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Sample records for 54mn 60co 85sr

  1. Soil-to-plant transfer of 54Mn, 60Co, 85Sr and 137Cs deposited during the growing season of potato

    To measure the soil-to-plant transfer factors (TFa, m2 kg-1-fresh) of radionuclides deposited during the growing season of potato, a radioactive solution containing 54Mn, 60Co, 85Sr and 137Cs was applied to the soil surfaces in soil boxes 2 d before seeding and three different times during the plant growth. For the Pre-Seeding Application (PSA), radionuclides were mixed with the topsoil (loamy sand and 5.2 in pH). The plant parts investigated were leaves, stems, tuber skin and tuber flesh. The TFa values of 54Mn, 60Co, 85Sr and 137Cs from the PSA were in the ranges of 1.9 x 10-4∼1.5 x 10-2, 1.8 x 10-4∼7.5 x 10-4, 4.0 x 10-4∼1.6 x 10-2, 1.5 x 10-4∼3.9 x 10-4, respectively, for different plant parts. The TFa values from the growing-time applications were on the whole a few times lower than those from the PSA. For 54Mn, 85Sr and 137Cs, the TFa values from the early- or middle-growth-stage application were higher than those from the late-growth-stage application, whereas the opposite was true for 60Co. Leaves and tuber flesh had the highest and lowest TFa values, respectively, in most cases. The total uptake from soil by the four plant parts was in the range of 0.05∼3.16%. In the third year following the PSA, the TFa values of 54Mn, 60Co and 137Cs were 11∼25%, 21∼25% and 38∼67% of those in the first year, respectively, depending on the plant parts. The present results can be used for estimating the radiological impact of an acute radioactive deposition during the growing season of potato and for testing the validity of relevant food-chain models

  2. Distribution of 60Co and 54Mn in graphite material of irradiated HTGR fuel assemblies

    Distribution of 60Co and 54Mn was measured in the graphite sleeves and blocks of the third and fourth HTGR fuel assemblies irradiated in the Oarai Gas Loop-1 (OGL-1), which is a high temperature inpile gas loop installed in the Japan Materials Testing Reactor (JMTR) of Japan Atomic Energy Research Institute (JAERI). Axial and circumferential profiles were obtained by gamma spectrometry, and radial profiles by lathe sectioning with gamma spectrometry. Distribution of 60Co is in good agreement with that of thermal neutron flux, and the Co content in the graphite is estimated to be -- 1 x 10-9 in weight fraction. Concentration of 54Mn decreases toward the axial center in its axial profile, and radially is almost uniform inside and appreciably higher at free surfaces. An estimated Fe content of --10-8 in wight fraction is smaller by two orders of magnitude than that from chemical analysis. Higher concentraion of 60Co and 54Mn at the free surfaces suggests the importance of transportation process of these nuclides in the coolant loop. (author)

  3. Retention of 60Co, 85Sr and 137Cs on inorganic ion exchangers

    The aim of the study is the treatment of radioactive wastes produced in plutonium fuel fabrication or in spent fuel reprocessing by inorganic ion exchangers for ultimate storage. This rapport, gives the distribution coefficients of 60Co, 85Sr, 137Cs (in sodium nitrate medium at different concentration of sodium: .23g/l, 1 g/l, 10 g/l) obtained with different inorganic exchangers: titanium oxyde, sodium titanate, sodium zirconate, sodium niobate, sodium tantalate, titanium phosphate, zirconium phosphate, ammonium phosphotungstate in zirconium phosphate, polyantimonic acid amorphous aluminosilicate and several zeolites (ZBS 15 from OXYMIN, ZEOLON 400, ZEOLON 500, ZEOLON 900 from Norton, IE 96, A 51, 13 X from Union Carbide)

  4. The use of ion exchange chromatography in the cyclotron production of the radioisotopes 85Sr, 54Mn, 57Co and 109Cd

    This dissertation shows the successful application of ion exchange chromatography to the isolation of carrier free cyclotron produced radioisotopes. A simple method is presented for the isolation of 85Sr from a 10 g rubidium chloride target. Cation exchange with AG50-X12 is used to retain 85Sr from a bombarded target dissolved in 0.1 mol/dm3 hydrochloric acid. Rubidium is effectively eluted with 0.5 mol/dm3 hydrochloric acid and trace impurities such as copper, iron and 65Zn are eluted with 0.5 mol/dm3 hydrochloric acid/φ=0.95 acetone (where φ is the volume fraction of acetone). Strontium-85 is eluted in nearly 100% yield with 3.0 mol/dm3 nitric acid. The isolation of 54Mn, 57Co and 109Cd from a composite iron-silver target is performed with AG50-X4 cation exchange resin in a hydrochloric acid-acetone medium subsequent to the removal of silver by reduction with hydrazine hydrate. Cadmium-109 is eluted with 0.1 mol/dm3 hydrochloric acid/φ=0.80 acetone and is further refined by absorption onto a AG1-X8 anion exchange column and subsequent washing with 0.25 mol/dm3 nitric acid/0.1 mol/dm3 hydrobromic acid. The elution of copper, iron, 65Zn and other impurities from the cation exhanger is performed with 0.5 mol/dm3 hydrochloric acid/φ=0.83 acetone. Cobalt-57 is quantitively eluted with 0.35 mol/dm3 hydrochloric acid/φ=0.90 acetone, and 54Mn, the remaining element on the column, is recovered with 3.0 mol/dm3 hydrochloric acid

  5. Evaluation of small scale laboratory and pot experiments to determine realistic transfer factors for the radionuclides 90Sr, 137Cs, 60Co and 54Mn

    Transfer factors for the root uptake of 90Sr, 137Cs, 60Co and 54Mn were compared using outdoor lysimeters, Kick-Brauckmann experimental pots under greenhouse conditions and Neubauer cups under growth chamber conditions. The uptake was studied in barley, potatoes, sugar beet and salad vegetables grown on either podsolic or loess soil. The transfer factors for these radionuclides under the specific conditions of the small scale Neubauer cup experiments differed greatly from those obtained from the outdoor lysimeter. In the pot experiments, the transfer factors for 90Sr, 137Cs and 54Mn showed less deviation from the lysimeter results especially in crops grown on podsolic soil. For 60Co, the transfer factors varied for the different crops grown. Transfer factors obtained in pot experiments can only be applicable to a limited extent to field conditions; factors influencing the transfer factors in pot experiments include soil volume, root density, root/shoot ratio, water supply and fertilizer application rate. (UK)

  6. Transport of 85Sr, 60Co, 65Zn and 109Cd in two forest soils as observed in undisturbed soil columns

    Undisturbed soil columns of 20 cm in diameter and about 40 cm length were taken in a spruce stand (podsolic parabrown earth) and in a pine stand (podsol). In the laboratory the transport of 85Sr, 60Co, 65Zn and 109Cd was investigated under unsaturated conditions by periodical irrigation of the columns with rainwater and observation of the resulting depth profiles with a scanner technique as a function of time for three years. From the activity distributions obtained, the residence half-times and mean rates of migration of the radionuclides in the various soil horizons were evaluated with a compartment model. - In the top layer of the soil from the spruce stand (consisting of organic material only) the mean migration rate of 85Sr, 65Zn and 109Cd was 2.0 ± 0.05 cm/y and thus rather similar to that of 60Co (1.7 ± 0.3 cm/y). In the corresponding layer from the pine stand the mean migration rate of 85Sr, 65Zn and 109Cd was only 0.87 ± 0.06 cm/y (60Co:0.5 ± 0.10 cm/y). Since the water flux in the columns from the pine stand was even higher than in those from the spruce stand, the radionuclides seem to be sorbed stronger by organic material derived from pine needles than from spruce needles (the pH was about 3 in both soils). In the underlaying mineral soil the migration rate of the radionuclides was considerably faster than in the organic layer (between 2.5 and 10 cm/y), but a statistical difference between the values observed in the two stands or between the radionuclides was not apparent. (orig.)

  7. In situ determination of the distribution of 110Agm, 58Co, 60Co and 54Mn between fresh water and suspended matter

    In order to obtain data on the equilibrium conditions and the exchange kinetics of radionuclides between water and suspended matter in natural conditions, an in situ experiment was carried out in the nuclear power plant of Golfech (France). In this plant, an experimental physical model of river systems, represented by a channel, was built. Before being discharged into the Garonne river, part of the radioactive effluents, previously mixed with water originating from the cooling system, are diverted to a channel where different phenomena generally occurring in a river can be simulated. The experiment presented in the paper was undertaken during a scheduled discharge of low activity wastes; the suspended matter was sampled at four points along the channel using sequential filtration. The results give information about: (1) The influence of the particle size on the process of radionuclide adsorption by suspended matter. The uptake of radioactivity is generally higher for the smallest particles (size 110Agm, size 58Co, 60Co and 54Mn). (2) The exchange kinetics between water and suspended matter. Generally, radioactive equilibrium is rapidly attained. Consequently, it is possible to calculate the global distribution coefficient (Kd) value of each radionuclide (110Agm, 58Co, 60Co and 54Mn) and to determine exactly the specific Kd value for each granulometric class (class 1 > 10 μm; 10 μm < class 2 < 2.5 μm; 2.5 μm < class 3 < 0.5 μm). (author). 11 refs, 3 figs, 1 tab

  8. Cosmic ray half life of 54Mn

    A search for the β+ decay of 54Mn has established an upper limit of 4.4 x 10-8 for this branching ratio, and a lower limit of 13.3 for the log ft value for this second forbidden unique transition. Assuming that the β- decay branch has the same log ft value, then its partial half life must be greater than 4 x 104 years. Experiments to directly measure the β- decay rate of 54Mn are now in progress. 6 refs., 2 figs

  9. Internal bremsstrahlung endpoint energy of 54Mn

    For 54Mn there is a discrepancy between the QEC obtained from the endpoint energy of the internal bremsstrahlung (IB) spectrum which accompanies the electron capture decay (QEC=1353±8 keV) and that obtained from the accepted mass differences (QEC=1377±1 keV). This Q value is needed to deduce the partial-half life of the astrophysically interesting β- decay of 54Mn from the recently measured β+ partial half-life. To resolve this discrepancy, we have remeasured the endpoint energy of the IB spectrum, by recording coincidences between the IB and the 835-keV γ ray, both detected in Compton-suppressed Ge detectors. The QEC we deduce is 1379±8 keV, in agreement with the accepted mass differences. (c) 2000 The American Physical Society

  10. Search for the β+ decay of 54Mn

    We have performed a search for the β+ decay of 54Mn by looking for back-to-back 511-keV γ rays in two high-purity Ge detectors. No excess of events above background was observed, and a limit of 5.7x10-7% has been established for the β+ branch. The significance of this result for the use of 54Mn as a cosmic ray chronometer is discussed

  11. Lifetimes of excited states in 54Mn and 53Cr

    The recoil-distance method has been used in conjection with the 51V(α, n) and 50Ti(α, n) reactions to investigate the lifetimes of four levels in 54Mn and four in 53Cr. The mean lives obtained are as follows: 53Cr(Esub(x)= 1006 keV), tau 53Cr(Esub(x) = 1537 keV), tau = 33.2 +- 1.6 ps; 53Cr(Esub(x) = 2173 keV), tau = 13.9 +- 1.1 ps; 53Cr(Esub(x) = 2707 keV), tau = 3.4 +-1.4 ps; 54Mn(Esub(x) = 156 keV), tau = 302 +- 24 ps; 54Mn(Esub(x) = 368 keV), tau = 8.9 +- 1.9 ps; 54Mn(Esub(x) = 408 keV), tau = 2.7 +- 0.8 ps; 54Mn(1073 keV), tau = 321 +- 13 ps. In addition, the Doppler-shift attenuation method has been used to investigate ten lifetimes in 53Cr and fourteen in 54Mn. The results extracted are discussed, and compared with previous experiments and with theoretical predictions. (author)

  12. Internal bremsstrahlung endpoint energy of {sup 54}Mn

    Hindi, M. M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Larimer, R.-M. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Norman, E. B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rech, G. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2000-05-01

    For {sup 54}Mn there is a discrepancy between the Q{sub EC} obtained from the endpoint energy of the internal bremsstrahlung (IB) spectrum which accompanies the electron capture decay (Q{sub EC}=1353{+-}8 keV) and that obtained from the accepted mass differences (Q{sub EC}=1377{+-}1 keV). This Q value is needed to deduce the partial-half life of the astrophysically interesting {beta}{sup -} decay of {sup 54}Mn from the recently measured {beta}{sup +} partial half-life. To resolve this discrepancy, we have remeasured the endpoint energy of the IB spectrum, by recording coincidences between the IB and the 835-keV {gamma} ray, both detected in Compton-suppressed Ge detectors. The Q{sub EC} we deduce is 1379{+-}8 keV, in agreement with the accepted mass differences. (c) 2000 The American Physical Society.

  13. Soil radiochromatography using 22Na, 85Sr, and 58Co

    A laboratory study of radionuclide movement and adsorption in soil has been performed. A commercial, high-performance, liquid chromatography system, employing an ultraviolet adsorption detector, was supplemented with a real-time radiation monitor of the column effluent. Columns packed with various soils and their size separates were injected with 22Na, 85Sr, and 58Co using various CaCl2 solutions for eluting solvents to simulate groundwater. The near identical behavior of 85Sr and Ca allowed the elution volumes of the Sr peaks to be used for the calculation of the cation retention capacities of the soils which agreed with their measured cation exchange capacities. Treatment with NaOH increased the cation exchange capacity of one column by 50%. Acetone or sodium benzoate proved useful for measuring column void volumes using the ultraviolet detector because they eluted at exactly the calculated void volumes for all soil columns. Methods to measure a soil's retardation factor (R/sub d/) and distribution coefficient (K/sub d/) for each isotope from the experimental elution patterns were developed. Excellent simulations of the elution peaks were attained using the Lapidus-Amundson equation, which required inputs of flow rate, K/sub d/, bulk density, porosity, the dispersion coefficient, and column length. The factors determining the elution volume of either 22Na or 85Sr were the cation exchange capacity of the column and the concentration of Ca in the eluting solution. Elution of these isotopes was not affected by the presence of complexing organic acids, EDTA, or acidic and basic soil organic matter extracts. On the other hand, 58Co exhibited enhanced mobility when complexed with EDTA but not with other organic acids or soil extracts. A significant amount of 58Co was strongly adsorbed by the soils and could be removed only by washing with strong mineral acid

  14. Double K-shell ionization probability in 54Mn

    We have measured the probability of double K-shell vacancy production in the electron capture decay of 54Mn to the 835-keV level of 54Cr. The probability was deduced from the number of triple coincidences among the Cr hypersatellite and satellite x rays emitted in filling the double vacancy and the 835-keV γ ray. The probability of double K-shell vacancy production per K-shell electron capture (PKK) was found to be (2.3-0.5+0.8)x10-4. Comparisons to previous experimental results and theoretical calculations are discussed

  15. Age influence on retention, distribution and internal doses of 85Sr in rat

    After I.V. 85Sr, the whole body 85Sr-retentions in rats were fit to two compartment exponential equations. The equation parameters showed a significantly difference between the young group and both the adult and old groups (p 2) for 85Sr in the slow compartment decreased in regular order from the young to the old groups. In the bone 85Sr-retention equations Tb2 of the slow compartment for 85Sr in the young group was significantly lower than the adult and old groups. The doses of the whole body and red-marrow for young rats were 4.2 times as much as those of adult rats, and 6.2 and 5.9 times as much as those old rats. The dose-cumulative speeds was most quick in the young groups and similar in the adult and the old

  16. STABLE SR VS 85SR SORPTION FROM SIMULATED WASTE SOLUTIONS BY MST AND MMST

    Taylor-Pashow, K.; Hobbs, D.

    2012-04-02

    A series of tests were performed to examine the sorption of stable Sr versus the sorption of {sup 85}Sr by monosodium titanate (MST) and modified monosodium titanate (mMST) from simulated waste solutions. Earlier testing indicated a discrepancy between the decontamination factors (DFs) obtained by measuring the stable Sr concentrations by inductively coupled plasma - mass spectroscopy (ICP-MS) and the {sup 85}Sr activities by gamma spectroscopy. One hypothesis to explain this discrepancy was that the stable Sr and {sup 85}Sr were in different chemical forms in the simulated solutions. Several simulants were prepared using different methods for adding the Sr and performance tests were carried out using MST and mMST to determine the Sr and {sup 85}Sr DFs with the various simulants. Testing indicated no discrepancy between the Sr and {sup 85}Sr DFs in tests with these simulants.

  17. Preparatory on manganose salts of carboxilic acids labelled with 54Mn and comparison with 54MnCl2 in liquid scintillation counting

    Procedures for scintillation sample preparation of manganose dimethylbutirate, decanoate and palmitate, labelled with 54Mn are described. Their quenching effect, spectral evolution and counting stability along several weeks are analysed in liquid scintillation measurements with Toluene, HlSafe II, PCS, Instagel, Dioxane-naphtalene and Toluene-alcohol. For comparison, inorganic 54MnCl2 samples are also studied, resulting in acceptable counting stability but showing greater quenching and signs of little spectral degradation against the organic samples. (author) 14 fig. 15 ref

  18. Comparison of transfer factors of 85Sr and 134Cs for some Greek soils and crops

    The 'soil-plant' transfer factors (TF) of 85Sr and 134Cs was studied in two successive and similar in design glasshouse experiments. Plant species of wheat, alfalfa, radish, string bean, cucumber, lettuce (only for 85Sr) and endive (only for 134Cs) were grown in pots on eight Greek soils differing significantly in their physical and chemical properties. After the necessary measurements and analysis, big differences were detected in the transfer factors of both radionuclides for the soil types. The TFs of 85Sr were higher than those of 134Cs and for the tested crops and soils ranged between 0.3 and 36.5 for 85Sr and between 0.01 and 1.72 - for 134Cs. For 85Sr the TFs of the edible parts were much lower than those of the rest plant material, while this difference was not so high for 134Cs. The correlation between TFs and pH, negative in all cases, was significant or highly significant for all tested crops or plant parts (for 85Sr r=-0.89, for 134Cs r=-0.82). The values of TRs indicated a trend towards negative correlation with other soil properties (cation exchange capacity - CEC, clay %). The exchangeable (Ca+Mg) cations as well as exchangeable bases, expressed as percentages of CEC, gave a significant or highly significant correlation with TFs of both radionuclides. (author)

  19. Galactic Confinement Time of Iron-Group Cosmic Rays Derived from the {sup 54}Mn Chronometer

    Zaerpoor, K.; Dragowsky, M.R.; Krane, K.S. [Physics Department, Oregon State University, Corvallis, Oregon 97331 (United States); Chan, Y.D.; Isaac, M.C.; Larimer, R.M.; Macchiavelli, A.O.; Macleod, R.W.; Norman, E.B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); DiGregorio, D.E. [Laboratorio TANDAR-Comision Nacional de Energia Atomica, Buenos Aires, 1429 (Argentina); Hindi, M.M. [Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States); Miocinovic, P. [Physics Department, University of California, Berkeley, California 94720 (United States)

    1997-12-01

    The {beta} -decay half-life of {sup 54}Mn is needed to employ this isotope as a cosmic ray chronometer. We have determined the partial half-life of {sup 54}Mn for positron emission by counting a highly purified 35-{mu}Ci source of {sup 54}Mn in GAMMASPHERE to search for the astrophysically interesting {beta}{sup +} decay branch through the observation of coincident positron-annihilation {gamma} rays. A careful analysis of 97hours of source counting and 61hours of background shows a net signal of 24{plus_minus}10 back-to-back 511-511keV coincident events. Based on this result, the branch for this decay mode is (2.2{plus_minus}0.9){times}10{sup {minus}7}{percent} . The implications of this result for the {sup 54}Mn cosmic-ray chronometer problem are discussed. {copyright} {ital 1997} {ital The American Physical Society}

  20. Separation of 54Mn from Irradiated Natural Fe2O3 Using Anion Exchange Resin

    Preparation of radioisotope from natural target has an advantage namely the production is cheaper, but the produced radioisotope may content radionuclidic impurities. Preparation of 54Mn from irradiated natural Fe2O3 has a problem due to 59Fe impurity. The separation of 54Mn from irradiated natural Fe2O3 has been carried out by means of solving irradiated target using HCl and dowex resin 1 x 8 Cl form. The separation of 54Mn from irradiated natural Fe2O3 showed a good result by 8 N HCl concentration and 90 minute contact time and efficiency was 7.55 % 54Mn and 94.13 % for 59Fe. (author)

  1. Galactic Confinement Time of Iron-Group Cosmic Rays Derived from the 54Mn Chronometer

    The β -decay half-life of 54Mn is needed to employ this isotope as a cosmic ray chronometer. We have determined the partial half-life of 54Mn for positron emission by counting a highly purified 35-μCi source of 54Mn in GAMMASPHERE to search for the astrophysically interesting β+ decay branch through the observation of coincident positron-annihilation γ rays. A careful analysis of 97hours of source counting and 61hours of background shows a net signal of 24±10 back-to-back 511-511keV coincident events. Based on this result, the branch for this decay mode is (2.2±0.9)x10-7% . The implications of this result for the 54Mn cosmic-ray chronometer problem are discussed. copyright 1997 The American Physical Society

  2. Effect of plant species on the specific activity of 65Zn and 54Mn

    The effect of five plant species on the specific activity of 65Zn and 54Mn is studied. Soybean (Glycine max (L.) Merril), bean (Phaseolus vulgaris, L.), rice (Oryza sativa, L.), wheat (Triticum aestivum, L.) and tomato (Lycopersium esculentum Mill) were grown in PV and TE soils labelled with 65Zn and 54Mn. The plants were harvested 30 days after seeding and specific activities of zinco and manganese were determined in the above ground part and in the roots. (M.A.C.)

  3. Comparative kinetics of 47Ca, 85Sr and 226Ra in the freshwater turtle, Trachemys scripta

    The kinetics of 47Ca, 85Sr and 226Ra were compared in the yellow-bellied slider, a common freshwater turtle of the southeastern USA. The absorption and elimination processes were examined as a function of stable dietary Ca, season, age and sex of the animals. Turtles were gavaged with radionuclides and serial whole-body analyses were performed on the live animals for up to 480 days. Only in the juvenile age class did reduced dietary Ca cause a significant increase in 85Sr absorption. The absorption of 85Sr and 226Ra in the adult male, adult female and hatchling groups was unaffected by dietary Ca. Mean absorption was greater than that which has been reported for other organisms and significantly differed among isotopes. The high absorption values were not restricted to immatures, but continued into maturity. Elimination rates were not affected by the dietary treatment, nor were isotopic differences in elimination observed. Annual mean elimination rate constants pooled among animal groups, were 0.22 ± 0.07 for 85Sr and 0.26 ± 0.18 for 226Ra. Retention was strongly affected by season with the greatest elimination occurring in the summer and declining to levels that were not distinguishable from zero in the winter. Elimination rate constants for hatchlings were greater than for the other age groups. (author)

  4. The transfer parameter of environmental 85Sr radiostrontium trough soil - spinach plant (Amaranthus sp.) Pathway

    The radionuclide transfer from soil to crop is a pathway of the radionuclide to contaminate human body. Soil plant interaction can be examined by several parameter such as transfer factor (Ft) and transfer rate coefficient (k12). An experiment about radiostrontium transfer from soil to crop had been conducted to determine the plant ability in radiostrontium accumulation for human internal doses assessment. Crop represented by commonly consumed by people, spinach (Amaranthus sp.), was cultivated in soil contaminated with 85Sr for about 2 months. Every five days the soil and plants were sampled, dried, and the 85Sr activities were measured using gamma spectrometer. The measurement results showed that the spinach crop were able to absorb and accumulate 85Sr. The Ft value obtained from this experiment is about 3, whereas the k12 values are 9.99 x 10-3 day-1 and 9.98 x 10-3 day-1, for 041 days, respectively. The 85Sr soil - plant transfer parameter is expected to be used for radiological impact assessment in the case of Sr radionuclide contamination in soil. The obtained Ft and k12 can be use for predicting Sr radioactivities in edible parts of plants in certain period after soil contamination with radiostrontium. (author)

  5. Cosmic-ray history derived from the 54Mn, 56Ni and 144Pm chronometers

    Sources of 54Mn, 56Ni, and 144Pm were placed at the center of the Gammasphere array and searches were made for the astrophysically interesting β+ decay modes of these isotopes. The results of these searches are presented and the implications for cosmic-ray physics are discussed

  6. 54Mn absorption and excretion in rats fed soy protein and casein diets

    Rats were fed diets containing either soy protein or casein and different levels of manganese, methionine, phytic acid, or arginine for 7 days and then fed test meals labeled with 2 microCi of 54Mn after an overnight fast. Retention of 54Mn in each rat was measured every other day for 21 days using a whole-body counter. Liver manganese was higher (P less than 0.0001) in soy protein-fed rats (8.8 micrograms/g) than in casein-fed rats (5.2 micrograms/g); manganese superoxide dismutase activity also was higher in soy protein-fed rats than in casein-fed rats (P less than 0.01). There was a significant interaction between manganese and protein which affected manganese absorption and biologic half-life of 54Mn. In a second experiment, rats fed soy protein-test meals retained more 54Mn (P less than 0.001) than casein-fed rats. Liver manganese (8.3 micrograms/g) in the soy protein group was also higher than that (5.7 micrograms/g) in the casein group (P less than 0.0001), but manganese superoxide dismutase activity was unaffected by protein. Supplementation with methionine increased 54Mn retention from both soy and casein diets (P less than 0.06); activity of manganese superoxide dismutase increased (P less than 0.05) but liver manganese did not change. The addition of arginine to casein diets had little effect on manganese bioavailability. Phytic acid affected neither manganese absorption nor biologic half-life in two experiments, but it depressed liver manganese in one experiment. These results suggest that neither arginine nor phytic acid was the component in soy protein which made manganese more available from soy protein diets than casein diets

  7. Removal of 54Mn from the mouse body by dilution with stable manganese and by chelation with DTPA

    54Mn is one of the activation products generated in nuclear reactors. This study was carried out to find a method appropriate for the removal of 54Mn. Intraperitoneal administration of stable manganese effectively promoted the excretion of 54Mn from the mouse body. The efficacy for removing 54Mn was estimated to be 56, 67, 77 and 82% for manganese doses of 0.3, 1, 3 and 10 mg/kg, respectively. Oral administration of stable manganese was also effective for the removal of 54Mn, but the efficacy was inferior to that obtained by intraperitoneal administration because of low gastrointestinal absorption of manganese. Ca-DTPA and Zn-DTPA promoted the excretion of 54Mn when administered 1 h after administration of 54Mn, but these chelating agents had little effect when administered after 3 h or more. Zn-DTPA was less effective than Ca-DTPA. These results demonstrate that dilution with stable manganese is more effective than chelation with DTPA for the removal of 54Mn from the body. (author)

