasing applied stress; and depending on the graphite grade and orientation, the modulus then increased, decreased or remained constant upon unloading. These tests were repeated while observing the microstructure during the load/unload cycles. Initial decreases in transmission velocity with compressive load are attributed to microcrack formation within filler and binder phases. Three distinct types of behaviour occur on unloading, depending on the grade, irradiation, and loading direction. These different behaviours can be explained in terms of the material microstructure observed from the microscopy performed during loading.

  6. A discussion of possible mechanisms affecting fission product transport in irradiated and unirradiated nuclear grade graphite

    International Nuclear Information System (INIS)

    Firth, M.J.

    1977-09-01

    137 Cs, 85 Sr, and sup(110m)Ag adsorption experiments were conducted on three graphite powders with differing amounts of specific basal and edge surface areas. No direct proportionality was found between the specific amounts of the isotopes adsorbed and either of the surface characteristics. There appears to be some correlation with the specific basal surface area despite the fact that each isotope behaves differently. Factors that might influence the adsorption behaviour of Cs and Ag during reactor irradiation and heat treatment of nuclear grade graphites are discussed. These include the form of Cs with the graphite surface. A model based on Cs adsorption at vacancy clusters is used to analyse adsorption experiments. A possible explanation for the behaviour of Ag through the migration of graphite impurities from the bulk of the graphite to the pore surface is also discussed. (author)

  7. Plastic flow properties and fracture toughness characterization of unirradiated and irradiated tempered martensitic steels

    International Nuclear Information System (INIS)

    Spaetig, P.; Bonade, R.; Odette, G.R.; Rensman, J.W.; Campitelli, E.N.; Mueller, P.

    2007-01-01

    We investigate the plastic flow properties at low and high temperature of the tempered martensitic steel Eurofer97. We show that below room temperature, where the Peierls friction on the screw dislocation is active, it is necessary to modify the usual Taylor's equation between the flow stress and the square root of the dislocation density and to include explicitly the Peierls friction stress in the equation. Then, we compare the fracture properties of the Eurofer97 with those of the F82H steel. A clear difference of the fracture toughness-temperature behavior was found in the low transition region. The results indicate a sharper transition for Eurofer97 than for the F82H. Finally, the shift of the median toughness-temperature curve of the F82H steel was determined after two neutron irradiations performed in the High Flux Reactor in Petten

  8. Revised ANL-reported tensile data for unirradiated and irradiated (FFTF, HFIR) V-Ti and V-Cr-Ti alloys

    International Nuclear Information System (INIS)

    Billone, M.C.

    1998-01-01

    The tensile data for all unirradiated and irradiated vanadium alloys samples tested at Argonne National Laboratory (ANL) have been critically reviewed and, when necessary, revised. The review and revision are based on reanalyzing the original load-displacement strip chart recordings by a methodology consistent with current ASTM standards. For unirradiated alloys (162 samples), the revised values differ from the previous values as follows: -11±19 MPa (-4±6%) for yield strength (YS), -3±15 MPa (-1±3%) for ultimate tensile strength (UTS), -5±2% strain for uniform elongation (UE), and -4±2% strain for total elongation (TE). Of these changes, the decrease in -1±6 MPa (0±1%) for UTS, -5±2% for UE, and -4±2% for TE. Of these changes, the decrease in UE values for alloys irradiated and tested at 400--435 C is the most significant. This decrease results from the proper subtraction of nongauge-length deformation from measured crosshead deformation. In previous analysis of the tensile curves, the nongauge-length deformation was not correctly determined and subtracted from the crosshead displacement. The previously reported and revised tensile values for unirradiated alloys (20--700 C) are tabulated in Appendix A. The revised tensile values for the FFTF-irradiated (400--600 C) and HFIR-irradiated (400 C) alloys are tabulated in Appendix B, along with the neutron damage and helium levels. Appendix C compares the revised values to the previously reported values for irradiated alloys. Appendix D contains previous and revised values for the tensile properties of unirradiated V-5Cr-5Ti (BL-63) alloy exposed to oxygen

  9. Thermogravimetric studies of the thermooxidative stability of irradiated and unirradiated polyethylene

    International Nuclear Information System (INIS)

    Gal, O.; Novakovic, Lj.; Stannett, V.T.

    1983-01-01

    The addition of antioxidants to polymers increases their thermooxidative stability as indicated by a delay and/or a retardation of degradation. The present paper considers the influence of the nature of the antioxidant (hindered phenols, aromatic amines, and organic compounds containing sulphur atoms) on the thermooxidative behaviour of a low density polyethylene at 200 deg C. The following characteristics have been measured in polymer samples with zero; 0.1; 0.5; and 1.0 wt% content of antioxidant: the induction time of the oxidation process, rate of autoxidation and rate of polymer degradation (up to about 20% weight loss). The difference in thermal stability in radiation crosslinked material and comparative retardation of the thermooxidative degradation is observed up to an absorbed dose of 200 kGy. (author)

  10. Thermogravimetric studies of the thermooxidative stability of irradiated and unirradiated polyethylene. Pt. 1. Effect of antioxidant

    Energy Technology Data Exchange (ETDEWEB)

    Gal, O; Novakovic, Lj [Institut za Nuklearne Nauke Boris Kidric, Belgrade (Yugoslavia); Stannett, V T [North Carolina State Univ., Raleigh (USA)

    1983-01-01

    The addition of antioxidants to polymers increases their thermooxidative stability as indicated by a delay and/or a retardation of degradation. The present paper considers the influence of the nature of the antioxidant (hindered phenols, aromatic amines, and organic compounds containing sulphur atoms) on the thermooxidative behaviour of a low density polyethylene at 200 deg C. The following characteristics have been measured in polymer samples with zero; 0.1; 0.5; and 1.0 wt% content of antioxidant: the induction time of the oxidation process, rate of autoxidation and rate of polymer degradation (up to about 20% weight loss). The difference in thermal stability in radiation crosslinked material and comparative retardation of the thermooxidative degradation is observed up to an absorbed dose of 200 kGy.

  11. Tensile and fracture toughness properties of copper alloys and their HIP joints with austenitic stainless steel in unirradiated and neutron irradiated condition

    International Nuclear Information System (INIS)

    Taehtinen, S.; Pyykkoenen, M.; Singh, B.N.; Toft, P.

    1998-03-01

    The tensile strength and ductility of unirradiated CuAl25 IG0 and CuCrZr alloys decreased continuously with increasing temperature up to 350 deg C. Fracture toughness of unirradiated CuAl25 IG0 alloy decreased continuously with increasing temperature from 20 deg C to 350 deg C whereas the fracture toughness of unirradiated CuCrZr alloy remained almost constant at temperatures up to 100 deg C, was decreased significantly at 200 deg C and slightly increased at 350 deg C. Fracture toughness of HIP joints were lower than that of corresponding copper alloy and fracture path in HIP joint specimen was always within copper alloy side of the joint. Neutron irradiation to a dose level of 0.3 dpa resulted in hardening and reduction in uniform elongation to about 2-4% at 200 deg C in both copper alloys. At higher temperatures softening was observed and uniform elongation increased to about 5% and 16% for CuAl25 IG0 and CuCrZr alloys, respectively. Fracture toughness of CuAl25 IG0 alloy reduced markedly due to neutron irradiation in the temperature range from 20 deg C to 350 deg C. The fracture toughness of the irradiated CuCrZr alloy also decreased in the range from 20 deg C to 350 deg C, although it remained almost unaffected at temperatures below 200 deg C and decreased significantly at 350 deg C when compared with that of unirradiated CuCrZr alloy. (orig.)

  12. Unirradiated cells rescue cells exposed to ionizing radiation: Activation of NF-κB pathway in irradiated cells

    Energy Technology Data Exchange (ETDEWEB)

    Lam, R.K.K. [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); Han, Wei [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N., E-mail: peter.yu@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong (Hong Kong); State Key Laboratory in Marine Pollution, City University of Hong Kong (Hong Kong)

    2015-12-15

    Highlights: • Rescue effect was observed in both irradiated and HeLa and NIH/3T3 cells. • Novel setup and procedures to separate the rescue signals and the bystander signals. • Confirmed activation of NF-κB pathway in rescue effect using activation inhibitor. • Confirmed activation of NF-κB pathway in rescue effect using anti-NF-κB p65 antibody. - Abstract: We studied the involvement of NF-κB pathway activation in the rescue effect in HeLa and NIH/3T3 cells irradiated by α particles. Firstly, upon irradiation by 5 cGy of α particles, for both cell lines, the numbers of 53BP1 foci/cell at 12 h post-irradiation were significantly smaller when only 2.5% of the cell population was irradiated as compared to 100% irradiation, which demonstrated the rescue effect. Secondly, we studied the effect of NF-κB on the rescue effect through the use of the NF-κB activation inhibitor BAY-11-7082. Novel experimental setup and procedures were designed to prepare the medium (CM) which had conditioned the bystander cells previously partnered with irradiated cells, to ensure physical separation between rescue and bystander signals. BAY-11-7082 itself did not inflict DNA damages in the cells or have effects on activation of the NF-κB response pathway in the irradiated cells through direct irradiation. The rescue effect was induced in both cell lines by the CM, which was abrogated if BAY-11-7082 was added to the CM. Thirdly, we studied the effect of NF-κB on the rescue effect through staining for phosphorylated NF-κB (p-NF-κB) expression using the anti-NF-κB p65 (phospho S536) antibody. When the fraction of irradiated cells dropped from 100% to 2.5%, the p-NF-κB expression in the cell nuclei of irradiated NIH/3T3 cells increased significantly, while that in the cell nuclei of irradiated HeLa cells also increased although not significantly. Moreover, the p-NF-κB expression in the cell nuclei of irradiated HeLa cells and NIH/3T3 cells treated with CM also increased

  13. Ductility and failure behaviour of both unirradiated and irradiated zircaloy-4 cladding using plane strain tensile specimens

    International Nuclear Information System (INIS)

    Carassou, S.; Le Saux, M.; Pizzanelli, J.P.; Rabouille, O.; Averty, X.; Poussard, C.; Cazalis, B.; Desquines, J.; Bernaudat, C.

    2010-01-01

    In this work, eight PST (Plan Strain Tensile) tests machined from a Zircaloy-4 (Zy-4) cladding irradiated up to 5 annual cycles have been performed at 280, 350 and 480 Celsius degrees. The specimen displacements during the tests were filmed and digitally recorded to allow the use of a Digital Image Correlation (DIC) analysis technique to experimentally determine the local strains on the outer surface of the specimens. The plane strain conditions have been verified and prevail over a wide area between the notches of the specimen, as expected from full 3D FE numerical analysis performed in support of the tests. For the first time, the location of the onset of fracture for this geometry on irradiated material has been experimentally observed: at 280 C.degrees, crack initiates in the vicinity of the notches, in an area where plane strain conditions are not fulfilled, and for a local circumferential strain value of about 5%. At 350 C. degrees and 480 C. degrees, cracks initiate at a location where plane strain conditions prevail, for circumferential strain values respectively close to 10% and greater than 50%. These results have been compared to results obtained previously by similar test on fresh and hydrided material, as well as tests performed as support to the study. At 350 C. degrees, the homogeneous 700 ppm hydrided Zy-4 and the Zy-4 irradiated during 5 annual cycles exhibit similar fracture behaviour, for both fracture hoop strain values (10%) and fracture mode (through-wall slant fracture). For the irradiated material, it has clearly been established that at 350 C. degrees, a brittle fracture occurs at the outer surface in the hydride rim. The crack propagates subsequently toward the inner surface and the notches, where final fracture occurs

  14. Impact of creep-fatigue interaction on the lifetime of a dispersion strengthened copper alloy in unirradiated and irradiated conditions

    International Nuclear Information System (INIS)

    Singh, B.N.; Toft, P.; Stubbins, J.F.

    2001-06-01

    Creep-fatigue interaction behaviour of a dispersion strengthened copper alloy was investigated at 22 and 250 deg. C. To determine the effect of irradiation a number of fatigue specimens were irradiated at 250 deg. C to a dose level of 0.3 dpa and were tested at 250 deg. C. The creep-fatigue interaction was simulated by applying a certain hold-time on both tension and compression sides of the cyclic loading with a frequency of 0.5 Hz. Hold-times of 0,2, 5, 10, 100 and 1000 seconds were used. For a given hold-time, the real lifetime and the number of cycles to failure were determined at different strain amplitudes. Post-deformation micro-structures and fracture surfaces were investigated using transmission and scanning electron microscopes, respectively. The main results of these investigations are presented and their implications are briefly discussed in the present report. The central conclusion emerging from the present work is that a hold-time of 10 seconds or less causes a drastic decrease in the real lifetime as well as in the number of cycles to failure, particularly at low levels of strain amplitudes. A combination of higher temperature, higher strain amplitude and longer hold-time, on the other hand, may lead to an improvement in the lifetime. The irradiation at 250 deg. C to a dose level of 0.3 dpa does not play any significant role in determining the lifetime under creep-fatigue testing conditions. (au)

  15. The Effect of E-Selen Antioxidant on the Fatty Acids Content of the Homogenate of Unirradiated and Irradiated Pupae of Ceratitis Capitata

    International Nuclear Information System (INIS)

    Zaghloul, Y.S.; Abbassy, S.A.; Elakhdar, E.A.H.; Elakhdar, E.A.H.

    2011-01-01

    As antioxidant E-selen was added to the larval artificial diets of the Mediterranean fruit fly, Ceratitis capitata. The produced full grown pupae were exposed to gamma rays at dose rate of 90 Gy. The fatty acid contents of the normal and irradiated insects were analyzed to test to what extent, the uptake of the antioxidant will ameliorate the physiological damage induced to the medfly pupae, as a result of their exposure to irradiation. The results obtained by using Gas-liquid chromatography of fatty acid methyl esters, showed the palmitic and oleic acids to be the most predominant fatty acids in all pupal homogenates in both normal and irradiated pupae, either by the uptake of doses of the E-selen or without. The uptake of E-Selen with a dose of 0.3 mg led to a complete absence of the lauric and myristic acids in the homogenates of the unirradiated pupae of the medfly. This absence of lauric and myristic acids was accompanied by a decrease in the concentrations of the palmitic and linoleic acids reaching 25.17% and 32.98%, respectively as compared to pupae without the uptake of antioxidant. The concentrations of both the stearic and oleic acids showed an obvious increment reaching 199.22% and 58.94%, respectively, relative to those reared on the defined media and no added E.Selen. Exposure of the pupae to a dose of 90 Gy, resulted in an increment in the concentrations of the saturated lauric and myristic acid reaching 96.77% and 34.07%, respectively, relative to the untreated ones. While, at the same dose level, there were decrements in the concentrations of the palmitic, stearic, oleic and linoleic acids with percentages reaching 6.4, 9.22, 3.65 and 1.15%, respectively as compared to unirradiated controls. Irradiation of the pupae with sterilizing dose (90 Gy) after up taking the E-Selen in their larval diets, led to the increase of the concentrations of lauric, oleic and linoleic acids by ratios of 16.82, 8.84 and 29.26%, respectively as compared to their

  16. Facts about food irradiation: Irradiation and food additives and residues

    International Nuclear Information System (INIS)

    1991-01-01

    This fact sheet considers the issue of the irradiation of food containing food additives or pesticide residues. The conclusion is that there is no health hazard posed by radiolytic products of pesticides or food additives. 1 ref

  17. The influence of Boron on creep-rupture behaviour of austenitic unstabilized and Nb-stabilized stainless steel X8CrNi 1613 in unirradiated and irradiated condition

    International Nuclear Information System (INIS)

    Sen, Susant Kumar.

    1976-10-01

    The present study deals with influence of boron on creep-rupture behaviour in unirradiated condition at 650 0 C along with precipitation behaviour, heat-treatment and recrystallization of unstabilized and stabilized steel. The results of creep-rupture tests on unirradiated specimens show that boron exerts a beneficial effect on the rupture life and ductility. Boron losses its beneficial effect on creep properties in unstabilized steel by prolong creeping. The magnitude of beneficial effect of Boron on creep properties depends upon the initial boron distribution which influences the number, size and distribution of the precipitates. Boron promotes the precipitation of type M 23 C 6 Carbides in the grain as well as at the grain boundary. Boron segregates in atomic form during slow cooling from austenitizing temperature. The recrystallization will be delayed by the presence of boron. The results of creep tests at 650 0 C shows that boron exerts a beneficial effect on creep life of irradiated steels. (orig./GSC) [de

  18. A study of the behaviour of irradiated or unirradiated grafts in the camera aquosa of irradiated and unirradiated animals; Etude du comportement d'un greffon irradie ou non, transplante dans la chambre anterieure de l'oeil d'un animal irradie ou non

    Energy Technology Data Exchange (ETDEWEB)

    Djalali-Behzad, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-06-01

    Following grafts of new born mice spinal ganglia in the 'camera aquosa' of adult mice, the authors tried hematopoietic tissue grafts in the same conditions. The growth of iso-logous and hetero-logous bone marrow in the 'camera aquosa' showed that this tissue, even after exposure to supralethal doses, was capable of survival and growth. A counter-experiment with non irradiated bone marrow grafts in the 'camera aquosa' of rats delivered 700 rads led to the conclusion that the environment, intoxicated by exposure, acted on the graft so that after vascularization it became unable to grow. (author) [French] Apres avoir greffe des ganglions rachidiens de souriceaux nouveaux-nes dans la chambre anterieure de l'oeil de souris adultes, l'auteur a tente de greffer du tissu hematopoietique de la meme facon. La proliferation de la moelle osseuse isologue et heterologue, dans la chambre anterieure de l'oeil, lui a permis de mettre en evidence une certaine capacite de survie et de proliferation de ce tissu irradie meme a dose supraletale. Par une contre-experimentation, c'est-a-dire par la greffe de moelle non irradiee dans la chambre anterieure de rats irradies a 700 rads, il conclut que le milieu ambiant, intoxique par l'irradiation, agit sur le greffon de telle sorte que ce dernier, apres s'etre vascularise, devient depourvu de son aptitude de proliferation. (auteur)

  19. A study of the behaviour of irradiated or unirradiated grafts in the camera aquosa of irradiated and unirradiated animals; Etude du comportement d'un greffon irradie ou non, transplante dans la chambre anterieure de l'oeil d'un animal irradie ou non

    Energy Technology Data Exchange (ETDEWEB)

    Djalali-Behzad, G. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-06-01

    Following grafts of new born mice spinal ganglia in the 'camera aquosa' of adult mice, the authors tried hematopoietic tissue grafts in the same conditions. The growth of iso-logous and hetero-logous bone marrow in the 'camera aquosa' showed that this tissue, even after exposure to supralethal doses, was capable of survival and growth. A counter-experiment with non irradiated bone marrow grafts in the 'camera aquosa' of rats delivered 700 rads led to the conclusion that the environment, intoxicated by exposure, acted on the graft so that after vascularization it became unable to grow. (author) [French] Apres avoir greffe des ganglions rachidiens de souriceaux nouveaux-nes dans la chambre anterieure de l'oeil de souris adultes, l'auteur a tente de greffer du tissu hematopoietique de la meme facon. La proliferation de la moelle osseuse isologue et heterologue, dans la chambre anterieure de l'oeil, lui a permis de mettre en evidence une certaine capacite de survie et de proliferation de ce tissu irradie meme a dose supraletale. Par une contre-experimentation, c'est-a-dire par la greffe de moelle non irradiee dans la chambre anterieure de rats irradies a 700 rads, il conclut que le milieu ambiant, intoxique par l'irradiation, agit sur le greffon de telle sorte que ce dernier, apres s'etre vascularise, devient depourvu de son aptitude de proliferation. (auteur)

  20. Stress corrosion crack growth in unirradiated zircaloy

    International Nuclear Information System (INIS)

    Pettersson, K.

    1978-10-01

    Experimental techniques suitable for the determination of stress corrosion crack growth rates in irradiated Zircaloy tube have been developed. The techniques have been tested on unirradiated. Zircaloy and it was found that the results were in good agreement with the results of other investigations. Some of the results were obtained at very low stress intensities and the crack growth rates observed, gave no indication of the existance of a K sub(ISCC) for iodine induced stress corrosion cracking in Zircaloy. This is of importance both for fuel rod behavior after a power ramp and for long term storage of spent Zircaloy-clad fuel. (author)

  1. Additive action model for mixed irradiation

    International Nuclear Information System (INIS)

    Lam, G.K.Y.

    1984-01-01

    Recent experimental results indicate that a mixture of high and low LET radiation may have some beneficial features (such as lower OER but with skin sparing) for clinical use, and interest has been renewed in the study of mixtures of high and low LET radiation. Several standard radiation inactivation models can readily accommodate interaction between two mixed radiations, however, this is usually handled by postulating extra free parameters, which can only be determined by fitting to experimental data. A model without any free parameter is proposed to explain the biological effect of mixed radiations, based on the following two assumptions: (a) The combined biological action due to two radiations is additive, assuming no repair has taken place during the interval between the two irradiations; and (b) The initial physical damage induced by radiation develops into final biological effect (e.g. cell killing) over a relatively long period (hours) after irradiation. This model has been shown to provide satisfactory fit to the experiment results of previous studies

  2. NSRR experiment with un-irradiated uranium-zirconium hydride fuel. Design, fabrication process and inspection data of test fuel rod

    Energy Technology Data Exchange (ETDEWEB)

    Sasajima, Hideo; Fuketa, Toyoshi; Ishijima, Kiyomi; Kuroha, Hiroshi; Ikeda, Yoshikazu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Aizawa, Keiichi

    1998-08-01

    An experiment plan is progressing in the Nuclear Safety Research Reactor (NSRR) to perform pulse-irradiation with uranium-zirconium hydride (U-ZrH{sub x}) fuel. This fuel is widely used in the training research and isotope production reactor of GA (TRIGA). The objectives of the experiment are to determine the fuel rod failure threshold and to investigate fuel behavior under simulated reactivity initiated accident (RIA) conditions. This report summarizes design, fabrication process and inspection data of the test fuel rods before pulse-irradiation. The experiment with U-ZrH{sub x} fuel will realize precise safety evaluation, and improve the TRIGA reactor performance. The data to be obtained in this program will also contribute development of next-generation TRIGA reactor and its safety evaluation. (author)

  3. Longitudinal growth in children with non-Hodgkin's lymphoma and children with acute lymphoblastic leukemia: Comparison between unirradiated and irradiated patients

    International Nuclear Information System (INIS)

    Marky, I.; Samuelsson, B.O.; Mellander, L.; Karlberg, J.

    1991-01-01

    Longitudinal growth was studied in children treated for non-Hodgkin's lymphoma (NHL). The aim of the study was to compare these children's growth velocity with findings in a previous study we performed on age-matched children with acute lymphoblastic leukemia (ALL) who received cranial irradiation. Nine children with NHL with an onset time of treatment between 4 and 9 years of age (mean 6.5 years) were studied with annual body measurements taken from the time of the diagnosis and thereafter annually during the following 4 years. None of the children received cranial irradiation. During the first treatment year a significantly low mean height velocity was observed (-1.4 standard deviation score [SDS]) for the NHL group. The consecutive two 1 year periods showed a normalization of the mean height velocity. For the group of children with ALL, there was a more prominent negative effect on height during the first 2 years of treatment than for the NHL group in the present study. After the cessation of therapy, the children with NHL showed a reduced catch-up growth compared with the children with ALL. The explanation offered is that cranial irradiation has a heavier impact on growth than chemotherapy during the first 2 years of treatment, but an intense chemotherapy during the maintenance period could have a considerable impact in blunting growth

  4. The effect of ultraviolet and visible radiation on the readout obtained from γ-irradiated and unirradiated CaSO4:Dy in teflon discs

    International Nuclear Information System (INIS)

    Bartnik, D.L.; Calvert, R.L.; Young, J.G.

    1982-07-01

    The effect of ultraviolet and visible radiation on the readout obtained from the main dosimetry peak of CaSO 4 :Dy in teflon discs is explained by the net result of three separate factors, namely (i) an inherent response, (ii) a phototransfer and (iii) an optical bleaching. Their dependence on wavelength, irradiance and radiant exposure has been studied using a fluorescent light enclosed in a perspex diffuser and a 200W mercury-xenon lamp in conjunction with narrow bandpass filters to isolate specific wavelengths

  5. Effects of irradiation on the fracture behavior of austenitic stainless steels

    International Nuclear Information System (INIS)

    Grossbeck, M.L.; Stiegler, J.O.; Holmes, J.J.

    1977-01-01

    Fracture in irradiated materials occurs by mechanisms which occur in unirradiated materials in addition to mechanisms related to irradiation phenomena. The paper examines radiation effects in austenitic stainless steels for use as core structural materials in fast breeder reactors

  6. Identification of irradiated food additives by photostimulated luminescence (PSL) method

    International Nuclear Information System (INIS)

    Yun, Hye Jeong; Kwon, Joong Ho; KIm, Dong Ho; Hur, Jung Mu; Yang, Suh Yung; Lee, Byoung Hun

    2008-01-01

    Photostimulated luminescence (PSL), electron spin resonance (ESR) and thermoluminescence (TL) analyses were conducted to detect whether 258 kinds of extracted and powdered forms food additives were irradiated or not. In a view of the PSL results, 9 kinds of the extracted and powdered samples (3.2%) showed over 5,000 photon counts (60 sec) -1 and these samples were judged to be irradiation-positive. Thirty nine kinds of the samples (15.6%) yielded 700-5,000 photon counts (60 sec) -1 and these samples were grouped into irradiation-potential, while the samples showed below 700 photon counts (60 sec) -1 sec were judged to be irradiation-negative. TL glow curves for minerals separated from 5 samples were detected at 150 degrees C with high intensity. However, TL analysis did not apply to other irradiation-positive and irradiation-potential samples because the minerals for TL detection were not separated from the samples. ESR measurements for irradiation-positive and irradiation-potential samples, judged by PSL detection, showed no specific signals to irradiation. The results indicated that PSL could be applied to identify irradiation treatment of extracted and powdered food additives, while TL was optional and ESR was not suitable for detection extracted and powdered food additives

  7. Effects of gamma irradiation on antioxidants and ultraviolet stabilizers

    International Nuclear Information System (INIS)

    Kawamura, Yoko; Miura, Makiko; Miura, Yukiko; Yamada, Takashi

    1998-01-01

    The effects of gamma irradiation on 18 kinds of antioxidants and 10 kinds of ultraviolet stabilizers, intact or in a polyethylene sheet, were studied. After irradiating at a 30kGy dose, the content of additives themselves did not change and new degradation products were not found. While most antioxidants in polyethylene had a decreased content after irradiation, most ultraviolet stabilizers did not change. During the migration tests with aqueous food simulants, additives were not released from either irradiated or unirradiated sheets. For the migration tests with n-heptane, however, all additives were released from the unirradiated sheet, while most of the antioxidants were not released or released only slightly. (author)

  8. Bystander apoptosis in human cells mediated by irradiated blood plasma

    Energy Technology Data Exchange (ETDEWEB)

    Vinnikov, Volodymyr, E-mail: vlad.vinnikov@mail.ru [Grigoriev Institute for Medical Radiology of the National Academy of Medical Science of Ukraine (Ukraine); Lloyd, David; Finnon, Paul [Centre for Radiation, Chemical and Environmental Hazards of the Health Protection Agency of the United Kingdom (United Kingdom)

    2012-03-01

    Following exposure to high doses of ionizing radiation, due to an accident or during radiotherapy, bystander signalling poses a potential hazard to unirradiated cells and tissues. This process can be mediated by factors circulating in blood plasma. Thus, we assessed the ability of plasma taken from in vitro irradiated human blood to produce a direct cytotoxic effect, by inducing apoptosis in primary human peripheral blood mononuclear cells (PBM), which mainly comprised G{sub 0}-stage lymphocytes. Plasma was collected from healthy donors' blood irradiated in vitro to 0-40 Gy acute {gamma}-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 Degree-Sign C. Additionally, plasma from in vitro irradiated and unirradiated blood was tested against PBM collected from blood given 4 Gy. Apoptosis in reporter PBM was measured by the Annexin V test using flow cytometry. Plasma collected from unirradiated and irradiated blood did not produce any apoptotic response above the control level in unirradiated reporter PBM. Surprisingly, plasma from irradiated blood caused a dose-dependent reduction of apoptosis in irradiated reporter PBM. The yields of radiation-induced cell death in irradiated reporter PBM (after subtracting the respective values in unirradiated reporter PBM) were 22.2 {+-} 1.8% in plasma-free cultures, 21.6 {+-} 1.1% in cultures treated with plasma from unirradiated blood, 20.2 {+-} 1.4% in cultures with plasma from blood given 2-4 Gy and 16.7 {+-} 3.2% in cultures with plasma from blood given 6-10 Gy. These results suggested that irradiated blood plasma did not cause a radiation-induced bystander cell-killing effect. Instead, a reduction of apoptosis in irradiated reporter cells cultured with irradiated blood plasma has implications concerning oncogenic risk from mutated cells surviving after high dose in vivo irradiation (e.g. radiotherapy) and requires further study.

  9. Bystander apoptosis in human cells mediated by irradiated blood plasma

    International Nuclear Information System (INIS)

    Vinnikov, Volodymyr; Lloyd, David; Finnon, Paul

    2012-01-01

    Following exposure to high doses of ionizing radiation, due to an accident or during radiotherapy, bystander signalling poses a potential hazard to unirradiated cells and tissues. This process can be mediated by factors circulating in blood plasma. Thus, we assessed the ability of plasma taken from in vitro irradiated human blood to produce a direct cytotoxic effect, by inducing apoptosis in primary human peripheral blood mononuclear cells (PBM), which mainly comprised G 0 -stage lymphocytes. Plasma was collected from healthy donors’ blood irradiated in vitro to 0–40 Gy acute γ-rays. Reporter PBM were separated from unirradiated blood with Histopaque and held in medium with the test plasma for 24 h at 37 °C. Additionally, plasma from in vitro irradiated and unirradiated blood was tested against PBM collected from blood given 4 Gy. Apoptosis in reporter PBM was measured by the Annexin V test using flow cytometry. Plasma collected from unirradiated and irradiated blood did not produce any apoptotic response above the control level in unirradiated reporter PBM. Surprisingly, plasma from irradiated blood caused a dose-dependent reduction of apoptosis in irradiated reporter PBM. The yields of radiation-induced cell death in irradiated reporter PBM (after subtracting the respective values in unirradiated reporter PBM) were 22.2 ± 1.8% in plasma-free cultures, 21.6 ± 1.1% in cultures treated with plasma from unirradiated blood, 20.2 ± 1.4% in cultures with plasma from blood given 2–4 Gy and 16.7 ± 3.2% in cultures with plasma from blood given 6–10 Gy. These results suggested that irradiated blood plasma did not cause a radiation-induced bystander cell-killing effect. Instead, a reduction of apoptosis in irradiated reporter cells cultured with irradiated blood plasma has implications concerning oncogenic risk from mutated cells surviving after high dose in vivo irradiation (e.g. radiotherapy) and requires further study.

  10. Kraft cooking of gamma irradiated wood, (1). Effect of alcohol additives on pre-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, M; Meshitsuka, G; Nakano, J [Tokyo Univ. (Japan). Faculty of Agriculture

    1979-12-01

    Studies have been made of kraft cooking of gamma irradiated wood. Beech (Fagus crenata Blume) wood meal suspended in aqueous alkaline alcohol was irradiated up to 1.5 KGy (0.15 Mrad) with gamma rays from a Co-60 source in the presence or absence of oxygen. The irradiated wood meals were washed thoroughly with fresh water, air dried and cooked under the ordinary cooking conditions. The results are summarized as follows: (1) Pre-irradiation in aqueous alkali have negligible effect on kraft cooking. (2) In the case of ethanol addition (50 g/l), pre-irradiation in vacuo shows acceleration of delignification and stabilization of carbohydrates during kraft cooking. Cooked yield gain by pre-irradiation was about 1.2 in all, over the range of delignification from 80 to 90%. Aqueous ethanol without alkali also shows positive but smaller effect than that with alkali. (3) Propanol, iso-propanol and butanol show positive but smaller effects than ethanol. However, methanol does not show any positive effect. (4) Irradiation in the presence of oxygen does not show any attractive effect on kraft cooking.

  11. Identification of irradiated spices with luminescence measurements: a European intercomparison

    Energy Technology Data Exchange (ETDEWEB)

    Heide, L; Guggenberger, R; Boegl, K W [Federal Health Office, Neuherberg/Muenchen (Germany, F.R.). Inst. for Radiation Hygiene

    1989-01-01

    Blind tests were performed measuring the thermoluminescence intensity on samples from 10 different spices that were either irradiated or unirradiated. The chemiluminescence was measured on 10 additional spice samples. Twelve institutions participated in this collaborative study. Thresholds were defined which, when exceeded, declare samples as irradiated. The recovering rate was nearly 100% for samples investigated by thermoluminescence. Only one out of 495 irradiated samples was not identified. By using chemiluminescence, the participants succeeded in identifying 99% of unirradiated samples and 75% of irradiated samples from a total of 490 samples. (author).

  12. Transport insurance of unirradiated nuclear fuels

    International Nuclear Information System (INIS)

    Matto, H.

    1985-01-01

    Special conditions must be taken into account in transport insurance for nuclear materials even if the nuclear risk involved is negligible, as in shipments of unirradiated nuclear fuels. The shipwreck of the 'Mont Louis' has raised a number of open points which must be solved pragmatically within the framework of transport insurance. Some proposals are outlined in the article. (orig.) [de

  13. Experimental studies on the sterile male technique of spodoptera litura (F. ) by the gamma radiation from /sup 137/Cs, 3. Experiments of the mating competitiveness between moths irradiated as pupae and unirradiated ones in the field cage

    Energy Technology Data Exchange (ETDEWEB)

    Tsukuda, R; Kiyoku, M [Okayama Univ. (Japan). Faculty of Agriculture

    1973-10-01

    Experiments of the mating competitiveness between the substerilized tobacco cutworms and the normal ones were carried out in a field cage (200 x 120 x 180 cm/plot). Pupae of seven days old reared on an artificial medium during the larval stage irradiated with 12 kR of the gamma rays to substerilize. The normal adults were cultured using leaves of cabbages. Cabbages and soybeans were planted in the purpose of egg laying for adult females mated with males in the cage. Substerilized males only or both substerilized males and females were combined with normal males and females. The mating behavior, longevity, egg deposition, percentage of egg hatch and spermatophore in a receptaculum seminis were investigated. When more than ten substerilized and one normal males were exposed to one female, or more than fourteen substerilized and two normal males were combined two normal females, the substerilized males showed high competitiveness with normal males for virgin females. When both five substerilized males and females placed together with one pair of normal male and female in the cage, or each ten substerilized males and females with each two normals, these substerilized males showed full competitiveness. In addition, it was found that offspring obtained from the combination between substerilized males and normal females were sterile.

  14. Results from In-pile experiments on LWR fuel rod behavior under LOCA conditions with unirradiated rods

    International Nuclear Information System (INIS)

    Sepold, L.; Karb, E.H.; Pruessmann, M.

    1981-06-01

    This report summarizes the results of the FR2-in-pile tests at KfK (Kernforschungszentrum Karlsruhe) with unirradiated test rods. The in-pile tests with the objective of investigating the influence of a nuclear environment on the mechanisms of fuel rod failure were being performed with irradiated and unirradiated single rods of a PWR design in the DK loop of the FR2 reactor. The main parameter of the test program was the burnup, ranging from 2.500 to 35.000 MWd/t. The program with unirradiated specimens comprised the series A and B with a total of 14 tests. (orig.) [de

  15. Environmental Cracking and Irradiation Resistant Stainless Steels by Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B.

    2018-03-30

    Metal additive manufacturing (AM), or metal 3D printing is an emergent advanced manufacturing method that can create near net shape geometries directly from computer models. This technology can provide the capability to rapidly fabricate complex parts that may be required to enhance the integrity of reactor internals components. Such opportunities may be observed during a plant refueling outage and AM parts can be rapidly custom designed, manufactured and deployed within the outage interval. Additive manufacturing of stainless steel (SS) components can add business benefits on fast delivery on repair hardware, installation tooling, new design prototypes tests, etc. For the nuclear industry, the supply chain is always an issue for reactor service. AM can provide through-life supply chain (40-60 years) for high-value low-volume components. In the meantime, the capability of generating complex geometries and functional gradient materials will improve the performance, reduce the overall component cost, plant asset management cost and increase the plant reliability by the improvement in materials performance in nuclear environments. While extensive work has been conducted regarding additively manufacturing of austenitic SS parts, most efforts focused only on basic attributes such as porosity, residual stress, basic tensile properties, along with components yield and process monitoring. Little work has been done to define and evaluate the material requirements for nuclear applications. Technical gaps exist, which limit this technology adoption in the nuclear industry, which includes high manufacturing cost, unknown risks, limited nuclear related data, lack of specification and qualification methods, and no prior business experience. The main objective of this program was to generate research data to address all these technical gaps and establish a commercial practice to use AM technology in the nuclear power industry. The detailed objectives are listed as follows: (1

  16. Unirradiated cladding rip-propagation tests

    International Nuclear Information System (INIS)

    Hu, W.L.; Hunter, C.W.

    1981-04-01

    The size of cladding rips which develop when a fuel pin fails can affect the subassembly cooling and determine how rapidly fuel escapes from the pin. The object of the Cladding Rip Propagation Test (CRPT) was to quantify the failure development of cladding so that a more realistic fuel pin failure modeling may be performed. The test results for unirradiated 20% CS 316 stainless steel cladding show significantly different rip propagation behavior at different temperatures. At room temperature, the rip growth is stable as the rip extension increases monotonically with the applied deformation. At 500 0 C, the rip propagation becomes unstable after a short period of stable rip propagation. The rapid propagation rate is approximately 200 m/s, and the critical rip length is 9 mm. At test temperatures above 850 0 C, the cladding exhibits very high failure resistances, and failure occurs by multiple cracking at high cladding deformation. 13 figures

  17. Dissolution experiments of unirradiated uranium dioxide pellets

    International Nuclear Information System (INIS)

    Ollila, K.

    1985-01-01

    The purpose of this study was to measure the dissolution rate of uranium from unirradiated uranium dioxide pellets in deionized water and natural groundwater. Moreover, the solubility limit of uranium in natural groundwater was measured. Two different temperatures, 25 and 60 deg C were used. The low oxygen content of deep groundwater was simulated. The dissolution rate of uranium varied from 10 -7 to 10 -8 g cm -2 d -1 . The rate in reionized water was one order of magnitude lower than in groundwater. No great difference was observed between the natural groundwaters with different composition. Temperature seems to have effect on the dissolution rate. The solubility limit of uranium in natural groundwater in reducing conditions, at 25 deg C, varied from 20 to 600 μg/l and in oxidizing conditions, at 60 deg C, from 4 to 17 mg/l

  18. Truck accident involving unirradiated nuclear fuel

    International Nuclear Information System (INIS)

    Carlson, R.W.; Fischer, L.E.

    1993-01-01

    In the early morning of Dec. 16, 1991, a severe accident occurred when a passenger vehicle traveling in the wrong direction collided with a tractor trailer carrying 24 unirradiated nuclear fuel assemblies in 12 containers on Interstate I-91 in Springfield, Massachusetts. This paper documents the mechanical circumstances of the accident and assesses the physical environment to which the containers were exposed and the response of the containers and their contents. The accident involved four impacts where the truck was struck by the car, impacted on the center guardrail, impacted on the outer concrete barrier and came to rest against the center guardrail. The impacts were followed by a fire that began in the engine compartment, spread to the tractor and cab, and eventually spread to the trailer and payload. The fire lasted for about three hours and the packages were involved in the fire for about two hours. As a result of the fire, the tractor-trailer was completely destroyed and the packages were exposed to flames with temperatures between 1,300 F and 1,800 F. The fuel assemblies remained intact during the accident and there was no release of any radioactive material during the accident. This was a very severe accident; however, the injuries were minor and at no time was the public health and safety at risk

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

    International Nuclear Information System (INIS)

    Kawamura, Yoko; Sayama, Kayo; Yamada, Takashi

    2000-01-01

    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)

  20. Nuclear Materials Management in a Recovery Facility for Unirradiated Enriched Uranium; Gestion des Matieres Nucleaires dans une Installation de Recuperation d'Uranium Enrichi Non Irradie; Administrativno-khozyajstvennyj uchet yadernykh materialov na ustanovke po regeneratsii neobluchennogo obogashchennogo urana; Administracion de Materiales Nucleares en una Planta de Recuperacion para Uranio Enriquecido No Irradiado

    Energy Technology Data Exchange (ETDEWEB)

    Jasny, G. R. [Union Carbide Corporation, Oak Ridge, TN (United States)

    1966-02-15

    The United States Atomic Energy Commission's Y-12 Plant, in Oak Ridge, Tennessee, has been processing and recovering various forms of unirradiated enriched uranium for over twenty years. Today, the Y-12 recovery facilities consist of a semi-continuous train of unit operations including dissolution, combustion, evaporation, extraction, denitration, and hydrofluorination. The processing and storage equipment is of restricted geometry and has a combined capacity of several hundred kilograms of enriched Uranium per month. Feed to the recovery operation comes both from the Plant and from other USAEC installations in the United States. This feed has included, at one time or another, practically every type of unirradiated enriched uranium scrap. Physical control is maintained successfully by the following techniques: 1. Careful design of equipment to permit cleaning and sampling and to minimize material trapping; 2. Continuous monitoring of all discards and waste streams including sewer and stack effluents and contaminated discards; 3. Periodic physical inventories; 4. Careful sampling and analysis of all external feed streams and product streams; 5. Stringent control of the quality of analytical measurements and of sampling; 6. Assignment of the responsibility for material control to operating personnel rather than to accounting personnel; 7. Careful indoctrination of operating personnel. Information input to the nuclear material accounting system is achieved by means of a paper flow closely paralleling the physical flow of material, i.e. batch identity is maintained by means of individual batch cards and batch disposition is signalled by transfer of the batch card to the nuclear material accounting department. Most accounting operations are performed on electronic data-processing equipment. In addition to the records and calculations required for material balances, historical records of hold-up and concentration are kept to detect anomalies in input-output or inventory

  1. Irradiation and additive combinations on the pathogen reduction and quality of poultry meat.

    Science.gov (United States)

    Ahn, Dong U; Kim, Il Suk; Lee, Eun Joo

    2013-02-01

    Reduction of foodborne illnesses and deaths by improving the safety of poultry products is one of the priority areas in the United States, and developing and implementing effective food processing technologies can be very effective to accomplish that goal. Irradiation is an effective processing technology for eliminating pathogens in poultry meat. Addition of antimicrobial agents during processing can be another approach to control pathogens in poultry products. However, the adoption of irradiation technology by the meat industry is limited because of quality and health concerns about irradiated meat products. Irradiation produces a characteristic aroma as well as alters meat flavor and color that significantly affect consumer acceptance. The generation of a pink color in cooked poultry and off-odor in poultry by irradiation is a critical issue because consumers associate the presence of a pink color in cooked poultry breast meat as contaminated or undercooked, and off-odor in raw meat and off-flavor in cooked meat with undesirable chemical reactions. As a result, the meat industry has difficulties in using irradiation to achieve its food safety benefits. Antimicrobials such as sodium lactate, sodium diacetate, and potassium benzoate are extensively used to extend the shelf-life and ensure the safety of meat products. However, the use of these antimicrobial agents alone cannot guarantee the safety of poultry products. It is known that some of the herbs, spices, and antimicrobials commonly used in meat processing can have synergistic effects with irradiation in controlling pathogens in meat. Also, the addition of spices or herbs in irradiated meat improves the quality of irradiated poultry by reducing lipid oxidation and production of off-odor volatiles or masking off-flavor. Therefore, combinations of irradiation with these additives can accomplish better pathogen reduction in meat products than using them alone even at lower levels of antimicrobials/herbs and

  2. Effect of SiO2 addition and gamma irradiation on the lithium borate glasses

    Science.gov (United States)

    Raut, A. P.; Deshpande, V. K.

    2018-01-01

    The physical properties like density, glass transition temperature (Tg), and ionic conductivity of lithium borate (LB) glasses with SiO2 addition were measured before and after gamma irradiation. Remarkable changes in properties have been obtained in the physical properties of LB glasses with SiO2 addition and after gamma irradiation. The increase in density and glass transition temperature of LB glasses with SiO2 addition has been explained with the help of increase in density of cross linking due to SiO4 tetrahedra formation. The increase in ionic conductivity with SiO2 addition was explained with the help of ‘mixed glass former effect’. The increase in density and Tg of LB glasses with SiO2 addition after gamma irradiation has been attributed to fragmentation of bigger ring structure into smaller rings, which increases the density of cross linking and hence compaction. The exposure of gamma irradiation has lead to decrease in ionic conductivity of LB glasses with SiO2 addition. The atomic displacement caused by gamma irradiation resulted in filling of interstices and decrease in trapping sites. This explains the obtained decrease in ionic conductivity after gamma irradiation of glasses. The obtained results of effect of SiO2 addition and gamma irradiation on the density, Tg and ionic conductivity has been supported by FTIR results.

  3. Adrenal and plasma corticosterone changes in continuously irradiated rats. II. Dependence on additional stress factors

    Energy Technology Data Exchange (ETDEWEB)

    Malatova, Z; Ahlers, I; Praslicka, M [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

    1978-01-01

    Adrenal and plasma corticosterone levels were followed in continuously irradiated rats in dependence on additional stress factors - transport of animals, handling and overnight fasting. Rats were gamma irradiated on an open experimental field with a daily dose rate of 15.48x10/sup -3/ C/kg (60 R) continuously up to a total exposure of 387.0x10/sup -3/ C/kg (1500 R) and analyzed after irradiation. The continuous irradiation increased the adrenal and plasma corticosterone concentrations in all groups of animals. The transport and weighing increased mainly adrenal corticosterone in all three groups, irradiated, non-irradiated controls from the field and intact laboratory controls. The scatter of the results made reproducibility difficult. Overnight fasting increased the absolute values in all groups. The radiation effect was evident especially in adrenal corticosterone values of non-handled animals.

  4. An analysis of irradiation creep in nuclear graphites

    International Nuclear Information System (INIS)

    Neighbour, G.B.; Hacker, P.J.

    2002-01-01

    Nuclear graphite under load shows remarkably high creep ductility with neutron irradiation, well in excess of any strain experienced in un-irradiated graphite (and additional to any dimensional changes that would occur without stress). As this behaviour compensates, to some extent, some other irradiation effects such as thermal shutdown stresses, it is an important property. This paper briefly reviews the approach to irradiation creep in the UK, described by the UK Creep Law. It then offers an alternative analysis of irradiation creep applicable to most situations, including HTR systems, using AGR moderator graphite as an example, to high values of neutron fluence, applied stress and radiolytic weight loss. (authors)

  5. Valency stabilization of Polyvalent Iron Ions in Solution By some Organic additives during Gamma Irradiation

    International Nuclear Information System (INIS)

    Barakat, M.F.; Abdel Hamid, M.M.

    2012-01-01

    Valency stabilization of polyvalent ions in gamma irradiated aqueous solutions is sometimes necessary for the success of some chemical operations. In some previous publications valency stabilization of some polyvalent ions in solution upon gamma irradiation was achieved by using additives capable of interacting with the oxidizing or reducing species formed by water radiolysis in the medium. The results showed that the duration of valency stabilization depends on the concentration of the additives used.In the present work, a series of some organic additives has been used to investigate their capability in inducing valency stabilization of polyvalent iron ions when subjected to extended gamma irradiation periods. The results showed that the efficiency of valency stabilization depends on the amount and chemical structure of the organic additive used

  6. Bromate Formation Characteristics of UV Irradiation, Hydrogen Peroxide Addition, Ozonation, and Their Combination Processes

    Directory of Open Access Journals (Sweden)

    Naoyuki Kishimoto

    2012-01-01

    Full Text Available Bromate formation characteristics of six-physicochemical oxidation processes, UV irradiation, single addition of hydrogen peroxide, ozonation, UV irradiation with hydrogen peroxide addition (UV/H2O2, ozonation with hydrogen peroxide addition (O3/H2O2, and ozonation with UV irradiation (O3/UV were investigated using 1.88 μM of potassium bromide solution with or without 6.4 μM of 4-chlorobenzoic acid. Bromate was not detected during UV irradiation, single addition of H2O2, and UV/H2O2, whereas ozone-based treatments produced . Hydroxyl radicals played more important role in bromate formation than molecular ozone. Acidification and addition of radical scavengers such as 4-chlorobenzoic acid were effective in inhibiting bromate formation during the ozone-based treatments because of inhibition of hydroxyl radical generation and consumption of hydroxyl radicals, respectively. The H2O2 addition was unable to decompose 4-chlorobenzoic acid, though O3/UV and O3/H2O2 showed the rapid degradation, and UV irradiation and UV/H2O2 showed the slow degradation. Consequently, if the concentration of organic contaminants is low, the UV irradiation and/or UV/H2O2 are applicable to organic contaminants removal without bromate formation. However, if the concentration of organic contaminants is high, O3/H2O2 and O3/UV should be discussed as advanced oxidation processes because of their high organic removal efficiency and low bromate formation potential at the optimum condition.

  7. Which techniques for an additional irradiation of the tumour bed in a breast cancer?

    International Nuclear Information System (INIS)

    Chenna, H.; Iraqi, M.; Ahmedou, M.M.; Berhil, H.; El Kacemi, H.; Hassouni, K.; Kebdani, T.; Benjaafar, N.; El Gueddari, B.K.

    2010-01-01

    The authors report a comparison of different techniques for an additional irradiation of the tumour bed, in terms of local control and aesthetic result in the case of a breast cancer. This additional irradiation has been delivered by electron beam in five fractions, high dose rate curie-therapy in two fractions, photon beam in five or six fractions, and low dose rate curie-therapy. The dose increase in the tumour bed allows the local control rate to be increased without compromising aesthetic results. However, the comparison of the different boost techniques does not reveal significant differences. Short communication

  8. Evaluation of the limulus amoebocyte lysate test in conjunction with a gram negative bacterial plate count for detecting irradiation of chicken

    Science.gov (United States)

    Scotter, Susan L.; Wood, Roger; McWeeny, David J.

    A study to evaluate the potential of the Limulus amoebocyte lysate (LAL) test in conjuction with a Gram negative bacteria (GNB) plate count for detecting the irradiation of chicken is described. Preliminary studies demonstrated that chickens irradiated at an absorbed dose of 2.5 kGy could be differentiated from unirradiated birds by measuring levels of endotoxin and of numbers of GNB on chicken skin. Irradiated birds were found to have endotoxin levels similar to those found in unirradiated birds but significantly lower numbers of GNB. In a limited study the test was found to be applicable to birds from different processors. The effect of temperature abuse on the microbiological profile, and thus the efficacy of the test, was also investigated. After temperature abuse, the irradiated birds were identifiable at worst up to 3 days after irradiation treatment at the 2.5 kGy level and at best some 13 days after irradiation. Temperature abuse at 15°C resulted in rapid recovery of surviving micro-organisms which made differentiation of irradiated and unirradiated birds using this test unreliable. The microbiological quality of the bird prior to irradiation treatment also affected the test as large numbers of GNB present on the bird prior to irradiation treatment resulted in larger numbers of survivors. In addition, monitoring the developing flora after irradiation treatment and during subsequent chilled storage also aided differentiation of irradiated and unirradiated birds. Large numbers of yeasts and Gram positive cocci were isolated from irradiated carcasses whereas Gram negative oxidative rods were the predominant spoilage flora on unirradiated birds.

  9. Evaluation of the Limulus amoebocyte lysate test in conjunction with a gram negative bacterial plate count for detecting irradiation of chicken

    International Nuclear Information System (INIS)

    Scotter, S.L.; Wood, R.; McWeeny, D.J.

    1990-01-01

    A study to evaluate the potential of the Limulus amoebocyte lysate (LAL) test in conjunction with a Gram negative bacterial (GNB) plate count for detecting the irradiation of chicken is described. Preliminary studies demonstrated that chickens irradiated at an absorbed dose of 2.5 kGy could be differentiated from unirradiated birds by measuring levels of endotoxin and of numbers of GNB on chicken skin. Irradiated birds were found to have endotoxin levels similar to those found in unirradiated birds but significantly lower numbers of GNB. In a limited study the test was found to be applicable to birds from different processors. The effect of temperature abuse on the microbiological profile, and thus the efficacy of the test, was also investigated. After temperature abuse, the irradiated birds were identifiable at worst up to 3 days after irradiation treatment at the 2.5 kGy level and at best some 13 days after irradiation. Temperature abuse at 15 0 C resulted in rapid recovery of surviving micro-organisms which made differentiation of irradiated and unirradiated birds using this test unreliable. The microbiological quality of the bird prior to irradiation treatment also affected the test as large numbers of GNB present on the bird prior to irradiation treatment resulted in larger numbers of survivors. In addition, monitoring the developing flora after irradiation treatment amd during subsequent chilled storage also aided differentiation of irradiated and unirradiated birds. Large numbers of yeast and Gram positive cocci were isolated from irradiated carcasses whereas Gram negative oxidative rods were the predominant spoilage flora on unirradiated birds. (author)

  10. Evaluation of the Limulus amoebocyte lysate test in conjunction with a gram negative bacterial plate count for detecting irradiation of chicken

    Energy Technology Data Exchange (ETDEWEB)

    Scotter, S L; Wood, R; McWeeny, D J [Ministry of Agriculture, Fisheries and Food, Norwich (UK). Food Science Lab.

    1990-01-01

    A study to evaluate the potential of the Limulus amoebocyte lysate (LAL) test in conjunction with a Gram negative bacterial (GNB) plate count for detecting the irradiation of chicken is described. Preliminary studies demonstrated that chickens irradiated at an absorbed dose of 2.5 kGy could be differentiated from unirradiated birds by measuring levels of endotoxin and of numbers of GNB on chicken skin. Irradiated birds were found to have endotoxin levels similar to those found in unirradiated birds but significantly lower numbers of GNB. In a limited study the test was found to be applicable to birds from different processors. The effect of temperature abuse on the microbiological profile, and thus the efficacy of the test, was also investigated. After temperature abuse, the irradiated birds were identifiable at worst up to 3 days after irradiation treatment at the 2.5 kGy level and at best some 13 days after irradiation. Temperature abuse at 15{sup 0}C resulted in rapid recovery of surviving micro-organisms which made differentiation of irradiated and unirradiated birds using this test unreliable. The microbiological quality of the bird prior to irradiation treatment also affected the test as large numbers of GNB present on the bird prior to irradiation treatment resulted in larger numbers of survivors. In addition, monitoring the developing flora after irradiation treatment amd during subsequent chilled storage also aided differentiation of irradiated and unirradiated birds. Large numbers of yeast and Gram positive cocci were isolated from irradiated carcasses whereas Gram negative oxidative rods were the predominant spoilage flora on unirradiated birds. (author).

  11. Graphene with outstanding anti-irradiation capacity as multialkylated cyclopentanes additive toward space application

    Science.gov (United States)

    Fan, Xiaoqiang; Wang, Liping

    2015-07-01

    Multialkylated cyclopentanes (MACs), a class of synthetic hydrocarbon fluid have attracted intensive interest as possible space lubricants due to a series of unique physical and chemical properties. Here, we used graphene with high mechanical strength and chemical inertness as lubricant additive to explore its potential for space application. The effects of space irradiation on graphene and the tribological properties of graphene as lubricant additive were firstly investigated in detail under simulated space environment composed of high vacuum, high/low temperature and irradiation. Results demonstrate that graphene not only possesses outstanding anti-irradiation capacity but also significantly improves the space performance and tribological properties of MACs, which depends on the excellent physicochemical properties and high load-carrying ability of graphene as well as more effective separation of the sliding surfaces.

  12. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Francisco D. Díaz-Coutiño

    2009-04-01

    Full Text Available A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  13. Synthesis of γ-Nitro Aliphatic Methyl Esters Via Michael Additions Promoted by Microwave Irradiation

    OpenAIRE

    Escalante, Jaime; Díaz-Coutiño, Francisco D.

    2009-01-01

    A simple and efficient protocol has been developed for the direct synthesis of γ-nitrobutyric acid methyl esters under microwave irradiation. This methodology reduces reaction times from days to minutes, compared to conventional conditions. Additionally, these conditions increased yields and provided cleaner reactions.

  14. Use of SCGE method for detection of DNA comet in irradiated samples of poultry and shrimp

    International Nuclear Information System (INIS)

    Rajaei, R.; Hosseini, S.L.

    2005-01-01

    DNA in food may sustain damage by gamma irradiation.This damage can be detected by a sensitive technique, called single cell gel electrophoresis. This is a simple and low-cost technique for rapid screening of the cells of irradiated foodstuffs. For this purpose, poultry and shrimp samples were irradiated by the 60 Co gamma radiation. The radiation doses for poultry were 2,5 and 7 kGy and for shrimp were 3 and 7kGy, respectively. The irradiation samples were compared with those of unirradiated types (control). In addition, the effects of shelf-life and temperature were considered on the poultry samples only. We have found that this technique is easily applicable for identification of irradiated from unirradiated samples and it is found to be irrespective of the applied dose. It is worth mentioning that any DNA change arising from any source, for example temperature fluctuation, may be detected by the single cell gel electrophoresis technique

  15. Microhardness measurement in AISI 321 stainless steel with niobium additions before and after fast neutron irradiation

    International Nuclear Information System (INIS)

    Galli, V.L.; Lucki, G.

    1980-01-01

    Data about influence of neutron irradiation on the microhardness of stainless steel of type AISI 321 with 0.05 and 0.1wt.% Nb additions are presented. The microhardness measurements were made in the range of 300 to 650 0 C, before and after fast neutron irradiation with fluences about 10 17 n/cm 2 . Our results indicate that radiation damage peaks occur around 480 0 C for the stainless steel of type AISI 321 without Nb addition, around 500 0 C for the composition with 0.05 wt.% Nb addition and around 570 0 C for the composition with 0.1 wt.% Nb addition. Microhardness data are in agreement with those obtained by means of electrical resistivity measurements, performed at the same conditions. (Author) [pt

  16. Irradiation performance of coated fuel particles with fission product retaining kernel additives

    International Nuclear Information System (INIS)

    Foerthmann, R.

    1979-10-01

    The four irradiation experiments FRJ2-P17, FRJ2-P18, FRJ2-P19, and FRJ2-P20 for testing the efficiency of fission product-retaining kernel additives in coated fuel particles are described. The evaluation of the obtained experimental data led to the following results: - zirconia and alumina kernel additives are not suitable for an effective fission product retention in oxide fuel kernels, - alumina-silica kernel additives reduce the in-pile release of Sr 90 and Ba 140 from BISO-coated particles at temperatures of about 1200 0 C by two orders of magnitude, and the Cs release from kernels by one order of magnitude, - effective transport coefficients including all parameters which contribute to kernel release are given for (Th,U)O 2 mixed oxide kernels and low enriched UO 2 kernels containing 5 wt.% alumina-silica additives: 10g sub(K)/cm 2 s -1 = - 36 028/T + 6,261 (Sr 90), 10g Dsub(K)/cm 2 c -2 = - 29 646/T + 5,826 (Cs 134/137), alumina-silica kernel additives are ineffective for retaining Ag 110 m in coated particles. However, also an intact SiC-interlayer was found not to be effective at temperatures above 1200 0 C, - the penetration of the buffer layer by fission product containing eutectic additive melt during irradiation can be avoided by using additives which consist of alumina and mullite without an excess of silica, - annealing of LASER-failed irradiated particles and the irradiation test FRJ12-P20 indicate that the efficiency of alumina-silica kernel additives is not altered if the coating becomes defect. (orig.) [de

  17. The effects of electron beam irradiation on additives present in food-contact polymers

    International Nuclear Information System (INIS)

    Crowson, Andrew.

    1991-09-01

    A range of additives (Irganox 1010, Irganox 1076, Irganox 1330, Irgafos 168 and Tinuvin 622) has been incorporated into a variety of food-contact polymers including polypropylene and low density polyethylene. Samples of these stabilized polymers were subjected to electron-beam or gamma irradiation to receive doses of 1,5,10,25 and 50 kGy. The effects of electron-beam irradiation on the amount of extractable antioxidant in polymers were determined. Using hplc techniques it was found that there was a dose-related reduction in the amount of extractable antioxidant similar to that caused by gamma irradiation. The magnitude of this reduction was found to be dependent upon the nature of both the antioxidant and the polymer type. Electron-beam irradiation was also found to cause a dose-related reduction in the levels of the antioxidants Irganox 1010 and Irganox 1076 migrating from polymers into a food simulant. This effect was similar to that caused by gamma irradiation. (author)

  18. Longevity of irradiated burros

    International Nuclear Information System (INIS)

    Lushbaugh, C.C.; Brown, D.G.; Frome, E.L.