  8. Transfer of 226Ra, 85Sr and 137Cs from milk to milk products

    Transfer of 226Ra, 85Sr and 137Cs from cow and sheep milk to various Syrian dairy products has been evaluated. Dairy products include Kashkivan cheese, braided cheese, Haloom cheese, Sircassian cheese, liquid cheese, native cheese, cottage, thick yogurt, butter and milk cream. The results showed that the percentage of 226Ra, 85Sr and 137Cs transferred from cow milk to milk cream (Pt = food processing retention factor x processing efficiency x 100%) has reached 32%, 16% and 7%, respectively. Butter and liquid cheese were found to have the lowest percentage of transferred 226Ra, 85Sr and 137Cs. Most of the obtained Pt values of the studied radionuclides in thick yogurt were relatively low in spite of the high processing efficiencies of thick yogurt. Moreover, the transfer, Pt, of the studied radionuclides from cow milk to the prepared cheese was higher than those values determined for sheep milk. This is due to differences in chemical compositions of each type of milk. On the other hand, the treatment of Native cheese, most commonly consumed cheese in Syria, with different concentrations of NaCl solutions showed that 137Cs was completely removed from cheese soaking in 5% NaCl solution (soaking time of 48 hours), while 40% of 226Ra and 80% of 85Sr were also decontaminated using 0-2.5% NaCl solutions and soaking time of 48 hours. Based on the obtained results, industrialization processes of the dairy products that resulted the removal of radionuclides have been identified. (author)

  9. Chelation in metal intoxication X: influence of different polyaminocarboxylic acids and thiol chelators in the excretion and tissue distribution of 54Mn in rat

    The influence of some selected polyaminocarboxylic acids and thiol metal binding agents on the urinary and faecal excretions of 54Mn and on the tissue distribution of 54Mn in 54MnC12 administered rats was studied to find a suitable chelating drug for Mn poisoning. HEDTA, CDTA, DTPA and TTHA were highly successful in enhancing the excretion of 54Mn and reducing the tissue levels of 54Mn in rats. The thiol chelators viz. D L-penicillamine, N-acetyl D L-penicillamine and DMS could neither influence the excretion nor the tissue distribution of 54Mn suggesting poor affinity of the metal towards sulfhydryl groups

  10. Transfer Factors of 137Cs and 85Sr by Freshwater Fish in Tropical Environment

    The experiment was set up to determine the radionuclide transfer factors (T.F.) of 137Cs and 85Sr by tropical freshwater fish. Mixed breeding catfish between Thai catfish (Clarias acrocephalus) and African catfish (Clarias garispinus African sharptooth) were exposed to 137Cs and 85Sr in two 1000-L tanks for 42 days during uptake phase. The calculated T.F. at equilibrium, in flesh, bone, skin plus fin and head were 3.2, 2.6, 1.6 and 1.5 L.kg-1 for 137Cs and 0.1, 4, 1 and 17 L.kg-1 for 90Sr, respectively. These results revealed a much lower values than reported elsewhere for temperate environment, however were in accordance with the tropical values as observed by others. The biological half-lives of 137Cs and 85Sr in flesh part were 41 and 4 days respectively. It is then imperative that suitable T.F. values are employed in the models to predict the transport of radionuclides within the particular ecosystem and the potential dose to man. Thus the relationship between routine release of radionuclides and resulting dose to man can be established and corresponding release limits stipulated for that particular nuclear site

  11. Metabolism of 60Co in mollusca

    After mollusca were bred in 60Co-labeled sea water or were given 60Co-labeled feed for certain hours, their tissues including the liver were removed as experimental samples. 60Co metabolism was observed by the Sephadex gel filtration profile. A gel chromatogram of the liver in gastropoda showed a marked peak of 60Co on the high-molecular side. Although the peak was observed on both high- and low-molecular sides in pelecypoda, it was more marked on the high-molecular side than on the low-molecular side. In cephalopoda, the peak pattern was similar to that in the other mollusca, but the proportion of low-molecular components was comparatively large. The gel filtration profile of 60Co in various tissues of cephalopoda revealed the incorporation of 60Co into the high-molecular components in blood, three peaks in the kidneys, and the incorporation of 60Co into the low-molecular components in the branchial heart. The metabolism of 60Co was dependent upon the chemical form of Co in gastropoda, and organic 60Co was specifically observed in the high-molecular components. (Namekawa, K.)

  12. 60Co levels in the seawater regions

    In order to assess the contribution from nuclear power facilities to the 60Co levels in seawater regions, it is essential to grasp the background values of 60Co. The following matters are described: 60Co sources and the respective inputs; nuclear test fallout and nuclear power plants; the 60Co levels in overseas countries; the 60Co levels in Japan; the 60Co levels from nuclear power plants in Fukui prefecture. In the seawater regions around Japan, there have been numerous instances of 60Co detection; several pCi/kg of dry earth in sea bottom earth and about 1 pCi/kg of raw material in marine life can be considered as the background levels due to nuclear test fallout and nuclear-powered submarines. In the seawater regions of Fukui prefecture, the 60Co levels appreciably exceeded the above background due to the nuclear power plants, which are insignificant concerning the radiation exposure of the local people. (Mori, K.)

  13. Comparison of histomorphometry and 85Sr uptake in induced heterotopic bone in rats

    Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by 85Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of 85Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)] and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min implant)/counts/min/mg os ilium)]. The osteoquantum index showed a linear relationship to the area of the induced bone with a correlation coefficient (r) of 0.90. Only weak linear relationships were found between the osteogenic index and the area of the bone (r = 0.32) and between the osteogenic index and the osteoquantum index (r = 0.33). The osteoquantum index and the area of the induced bone both increased with increasing mass of implanted DBM, whereas the osteogenic index did not change. (au)

  14. Comparison of histomorphometry and [sup 85]Sr uptake in induced heterotopic bone in rats

    Solheim, E.; Pinholt, E.M. (Institute for Surgical Research, Rikshospitalet, University of Oslo (Norway)); Bang, G. (Department of Oral Pathology and Forensic Odontology, University of Bergen (Norway)); Sudmann, E. (Hagavik Orthopedic Hospital, University of Bergen (Norway))

    1992-01-01

    Heterotopic bone formation in the abdominal muscle of 45 male 8-week-old Wistar rats induced by implantation of 5, 10, or 15 mg demineralized bone (DBM) powder was evaluated at 4 weeks by [sup 85]Sr uptake of the implants and area histomorphometry of the induced bone. Two indices of [sup 85]Sr uptake were calculated: the osteogenic index [(counts/min/mg implant)/(counts/min/mg os ilium)] and an index that we have called the osteoquantum index in which the weight of the implant is disregarded [(counts/min implant)/(counts/min/mg os ilium)]. The osteoquantum index showed a linear relationship to the area of the induced bone with a correlation coefficient (r) of 0.90. Only weak linear relationships were found between the osteogenic index and the area of the bone (r = 0.32) and between the osteogenic index and the osteoquantum index (r = 0.33). The osteoquantum index and the area of the induced bone both increased with increasing mass of implanted DBM, whereas the osteogenic index did not change. (au).

  15. Curing time effect on the fraction of 60Co from cement matrix

    Cement has been successfully used in Radioactive Waste Management to immobilize a wide range of waste including filter sludges, ion-exchange resins and evaporator concentrates produced in nuclear power plants. In any assessment of cement-immobilized radwaste composites, leach of radionuclides (60Co, 137Cs, 54Mn) is an important factor, for it must be assumed that the composite material will eventually come into contact with leachant solutions. Cement and concrete are widely used in low-level waste management both as a means of solidifying waste and for containment of dry or liquid wastes.At present there is also widespread interest in the use of near-surface concrete trench system for the disposal of radwaste materials.Typical concrete is a mixture of cement, sand, water in various proportions,that together determine the structural properties and tightness of the poured material

  16. Heavy metal effect on uptake and translocation of 134Cs and 85Sr in aubergine plants

    Aubergine plants were treated either with radionuclides or with heavy metals and subsequently (24 h after) with radionuclides, in order to determine the effects of heavy metals (Zn, Cd and Ni) on the behaviour of radiocesium and radiostrontium in plants; the treatments were carried out at anthesis and when fruits were present. It was observed that the treatment of leaves and fruits with heavy metals did not influence the direct uptake of radionuclides and their translocation. 134Cs deposited on the surface of the leaves is transferred to the edible parts of plants to the extent of 0.70% (anthesis) and 0.45% (with covered fruits), while the translocation of 85Sr was found to be negligible, as compared with radiocesium (0.007 and 0.001%, respectively). Strontium activity in fruits is more largely due to direct uptake, while cesium activity in fruits is due to both direct uptake and translocation from leaves

  17. Suppression of the stellar enhancement factor and the reaction 85Rb(p,n)85Sr

    Rauscher, T; Gyürky, Gy; Simon, A; Fülöp, Z; Somorjai, E

    2009-01-01

    It is shown that a Coulomb suppression of the stellar enhancement factor occurs in many endothermic reactions at and far from stability. Contrary to common assumptions, reaction measurements for astrophysics with minimal impact of stellar enhancement should be preferably performed for those reactions instead of their reverses, despite of their negative reaction Q-value. As a demonstration, the cross section of the astrophysically relevant 85Rb(p,n)85Sr reaction has been measured by activation between 2.16<=E_{c.m.}<= 3.96 MeV and the astrophysical reaction rates at p-process temperatures for (p,n) as well as (n,p) are directly inferred from the data. Additionally, our results confirm a previously derived modification of a global optical proton potential. The presented arguments are also relevant for other alpha- and proton-induced reactions in the p-, rp-, and nu-p-processes.

  18. Response of orange plants to foliar application for manganese using 54Mn

    The greenhouse experiment was designed using MnSO4 as a single element or in a mixture of Mn-Fe-Zn sulphate at rates of 0.5 and 1.0%. The solutions were adjusted to pH6.0, and Tween 20 at 0.5% (vol./vol.) was added. The prepared solutions were labelled with carrier free 54Mn. Two year old orange seedlings were arranged in a complete randomized block design to study the foliar absorption, translocation and percentage use of 54Mn. A field experiment was also carried out on 40 year old Balady orange trees (Citrus sinensis, Osbeck) grown in sandy clay loam soil. These trees were suffering from micronutrient deficiencies, in particular Mn. Their response to foliar application of MnSO4 or a mixture of Mn, Fe and Zn sulphates at 0.5 and 1.0% was studied. The vegetative growth, nutritional status and productivity of the treated trees were estimated. The total absorption, translocation and percentage use of 54Mn were greatly affected, depending on the spraying treatment. The percentage use of MnSO4 at 0.5% was more than that at 1.0%, and its value for MnSO4 was twice as high as that of the mixture. The growth parameter were significantly increased by spraying the orange trees with MnSO4 or a mixture of MnSO4 + FeSO4 + ZnSO4; the highest response was found with MnSO4 alone at 1.0%. The leaf N, P and K levels were slightly affected by all the spraying treatments. However, the Mn level in the orange leaves was markedly increased and MnSO4 was more effective in supplying the orange trees with Mn than the mixture. The orange yield increased significantly with all the treatments as a result of spraying the trees, but the rate of increase varied according to the spraying solution. In general, from the nutritional point of view, spraying orange trees suffering from Mn deficiency with MnSO4 at 0.5% could be recommended for correcting this deficiency within a few days and for improving the productivity of the trees. (author). 17 refs, 4 tabs

  19. Sorption of 60 Co on inorganic solids

    The behavior of sorption of the 60 Co in aqueous solution under static conditions to different values of pH of the aqueous solution (1, 3, 5, 7, and 10) on MgO, MnO2, SnO, TiO2, activated carbon and calcinate hydrotalcite was investigated. It was found that the best sorbents of the 60 Co was the MnO2, activated carbon and TiO2 whose sorption was incremented when increasing the pH value of the aqueous solutions, in the one case of the hydrated oxides, the 60 Co interacted with the electrically charged surface of the sorbents that depends on the pH of the solution and of the point of zero charge (zpc) of the sorbent. (Author)

  20. Variations in soil-to-red pepper transfer factors of radionuclides with time of their application and fruit harvest

    A mixed solution of 54Mn, 60Co, 85Sr and 137Cs was applied to the soil of culture boxes in a greenhouse 2 days before transplanting red pepper and at 3 different times during its growth for investigating transfer factors (m2/kg-dry) for its green and red fruits. Transfer factors varied with radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly radionuclide, application time and harvest time by factors of about 20-100. They decreased mostly in the order of 85Sr>54Mn>60Co>137Cs while 54Mn and 60Co was higher than 85Sr when time lapse between application and harvest was short. Transfer factors of 85Sr and 137Cs at the last application were lower than those at the previous one by factors of 3-20 depending on harvest time. Variations in 54Mn and 60Co transfer factors with application time after transplanting were comparatively low. Transfer factors of 54Mn, 60Co and 85Sr mixed with topsoil before transplanting were up to 3-9 times higher than those for the application onto soil surface 2 days after transplanting root-uptake concentrations of the radionuclides in red pepper fruit and taking proper measures for its harvest and consumption at the event of an accidental release during the growing season of red pepper

  1. Evidence for correlations between fluctuations in 54Mn decay rates and solar storms

    Mohsinally, T.; Fancher, S.; Czerny, M.; Fischbach, E.; Gruenwald, J. T.; Heim, J.; Jenkins, J. H.; Nistor, J.; O'Keefe, D.

    2016-02-01

    Following recent indications that several radioactive isotopes show fluctuating decay rates which may be influenced by solar activity, we present findings from a 2 year period of data collection on 54Mn. Measurements were recorded hourly from a 1 μCi sample of 54Mn monitored from January 2010-December 2011. A series of signal-detection algorithms determine regions of statistically significant fluctuations in decay behaviour from the expected exponential form. The 239 decay flags identified during this interval were compared to daily distributions of multiple solar indices, generated by NOAA, which are associated with heightened solar activity. The indices were filtered to provide a list of the 413 strongest events during a coincident period. We find that 49% of the strongest solar events are preceded by at least 1 decay flag within a 48 h interval, and 37% of decay flags are followed by a reported solar event within 48 h. These results are significant at the 0.9σ and 2.8σ levels respectively, based on a comparison to results obtained from a shuffle test, in which the decay measurements were randomly shuffled in time 10,000 times. We also present results from a simulation combining constructed data reflecting 10 sites which compared and filtered decay flags generated from all sites. The results indicate a potential 35% reduction in the false positive rate in going from 1 to 10 sites. By implication, the improved statistics attest to the benefit of analysing data from a larger number of geographically distributed sites in parallel.

  2. Absorption and biological half-life in humans of intrinsic and extrinsic 54Mn tracers from foods of plant origin

    Absorption and biological half-life of 54Mn were measured in adult men and women fed foods labeled intrinsically or extrinsically with 54Mn. Each subject consumed a series of three test meals consisting of a food labeled intrinsically, a food labeled extrinsically or MnCl2 (control) served in random order. The foods tested were lettuce, spinach, wheat and sunflower seeds. Lettuce meals and their controls contained 9.65 mumol Mn; other meals contained 22.50 mumol Mn. In addition to the test food or MnCl2, each meal consisted of vegetable oil (5 g), salt (NaCl, 0.15 g) and crackers (10 g), which provided 0.55 mumol Mn. There were no differences in percentage of Mn absorption or biological half-life of 54Mn for any of the intrinsically/extrinsically labeled food pairs. Absorption of 54Mn from MnCl2 (8.90%) was greater than from lettuce (5.20%), spinach (3.81%), wheat (2.16%) or sunflower seeds (1.71%), but the biological half-life did not vary with the source of Mn. Absorption of 54Mn from lettuce was significantly (P less than 0.05) greater than from wheat or sunflower seeds. Although the Mn dose in the test meal was less for lettuce than for the other foods, there was no difference in Mn absorption from MnCl2 between the subjects fed lettuce and subjects fed other foods. There was no correlation of either 54Mn absorption or biological half-life with whole blood or plasma Mn

  3. Bioaccumulation of 137Cs and 85Sr by an Australian sub-tropical freshwater teleost (Bidyanus bidyanus)

    Adult Silver Perch (Bidyanus bidyanus) were exposed to 137Cs and 85Sr for 8 weeks to determine radionuclide concentration factors (CFs) for use in a dose assessment model database for sub-tropical and tropical ecosystems. At equilibrium, the fresh weight CFs for 137Cs and 85Sr in the flesh of B. bidyanus were 12.6±5.2 kg l-1 (mean±S.E.) and 0.73±0.21 kg l-1, respectively. The mean CFs were considerably lower than those expected for temperate freshwater fish, but were consistent with recently reported values for other sub-tropical and tropical freshwater fish. The results indicate that the use of recommended CFs for radiological dose assessment models, based on temperate freshwater fish, may provide overestimates of dose when applied to sub-tropical and tropical fish. The biological half-lives of 137Cs (19±2 days) and 85Sr (5±1 days) in the flesh of B. bidyanus, estimated from a one-compartment exponential uptake model, were lower than reported values for four other species of sub-tropical and tropical freshwater fish. Cesium-137 was distributed in B. bidyanus as follows: flesh (63%)>skin/scales (22%)>bone (15%). Conversely, 85Sr showed similar activities in the bone and skin/scales that were still increasing after eight weeks, while the levels in the flesh remained relatively low. Analysis of the skin/scales component showed that the majority of 85Sr (=94%) was located in the scales

  4. Regional alterations in long bone 85Sr clearance produced by internal fixation devices. Part II. Histomorphometry

    The effects of each of the surgical stages involved in compression plating on the development of cortical thinning and porosity were assessed in the intact midshaft, stress-shielded femoral segments of adult mongrel dogs 6 months postoperatively. The data were evaluated in terms of a postsurgical tetracycline-based measure of remodeling and terminal 85Sr clearance (SrC) values for the plated segments of bone. Drilling had no effect on any parameter. Screw application was associated with minimal cortical thinning (p less than 0.05), while plate fixation clearly promoted thinning (p less than 0.01) and porosity (p less than 0.05). The percentage of labeled osteons, a measure of remodeling activity, increased only after plate fixation (p less than 0.05), and the labeling patterns suggested that most osteons had formed during the first 4 postsurgical months. That none of these changes were correlated with the 6-month SrC values suggests that the development of plate-induced osteopenia involves disparate histomorphometric time constants, rather than lack of any association

  5. Cosmic-ray history derived from the {sup 54}Mn, {sup 56}Ni and {sup 144}Pm chronometers

    Zaerpoor, K.; Chan, Y.D.; DiGregorio, D.E.; Dragowsky, M.R.; Hindi, M.M.; Isaac, M.C.P.; Krane, K.S.; Larimer, R.-M.; Macchiavelli, A.O.; Macleod, R. W.; Miocinovic, P.; Norman, E.B.; Robinson, S.J

    1999-07-26

    Sources of {sup 54}Mn, {sup 56}Ni, and {sup 144}Pm were placed at the center of the Gammasphere array and searches were made for the astrophysically interesting {beta}{sup +} decay modes of these isotopes. The results of these searches are presented and the implications for cosmic-ray physics are discussed.

  6. Loss of 51Cr, 54Mn, 57Co, 59Fe, 65Zn and 134Cs by the mussel Mytilus

    The loss of 51Cr, 54Mn, 57Co, 59Fe, 65Zn and 134Cs from naturally growing mussels (Mytilus edulis) was followed in a temperate estuarine environment -a Danish fjord - by individual whole-body countings on a Ge(Li) detector. The mussels accumulated the radionuclides in the laboratory from food and water and were brought back to their natural environment in small plastic cages. The loss curves for 12 animals from July - August 1979 until November 1979 (20-50C) were resolved in a slow compartment with 140-215 d biological half-life for 57Co, 54Mn, 51Cr and 59Fe, and 87 d for 65Zn, and a medium compartment with a biological half-life of 4-7 d for all nuclides. The long-lived compartments of 65Zn, 57Co and 54Mn were followed in four individual animals from August 1979 to August 1980. For 65Zn a seasonal effect was clearly demonstrated as the biological half-life was prolonged from 87 d during autumn 1979 to 347 d in the cold period (0-50C), whereas it decreased again during the summer of 1980. For 57Co and 54Mn the long-term excretion study revealed an extra-slow compartment, as the long half-life in the cold period (approximately 600 d) persisted during the summer of 1980. This is explained by association with the shell. (author)

  7. Development of irradiator {sup 60}Co sources

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

    2011-07-01

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

  8. Development of irradiator 60Co sources

    According to a recent report by the International Agency for Research on Cancer (IARC) / WHO (2008-2010), the global impact of cancer more than doubled in 30 years. In this report, it was estimated that occurred about 12 million new cancer cases and 7 million deaths. In Brazil in 2010, with estimates for the year 2011, point to the occurrence of 489,270 new cases of cancer. Among the possibilities for cancer treatment, radiotherapy is one of the most important therapeutic and resources used to combat it. However, inherent complications of treatment can occur such as tiredness, loss of appetite, radiodermatitis and in more extreme cases late radionecrosis. In order to reproduce a point of radionecrosis in the vicinity of radiodermatitis to mimic these effects in animals, producing a model for assessment of tissue repair, we propose the setting up of an irradiator source of collimated 60Co. The development of was based on 11 sources of 60Co with 1 mm thickness that were inserted by inference in stainless steel 'gate-source' screw (patent pending) and later adjusted in a cross-shaped arrangement reinforced so that the beam radiation is directed to a target point, saving for other regions around this target point. The main use of this irradiator with sources of 60Co is just one cause radionecrosis point (target point) of approximately 5 mm2 with a surrounding and adjacent area of radiodermatitis around about 8 to 10 mm2 in laboratory animals for subsequent coating with epidermal-dermal matrix populated by a cell culture of human fibroblasts, keratinocytes and mesenchymal stem cells. With that said, its use will be valuable for evaluation of curative treatments against the bone and radionecrosis or palliative treatment rather than as it is currently assumed. (author)

  9. Loss of 60 Co, 134 Cs and 137 Cs during the leaching test in the conditioned ion exchanger block

    The goal of this work is the study on immobilization of spent ion exchangers during the treatment of liquid radioactive wastes from Decontamination Center as a monolithic block, so that the safety of the environment be ensured during final disposal, according to international standards, all along the required time for radionuclide decay until an acceptable level is attained. The spent resin contains a lot of radionuclides (54 Mn, 57 Co, 58 Co, 60 Co, 134 Cs and 137 Cs) requiring the finding of a matrix suitable for all these radionuclides. As a result of experiments performed on the simulated waste containing the same radionuclides (immobilization in cement, bitumen and organic polymers), it was determined that the most suitable matrix is industrial bitumen, I 60-70, made in Romania. (authors)

  10. Measurement of Ca channel activity of isolated adult rat heart cells using 54Mn

    Isolated adult rat heart cells incubated with 5 microM Mn in a medium with 1 mM Ca showed a rapid phase of Mn binding plus a slow phase of Mn uptake. The rapid phase was extracellular binding, as judged by its temperature-insensitive removal by ethylene glycol bis(beta-aminoethyl ether) N, N'-tetraacetic acid. The slow linear phase represented cellular uptake, as judged by its release with digitonin plus the ionophore A23187. Isoproterenol increased the linear rate of Mn uptake and induced spontaneous beating activity in some cells. Both effects were inhibited by nitrendipine. Electrical stimulation of the cells in suspension increased the linear rate of cellular Mn uptake. The increase was potentiated by isoproterenol, and inhibited by nitrendipine or verapamil. Stimulation-dependent Mn uptake (per milligram protein) was greater for cells from 5- to 6-week-old rats than for 8- to 9-month-old female retired breeder rats, in the presence of isoproterenol. Ryanodine increased the stimulation-dependent Mn uptake in the presence of isoproterenol, but not in its absence. We conclude: (i) that cellular uptake of 54Mn is a good probe of Ca channel function; (ii) that isoproterenol promotes Mn influx by the channel in isolated heart cells; (iii) that cells from young rats (5-6 weeks) have a higher beta-adrenergically induced Ca channel activity than cells from mature rats (8-9 months); and (iv) that ryanodine promotes Ca channel activity (perhaps indirectly) in the presence of isoproterenol

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

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

    2003-07-01

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

  12. Vehicle mobile 60Co container inspection system

    This paper presents a mobile 60Co container inspection system (CIS) and its performance. With all devices including industrial 60Co source, high sensitive gas-ionized array detector, image treatment and control system, inspection driving device on a vehicle, the vehicle mobile CIS has advantages of high agility and climate resistance, and it can complete emergent inspection. The mobile CIS contains equipment-vehicle and control-vehicle. Equipment-vehicle and object-container are still, while a folding detector gantry is moving through a folding rail on the equipment-vehicle and completes the inspection. the mobile CIS has the inspection characteristics similar to the fixed system and it can be used in worse circumstances. Its CI (Contrast Indicator) and IQI (Image Quality Indicator) for 100 mm steel plate attain to 0.5% and 2.5% respectively, and the SP (Space Penetration) is about 240 mm (Fe). Maximum dose per scanning is about 5 μGy, scanning speed is varied from 6 to 18 m/min, and maximum transformational speed is 90 km/h

  13. Accumulation of radioactive corrosion products on steel surfaces of VVER-type nuclear reactors. II. 60Co

    In the case of intact fuel claddings, the predominant source of radioactivity in the primary circuits of water-cooled nuclear reactors is the activation of corrosion products in the core. The most important corrosion product radionuclides in the primary coolant of pressurized water reactors (PWRs) are 60Co, 58Co, 51Cr, 54Mn, 59Fe (as well as 110mAg in some Soviet-made VVER-type reactor). The second part of this series is focused on the complex studies of the formation and build-up of 60Co-containing species on an austenitic stainless steel type 08X18H10T (GOST 5632-61) and magnetite-covered carbon steel often to be used in Soviet-planned VVERs. The kinetics and mechanism of the cobalt accumulation were studied by a combination (coupling) of an in situ radiotracer method and voltammetry in a model solution of the primary circuit coolant. In addition, independent techniques such as X-ray photoelectron spectroscopic (XPS) and ICP-OES are also used to analyze the chemical state of Co species in the passive layer formed on stainless steel as well as the chemical composition of model solution. The experimental results have revealed that: (i) The passive behavior of the austenitic stainless steel at open-circuit conditions, the slightly alkaline pH and the reducing water chemistry can be considered to be optimal to minimize the 60Co contamination. (ii) The highly potential dependent deposition of various Co-oxides at E>1.10 V (vs. RHE) offers a unique possibility to elaborate a novel electrochemical method for the decrease or removal of cobalt traces from borate-containing coolants contaminated with 60Co and/or 58Co radionuclides

  14. Time-dependent transfer of 137Cs, 85Sr and 65Zn to earthworms in highly contaminated soils.

    Keum, Dong-Kwon; Jun, In; Lim, Kwang-Muk; Choi, Yong-Ho; Howard, Brenda J

    2013-12-01

    The transfer characteristics of (137)Cs, (85)Sr and (65)Zn to earthworms (Eisenia andrei) in soils with different amounts of the radionuclides have been investigated. The time-dependent whole-body concentration ratios (CR) were derived for worms in artificially contaminated soils with three different activity concentrations. Two parameters of a first order kinetic model, the equilibrium concentration ratio (CR(eq)) and the effective loss rate constant (k), were estimated by a comparison of experimental CR results with model predictions. The estimated CR(eq) (Bq/kg fresh worm per Bq/kg dry soil) ranged from 3.9 × 10(-4) to 4.1 × 10(-3) for (137)Cs, 1.39 × 10(-3) to 2.94 × 10(-2) for (85)Sr, and 1.39 × 10(-3) to 5.0 × 10(-2) for (65)Zn, and consistently decreased with increasing soil activity concentration but the trend was not statistically significant. The CR(eq) for (137)Cs was one to two orders of magnitude lower than previously reported CR(wo-soil) values (based on field data with much less contaminated soil), that for (85)Sr was comparable with other reported values and for (65)Zn was less two to three orders of magnitude lower than CR(wo-soil) values for stable zinc. The estimated k (d(-1)) values ranged from 9 × 10(-2) to 1.4 × 10(-1) for (137)Cs, 7 × 10(-2) to 2 × 10(-1) for (85)Sr, and 6 × 10(-2) to 1.8 × 10(-1) for (65)Zn, and did not show a relationship with soil activity concentration. The effect of CR(eq) on the total dose rate was insignificant for (137)Cs or (65)Zn because external dose rates to the soil dwelling earthworms due to these radionuclides were much greater than the internal dose rate. In contrast, the total dose from (90)Sr was determined by the internal dose rate and therefore proportional to the CR(eq). PMID:22948029

  15. Contamination of Chinese cabbage with 85Sr, 103Ru and 134Cs related to time of foliar application

    A solution containing 85Sr, 103Ru and 134Cs was applied to Chinese cabbage in a greenhouse via foliar spraying at 5 different times during its growth. Interception of the applied activity by plant showed no difference among radionuclides and increased with decreasing time interval between application and harvest. The maximum interception factor observed was 0.87. Percentages of the intercepted activity remaining in the whole leaves at harvest varied 16-58 % for 85Sr, 15-73 % for 103Ru and 33-64 % for 134Cs, with application time and those for the inner leaves (without 6 outmost leaves) varied 2-35 %, 0.4-46 % and 14-40 %, respectively. It was demonstrated that rain plays an important role in weathering loss of the activity. Tying the upper end of the plant prior to the last application lowered interception and remaining activity in the inner leaves by factors of 3-4. Present results can be referred to in predicting the radionuclide concentration in Chinese cabbage and deciding counter-measures at the time of an accidental release from the nuclear installation

  16. Accumulation and excretion of 60Co by marine organisms

    The biological half-life of 60Co accumulated from seawater by marine fish was 20-50 days. It was slightly longer in the liver and muscles than in the whole body. Feed including natural feed organisms contributed more to the total body burden of 60Co than environmental waters. The total body burden of 60Co via feed varied according to the organism species, kinds of feed and the root of incorporation. Transfer ratio of 60Co from the water into the organisms was higher than that from the marine sediments having high affinity of Co into the organisms. The elevated water temperature promoted the biological activity, resulting in the increased bioaccumulation of radioactive Co. Concentration coefficients of 60Co by mollusca and seaweeds were generally high. In particular, organic 60Co was more likely to be accumulated than inorganic 60Co. The biological half-life of organic 60Co was longer than inorganic 60Co in mollusca, while it was the same as or shorter than inorganic 60Co in the other organisms. (Namekawa, K.)

  17. Foliar and root uptake of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn in processing tomato plants (Lycopersicon esculentum Mill.)

    Brambilla, M. E-mail: radlab@pc.unicatt.it; Fortunati, P.; Carini, F

    2002-07-01

    The results of an experimental study on the behaviour of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn in processing tomato plants grown in peat substrate are presented. Plants were contaminated by wet deposition of {sup 134}Cs, {sup 85}Sr and {sup 65}Zn, either by sprinkling the above ground part at two phenological stages or by administering {sup 134}Cs, {sup 85}Sr and {sup 65}Zn to the soil. The plants contaminated at the second phenological stage intercepted 38.3% less than those contaminated at the first stage, although leaf area increased by more than double. Transfer coefficients from peat soil to ripe fruit for {sup 134}Cs are significantly higher than those for {sup 85}Sr and {sup 65}Zn. Leaf to fruit transfer coefficients for {sup 134}Cs are one order of magnitude higher than for {sup 65}Zn and two orders higher than for {sup 85}Sr. Only when deposition affects fruits, as at the second phenological stage, are transfer coefficients to fruits similar for the three radionuclides.

  18. Transfer of 60Co from midwater squid to sperm whales

    Sperm whales are notable squid-eaters. They feed mainly on medium to large-sized cephalopods at midwater levels and defecate near the surface. This suggests the existence of an upward transport of 60Co by sperm whales from the mesopelagic zone (150-1,200m). To elucidate this squid-whale route for this artificial radionuclide, 60Co content was determined in squid and in predator whales captured by commercial whaling. In the Cephalopoda livers 60Co levels of 30-500 mBq kg-1 wet were found and in the viscera of Odontoceti (toothed whales) 15-40 mBq kg-1 wet. About 0.3% of 60Co ingested was estimated to be retained in a 23-year-old male sperm whale. In the livers of Bryde's whales, 60Co levels of 40-80 mBq kg-1 wet were detected, but not in euphausiids and sardines, their possible prey. The level of Co in sperm whales was nearly the same as in Bryde's whales. Specific radioactivity 60Co/59Co in mBq μg-1 was several times higher in sperm whale (1.1-1.6) than in cephalopods (0.19-0.77). Eating prey with a high content of 60Co in the 1960's may have contributed to the present body burden in sperm whales with a long-life span. However, the origin of 60Co in Bryde's whales is unknown. (author)

  19. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (orthoptera: blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    The rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum) are described when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. The authors did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. The results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr, which was lost by defecation

  20. Bioelimination of 51Cr and 85Sr by cockroaches, Gromphadorhina portentosa (Orthoptera: Blaberidae), as affected by mites, Gromphadorholaelaps schaeferi (parasitiformes: laelapidae)

    This paper describes rates of Chromium-51 and Strontium-85 assimilation and bioelimination by the hissing cockroach, Gromphadorhina portentosa (Schaum), when the symbiotic mite, Gromphadorholaelaps schaeferi Till, was present or removed. Mite-infested cockroaches had significantly higher rates of 51Cr elimination relative to mite-free cockroaches, implying more rapid gut clearance times. We did not find a significant mite effect on 85Sr elimination by the host, but mite effects could have been masked by the apparently unique process of nutrient assimilation and elimination by G. portentosa. Conventional models of radioactive tracer bioelimination predict a rapid initial loss of tracer due to gut clearance, followed by a slower loss due to excretion of assimilated tracer. Our results indicated that assimilated 85Sr was eliminated earlier than unassimilated 85Sr was lost by defecation

  1. Research and construction of 60Co container inspection system

    The author presents a special kind of container inspection system, in which the radiation source is a 60Co industrial radiography source of 100-300 Ci. By the adoption of special high sensitivity array detector and other technical solutions, this 60Co container inspection system possesses nice properties. Its 'image quality indicator (IQI)' and 'contrast indicator (CI)' for 100 mm steel plate are equal to 0.7% and 2.5% respectively. Its 'steel penetration (SP)' is about 240 mm. The 60Co container inspection system is much cheaper and more reliable than the accelerator inspection system, and the area for its installation and operation is much smaller. The 'Steel Penetration (SP)' of 60Co system is much higher than that of X-ray machine inspection system. The another merit of 60Co system is the feasibility of designing and constructing a movable type

  2. Optimisation by mathematical modeling of physicochemical characteristics of concrete containers in radioactive waste management

    Plećaš Ilija

    2013-01-01

    Full Text Available A method for obtaining an optimal concrete container composition used for storing radioactive waste from nuclear power plants is developed. It is applied to the radionuclides 60Co, 137Cs, 85Sr, and 54Mn. A set of recipes for concrete composition leading to an optimal solution is given.

  3. Investigation of the transfer of 90Sr, 137Cs, 60Co, and 54Mn from soil to plant, and of the main soil parameters that have influence on the transfer process

    In lysimetric field experiments with 2 soil types most common in the Federal Republic of Germany the effects of a continuous contamination as well as of a temporary contamination of the soil caused by a possible accident were simulated to allow forecastings on the resorption of radionuclides by farm plants. Parallel pot experiments (8 kg of soil) in greenhouses and in the field and small pot experiments under reproducible climatic chamber conditions were to examine wether or not transfer data from laboratory and pot experiments can be applied to field conditions. In addition to this, soil types representative according to soil mapping were taken from the locations of the nuclear power plants Biblis and Stade, and their properties were determined. In large-scale comparative pot experiments the relative transfer factors were determined. (orig./DG)

  4. Areal distribution of 60Co, 137Cs, and 90Sr in streambed gravels of White Oak Creek Watershed, Oak Ridge, Tennessee

    The concentrations of 90Sr, 60Co, and 137Cs in streambed gravels from contaminated drainages in White Oak Creek Watershed were determined. Methods to determine the relative contributions of various sources to the total discharge from the watershed were developed. Principal sources of 90Sr were: ORNL plant effluents (50%), leaching from solid waste disposal area (SWDA) 4 (30%), and leaching from SWDA 5 (10%). Minor sources included SWDA 3, the Molten Salt Reactor Facility, and intermediate-level liquid waste pit 1 with each representing 4% or less of the total basin discharge. The cooling water effluent from the High-Flux Isotope Reactor was the dominant source of 60Co contamination in the watershed. ORNL plant effluents accounted for almost all the 137Cs discharge from White Oak Creek basin. Downstream radionuclide concentrations were constant until significant dilution by other tributaries occurred. Any future activities giving rise to additional contamination can now be identified. Distribution coefficients between streambed gravels and streamwater for 85Sr, 60Co, and 137Cs were 50, 560, and 8460 ml/g, respectively. An abridged radiochemical fractionation developed for 90Sr was found to be as accurate and precise for these samples as the standard 90Sr method above levels of 2 dpm/g

  5. Radioecological studies of 90Sr in limnological ecosystems. Accumulation and excretion of 85Sr in goldfish, Carassius auratus auratus, rearing in the radioactive freshwater

    Accumulation and excretion of 85Sr in goldfish, Carassius auratus auratus, rearing in the radioactive freshwater were investigated in order to elucidate the accumulation mechanism of 90Sr in naturally living fishes. The accumulation of 85Sr, expressed in concentration ratio (CR) between fish and water, in whole body of the fish showed a increasing tendency with the rearing time, and the CR value reached 5.4±0.4 (mean±standard error) at 7th day. On the other hand, the excretion of 85Sr, expressed in retention rate, in whole body rearing in non-radioactive freshwater following the accumulation above the 7 days demonstrated a rapid decreasing at first few days, and then a gradual decreasing tendency indicating the biological half lives about 4 days and 205 days, respectively. The retention rate resulted in nearly 75% of initial radioactivity, i.e. 25% of excretion, at 25th day. As for the tissues and organs, the CR values of 85Sr reared in the radioactive freshwater for 7 days were 62.3 (vertebra: bone), 31.1 (scale), 12.5 (gill), 0.6 (viscera) and 0.4 (muscle). On the other hand, higher excretion was found in the viscera and the muscle than that in the bone, the scale and the gill. It is so suggested that the metabolic turnover rate of this radionuclide is different among these tissues and organs particularly characterizing higher accumulation and lower excretion in the vertebra (bone) and scale. (author)

  6. 60Co retention by a freshwater planktonic alga Scenedesmus obliquus

    This paper presents the results of various decontamination experiments aimed at evaluating 60Co retention by Scenedesmus obliquus, and the respective role played by absorption and adsorption in the contamination of the alga by this radionuclide. The physiological condition of cells is not involved in radiocobalt desorption, which seems to indicate that the phenomenon is of a passive nature. When the precontamination time is extended, the proportion of adsorbed 60Co decreases, and the final percentage of radionuclide retained increases. These results are confirmed by bringing cells into contact with a strong chelating agent. The elimination of 60Co in the presence of EDTA undergoes a sharp decrease which is correlated with the increase in the duration of the precontamination phase. The use of a weaker complexing agent, such as NaCl, leads to the hypothesis of there being 2 types of 60Co receptor on cell membranes. (author)

  7. Effect of hydrocortisone on total body calcium in rats. [/sup 47/Ca and /sup 85/Sr tracer techniques

    Yasumura, S.; Ellis, K.J.; Cohn, S.H.

    1976-11-01

    Administration of 5 mg. of hydrocortisone acetate to rats every other day for 2 weeks resulted in growth retardation and weight loss as indicated by body weights of experimental animals, which averaged 33 percent lower than those of the controls, and a significant decrease in the length of the tibiae and femurs (p less than 0.01 for treated vs controls). However, despite the smaller size of the treated animals, the values for total body calcium (TBCa) and the calcium in the tibia and femur did not differ significantly from control values. Thus, there was more calcium per unit length of bone, resulting in an increase in the skeletal density of treated rats. This finding was confirmed by x-ray examination of these bones. The net intestinal absorption of calcium (rate of initial entry) calculated from plasma levels following an oral and intravenous dose of /sup 47/Ca and /sup 85/Sr, respectively, was not significantly different in hydrocortisone-treated rats compared to controls. This would indicate that the rate of intestinal absorption of calcium is unimpaired despite the administration of massive doses of corticosteroids. When the animals were placed on a calcium-deficient diet, both TBCa and tibia and femur calcium levels were decreased. Subsequent administration of hydrocortisone did not alter the calcium values. The results of this study are compatible with the hypothesis that hydrocortisone promotes weight loss, retards growth, but inhibits the rate of bone resorption.

  8. A sorption study of 85Sr, 137Cs and 227Th onto glacial sand as part of an interlaboratory exercise

    A number of radionuclide batch sorption tests have been carried out on core material from boreholes on the BNFL Drigg site, Cumbria, as part of an intercomparison exercise with BNFL, Sellafield. This report describes the nature of the materials used, the method and the results of the BGS side of the interlaboratory exercise. Another report will describe the intercomparison. These experiments formed part of a wider programme of laboratory tests by BGS to ascertain the sorption properties of the Drigg sands and silts as an information base for designing artificial in-situ radionuclide migration experiments on site at Drigg. Three radionuclides were used, 85Sr, 137Cs, and 227Th. Interestingly, although sorption of strontium was about 15 times less than for thorium, the pattern of sorption as a function of borehole depth i.e. mineralogical composition, was very similar. Sorption of 137Cs was found to be non-linear, depending strongly on caesium concentration in the groundwater. Isotherm fits were used to determine the energy of sorption in the ion exchange process, the mechanism responsible for uptake. There is a need for a standard batch sorption method to be in common use. (author)

  9. Studies of radioactivity of vegetables: determination of transfer factors 85Sr and 134Cs in some vegetables

    The radioisotope uptake of potato and culinary dry bean was studied in field experiments on meadow soil enriched with vermiculite and humanite by artificial soil contamination. The isotope uptake from the soil was characterized by a transfer factor (TF). Based on the results of the potato experiment it was found that the TF value characterizing the 134Cs contamination of the crop, changed between 1.31 - 0.77*10-4 m2 (kg dry matter)-1 on high humus content soil (treated with humanite) and on soil treated with vermiculite, while it was 22-45 % higher in plants grown on the radioactive control plots. lt was 1.69*10-4 m2 (kg dry matter)2-1 in average. The TF values of 85Sr uptake of potato are several times higher than those of experiments treated by isotope 134Cs. The TF values fluctuated between 5.30-7.33*10-4 m2 (kg dry matter)-1 in soils treated with the additives, while on the plots with radioactive contamination it was 8.42*10-4 m2 (kg dry matter)-1. Based on the results of 134Cs studies of edible part of dry bean, it could be stated that after the soil contamination the TF value was 0.99*10-4 m2 (kg dry matter)-1 in average. According to the activity results of the experiments there was significant difference between the contamination of the plant parts. Refs. 6 (author)

  10. Treatment of boundary conditions in through-diffusion: A case study of (85)Sr(2+) diffusion in compacted illite.

    Glaus, M A; Aertsens, M; Maes, N; Van Laer, L; Van Loon, L R

    2015-01-01

    Valuable techniques to measure effective diffusion coefficients in porous media are an indispensable prerequisite for a proper understanding of the migration of chemical-toxic and radioactive micropollutants in the subsurface and geosphere. The present article discusses possible pitfalls and difficulties in the classical through-diffusion technique applied to situations where large diffusive fluxes of cations in compacted clay minerals or clay rocks occur. The results obtained from a benchmark study, in which the diffusion of (85)Sr(2+) tracer in compacted illite has been studied using different experimental techniques, are presented. It is shown that these techniques may yield valuable results provided that an appropriate model is used for numerical simulations. It is further shown that effective diffusion coefficients may be systematically underestimated when the concentration at the downstream boundary is not taken adequately into account in modelling, even for very low concentrations. A criterion is derived for quasi steady-state situations, by which it can be decided whether the simplifying assumption of a zero-concentration at the downstream boundary in through-diffusion is justified or not. The application of the criterion requires, however, knowledge of the effective diffusion coefficient of the clay sample. Such knowledge is often absent or only approximately available during the planning phase of a diffusion experiment. PMID:26004771

  11. Treatment of boundary conditions in through-diffusion: A case study of 85Sr2 + diffusion in compacted illite

    Glaus, M. A.; Aertsens, M.; Maes, N.; Van Laer, L.; Van Loon, L. R.

    2015-06-01

    Valuable techniques to measure effective diffusion coefficients in porous media are an indispensable prerequisite for a proper understanding of the migration of chemical-toxic and radioactive micropollutants in the subsurface and geosphere. The present article discusses possible pitfalls and difficulties in the classical through-diffusion technique applied to situations where large diffusive fluxes of cations in compacted clay minerals or clay rocks occur. The results obtained from a benchmark study, in which the diffusion of 85Sr2 + tracer in compacted illite has been studied using different experimental techniques, are presented. It is shown that these techniques may yield valuable results provided that an appropriate model is used for numerical simulations. It is further shown that effective diffusion coefficients may be systematically underestimated when the concentration at the downstream boundary is not taken adequately into account in modelling, even for very low concentrations. A criterion is derived for quasi steady-state situations, by which it can be decided whether the simplifying assumption of a zero-concentration at the downstream boundary in through-diffusion is justified or not. The application of the criterion requires, however, knowledge of the effective diffusion coefficient of the clay sample. Such knowledge is often absent or only approximately available during the planning phase of a diffusion experiment.

  12. Uptake and translocation of 54Mn and 65Zn applied on foliage and bark surfaces on balsam fir (Abies balsamea (L.) Mill.) seedlings

    Uptake and translocation of 54Mn and 65Zn in balsam fir [Abies balsamea (L.) Mill.] seedlings were studied with the radioisotopes applied directly on shoot or main-stem surfaces in a growth chamber. Concentration and distribution of the absorbed radioisotopes in different plant parts depended on distances between source (the application site) and sink (the rest of the seedling), as well as on tissue growth activity. Acidic wetness significantly enhanced radioisotope absorption. 54Mn and 65Zn were found to be concentrated primarily in 1-year old needles at the middle and top levels of the seedling crown. There were significant (P < 0.05) differences in accumulation (Bq g−1) between 54Mn and 65Zn in needles and twigs from foliar uptake. The absorption by seedlings (including the washed application shoot) 70 days after application was 24–32% of the remaining activities for 54Mn and 25–30% for 65Zn. Less than 1% of the absorbed isotopes was translocated from the bark application sites to other plant organs, whereas more than 54% of the activity absorbed at 1-year old shoots moved to the rest of the seedling. (author)

  13. A comparison of pdd for 60Co teletherapy units

    Although BJR supplement No 17 provides TAR and PDD tables for 60Co gamma rays, due to inherent differences hat exists among individual teletherapy machine and their source it is essential to measure TAR and PDD that are applicable for user's teletherapy unit. TAR and PDD values for different field sizes at 80 cm SSD, open field, gantry angle 0o, collimator angle 0o were determined in CIRUS 60Co teletherapy unit by ionization chamber NE2570/1B Farmer type. PDD for a standard field size 10 10 cm2, open field, gantry angle 0o,Collimate angle 0o were determined in MEDNIF FYC 2600H 60Co teletherapy unit by using ionization chamber RT101. That experimentally measured PDD values for both units were compared with published values in BJR supplement No 17. The experimentally measured values for CIRUS 60Co showed up to 0.8% deviation at maximum and that for MEDNIF 60Co showed up to 4.5% deviation at maximum. This study investigated the discrepancy between the BJR values and experimentally determined values for two teletherapy units in Nepal

  14. Concentration of 60Co by marine organisms through sediments

    Uptake of 60Co absorbed on sea sands by benthic marine organisms was observed in laboratory experiments, since the radioactive cobalt released from nuclear power plants or other establishments into coastal seawater trends to be absorbed on sea sediments and also various kinds of marine organisms live in bottom sediments. Few kinds of flatfishes (Limanda spp.) and shrimp (Trachypenaeus curvirostris) were reared in aquariums contained seawater and sea sands which were highly contaminated with 60Co previously, and whole body retention and distribution of radioactivity were measured on the organisms taken up from the aquariums occasionally by a scintillation counter. Uptake of 60Co from ingested sea sands was also observed on the flatfishes administrating the contaminated sands orally. Concentration of 60Co by the flatfishes reared in the sands was not significant while the shrimp showed high retention of the radioactivity. The food habit of shrimp which usually feeds on organic detritus with other small benthic organisms is different from that of flatfishes, one of the carnivorous, and considered to bring the difference on the pathway of radionuclides concentration. Assimilation of 60Co via the digestive tract of flatfishes through the sands was estimated as about 10 per cent of the administrated radioactivity. (auth.)

  15. On the Spirulina platensis - 60 Co2+ bioaccumulation system

    Radiochemical studies, IR spectrometry and electron microscopy studies have been carried out with the purpose of establishing the mechanisms involved in the bioaccumulation of 60 Co2+ in the blue alga Spirulina platensis. By measuring the radioactivity it was determined that, without ionic competition, an one week old culture of Spirulina platensis can retain up to 65% of the 60 Co2+ ions from a slightly radioactive solution. Sodium carbonate is involved in the mechanism of the bioaccumulation of these β + γ - radiocations (a phenomenon evidenced by IR spectrometry). Electronic microscopy studies point out that the compounds resulted from the interaction between the exopolysaccharides and 60 Co2+ disperse in the solution. Thus, even though the radiocobalt is completely blocked up in complex compounds, it is not completely retained on the surface and inside of the alga. (authors)

  16. Decontamination of fermented chicken feet by 60Co irradiation

    Fermented chicken feet was treated by 60Co irradiation, and the aerobic plate count, enumeration of coliforms, pathogens and TBARS value were measured during storage. The results showed that, aerobic plate count of all irradiated samples was lower than control, and enumeration of coliforms, and pathogens of Staphylococcus aureus, Shigella, Salmonella were not detected. TBARS value of all treatments was stable during 60 d storage. It could be concluded that 60Co irradiation of chicken feet was an effective method to prolong its shelf life. (authors)

  17. Dosimetric evaluation of Radiotherapy units wit 60Co

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services (60 Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of 60 Co radiotherapy units. (Author)

  18. Structure, non-stoichiometry and thermodynamic properties of Bi1.85Sr2Co1.85O7.7−δ ceramics

    Highlights: • Cobaltite Bi1.85Sr2Co1.85O7.7−δ was prepared and its structure was refined. • Oxygen non-stoichiometry of Bi1.85Sr2Co1.85O7.7−δ was determined by TG. • Thermodynamic properties were measured by PPMS, DSC and drop calorimetry. • The heat capacity was analyzed using combined Debye–Einstein model. - Abstract: The structure and oxygen non-stoichiometry of misfit layered cobaltite Bi1.85Sr2Co1.85O7.7−δ was determined by Rietveld analysis and by thermogravimetric measurements. The heat capacity and enthalpy increments of pseudo-ternary oxide Bi1.85Sr2Co1.85O7.7−δ was measured by the relaxation time method (PPMS) from 2 K to 256 K, by differential scanning calorimetry (DSC) from 258 K to 355 K and by the drop calorimetry from 573 K to 1153 K. Above room temperature the temperature dependence of the molar heat capacity in the form Cpm = (305.8 + 0.07325 · T − 4702536 · T−2) J K−1 mol−1 was derived by the least-squares method from the experimental data. The heat capacity was analyzed in terms of a combined Debye–Einstein model. The molar entropy Sm∘(298.15)=317.7 J mol−1 K−1 was evaluated from the low temperature heat capacity measurements

  19. Interface Resistance between FeCr Interconnects and La0.85Sr0.15Mn1.1O3

    Mikkelsen, Lars; Neufeld, Kai; Hendriksen, Peter Vang

    2009-01-01

    The long term oxidation behaviour and the electrical interface resistance between FeCr interconnects and La0,85Sr0,15Mn1,1O3 plates was studied by a DC four-point method in air at 750{degree sign}C for 10000 h. The tested FeCr alloys were: Crofer 22 APU, Sanergy HT, Plansee IT10, Plansee IT11...

  20. Metal-insulator transition in the spin-glass system La0.85Sr0.15CoO3

    Electrical resistivity measurements (20-300 K) show a metal-insulator transition in low-temperature-sintered samples of the spin-glass insulating composition La0.85Sr0.15CoO3. Insulating behaviour is observed only for samples sintered at high temperatures. The results can explain the widely differing electrical resistivity behaviour reported for different compositions in the La1-xSrxCoO3 system. (author). Letter-to-the-editor

  1. Comparative analysis of 60Co intensity-modulated radiation therapy

    Fox, Christopher; Romeijn, H. Edwin; Lynch, Bart; Men, Chunhua; Aleman, Dionne M.; Dempsey, James F.