    1986-01-01

    During the course of external radiation exposures of burros to establish a dose-response curve for acute mortality after total irradiation, some of the animals at the three lowest exposures to gamma photons survived. These groups of 10, 9, and 10 burros were exposed to 320, 425, and 545 R, respectively. There were 10 unirradiated controls. In 1953, 20 burros were exposed to 375 R (gamma) in 25-R/week increments without acute mortality and were added to the life-span study. In 1957, 33 burros were exposed to mixed neutron-gamma radiation from nuclear weapons, and 14 controls were added. The total number of irradiated burros in the study was increased to 88 by the addition of 6 animals irradiated with 180 rads of neutron and gamma radiation (4:1) in a Godiva-type reactor in 1959. In this experiment two acute deaths occurred which were not included in the analysis. In the first 4 years after the single gamma exposures, there were deaths from pancytopenia and thrombocytopenia, obviously related to radiation-induced bone-marrow damage. After that period, however, deaths were from common equine diseases; no death has resulted from a malignant neoplasm. Of the original 112 burros, 15 survive (10 irradiated and 5 controls). Survival curves determined for unirradiated and neutron-gamma- and gamma-irradiated burros showed significant differences. The mean survival times were: controls, 28 years; gamma irradiation only, 26 years; and neutron-gamma irradiation, 23 years. 3 refs., 4 figs., 1 tab

  19. Sterilization of proteinaceous food additives by irradiation. Temperature dependent changes in intensity of ESR signals generated by electron beam irradiation

    International Nuclear Information System (INIS)

    Sakaue, Kazushi; Murata, Yoshiyuki; Higashimura, Yutaka; Hayashi, Toru; Todoriki, Setsuko; Tada, Mikiro

    1999-01-01

    Thaumatin, egg white and soybean protein were selected as samples of proteinous food additives, and changes in the intensity of signals appearing in them after they had been irradiated with electron beams were measured by ESR. It was found by such measurement that the positions of signals of thaumatin and soy proteins are nearly the same. Changes in the intensity of radicals in thaumatin calculated on the basis of the coefficients of the respective approximations obtained by using thaumatin which had been irradiated and then stored at 4degC, 25degC, 37degC and 60degC showed that there is a temperature range to determine the remaining of such radicals (inner: 19.7degC, outer: 15.23degC) and that such radicals tend to decrease straight line-wise. It was confirmed that the intensity of signals in the protein powder such thaumatin and soy protein would not be affected at the storage condition below 15degC. (author)

  20. Sterilization of proteinaceous food additives by irradiation. Temperature dependent changes in intensity of ESR signals generated by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaue, Kazushi; Murata, Yoshiyuki [Graduate School of Natural Science and Technology, Okayama Univ., Okayama (Japan); Higashimura, Yutaka [San-Ei Gen F.F.I., Inc., Osaka (Japan); Hayashi, Toru; Todoriki, Setsuko [National Food Research Institute, Ministry of Agriculture, Tsukuba, Ibaraki (Japan); Tada, Mikiro [Okayama Univ. (Japan). Faculty of Agriculture

    1999-09-01

    Thaumatin, egg white and soybean protein were selected as samples of proteinous food additives, and changes in the intensity of signals appearing in them after they had been irradiated with electron beams were measured by ESR. It was found by such measurement that the positions of signals of thaumatin and soy proteins are nearly the same. Changes in the intensity of radicals in thaumatin calculated on the basis of the coefficients of the respective approximations obtained by using thaumatin which had been irradiated and then stored at 4degC, 25degC, 37degC and 60degC showed that there is a temperature range to determine the remaining of such radicals (inner: 19.7degC, outer: 15.23degC) and that such radicals tend to decrease straight line-wise. It was confirmed that the intensity of signals in the protein powder such thaumatin and soy protein would not be affected at the storage condition below 15degC. (author)

  1. Post irradiation examination of garter springs from Indian PHWRs

    International Nuclear Information System (INIS)

    Dubey, J.S.; Shah, Priti Kotak; Mishra, Prerna; Singh, H.N.; Alur, V.D.; Kumar, Ashwini; Bhandekar, A.; Pandit, K.M.; Anantharaman, S.

    2013-12-01

    Irradiated Zr-2.5Nb-0.5Cu garter springs, belonging to Indian Pressurised Heavy Water Reactors, which had experienced 8 to 10 Effective Full Power Years of operation were subjected to visual, dimensional, chemical, metallographic examination and relevant mechanical tests. Methodology of the tests conducted and results are presented. The digital photographs were used to measure the inner and outer circumferences by image processing. The hydrogen (H) content in the spring coils were measured using Differential Scanning Calorimetry (DSC). In the stretch test, all the irradiated GSs were found to require an additional load, as compared to unirradiated GS, to produce a given amount of residual extension which indicated that the irradiated GSs had undergone significant irradiation hardening. The crush test results showed that the minimum load required to crush the coil or cause a sudden sideways shift in the grips was higher than 400 N/coil, much higher than the design load. The test results indicated that the irradiated GS, after 10 EFPY of operation, have adequate strength and ductility to continue to meet the design intent. Mechanical tests were carried out on irradiated girdle wires taken out of the loose fit garter springs (GS) from (NAPS-1, ∼ 8.5 EFPY) and tight fit garter spring from KAPS-2 (∼ 8.0 EFPY) PHWRs. Tensile tests on the irradiated girdle wires, showed irradiation hardening in the material and reduction in ductility. The irradiated girdle wires have around 4 to 5% residual ductility level against the 15% ductility of unirradiated wire. The fracture surfaces of the irradiated as well as the un-irradiated girdle wires were observed in SEM. (author)

  2. The role of additives in the recombination luminescence mechanism of irradiated 2-methyltetrahydrofuran glasses

    International Nuclear Information System (INIS)

    Krauss, K.H.; Boes, J.

    1981-01-01

    The radiothermoluminescence (RTL) of γ-irradiated pure glassy 2-methyltetrahydrofuran (2-MTHF) and of 2-MTHF glasses containing additives was measured. For pure 2-MTHF a very weak luminescence peak at 93 K (heating rate 0,05 K/s) was found which in the presence of certain additives was enhanced by several orders of magnitude. Using data of radiothermoluminescence, absorption and phosphorescence measurements and bleaching experiments an attempt was made to derive a reaction mechanism. It was found to exist different possibilities for activation the ionic species to give recombination luminescence. (author)

  3. Transmission electron microscopy of oxide dispersion strengthened (ODS) molybdenum: effects of irradiation on material microstructure

    International Nuclear Information System (INIS)

    Baranwal, R.; Burke, M.G.

    2003-01-01

    Oxide dispersion strengthened (ODS) molybdenum has been characterized using transmission electron microscopy (TEM) to determine the effects of irradiation on material microstructure. This work describes the results-to-date from TEM characterization of unirradiated and irradiated ODS molybdenum. The general microstructure of the unirradiated material consists of fine molybdenum grains (< 5 (micro)m average grain size) with numerous low angle boundaries and isolated dislocation networks. 'Ribbon'-like lanthanum oxides are aligned along the working direction of the product form and are frequently associated with grain boundaries, serving to inhibit grain boundary and dislocation movement. In addition to the 'ribbons', discrete lanthanum oxide particles have also been detected. After irradiation, the material is characterized by the presence of nonuniformly distributed large (∼ 20 to 100 nm in diameter), multi-faceted voids, while the molybdenum grain size and oxide morphology appear to be unaffected by irradiation

  4. Biological response to the synergistic effect of synthetic colour additives and gamma irradiation on rats

    International Nuclear Information System (INIS)

    Ashry, O.M.; Kafafy, Y.A.; Salama, S.F.

    2007-01-01

    This Study was conducted to determine the effect of the inevitable intake of synthetic colour additives in our everyday life and radiation exposure on the levels of some physiological parameters. Female rats were divided into: I- Control group. 2- Group administrated an azo dye mixture of tartrazine and brilliant blue orally for 2 weeks (100 mg/Kg body wt). 3- Group received gamma radiation of 5 Gy. 4- Animals received the dyes mixture for 2 weeks and irradiation. Rats were examined on the 1st, 3rd and 7th days post irradiation or dyes treatment followed by irradiation. Dyes treatment induced significant decreases in hemoglobin (Hb), hematocrit (Ht), red blood cells (RBCs), alkaline phosphatase (ALP) activity. Significant increases of plasma total proteins and albumin levels were recorded. No significant changes of alanine aminotransferase (ALT) activity, iron (Fe), cupper (Cu) and zinc (Zn) levels were noted. Irradiation induced significant decline in Hb, Ht, RBCs, Cu and Fe levels. Significant increases of glucose (7th day), uric acid (3rd and 7 days), total proteins (3rd day) levels, and ALT activity, while no changes were recorded in ALP, albumin or Zn levels. Dual treatment of irradiation and dyes aggravated the radiation-induced changes. Bearing in mind that safety concerns overweighed the approval of use of synthetic colors, the utilization of these colors in drug and food manufacturing should be limited to minimize the physiological disturbances and the risk concomitant to environmental oxidative stress. During the last decade, extensive studies on the use of colors in processed foods, drinks, drugs and cosmetics confirmed that they may act as xenobiotics (Guengerich, 1995). With the increasing awareness of possible health hazards associated with their use more attention has been focused on the biological

  5. Reaction of unirradiated high-density fuel with aluminum

    International Nuclear Information System (INIS)

    Wiencek, T.C.; Meyer, M.K.; Prokofiev, I.G.; Keiser, D.D.

    1997-01-01

    Excellent dispersion fuel performance requires that fuel particles remain stable and do not react significantly with the surrounding aluminum matrix. A series of high-density fuels, which contain uranium densities >12 g/cm 3 , have been fabricated into plates. As part of standard processing, all of these fuels were subjected to a blister anneal of 1 h at 485 deg. C. Changes in plate thickness were measured and evaluated. From these results, suppositions about the probable irradiation properties of these fuels have been proposed. In addition, two fuels, U-10 wt% Mo and U 2 Mo, were subjected to various heat treatments and were found to be very stable in an aluminum matrix. On the basis of the experimental data, hypotheses of the irradiation behavior of these fuels are presented. (author)

  6. Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Mastro, Nelida L. del

    2015-01-01

    Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s -1 , energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

  7. Electron beam irradiation and addition of poly(vinyl alcohol) affect gelatin based-films properties

    Energy Technology Data Exchange (ETDEWEB)

    Inamura, Patricia Y.; Mastro, Nelida L. del, E-mail: pinamura@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    Gelatin is a mixture of high molecular weight polypeptides, product of denaturation, and partial structural degradation of collagen, and one of the first materials employed as biomaterials. Aqueous solutions of gelatin (10%), glycerin as plasticizer and poly(vinyl alcohol) (PVA) up to 10% were prepared in a water bath at 70 deg C under constant stirring. Films were irradiated with 10 and 20 kGy using an electron beam accelerator, dose rate of 22.4 kGy s{sup -1}, energy 1.407 MeV, at room temperature, in the presence of air. After irradiation, mechanical properties, color measurements, water absorption, moisture and film solubility were analyzed. The films showed an improvement in maximum force to rupture the film with increase of the irradiation dose. The higher the puncture force to rupture the lower the elongation at break. Colorimetric tests showed significant differences between samples, and also differences depending of the applied radiation dose, and analyzed color parameter. In water absorption tests a decrease of absorption percentage was found with the increase of the dose for PVA free and 5% PVA samples. The addition of PVA increased the water absorption for all applied doses. The modifications in gelatin colloids can be appointed to radiation-induced crosslinking. Also, the PVA concentration in the samples influenced the resultant material properties. (author)

  8. Embryogenesis in gamma-irradiated habituated ovular callus of the 'Shamouti' orange as affected by auxin and by tissue age

    International Nuclear Information System (INIS)

    Kochba, J.; Spiegel-Roy, P.

    1977-01-01

    The response of habituated embryogenic ovular callus of the 'Shamouti' orange, Citrus sinensis, to gamma irradiation was studied. Stimulation of embryogenesis was observed when only callus, but not when the medium was irradiated. Age of callus prior to subculture modified the response to irradiation as regards optimal dose for embryogenesis and radiosensitivity. Radiation intensities also modified callus response to radiation dose. Addition of unirradiated IAA to irradiated callus cultures increased embryo formation and furthered development of embryos into plantlets, with some combinations of radiation dose and IAA concentration. Addition of IAA also decreased radiosensitivity at high doses (32 kR). (author)

  9. Detection of irradiated peppers by viscosity measurement at extremely high pH

    International Nuclear Information System (INIS)

    Hayashi, Toru; Todoriki, Setsuko

    1996-01-01

    The viscosities of aqueous suspensions of irradiated peppers determined after heat gelatinization were influenced by the pH of the suspension to a greater degree than those of unirradiated ones. Viscosity measurement under an extremely alkaline condition (pH 13.8) resulted in a significant different between irradiated peppers and unirradiated ones, irrespective of the planting locality and storage period. All of the pepper samples irradiated at 5 kGy showed viscosity values significantly lower than unirradiated ones. (Author)

  10. Protection of a protein against irradiation-induced degradation by additives in the solid state

    International Nuclear Information System (INIS)

    Shalaev, E.; Reddy, R.; Kimball, R.N.; Weinschenk, M.F.; Guinn, M.; Margulis, L.

    2003-01-01

    The impact of ionizing radiation on a globular protein (porcine somatotropin, pST) in the solid state was studied using rate of dissolution, high-performance liquid chromatography, and Electron spin resonance (ESR) in the presence of different additives. o-Vanillin stabilized pST against irradiation-induced degradation whereas effects of trolox and isopropyl alcohol were less significant. Stabilization effect of o-vanillin has been related to the energy transfer from pST molecules to the additive which was facilitated by formation of covalent bonds between o-vanillin and pST molecules. Anticorrelation between the level of free radicals and chemical degradation (i.e. degradation increased with decrease in a free radical level) was observed in the presence of o-vanillin

  11. Electron spin resonance (ESR) studies on irradiated cocoa beans and niger seeds

    International Nuclear Information System (INIS)

    Mangaonkar, S.R.; Natarajan, V.; Sastry, M.D.; Desai, S.R.P.; Kulkarni, P.R.

    1997-01-01

    Electron spin resonance (ESR) spectra of irradiated (10kGy) and unirradiated cocoa beans and niger seeds have been compared. Unirradiated cocoa beans failed to give any ESR signal, whereas after irradiation (10kGy) an ESR signal at g = 2.0042 was observed. However, ESR signals are given by both irradiated and unirradiated niger seeds. The intensity of signal was found to be dose-dependent up to 10kGy for both seeds. The signals were stable up to 180 days in both cases. The results indicate the possibility of using ESR for distinguishing between irradiated and unirradiated cocoa beans but not for niger seeds

  12. PHOTODYNAMIC THERAPY FOR HEAD AND NECK BASAL CELL SKIN CANCER WITH ADDITIONAL INTERSTITIAL LASER IRRADIATION

    Directory of Open Access Journals (Sweden)

    V. N. Kapinus

    2017-01-01

    Full Text Available The article is devoted to the development and evaluation of the effi ciency of photodynamic therapy (PDT with photosensitizer photolon with additional interstitial laser irradiation in patients with head and  neck basal cell skin cancer (BCSC. Treatment was performed in 55  patients. On the fi rst stage, all patients underwent photodynamic  therapy with interstitial irradiation using fl exible optical fi bers with  cylindrical diffuser, on the second stage PDT with distant delivery of  laser at a dose of 50-300 J/cm2 was carried out. During the follow- up period of 6 months to 4 years in 13 (23.6% of the 55 patients a  recurrence of the disease was diagnosed. A higher rate of recurrence was in the group of patients who underwent PDT for recurrent  neoplasms compared with patients with primary disease (37.5% and 4.3%, respectively, in patients with endophytic growth of the tumor compared to patients with exophytic component (30.0% and 16.0%,respectively and in patients with large tumors (up to 2.0 cm – 14.3%, from 2.0 to 5.0 cm – 16.7% and more than 5.0 cm – 54.4%.

  13. Scintillation activity in an unirradiated single crystal of 3-hydroxyxanthine

    International Nuclear Information System (INIS)

    Cooke, D.W.; Jahan, M.S.; Alexander, C. Jr.

    1976-01-01

    A method of growing single crystals (approximately 4mm long) of 3-hydroxyxanthine is described. Observed scintillations occurring in an unirradiated single crystal of this potent oncogen as the temperature is lowered from 300 to 90 K are shown. It was found that these scintillations occur upon heating or cooling and do not diminish in activity as the number of heating and cooling cycles increase. It was found that a short duration u.v. exposure would terminate the scintillation activity and various attempts (such as annealing and pressure changes) to rejuvenate them were unsuccessful. With these observations in mind speculation is made concerning the mechanisms associated with the production of purine N-oxide derivatives. (U.K.)

  14. Effects of additives on 2,4,6-trinitrotoluene (TNT) removal and its mineralization in aqueous solution by gamma irradiation

    International Nuclear Information System (INIS)

    Lee, Byungjin; Jeong, Seung-Woo

    2009-01-01

    The effects of additives (i.e., methanol, EDTA, mannitol, thiourea, nitrous oxide, oxygen and ozone) on gamma irradiation of 2,4,6-trinitrotoluene (TNT) were investigated to elucidate the initial reaction mechanism of TNT degradation and suggest an practical method for complete by-product removal. All additives, except thiourea, significantly increased the TNT removal efficiency by gamma irradiation. The overall results of the additive experiments implied that the TNT decomposition would be initiated by ·OH, e aq - , and HO 2 ·/O 2 · - , and also implied that ·H did not have any direct effect on the TNT decomposition. Additions of methanol and nitrous oxide were more effective in TNT removal than the other additives, achieving complete removal of TNT at doses below 20 kGy. Total organic carbon (TOC) of the irradiated solution was analyzed to evaluate the degree of TNT mineralization under the additive conditions. TOC under the nitrous oxide addition was removed rapidly, and complete TNT mineralization was thus achieved at 50 kGy. Methanol addition was very effective in the TNT removal, but it was not effective in reduction in TOC. Trinitrobenzene (TNB), oxalic acid and glyoxalic acid were detected as radiolytic organic by-products, while ammonia and nitrate were detected as radiolytic inorganic by-products. The most efficient TNT removal and its mineralization by gamma irradiation would be achieved by supersaturating the solution with nitrous oxide before irradiation.

  15. Effect of irradiation on poly(vinyl chloride)/epoxidized natural rubber blend in the presence of additives: FTIR analysis

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Dahlan; Baharin, A.; Nasir, M.

    2001-01-01

    The effect of irradiation on the structure of 50/50 poly(vinyl chloride)/epoxidized natural rubber blend (PVC/ENR) was studied using the Fourier Transform Spectroscopy (FTIR). The 50/50 PVC/ENR blend was irradiated by using 3.0 MeV electron beam machine at 0 and 200 kGy irradiation doses. The influence of several additives such as TMPTA, Irganox 1010, and tribasic lead sulfate on the irradiation induced changes of the blend was investigated. It was found that upon irradiation, ring opening of the epoxide groups, oxidation as well crosslinking at residual double bonds occurred, leading to decreases in the intensities of the epoxide and cis double bond bands and an increases in ether and furan bands. The addition of Irganox 1010 and tribasic lead sulfate were found to inhibit the irradiation-induced reaction in the blend to a considerable extent. The importance of TMPTA in preventing the intramolecular ring opening side chain reaction was also discussed. However, studies did not reveal the exact nature of the irradiation-induced reactions involved in the blend. (Author)

  16. In vivo mutagenicity studies in rats mice and Chinese hamsters fed irradiated foodstuffs - chicken, fish, dates, pulses, mangoes and cocoa beans

    International Nuclear Information System (INIS)

    Renner, H.W.

    1982-01-01

    Three in vivo genetic toxicity tests were performed in rats, mice and Chinese hamsters to detect possible mutagenic effects of irradiated chicken, dried dates, fish, cocoa beans, pulses and mangoes. The tests employed were the micronucleus test and sister-chromatid exchange (SCE) test for irradiated and unirradiated samples of all foodstuffs listed, and the spermatogonia test, (including SCE technique) in mice for irradiated and unirradiated chicken, fish and dates only. In the case of cocoa beans, the mutagenicity tests were performed on an additional test group fed beans fumigated with ethylene oxide. The different mammalian species used for the various experiments are given below. None of the tests provided any evidence of mutagenicity induced by irradiation in any of the foodstuffs studied. Moreover, these tests are currently considered to be the most sensitive in vivo mutagenicity tests in mammals. (orig.)

  17. Heavy-Section Steel Irradiation Program

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    In FY1990 the Heavy-Section Steel Irradiation (HSSI) Program was arranged into 8 tasks: (1) program management, (2) K Ic curve shift in high-copper welds, (3) K Ia curve shift in high-copper welds, (4) irradiation effects on cladding, (5) K Ic and K Ia curve shifts in low upper-shelf (LUS) welds, (6) irradiation effects in a commercial LUS weld, (7) microstructural analysis of irradiation effects, and (8) in-service aged material evaluations. Of particular interest are the efforts in FY1990 concerning the shifts in fracture toughness and crack arrest toughness in high-copper welds, the unirradiated examination of a LUS weld from the Midland reactor, and the continued investigation into the causes of accelerated low-temperature embrittlement recently observed in RPV support steels. In the Fifth and Sixth Irradiation Series, designed to examine the shifts and possible changes in shape in the ASME K Ic and K Ia curves for two irradiated high-copper welds, it was seen that both the lower bound and mean fracture toughness shifts were greater than those of the associated Charpy-impact energies, whereas the shifts in crack arrest toughness were comparable. The irradiation-shifted fracture toughness data fell slightly below the appropriately indexed ASME K Ic curve even when it was shifted according to Revision 2 of Regulatory Guide 1.99 including its margins. The beltline weld, which was removed from the Midland reactor, fabricated by Babcock and Wilcox, Co. using Linde 80 flux, is being examined in the Tenth Irradiation Series to establish the effects of irradiation on a commercial LUS weld. A wide variation in the unirradiated fracture properties of the Midland weld were measured with values of RT NDT ranging from -22 to 54F through its thickness. In addition, a wide range of copper content from 0.21 to 0.45 wt % was found, compared to the 0.42 wt % previously reported

  18. Physicochemical evaluation of the effects of irradiation and evisceration on the conservation of refrigerated blackfin tuna (Thunnus atlanticus)

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Maria L.G.; Marsico, Eliane T. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Faculdade de Veterinaria. Dept. de Tecnologia de Alimentos], e-mail: marialuciaguerra@yahoo.com.br, e-mail: elianee@vm.uff.br; Vital, Helio C. [Centro Tecnologico do Exercito (CTEx), Rio de Janeiro, RJ (Brazil). Secao de Defesa Nuclear], e-mail: vital@ctex.eb.br

    2009-07-01

    Tuna is among the most traded fishes in Brazil, however efficiently delaying its fast deterioration is still a major practical challenge. Irradiation has been proposed as a safe and powerful alternative tool for conservation of seafood. This work investigated the effects of irradiation on the physicochemical quality of refrigerated blackfin tuna (Thunnus atlanticus). Analyses of pH, total volatile bases (TVB-N), ammonia and biogenic amines (histamine, cadaverine and putrescine) were performed in order to determine the degree of conservation. The samples were subjected to four different treatments aiming at evaluating the efficiency of irradiation, evisceration and both combined. The figures measured for those parameters, all of them related to the degree of conservation, were found to increase with time regardless of the treatment. In addition, data for irradiated samples remained consistently lower than for unirradiated ones, indicating a better level of preservation that led to an extended shelf life of 14 days. In contrast, excessive levels of those indicators of degradation were found in unirradiated samples after 7 to 10 days of storage. In addition, some evidence was found that evisceration slightly increased quality, consequently promoting a small extension in shelf life of unirradiated samples. Finally, it can be concluded with basis on the results of the physicochemical parameters studied that treatment of fresh refrigerated blackfin tuna by irradiation with 2.5 kGy efficiently preserved freshness and extended the shelf life of the product from 7 to 14 days. (author)

  19. Physicochemical evaluation of the effects of irradiation and evisceration on the conservation of refrigerated blackfin tuna (Thunnus atlanticus)

    International Nuclear Information System (INIS)

    Monteiro, Maria L.G.; Marsico, Eliane T.; Vital, Helio C.

    2009-01-01

    Tuna is among the most traded fishes in Brazil, however efficiently delaying its fast deterioration is still a major practical challenge. Irradiation has been proposed as a safe and powerful alternative tool for conservation of seafood. This work investigated the effects of irradiation on the physicochemical quality of refrigerated blackfin tuna (Thunnus atlanticus). Analyses of pH, total volatile bases (TVB-N), ammonia and biogenic amines (histamine, cadaverine and putrescine) were performed in order to determine the degree of conservation. The samples were subjected to four different treatments aiming at evaluating the efficiency of irradiation, evisceration and both combined. The figures measured for those parameters, all of them related to the degree of conservation, were found to increase with time regardless of the treatment. In addition, data for irradiated samples remained consistently lower than for unirradiated ones, indicating a better level of preservation that led to an extended shelf life of 14 days. In contrast, excessive levels of those indicators of degradation were found in unirradiated samples after 7 to 10 days of storage. In addition, some evidence was found that evisceration slightly increased quality, consequently promoting a small extension in shelf life of unirradiated samples. Finally, it can be concluded with basis on the results of the physicochemical parameters studied that treatment of fresh refrigerated blackfin tuna by irradiation with 2.5 kGy efficiently preserved freshness and extended the shelf life of the product from 7 to 14 days. (author)

  20. Effect of combinations of gamma irradiation, hot water, Sodium chloride, and Acetic acid treatments on potato-dry rot

    International Nuclear Information System (INIS)

    El-Zayat, M.M.; Farahat, A.A.; Saad, N.H.; Shaarawy, N.S.M.

    1992-01-01

    Gamma irradiation increased the severity of dry rot in potato tubers when they were inoculated with any of 4 species of Fusarium, previously isolated either from irradiated or unirradiated tubers. Treating either irradiated or unirradiated tubers with warm water or sodium chloride solutions following inoculation with F. roseum also increased the severity of dry rot to some extent

  1. High resolution X-ray diffraction studies on unirradiated

    Indian Academy of Sciences (India)

    High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li3+ ion beams at room temperature with a fluence value of 1 × 1014 ions/cm2. The diffraction curves of the ...

  2. Etching kinetics of swift heavy ion irradiated silicone rubber with insoluble additives or reaction products

    International Nuclear Information System (INIS)

    Fink, D.; Mueller, M.; Petrov, A.; Farenzena, L.; Behar, M.; Papaleo, R.P.

    2003-01-01

    It is normally understood as a basic precondition of the etching of swift heavy ion tracks in polymers that both the additives and etching products are soluble in the etchant. If this is not given, the polymer surface may be gradually blocked by the deposition of the insoluble material that acts as a diffusion barrier for the penetration of fresh etchant into the tracks, and therefore the effective track etching speed will gradually be reduced. The etching kinetics is developed for that case, and the theory is compared with first experimental findings. For that purpose we have taken commercial silicone rubber foils as test materials, that were irradiated with GeV heavy ions through a mask at a fluence that corresponds to the onset of track overlapping. After etching with NaOH, the corresponding etching speed was recorded via the reduction of the foil thickness. The etching speed is seen to decrease with exposure time, in parallel to the development of an insoluble surface layer. It is discussed how to prevent that surface blocking, to maintain a high etching speed

  3. A Criticality Safety Study on Storing Unirradiated Cintichem-Type Targets at Sandia National Laboratories

    International Nuclear Information System (INIS)

    Romero, D.J.; Parma, E.J.; Busch, R.D.

    1999-01-01

    This criticality safety analysis is performed to determine the effective multiplication factor (k eff ) for a storage cabinet filled with unirradiated Cintichem-type targets. These targets will be used to produce 99 Mo at Sandia National Laboratories and will be stored on-site prior to irradiation in the Annular Core Research Reactor. The analysis consisted of using the Monte Carlo code MCNP (Version 4A) to model and predict the k eff for the proposed dry storage configuration under credible loss of geometry and moderator control. Effects of target pitch, non-uniform loading, and target internal/external flooding are evaluated. Further studies were done with deterministic methods to verify the results obtained from MCNP and to obtain a clearer understanding of the parameters affecting system criticality. The diffusion accelerated neutral particle transport code ONEDANT was used to model the target in a one-dimensional, infinite half-slab geometry and determine the critical slab thickness. Hand calculations were also completed to determine the critical slab thickness with modified one-group, and one-group, two region approximations. Results obtained from ONEDANT and the hand calculations were compared to applicable cases in a commonly used criticality safety analysis handbook. Overall, the critical slab thicknesses obtained in the deterministic analysis were much larger than the dimensions of the cabinet and further support the predictions by MCNP that a critical system cannot be attained for the base case or in conditions where loss of geometry and moderation control occur

  4. The effect of boron additions on irradiation-induced order changes in Ni3Al intermetallic compounds

    International Nuclear Information System (INIS)

    Njah, N.; Gilbon, D.; Dimitrov, O.

    1995-01-01

    The effects of boron additions (0.1 wt%) on the kinetics of atomic order changes in a Ni 76 Al 24 intermetallic compound, under 1 MeV electron irradiation, were investigated at temperatures of 293 K and 410 K and displacement rates of 0.09 x 10 -3 to 4.7 x 10 -3 dpa.s -1 . In these irradiation conditions, a state of residual order was obtained for long irradiation times, characterized by a steady state order parameter S∞; it corresponds to a competition between two opposite features: irradiation disordering and thermal reordering enhanced by irradiation. Boron additions did not affect the efficiency of irradiation-induced disordering: the disordering cross-section (or, equivalently, the number of replacements per displacement var-epsilon) were comparable with and without a boron addition. By contrast, the S∞ values at 293 K were much lower in the alloy containing boron. Since boron does not change the disordering rate, the large difference between the values obtained in undoped and in boron-doped alloys shows that the reordering rate is strongly reduced by the presence of boron. Thus, boron modifies the mobility of the defects responsible for the irradiation-enhanced diffusion. The data on dislocation-loop size and the reordering kinetics suggest that vacancies are trapped by boron at low temperatures and immobilized, probably by the formation of a boron-vacancy complex. The effect becomes weaker at higher displacement rates and higher temperatures, probably due to the boron-vacancy complexes becoming unstable. It is proposed that two different reordering mechanisms may be operative at 293 K, according to the presence of boron: reordering is promoted by vacancy migration in the Ni 76 Al 24 alloy, whereas in the Ni 76 Al 24 (0.1 wt%B) alloy, it is promoted by the migration of split-interstitials or/and of low-mobility vacancy-boron complexes

  5. Investigation of physical detection markers in irradiated foods under different radiation sources and post-irradiation storage conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Joong Ho; Kim, Gui Ran; Ahn, Jae Jun; Kim, Dong Gil; Jin, Qiong Wen; Park, Ju Hwan; Lee, Ji Hyun [Kyungpook National University, Daegu (Korea, Republic of)

    2010-04-15

    In PSL analysis, all unirradiated samples showed less than 700 (negative) photon counts (PCs). At 5 kGy, spice samples showed PCs in range of 700-5,000 (intermediate), while grains, legumes, root-crops, and seasonings samples showed PCs over 5,000 (positive). This PSL based-detection of radiation treatment was possible even after 24 months of storage. In TL analysis, TL glow curve was characteristically different between unirradiated and irradiated samples. Glow curves were observed in temperature ranges of 150-250 .deg. C for irradiated and over 300 .deg. C for unirradiated samples. TL ratio (TL{sub 1}/TL{sub 2}) provided valuable additional confirmations as unirradiated sample showed values less than 0.1, while irradiated sample showed more than 0.1. However, with storage time, TL intensity and TL ratio decreased but discrimination was still possible even after storage of 24 months. Samples stored at room temperature with exposure to direct or indirect light enhanced the mentioned decrease of TL intensity and TL ratio as compared to low temperature storage in dark room. In ESR analysis, legumes and spices showed radiation-induced cellulose radicals, while seasonings showed multi-component signals of radiation-induced crystalline sugar radical. These radiation-induced radicals could be potential markers for the detection of radiation treatments in subjected samples. The decreasing trend was also found for radiation-specific ESR signals of cellulose and crystalline sugar radicals during storage. However, radiation-induced radicals in legumes, powdered pepper and seasonings were detectable even after 6 months of storage

  6. The effects of gamma-irradiation on additives in food-contact polymers

    Science.gov (United States)

    Smith, Christine

    A range of antioxidants (BHT, Irganox 1010, 1076, 1330 and Irgafos 168) were incorporated into polymers (polyethylene, polypropylene, polystyrene and polyvinyl chloride) and subjected to increasing doses of gamma-irradiation (1,5,10,20,25,35 and 50 kGy) from a cobalt-60 source.The amount of extractable antioxidant from the stabilised polymers was determined chromatographically and a gradual diminution in the total extractable levels of each antioxidant was observed as irradiation progressed, the extent depending on the nature of both the antioxidant and the polymer 2,6-Di-t-butyl-1,4-benzoquinone was shown to be an extractable degradation product, arising from the effects of gamma-irradiation on the phenolic antioxidants. The extractable degradation product arising from the phosphite antioxidant, Irgafos 168, was identified as tris(2,4-di-t-butylphenyl)phosphate. It was demonstrated using 14C-labelled Irganox 1076 that degradation products formed during gamma-irradiation are becoming covalently bound to the polymer, as a result of radical coupling processes. There is a pronounced increase in the extent of covalent binding from 0.4% before irradiation to a minimum of 12.4% after an exposure to 50 kGy. Evidence has also been presented of covalent binding of the degradation product of Irgafos 168 to the polypropylene matrix, via polymeric radicals formed during irradiation. Finally, the effects of gamma-irradiation on the extent of migration of antioxidants from polyolefins into food simulants was studied. It was found that irradiation leads to a decrease in the extent to which hindered phenolic antioxidants migrate from polyolefins into fatty media, consistent with the reduction in extractable antioxidant levels and the increase in the extent of antioxidant-polymer binding.

  7. Improving the efficiency of CDTN's Gamma Irradiation Laboratory with additional designed turntables

    International Nuclear Information System (INIS)

    Silva, Luiz Leite da; Albino, Sergio Celeghini; Candido, Marcos Antonio; Grossi, Pablo Andrade; Correa, Ricardo Ferracini; Pinto, Fausto Carvalho

    2007-01-01

    The Gamma Irradiation Laboratory (LIG) of CDTN was originally supplied with four turntables. Operating with this configuration was a loss of time and irradiation volume, what induced the Irradiator's staff creating an optimisation production program. Firstly, the staff requests the Gamma Irradiator Manufacturer a quotation for new turntables, but the price was very high. Secondly, the CDTN Design Group was invited to develop new LIG turntables. The groups worked together and found a very good solution. The new turntables are much cheaper and their rotating plate diameters are increased in 5 cm and four of them were made to attend the LIG demand. They have been in operation without significant problems for 1.5 years and absorbed an estimated dose of 7 MGy. This fact confirms the design and materials good quality. Operating with the eight turntables was possible to improve the LIG irradiation capacity in six times in weigh and in volume. Irradiation time is reduced; nowadays doses up to 5 KGy can be done in the same day. For irradiation doses greater than 5 KGy, the process was speeded up by positioning the new turntables in the spaces between the original ones. With this operational configuration the samples receive the dose escaped in those spaces. Calculation of the new dose necessary for the sample is done and it is repositioned in the internals turntables to finish the irradiation process. With this technique the samples do not need to wait so much on the line. The scope of the research program includes day and night operation. Continuously operating in association with the four new turntables enhanced the original operational capacity of the LIG fifteen times. The objectives of this work are to present the developed turntables characteristics and the results acquired. (author)

  8. Multigeneration feeding studies with an irradiated whole diet

    International Nuclear Information System (INIS)

    Aravindakshan, M.; Chaubey, R.C.; Chauhan, P.S.; Sundaram, K.

    1978-01-01

    Multigeneration feeding studies have been carried out to investigate the effects of long-term feeding of an irradiated whole diet in Wistar rats. The parent and the four successive generations were fed on a nutritionally adequate test diet exposed to either 0.2 or 2.5Mrad gamma radiation and the effects, if any, on various parameters of animal health were assessed. In addition to an unirradiated test control, a historical control group fed on stock laboratory rations was also employed for comparison. The test diet consisted of various components including some of the basic ingredients of human diet in India. Exposure of the test diet to 0.2 or 2.5Mrad did not affect the food efficiency ratio and there were no significant differences in the growth rates of animals fed on unirradiated or irradiated diets. Reproductive performance of the rats fed on irradiated or unirradiated diets belonging to the parent, first, second or third generations were also comparable. Mortality rates and reproductive function in relation to age were also not altered due to feeding of irradiated whole diets. The haematological profile and the serum enzymes of the animals of all the generations fed irradiated diets were within normal limits. Though some differences were observed in the relative weights of some organs, these effects were limited to a particular generation, did not show any definite pattern and could not be related to the ingestion of irradiated diets. First-generation rats examined at 100-104 weeks for gross pathological manifestations including tumour incidence also did not indicate any significant differences among groups. (author)

  9. Toxicity of some insecticides to F1 progeny of the cotton leaf worm; Spodoptera littoralis (Boisd) gamma irradiated as parental pupae (Lepidoptera: Noctuidae)

    International Nuclear Information System (INIS)

    El-Shall, S.S.A.; Hazaa, M.A.M.; Alm El-Din, M.M.S.

    2006-01-01

    The response of the F1 Progeny of Cotton Leaf worm; Spodoptera littoralis Boisd, (from male irradiated as parental pupae with 0, 50, 100 and 150 Gy of gamma irradiation) to Silicron, Atabron and Catabroun were studied. The lethal concentration doses of insecticides that kill 10,50 and 90 % of population (LC 10 , LC 50 and LC 90 ); The lethal time that kill 50% of population (LT 50 ) and the Tolerance Ratio(T.R) to the different previous insecticides were employed as parameters for measuring the response of irradiated and un-irradiated progeny. The results indicated that, the dose of irradiation and time post insecticides application had a great role in alter the response of F1 progeny of S. littoralis to the different-insecticides. Also, gamma irradiation increased the toxicity of Silicron at 2 and 4 days post insecticide treatments. By time elapsing after insecticide application the irradiated larvae became virtually the same degree of susceptibility as compared to non-irradiated ones. As well, 50 Gy slightly alter the toxicity of Atabron, while population irradiated with 100 and 150 Gy showed a high level of susceptibility to Atabron at 22 and 26 days post insecticide treatments as compared to un-irradiated population. In addition, the toxicity of Catabroun increased in case of irradiated population at most of interval time post insecticide treatments as compared to un-irradiated ones. Furthermore, a Comparison was made and discussed between the susceptibility of irradiated population only, population treated with insecticides only and population treated with both insecticides and radiation by using the standard parameter LT 50

  10. Characterization of phosphorus segregation in neutron-irradiated Russian pressure vessel steel weld

    International Nuclear Information System (INIS)

    Miller, M.K.; Jayaram, R.; Russell, K.F.

    1995-01-01

    An atom probe field ion microscopy characterization of three Russian pressure vessel steels has been performed. Field ion micrographs of several lath boundaries have indicated that they are decorated with a semicontinuous film of discrete brightly-imaging precipitates that were identified as molybdenum carbonitrides. In addition, extremely high phosphorus levels were measured at the lath boundaries. The phosphorus was found to be confined to an extremely narrow region indicative of monolayer type segregation. The phosphorus coverage determined from the atom probe results of the unirradiated materials agree with predictions based on McLean's equilibrium model of grain boundary segregation. The boundary phosphorus coverage of a neutron-irradiated weld material was significantly higher than in the unirradiated material. Ultrafine darkly-imaging copper- and phosphorus-enriched precipitates were also observed in the matrix of the neutron-irradiated material. (orig.)

  11. Irradiated recycled plastic as a concrete additive for improved chemo-mechanical properties and lower carbon footprint.

    Science.gov (United States)

    Schaefer, Carolyn E; Kupwade-Patil, Kunal; Ortega, Michael; Soriano, Carmen; Büyüköztürk, Oral; White, Anne E; Short, Michael P

    2018-01-01

    Concrete production contributes heavily to greenhouse gas emissions, thus a need exists for the development of durable and sustainable concrete with a lower carbon footprint. This can be achieved when cement is partially replaced with another material, such as waste plastic, though normally with a tradeoff in compressive strength. This study discusses progress toward a high/medium strength concrete with a dense, cementitious matrix that contains an irradiated plastic additive, recovering the compressive strength while displacing concrete with waste materials to reduce greenhouse gas generation. Compressive strength tests showed that the addition of high dose (100kGy) irradiated plastic in multiple concretes resulted in increased compressive strength as compared to samples containing regular, non-irradiated plastic. This suggests that irradiating plastic at a high dose is a viable potential solution for regaining some of the strength that is lost when plastic is added to cement paste. X-ray Diffraction (XRD), Backscattered Electron Microscopy (BSE), and X-ray microtomography explain the mechanisms for strength retention when using irradiated plastic as a filler for cement paste. By partially replacing Portland cement with a recycled waste plastic, this design may have a potential to contribute to reduced carbon emissions when scaled to the level of mass concrete production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Effects of sintering additives on the microstructural and mechanical properties of the ion-irradiated SiCf/SiC

    Science.gov (United States)

    Fitriani, Pipit; Sharma, Amit Siddharth; Yoon, Dang-Hyok

    2018-05-01

    SiCf/SiC composites containing three different types of sintering additives viz. Sc-nitrate, Al2O3-Sc2O3, and Al2O3-Y2O3, were subjected to ion irradiation using 0.2 MeV H+ ions with a fluence of 3 × 1020 ions/m2 at room temperature. Although all composites showed volumetric swelling upon ion irradiation, SiCf/SiC with Sc-nitrate showed the smallest change followed by those with the Al2O3-Sc2O3 and Al2O3-Y2O3 additives. In particular, SiCf/SiC containing the conventional Al2O3-Y2O3 additive revealed significant microstructural changes, such as surface roughening and the formation of cracks and voids, resulting in reduced fiber pullout upon irradiation. On the other hand, the SiCf/SiC with Sc-nitrate showed the highest resistance against ion irradiation without showing any macroscopic changes in surface morphology and mechanical strength, indicating the importance of the sintering additive in NITE-based SiCf/SiC for nuclear structural applications.

  13. Application of gamma irradiation in ginseng for both photodegradation of pesticide pentachloronitrobenzene and microbial decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Hsiao-Wei [Department of Food Science and Biotechnology, National Chung Hsing University, 250, Kuo Kuang Road, Taichung 402, Taiwan (China); Hsieh, Ming-Fa [Department of Biomedical Engineering, Chung Yuan Christian University, 200, Chung Pei Road, Chungli 320, Taiwan (China); Wang, Ya-Ting; Chung, Hsiao-Ping [Nuclear Science and Technology Development Center, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China); Hsieh, Po-Chow; Lin, I-Hsin [Committee on Chinese Medicine and Pharmacy, Department of Health, Executive Yuan, Taipei 104, Taiwan (China); Chou, Fong-In, E-mail: fichou@mx.nthu.edu.tw [Nuclear Science and Technology Development Center, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China); Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 300, Taiwan (China)

    2010-04-15

    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 IC{sub 50} 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.

  14. Body composition changes following the supplementation of different food additives to irradiated animals

    International Nuclear Information System (INIS)

    Fahmy, M.O.

    1980-01-01

    This study was conducted to examine the hypothesis that deposition of fat and / or protein in animal's body before irradiation or using radio - protector material such as soyabean oil may reduce the hazard effects of radiation on life span, body weight and body compartments. Therefore, 286 mice ( 144 males and 142 females) after chemical maturity were used in this study. The animals were divided to 4 major groups. The first group was fed on chow diet, the second group was fed on radioprotector diet ( basel diet), the third group was fed on high energy diet and the forth group fed on high protein diet, for 7 weeks before the exposure to gamma-rays. At the exposure day each nutritional group was divided to 3 exposure treatments ( non-irradiated, 800 and 1200 rads). The previous hypothesis was studied for 42 days after irradiation

  15. Microbiological and biochemical characteristics of ground beef as affected by gamma irradiation, food additives and edible coating film

    Energy Technology Data Exchange (ETDEWEB)

    Ouattara, B.; Giroux, M.; Yefsah, R.; Smoragiewicz, W.; Saucier, L.; Borsa, J.; Lacroix, M. E-mail: monique.lacroix@inrs-iaf.uquebec.ca

    2002-03-01

    The current interest in 'minimally processed foods' has attracted the attention for combination of mild treatments to improve food safety and shelf-life extension. The present study was conducted to evaluate the combined effect of gamma irradiation and incorporation of naturally occurring antimicrobial compounds on microbial and biochemistry characteristics of ground beef. Ground beef patties (23% fat ) were purchased from a local grocery store (IGA, Laval, Que., Canada) and divided into 3 separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid, and (iii) ground beef with 0.5% ascorbic acid and coated with a protein-based coating containing selected spices. Samples were irradiated at 0, 1, 2, and 3 kGy final dose at the CIC. Samples were stored at 4 deg. C and evaluated periodically for microbial growth, total thiobarbituric reactive substances (TBARS) and free sulfydryl content. At the end of the storage period, Enterobacteriaceae, Lactic acid bacteria, Pseudomonas and Brochothrix thermosphacta were enumerated. Regardless of the treatment group, irradiation significantly (p{<=}0.05) reduced the total aerobic plate counts (APC). Irradiation doses of 1, 2, and 3 kGy produced immediate reduction of 2, 3, and 4 log units of APCs, respectively. Also, shelf-life periods were higher for ground beef samples containing food additives. Lactic acid bacteria and Brochothrix thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. Concentration of TBARS and free sulfydryl concentrations were stabilized during post-irradiation storage for samples containing ascorbic acid and coated with the protein-based coating containing spices.

  16. Microbiological and biochemical characteristics of ground beef as affected by gamma irradiation, food additives and edible coating film

    International Nuclear Information System (INIS)

    Ouattara, B.; Giroux, M.; Yefsah, R.; Smoragiewicz, W.; Saucier, L.; Borsa, J.; Lacroix, M.

    2002-01-01

    The current interest in 'minimally processed foods' has attracted the attention for combination of mild treatments to improve food safety and shelf-life extension. The present study was conducted to evaluate the combined effect of gamma irradiation and incorporation of naturally occurring antimicrobial compounds on microbial and biochemistry characteristics of ground beef. Ground beef patties (23% fat ) were purchased from a local grocery store (IGA, Laval, Que., Canada) and divided into 3 separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid, and (iii) ground beef with 0.5% ascorbic acid and coated with a protein-based coating containing selected spices. Samples were irradiated at 0, 1, 2, and 3 kGy final dose at the CIC. Samples were stored at 4 deg. C and evaluated periodically for microbial growth, total thiobarbituric reactive substances (TBARS) and free sulfydryl content. At the end of the storage period, Enterobacteriaceae, Lactic acid bacteria, Pseudomonas and Brochothrix thermosphacta were enumerated. Regardless of the treatment group, irradiation significantly (p≤0.05) reduced the total aerobic plate counts (APC). Irradiation doses of 1, 2, and 3 kGy produced immediate reduction of 2, 3, and 4 log units of APCs, respectively. Also, shelf-life periods were higher for ground beef samples containing food additives. Lactic acid bacteria and Brochothrix thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. Concentration of TBARS and free sulfydryl concentrations were stabilized during post-irradiation storage for samples containing ascorbic acid and coated with the protein-based coating containing spices

  17. Investigations on the detection of irradiated food by measuring the viscosity of suspended spices and dried vegetables

    Science.gov (United States)

    Heide, L.; Nürnberger, E.; Bögl, K. W.

    Studies on the viscosity behavior were performed with 20 different spices or dried vegetables. In nine spices (cinnamon, ginger, mustard seed, celery, onions, shallots, lemon peel, black and white pepper) differences between unirradiated and irradiated samples were observed. Further lots were investigated to estimate the variations of viscosity depending on the origin of the samples. Additional storage experiments showed that measuring the viscosity may be a simple method to identify some radiation treated spices even after years.

  18. Effect of additional minor elements on accumulation behavior of point defects under electron irradiation in austenitic stainless steels

    International Nuclear Information System (INIS)

    Sekio, Yoshihiro; Yamashita, Shinichiro; Takahashi, Heishichiro; Sakaguchi, Norihito

    2014-01-01

    Addition of minor elements to a base alloy is often applied with the aim of mitigating void swelling by decreasing the vacancy diffusivity and flux which influence vacancy accumulation behavior. However, the comparative evaluations of parameters, such as the diffusivity and flux, between a base alloy and modified alloys with specific additives have not been studied in detail. In this study, type 316 austenitic stainless steel as a base alloy and type 316 austenitic stainless steels modified with vanadium (V) or zirconium (Zr) additions were used to perform evaluations from the changes of widths of the void denuded zone (VDZ) formed near a random grain boundary during electron irradiation because these widths depend on vacancy diffusivity and flux. The formations of VDZs were observed in in-situ observations during electron irradiation at 723 K and the formed VDZ widths were measured from the transmission electron microscopic images after electron irradiation. As a result, the VDZs were formed in both steels without and with V, and respective widths were ∼119 and ∼100 nm. On the other hand, the VDZ formation was not observed clearly in the steel with Zr. From the measured VDZ widths in the steels without and with V addition, the estimated ratio of the vacancy diffusivity in the steel with V to that in the steel without V was about 0.50 and the estimated ratio of the vacancy flux in the steel with V to that in the steel without V was about 0.71. This result suggests that the effect of additional minor elements on vacancy accumulation behaviors under electron irradiation could be estimated from evaluations of the VDZ width changes among steels with and without minor elements. Especially, because void swelling is closely related with the vacancy diffusion process, the VDZ width changes would also be reflected on void swelling behavior. (author)

  19. Moessbauer spectroscopy and additional study of neutron irradiated Cr-doped metallic glasses

    International Nuclear Information System (INIS)

    Miglierini, M.; Sitek, J.; Mihalik, M.; Zentko, A.

    1990-01-01

    Concentration and fluence dependent tendency of FeNiCrMoSiB metallic glass towards disordering as well as a decrease of the Curie temperature were revealed by Moessbauer and electron-positron annihilation spectroscopies and initial permeability measurements, respectively. The observed changes can be assigned to irradiation-induced defects resulting in fluctuations in chemical and/or topological short-range order. (orig.)

  20. Modeling the influence of high dose irradiation on the deformation and damage behavior of RAFM steels under low cycle fatigue conditions

    Energy Technology Data Exchange (ETDEWEB)

    Aktaa, J. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research II, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)], E-mail: aktaa@imf.fzk.de; Petersen, C. [Forschungszentrum Karlsruhe GmbH, Institute for Materials Research II, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2009-06-01

    A viscoplastic deformation damage model developed for RAFM steels in the reference un-irradiated state was modified taking into account the irradiation influence. The modification mainly consisted in adding an irradiation hardening variable with an appropriate evolution equation including irradiation dose driven terms as well as inelastic deformation and thermal recovery terms. With this approach, the majority of the material and temperature dependent model parameters are no longer dependent on the irradiation dose and only few parameters need to be determined by applying the model to RAFM steels in the irradiated state. The modified model was then applied to describe the behavior of EUROFER 97 observed in the post irradiation examinations of the irradiation programs ARBOR 1, ARBOR 2 and SPICE. The application results will be presented and discussed in addition.

  1. Identification of gamma-irradiated foodstuffs by chemiluminescence measurements in Taiwan

    Science.gov (United States)

    Ma, Ming-Shia Chang; Chen, Li-Hsiang; Tsai, Zei-Tsan; Fu, Ying-Kai

    In order to establish chemiluminescence (CL) measurements as an identification method for γ-irradiated foodstuffs in Taiwan, ten agricultural products including wheat flour, rice, ginger, potatoes, garlic, onions, red beans, mung beans, soy beans, xanthoxylon seeds and Japanese star anises have been tested to compare CL intensities between untreated samples and samples subject to a 10 kGy γ-irradiation dose. Amongst them, wheat flour is the most eligible product to be identified by CL measurements. The CL intensities of un-irradiated and irradiated flour have shown large differences associated with a significant dose-effect relationship. Effects of three different protein contents of flour, unsieved and sieved (100-200 mesh), the reproducibility and the storage experiment on CL intensities at various doses were investigated in this study. In addition, the white bulb part of onions has shown some CL in irradiated samples. The CL data obtained from the other eight agricultural products have shown large fluctuations and cannot be used to differentiate between irradiated and un-irradiated samples.

  2. Identification of gamma-irradiated foodstuffs by chemiluminescence measurements in Taiwan

    International Nuclear Information System (INIS)

    Mingshia Chang Ma; Lihsiang Chen; Zeitsan Tsai; Yingkai Fu

    1992-01-01

    In order to establish chemiluminescence (CL) measurements as an identification method for γ-irradiated foodstuffs in Taiwan, ten agricultural products including wheat flour, rice, ginger, potatoes, garlic, onions, red beans, mung beans, soy beans, xanthoxylon seeds and Japanese star anises have been tested to compare CL intensities between untreated samples and samples subject to a 10 kGy γ-irradiation dose. Amongst them, wheat flour is the most eligible product to be identified by CL measurements. The CL intensities of un-irradiated and irradiated flour have shown large differences associated with a significant dose-effect relationship. Effects of three different protein contents of flour, unsieved and sieved (100-200 mesh), the reproducibility and the storage experiment on CL intensities at various doses were investigated in this study. In addition, the white bulb part of onions has shown some CL in irradiated samples. The CL data obtained from the other eight agricultural products have shown large fluctuations and cannot be used to differentiate between irradiated and un-irradiated samples. (Author)

  3. Reduction of irradiation off-odor and lipid oxidation in ground beef by {alpha}-tocopherol addition and the use of a charcoal pack

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, S.H. [Busan Regional Food and Drug Administration, Busan 608-829 (Korea, Republic of); Jang, A. [National Institute of Animal Science, RDA, Suwon 441-706 (Korea, Republic of); Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, J.K. [Cooperative Research, Extension, and Education Service, Northern Marianas College, Saipan, MP 96950 (Korea, Republic of); Song, H.P. [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, J.H. [Cooperative Research, Extension, and Education Service, Northern Marianas College, Saipan, MP 96950 (Korea, Republic of); Lee, M. [Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Jo, C. [Department of Animal Science and Biotechnology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)], E-mail: cheorun@cnu.ac.kr

    2009-02-15

    A combination of a charcoal pack during irradiation and {alpha}-tocopherol addition into ground beef was applied to eliminate an irradiation characteristic off-odor and to retard the lipid oxidation caused by the irradiation process. Ground beef was mixed with 200 ppm {alpha}-tocopherol and gamma irradiated with 0, 5, and 10 kGy with or without a charcoal pack present during the irradiation treatment. The pH of the control group was lower than that of {alpha}-tocopherol and charcoal pack treatment initially but increased rapidly and showed higher pH at day 7. Addition of {alpha}-tocopherol with or without charcoal pack addition showed lower 2-thiobarbituric acid reactive substances values in irradiated ground beef at days 3 and 7 compared to those without addition. The color of ground beef was not significantly affected by the treatment. However, odor preference result showed that 10 kGy-irradiated ground beef with a combination of charcoal pack and {alpha}-tocopherol addition had higher scores than the control group regardless of irradiation. Solid-phase microextraction (SPME) gas chromatograph/mass spectrometry (GC/MS) analysis identified various volatile compounds that were created by irradiation of ground beef. These compounds were reduced or eliminated when a charcoal pack was used during the irradiation process. The results of the present study imply that combination of packaging with a charcoal pack during the irradiation process and addition of {alpha}-tocopherol into ground beef is a good method to effectively eliminate an irradiation off-odor and retard the lipid oxidation development in ground beef caused by irradiation.

  4. Reduction of irradiation off-odor and lipid oxidation in ground beef by α-tocopherol addition and the use of a charcoal pack

    International Nuclear Information System (INIS)

    Sohn, S.H.; Jang, A.; Kim, J.K.; Song, H.P.; Kim, J.H.; Lee, M.; Jo, C.

    2009-01-01

    A combination of a charcoal pack during irradiation and α-tocopherol addition into ground beef was applied to eliminate an irradiation characteristic off-odor and to retard the lipid oxidation caused by the irradiation process. Ground beef was mixed with 200 ppm α-tocopherol and gamma irradiated with 0, 5, and 10 kGy with or without a charcoal pack present during the irradiation treatment. The pH of the control group was lower than that of α-tocopherol and charcoal pack treatment initially but increased rapidly and showed higher pH at day 7. Addition of α-tocopherol with or without charcoal pack addition showed lower 2-thiobarbituric acid reactive substances values in irradiated ground beef at days 3 and 7 compared to those without addition. The color of ground beef was not significantly affected by the treatment. However, odor preference result showed that 10 kGy-irradiated ground beef with a combination of charcoal pack and α-tocopherol addition had higher scores than the control group regardless of irradiation. Solid-phase microextraction (SPME) gas chromatograph/mass spectrometry (GC/MS) analysis identified various volatile compounds that were created by irradiation of ground beef. These compounds were reduced or eliminated when a charcoal pack was used during the irradiation process. The results of the present study imply that combination of packaging with a charcoal pack during the irradiation process and addition of α-tocopherol into ground beef is a good method to effectively eliminate an irradiation off-odor and retard the lipid oxidation development in ground beef caused by irradiation

  5. Effluent and gamma-irradiated digested sludge additions on calcareous soils

    International Nuclear Information System (INIS)

    Lee-Rodriguez, V.

    1978-01-01

    The long-term use of sewage effluent and the use of gamma-irradiated treated digested sewage sludge (RDSS) were studied under field and greenhouse conditions, respectively. The purpose of this investigation was to: (1) study the effect of long and short-term application of secondary sewage effluent and RDSS, respectively, on the buildup of iron and phytotoxicity problems on calcareous soils; (2) study the potential phytotoxicity of RDSS and observe the micronutrient fertilizer value of RDSS through three successive plantings on calcareous soil; (3) evaluate RDSS as a source of iron in a soil known to be severely iron-deficient

  6. Performance evaluation of the European Committee Standardization Method EN1785 for the detection of irradiated processed food

    International Nuclear Information System (INIS)

    Tsutsumi, Tomoaki; Adachi, Rika; Takatsuki, Satoshi; Matsuda, Rieko; Teshima, Reiko; Nei, Daisuke; Kameya, Hiromi; Todoriki, Setsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko

    2014-01-01

    2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB) are specific radiolytic products in irradiated lipid-containing food and can be used to detect irradiated foods. We previously reported a performance evaluation test in a single laboratory for qualitative detection methods using DCB and TCB as markers for irradiated foods. EN1785, a European Committee Standardization Method, has been widely used for qualitative detection of DCB and TCB in irradiated foods. Here, we evaluated the applicability of EN1785 to camembert cheese, liquid whole egg, sausage and eel grilled without seasoning by using our evaluation test. In this test, extracted lipids from the food were used as negative samples. The lipids spiked with DCB and TCB were used as positive samples. For each food type, 4 negative and 16 positive samples were analyzed by EN1785. All of the negative samples were judged negative and all of the positive samples were judged positive. Thus, EN1785 should be able to detect irradiation in the tested food. Additionally, to confirm the ability of the validated method to detect irradiated food, the same type of food examined above, both unirradiated and irradiated at doses of 0.5-4 kGy, were analyzed by the method. All of the unirradiated samples were judged negative and all of the irradiated samples were judged positive. (author)

  7. Effect of Ti additions on the swelling of electron irradiated austenitic steels and Ni alloys

    International Nuclear Information System (INIS)

    Gilbon, D.; Didout, G.; Le Naour, L.; Levy, V.

    1979-01-01

    It has been shown that titanium is a beneficial additive for the swelling of austenitic steels. The amplitude of the effects observed depends much on the nature and concentration of the other additives in the austenitic matrix [fr

  8. Application of gamma irradiation for storage potato

    International Nuclear Information System (INIS)

    Rezaee, M.; Almasi, M.

    2009-01-01

    Since deficiency of controlled store in Iran and environmental problems of chemical material the use of gamma irradiation to control sprouting and increase the length of storage time of potatoes has been proposed as an alternative to cold storage or the use of chemical sprout suppressants. In this study potatoes of Agria Variety were irradiated at a dose of 0.10 KGY and stored along with the unirradiated controls at 12±3°C for a period of more than 6 month from October to April .After 4 month of storage the sprouting ranged from 5 to 12% in irradiated potatoes and 45 to 74% in unirradiated samples and after 6 month the unirradiated potatoes were discarded because of heavy sprouting and rotting. The rot attack was approximately double in unirradiated samples. It was found that losses through dehydration were 10.3 to 15.1 % in the irradiated potatoes. Also a comparative study of reducing and non-reducing sugars, vitamin-C content, total sugar, starch and protein was carried out between unirradiated and irradiated samples. The results suggested the efficacy of Gamma irradiation for ensuring availability of the storing quality of potato during lean periods from October to April. (author)

  9. Effect of irradiation on vitamin C and acidity

    International Nuclear Information System (INIS)

    Jiravatana, V.

    1971-01-01

    Effect of gamma radiation on the total carbohydrates content of Hom Tong banana stored for various time was discussed. The total carbohydrates of unirradiated banana increased more rapidly during storage than those of irradiated ones. Radiation did not appear to have any effect on the total carbohydrate content in the banana. No significant difference was found on the total carbohydrates between irradiated and unirradiated banana at the same stage of ripeness

  10. Additive effects of 5-Aza-2'-deoxycytidine and irradiation on clonogenic survival of human medulloblastoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Patties, Ina; Jahns, Jutta; Kortmann, Rolf-Dieter; Glasow, Annegret [Dept. of Radiotherapy and Radiooncology, Universitaetsklinikum Leipzig AoeR (Germany); Hildebrandt, Guido [Dept. of Radiotherapy and Radiooncology, Universitaetsklinikum Leipzig AoeR (Germany); Dept. of Radiotherapy, Univ. of Rostock (Germany)

    2009-05-15

    Background and purpose: in recent years, epigenetic modulators were introduced into tumor therapy. Here, the authors investigated the antitumor effect of 5-aza-2'-deoxycytidine-(5-aza-dC-)induced demethylation combined with irradiation on human medulloblastoma (MB) cells, which form the most common malignant brain tumor in children. Material and methods: three MB cell lines were treated with 5-aza-dC in a low-dose (0.1 {mu}M, 6 days) or high-dose (3/5 {mu}M, 3 days) setting and irradiated with 2, 4, 6, or 8 Gy single dose on an X-ray unit. Methylation status and mRNA expression of three candidate genes were analyzed by methylation-specific PCR (polymerase chain reaction) and quantitative real-time RT-PCR. Cell survival and mortality were determined by trypan blue exclusion test. Proliferation was analyzed by BrdU incorporation assay, and long-term cell survival was assessed by clonogenic assay. Results: 5-aza-dC treatment resulted in partial promoter demethylation and increased expression of hypermethylated candidate genes. A significant decrease of vital cell count, proliferation inhibition and increase of mortality was observed in 5-aza-dC-treated as well as in irradiated MB cells, whereby combination of both treatments led to additive effects. Although high-dose 5-aza-dC treatment was more effective in terms of demethylation, clonogenic assay revealed no differences between high- and low-dose settings indicating no relevance of 5-aza-dC-induced demethylation for decreased cell survival. MB cells pretreated with 5-aza-dC showed significantly lower plating efficiencies than untreated cells at all irradiation doses investigated. Analysis of surviving curves in irradiated MB cells, however, revealed no significant differences of {alpha}-, {beta}-values and 2-Gy surviving fraction with or without 5-aza-dC treatment. Conclusion: 5-aza-dC did not enhance radiation sensitivity of MB cells but significantly reduced the clonogenicity versus irradiation alone, which

  11. Cytological evidence for DNA chain elongation after UV irradiation in the S phase

    International Nuclear Information System (INIS)

    Minka, D.F.; Nath, J.

    1981-01-01

    Human cells irradiated with UV light synthesize lower molecular weight DNA than unirradiated cells. This reduction in molecular weight is greater in xeroderma pigmentosum (XP) cells than in normal cells. The molecular weight of DNA is further reduced by the addition of caffeine to XP cells. By several hours after irradiation, DNA fragments are barely detectable. Cells from excision-proficient and excision-deficient XP patients were studied autoradiographically to produce cytological evidence of DNA chain elongation. Replicate cultures with and without caffeine were synchronized and irradiated with UV light during the S phase. Caffeine was removed in G2, and the cells were labeled with 3 H-thymidine. Results showed significantly increased labeling during G2 of excision-deficient XP cells. Labeling was dependent on the time of irradiation and presence of caffeine. The XP variant cells had no increase in labeling for any irradiation time

  12. Modeling of helium bubble nucleation and growth in neutron irradiated boron doped RAFM steels

    International Nuclear Information System (INIS)

    Dethloff, Christian; Gaganidze, Ermile; Svetukhin, Vyacheslav V.; Aktaa, Jarir

    2012-01-01

    Reduced activation ferritic/martensitic (RAFM) steels are promising candidates for structural materials in future fusion technology. In addition to other irradiation defects, the transmuted helium is believed to strongly influence material hardening and embrittlement behavior. A phenomenological model based on kinetic rate equations is developed to describe homogeneous nucleation and growth of helium bubbles in neutron irradiated RAFM steels. The model is adapted to different 10 B doped EUROFER97 based heats, which already had been studied in past irradiation experiments. Simulations yield bubble size distributions, whereby effects of helium generation rate, surface energy, helium sinks and helium density are investigated. Peak bubble diameters under different conditions are compared to preliminary microstructural results on irradiated specimens. Helium induced hardening was calculated by applying the Dispersed Barrier Hardening model to simulated cluster size distributions. Quantitative microstructural investigations of unirradiated and irradiated specimens will be used to support and verify the model.

  13. Modeling of helium bubble nucleation and growth in neutron irradiated boron doped RAFM steels

    Energy Technology Data Exchange (ETDEWEB)

    Dethloff, Christian, E-mail: christian.dethloff@kit.edu [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Gaganidze, Ermile [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Svetukhin, Vyacheslav V. [Ulyanovsk State University, Leo Tolstoy Str. 42, 432970 Ulyanovsk (Russian Federation); Aktaa, Jarir [Karlsruhe Institute of Technology (KIT), Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2012-07-15

    Reduced activation ferritic/martensitic (RAFM) steels are promising candidates for structural materials in future fusion technology. In addition to other irradiation defects, the transmuted helium is believed to strongly influence material hardening and embrittlement behavior. A phenomenological model based on kinetic rate equations is developed to describe homogeneous nucleation and growth of helium bubbles in neutron irradiated RAFM steels. The model is adapted to different {sup 10}B doped EUROFER97 based heats, which already had been studied in past irradiation experiments. Simulations yield bubble size distributions, whereby effects of helium generation rate, surface energy, helium sinks and helium density are investigated. Peak bubble diameters under different conditions are compared to preliminary microstructural results on irradiated specimens. Helium induced hardening was calculated by applying the Dispersed Barrier Hardening model to simulated cluster size distributions. Quantitative microstructural investigations of unirradiated and irradiated specimens will be used to support and verify the model.

  14. A study on the proton irradiation effect of reactor materials using cyclotron

    International Nuclear Information System (INIS)

    Chi, Se Hwan; Park, Jong Man; Park, Deuk Keun; Lee, Bong Sang; Oh, Jong Myung

    1993-02-01

    Understanding on radiation damage of important structural materials is important for safe operation and radiation damage evaluation of new reactor structural materials. This study was performed to simulate and evaluate 14 MeV neutron irradiation effects on mechanical properties of candidate structural materials (HT-9/SS316) of next generation reactors (FBR, Fusion) irradiated by Cyclotron(MC-50) using SP test technique. After qualification of SP test techniques from J IC and ε qf correlation, SP tests were performed to evaluate 16MeV proton irradiation effects on mechanical properties of irradiated and unirradiated HT-9/SS316 steels. Test results were evaluated for ε qf , energy and displacement up to failure and J IC change. In addition, damaged zone and dpa upon depth after irradiation were calculated using TRIM code and Doppler broadening line shapes were measured to evaluate defects for 15% cold worked HT-9 steel using PAS. (Author)

  15. Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

    International Nuclear Information System (INIS)

    Beshir, W.B.

    2014-01-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose–response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months. The calculated G-value (The number of radicals per 100 eV of absorbed energy) for cardamom and cloves was found 0.07±0.01 and 0.055±0.01, respectively. - Highlights: • The EPR analysis of cardamom and cloves prove the sample has been irradiated or not. • Dose additive can be used for evaluation of the absorbed dose in cardamom and cloves. • The 3rd polynomial function can be used to fit the data and the estimated dose. • The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over 2 months

  16. Safety analysis report for packaging: the ORNL HFIR unirradiated fuel element shipping container

    International Nuclear Information System (INIS)

    Evans, J.H.; Boulet, J.A.M.; Eversole, R.E.

    1977-11-01

    The ORNL HFIR unirradiated fuel element shipping container was designed and fabricated at the Oak Ridge National Laboratory for the transport of HFIR unirradiated fuel elements. The container was evaluated analytically and experimentally to determine its compliance with the applicable regulations governing containers in which radioactive and fissile materials are transported, and the evaluation is the subject of this report. Computational and test procedures were used to determine the structural integrity and thermal behavior of the cask relative to the general standards for normal conditions of transport and the standards for the hypothetical accident conditions. The results of the evaluation demonstrate that the container is in compliance with the applicable regulations

  17. Proof tests of irradiated and unirradiated EBR-II subassembly ducts

    International Nuclear Information System (INIS)

    Ruther, W.E.; Chopra, P.S.; Lambert, J.D.B.

    1977-01-01

    A series of dynamic pressure tests have been conducted within EBR-II subassembly ducts. The tests were designed to simulate bursting of a driver-fuel element in a cluster of such elements at their burnup limit during off-normal conditions in EBR-II. The major objective of the tests was to assure that such failure, which might cause rapid release of stored fission gas, would not deform or otherwise damage subassembly ducts in a way that would hinder movement of a control rod. The test results are described

  18. Interaction between UO2 kernel and pyrocarbon coating in irradiated and unirradiated HTR fuel particles

    International Nuclear Information System (INIS)

    Drago, A.; Klersy, R.; Simoni, O.; Schrader, K.H.

    1975-08-01

    Experimental observations on unidirectional UO 2 kernel migration in TRISO type coated particle fuels are reported. An analysis of the experimental results on the basis of data and models from the literature is reported. The stoichiometric composition of the kernel is considered the main parameter that, associated with a temperature gradient, controls the unidirectional kernel migration

  19. Irradiation of Liquid Fungi Isolated Media from Contaminated Sources with Heavy Metals Additive

    International Nuclear Information System (INIS)

    Tawfiq, E.; Mohamed, A.A.; El-Kabbany, H.M.

    2012-01-01

    Occupational lead exposure is an important health issue in Egyptian workers, employees of paint factories, workers of copying centres, drivers, and tile making factories are in higher risk of lead toxicity. Wastewater, particularly from electroplating, paint, leather, metal and tanning industries, contain enormous amount of heavy metals. Microorganisms including fungi have been reported to exclude heavy metals from wastewater through bioaccumulation and bio sorption at low cost and in eco-friendly way. Low level lead exposure can significantly induce motor dis functions and cognitive impairment in children. Seventy six fungal isolates tolerant to heavy metals like Pb, Cd, Cr and Ni were isolated from sewage, sludge and industrial effluents containing heavy metals. Four fungi (Phanerochaete chrysosporium, Aspergillus awamori, Aspergillus flavus, Trichoderma viride) were included in this study. The majority of the fungal isolates were able to tolerate up to 400 ppm concentration of Pb, Cd, Cr and Ni. The most heavy metal tolerant fungi were studied for removal of heavy metals from liquid media at 50 ppm concentration. Results indicated removal of substantial amount of heavy metals by some of the fungi with respect to Pb, Cd, Cr and Ni with maximum uptake of 59.67, 16.25, 0.55 and 0.55 mg/g by fungi Pb 3 (Aspergillus terreus), Trichoderma viride, C r 8 (Trichoderma longibrachiatum), and isolate Ni 27 (A. niger), respectively. This indicated the potential of these fungi as bio sorbent for removal of heavy metals from wastewater and industrial effluents containing higher concentration of heavy metals. The F-ratio was 0.55 and gives non-significant as irradiated

  20. Irradiation processing of potatoes, onions and garlic

    International Nuclear Information System (INIS)

    Jan, M.; Starr, A.; Wahid, M.; Ahmad, A.; Khan, I.

    1992-07-01

    In this report, studies have been conducted on irradiation preservation of potatoes, onions and garlic involving different varieties, harvesting season and storage life. As a result of these investigations, optimum conditions were established for each crop. The effect of irradiation and storage on sprouting, rottage and weight loss of potatoes is presented. The sprouting initiated in the unirradiated samples after 2 months reaching 51, 80 and 100% on 4, 5 and 6 months storage respectively. Weight losses were observed in the irradiated and unirradiated samples. (A.B.)

  1. The GR-value deviation from the additivity rule for irradiated systems containing heterocyclic compounds

    International Nuclear Information System (INIS)

    Nanobashvili, H.M.; Shanidze, G.V.; Khidesheli, G.I.; Panchvidze, M.V.

    1988-01-01

    The investigation of the low temperature radiolysis of binary systems containing heterocyclic compounds has been carried out. In the systems under study the G R -value deviation from the additivity rule is observed due to the energy transfer processes from matrix molecules. It is shown that heterocyclic compounds are good radioprotectors. (author)

  2. Structural changes of polytetrafluoroethylene during irradiation in oxygen

    International Nuclear Information System (INIS)

    Liu, Shuling; Fu, Congli; Gu, Aiqun; Yu, Zili

    2015-01-01

    To study the effect of irradiation on PTFE structure and prepare modified PTFE micropowder, PTFE was irradiated with dose up to 4 MGy in oxygen at room temperature. The structures of both irradiated and unirradiated PTFE samples were comparatively characterized by IR, XPS, Raman spectra and XRD measurement. The results showed that new groups of acyl fluoride (COF), carboxylic acid (COOH) and trifluoromethyl (CF 3 ) were formed under heavy radiation exposure in oxygen. In addition, the expansion of crystallite size or crystal lattice was first reported for the irradiated PTFE. The formation of new chemical groups and the expansion of crystallite size were elucidated by structural changes occurring in irradiation. - Highlights: • The structural change of PTFE irradiated in O 2 is different from that in vacuum. • The double bond is not found in PTFE after irradiation in oxygen. • The new groups like COF, COOH and CF 3 are formed in PTFE after irradiation. • The expansion of crystallite size is observed in the irradiated PTFE

  3. Precession electron diffraction for SiC grain boundary characterization in unirradiated TRISO fuel

    International Nuclear Information System (INIS)

    Lillo, T.M.; Rooyen, I.J. van; Wu, Y.Q.

    2016-01-01

    Highlights: • SiC grain orientation determined by TEM-based precession electron diffraction. • Orientation data improved with increasing TEM sample thickness. • Fraction of low angle grain boundaries lower from PED data than EBSD data. • Fractions of high angle and CSL-related boundaries similar to EBSD data. - Abstract: Precession electron diffraction (PED), a transmission electron microscopy-based technique, has been evaluated for the suitability for evaluating grain boundary character in the SiC layer of tristructural isotropic (TRISO) fuel. This work reports the effect of transmission electron microscope (TEM) lamella thickness on the quality of data and establishes a baseline comparison to SiC grain boundary characteristics, in an unirradiated TRISO particle, determined previously using a conventional electron backscatter diffraction (EBSD) scanning electron microscope (SEM)-based technique. In general, it was determined that the lamella thickness produced using the standard focused ion beam (FIB) fabrication process (∼80 nm), is sufficient to provide reliable PED measurements, although thicker lamellae (∼120 nm) were found to produce higher quality orientation data. Also, analysis of SiC grain boundary character from the TEM-based PED data showed a much lower fraction of low-angle grain boundaries compared to SEM-based EBSD data from the SiC layer of a TRISO-coated particle made using the same fabrication parameters and a SiC layer deposited at a slightly lower temperature from a surrogate TRISO particle. However, the fractions of high-angle and coincident site lattice (CSL)-related grain boundaries determined by PED are similar to those found using SEM-based EBSD. Since the grain size of the SiC layer of TRSIO fuel can be as small as 250 nm (Kirchhofer et al., 2013), depending on the fabrication parameters, and since grain boundary fission product precipitates in irradiated TRISO fuel can be nano-sized, the TEM-based PED orientation data

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

    International Nuclear Information System (INIS)

    Ishidate, M. Jr.; Yoshikawa, Kunie; Sofuni, Toshio; Iwahara, Shigeo; Sibuya, Tohru.

    1981-01-01

    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)

  5. New method to calculate the mechanical properties of unirradiated fuel cladding from ring tensile tests

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Rengel, M.A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain); Consejo de Seguridad Nuclear (CSN), Justo Dorado 11, E-28040 Madrid (Spain); Gomez, F.J.; Ruiz-Hervias, J.; Caballero, L.; Valiente, A. [Departamento de Ciencia de Materiales, UPM, E.T.S.I. Caminos, Canales y Puertos, Profesor Aranguren s/n, E-28040 Madrid (Spain)

    2009-06-15

    displacement of the loading piece and another one between the equivalent stress in the same point and the nominal applied stress. In the first iteration a calculation is performed with an approximate plastic stress-strain law, and the two above-mentioned relationships are used to determine a new law from the experimental results. In the second iteration the calculation takes into account the new plastic stress-strain law and determines two new relationships. After a few iterations an excellent fit is obtained. This method is an improvement of the original method by Arsene and Bai [3] and allows obtaining the plastic stress-strain curve in the hoop direction in a consistent way. The experimental data used in this work to check the validity of the procedure have been obtained on unirradiated Zirlo cladding, with the standard alloy composition and geometry (outer diameter of the cladding 9.5 mm and a wall thickness of 0.56 mm). References: [1]. Arsene, S.; Bai, J.B. A new approach to measuring transverse properties of structural tubing by a ring test, Journal of Testing and Evaluation, 24: 386-391 (1996) [2]. Arsene, S.; Bai, J. 'A new approach to measuring transverse properties of structural tubing by a ring test-experimental investigation', Journal of Testing and Evaluation, 26: 26-30 (1998) [3]. Arsene, S.; Bai, J.B.; 'Hydride embrittlement and irradiation effects on the hoop mechanical properties of pressurized water reactor (PWR) and boiling-water reactor (BWR) zircaloy cladding tubes: Part I. Hydride embrittlement in stress-relieved, annealed, and recrystallized zircaloys at 20 deg. C and 300 deg. C', Metallurgical and materials and transactions A, 34A: 553-566 (2003) [4]. Chang-Sun Seok, Bong-Kook, K.Linga, 'The properties of the ring and burst creep of zirlo claddings', Engineering Failure Analysis, 13: 389-397 (2006). (authors)

  6. The dissolution of unirradiated UO2 fuel pellets under simulated disposal conditions

    International Nuclear Information System (INIS)

    Ollila, K.; Leino-Forsman, H.

    1993-03-01

    The dissolution behaviour of unirradiated UO 2 pellets was studied as a function of water composition under oxidizing and reducing conditions at 25 deg C. The waters included deionized water as the reference water, sodium bicarbonate solutions with varying bicarbonate content, and two different synthetic groundwaters. The release of uranium was measured during static batch dissolution experiments of long duration (3-4 years)

  7. Non-targeted mutagenesis of unirradiated lambda phage in Escherichia coli

    International Nuclear Information System (INIS)

    Wood, R.D.; Hutchinson, F.

    1984-01-01

    Non-targeted mutagenesis of lambda phage by ultraviolet light is the increase over background mutagenesis when non-irradiated phage are grown in irradiated Escherichia coli host cells. Such mutagenesis is caused by different processes from targeted mutagenesis, in which mutations in irradiated phage are correlated with photoproducts in the phage DNA. Non-irradiated phage grown in heavily irradiated uvr + host cells showed non-targeted mutations, which were 3/4 frameshifts, whereas targeted mutations were 2/3 transitions. For non-targeted mutagenesis in heavily irradiated host cells, there were one or two mutant phage per mutant burst. From the results of a series of experiments with various mutant host cells, a major pathway of non-targeted mutagenesis by ultraviolet light was proposed which acts in addition to ''SOS induction''. This pathway involves binding of the enzyme DNA polymerase I to damaged genomic DNA, and low polymerase activity leads to frameshift mutations during semiconservative DNA replication. The data suggest that this process will play a much smaller role in ultraviolet mutagenesis of the bacterial genome than it does in the mutagenesis of lambda phage. (author)

  8. Non-targeted mutagenesis of unirradiated lambda phage in Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.D.; Hutchinson, F. (Yale Univ., New Haven, CT (USA). Dept. of Molecular Biophysics and Biochemistry)

    1984-03-05

    Non-targeted mutagenesis of lambda phage by ultraviolet light is the increase over background mutagenesis when non-irradiated phage are grown in irradiated Escherichia coli host cells. Such mutagenesis is caused by different processes from targeted mutagenesis, in which mutations in irradiated phage are correlated with photoproducts in the phage DNA. Non-irradiated phage grown in heavily irradiated uvr/sup +/ host cells showed non-targeted mutations, which were 3/4 frameshifts, whereas targeted mutations were 2/3 transitions. For non-targeted mutagenesis in heavily irradiated host cells, there were one or two mutant phage per mutant burst. From the results of a series of experiments with various mutant host cells, a major pathway of non-targeted mutagenesis by ultraviolet light was proposed which acts in addition to ''SOS induction''. This pathway involves binding of the enzyme DNA polymerase I to damaged genomic DNA, and low polymerase activity leads to frameshift mutations during semiconservative DNA replication. The data suggest that this process will play a much smaller role in ultraviolet mutagenesis of the bacterial genome than it does in the mutagenesis of lambda phage.

  9. Effect of fast-neutron irradiation on plastic deformation of Type 304 stainless steel

    International Nuclear Information System (INIS)

    Yamada, H.

    1978-01-01

    Plastic deformation of EBR-II-irradiated Type 304 stainless steel was investigated by a stress-relaxation method. The stress-strain-rate relationships for the irradiated specimens at room temperature are concave upward, which are similar to those for the unirradiated specimens. However, concave downward behavior in the stress-strain-rate relationships were observed at much lower temperatures for the irradiated specimens in contrast to the unirradiated specimens. These results were analyzed succccessfully using Hart's mechanical equation-of-state concept. It was found that the hardness sigma*, which is the minimum stress necessary for the dislocation to overcome obstacles without thermal activation, increases linearly with fast-neutron fluence. This increase in sigma* is consistent with so-called ''irradiation hardening.'' In addition, resistance to dislocation glide, which is quantitatively measured in terms of sigma 0 , was observed to decrease linearly with fast-neutron fluence. The decrease in sigma 0 can be attributed to a decrease of solute drag due to irradiation-induced solute segregation

  10. Study of modified polypropylene nanocomposites by gamma irradiation with addition of cloisite clay

    International Nuclear Information System (INIS)

    Komatsu, Luiz G.H.; Oliani, Washington L.; Parra, Duclerc F.; Lugao, Ademar B.

    2011-01-01

    Nanomaterials, and, in particular, nanoreinforcements for polymer composites have been the subject of intense research, development and commercialization. Clay-containing polymeric nanocomposites (CPNCs) are used as either functional or structural materials, large-volume CPNCs with a commodity or engineering polymer as the matrix, where the mechanical behavior is the main concern (followed by gas-vapor barrier properties, flammability, etc.). This work concerns to the study of the mechanical, thermal and morphological behavior nanocomposite, (HMSPP) Polypropylene High Melt Strength (obtained at dose of 12.5 kGy) and addition of 5 and 10 wt% of organoclay with Cloisite 20A nanocomposite. Agent compatibilizer polypropylene-graft, (PP-g-AM) was added at 3% concentration and the clay was dispersed through melt intercalation technique using a twin-screw extruder). We observed an increase in traction rupture. The mechanical behavior was evaluated by strength, the thermal behavior were evaluated by the technique of differential scanning calorimetry, the morphology of the nanocomposites was studied by scanning electron microscopy, melt flow index and Fourier transformed infrared spectroscopy in nanocomposites Cloisite 20 A at 10% wt. (author)

  11. Comparative study of thermoluminescence detection methods for irradiated spices

    International Nuclear Information System (INIS)

    Kawamura, Y.; Kojima, K.; Sugita, T.; Yamada, T.; Saito, Y.

    1995-01-01

    The thermoluminescence (TL) detection methods for irradiated spices were compared using spice samples obtained on the Japanese market, irradiated at doses of 1, 5, 10 and 30 kGy and stored for 1 year before analysis. The TL intensities of irradiated spices were stable for 1 year after irradiation. Measurement with whole samples failed to identify irradiated samples. Minerals were separated from spices in sodium tungstate saturated solution and/or sodium polytungstate solution. The TL intensity of minerals which had undergone irradiation was significantly increased for all samples. However, the ranges of TL intensity of irradiated and unirradiated samples overlapped. Clear discrimination has been obtained between the TL ratios of irradiated and unirradiated spices by using normalized measurement with reirradiation. The detection limit in terms of irradiation dose is 1 kGy even in a sample that has been irradiated 1 year prior to analysis. Normalization is the best technique currently available for thermoluminescence analysis to identify irradiated spices

  12. The use of Citrus tissue culture for mutation breeding. Effects of plant growth substances and gamma irradiation on embryogenesis

    International Nuclear Information System (INIS)

    Kochba, J.; Spiegel-Roy, P.

    1976-01-01

    An embryogenic callus subcultured from unfertilized ovules of the 'Shamouti' orange (Citrus sinensis) was established and is used for mutation-breeding. The callus is habituated and lines of differing embryogenic potential were established. The effect of growth substances and of gamma-irradiation on embryogenesis were studied. Auxins and cytokinins inhibited embryogenesis while inhibitors of auxin synthesis and a cytokinin antagonist significantly stimulate embryogenesis in an embryogenic line. A non-embryogenic callus line did not respond to these treatments. Stimulation of embryogenesis was observed when callus but not when the medium was irradiated. Age of callus prior to subculture and irradiation intensities modify irradiation induced embryogenesis by changing optimal dose range and radiosensitivity of the callus. Addition of IAA to unirradiated medium resulted in increased embryogenesis and greatly stimulated plantlet development in certain combinations of irradiation dose and IAA concentration. (author)

  13. Irradiation of onions on a large scale

    International Nuclear Information System (INIS)

    Kawashima, Koji; Hayashi, Toru; Uozumi, J.; Sugimoto, Toshio; Aoki, Shohei

    1984-01-01

    A large number of onions of var. Kitamiki and Ohotsuku were irradiated in September followed by storage at 0 deg C or 5 deg C. The onions were shifted from cold-storage facilities to room temperature in mid-March or in mid-April in the following year. Their sprouting, rooting, spoilage characteristics and sugar content were observed during storage at room temperature. Most of the unirradiated onions sprouted either outside or inside bulbs during storage at room temperature, and almost all of the irradiated ones showed small buds with browning inside the bulb in mid-April irrespective of the storage temperature. Rooting and/or expansion of bottom were observed in the unirradiated samples. Although the irradiated materials did not have root, they showed expansion of bottom to some extent. Both the irradiated and unirradiated onions spoiled slightly unless they sprouted, and sprouted onions got easily spoiled. There was no difference in the glucose content between the unirradiated and irradiated onions, but the irradiated ones yielded higher sucrose content when stored at room temperature. Irradiation treatment did not have an obvious effect on the quality of freeze-dried onion slices. (author)

  14. Analysis of gamma irradiated pepper constituents, 5

    International Nuclear Information System (INIS)

    Takagi, Kazuko; Okuyama, Tsuneo; Ishikawa, Toshihiro.

    1988-01-01

    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 C 8 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. Microstructural evolution in modified 9Cr-1Mo ferritic/martensitic steel irradiated with mixed high-energy proton and neutron spectra at low temperatures

    International Nuclear Information System (INIS)

    Sencer, B.H.; Garner, F.A.; Gelles, D.S.; Bond, G.M.; Maloy, S.A.

    2002-01-01

    Modified 9Cr-1Mo ferritic/martensitic steel was exposed at 32-57 deg. C to a mixed proton/neutron particle flux and spectrum at the Los Alamos Neutron Science Center. The microstructure of unirradiated 9Cr-1Mo consists of laths, dislocations and carbides. Examination of electron diffraction patterns obtained from extraction replicas of unirradiated 9Cr-1Mo revealed that the precipitate microstructure was primarily dominated by M 23 C 6 carbides. The post-irradiation microstructure contained black-spot damage in addition to precipitates and dislocations. Examination of electron diffraction patterns revealed diffuse rings from M 23 C 6 carbides, indicating amorphization and/or nanocrystallinity. Crystalline MC carbides were also found. No cavity formation was found although a significant amount of helium and hydrogen generation had been generated. TEM-EDS examination of extraction replicas for carbides from unirradiated and irradiated samples did not show any detectable changes in composition of either M 23 C 6 or MC carbides. There was also no evident change in carbide size. Lattice images of M 23 C 6 carbides revealed an amorphous microstructure following irradiation, but MC carbides were still crystalline

  16. Effect of gamma irradiation on chemical composition and nutritive value of sorghum grains

    International Nuclear Information System (INIS)

    Mekkawy, S.H.

    1996-01-01

    Sorghum grains were gamma irradiated at 0, 10, 50, 100, 150 and 200 KGy doses using cobalt-60 source. Irradiated and unirradiated sorghum samples were analyzed for crude fiber contents, total nitrogen, fat, ash and tannic acid. Neutral-detergent fiber (NDF), acid-detergent fiber (ADF) and acid detergent lignin (ADL) were also determined. In addition, digestibility coefficient received special attention. The irradiated sorghum grains were incorporated into basal diets and fed to rats during the digestion trials. The results indicated that gamma irradiation had no effects on total nitrogen, fat and ash contents of sorghum grains. Irradiation treatments of sorghum did not cause a pronounced effect on tannic acid content even those received the highest irradiation dose (200 kGy). Moreover, the irradiation treatments decreased the NDF content of sorghum especially those subjected to 100 or 200 kGy. On the other hand, the ADF and ADL values did not show a remarkable change due to irradiation treatments. Hemicellulose content was decreased with the increase of irradiation dose levels. Also, it was noticed that feeding rats on basal diets enriched with irradiated sorghum grains had a beneficial effects on digestibility coefficient. This trend was obvious with animals supplemented with sorghum grains subjected to the relatively high irradiation dose levels. 4 tabs

  17. Life table of grape phylloxera on some irradiated in vitro cultured rootstocks

    International Nuclear Information System (INIS)

    Makee, H.; Charbaji, T.; Ayyoubi, Z.; Idris, I.

    2008-01-01

    The life table of local strain of grape phylloxera on the most commonly used rootstocks: Ru140, R99 and 3309C and one local variety ''Helwani'' which were in vitro cultured and treated with low doses of gamma irradiation was determined. Additionally, the effect of different concentrations of IAA on reproduction and development of phylloxera, which infested the roots of our local grape variety H elwani , was evaluated. Our results showed that the life table of grape phylloxera was different between irradiated and unirradiated in vitro plants. The survival, fecundity and developmental time were reduced by applying irradiation. Thus, low doses of gamma irradiation increased grape resistance to phylloxera. There was a positive effect of IAA on the resistance of ''Helwani'' to phylloxera when it was infested at old age (80-d-old). However, the susceptible of ''Helwani'' to phylloxera was increased when it was infested at young age (40-d-old). (author)

  18. Mechanical and irradiation properties of zirconium alloys irradiated in HANARO

    International Nuclear Information System (INIS)

    Kwon, Oh Hyun; Eom, Kyong Bo; Kim, Jae Ik; Suh, Jung Min; Jeon, Kyeong Lak

    2011-01-01

    These experimental studies are carried out to build a database for analyzing fuel performance in nuclear power plants. In particular, this study focuses on the mechanical and irradiation properties of three kinds of zirconium alloy (Alloy A, Alloy B and Alloy C) irradiated in the HANARO (High-flux Advanced Neutron Application Reactor), one of the leading multipurpose research reactors in the world. Yield strength and ultimate tensile strength were measured to determine the mechanical properties before and after irradiation, while irradiation growth was measured for the irradiation properties. The samples for irradiation testing are classified by texture. For the irradiation condition, all samples were wrapped into the capsule (07M-13N) and irradiated in the HANARO for about 100 days (E > 1.0 MeV, 1.1 10 21 n/cm 2 ). These tests and results indicate that the mechanical properties of zirconium alloys are similar whether unirradiated or irradiated. Alloy B has shown the highest yield strength and tensile strength properties compared to other alloys in irradiated condition. Even though each of the zirconium alloys has a different alloying content, this content does not seem to affect the mechanical properties under an unirradiated condition and low fluence. And all the alloys have shown the tendency to increase in yield strength and ultimate tensile strength. Transverse specimens of each of the zirconium alloys have a slightly lower irradiation growth tendency than longitudinal specimens. However, for clear analysis of texture effects, further testing under higher irradiation conditions is needed

  19. Detection of 8-hydroxydeoxyguanine in the Irradiated Orange and Spice

    International Nuclear Information System (INIS)

    Alam, Mohammad Khorshed.

    2007-01-01

    A study was carried out to detect the chemical change that might occur in irradiated orange and spice. Oxidative DNA damage can induce the production of 8-hydroxydeoxyguanine (8-OHdG) and thus the level of 8-hydroxydeoxyguanine was investigated using enzyme linked immunosorbent assay (ELISA) in the irradiated orange and spice which was compared with the unirradiated samples. By the difference in the oxidized guanine level that produce 8-hydroxydeoxyguanine in the irradiated and unirradiated samples, it can be clearly understood that detection of irradiated orange and spice is possible using monoclonal antibody for 8-hydroxydeoxyguanine in the ELAISA assay.(author)

  20. Study on the behavior of unirradiated light water reactor fuel with iodine-127 under the reactivity initiated accident (RIA) conditions

    International Nuclear Information System (INIS)

    Sasajima, Hideo; Yanagisawa, Kazuaki; Kanazawa, Hiroyuki

    1988-07-01

    In a light water reactor fuel, a stress arised from pellet-cladding interaction (PCI) will have possibility to cause stress corrosion claddling (PCI failure) under an environment of corrosive fission product ; line iodine. A pulse irradiation experiment by NSRR was carried out to examine whether or not an unirradiated NSRR standard fuel rod in which 1.3 mg (33 x 10 -6 g/cm 2 ) of iodine was artificially filled could cause the PCI failure. Obtained results are: (1) The fuel rods with iodine did not fail both at deposited energy levels of 268 and 280 cal/g · UO 2 . On the other hand, the fuel rods without iodine failed at the same energy levels due to thinning of the cladding wall thickness. Within this experimental scope, PCI-failure did not occur on iodine filled fuel rods. (2) At a periphery of the fuel pellet of iodine filled rod, an uniform torus ring was formed. The torus ring consisted of an equi-axed large grains at 268 cal/g · UO 2 and a columnar ones at 280 cal/g · UO 2 . The torus ring was not formed in the fuel without iodine. (author)

  1. The irradiation effects and processing dose for pet foods decontamination

    International Nuclear Information System (INIS)

    Zhu Jiating; Feng Min; Liu Chunquan; Zhao Yongfu; Jin Yudong; Ji Ping; Ha Yiming; Gao Meixu; Li Shurong; Wang Feng; Zhou Hongjie

    2009-01-01

    The applied dose range of irradiation processing of 4 kinds of pet foods had been studied. More than 92% microorganisms was inactive at the irradiation dose of 4 kGy, while more than 99% was inactive at 6 kGy. The microorganism load of irradiated pet food by 8 kGy met the requirement of national standards. The 10 kGy irradiation could sterilize the treated pet food. Salmonella had not been checked in irradiated or unirradiated samples. When irradiation dose ranged 4-10 kGy, there was no significant difference on contents of moisture, fat, protein, coarse fiber, carbohydrates, minerals (not including Calcium) or amino acids between irradiated and un-irradiated pet food. There was also no significant change on sensory quality of irradiated samples within this dose range. It is concluded that the recommended irradiation processing dose range for pet foods is 4-10 kGy. (authors)

  2. Irradiation effect on onion keeping-quality after sea-shipment from Argentina to the Netherlands

    International Nuclear Information System (INIS)

    Wolters, T.C.; Langerak, D.I.; Curzio, O.A.; Croci, C.A.

    1990-01-01

    Onion losses occur due to sprouting and rot. Onion cultivar Valenciana was irradiated with 60 Gy, shipped from Argentina to the Netherlands, and stored 6 months at 4 degrees C. The rot in unirradiated samples increased after 4 months while rot in irradiated samples remained almost constant. Irradiation almost completely prevented sprouting. Storage losses were 50% for unirradiated and 20% for irradiated samples. Irradiated samples showed an improvement in general appearance. Irradiation reduced weight loss and damaged bulbs were more susceptible to storage rot

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

    International Nuclear Information System (INIS)

    Wu, J.J.; Yang, J.S.

    1994-01-01

    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

  4. Repair of membrane damage in X-irradiated E. coli

    International Nuclear Information System (INIS)

    Gillies, N.E.; Ratnajothi, N.H.; Hewamanna, R.; Obioha, F.I.

    1984-01-01

    When E. coli B/r or E. coli K12 AB1157 were X-irradiated in the presence of oxygen and incubated immediately after irradiation in broth containing penicillin in concentration that on its own was not lethal to unirradiated bacteria, substantial additional killing was caused. When treatment with penicillin was delayed for increasing times after irradiation the additional killing became progressively less. These results were interpreted as demonstrating the repair or removal of oxygen-dependent radiation-induced lesions in the bacterial membranes. Removal of these lesions was inhibited by incubation of the irradiated bacteria at low temperature before treatment with penicillin or by exposing the cells to a non-lethal concentration of toluene before irradiation. These observations suggest that an enzymatic repair process may be involved in the removal of the membrane lesions. The fatty acid mutant E. coli K 1060 proved exceptional in that some additional killing by penicillin was detectable after anaerobic as well as aerobic irradiation. This points to the importance of membrane composition in the development of those radiation lesions that are brought to light by penicillin treatment. (author)

  5. Low cycle fatigue behaviour of neutron irradiated copper alloys at 250 and 350 deg. C

    DEFF Research Database (Denmark)

    Singh, B.N.; Stubbins, J.F.; Toft, P.

    2000-01-01

    V) to influence levels of 1.0 - 1.5 x 1024 n/m2 (E> 1 MeV) at 250 and 350 deg. C. These irradiations were carried out in temperature controlled rigs where the irradiation temperature was monitored and controlledcontinuously throughout the whole irradiation experiment. Both unirradiated and irradiated speciments...

  6. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of aniseed (pimpinella anisum)

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2007-01-01

    Seeds of anise (pimpinella anisum) were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60 Co package irradiator. Irradiated and unirradiated samples were stored at room temperature. Microbial population on seeds, total and inorganic soluble solids in water extract and sensory properties of the latter were evaluated after 0, 6 and 12 months of storage. The results indicated that gamma irradiation reduced the aerobic plate counts of aniseed. Immediately after irradiation, the total soluble solids in an extract of irradiated seeds were greater than those of unirradiated ones. The total soluble solids in an extract of irradiated and un-irradiated seeds increased after 6 and 12 months of storage. There were no significant differences (p>0.05) in inorganic soluble solids between the water extract of irradiated and unirradiated aniseeds. Sensory evaluation indicated that gamma irradiation improved sensory characteristics of aniseed water extract tested immediately after irradiation. However, after 12 months of storage, no significant differences (P>0.05) were found in color, taste or flavor between extract of irradiated and unirradiated seeds. (author)

  7. A review of the rates of reaction of unirradiated uranium in gaseous atmospheres

    International Nuclear Information System (INIS)

    Pearce, R.J.

    1989-10-01

    The review collates available quantitative rate data for the reaction of unirradiated uranium in dry and moist air, steam and carbon dioxide based atmospheres at temperatures ranging from room temperature to above the melting point of uranium. Reactions in nitrogen and carbon monoxide are also considered. The aim of the review is to provide a compilation of base data for the hazard analysis of fault conditions relating to Magnox fuel. (author)

  8. A highway accident involving unirradiated nuclear fuel in Springfield, Massachusetts, on December 16, 1991

    International Nuclear Information System (INIS)

    Carlson, R.W.; Fischer, L.E.

    1992-06-01

    In the early morning of Dec. 16, 1991, a severe accident occurred when a passenger vehicle traveling in the wrong direction collided with a tractor trailer carrying 24 unirradiated nuclear fuel assemblies in 12 containers on Interstate I-91 in Springfield, Massachusetts. The purpose of this report is to document the mechanical circumstances of the severe accident, confirm the nature and quantity of the radioactive materials involved, and assess the physical environment to which the containers were exposed and the response of the containers and their contents. The report consists of five major sections. The first section describes the circumstances and conditions of the accident and the finding of facts. The second describes the containers, the unirradiated nuclear fuel assemblies, and the tie down arrangement used for the trailer. The third describes the damage sustained during the accident to the tractor, trailer, containers, and unirradiated nuclear fuel assemblies. The fourth evaluates the accident environment and its effects on the containers and their contents. The final section gives conclusions derived from the analysis and fact finding investigation. During this severe accident, only minor injuries occurred, and at no time was the public health and safety at risk

  9. Preliminary investigation on the extension of shelf-life of boiled Chub mackerel by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P; Prombubesara, C; Songprasertchai, S

    1971-12-31

    The influence of irradiation on the extension of shelf-life of boiled Chub mackerel stored at room temperature (25-30{sup 0}C) was investigated. It was found that boiled Chub mackerel irradiated at 0.1, 0.2, or 0.3 Mrad could be kept with good organoleptic properties at room temperature for 5, 8, and 11 days respectively; while the unirradiated sample could be kept for only 2 days. Boiled Chub mackerel used in this study was found to be heavily contaminated with microorganisms. Irradiation at doses mentioned caused reduction of more than 99% of bacteria. Bacillus and Acinetobacter were found to predominate in the irradiated boiled mackerel. The predominant flora in unirradiated boiled mackerel included Micrococcus, Staphylococcus, Bacillus, Acinetobacter, and Proteus. E. coli was always detected in unirradiated samples and was occasionally detected only in samples irradiated at 0.1 Mrad. Trimethylamine nitrogen (TMA-N) content, total volatile basic nitrogen (TVB-N) content, and total bacterial count (TBC) were used as indices of decomposition of both irradiated and unirradiated samples. TMA-N and TBC were found to be good indices of quality of only unirradiated boiled Chub mackerel, whereas TVB-N was found to be a good index of quality of both irradiated and unirradiated samples.

  10. Comparison of ring compression testing to three point bend testing for unirradiated ZIRLO cladding

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2015-04-01

    Safe shipment and storage of nuclear reactor discharged fuel requires an understanding of how the fuel may perform under the various conditions that can be encountered. One specific focus of concern is performance during a shipment drop accident. Tests at Savannah River National Laboratory (SRNL) are being performed to characterize the properties of fuel clad relative to a mechanical accident condition such as a container drop. Unirradiated ZIRLO tubing samples have been charged with a range of hydride levels to simulate actual fuel rod levels. Samples of the hydrogen charged tubes were exposed to a radial hydride growth treatment (RHGT) consisting of heating to 400°C, applying initial hoop stresses of 90 to 170 MPa with controlled cooling and producing hydride precipitates. Initial samples have been tested using both a) ring compression test (RCT) which is shown to be sensitive to radial hydride and b) three-point bend tests which are less sensitive to radial hydride effects. Hydrides are generated in Zirconium based fuel cladding as a result of coolant (water) oxidation of the clad, hydrogen release, and a portion of the released (nascent) hydrogen absorbed into the clad and eventually exceeding the hydrogen solubility limit. The orientation of the hydrides relative to the subsequent normal and accident strains has a significant impact on the failure susceptability. In this study the impacts of stress, temperature and hydrogen levels are evaluated in reference to the propensity for hydride reorientation from the circumferential to the radial orientation. In addition the effects of radial hydrides on the Quasi Ductile Brittle Transition Temperature (DBTT) were measured. The results suggest that a) the severity of the radial hydride impact is related to the hydrogen level-peak temperature combination (for example at a peak drying temperature of 400°C; 800 PPM hydrogen has less of an impact/ less radial hydride fraction than 200 PPM hydrogen for the same thermal

  11. A study on density, porosity and grain size of unirradiated ROX fuels and simulated ROX fuels

    International Nuclear Information System (INIS)

    Yanagisawa, Kazuaki; Shirasu, Noriko; Ohmichi, Toshihiko

    1999-05-01

    The unirradiated ROX fuels made of (1) 23wt%PuO 2 -17wt%SZR-56wt%Al 2 O 3 -4wt%MgO (ROX-SZR) and (2) 20wt%PuO 2 -29wt%ThO 2 -48wt%Al 2 O 3 -3wt%MgO (ROX-ThO 2 ) were fabricated by JAERI. Additionally, 9 simulated ROX fuels (used UO 2 instead of PuO 2 ) were fabricated by NFI. Densities, porosity and grain sizes of those were studied. Obtained results are: (1) ROX fuels: The estimated theoretical density (TD) was 5.6g/cc for the ROX-SZR and 6.2g/cc for the ROX-ThO 2 . Those were about half of that in UO 2 (10.96g/cc). As-fabricated density determined was 4.6g/cc (82%TD) for the former and 5.2g/cc (83%TD) for the latter. The %TD of those was low than that of UO 2 (95%TD). One of main reason is that the ROX fuels were sintered at temperature of 1,400degC while UO 2 was sintered at temperature of 1,700degC. The average pore diameter was about 3 μm and the porosity was 17-18%, implying that the ROX fuels were resulted in containing a lot of small pores 2 . As-fabricated density determined in the present study was about 4.5-5.5g/cc. The %TD of the simulated ROX fuels ranged about 94-98%TD. They were in the same as that of UO 2 because as high sintering temperature of 1,750degC as UO 2 . The average pore diameter was about 4-8 μm and the porosity was <6%. Grain size was revealed to be about 1-4 μm. (author)

  12. Thermal analysis applied to irradiated propolis

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Andrea Harumi; Machado, Luci Brocardo; Mastro, N.L. del E-mail: nelida@usp.br

    2002-03-01

    Propolis is a resinous hive product, collected by bees. Raw propolis requires a decontamination procedure and irradiation appears as a promising technique for this purpose. The valuable properties of propolis for food and pharmaceutical industries have led to increasing interest in its technological behavior. Thermal analysis is a chemical analysis that gives information about changes on heating of great importance for technological applications. Ground propolis samples were {sup 60}Co gamma irradiated with 0 and 10 kGy. Thermogravimetry curves shown a similar multi-stage decomposition pattern for both irradiated and unirradiated samples up to 600 deg. C. Similarly, through differential scanning calorimetry , a coincidence of melting point of irradiated and unirradiated samples was found. The results suggest that the irradiation process do not interfere on the thermal properties of propolis when irradiated up to 10 kGy.

  13. On the Thermal Conductivity Change of Matrix Graphite Materials after Neutron Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young-Woo; Yeo, Seunghwan; Kim, Eung-Seon; Sah, Injin; Park, Daegyu; Kim, Youngjun; Cho, Moon Sung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    In this work, the variations of the thermal conductivity of the A3-3 matrix graphite after neutron irradiation is discussed as well as of the IG-110 graphite for comparison. Neutron irradiation of the graphite specimens was carried out as a part of the first irradiation test of KAERI's coated particle fuel specimens by use of Hanaro research reactor. This work can be summarized as follows: 1) In the evaluation of the specific heat of the graphite materials, various literature data were used and the variations of the specific heat data of all the graphite specimens are observed well agreed, irrespectively of the difference in specimens (graphite and matrix graphite and irradiated and un-irradiated). 2) This implies that it should be reasonable that for both structural graphite and fuel matrix graphite, and even for the neuron-irradiated graphite, any of these specific heat data set be used in the calculation of the thermal conductivity. 3) For the irradiated A3-3 matrix graphite specimens, the thermal conductivity decreased on both directions. On the radial direction, the tendency of variation upon temperature is similar to that of unirradiated specimen, i.e., decreasing as the temperature increases. 4) In the German irradiation experiments with A3-27 matrix graphite specimens, the thermal conductivity of the un-irradiated specimen shows a decrease and that of irradiated specimen is nearly constant as the temperature increases. 5) The thermal conductivity of the irradiated IG-110 was considerably decreased compared with that of un-irradiated specimens The difference of the thermal conductivity of un-irradiated and irradiated IG-110 graphite specimens is much larger than that of un-irradiated and irradiated A3-3 matrix graphite specimens.

  14. Effect of the irradiation of bacteria upon their survival rate during conventional methods of meat preservation

    International Nuclear Information System (INIS)

    Szczawinska, M.

    1981-01-01

    The purpose of this paper is to define the effect of irradiation upon the survival rate of non-sporing bacteria (Staphylococcus aureus, Salmonella typhimurium, Escherichia coli, Pseudomonas fluorescens) during basic methods of meat preservation. The bacteria were irradiated in broth by X-rays at a dose that destroyed about 90% of the bacteria (D 10 ). The survival rate of unirradiated and irradiated bacteria during cooling and freezing, in solutions of sodium chloride, nitrates and liquid smoke, was defined. The number of microorganisms was determined directly after irradiation as well as 1, 3, 7, 14, 21 and 28 days after irradiation. The effect of irradiation upon heat resistance of the examined species of bacteria was also defined. The microorganisms were heated in broth, at 70 0 C for 1, 2 and 5 minutes. The obtained results were subjected to statistical analysis. On the basis of the research results, a faster dying rate of irradiated populations of S. aureus and E. coli during any type of preservation treatment, the lack of any reaction to irradiation regarding the survival rate of S. typhimurium, and the lack of any effect of irradiation upon the rate of deterioration of P. fluorescens during freezing and storage in a solution with 10% addition of NaCI, were observed. On the other hand, a pronounced effect of irradiation upon the lowering of the heat resistance of the bacteria, as well as delayed growth in other variants of the experiment, was determined. (author)

  15. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Lan, K.N. [Post-harvest Technology Institute, 4, Ngo Quyen-Ha Noi (Viet Nam); Lam, N.D. [Ha Noi Radiation Center, VAEC, 5T-160, Nghiado, Tuliem, Ha Noi (Viet Nam); Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Preliminary test of mango (Mangifera indica) preservation by irradiated chitosan coating has been investigated. The coating by using irradiated chitosan in 1.5% solution has extended the shelf life of mango from 7 to 15 days. At the 15th day mango coated by irradiated chitosan has been keeping good color, natural ripening, without spoilage, weight loss 10%, whereas the mango without coating was spoiled completely and the coating of fruit with unirradiated chitosan inhibited the ripening. (author)

  16. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Lan, K.N.; Lam, N.D.; Kume, Tamikazu

    2000-01-01

    Preliminary test of mango (Mangifera indica) preservation by irradiated chitosan coating has been investigated. The coating by using irradiated chitosan in 1.5% solution has extended the shelf life of mango from 7 to 15 days. At the 15th day mango coated by irradiated chitosan has been keeping good color, natural ripening, without spoilage, weight loss 10%, whereas the mango without coating was spoiled completely and the coating of fruit with unirradiated chitosan inhibited the ripening. (author)

  17. INFLUENCE OF SOME ANTIMICROBIAL FOOD ADDITIVES AND GAMMA IRRADIATION ON THE FUNGAL STATUS AND ORGANOLEPTIC QUALITY OF LOCAL STORED CHEESE

    International Nuclear Information System (INIS)

    MATTAR, Z.A.

    2008-01-01

    The present investigation was carried out to study the effectiveness of some antimicrobial food additives on the microbial status and organoleptic quality of local cheese stored at 25 0 C for six weeks. Aspergillus flavus, Penicillium citrinum and Aspergillus niger were the predominant genera isolated from cheese samples. Treatment with propionic acid (600 and 1000 ppm), potassium sorbate (2000 and 3000 ppm) and sodium chloride (4 and 8%) decrease significantly the total fungal count of cheese less than 106/g over 4 weeks of storage at 25 0 C. Gamma irradiation with 3 kGy completely inhibited the growth of mycelia and no mycotoxins were detected. Treatment cheese with propionic acid (1000 ppm), potassium sorbate (3000 ppm) and sodium chloride (8%) developed no detectable spoilage odour during 3 weeks of storage at 25 0 C whereas untreated cheese was spoiled between one to two weeks. The results of the present study revealed that the use of the antimicrobial food preservatives play a great role on the inhibition of microorganisms contaminating stored cheese without cussing any organoleptic quality

  18. Studies on the influences of. gamma. -ray irradiation upon food additives, (7). Radiolysis of 5'-nucleotides due to. gamma. -ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, M [Shimonoseki Univ. of Fisheries, Yamaguchi (Japan); Gohya, Y; Ishio, S

    1981-08-01

    The effect of ..gamma..-ray irradiation on inosine-5'-monophosphate (5'-IMP) and guanosine-5'-monophosphate (5'-GMP) in aqueous solution and in ''kamaboko'' was investigated to evaluate the rate of decomposition and to elucidate the safety of the decomposed products, under the concentration of 0.025% and irradiation dose of 3.00 x 10/sup 5/ rad. Ribose-phosphate compound, inorganic phosphate and 2'-, 3'-nucleotides were ascertained when either 5'-IMP or 5'-GMP aqueous solution was irradiated. G value of 5'-IMP and 5'-GMP in aqueous solution were estimated to be 1.29 and 0.97, respectively. The radiolysis of both 5'-IMP and 5'-GMP in ''kamaboko'' was hardly proceeded.

  19. Evaluation of two intracavitary high-dose-rate brachytherapy devices for irradiating additional and irregularly shaped volumes of breast tissue

    International Nuclear Information System (INIS)

    Lu, Sharon M.; Scanderbeg, Daniel J.; Barna, Patrick; Yashar, William; Yashar, Catheryn

    2012-01-01

    The SAVI and Contura breast brachytherapy applicators represent 2 recent advancements in brachytherapy technology that have expanded the number of women eligible for accelerated partial breast irradiation in the treatment of early-stage breast cancer. Early clinical experience with these 2 single-entry, multichannel high-dose-rate brachytherapy devices confirms their ease of use and dosimetric versatility. However, current clinical guidelines for SAVI and Contura brachytherapy may result in a smaller or less optimal volume of treated tissue compared with traditional interstitial brachytherapy. This study evaluates the feasibility of using the SAVI and Contura to irradiate larger and irregularly shaped target volumes, approaching what is treatable with the interstitial technique. To investigate whether additional tissue can be treated, 17 patients treated with the SAVI and 3 with the Contura were selected. For each patient, the planning target volume (PTV) was modified to extend 1.1 cm, 1.3 cm, and 1.5 cm beyond the tumor bed cavity. To evaluate dose conformance to an irregularly shaped target volume, 9 patients treated with the SAVI and 3 with the Contura were selected from the original 20 patients. The following asymmetric PTV margin combinations were assessed for each patient: 1.5/0.3, 1.3/0.3, and 1.1/0.3 cm. For all patients, treatment planning was performed, adopting the National Surgical Adjuvant Breast and Bowel Project guidelines, and dosimetric comparisons were made. The 6–1 and 8–1 SAVI devices can theoretically treat a maximal tissue margin of 1.5 cm and an asymmetric PTV with margins ranging from 0.3 to 1.5 cm. The 10–1 SAVI and Contura can treat a maximal margin of 1.3 cm and 1.1 cm, respectively, and asymmetric PTV with margins ranging from 0.3–1.3 cm. Compared with the Contura, the SAVI demonstrated greater dosimetric flexibility. Risk of developing excessive hot spots increased with the size of the SAVI device. Both the SAVI and Contura

  20. Depth distribution of Frank loop defects formed in ion-irradiated stainless steel and its dependence on Si addition

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dongyue, E-mail: dychen@safety.n.t.u-tokyo.ac.jp [The University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 (Japan); Murakami, Kenta [The University of Tokyo, Nuclear Professional School, School of Engineering, 2-22 Shirakata-Shirane, Tokai-mura, Ibaraki 319-1188 (Japan); Dohi, Kenji; Nishida, Kenji; Soneda, Naoki [Central Research Institute of Electric Power Industry, 2-11-1 Iwado-kita, Komae, Tokyo 201-8511 (Japan); Li, Zhengcao, E-mail: zcli@tsinghua.edu.cn [Tsinghua University, School of Materials Science and Engineering, Beijing 100084 (China); Liu, Li; Sekimura, Naoto [The University of Tokyo, Department of Nuclear Engineering and Management, School of Engineering, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-8656 (Japan)

    2015-12-15

    Although heavy ion irradiation is a good tool to simulate neutron irradiation-induced damages in light water reactor, it produces inhomogeneous defect distribution. Such difference in defect distribution brings difficulty in comparing the microstructure evolution and mechanical degradation between neutron and heavy ion irradiation, and thus needs to be understood. Stainless steel is the typical structural material used in reactor core, and could be taken as an example to study the inhomogeneous defect depth distribution in heavy ion irradiation and its influence on the tested irradiation hardening by nano-indentation. In this work, solution annealed stainless steel model alloys are irradiated by 3 MeV Fe{sup 2+} ions at 400 °C to 3 dpa to produce Frank loops that are mainly interstitial in nature. The silicon content of the model alloys is also tuned to change point defect diffusion, so that the loop depth distribution influenced by diffusion along the irradiation beam direction could be discussed. Results show that in low Si (0% Si) and base Si (0.42% Si) samples the depth distribution of Frank loop density quite well matches the dpa profile calculated by the SRIM code, but in high Si sample (0.95% Si), the loop number density in the near-surface region is very low. One possible explanation could be Si’s role in enhancing the effective vacancy diffusivity, promoting recombination and thus suppressing interstitial Frank loops, especially in the near-surface region, where vacancies concentrate. By considering the loop depth distribution, the tested irradiation hardening is successfully explained by the Orowan model. A hardening coefficient of around 0.30 is obtained for all the three samples. This attempt in interpreting hardening results may make it easier to compare the mechanical degradation between different irradiation experiments.

  1. Protoplast fusion in Streptomyces: fusions involving ultraviolet-irradiated protoplasts

    International Nuclear Information System (INIS)

    Hopwood, D.A.; Wright, H.M.

    1981-01-01

    Protoplasts of Streptomyces coelicolor showed the same ultraviolet killing kinetics as spores. Irradiated protoplasts gave rise to recombinants when they were fused with unirradiated protoplasts of a strain carrying complementary genetic markers. The decline with u.v. fluence in the capacity of irradiated protoplasts to yield recombinants inheriting individual markers was some six times less steep than the survival of unfused protoplasts; thus, for example, protoplasts reduced to only 0.01% survival still yielded 10% as many recombinants as unirradiated protoplasts. Each of six widely separated markers of the irradiated parent was inherited independently of the others, with a frequency falling exponentially with u.v. fluence. (author)

  2. Physico-chemical changes in heavy ions irradiated polymer foils by differential scanning calorimetry

    International Nuclear Information System (INIS)

    Ciesla, K.; Trautmann, Ch.; Vansant, E.F.

    1994-01-01

    The sample of commercial PETP (Hostaphan) and very heavy ions irradiated products were investigated by differential scanning calorimetry in nitrogen flow. Irradiation were performed with Dy ions of 13 MeV/u with fluences 5 x 10 10 ions/cm 2 . Differences were observed in melting behaviour of unirradiated and irradiated foils. The influence of irradiation conditions on the results was noticed. Moreover the samples of polyimide (Kapton) and polycarbonate (Macrofol) irradiated in similar conditions were examined by DSC. The DSC traces have been compared with those of unirradiated reference samples. (author). 8 refs, 5 figs

  3. Bacterial spoilage profiles to identify irradiated fish

    International Nuclear Information System (INIS)

    Alur, M.D.; Venugopal, V.; Nerkar, D.P.; Nair, P.M.

    1991-01-01

    Effects of low dose gamma-irradiation of fish product on spoilage potentials of bacteria (Aeromonas hydrophila, Salmonella typhimurium, Bacillus megaterium, and Pseudomonas marinoglutinosa) and mixed flora were examined for ability to proliferate in radurized fish and produce volatile acids (TVA) and bases (TVBN). Bacteria proliferated well in unirradiated and irradiated fish, but formation of VA and VB were lower in irradiated than unirradiated counterparts. This was found in Bombay duck, Indian mackerel, white pomfret, seer and shrimp gamma-irradiated at 0 to 5 kGy under ice. TVA and TVBN produced by the organisms or mixed flora from fish were only 30-50% those of controls. A method for identifying radiation-processed fish could evolve based on lower susceptibility of irradiated fish to bacterial spoilage

  4. An experimental study of the effect of total lymphoid irradiation on the survival of skin allografts

    International Nuclear Information System (INIS)

    Park, Charn Il; Han, Man Chung

    1981-01-01

    The study was undertaken to determine the effect of fractionated high-dose total lymphoid irradiation (TLI) on the survival of skin allograft despite major histocompatibility difference. Total lymphoid irradiation is a relatively safe form of radiotherapy, has been used extensively to treat lymphoid malignancies in humans with few side effects. A total of 90 rats, Sprague-Dawley rat as recipient and Wistar rat as donor, were used for the experiment, of which 10 rats were used to determine mixed lymphocyte response (MLR) for antigenic difference and skin allografts was performed in 30 rats given total lymphoid irradiation to assess the immunosuppressive effect of total lymphoid irradiation despite major histocompatibility difference. In addition, the peripheral white blood cell counts and the proportion of lymphocytes was studied in 10 rats given total lymphoid irradiation but no skin graft to determine the effects of bone marrow suppression. The results obtained are summarized as follows. 1. The optimum dose of total lymphoid irradiation was between 1800 rads to 2400 rads. 2. The survival of skin graft on rats given total lymphoid irradiation (23.2 ± 6.0 days) was prolonged about three folds as compared to unirradiated control (8.7 ± 1.3 days). 3. Total lymphoid irradiation resulted in a severe leukopenia with marked lymphopenia, but the count was normal by the end of 3rd week. 4. The study suggests that total lymphoid irradiation is a nonlethal procedure that could be used successfully in animals to transplant allograft across major histocompatibility barriers

  5. An experimental study of the effect of total lymphoid irradiation on the survival of skin allografts

    Energy Technology Data Exchange (ETDEWEB)

    Park, Charn Il; Han, Man Chung [College of Medicine, Seoul National University, Seoul (Korea, Republic of)

    1981-06-15

    The study was undertaken to determine the effect of fractionated high-dose total lymphoid irradiation (TLI) on the survival of skin allograft despite major histocompatibility difference. Total lymphoid irradiation is a relatively safe form of radiotherapy, has been used extensively to treat lymphoid malignancies in humans with few side effects. A total of 90 rats, Sprague-Dawley rat as recipient and Wistar rat as donor, were used for the experiment, of which 10 rats were used to determine mixed lymphocyte response (MLR) for antigenic difference and skin allografts was performed in 30 rats given total lymphoid irradiation to assess the immunosuppressive effect of total lymphoid irradiation despite major histocompatibility difference. In addition, the peripheral white blood cell counts and the proportion of lymphocytes was studied in 10 rats given total lymphoid irradiation but no skin graft to determine the effects of bone marrow suppression. The results obtained are summarized as follows. 1. The optimum dose of total lymphoid irradiation was between 1800 rads to 2400 rads. 2. The survival of skin graft on rats given total lymphoid irradiation (23.2 {+-} 6.0 days) was prolonged about three folds as compared to unirradiated control (8.7 {+-} 1.3 days). 3. Total lymphoid irradiation resulted in a severe leukopenia with marked lymphopenia, but the count was normal by the end of 3rd week. 4. The study suggests that total lymphoid irradiation is a nonlethal procedure that could be used successfully in animals to transplant allograft across major histocompatibility barriers.