    2008-06-01

    In this study, we perform a scientific comparative analysis of using 60Co beams in intensity-modulated radiation therapy (IMRT). In particular, we evaluate the treatment plan quality obtained with (i) 6 MV, 18 MV and 60Co IMRT; (ii) different numbers of static multileaf collimator (MLC) delivered 60Co beams and (iii) a helical tomotherapy 60Co beam geometry. We employ a convex fluence map optimization (FMO) model, which allows for the comparison of plan quality between different beam energies and configurations for a given case. A total of 25 clinical patient cases that each contain volumetric CT studies, primary and secondary delineated targets, and contoured structures were studied: 5 head-and-neck (H&N), 5 prostate, 5 central nervous system (CNS), 5 breast and 5 lung cases. The DICOM plan data were anonymized and exported to the University of Florida optimized radiation therapy (UFORT) treatment planning system. The FMO problem was solved for each case for 5-71 equidistant beams as well as a helical geometry for H&N, prostate, CNS and lung cases, and for 3-7 equidistant beams in the upper hemisphere for breast cases, all with 6 MV, 18 MV and 60Co dose models. In all cases, 95% of the target volumes received at least the prescribed dose with clinical sparing criteria for critical organs being met for all structures that were not wholly or partially contained within the target volume. Improvements in critical organ sparing were found with an increasing number of equidistant 60Co beams, yet were marginal above 9 beams for H&N, prostate, CNS and lung. Breast cases produced similar plans for 3-7 beams. A helical 60Co beam geometry achieved similar plan quality as static plans with 11 equidistant 60Co beams. Furthermore, 18 MV plans were initially found not to provide the same target coverage as 6 MV and 60Co plans; however, adjusting the trade-offs in the optimization model allowed equivalent target coverage for 18 MV. For plans with comparable target coverage

  2. Dosimetric evaluation of Radiotherapy units wit {sup 60}Co; Evaluacion dosimetrica de unidades de radioterapia con {sup 60}Co

    Leon, B. Salinas de; Tovar M, V.; Becerril V, A. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    2000-07-01

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services ({sup 60} Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of {sup 60} Co radiotherapy units. (Author)

  3. The data correction algorithms in 60Co train inspection system

    Because of the physical characteristics of the 60Co train inspection system and the application of high-speed data collection system based on current integral, the original images have been distorted in a certain degree. Authors investigate into the reasons why the distortion comes into being, and accordingly present the data correction algorithm

  4. Development of 60Co cargo train inspection system

    The author introduces the research and development of 60Co cargo train inspection system. With the use of radiography principle, every car image is acquired when the cargo train runs through the inspection channel. It is evaluated whether the cargo in car matches the corresponding customs declaration information with digital image processing techniques. The system has been installed in railway port at Manzhouli Customs

  5. The influence of antibiotics on the adsorption kinetics of 54-Mn and 59-Fe on suspended particles in river Elbe water

    Many pollutants in river water are mainly transported by suspended particles. It depends on many physical and chemical parameters how these pollutants are distributed between water and suspended particles. Much effort has been made for measuring this distribution. Our examination has dealt with the determination of influences on the adsorption kinetics of some metal ions from water to suspended particles. We used 54-MnCl2 and 59-FeCl3 as tracers. (orig.)

  6. Radiolytic degradation scheme for 60Co-irradiated corticosteroids

    Kane, M.P.; Tsuji, K.

    1983-01-01

    The cobalt 60 radiolytic degradation products have been identified in the following corticosteroids: cortisone, cortisone acetate, hydrocortisone, hydrocortisone acetate, hydrocortisone sodium succinate, isoflupredone acetate, methylprednisolone, methylprednisolone acetate, prednisolone, prednisolone acetate, and prednisone. Two major types of degradation processes have been identified: loss of the corticoid side chain on the D-ring to produce the C-17 ketone and conversion of the C-11 alcohol, if present, to the C-11 ketone. Minor degradation products derived from other changes affecting the side chain are also identified in several corticosteroids. These compounds are frequently associated in corticosteroids as process impurities or degradation compounds. No new radiolytic compounds unique to 60Co-irradiation have been found. The majority of corticosteroids have been shown to be stable to 60Co-irradiation. The rates of radiolytic degradation ranged from 0.2 to 1.4%/Mrad.

  7. Distribution of 60Co in steel samples from Hiroshima

    This paper describes ultra low-level gamma-ray spectrometry measurements of the 60Co activity distribution inside one 52 mm and one 41 mm thick steel sample. The samples had been exposed to the Hiroshima atomic bomb and were from the Aioi bridge and the Yokogawa bridge. Both samples were measured in a recent study aiming to back up model calculation of Hiroshima dosimetry. The 60Co activity distributions found in this study support the assumptions made in the previous study. - Highlights: ► The Co-60 activity distribution within two thick steel samples from Hiroshima was measured. ► Activities down to 0.1 mBq were measured using underground gamma-ray spectrometry systems. ► The distribution confirms assumptions made in previous studies. ► Further support to the Dosimetry System 02 is provided.

  8. Software program in 60Co container inspection system

    The author analyzes the features and limits of the present container inspection system in the world, and puts forward a new inspection apparatus with 60Co as radiography source and microcomputer network to complete inspecting image's acquisition, transmission, assignment, process, inspection, control and information management etc. The author emphasizes on task analysis and technical request in the system, discusses the software running environment and developing environment, the tasks logical division, and makes clear the design's idea, object and style

  9. Effects of 60Co administration on early placental cells

    The effects of 60Co administration on early placental cells were studied. Placental tissue and embryo obtained by induced abortion (6 - 13 weeks gestational age) were placed in the minimal essential medium (MEM) and irradiated with various doses of 60Co. After irradiation, the villi were cultured in a CO2 incubater at 370C. Cell growth process was observed every day with the phase-contrast microscope. Between 1 and 5 days epitheloid cells were dominant, but from about 7th day on fibroblastic cells dominated the culture. In placental tissue irradiated with 100, 200, 500 rad, fibroblastic cells began to grow earlier than in non-treated. Over 3000 rad 60Co inhibited the growth of cells and a culture was impossible. For each dose, the tissue was incubated for various periods of time, exposed to tritiated thymidine for the last hour and autoradiogram was prepared by the dipping method. The labeling index of irradiated trophoblasts showed a significant decrease compared with controls. A chromosome study was made in irradiated in vitro cell lines of fetus and placenta. There was no significant difference between the two cell lines concerning the frequency of chromosome aberration, which tended to increase as the chromosome becomes longer. It is concluded that the trophoblast is highly radiosensitive and that irradiation early in pregnancy may damage DNA synthesis in the trophoblast, and induce abortion. (author)

  10. Fabrication, qualification and calibration of 60 Co sealed sources

    Argentina produces about 5% of the worldwide production of 60 Co radioisotope (3,000,000 of Ci/year) whose main application is the radio sterilization of disposable medical consumables, the radiating therapy, and the food preservation for human consumption. From 1985 to the present 56,000,000 Ci were produced. At first all the generated 60 Co was exported in bulk to the sealed sources producers, but now the local production of sources has been consolidated and 100% of the 60 Co is used to manufacture sealed sources. That is a successful production of around 400 sealed sources, 70% of which have been made during the last three years. Mainly 95% of the sealed sources for industrial applications were exported to the United States, Europe, Japan and China. These countries are the main importation centers. The local and regional markets are the most important users of the sources for x-ray radiography. At present 8% of the total sources that were produced are used as x-ray sources. The present work describes the development of the sequence of manufacture of simple and double encapsulated radioactive sources, which includes the in-process inspection, the certification of the sealed sources according the designation E66646 (5,7) of the ISO 2919:1999(E) standard and a statistical quality control analysis of the penetration of the seam weld of the end caps. (author)

  11. Local blood flow, 99mTc-MDP retention and 85Sr retention in femur and tibia of rats: local differentiation and inter-relations

    Variations were studied in blood flow, retention of 99mTc-methylenediphosphonate (MDP) and 85SrCl2 in the femur and in the tibia of rats. The objective of the experiments was to assert local differences in the blood flow and similar patterns, if any, in the retention of both radionuclides in the long bones of the hind leg of the rat. The results showed a significant differentiation in the blood flow in both the femur and the tibia, with high levels in the growth-active parts and low levels in the diaphyses. The lowest levels were found in the distal terminal part of the tibia. A marked similarity was observed in the patterns of blood flow distribution and 99mTc-MDP retention, this both in quality and in quantity. The retention was found to be significantly higher in the growth-active parts, i.e., in the distal methaphysis of the femur and in the proximal metaphysis os the tibia, while several times lower values were found for the other parts of the bones. However, age dependence was observed in the distribution and some other factors may play a role. Thus, a quantitative relationship was excluded. The initial retention of 85Sr showed a similar pattern with high levels in the growth-active parts of the bones. However, the values quickly decreased with time, which may have been associated with the metabolism of minerals. In the other parts of the bones, the differences in 85Sr retention were insignificant. It is believed that local blood flow may affect the behavior of both osteotropic materials as a common regulating factor. (L.O.). 3 figs., 1 tab., 22 refs

  12. ESR phase competition study of Pr0.5(Ca0.85Sr0.15)0.5MnO3

    We report an electron spin resonance (ESR) study of the competing phases at the crossover from localized to itinerant behaviour on the polycrystalline Pr0.5(Ca0.85Sr0.15)0.5MnO3 compounds. From the temperature dependence of the ESR intensity, we derived the transition temperatures to charge order (TCO=230 K), and antiferromagnetic (TN=150 K) states. In addition, at T<200 K, a ferromagnetic minority phase was found, that coexists with the paramagnetic and antiferromagnetic phases. We perform simulations of the ESR spectra that reproduce the behaviour found at different temperatures

  13. Optical properties of La0.85(Sr,Ba)0.15MnO3 single crystals in infrared spectral range

    The optical spectra (reflection and absorption) of La0.85Sr0.15MnO3 (LSM) and La0.85Ba0.15MnO3 (LBM) single crystals are studied in the infrared range, where the interaction of charge carriers with light dominates. In paramagnetic state, the small lattice polarons dominate the optical properties of LBM single crystal but in the optical spectra of LSM crystal the polarons manifest themselves weaker. The activation energy of polaron hopping E a is determined

  14. Study of La1.85Sr0.15CuO4 superconducting phase synthesis by ion beam mixtures

    In order to synthesize the superconducting phase La1.85Sr0.15CuO4 powders of La2O3, CuO, and SrCO3 are usually ground together and annealed at high temperature. We studied another original way: the possibility of using accelerated ions in order to mix the atomic species of thin multilayered films of La(OH)3, Sr(OH)2, and Cu and to synthesize crystalline La1.85Sr0.15CuO4. In the first part of this work, we present a review of ion beam mixing in relation to particle-matter interactions. The second part is devoted to a description of our implementation of ion beam analysis techniques and to the determination of experimental uncertainties. The use of X ray diffraction in order to study the films structures is also presented. In the third part, we show that irradiation does not generally lead to very large mixing ratios in our films but induces partial or total desorption of O and H. This is presumably related to the thermodynamic properties of the various coexisting ceramic phases. We do however find evidence of cristalline La2CuO4 formation under irradiation for a specific multilayer configuration. The critical parameters of this method are shown to be the initial configuration of the multilayer and the irradiation temperature. 64 refs

  15. Processing and properties of superconducting La[sub 1. 85]Sr[sub 0. 15]CuO[sub 4] powder by double-step calcining

    Alconchel, Silvia A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina)); Ulla, Maria A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina)); Lombardo, Eduardo A. (Instituto de Investigaciones en Catalisis y Petroquimica, INCAPE (FIQ,UNL-CONICET), Santiago del Estero 2829, 3000 Santa Fe (Argentina))

    1994-11-01

    The preparation of single-phase tetragonal La[sub 1.85]Sr[sub 0.15]CuO[sub 4] powder using two consecutive thermal cycles is described. Freeze-dried or evaporated lanthanum, strontium and copper acetates were used as precursor materials. The effect of the reaction temperature (in the second cycle) on the characteristics of high-T[sub c] superconductor was studied by X-ray diffraction, idometric titration, temperature-programmed reduction, scanning electron microscopy and electrical resistivity measurements.Monophasic powder was obtained by reacting freeze-dried precursors at a final temperature of 1253 K for 8 h. The reduction of La[sub 1.85]Sr[sub 0.15]CuO[sub 4] occurred in one step at 744 K. Thermal treatments in either N[sub 2] or O[sub 2] strongly affect the hydrogen consumption profile.Monophasic sintered pellets were obtained from freeze-dried precursors calcined at final temperatures between 973 and 1253 K. The microstructure of sintered bodies was characterized by equiaxed grains of about 0.5 [mu]m. Evaporated precursors did not yield powder or single phase sintered material, and gave a grain size of about 1 [mu]m. The critical temperature ranged between 36.7 and 37.3 K and [Delta]T[sub c] between 2.8 and 4.8 K. ((orig.))

  16. Sorption and desorption of 85Sr, 125I and 152,154Eu on columns of crushed crystalline rocks under dynamic conditions

    A comparison of transport parameters from breakthrough curves has shown that the transport of 85Sr is retarded moderately and increases in order: diorite-I + sorption appears to be reversible and 85Sr can be desorbed (displaced) from the crushed rocks with groundwater. Sorption of l25I- is almost negligible and radioiodide was transported by groundwater with any distinct retardation. Retardation of l52,154Eu3+ is extensive due to its very strong sorption by rocks. Desorption with groundwater is little effective, but Eu can be displaced with an acid mixture almost completely, the retardation coefficient increasing in order: granite ≅ gabbro < tonalite < diorite-II < diorite-I. It is reasonable to assume that acid rains stimulate significantly mobilization of the Sr and Eu (Am) radionuclides. The integral form of an 1-D ADE equation proved useful in fitting the experimental values and modelling the breakthrough curves. A good agreement was obtained between the observed and calculated values by using a simple theoretical relation. The static method was also found to give considerably higher values of the distribution and retardation coefficients of radionuclides in crushed crystalline rocks

  17. Determination of 60Co sorption in natural clinoptilolite

    It was studied the clinoptilolite behavior coming from a deposit in Taxco, Guerrero in hydration and stabilization conditions with sodium for determining its sorption properties. The ion exchange process was carried out through gamma spectrometry using a CoCl2 solution marked with 60 Co at p H 6.5 in different contact times. It was observed a maximum sorption of 0.408 m eq Co+2/g mineral, from 0.314 m eq Co+2/g mineral correspond at ion exchange. (Author)

  18. Sorption of 60 Co in natural zeolite (clinoptilolite)

    A Mexican zeolite (clinoptilolite) from Taxco, Guerrero, was partially stabilized with sodium cations. Radioactive Cobalt (60 Co) was used to study the Co 2+ sorption in the stabilized zeolite (Na+). It was found that sorption in general does not favour the diffusion of cobalt between framework, it explains because of it is a natural zeolite and its composition heterogeneous decrease its exchange capacity by the generated competence to the existence other type of exchange ions. The cobalt retention reached the highest level, around 0.408 m eq Co2+ /g in the Na-Clinoptilolite. The crystallinity of the aluminosilicates was maintained during experiments, it was verified by XRD patterns. (Author)

  19. Application of 65Zn and 54Mn isotopic dilution for evaluation of available soil manganese and zinc fractions in Western Slovak region

    This paper mapped the accumulation and availability of zinc and manganese in young wheatgrass plants (Triticum aestivum L.) grown in typical agricultural soil (Calcic Phaenozem) of Western Slovakia. For estimation of zinc and manganese availability the biological, chemical and radiochemical methods with application of 65Zn and 54Mn isotopic dilution and gamma spectrometry were used. Radiochemical and statistical analyses of obtained metal concentrations in plant tissues, soil samples, soil extracts and isotopically exchangeable fractions (E-values) confirmed the significant correlations mainly between wheatgrass concentrations and E-values. Results showed the important role of isotopic dilution methods for quantification of available metal fractions. (author)

  20. Influence of plant roots upon the mobility of radionuclides in soil, with respect to location of contamination below the surface

    The movement of 85Sr, 137Cs, 54Mn and 60Co in the 50 cm soil profile was studied with and without the presence of plant roots (triticum aestivum) in order to investigate the influence of roots and depth contamination upon the migration of radionuclides. The water table was maintained manually at 3 cm from the bottom. The physicochemical characteristics (Eh Fe-2, NH4+, pH and moisture content) as well as the total and extractable radioactivity were investigated. In the discrete contamination, where the location of contamination varied within the soil profile (0-5, 25-30 or 45-50 cm from the top), the influence of location upon the movement of these radionuclides was also studied. It was found that the changes in the soil physicochemical characteristics influenced the mobility of the four radionuclides. The extractability of 54Mn and 60Co was significantly increased in the reducing region of the soil, whereas that of 85Sr, 137Cs was not. Plant roots excerted significant effects upon the soil characteristics, via, reducing the Eh pH and moisture content of the soil; increasing the extractability of both 54Mn and 60Co from the depth of 35 cm downwards. Radionuclide migration occurred via physicochemical and biological transport. The biological transport via plant roots was of particular importance for 137Cs. Location of contamination had a significant influence upon the mobility of radionuclides. The migration of radionuclides was in the sequence of contamination in middle > bottom > top. The degree of the influence varied with radionuclides concerned. In the top layer contamination, the rank of the migration from the contamination layers, on the other hand 54Mn, 60Co and 137Cs were more mobile and the movement was: 85Sr54Mn60Co > 137Cs. In the middle and bottom contamination layers, on the other hand, 54Mn and 60Co and 137Cs were more mobile and the movement was 85Sr54Mn60Co ∼ 137Cs. (author)

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

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

    2015-07-15

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

  2. Study of 60Co as gamma source in backscatter gamma densitometers

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

  3. Planning a 60Co Irradiation Facility for Fruit Preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  4. Planning a 60Co irradiation facility for fruit preservation

    A conceptual design for a conveyor system is proposed for use in fruit irradiation. The seasonal nature of the fruit harvest requires that the 60Co source inventory should be sufficient to meet the demand at peak season, but this would be excessive at the beginning and towards the end of the harvest. Because of the short crop period the possibility of other irradiation services should be exploited to ensure full utilization of the facility. For successful extension of fruit shelf-life rigid practices in pre-irradiation treatment are essential and careful packaging is indispensable to the operation of the irradiator. Based on the time required for construction and equipment supply, a period of 18 months should be assumed for completion of the project. (author)

  5. Fieldbus: technology application in a 60Co sterilization plant

    Process instrumentation was made by pressure signals in the 1940s. In the 1960s, 4-20 mA analogue signals were introduced. The development of digital processors in the 1970s sparked the use of computers to monitor and control instruments from a central point. In the 1980s smart sensors were developed and implemented in digital control, microprocessor environments. Fieldbus is a generic-term that describes a new digital communications network. The network is a digital, bi-directional, multidrop, serial-bus, and communications network used to link isolated field devices, such as controllers, transducers, actuators and sensors. Fieldbus technology may improve quality, reduce costs and increase efficiency because information is transmitted digitally without analog to digital or digital to analog converters, which also minimizes hardware errors. Fieldbus communication is based on two-wire communication, interconnecting all the components in the system. This paper introduces Fieldbus technology in a 60Co sterilization plant

  6. Retention of ingested (60)Co by a freshwater fish

    The experiment was carried out on a group of 10 carp receiving the soft tissue of previously contaminated lymnaea as food. Ingestion by carp of 45 daily rations, distributed over a 63-day period, resulted in a low retention of the radionuclide. The contamination kinetics showed that the steady state should be reached after only 225 days. The 60Co transfer factor was approximately 10−2 and the retention factor about 3.3 x 10−3. During the depuration phase, radiocobalt elimination by the carp developed in accordance with an exponential model based on the existence of two biological half-lives of 1.5 and 35 days which indicate a high Co turnover. During both phases of the experiment, urinary and branchial excretion appeared to be higher than faecal excretion

  7. Effect of 60 Co gamma radiation on crystalline proteins

    In order to study the effects of 60 Co gamma radiation on crystalline proteins an in vitro system was set up. For that, aqueous solutions from bovine crystalline were used irradiated with 0, 5.000, 10.000, 15.000, 20.000 and 25.000 Gy. The treatment led to protein alterations determined by different methods. By turbidimetry the formation of aggregates that increased with the radiation dose was revealed. The same observation was done from viscosity data and from the UV spectrum of the samples. From amino acid analysis and fluorimetry determinations, tryptophan appeared as the most sensitive amino acid. An increase in the free-S H-groups was also observed. After the standardization of the method, the radio modifier capability of glutathione, amino ethyl thiourea, mercapto ethyl alanine and dimethyl sulfoxide was tested. The results showed that in the presence of those substances the radiation effect was diminished. (author)

  8. Effect of 60Co radiation on peritoneal cells

    This work deals with the effect of 60Co gamma irradiation on the levels and quality of peritoneal cells of albino mice. The cells were obtained from peritoneal exudate, fixed and stained in 30% glacial acetic acid containing 0,5% cristal violet. Os exudates from irradiated and control animals the qualitative analysis and the counting of different cell populations were performed one hour, three days and six days after irradiation with 9 Gy. All the cell populations from the peritoneal exudate shown a decrease 3 days after the irradiation with 9.0. Gy but the different cellular populations dimished in unlike proportions. The data reaffirm the discrepance in radiosensivity of the diverse peritoneal cell populations. (author)

  9. Seed germination of peanuts irradiated with cobalt (60CO)

    This work was realized to evaluate the effect of gamma irradiation (60Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  10. Thickness dependence of superconductivity and resistivity in La{sub 1.85}Sr{sub 0.15}CuO{sub 4} films

    Sato, Hisashi [NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato Wakamiya, Atsugi-shi, Kanagawa 243-0198 (Japan)], E-mail: hisashi@will.brl.ntt.co.jp

    2008-07-01

    The temperature dependence of resistivity was measured for (0 0 1), (1 0 0) and (1 1 0)-oriented La{sub 1.85}Sr{sub 0.15}Cu{sub 4} (LSCO) thin films with thickness between 1 and 90 nm on LaSrAlO{sub 4} (LSAO) substrates. As thickness increases, superconductivity appears for (0 0 1) films at 3 nm, whereas it appears for (1 0 0) and (1 1 0) films at 23 nm. The difference is explained by compressive strain in the c-axis direction for (1 0 0) and (1 1 0) films caused by a smaller c-axis length in LSAO than in LSCO. It is suggested that small lengths of Cu-O bonds perpendicular to CuO{sub 2} planes degrade superconductivity in this system.

  11. Transport properties of Ru-doped La1.85Sr0.15CuO4 and the effect of carrier concentration compensation

    This paper is a study of the structure and transport properties of Ru-doped La1.85Sr0.15CuO4. It is found that Ru substitution for Cu has two effects. (1) Ru doping introduces disorder into the system, which causes a metal-insulator transition with high localization. (2) There is a hole-filling effect due to the valence of the Ru ion being higher than that of the Cu ion. Increase of the strontium content could compensate for the imbalance of valence caused by doping with the high-valence Ru ion. A universal curve for Tc versus the number of holes per Cu site is observed for the La2-ySryCu1-xRuxO4 system, indicating that a rigid-band model holds and Tc correlates with features in the density of states, such as a Van Hove singularity

  12. EPR study of Fe-doped La sub 1. 85 Sr sub. 15 CuO sub 4. [La-Sr-Cu-Fe-O

    Sienkiewicz, A.; Cieplak, M.Z. (Inst. of Physics, Polish Academy of Sciences, Warsaw (Poland)); Gang Xiao (Dept. of Physics, Brown Univ., Providence, RI (USA)); Chien, C.L. (Dept. of Physics and Astronomy, Johns Hopkins Univ., Baltimore, MD (USA))

    1990-10-15

    We study EPR of Fe-doped La{sub 1.85}Sr{sub 0.15}CuO{sub 4} for the dopant content from 0 to 10 at.%. The g-factor of the Fe{sup 3+} resonance line decreases rapidly in the low temperature region and then remains constant. Depending on temperature and impurity content the linewidth displays two distinct behaviors. We associate the low temperature behavior with the occurrence of a spin-glass phase due to Fe-Fe dipole-dipole interactions. Correlation of the EPR and transport properties at high temperatures suggests the presence of RKKY mechanism which is strongly influenced by localization of free carriers. (orig.).

  13. Strain Relaxation in Thin Films of La1.85Sr0.15CuO4 Grown by Pulsed Laser Deposition

    Zaytseva, I.; Cieplak, M. Z.; Abal'Oshev, A.; Berkowski, M.; Domukhovski, V.; Paszkowicz, W.; Shalimov, A.

    2007-01-01

    X-ray diffraction, resistivity, and susceptibility measurements are used to examine the effects of film thickness d (from 17 to 250 nm) on the structural and superconducting properties of La1.85Sr0.15CuO4 films grown by pulsed laser deposition on SrLaAlO4 substrates. For each d the film sgrow with a variable strain, ranging from a large compressive strain in the thinnest films to a negligible or tensile strain in thick films. Our results indicate that the tensile strain is not caused by the off-stoichiometric layer at the substrate-film interface. Instead, it may be caused by the extreme oxygen deficiency in some of the films.

  14. Superconductivity and the metal-insulator transition in La sub 1. 85 Sr sub 0. 15 CuO sub 4

    Cieplak, M.Z.; Guha, S.; Kojima, H.; Lindenfeld, P. (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States)); Gang Xiao (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States) Dept. of Physics, Brown Univ., Providence, RI (United States)); Xiao, J.Q.; Chien, C.L. (Serin Physics Lab., Rutgers Univ., Piscataway, NJ (United States) Dept. of Physics, Johns Hopkins Univ., Baltimore, MD (United States))

    1991-12-01

    Measurements on La{sub 1.85}Sr{sub 0.15}CuO{sub 4} with five different substitutions for the Cu show that the M-I transition occurs in each case at an impurity concentration x{sub MI} higher than the value x{sub c} at which superconductivity disappears. While x{sub c} correlates with the magnitude of the local magnetic moment, we show that the M-I transition is the result of the superposition of the disorder and of the change in carrier concentration as obtained from the Hall effect. On the metallic side the normal-state conductivity changes linearly with {radical}T over a wide range of temperature. The normal-state conductivity extrapolated to zero temperature exhibits a critical exponent close to one as the M-I transition is approached. (orig.).