  6. Plant-scale anodic dissolution of unirradiated N-Reactor fuel

    International Nuclear Information System (INIS)

    Gay, E.C.; Miller, W.E.; Laidler, J.J.

    1995-01-01

    Anodic dissolution tests were made with unirradiated N-Reactor fuel to determine the fuel segment length, diameter, and shape required for high throughput electrorefiner treatment for ultimate disposal in a geologic repository. Based on these tests, a conceptual design was produced of an electrorefiner for a full-scale plant to process N-Reactor spent fuel. In this design, the diameter of an electrode assembly is about 0.6 m (25 in.). Eight of these assemblies in an electrorefiner would accommodate a 1.333-metric-ton batch of N-Reactor fuel. Electrorefining would proceed at a rate of 40 kg uranium per hour

  7. Safety Analysis Report for Packaging: The unirradiated fuel shipping container USA/9853/AF

    International Nuclear Information System (INIS)

    1991-01-01

    The HFBR Unirradiated Fuel Shipping Container was designed and fabricated at the Oak Ridge National Laboratory in 1978 for the transport of fuel for the High Flux Beam Reactor (HFBR) for Brookhaven National Laboratory. The package has been evaluated analytically, as well as the comparison to tests on similar packages, to demonstrate compliance with the applicable regulations governing packages in which radioactive and fissile materials are transported. The contents of this Safety Analysis Report for Packaging (SARP) are based on Regulatory Guide 7.9 (proposed Revision 2 - May 1986), 10 CFR Part 71, DOE Order 1540.2, DOE Order 5480.3, and 49 CFR Part 173

  8. Testicular damage in rats fed on irradiated diets

    International Nuclear Information System (INIS)

    Kushwaha, A.K.S.; Hasan, S.S.

    1986-01-01

    Feeding effect of irradiated diets was studied on the pups born to mother fed either on irradiated normal diet or irradiated low protein diet. The study indicated that pups born to mother fed on the irradiated low protein diet had fewer spermatogonial cells in the testes than those given irradiated normal diet and unirradiated low protein diet. Similarly, pups maintained on the irradiated low protein diet showed marked decrease in alkaline phosphatase and cholesterol contents in the testes rather than in the pups fed irradiated normal as well as unirradiated low protein diets. The irradiated low protein diet fed pups showed increased depletion and vacuolization of adrenocortical and medullary cells. 13 refs., 15 figures. (author)

  9. Testicular damage in rats fed on irradiated diets

    Energy Technology Data Exchange (ETDEWEB)

    Kushwaha, A K.S.; Hasan, S S

    1986-12-01

    Feeding effect of irradiated diets was studied on the pups born to mother fed either on irradiated normal diet or irradiated low protein diet. The study indicated that pups born to mother fed on the irradiated low protein diet had fewer spermatogonial cells in the testes than those given irradiated normal diet and unirradiated low protein diet. Similarly, pups maintained on the irradiated low protein diet showed marked decrease in alkaline phosphatase and cholesterol contents in the testes rather than in the pups fed irradiated normal as well as unirradiated low protein diets. The irradiated low protein diet fed pups showed increased depletion and vacuolization of adrenocortical and medullary cells. 13 refs., 15 figures.

  10. The preliminary studies on parasitization of Trichogramma chilonis on Helicoverpa armigera eggs and eggs from irradiated Helicoverpa armigera moths

    International Nuclear Information System (INIS)

    Wang Endong; Lu Daguang; Liu Xiaohui; Li Yongjun; Zhang Shuyong; Liu Qiongru; Wang Huasong

    2002-01-01

    The parasitization rates of Trichogramma chilonis on 250 Gy irradiated and unirradiated fresh eggs of cotton bollworm, Helicoverpa armigera, were not significantly different. The parasitization rate on irradiated chill-stored eggs of H. armigera was lower than that on irradiated fresh eggs. The parasitization rates on eggs from 250 Gy irradiated H. armigera moths depended on their embryonated rates

  11. Chromosome aberrations in F1 from irradiated male mice studied by their synaptonemal complexes

    International Nuclear Information System (INIS)

    Kalikinskaya, E.I.; Kolomiets, O.L.; Shevchenko, V.A.; Bogdanov, Yu.F.

    1986-01-01

    Possible implications of surface-spread synaptonemal complex (SC) karyotyping in analysing the causes of sterility of F 1 from irradiated male mice are demonstrated in this work. After irradiation by 137 Cs γ-rays at a dose of 5 Gy the males were mated to unirradiated females and genetic analysis of fertility in the F 1 progeny was carried out. Males with abnormal fertility were examined for the presence of chromosome aberrations in diakinesis-metaphase I and in pachytene by the method of surface-spread SC karyotyping. In most cases, SC karyotyping provides additional information and permits the detection and analysis of aberrations that are not revealed in diakinesis. Two reciprocal translocations, one X autosomal and one nonreciprocal translocation were discovered in five F 1 males studied. It is concluded that the method is efficient in detecting translocations in pachytene in partially fertile F 1 hybrids of irradiated and normal mice. (orig.)

  12. Studies on the influences of. gamma. -ray irradiation upon food additives, (6). Radiolysis of monosodium glutamate due to. gamma. -ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, M [Shimonoseki Univ. of Fisheries, Yamaguchi (Japan); Gohya, Y; Ishio, S

    1981-08-01

    The effect of ..gamma..-ray irradiation on monosodium glutamate (MSG) in aqueous solution and in ''kamaboko'' was investigated to evaluate the rate of decomposition of MSG and to elucidate the safety of the decomposed products, under the concentration of 106.9 mmol/l aqueous solution and 1% content of MSG in ''kamaboko''. In aqueous solution, MSG was decomposed by ..gamma..-ray irradiation, and G value was estimated to be 1.24. The decomposition of MSG resulted from deamination reaction was estimated to be 40% of the total decomposition. Glutamic acid content decreased as the dose of ..gamma..-ray increased in MSG-enriched ''kamaboko'', while it increased as the dose of ..gamma..-ray increased in MSG-free ''kamaboko''. Glutamic acid was liberated from the protein in ''kamaboko'', therefore the apparent decomposition rate of MSG in ''kamaboko'' was regarded as lower than actual.

  13. Studies on the influences of. gamma. -ray irradiation upon food additives, (8). Influences of. gamma. -ray irradiation on polyphosphates in aqueous solution and in 'kamaboko'

    Energy Technology Data Exchange (ETDEWEB)

    Hamada, M; Ishio, S [Kyushu Univ., Fukuoka (Japan). Faculty of Agriculture

    1981-08-01

    The effect of ..gamma..-ray irradiation on polyphosphates in aqueous solution and in ''kamaboko'' was investigated to evaluate the rate of decomposition and to examine the safety of the decomposed products. Tripolyphosphate, pyrophosphate and o-phosphate in aqueous solution were very stable against ..gamma..-ray irradiation, respectively. Tripolyphosphate added to ''surimi'' (minced and washed flesh of Alaska Pollack) completely changed to o-phosphate during the period of processing ''kamaboko'', but pyrophosphate was retained. Pyrophosphate content in ''kamaboko'' decreased in proportion to the dose of ..gamma..-ray. Decreased pyrophosphate was presumed to change into such products as insolubles which can not be extracted with 6% per chloric acid solution. Both tripolyphosphate and pyrophosphate changed enzymatically to o-phosphate. The activity of exopolyphosphatase in ''surimi'' was still retained. Polyphosphates added to ''surimi'' changed completely to o-phosphate during the frozen storage of ''surimi'', therefore, the application of ..gamma..-ray irradiation on ''kamaboko'' was considered not to induce any injurious substances from polyphosphates.

  14. Nonane as a radiolytic product in irradiated bacon

    International Nuclear Information System (INIS)

    Singh, H.; Guerrero, A.; Kremers, W.

    1993-01-01

    Formation of nonane in irradiated bacon has been confirmed by gas chromatographic/mass spectrometric (GC/MS) analysis of irradiated nitrogen-flushed homogenized bacon in scaled glass vials. Unirradiated bacon did not show the presence of nonane under similar conditions

  15. Thermal Decompositon Studies Of Pre-Irradiated Nickel (II) Azides ...

    African Journals Online (AJOL)

    The effect of pre-irradiation on the thermal decomposition of three samples of nickel (II) azide was studied. It was found that the rates of thermal decomposition of Ni(OH)N3 increased substantially with increase in pre-irradiation dosage. The initial reaction rates change from time-dependant nucleation law for the unirradiated ...

  16. Survival and mutagenesis in UV-irradiated phage: Multi-hit kinetics of mutation induction and lack of indirect induction by infection with UV-irradiated phage of error-prone repair

    International Nuclear Information System (INIS)

    Krauss, G.; Mennigmann, H.D.; Kaplan, R.W.

    1980-01-01

    The paper is concerned with the question of whether Weigle-reactivation (WR) and Weigle-mutagenesis (WM) can be indirectly induced by infection with UV-irradiated phage. Experiments neither with phage lambda of Escherichia coli nor with phage kappa of Serratia marcescens show such induction. In this respect phage DNA differs from F'-DNA or Hfr-DNA; possible explanations are discussed. In both systems clear plaque mutations can also be induced by UV without irradiation of the host cells; they appear, in unirradiated and irradiated host cells, with an increase in frequency which is greater than proportional to the UV dose. It is concluded that mutation induction of phage in the unirradiated host cells is due to a low level constitutive mutagenic repair; this could either be due to 'spontaneous' induction of the mutagenic SOS function or it could be a mechanism different from this one. Host irradiation would give rise to additional activity by the induced SOS function leading to WR and WM. It is further concluded that deviation of the induction kinetics from a linear dose-dependence is not due to the necessary induction of SOS functions. (author)

  17. Evaluation of irradiation hardening of proton irradiated stainless steels by nanoindentation

    International Nuclear Information System (INIS)

    Yabuuchi, Kiyohiro; Kuribayashi, Yutaka; Nogami, Shuhei; Kasada, Ryuta; Hasegawa, Akira

    2014-01-01

    Ion irradiation experiments are useful for investigating irradiation damage. However, estimating the irradiation hardening of ion-irradiated materials is challenging because of the shallow damage induced region. Therefore, the purpose of this study is to prove usefulness of nanoindentation technique for estimation of irradiation hardening for ion-irradiated materials. SUS316L austenitic stainless steel was used and it was irradiated by 1 MeV H + ions to a nominal displacement damage of 0.1, 0.3, 1, and 8 dpa at 573 K. The irradiation hardness of the irradiated specimens were measured and analyzed by Nix–Gao model. The indentation size effect was observed in both unirradiated and irradiated specimens. The hardness of the irradiated specimens changed significantly at certain indentation depths. The depth at which the hardness varied indicated that the region deformed by the indenter had reached the boundary between the irradiated and unirradiated regions. The hardness of the irradiated region was proportional to the inverse of the indentation depth in the Nix–Gao plot. The bulk hardness of the irradiated region, H 0 , estimated by the Nix–Gao plot and Vickers hardness were found to be related to each other, and the relationship could be described by the equation, HV = 0.76H 0 . Thus, the nanoindentation technique demonstrated in this study is valuable for measuring irradiation hardening in ion-irradiated materials

  18. Irradiation of onions with the commercial potato irradiator

    International Nuclear Information System (INIS)

    Aoki, Shohei; Kawashima, Koji; Hayasi, Toru

    1983-01-01

    Three varieties of onion harvested in Hokkaido were irradiated with the Shohoro Potato Irradiator on 29th September, 1981. One ton of each of the varieties, Kitamiki (KI), Ohohtsuku (OH) and Furanui (FU), was used in this investigation. Onions had longer dormancy period in the order of FU>OH>KI. Higher sprouting percentage was obtained in the unirradiated onions, while they were stored at a higher temperature or stored for a longer period. Generally, unirradiated onions sprouted before they were deteriorated. Thus the number of deteriorated bulbs in the unirradiated onions was superficially less than that in the irradiated ones. When the onions which were taken from warehouses on 26th March, 1982 were stored at room temperature, the percentage of wholesome bulbs was higher in KI and OH than FU. Small buds in some of the irradiated onions turned dark after a long storage time. Quantitative estimation of this phenomena is left to be resolved. There was little relationship between the weight loss and the number of wholesome onions. (author)

  19. The role of food irradiation in terms of value addition and extension of shelf life of agri. materials (from FARM to Consumer)

    International Nuclear Information System (INIS)

    Prakash, V.

    2001-01-01

    Today, with the advent of modern processing techniques in the area of value addition to agri resources, food irradiation has made a big dent in terms of extension of shelf life and confidence of making the food free from microbial and other contaminants and need to be really harnessed more than what we are doing. However, there is still certain amount of stigma attached to this technology not because the technology is un-ripe but it is because of lack of awareness with the masses as regards to the safety of the foods that are processed by irradiation

  20. Study on creep-fatigue life of irradiated austenitic stainless steel

    International Nuclear Information System (INIS)

    Ioka, Ikuo; Miwa, Yukio; Tsuji, Hirokazu; Yonekawa, Minoru; Takada, Fumiki; Hoshiya, Taiji

    2001-01-01

    The low cycle creep-fatigue test with tensile strain hold of the austenitic stainless steel irradiated to 2 dpa was carried out at 823K in vacuum. The applicability of creep-fatigue life prediction methods to the irradiated specimen was examined. The fatigue life on the irradiated specimen without tensile strain hold time was reduced by a factor of 2-5 in comparison with the unirradiated specimen. The decline in fatigue life of the irradiated specimen with tensile strain hold was almost equal to that of the unirradiated specimen. The creep damage of both unirradiated and irradiated specimens was underestimated by the time fraction rule or the ductility exhaustion rule. The creep damage calculated by the time fraction rule or the ductility exhaustion rule increased by the irradiation. The predictions derived from the linear damage rule are unsafe as compared with the experimental fatigue lives. (author)

  1. Effects of grafts of single anterior pituitary glands on the incidence and type of mammary neoplasm in neutron- or γ-irradiated Fischer female rats

    International Nuclear Information System (INIS)

    Clifton, K.H.; Douple, E.B.; Sridharan, B.N.

    1976-01-01

    Three batches comprised of 48 young adult Fischer female rats each were subjected to total-body irradiation with 50 rads modified fission neutrons, or were given 600 rads 137 Cs γ-rays, or served as unirradiated controls. On the day following exposure, one-half of each batch was grafted with a single anterior pituitary gland beneath the left kidney capsule. The animals were observed for mammary neoplasia and all those that died during the experiment were autopsied. The experiment was terminated 538 +- 13 days after irradiation when all neutron-irradiated, pituitary-grafted animals had one or more mammary tumors. Only 2 of the 23 untreated rats that survived until termination of the experiment developed mammary fibroadenomas, and none had mammary carcinomas. The incidence of fibroadenomas was increased, and a single carcinoma was found in unirradiated rats with pituitary grafts. Irradiation alone caused an increase in the incidence of mammary fibroadenomas and the appearance of carcinomas. Fibroadenomas were markedly increased by the addition of pituitary grafts to irradiation. Carcinoma incidence was less markedly affected. The neutron dose of 50 rads was slightly more effective in inducing mammary neoplasms than the 600-rad dose of γ-rays

  2. Dissolution of unirradiated UO{sub 2} fuel in synthetic groundwater. Final report (1996-1998)

    Energy Technology Data Exchange (ETDEWEB)

    Ollila, K. [VTT Chemical Technology, Espoo (Finland)

    1999-05-01

    This study was a part of the EU R and D programme 1994-1998: Nuclear Fission Safety, entitled `Source term for performance assessment of spent fuel as a waste form`. The research carried out at VTT Chemical Technology was focused on the effects of granitic groundwater composition and redox conditions on UO{sub 2} solubility and dissolution mechanisms. The synthetic groundwater compositions simulated deep granitic fresh and saline groundwaters, and the effects of the near-field material, bentonite, on very saline groundwater. Additionally, the Spanish granite/bentonite water was used. The redox conditions (Eh), which are obviously the most important factors that influence on UO{sub 2} solubility under the disposal conditions of spent fuel, varied from strongly oxidising (air-saturated), anaerobic (N{sub 2}, O{sub 2} < l ppm) to reducing (N{sub 2}, low Eh). The objective of the air-saturated dissolution experiments was to yield the maximum solution concentrations of U, and information on the formation of secondary phases that control the concentrations, with different groundwater compositions. The static batch solubility experiments of long duration (up to 1-2 years) were performed using unirradiated UO{sub 2} pellets and powder. Under anaerobic and reducing conditions, the solubilities were also approached from oversaturation. The results of the oxic, air-saturated dissolution experiments with UO{sub 2} powder showed that the increase in the salinity (< 1.7 M) had a minor effect on the measured steady-state concentrations of U. The concentrations, (1.2 ...2.5) x 10{sup -5} M, were at the level of the theoretical solubility of schoepite or another uranyl oxide hydrate, e.g. becquerelite (possibly Na-polyuranate). The higher alkalinity of the fresh (Allard) composition increased the aqueous U concentration. Only some kind of oxidised U-phase (U{sub 3}O{sub 8}-UO{sub 3}) was identified with XRD when studying possible secondary phases after the contact time of one year

  3. Dissolution of unirradiated UO2 fuel in synthetic groundwater. Final report (1996-1998)

    International Nuclear Information System (INIS)

    Ollila, K.

    1999-05-01

    This study was a part of the EU R and D programme 1994-1998: Nuclear Fission Safety, entitled 'Source term for performance assessment of spent fuel as a waste form'. The research carried out at VTT Chemical Technology was focused on the effects of granitic groundwater composition and redox conditions on UO 2 solubility and dissolution mechanisms. The synthetic groundwater compositions simulated deep granitic fresh and saline groundwaters, and the effects of the near-field material, bentonite, on very saline groundwater. Additionally, the Spanish granite/bentonite water was used. The redox conditions (Eh), which are obviously the most important factors that influence on UO 2 solubility under the disposal conditions of spent fuel, varied from strongly oxidising (air-saturated), anaerobic (N 2 , O 2 2 , low Eh). The objective of the air-saturated dissolution experiments was to yield the maximum solution concentrations of U, and information on the formation of secondary phases that control the concentrations, with different groundwater compositions. The static batch solubility experiments of long duration (up to 1-2 years) were performed using unirradiated UO 2 pellets and powder. Under anaerobic and reducing conditions, the solubilities were also approached from oversaturation. The results of the oxic, air-saturated dissolution experiments with UO 2 powder showed that the increase in the salinity ( -5 M, were at the level of the theoretical solubility of schoepite or another uranyl oxide hydrate, e.g. becquerelite (possibly Na-polyuranate). The higher alkalinity of the fresh (Allard) composition increased the aqueous U concentration. Only some kind of oxidised U-phase (U 3 O 8 -UO 3 ) was identified with XRD when studying possible secondary phases after the contact time of one year with all groundwater compositions. Longer contact times are needed to identify secondary phases predicted by modelling (EQ3/6). In the anoxic dissolution experiments with UO 2 pellets, the

  4. Modification of water absorption capacity of a plastic based on bean protein using gamma irradiated starches as additives

    International Nuclear Information System (INIS)

    Koeber, E.; Gonzalez, M.E.; Gavioli, N.; Salmoral, E.M.

    2007-01-01

    Some properties of a bean protein-starch plastic were modified by irradiation of the starch. Two kinds of starch from bean and cassava were irradiated with doses until 50 kGy before their inclusion in the composite. Water absorption of the resultant product was reduced by 36% and 60% in materials containing bean and cassava starch, respectively. A large decline in the elongation is observed till 10 kGy in both materials, while tensile strength diminished by 11% in the cassava composite

  5. Effects of irradiation on the volatile compounds of garlic (Allium sativum L)

    International Nuclear Information System (INIS)

    Wu, J.J.; Yang, J.S.; Liu, M.S.

    1996-01-01

    The effects of 0.15 kGy gamma irradiation on the content of volatile compounds in garlic bulbs during storage at room temperature were evaluated. The content of diallyl disulphide decreased immediately after irradiation. However, at the end of 8-month storage both irradiated and unirradiated samples showed a significant increase in diallyl disulphide

  6. In vivo UVB irradiation induces clustering of Fas (CD95) on human epidermal cells

    DEFF Research Database (Denmark)

    Bang, Bo; Gniadecki, Robert; Larsen, Jørgen K

    2003-01-01

    a single dose of UVB irradiation. Normal healthy individuals were irradiated with three minimal erythema doses (MED) of UVB on forearm or buttock skin. Suction blisters from unirradiated and irradiated skin were raised, and Fas, FasL, and apoptosis of epidermal cells quantified by flow cytometry...

  7. Positron annihilation and Moessbauer studies of neutron irradiated reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Brauer, G.; Matz, W.; Liszkay, L.; Molnar, B.

    1990-11-01

    Positron annihilation (lifetime, Doppler broadening) and Moessbauer studies on unirradiated, neutron irradiated and neutron irradiated plus annealed reactor pressure vessel steels (Soviet type 15Kh2NMFA) are presented. The role of microstructural properties and the formation of irradiation-induced precipitates is discussed. (orig.) [de

  8. Permeabilization of ultraviolet-irradiated chinese hamster cells with polyethylene glycol and introduction of ultraviolet endonuclease from Micrococcus luteus

    International Nuclear Information System (INIS)

    Yarosh, D.B.; Setlow, R.B.

    1981-01-01

    Chinese hamster V-79 cells were made permeable by treatment with polyethylene glycol and then incubated with a Micrococcus luteus extract containing ultraviolet-specific endonuclease activity. This treatment introduced nicks in irradiated, but not in unirradiated, deoxyribonucleic acid. The nicks remained open for at least 3 h; there was no loss of endonuclease-sensitive sites, and no excision of dimers as measured by chromatography was detected. In addition, there was no increase in ultraviolet resistance in treated cells. This suggests that the absence of a significant amount of excision repair in rodent cells is due to the lack of both incision and excision capacity

  9. Microstructural characterization of second phase irradiated Zircaloy-4 particles

    International Nuclear Information System (INIS)

    Flores, Alejandra V.; Vizcaino, Pablo; Banchik, Abraham D.; Bozzano, Patricia B.; Versaci, Raul A.

    2007-01-01

    X-ray diffraction diagrams of neutron irradiated Zircaloy-4 were obtained at the LNLS with the aim to obtain bulk information about the amorphization process in which the Zircaloy-4 second phase particles (SPPs) undergoes due to neutron irradiation. Owing to the low concentration of the SPPs in the alloy (∼0.4 V %), no data regarding to the bulk were obtained until now. The synchrotron experiences allowed to detect five of the more intense lines of the phase C 14 (SPPs structure) in unirradiated Zircaloy-4: (110) θ, (103) θ, (112) θ, (201) θ and (004) θ in the 34 degrees ≤ θ2≤45 degrees Bragg angle range and others of minor intensity. The diagrams of the samples irradiated at moderate doses (1020n/cm 2 ) show these lines even in the as received samples. In contrast, none of these lines are observed for high fluence samples (∼1022neutrons/cm 2 ). In addition, in similar high fluence samples annealed 24 h or 72 h at 600 C degrees the intensity rises just at the 2q range where the C 14 lines were observed, showing a wide peak. That peak is interpreted as a result of the superposition of unresolved diffraction lines corresponding to the Zircaloy SPPs which are in a reconstitution process of crystallization. Analytical Electron Microscopy techniques were used, in order to study the effects on the Zircaloy-4 SPPs and compared with samples of the same material without irradiation. Spots in SAD patterns of non irradiated SPPS, evidences the presence of a C 14 structure, but in irradiated SSP SAD patterns evidences the beginning of an amorphization process. Another important feature to point out is the different Fe / Cr ratio presented in both irradiated and non irradiated SSPs. In non irradiated precipitates the Fe / Cr ratio is approximately 1.5, while in irradiated precipitates the Fe / Cr ratio becomes near 1.0. (author) [es

  10. Protein aggregation in aqueous casein solution. Effect of irradiation, dose level, concentration, storage and additives (carbohydrate and lipid)

    Energy Technology Data Exchange (ETDEWEB)

    Yousri, R M

    1980-06-01

    From the vast amount of research efforts dealing with various aspects of radiation effects on foods and food components, it is apparent up to now that much remains to be studied in depth, much may have to be added or corrected about radiation-induced physico-chemical changes in foods. A great many reactions that take place when foodstuffs are subjected to ionizing radiation are still not fully understood. The better understanding of some of the radiation-induced changes in pure proteins as such or in mixture with other food constituents could yield much data which could be meaningfully extrapolated to intact foods and consequently could help to improve the assessment of the wholesomeness of irradiated foods. It was the purpose of our investigations to elucidate some of the changes in the chemical structure of a pure protein (casein), irradiated as such or with added carbohydrate and/or lipid. The effect of subsequent storage of the irradiated solutions has been also examined. The formation of protein aggregates was studied by gel filtration technique. The application of thin-layer gel filtration, its speed and adaptability to very small samples facilitated the measurements of the extent of aggregation which occurred in protein molecules after irradiation.

  11. The lethal interaction of x ray and penicillin induced lesions following x-irradiation of Escherichia coli B/r in the presence of hypoxic cell sensitizers

    International Nuclear Information System (INIS)

    Gillies, N.E.; Obioha, F.I.

    1982-01-01

    When Escherichia coli B/r were x-irradiated under anoxia in the presence of different electron-affinic sensitizers and then incubated in broth containing penicillin (at a concentration that did not kill unirradiated cells) additional killing of the bacteria occurred provided the sensitizers were of relatively high lipophilicity. The overall effect was to increase the efficiency of these sensitizers. It is concluded that sensitizer-dependent latent radiation lesions(s) are produced in membrane components of the cell envelope that interact with damage caused by penicillin in the peptidoglycan layer and this causes the additional lethality

  12. Identification of irradiated pasteurized egg products: a combined method to use in routine control

    International Nuclear Information System (INIS)

    Helle, N.; Schulzki, G.; Linke, B.; Spiegelberg, A.; Boegl, K.W.; Schreiber, G.A.; Grabowski, H.U. v.; Pfordt, J.; Mauermann, U.; Juelicher, S.; Bischoff, C.; Vater, N.; Heitmann, M.

    1993-01-01

    Pasteurized egg products (whole egg, egg yolk and egg white) were tested for irradiation treatment in the German food control laboratories in Oldenburg/Niedersachsen and Kassel/Hessen as well as in the food irradiation laboratory of the German federal health office. Gas chromatographic/mass spectrometric measurements on the fat components of egg-products showed clearly whether the product had been irradiated or not. While in unirradiated samples no traces of special hydrocarbons (according to the fatty acid composition of egg) and no traces of the irradiation-specific compound 2-Dodecyl-cyclobutanone were found, irradiated control samples as well as products of two belgian suppliers contained these substances. Additionally, regarding the rather high time consumption of gas chromatography, electron spin resonance (ESR)-measurements were carried out on the packaging material of egg products. Irradiated packaging material (cellulose) could be easily detected by the appearance of a signal pair in the ESR spectrum (cellulose radical). ESR measurements are very fast and easy to perform so that this method can be used for screening. Microbiological investigations showed remarkably reduced total numbers of microorganisms for some irradiated samples, but the microbiological status is influenced by other factors like storage-time and -temperature, so that microbiological tests can not be used successfully for screening on irradiation treatment [de

  13. Repair and mutagenesis of herpes simplex virus in UV-irradiated monkey cells

    International Nuclear Information System (INIS)

    Lytle, C.D.; Goddard, J.G.; Lin, C.H.

    1980-01-01

    Mutagenic repair in mammalian cells was investigated by determining the mutagenesis of UV-irradiated or unirradiated herpes simplex virus in UV-irradiated CV-1 monkey kidney cells. These results were compared with the results for UV-enhanced virus reactivation (UVER) in the same experimental situation. High and low multiplicities of infection were used to determine the effects of multiplicity reactivation (MR). UVER and MR were readily demonstrable and were approximately equal in amount in an infectious center assay. For this study, a forward-mutation assay was developed to detect virus mutants resistant to iododeoxycytidine (ICdR), probably an indication of the mutant virus being defective at its thymidine kinase locus. ICdR-resistant mutants did not have a growth advantage over wild-type virus in irradiated or unirradiated cells. Thus, higher fractions of mutant virus indicated greater mutagenesis during virus repair and/or replication. The data showed that: (1) unirradiated virus was mutated in unirradiated cells, providing a background level of mutagenesis; (2) unirradiated virus was mutated about 40% more in irradiated cells, indicating that virus replication (DNA synthesis) became more mutagenic as a result of cell irradiation; (3) irradiated virus was mutated much more (about 6-fold) than unirradiated virus, even in unirradiated cells; (4) cell irradiation did not change the mutagenesis of irradiated virus except at high multiplicity of infection. High multiplicity of infection did not demonstrate UVER or MR alone to be either error-free or error-prone. When the two processes were present simultaneously, they were mutagenic. (orig.)

  14. Identification of irradiated pepper by ESR measurement

    International Nuclear Information System (INIS)

    Morishita, Norio; Kume, Tamikazu; Kawakami, Waichiro; Ishigaki, Isao

    1988-01-01

    The possibility of using electron spin resonance (ESR) for identification of irradiated black and white pepper was examined. The ESR spectra induced by irradiation with 10 kGy are clearly distinguishable from that of unirradiated samples. The intensity of signal induced by irradiation was markedly reduced during 2 weeks storage but it was slowly reduced on further storage. The difference of intensity between the irradiated and unirradiated samples can be distinguished after 13 weeks storage. In this experiment, ground black pepper, ground white pepper and whole white pepper can be identified after 13 weeks. On the other hand, whole black pepper cannot be identified after 8 weeks because of the variation of values. It suggests that the suitable method for sample preparation such as separation of pellicle of whole black pepper is required before ESR measurement. (author)

  15. Stress corrosion testing of irradiated cladding tubes

    International Nuclear Information System (INIS)

    Lunde, L.; Olshausen, K.D.

    1980-01-01

    Samples from two fuel rods with different cladding have been stress corrosion tested by closed-end argon-iodine pressurization at 320 0 C. The fuel rods with stress relieved and recrystallized Zircaloy-2 had received burnups of 10.000 and 20.000 MWd/ton UO 2 , respectively. It was found that the SCC failure stress was unchanged or slightly higher for the irradiated than for the unirradiated control tubes. The tubes failed consistently in the end with the lowest irradiation dose. The diameter increase of the irradiated cladding during the test was 1.1% for the stress-relieved samples and 0.24% for the recrystallized samples. SEM examination revealed no major differences between irradiated and unirradiated cladding. A ''semi-ductile'' fracture zone in recrystallized material is described in some detail. (author)

  16. [Identification of irradiated abalone by ESR spectroscopy].

    Science.gov (United States)

    Song, Yeping; Wang, Chuanxian; Yang, Zhenyu; Zhong, Weike; Geng, Jinpei; Lu, Di; Ding, Zhuoping

    2012-05-01

    To establish an analytical method for the detection and identification of irradiated abalone by electron spin resonance spectroscopy. Electron spin resonance (ESR) was used to study the spectral characteristics of abalone and the characteristic peak for quantitation. There were obvious different ESR spectra between unirradiated and irradiated abalone. The g factor for unirradiated abalone was 2.0055-2.0060, the g1 and g2 factor for irradiated abalone were (2.0027 +/- 0.0001) and (1.9994 +/- 0.0001), respectively. The ESR signal intensity of characteristic peak was positively correlated with absorbed dose in the range of 0.5 - 10 kGy, left peak was the characteristic peak for quantitation and the detection limit was abalone. ESR spectroscopy is an effective method to determine whether the abalone being irradiated or not.

  17. Effects of gamma irradiation dose and timing of treatment after harvest on the storeability of garlic bulbs

    International Nuclear Information System (INIS)

    Kwon, J.H.; Byun, M.W.; Cho, H.O.

    1985-01-01

    The effect of gamma irradiation dose and time of treatment after harvest on the storage of garlic bulbs was investigated. The effectiveness of irradiation for external sprout inhibition was not affected by the treatment time within 45 days after harvest. At 285 days after harvest, irradiation of 50 - 150 Gy caused about 6% less decrease in weight loss compared with the unirradiated group, and spoilage rates of the unirradiated and irradiated cloves were 100% and 17 - 20%, respectively. For the overall storageability of garlic bulbs, 75 Gy was shown to be the minimal optimum dose, and there was no apparent effect depending upon the time of irradiation treatment after harvest

  18. Storage of irradiated strawberry fruits

    International Nuclear Information System (INIS)

    Popova, L.

    1977-01-01

    Pocahontas strawberries both of green house and field production have been stored at 3 deg C for 10 and 12 days, respectively, after treatment with 100000, 200000 and 300000 Roe in comparison with unirradiated fruits. No explicit correlation was observed regarding the keeping qualities of fruits, their chemical composition (dry matter, sugars, acids and vitamin C) when stored after a different gamma-ray irradiation. (S.P.)

  19. In-vitro Degradation Behaviour of Irradiated Bacterial Cellulose Membrane

    International Nuclear Information System (INIS)

    Darwis, D.; Khusniya, T.; Hardiningsih, L.; Nurlidar, F.; Winarno, H.

    2012-01-01

    Bacterial cellulose membrane synthesized by Acetobacter xylinum in coconut water medium has potential application for Guided bone Regeneration. However, this membrane may not meet some application requirements due to its low biodegradation properties. In this paper, incorporation of gamma irradiation into the membrane is a developed strategy to increase its biodegradability properties. The in-vitro degradation study in synthetic body fluid (SBF) of the irradiated membrane has been analyzed during periods of 6 months by means of weight loss, mechanical properties and scanning electron microscopy observation compared to that the un-irradiated one. The result showed that weight loss of irradiated membrane with 25 kGy and 50 kGy and immersed in SBF solution for 6 months reached 18% and 25% respectively. While un-irradiated membrane did not give significant weight loss. Tensile strength of membranes decreases with increasing of irradiation dose and further decreases in tensile strength is observed when irradiated membrane was followed by immersion in SBF solution. Microscope electron image of cellulose membranes shows that un-irradiated bacterial cellulose membrane consists of dense ultrafine fibril network structures, while irradiation result in cleavage of fibrils network of cellulose. The fibrils network become loosely after irradiated membrane immersed in SBF solution due to released of small molecular weight carbohydrates formed during by irradiation from the structure (author)

  20. Detection of irradiated potatoes by impedance measurements

    International Nuclear Information System (INIS)

    Hayashi, Toru; Sugiyama, Junnichi; Otobe, Kazuki; Todoriki, Setsuko

    1993-01-01

    The impedance ratio at 5kHz to 50kHz (Z 6K /Z 50K ) determined at 22degC at an apical region of potato tuber which was pre-incubated at 22degC for 3 days or longer resulted in the best detection of radian treatment. Irradiated potatoes of 10 cultivars could be detected with this method, and potatoes 'Danshaku' commercially irradiated at Shihoro could be distinguished from unirradiated 'Danshaku'. (author)

  1. Erythrokinetics in mice bearing tumours in either preirradiated or unirradiated tissue

    International Nuclear Information System (INIS)

    Jirtle, R.L.; Clifton, K.H.

    1978-01-01

    Experiments were designed to clarify the causes of anaemia in hosts bearing tumours in either unirradiated or preirradiated tissue. Isotopic methods are described which enable the estimation of erythrocyte destruction and production rates, and the potential red cell life spans in tumour-bearing animals. In this experimental system, anaemia (a) is in large part due to accelerated random erythrocyte loss, (b) is exacerbated as tumours grow by a progressive reduction in the potential erythrocyte life span due to intrinsic erythrocyte defects. (c) is accompanied by an increase in erythrocyte production of six- to ten-fold and (d) is postponed in onset and decreased in magnitude by preirradiation of the tumour transplant site. (author)

  2. Effect of helium pressure on the response of unirradiated UO2 subjected to thermal transients

    International Nuclear Information System (INIS)

    Fenske, G.R.; Chapello, P.M.; Emerson, J.E.; Poeppel, R.B.

    1983-01-01

    The effect of helium pressure on the transient response of unirradiated depleted UO 2 subjected to simulated hypothetical loss-of-flow accidents in a gas-cooled fast reactor was examined by use of the direct electrical heating technique. Transient tests were performed at pressures ranging from 7 to 10 X 10 5 Pa(7 to 10 atm) to 7 to 8 MPa (70 to 80 atm) on radially restrained and unrestrained fuel segments. The average heating rates ranged from about17 to 240 J/g x s. The results indicate that while the mechanical integrity of the fuel segment was independent of the test pressure, the rapid ejection of molten fuel from pellet interfaces of unrestrained fuel, observed at the lower pressures, was delayed or suppressed at the higher pressures

  3. Plant-scale anodic dissolution of unirradiated N-Reactor fuel

    International Nuclear Information System (INIS)

    Gay, E.C.; Miller, W.E.; Laidler, J.J.

    1995-01-01

    Anodic dissolution tests were made with unirradiated N-Reactor fuel to determine the fuel segment length, diameter, and shape required for high throughput electro-refiner treatment for ultimate disposal in a geologic repository. Based on these tests, a conceptual design was produced of an electro-refiner for a full-scale plant to process N-Reactor spent fuel. In this design, the diameter of an electrode assembly is about 0.6 m (25 in.). Eight of these assemblies in an electro-refiner would accommodate a 1.333-metric-ton batch of N-Reactor fuel. Electrorefining would proceed at a rate of 40 kg uranium per hour. (author)

  4. Erythrokinetics in mice bearing tumours in either preirradiated or unirradiated tissue

    Energy Technology Data Exchange (ETDEWEB)

    Jirtle, R L; Clifton, K H [Wisconsin Univ., Madison (USA). Div. of Clinical Oncology

    1978-11-01

    Experiments were designed to clarify the causes of anaemia in hosts bearing tumours in either unirradiated or preirradiated tissue. Isotopic methods are described which enable the estimation of erythrocyte destruction and production rates, and the potential red cell life spans in tumour-bearing animals. In this experimental system, anaemia (a) is in large part due to accelerated random erythrocyte loss, (b) is exacerbated as tumours grow by a progressive reduction in the potential erythrocyte life span due to intrinsic erythrocyte defects. (c) is accompanied by an increase in erythrocyte production of six- to ten-fold and (d) is postponed in onset and decreased in magnitude by preirradiation of the tumour transplant site.

  5. Use of electron spin resonance technique for identifying of irradiated foods

    International Nuclear Information System (INIS)

    El-Shiemy, S.M.E

    2008-01-01

    The present investigation was carried out to establish the electron spin resonance (ESR) technique for identifying of some irradiated foodstuffs, i.e. dried fruits (fig and raisin), nuts (almond and pistachio) and spices (fennel and thyme). Gamma rays were used as follows: 0, 1, 3 and 5 kGy were given for dried fruits, while 0, 2, 4 and 6 kGy were given for nuts. In addition, 0, 5, 10 and 15 kGy were given for spices. All treatments were stored at room temperature (25±2 degree C) for six months to study the possibility of detecting its irradiation treatment by ESR spectroscopy. The obtained results indicated that ESR signal intensities of all irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation. So, all irradiated samples under investigation could be differentiated from unirradiated ones immediately after irradiation treatment. The decay that occur in free radicals which responsible of ESR signals during storage periods at ambient temperature showed a significant minimize in ESR signal intensities of irradiated samples. Therefore, after six months of ambient storage the detection was easily possible for irradiated dried fig with dose ≥ 3 kGy and for all irradiated raisin and pistachio (shell). Also, it was possible for irradiated fennel with dose ≥ 10 kGy and for irradiated thyme with dose ≥15 kGy. In contrast, the identification of all irradiated samples of almond (shell as well as edible part) and pistachio (edible part) was impossible after six months of ambient storage.

  6. Use of electron spin resonance technique for identifying of irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    El-Shiemy, S M E

    2008-07-01

    The present investigation was carried out to establish the electron spin resonance (ESR) technique for identifying of some irradiated foodstuffs, i.e. dried fruits (fig and raisin), nuts (almond and pistachio) and spices (fennel and thyme). Gamma rays were used as follows: 0, 1, 3 and 5 kGy were given for dried fruits, while 0, 2, 4 and 6 kGy were given for nuts. In addition, 0, 5, 10 and 15 kGy were given for spices. All treatments were stored at room temperature (25{+-}2 degree C) for six months to study the possibility of detecting its irradiation treatment by ESR spectroscopy. The obtained results indicated that ESR signal intensities of all irradiated samples were markedly increased correspondingly with irradiation dose as a result of free radicals generated by gamma irradiation. So, all irradiated samples under investigation could be differentiated from unirradiated ones immediately after irradiation treatment. The decay that occur in free radicals which responsible of ESR signals during storage periods at ambient temperature showed a significant minimize in ESR signal intensities of irradiated samples. Therefore, after six months of ambient storage the detection was easily possible for irradiated dried fig with dose {>=} 3 kGy and for all irradiated raisin and pistachio (shell). Also, it was possible for irradiated fennel with dose {>=} 10 kGy and for irradiated thyme with dose {>=}15 kGy. In contrast, the identification of all irradiated samples of almond (shell as well as edible part) and pistachio (edible part) was impossible after six months of ambient storage.

  7. Color changes of vienna sausage by gamma irradiation

    International Nuclear Information System (INIS)

    Kume, Tamikazu; Aoki, Shohei; Sato, Tomotaro

    1978-01-01

    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.)

  8. Atom probe characterization of nano-scaled features in irradiated Eurofer and ODS Eurofer steel

    International Nuclear Information System (INIS)

    Rogozkin, S.; Aleev, A.; Nikitin, A.; Zaluzhnyi, A.; Vladimirov, P.; Moeslang, A.; Lindau, R.

    2009-01-01

    Outstanding performance of oxide dispersion strengthened (ODS) steels at high temperatures and up to high doses allowed to consider them as potential candidates for fusion and fission power plants. At the same time their mechanical parameters strongly correlate with number density of oxide particles and their size. It is believed that fine particles are formed at the last stage of sophisticated production procedures and play a crucial role in higher heat- and radiation resistance in comparison with conventional materials. However, due to their small size - only few nanometers, characterization of such objects requires considerable efforts. Recent study of ODS steel by tomographic atom probe, the most appropriate technique in this case, shown considerable stability of these particles under high temperatures and ion-irradiation. However, these results were obtained for 12/14% Cr with addition of 0.3% Y 2 O 3 and titanium which is inappropriate in case of ODS Eurofer 97 and possibility to substitute neutron by ion irradiation is still under consideration. In this work effect of neutron irradiation on nanostructure behaviour of ODS Eurofer are investigated. Irradiation was performed on research reactor BOR-60 in SSC RF RIAR (Dimitrovgrad, Russia) up to 30 dpa at 280 deg. C and 580 deg. C. Recent investigation of unirradiated state revealed high number density of nano-scaled features (nano-clusters) even without addition of Ti in steel. It was shown that vanadium played significant role in nucleation process and core of nano-clusters was considerably enriched with it. In irradiated samples solution of vanadium in matrix was observed while the size of particles stayed practically unchanged. Also no nitrogen was detected in these particles in comparison with unirradiated state where bond energy of N with V was considered to be high as VN 2+ ions were detected on mass-spectra. (author)

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

    International Nuclear Information System (INIS)

    Shibuya, Tohru; Murora, Tetsuro; Iwahara, Shigeo; Hashimoto, Koroku; Minegishi, Atsuko.

    1982-01-01

    Alcohol extracts freshly prepared from gamma-irradiated and unirradiated potatoes were tested for the ability to induce dominant lethals in BDF 1 mice. Male mice were given 0.5 ml of extract twice a day, p.o., for 7 days and then mated with untreated female mice. Female mice were sacrificed on about the 13th day of pregnancy. No significant difference was observed in the number of living inplants between the group treated with extract prepared from unirradiated potatoes and that treated with the extract from 150 Gy (15 krad) irradiated potatoes. (author)

  10. Low-dose gamma irradiation following hot water immersion of papaya (Carica papaya linn.) fruits provides additional control of postharvest fungal infection to extend shelf life

    International Nuclear Information System (INIS)

    Rashid, M.H.A.; Grout, B.W.W.; Continella, A.; Mahmud, T.M.M.

    2015-01-01

    Low-dose gamma irradiation (0.08 kGy over 10 min), a level significantly below that required to satisfy the majority of international quarantine regulations, has been employed to provide a significant reduction in visible fungal infection on papaya fruit surfaces. This is appropriate for local and national markets in producer countries where levels of commercial acceptability can be retained despite surface lesions due to fungal infection. Irradiation alone and in combination with hot-water immersion (50 °C for 10 min) has been applied to papaya (Carica papaya L.) fruits at both the mature green and 1/3 yellow stages of maturity. The incidence and severity of surface fungal infections, including anthracnose, were significantly reduced by the combined treatment compared to irradiation or hot water treatment alone, extending storage at 11 °C by 13 days and retaining commercial acceptability. The combined treatment had no significant, negative impact on ripening, with quality characteristics such as surface and internal colour change, firmness, soluble solids, acidity and vitamin C maintained at acceptable levels. - Highlights: • Storage of papaya extended to 28 days whilst retaining commercial quality. • Additive effect of low gamma irradiation (0.08 kGy over 10 min) and hot-water treatment. • Significant reduction in surface fungal lesions. • No significant impact on colour change or flesh quality during storage

  11. Detection of irradiation treatment of foods using DNA 'comet assay'

    International Nuclear Information System (INIS)

    Khan, Hasan M.; Delincee, Henry

    1998-01-01

    Microgel electrophoresis of single cells (DNA comet assay) has been investigated to detect irradiation treatment of some food samples. These samples of fresh and frozen rainbow trout, red lentil, gram and sliced almonds were irradiated to 1 or 2 kGy using 10 MeV electron beam from a linear accelerator. Rainbow trout samples yielded good results with samples irradiated to 1 or 2 kGy showing fragmentation of DNA and, therefore, longer comets with no intact cells. Unirradiated samples showed shorter comets with a significant number of intact cells. For rainbow trout stored in a freezer for 11 days the irradiated samples can still be discerned by electrophoresis from unirradiated samples, however, the unirradiated trouts also showed some longer comets besides some intact cells. Radiation treatment of red lentils can also be detected by this method, i.e. no intact cells in 1 or 2 kGy irradiated samples and shorter comets and some intact cells in unirradiated samples. However, the results for gram and sliced almond samples were not satisfactory since some intact DNA cells were observed in irradiated samples as well. Probably, incomplete lysis has led to these deviating results

  12. Chemical aspects of irradiated mangoes

    International Nuclear Information System (INIS)

    Singh, H.

    1990-06-01

    Mango is an important and very popular tropical fruit. Because of its short shelf life, however, its use is restricted to the areas of production. Since mango is a climacteric fruit, it is possible to extend its shelf life by delaying the ripening process and senescence by irradiation. The ripening process is very complex: it appears that the radiation-induced delay in ripening may be mediated through the inhibition of the enzyme(s) involved in ethylene production. The dose required for shelf-life extension is ≤1.5 kGy. Higher doses can lead to scalding, flesh darkening and development of hollow pockets. This review focuses on the chemical aspects of radiation-induced shelf-life extension of mangoes. At the low irradiation doses required for this shelf-life extension (≤1.5 kGy), the chemical effects are negligible. Irradiation does not affect the carotenoid levels, and has only a minor effect on the vitamin C level in a few mango varieties. No significant differences in the free and total (hydrolyzed) amino acids, or the protein content of Kent mangoes, have been detected between irradiated and unirradiated samples. During ripening of the mangoes the reducing sugar and the total sugar levels increase, but in the majority of the mango varieties these levels remain very similar in irradiated and unirradiated samples. There are some differences in the volatile compounds between irradiated and unirradiated Kent mangoes; however, these differences have no apparent effect on the taste and flavor of the irradiated mangoes

  13. The dependence of luminescence lifetimes on additive irradiation in natural sedimentary quartz: sands from Santa Elina, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Chithambo, M.L. [Department of Physics and Electronics, Rhodes University, P.O. Box 94, Grahamstown 6140 (South Africa); Ogundare, F.O. [Department of Physics, University of Ibadan, Ibadan (Nigeria); Feathers, J. [Department of Anthropology, University of Washington, P.O. Box 353100, Seattle, WA 98195-3100 (United States); Hong, D.G. [Department of Physics, Kangwon National University, Chuncheon, Kangwon-Do 200-701 (Korea)

    2008-07-01

    Time-resolved luminescence and its component lifetimes have been measured from natural quartz in order to interpret the associated dynamics of luminescence emission. The influence of beta irradiation, and measurement temperature on the lifetimes have been investigated and parameters of the kinetics involved calculated. The results are explained by considering the extent of non-radiative processes and the role of charge transfer between several types of luminescence centres. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. The dependence of luminescence lifetimes on additive irradiation in natural sedimentary quartz: sands from Santa Elina, Brazil

    International Nuclear Information System (INIS)

    Chithambo, M.L.; Ogundare, F.O.; Feathers, J.; Hong, D.G.

    2008-01-01

    Time-resolved luminescence and its component lifetimes have been measured from natural quartz in order to interpret the associated dynamics of luminescence emission. The influence of beta irradiation, and measurement temperature on the lifetimes have been investigated and parameters of the kinetics involved calculated. The results are explained by considering the extent of non-radiative processes and the role of charge transfer between several types of luminescence centres. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Evidence against a systemic humoral factor controlling the intestinal compensatory response following X-irradiation

    International Nuclear Information System (INIS)

    Sharp, J.G.; Osborne, J.W.; Iowa Univ., Iowa City

    1981-01-01

    The investigation was devised to determine whether changes noted in the unirradiated duodenum and colon of single rats after X-irradiation of only the exteriorized rat jejunum and ileum are mediated by a systemic humoral factor. Littermate Holtzman male rats were joined in parabiosis and one month later, the temporarily exteriorized jejunum and ileum of one member was exposed to 1.000 R of 250 kVp X-irradiation. Two days after X-irradiation, and 1, 12 and 24 h after 1 μCi/g bodyweight 3 H-thymidine was injected i.p. rats were sacrificed and appropriate tissues removed. Single rats which had the exteriorized jejunum and ileum irradiated were studied from 1-3 days after irradiation. Crypt cell migration rates were determined employing autoradiography. Tritium content and columnar cell migration rate in duodenum and colon of unirradiated rats compared to irradiated rats indicated that irradiation of one member of the pair had no effect on tritium incorporation or epithelial cell migration in the duodenum or colon of the unirradiated partner. Epithelial cell proliferation and crypt cell migration were increased in unirradiated duodenum and colon of single intestine-irradiated rats. Essentially the same changes were seen in the irradiated member of a parabiotic pair, but none of these changes were noted in the unirradiated member. The absence of stimulation in the unirradiated parabiont suggests that either a systemic humoral factor is not present after X-irradiation or is not present in sufficient concentration to be detected by these methods. (orig./MG)

  16. Expression profiling of murine lung 70 days following exposure to fractionated or acute dose of 1.0 Gy 56Fe- particle irradiation

    Data.gov (United States)

    National Aeronautics and Space Administration — Irradiation of the K-rasLA1 mouse model with a fractionated dose of 1.0Gy 56Fe- particles increases the incidence of invasive carcinoma compared to unirradiated...

  17. Effects of feeding irradiated wheat to malnourished children

    International Nuclear Information System (INIS)

    Bhaskaram, C.; Sadasivan, G.

    1975-01-01

    Fifteen children suffering from severe protein-calorie malnutrition were divided into three groups of five each and received diets containing either unirradiated, freshly irradiated, or stored irradiated wheat. All the children were hospitalized for a period of 6 weeks and leukocyte cultures were done initially and at intervals of 2 weeks. Children receiving freshly irradiated wheat developed polyploid cells and certain abnormal cells in increasing number as the duration of feeding increased and showed a gradual reversal to basal level of nil after withdrawal of irradiated wheat. In marked contrast, none of the children fed unirradiated diet developed any abnormal cells while children fed stored irradiated wheat showed polyploid and abnormal cells in significantly decreased numbers. Though the biological significance of polyploidy is not clear, its association with malignancy makes it imperative that the wholesomeness of irradiated wheat for human consumption be very carefully assessed. (U.S.)

  18. Effect of Gamma-irradiation on aflatoxin B1 produced by aspergillus parasiticus in barley containing antimicrobial food additives

    International Nuclear Information System (INIS)

    Aziz, N.H.; Abd El-Rehim, L.M.; El-Far, M.A.

    1999-01-01

    Influence of gamma irradiation on, growth and aflatoxin B 1 produced by aspergillus parasiticus in ba supplemented with sodium chloride, potassium sorbate and sodium benzoate was investigated. Total viable population of A. Parasiticus and aflatoxin B 1 production decreased significantly by increasing gamma irradiation doses. No growth or aflatoxin B 1 production occurred at 4.0 KGy. Increasing the concentration of NaCl reduced the total viable population A. Parasiticus as well as the accumulation of aflatoxin B 1 . No growth and aflatoxin B 1 production occurred in barley treated with 2.0 KGy and 6% NaCl. Potassium sorbate and sodium benzoate at concentration 500 ppm reduced the population of A. Parasiticus and the levels of aflatoxin B 1 over 100 days. At 2.0 KGy, a sharp drop in aflatoxin B 1 level occurred in barley by 2% NaCl and 500 ppm potassium sorbate and sodium benzoate. At 2.0 KGy, 2% NaCl and 1000 ppm potassium sorbate and sodium benzoate completely inhibited growth and aflatoxin B 1 production by A. parasiticus for 100 days of incubation

  19. Effects of electron irradiation on LDPE/MWCNT composites

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jianqun [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Li, Xingji, E-mail: lxj0218@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Liu, Chaoming; Rui, Erming [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Liqin [School of Mechatronics, Harbin Institute of Technology, Harbin 150001 (China)

    2015-12-15

    In this study, mutiwalled carbon nanotubes (MWCNTs) were incorporated into low density polyethylene (LDPE) in different concentrations (2%, 4% and 8%) using a melt blending process. Structural, thermal stability and tensile property of the unirradiated/irradiated LDPE/MWCNT composites by 110 keV electrons were investigated by means of scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), Raman spectroscopy, electron paramagnetic resonance (EPR) spectroscopy, thermogravimetric analysis (TGA) and uniaxial tensile techniques. Experimental results show that the addition of MWCNTs obviously increases the ultimate tensile strength of LDPE and decreases the elongation at break, which is attributed to the homogeneous distribution of the MWCNTs in LDPE and intense interaction between MWCNTs and LDPE matrix. Also, the electron irradiation further increases the ultimate tensile strength of LDPE/MWCNT composites, which can be ascribed to the more intense interaction between MWCNTs and LDPE matrix, and the formation of crosslinking sites in LDPE matrix induced by the electron irradiation. The addition of MWCNTs significantly enhances thermal stability of the LDPE due to the hindering effect and the scavenging free radicals, while the electron irradiation decreases thermal stability of the LDPE/MWCNT composites since the structure of the MWCNTs and LDPE matrix damages.

  20. Time course of development of metastasis in irradiated Lewis lung carcinoma

    International Nuclear Information System (INIS)

    Ohizumi, Yukio; Maezawa, Hiroshi; Mori, Tomoyuki

    1988-01-01

    The influence of local irradiation on the development of metastases and primary tumor volume was studied in Lewis lung carcinoma growing intramuscularly in the hind leg of C57BL/6 mice. The time course of development of metastases was determined from the size of the lung colonies at autopsy by determining the growth rate of the colonies. Irradiation within five days after tumor cell injection inhibited the incidence of metastases in accordance with irradiation dose. For irradiation more than seven days after the injection, promotion of metastases was observed around the time of the experiment as a function of irradiation dose and tumor volume. After the irradiation phase, the development of metastases was inhibited in accordance with radiation dose. When delay in metastasis was defined as additional days needed to develop two or ten colonies compared with controls, the relationship between delay and dose was linear. At the regrowth phase of the primary tumor, the incidence of metastases from the irradiated tumor was reduced in comparison with that from unirradiated tumors of the same size. Inhibition of metastases was observed only at 5 Gy and showed slight dose-dependency. Mechanisms in the development of metastases as they related to these findings are also discussed. (autho)

  1. Byproducts Utilization Program: Sewage Sludge Irradiation Project. Progress report, July-December 1983

    Energy Technology Data Exchange (ETDEWEB)

    1984-12-01

    Engineering support for a demonstration-scale irradiator design included assisting the City of Albuquerque in preparing a comprehensive site plan for their proposed sludge handling and treatment facilities. The solar sludge dryer has been delivered to SNLA. A preliminary sludge drying experiment indicated the importance of optimizing stirring and air flow. Installation of instrumentation and mechanical equipment continued. The Sandia Irradiator for Dried Sewage Solids (SIDSS) was used to irradiate 23 tons of dried, digested sewage sludge for the New Mexico State University (NMSU) Department of Crop and Soil Sciences. Gamma Irradiation Facility (GIF) operations included irradiation of ground pork for Toxoplasma gondii inactivation experiments, irradiation of surgical supplies and soil samples. Beneficial Uses Shipping Systems (BUSS) cask activities included near completion of the two full-scale cask bodies. Work continued on the Cask Safety Analysis Report (SAR) including additional analyses to reconfigure the six strontium fluoride capsules and/or reduce the number of capsules accommodated. NMSU has indicated no regrowth of salmonellae occurred in the irradiated sludge stockpile, while salmonellae did regrow in the unirradiated stockpile. Analyses of raw and digested sewage sludge from the Albuquerque Waste Water Treatment Plant showed levels of Yersinia enterocolitica (a human pathogen of emerging significance) to be below detection limits.

  2. Byproducts Utilization Program: Sewage Sludge Irradiation Project. Progress report, July-December 1983

    International Nuclear Information System (INIS)

    1984-12-01

    Engineering support for a demonstration-scale irradiator design included assisting the City of Albuquerque in preparing a comprehensive site plan for their proposed sludge handling and treatment facilities. The solar sludge dryer has been delivered to SNLA. A preliminary sludge drying experiment indicated the importance of optimizing stirring and air flow. Installation of instrumentation and mechanical equipment continued. The Sandia Irradiator for Dried Sewage Solids (SIDSS) was used to irradiate 23 tons of dried, digested sewage sludge for the New Mexico State University (NMSU) Department of Crop and Soil Sciences. Gamma Irradiation Facility (GIF) operations included irradiation of ground pork for Toxoplasma gondii inactivation experiments, irradiation of surgical supplies and soil samples. Beneficial Uses Shipping Systems (BUSS) cask activities included near completion of the two full-scale cask bodies. Work continued on the Cask Safety Analysis Report (SAR) including additional analyses to reconfigure the six strontium fluoride capsules and/or reduce the number of capsules accommodated. NMSU has indicated no regrowth of salmonellae occurred in the irradiated sludge stockpile, while salmonellae did regrow in the unirradiated stockpile. Analyses of raw and digested sewage sludge from the Albuquerque Waste Water Treatment Plant showed levels of Yersinia enterocolitica (a human pathogen of emerging significance) to be below detection limits

  3. Mechanical properties of irradiated rubber-blends

    International Nuclear Information System (INIS)

    Nasr, G.M.; Madani, M.

    2005-01-01

    A study has been made on blend ratios of natural rubber (NR) and acrylonitrile butadiene rubber (NBR) that are loaded with general purpose furnace (GPE) carbon black and irradiated at different gamma radiation doses. It was fount that the mechanical properties of such blend are highly affected by γ- irradiation dose and the composition ratios of its constituents. The elongation at break for blends was found to increase slightly with increasing NBR loafing which is mainly due to the stiffness of blending matrix formation between NR and GPF carbon black particles. The hysteresis loss, extension ratio and shape factor have been calculated for the different un-irradiated and irradiated samples

  4. Characterization of blend hydrogels based on plasticized starch/cellulose acetate/carboxymethyl cellulose synthesized by electron beam irradiation

    Science.gov (United States)

    Senna, Magdy M.; Mostafa, Abo El-Khair B.; Mahdy, Sanna R.; El-Naggar, Abdel Wahab M.

    2016-11-01

    Blend hydrogels based on aqueous solutions of plasticized starch and different ratios of cellulose acetate (CA) and carboxymethyl cellulose (CMC) were prepared by electron beam irradiation (EB). The blends before and after EB irradiation were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The physico-chemical properties of blend hydrogels prepared by electron beam irradiation were improved compared to unirradiated blends.

  5. Effect of gamma irradiation on microbial load, chemical and sensory evaluation of chicken meat

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2008-03-01

    The effect of gamma irradiation on microbial load, chemical sensory characteristics of chicken meat has been evaluated. Chicken 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 Degree Centigrade). Immediately after irradiation, general composition, microbiological and sensory evaluation of chicken meat were done. Microbiological and chemical analysis of chicken meat were evaluated at weekly up to end of the storage period. The results indicated that all doses of gamma irradiation reduced the microbial load, and increased the shelf-life of chicken meat. Total acidity, volatile basic nitrogen (VBN) and lipid oxidation value in chicken meat were not affected by gamma irradiation. Sensory evaluation showed no significant differences between irradiated and un-irradiated chicken meat. (author)

  6. Effect of gamma irradiation on microbial load, chemical and sensory evaluation of chicken meat

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2009-01-01

    The effect of gamma irradiation on microbial load, chemical sensory characteristics of chicken meat has been evaluated. Chicken 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 Degree Centigrade). Immediately after irradiation, general composition, microbiological and sensory evaluation of chicken meat were done. Microbiological and chemical analysis of chicken meat were evaluated at weekly up to end of the storage period. The results indicated that all doses of gamma irradiation reduced the microbial load, and increased the shelf-life of chicken meat. Total acidity, volatile basic nitrogen (VBN) and lipid oxidation value in chicken meat were not affected by gamma irradiation. Sensory evaluation showed no significant differences between irradiated and un-irradiated chicken meat. (author)

  7. Suitability of the thermoluminescence method for detection of irradiated foods

    International Nuclear Information System (INIS)

    Pinnioja, S.

    1993-01-01

    Irradiated foods can be detected by thermoluminescence (TL) of contaminating minerals. Altogether about 300 lots of herbs, spices, berries, mushrooms and seafood were studied by the TL method. Irradiated herbs and spices were easily differentiated from unirradiated ones two years after irradiation of a 10 kGy dose. The mineral composition of seafood was variable; and while calcite was suitable for the TL analysis, aragonite and smectite gave unreliable results. Control analyses during two years confirmed the reliability of TL method. (author)

  8. Precipitates in irradiated Zircaloy

    International Nuclear Information System (INIS)

    Chung, H.M.

    1985-10-01

    Precipitates in high-burnup (>20 MWd/kg U) Zircaloy spent-fuel cladding discharged from commercial boiling- and pressurized-water reactors have been characterized by TEM-HVEM. Three classes of primary precipitates were observed in the irradiated Zircaloys: Zr 3 O (2 to 6 nm), cubic-ZrO 2 (greater than or equal to 10 nm), and delta-hydride (35 to 100 nm). The former two precipitations appears to be irradiation induced in nature. Zr(Fe/sub x/Cr/sub 1-x/) 2 and Zr 2 (Fe/sub x/Ni/sub 1-x/) intermetallics, which are the primary precipitates in unirradiated Zircaloys, were largely dissolved after the high burnup. It seems, therefore, that the influence of the size and distribution of the intermetallics on the corrosion behavior may be quite different for the irradiated Zircaloys

  9. Ferrobielastic twinning in irradiated quartz

    International Nuclear Information System (INIS)

    Shiau, S.M.

    1986-01-01

    Cultured quartz is usually free from electrical twinning; however, it may occur if the seed crystal is twinned or if undue applied forces are exerted on the crystal. Ferrobielastic twinning was studied optically (photoelastic effect) and electrically (piezoelectric effect). At room temperature, twins were perceptible at stresses of about 2.l5 x 10 8 N/m 2 , and crystals switched from their original states to the alternative twin states at stresses about 5.0 x 10 8 N/m 2 (called coercive stress). The decrease in coercive stress with increasing temperature was observed, and these coercive stresses become very low as temperatures reach to 300 0 C. The effects of irradiation on the twinning in quartz were also studied. The presence of defects produced by irradiation was utilized to pin the domain wall motion. Both neutrons and gamma rays were employed. The stress required to nucleate an appreciable volume of twins is about twice as high for irradiated crystals than for those unirradiated. This result demonstrated that the irradiated crystals can tolerate higher stresses. However, the coercive stress for complete switch-over was not much different for irradiated and unirradiated crystals. It appears that the defects caused by irradiation eliminate the initial twinning events but do not affect switch-over

  10. Fracture toughness of irradiated beryllium

    International Nuclear Information System (INIS)

    Beeston, J.M.

    1978-01-01

    The fracture toughness of nuclear grade hot-pressed beryllium upon irradiation to fluences of 3.5 to 5.0 x 10 21 n/cm 2 , E greater than 1 MeV, was determined. Procedures and data relating to a round-robin test contributing to a standard ASTM method for unirradiated beryllium are discussed in connection with the testing of irradiated specimens. A porous grade of beryllium was also irradiated and tested, thereby enabling some discrimination between the models for describing the fracture toughness behavior of porous beryllium. The fracture toughness of unirradiated 2 percent BeO nuclear grade beryllium was 12.0 MPa m/sup 1 / 2 /, which was reduced 60 percent upon irradiation at 339 K and testing at 295 K. The fracture toughness of a porous grade of beryllium was 13.1 MPa m/sup 1 / 2 /, which was reduced 68 percent upon irradiation and testing at the same conditions. Reasons for the reduction in fracture toughness upon irradiation are discussed

  11. Influence of bromouracil density labelling on viability of UV irradiated Escherichia coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Brozmanova, J [Slovenska Akademia Vied, Bratislava (Czechoslovakia). Vyskumny Ustav Onkologicky

    1976-01-01

    Influence of 5-bromouracil cultivation on cell viability and DNA synthesis in the Escherichia coli B/r thy/sup -/ trp/sup -/ Hcr/sup +/ and Escherichia coli C thy-321 strains was followed. It was found that a 120 min cultivation in the bromouracil medium (unirradiated cells) does not essentially influence the viability of the two investigated strains but has an inhibitory effect on DNA synthesis in cells of the E. coli B/r Hcr/sup +/ strain. However, cultivation with bromouracil after ultraviolet irradiation leads to a decreased surviving ability of the irradiated cells of both investigated strains. Repair of damage induced by ultraviolet radiation probably exhausts a considerable proportion of repair activity, so that additional injury produced by bromouracil cultivation cannot be liquidated immediately.

  12. Neutron irradiation effects on grain-refined W and W-alloys

    International Nuclear Information System (INIS)

    Hasegawa, A.; Fukuda, M.; Tanno, T.; Nogami, S.; Yabuuchi, K.; Tanaka, T.; Muroga, T.

    2014-10-01

    Microstructural data of neutron irradiated Tungsten (W) such as size and number density of voids and precipitates obtained by W up to 1.5dpa irradiation in the temperature range of 400-800degC were compiled quantitatively. Nucleation and growth process of these defects were clarified and a qualitative prediction of the damage structure development and hardening of W in fusion reactor environments were made taking into account the solid transmutation effects for the first time. To improve recrystallization behavior and low temperature embrittlement, grain refined-W alloys were fabricated by K- or La-doping method. Rhenium addition to the grain refining process was also examined to improve mechanical properties. Characterizations of unirradiated materials were performed. (author)

  13. Effects of gamma irradiation on the sperm transmission and oviposition response in Helicoverpa armigera (L. Noctuidae)

    International Nuclear Information System (INIS)

    Liu Xiaohui; Wang Huasong; Song Jiaxiang

    1999-12-01

    The transmission of sperm by unirradiated and irradiated cotton bollworm, Helicoverpa armigera, was studied by live dissection of the female immediately after the initiation of mating. In cotton bollworm the sperm transfer was a rather complex process. In fact, the unirradiated male failed to transfer sperm in about 19% of their matings. After being irradiated with 250 Gy and 400 Gy, the aberrations of sperm transmission were about 21% and 50% respectively. The failure of spermatophore 'cap' location was an important reason of sperm transmission aberrations. When female mated to high-dose-irradiated males, its oviposition response appeared abnormal

  14. Herpes simplex virus produces larger plaques when assayed on ultraviolet irradiated CV1 cells

    International Nuclear Information System (INIS)

    Coohill, T.P.; Babich, M.A.; Taylor, W.D.; Snipes, W.

    1980-01-01

    Plaque development for either untreated or UV treated irradiated Herpes simplex virus Type 1 was faster when assayed on UV irradiated CV1 cells. This Large Plaque Effect only occurred if a minimum delay of 12h between cell irradiation and viral inoculation was allowed. Shorter delays gave plaques that were smaller than controls (unirradiated virus-unirradiated cells). The effect was maximal for a 48-h delay and remained unchanged for delays as long as 84h. The effect was greatest for cell exposures of 10Jm -2 . (author)

  15. Positron annihilation and thermally stimulated current of electron beam irradiated polyetheretherketone

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, Shigetaka; Shinyama, Katsuyoshi; Baba, Makoto [Hachinohe Inst. of Tech., Hachinohe, Aomori (Japan); Suzuki, Takenori

    1997-03-01

    Positron lifetime measurements were applied to electron beam irradiated poly(ether-ether-ketone). The lifetime, {tau}{sub 3}, of the ortho-positronium of unirradiated and 5 MGy irradiated specimen became rapidly longer above about 150degC. {tau}{sub 3} of 50 MGy and 100 MGy irradiated specimen was shorter than that of unirradiated one. Thermally stimulated current (TSC) decreased with increasing the dose before voltage application. In the case of voltage application, a TSC peak appeared and the peak value decreased with increased the dose. The correlation between the results of positron annihilation and TSC was investigated. (author)

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

    International Nuclear Information System (INIS)

    Hayashi, T.; Todoroki, S.

    1994-01-01

    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

  17. Elevated-temperature tensile properties of 2 1/4 Cr-1 Mo steel irradiated in the EBR-II, AD-2 experiment

    International Nuclear Information System (INIS)

    Klueh, R.L.; Vitek, J.M.

    1984-01-01

    The effect of irradiated on the tensile properties of 2 1/4 Cr-1 Mo steel was determined for specimens irradiation in EBR-II at 390 to 550 0 C. Unirradiated control specimens and specimens aged for 5000 h at the irradiation temperatures were also tested. Irradiation to approximately 9 dpa at 390 0 C increased the strength and decreased the ductility compared with the unirradiated and aged specimens. Softening occurred in samples irradiated and tested at 450, 500, and 550 0 C

  18. Molecular Understanding of Growth Inhibitory Effect from Irradiated to Bystander Tumor Cells in Mouse Fibrosarcoma Tumor Model

    Science.gov (United States)

    Desai, Sejal; Srambikkal, Nishad; Yadav, Hansa D.; Shetake, Neena; Balla, Murali M. S.; Kumar, Amit; Ray, Pritha; Ghosh, Anu

    2016-01-01

    Even though bystander effects pertaining to radiation risk assessment has been extensively studied, the molecular players of radiation induced bystander effect (RIBE) in the context of cancer radiotherapy are poorly known. In this regard, the present study is aimed to investigate the effect of irradiated tumor cells on the bystander counterparts in mouse fibrosarcoma (WEHI 164 cells) tumor model. Mice co-implanted with WEHI 164 cells γ-irradiated with a lethal dose of 15 Gy and unirradiated (bystander) WEHI 164 cells showed inhibited tumor growth, which was measured in terms of tumor volume and Luc+WEHI 164 cells based bioluminescence in vivo imaging. Histopathological analysis and other assays revealed decreased mitotic index, increased apoptosis and senescence in these tumor tissues. In addition, poor angiogenesis was observed in these tumor tissues, which was further confirmed by fluorescence imaging of tumor vascularisation and CD31 expression by immuno-histochemistry. Interestingly, the growth inhibitory bystander effect was exerted more prominently by soluble factors obtained from the irradiated tumor cells than the cellular fraction. Cytokine profiling of the supernatants obtained from the irradiated tumor cells showed increased levels of VEGF, Rantes, PDGF, GMCSF and IL-2 and decreased levels of IL-6 and SCF. Comparative proteomic analysis of the supernatants from the irradiated tumor cells showed differential expression of total 24 protein spots (21 up- and 3 down-regulated) when compared with the supernatant from the unirradiated control cells. The proteins which showed substantially higher level in the supernatant from the irradiated cells included diphosphate kinase B, heat shock cognate, annexin A1, angiopoietin-2, actin (cytoplasmic 1/2) and stress induced phosphoprotein 1. However, the levels of proteins like annexin A2, protein S100 A4 and cofilin was found to be lower in this supernatant. In conclusion, our results provided deeper insight about

  19. Molecular Understanding of Growth Inhibitory Effect from Irradiated to Bystander Tumor Cells in Mouse Fibrosarcoma Tumor Model.

    Directory of Open Access Journals (Sweden)

    Sejal Desai

    Full Text Available Even though bystander effects pertaining to radiation risk assessment has been extensively studied, the molecular players of radiation induced bystander effect (RIBE in the context of cancer radiotherapy are poorly known. In this regard, the present study is aimed to investigate the effect of irradiated tumor cells on the bystander counterparts in mouse fibrosarcoma (WEHI 164 cells tumor model. Mice co-implanted with WEHI 164 cells γ-irradiated with a lethal dose of 15 Gy and unirradiated (bystander WEHI 164 cells showed inhibited tumor growth, which was measured in terms of tumor volume and Luc+WEHI 164 cells based bioluminescence in vivo imaging. Histopathological analysis and other assays revealed decreased mitotic index, increased apoptosis and senescence in these tumor tissues. In addition, poor angiogenesis was observed in these tumor tissues, which was further confirmed by fluorescence imaging of tumor vascularisation and CD31 expression by immuno-histochemistry. Interestingly, the growth inhibitory bystander effect was exerted more prominently by soluble factors obtained from the irradiated tumor cells than the cellular fraction. Cytokine profiling of the supernatants obtained from the irradiated tumor cells showed increased levels of VEGF, Rantes, PDGF, GMCSF and IL-2 and decreased levels of IL-6 and SCF. Comparative proteomic analysis of the supernatants from the irradiated tumor cells showed differential expression of total 24 protein spots (21 up- and 3 down-regulated when compared with the supernatant from the unirradiated control cells. The proteins which showed substantially higher level in the supernatant from the irradiated cells included diphosphate kinase B, heat shock cognate, annexin A1, angiopoietin-2, actin (cytoplasmic 1/2 and stress induced phosphoprotein 1. However, the levels of proteins like annexin A2, protein S100 A4 and cofilin was found to be lower in this supernatant. In conclusion, our results provided deeper

  20. Microwave Assisted Synthesis of ZnO Nanoparticles: Effect of Precursor Reagents, Temperature, Irradiation Time, and Additives on Nano-ZnO Morphology Development

    Directory of Open Access Journals (Sweden)

    Gastón P. Barreto

    2013-01-01

    Full Text Available The effect of different variables (precursor reagents, temperature, irradiation time, microwave radiation power, and additives addition on the final morphology of nano-ZnO obtained through the microwave assisted technique has been investigated. The characterization of the samples has been carried out by field emission scanning electron microscopy (FE-SEM in transmission mode, infrared (FTIR, UV-Vis spectroscopy, and powder X-ray diffraction (XRD. The results showed that all the above-mentioned variables influenced to some extent the shape and/or size of the synthetized nanoparticles. In particular, the addition of an anionic surfactant (sodium di-2-ethylhexyl-sulfosuccinate (AOT to the reaction mixture allowed the synthesis of smaller hexagonal prismatic particles (100 nm, which show a significant increase in UV absorption.

  1. Mechanical properties of irradiated beryllium

    International Nuclear Information System (INIS)

    Beeston, J.M.; Longhurst, G.R.; Wallace, R.S.

    1992-01-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10 25 n/m 2 (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.)

  2. Mechanical properties of irradiated beryllium

    Science.gov (United States)

    Beeston, J. M.; Longhurst, G. R.; Wallace, R. S.; Abeln, S. P.

    1992-10-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 × 10 25 n/m 2 ( E > 1 MeV) at an irradiation temperature of 75°C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium.

  3. Lifespan studies on different strains of mice exposed chronically to low levels of whole body gamma irradiation

    International Nuclear Information System (INIS)

    Fox, L.A.; Klein, A.K.; Cain, G.R.; Rosenblatt, L.S.

    1982-01-01

    Several strains of mice, chosen for their predisposition to immunohematological disorders, were exposed to low levels of 60 irradiation continuously for four weeks. All individuals were subsequently followed throughout their lifetimes. W/W/sup v/ mice, which are tyically subject to a stem cell deficiency, had a lower cumulative survival rate for the irradiated group than for the unirradiated controls. Irradiated RF/sub j/ mice had a dramatically lower cumulative survival rate than their unirradiated controls. Conversely, BXSB mice, which have a lumphoproliferative autoimmune disorder, had a higher cumulative survival rate after chronic irradiation than did unirradiated BXSBs. Irradiation had no effect upon the survival rate curves of the NZB strain, the murine model for Lupus Erythematosus

  4. Dearomatization of jet fuel on irradiated platinum-supported catalyst

    International Nuclear Information System (INIS)

    Mucka, V.; Ostrihonova, A.; Kopernicky, I.; Mikula, O.

    1983-01-01

    The effect of ionizing radiation ( 60 Co #betta#-rays) on Pt-supported catalyst used for the dearomatization of jet fuel with distillation in the range 395 to 534 K has been studied. Pre-irradiation of the catalyst with doses in the range 10 2 to 5 x 10 4 Gy leads to the partial catalyst activation. Irradiation of the catalyst enhances its resistance to catalyst poisons, particularly to sulphur-compounds, and this is probably the reason for its catalytic activity being approx. 60 to 100% greater than that of un-irradiated catalyst. Optimum conditions for dearomatization on the irradiated catalyst were found and, by means of a rotary three-factorial experiment, it was shown that these lie at lower temperatures and lower pressures than those for un-irradiated catalyst. (author)

  5. Detection of Argentine onions treated with 60 Co irradiation

    International Nuclear Information System (INIS)

    Romanelli, Maria Fernanda; Sebastiao, Katia I.; Leite, Quilma R.; Koseki, Paula M.; Hamasaki, Koji; Villavicencio, Anna Lucia H.; Croci, Clara

    2000-01-01

    Brazil has been the most important MERCOSUL's purchaser of fresh onions from Argentina. The increased claim for this fresh product has forced a consensus between the members nations, as regards to phytosanitary restrictions. The radio inhibition is described on National Food Codes in Brazil and Argentina. Methods of food irradiation detection must be performed, since they increase the consumer confidence. Quick and simple screening tests indicate whether a food product has been irradiated or not. This present study verified the DNA fragments of argentine fresh onions, produced during radiation process and 6 months of storage period. The DNA fragments are analyzed for detection of irradiated foods. The irradiated onions presented extensive DNA migrations, as comets, when submitted to agarose gel electrophoresis. They also showed more shelf life compared to the unirradiated onions. The unirradiated samples exhibited only limited DNA migration. This initial screen method showed to be effective for detection of irradiated onions. (author)

  6. Proton irradiation studies on Al and Al5083 alloy

    Science.gov (United States)

    Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

    2017-10-01

    The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

  7. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of licorice extract

    International Nuclear Information System (INIS)

    Al-Adawi, M. A.; Al-Kaed, A.; Al-Bachir, M.

    2002-08-01

    Extract of licorice roots were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60 C package irradiator. Irradiated and unirradiated samples were stored at room temperatures. Microbial population on extract, chemical changes and sensory properties of produced juice of licorice were evaluated after 0 and 12 months or storage. The results indicated that gamma irradiation reduced the counts of microorganisms. D 10 of total count and klebsiella spp. were about 14 and 0.7 kGy respectively. The mineral ions (Na, Ca and K) concentration in juice produced from irradiated extract were lower than non-irradiated ones. Glycyrrhetinic acid and maltose concentration in juice produced from irradiated extract were higher than non-irradiated ones. Sensory evaluation indicated that no significant differences (P> 0.05) were fond between juice produced from irradiated and unirradiated extract in color, taste, or odor. (author)

  8. Effect of gamma irradiation on microbiological, chemical and sensory characteristics of aniseed (anisum vulgare)

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    2002-09-01

    Seeds of ansium were exposed to doses of 0, 5, 10, 15 and 20 kGy in a 60 Co 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)

  9. Anti radiation action of 'Vin-Vita' food additive solution in 'Kuyalnik' mineral water under sublethal gamma-irradiation conditions

    International Nuclear Information System (INIS)

    Baraboj, V.A.; Lobasyuk, B.O.; Oleksyijenko, N.O.; Kujev, V.L.; Goncharov, M.Yi.; Smul's'kij, S.P.; Kolker, Yi.A.; Babov, K.D.

    1996-01-01

    The study involved four groups of female Wistar rats. Protective anti radiation action of 'Vin-Vita' food additive solution in 'Kuyalnik' mineral water especially in the concentration of 500 mg/l has been revealed, which was proved by hemoglobin, hematocrit, ESR, white blood parameters and animal behaviour

  10. Delayed metamorphosis and recurrence of bacterial infection in irradiated Rana clamitans tadpoles

    International Nuclear Information System (INIS)

    Hart, D.R.

    1982-03-01

    X-ray doses of 5 and 10 Gy (1 Gy/min) given to premetamorphic Green Frog (Rana clamitans) tadpoles delayed their metamorphosis relative to unirradiated controls. Previous pathogenic bacterial infections recurred in irradiated animals prior to metamorphic climax. Limited mortality occurred during metamorphic climax, 80-105 days after irradiation

  11. Influence of a sublethal irradiation on the immune response of the mouse against sheep erythrocytes

    International Nuclear Information System (INIS)

    Beaumariage, M.L.; Hiesche, K.; Moeller, E.; Revesz, L.; Haot, J.

    1975-01-01

    In the CBA mice, the immunological response of the spleen cells (RFC and PFC direct and indirect) against the sheep erythrocytes is highly depressed by a 400R dose of X rays. The recovery is not complete at the 30th day after irradiation. The response of the bone marrow cells either irradiated or unirradiated to the antigenic stimulation is very low [fr

  12. Gamma-irradiation activates biochemical systems: induction of nitrate reductase activity in plant callus.

    OpenAIRE

    Pandey, K N; Sabharwal, P S

    1982-01-01

    Gamma-irradiation induced high levels of nitrate reductase activity (NADH:nitrate oxidoreductase, EC 1.6.6.1) in callus of Haworthia mirabilis Haworth. Subcultures of gamma-irradiated tissues showed autonomous growth on minimal medium. We were able to mimic the effects of gamma-irradiation by inducing nitrate reductase activity in unirradiated callus with exogenous auxin and kinetin. These results revealed that induction of nitrate reductase activity by gamma-irradiation is mediated through i...

  13. Irradiated Foods Detection by Thermoluminescence (TL) and DEFT/APC Analysis

    International Nuclear Information System (INIS)

    Choi, I.D.; Kang, E.K.; Yang, J.S.

    2004-01-01

    Irradiated food detection methods such as Thermoluminescence (TL) and Direct Epifluorescent Filter Technique and Aerobic Plate Count (DEFT/APC) methods were evaluated. Fresh green-onion, onion, and ginger were irradiated at 0, 0.3, 0.6, and 0.9 kGy. Difference in log DEFT/APC units between irradiated and un-irradiated samples was less than 2 long units, below the average threshold value (3-4 long units) of international researches

  14. Correlation of Yield Stress And Microhardness in 08cr16ni11mo3 Irradiated To High Dose In The Bn-350 Fast Reactor

    International Nuclear Information System (INIS)

    Maksimkin, O.P.; Gusev, M.N.; Tivanova, O.S.; Silnaygina, N.S.; Garner, Francis A.

    2006-01-01

    The relationship between values of the microhardness and the engineering yield stress in steel 08Cr16Ni11Mo3 (Russian analog of AISI 316) heavily irradiated in the BN-350 reactor has been experimentally derived. It agrees very well with the previously published correlation developed by Toloczko for unirradiated 316 in a variety of cold-work conditions. Even more importantly, when the correlation is derived in the K δ format where the correlation involves changes in the two properties, we find excellent agreement with a universal K δ correlation developed by Busby and coworkers. With this K δ correlation, one can predict the value of yield stress in irradiated material based on measured values of microhardness. The technique is particularly suitable when the material of interest is in an inconvenient location or configuration, or when significant gradients in mechanical properties are anticipated over small dimensions. This approach makes it possible to reduce the labor input and risk when conducting such work. It appears that the derived correlation is equally applicable to both Russian and Western austenitic steel, and also in both irradiated and unirradiated conditions. Additionally, this report points out that microhardness measurements must take into account that high temperature sodium exposure alters the metal surface to produce ferrite, and therefore the altered layers should be removed prior to testing

  15. Examination of fast reactor fuels, FBR analytical quality assurance standards and methods, and analytical methods development: irradiation tests. Progress report, April 1--June 30, 1976, and FY 1976

    International Nuclear Information System (INIS)

    Baker, R.D.

    1976-08-01

    Characterization of unirradiated and irradiated LMFBR fuels by analytical chemistry methods will continue, and additional methods will be modified and mechanized for hot cell application. Macro- and microexaminations will be made on fuel and cladding using the shielded electron microprobe, emission spectrograph, radiochemistry, gamma scanner, mass spectrometers, and other analytical facilities. New capabilities will be developed in gamma scanning, analyses to assess spatial distributions of fuel and fission products, mass spectrometric measurements of burnup and fission gas constituents and other chemical analyses. Microstructural analyses of unirradiated and irradiated materials will continue using optical and electron microscopy and autoradiographic and x-ray techniques. Analytical quality assurance standards tasks are designed to assure the quality of the chemical characterizations necessary to evaluate reactor components relative to specifications. Tasks include: (1) the preparation and distribution of calibration materials and quality control samples for use in quality assurance surveillance programs, (2) the development of and the guidance in the use of quality assurance programs for sampling and analysis, (3) the development of improved methods of analysis, and (4) the preparation of continuously updated analytical method manuals. Reliable analytical methods development for the measurement of burnup, oxygen-to-metal (O/M) ratio, and various gases in irradiated fuels is described

  16. Fracture mechanics behaviour of neutron irradiated Alloy A-286

    International Nuclear Information System (INIS)

    Mills, W.J.; James, L.A.

    The effect of fast-neutron irradiation on the fatigue-crack propagation and fracture toughness behaviour of Alloy A-286 was characterized using fracture mechanics techniques. The fracture toughness was found to decrease continuously with increasing irradiation damage at both 24 deg. C and 427 deg. C. In the unirradiated and low fluence conditions, specimens displayed appreciable plasticity prior to fracture, and equivalent Ksub(Ic) values were determined from Jsub(Ic) fracture toughness results. At high irradiation exposure levels, specimens exhibited a brittle Ksub(Ic) fracture mode. The 427 deg. C fracture toughness fell from 129 MPa√m in the unirradiated condition to 35 MPa√m at an exposure of 16.2 dpa (total fluence of 5.2x10 22 n/cm 2 ). Room temperature fracture toughness values were consistently 40 to 60 percent higher than the 427 deg. C values. Electron fractography revealed that the reduction in fracture resistance was attributed to a fracture mechanism transition from ductile microvoid coalescence to channel fracture. Fatigue-crack propagation tests were conducted at 427 deg. C on specimens irradiated at 2.4 dpa and 16.2 dpa. Crack growth rates at the lower exposure level were comparable to those in unirradiated material, while those at the higher exposure were slightly higher than in unirradiated material. (author)

  17. Ultraviolet irradiation initiates ectopic foot formation in regenerating ...

    Indian Academy of Sciences (India)

    If the head or base piece of a bisected hydra is irradiated and recombined with the unirradiated missing part, regeneration proceeds normally indicating that exposure of a body part with either an intact head or foot to UVC does not influence pattern formation. Most significantly, in the middle piece, but not in the head or the ...

  18. Application of thermoluminescence measurements to detect irradiated strawberries

    International Nuclear Information System (INIS)

    Heide, L.; Guggenberger, R.; Bogl, K.W.

    1990-01-01

    The thermoluminescence intensity of unirradiated and irradiated strawberries was studied with regard to dose response, storage time, and different varieties. An identification method could finally be developed. Further investigations were carried out to determine the origin of the thermoluminescence effect, which was found to be attributable to mineral grains adhering to the sample surface

  19. Identification of irradiated crab using EPR

    Energy Technology Data Exchange (ETDEWEB)

    Maghraby, A. [Radiation Dosimetry Department, National Institute for Standards (NIS), Ministry of Scientific Research, Haram, 12211- Giza, P.O. Box: 136 (Egypt)]. E-mail: maghrabism@yahoo.com

    2007-02-15

    EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response.

  20. Identification of irradiated crab using EPR

    International Nuclear Information System (INIS)

    Maghraby, A.

    2007-01-01

    EPR spectroscopy is a fast and powerful technique for the identification of irradiated food. Crab exoskeleton was divided into six parts: dactyl, cheliped, carapace, apron, swimming legs, and walking legs. Samples of the exoskeleton were prepared and irradiated to Cs-137 gamma radiation in the range (1.156-5.365 kGy). EPR spectra of unirradiated as well as irradiated samples were recorded and analyzed. Response to gamma radiation was plotted for each part of the exoskeleton, dactyl was found to be the most sensitive part, followed by the apron (38%), cheliped (37%), walking legs (30%), swimming legs (24%), and carapace (21%) relative to the dactyl response

  1. Genetic effects of feeding irradiated wheat to mice

    International Nuclear Information System (INIS)

    Vijayalaxmi

    1976-01-01

    The effects of feeding irradiated wheat in mice on bone marrow and testis chromosomes, germ cell numbers and dominant lethal mutations were investigated. Feeding of freshly irradiated wheat resulted in significantly increased incidence of polyploid cells in bone marrow, aneuploid cells in testis, reduction in number of spermatogonia of types A, B and resting primary spermatocytes as well as a higher mutagenic index. Such a response was not observed when mice were fed stored irradiated wheat. Also there was no difference between the mice fed un-irradiated wheat and stored irradiated wheat. (author)

  2. The effect of using irradiated sludge as an organic fertilizer on the soil characteristics and productivity of yellow corn

    International Nuclear Information System (INIS)

    Takriti, S.; Khalifa, K.

    2003-08-01

    A field experiment was conducted at Deir- El-Hajar research station near Damascus, to study the effect of using irradiated sludge (5 KGy) and unirradiated sludge (0 KGy) as an organic fertilizer on productivity of corn and some soil characteristics. The results showed that increment of grain yield of corn by 20% when applying 1kg/m 2 from unirradiated sludge and 37% when applying irradiated sludge. Also it was found increment in productivity of the other parts of corn (cobs, stems and leaves) compared with control plots. The concentration and accumulation of heavy metals (Zn, Co, Cu, Pb, Cr) in corn were low and less than critical limits for all treatment. The accumulation for these metals in corn plants was not clear at end of the experiment. The highest accumulation for Cu was in grain, Cr and Zn in cobs, and Fe was in stems and leaves. Addition of sludge at different rates had no negative effect on the accumulation of the studied heavy metals in the soil. (author)

  3. Roughage digestibility and velocity of its passage through the alimentary tract of wethers as affected by mineral additives and gamma irradiation

    International Nuclear Information System (INIS)

    Sandev, S.

    1976-01-01

    Balance trials conducted with wethers established the apparent digestibility of roughage and the velocity of its passage through the alimentary tract. All rations amounted to 1000 g daily. Studied was the influence of 4% bentonit supplementation of the ration of ground meadow hay and of 7% bentonit to ration of 60%. ground lucerne hay and 40% concentrate. 4% bentonit supplementation did not affect the velocity of passage through the alimentary tract, but 7% bentonit supplementation depressed apparent digestibility. The addition of 12 g MgO and 5 NaHCO 3 to a ration of 1000 g finely ground meadow hay was studied under the same conditions. There were no considerable changes in digestibility and velocity of passage. Acetic acid molar ratio was slightly enhanced. The influence of gamma irradiation on pellets of 85% meadow hay and 15% concentrate was studied also under the same conditions. The irradiation dose was 4 Mr. Crude fat digestibility went up and that of crude fiber - dropped. However, organic matter digestibility was not affected. These data resemble the results obtained with complete roughage ration mixtures following pelleting. (author)

  4. Evaluation of the synergistic effect of gamma irradiated Steinernema scapterisci and soil depth in controlling Bactrocera zonata Saunders (Diptera: Tephritidae

    Directory of Open Access Journals (Sweden)

    R.M. Sayed

    2018-01-01

    Full Text Available The Peach fruit fly, Bactrocera zonata (Saunders is a serious devastating pest in Egypt. This pest spends in soil from full grown larvae till adult emergence. Therefore, the present study was planned to evaluate the pathogenicity of Steinernema scapterisci against larvae and 1 day old pupae (at different soil depths, and to investigate the effect of gamma radiation on its virulence. The results revealed that adult emergence percentage decrease as the soil depth and S. scapterisci concentration increase. In contrast, the larval mortality increased with S. scapterisci concentration increased. In addition, this study showed that gamma irradiation of S. scapterisci juveniles with 2Gy increased its virulence against both larvae and pupae, which presented by lower LC50 values than unirradiated S. scapterisci. Subsequently, it could be concluded that 2Gy irradiated S. scapterisci can serve as a bio-tolerated control method for B. zonata.

  5. Radiation enhanced reactivation of irradiated human adenovirus type 2 in human cells

    International Nuclear Information System (INIS)

    Jeeves, W.P.

    1981-04-01

    Radiation-enhanced reactivation (ER) of a radiation-damaged mammalian virus is the term given to the observation that the survival of irradiated virus can be enhanced by irradiation of an appropriate host cell prior to infection. In this work, both UV-enhanced reactivation (UVER) and gamma-ray-enhanced reactivation (γRER) of irradiated human adenovirus type 2 (AD 2) were studied in a variety of normal and DNA repair-deficient human fibroblast host cell strains. In order to examine the lesion specificity of ER in human cells, experiments were performed using UV-irradiated and γ-irradiated virus. The investigation was carried out using a sensitive technique of indirect immunofluorescence, according to which irradiated and unirradiated cell cultures were infected with irradiated or unirradiated AD 2 and were subsequently examined for the presence of viral structural antigens ('V' Ag) at a fixed time after infection

  6. Preoperative irradiation and surgery for recurrent rectal cancer. Will intraoperative radiotherapy (IORT) be of additional benefit? A prospective study

    International Nuclear Information System (INIS)

    Wiig, Johan Nicolay; Tveit, Kjell Magne; Poulsen, Jan Peter; Olsen, Dag Rune; Giercksky, Karl-Erik

    2002-01-01

    Background: The therapeutic gain of surgery for recurrent rectal cancer is not clear, particularly with regard to the addition of intraoperative radiotherapy (IORT). Methods: Patients (107) with isolated pelvic recurrence of rectal cancer received preoperative external radiotherapy of 46-50 in 2 Gy fractions. At surgery 59 patients had IORT 12-18 Gy. Survival and local recurrence was analysed with regard to surgical resection stages and IORT. Results: Patients (44) had R0- and 39 R1-resections, 24 R2-resections or exploratory laparotomy. IORT was given most often after R1-resections, least in R0-patients. Estimated 5-year survival was overall around 30%, around 60% in the R0-, around 25% for R1- and 0% in R2-patients. Local recurrence was around 30% in the R0- and around 65% in R1-stage patients. R0-/R1-stage patients survived statistically significantly longer than the R2-group otherwise there was no statistical significant difference between IORT and non-IORT groups in any R-stages regarding overall survival or local recurrence. Conclusions: Macroscopic removal of the recurrence improves survival. Whether R0- is better than R1-resections is not clear. The effect of IORT is not a major one. IORT need be evaluated in randomised controlled trials

  7. Irradiation behavior of graphite shielding materials for FBR

    International Nuclear Information System (INIS)

    Maruyama, Tadashi; Kaito, Takeji; Onose, Shoji; Shibahara, Itaru

    1994-01-01

    Thirteen kinds of isotropic graphites with different density and maximum grain size were irradiated in the experimental fast reactor 'JOYO' to fluences from 2.11 to 2.86x10 26 n/m 2 (E>0.1 MeV) at temperatures from 549 to 597degC. Postirradiation examination was carried out on dimensional change, elastic modulus, and the thermal conductivity. The result of measurement of dimensional change indicated that the graphites irradiated at lower fluences showed shrinkage upon neutron irradiation followed by increase with increasing neutron fluences, irrespective of differences in material parameters. The Young's modulus and Poisson's ratio increased to two to three times of unirradiated values. A large scatter found in Poisson's ratio of unirradiated materials became very small and a linear dependency on density was obtained after irradiation. The thermal conductivity decreased to one-fifth to one-tenth of unirradiated values, but the change in specific heat was negligibly small. The results of postirradiation examination indicated that the changes in physical properties of high density, isotropic graphites were mainly dominated by the irradiation condition rather than their material parameters. Namely, the effects of irradiation induced defects on physical properties of heavily neutron-irradiated graphites are much larger than that of defects associated with as-fabricated specimens. (author)

  8. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    Energy Technology Data Exchange (ETDEWEB)

    Arbeitman, Claudia R.; Grosso, Mariela F. del [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Behar, Moni [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); García Bermúdez, Gerardo, E-mail: ggb@tandar.cnea.gov.ar [CONICET – Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina); Gerencia de Investigación y Aplicaciones, TANDAR-CNEA (Argentina); Escuela de Ciencia y Tecnología, UNSAM (Argentina)

    2013-11-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology.

  9. Effects of irradiated biodegradable polymer in endothelial cell monolayer formation

    International Nuclear Information System (INIS)

    Arbeitman, Claudia R.; Grosso, Mariela F. del; Behar, Moni; García Bermúdez, Gerardo

    2013-01-01

    In this work we study cell adhesion, proliferation and cell morphology of endothelial cell cultured on poly-L-lactide acid (PLLA) modified by heavy ion irradiation. Thin films of PLLA samples were irradiated with sulfur (S) at energies of 75 MeV and gold (Au) at 18 MeV ion-beams. Ion beams were provided by the Tandar (Buenos Aires, Argentina) and Tandetron (Porto Alegre, Brazil) accelerators, respectively. The growth of a monolayer of bovine aortic endothelial cells (BAEC) onto unirradiated and irradiated surfaces has been studied by in vitro techniques in static culture. Cell viability and proliferation increased on modified substrates. But the results on unirradiated samples, indicate cell death (necrosis/apoptosis) with the consequent decrease in proliferation. We analyzed the correlation between irradiation parameters and cell metabolism and morphology

  10. Improvement of colour strength and colourfastness properties of gamma irradiated cotton using reactive black-5

    International Nuclear Information System (INIS)

    Ahmad Bhatti, Ijaz; Adeel, Shahid; Nadeem, Raziya; Asghar, Toheed

    2012-01-01

    The dyeing behaviour of gamma irradiated cotton fabric using Reactive Black-5 dye powder has been investigated. The mercerized, bleached and plain weaved cotton fabric was irradiated to different absorbed doses of 100, 200, 300, 400, 500 and 600 Gy using Co-60 gamma irradiator. Dyeing was performed using irradiated and un-irradiated cotton with dye solutions. The dyeing parameters such as temperature of dyeing, time of dyeing and pH of dyeing solutions were optimised. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton in CIE Lab system using Spectra flash SF650. Methods suggested by International Standard Organisation (ISO) were employed to study the effect of gamma irradiation on the colourfastness properties of dyed fabric. It is found that gamma irradiated cotton dyed with Reactive Black-5 has not only improved the colour strength but also enhanced the rating of fastness properties. - Highlights: ► Optimum absorbed dose for cotton is 500 Gy using un-irradiated Reactive Black-5. ► Optimum dyeing conditions: 60 °C, 30 min and dyeing pH is10. ► At optimum conditions colour strength and fastness properties are enhanced. ► Gamma irradiation can improve dyeing characters of other dyed fabrics.

  11. Thermal decomposition of γ-irradiated lead nitrate

    International Nuclear Information System (INIS)

    Nair, S.M.K.; Kumar, T.S.S.

    1990-01-01

    The thermal decomposition of unirradiated and γ-irradiated lead nitrate was studied by the gas evolution method. The decomposition proceeds through initial gas evolution, a short induction period, an acceleratory stage and a decay stage. The acceleratory and decay stages follow the Avrami-Erofeev equation. Irradiation enhances the decomposition but does not affect the shape of the decomposition curve. (author) 10 refs.; 7 figs.; 2 tabs

  12. First results of laser welding of neutron irradiated stainless steel

    International Nuclear Information System (INIS)

    Osch, E.V. van; Hulst, D.S. d'; Laan, J.G. van der.

    1994-10-01

    First results of experimental investigations on the laser reweldability of neutron irradiated material are reported. These experiments include the manufacture of 'heterogeneous' joints, which means joining of irradiated stainless steel of type AISI 316L-SPH to 'fresh' unirradiated material. The newly developed laser welding facility in the ECN Hot Cell Laboratory and experimental procedures are described. Visual inspections of welded joints are reported as well as results of electron microscopy and preliminary metallographic examinations. (orig.)

  13. Post irradiation examination of type 316 stainless steels for in-pile Oarai water loop No.2 (OWL-2)

    International Nuclear Information System (INIS)

    Shibata, Akira; Kimura, Tadashi; Nagata, Hiroshi; Aoyama, Masashi; Kanno, Masaru; Ohmi, Masao

    2010-11-01

    The Oarai water loop No.2 (OWL-2) was installed in JMTR in 1972 for the purpose of irradiation experiments of fuel element and component material for light water reactors. Type 316 stainless steels (SSs) were used for tube material of OWL-2 in the reactor. But data of mechanical properties of highly irradiated Type 316 SSs has been insufficient since OWL-2 was installed. Therefore surveillance tests of type 316 SSs which were irradiated up to 3.4x10 25 n/m 2 in fast neutron fluence (>1 MeV) were performed. Meanwhile type 316 stainless steel (SS) is widely used in JMTR such as other irradiation apparatus and irradiation capsule, and additional data of type 316 SSs irradiated higher is required. Therefore post irradiation examinations of surveillance specimens made of type 316 SSs which were irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence were performed and reported in this paper. In this result of surveillance tests of type 316 SSs irradiated up to 1.0x10 26 n/m 2 , tensile strength increase with increase of Neutron fluence and total elongation decreased with increase of Neutron fluence compared to unirradiated specimens and specimens irradiated up to 3.4x10 25 n/m 2 . This tendency has good agreement with results of 10 24 - 10 25 n/m 2 in fast neutron fluence. More than 37% in total elongation was confirmed in all test conditions. It was confirmed that type 316 SS irradiated up to 1.0x10 26 n/m 2 in fast neutron fluence has enough ductility as structure material. (author)

  14. Physico Mechanical Properties of Irradiated Waste Rubber Cement Mortar

    International Nuclear Information System (INIS)

    Younes, M.M.

    2010-01-01

    In the present study a partial replacement of aggregate with two different ratios of waste rubber (5%, 10%) with the addition of a constant ratio of rice husk ash (RHA), 5% was carried out. The hardened cement mortar used the optimum water of consistency. The specimens were molded into 1 inch cubic moulds .The specimens were first cured for 24 hours, at 100% relative humidity and then cured under tap water for 3, 7 and 28 days followed by irradiation at different doses of gamma irradiation namely 5 and 10 kGy. The physico-chemical and mechanical properties such as compressive strength, total porosity and bulk density were studied for the three types of specimens. The results showed that the values of the compressive strength, bulk density and chemically combined water of the blended cement mortar paste (OPC-RHA) increase ,while blended cement mortar paste with 5% RHA and 5, 10% waste rubber decrease. The results were confirmed by scanning electron microscopy and thermal behavior of the specimens. Also, it was observed that the irradiated sample was thermally more stable than the unirradiated one

  15. Life table of grape phylloxera on some irradiated in vitro cultured rootstocks

    International Nuclear Information System (INIS)

    Makee, H.; Charbaji, T.; Ayyoubi, Z.; Idris, I.

    2007-08-01

    The life table of local strain of grape phylloxera on the most commonly used rootstocks; Ru140, R99 and 3309 C and one local variety Helwani, which were in vitro cultured and treated with low doses of gamma irradiation was determined. Additionally, the effect of different concentrations of IAA on reproduction and development of phylloxera, which infested the roots of our local grape variety Helwani, was evaluated. Our results showed that the life table of grape phylloxera was different between irradiated and unirradiated in vitro plants. The survival, fecundity and developmental time were reduced by applying irradiation. Thus, low doses of gamma irradiation increased grape resistance to phylloxera. The was a positive effect of of IAA on the resistance of Helwani to phylloxera when it was infested at old age (80-d-old). However, the susceptible of Helwani to phlloxera was increased when it was infested at young age (40-d-old). The present study provides good information on the possibility of using irradiation and hormone to increase the resistance of grape to phylloxera.(author)

  16. Augmentation of transfer of experimental autoimmune thyroiditis (EAT) in mice by irradiation of recipients

    International Nuclear Information System (INIS)

    Williams, W.V.; Kyriakos, M.; Sharp, G.C.; Braley-Mullen, H.

    1987-01-01

    Experimental autoimmune thyroiditis (EAT) can be adoptively transferred to normal syngeneic recipients using spleen cells from susceptible strains of mice primed in vivo with mouse thyroglobulin (MTg) and lipopolysaccharide (LPS) following in vitro activation of spleen cells by culture with MTg. Irradiation of recipient animals markedly augments the severity of thyroiditis induced in this system. Irradiation of recipients does not alter the time course of the development of thyroiditis, nor does it alter the requirement for both in vivo priming and in vitro activation of spleen cells for the development of EAT. Spleen cells from EAT-resistant strains of mice (e.g., Balb/c) do not induce EAT in irradiated recipients. Irradiated recipients develop significant levels of anti-MTg antibodies while unirradiated recipients have little detectable antibody response. The augmenting effect of irradiation can be substantially reversed by transferring naive spleen cells to recipients prior to the transfer of MTg/LPS-primed in vitro-activated spleen cells. In addition athymic CBA/Tufts nude mice develop more severe EAT than CBA/Tufts nude/+ littermates following transfer of activated CBA/J spleen cells. These data suggest that natural suppressor cells may regulate the development of EAT at the effector cell level

  17. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  18. X-ray irradiation and Rho-kinase inhibitor additively induce invasiveness of the cells of the pancreatic cancer line, MIAPaCa-2, which exhibits mesenchymal and amoeboid motility

    International Nuclear Information System (INIS)

    Fujita, Mayumi; Otsuka, Yoshimi; Yamada, Shigeru; Iwakawa, Mayumi; Imai, Takashi

    2011-01-01

    Tumor cells can migrate and invade tissue by two modes of motility: mesenchymal and amoeboid. X-ray or γ-ray irradiation increases the invasiveness of tumor cells with mesenchymal motility through the induction of matrix metalloproteinases (MMP), and this increase is suppressed by MMP inhibitors (MMPI). However, the effects of X-ray or γ-ray irradiation on the invasiveness of tumor cells with amoeboid motility remain unclear. We investigated the effect of irradiation on amoeboid motility by using cells of the human pancreatic cancer line, MIAPaCa-2, which exhibits both modes of motility. The X-ray-induced invasiveness of MIAPaCa-2 cells was associated with the upregulation of MMP2 at both the RNA and protein levels and was inhibited by MMPI treatment. Amoeboid-mesenchymal transition was slightly induced after irradiation. The MMPI treatment caused mesenchymal-amoeboid transition without significant increase in invasiveness, while the ROCK inhibitor (ROCKI) stimulated amoeboid-mesenchymal transition and enhanced invasiveness under both non-irradiated and irradiated conditions. This ROCKI-induced transition was accompanied by the upregulation of MMP2 mRNA and protein. Exposure to both irradiation and ROCKI further enhanced MMP2 expression and had an additive effect on the invasiveness of MIAPaCa-2 cells. Additionally, exposure to MMPI led to significant suppression of both radiation-induced and the basal invasiveness of MIAPaCa-2 cells. This suggests that ROCKI treatment, especially with concomitant X-ray irradiation, can induce invasion of cancer cells and should be used only for certain types of cancer cells. Simultaneous use of inhibitors, ROCKI and MMPI may be effective in suppressing invasiveness under both X-ray-irradiated and non-irradiated conditions. (author)

  19. Effect of gamma irradiation on linear low density polyethylene/magnesium hydroxide/sepiolite composite

    International Nuclear Information System (INIS)

    Shafiq, Muhammad; Yasin, Tariq

    2012-01-01

    Radiation crosslinking is generally used to improve the thermo-mechanical properties of the composites. A study has been carried out to investigate the effect of gamma radiation on the thermo-mechanical properties of linear low density polyethylene containing magnesium hydroxide (MH) and sepiolite (SP) as non-halogenated flame retardant additives. The developed composites are irradiated at different doses upto maximum of 150 kGy. Infrared spectra of the irradiated composites reveal the reduction in the intensity of O-H band with increase in the absorbed doses, thus indicates a distinct structural change in MH at higher doses. The thermogravimetric analysis results of unirradiated and composites irradiated at low doses (≤75 kGy) show two steps weight loss, which is changed to single step at higher doses with lower thermal stability. The melting temperature (T m ) and crystallization temperature (T c ) of irradiated composites are lowered with irradiation whereas Vicat softening temperature (VST) is increased. The increasing trend in gel content with increase in the absorbed dose confirms the presence of crosslinked network. The mechanical properties, results show significant improvement in the modulus of irradiated composites. The results also confirm that MH gradually loses its OH functionality with irradiation. - Highlights: → We have studied the effect of γ radiation on LLDPE containing Mg(OH) 2 and sepiolite. → IR spectra of the irradiated composites show reduction in the intensity of O-H band. → Reduction in OH band show a distinct structural change in Mg(OH) 2 at higher doses. → TGA results show two steps weight loss at low doses and one step at higher doses. → These results confirm that MH gradually loses its OH functionality with irradiation.

  20. Safe storage of premature maize ears through gamma radiation and irradiation effect on chemical composition

    International Nuclear Information System (INIS)

    Gupta, H.O.; Singh, N.N.; Roy, M.K.

    2003-01-01

    Marked differences were observed between unirradiated and irradiated premature ears (early dough stage) of maize during storage. Some molds were developed on the grains and deterioration set in at the peduncle and stone of maize in the unirradiated ears, whereas no such symptoms were observed in the 3 kGy irradiated ears even after 45 days of storage. Changes in chemical constituents viz. starch, protein, total sugars were observed in the ears without adversely affecting the quality traits through radiation although 100 grains weight reduced slightly. (author)

  1. Detection of irradiation treatment of foods using DNA 'comet assay'

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Hasan M.; Delincee, Henry

    1998-06-01

    Microgel electrophoresis of single cells (DNA comet assay) has been investigated to detect irradiation treatment of some food samples. These samples of fresh and frozen rainbow trout, red lentil, gram and sliced almonds were irradiated to 1 or 2 kGy using 10 MeV electron beam from a linear accelerator. Rainbow trout samples yielded good results with samples irradiated to 1 or 2 kGy showing fragmentation of DNA and, therefore, longer comets with no intact cells. Unirradiated samples showed shorter comets with a significant number of intact cells. For rainbow trout stored in a freezer for 11 days the irradiated samples can still be discerned by electrophoresis from unirradiated samples, however, the unirradiated trouts also showed some longer comets besides some intact cells. Radiation treatment of red lentils can also be detected by this method, i.e. no intact cells in 1 or 2 kGy irradiated samples and shorter comets and some intact cells in unirradiated samples. However, the results for gram and sliced almond samples were not satisfactory since some intact DNA cells were observed in irradiated samples as well. Probably, incomplete lysis has led to these deviating results.

  2. Shelf-life extension of minimally processed and gamma irradiated red beet (Beta vulgaris ssp. vulgaris L.), Cv. early wonder

    International Nuclear Information System (INIS)

    Hernandes, Nilber Kenup; Vital, Helio de Carvalho; Coneglian, Regina Celi Cavestre

    2007-01-01

    This work investigated the effects of gamma irradiation on the shelf-life extension and safety of minimally processed red beet (Beta vulgaris ssp. vulgaris L.) by performing microbiological, chemical and sensory analyses. Red beets were harvested 73 days after transplanting and their tuberous parts were minimally processed and separated in two groups: control (non-irradiated) and irradiated (0.5, 1.0 and 1.5 kGy). Tests for Salmonella sp., total and fecal coliforms, total count of aerobic mesophilic and lactic-acid bacteria were performed during the 21-day storage at 8 deg C. They indicated that the samples irradiated with 1.0 and 1.5 kGy remained in good conditions throughout storage while the unirradiated samples did not last 7 days. Chemical analyses indicated that the concentrations of vitamins B1 and B2 were not affected by irradiation. In contrast the amounts of fructose and glucose increased during storage while the one for sucrose decreased. In addition four series of sensory evaluations including appearance and aroma indicated that the samples irradiated with 1.0 and 1.5 kGy remained good for consumption for 20 days. Therefore it was concluded that the use of the doses of 1.0 and 1.5 kGy produced the best effects on the conservation of the samples without harming the sensory characteristics and nutritional constituents tested. (author)

  3. Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI Series 5

    International Nuclear Information System (INIS)

    Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O.; Menke, B.H.

    1992-10-01

    The Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program obtained a statistically significant fracture toughness data base on two high-copper (0.23 and 0.31 wt %) submerged-arc welds to determine the shift and shape of the K Ic curve as a consequence of irradiation. Compact specimens with thicknesses to 101.6 mm (4 in) in the irradiated condition and 203.2 mm (8 in) in the unirradiated condition were tested, in addition to Charpy impact, tensile, and drop-weight specimens. Irradiations were conducted at a nominal temperature of 288 degree C and an average fluence of 1.5 x 10 19 neutrons/cm 2 (>l MeV). The Charpy 41-J temperature shifts are about the same as the corresponding drop-weight NDT temperature shifts. The irradiated welds exhibited substantial numbers of cleavage pop-ins. Mean curve fits using two-parameter (with fixed intercept) nonlinear and linearized exponential regression analysis revealed that the fracture toughness 100 MPa lg-bullet √m shifts exceeded the Charpy 41-J shifts for both welds. Analyses of curve shape changes indicated decreases in the slopes of the fracture toughness curves, especially for the higher copper weld. Weibull analyses were performed to investigate development of lower bound curves to the data, including the use of a variable K min parameter which affects the curve shape

  4. Investigation of the effects of irradiation for quarantine treatment purposes on food quality and hygiene in citrus fruits

    International Nuclear Information System (INIS)

    2010-01-01

    Mediterranean fruit fly (Ceratitis capitata) is a major problem in citrus production sector in Turkey. In order to overcome this problem, required irradiation doses were investigated for the quarantine treatment for 'Yafa' orange (Citrus sinensis (L) Osb.), 'Star ruby' grapefruit (Citrus paradisi Macf.); 'Satsuma' tangerine (Citrus reticulata Blanco) in this project. Chemical, physical and microbiological properties of unirradiated and irradiated (0.5, 1.0 and 1.5 kGy) fruits were determined in terms of weight loss, water soluble dry matter, pH, titratable acidity, alcohol insoluble pectin, apparent color of fruits, reducing sugar, total carotenoid, flavonoid, vitamin C contents, sensory properties of fruits, total aerob mesophilic bacteria and total yeast and mould counts of fruits. Results showed that, 0.1 kGy gamma irradiation dose is sufficient for effective quarantine treatment against the Mediterranean fruit fly in citrus fruits, low dose irradiation (≤1.0 kGy) applications had no detrimental effects on citrus fruits' quality except tangerines, microbial load of fruits were seriously affected by irradiation at 1.0 kGy. In addition, under this work we noticed that, irradiated citrus fruits could be detected by using DNA comet analysis method.

  5. Preliminary microstructural characterization by transmission electron microscopy of 14 MeV neutron irradiated type 316 stainless steel

    International Nuclear Information System (INIS)

    Echer, C.J.

    1977-01-01

    Substantial changes in the mechanical properties of 316 stainless steel were observed after neutron irradiation (phi/sub t/ = 2.3 x 10 21 n/m 2 and E = 14 MeV) at 25 0 C. Comparison of microstructures of the unirradiated and neutron irradiated materials were evaluated using transmission electron microscopy. Evidence of small defect clusters in the irradiated material was found. These findings are consistent with other investigators also evaluating low dose irradiations

  6. Effects of low dose irradiation on the K-value and hypoxanthine concentration of fish fillets

    International Nuclear Information System (INIS)

    Williams, D.J.; Mitchell, G.E.; Nottingham, S.M.; Jarrett, S.J.; Petroff, M.

    1993-01-01

    Fillets of five fish species were irradiated at 0, 1 and 3kGy to investigate whether the K-value test of freshness can be applied to irradiated fish. Following irradiation, the fillets were stored on ice and sampled regularly for K-value analysis. Hypoxanthine (Hx) and total nucleotide content were also determined on fillets of two species. K-values of irradiated fillets were generally lower than those of unirradiated controls. Hypoxanthine levels paralleled the K-value changes. These results indicated that quality standards based on K-values or Hx levels that have been set for unirradiated species cannot be directly applied to fish that has been irradiated. Total nucleotide content did not appear to be affected by irradiation

  7. TEMPO addition into pre-irradiated fluoropolymers and living-radical graft polymerization of styrene for preparation of polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, Shin-ichi, E-mail: sawada.shinnichi@jaea.go.j [Conducting Polymer Materials Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Department of Nuclear Engineering and Management, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Suzuki, Akihiro; Terai, Takayuki [Department of Nuclear Engineering and Management, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Maekawa, Yasunari, E-mail: maekawa.yasunari@jaea.go.j [Conducting Polymer Materials Research Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2010-04-15

    We prepared proton exchange membranes (PEMs) by 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO)-mediated living-radical graft polymerization (LRGP) of styrene into fluoropolymer films and subsequent sulfonation. Poly(vinylidene fluoride) (PVDF) and poly(ethylene-co-tetrafluoroethylene) (ETFE) films were first irradiated and then treated with TEMPO solutions in various solvents. TEMPO addition was confirmed by the test of styrene grafting into TEMPO-treated films at 60 deg. C, at which the LRGP never proceeds. This test enabled us to differentiate the LRGP from the conventional graft polymerization. In order to gain a deep insight about TEMPO-addition reaction, the TEMPO-penetration behavior into the base polymer films was examined by a permeation experiment and computer simulation. Xylene and dioxane were appropriate solvents for the complete introduction of TEMPO into PVDF and ETFE films, respectively. Then, the LRGP of styrene was performed based on the fully TEMPO-capped films at 125 deg. C with various solvents. By using an alcoholic solvent, the degree of grafting was enhanced and it reached a maximum of 38%. This grafted film was sulfonated to prepare a PEM showing an ion exchange capacity of 2.2 meq/g and proton conductivity of 1.6x10{sup -1} S/cm.

  8. Effect of gamma irradiation on storability of two cultivars of Syrian grapes (Vitis Vinifera)

    International Nuclear Information System (INIS)

    Al-Bachir, M.

    1999-01-01

    This study was initiated to investigate the effect of gamma irradiation on storability of two local table grape varieties: Baladi and Helwani. The experiments were performed in 1995 and 1996, when both varieties were treated with 0, 0.5, 1.0 and 1.5 kGy in the first year. In the second year two additional doses were used 0.1 and 0.25 kGy for Helwani and 2.0 and 2.5 kGy for Baladi. Irradiated and unirradiated fruits were stored in a refrigerated room (temperature, 1-2 Centigrade). Weight loss, spoilage and total loss were evaluated every 2 and 4 weeks of storage for Baladi and Helwani, respectively. The results have shown that gamma irradiation improved the storability of both varieties. in addition, irradiation prevented molding and prolonged the storage time. The optimum doses for improving the storability were 0.5-1.0 kGy for Halwani and 1.5-2.0 kGy for the storage periods can be extended by 50% using these optimal doses for both varieties. (author)

  9. Effect of gamma irradiation on storability of two cultivars of Syrian grapes Vitis vinifera

    International Nuclear Information System (INIS)

    Al Bashir, M.

    1999-01-01

    This study was initiated to investigate the effect of gamma irradiation on storability of two local table grape varieties: Baladi and Helwani. The experiments were performed in 1995 and 1996, when both varieties were treated with 0, 0.5, 1.0 and 1.5 kGy in the first year. In the second year two additional doses were used 0.1 and 0.25 kGy for Helwani and 2.0 and 2.5 kGy for Baladi. Irradiated and unirradiated fruits were stored in a refrigerated room (temperature, 1–2°C). Weight loss, spoilage and total loss were evaluated every 2 and 4 weeks of storage for Baladi and Helwani, respectively. The results have shown that gamma irradiation improved the storability of both varieties. In addition, irradiation prevented molding and prolonged the storage time. The optimum doses for improving the storability were 0.5–1.0 kGy for Helwani and 1.5–2.0 kGy for Baladi, and the storage periods can be extended by 50% using these optimal doses for both varieties

  10. Effect of gamma irradiation on storability of two cultivars of Syrian grapes ( Vitis vinifera)

    Science.gov (United States)

    Al-Bachir, M.

    1999-06-01

    This study was initiated to investigate the effect of gamma irradiation on storability of two local table grape varieties: Baladi and Helwani. The experiments were performed in 1995 and 1996, when both varieties were treated with 0, 0.5, 1.0 and 1.5 kGy in the first year. In the second year two additional doses were used 0.1 and 0.25 kGy for Helwani and 2.0 and 2.5 kGy for Baladi. Irradiated and unirradiated fruits were stored in a refrigerated room (temperature, 1-2°C). Weight loss, spoilage and total loss were evaluated every 2 and 4 weeks of storage for Baladi and Helwani, respectively. The results have shown that gamma irradiation improved the storability of both varieties. In addition, irradiation prevented molding and prolonged the storage time. The optimum doses for improving the storability were 0.5-1.0 kGy for Helwani and 1.5-2.0 kGy for Baladi, and the storage periods can be extended by 50% using these optimal doses for both varieties.

  11. A germination test: an easy approach to know the irradiation

    International Nuclear Information System (INIS)

    Khawar, A.; Bhatti, I.A.; Bhatti, H.N.

    2010-01-01

    Food irradiation is an evolving preserving technique that provides a shield against the spoilage and might have a potential to ensure the food safety and security world wide. In the present study, feasibility to apply germination test to distinguish an un-irradiated and irradiated samples of wheat, maize, chickpea and black eye beans was checked. Samples were irradiated to the absorbed doses ranging from 0-10 kGy using Co-60 gamma irradiator and were germinated in plant growth chamber. Root and shoot lengths were measured at 7th day after gamma radiation treatment. In all the irradiated samples root and shoot lengths were decreased with the increase in radiation absorbed doses. The seeds irradiated to the absorbed doses more than 2 kGy were not germinated. Germination test proved as an easy and simple method to detect irradiation in wheat, maize, chickpea and black eye beans irradiated even at low absorbed doses. (author)

  12. Flow sheet development for the dissolution of unirradiated Mark 42 fuel tubes in F-Canyon, Part II

    International Nuclear Information System (INIS)

    Murray, A.M.