  15. Metallic Nonsuperconducting Phase and D -Wave Superconductivity in Zn-Substituted La{sub 1.85}Sr{sub 0.15}CuO{sub 4}

    Karpinska, K. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Cieplak, Marta Z. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States); Guha, S. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States); Malinowski, A. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Skoskiewicz, T. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Plesiewicz, W. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Berkowski, M. [Institute of Physics, Polish Academy of Sciences, 02 668 Warsaw, (Poland); Boyce, B. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106 (United States); Lemberger, Thomas R. [Department of Physics, The Ohio State University, Columbus, Ohio 43210-1106 (United States); Lindenfeld, P. [Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019 (United States)

    2000-01-03

    Measurements of the resistivity, magnetoresistance, and penetration depth were made on films of La{sub 1.85} Sr{sub 0.15} CuO{sub 4} , with up to 12 at. % of Zn substituted for the Cu. The results show that the quadratic temperature dependence of the inverse square of the penetration depth, indicative of d -wave superconductivity, is not affected by doping. The suppression of superconductivity leads to a metallic nonsuperconducting phase, as expected for a pairing mechanism related to spin fluctuations. The metal-insulator transition occurs in the vicinity of k{sub F}l{approx_equal}1 , and appears to be disorder driven, with the carrier concentration unaffected by doping. (c) 1999 The American Physical Society.

  16. Current induced degradation of the La0.85Sr0.15MnO3+/YSZ8 and Pt/YSZ8 interfaces

    Knudsen, Tine; Jacobsen, Torben; Skou, Eivind

    Electrochemical reduction of oxygen by the use of both a cone shaped La0.85Sr0.15MnO3+δ electrode and Platinum electrodes together with the solid electrolyte YSZ8, induced significant changes in the materials. The cone was after use no longer homogenous (EDX analysis in figure), and the cone top...... electrode set-up with three identical Pt-electrodes. The cathode was polarized –0.1V at 1000oC in air in 85 days. The current through the anode and cathode was measured and is displayed in figure (). The current increased the first 50 days, where after is became approximately constant. Inspection showed...

  17. Assessment of bone formation and bone resorption in osteoporosis: a comparison between tetracycline-based iliac histomorphometry and whole body 85Sr kinetics

    Bone formation and resorption have been measured in patients with idiopathic osteoporosis by histomorphometry of 7.5-mm trephine biopsies and in the whole body by 85Sr radiotracer methodology and calcium balances. The studies were synchronized and most were preceded by double in vivo tetracycline labeling. Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy. Correction of the kinetic data for long-term exchange, using 5 months' serial whole body counting of retained 85Sr, improved the fit of the kinetic to the histological data. A statistical analysis of the measurement uncertainties showed that the residual scatter in the best correlations (between exchange-corrected bone formation rates and double-labeled osteoid surface indices) could be attributed to measurement imprecision alone. The exchange-corrected resorption rate correlated fairly well with iliac trabecular resorption surfaces, and using a volume referent rather than a surface referent for the histological index improved the statistical fit when patients with therapeutically accelerated bone turnover were included. A much better correlation was obtained by including osteoid volume acting as an independent predictor of bone resorption in a bivariate regression with a resorption surface index. The residual errors could then be accounted for by known measurement uncertainties. Whereas osteoid taking a double label closely predicted the kinetic rate of bone formation, further analysis suggested that osteoid that took no label or a single label was more closely related to bone resorption, presumably as a secondary result of the coupling of bone formation to bone resorption

  18. Uptake, distribution and metabolic fate of 59Fe, 58Co, 54Mn and 65Zn in plants and their mobility and availability to crops in typical black and laterite soils

    Studies were undertaken on typical soils of India. Nutrient culture experiments indicated that with identical plant growth periods the accumulation in aerial tissues of 65Zn and 54Mn was greater than that of 58Co and 59Fe. The distribution of 59Fe, 58Co and 65Zn in the various aerial organs of bean plants was generally uniform whereas the distribution of 54Mn followed an acropetal gradient. The chemical association of 59Fe, 58Co and 65Zn in the edible bean pods was predominantly with lipids and ionic forms whereas 54Mn association was mainly with ionic forms. The plant uptake of these radionuclides from typical black and laterite soils showed maximum accumulation of 54Mn followed by 65Zn, 59Fe and 58Co in both soil types and the uptake was greater from the laterite soil than from the black soil. Flooding treatment of rice, while showing a reduction of 59Fe uptake, showed an increase in plant uptake of 58Co, 54Mn and 65Zn in both soil types. Organic matter addition resulted in a significant reduction of 59Fe and 58Co in the laterite soil and of 65Zn in the black soil. All the four nuclides were completely immobile in the two soil types when leached with rain water or irrigation waters or when treated with organic matter. However, leaching with 10-2 M EDTA solution induced a rapid breakthrough of all the four radionuclides. (author)

  19. Establishment of a production line for the fabrication of mega-curie sealed 60Co sources

    In order to change the status that highly radioactive 60Co sources in China are de- pendent on imports, the fabrication technology of sealed 60Co sources was successfully developed and a mega Curie production line was established. This paper describes the hot cell facilities for the 60Co source encapsulation and quality control, the model and main technical parameters of the sealed 60Co source, the fabrication process, some key techniques in the re- search and development of the sealed 60Co source, etc. (authors)

  20. Accumulation, Toxicity And Elimination Of 60Co In Some Aquatic Bivalves

    The present study was undertaken to evaluate the importance of some common bivalve oysters namely Caelatura teretiusculua and Caelatura companyoi as new radiobioindicators for 60Co in Egyptian aquatic environment.The uptake and accumulation of 60Co in water were followed for four weeks to evaluate the following:1-Maximum uptake as concentration factor values.2-The rate of survival of bivalves at different activity levels of 60Co to estimate its toxic effect.3-The lethal dose (LD50) of 60Co.4-The effect of ph of 60Co polluted water on survival of biota.5-The competitive effects of Zn+2 and Fe+3 with 60Co on the uptake and accumulation.6-The effect of biota weight on the uptake of 60Co.7-Elimination of the accumulated 60Co by such biota in water and in 10-4M ethylene diamine tetra acetic acid (EDTA) as chelating agent that enhance the bivalve to release the accumulated radioisotope.The results showed that 60Co was highly taken up by the investigated biota with high concentration factor values and that EDTA enhanced the decontamination of 60Co than water. It could be concluded that the investigated bivalves can be used as good radiobioindicators for pollution of water with 60Co.

  1. Transference kinetics of 60Co in an aquatic-terrestrial ecosystem

    The dynamics of transportation, accumulation, disappearance and distribution of 60Co in a simulated aquatic-terrestrial ecosystem was studied by isotope-tracer technique. In the aquatic system, 60Co was transported and transformed via depositing, coupling with ions and adsorption. The absorption resulted in the redistribution and accumulation of 60Co in each compartment of the system. Specific activities of 60Co in water started sharply and gently decreased. The sediment accumulated a large amount of 60Co by adsorption and ion exchange. The hornwort (Ceralophyllum demersum) could also adsorb a large amount of 60Co in a short time, because of its large specific surface area. Fish (Carassius auratus) and snail (Bellamya purificata) had a poor capacity of adsorbing 60Co. The distribution of 60Co in the fish was mainly in the viscera, and the amount of 60Co in the snail flesh was greater than that in the shell. The amount of 60Co in individual compartment in the system was changed with time. The highest specific activity of 60Co in the bean of the terrestrial system remained in the root nodule. (authors)

  2. Influence of pH-buffer action on desorption behavior of 60Co adsorbed on sand

    In order to clarify influence of pH-buffer action of soil on desorption behavior of radionuclides absorbed on a soil, a batch type desorption experiment, in which a coastal sand adsorbed 60Co was contacted with an aqueous solution of 4, 7 or 10 in pH, was performed. When pH of the solution became higher, the desorption ratio of 60Co from the sand to the solution decreased, while the abundance ratio of non-cationic 60Co species increased. Relationship between the pH of solution and the desorption ratio of 60Co could been explained by a pH dependency of negative charge density on the sand surface. It was found that the non-cationic 60Co species in the solution was colloidal {60Co (OH)2}n, which was formed by hydrolysis of 60Co2+ at buffered pH. (author)

  3. Transfer factors of radionuclides from Andsols to some selected crops

    In order to obtain the applicable transfer factor for Japanese environment, we performed radiotracer experiments on the uptake of 137Cs, 85Sr, 54Mn, 60Co and 65Zn by leaf vegetables (two cabbages, komatsuna, spinach and lettuce), root vegetables (radish and carrot) and other crops (wheat, soy bean sweet potato and tomato) using the Andosol (Kuroboku soil), the most common of Japanese arable soils. The ranges of TFs (on a dry weight basis) of 137Cs, 85Sr, 60Co, 54Mn and 65Zn for edible parts of crops (leaf vegetables, root vegetables, wheat and soy bean) were 0.09 - 1.42, 0.24 - 3.7, 0.019 - 1.5, 0.31 - 12 and 0.68 - 14, respectively. TFs were, in most cases in the order Mn, Zn, Sr > Cs > Co. (author)

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

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

  5. Response of adrenal gland to whole body 60Co irradiation

    Whole body of the adult albino rates was exposed to 60Co radiation in a single dose of 600 R. Following irradiation the adrenal serotonin level was found higher till the end of 8th week except a fall on 14th day, whereas the blood 5HT level remained lower than the normal except a slight rise at the end of 1st week and dropped down at 14 days followed by a further rise. The blood catecholamine level was found increased at the end of 14th day followed by a fall at 4th and 8th weeks, but the levels were moving round the normal value. The histological studies of adrenal gland showed degranulation and hypertrophy of adrenal cortex and medullary cells at various intervals of post-irradiation. On the whole it is observed that maximum changes in the level of biogenic amines take place within 14 days after irradiation, and maximum rate of mortality also coincide with this period. Thus bringing out the fact that adrenal bioamines play an important role in the vital activities of the animals. (author)

  6. ONE CASE OF LEUKEMIA INDUCED BY 60Co ACCIDENT

    邵松生; 冯嘉林; 等

    1995-01-01

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

  7. Determination of Absorbed Dose in Large 60-Co Fields Radiotherapy

    Radiation in radiotherapy has selective impact on ill and healthy tissue. During the therapy the healthy tissue receives certain amount of dose. Therefore dose calculations in outer radiotherapy must be accurate because too high doses produce damage in healthy tissue and too low doses cannot ensure efficient treatment of cancer cells. A requirement on accuracy in the dose calculations has lead to improvement of detectors, and development of absolute and relative dosimetry. Determination of the dose distribution with use of computer is based on data provided by the relative dosimetry. This paper compares the percentage depth doses in cubic water phantoms of various dimensions with percentage depth doses calculated with use of Mayneord factor from the experimental depth doses measured in water phantom of large dimension. Depth doses in water phantoms were calculated by the model of empirical dosimetrical functions. The calculations were based on the assumption that large 60Co photon field exceeds the phantom's limits. The experimental basis for dose calculations by the model of empirical dosimetrical functions were exposure doses measured in air and dose reduction factors because of finite phantom dimensions. Calculations were performed by fortran 90 software. It was found that the deviation of dosimetric model was small in comparison to the experimental data. (author)

  8. 60Co γ-irradiation induced mutation breeding of ginger

    Sprout rhizome and plumelet rhizome of Laiwu ginger were irradiated by 60Co γ-rays at different doses (20, 25, 30 and 35 Gy), and the variations at the VM1, VM2, and VM3 generations were studied. The results showed that the inhibition effect of irradiation on the VM1 generation was found to be increased as the dose increased, and the sprout rhizome was more sensitive to γ-irradiation than the plumelet rhizome. The LD50 and LD60 dose of plumelet rhizomes were 20 and 25 Gy, respectively, and the optimum irradiation dose was 25Gy. The LD50 and LD60 dose of sprout rhizomes were below 20 Gy. Seven types of mutants were found and selected in VM2 generation. The induced mutation characters were unstable in the VM3 generation. Three mutant lines (GDC2531, PZC3026, ZLX2007) selected from VM3 generation showed high yield, and fresh weight of rhizomes increased 33.5%, 27.5% and 24.9%, respectively compared to control. (authors)

  9. Disturbed tooth formation by 60Co-gamma-ray radiation

    The molar of guinea pigs was irradiated with 60Co-#betta# ray for daily observations of the manifestation of disturbed tooth formation by microradiography and the time registration by tetracycline-labelling. Irradiation first injured young blast cells of the dentin in the growth phase, dental pulp cells, and cells of the enamel. The portion composed of injured cells formed a depressed ''constriction'' from the dental pulp side toward the border between the enamel and dentin. The cells of the enamel injured by irradiation in the growth phase later formed a very thin irregular stroma. In contrast, cells in the differentiation or subsequent phase at the time of irradiation and cells probably having started to grow after irradiation proceeded with formation of a normal stroma and calcification. No uniform relation was obtained between the histological staining of the organic stroma of normal or abnormal dentin and calcification. Labelling with tetracycline revealed that the irradiation conditions in the present study provoked hardly any changes in the speed of tooth eruption. (Chiba, N.)

  10. Effect of 60CO radiation processing in mate (Ilex paraguariensis)

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

  11. Effect of 60Co radiation processing in mate (Ilex paraguariensis)

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

  12. Placental transfer of 60Co as a function of gestation age

    The transfer of 60Co from mother to foetus in relation to the time of gestation was examined 24 hrs after injecting 5 μCi of 60CoCl2 to the pregnant rat on 15th - 21st day of gestation. The radioactivity of foetuses, placentae as well as liver, kidney and femur of mother was determined. It was found that activity of 60Co transferred to the foetus body increased with the time of gestation. (author)

  13. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10-3). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BFS do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  14. Studies on the transportation dynamics of 60Co in simulated ecosystem

    The isotope tracer techniques were applied to study the transportation, accumulation and distribution of 60Co in the pot-cultivated tomato-soil, aquatic and terrestrial ecosystems. Based on the principle of tracer dynamic compartment models, the mathematical formulae were established via computer simulation to describe the 60Co behavior patterns in ecosystems and thus provided some basic information for elucidating the behavior of 60Co in the environment. The results are as follows: (1) When 60Co was introduced into the tomato-soil system, 60Co was transported and accumulated in the soil and adsorbed by tomato root quickly, then transported to the above-ground plant. (2) The behavior patterns of 60Co in the tomato-soil system could be described using the opened two-compartment model. (3) When 60Co was introduced into aquatic system in the form of 60Co-CoCl2, it was transported and transformed via deposit, complexation with other ions, adsorption and absorption by aquatic living things and led to the distribution and accumulation in individual part of the living things. (4) The behavior pattern of 60Co in the aquatic-terrestrial ecosystem could be described by using opened five-compartment model

  15. Ionic Liquid Type Crown Ether as a Novel Medium for Liquid-Liquid Extraction of the Radioactive Metal Ion 85Sr2+

    1,13-dichloro-4,7,10-trioxatridecane (2-[2-(1-chloro-2-ethoxy)ethoxy]ethyl chloride) was synthesized by chlorination of 1,13-dihydroxy-4,7,10-trioxatridecane (triethylene glycol). Treatment with imidazole and sodium ethoxide provided 1N,1N'- tris(oxoethylene)-diimidazole, which was then converted to an ionic liquid type crown ether (ILCE) with reaction with 1,9-dichloro-3,6-trioxaoctane. The anion of the ILCE was then exchanged by an anion exchange method. Ultimately, a very efficient synthetic pathway was developed for the preparation of ILCEs having various physical and chemical characteristics by a modification of the polyethylene glycol chain length and anions. The 85Sr2+ was successfully extracted into the [(3,2)OEtIm][Cl] phase, but was not extracted into the [(2,2)OEtIm][Cl], [(3,3)OEtIm][Cl] and [(4,3)OEtIm][Cl] phases. (author)

  16. Ionic liquid-type crown ether as a novel medium for a liquid/liquid extraction of radioactive metal ion 85Sr2+

    1,13-Dichloro-4,7,10-trioxatridecane (2-[2-(1-chloro-2-ethoxy)ethoxy] ethyl chloride) (3a) was synthesized by a chlorination of 1,13-dihydroxy-4,7,10-trioxatridecane (triethylene glycol). And it was treated with imidazole and sodium ethoxide to give the 1N, 1N'-tris(oxoethylene)-diimidazole (3b), which was then converted to ionic liquid-type crown ether (ILCE) 3 with a reaction with 1,9-dichloro-3,6-trioxaoctane (2a). Further, the anion of ILCE was exchanged by an anion-exchange method. Ultimately, we developed a very efficient synthetic pathway for ILCEs 1-4 which have various physical and chemical characteristics by a modification of the polyethylene glycol chain length and anions. 85Sr2+ was successfully extracted into the [(3,2)OEtIm][Cl] (3) phase, but it was not extracted into the [(2,2)OEtIm][Cl] (1), [(3,3)OEtIm][Cl] (2), and [(4,3)OEtIm][Cl] (4) phases. (author)

  17. Critical fields and the critical current density of La/sub 1.85/Sr/sub 0.15/CuO4

    A detailed investigation of the magnetic and transport properties of La/sub 1.85/Sr/sub 0.15/CuO4 in the superconducting state is presented. It is concluded that the magnetic and transport behavior is that of a granular type-II superconductor in which strongly superconducting grains are coupled via weak superconducting links. Five characteristic fields are identified. H/sub c/1/sup w/ (≅1 Oe at 4 K) is the field at which the first vortex line penetrates the weak links. At H = H/sup w/ (≅11 Oe at 4.2 K) the London penetration depth in the weak links is very large compared to their dimensions. H/sub c/1/sup g/ (≅300 Oe at 4.2 K) defines the first flux thread entering the grains themselves. H/sup g/ is the value above which the magnetic behavior of the grain is thought to be governed by Abrikosov's negative surface energy model. The critical current density measured by the resistivity technique is about 8 A cm2 and is imposed by the sample size and compositional inhomogeneities and by H/sub c/1/sup w/, whereas the bulk (or intragrain) critical density could attain 105--106 A/cm2

  18. Critical fields and the critical current density of La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/

    Senoussi, S.; Oussena, M.; Ribault, M.; Collin, G.

    1987-09-01

    A detailed investigation of the magnetic and transport properties of La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ in the superconducting state is presented. It is concluded that the magnetic and transport behavior is that of a granular type-II superconductor in which strongly superconducting grains are coupled via weak superconducting links. Five characteristic fields are identified. H/sub c//sub 1//sup w/ (approx. =1 Oe at 4 K) is the field at which the first vortex line penetrates the weak links. At H = H/sup w/ (approx. =11 Oe at 4.2 K) the London penetration depth in the weak links is very large compared to their dimensions. H/sub c//sub 1//sup g/ (approx. =300 Oe at 4.2 K) defines the first flux thread entering the grains themselves. H/sup g/ is the value above which the magnetic behavior of the grain is thought to be governed by Abrikosov's negative surface energy model. The critical current density measured by the resistivity technique is about 8 A cm/sup 2/ and is imposed by the sample size and compositional inhomogeneities and by H/sub c//sub 1//sup w/, whereas the bulk (or intragrain) critical density could attain 10/sup 5/--10/sup 6/ A/cm/sup 2/.

  19. Bioremediation of {sup 60}Co from simulated spent decontamination solutions

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

    2004-07-26

    Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

  20. The effect of 60Co-γ ray on fertilized eggs and growing change in chicken

    The fertilized eggs were stimulated by 60Co-γ ray of different doses. The experimental results show that the rate of hatching of different fertilized eggs reaches the maximum when the dose of 60Co-γ ray is 300rad. And, the higher the dose of 60Co-γ ray is used, the lower the rate of breeding and hatching are obtained. It is concluded that it is beneficial to growing of cock and the fertilized eggs are stimulated by the 60Co-γ ray of low doses. However, the growing of hen is inhibited and eggs are early produced with the low dose treatment of 60Co-γ ray

  1. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial.

    Bignell, L J; Mo, L; Alexiev, D; Hashemi-Nezhad, S R

    2010-01-01

    Radiation transport simulations of the most probable gamma- and X-ray emissions of (123)I and (54)Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an (123)I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%. PMID:20036571

  2. Sensitivity and uncertainty analysis of the simulation of 123I and 54Mn gamma and X-ray emissions in a liquid scintillation vial

    Radiation transport simulations of the most probable gamma- and X-ray emissions of 123I and 54Mn in a three photomultiplier tube liquid scintillation detector have been carried out. A Geant4 simulation was used to acquire energy deposition spectra and interaction probabilities with the scintillant, as required for absolute activity measurement using the triple to double coincidence ratio (TDCR) method. A sensitivity and uncertainty analysis of the simulation model is presented here. The uncertainty in the Monte Carlo simulation results due to the input parameter uncertainties was found to be more significant than the statistical uncertainty component for a typical number of simulated decay events. The model was most sensitive to changes in the volume of the scintillant. Estimates of the relative uncertainty associated with the simulation outputs due to the combined stochastic and input uncertainties are provided. A Monte Carlo uncertainty analysis of an 123I TDCR measurement indicated that accounting for the simulation uncertainties increases the uncertainty of efficiency of the logical sum of double coincidence by 5.1%.

  3. Strain accommodation through facet matching in La1.85Sr0.15CuO4/Nd1.85Ce0.15CuO4 ramp-edge junctions

    M. Hoek

    2015-08-01

    Full Text Available Scanning nano-focused X-ray diffraction and high-angle annular dark-field scanning transmission electron microscopy are used to investigate the crystal structure of ramp-edge junctions between superconducting electron-doped Nd1.85Ce0.15CuO4 and superconducting hole-doped La1.85Sr0.15CuO4 thin films, the latter being the top layer. On the ramp, a new growth mode of La1.85Sr0.15CuO4 with a 3.3° tilt of the c-axis is found. We explain the tilt by developing a strain accommodation model that relies on facet matching, dictated by the ramp angle, indicating that a coherent domain boundary is formed at the interface. The possible implications of this growth mode for the creation of artificial domains in morphotropic materials are discussed.

  4. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818) DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818)

    Elaine Barros da Costa CARVALHO; Melo, Ana Maria Mendonça de Albuquerque; Mauricy Alves da MOTTA

    1999-01-01

    The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony...

  5. In Vivo Internal Decontamination of 134Cs and 60Co from Male Albino Rats

    The Present work aimed to evaluate the therapeutic role of prussian blue (PB), vermiculite and calcium trisodium salt of diethylenetriaminepentaacetic acid (DTPA) as internal de contaminants of radio-active cesium and/ or cobalt in adult male albino rats. Radionuclides were given as a single doses; 60Co was introduced orally, subcutaneously or intraperitoneally (ip) while 134Cs was taken orally or in combination with ip injection of 60Co. The de contaminants were supplied daily for three weeks immediately after 60Co or 134Cs intake; oral dose of PB + vermiculite treated the oral 134Cs group, oral and subcutaneous 60Co groups and combined 60Co and 134Cs groups. Rats receiving ip dose of 60Co were treated with daily ip dose of DTPA while the three de contaminants were added to the combined 60Co and 134Cs groups.Haemoglobin concentration (Hb), haematocrite percentage (Ht), red blood cells count (RBC's), as well as liver function tests (total bilirubine, total protein, albumin, globulin, A/ G ratio, alanine transaminase (ALT), spartic transaminase (AST) and alkaline phosphatase (ALP)) were analyzed in all groups. The data obtained revealed that internal contamination by radioactive materials causes a significant decrease in the RBC's counts, Hb concentration, haematocrit value, serum total proteins and albumin. On the other hand, the therapeutic agents caused a significant amelioration in the changes produced by internal contamination with variable degree. Thus, it could be concluded that the therapeutic agents might provide a protection against internal contamination hazards

  6. Superconductivity in bulk and thin films of La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub δ/ and Ba2YCu3O/sub 7-//sub δ/

    A laser-ablation technique was used to deposit thin films from the bulk oxides La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub δ/ and Ba2YCu3O/sub 7-//sub δ/, whose superconductivity properties were investigated by dc resistivity, complex ac susceptibility, and microwave response. The latter technique was employed to establish that the thin films have superconducting regions with properties similiar to the bulk materials

  7. Retention and translocation of foliar applied {sup 239,240}Pu and {sup 241}Am, as compared to {sup 137}Cs and {sup 85}Sr, into bean plants (Phaseolus vulgaris)

    Henner, P. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)]. E-mail: pascale.henner@irsn.fr; Colle, C. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France); Morello, M. [Institute for Radioprotection and Nuclear Safety, Environment and Emergency Operations Division, Department for the Study of Radionuclides Behaviour in Ecosystems, Laboratory of Radioecology and Ecotoxicology, IRSN/DPRE/SECRE/LRE, Cadarache Centre, Building 186, BP 3, 13115 Saint-Paul-lez-Durance (France)

    2005-07-01

    Foliar transfer of {sup 241}Am, {sup 239,240}Pu, {sup 137}Cs and {sup 85}Sr was evaluated after contamination of bean plants (Phaseolus vulgaris) at the flowering development stage, by soaking their first two trifoliate leaves into contaminated solutions. Initial retentions of {sup 241}Am (27%) and {sup 239,240}Pu (37%) were higher than those of {sup 137}Cs and {sup 85}Sr (10-15%). Mean fraction of retained activity redistributed among bean organs was higher for {sup 137}Cs (20.3%) than for {sup 239,240}Pu (2.2%), {sup 241}Am (1%) or {sup 85}Sr (0.1%). Mean leaf-to-pod translocation factors (Bq kg{sup -1}dry weight pod/Bq kg{sup -1}dry weight contaminated leaves) were 5.0 x 10{sup -4} for {sup 241}Am, 2.7 x 10{sup -6} for {sup 239,240}Pu, 5.4 x 10{sup -2} for {sup 137}Cs and 3.6 x 10{sup -4} for {sup 85}Sr. Caesium was mainly recovered in pods (12.8%). Americium and strontium were uniformly redistributed among leaves, stems and pods. Plutonium showed preferential redistribution in oldest bean organs, leaves and stems, and very little redistribution in forming pods. Results for americium and plutonium were compared to those of strontium and caesium to evaluate the consistency of the attribution of behaviour of strontium to transuranium elements towards foliar transfer, based on translocation factors, as stated in two radioecological models, ECOSYS-87 and ASTRAL.

  8. Development of technology for the large-scale preparation of 60Co polymer film source

    60Co sources (∼37 kBq) in the form of a thin film are widely used in position identification of perforation in offshore oil-well explorations. This paper describes the large-scale preparation of such sources using a radioactive polymer containing 60Co. 60Co was extracted into chloroform containing 8-hydroxyquinoline. The chloroform layer was mixed with polymethyl methacrylate (PMMA) polymer. A large film was prepared using the polymer solution containing the complex. The polymer film was then cut into circular sources, mounted on a source holder and supplied to various users

  9. Development and evaluation of a technique for in vivo monitoring of 60Co in human lungs

    de Mello, J. Q.; Lucena, E. A.; Dantas, A. L. A.; Dantas, B. M.

    2016-07-01

    60Co is a fission product of 235U and represents a risk of internal exposure of workers in nuclear power plants, especially those involved in the maintenance of potentially contaminated parts and equipment. The control of 60Co intake by inhalation can be performed through in vivo monitoring. This work describes the evaluation of a technique through the minimum detectable activity and the corresponding minimum detectable effective doses, based on biokinetic and dosimetric models of 60Co in the human body. The results allow to state that the technique is suitable either for monitoring of occupational exposures or evaluation of accidental intake.

  10. Effects of some chelating agents on the uptake and distribution of 54Mn(II) in the brown trout (Salmo trutta)

    The effects of humic acids, which are natural metal-complexing compounds, and potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithicarbamate, which are sulphur-containing man-made chelating agents, on the uptake and tissue distribution of 54Mn(II) were studied in brown trout (Salmo trutta). Fish were exposed for 7 days to 0.1 μg Mn(II)x.-2 as NmCl2 (l μCia 54Mnxl-1) with or without chelat agents. Examination of the partition of Mn between octanol and a Tris-HCl buffer in the presence of these compounds was also performed. Humic acids had only small effects on Mn uptake and distribution in trout, probably because of the low stability of Mn-humate complexes. Partition of Mn in the presence of potassium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate between octanol and Tris-HCl buffer showed formation of lipophilic complex with the latter two compounds, but not with the former. However, these four chelating agents all decreased Mn uptake in the trout by 40-45%. These substances also changed the distribution of Mn within the fish, with a higher proportion of the metal being present in some visceral organs and a smaller proportion being localized in some non-parenchymateous tissues, such as skin, fins and bones. The mechanisms underlying these effects are not known. however, the interaction of chelating agents with the Mn, although weak, may have partially withdrawn the metal from the uptake process inthe gills. The redistribution of Mn in the fish may be due to the binding of the metal to complexing compounds which have reached the intestinal lumen. Previous studies with other metals have shown increased or unchanged metal levels in tissues of fish at exposure together with potasium ethylxanthate, sodium diethyldithiophosphate, sodium dimethyldithiocarbamate, and sodium diethyldithiocarbamate, but decreased metal levels have not been observed before. (au) (37 refs.)

  11. Soil-water distribution coefficients and plant transfer factors for 134Cs, 85Sr and 65Zn under field conditions in tropical Australia

    Measurements of soil-to-plant transfer of 134Cs, 85Sr and 65Zn from two tropical red earth soils ('Blain' and 'Tippera') to sorghum and mung crops have been undertaken in the north of Australia. The aim of the study was to identify factors that control bioaccumulation of these radionuclides in tropical regions, for which few previous data are available. Batch sorption experiments were conducted to determine the distribution coefficient (Kd) of the selected radionuclides at pH values similar to natural pH values, which ranged from about 5.5 to 6.7. In addition, Kd values were obtained at one pH unit above and below the soil-water equilibrium pH values to determine the effect of pH. The adsorption of Cs showed no pH dependence, but the Kd values for the Tippera soils (2300-4100 ml/g) exceeded those for the Blain soils (800-1200 ml/g) at equilibrium pH. This was related to the greater clay content of the Tippera soil. Both Sr and Zn were more strongly adsorbed at higher pH values, but the Kd values showed less dependence on the soil type. Strontium Kds were 30-60 ml/g whilst Zn ranged from 160 to 1630 ml/g for the two soils at equilibrium pH. With the possible exception of Sr, there was no evidence for downward movement of radionuclides through the soils during the course of the growing season. There was some evidence of surface movement of labelled soil particles. Soil-to-plant transfer factors varied slightly between the soils. The average results for sorghum were 0.1-0.3 g/g for Cs, 0.4-0.8 g/g for Sr and 18-26 g/g for Zn (dry weight) with the initial values relating to Blain and the following values to Tippera. Similar values were observed for the mung bean samples. The transfer factors for Cs and Sr were not substantially different from the typical values observed in temperate studies. However, Zn transfer factors for plants grown on both these tropical soils were greater than for soils in temperate climates (by more than an order of magnitude). This may be

  12. Transfer and translocation of {sup 241}Am, {sup 239}Pu, {sup 137}Cs and {sup 85}Sr after partial foliar contamination of bean plants

    Henner, P.; Colle, C.; Morello, M. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Bean plants at the flowering development stage were contaminated by soaking their two first leaves for 3 hours in a solution containing one of the actinides {sup 241}Am or {sup 239}Pu, or both {sup 137}Cs and {sup 85}Sr. The aim of the study was to assess the adequacy of using the values of Cs/Sr for the foliar transfer parameters of transuranic actinides, as used for example in the ASTRAL code to calculate the contamination of agricultural products after a nuclear accident. Secondly, these experiments were launched to tentatively determine specific values for the foliar transfer parameters for Am and Pu, despite technical limitations due to high radiotoxicity of these isotopes which prevented the contamination of the whole foliage of bean plants. Cs and Sr were used to compare the results with those obtained with other modes of contamination, by dry deposition of aerosols for example. Results showed that the soaking protocol was adequate to compare the foliar transfer of various radionuclides, although it should be difficult to provide specific values because of partial contamination of the foliage. Foliar transfer factors, expressed as Bq.kg{sup -1}{sub dw} {sub pods}/Bq.L{sup -1}{sub solution} (2.5x10{sup -2}) and translocation factors, dimensionless, (2.3x10{sup -3}) for Am and for Pu (1.5x10{sup -3} and 7.5x10{sup -5} respectively), compared to those for Sr (respectively 3.6x10{sup -3} and 5.9x10{sup -4}) and for Cs (respectively 2.9x10{sup -1} and 1.3x10{sup -1}), were studied using this procedure. Transfer and translocation factors for Am were significantly higher than those for Sr, but were smaller than those for Cs. Therefore, Am can be classified as a medium mobile radionuclide in plant. Transfer and translocation of Pu were significantly lower than these for Sr and for Am. Besides, the transfer and translocation factors of Am and Pu only differed from one order of magnitude or less from the one of Sr, which could be in the usual range of variation

  13. Monte Carlo calculation of 60Co γ-ray's albedo-dose rate from the air

    The Monte Carlo calculation of 60Co γ-ray's albedo-dose rate from the air is reported. A formula is presented with which the relations of the albedo-doserate with some parameters are simulated and fitted

  14. Manufacture of 60Co source irradiation facility and measurement of radiation filed

    60Co source radiation facility is an important equipment to produce reference radiation filed, according to national standard, the scattered dose rate must be less than 5% of the total dose rate in the reference radiation filed. Scattered radiation contribution and uniformity of reference radiation field are important parameters to describe the radiation performance of 60CO source irradiation device, Monte Carlo method was used to study the scattered radiation and uniformity of the reference radiation filed to provide theoretical basis for the design of 60CO source irradiating device in order to avoid economic losses caused by design mistakes. When 60CO source irradiating device was manufactured, PTW ionization chamber was used to measure the irradiation field. The results showed that the scattered radiation and uniformity of the radiation filed were in good agreement with the simulation results. The radiation performance met the design requirements. (authors)

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

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

  16. Bioremediation of 60Co from simulated spent decontamination solutions of nuclear power reactors by bacteria

    The spent decontamination solutions generated from nuclear power reactors contain radionuclides of cobalt (60Co, 56Co and 57Co) along with a large excess (105) of non-radioactive metal ions (Fe, Ni and Cr). Our previous studies demonstrated that bioremediation of 60Co from simulated effluents using fungal biomass can provide an alternative to conventional ion exchangers. In this study, we used several bacteria to further improve the process of bioremediation by decreasing biomass requirement and treatment period. Further, metabolite activation in specific bacterial species resulted in enhanced bioremediation of 60Co from simulated effluent. Optimization of conditions in simulated effluent for the eight bacterial species to accomplish maximum 60Co removal is discussed. (author)

  17. Histological variations in liver of freshwater fish Oreochromis mossambicus exposed to 60Co gamma irradiation

    The irradiation effect of 60Co at the three dose level of 3 mGy, 30 mGy and 300 mGy on the histology of liver of the freshwater fish Oreochromis mossambicus was investigated. The liver of O. mossambicus was dissected out and processed for light microscopy studies. 60Co exposed O. mossambicus were found to result in several alterations in the histoarchitecture of liver. The alterations included mild congestion of blood vessels, structural alteration, cellular swelling, vacuolation and necrotic liver cells, indicating a definite response to 60Co irradiation. The results suggest that the liver of O. mossambicus exposed to 60Co were structurally altered with increasing dose levels. It is to record that alteration in the liver does not affect the physiology, behaviour or lethality of the individuals. Self regulating mechanisms would have influenced the liver to remain sustained. To confirm the same further studies in the direction by increasing dose level is required. - Highlights: ► Fish Oreochromis mossambicus irradiated to the dose of 3 mGy, 30 mGy and 300 mGy. ► Histoarchitecture of liver altered with increasing dose levels of 60Co. ► Alteration in the liver does not affect the physiology, behaviour or lethality. ► Self regulating mechanisms might have prevented from Lethality. ► HSI index value for exposed group reported (60Co.

  18. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to 60Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body 60Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that 60Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, 60CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on 60Co bioaccumulation by mollusks. Analysis of 60Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the 60Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential

  19. Comparative uptake from sea water and tissue distribution of 60Co in marine mollusks

    Carvalho, F.P.

    1987-07-01

    Five different species of marine mollusks, Mytilus galloprovincialis Lmk., Tapes decussatus L., Cerastoderma (Cardium) edule (L.), Donax vittatus (da Costa) and Patella vulgata L., were exposed to /sup 60/Co-labelled sea water under laboratory conditions. After a 1-mo exposure, tested species reached different whole-body /sup 60/Co concentration factors (CF) over radioactive sea water of 73 +/- 27, 22 +/- 10, 84 +/- 25, 6.3 +/- 1.4 and 31 +/- 10, respectively, which are not dependent upon the size of mollusks. Equations for the experimental uptake curves, obtained using a multi-exponential model, indicate that /sup 60/Co uptake by mollusks involves two or three compartments, according to the species. In all species, the larger compartments turn over with long biological half-lives, dependent upon species. At the beginning of the experiment, /sup 60/CoCl2 added to sea water was mainly in cationic forms. These forms were progressively converted into anionic plus neutral forms most likely due to complex formation with organic ligands. With time this physico-chemical evolution had a lowering effect on /sup 60/Co bioaccumulation by mollusks. Analysis of /sup 60/Co in tissues revealed that Donax shell and mantle do not accumulate the radionuclide in great quantities, generating the low whole-body concentration factor found. In contrast, shell and mantle from all other species displayed variable but high CFs. Shell by itself accounts for more than half of the /sup 60/Co whole-body burden. Among soft tissues, gills and viscera displayed the highest CF and muscle the lowest. From these experiments, one may conclude that significant differences among species do exist regarding Co bioaccumulation potential.

  20. Mechanisms of60Co uptake and loss by Scenedesmus obliquus and transfer to two benthic organisms

    The affinity of Scenedesmus obliquus for 60Co has been confirmed under various experimental conditions allowing for the age of cultures, the physiological state of the cells, the radioactivity level and stable cobalt concentration in the medium, and the acute or periodic nature of the contamination. The dry weight 60Co concentration factor may reach 4x104 in LCO culture medium and is about 104 in natural water. 60Co uptake by algae is a 95% passive phenomenon, initiated by radionuclide absorption on the cell walls and followed by intracellular diffusion in accordance with Fick's law. From the initial cationic form, radiocobalt develops anion forms at a rate proportional to the algal biomass, resulting in lower contamination of old and dense cultures. After transfer in natural or artificial nonradioctive medium, 60Co is eliminated by Scenedesmus obliquus, mainly as Co2+ ions, according to a two-phase exponential process with two biological half-lives. The study of radioactive cobalt transfer from algae to gammarids and to midge larvae reveals the extend to which phytoplankton predominate over water and sediment in contaminating these two organisms. The total 60Co uptake depends significantly on whether the cells are incorporated in or deposited on the sediment. No biomagnification phenomenon of the radionuclide was found in any case, as the transfer factor was less than 1. Depuration of 60Co by organisms involved a two-phase exponential process regardless of whether uptake occured directly or from food. The presence of sediment appears to reduce the 60Co desorption rate, but from 85 to 95% of the initial quantity is eliminated. This percentage does not depend on the transfer pathway or the presence of organic matter, and indicates very slight assimilation of radiocobalt ingested with algal cells

  1. 60Co deposition on carbon-steel structural materials after seawater infiltration in BWR plant

    Seawater infiltration occurred during shutdown of the Hamaoka Unit 5 (H-5). Chloride ion (Cl-) is known to affect the corrosion behavior of carbon steel, and it may change the properties of the oxide film formed on the surface. 60Co deposition in high-temperature water is strongly related to the oxide film properties, and any change in the properties may affect the 60Co deposition after the plant is restarted. This paper shows the results of 60Co deposition tests of carbon steels under simulated H-5 water conditions. Specimens for the 60Co deposition tests were prepared in three steps, which simulated the conditions of normal plant operation, seawater infiltration, and chemical decontamination after the infiltration. The first step was a prefilming step under Normal Water Condition (NWC). The second step included two different conditions: seawater infiltration and keeping after infiltration. Prefilmed specimens were immersed in 450 ppm Cl- diluted artificial seawater at 513 K for 24 hours. Following that, the specimens were immersed in 50 ppm Cl- diluted artificial seawater at 323 K for 100-500 hours. During the second step, the prefilming oxide (NiFe2O4) flaked off in spots. In the third step, the oxide remaining on some specimens after the second step was removed chemically. The three types of prepared specimens, that is, a prefilmed specimen, an exposed specimen, and an oxide-removed specimen, were used for the 60Co deposition tests using 0.015 Bq/cm3 60Co solution for 500 or 1000 hours under NWC conditions. After the deposition tests, the 60Co activity was measured with a Ge detector. From the results of the deposition test, at the spots where flaking occurred in the second step, only loose hematite was formed, and generation of a new protective film was not observed. The amount of 60Co deposited on the exposed specimen was more than that on the prefilmed and oxide-removed specimens. The simulated infiltrating conditions inhibited the regeneration of a

  2. Monte Carlo dosimetry for 125I and 60Co in eye plaque therapy

    Monte Carlo calculations of radiation dosimetry using morse code are performed for 125I and 60Co point sources in a cylindrical head phantom that simulates the geometry of eye plaque therapy for choroidal melanoma. We obtain the dose variation in the eye at submillimeter intervals over distances as close as 1 mm and up to 2.5 cm from the source. The calculations for 125I are performed for the phantom media of water, protein, and a homogenized protein--water mixture simulating the composition of the eye. Relative dose functions for 125I for these phantom media are fitted to second-degree polynomials. Agreement is found with published results. The relative dose function for 60Co at eye position in the water head phantom is fitted to a third-degree polynomial and compared with that for 60Co at the center of a large water sphere. A boundary effect due to the head phantom--air interface on the dose distribution for 60Co is demonstrated. The dose falloff with distance is faster for the eye geometry compared with the bulk geometry. We also show that the relative dose distributions within the tumor are comparable for 125I and 60Co by comparing their relative dose functions. This result is consistent with the success of clinical trials of large melanoma treatments with 125I plaques

  3. Different gamma ray (60 Co) dose effects on Sorghum genotype germination

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

  4. Adsorption kinetic regime of cocrystallization. The system ZnC/sub 2/O/sub 4/x2H/sub 2/O-/sup 54/MnC/sub 2/O/sub 4/x2H/sub 2/0. 1. Adsorption and surface cocrystallization of /sup 54/Mn

    Melikhov, I.V.; Berdonosova, D.G.; Pencheva, Zh.

    1984-01-01

    The ZnC/sub 2/O/sub 4/x2H/sub 2/O finely divided deposit surface properties have been investigated by the methods of electron microscopy, gas adsorption and isotopic exchange in /sup 65/Zn /sup 54/Mn adsorption from aqueous solutions with Mn/sup 2 +/ initial concentration of 4x10/sup -6/ - 5x10/sup -4/ mol/l has been studied using the same deposit. Characteristic frequencies of Zn/sup 2 +/ and Mn/sup 2 +/ transitions between layers, zinc and manganese oxalates masses in the first and second layers and local coefficients of cocrystallization of manganese and zinc oxalates in near-surface layers (lambda=0.38+-0.05 and lambda/sub 2/=0.17+-0.04) have been calculated using representation on successive Zn/sup 2 +/ and Mn/sup 2 +/ transition to three near-surface monolayers and on reverse translation motion. A formula for the connection of lambda sub(..gamma..) coefficients (is a number of the surface layer) with a layer-to-surface distance has been derived. A possibility of the forecast of a dependence of effective cocrystallization coefficient of impurity with growing crystals on crystal growth rate has been revealed.

  5. Superconductivity in bulk and thin films of La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4-//sub delta/ and Ba/sub 2/YCu/sub 3/O/sub 7-//sub delta/

    Moorjani, K.; Bohandy, J.; Adrian, F.J.; Kim, B.F.; Shull, R.D.; Chiang, C.K.; Swartzendruber, L.J.; Bennett, L.H.

    1987-09-01

    A laser-ablation technique was used to deposit thin films from the bulk oxides La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub delta/ and Ba/sub 2/YCu/sub 3/O/sub 7-//sub delta/, whose superconductivity properties were investigated by dc resistivity, complex ac susceptibility, and microwave response. The latter technique was employed to establish that the thin films have superconducting regions with properties similiar to the bulk materials.

  6. Atomic-resolution studies of epitaxial strain release mechanisms in La_(1.85)Sr_(0.15)CuO_(4)/La_(0.67)Ca_(0.33)MnO_(3) superlattices

    Biskup Zaja, Nevenko; Das, S.; González-Calbet, J. M.; Bernhard, C.; Varela del Arco, María

    2015-01-01

    In this paper we present an atomic-resolution electron microscopy study of superlattices (SLs) where the colossal magnetoresistant manganite La_(0.67)Ca_(0.33)MnO_(3) (LCMO) and the high critical temperature superconducting cuprate La_(1.85)Sr_(0.15)CuO_(4 (LSCO) are combined. Although good quality epitaxial growth can be achieved, both the choice of substrate and the relatively large lattice mismatch between these materials (around 2%) have a significant impact on the system properties...

  7. Magnetic pair-breaking effects: Moment formation and critical doping level in superconducting La1.85Sr0.15Cu1-xAxO4 systems (A=Fe,Co,Ni,Zn,Ga,Al)

    We have conducted a systematic study on the effect of Cu-site doping in La1.85Sr0.15CuO4 system. The relations between Tc and doping level as well as the critical doping levels xc have been determined accurately for the Fe-, Co-, Ni-, Zn-, Ga-, and Al-doped systems. Every dopant either carries an intrinsic magnetic moment or induces a net moment on the Cu-O2 plane. The size of the moment is correlated with the suppression of superconductivity, consistent with the magnetic-pair-breaking effect. The ground states of the dopants have also been determined

  8. Changes of collagen metabolism induced by 60Co γ-ray external irradiation

    Objective: To study the changes and molecular mechanism of collagen metabolism induced by 60Co γ-ray external irradiation of local tissues. Methods: After the hip skin of rabbits was irradiated with 60Co γ-rays, the changes of collagen metabolism and collagen contents of the rabbits' skin of different sex groups were determined. Results: The γ-rays decreased the soluble collagen contents (especially type III) and increased the activity of MMPs in local tissues. Although the radiation affected the contents of serum SOD, 5-HT, and LPO, its influence on the contents in local tissues was not remarkable. There were changes of collagen metabolism in local tissues after radiation injury, but no differences were found in SOD, 5-HT, LPO, and glucosamine of tissues. Conclusion: The main mechanism of skin burn induced by 60Co γ-rays may be that the changes of collagen metabolism bring about the pathological effect

  9. Soil to plant transfer of 137Cs and 60Co in Ferralsol, Nitisol and Acrisol

    In this study, soil to plant transfer factor values were determined for 137Cs and 60Co in radish (Raphanus sativus), maize (Zea mays L.) and cabbage (Brassica oleracea L. var. capitata) growing in gibbsite-, kaolinite- and iron-oxide-rich soils. After 3 years of experiment in lysimeters it was possible to identify the main soil properties able to modify the soil to plant transfer processes, e.g. exchangeable K and pH, for 137Cs, and organic matter for 60Co. Results of sequential chemical extraction were coherent with root uptake and allowed the recognition of the role of iron oxides on 137Cs behaviour and of Mn oxides on 60Co behaviour. This information should provide support for adequate choices of countermeasures to be applied on tropical soils in case of accident or for remediation purposes

  10. Characterization of 60Co dose distribution using BEAMnrc Monte Carlo code

    In this study BEAMnrc based on EGSnrc as Monte Carlo code has been used for modeling and simulating 60Co machine in radioisotope centre of Khartoum (RICK), Two fields size ( 5 cm x 5 cm and 35 cm x 35 cm), were been studied, to define the characterization of 60Co machine and to investigate the effect of increasing the surface to skin distance (SSD) on the 60Co machine properties, e.g.; beam profile and percentage depth dose (Pdd). For the narrow field size there is a small change observed in the curves representing beam profile and the percentage depth dose when increasing the distance by 5 cm, for the wide fi ld size there relatively clear different in curves. The study results been compared with other previous studies and clear consistence observed. (Author)

  11. Quality control and calibration of the ZEUS forward and rear calorimeters with 60Co sources

    We present the motivation for and the design of a mobile 60Co source system used as part of the quality control and calibration monitoring scheme for the ZEUS calorimeters. A 2 mCi 60Co source is pushed by a computer controlled drive mechanism through guide tubes which extend into the calorimeter. Measurements of induced photocurrents as a function of the source position allow checks on the calorimeter response. We present results obtained during the initial scan of all 1024 towers of the forward and rear calorimeter modules. (orig.)

  12. Phonon, magnon and electron contributions to low temperature specific heat in metallic state of La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3 manganites

    Dinesh Varshney; Irfan Mansuri; E Khan

    2013-12-01

    The reported specific heat \\ () data of the perovskite manganites, La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3, is theoretically investigated in the temperature domain 3 ≤ ≤ 50 K. Calculations of \\ () have been made within the three-component scheme: one is the fermion and the others are boson (phonon and magnon) contributions.Lattice specific heat is well estimated fromthe Debye temperature for La0.85Sr0.15MnO3 and Er0.8Y0.2MnO3 manganites. Fermion component as the electronic specific heat coefficient is deduced using the band structure calculations. Later on, following double-exchange mechanism the role of magnon is assessed towards specific heat and found that at much low temperature, specific heat shows almost T3/2 dependence on the temperature. The present investigation allows us to believe that electron correlations are essential to enhance the density of states over simple Fermi-liquid approximation in the metallic phase of both the manganite systems. The present numerical analysis of specific heat shows similar results as those revealed from experiments.

  13. A description of 60Co gamma irradiation facilities in the Radiation Biology and Health Physics branch

    The Radiation Biology and Health Physics Branch manages three 60Co irradiation facilities, to (Gammabeam 150C, Gammacell 200 and Gammacell 220) provide a range of dose rates suitable for variety of applications. This report describes the physical characteristics of the facilities, a description of the dosimetry and operating procedures. (author). 6 refs., tabs., figs

  14. The measurement of some signals for control system of 60Co scan system for freight train

    The 60Co Scan system for Freight Train has an automatic inspection flow, so it is very crucial that the measurement of the signals for the automatic control system. In this paper, we mainly introduce the identification of the intervals between two freight train carriage, the measurement of the train speed, and identification of freight train

  15. Design and realization of the review station of 60Co train inspection system

    The author illustrates design and realization of the review station software of 60Co train inspection system (TCT-SCAN). The software have two remarkable functions: processing images of carriages and accessing information of inspection, which are provided by two processes respectively. The communication between processes is realized by memory-mapped file

  16. Effect of 60Co γ-ray irradiation on salmonella in high immunity egg yolk

    Salmonella were inoculated into the yolk and irradiated with different dose of 60Co γ-ray. The results show that 3 kGy irradiation dose can kill all Salmonella in the yolk and D10 value of Salmonella in the yolk is 0.36-0.46 kGy

  17. Mutant in tobacco anther culture induced by 60Co γ-rays

    The tobacco anthers at uninucleate eccentric stage were irradiated by 60Co γ-rays for the purpose of inducing desirable mutants. The results showed that the induction frequency of plantlets increased following 1kR of 60Co γ-rays treatment. However, the time of plantlet induction was delayed and the percentage of responding anthers as well as the number of plantlets induced per anther significantly decreased after 3kR of 60Co γ-ray radiation which was considered as a semilethal exposure. The plantlet numbers induced per anther were extremely low following 6kR of 60Co γ-ray radiation. A white flower mutant appeared in the induced progenies. The tobacco leaf quality of this mutant were significantly improved as compared with its parental line. The mutant line has been tested and proved to have commercial value though the resistance to the black shank of tobacco slightly decreased as compared with the parental line

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

    Luciana Tourinho Campos

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

  19. Comparison of dosimetric standards of Canada and France for photons at 60Co and higher energies

    We report the results of a comparison of the dosimetric standards of Canada and France for photon beams at 60Co and a few higher energies. The present primary standard of absorbed dose to water for NRC, Canada is based on measurements made with a sealed water calorimeter. The corresponding standard of the LNHB, France is based on measurements made with a graphite calorimeter at 60Co energy and transferred to absorbed dose to water for 60Co and higher-energy photon beams using both ion chambers and Fricke dosemeters as transfer instruments. To make this comparison, we used three graphite-walled NE2571 Farmer chambers. The absorbed dose to water determined by the LNHB was greater than that determined by NRC by 0.20% at 60Co energy. This difference is not significant given the uncertainties on the standards. In order to do the comparison for higher-energy photons, we interpolated the NRC data set at the beam qualities used at the LNHB. When %dd(10)x is used as the method of specifying beam quality, the determination of absorbed dose to water by the LNHB is about 0.2% greater than that determined by NRC and consistent with the results at 60Co. However, when using TPR20,10 as the beam quality specifier, the LNHB determination is greater than the NRC's determination by 0.8% and 1.2% at 12 and 20 MV respectively. This discrepancy, which systematically increases with increasing energy, eventually exceeds the uncertainties in the ratio of the standards, estimated to be 0.7%. This underscores the importance of selecting the method of specifying beam quality, either %dd(10)x or TPR20,10, at least for the 'soft' beams used by NRC in this comparison. In the case of the air kerma standards, which were also compared at 60Co energy, the LNHB determination was greater than NRC's by 0.14%, which is not significant given the uncertainties on the standards. (author)

  20. Systematic study of (La sub 1 minus x Gd sub x ) sub 1. 85 Sr sub 0. 15 CuO sub 4 (0 le x le 1): Structure, superconductivity, resistivity, and magnetic properties

    Xiao, G.; Cieplak, M.Z.; Chien, C.L. (Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218 (US))

    1989-09-01

    A room-temperature structural phase diagram has been determined in (La{sub 1{minus}{ital x}}Gd{sub {ital x}}){sub 1.85}Sr{sub 0.15}CuO{sub 4} system (0{le}{ital x}{le}1). There exist three stable phases ({ital T}, {ital T}{sup *} and {ital T}{prime}), in which the local Cu-O unit is an octahedron, a pyramid, and a square, respectively. The Jahn-Teller distortion is reduced in the order of {ital T}, {ital T}{sup *}, and {ital T}{prime}. For each phase, there is a solubility region. No magnetic ordering is found in the {ital T} and {ital T}{sup *} phase, both of which exhibit paramagnetism with a constant Gd magnetic moment consistent with that of Gd{sup 3+}. In Gd{sub 2}CuO{sub 4} and Gd{sub 1.85}Sr{sub 0.15}CuO{sub 4}, the initial susceptibility indicates a Neel state in the Cu-O{sub 2} plane at {ital T}{sub {ital N}}=285 K and another magnetic transition at low temperature. {ital T}{sub {ital N}} is not sensitive to the Sr doping at all, indicating that extra holes cannot be doped onto the Cu-O{sub 2} plane. While the {ital T}{sup *} and {ital T}{prime} phases are insulating, exhibiting a variable-range hopping behavior, the Gd-doped (La{sub 1{minus}{ital x}}Gd{sub {ital x}}){sub 1.85}Sr{sub 0.15}CuO{sub 4} ({ital x}{le}0.1) is superconducting with {ital T}{sub {ital c}} reducing with increasing Gd concentration. The suppression of {ital T}{sub {ital c}} is not due to a variation of the electron-boson coupling strength which remains unchanged in the system, but correlates closely with the low-temperature resistivity anomaly. Such an anomaly can be best described by a logarithmic temperature dependence.