    1999-01-01

    Two dissolution flow sheets were tested for the desorption of unirradiated Mark 42 fuel tubes. Both the aluminum (from the can, cladding, and fuel core) and the plutonium oxide (PuO 2 ) are dissolved simultaneously, i.e., a co-dissolution flow sheet. In the first series of tests, 0.15 and 0.20 molar (M) potassium fluoride (KF) solutions were used and the dissolution extended over several days. In the other series of tests, solutions with higher concentrations of fluoride (0.25 to 0.30 M) were used. Calcium fluoride (CaF 2 ) was used in those tests as the fluoride source

  13. Properties of unirradiated fuel element graphites H-451 and SO818. [Bulk density, tensile properties, thermal expansion, thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Engle, G.B.; Johnson, W.R.

    1976-10-08

    Nuclear graphites H-451, lot 440 (Great Lakes Carbon Corporation (GLCC)), and SO818 (Airco Speer Division, Air Reduction Corporation (AS)) are described, and physical, mechanical, and chemical property data are presented for the graphites in the unirradiated state. A summary of the mean values of the property data and of data on TS-1240 and H-451, lot 426, is tabulated. A direct comparison of H-451, lot 426, chosen for Fort St. Vrain (FSV) fuel reload production, TS-1240, and SO818 may be made from the table. (auth)

  14. Application of fire-retardant treatment to the wood in Type A unirradiated nuclear fuel outer containers

    International Nuclear Information System (INIS)

    Whitlow, J.D.; Luna, R.E.

    1992-01-01

    Packagings for transporting unirradiated nuclear fuel assemblies in the United States are commonly constructed as rectangular boxes consisting of a metal inner container, a wooden outer container, and cushioning material separating the two. The wood in the outer container is a potential source of fuel for fire. Use of a fire-retardant treatment on the wood may reduce or eliminate the damage to nuclear fuel assemblies in some types of accidents involving fire. The applicability of using fire-retardant treatments on the wood of outer containers is addressed. An approximate cost-benefit analysis to determine if fire-retardant treatments are economically justified is presented. (Author)

  15. Solubility of unirradiated UO2 fuel in aqueous solutions. Comparison between experimental and calculated (EQ3/6) data

    International Nuclear Information System (INIS)

    Ollila, K.

    1995-11-01

    The solubility behaviour of unirradiated UO 2 pellets was studied under oxic (air-saturated) and anoxic (N 2 ) conditions in deionized water, in sodium bicarbonate solutions with varying bicarbonate content (60 - 600 ppm), in Allard groundwater simulating granitic fresh groundwater conditions, and in bentonite water simulating the effects of bentonite on granitic fresh groundwater (25 deg C). The release of uranium was measured during static batch dissolution experiments of long duration (2-6 years). A comparison was made with the theoretical solubility data calculated with the geochemical code EQ3/6 in order to evaluate solubility (steady state) limiting factors. (orig.) (26 refs., 32 figs., 13 tabs.)

  16. Simulation model for electron irradiated IGZO thin film transistors

    Science.gov (United States)

    Dayananda, G. K.; Shantharama Rai, C.; Jayarama, A.; Kim, Hyun Jae

    2018-02-01

    An efficient drain current simulation model for the electron irradiation effect on the electrical parameters of amorphous In-Ga-Zn-O (IGZO) thin-film transistors is developed. The model is developed based on the specifications such as gate capacitance, channel length, channel width, flat band voltage etc. Electrical parameters of un-irradiated IGZO samples were simulated and compared with the experimental parameters and 1 kGy electron irradiated parameters. The effect of electron irradiation on the IGZO sample was analysed by developing a mathematical model.

  17. Thermoluminescence (TL) in the identification of irradiated food

    International Nuclear Information System (INIS)

    Luthra, J.M.

    1992-01-01

    Due to progressive expansion of commercial food irradiation in recent years, the interest in detecting whether a food has been irradiated or not is growing fast and research in several methods for identification of various irradiated food stuffs is the order of the day. TL has emerged as one of the most promising tool for distinguishing between irradiated and unirradiated food. Advantages of TL method over other physical methods, its application to various foods, limitation and present state of art are discussed.(author). 9 refs., 3 tabs

  18. The effect of irradiation on the sensorial quality behaviour of packed fresh fish

    International Nuclear Information System (INIS)

    Reinacher, E.

    1978-01-01

    Cod from the Baltic Sea was irradiated with 10 krad X-rays and pached in ice with the objective to preserve it for a longer period while retaining a satisfactory sensorial quality. The vacuum-packed, irradiated cod fillet kept its quality 5 days longer than usual. On the other hand, aerobically packed, irradiated cod did not keep its quality longer than whole, unirradiated fish that was openly stored in ice. (AJ) [de

  19. Progress report on irradiation experiment on small size specimens in high temperature flux module

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, M.; Jacquet, P.; Chaouadi, R.

    2011-02-15

    This report describes the progress made in IFREC/DEMO Research and Development Program during the year 2010 at SCK/CEN. This task is part of demonstrating the possibility to irradiate small specimens in the HFTM modules that will be used in DEMO. Different small specimens of three candidate materials of DEMO fusion reactor will be irradiated with the objective of validating the specimen geometry and size to reliably characterize the mechanical properties of unirradiated and in future of irradiated materials.

  20. An investigation of the genetic toxicology of irradiated foodstuffs using short-term test systems

    International Nuclear Information System (INIS)

    Phillips, B.J.; Kranz, E.; Elias, P.S.

    1980-01-01

    As part of a programme of short-term tests used to detect possible genetic toxicity in irradiated foodstuffs, cultured Chinese hamster ovary cells were exposed to extracts and digests of irradiated and unirradiated dates, fish and chicken and subjected to tests for cytotoxicity, sister chromatid exchange induction and mutation to thioguanine resistance. The results showed no evidence of genetic toxicity induced in food by irradiation. The general applicability of cell culture tests to the detection of mutagens in food is discussed. (author)

  1. Irradiation damage and recovery in shoot apices of sweet cherry (Prunus avium L.)

    International Nuclear Information System (INIS)

    Saamin, S.; Thompson, M.M.

    1990-01-01

    Full text: Dormant scions of 'Bing' were exposed to fractionated 6kR gamma rays and then grafted. Irradiated and unirradiated main buds were sampled at 3 day intervals for one month. Buds were fixed in FAA, longitudinally sectioned, and stained with hematoxylin. Both random and localised cell damage was observed in irradiated apices. There was evidence of radiosensitivity gradient in the shoot apex. Recovery from irradiation damage was via flank meristem, central meristem, or leaf primordia and axillary meristems. (author)

  2. Dissolution rates of unirradiated UO2, UO2 doped with 233U, and spent fuel under normal atmospheric conditions and under reducing conditions using an isotope dilution method

    International Nuclear Information System (INIS)

    Ollila, Kaija; Albinsson, Yngve; Oversby, Virginia; Cowper, Mark

    2003-10-01

    The experimental results given in this report allow us to draw the following conclusions. 1) Tests using unirradiated fuel pellet materials from two different manufacturers gave very different dissolution rates under air atmosphere testing. Tests for fragments of pellets from different pellets made by the same manufacturer gave good agreement. This indicates that details of the manufacturing process have a large effect on the behavior of unirradiated UO 2 in dissolution experiments. Care must be taken in interpreting differences in results obtained in different laboratories because the results may be affected by manufacturing effects. 2) Long-term tests under air atmosphere have begun to show the effects of precipitation. Further testing will be needed before the samples reach steady state. 3) Testing of unirradiated UO 2 in systems containing an iron strip to produce reducing conditions gave [U] less than detection limits ( 235 U added as spike was recovered, indicating that 90% of the spike had precipitated onto the solid sample or the iron strip. 9) Tests of UO 2 pellet materials containing 233 U to provide an alpha decay activity similar to that expected for spent fuel 3000 and 10,000 years after disposal showed that the pellet materials behaved as expected under air atmosphere conditions, showing that the manufacturing method was successful. 10) Early testing of the 233 U-doped materials under reducing conditions showed relatively rapid (30 minute) dissolution of small amounts of U at the start of the puff test procedure. Results of analyses of an acidified fraction of the same solutions after 1 or 2 weeks holding indicate that the solutions were inhomogeneous, indicating the presence of colloidal material or small grains of solid. 11) Samples from the 233 U-doped tests initially indicated dissolution of solid during the first week of testing, with some indication of more rapid dissolution of the material with the higher doping. 12) The second cycle of testing

  3. Irradiation detection of coffee mate by electron spin resonance (ESR)

    Energy Technology Data Exchange (ETDEWEB)

    Ozsayin, Fulya [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey); Polat, Mustafa, E-mail: polat@hacettepe.edu.t [Physics Engineering Department, Hacettepe University, 06800 Ankara (Turkey)

    2011-06-15

    Un-irradiated coffee mate samples do not exhibit any ESR signal. However, the samples exposed to UV and gamma radiation exhibit an ESR singlet and a large unresolved ESR signal, respectively. The dose-response curves of the samples exposed to UV and gamma radiations were found to be described well by an exponential and linear functions, respectively. Variable temperature and fading studies at room temperature showed that the radiation-induced radicals in coffee mate sample are very sensitive to temperature. The discrimination between un-irradiated and irradiated coffee mate samples can be done just comparing their ESR spectra. However, determination of the radiation dose received by the sample cannot be possible because of the fast decay of signal intensity at room temperature.

  4. Improving microbiological safety and maintaining sensory and nutritional quality of pre-cut tomato and carrot by gamma irradiation

    International Nuclear Information System (INIS)

    Mohácsi-Farkas, Cs.; Nyirő-Fekete, B.; Daood, H.; Dalmadi, I.; Kiskó, G.

    2014-01-01

    Pre-cut tomato and carrot were irradiated with doses of 1.0, 1.5 and 2 kGy. Unirradiated control and irradiated samples were compared organoleptically by a sensory panel. Microbiological analyses were performed directly after irradiation and during post-irradiation storage for 8 days at 5 °C. Ascorbic acid contents, composition of carotenoids and tocopherols were determined. Statistically significant differences of sensory scores between unirradiated and irradiated samples were observed only in the texture of sliced carrots. Total aerobic viable cell counts have been reduced by about two log cycles with 1.5 kGy dose. Total coliforms and moulds were below the detection limit of 15 CFU/g in the irradiated samples during the refrigerated storage. Yeasts were relatively resistant part of the microbiota of pre-cut tomatoes, but 2 kGy dose reduced them below the detection limit. In pre-cut tomatoes, alpha-tocopherol and some carotenoids seemed to be the most radio-sensitive losing approximately one-third of their original concentrations at the dose of 2 kGy. At this dose tocopherols and the level of ascorbic acid decreased also one-third of the initial level in sliced carrots. Additional experiments were conducted to study the effect of irradiation and storage on the population of Listeria monocytogenes and Listeria innocua artificially inoculated on cut tomato and carrot. Cell numbers of both test organisms decreased by at least two log-cycles as an effect of 1 kGy dose. Our studies confirmed earlier findings on a temporary antilisterial effect of freshly cut carrot tissue. No re-growth of Listeria was observed during the studied storage period. The results of these studies suggest that irradiation with 1 kGy gamma rays could improve sufficiently the microbiological safety of the investigated pre-cut produce to satisfy the requirement of low microbial raw diets with acceptable nutritional quality and without diminishing significantly the organoleptic parameters of the

  5. Preliminary examination of induced radioactivity in pepper by 10 MeV electron irradiation

    International Nuclear Information System (INIS)

    Katayama, Tadashi; Furuta, Masakazu; Sibata, Setsuko; Ito, Norio; Mizohata, Akira; Matsunami, Tadao; Toratani, Hirokazu; Takeda, Atsuhiko.

    1991-01-01

    β-ray measurement was performed on 10 MeV electron-irradiated black pepper and white pepper with liquid scintillation counter in order to reconfirm the wholesomeness of irradiated foods and present unambiguous data to general consumers concerning about the induced radioactivity in the irradiated foods. In irradiated black pepper no radioactivity other than from natural source, un-irradiated one, was detected. But in irradiated white pepper, it was suggested that induced radioactivity might be detected if the detection method was more improved. (author)

  6. EPR investigation of some traditional oriental irradiated spices

    International Nuclear Information System (INIS)

    Duliu, Octavian G.; Georgescu, Rodica; Ali, Shaban Ibrahim

    2007-01-01

    The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and 60 Co γ-ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), and saffron (Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After γ-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 o C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices

  7. EPR investigation of some traditional oriental irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Duliu, Octavian G. [University of Bucharest, Department of Atomic and Nuclear Physics, Magurele, C.P. MG-11, RO-077125 Bucharest (Romania)]. E-mail: duliu@pcnet.ro; Georgescu, Rodica [National Institute for Physics and Nuclear Engineering -Horia Hulubei, C.P. MG-6, RO-077125 Bucharest (Romania); Ali, Shaban Ibrahim [University of Bucharest, Department of Atomic and Nuclear Physics, Magurele, C.P. MG-11, RO-077125 Bucharest (Romania)

    2007-06-15

    The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and {sup 60}Co {gamma}-ray irradiated cardamom (Elettaria cardamomum L. Maton, Zingiberaceae), ginger ((Zingiber officinale Rosc., Zingiberaceae), and saffron (Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After {gamma}-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 {sup o}C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices.

  8. EPR investigation of some traditional oriental irradiated spices

    Science.gov (United States)

    Duliu, Octavian G.; Georgescu, Rodica; Ali, Shaban Ibrahim

    2007-06-01

    The 9.50 GHz electron paramagnetic resonance (EPR) spectra of unirradiated and 60Co γ-ray irradiated cardamom ( Elettaria cardamomum L. Maton, Zingiberaceae), ginger (( Zingiber officinale Rosc., Zingiberaceae), and saffron ( Crocus sativus L., Iridaceae) have been investigated at room temperature. All unirradiated spices presented a weak resonance line with g-factors around free-electron ones. After γ-ray irradiation at an absorbed dose of up to 11.3 kGy, the presence of EPR spectra whose amplitude increase monotonously with the absorbed dose has been noticed with all spices. A 100 °C isothermal annealing of 11.3 kGy irradiated samples has shown a differential reduction of amplitude of various components that compose initial spectra, but even after 3.6 h of thermal treatment, the remaining amplitude represents no less then 30% of the initial ones. The same peculiarities have been noticed after 83 days storage at room temperature but after 340 days storage at ambient conditions only irradiated ginger displays a weak signal that differs from those of unirradiated sample. All these factors could be taken into account in establishing at which extent the EPR is suitable to evidence any irradiation treatment applied to these spices.

  9. Irradiation of meat products, chicken and use of irradiated spices for sausages

    Energy Technology Data Exchange (ETDEWEB)

    Kiss, I.F.; Beczner, J.; Zachariev, Gy. (Central Food Research Inst., Budapest (Hungary)); Kovacs, S. (Veterinary and Food Control Centre, Budapest (Hungary))

    1990-01-01

    The shelf-life of packed minced meat has been increased at least threefold at 4{sup 0}C by applying a 2 kGy dose. Results have been confirmed by detailed quantitative microbiological examinations. Sensory evaluations show no significant difference between the unirradiated and irradiated samples. The optimal average dose was 4 kGy for packed-frozen chicken. The number of mesophilic aerobic microbes was reduced by 2, that of psychrotolerant by 2-3 and that of Enterobacteriaceae by 3-4 orders of magnitude by 4 kGy. S. aureus and Salmonella could not be detected in the irradiated samples. in 1984-1985 5100 kg irradiated chickens were marketed labelled as radiation treated. Irradiated spices (5 kGy) were used in the production of sausages (heat-treated and non-heat-treated) under industrial conditions. The microbiological contamination of irradiated spices was lower than that of ethylene oxide treated ones. The cell count in products made with irradiated spices was lower than in those made with unirradiated spices. The sausages proved to be of very good quality. In accordance with the permission, products were marketed and because of the low ratio of spices there was no need to declare them as using irradiated spices. (author).

  10. Irradiation of meat products, chicken and use of irradiated spices for sausages

    International Nuclear Information System (INIS)

    Kiss, I.F.; Beczner, J.; Zachariev, Gy.; Kovacs, S.

    1990-01-01

    The shelf-life of packed minced meat has been increased at least threefold at 4 0 C by applying a 2 kGy dose. Results have been confirmed by detailed quantitative microbiological examinations. Sensory evaluations show no significant difference between the unirradiated and irradiated samples. The optimal average dose was 4 kGy for packed-frozen chicken. The number of mesophilic aerobic microbes was reduced by 2, that of psychrotolerant by 2-3 and that of Enterobacteriaceae by 3-4 orders of magnitude by 4 kGy. S. aureus and Salmonella could not be detected in the irradiated samples. in 1984-1985 5100 kg irradiated chickens were marketed labelled as radiation treated. Irradiated spices (5 kGy) were used in the production of sausages (heat-treated and non-heat-treated) under industrial conditions. The microbiological contamination of irradiated spices was lower than that of ethylene oxide treated ones. The cell count in products made with irradiated spices was lower than in those made with unirradiated spices. The sausages proved to be of very good quality. In accordance with the permission, products were marketed and because of the low ratio of spices there was no need to declare them as using irradiated spices. (author)

  11. Irradiation of meat products, chicken and use of irradiated spices for sausages

    Science.gov (United States)

    Kiss, I. F.; Beczner, J.; Zachariev, Gy.; Kovács, S.

    The shelf-life of packed minced meat has been increased at least threefold at 4°C by applying a 2 kGy dose. Results have been confirmed by detailed quatitative microbiological examinations. Sensory evaluations show no significant difference between the unirradiated samples. The optimal average dose was 4 kGy for packed-frosen chicken. The number of mesophilic aerobic microbes was reduced by 2, that of psychrotolerant by 2-3 and that of Enterbacteriaceae by 3-4 orders of magnitude by 4 kGy. S. aureus and Salmonella could not be detected in the irradiated samples. In sensory evaluations there was no significant difference between untreated and irradiated samples. In 1984-1985 5100 kg irradiated chickens were marketed labelled as radiation treated. Irradiated spices (5 kGy) were used in the production of sausages (heat-treated and non-heat-treated) under industrial conditions. The microbiological contamination of irradiated spices was lower than that of ethylene oxide treated ones. The cell count in products made with irradiated spices was lower than in those made with unirradiated spices. The sausages proved to be of very good quality. In accordance with the permission, products were marketed and because of the low ratio of spices there was no need to declare them as using irradiated spices.

  12. Stability Studies of Certain Chemotherapeutic Agents Following Gamma Irradiation and Silver Nanoparticles Conjugation

    International Nuclear Information System (INIS)

    El-Sayyad, Gh.E.S.M.

    2014-01-01

    The Chemical stability of drug is of great importance since it becomes less effective as it undergoes degradation in case of applied of gamma irradiation process. The application of gamma irradiation for different chemotherapeutic agents Such as (ofloxacin, sodium ampicillin, sodium cefotaxime, gentamycin and amoxicillin) and studying the effect of applied doses on chemical structure and biological activity of the irradiated antibiotics compared to unirradiated ones was studied by ultraviolet-Visible spectrophotometer (UV-Visible), Fourier transform infrared spectroscopy measurements (FTIR spectra) and high performance liquid chromatography (HPLC) in addition to microbiological assay were run before and after irradiation to probe any change after irradiation. The results showed that all of the irradiated compounds remain stable and radio resistant; retaining their structure and activity unchanged up to 25 KGy. The radiation-induced AgNPs synthesis is a simple, clean which involves radiolysis of aqueous solution that provides an efficient method to reduce metal ions. Also, in this study, Bacillus megaterium was found to be an effective biological tool for the extracellular biosynthesis of stable AgNPs which are highly stable and this method has advantages over other methods as the organism used here is safe. This study would therefore lead to an easy procedure for producing silver nanoparticles with the added advantage of bio safety. The Synthesized AgNPs exhibit remarkable antimicrobial activity against both Gram-positive and Gram negative bacterial strains regardless of their drug-resistant mechanisms. The bactericidal activity have proved that AgNPs kill bacteria at such low concentrations (units of ppm), which Stability Studies of Certain Chemotherapeutic Agents Following Gamma Irradiation and Silver Nanoparticles Conjugation. do not reveal acute toxic effects on human cell, in addition to overcoming resistance, and lowering cost when compared to conventional

  13. Analysis of spices irradiated in Uruguay

    International Nuclear Information System (INIS)

    Montalban, Antonio; Abreu, Anibal

    1999-01-01

    This paper considered the benefit evaluation of the irradiation processing for the spices within of our regional market .the objective was to raise the competitive of the point of view of quality .There are same problems for the use spices in food, because they are normally with a load of microorganisms , principally in the elaboration of food prepared and sausages.This study analyzed the irradiation for decontamination of spices at a dose level of 10 kgy in comparison with unirradiated products. It was elected different types of spices and producers, and evaluated the final results to the local market

  14. Analysis Of Irradiated Spices In Uruguay

    International Nuclear Information System (INIS)

    Montalban, Antonio; Abreu, Anibal V.

    1999-01-01

    This paper considered the benefit evaluation of the Irradiation processing for the spices within of our regional market .The objective was to raise the competitive of the point of view of quality . There are same problems for the use spices in food, because they are normally with a load of microorganisms , principally in the elaboration of food prepared and sausages. This study analyzed the irradiation for decontamination of spices at a dose level of 10 Kgy in comparison with unirradiated products. It was elected different types of spices and producers , and evaluated the final results to the local market

  15. Identification of irradiated potatoes by impedance

    International Nuclear Information System (INIS)

    Singh, Rita; Singh, Antaryami; Wadhawan, A.K.

    1997-01-01

    The electrical impedance of potatoes irradiated at 60, 90, 150 and 1000 Gy was measured using various frequencies of alternating current. The impedance of the irradiated potatoes was higher than the unirradiated potatoes particularly in the frequency range of 100 Hz to 10 kHz. The ratio of the impedance at 5 kHz to that at 50 Hz (Z5k/Z50) was found to be the best indicator for detection of radiation treatment. (author). 4 refs., 2 figs

  16. Cooperation of terminal deoxynucleotidyl transferase with DNA polymerase α in the replication of ultraviolet-irradiated DNA

    International Nuclear Information System (INIS)

    Yoshida, S.; Masaki, S.; Nakamura, H.; Morita, T.

    1981-01-01

    The amount of DNA synthesis in vitro with the ultraviolet-irradiated poly(dT).oligo(rA) template initiators catalysed by DNA polymerase α (Masaki, S. and Yoshida, S., Biochim. Biophys. Acta 521, 74-88) decreased with the dose of ultraviolet-irradiation. The ultraviolet irradiation to the template, however, did not affect the rate of incorporation of incorrect deoxynucleotides into the newly synthesized poly(dA). The addition of terminal deoxynucleotidyl transferase to this system enhanced the DNA synthesis to a level which is comparable to that of the control and it concomitantly increased the incorporation of the mismatched deoxynucleotide into the newly synthesized poly(dA) strands. On the other hand, with an unirradiated template initiator, the misincorporation was only slightly enhanced by the addition of terminal deoxynucleotidyl transferase. The sizes of newly synthesized DNA measured by the sedimentation velocities were found to be smaller with the ultraviolet-irradiated templates but they increased to the control level with the addition of terminal deoxynucleotidyl transferase to the systems. These results suggest that terminal deoxynucleotidyl transferase can help DNA polymerase α to bypass thymine dimers in vitro by the formation of mismatched regions at the positions opposite to pyrimidine dimers on the template. (Auth.)

  17. Study of Irradiation Effects on the Fracture Properties of A533-Series Ferritic Steels

    International Nuclear Information System (INIS)

    Lee, Yong Bok; Lee, Gyeong Geun; Kwon, Jun Hyun

    2011-01-01

    Since the Kori nuclear power plant unit 3 (Kori-3) was founded in 1986, the surveillance tests have been conducted five times. One of the primary objectives of the surveillance test is to determine the effects of irradiation on reactor pressure vessel (RPV) steel embrittlement. The RPV is made out of ferritic steels such as SA533 type B class 1, which were used for early nuclear power plants industry including Kori-2, 3, 4 and Yonggwang-1, 2 units in Korea. The Westinghouse supplied Kori-3 with the RPV steels ASTM A533 grade B class 1, which is equivalent to SA533 type B class 1. The irradiation effects on tensile properties in ASTM A533 grade B class 1 steel had been studied by Steichen and Williams. They experimentally determined the effect of strain rate and temperature on the tensile properties of unirradiated and irradiated A533 grade B steel 1. The effects of neutron irradiation on ferritic steels could be determined from tensile properties, as well as the fracture strength and toughness measurements. Hunter and Williams have reported that the strength and ductility for unirradiated material at a low strain rate increase with decreasing test temperature. Also, neutron irradiation increases strength and decreases ductility. Crosley and Ripling revealed that the yield strength of unirradiated material rapidly increases with the strain rate. Therefore, yield strength for unirradiated and irradiated materials should be determined by test parameters along with strain rate and temperature. In this study we compare ASTM A533 grad B class 1 steel obtained from several papers with SA533 type B class 1 steel taken from the surveillance data of Kori-3 unit, whose mechanical property of unirradiated and irradiated materials was correlated with the rate-temperature parameter

  18. Longevity of irradiated burros

    International Nuclear Information System (INIS)

    Lushbaugh, C.C.; Brown, D.G.; Frome, E.L.

    1984-01-01

    The unique radioresistance of burros has resulted in a large-animal life-span study that began in 1951. During the course of radiation exposures, some animals at three low exposures to gamma photons survived (10, 10, and 9 exposed to 320, 425, and 545 R, respectively). In 1953, 20 burros exposed to 375 R (gamma) in 25-R/wk increments were added to this life-span study. In 1957, 33 burros exposed to mixed neutron-gamma radiation from nuclear weapons were added. Six burros exposed to 180 rads of neutron and gamma radiation (4:1) in a ''Godiva-type'' reactor were added in 1959 along with 22 controls. In the first 4 years after the single gamma exposures (320-545 R), there were deaths from pancytopenia and thrombocytopenia). Afterward, however, all deaths have been attributable to common equine diseases; none from malignancies. Today, 20 of the original 112 burros in these studies survive (13 irradiated and 7 controls). Survival curves determined for unirradiated and neutron-gamma and gamma-only irradiated burros show significant differences. Median survival time: controls, 28 yrs; gamma irradiation, 26 yrs; neutron-gamma irradiation, 23 yrs. A Weibull probability analysis predicts maximum life-span to be 42 yrs

  19. Chemical changes after irradiation and post-irradiation storage in tilapia and Spanish mackerel

    International Nuclear Information System (INIS)

    Al-Kahtani, H.A.; Abu-Tarboush, H.M.; Bajaber, A.S.; Atia, M.; Abou-Arab, A.A.; El-Mojaddidi, M.A.

    1996-01-01

    Influence of gamma irradiation (1.5-10 kGy) and post-irradiation storage up to 20 days at 2 +/- 2 degrees C on some chemical criteria of tilapia and spanish mackerel were studied. Total volatile basic nitrogen formation was lower in irradiated fish than in the unirradiated. Irradiation also caused a larger increase in thiobarbituric acid values which continued gradually during storage. Some fatty acids decreased by irradiation treatments at all doses. Thiamin loss was more severe at higher doses (greater than or equal to 4.5 kGy), whereas riboflavin was not affected. Alpha and gamma tocopherols of tilapia and alpha, beta, gamma, and delta tocopherols, in Spanish mackerel, decreased with increased dose and continued to decrease during 20-day post-irradiation storage

  20. An electron spin resonance study of some gamma-irradiated fruits

    International Nuclear Information System (INIS)

    Maloney, D.R.; Tabner, B.J.; Tabner, V.A.

    1992-01-01

    The ESR spectra of the seeds, skins and stalks of unirradiated and γ-irradiated Chilean white grapes have been obtained and the results compared to those previously reported for Cape black grapes. The high degree of reproducibility of the spectra obtained from the stalks of different varieties of grapes suggest that ESR spectroscopy could form the basis of a viable test to determine their irradiation history. The condition of the stalk prior to irradiation has been found to have little effect on the resulting spectra. The spectra from the stalks, skins and seeds of unirradiated and γ-irradiated apples, pears and cherries have also been examined. Although most of the spectra from irradiated components exhibit extra features, they are sometimes short-lived and restrict the development of ESR as a viable test. (author)

  1. Influence of whole body irradiation on induction of the hepatic microsomal system metabolizing drugs

    International Nuclear Information System (INIS)

    Szyszko, A.; Bitny-Szlachto, S.

    1977-01-01

    Effects of whole body irradiation (600 R) on rat liver aminophenazone demethylase activities of the liver homogenate 10,000 X g supernatant and its microsomal fraction were compared. Either activities were found to be decreased by irradiation by some 35%. The phenobarbital treatment (3 x 100 mg/kg i.p.) has turned out to provide higher relative augmentation of the liver demethylase activity in irradiated than in unirradiated rats. The cytoplasmic activity was found to be augmented by phenobarbital treatment 2,21-fold in unirradiated, and 3,20-fold in irradiated rats, and the microsomal activity increased 3,28-fold and 3,77-fold, respectively. Microsomal levels of cytochrome P-450 were found to be not affected by irradiation. (author)

  2. Batch scale strength of garlic by irradiation combined with natural low temperature

    International Nuclear Information System (INIS)

    Cho, H.O.; Kwon, J.H.; Byun, M.W.

    1984-01-01

    An attempt was made on the development of a commercial scale storage method of garlic by irradiation. Irradiated garlics with 50, 100 and 150 Gy were stored at natural low temperature storage room (12±6°C, 75-85% RH) and the physicochemical properties during the 10 months storage were investigated. The unirradiated garlic was mostly sprouted after 8 months storage, whereas the sprouting of all irradiated groups was completely inhibited until 10 months storage, The rotting rate and weigh loss of garlic after 10 months storage were reduced by 25 to 54% at 100 Gy irradiation compared with those of an unirradiated group. The moisture content remained relatively constant during the whole storage period. The total sugar content was increased with storage period. Ascorbic acid content was also decreased until 8 months storage but its content was rapidly increased along with sprouting. Garlic was marketable after 10 months storage by 100 Gy irradiation combined with natural low temperature. (author)

  3. Effect of daily low dose gamma irradiation on growth and differentiation of human myeloid leukaemic bone marrow in diffusion chambers

    Energy Technology Data Exchange (ETDEWEB)

    Greenberger, J S [Joint Center for Radiation Therapy, Department of Radiation and Sidney Farber Cancer Institute; Chang, J M; King, V; Fulmer, S; Balzuno, S; Moloney, W C [Division of Hematology, Department of Medicine, Brigham and Women' s Hospital Harvard Medical School, Boston, USA

    1981-01-01

    Bone marrow from each of 8 untreated patients with myeloproliferative disorders was grown in diffusion chambers in 760 rad total body irradiated rats. Rats were exposed to 11.5, 57.5, or 108.5 rad daily for 14-21 and cell growth compared to that detected in unirradiated chambers. Cells from acute myelogenous leukaemia patients exposed to 11.5 rad per d grew for 11-21 d and there was no consistent stimulation of differentiation of immature granulocytic cells to mature granulocytes that was attributable to irradiation. Cells from a chronic myeloid leukaemia patient in chronic phase or blast crisis, and a polycythaemia vera patient with myeloid metaplasia showed signigicant morphologic differentiation from immature to mature granulocytes in control chambers with no additional effect of daily irradiation. Marrow specimens from 2 AML patients exposed to each of 3 daily dose fractions over 14 d revealed a dose-dependent decrease in immature granulocytes with no persistent increase in mature granulocytes. In both irradiated and control chambers, macrophages increased over 21 d. Thus, cells from patients with myeloprofilerative disorders may not necessarily differentiate to mature granulocytes following in vivo exposure to ionizing irradiation.

  4. White-matter abnormalities in unirradiated patients cured of primary central nervous system lymphoma

    International Nuclear Information System (INIS)

    Kim, L.; Hochberg, F.H.; Shaeffer, P.

    2000-01-01

    On MRI, primary brain tumors are commonly seen as contrast-enhancing masses surrounded by areas of abnormal signal on T2-weighted images. Following successful treatment tumors may no longer show contrast enhancement. The residual abnormalities are assumed to be represent ''edema'' and infiltrating tumor cells. We report nine patients with primary lymphoma of the central nervous system who had complete responses to intravenous methotrexate, but did not receive intrathecal chemotherapy or cranial irradiation. After complete resolution of contrast-enhancing lesions, persistent abnormalities on T2-weighted images in the region of prior tumor were initially assumed to reflect residual viable tumor. As they remained unchanged for years, however, this may not hold true in the cases in which primary central nervous system lymphoma responds to chemotherapy alone. (orig.)

  5. Effects of fast neutron irradiation on thermal conductivity of Li2O and LiAlO2

    International Nuclear Information System (INIS)

    Ethridge, J.L.; Baker, D.E.

    1987-03-01

    Li 2 O and LiAlO 2 are two candidates for solid breeder materials in the United States' Fusion Power Program. Critical to breeder design efforts are thermophysical data, the bulk of which have only recently become available, for unirradiated lithium ceramics. This paper expands the current limited database by presenting thermal conductivity data between 373-1173K for both materials following fast neutron irradiation. Samples were irradiated at 773-1173K to lithium burnups ≤11.5 /times/ 10 20 captures/cm 3 . Comparisons are made between these data and those from unirradiated archive samples of these same materials. 15 refs., 10 figs., 2 tabs

  6. Technological Feasibility of Preserving Meat, Poultry and Fish Products by Using a Combination of Conventional Additives, Mild Heat Treatment and Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Wierbicki, E. [United States Army Natick Research and Development Laboratory, Natick, MD (United States)

    1981-09-15

    Radappertization, or irradiation sterilization of meats and other protein foods (poultry, seafoods) is a new processing method applicable to pre-cooked (enzyme inactivated) foods that are hermetically sealed (either in metal cans, flexible pouches, or metal or plastic trays) and involves irradiation to sterilizing doses of either gamma rays (from a cobalt-60 or caesium-137 source) or by X-rays and electrons. The process is particularly applicable to pre-cooked meat, poultry, fin fish, and shellfish, as well as to dry foods, animal feed, and spices. The resulting radappertized products are free from food spoilage microorganisms and organisms of public health significance, including the pathogens such as C. botulinum, salmonellae, trichinae, etc. The radappertized products can be stored without refrigeration for long periods (years), the limiting factor being the integrity of the primary packaging material. Irradiation sterilization of cured meats allows complete elimination or a drastic reduction of incoming nitrite to the levels needed only for characteristic colour and flavour of the items while providing protection against C. botulinum by irradiation. The irradiated-cured products with the low levels of added nitrite are free from residual nitrite and nitrosamines, including nitrosopyrrolidine in fried bacon. In recent co-operative research with the US Department of Agriculture, it was shown that irradiation also destroys pre-formed nitrosamines in bacon. The technology of the process was developed by the US National Food Irradiation Program and the US Army from 1953 to 1980. The US Army spearheaded the development of this new technology to the point where the food irradiation potentials have become meaningful within the broad scope of national and international interests. Therefore, it was highly appropriate that, effective 1 October 1980, the responsibility for the programme at this stage was transferred to the US Department of Agriculture which has been

  7. Irradiation response in titanium modified austenitic stainless steels prepared by rapid solidification processing. Pt. 3. A model for the effect of titanium addition

    Energy Technology Data Exchange (ETDEWEB)

    Imeson, D.; Tong, C.H.; Parker, C.A.; Vander Sande, J.B.; Grant, N.J.; Harling, O.K. (Massachusetts Inst. of Tech., Cambridge (USA). Dept. of Materials Science and Engineering; Massachusetts Inst. of Tech., Cambridge (USA). Nuclear Reactor Lab.)

    1984-05-01

    Titanium carbide precipitation on dislocations during irradiation and recoil-induced particle dissolution are considered. The outline analysis given indicates that complete swelling suppression may occur in favorable conditions due to a counterbalancing of the effective dislocation interstitial bias. The behavior is, however, not stable against a return to normal swelling levels for type 316 steels. A model is presented which may serve as a basis for the interpretation of some aspects of the irradiation response in this system.

  8. Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI series 5

    International Nuclear Information System (INIS)

    Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O.; Menke, B.H.

    1992-10-01

    The Fifth Irradiation Series in the Heavy-Section Steel irradiation (HSSI) Program was aimed at obtaining a statistically significant fracture toughness data base on two weldments with high-copper contents to determine the shift and shape of the K lc curve as a consequence of irradiation. The program included irradiated Charpy V-notch impact, tensile, and drop-weight specimens in addition to compact fracture toughness specimens. Compact specimens with thicknesses of 25.4, 50.8, and 101.6 mm [1T C(T), 2T C(T), and 4T C(T), respectively] were irradiated. Additionally, unirradiated 6T C(T) and 8T C(T) specimens with the same K lc measuring capacity as the irradiated specimens were tested. The materials for this irradiation series were two weldments fabricated from special heats of weld wire with copper added to the melt. One lot of Linde 0124 flux was used for all the welds. Copper levels for the two welds are 0.23 and 0.31 wt %, while the nickel contents for both welds are 0.60 wt %. Twelve capsules of specimens were irradiated in the pool-side facility of the Oak Ridge Research Reactor at a nominal temperature of 288 degree C and an average fluence of about 1.5 x 10 19 neutrons/cm 2 (> 1 MeV). This volume, Appendices E and F, contains the load-displacement curves and photographs of the fracture toughness specimens from the 72W weld (0.23 wt % Cu) and the 73 W weld (0.31 wt % Cu), respectively

  9. Technological feasibility of preserving meat, poultry and fish products by using a combination of conventional additives, mild heat treatment and irradiation

    International Nuclear Information System (INIS)

    Wierbicki, E.

    1981-01-01

    Radappertization is particularly applicable to precooked meat, poultry, fin fish, and shellfish, as well as to dry foods, animal feed, and spices. The resulting radappertized products are free from food spoilage microorganisms and organisms of public health significance, including the pathogens such as C. botulinum, salmonellae, trichinae, etc. The radappertized products can be stored without refrigeration for long periods (years), the limiting factor being the integrity of the primary packaging material. Irradiation sterilization of cured meats allows complete elimination or a drastic reduction of incoming nitrite to the levels needed only for characteristic colour and flavour of the items while providing protection against C. botulinum by irradiation. The irradiated-cured products with the low levels of added nitrite are free from residual nitrite and nitrosamines, including nitrosopyrrolidine in fried bacon. In recent co-operative research with the US Department of Agriculture, it was shown that irradiation also destroys pre-formed nitrosamines in bacon. The technology of the process was developed by the US National Food Irradiation Program and the US Army from 1953 to 1980. The US Army spearheaded the development of this new technology to the point where the food irradiation potentials have become meaningful within the broad scope of national and international interests. Therefore, it was highly appropriate that, effective 1 October 1980, the responsibility for the programme at this stage was transferred to the US Department of Agriculture which has been designated as the leading agency for the US Federal food and nutrition programmes

  10. Storage properties of irradiated potatoes and onions. Part of a coordinated programme on the Asian Regional Cooperative Project on Food Irradiation

    International Nuclear Information System (INIS)

    Hayashi, T.

    1984-12-01

    Quality changes with regard to browning of inner buds and sprouting of irradiated onions variety Kitamiki and Ohotsuku were investigated. One ton of each variety was irradiated with either 38.1 or 65.2 Gy at the Commercial Potato Irradiator in Shihoro and stored either at 0 deg. C or 5 deg. C. After 6 months of storage, they were taken out to be stored at room temperature. It was observed that green inner buds developed in most unirradiated onions which showed no external sprouting irrespective of storage temperature. Irradiated onions show no external or internal sprouting but exhibited browning of small inner buds. Unirradiated onions rooted slightly during storage at low temperature. None of the irradiated samples showed rooting. Neither of the samples spoiled significantly during storage. It was concluded that storage at room temperature accelerated sprouting and development of green inner buds of unirradiated onions and browning of small inner buds in irradiated ones. During off-seasons, only irradiated onions stored at low temperatures have qualities of commercial significance

  11. Evaluation of neutron irradiation embrittlement in the Korean reactor pressure vessel steels (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J. H.; Lee, B. S.; Chi, S. H.; Kim, J. H.; Oh, Y. J.; Yoon, J. H.; Kwon, S. C.; Park, D. G.; Kang, Y. H.; Choo, K. N.; Oh, J. M.; Park, S. J.; Kim, B. K.; Shin, Y. T.; Cho, M. S.; Sohn, J. M.; Kim, D. S.; Choo, Y. S.; Ahn, S. B.; Oh, W. H. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2001-05-01

    Reactor pressure vessel materials, which were produced by a domestic company, Doosan Heavy Industries and construction Co., Ltd., have been evaluated using the neutron irradiation facility HANARO. For this evaluation, instrumented capsules were used for neutron irradiation of various kinds of specimens made of different heats of steels, which are VCD(Y4), VCD+Al(U4), Si+Al(Y5), U4 weld metal, and U4 HAZ, respectively. The fast neutron fluence levels ranged 1 to 5 (x10{sup 19} n/cm{sup 2}, E>1MeV) depending on the specimens and the irradiation temperature was controlled within 290{+-}10 deg C. The test results showed that, in the ranking of the material properties of the base metals, both before and after neutron irradiation, Y5 is the best, U4 the next and Y4 the last. Y4 showed a substantial change by neutron irradiation as well as the properties was worse than others in the unirradiated state. However, Y5, which showed the best properties in unirradiated state, was also the best in the resistance for irradiation embrittlement and one can hardly detect the property change after irradiation. The weldment showed a reasonably good resistance to irradiation embrittlement while the unirradiated properties were worse than base metals. The RPV steels are all expected to meet the screening criteria of the USNRC codes and regulations during the end of plant life. 39 refs., 42 figs., 27 tabs. (Author)

  12. Shelf-life extension and improvement of the microbiological quality of smoked salmon by irradiation

    International Nuclear Information System (INIS)

    Hammond, A.A.I.; El-Mongy, T.M.

    1992-01-01

    Cold-smoked salmon locally available was irradiated at 2 and 4 kGy. Irradiated and unirradiated samples were stored at refrigeration temperature (2-3 degrees C). Microbiological and sensory qualities were studied immediately after irradiation and during storage. Irradiation at 2 kGy caused a great reduction in all the tested microbial population, thus improving the hygienic quality of smoked salmon to meet the microbiological limits for the top-grade quality. Moreover, irradiated samples at 4 kGy were free from coliform bacteria, fecal streptococci and Staph. aureus over the entire storage period. Unirradiated samples reached the maximum accepted mesophilic plate count after only one month of storage, while those irradiated at 2 and 4 kGy reached this level after 3 and 4 months, respectively. No differences in sensory qualities were found by the taste panel between unirradiated samples and those irradiated at 2 kGy, but they observed a distinct loss in normal cherry red color of the samples irradiated at 4 kGy

  13. Identification of irradiated spices by the use of thermoluminescence method (TL)

    Energy Technology Data Exchange (ETDEWEB)

    Sharifzadeh, M.; Sohrabpour, M. (Atomic Energy Organization of Iran, Teheran (Iran, Islamic Republic of))

    In this paper the results of the investigation of identification of irradiated spices by the use of thermoluminescence method is reported. The materials used were black and red peppers, turmeric, cinnamon, and garlic powder. Gamma Cell 220 was used for irradiating samples at dose values of 2.5, 5, 7.5 and 10 kGy respectively. The TL intensity of the unirradiated spices as well as the fading characteristics of the irradiated samples having received a dose of 10 kGy have been measured. Post-irradiation temperature treatment of the irradiated (10 kGy) and unirradiated samples at 60[sup o]C and 100[sup o]C for 24 hours have also been performed. The results show that the TL intensities of unirradiated and irradiated samples from different batches of each spice are fairly distributed. A reasonable TL intensity versus dose has been observed in nearly all cases. Based on the observation made it is possible to distinguish irradiated spices after (4-9) months post-irradiation. (author).

  14. Identification of irradiated spices by the use of thermoluminescence method (TL)

    International Nuclear Information System (INIS)

    Sharifzadeh, M.; Sohrabpour, M.

    1993-01-01

    In this paper the results of the investigation of identification of irradiated spices by the use of thermoluminescence method is reported. The materials used were black and red peppers, turmeric, cinnamon, and garlic powder. Gamma Cell 220 was used for irradiating samples at dose values of 2.5, 5, 7.5 and 10 kGy respectively. The TL intensity of the unirradiated spices as well as the fading characteristics of the irradiated samples having received a dose of 10 kGy have been measured. Post-irradiation temperature treatment of the irradiated (10 kGy) and unirradiated samples at 60 o C and 100 o C for 24 hours have also been performed. The results show that the TL intensities of unirradiated and irradiated samples from different batches of each spice are fairly distributed. A reasonable TL intensity versus dose has been observed in nearly all cases. Based on the observation made it is possible to distinguish irradiated spices after (4-9) months post-irradiation. (author)

  15. Entire litters developed from transferred eggs in whole body x-irradiated female mice

    International Nuclear Information System (INIS)

    Lin, T.P.

    1980-01-01

    The sensitivity of mouse eggs to sublethal x-irradiation was determined in vitro and in vivo with regard to the development of donor litters in foster mothers. One thousand seven hundred fifty-eight unfertilized eggs of agouti dark-eyed donor mice were transferred into 293 unirradiated or x-irradiated, mated female pink-eyed mice. Two hundred thirty-nine recipients became pregnant; of these 35 produced litters containing solely dark-eyed fetuses. Sublethal doses of x-radiation administered to donor eggs in vitro before transferring into unirradiated recipients did not influence significantly the number of litters of exclusively dark-eyed fetuses produced. However, recipients irradiated by 250 roentgens (r) produced more solely dark-eyed litters than did those irradiated with 100 r. In 21 pregnant females irradiated by 100 r, only 3 (14%) developed solely dark-eyed fetuses as compared to 22 pregnant females irradiated by 250 r, of which 13 (59%) developed solely dark-eyed fetuses, all from unirradiated, transferred eggs. Of another group of 22 pregnant females which received 250 r body irradiation and subsequently received eggs also irradiated by 250 r, only 7 (32%) produced litters of dark-eyed fetuses. No one female of these three groups carried native fetuses. Such radiation-induced infertility resulting from damage of native eggs rather than loss of mother's ability to carry a pregnancy, is frequently remedied by egg transfer

  16. Microstructural examination of irradiated zircaloy-2 pressure tube material

    International Nuclear Information System (INIS)

    Srivastava, D.; Tewari, R.; Dey, G.K.; Sah, D.N.; Banerjee, S.

    2005-01-01

    Irradiation induced microstructural changes in Zr alloys strongly influence the creep, growth and mechanical properties of pressure tube material. Since dimensional changes and mechanical property degradation can limit the life of pressure tube, it is essential to study and develop an understanding of the microstructure produced by neutron irradiation, by examining samples taken from the irradiated components. In the present work, an effort has been made to examine, microstructure of the Zircaloy-2 pressure tube material irradiated in the Indian Pressurized Heavy Water Reactor (PHWR). The present work is a first step towards a comprehensive program of characterization of microstructure of reactor materials after irradiation to different fluence levels in power reactors. In this study, samples from a Zircaloy-2 pressure tube, which had been in operation in the high flux region of Rajasthan Atomic Power Station Unit 1, for a period for 6.77 effective full power years (EFPYs), have been prepared and examined. The samples selected from the tube are expected to have a cumulative radiation damage of about 3 dpa. Samples prepared from the off cuts of RAPS-1 pressure tubes were also studied for examining the unirradiated microstructure of the material. The samples were examined in a 200kV JEOL 2000 FX microscope. This paper presents the distinct features observed in irradiated sample and a comprehensive comparison of the microstructures of the unirradiated and irradiated material. The effect of annealing on the annihilation of the defects generated during irradiation has been also studied. The bright field micrographs revealed that microstructure of the irradiated samples was different in many respects from the microstructure of the unirradiated samples. The presence of defect structure in the form of loops etc could be seen in the irradiated sample. These loops were mostly c-type loops lying in the basal plane. The dissolution and redistribution of the precipitates were

  17. Irradiation effects test series, test IE-5. Test results report

    International Nuclear Information System (INIS)

    Croucher, D.W.; Yackle, T.R.; Allison, C.M.; Ploger, S.A.

    1978-01-01

    Test IE-5, conducted in the Power Burst Facility at the Idaho National Engineering Laboratory, employed three 0.97-m long pressurized water reactor type fuel rods, fabricated from previously irradiated zircaloy-4 cladding and one similar rod fabricated from unirradiated cladding. The objectives of the test were to evaluate the influence of simulated fission products, cladding irradiation damage, and fuel rod internal pressure on pellet-cladding interaction during a power ramp and on fuel rod behavior during film boiling operation. The four rods were subjected to a preconditioning period, a power ramp to an average fuel rod peak power of 65 kW/m, and steady state operation for one hour at a coolant mass flux of 4880 kg/s-m 2 for each rod. After a flow reduction to 1800 kg/s-m 2 , film boiling occurred on one rod. Additional flow reductions to 970 kg/s-m 2 produced film boiling on the three remaining fuel rods. Maximum time in film boiling was 80s. The rod having the highest initial internal pressure (8.3 MPa) failed 10s after the onset of film boiling. A second rod failed about 90s after reactor shutdown. The report contains a description of the experiment, the test conduct, test results, and results from the preliminary postirradiation examination. Calculations using a transient fuel rod behavior code are compared with the test results

  18. Irradiation effects test Series Scoping Test 1: test results report

    International Nuclear Information System (INIS)

    Quapp, W.J.; Allison, C.M.; Farrar, L.C.

    1977-09-01

    The report describes the results of the first scoping test in the Irradiation Effects Test Series conducted by the Thermal Fuels Behavior Program, which is part of the Water Reactor Research Program of EG and G Idaho, Inc. The research is sponsored by the United States Nuclear Regulatory Commission. This test used an unirradiated, three-foot-long, PWR-type fuel rod. The objective of this test was to thoroughly evaluate the remote fabrication procedures to be used for irradiated rods in future tests, handling plans, and reactor operations. Additionally, selected fuel behavior data were obtained. The fuel rod was subjected to a series of preconditioning power cycles followed by a power increase which brought the fuel rod power to about 20.4 kW/ft peak linear heat rating at a coolant mass flux of 1.83 x 10 6 lb/hr-ft 2 . Film boiling occurred for a period of 4.8 minutes following flow reductions to 9.6 x 10 5 and 7.5 x 10 5 lb/hr-ft 2 . The test fuel rod failed following reactor shutdown as a result of heavy internal and external cladding oxidation and embrittlement which occurred during the film boiling operation

  19. Special Analysis for the Disposal of the INL Waste Associated with the Unirradiated Light Water Breeder Reactor (LWBR) Waste Stream at the Area 5 Radioactive Waste Management Site

    Energy Technology Data Exchange (ETDEWEB)

    Shott, Gregory [National Security Technologies, LLC, Las Vegas, NV (United States)

    2017-03-21

    This special analysis (SA) evaluates whether the Idaho National Laboratory (INL) Waste Associated with the Unirradiated Light Water Breeder Reactor (LWBR) waste stream (INEL167203QR1, Revision 0) is suitable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). Disposal of the INL Waste Associated with the Unirradiated LWBR waste meets all U.S. Department of Energy (DOE) Manual DOE M 435.1-1, “Radioactive Waste Management Manual,” Chapter IV, Section P performance objectives (DOE 1999). The INL Waste Associated with the Unirradiated LWBR waste stream is recommended for acceptance with the condition that the total uranium-233 (233U) inventory be limited to 2.7E13 Bq (7.2E2 Ci).

  20. Control of tapeworms by irradiation

    International Nuclear Information System (INIS)

    Verster, A.; Van den Heever, L.W.

    1976-01-01

    Cysticerci of Taenia solium were exposed to gamma radiation in doses varying from 20-140 krad. Radiation had an adverse effect on the ability of the cysticerci to evaginate in vitro after a time lag of 9 days. This effect was most marked at doses of 100 krad and higher, thus no cysticerci exposed to 140, 120 and 100 krad evaginated after 12, 18 and 21 days, respectively. On Day + 24, when 60% of the control cysticerci evaginated, 55%, 50%, 30% and 40% of the cysticerci exposed to 20, 40, 60, and 80 krad, respectively, evaginated in vitro. Cysticerci exposed to radiation doses of 20-120 krad are as infective to golden hamsters as are unirradiated cysticerci. Cestodes resulting from irradiated cysticerci, however, cannot maintain themselves indefinitely, and are excreted or digested at varying times from Day + 12 onwards. Moreover, cestodes resulting from such irradiated cysticerci do not grow, but are resorbed, and finally consist of only a scolex. By Day + 30 the mean length of the worms resulting from the unirradiated cysticerci is 173,8 mm, while those resulting from cysticerci exposed to 20 and 40 krad consist of scolices only and the hamsters fed material exposed to 60 krad were negative. It appears, therefore, that radiation inhibits the ability of the cells in the neck region to divide and thus form new proglottids. Carcasses infested with cysticercosis can possibly be rendered fit for human consumption by exposure to gamma radiation at doses between 20 and 60 krad

  1. Competitiveness values of irradiated adults of callosobruchus maculatus (F.) irradiated as mature pupae

    International Nuclear Information System (INIS)

    Ahmed, M.Y.Y.

    1981-01-01

    When mature pupae of Callosobruchus maculatus were treated with 3 Krad, the resulting adults were sterile when they were paired with untreated opposite sex. Males and females both treated with a sterilizing dose (3 Krad) and confined with untreated (U) males and females at a I male: I female: U male: U female (irradiated males: irradiated females: unirradiated males: unirradiated females) ratio caused 69.1% infertility in the resulting eggs. When the ratio of sterile males and females was increased to 5.5:1:1; 10:10:1:1 or 15:1:1 (I male: female: U male: U female) the percentage infertility reached 82.5, 95.0 and 100.0, respectively. The percentage of observed infertility was less than the expected infertility for the ratios 1:1:1:1:5:5:1:1 and 10:10:1:1, but it was exceeded with the highest ratio used (15:15:1:1). Competitiveness values for irradiated adults increased with an increasing ratio of irradiated to unirradiated adults. Since the ratio of 15:15:1:1 gave rise to 100% egg infertility (the expected infertility was 99.6%), no F 1 adults was produced; and the competitiveness value slightly exceeded 1.0 (i.e. the sterile adults were fully competitive with the normal ones). These results indicated that irradiation with 3 Krad, a sterilizing dose, did not decrease sexual competitiveness of irradiated adults. Also, the release of (I) females together with (I) males could give good results in controlling a population of C. maculatus in a autocidal control program; and, therefore, separation of the sexes prior to release is probably unnecessary. (author)

  2. A prospective neurocognitive evaluation of children treated with additional chemotherapy and craniospinal irradiation following isolated central nervous system relapse in acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Kumar, Parvesh; Mulhern, Raymond K.; Regine, William F.; Rivera, Gaston K.; Kun, Larry E.

    1995-01-01

    Purpose: A prospective assessment of neurocognitive performance was conducted in children with acute lymphoblastic leukemia (ALL) following isolated central nervous system (CNS) relapse to evaluate the impact of additional systemic/intrathecal (IT) chemotherapy and craniospinal irradiation (CSI) upon long-term intellectual function. Methods and Materials: Twenty-one children with ALL manifesting an isolated CNS relapse between 1984 through 1989 underwent serial evaluations of intellectual function. Neurocognitive function was measured by the full-scale intelligence quotient (FSIQ) as determined by the age-appropriate Wechsler Intelligence Scale and by achievement in reading, math, and spelling as assessed by the Wide Range Achievement Test (WRAT). Intelligence testing was initiated following isolated CNS relapse after clearance of cerebrospinal fluid (CSF) cytology but prior to CSI and continued at annual intervals for a minimum of 4 years postmeningeal failure. Protocol treatment for isolated CNS relapse consisted of reinduction and maintenance systemic therapy, intrathecal (IT) triple-agent chemotherapy, and early CSI (cranium to 24 Gy and spine to 15 Gy at 1.5 Gy/fraction) as outlined on the institutional 'Total XI' trial. Results: All 21 children attained secondary CNS remission and underwent the planned additional systemic/IT chemotherapy and CSI. Fourteen of the 21 children remain in secondary continuous remission, while the remaining 7 experienced a second relapse and were removed from further neurocognitive assessment. For the eight female and six male long-term survivors, mean ages at original diagnosis and at CSI were 5.7 years (range = 0.6-16.2) and 7.0 years (range = 1.8-17.0), respectively. At a median follow-up interval of 4.6 years (ranges 1.7-6.8) post-CNS relapse, comparison of group mean initial to final FSIQs revealed no statistically significant difference between the two measures (94.5 vs. 95.9, respectively, n = 11, p = 0.52). None of the

  3. Positron lifetime studies of 100-MeV oxygen irradiated Pb-doped Bi-2223 superconductors

    NARCIS (Netherlands)

    Banerjee, T.; Viswanath, R.N.; Kanjilal, D.; Kumar, R.; Ramasamy, S.

    2000-01-01

    Positron lifetime studies have been carried out for unirradiated and 100-MeV oxygen ion irradiated Pb-doped Bi-2223 superconductors. The analysis of positron lifetime spectra revealed three lifetime components: a short lifetime, τ1 = 153–196 ps; an intermediate lifetime, τ2 = 269–339 ps; and a long

  4. Lift-based up-ender and methods using same to manipulate a shipping container containing unirradiated nuclear fuel

    Science.gov (United States)

    Nilles, Michael J.

    2017-08-01

    A shipping container containing an unirradiated nuclear fuel assembly is lifted off the ground by operating a crane to raise a lifting tool comprising a winch. The lifting tool is connected with the shipping container by a rigging line connecting with the shipping container at a lifting point located on the shipping container between the top and bottom of the shipping container, and by winch cabling connecting with the shipping container at the top of the shipping container. The shipping container is reoriented by operating the winch to adjust the length of the winch cabling so as to rotate the shipping container about the lifting point. Shortening the winch cabling rotates the shipping container about the lifting point from a horizontal orientation to a vertical orientation, while lengthening the winch cabling rotates the shipping container about the lifting point from the vertical orientation to the horizontal orientation.

  5. Storage for the Fast Flux Test Facility unirradiated fuel in the Plutonium Finishing Plant Complex, Hanford Site, Richland, Washington

    International Nuclear Information System (INIS)

    1992-01-01

    This Environmental Assessment evaluates the proposed action to relocate and store unirradiated Fast Flux Test Facility fuel in the Plutonium Finishing Plant Complex on the Hanford Site, Richland, Washington. The US Department of Energy has decided to cease fuel fabrication activities in the 308 Building in the 300 Area. This decision was based on a safety concern over the ability of the fuel fabrication portion of the 308 Building to withstand a seismic event. The proposed action to relocate and store the fuel is based on the savings that could be realized by consolidating security costs associated with storage of the fuel. While the 308 Building belowgrade fuel storage areas are not at jeopardy by a seismic event, the US Department of Energy is proposing to cease storage operations along with the related fabrication operations. The US Department of Energy proposes to remove the unirradiated fuel pins and fuel assemblies from the 308 Building and store them in Room 192A, within the 234-5Z Building, a part of the Plutonium Finishing Plant Complex, located in the 200 West Area. Minor modifications to Room 192A would be required to accommodate placement of the fuel. The US Department of Energy estimates that removing all of the fuel from the 308 Building would save $6.5 million annually in security expenditures for the Fast Flux Test Facility. Environmental impacts of construction, relocation, and operation of the proposed action and alternatives were evaluated. This evaluation concluded that the proposed action would have no significant impacts on the human environment

  6. Influence of X-ray irradiation on the bacteriological and chemical quality of fresh fish in ice

    International Nuclear Information System (INIS)

    Karnop, G.; Antonacopoulos, N.

    1977-01-01

    Judging by bacteriological and chemical criteria, the natural decay of ice-stored whole Baltic cod, after aerobic packing and irradiation with 100 krad, was delayed by more than 7 days as compared to unpacked non-irradiated cod. With vacuum-packed irradiated cod fillet, the usual decay symptoms determinable through bacteriology and chemistry set in more than 10 days later than with unirradiated unpacked fillet. (orig.) [de

  7. The effect of microstructural change on the Charpy impact properties of the high-strength ferritic/martensitic steel (PNC-FMS) irradiated in JOYO/MARICO-1

    International Nuclear Information System (INIS)

    Yano, Yasuhide; Akasaka, Naoaki; Yoshitake, Tsunemitsu; Abe, Yasuhiro

    2004-03-01

    It is well known that the irradiation embrittlement is one of the most important issues to apply ferritic steels for FBR core materials, although ferritic steels have been considered to be candidate core materials of the commercialized FBR core material because of their superior swelling resistance. In order to evaluate the effects of microstructural changes during irradiation on the Charpy impact properties of the high-strength ferritic/martensitic steel (PNC-FMS), microstructural observations were performed with transmission electron microscopy on ruptured halves of the half-sized Charpy specimens of PNC-FMS irradiated in the JOYO/MARICO-1. The results obtained in this study are as follows: (1) There was remarkable disappearance of the lath of martensite in the samples irradiated at 650degC, although there was no significant change in microstructures, especially the lath of martensite between the samples irradiated at 500degC and unirradiated. The disappearance of martensitic lath in the samples irradiated at 650degC was larger than that of the samples thermally aged at 650degC. (2) The ductile-brittle transition temperature (DBTT) of irradiated PNC-FMS is judged to increase with the disappearance of martensitic lath and to decrease with the recovery in dislocations. (3) The decrease in the upper shelf energy (USE) of irradiated PNC-FMS is significantly accompanied by the change of precipitation behavior. (4) The Charpy impact properties and microstructures of PNC-FMS irradiated at 500degC were superior under these irradiation conditions. In future, it is necessary to establish how to evaluate Charpy impact properties in a high fluence region, based on theoretical methods introduced from the data gained in low fluence experiments, in addition to expanding the data area widely. (author)

  8. Sensory quality of irradiated onion and garlic bulbs

    International Nuclear Information System (INIS)

    Curzio, O.A.; Urioste, A.M.