  1. Seed germination of peanuts irradiated with cobalt ({sup 60}CO); Germinacao de sementes de amendoim irradiadas com cobalto ({sup 60}Co)

    Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B., E-mail: niedjamarizze@yahoo.com.b, E-mail: josivanda@deag.ufcg.edu.b, E-mail: elvirabe@gmail.co [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia Agricola; Leal, Artur S. Cavalcanti, E-mail: arturcleal@yahoo.com.b [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    This work was realized to evaluate the effect of gamma irradiation ({sup 60}Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  2. Doses in sensitive organs during prostate treatment with a 60Co unit

    Using thermoluminiscent dosimeters the absorbed dose in the bladder, rectum and thyroid have been evaluated when 200 cGy was applied to the prostate. The treatment was applied with a 60Co unit. A water phantom was built and thermoluminiscent dosimeters were located in the position where the prostate, bladder, rectum and thyroid are located. The therapeutic beam was applied in 4 irradiations at 0, 90, 180 and 270° with the prostate at the isocenter. The TLDs readouts were used to evaluate the absorbed dose in each organ. The absorbed doses were used to estimate the effective doses and the probability of developing secondary malignacies in thyroid, rectum and bladder. - Highlights: • The absorbed doses in the bladder, rectum and thyroid were measured. • Measurements were done during prostate treatment with a 60Co unit. • TLD100s in a water phantom were used. • The effective doses were also estimated

  3. Effect of 60Co-γ ray irradiation on green coffee beans, 1

    Green coffee beans were irradiated with 60Co-γ rays at doses of 0, 0.05, 0.5, 5.0 and 10.0 Mrad and the changes of general components in green and roast coffee beans were investigated together with those of the organoleptic properties of roast beans during storage according to the cup testing. In case of Brazil santos beans, irradiation of some 0.05 Mrad 60Co-γ ray gave rather favourable mild flavour and no harmful influence on the quality of coffee, and moreover, would tend to extend the shelf life of roast beans. But influence of irradiation on the quality of coffee differed somewhat between two cultivars, Brazil santos and Colombia. (auth.)

  4. Removal of 60Co and 134Cs from radioactive process waste water by flotation

    The removal of 134Cs and 60Co from radioactive process waste water using cetyl pyridinium chloride (CPC) as a collector and cobalt(II) hexacyanoferrate(II) as a precipitant for 60Co and sorbent (ion exchanger) for 13'4Cs was intensively investigated and the best removal conditions could be established. The results indicate that under the optimum conditions removals higher than 96% and 97% could be achieved for Co(II) and Cs(I), respectively. Cobalt(II) hexacyanoferrate(II) was found to have high affinity for cesium and can preferentially remove it in presence of relatively high amounts of other alkali or alkaline earth cations. A two-stage flotation process was successfully tested for the removal of both Cs(I) and Co(II) from waters containing both cations. (author) 59 refs.; 8 figs.; 2 tabs

  5. National comparison of activity measurements of 131I, 60Co, and 133Ba in Indonesia

    National comparisons of radioactivity measurements of 131I and 60Co (in 2010) and of 133Ba (in 2011) were carried out within the framework of the National Radiation Metrology Laboratory Program of Indonesia, coordinated by PTKMR-BATAN. Eleven laboratories took part in the comparison, and all measurements were made using gamma spectrometry, on point sources with an activity between 2000 Bq and 6000 Bq. Several laboratories reported values which were more than 10% different from the reference value for 131I and 133Ba. Possible reasons for these differences are discussed. This program will be continued with other radionuclides to maintain and control quality assurance for the local laboratories. - Highlights: • PTKMR-BATAN coordinated national comparison of 131I, 60Co and 133Ba. • Eleven laboratories took part in the comparison. • All measurements were done using gamma spectrometry methods. • For 131I and 133Ba, 3 laboratories have more than 10% difference from reference laboratory value

  6. Dosimetric response of united, commercially available CTA foils for 60Co gamma rays

    The usefulness of two kinds of untinted CTA foils: Fuji CTR-125 dosimetric foil and technical CTA-T foil, produced by 'Zaklady Chemiczne, 'Gorzow Wielkopolski' as support for light-sensitive layers of amateur photo-films, for 60Co gamma ray dosimetry was investigated. In spite of rather bad physical parameters of the technical foil (spread of foil thickness, high and different initial absorbance) the dosimetric response of both foils for 60Co gamma rays was similar. The CTA-T foil can be used for routine dosimetry providing that dosimetric signals have to be calculated exactly as recommended by the ASTM (American Society for Testing and Materials) standard, i.e. as the difference of absorbance of irradiated and (the same) non-irradiated foil. Any other approach may lead to high errors of dose evaluation. The last is true also for other CTA foils, especially after long self-life. (author)

  7. The teratogenic effects of low dose 60Co γ-rays on the early pregnant rats

    The pregnant Wistar rats were exposed to 0.5 Gy and 1.0 Gy 60Co γ-rays at the 9th day after conception. The results: 60Co γ-rays at dose of 1.0 Gy could induced many defects: excenphaly, hydrocephalus, gastroschisis, cleft palate and cleft lip, anophthalmia, microphthalmia, shorten tail and absent tail in surviving fetuses. The growth retardation was found from the parameters of fetal weight, height, head circle and development of skeleton. In the group of radiation dose 0.5 Gy, only hydrocephalus, absent tail and growth retardation of skeleton appeared. The results suggest that low-dose exposure in the early pregnant rats can induce fetal defects and growth retardation. The probable mechanism of teratogen and growth retardation was discussed. The cAMP levels of brain and liver of rat fetuses were reported

  8. SV40 DNA amplification and reintegration in surviving hamster cells after 60Co γ-irradiation

    SV40-transformed Chinese hamster embryo cells were exposed to 60Co γ-irradiation and the fate of the integrated SV40 sequences was pursued over a period of 20 days following radiation exposure. As shown by colony hybridization, integrated SV40 sequences were amplified in surviving and non-surviving cells. At later times, however, clonal sublines of surviving cells grown for 20-30 cell generations after irradiation had lost most of their amplified SV40 copies but showed altered restriction fragment patterns indicating reintegration of SV40 sequences at new sites of the hamster genome. This suggest that 60Co γ-irradiation can generate mutations by inducing over-replication of chromosome segments that are then substrates of enzymatic rearrangements. (author)

  9. Long-term clearance of accidentally inhaled 60Co aerosols in humans

    Long-term body retention was measured on six workers inhaling 60Co aerosols incidentally during manipulation with a high activity 60Co source. An improved whole body counter technique and calibration provided good conditions to follow the body clearance over 4 years. A two-detector profile scanning arrangement was used to measure the activity distribution 'in vivo' over the lung region. The observed whole body retention followed a two-exponential time function between 10-1500 days. The consistency of the measured retention pattern with ICRP inhalation model was investigated assuming different aerosol size distributions. A possible extension of ICRP lung model is proposed to take into account the actual pulmonary lung clearance determined individually. (R.P.) 29 refs.; 15 figs.; 6 tabs

  10. Cataract production in mice by fractionated doses of 12C particles or 60Co gamma radiation

    The objective of our study was to evaluate the sparing effects of long-term dose fractionation with high LET 12C ions and 60Co gamma radiation. Because cataract examinations could be performed nondestructively, mice dedicated to studies of life shortening and carcinogenic response to photons and heavy charged particles were available for study. The project's staffing was such that slit-lamp biomicroscopic examinations could be performed only on CB6F1 male mice that received single or fractionated doses of 225 MeV/amu 12C ions and animals that received a single or fractionated dose of 60Co gamma radiation of 4.17 Gy. A total of 24 fractionated doses were administered weekly. Using a semiquantitative scoring system, the severity of cataract response was evaluated at three sample times following the single dose or first fractionated dose

  11. Analysis of the microbial growth in {sup 60}Co {gamma}-irradiated foods by calorimetry

    Furuta, Masakazu; Hayashi, Toshio [Osaka Pref. Univ., Research Institute for Advanced Science Technology, Sakai, Osaka (Japan); Hamasaki, Koji; Wirkner, Sandra; Constantinoiu, Elena; Takahashi, Katsutada [Osaka Pref. Univ., College of Agriculture, Sakai, Osaka (Japan)

    2002-09-01

    Using a heat conduction calorimeter equipped with 24 sample units the heat evolutions from growing {sup 60}Co {gamma}-irradiated bioburden of black pepper seeds and frozen beef were detected in the form of growth thermograms. {sup 60}Co {gamma}-irradiation affected the growth pattern in which a dose-dependent reduction of the growth rate constant was observed together with the retardation in growth, indicating a combination of bactericidal and bacteriostatic effects. We successfully determined the minimal inactivation doses for the two food samples using the relationship between the irradiation dose and the retardation in growth t{sub {alpha}}, or the growth rate constant {mu} obtained from the growth thermograms. These results strongly suggested the possibility of calorimetry as measure of predictive microbiology in food irradiation. (author)

  12. The effect of 60Co gamma radiation on human serum gamma-globulin

    The effect of 60Co gamma radiation on human serum gamma-globulin was studied in vitro experiments. Solutions of 0.5 percent gamma-globulin were exposed to 0.2, 0.5, 1.0 and 1.9 Mrad doses 60Co gamma irradiation. Experiments showed that electrophoretic mobility of serum gamma-globulin decreased after gamma irradiation. No significant change in gamma-globulin UV absorption spectrum was observed at 0.2, 0.5, 1.0 and 1.9 Mrad doses. Gamma-globulin becomes progressively less soluble in water as the radiation doses is increased. Radiation induced transformation into insoluble gamma-globulin agregates and scission products. (author)

  13. Experiments for inactivation of mycoplasms and bacteria in calf sera, using 60Co irradiation

    The use of 60Co gamma radiation to inactivate mycoplasms in calf serum, newborn calf serum, and fetal calf serum is reported. A dose of 3 kGy, independent of dose rate, was found to be sufficient for inactivation in the above sera of several mycoplasms, including Acholeplasma laidlawii, Mycoplasma orale, M. arginini, M. hyorhinis, and M. bovis. The critical dose proved to be at 2 kGy. No difference was found to exist between the above species in susceptibility to irradiation in diluted sera (50% and 10% in Eagle MEM). Sensibility of wild mycoplasm strains was found to be identical with that of laboratory strains. Hence, 60Co gamma irradiation of sera appears to be a safe method by which to make sera free of mycoplasms. Bacillus subtilis in calf serum was inactivated by doses above 18 kGy, with the critical dose being 15 kGy. (author)

  14. The realization of 60Co container inspection system's check-in station

    The functional design and realizing mode of the check-in station software of 60Co container inspection system are illustrated. Check-in station plays an important role in 60Co container inspection system. It undertakes the tasks of inputting the container's relative information, flow control of containers waiting for inspections and the information transfer. Of all the information of check-in station inputs, the customs declaration or the encasement declaration is the main information to be input. In this software, they are input by scanner and the control module of scanner is programmed according to Twain criterion. As Twain criterion is generally followed by image industry, this software has high generality and facility independence

  15. Image acquisition, transmission and assignment in 60Co container inspection system

    The author describes the data acquisition mode and image reconstruction method in 60Co container inspection system, analyzes the relationship between line pick period and geometry distortion, makes clear the demand to data transmitting rate. It discusses several data communication methods, draws up a plan for network, realizes automatic direction and reasonable assignment of data in the system, cooperation of multi-computer and parallel processing, thus greatly improves the systems inspection efficiency

  16. Immobilization of 60Co and 90Sr ions using red mud from aluminum industry

    Milenković Aleksandra S.; Smičiklas Ivana D.; Marković Jelena P.; Vukelić Nikola S.

    2014-01-01

    The removal of 60Co and 90Sr from the aqueous phase was tested using red mud - the fine grained residue from bauxite ore processing. This industrial waste represents a mixture of numerous minerals, mainly oxides and hydroxides of Fe, Al, Si, and Ti. Experiments were conducted as a function of contact time, pH, and pollutant concentrations. Kinetic data were well fitted with a pseudo-second order equation. The calculated rate constants and initial sorption r...

  17. A case study of medical intervention following intake of 60Co

    The present study is based on the follow up study of a case of 60Co internal contamination using whole body counting and bioassay analysis. The effect of medical intervention applied on the subject is studied. Medical intervention with D-penicillamine (250 mg x 4 daily) orally was administered from thirteenth day of initial exposure for about a fortnight, which showed reduction of activity present by 33.4% through urine. (author)

  18. Study on the possibility of using a 60 Co therapeutical unity in Intensity Modulated Radiotherapy (IMRT)

    With the increasing advances in complex treatment techniques, there is a tendency to obtain more sophisticated equipment to deliver the dose. The use of 3D conformal radiotherapy is now routine in many radiotherapy facilities as well as the utilization of intensity modulated radiotherapy (IMRT). Both are usually implemented using linear accelerators equipped with multi leaves collimators, which create the conformity and the fluence distributions required. However, the complexity of increasingly sophisticated equipment, such as linear accelerators, requires a frequent quality control of their operation, as well as a detailed and constant maintenance. Even carrying out these procedures, the accelerators may present technical problems interrupting for a long time a treatment using the IMRT technique. Despite the clear practical and technological advantages that linear accelerators have on 60Co irradiators, these devices occupy an important place in radiotherapy, mainly due to the low cost of equipment installation and maintenance when compared to those required by accelerators. Many radiotherapy facilities that work with IMRT have tele therapeutic isocentric 60Co units. In principle, such equipment would be able to be used for treatment with IMRT using compensating blocks to modulate the beam. This study investigates this possibility and shows that it is feasible. The comparison of treatment plans of a head-and-neck cancer and other of a cancer of the central nervous system, based on a 60Co irradiator and a Linac 2300 C/D, presented advantages for the 60Co irradiator. Furthermore; the delivery of dose obtained with the two systems showed themselves equivalent when compared to their respective plans. (author)

  19. Monte Carlo simulation of a digital coincidence system applied to 60Co standardization

    The Laboratorio de Metrologia Nuclear (LMN) at the Instituto de Pesquisas Energeticas e Nucleares (IPEN) is developing a Digital Coincidence System (DCS), including the design of the proper acquisition electronics and analysis software. A brief discussion about the measurement methodology and the electronics operation is presented. This work is focused on the results of the designed software (the Monte Carlo simulation of 60Co decay data and the Coincidence Data Analysis), which are in good agreement with the experimental data. (author)

  20. Studies on bioaccumulation of 152Eu, 137Cs, 60Co by different algal genera

    In the present paper, the bioaccumulation of a mixture of potentially hazardous, long lived radionuclides 152Eu, 137Cs and 60Co by five algal genera of three different family, viz.: Lyngbya and Phormidium from cyanophyceae; Phizoclonium and Chaetomorpha from chlorophyceae and Catenella from rhodophyceae have been studied. Because of the long half life and high solubility, these radionuclides are considered the most hazardous in the nuclear spent fuel

  1. A positron 1D-ACAR spectrometer for the study of 60Co containing materials

    In order to study some micro-structural changes in irradiated nuclear reactor-pressure vessel steels using a positron annihilation technique, a new three-detector set-up, suitable for a positron 1-dimensional angular correlation of annihilation radiation (1D-ACAR) study of 60Co-containing materials, was developed. The design of the equipment as well as results from test measurements are described. (orig.)

  2. Comparison of the electrodynamic properties of sintered YBa2Cu3O/sub 7-//sub y/ and La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub y/

    The reflectivity in the superconducting and normal states of YBa2Cu3O/sub 7-//sub y/ has been reproduced with the effective-medium theory plus an anisotropic dielectric function and the Mattis-Bardeen conductivity with a gap value 2Δ/k/sub B/T/sub c/ = 2.5 to 2.7. We find that the lowest ir-active phonon polarized in the high-conductivity plane produces structure in the superconducting gap, the lowest-frequency phonon perpendicular to the plane is overdamped, and that the electronic susceptibility is more isotropic for YBa2Cu3O/sub 7-//sub y/ than for La/sub 1.85/Sr/sub 0.15/CuO/sub 4-//sub y/

  3. Development and characterization of a new graphite ionization chamber for dosimetry of 60Co beams

    Ionization chambers are the most employed dosimeters for precise measurements, as those required in radiotherapy. In this work, a new graphite ionization chamber was developed and characterized in order to compose a primary standard system for the beam dosimetry of the 60Co sources. This dosimeter is a cylindrical type ionization chamber, with walls and collecting electrode made of high-purity graphite, and the insulators and stem made of Teflon®. The walls are 3.0 mm thick, and it has a sensitive volume of 1.40 cm3. The characterization was divided in two steps: experimental and Monte Carlo evaluations. This new dosimeter was evaluated in relation to its saturation curve, ion collection efficiency, polarity effect, short- and medium-term stabilities, leakage current, stabilization time, linearity of response and angular dependence. All results presented values within the established limits. The second part of the characterization process involved the determination of the correction factors, obtained by Monte Carlo simulations. Comparing these correction factors values with those from other primary standard laboratories, the highest differences were those for the wall and stem correction factors. The air-kerma rate of the 60Co source was determined with this new dosimeter and with the IPEN standard system, presenting a difference of 1.7%. These results indicate that this new dosimeter may be used as a primary standard system for 60Co gamma beams. (author)

  4. Responses of commercial broiler chicks to 60Co gamma-rays

    A total of 360 chicks of Nichols line at one-day old were used in this study. Within each sex, the chicks were divided into three exposure treatments (non-irradiated, 400 rads and 800 rads). The source of irradiation was 60Co gamma-rays. The results can be summarized as follows: Of the 360 chicks used in this study, only 10 chicks died during the experimental period. Radiation induced a reduction in body weight in both sexes during the growth period. Gamma-rays reduce the feed intake in both sexes. Moreover, the feed conversion ratio for the irradiated chicks was higher than that the non-irradiated birds. While red blood cells and hemoglobin content were higher in the irradiated chicks, white blood cells count and especially lymphocytes did not affect by 60Co gamma-rays. Gamma-rays had no effect on carcass, bone, meat and giblets as fractions of body weight in both sexes. Moreover, meat water content decreased and meat fat content increased in irradiated chicks. The total length and the total weight of the GI tract decreased due to 60Co gamma-rays. The response of the different regions of the GI tract to this rays is different. Moreover, the effect of this radiation on the GI tract is dependent upon the body weight irrespective of the sex. (orig./MG)

  5. 60Co accumulation from sediment and planktonic algae by midge larvae (Chironomus luridus)

    This paper reports the results of several experiments carried out to evaluate uptake and retention by a limicolous midge larva of 60Co retained in sediment, either adsorbed on mineral particles or bound to planktonic algae. In order to determine their relative contributions in radionuclide accumulation, the different vectors (water, algae and sediment) were first labelled individually and then simultaneously. 60Co accumulation from water and from algae results in a maximum concentration factor of 30 and in a mean trophic transfer factor of 4·5 × 10−3. The level of contamination of midge larvae from sediment is markedly influenced by the presence of endogenous organic matter. Thus the radionuclide transfer factor is about twice as high for larvae placed in labelled raw sediment than for larvae placed in labelled incinerated sediment, in the presence as in the absence of contaminated planktonic algae. Irrespective of the contamination conditions, 60Co depuration from midge larvae is a very rapid phenomenon that corresponds, in all cases, to a radionuclide half-life of only a few days

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

    Xiang, Yulin; Xiang, Yuxiu; Wang, Lipeng

    2016-03-01

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

  7. Decontamination of salmonella from the coastal fish meals by 60Co γ ray irradiation

    The decontamination fo salmonellae from fish meal samples by irradiation which 60Co γ ray was examined. Sixteen strains of Salmonella were used. A composite fish meal sample was prepared by mixing with different coastal meals, and after radiation sterilization at a dose of 20 kGy 60Co γ ray, which was employed as the salmonella-free meal sample. D10 values of test strains determined in buffered saline were found to range from 0.08 to 0.36 kGy, and inactivation factors at a dose of 1 kGy ranged from 102.8 to 1013. D10 values of test strains determined in the salmonella-free meal sample ranged from 0.59 to 1.64 kGy, and the inactivation factors at a dose of 10 kGy were found to range from 106.1 to 1017. Interestingly the D10 values of salmonellae determined in fish meal samples were 10 times as much compared with those determined in buffered saline. From the commercial aspects of coastal fish meal production, destruction of salmonellae in fish meals by 60Co γ ray irradiation was found to be much more practical than other methods such as dry heating and ethylene oxide fumigation. (author)

  8. Effects of 60Co γ-radiation on the embryo development of goldfish

    The effects of 60Co γ-radiation on the development of goldfish embryos were investigated by different doses and different dose rate. The results showed that 0.5-1.0 Gy 60Co γ-radiation could speed up the development of embryos, but did not cause higher hatching rate. 0.5-1.0 Gy 60Co γ-radiation caused hyperradiosensitivity on goldfish embryos, whereas 2.0-4.0 Gy caused increased radioresistance. Embryos at 4-8 cell stage showed higher survival rate and lower abnormal embryo rate than embryos at multicellular stage or early gastrula stage when radiated at the same dose and dose rate. The results also showed that the radiation at low dose rate (lower than 1.0 Gy/min) could cause more serious damage than the relative higher dose rate (1.0 Gy/min). Early embryos radiated at 1.0 Gy/min dose rate and lower than 2.5 Gy were suggested for the breeding. (authors)

  9. Leaching of 60Co, 137Cs and 226Ra in lysimeter experiments

    The present report describes the first results obtained from lysimeter experiments started in 1990. The lysimeter plant consists of twelve soil monoliths from four different sites (three replicates each). Since 1990 the following agricultural crops were grown: endive, corn, winter wheat, mustard, sugar beet and potato. Gravitational water ranged from 3.9 % to 18.3 % of precipitation plus irrigation water, calculated as half years average values excluding the first six months of operation. The two Cambisols on sediments exhibited a mean percentage of approx. 10 %. The Dystric Cambisol on silicate rock and the Gleysol showed average values of 20 %. In 1990 the top layers (20 cm) were contaminated with three radionuclides. The leaching of the contaminants 60Co, 137Cs and 226Ra differed distinctly between the elements. The lowest leaching rates were observed for 137Cs, followed by 60Co. The 226Ra-concentrations in the gravitational water were clearly highest of all. However, the comparison of the 226Ra/2228Ra ratios in deep soil layers and in gravitational water showed that the 226Ra measured in the leachate originates from the natural contents in the subsoil and not from the artificial 226Ra contamination of the topsoil. The mobility of the artificial radionuclides decreased therefore in the following order: 60Co > (226Ra) > 137Cs. (author)

  10. Transfer and mobility of 137 Cs and 60 Co in oxisol and alfisol

    One manner to assess potential mobility of radionuclides in soils is the use of sequential extraction procedures. These procedures intend to provide the radionuclide partitioning in geochemical phases of soil affected by changes in physico-chemical conditions. In this study a new sequential chemical extraction protocol was choose to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties. The results of sequential procedure was further compared with soil to plant transfer factors data for maize and radish and with soil properties, showing rather consistent results. The 137 Cs distribution in soil showed that Fe oxides are the main sink for this element and after 14 years after contamination the 137 Cs was still available for plants. The 60 Co distribution showed that Mn oxides are the main sink for this element in Alfisol and 5 years after contamination no 60 Co was detected as bioavailable neither detectable in maize. The knowledge of the bio-geochemical behavior of radionuclides in soil system can be useful for risk assessment studies, to be applied in the case of nuclear accident or contamination scenarios. (author)

  11. A new parallel-plate graphite ionization chamber as a 60Co gamma radiation reference instrument

    The calibration procedure in radiotherapy treatments is very important and a sensitive task due to the high doses delivered to the patients. Generally, the air-kerma cavity standards for 60Co gamma rays are graphite cavity ionization chambers. In this work a new parallel-plate graphite ionization chamber was studied to analyze its potential use as a reference instrument. In order to evaluate its performance in 60Co beams, it was submitted to several characterization tests. Moreover, Monte Carlo simulations were undertaken using the EGSnrc code to study the influence of the chamber components on its response. The results obtained showed that this new ionization chamber presented a satisfactory performance in all evaluated tests. - Highlights: ► A new ionization chamber was characterized as a reference dosimeter for 60Co beams. ► The EGSnrc code was used to determine the influence of the chamber components. ► The characterization test results were within the recommended limits. ► The results showed that this dosimeter may be used as a reference dosimeter

  12. Superconducting and normal-state properties of La/sub 1. 85/Sr/sub 0. 15/Cu/sub 1-//sub x/Ga/sub x/BO/sub 4/

    Cieplak, M.Z.; Xiao, G.; Bakhshai, A.; Chien, C.L.