    1994-01-01

    The radioinhibition process has shown to prolong shelf-life of ''Valenciana sintetica 14'' onion variety and ''Colorado'' garlic variety. Sensory attributes of the irradiated bulbs were tested monthly by trained judges during extended storage in warehouse conditions (6-32C, R.H. 40-50%). The sensory properties observed were external and internal appearance, firmness and odor. The irradiated bulbs were judged to be superior in quality with respect to internal and external appearance (p 0.01) and firmness (p 0.01), after 180 days postharvest. The irradiated bulbs showed no difference in odor (p 0.05), when compared to unirradiated ones, through the storage period

  9. Some features of irradiated chitosan and its biological effect

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi [Nuclear Research Institute, VAEC, Dalat (Viet Nam); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G{sub d}) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  10. Recovery of fertility un irradiated Epestia cautella (Walker) (Lepidoptera: Phycitidae)

    International Nuclear Information System (INIS)

    Makee, H.

    1995-01-01

    The recovery of damaged sperm of Epestia cautella irradiated with 10 krad was determined. Two groups of irradiated 1-day-old males were taken. The males of the first group were mated repeatedly with virgin unirradiated females. While the mating of the males of the second group was delayed for various intervais after treatment. Percentage egg hatch was used to detect any changes in the fertility of the damaged sperm. The results showed that neither when the irradiated males were mated successively nor when their mating was delayed after treatment, did the viability of their damaged sperm recover. (author). 2 refs., 2 tabs

  11. Some features of irradiated chitosan and its biological effect

    International Nuclear Information System (INIS)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi; Yoshii, Fumio; Kume, Tamikazu

    2001-01-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G d ) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  12. Studies on apple preservation by 60 -gamma irradiation

    International Nuclear Information System (INIS)

    Wang Chuanyao; Jiang Mengyue; Gao Meixu

    1992-01-01

    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

  13. Postirradiation examination results for the Irradiation Effects Test 2

    International Nuclear Information System (INIS)

    Ploger, S.A.; Kerwin, D.K.; Croucher, D.W.

    1978-01-01

    This report presents the postirradiation examination results of Test IE-2 in the Irradiation Effects Test Series conducted under the Thermal Fuels Behavior Program. The objectives of this test were to evaluate the influence of previous cladding irradiation and fuel-cladding diametral gap on fuel rod behavior during a power ramp and during film boiling operation. Test IE-2, conducted in the Power Burst Facility at the Idaho National Engineering Laboratory, employed two 0.97-m-long pressurized water reactor type fuel rods fabricated from previously irradiated zircaloy-4 cladding and two similar rods fabricated from unirradiated cladding. The four rods were subjected to a preconditioning period, followed by a power ramp to an average peak rod power of 68 kW/m and steady state operation for one hour at an individual rod coolant mass flux of 4880 kg/s . m 2 . After a flow reduction to 2550 kg/s . m 2 , film boiling occurred on three rods. An additional flow reduction to 2245 kg/s . m 2 produced film boiling on the remaining fuel rod. Maximum time in film boiling was 90 s. None of the four fuel rods failed during the test. Damage caused by film boiling, as characterized by oxidation, oxide spalling, and collapse at fuel pellet interfaces, was found on all four rods. Film boiling regions on these rods showed evidence of fuel melting, fuel centerline void formation, and internal cladding oxidation resulting from fuel-cladding reaction. Effects of fuel-cladding diametral gap and cladding irradiation are summarized. Measured temperatures and metallographically estimated temperatures are compared at several axial fuel rod locations

  14. Detection of gamma-irradiated peanuts by ESR spectroscopy and GC analysis of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Wei Mingli; An Li [Institute of Agro-food Science and Technology, Chinese Academy of Agricultural Sciences, 100193 Beijing (China); Yi Mingha, E-mail: wangyilwm@163.co [Institute of Agro-food Science and Technology, Chinese Academy of Agricultural Sciences, 100193 Beijing (China); Feng Wang [Institute of Agro-food Science and Technology, Chinese Academy of Agricultural Sciences, 100193 Beijing (China); Yan Lizhang [Division of Metrology in Ionizing Radiation and Medicine, National Institute of Metrology, 100013 Beijing (China)

    2011-03-15

    Peanuts were analyzed by electron spin resonance (ESR) spectroscopy and gas chromatography (GC) before and after gamma irradiation. Using European protocols, the validity and effectiveness of these two techniques were compared with regard to sample preparation, sample and solvent consumption and dose-response curves after irradiation. The results showed the possibility of using ESR and GC for distinguishing between irradiated and unirradiated peanuts. A radiation dose of 0.1 kGy could be detected by ESR but not by GC. The results also indicated that GC is an effective method for qualitative analysis of irradiated peanut, while ESR is suitable for the rapid detection of irradiated peanuts.

  15. Improvement of Microbiological and Sensory Quality of Fried Seasoning Anchovy Fish Snack by Gamma Irradiation

    International Nuclear Information System (INIS)

    Prakongsil, Panchalee; Neramitmansook, Naruemon; Phianphak, Wannipa; Kaewchoung, Pravait

    2009-07-01

    Full text: Microbiological and sensory qualities of gamma irradiated fried seasoning anchovy fish snack were evaluated. The samples were packed in polyethylene bags and stored under three different conditions. In Group I, the fish snacks were vacuum-packed and stored at room temperature. In Group II, the bags were sealed normally and stored at room temperature. Group-III samples were packed as in Group II but they were stored at 18 O C. Gamma irradiation was applied at the minimum absorbed dose of 2.0 kGy. Microbiological qualities were evaluated at 1, 2 and 3 months post irradiation. At three months, unirradiated samples from all three storage conditions were found with their total bacterial counts exceeding the limit for the quality standard of the Ministry of Industry (>10 3 cfu/g), while the total bacterial counts from irradiated samples were 1 log cycle fewer than those from unirradiated samples. The total yeast and mold counts produced by irradiated samples were within the limit throughout the three-month storage for all three conditions. E. coli, Salmonella spp., S. aureus and Clostridium spp. were not found under all storage conditions for both irradiated and unirradiated samples. No significant differences in the sensory quality were observed between irradiated and unirradiated samples for all three conditions. Although irradiated fried seasoning anchovy fish snack in a vacuum pack yielded better microbiological qualities than irradiated samples in a normal-sealed pack, samples in a normal-sealed pack stored at room temperature would be more appropriate for commercial production when production costs were considered

  16. Spectrophotometric analysis of irradiated spices

    Energy Technology Data Exchange (ETDEWEB)

    Josimovic, L; Cudina, I

    1987-01-01

    Seven different spices (thyme, cinnamon, coriander, caraway, pimento, paprika, black pepper) were treated by gamma radiation at an absorbed dose of 10 kGy, and the effect on chemical quality was determined. The effects of this dose were assessed by spectrophotometric analysis of some water-soluble constituents of spices (carbohydrates; carbonyl compounds) and on the content of water-insoluble steam-volatile oils. The colour of paprika and the content of piperine in pepper held in different packaging materials were measured in unirradiated and irradiated samples as a function of storage time. In all cases irradiation does not bring about any distinct qualitative or quantitative chemical changes based on spectrophotometric analysis of spice extracts.

  17. Identification of irradiated meat using electron spin resonance (ESR) spectroscopy and estimation of applied dose using re-irradiation

    International Nuclear Information System (INIS)

    Chawla, S.P.; Thomas, Paul; Bongirwar, D.R.

    2001-01-01

    An in-house blind trail on bone-in meat chunks was carried out in which 35 coded samples were correctly identified. The samples were either left unirradiated or had been irradiated to dose of 1, 2.5 or 4 kGy. Using re-irradiation, the dose received by the samples were determined with either linear, quadratic or exponential equation. The quadratic or exponential equation gave more successful estimates of irradiation dose whereas linear fit equations tend to over estimate the dose. (author)

  18. Change in physical properties of high density isotropic graphites irradiated in the ?JOYO? fast reactor

    Science.gov (United States)

    Maruyama, T.; Kaito, T.; Onose, S.; Shibahara, I.

    1995-08-01

    Thirteen kinds of isotropic graphites with different density and maximum grain size were irradiated in the experimental fast reactor "JOYO" to fluences from 2.11 to 2.86 × 10 26 n/m 2 ( E > 0.1 MeV) at temperatures from 549 to 597°C. Postirradiation examination was carried out on the dimensional changes, elastic modulus, and thermal conductivity of these materials. Dimensional change results indicate that the graphites irradiated at lower fluences showed shrinkage upon neutron irradiation followed by increase with increasing neutron fluences, irrespective of differences in material parameters. The Young's modulus and Poisson's ratio increased by two to three times the unirradiated values. The large scatter found in Poisson's ratio of unirradiated materials became very small and a linear dependence on density was obtained after irradiation. The thermal conductivity decreased to one-fifth to one-tenth of unirradiated values, with a negligible change in specific heat. The results of postirradiation examination indicated that the changes in physical properties of high density, isotropic graphites were mainly dominated by the irradiation condition rather than their material parameters. Namely, the effects of irradiation induced defects on physical properties of heavily neutron-irradiated graphites are much larger than that of defects associated with as-fabricated specimens.

  19. Change in physical properties of high density isotropic graphites irradiated in the ''JOYO'' fast reactor

    International Nuclear Information System (INIS)

    Maruyama, T.; Kaito, T.; Onose, S.; Shibahara, I.

    1995-01-01

    Thirteen kinds of isotropic graphites with different density and maximum grain size were irradiated in the experimental fast reactor ''JOYO'' to fluences from 2.11 to 2.86x10 26 n/m 2 (E>0.1 MeV) at temperatures from 549 to 597 C. Postirradiation examination was carried out on the dimensional changes, elastic modulus, and thermal conductivity of these materials. Dimensional change results indicate that the graphites irradiated at lower fluences showed shrinkage upon neutron irradiation followed by increase with increasing neutron fluences, irrespective of differences in material parameters. The Young's modulus and Poisson's ratio increased by two to three times the unirradiated values. The large scatter found in Poisson's ratio of unirradiated materials became very small and a linear dependence on density was obtained after irradiation. The thermal conductivity decreased to one-fifth to one-tenth of unirradiated values, with a negligible change in specific heat. The results of postirradiation examination indicated that the changes in physical properties of high density, isotropic graphites were mainly dominated by the irradiation condition rather than their material parameters. Namely, the effects of irradiation induced defects on physical properties of heavily neutron-irradiated graphites are much larger than that of defects associated with as-fabricated specimens. (orig.)

  20. Applicability of impedance measuring method to the detection of irradiation treatment of potatoes

    International Nuclear Information System (INIS)

    Hayashi, Toru; Todoriki, Setsuko; Otobe, Kazunori; Sugiyama, Junnichi

    1993-01-01

    The incubation condition of potato tubers prior to impedance measurement greatly influenced the reliability of detection of irradiated potatoes; the impedance ratio at 5 kHz to 50 kHz (Z 5k /Z 50k ) determined at 22degC at an apical region of tuber which was pre-incubated at 22degC for 3 days or longer resulted in the best detection of radiation treatment of potatoes. The impedance ratio was dependent upon dose applied to potato tubers. Potatoes irradiated at 100 Gy could be distinguished from unirradiated potatoes for 10 cultivars of potatoes. The impedance ratio of potatoes irradiated at the same dose was little influenced by the planting locality if the cultivar was the same, although the ratio varied with potato cultivars. These results indicate that irradiated potatoes can be detected if the potato cultivar is known. Potatoes 'Danshaku' commercially irradiated at the Shihiro Potato Irradiation Center could be differentiated from unirradiated 'Danshaku' at different planting localities; the impedance ratio was lower than 2.75 for the unirradiated potatoes and higher than 2.75 for the irradiated ones. (author)

  1. Consumer response to irradiated spices in Egypt

    International Nuclear Information System (INIS)

    El-Khateeb, M.A.; El-Fouly, M.Z.; Farag, M.D.; Abdel Karim, H.A.; Saad El-Din, N.

    2000-01-01

    This study analyses the response of the consumer about irradiated spices. The spices under investigation were black pepper, cumin and coriander. The results of the sensory test the panelists ( 136 person) failed to indicate any difference between the irradiated and unirradiated black pepper, cumin and coriander. The percentages of correct answer were 26.92 29.23, 29.23 and 27.27. Five hundred post card were issued for black pepper to test the opinion of the consumer acceptance for the irradiated black pepper. The result of their opinion were 62.2% of the consumers who would buy irradiated black pepper, 14.6% would not buy it and 23.2% were undecided

  2. Influence of conditioned psychological stress on immunological recovery in mice exposed to low-dose x irradiation

    International Nuclear Information System (INIS)

    Sato, K.; Flood, J.F.; Makinodan, T.

    1984-01-01

    A study was initiated to determine the effects of psychological stress on the immune response in BALB/c mice recovering from exposure to a low dose of ionizing radiation. Mice were first subjected to conditioning training for 12 days, then exposed to 200 R, subjected to psychological stress for 14 days, and assessed for peak anti-sheep RBC response. The seven treatment groups included two unirradiated groups and five irradiated groups. Mice exposed to 200 R and then subjected to conditioned psychological stress responded less vigorously to antigenic stimulation than those of the other irradiated groups. The psychological stress imposed upon these mice did not influence the antibody-forming capacity of unirradiated mice. These results indicate that a psychological stress which did not affect the immunological activity of unirradiated mice can curtail the immunological recovery of mice exposed to low doses of ionizing radiation

  3. Use of high irradiation doses for preservation of canned beef

    International Nuclear Information System (INIS)

    Hammad, A.A.I; Salem, F.A.; El-Sahy, K.M.; Rady, A.; Badr, H.H.

    1997-01-01

    The effect of high irradiation doses (11.25,22.5 and 45 KGy) on the bacteriology, organoleptic quality and shelf - life extension of beef meat that are hermetically sealed in metal cans was investigated in comparison with commercial heat sterilization. The unirradiated cans of pre cooked (enzyme inactivated) unirradiated beef were swollen after only one month of storage at ambient temperature (20-30 degree). Application of 11.25 and 22.5 kGy to vacuum packed and enzyme inactivated beef was not enough for sterilization and only delayed swelling of beef cans. Application of 45 KGy irradiation dose prevented swelling of beef vans up to 12 months at ambient temperature and provided meat product, similar to the commercial heat sterilized one, organoleptically acceptable and microbiologically safe. Running title: Radiation sterilization of meat

  4. Quality index of oils extracted from {gamma}-irradiated peanuts (Arachis hypogaea L.) of the golden and bari varieties

    Energy Technology Data Exchange (ETDEWEB)

    Bhatti, Ijaz Ahmad, E-mail: ijazchem@yahoo.co [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Ashraf, Syra; Shahid, Muhammad [Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad 38040 (Pakistan); Asi, Muhammad Rafique [Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad (Pakistan); Mehboob, Shahid [Department of Zoology, GC University, Faisalabad (Pakistan)

    2010-12-15

    Two varieties of peanuts were irradiated to 4, 6 and 8 kGy with Co{sup 60}. Their proximate compositions remained unaffected, but microbes were eliminated completely after irradiation to 8 kGy. HPLC was used to study tocopherols of irradiated and unirradiated oil samples. There were dose-dependent differences in physico-chemical values between the control and irradiated samples. Significant changes in tocopherol concentrations and peroxide values in the oils were observed after irradiation to 8 kGy. Fatty acid compositions did not change significantly. The study has shown that irradiation is an effective tool in preservation of peanut oil.

  5. Sexual competitiveness of gamma irradiated red flour beetle, tribolium castaneum (herbst)

    International Nuclear Information System (INIS)

    Satar, A.; Khan, A.; Khattak, S.U.; Salihan, Z.

    1989-01-01

    Studies on the sexual competitiveness of radiated male and female adults of tribolium castaneum were conducted under controlled laboratory conditions. The results evaluated on the basis of tendency infertility and competitiveness showed that a ratio of 5:1:1 (Irradiated male/female: Unirradiated male/female: Unirradiated female/male) was the best followed by 4:1:1, 3;1:1, 2:1:1 and 1:1:1 in both the sexes. However, females were found more competitive than male. (author)

  6. Preservation of ethnic food dodol combination of irradiation and atmosphere modified packaging

    International Nuclear Information System (INIS)

    Tanhindarto, Rindy P

    1998-01-01

    An investigation was conducted to determine the suitable types of modified atmosphere treatment combined with irradiation to extend the storage life of dodol at room temperature. The samples were obtained from the manufacture and the production date was known. The sample were vacuum-packed, vacuum-packed with N 2 , and vacuum-packed with CO 2 in polyethylene laminated nylon pouches. A part of the samples were unirradiated, and the irradiated ones received total doses of 2,5 and 5 kGy. The quality of the samples were determined by chemical, microbiological, and organoleptic test. The results showed that the three types of packaging combined with irradiation were not significant. The storage life of irradiation treatment with the doses of 2,5 and 5 kGy combined with modified atmosphere treatment dodol could be extended up to 10 and 12 months, respectively. For Unirradiated dodol, the storage life could be extended up to 8 months. (authors)

  7. Re-weldability tests of irradiated Inconel 625 by TIG welding method

    International Nuclear Information System (INIS)

    Tsuchiya, K.; Shimizu, M.; Kawamura, H.; Matsuda, F.; Kalinin, G.

    1998-01-01

    Inconel 625 is one of the possible materials for the vacuum vessel (VV) and for the in-vessel components of fusion reactors where high strength and high electrical resistance are required. In particular, Inconel 625 is used for the VV of JET and for flexible branch pipe lines in the ITER design. One of the most important issues for their applications is its re-weldability between un-irradiated and irradiated materials. This has a large impact on the design of in-vessel components. In this study, re-weldability of un-irradiated and/or irradiated Inconel 625 that has been welded by the tungsten inert gas (TIG) welding process has been examined, and effect of helium generation amount on mechanical properties of the weld joint has been discussed. (authors)

  8. Research On Degradation Of Silk Fibroin By Combination Of Electron Beam Irradiation And Hydrothermal Processing

    International Nuclear Information System (INIS)

    Nguyen Thi Kim Lan; Dang Van Phu; Le Anh Quoc; Nguyen Quoc Hien

    2014-01-01

    Silk fibers and silk proteins have been demonstrated to be useful to apply in the textile industry, biomedical, cosmetics, pharmaceuticals. In this study, the effects of electron beam (EB) irradiation combined with hydrothermal processing to the solubility of silk fibroin and generation of soluble silk protein were investigated. The solubility of unirradiated and irradiated fibroin were greater than 80 % when hydrothermal degradation was performed in the sodium hydroxide solution at appropriate concentration of 0.05 M. However, the solubility of irradiated fibroin was greater than that of unirradiated sample. The protein content increased from 0.4617 to 0.6530 mg/mg when irradiation doses increased from 0 to 200 kGy, respectively. The molecular weight of protein was determined by SDS-PAGE method. The characteristics of silk protein were confirmed by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). (author)

  9. Extending shelf-life and economic evaluation of strawberry irradiated in Egypt

    International Nuclear Information System (INIS)

    Mahmoud, A.A.

    1988-01-01

    This study was made on ''Egypt's mega gamma I'' irradiator the radiation which is cobalt-60. The following dose was studied in detail 3.5 KGy, was compared with unirradiated sample was studied at the same time. The storage conditions for refrigeration were 4+-1 0 C. During storage periodic fruits were carried out as certain organoleptic properties. The refrigerated irradiated fruits have a shelf life of more than 30 days, whereas the unirradiated ones last only up to 14 days. On the other side the study of economic evaluation of irradiated strawberry showed that the activity of cobalt-60 source needed to satisfy requirement of gamma-irradiation processing of the annual strawberry production in Egypt has been figured a 0.563 Mci for a total activity

  10. Bacteriological quality of freshly processed broiler chickens as affected by carcass pretreatment and gamma irradiation

    International Nuclear Information System (INIS)

    Lamuka, P.O.; Sunki, G.R.; Chawan, C.B.; Rao, D.R.; Shackelford, L.A.

    1992-01-01

    Chicken carcasses dipped in whey fermented by Streptococcus thermophilus, lactic acid solution or water and irradiated at 2.5 kGy by 60Co were evaluated for bacteriological quality on day 1, day-3 and at 3-day intervals for an 18-day storage (4 degrees C) period. Unirradiated carcasses treated similarly were used as control. Gram negative bacteria, Yersinia and Campylobacter counts were significantly (p0.01) lower in irradiated samples, but no significant (p0.05) differences were observed ammong the dipping solutions. Salmonellae were completely eliminated in irradiated samples. Whey fermented by S. thermophilus reduced the proportion of Salmonella contaminated carcasses from 67% to 20%. As evidenced by the bacterial counts the shelf-life was found to be 15 days for irradiated carcasses compared to about 6 days for the unirradiated samples

  11. Food irradiation

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    Food preservation by irradiation is one part of Eisenhower's Atoms for Peace program that is enjoying renewed interest. Classified as a food additive by the Food, Drug, and Cosmetic Act of 1958 instead of a processing technique, irradiation lost public acceptance. Experiments have not been done to prove that there are no health hazards from gamma radiation, but there are new pressures to get Food and Drug Administration approval for testing in order to make commercial use of some radioactive wastes. Irradiation causes chemical reactions and nutritional changes, including the destruction of several vitamins, as well as the production of radiolytic products not normally found in food that could have adverse effects. The author concludes that, lacking epidemiological evidence, willing buyers should be able to purchase irradiated food as long as it is properly labeled

  12. Effect of Irradiation Maternal Diets on the Post-natal Development of Brain Rat Pups

    International Nuclear Information System (INIS)

    Hasan, S.S.

    2005-09-01

    Full text: Effect of Protein-calorie malnutrition was studied on the pups born to mothers receiving either irradiated normal diet (consisted equal parts of gram and wheat) or irradiation low protein diet (consisted one part of normal diet and three parts of heat). Level of DNA, RNA and protein content were found markedly reduced in the brain of irradiated low protein diet fed pups than in the pups fed on the irradiated normal diet. Glucose 6-phosphate dehydrogenase activity was found lower while catalase and lipid peroxidation activity were higher in the pups given irradiated low protein diet, compared whit the pups fed irradiated normal diet. On the whole both the irradiated low protein diet as well as irradiated normal diet fed pups showed higher index of biochemical changes than in the unirradiated low protein diet fed pups. Post-natal mortality was 60% in the pups given irradiated low protein diet, whereas the pups fed on the irradiated normal diet and unirradiated low protein diet did not show any death. The study given evidence that feeding of the irradiated low protein diet interferes more with the development of brain compared with the pups fed on irradiated normal diet

  13. effect of gamma irradiation on the biochemical and microbiological properties of the volatile constituents of coriander fruits

    International Nuclear Information System (INIS)

    Abdelaleem, M.A.

    2008-01-01

    This study was carried out to examine how irradiation can enrich the application of both coriander fruits (irradiated or not irradiated) at dose 2, 4 and 8 kGy and their essential oil at dose 4, 8 and 12 kGy as antimicrobial, antioxidant and enrich biological effect. The data could be summarized as follow:The essential oil content of irradiated coriander at dose 8 kGy was the lowest content. Moreover, the storage period of coriander fruits 12 months reduce the essential oil content to reach 0.33% in irradiated coriander at dose 8 kGy and 0.35 % in unirradiated coriander. The results found that the irradiation at dose 8 kGy eliminate most of microbial contamination of coriander fruits. In addition, 4 kGy was sufficient dose to lower the microbial load up to 0.1 x 10 2 cfu/g. Thus, 4 kGy was not only a typical dose for decontaminating coriander fruits, but also keeping the quality and sensory characteristics of coriander fruits and its essential oil.The essential oil content obtained by supercritical fluid extraction was 0.6%. Chemical properties of essential oil from irradiated coriander acid value and ester number was increased related to irradiation dose and highly increased related to storage period. While, physical properties were not showed any differences compared to control samples.GC/MS analysis represented that Linalool was 57.21% in control, increased to 63.69% and 60.24% in essential oil obtained from irradiated coriander fruits and irradiated essential oil.The threshold level of coriander essential oil added to sunflower oil was 0.1%. Oxidative stability period of sunflower oil free from antioxidants was 224 hr, while addition of 0.02% BHT to sunflower oil increased the oxidative stability to 125 %. While, addition of 0.05%, 0.1% and 0.2% essential oil obtained from irradiated coriander fruits caused detectable increments in the relative stability percentage of sunflower oil by 113.8%, 117.8% and 119.6%, respectively. The results illustrated that

  14. Gamma irradiation of mushrooms, preliminary studies: effect on O-diphenyl oxidase activity and amino acid content

    International Nuclear Information System (INIS)

    Bachman, S.; Gebicka, L.

    1992-01-01

    Mushrooms are a valuable food raw materials because of their nutritional and taste values. Post-harvest ripening, chemical composition (94% water) and possible microbial contamination decrease not only organoleptic and nutritional value, but also the shelf-life. As an objective method of evaluation of irradiated mushrooms we adopted activity determination of o-diphenyl oxidase (o-DPO) which is responsible for discoloration of the edible mushrooms and altered qualitative and quantitative content of amino acids. It was observed that doses up to 2 kGy did not cause any increase in the activity of o-DPO; irradiation also did not affect the taste. Mushrooms irradiated with doses up to 4 kGy were of good quality after 5 days of storage at 4 C, while the control samples (unirradiated) after the same time were considerably changed, probably due too post-harvest ripening. Immediately after exposure the activity of o-DPO increased in proportion to the dose used. During subsequent storage, however, no increase in o-DPO activity was observed. Irradiation used in the range from 0.2 to 0.4 kGy did not affect the nutritional value of the raw material. The results are an additional confirmation that radiation can be used for efficient preservation of mushrooms. (author). 14 refs, 6 tabs

  15. Thermal conductivity of fully dense unirradiated UO2: A new formulation from experimental results between 100 deg. C and 2500 deg. C, and associated fundamental properties

    International Nuclear Information System (INIS)

    Delette, G.; Charles, M.

    1997-01-01

    The various contributions to the thermal conductivity of UO 2 are first reviewed: contribution from phonons is preponderant up to 1600 deg. C; radiative contribution is negligible in the case of a polycrystalline sample, and is unable to account for the increase in conductivity observed above 1600 deg. C; electronic contribution, which seems patently to be responsible for this increase, is efficient from 1400 deg. C (electron-hole pairs treated as small polarons). Given the lack of decisive arguments on their actual efficiency, it was decided that, for temperatures above 2400 deg. C, neither a possible decrease in the electronic contribution due to vacancies, nor an additional possible contribution from Frenkel pairs would be described. We do not go therefore beyond the above-mentioned electronic contribution. In the light of these considerations, the law established by CEA for the thermal conductivity of unirradiated UO 2 , on the basis of a homogeneous set of measurements between 100 deg. C and 2500 deg. C, has been revised. A least-square method applied to the above measurements was used to derive simultaneously the four adjustable constants of the law which is henceforth proposed: λ = 1/A + BT+C/T 2 exp(-W/kT). The values of A, B, C, and W obtained, have the advantage of giving a better account of the high temperature results compared to the Martin recommendations (which has, by the way, the same physical form as above). Furthermore, this new law allows an extrapolation towards the melting point which is better founded than the earlier CEA law, while still respecting the value of the integrated thermal conductivity up to melting. Finally, various burnup effects (impurities, stoichiometry, etc.) can be formulated in physical terms. Moreover, the values of various fundamental properties connected with the derived constants have been determined: Debye temperature, Grueneisen parameter, Mott-Hubbard energy, electrical conductivity. These values are discussed and

  16. Irradiance gradients

    International Nuclear Information System (INIS)

    Ward, G.J.; Heckbert, P.S.; Technische Hogeschool Delft

    1992-04-01

    A new method for improving the accuracy of a diffuse interreflection calculation is introduced in a ray tracing context. The information from a hemispherical sampling of the luminous environment is interpreted in a new way to predict the change in irradiance as a function of position and surface orientation. The additional computation involved is modest and the benefit is substantial. An improved interpolation of irradiance resulting from the gradient calculation produces smoother, more accurate renderings. This result is achieved through better utilization of ray samples rather than additional samples or alternate sampling strategies. Thus, the technique is applicable to a variety of global illumination algorithms that use hemicubes or Monte Carlo sampling techniques

  17. Localized irradiations, Evaluation through ''comet assay''

    International Nuclear Information System (INIS)

    Giorgio, M.D.; Taja, M.R.; Nasazzi, N.B.; Bustos, N.; Cavalieri, H.; Bolgiani, A.

    2000-01-01

    During the last 50 years various radiation accidents involving localized irradiations occurred, resulting mainly from improper handling of sealed sources Co 60 , Cs 137 or Ir 192 at workplaces for industrial gammagraphy. Severe skin reaction may develop at the contact sites. Such inhomogeneous irradiations lead to a differential exposure of lymphocytes in lymphatic tissues or other organs that may recirculate into the peripheral blood producing a mixed irradiated and unirradiated population of lymphocytes. Applying the mathematical models ''Contaminated Poisson'' of Dolphin and Qdr method of Sasaki, a mean dose in the irradiated body area and its size can be estimated from unstable chromosome aberration scoring. This give an indication of the proportion of haemopoietic stem cell compartment involved in the overexposure. There are also different biophysical techniques that can give responses in biological dosimetry. The ''Comet Assay'' (single cell gel electrophoresis) is a sensitive and rapid method for DNA strand break detection in individual cells. The advantages of the technique include: collection of data at the level of individual cell; the need for small numbers of cells per sample; its sensitivity for detecting DNA damage and that virtually any eukaryote cell population is amenable to analysis. The objective of this work is to apply ''Comet Assay'' method to evaluate the effect of radiation on skin and subcutaneous tissues, differentiating irradiated from unirradiated body areas. It could provide a useful tool to estimate the extension and the dose in the irradiated region, contributing with the current techniques. In this first study, we evaluate the alkaline comet assay as a method for detection of DNA radiation induced damage in keratinocytes from primary culture obtained from full thickness skin biopsies of patients requiring grafts. Skin and, particularly, keratinocytes were selected as an appropriate cellular system due to: Skin, the first barrier

  18. Irradiation induced tensile property change of SA 508 Cl.3 reactor pressure vessel steels

    International Nuclear Information System (INIS)

    Chi, Se-Hwan; Hong, Jun-Hwa; Kuk, Il-Hiun

    1998-01-01

    Irradiation induced tensile property change of four kinds of reactor pressure vessel steels manufactured by different steel refining process was compared based on the differences in the unirradiated and irradiated microstructure. Microvickers hardness, indentation, and miniature tensile specimen tests were conducted for mechanical property measurement and optical microscope (OM) and transmission electron microscope (TEM) were used for microstructural characterization. Specimens were 2 irradiated to a neutron fluence of 2.7x10 19 n/cm 2 (E ≥ 1 MeV) at 288 deg. C. Investigation on the unirradiated microstructures showed largely a same microstructure in that tempered acicular bainite and ferrite with bainitic phase prevailing in the unirradiated condition. Band-shaped segregations were also clearly observed except a kind of materials. A large difference in the unirradiated microstructure appeared in the grain size and carbide microstructure. Of carbide microstructures, noticeable differences were observed in the size and distribution of cementite, and bainitic lath microstructures. No noticeable changes were observed in the optical and thin film TEM microstructures after irradiation. Complicated microstructural. state of heat treated bainitic low alloy microstructure prevents easy quantification of microstructural changes due to irradiation. Apparent differences, however, were observed in the results of mechanical testing. Results of tensile testing and hardness measurement show that a steel refined by vacuum carbon deoxidation(VCD) method exhibits the highest radiation hardening behavior. Some of mechanical testing results on irradiated materials were possible to understand based on the initial microstructure, but further investigations using a wide array of sophisticated tools (for example, SANS, APFIM) are required to understand and characterize irradiation induced defects that are responsible for irradiation hardening behavior but are not revealed by

  19. Ultra high vacuum fracture and transfer device for AES analysis of irradiated austenitic stainless steel

    International Nuclear Information System (INIS)

    Urie, M.W.; Panayotou, N.F.; Robinson, J.E.

    1980-01-01

    An ultrahigh vacuum fracture and transfer device for analysis of irradiated and non-irradiated SS 316 fuel cladding is described. Mechanical property tests used to study the behavior of cladding during reactor transient over-power conditions are reported. The stress vs temperature curves show minimal differences between unirradiated cladding and unfueled cladding. The fueled cladding fails at a lower temperature. All fueled specimens failed in an intergranular mode

  20. use of gamma irradiation for enhancing antibacterial activity of chitosan against pathogenic bacteria

    International Nuclear Information System (INIS)

    Taha, S.M.A.; Swailam, H.M.H.

    2009-01-01

    the effect of chitosan on growth of food poisoning bacteria including gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa and Salmonella typhimurium) and gram-positive bacteria (Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus) was investigated at ph 6.0 and 7.0 also, the effect of irradiation on the antibacterial activity of chitosan was studied . it was found that chitosan was more effective on the growth of gram-negative bacteria at ph 6 than ph 7 . addition of chitosan affected the growth of the tested pathogens in varying degrees compared to the control. as the concentration of chitosan increased, its effectiveness against these pathogens also increased. the growth for gram-positive and gram-negative bacterial isolates was completely inhibited at 0.6% chitosan after 72 hours of incubation. inactivation of these pathogens needs only 24 hour with 1.0% of chitosan. irradiation of chitosan at 50 kGy slightly increased the antimicrobial activity whereas at 100 kGy increased the antimicrobial activity and at 150 kGy the growth of these pathogens was completely inhibited . irradiation of chitosan at 50 kGy increased the flow index, whereas consistency index markedly decreased by increasing dose. the minimum inhibitory concentration (MIC) of unirradiated chitosan ranged from 0.35% to 0.50%, whereas the MIC of irradiated chitosan ranged from 0.1% to 0.45% depending on the bacteria and the irradiation dose used. these results demonstrate that irradiated chitosan was more effective to decontaminate pathogenic bacteria and can be easily used in different foods for enhancing health quality and ensuring safety

  1. Conductivity enhancement in SiO2 doped PVA:PVDF nanocomposite polymer electrolyte by gamma ray irradiation

    Science.gov (United States)

    Hema, M.; Tamilselvi, P.; Pandaram, P.

    2017-07-01

    Nanocomposite polymer electrolyte has been irradiated with 15 Gy Gamma rays. Exposure of gamma radiation caused scissoring and crosslinking of polymer chains thereby increasing amorphous phase of the polymer matrix because of which the ionic conductivity has been enhanced. Ionic conductivity of irradiated nanocomposite polymer electrolyte is enhanced to 9.4 × 10-4 Scm-1 at 303 K compared to un-irradiated system (σ ∼ 1.7 × 10-4 Scm-1). Temperature dependence of ionic conductivity of both un-irradiated and irradiated systems obeys VTF relation. Frequency and temperature dependence of dielectric and modulus of both systems have been analyzed. The ionic transference number of polymer electrolyte has been calculated by Wagner's polarization technique and it confirms that conducting species are predominantly due to ions in both systems.

  2. Effect of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3)

    International Nuclear Information System (INIS)

    Pandya, G.A.; Prakash, L.; Devasia, Preston; Modi, V.V.

    1988-01-01

    The effects of gamma-irradiated sludge on the growth and yield of rice (Oryza sativa L. var. GR-3) in pot cultures have been studied. Compared to plants grown only in soil, shoot length, root length, fresh weight, dry weight, total proteins, total soluble sugars, starch and chlorophyll content of plants grown in soil supplemented with unirradiated or gamma-irradiated sludge were found to be significantly increased. Irradiation of sludge significantly stimulated the linear growth of shoot and root systems as well as fresh and dry weights of plants, compared to those grown in soil containing unirradiated sludge. There was also an improvement in the grain yield (weight of seed) when plants were grown in soil supplemented with irradiated sludge. The results obtained suggest that the gamma-irradiated sewage sludge can be beneficially recycled for agricultural uses. (author)

  3. Development of a microbiological irradiation detection method for spices

    International Nuclear Information System (INIS)

    Koshikawa, T.; Takekawa, T.; Miyahara, M.

    2009-01-01

    In order to judge whether certain spices had been irradiated or not, we examined the possibility of developing a method based on the microbiological examination of spices. We used the total bacteria count in conjunction with the ratio of B. megaterium and B. cereus to the total bacteria count. The examination results of 6 kinds of spices with or without irradiation (black pepper, white pepper, coriander, paprika, ginger and turmeric), were as follows. Total bacteria counts over 10E5 CFU/g indicated that the samples were 'unirradiated'. When the total bacteria count was less than 10E5 CFU/g, and the ratio of B. megaterium and B. cereus to the total count was more than 30%, a history of irradiation of the samples was indicated. When ratios of B. megaterium and B. cereus were less than 30% and the total bacteria count was also less than 10E5 CFU/g, 'uncertainty' of irradiation was indicated. In this case, it would be possible to confirm whether spices were 'unirradiated' or 'irradiated' by using another detection method. This detection method was applicable to other spices except for paprika. The samples judged as 'irradiated' by using this detection method, surely proved to have a history of irradiation treatment

  4. Low-dose gamma irradiation following hot Water immersion of Papaya (Carica Papaya linn.) fruits provides additional control of postharvest fungal infection to extend shelf life

    DEFF Research Database (Denmark)

    Rashid, M.H.A.; Grout, Brian William Wilson; Continella, A.

    2015-01-01

    Low-dose gamma irradiation (0.08 kGy over 10 min), a level significantly below that required to satisfy the majority of international quarantine regulations, has been employed to provide a significant reduction in visible fungal infection on papaya fruit surfaces. This is appropriate for local an....... The combined treatment had no significant, negative impact on ripening, with quality characteristics such as surface and internal colour change, firmness, soluble solids, acidity and vitamin C maintained at acceptable levels....... and national markets in producer countries where levels of commercial acceptability can be retained despite surface lesions due to fungal infection. Irradiation alone and in combination with hot-water immersion (50 °C for 10 min) has been applied to papaya (Carica papaya L.) fruits at both the mature green...... and 1/3 yellow stages of maturity. The incidence and severity of surface fungal infections, including anthracnose, were significantly reduced by the combined treatment compared to irradiation or hot water treatment alone, extending storage at 11 °C by 13 days and retaining commercial acceptability...

  5. Soil solution dynamics of Cu and Zn in a Cu- and Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction.

    Science.gov (United States)

    Luo, Y M; Yan, W D; Christie, P

    2001-01-01

    A pot experiment was conducted to study soil solution dynamics of Cu and Zn in a Cu/Zn-polluted soil as influenced by gamma-irradiation and Cu-Zn interaction. A slightly acid sandy loam was amended with Cu and Zn (as nitrates) either singly or in combination (100 mg Cu and 150 mg Zn kg(-1) soil) and was then gamma-irradiated (10 kGy). Unamended and unirradiated controls were included, and spring barley (Hordeum vulgare L. cv. Forrester) was grown for 50 days. Soil solution samples obtained using soil moisture samplers immediately before transplantation and every ten days thereafter were used directly for determination of Cu, Zn, pH and absorbance at 360 nm (A360). Cu and Zn concentrations in the solution of metal-polluted soil changed with time and were affected by gamma-irradiation and metal interaction. gamma-Irradiation raised soil solution Cu substantially but generally decreased soil solution Zn. These trends were consistent with increased dissolved organic matter (A360) and solution pH after gamma-irradiation. Combined addition of Cu and Zn usually gave higher soil solution concentrations of Cu or Zn compared with single addition of Cu or Zn in gamma-irradiated and non-irradiated soils, indicating an interaction between Cu and Zn. Cu would have been organically complexed and consequently maintained a relatively high concentration in the soil solution under higher pH conditions. Zn tends to occur mainly as free ion forms in the soil solution and is therefore sensitive to changes in pH. The extent to which gamma-irradiation and metal interaction affected solubility and bioavailability of Cu and Zn was a function of time during plant growth. Studies on soil solution metal dynamics provide very useful information for understanding metal mobility and bioavailability.

  6. Effect of gamma-irradiation to prevent the spoilage of fried-Kamaboko

    Energy Technology Data Exchange (ETDEWEB)

    Ito, H; Siagian, E G [Japan Atomic Energy Research Inst., Takasaki, Gunma. Takasaki Radiation Chemistry Research Establishment

    1979-08-01

    The study was done to determine the effect of irradiation on the shelf life and quality of a fish meat jelly product named as Fried-Kamaboko which is sometimes called as Satsumaage. Fresh samples were packed and sealed in cellophane coated polyvinylchloride bag with nitrogen gas, and irradiated at 0, 300 and 500 krad followed by storage at 10/sup 0/C. The results showed that irradiation of 300 krad extended the shelf life of Fried-Kamaboko to be 20 days, in contrast to unirradiated samples which were kept only 3 to 6 days at 10/sup 0/C. The species of main microorganisms which grew in unirradiated samples were Micrococcus, Moraxella-Acinetobacter, lactic acid bacteria, yeasts and molds. Irradiation of Fried-Kamaboko at 300 krad reduced the aforementioned flora to the yeasts. The most radio-resistant microorganisms of Fried-Kamaboko was brownish black Fungi identified as Spicaria, and its D/sub 10/ value was obtained to be 130 krad. No remarkable difference was observed between the irradiated Fried-Kamaboko and unirradiated ones with respect to the organoleptic evaluation. But off-odor was slightly induced with the dose of 500 krad irradiation.

  7. Competitiveness value of the indian meal, plodia interpunctella (Hub). irradiated as full grown pupae

    International Nuclear Information System (INIS)

    Ahmed, M.Y.Y.; Elhawary, I.S.; Boshra, S.A.

    1992-01-01

    When 6-day-old pupae of the indian meal moth, plodia interpunctella (Hubner) were treated with 60 K.rad, the resulting adults were sterile when they paired with the untreated opposite sex. A ratio of 1:1:1 irradiated males, in irradiated males, and unirradiated females resulted in 41.0% infertile eggs. Ratios of irradiated to unirradiated males of 5:1, 10:1, 15:1, 20:1, or 25:1 produced 75.7, 91.7, 95.0 and 96.3% infertile eggs, respectively. Thus, irradiated males were competitive only at a ratio of 25:1. When both irradiated males and females were placed with unirradiated males and females to give ratios of 1:1:1:1, 5:5:1:1, 10:10:1:1: or 15:15:1:1:, the percentage of infertile eggs were 55.7, 81.0, 95.3, and 100.0% respectively, and competitiveness was good at all but the lowest ratio. Irradiation of 6-day-old pupae of the indian meal moth produced sexually competitive sterile adults when released at high flooding ratios, and results were better when both sexes released together.2 tab

  8. Effect of gamma-irradiation to prevent the spoilage of fried-Kamaboko

    International Nuclear Information System (INIS)

    Ito, Hitoshi; Siagian, E.G.

    1979-01-01

    The study was done to determine the effect of irradiation on the shelf life and quality of a fish meat jelly product named as Fried-Kamaboko which is sometimes called as Satsumaage. Fresh samples were packed and sealed in cellophane coated polyvinylchloride bag with nitrogen gas, and irradiated at 0, 300 and 500 krad followed by storage at 10 0 C. The results showed that irradiation of 300 krad extended the shelf life of Fried-Kamaboko to be 20 days, in contrast to unirradiated samples which were kept only 3 to 6 days at 10 0 C. The species of main microorganisms which grew in unirradiated samples were Micrococcus, Moraxella-Acinetobacter, lactic acid bacteria, yeasts and molds. Irradiation of Fried-Kamaboko at 300 krad reduced the aforementioned flora to the yeasts. The most radio-resistant microorganisms of Fried-Kamaboko was brownish black Fungi identified as Spicaria, and its D 10 value was obtained to be 130 krad. No remarkable difference was observed between the irradiated Fried-Kamaboko and unirradiated ones with respect to the organoleptic evaluation. But off-odor was slightly induced with the dose of 500 krad irradiation. (author)

  9. Effects of 3.1-MeV proton and 1-GeV Au-ion irradiation on the magnetic flux noise and critical current of YBa2Cu3O7-δ

    International Nuclear Information System (INIS)

    Shaw, T.J.; Clarke, J.; van Dover, R.B.; Schneemeyer, L.F.; White, A.E.

    1996-01-01

    We have used a dc superconducting quantum interference device to measure the spectral density of magnetic flux noise, S Φ (f), generated by vortex motion in crystals of YBa 2 Cu 3 O 7-δ (YBCO) both before and after irradiation with 3.1-MeV protons and 1-GeV Au ions. In addition, we have studied the effects of irradiation on the critical current J c of the same samples. Both types of irradiation reduced S Φ (f) at most temperatures and magnetic fields and increased J c at all temperatures and magnetic fields. By measuring S Φ (f) versus temperature, we extract the distribution of vortex pinning energies, D(U 0 ). Both crystals have peaks in D(U 0 ) near 0.1 eV and 0.2 eV before irradiation, and a much reduced peak near 0.1 eV after irradiation. The noise level after either kind of irradiation was substantially higher than in an unirradiated YBCO film. copyright 1996 The American Physical Society

  10. Mechanical properties and plasticity size effect of Fe-6%Cr irradiated by Fe ions and by neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Hardie, C.D., E-mail: chris.hardie@ukaea.uk [EURATOM/CCFE Association, Culham Centre for Fusion Energy (CCFE), Abingdon, Oxfordshire, OX14 3DB (United Kingdom); Department of Materials, University of Oxford, Oxford, OX1 3PH (United Kingdom); Odette, G.R.; Wu, Y. [UCSB Department of Mechanical Engineering, 2343 Engineering II Building, Santa Barbara, CA 93106-5070 (United States); Akhmadaliev, S. [Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, D-01328 Dresden (Germany); Roberts, S.G. [EURATOM/CCFE Association, Culham Centre for Fusion Energy (CCFE), Abingdon, Oxfordshire, OX14 3DB (United Kingdom); Department of Materials, University of Oxford, Oxford, OX1 3PH (United Kingdom)

    2016-12-15

    The mechanical behaviour of Fe6%Cr in the un-irradiated, self-ion irradiated and neutron irradiated conditions was measured and compared. Irradiations were performed to the same dose and at the same temperature but to very different damage rates for both methods. The materials were tested using nanoindentation and micromechanical testing, and compared with microstructural observations from Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT) reported elsewhere. Irradiated and un-irradiated micro-cantilevers with a wide range of dimensions were used to study the interrelationships between irradiation hardening and size effects in small-scale plasticity. TEM and APT results identified that the dislocation loop densities were ∼2.9 × 10{sup 22}m{sup −3} for the neutron irradiated material and only 1.4 × 10{sup 22}m{sup −3} for the ion irradiated material. Cr segregation to loops was only found for the neutron-irradiated material. The nanoindentation hardness increase due to neutron irradiation was 3 GPa and that due to ion irradiation 1 GPa. The differences between the effects of the two irradiation types are discussed, taking into account inconsistencies in damage calculations, and the differences in PKA spectra, dose rate and transmutation products for the two irradiation types.

  11. The application of an internal state variable model to the viscoplastic behavior of irradiated ASTM 304L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    McAnulty, Michael J., E-mail: mcanulmj@id.doe.gov [Department of Energy, 1955 Fremont Avenue, Idaho Falls, ID 83402 (United States); Potirniche, Gabriel P. [Mechanical Engineering Department, University of Idaho, Moscow, ID 83844 (United States); Tokuhiro, Akira [Mechanical Engineering Department, University of Idaho, Idaho Falls, ID 83402 (United States)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer An internal state variable approach is used to predict the plastic behavior of irradiated metals. Black-Right-Pointing-Pointer The model predicts uniaxial tensile test data for irradiated 304L stainless steel. Black-Right-Pointing-Pointer The model is implemented as a user-defined material subroutine in the finite element code ABAQUS. Black-Right-Pointing-Pointer Results are compared for the unirradiated and irradiated specimens loaded in uniaxial tension. - Abstract: Neutron irradiation of metals results in decreased fracture toughness, decreased ductility, increased yield strength and increased ductile-to-brittle transition temperature. Designers use the most limiting material properties throughout the reactor vessel lifetime to determine acceptable safety margins. To reduce analysis conservatism, a new model is proposed based on an internal state variable approach for the plastic behavior of unirradiated ductile materials to support its use for analyzing irradiated materials. The proposed modeling addresses low temperature irradiation of 304L stainless steel, and predicts uniaxial tensile test data of irradiated experimental specimens. The model was implemented as a user-defined material subroutine (UMAT) in the finite element software ABAQUS. Results are compared between the unirradiated and irradiated specimens subjected to tension tests.

  12. Comparative studies in the cellular immunostimulation by whole body irradiation

    International Nuclear Information System (INIS)

    Dietz, R.; Schwarze, G.

    1992-01-01

    The effect of the cellular immune response by total body irradiation was investigated. The transplant survival (skin grafts) was determined as immune parameter. Donors were colony bred Wistar rats and recipients were colony bred Sprague Dawley rats. The investigations were carried out with irradiated rats and with rats irradiated after thymectomy and/or adrenalectomy as well as with animals without irradiation. A single total-body irradiation (1 and 2 Gy) was administered. The skin graft survival in irradiated rats was significant shorter (radiogenic immunostimulation) than in unirradiated rats; there were no significant differences between the operated (thymectomy and/or adrenalectomy) and not operated animals. Including precedent examinations this radiogenic immunostimulation is caused by relativly selective inactivation of T-suppressor cells. (orig.) [de

  13. Tensile and fracture toughness test results of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Moons, F.; Puzzolante, J.L. [Centre d`Etude de l`Energie Nucleaire, Mol (Belgium)

    1998-01-01

    Tensile and fracture toughness test results of four Beryllium grades are reported here. The flow and fracture properties are investigated by using small size tensile and round compact tension specimens. Irradiation was performed at the BR2 material testing reactor which allows various temperature and irradiation conditions. The fast neutron fluence (>1 MeV) ranges between 0.65 and 2.45 10{sup 21} n/cm{sup 2}. In the meantime, un-irradiated specimens were aged at the irradiation temperatures to separate if any the effect of temperature from irradiation damage. Test results are analyzed and discussed, in particular in terms of the effects of material grade, test temperature, thermal ageing and neutron irradiation. (author)

  14. Stability of uranium silicides during high energy ion irradiation

    International Nuclear Information System (INIS)

    Birtcher, R.C; Wang, L.M.

    1991-11-01

    Changes induced by 1.5 MeV Kr ion irradiation of both U 3 Si and U 3 Si 2 have been followed by in situ transmission electron microscopy. When irradiated at sufficiently low temperatures, both alloys transform from the crystalline to the amorphous state. When irradiated at temperatures above the temperature limit for ion beam amorphization, both compounds disorder with the Martensite twin structure in U 3 Si disappearing from view in TEM. Prolonged irradiation of the disordered crystalline phases results in nucleation of small crystallites within the initially large crystal grains. The new crystallites increase in number during continued irradiation until a fine grain structure is formed. Electron diffraction yields a powder-like diffraction pattern that indicates a random alignment of the small crystallites. During a second irradiation at lower temperatures, the small crystallizes retard amorphization. After 2 dpa at high temperatures, the amorphization dose is increased by over twenty times compared to that of initially unirradiated material

  15. Irradiation effect on animal feeds and feedstuffs

    International Nuclear Information System (INIS)

    Kume, Tamikazu

    1983-10-01

    Aiming to secure the safety of animal feeds and develop the new resources, the effect of γ-irradiation on disinfection and the changes in components were investigated. Salmonellae and coliforms contaminating in animal feeds and feedstuffs were eliminated by 0.5 -- 0.6 Mrad and 0.5 -- 0.8 Mrad, and osmophilic moulds were sterilized by 0.7 -- 0.75 Mrad. From these results, it is concluded that the dose for disinfection of animal feeds is 0.8 Mrad. The main components were hardly changed by irradiation up to 5 Mrad, and the component changes in irradiated samples could be suppressed during storage while the components in unirradiated samples were markedly changed with the growth of osmophilic moulds. Histamine and lysinoalanine, which may cause the feed poisoning, were never accumulated in feedstuffs by irradiation. The nutritional value of chick feeds was not changed by 1.0 Mrad irradiation. From these results, it is considered that no problem for wholesomeness of animal feeds occurs by irradiation. Therefore, the irradiation is effective for disinfection and keeping the nutritional value of animal feeds during storage. Irradiation promotes the recovery of proteins in the wastewater by coagulation of proteins and improves the property of coagulants due to the degradation of polysaccharides. These results indicate that irradiation is effective to develop the new resources for animal feeds. (author)

  16. Mechanical properties of irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Beeston, J.M.; Longhurst, G.R.; Wallace, R.S. (EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.); Abeln, S.P. (EG and G Rocky Flats, Inc., Golden, CO (United States))

    1992-10-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10[sup 25] n/m[sup 2] (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.).

  17. Shipboard-irradiation of haddock

    International Nuclear Information System (INIS)

    Ehlermann, D.; Reinacher, E.; Antonacopoulos, N.

    1977-01-01

    Haddock caught during the 183rd and 185th voyage of the RV 'Anton Dohrn' off Faeroeer was gutted, washed and packed under vacuum in polyethylene pouches. The samples were irradiated with the onboard X-ray source. During one series of experiments a minimum dose of 65 krad and a maximum dose of 130 krad was used. During further series the minimal dose was set to 100 krad, resulting in maximum values of 140 krad and 180 krad. As judged by taste panel evaluation of steam-cooked, unseasoned filets, quality preservation of all samples during the first 16 days of iced storage did not depend on irradiation. After that period the fish had lost prime quality. At this time, irradiated samples were rated slightly better than unirradiated ones. Base on our results, the shipboard-irradiation of prepacked haddock cannot be recommended. This does not exclude that under different conditions (e.g. fishfilets in retail packages) beneficial effects of irradiation may be observed. (orig.) [de

  18. Effects of irradiation upon spices

    Energy Technology Data Exchange (ETDEWEB)

    1978-04-01

    ESR studies were performed on untreated and irradiated samples of paprika powder, ground black pepper, and a spice mixture of the following composition: paprika, 55%; black pepper, 14%; allspice, 9%; coriander, 9%; marjoram, 7%; cumin, 4%; and nutmeg, 2%. Gamma radiation doses from 0.5 to 5 Mrad were applied. In the case of paprika samples, the effect of moisture content on the formation and disappearance of radiation-induced free radicals was also investigated. Shortly after irradiation (on the day of radiation treatment) high amounts of free radicals were detected in irradiated spice samples but they diminished upon storage. After a period of 3 months the ESR signals of the irradiated samples approximated those of the controls. The free radicals found in unirradiated ground spices did not disappear during a storage period as long as one year. The formation and disappearance of radiation-induced free radicals were found to be strongly affected by the moisture content of samples. If a sample of low moisture content containing a high free radical concentration after irradiation was placed in an atmosphere of higher moisture content, the free radicals decayed rapidly.

  19. Shipboard-irradiation of haddock

    International Nuclear Information System (INIS)

    Ehlermann, D.; Reinacher, E.; Antonacopoulos, N.

    1977-01-01

    Haddock caught during the 183rd and 185th voyage of the RV 'Anton Dohrn' off Faeroer was gutted, washed and packed under vacuum in polythylene pouches. The samples were irradiated with the onboard X-ray source. During one series of experiments a minimum dose of 65 krad and a maximum dose of 130 krad was used. During further series the minimal dose was set to 100 krad, resulting in maximum values of 140 krad and 180 krad. As judged by taste panel evalution of steam-cooked, unseasoned filets, quality preservation of all samples during the first 16 days of iced storage did not depend on irradiation. After that period the fish had lost prime quality. At this time, irradiated samples were rated slightly better than unirradiated ones. On the basis of these results, the shipboard-irradiation of prepacked haddock cannot be recommended. This does not exclude that under different conditions (e.g. fishfilets in retail packages) beneficial effects of irradiation may be observed. (orig.) [de

  20. The freezing and thawing of water in poultry meat and vegetables irradiated by electrons at doses of 0.1-4 kGy

    International Nuclear Information System (INIS)

    Dubini, B.; Montecchia, F.; Ponzi-Bossi, M.G.; Messina, G.

    1993-01-01

    Poultry meat and some vegetables, irradiated by 5 MeV electrons (0.1-4 kGy), were analysed by differential scanning calorimetry, from 24 h after irradiation. The temperature and enthalpy transitions of the water contained in the irradiated samples were measured and compared with those of unirradiated samples. The authors analysed 18 meat and 10 vegetable samples for each irradiation dose together with a similar number of unirradiated controls. The mean supercooling temperatures of water in the irradiated poultry meat samples and in some vegetables are significantly lower than those of controls. Moreover, the freezing enthalpies of the irradiated poultry breast are significantly lower than those of controls, while they are unchanged in the other cases. The mean ice melting temperatures and enthalpies are similar for all samples. The amount of the lowering of the water-ice transition depends on the nature of the sample and is highest in poultry breast and lowest in vegetables. (author)

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

    International Nuclear Information System (INIS)

    Al-Bachir, M.; Zeinou, R.

    2006-12-01

    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)

  2. The Analysis of the General Performance and Mechanical Behavior of Unirradiated FeCrAl Alloys Before and After Welding

    Energy Technology Data Exchange (ETDEWEB)

    Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yamamoto, Yukinori [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-06-03

    The present report summarizes and discusses the preliminary results for the in-depth characterization of the modern, nuclear-grade FeCrAl alloys currently under development. The alloys were designed for enhanced radiation tolerance and weldability, and the research is currently being pursued by the Department of Energy (DOE) Nuclear Energy Enabling Technologies (NEET) program. Last year, seven candidate FeCrAl alloys with well-controlled chemistry and microstructures were designed and produced; welding was performed under well-controlled conditions. The structure and general performance of unirradiated alloys were assessed using standardized and advanced microstructural characterization techniques and mechanical testing. The primary objective is to identify the best candidate alloy, or at a minimum to identify the contributing factors that increase the weldability and radiation tolerance of FeCrAl alloys, therefore enabling future generations of FeCrAl alloys to deliver better performance parameters. This report is structured so as to describe these critical assessments of the weldability; radiation tolerance will be reported on in later reports from this program.

  3. Optical absorption of BaF2 crystals with different prehistory when irradiated by high-energy electrons

    International Nuclear Information System (INIS)

    Chinkov, E P; Stepanov, S A; Shtan'ko, V F; Ivanova, T S

    2016-01-01

    The spectra of stable optical absorption of BaF 2 crystals containing uncontrollable impurities after irradiation with 3 MeV electrons are studied at room temperature. The dependence of the efficiency of stable color accumulation in the region of emerging crossluminescence on the absorption coefficients measured near the fundamental absorption edge in unirradiated crystals of various prehistory is traced. (paper)

  4. Food irradiation: fiction and reality

    International Nuclear Information System (INIS)

    1991-01-01

    The International Consultative Group on Food Irradiation (IGCFI), sponsored by World Health Organization (WHO), Food and Agriculture Organization (FAO) and the International Atomic Energy Agency (IAEA), with the intention to provide to governments, especially those of developing countries, scientifically correct information about food irradiation, decided to organize a file and questions of general public interest. The document is composed by descriptive files related with the actual situation and future prospective, technical and scientific terms, food irradiation and the radioactivity, chemical transformations in irradiated food, genetic studies, microbiological safety of irradiated food, irradiation and harmlessness, irradiation and additives, packing, irradiation facilities control, process control, irradiation costs and benefits as well as consumers reaction

  5. Microstructural examination of irradiated vanadium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Chung, H.M. [Argonne National Lab., IL (United States)

    1997-04-01

    Microstructural examination results are reported for a V-5Cr-5Ti unirradiated control specimens of heat BL-63 following annealing at 1050{degrees}C, and V-4Cr-4Ti heat BL-47 irradiated in three conditions from the DHCE experiment: at 425{degrees}C to 31 dpa and 0.39 appm He/dpa, at 600{degrees}C to 18 dpa and 0.54 appm He/dpa and at 600{degrees}C to 18 dpa and 4.17 appm He/dpa.

  6. Identification of irradiated foods using the thermoluminescence apparatus TOLEDO - Preliminary study

    International Nuclear Information System (INIS)

    Vo Van Thuan; Pham Quang Vinh; Dang Thanh Luong; Pham Quang Dien

    1990-01-01

    The thermoluminescence (TL) method based on TOLEDO apparatus has been carried out, firstly in Vietnam, for identification of some irradiated dry food: paprika, pepper, curry and green beans. The TL effect of irradiation with dose 0.8 Mrad is greater than the effect of unirradiated samples at least by one order. The TOLEDO was proved to be able to determine TL intensity as function of absorbed dose and post-irradiation storage time. The measurement procedure is rapid and simple, that expect to be used as a standard control method of irradiated food. (author). 6 refs, 2 figs, 1 tab

  7. Unstable structure of ribosomal particles synthesized in. gamma. -irradiated Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Fujita, H; Morita, K [National Inst. of Radiological Sciences, Chiba (Japan)

    1975-06-01

    Stability of Escherichia coli ribosomes newly synthesized after ..gamma..-irradiation was compared with that of normal ribosomes. The ribosomal particles around 70-S synthesized in irradiated cells were more sensitive to digestion by pancreatic ribonuclease A. A larger number of the salt-unstable '50-S' precursor particles existed in the extract from irradiated cells than in the extract from unirradiated cells. These facts suggest that ribosomal particles, synthesized during an earlier stage in irradiated cells, maintain an incomplete structure even though they are not distinguishable from normal ribosomes by means of sucrose density-gradient centrifugation.

  8. Irradiation monitoring of spices by chemiluminescence method

    International Nuclear Information System (INIS)

    Bhatti, K.A.; Khan, H.M.; Sattar, A.; Ahmad, A.

    2001-01-01

    Some spices (cumin, coriander, black pepper and red pepper), commonly used due to their specific aroma and nutritional value were studied using chemiluminescence (CL) method to test whether the food has been irradiated or not. The spices were ground to different mesh sizes and subjected to gamma ray doses of 2.5, 5.0, 7.5 and 10 Kgy. The effect of radiation doses and particle size on the CL response of irradiated and un-irradiated samples was checked using luminol and lucigenin sensitizers. The storage experiment was also performed for all spices with both the sensitizers in order to pick the suitable sensitizer for CL study. During this study Co-60 gamma ray source and Bio-orbit 1250 luminometer were used after precise calibration

  9. Spectroscopic study of gamma irradiated bovine hemoglobin

    International Nuclear Information System (INIS)

    Maghraby, Ahmed Mohamed; Ali, Maha Anwar

    2007-01-01

    In the present study, the effects of ionizing radiation of Cs-137 and Co-60 from 4.95 to 743.14 Gy and from 40 Gy to 300 kGy, respectively, on some bovine hemoglobin characteristics were studied. Such an effect was evaluated using electron paramagnetic resonance (EPR) spectroscopy, and infra-red (IR) spectroscopy. Bovine hemoglobin EPR spectra were recorded and analyzed before and after irradiation and changes were explained in detail. IR spectra of unirradiated and irradiated Bovine hemoglobin were recorded and analyzed also. It was found that ionizing radiation may lead to the increase of free radicals production, the decrease in α-helices contents, which reflects the degradation of hemoglobin molecular structure, or at least its incomplete performance. Results also show that the combined application of EPR and FTIR spectroscopy is a powerful tool for determining structural modification of bovine hemoglobin samples exposed to gamma irradiation

  10. Irradiation detection of food by DNA Comet Assay

    International Nuclear Information System (INIS)

    Khan, A.A.; Delincee, H.

    1999-01-01

    Microgel electrophoresis of single cells or nuclei (DNA Comet Assay) has been investigated to detect irradiation treatment of more than 50 food commodities e.g. meats, seafood, cereals, pulses, nuts, fruits and vegetables, and spices. The foodstuffs have been exposed to radiation doses covering the range of potential commercial irradiation for inactivation of pathogenic and spoilage micro-organisms, for insect disinfestation and for shelf-life extension. The Comet Assay is based on detection of DNA fragments presumptive to irradiation. For most of the food items investigated, the assay can be applied successfully for irradiation detection by working out different conditions of the assay. However, with some of the foods difficulties arose due to - lack of discrimination between the irradiated and unirradiated food samples due to the presence of the same kinds of comets in both cases and the total absence of the typical intact cells in unirradiated samples. - Sufficient DNA material was not available from some of the foods. - Insufficient lysis of the cell walls in case of some plant foods. In conclusion, the DNA Comet Assay can help to detect the irradiation treatment of several varieties of foods using low-cost equipment in a short time of analysis. (orig.)

  11. Effect of gamma-irradiation on oocysts of Eimeria necatrix

    International Nuclear Information System (INIS)

    Singh, J.; Gill, B.S.

    1975-01-01

    Effect of γ radiation on oocysts of Eimeria necatrix was investigated. It was observed that oocysts exposed to 200kR or above did not sporulate. Irradiation at 10 to 150kR caused a progressive decrease in sporulation. Irradiation affected normal development of unsporulated oocysts as the zygote protoplasm divided into unequal masses or was shattered into granules. Increase in the intensity of irradiation of sporulated oocysts resulted in the progressive decrease in severity of the resultant infections in chicks and their effects - mortality, type of lesions developed, total oocyst production and immunity produced - were comparable with infections induced by decreasing the number of unirradiated oocysts. Infection produced by 1000 unirradiated oocysts was comparable with that resulting from 50,000 oocysts irradiated at 25kR. Infection obtained with 20,000 unexposed oocysts approximated to that produced by 50,000 oocysts irradiated at 2.5kR. It was concluded that irradiation abolished infectivity of the oocysts/sporozoites rather than bringing about attenuation of the parasite. (author)

  12. Evaluation of irradiation in foods using DNA comet assay

    International Nuclear Information System (INIS)

    Khawar, Affaf; Bhatti, Ijaz Ahmad; Khan, Q.M.; Ali, T.; Khan, A.I.; Asi, M.R.

    2011-01-01

    Comet assay is a rapid, inexpensive and sensitive biological technique to detect DNA damage in food stuffs by irradiation. In this study the Comet assay is applied on foods of plant and animal origins. Samples were irradiated by using 60 Co gamma-radiation source. The applied doses were 2, 6 and 10 kGy for food of plant origin and 0.5, 1 and 2 kGy for meat items. The un-irradiated and irradiated samples were clearly differentiated on the basis of DNA fragmentation. During the electrophoresis study, it was found that in un-irradiated cells DNA remained intact and appeared as Comets without tail whereas in irradiated cells Comets with tails were visible due to stretching of fragmented DNA. Moreover, it was also revealed that the DNA tail length was dose dependent. Dry food stuffs (seeds) showed good results as compared to moist foods (meat, fruits and vegetables) due to the absence of background damage. (author)

  13. Quality control in the process and in the irradiated food

    International Nuclear Information System (INIS)

    Farrar IV, H.

    1997-01-01

    In the irradiation process, absorbed dose is the key parameter that must be controlled. In general, the minimum absorbed dose needed to accomplish a desired effect, such as insect disinfestation or pathogen reduction, is already known from previous research, and is often prescribed by government regulations. The irradiation process is effective, however, only if the food can tolerate this dose without experiencing unwanted changes in flavor or appearance. The dose that food can tolerate often depends on such things as the variety of the fruit or vegetable, where it was grown, the season in which it was harvested and the length of time between harvesting and irradiation. Once the minimum and maximum doses are established, the irradiator operator must make sure that these dose limits are not exceeded. First, a dose mapping using many dosimeters must be undertaken to determine the locations of the minimum and maximum dose in the overall process load. From then on, the process load must always be the same, and, as a key step in the overall process control, dosimeters need to be placed from time to time only at the minimum or maximum locations. The dosimeters must be calibrated and directly trackable to national or international standards, and a fool-proof method of labelling and segregating irradiated from unirradiated product must be used. Radiation sensitive indicators that may help identify irradiated from unirradiated food should not be relied upon, and are not a substitute fro proper dosimetry. (Author)

  14. Quality control in the process and in the irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, IV, H [Chairman, ASTM Subcommittee E10.01 ` Dosimetry for Radiation Processing` , 18 Flintlock Lane, Bell Canyon, California 91307-1127 (United States)

    1998-12-31

    In the irradiation process, absorbed dose is the key parameter that must be controlled. In general, the minimum absorbed dose needed to accomplish a desired effect, such as insect disinfestation or pathogen reduction, is already known from previous research, and is often prescribed by government regulations. The irradiation process is effective, however, only if the food can tolerate this dose without experiencing unwanted changes in flavor or appearance. The dose that food can tolerate often depends on such things as the variety of the fruit or vegetable, where it was grown, the season in which it was harvested and the length of time between harvesting and irradiation. Once the minimum and maximum doses are established, the irradiator operator must make sure that these dose limits are not exceeded. First, a dose mapping using many dosimeters must be undertaken to determine the locations of the minimum and maximum dose in the overall process load. From then on, the process load must always be the same, and, as a key step in the overall process control, dosimeters need to be placed from time to time only at the minimum or maximum locations. The dosimeters must be calibrated and directly trackable to national or international standards, and a fool-proof method of labelling and segregating irradiated from unirradiated product must be used. Radiation sensitive indicators that may help identify irradiated from unirradiated food should not be relied upon, and are not a substitute fro proper dosimetry. (Author)

  15. Quality control in the process and in the irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Farrar IV, H. [Chairman, ASTM Subcommittee E10.01 `Dosimetry for Radiation Processing`, 18 Flintlock Lane, Bell Canyon, California 91307-1127 (United States)

    1997-12-31

    In the irradiation process, absorbed dose is the key parameter that must be controlled. In general, the minimum absorbed dose needed to accomplish a desired effect, such as insect disinfestation or pathogen reduction, is already known from previous research, and is often prescribed by government regulations. The irradiation process is effective, however, only if the food can tolerate this dose without experiencing unwanted changes in flavor or appearance. The dose that food can tolerate often depends on such things as the variety of the fruit or vegetable, where it was grown, the season in which it was harvested and the length of time between harvesting and irradiation. Once the minimum and maximum doses are established, the irradiator operator must make sure that these dose limits are not exceeded. First, a dose mapping using many dosimeters must be undertaken to determine the locations of the minimum and maximum dose in the overall process load. From then on, the process load must always be the same, and, as a key step in the overall process control, dosimeters need to be placed from time to time only at the minimum or maximum locations. The dosimeters must be calibrated and directly trackable to national or international standards, and a fool-proof method of labelling and segregating irradiated from unirradiated product must be used. Radiation sensitive indicators that may help identify irradiated from unirradiated food should not be relied upon, and are not a substitute fro proper dosimetry. (Author)

  16. Storage properties of gamma-irradiated semi-dried fish varieties

    International Nuclear Information System (INIS)

    Vinh, P.Q.; Alur, M.D.; Nair, P.M.

    1993-01-01

    Several varieties of semi-dried unirradiated and irradiated (1 and 3 kGy) fish, namely, anchovies (Stolephorus commersonii), Bombay duck (Harpodon nehereus), shrimp (Penaeus indicus) and Vietnam scad (Alepes mate) were stored at ambient temperature (26 degree C). During the course of storage, quality characteristics such as total bacterial count (TBC), mould count and biochemical indices of freshness were studied. These studies indicated that initial TBC of semi-dried fish varied from 700-5400 cfu per g of fish, while mould could ranged from 27-1500 cfu per g. However, upon irradiation at 3 kGy, initial bacterial load was considerably reduced. Vietnam scad was not contaminated with mould after 3-5 months of storage at room temperature. Indices such as TVA and TVBN increased during storage at room temperature for both unirradiated and irradiated samples

  17. Effect of bonding and bakeout thermal cycles on the properties of copper alloys irradiated at 350 deg. C

    International Nuclear Information System (INIS)

    Singh, B.N.; Eldrup, M.; Toft, P.; Edwards, D.J.

    1997-02-01

    Screening experiments were carried out to investigate the effect of bonding and bakeout thermal cycles on microstructure, mechanical properties and electrical resistivity of the oxide dispersion strengthened (GlidCop, CuAl-25) and the precipitation hardened (CuCrZr, CuNiBe) cooper alloys. Tensile specimens of CuCrZr and CuNiBe alloys were given various heat treatments corresponding to solution anneal, prime-ageing, and bonding thermal treatment followed by re-ageing and the reactor bakeout treatment at 350 deg. C for 100 h. Tensile specimens of CuAl-25 were given the heat treatment corresponding to the bonding thermal cycle. A number of heat treated specimens were neutron irradiated at 350 deg. C to a dose level of ∼ 0.3 dpa in the DR-3 reactor at Risoe. Both unirradiated and irradiated specimens with various heat treatments were tensile tested at 350 deg. C. The microstructure and electrical resistivity of these specimens were determined in the unirradiated as well as irradiated conditions. The post-deformation microstructure of the irradiated specimens was also investigated. The fracture surfaces of both unirradiated and irradiated specimens were examined. Results of these investigations are reported in the present report. The results are briefly discussed in terms of thermal and irradiation stability of precipitates and particles and irradiation-induced segregation, precipitation and recovery of dislocation microstructure. (au) 6 tabs., 24 ills., 9 refs

  18. Correlation of yield stress and microhardness in 08Cr16Ni11Mo3 stainless steel irradiated to high dose in the BN-350 fast reactor

    International Nuclear Information System (INIS)

    Gusev, M.N.; Maksimkin, O.P.; Tivanova, O.V.; Silnaygina, N.S.; Garner, F.A.

    2006-01-01

    The relationship between the microhardness and the engineering yield stress in 08Cr16Ni11Mo3 steel after irradiation in the BN-350 reactor has been experimentally derived and agrees with a previously published correlation developed by Toloczko for unirradiated 316 in a variety of cold-work conditions. Even more importantly, when the correlation is derived in the K Δ format where the correlation involves changes in the two properties, excellent agreement is found with a universal K Δ correlation developed by Busby and coworkers. Additionally, this report points out that microhardness measurements must take into account that sodium exposure at high temperature and neutron fluence alters the metal surface to produce ferrite, and therefore the altered layers should be removed prior to testing

  19. Effect of gamma irradiation on bitter pit of apple fruits (Malus Domestica Borkh)

    International Nuclear Information System (INIS)

    Al-Bachir, M.; Farah, S.

    2000-12-01

    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)

  20. Microstructure and grain size effects on irradiation hardening of low carbon steel for reactor tanks

    Energy Technology Data Exchange (ETDEWEB)

    Milasin, N [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1964-05-15

    Irradiation hardening of steel for reactor pressure vessels has been studied extensively during the past few years. A great number of experimental results concerning the behaviour of these steels in the radiation field and several review papers (1,2) have been published. Most of the papers deal with the effects of specific metallurgical factors or irradiation conditions (temperature, flux) on irradiation hardening and embrittlement. In addition, a number of experiments are performed to give evidence on the mechanism of irradiation hardening of these steels. However, this mechanism is still unknown due to the complexity of steel as a system. Among different methods used in radiation damage studies, the changes of mechanical properties have been mainly investigated. By using Hall-Petch's empirical relation, {sigma}{sub y}={sigma}{sub i}+k{sub y} d{sup -1/2} between lower yield stress, {sigma}{sub y}, and grain size, 2d, the information about the effect of irradiation on the parameters {sigma}{sub i} and k{sub y} is obtained. Taking as a base interpretation of {sigma}{sub i} and k{sub y} given by Petch and his co-workers it has been concluded that radiation does not change the stress to start slip but that it increase the friction that opposes the passage of free dislocations across a slip plane. In attempting to apply Hall-Petch's relation to one unirradiated ferritic steel with a carbon content higher than 0.15% some difficulties were encountered. The results obtained indicate that the influence of grain size can not be isolated from other factors introduced by the treatments used to produce different grain sizes. This paper deals with a similar problem in the case of irradiated steel. The results obtained give the changes of the mechanical properties of steel in neutron irradiation field as a function of microstructure and grain size. In addition, the mechanical properties of irradiated steel are measured after annealing at 150 deg C and 450 deg C. On the basis of

  1. Microstructure and grain size effects on irradiation hardening of low carbon steel for reactor tanks

    International Nuclear Information System (INIS)

    Milasin, N.

    1964-05-01

    Irradiation hardening of steel for reactor pressure vessels has been studied extensively during the past few years. A great number of experimental results concerning the behaviour of these steels in the radiation field and several review papers (1,2) have been published. Most of the papers deal with the effects of specific metallurgical factors or irradiation conditions (temperature, flux) on irradiation hardening and embrittlement. In addition, a number of experiments are performed to give evidence on the mechanism of irradiation hardening of these steels. However, this mechanism is still unknown due to the complexity of steel as a system. Among different methods used in radiation damage studies, the changes of mechanical properties have been mainly investigated. By using Hall-Petch's empirical relation, σ y =σ i +k y d -1/2 between lower yield stress, σ y , and grain size, 2d, the information about the effect of irradiation on the parameters σ i and k y is obtained. Taking as a base interpretation of σ i and k y given by Petch and his co-workers it has been concluded that radiation does not change the stress to start slip but that it increase the friction that opposes the passage of free dislocations across a slip plane. In attempting to apply Hall-Petch's relation to one unirradiated ferritic steel with a carbon content higher than 0.15% some difficulties were encountered. The results obtained indicate that the influence of grain size can not be isolated from other factors introduced by the treatments used to produce different grain sizes. This paper deals with a similar problem in the case of irradiated steel. The results obtained give the changes of the mechanical properties of steel in neutron irradiation field as a function of microstructure and grain size. In addition, the mechanical properties of irradiated steel are measured after annealing at 150 deg C and 450 deg C. On the basis of the experimental results obtained the relative microstructure and

  2. The key role of miR-21-regulated SOD2 in the medium-mediated bystander responses in human fibroblasts induced by α-irradiated keratinocytes

    International Nuclear Information System (INIS)

    Tian, Wenqian; Yin, Xiaoming; Wang, Longxiao; Wang, Jingdong; Zhu, Wei; Cao, Jianping; Yang, Hongying

    2015-01-01

    Highlights: • After co-culture with α-irradiated HaCaT cells, WS1 cells displayed oxidative stress and DNA damage. • Increased miR-21 expression in bystander cells was critical to the occurrence of RIBEs. • SOD2 of bystander cells played an important role in bystander responses. • miR-21 mediated bystander effects through its regulation on SOD2. - Abstract: Radiation-induced bystander effect (RIBE) is well accepted in the radiation research field by now, but the underlying molecular mechanisms for better understanding this phenomenon caused by intercellular communication and intracellular signal transduction are still incomplete. Although our previous study has demonstrated an important role of miR-21 of unirradiated bystander cells in RIBEs, the direct evidence for the hypothesis that RIBE is epigenetically regulated is still limited and how miR-21 mediates RIBEs is unknown. Reactive oxygen species (ROS) have been demonstrated to be involved in RIBEs, however, the roles of anti-oxidative stress system of cells in RIBEs are unclear. Using transwell insert co-culture system, we investigated medium-mediated bystander responses in WS1 human fibroblasts after co-culture with HaCaT keratinocytes traversed by α-particles. Results showed that the ROS levels in unirradiated bystander WS1 cells were significantly elevated after 30 min of co-culture, and 53BP1 foci, a surrogate marker of DNA damage, were obviously induced after 3 h of co-culture. This indicates the occurrence of oxidative stress and DNA damage in bystander WS1 cells after co-culture with irradiated keratinocytes. Furthermore, the expression of miR-21 was increased in bystander WS1 cells, downregulation of miR-21 eliminated the bystander responses, overexpression of miR-21 alone could induce bystander-like oxidative stress and DNA damage in WS1 cells. These data indicate an important mediating role of miR-21 in RIBEs. In addition, MnSOD or SOD2 in WS1 cells was involved in the bystander effects

  3. The key role of miR-21-regulated SOD2 in the medium-mediated bystander responses in human fibroblasts induced by α-irradiated keratinocytes

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Wenqian; Yin, Xiaoming; Wang, Longxiao; Wang, Jingdong; Zhu, Wei; Cao, Jianping [School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu Province 215123 (China); Yang, Hongying, E-mail: yanghongying@suda.edu.cn [School of Radiation Medicine and Protection, Medical College of Soochow University/Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 199 Renai Road, Suzhou Industrial Park, Suzhou, Jiangsu Province 215123 (China); Institute of Radiotherapy & Oncology, Soochow University (China)

    2015-10-15

    Highlights: • After co-culture with α-irradiated HaCaT cells, WS1 cells displayed oxidative stress and DNA damage. • Increased miR-21 expression in bystander cells was critical to the occurrence of RIBEs. • SOD2 of bystander cells played an important role in bystander responses. • miR-21 mediated bystander effects through its regulation on SOD2. - Abstract: Radiation-induced bystander effect (RIBE) is well accepted in the radiation research field by now, but the underlying molecular mechanisms for better understanding this phenomenon caused by intercellular communication and intracellular signal transduction are still incomplete. Although our previous study has demonstrated an important role of miR-21 of unirradiated bystander cells in RIBEs, the direct evidence for the hypothesis that RIBE is epigenetically regulated is still limited and how miR-21 mediates RIBEs is unknown. Reactive oxygen species (ROS) have been demonstrated to be involved in RIBEs, however, the roles of anti-oxidative stress system of cells in RIBEs are unclear. Using transwell insert co-culture system, we investigated medium-mediated bystander responses in WS1 human fibroblasts after co-culture with HaCaT keratinocytes traversed by α-particles. Results showed that the ROS levels in unirradiated bystander WS1 cells were significantly elevated after 30 min of co-culture, and 53BP1 foci, a surrogate marker of DNA damage, were obviously induced after 3 h of co-culture. This indicates the occurrence of oxidative stress and DNA damage in bystander WS1 cells after co-culture with irradiated keratinocytes. Furthermore, the expression of miR-21 was increased in bystander WS1 cells, downregulation of miR-21 eliminated the bystander responses, overexpression of miR-21 alone could induce bystander-like oxidative stress and DNA damage in WS1 cells. These data indicate an important mediating role of miR-21 in RIBEs. In addition, MnSOD or SOD2 in WS1 cells was involved in the bystander effects

  4. Heavy-Section Steel Irradiation Program

    International Nuclear Information System (INIS)

    Corwin, W.R.

    1990-08-01

    The primary goal of the Heavy-Section Steel Irradiation Program is to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior (particularly the fracture toughness properties) of typical pressure-vessel steels as they relate to light-water-reactor pressure-vessel integrity. The program includes direct continuation of irradiation studies previously conducted by the Heavy-Section Steel Technology Program augmented by enhanced examinations of the accompanying microstructural changes. Effects of specimen size; material chemistry; product form and microstructure; irradiation fluence, flux, temperature, and spectrum; and postirradiation annealing are examined on a wide range of fracture properties. Detailed statistical analyses of the fracture data on K Ic shift of high-copper welds were performed. Analysis of the first phase of irradiated crack-arrest testing on high-copper welds was completed. Final analysis and publication of the results of the second phase of the irradiation studies on stainless steel weld-overlay cladding were completed. Determinations were made of the variations in chemistry and unirradiated RT NDT of low upper-shelf weld metal from the Midland reactor. Final analyses were performed on the Charpy impact and tensile data from the Second and Third Irradiation series on low upper-shelf welds, and the report on the series was drafted. A detailed survey of existing data on microstructural models and data bases of irradiation damage was performed, and initial development of a reaction-rate-based model was completed. 40 refs., 7 figs., 4 tabs

  5. Improving smoked herring quality by gamma irradiation

    International Nuclear Information System (INIS)

    Zahran, D.A.; Abd El-Wahab, S.A.; Hendy, B.A.

    2009-01-01

    Smoked herring which is a highly purchasable product in Egypt, was exposed to different gamma irradiation doses (1.5,3.0 and 5.0 kGy) and stored at environmental temperature (12± 2 deg C) until spoilage of the control. Microbiological, chemical and sensory analyses were performed throughout storage to monitor the quality attributes. It is worthy to mention that irradiation reduced the population of bacteria and the effect was more pronounced at the highest dose used (5.0 kGy). At the same time 1.5 kGy completely eliminated staphylococcus aureus (coagulase + ve) and coliforms. By chemical analysis, there was significant decrease in average moisture content by different gamma irradiation doses and storage. Although the average thiobarbituric acid reactive substances (TBARS) increased slightly by γ-irradiation, this increase was highly significant by storage . At the same time there was a significant (p< 0.05)decrease in the average trimethylamine (TMA) value of all irradiated samples compared with unirradiated control, this value increased significantly by storage. interestingly, the average histamine value decreased significantly in all irradiated samples. The sensory analysis revealed a highly significant difference in the average acceptability scores between different irradiation doses used and also by storage. Therefore it could be concluded that the quality of smoked herring during storage at environmental temperature (12 ± 2 deg C) could be improved by using 5.0 kGy γ -irradiation

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

    International Nuclear Information System (INIS)

    Inaba, Masamitsu; Meshitsuka, Gyosuke; Ishizu, Atsushi; Nakano, Junzo

    1981-01-01

    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 14 C-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)

  7. Electron-beam irradiation effects on mechanical properties of PEEK/CF composite

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Seguchi, Tadao

    1989-01-01

    Carbon fibre-reinforced composite (PEEK/CF) using polyarylether-ether-ketone (PEEK) as a matrix material was prepared and electron-beam irradiation effects on the mechanical properties at low and high temperatures were studied. The flexural strength and modulus of the unirradiated PEEK/CF were almost the same as those of carbon fibre-reinforced composites with epoxide resin. The mechanical properties at room temperature were little affected by irradiation up to 180 MGy, but in the test at 77K the strength of the specimens irradiated over 100 MGy was slightly decreased. The mechanical properties of the unirradiated specimen decreased with increasing testing temperature, but the high-temperature properties were improved by irradiation, i.e. the strength measured at 413K for the specimen irradiated with 120 MGy almost reached the value for the unirradiated specimen measured at room temperature. It was apparent from the viscoelastic measurement that the improvement of mechanical properties at high temperature resulted from the high-temperature shift of the glass transition of the matrix PEEK caused by radiation-induced cross-linking. (author)

  8. Muonic molecular formation under laser irradiation and in the clustered ion molecule (The effect of protonium additive on the muon catalyzed fusion cycle)

    International Nuclear Information System (INIS)

    Takahashi, Hiroshi.

    1988-01-01

    The formation rate of the dtμ molecule is very sensitive to the differences in the vibrational rotational level between D 2 and [(dtμ)-d-2e/] molecules. The density effect of the normalized reaction rate has been studied by the resonance broadening due to collisional quenching. The surrounding molecules of the molecule forming dt/mu/ act as the third body which takes out the excess energy forming dt/mu/ from t/mu/, and the formation reaction occurs with the excitation of the vibrational state just below the threshold energy. By using the laser as the third body, the rate of resonance formation can be increased. In my last paper, the formation rate was calculated under high-intensity laser irradiation, using Vinitsky's model assuming that the laser interacts directly with the deuteron and modulates the interaction between t/mu/ and d/sub 2/ nuclei. However, the laser interacts more strongly with the electrons, because the interaction energy of the laser and the charged particle is proportional to the velocity of the particle's motion, and the velocity of the electron is a few thousand times greater than the velocity of the nuclei. This interaction with electrons was neglected in my last paper. In the present paper, the enhancement of the dt/mu/ formation rates by the strong laser irradiation is studied, taking into account the laser electron interaction; It was shown that the enhancement can be achieved by an intensity lower than the one described previously. 29 refs., 5 figs., 3 tabs

  9. Effects of gamma irradiation and storage temperature on carotenoids and ascorbic acid content of mangoes on ripening

    International Nuclear Information System (INIS)

    Thomas, P.; Janave, M.T.

    1975-01-01

    Synthesis and accumulation of carotenoids in the flesh of Alphonso mangoes on ripening was found to be maximal in fruits stored at tropical ambient temperatures (28 0 to 32 0 C). Gamma irradiation of preclimacteric fruits at 25 krad did not affect the formation of carotenoids. Storage of preclimacteric fruits either irradiated or unirradiated at 7 to 20 0 C for 16 to 43 days caused a substantial reduction in carotenoid formation even when these fruits were subsequently ripened under optimal conditions. Regardless of storage temperature, carotenes always exceeded xanthophylls in the ripe fruits and, in general, irradiated fruits showed higher levels of carotenes in comparison with unirradiated samples. Ascorbic acid loss during ripening was maximum at ambient temperatures while lengthy storage at low temperatures caused a net increase in ascorbic acid levels. Irradiation seemed to accentuate the loss in ascorbic acid during ripening. (author)

  10. Facilitation of syngeneic stem cell engraftment by anti-class I monoclonal antibody pretreatment of unirradiated recipients

    International Nuclear Information System (INIS)

    Voralia, M.; Semeluk, A.; Wegmann, T.G.

    1987-01-01

    We have established a murine model of syngeneic bone marrow transplantation based on the use of monoclonal antibody as the sole conditioning regimen in unirradiated recipients. Administration of a single injection of monoclonal antibody directed against major histocompatibility complex-encoded class I determinants facilitated permanent hemopoietic stem cell engraftment without any apparent side-effects. Whereas untreated hosts exhibited a maximal chimerism of 15% at donor cell doses of up to 12 X 10(7) bone marrow cells, pretreatment by 2 mg of anti-class I antibody one week prior to transplantation of 3 X 10(7) syngeneic bone marrow cells resulted in a mean donor representation of about 80%. The antibody can be given up to four weeks prior to transplantation, and the degree of donor engraftment observed is a function of the dose of antibody administered. The fact that specific antibody enhanced engraftment in two strain combinations indicates that antibody is the active agent in facilitating engraftment and that facilitation is not strain-restricted. Anti-class I antibodies of the IgG2a, but not IgG1, isotype are effective in promoting engraftment. Although the isotype requirement suggests a role for antibody-mediated cytotoxicity in promoting stem cell engraftment, the extensive time-frame of facilitation suggests that other effects of the antibody may also be involved. The model of syngeneic bone marrow transplantation we describe here will be useful in studying the mechanisms regulating stem cell engraftment and may have potential clinical application as an approach to autologous marrow transplantation

  11. Techno-economic feasibility of food irradiation in Ghana

    International Nuclear Information System (INIS)

    Appiah, V.; Nketsia-Tabiri, J.; Bansa, D.; Montford, K.G.; Sakyi Dawson, E.; Alhassan, R.; Edwards, J.

    2002-01-01

    The major causes of spoilage in the post-harvest handling of yam were identified as poor harvest, storage and transportation conditions and physiological damage. The effect of gamma irradiation on yam and maize storage and their functionality in the Ghanaian food system were determined. Results indicated that all unirradiated yams sprouted by the 3rd month of storage. Gamma irradiation at a dose of 120-130 Gy effectively inhibited sprouting of yams for 6 months under ambient conditions. There was less rotting in yams stored on the barn compared to those stored on the ground and less rotting in the irradiated yam stored on the barn. Food products from irradiated yams were judged better in quality than those from unirradiated ones. Semi-commercial studies on radiation preservation of maize were conducted with the view to determining the effect of radiation treatment on the physico-chemical and functional properties as well as the microbiological quality of maize. The study also investigated techno-economic feasibility of radiation preservation of maize in Ghana and consumer attitudes towards foods such as 'Ga kenkey' and 'Fanti kenkey' prepared from irradiated maize. In the first study 127 bags of 50kg maize were used. Maize was repacked in 5-kg consumer packs made from 0.003mm thick polyethylene bags. Ten of the consumer packs were put into woven polypropylene sacks to make up 50kg bag of maize. Eighty-seven bags of maize were irradiated to a minimum of 2.6 and maximum of 5.6 kGy gamma radiation. Both the irradiated and the unirradiated maize were stored for six months in a commercial warehouse. Results indicated that the moisture content (7.2-7.8%), free fatty acid (<0.1%) and peroxide value (35-40 mEq/kg fat) of the maize were stable during storage. The initial mould count of 100-156 cfu/g decreased to 30-43 cfu/g; Aspergillus oryzae and Asp. tamari were identified. Sitophilus sp. was the predominant insect in the control but was replaced by Rhyzopertha sp. in the

  12. Techno-economic feasibility of food irradiation in Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Appiah, V; Nketsia-Tabiri, J; Bansa, D; Montford, K G [Department of Food Science and Radiation Processing, Biotechnology and Nuclear Agriculture Research Institute (Ghana); Sakyi Dawson, E [Department of Food Science and Nutrition, University of Ghana (Ghana); Alhassan, R [Department of Agriculture Economics, Faculty of Agriculture, University of Ghana (Ghana); Edwards, J [Ghana Food Distribution Corporation (Ghana)

    2002-05-01

    The major causes of spoilage in the post-harvest handling of yam were identified as poor harvest, storage and transportation conditions and physiological damage. The effect of gamma irradiation on yam and maize storage and their functionality in the Ghanaian food system were determined. Results indicated that all unirradiated yams sprouted by the 3rd month of storage. Gamma irradiation at a dose of 120-130 Gy effectively inhibited sprouting of yams for 6 months under ambient conditions. There was less rotting in yams stored on the barn compared to those stored on the ground and less rotting in the irradiated yam stored on the barn. Food products from irradiated yams were judged better in quality than those from unirradiated ones. Semi-commercial studies on radiation preservation of maize were conducted with the view to determining the effect of radiation treatment on the physico-chemical and functional properties as well as the microbiological quality of maize. The study also investigated techno-economic feasibility of radiation preservation of maize in Ghana and consumer attitudes towards foods such as 'Ga kenkey' and 'Fanti kenkey' prepared from irradiated maize. In the first study 127 bags of 50kg maize were used. Maize was repacked in 5-kg consumer packs made from 0.003mm thick polyethylene bags. Ten of the consumer packs were put into woven polypropylene sacks to make up 50kg bag of maize. Eighty-seven bags of maize were irradiated to a minimum of 2.6 and maximum of 5.6 kGy gamma radiation. Both the irradiated and the unirradiated maize were stored for six months in a commercial warehouse. Results indicated that the moisture content (7.2-7.8%), free fatty acid (<0.1%) and peroxide value (35-40 mEq/kg fat) of the maize were stable during storage. The initial mould count of 100-156 cfu/g decreased to 30-43 cfu/g; Aspergillus oryzae and Asp. tamari were identified. Sitophilus sp. was the predominant insect in the control but was replaced by Rhyzopertha sp. in the

  13. Survival of Lymphatic Cells after X-Irradiation in Mice

    Energy Technology Data Exchange (ETDEWEB)

    Vos, O. [Medical Biological Laboratory, National Defense Research Organization TNO, Ruswuk, Z.H. (Netherlands)

    1967-07-15

    Lymphatic tissues are generally classified among the most radiosensitive tissues of the body. The main reason for this is that histologically extensive destruction is found within a few hours after irradiation. We tried to estimate the degree of cellular degeneration by making cell suspensions from lymph nodes and thymus of mice at different times after X-irradiation with 800 R or at 24 h after radiation with different doses. The numbers of normal viable cells we obtained were expressed as percentages of the cells recovered from unirradiated control mice.

  14. Dynamic Efficiency Measurements for Irradiated ATLAS Pixel Single Chip Modules

    CERN Document Server

    Pfaff, Mike; Grosse-Knetter, Jorn

    2011-01-01

    The ATLAS pixel detector is the innermost subdetector of the ATLAS experiment. Due to this, the pixel detector has to be particularly radiation hard. In this diploma thesis effects on the sensor and the electronics which are caused by irradiation are examined. It is shown how the behaviour changes between an unirradiated sample and a irradiated sample, which was treated with the same radiation dose that is expected at the end of the lifetime of ATLAS. For this study a laser system, which is used for dynamic efficiency measurements was constructed. Furthermore, the behaviour of the noise during the detection of a particle was evaluated studied.

  15. Identification of irradiated mangoes by means of ESR spectroscopy

    International Nuclear Information System (INIS)

    Bustos, M.E.; Romero, M.E.; Gutierrez, A.; Azorin, J.

    1996-01-01

    Samples of mango varieties Tommy Atkins, Haiden and Ataulfo were irradiated with 60 Co gamma radiation at doses in the range 0.15-1.0 kGy, and stored at room temperature for lapses of time up to 72 h. They were then studied by ESR spectrometry. Results show that the ESR signal of the irradiated samples is higher than that of the unirradiated samples, and this is found even at the minimum radiation dose of 0.15 kGy. The ESR signal remained stable during the storage time. The ESR signals obtained for hydroheated mangoes show insignificant differences with respect to the control samples. (author)

  16. Development of detection methods for irradiated foods

    International Nuclear Information System (INIS)

    Yang, Jae Seung; Kim, Chong Ki; Lee, Hae Jung; Kim, Kyong Su

    1999-04-01

    To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats. The analysis of DNA damage made on single cells by agarose gel electrophoresis (DNA 'comet assay') can be used to detect irradiated food. All the samples irradiated with over 0.3 kGy were identified to detect post-irradiation by the tail length of their comets. Irradiated samples showed comets with long tails, and the tail length of the comets increased with the dose, while unirradiated samples showed no or very short tails. As a result of the above experiment, the DNA 'comet assay' might be applied to the detection of irradiated grains as a simple, low-cost and rapid screening test. When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from leic acid. 1,7 hexadecadiene was the highest amount in irradiated beef, pork and chicken. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1,7-hexadecadiene and 8-heptadecen were detected as major compounds. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks

  17. Development of detection methods for irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Seung; Kim, Chong Ki; Lee, Hae Jung [Korea Atomic Energy Research Insitiute, Taejon (Korea, Republic of); Kim, Kyong Su [Chosun University, Kwangju (Korea, Republic of)

    1999-04-01

    To identify irradiated foods, studies have been carried out with electron spin resonance (ESR) spectroscopy on bone containing foods, such as chicken, pork, and beef. The intensity of the signal induced in bones increased linearly with irradiation doses in the range of 1.0 kGy to 5.0 kGy, and it was possible to distinguish between samples given low and high doses of irradiation. The signal stability for 6 weeks made them ideal for the quick and easy identification of irradiated meats. The analysis of DNA damage made on single cells by agarose gel electrophoresis (DNA 'comet assay') can be used to detect irradiated food. All the samples irradiated with over 0.3 kGy were identified to detect post-irradiation by the tail length of their comets. Irradiated samples showed comets with long tails, and the tail length of the comets increased with the dose, while unirradiated samples showed no or very short tails. As a result of the above experiment, the DNA 'comet assay' might be applied to the detection of irradiated grains as a simple, low-cost and rapid screening test. When fats are irradiated, hydrocarbons contained one or two fewer carbon atoms are formed from the parent fatty acids. The major hydrocarbons in irradiated beef, pork and chicken were 1,7-hexadecadiene and 8-heptadecene originating from leic acid. 1,7 hexadecadiene was the highest amount in irradiated beef, pork and chicken. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1,7-hexadecadiene and 8-heptadecen were detected as major compounds. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks.

  18. Immunological investigations of antigens released by normal and irradiated schistosomasa mansoni cercariae in vitro. Part of a coordinated programme on preparation of irradiated vaccines against some human diseases

    International Nuclear Information System (INIS)

    Catty, D.

    1982-07-01

    S.mansoni cercariae were γ-irradiated at 1-15 K rads, syringe transformed, and injected into groups of 20 mice (200 dose), with unirradiated controls. Aliquots of 1,500 cercariae irradiated at 1-40 K rads (plus unirradiated controls) were cultured in serum-free medium. It was found that irradiation does not inhibit release of a broad spectrum of antigens in culture over 6 hours until 20 K rads is delivered. Mice used as hosts for the graded cercarial irradiation vaccine were subdivided into groups of 10 and either left unchallenged or challenged at 6 weeks with a normal infection of 200 cercariae. Serum samples were taken from every mouse at regular intervals and antibodies titrated by solid phase radioimmunoassay. Injected parasites, whether irradiated or normal, always gave higher antibody titres to cercarial and egg antigens than the equivalent dose of normal (challenge) parasites infecting by the natural route. Challenge infection depressed anti-cercarial responses in mice exposed to irradiated larvae but boosted the response to normal injected parasites. Antibodies to SEA were in lower titre in all groups but rose from week 7 (1 week post-challenge) in the groups injected with normal and 1 K rad-treated parasites, where adults were previously established in the hosts. At 12 weeks all mice were sacrificed and perfused for adults. Egg yields in liver and intestine were determined. There was no evidence of protective immunity to challenge infection induced by injected unirradiated or 1 K rad-irradiated, transformed, cercariae, even though both sources of parasite gave rise to egg-laying adults. By contrast, the 5, 10 and 15 K rad vaccines gave protection of 36-49%, even though they gave rise to no persistent adults or any deposited eggs. The protective (immunising) properties of irradiation-attenuated vaccines of S.mansoni cercariae can thus be clearly correlated with their capacity to release antigens in the immediate post irradiation period

  19. Commercial feasibility and evaluation of consumer acceptance for certain irradiated food products in Egypt

    International Nuclear Information System (INIS)

    El-Fouly, Mohie Eldin Zohear; Karem, Hussein Abdel; El-Din, Nagwan Saad; El-Din Farag, Diaa; El-Khatib, Mervat; Mageed, Mahmoud Abdel

    2002-01-01

    Studies were carried out to assess consumer attitude towards food irradiation through questionnaires, sensory tests and market sale of irradiated products. The results showed that out of 1020 persons responded to the questionnaire, 62.43% accepted the irradiation technology while 70.45% were convinced with the advantages of irradiated food. About 73.97% of the respondents were willing to accept irradiation technology on a long term basis while 57.53% were willing to consume irradiated food if it was available in the market. Sensory tests on irradiated smoked fish, chicken, black pepper, coriander, Jew's mallow, broad bean and kidney beans using triangle test (difference test) and duo-trio test showed that the panelists consisting of 136 persons failed to indicate any difference between the irradiated and unirradiated food. About 92.2% of 144 persons participating in a lunch table of irradiated food opined that irradiated food was delicious and found no difference between the irradiated and unirradiated samples. Consumer comments recorded during the market sale of irradiated black pepper and broad beans indicated that 95.1% of the respondents found the irradiated (10kGy) black pepper of excellent or good quality while the percentage was 81.2% for irradiated (2 kGy) broad bean. The study also showed that 62.2% and 68.8% of the persons respectively would buy irradiated black pepper and broad bean again if they were available in the market. Studies on the economics of food irradiation showed that the cost of irradiation for one ton of frozen poultry as US $130.4; smoked fish US $78.2; spices US $260.1 and dried vegetable US $26. Economic evaluation of the study indicated that the average annual rate of return will be about 16.9% and the pay back period will be about 5.9 years. (author)

  20. Induced defects in neutron irradiated GaN single crystals

    International Nuclear Information System (INIS)

    Park, I. W.; Koh, E. K.; Kim, Y. M.; Choh, S. H.; Park, S. S.; Kim, B. G.; Sohn, J. M.

    2005-01-01

    The local structure of defects in undoped, Si-doped, and neutron irradiated free standing GaN bulk crystals, grown by hydride vapor phase epitaxy, has been investigated by employing Raman scattering and cathodoluminescence. The GaN samples were irradiated to a dose of 2 x 10 17 neutrons in an atomic reactor at Korea Atomic Energy Research Institute. There was no appreciable change in the Raman spectra for undoped GaN samples before and after neutron irradiation. However, a forbidden transition, A 1 (TO) mode, appeared for a neutron irradiated Si-doped GaN crystal. Cathodoluminescence spectrum for the neutron irradiated Si-doped GaN crystal became much more broadened than that for the unirradiated one. The experimental results reveal the generation of defects with locally deformed structure in the wurtzite Si-doped GaN single crystal

  1. Postirradiation examination results for the Irradiation Effects Scoping Test 2

    International Nuclear Information System (INIS)

    Mehner, A.S.

    1977-01-01

    The postirradiation examination results are reported for two rods from the second scoping test (IE-ST-2) of the Nuclear Regulatory Commission Irradiation Effects Program. The rods were irradiated in the in-pile test loop of the Power Burst Facility at the Idaho National Engineering Laboratory. Rod IE-005 was fabricated from fresh fuel and cladding previously irradiated in the Saxton Reactor. Rod IE-006, fabricated from fresh fuel and unirradiated cladding, was equipped with six developmental cladding surface thermocouples. The rods were preconditioned, power ramped, and then subjected to film boiling operation. The performance of the rods and the developmental thermocouples are evaluated from the post irradiation examination results. The effects of prior irradiation damage in cladding are discussed in relation to fuel rod behavior during a power ramp and subsequent film boiling operation

  2. High-water-base hydraulic fluid-irradiation experiments

    International Nuclear Information System (INIS)

    Bradley, E.C.; Meacham, S.A.

    1981-10-01

    A remote system for shearing spent nuclear fuel assemblies is being designed under the direction of the Consolidated Fuel Reprocessing Program (CFRP). The design incorporates a dual hydraulic fluid actuation system in which only one of the fluids, a high-water-base (HWBF), would be exposed to ionizing radiation and radioactive contamination. A commercially available synthetic, solution-type HWBF was selected as the reference. Single-sample irradiation experiments were conducted with three commercial fluids over a range of irradiation exposures. The physical and chemical properties of the irradiated HWBFs were analyzed and compared with unirradiated samples. In general, the results of the analyses showed increasing degradation of fluid properties with increasing irradiation dose. The results also indicated that a synthetic solution-type HWBF would perform satisfactorily in the remote shear system where irradiation doses up to 10 6 Gy (10 8 rad) are expected

  3. High-water-base hydraulic fluid-irradiation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, E.C.; Meacham, S.A.

    1981-10-01

    A remote system for shearing spent nuclear fuel assemblies is being designed under the direction of the Consolidated Fuel Reprocessing Program (CFRP). The design incorporates a dual hydraulic fluid actuation system in which only one of the fluids, a high-water-base (HWBF), would be exposed to ionizing radiation and radioactive contamination. A commercially available synthetic, solution-type HWBF was selected as the reference. Single-sample irradiation experiments were conducted with three commercial fluids over a range of irradiation exposures. The physical and chemical properties of the irradiated HWBFs were analyzed and compared with unirradiated samples. In general, the results of the analyses showed increasing degradation of fluid properties with increasing irradiation dose. The results also indicated that a synthetic solution-type HWBF would perform satisfactorily in the remote shear system where irradiation doses up to 10/sup 6/ Gy (10/sup 8/ rad) are expected.

  4. Action of caffeine on x-irradiated HeLa cells. IV. Progression delays and enhanced cell killing at high caffeine concentrations

    International Nuclear Information System (INIS)

    Tolmach, L.J.; Busse, P.M.

    1980-01-01

    The response of x-irradiated and unirradiated HeLa S3 cells to treatment with caffeine at concentrations between 1 and 10 nM has been examined with respect to both delay in progression through the cell generation cycle and enhancement of the expression of potentially lethal x-ray damage. Progression is delayed in a concentration-dependent fashion: the generation time is doubled at about 4 mM. The duration of G 1 is lengthened, and the rate of DNA synthesis is reduced, although the kinetics are different in the two phases; the rate of DNA synthesis is usually unaffected at 1 or 2 mM, while there is no concentration threshold for the slowing of progression through G 1 . Progression through G 2 appears to be unaffected by concentrations up to at least 10 mM. Killing of irradiated cells in G 2 is somewhat greater after treatment with the higher caffeine concentrations than reported previously for 1 mM. Moreover, an additional mode of killing is observed in irradiated G 1 cells which had been found previously to be only slightly affected by 1 mM caffeine; they suffer extensive killing at concentrations above 5 mM. The time-survival curves for irradiated, caffeine-treated G 1 and G 2 cells have characteristically different shapes. The dose-survival curves for cells treated with the higher caffeine concentrations display steeper terminal slopes and narrower shoulders

  5. Advanced Oxidation Treatment of Drinking Water and Wastewater Using High-energy Electron Beam Irradiation

    Directory of Open Access Journals (Sweden)

    Abbas Behjat

    2007-03-01

    Full Text Available Application of electron beam as a strong oxidation method for disinfection of drinking water and wastewater has been investigated. Drinking water samples were prepared from wells in rock zones in Yazd Province. Wastewater samples were collected from Yazd Wastewater Treatment Plant. Samples were irradiated by 10 MeV electron beam accelerator at Yazd Radiation Processing Center. The irradiation dose range varied from 0.5-5 kGy. Biological parameters and microbial agents such as aerobic mesophiles and coliforms including E. coli count before and after irradiation versus irradiation dose were obtained using MPN method. The data obtained from irradiated water and wastewater were compared with un-irradiated (control samples. The results showed a removal of 90% of all microorganisms at irradiation doses below 5 kGy, suggesting electron beam irradiation as an effective method for disinfection of wastewater.

  6. Quantitative detection of absorbed dose of irradiated dried fruit by ESR spectroscopy method

    International Nuclear Information System (INIS)

    Li Weiming; Ha Yiming; Zhao Yongfu; Zhang Yanli

    2011-01-01

    Sunflower seeds, walnuts, pistachios, and hazelnuts were used as experimental materials which were irradiated at 1.0, 3.0, 5.0 and 10.0 kGy, respectively. The relationships and correlations between ESR signal intensity and irradiation dosages were studied. The results showed that ESR spectra of irradiated samples were obviously different from that of CK, and the ESR signal intensity was positively related with the irradiation dose. After irradiation, the ESR intensity and spectrum shapes all changed and all four samples were clearly identified irradiated or unirradiated. The appearances of the two weak satellite lines which situated left and right to the intense singlet line in walnuts and pistachios proved the existence of cellulose radical. The detection dose limit of irradiated walnut was 1 kGy, and the detection limits of the other three samples were lower than 1 kGy. In conclusion, the ESR method could be used to irradiated. (authors)

  7. Effects of gamma irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB)

    International Nuclear Information System (INIS)

    Martineli, Maristella; Coneglian, Regina C.C.; Vasconcellos, Marco A.S.; Silva, Eduardo; Rocha, Janielio G.; Melo, Maruzanete P.; Vital, Helio C.

    2009-01-01

    Banana is a highly perishable climacteric fruit. In order to ensure fast and homogeneous ripening that will make its processing and commercialization easier, it is usually treated by climatization. On the other hand, irradiation is an interesting physical process capable of delaying ripening and extending the shelf life of fruits. This work investigated the competing effects of irradiation followed by climatization on the quality of 'Prata' banana (Musa acuminata x Musa balbisiana, AAB). All fruits were harvested in the preclimacteric stage, rinsed and stored at 27 deg C after being submitted to five different treatments. After hygienization, four out of five samples were exposed to gamma-ray at doses of 0.25 and 0.50 kGy. The unirradiated fruits were left for control and half of the irradiated samples were then climatized by exposure to CaC 2 . Measurements of fresh mass loss, total soluble solids, peel coloration and disease index were performed on five different dates for up to nine days in order to monitor quality and the degree of ripening. It was found that high temperatures prevailing during climatization and storage accelerated maturation in all fruits in spite of the use of irradiation, with the control becoming ripe in 3 days only. In addition, based on the consistent results from the experiments performed, it can be concluded that irradiation at the doses tested was unable to overcome the maturation effects produced by climatization. However, the sole use of irradiation with 0.25 kGy yielded the lowest figures for fresh mass loss and disease index in the samples, thus becoming the most attractive among the treatments tested. (author)

  8. Final report on neutron irradiation at low temperature to investigate plastic instability and a high temperature to study cavitation

    International Nuclear Information System (INIS)

    Singh, B.N.; Eldrup, M.; Golubov, S.I.; Edwards, D.J.; Jung, P.

    2005-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at 333 and 573 K. Electrical resistivity and tensile properties were measured both in the unirradiated and irradiated condition. Some additional specimens of pure iron were irradiated at 333 K to doses of 10-3, 10-2 and 10-1 dpa and tensile tested at 333 K. To investigate the effect of helium on cavity nucleation and growth, specimens of pure iron and EUROFER 97 were implanted with different amounts of helium at 323 K and subsequently neutron irradiated to doses of 10-3, 10-2 and 10-1 dpa at 323 K. Defect microstructures were investigated using positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). Numerical calculations, based on the production bias model (PBM) were carried out to study the details of evolution of cavities with and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been studied using the Kinetic Monte Carlo (KMC) code during a realistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops.The present report describes both experimental procedure and calculational methodology employed in the present work. The main results of all these investigations, both experimental and theoretical, are highlighted with appropriate examples. Finally, a brief summary is given of the main results conclusions. (au)

  9. Influence of gamma irradiation on mechanical and thermal properties of waste polyethylene/nitrile butadiene rubber blend

    Directory of Open Access Journals (Sweden)

    Raouf O. Aly

    2016-11-01

    Full Text Available Gamma irradiation radical–radical interaction crosslinking of elastomers and thermoplastic is a special type of crosslinking technique that has gained importance over conventional chemical crosslinking method as process is fast, pollution free, and simple. In this work a blend polymer, based on waste polyethylene and nitrile butadiene rubber, has been irradiated with gamma-rays, mechanically and thermally investigated at varying NBR content. FTIR and SEM techniques were used in addition to the swelling behavior to emphasize the blend formation. Mechanical properties like tensile strength, elongation at break and modulus at different elongations were studied and compared with those of unirradiated ones. A relatively low-radiation dose was found effective in improving the level of mechanical properties. Differential scanning calorimeter and thermogravimetric analysis were used to study the thermal characteristics of the irradiated polymer. Enhancement in thermal stability has been observed for higher NBR containing blends and via radiation-induced crosslinking up to ≈50 kGy.

  10. Potentiality of Melatonin as a Radiation Protector against Hemoglobin Damage in the Experimental Animals Due to Gamma Irradiation

    International Nuclear Information System (INIS)

    Farag, H.; Hassan, R. A.; Mohamed, Sh.

    2013-01-01

    Ionizing radiation causes serious damage in biological system. Some drugs and antioxidants are used to prevent such damage. In the present study two doses of melatonin (10 mg⁄kg and 30 mg⁄kg) were selected to be used for such purpose. The radioprotective effects of melatonin on hemoglobin of red blood cells from female mice was studied through UV absorption spectrum, ESR spectroscopy, dielectric measurements and relative viscosity .The results of Hemoglobin absorption indicate that a pronounced increase in the average value of peak position and width at half maximum W hmax followed by a decrease in the absorbance of sort band, decrease in absorption ratio A 578 / A 540 in addition to disappearance of globin band at 275 nm. The free radicals which are expected to be formed after exposing to γ-irradiation are detected by electron spin resonance spectroscopy (ESR). The results indicate that the intensity of ESR signal for hemoglobin extracted from animals exposed to γ- irradiation is greater as compared with normal hemoglobin. Dielectric measurements indicate that there is an increase in dielectric permittivity (ε‵), the dielectric loss (ε‶) and the a.c conductivity (σ ac ) while some decrease is noticed in the viscosity measurements after exposing to irradiation. The data obtained from the whole studied parameters after treating animals with melatonin become closer to those for unirradiated samples.

  11. Thermal conductivity of fully dense unirradiated UO{sub 2}: A new formulation from experimental results between 100 deg. C and 2500 deg. C, and associated fundamental properties

    Energy Technology Data Exchange (ETDEWEB)

    Delette, G; Charles, M [Commissariat a l` Energie Atomique, Grenoble (France)

    1997-08-01

    The various contributions to the thermal conductivity of UO{sub 2} are first reviewed: contribution from phonons is preponderant up to 1600 deg. C; radiative contribution is negligible in the case of a polycrystalline sample, and is unable to account for the increase in conductivity observed above 1600 deg. C; electronic contribution, which seems patently to be responsible for this increase, is efficient from 1400 deg. C (electron-hole pairs treated as small polarons). Given the lack of decisive arguments on their actual efficiency, it was decided that, for temperatures above 2400 deg. C, neither a possible decrease in the electronic contribution due to vacancies, nor an additional possible contribution from Frenkel pairs would be described. We do not go therefore beyond the above-mentioned electronic contribution. In the light of these considerations, the law established by CEA for the thermal conductivity of unirradiated UO{sub 2}, on the basis of a homogeneous set of measurements between 100 deg. C and 2500 deg. C, has been revised. A least-square method applied to the above measurements was used to derive simultaneously the four adjustable constants of the law which is henceforth proposed: {lambda} = 1/A + BT+C/T{sup 2}exp(-W/kT). The values of A, B, C, and W obtained, have the advantage of giving a better account of the high temperature results compared to the Martin recommendations (which has, by the way, the same physical form as above). Furthermore, this new law allows an extrapolation towards the melting point which is better founded than the earlier CEA law, while still respecting the value of the integrated thermal conductivity up to melting. Finally, various burnup effects (impurities, stoichiometry, etc.) can be formulated in physical terms. Moreover, the values of various fundamental properties connected with the derived constants have been determined: Debye temperature, Grueneisen parameter, Mott-Hubbard energy, electrical conductivity. These values

  12. Effect of addition of heavy metal ion on decolouration and degradation of azo dye in aqueous solution by gamma irradiation combined with ozone

    International Nuclear Information System (INIS)

    Lee, M.J.; Jin, J.H.; Nho, Y.C.; Arai, H.

    1998-01-01

    In decomposition of azo dyes solution by simultaneous application of gamma-ray and ozone treatment, the effect of addition of heavy metal ion upon decolouration and decomposition was studied. Cupric ion was used as a heavy metal ion. For the aqueous solution with and without addition of cupric ion, the degree of decolouration of 552 nm, the changes of pH, the reduction of TOC and BOD were measured as function of dose under condition of fixed concentration of ozone. It appeared that the addition of cupric ion played a positive role in decomposition of azo dye solution, but played a negative role in decolouration

  13. Dose determination in irradiated chicken meat by ESR method

    International Nuclear Information System (INIS)

    Polat, M.

    1996-01-01

    In this work, the properties of the radicals produced in chicken bones have been investigated by ESR technique to determine the amount of dose applied to the chicken meats during the food irradiation. For this goal, the drumsticks from 6-8 weeks old chickens purchased from a local market were irradiated at dose levels of 0; 2; 4; 6; 8 and 10 kGy. Then, the ESR spectra of the powder samples prepared from the bones of the drumsticks have been investigated. Unirradiated chicken bones have been observed to show a weak ESR signal of single line character. CO-2 ionic radicals of axial symmetry with g=1.9973 and g=2.0025 were observed to be produced in irradiated samples which would give rise to a three peaks ESR spectrum. In addition, the signal intensities of the samples were found to depend linearly on the irradiation dose in the dose range of 0-10 kGy. The powder samples prepared from chicken leg bones cleaned from their meats and marrow and irradiated at dose levels of 1, 2, 3, 4, 5, 6, B, 10, 12,14, 16, 1B, 20 and 22 kGy were used to get the dose-response curve. It was found that this curve has biphasic character and that the dose yield was higher in the 12-1B kGy dose range and a decrease appears in this curve over 18 kGy. The radical produced in the bones were found to be the same whether the irradiation was performed after stripping the meat and removing the marrow from the bone or before the stripping. The ESR spectra of both irradiated and non irradiated samples were investigated in the temperature range of 100 K-450 K and changes in the ESR spectra of CO-2 radical have been studied. For non irradiated samples (controls). the signal intensities were found to decrease when the temperature was increased. The same investigation has been carried out for irradiated samples and it was concluded that the signal intensities relative to the peaks of the radical spectrum increase in the temperature range of 100 K-330 K, then they decrease over 330 K. The change in the

  14. Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

    Science.gov (United States)

    Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

  15. Application of irradiated chitosan for fruit preservation

    Energy Technology Data Exchange (ETDEWEB)

    Kieu N. Lan [Post Harvest Technology Inst. of Vietnam (Viet Nam)

    2000-09-01

    Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by {gamma}-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

  16. Irradiation response of ODS Eurofer97 steel

    Energy Technology Data Exchange (ETDEWEB)

    Luzginova, N.V., E-mail: luzginova@nrg.eu [Nuclear Research and Consultancy Group, Petten (Netherlands); Nolles, H.S.; Pierick, P. ten; Bakker, T.; Mutnuru, R.K.; Jong, M.; Blagoeva, D.T. [Nuclear Research and Consultancy Group, Petten (Netherlands)

    2012-09-15

    Oxide dispersion strengthened (ODS) Eurofer97 steel (EU batch, 0.3 wt.% of Y{sub 2}O{sub 3} particles), produced by mechanical alloying followed by hot rolling, is irradiated in the High Flux Reactor in Petten, The Netherlands at three different irradiation temperatures (300, 450 and 550 Degree-Sign C) up to nominal doses of 1 dpa and 3 dpa. The effect of neutron irradiation on the mechanical properties of ODS Eurofer97 material is investigated. It is shown that the irradiation hardening of ODS Eurofer97 steel occurs at 300 Degree-Sign C, whereas during irradiation at 450 and 550 Degree-Sign C no changes in mechanical properties are observed compared to the unirradiated material. This effect is possibly a result of the annealing of the irradiation damage at temperatures higher than 300 Degree-Sign C. The observed shifts in the Ductile to Brittle Transition Temperatures due to irradiation at different temperatures are discussed and compared with non-ODS Eurofer97 steel.

  17. Application of irradiated chitosan for fruit preservation

    International Nuclear Information System (INIS)

    Kieu N, Lan; Nguyen D, Lam; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Application of irradiated chitosan has been investigated for coating of fruit preservation. Anti-fungal activity of chitosan was induced by γ-ray irradiation in dry condition at 25 kGy. The irradiated chitosan can suppress the growth of Aspergillus. spp. and Fusarium. spp. isolated from Vietnam mango. Fusarium. spp. was sensitive for irradiated chitosan than the other strains. The coating from irradiated chitosan solution at dose 31 kGy has prolonged the storage life of mango from 7 to 15 days. At the 15th day mango keeps good colour, natural ripening, without spoilage, weight loss 10%, whereas the control is spoiled completely and the sample of fruit with unirradiated chitosan coating could not ripe. The effect is due to the anti-fungal activity and change in physico-chemical properties of chitosan by irradiation. Radiation causes the decrease in viscosity affecting the gas permeability of coating film. The irradiated chitosan coating has positive effect on mango that is susceptible to chilling injury at low storage temperature. (author)

  18. Spherical nanoindentation of proton irradiated 304 stainless steel: A comparison of small scale mechanical test techniques for measuring irradiation hardening

    Science.gov (United States)

    Weaver, Jordan S.; Pathak, Siddhartha; Reichardt, Ashley; Vo, Hi T.; Maloy, Stuart A.; Hosemann, Peter; Mara, Nathan A.

    2017-09-01

    Experimentally quantifying the mechanical effects of radiation damage in reactor materials is necessary for the development and qualification of new materials for improved performance and safety. This can be achieved in a high-throughput fashion through a combination of ion beam irradiation and small scale mechanical testing in contrast to the high cost and laborious nature of bulk testing of reactor irradiated samples. The current work focuses on using spherical nanoindentation stress-strain curves on unirradiated and proton irradiated (10 dpa at 360 °C) 304 stainless st