    1989-03-01

    We have studied the superconducting and normal-state properties of La/sub 1.85/Sr/sub 0.15/(CU/sub 1-//sub x/Ga/sub x/)O/sub 4/ (085/Sr/sub 0.15/(Cu/sub 1-//sub x/Zn/sub x/)O/sub 4/ system. The disappearance of superconductivity is most likely due to the complete filling of the Cu local 3d band and not due to the pair-breaking effect induced by nonmagnetic disorder. The Ga doping induces localization of the Cu 3d holes as evidenced from the susceptibility measurements. The normal-state resistivity exhibits a minimum followed by a logarithmic increase as the temperature is lowered. The temperature of the minimum increases linearly with the Ga content. The logarithmic upturn in the resistivity indicates that neither an activation process nor variable range hopping is responsible for the low-temperature electronic transport. Among two other possible mechanisms, the Kondo effect and effect of localization and correlation, the Kondo effect gives a much better description of the temperature dependence of the resisitivity in the whole temperature range (4--300 K) and for all of the samples.

  13. Behavior of 60Co and 134Cs in a Canadian Shield lake over 5 years

    Radionuclides were added to the anoxic hypolimnion of a Canadian Shield lake to simulate the nuclear fuel waste disposal scenario where radionuclides might enter the bottom waters of a lake. The radionuclides remained in the hypolimnion until lake mixing at autumn turnover after which 60Co was rapidly lost and 134Cs was slowly lost from the water. Only 0.4% of the 60Co and 0.6% of the 134Cs remained in the water at year 5. Highest concentrations occurred in periphyton and filter feeders, Holopedium gibberum and clams (Anodonata grandis grandis). From maximum annual concentrations in clam tissues, it was estimated that the availability of 60Co for uptake had a half-time (t1/2) of 835 days in the lake, whereas that for 134Cs was 780 days. Loss rate coefficients, k, for the radionuclides from taxa ranged from 0.0008 to 0.0043 day-1 (t1/2=161-866 days) for 60Co and from 0.0009 to 0.005 day-1 (t1/2=139-770 days) for 134Cs. Cobalt-60 concentrations in forage fish were low, whereas 134Cs concentrations increased over the first year or two, then slowly declined. On the basis of k values measured for forage fish, the biological half-time of 134Cs in forage fish ranged from 428 to 630 days. Maximum 134Cs concentrations in forage fish were higher following hypolimnetic addition than epilimnetic addition. Relatively high 134Cs concentrations in periphyton at year 5 point to the importance of benthic pathways in the recycling of contaminants to higher trophic levels. The presence of 134Cs in biota 5 years after the addition, long after concentrations were no longer detectable in surface waters, is evidence of the persistence of Cs in aquatic systems. The k values (or t1/2 values) for the loss of 60Co and 134Cs from water and their uptake and loss from biota can be used to establish parameter values for assessment models. The results demonstrate that assessment models should account for the release of radionuclides from sediment and their subsequent recycling in the food chain

  14. Gamma 60Co DL50/30 of Biomphalaria glabrata (Say, 1818 DL50/30 raios gama de 60Co em Biomphalaria glabrata (Say, 1818

    Elaine Barros da Costa CARVALHO

    1999-11-01

    Full Text Available The variation of resistance to 60Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose to increasing doses of gamma radiation. Doses of 10, 20, 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell 60Co irradiator, were applied to the test groups and two groups control (non-irradiated of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL50/30 = 218.2 Gy was found greater than in cross-fecundation forms. These data point to a low radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon.A variação da resistência entre indivíduos em autofecundação e fecundação cruzada de Biomphalaria glabrata foram estudadas. Uma população de 480 moluscos foi observada durante 29 dias, distribuída em 8 grupos de caramujos isolados e 8 grupos em colônias após a exposição (30 caramujos por grupo-dose a doses crescentes de radiação gama. Foram usadas doses de 10, 20, 40, 60, 80, 160, 320 e 640 Gy de um irradiador Gamma-Cell 60Co. Dois grupos não irradiados - isolado e colônia - foram separados como controle e após a irradiação todos os caramujos voltaram para aquários onde viviam antes. A sobrevida foi estimada pela contagem diária dos animais vivos em cada grupo-dose, a partir do dia da irradiação. O resultado mostrou maior sobrevivência nos grupos isolados (DL50/30 = 218.2 Gy que nos grupos

  15. 60 Co 放射源运输容器屏蔽性能检测%Shielding Performance Measurements on Container for 60 Co Radioactive Sources Transport

    孙洪超; 李国强; 闫峰; 庄大杰; 孙树堂; 王学新

    2015-01-01

    工业及医疗用放射源主要包括60 Co、137 Cs、131 I、32 P、153 Sm、99 Mo、90 Sr、89 Sr等核素,射线形式有α、β、γ、中子等。本文针对运输活动中γ辐射,使用现有的60 Co放射源运输容器,开展辐射屏蔽性能检测技术研究。通过模拟计算和实验测量,得到运输容器最大装载活动情况下外部辐射水平,并对计算和实验结果进行了比较。针对放射源在屏蔽容器中安放位置发生偏移和放射源在容器中安放方式不同对容器外部的辐射水平影响进行了相关研究。研究结果可对今后完善放射性物质运输容器的辐射屏蔽性能检测提供一定的借鉴。%Some radioactive sources are often used in irradiation industry and radiothera‐py ,such as 60Co ,137Cs ,131I ,32P ,153Sm ,99Mo ,90Sr ,89Sr and so on .The radiation includeα、β、γ and n .The radiation from γ sources are the mostly concerned during the transporting of radioactive sources .The shielding performance measurements on con‐tainer for 60Co radioactive sources transport were discussed by using both Monte Carlo method simulation calculation and experiment measurement . Some important factors w as discussed w hich could affect the results of shielding performance measurements . The layout of radioactive sources had a important impact on the monitoring results of the external radiation levels of radiation sources transport container .The results affor‐ded the contribution to the improvement of the radiation monitoring and management of radioactive material transportation package .

  16. Detection and temporal variation of 60Co in the digestive glands of the common octopus, Octopus vulgaris, in the East China Sea

    60Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of 60Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with 60Co and without 60Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of 60Co and the source of 60Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of 60Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of 60Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of 60Co were identical and were temporary dumped into the East China Sea as a solid waste.

  17. Behavior of the sorption of 60 Co in aqueous solution on inorganic materials as function of p H

    The sorption of the 60 Co is evaluated in aqueous solution on Mg O, MnO2, TiO2, Sn O, activated carbon and hydrotalcite calcined as a function of the p H, using the method for lots and quantifying at the 60 Co for gamma spectrometry. Likewise it was explained the one behavior of the sorption of the 60 Co in the materials with base in the chemical species of this radioactive isotope in aqueous solution. The chemical species of the 60 Co in solution were identified by electrophoresis of high voltage for the different p H values. It was found that under the experimental conditions, the 60 Co showed a significant sorption on MnO2, TiO2 and activated carbon. On the other hand, in Mg O, Sn O and calcined hydrotalcite also was observed a sorption, although in smaller quantities. The studied hydrated metallic oxides retained the 60 Co for ion exchange via. It was found that the 60 Co was present as a cationic specie to p H 1, 3, 5 and 7 and like a neutral specie to alkaline p H. (Author)

  18. Comparison of treatment in soybean grains between 60Co and e-beans applications

    Soybean is the most important oleaginous cultivated in Brazil, who is the second largest exported in the world, and generates high incomes, direct and indirectly, its oils could be used since to cook even to machine's fuel and the nutrients become basic for the feeding human being, beyond its by-products, that offer great diversities of products for the nourishing industry. Between the main factors that limit the attainment of high incomes, are the illnesses caused by microorganism like fungi, bacteria, and viruses that, in general, are difficult to control and cause damages on harvest of billions of dollar every year. An alternative to minimize the losses is preserving the grains through the irradiation that can come today from two different main sources: e-beam and 60Co. Beyond power to be off when it will not be in use, the source of e-beams machines does not need to be recharged, is easily available, possess high tax of dose and low energy. However the 60Co have low dose rate, high energy and the photons emission is continuous. This work aims to compare the effects of the radiation through viscosimetry, DNA Comet Assay and Cooking time techniques in soybean grains at doses 0, 1.0, 3.0 and 5.0kGy irradiated in ambient temperature at 60Co source Gammacell 220 (A.E.C. Ltda) and in e-beam accelerator - Radiation Dynamics (Radiation Dynamics Co. model JOB, New York, USA), 1.5 MeV- 25mA with the lower dose. (author)

  19. Assessment of the mobility and bioavailability of 60 Co and 137 Cs in contaminated soils

    Results of a classical sequential chemical extraction procedure for 137 Cs in an acid Oxisol showed that after 3 years of contamination radiocesium remains potentially available for transfer processes: 40% bio-available, 20% mobile under oxidizing conditions and 40% bound to Fe and Mn oxides (available under reducing conditions). At this time, the transfer factor obtained in this soil was higher than values obtained in basic Oxisol and was higher than values obtained in soils from temperate climate areas. Seven years after the contamination, the 137 Cs distribution in this acid Oxisol have been changed as consequence of changes in soil properties: 8% bioavailable, 16% mobile under oxidizing conditions, 43% bound to Fe and Mn oxides and 33% strongly bound to soil compounds. Changes in the 137 Cs distribution in this soil were followed by reductions in soil to plant transfer factor. Between 1996 and 2000, the 137 Cs distribution, 137 Cs soil to plant transfer factor and soil properties in the basic Oxisol remained almost the same. The 60 Co distribution showed that Mn oxides is the main sink for this element and four years after contamination no 60 Co was detected as bioavailable or detectable in plants. In this study the use of an alternative sequential chemical extraction protocol to evaluate 60 Co and 137 Cs mobility under a large range of physico-chemical soil properties has shown to be very consistent with soil to plant transfer factors data for maize. The knowledge of bio-geochemical behavior of radionuclides in soil system can be used for the risk assessment in the case of nuclear accident or contamination scenarios. (author)

  20. The transfer of 60Co from feed into vitamin B12 in cow liver, milk and beef

    The transfer of the radionuclide 60Co from feed to milk, meat and the organs of a cow and its incorporation into vitamin B12 were studied in order to determine the transfer coefficient of 60Co into vitamin B12 in cattle. Upper limits of transfer coefficients for 60Co organically complexed into vitamin B12 were determined to be 6.0 x 10-5 days/litre in milk and 3.9 x 10-5 days/kg in meat, based on values measured after 140 days in bovine liver. (author)

  1. 60Co-γ Irradiation Affects the Enzymatic Antioxidant System of the Citrus Red Mite Panonychus citri (Acari: Tetranychidae)

    Ke Zhang; Zhibin Li; Shaowen Zhu; Qunfang Weng

    2014-01-01

    Radio-(60Co), which emits γ rays, has been used worldwide in pest control. The aim of the present study was to analyze the effect of effective-low-power 60Co-γ irradiation on the enzymatic antioxidant system of the citrus red mite Panonychus citri. One day old female adults were exposed to 0.4 kGy 60Co-γ irradiation and on the, 6th h, 1st day, 2nd day, and 5th day post treatment, the mites were euthanized for biochemical analysis. The activity of superoxide dismutase (SOD), catalase (CAT), p...

  2. The 1998 calibration of Australian secondary standards of exposure and absorbed dose at 60Co

    New calibration factors are reported for several of the ionization chambers maintained at the Australian Radiation Laboratory (ARL) and at the Australian Nuclear Science and Technology Organisation (ANSTO) as Australian secondary standards of exposure/air kerma and absorbed dose at 60Co. These calibration factors supplement or replace the calibration factors given in earlier reports. Updated 90Sr reference source data are given for the ARL chambers, and for two of the ANSTO chambers. These results confirm the stability of the secondary standards. A re-calibration of the ANSTO reference electrometer is reported. This was carried out using an improved method, which is fully described

  3. Infection of tissue-culture cells with 60Co gamma-irradiated malaria sporozoites

    Plasmodium berghei sporozoites, attenuated by radiation from a 60Co source (8 or 15 krads) retain the ability to enter WI38 human embryonic lung cells in vitro. During the first 24 hours of incubation, the sporozoites appear to undergo normal development into exoerythrocytic trophozoites. Further development appears abnormal, although the trophozoites persist in culture cells for at least 48 hours. Parasite reactivities to fluorescent-labelled, sporozoite-specific antisera are normal up to 48 hours in culture. These observations suggest that sporozoites used in vaccine preparations may enter host cells and transform into exoerythrocytic trophozoites in vivo, but that maturation of the exoerythrocytic stage may be incomplete. (author)

  4. Study on Several Characteristics of Agaricus blazei Murril Strain J3 Irradiated by 60Co

    WENG Bo-qi; JIANG Zhi-he; HUANG Ting-jun; CHEN Jian; ZHENG Wei-wen

    2003-01-01

    A new mutant strain J3 from Agaricus blazei Murril was obtained by 60Co irradiation. The yields of successive generations were increased more than 70% to compare with their original strain. The component analysis on amino acids and fatty acid illuminated that the nutrient value of strain J3 fruiting body was better than the original strain. The apparent nodule structure was found in the hyphea of J3 strain through the observation by scanning electron microscope. RAPD analysis showed the great difference of PCR fingerprints between J3 and its original strain. It is a promising mutant strain for further commercial development in the future.

  5. Effect of 60Co γ irradiation and GA3 treatment on mutation of Carica papaya L

    The seeds of Carica papaya L. were irradiated by 60Co γ-rays of 10-40 Gy and treated by GA3 of 10-50 mg/L after irradiation. The results showed that small nuclear cell percentage, chromosome variation percentage and leaf variability of papaya seedling increased with increase of irradiation dose, the pollen fertility and fruit quality decreased. GA3 of 10-50 mg/L treatment after irradiation could alleviate the irradiation harm, and the effect of lower concentration of GA3 was better than higher concentration with lower dose irradiation, however, the effect of higher concentration of GA3 was better with higher dose irradiation

  6. The studies on apple preservation by 60Co-γ irradiation

    Studies on 60Co-γ 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 kGy. With this dosage, the contents of vitamin C and titratable 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 kGy

  7. Effect of 60Co-irradiation on penicillin G procaine in veterinary mastitis products

    The effect of 60Co-irradation on penicillin G procaine in a peanut oil-based veterinary mastitis product was examined by reversed-phase high-performance liquid chromatography (HPLC). The HPLC method is capable of separating and quantifiying procaine, penicillin G, and various degradation compounds. Values obtained by the HPLC method on the product irradiated and stored at various temperatures correlated well with those of the microbiological assay. No significant decrease in the procaine was detected even after 4.0-Mrad irradiation. The HPLC method is applicable for analysis of other beta-lactam antibiotics

  8. Effects of 60Co-γ ray irradiation on antioxidant enzyme activities in tobacco

    Effects of 300Gy 60Co-γ ray irradiation on the activities of 3 antioxidant enzymes in tobacco were studied in this paper. The results showed that the activities of superoxide dismutase (SOD), peroxidas (POD) and catalse (CAT) in tobacco were gradually increased. All the activities of SOD POD and CAT reached the maximums at 12 h and then gradually decreased. Similar results were also observed in the expression of sod, pod and cat genes. These results indicated that the activities of antioxidant enzymes could play an important role in tobacco tolerance against irradiation

  9. Assessing deposition levels of 55Fe, 60Co and 63Ni in the Ignalina NPP environment

    Two RBMK-1500 reactor units operated in Lithuania in the 1987-2004 period (one of them was stopped for decommissioning in 2004). This study presents a preliminary investigation of surface deposition density levels of 55Fe and 63Ni in moss samples collected in the close vicinity of the Ignalina NPP. Non-destructive analysis by the HPGe gamma-spectrometry was followed by radiochemical separation. Radiochemical analysis was based on anion-exchange and extraction chromatography. 55Fe and 63Ni activities were measured by liquid scintillation counting (LSC). The results indicate that the deposition values of 55Fe are generally higher than those of 60Co and 63Ni.

  10. The influence of 60Co gamma irradiation for downy mildew infection on corn

    Corn seeds of Genjah kertas variety were irradiated with 60Co gamma in the range of 0 rad - 40.000 rads, at interval of 2000 rads, as preliminary investigation to obtain possibilities of corn mutation. Several agronomical effects of radiation on the seedling-plant such as seed germination, height of the seedling, ages of flowering, ages of harvesting, length and circle of the cob, 100U dry seeds weight, number and diameter of stomata, and percentage of downy mildew infection have been observed. The exact conclusion can be obtained only after testing the results of M2 and M3. (author)

  11. Effects of 60Co gamma radiation on Biomphalaria glabrata (Say, 1818) Embryo, I. Mortality

    A study was conducted on the radiosensitivity of Biomphalaria glabrata embryos submitted to doses of 5, 10,15,20 and 25 Gy of 60Co during the cleavage, blastula, gastrula, young trochophore and trochophore stages. Mortality was the parameter used to evaluated the damage induced by ionizing radiation. Susceptibility decreased with increasing embryo age and with decreased radiation dose. Estimated LD50 values (15 days) showed that the cleavage stage (4.3 Gy) was approximately four times more radiosensitive than the trochophore stage (17.0 Gy). The survival curves obtained for each embryo stage are discussed on the basis of the multitarget theory. (author)

  12. Dominant lethal mutation induced by continuous irradiation of 60Co gamma rays in mice

    Female and male mice were exposed to 60Co gamma rays for 10 days, the accumulative doses were 0.396-2.024 and 0.462-2.552 Gy respectively. The number of dominant lethal mutations was calculated as follows: PRE = CL - (ED + LD + VIA). The results showed that Preimplantation Loss (PRE) ranged from 1.222 to 3.714 for female mice and 0.0345 to 2.2308 for male mice. In both cases a linear dose-effect relationship was observed. The PRE of oocytes is 1.66 times higher than that of spermatids

  13. Radiation effects of polyolefin elastomer by 60Co γ-rays

    Polyolefin elastomer was irradiated in air or N2 to different doses by 60Co γ-rays. Gel fraction, mechanic performance and flame retarding property of the irradiated POE were investigated. G value of the POE crosslinked in air or N2 is 0.13 and 0.14, respectively. Gel fraction of the irradiated POE increased with both absorbed dose and sensitizer content, and the value of tensile strength and oxygen index (OI) increased to some extent after irradiation. The value of break at elongation decreased slightly after irradiation. (authors)

  14. Sensitivity of watermelon variety Bojura to mutant agents 60Co and EMS

    Nikolay Velkov; Nasya Tomlekova; Fatma Sarsu

    2016-01-01

    A study on the sensitivity of watermelon variety Bojura to mutagenic agents was carried out in 2013-2014. The goal was to establish effective doses for mutagenic treatment of dry seeds with 60Co gamma rays (80, 100, 200, 250, 350 and 450 Gy) and swollen seeds with water for 24 hours were treated with ethyl methanesulfonate (EMS) at a concentration of 2%. Dominant mutations were not observed in the M1 generation. Morphological changes in 14 of 1395 M2 plants were observed. Phenotypic variation...

  15. Impact of 60Co-γ-ray Sterilization of Tetracycline Hydrochloride Raw Materials%60Co-γ射线对盐酸四环素原料灭菌的研究

    黄波; 赵全如; 刘莉萍

    2014-01-01

    Different doses of 60Co-γ rays were compared for radiation sterilization on raw materials of tetracycline hydrochloride. By checking stability data, the optimal radiation dose of 60Co-γ rays on tetracycline hydrochloride raw materials was 9 kGy, at which its physical and chemical detection indicators were in line with the requirements of USP, and the sterility test results met the requirements..%采用不同剂量的60Co-γ射线对盐酸四环素原料进行辐射灭菌,结合稳定性考察数据,最终确定盐酸四环素原料的60Co-γ射线的辐射剂量为9 kGy时,其理化检测指标符合USP的要求,且无菌检查符合要求。

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

    Niédja M. C. Alves

    2011-03-01

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

  17. Radiation quality of tritium: A comparison with 60Co gamma rays

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

  18. Sorption behavior of human bone powder towards 60 Co and 65 Zn

    Human bone powder 30-40 Μ in diameter was prepared from human bone femurs as fat-free (FFB), protein-free (PFB) or left untreated as raw bone powder (RB). The sorption behavior of human bone powder towards60 Co and 65 Zn was studied. The uptake changed with the type of bone powder to be : PFB>FFB>RB. The increase in the concentration of cobalt(from 10-6 to 10-1 Mole/litre)and of zinc (from 10-7 to 10-4 M/1) increased the uptake of 60 Co and 65 Zn. Freunclich-type isotherm was successfully applied on the uptake data of both ions and the slopes of these isotherms were, nearly, directly proportional to their uptake values. The uptake was found to be less influenced by the PH. In case of cobalt the uptake increased till PH 4, followed by a plateau till PH 8 while in case of zinc the PH effect is much less pronounced

  19. Gamma {sup 60} Co D L {sub 50/30} of Biomphalaria glabrata (Say, 1818)

    Carvalho, Elaine Barros da Costa; Melo, Ana Maria Mendonca de Albuquerque; Motta, Mauricy Alves da [Pernambuco Univ., Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia

    1999-12-01

    The variation of resistance to {sup 60} Co gamma-rays of Biomphalaria glabrata was studied. A population of 480 mollusks was observed during 30 days - distributed in 8 groups of snails isolated and 8 groups of snails in colonies - after exposure (30 snails per group per dose) to increasing doses of gamma radiation. Doses of 10, 20 40, 60, 80, 160, 320 and 640 Gy from a Gamma-cell {sup 60} Co irradiator, were applied to the test groups and two groups control (non-irradiated) of snails - isolated and colony - were kept apart. After have been exposed, the snails were drew back to the aquaria where they were maintained before. The survival was estimated on a daily score of the alive animals in each group-dose, starting after the irradiation exposure day. As a result, the survival self-fertilization forms (DL{sub 50/30}=218.2 Gy) was found greater than in cross-fecundation forms. These data point to allow radio-resistance on the cross-fertilization forms - the sexual reproductive form - which is most found in nature. The lower radio-resistance of the cross-fertilization forms suggests the presence of some sex-linked hormonal factor related to this phenomenon. (author)

  20. Effects of 60Co γ-rays on PWM and LPS induced lymphocytes

    The relationship between lymphocytes induced by PWM and LPS was investigated by means of 3H-TdR and 14C-UR incorporation. The study showed that in votro, PWM-induced cells were able to promote the stimulating effect of LPS to B lymphocyte. The stimulating effect of PWM-induced cells was obviously weakened after PWM cells being irradiated with γ-rays. When PWM-induced cells and LPS-induced cells were incubated together, with one kind of cells exposed to 60Co γ-rays, incorporation value of 3H-TdR became much smaller and the synergetic function disappeared, especially, when PWM-induced cells were irradiated. For patients suffering from carcinoma of nasopharynx, when treated with 60Co γ-rays, the incorporation value in LPS-induced cells approached normal level, while the incorporation value in PWM-induced cells reduced significantly and the stimulating effect of PWM-induced cells on LPS-induced cells became much weaker. The fact described above demonstrated that PWM-induced cells have the function of T-helper cells and play a more important role in the synergy than LPS induced cells

  1. Effect of 60Co γ-rays on PWM and LPS induced lymphocytes

    The relationship between lymphocytes induced by PWM (pokeweed mitogen) and LPS (lipopolysaccharide) was investigated by means of 3H-TdR incorporation. The study showed that, in vitro, PWM-induced cells were able to promote the stimulating effect of LPS to B lymphocytes. The stimulating effect of PWM-induced cells was obviously weakened after PWM cells being irradiated with γ-rays. When PWM-induced cells and LPS-induced cells were incubated together, with one kind of cells exposed to 60Co γ-ray, incorporation value of 3H-TdR became much smaller and the synergetic function disappeared, especially, when PWM-induced cells were irradiated. For patients suffering from carcinoma of nasopharynx, while treated with 60Co γ-rays, the incorporation value in LPS-induced cells approached normal level, meanwhile, the incorporation value in PEM-induced cells reduced significantly and the stimulating effect of PWM-induced cells on LPS-induced cells became much weaker. The facts described above demonstrated that PWM-induced cells have the function of T-helper cells and play more important role in the synergy than LPS-induced cells

  2. Effects of testicular irradiation with 60Co in guinea pigs CAVIA PORCELLUS

    Improvements were made in restaint systems and in the technique of electroejaculation in guinea pigs, emphasizing safety, effectiveness and repetition. Arrangements for simultaneous testicular irradiation with 60Co in 5 animals and a phantom to test dose levels in the target region and scattering were also made. Effects of single and fractionated exposures on sperm were studied. A collimated point-shaped 60Co-machine calibrated to 7 R/min was used as radiation source. Groups of five 12 month aged male guinea pigs were exposed to either single testicular irradiation of 50, 100, 200 and 400 R or fractionated weekly testicular irradiation of 2, 5, 10 and 20 R, during 10 weeks. A last group was exposed to 4 fractionated testicular irradiations of 20 R at time intervals of 21 days and a group of 8 animals was used as control. Semen samples evaluations were made during 5 weeks before irradiation and in the subsequent 11 weeks. Abnormalities in sperm morphology were studied by William's method and phase contrast microscopy. Mean percentages of semen normal espermatzoons and spermatic abnormalities are shown in figures and photomicrographs. Marked differences on concentration, sperm motility and sperm abnormalities were found, but not on volume, in favour of 100 and 200 R single doses levels, as compared to fractionated 10 and 20 R. (Author)

  3. Humoral immune response against native or 60Co irradiated venom and mucus from stingray Paratrygon aiereba

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

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

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

    2007-07-01

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

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

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

  6. Effect of 60Co γ-rays on the lymphocyte subsets with monoclonal antibodies

    Three kinds of monoclonal antibodies (McAb), OkT4 McAb, OkT3 McAb and HI43, were used to identify T helper (Th). T suppresser (Ts) and B lymphocytes respectively. After lympbocytes were immediately exposed to 0.1 Gy, 0.25 Gy and 4 Gy 60Co γ-rays, 200 cells were counted to obtain the percentage of immunofluorescence positive cells. The results show that when the Th, Ts and B lymphocytes were irradiated by 0.1 Gy 60Co γ-rays, their abilities to combine with McAb decreased significantly. The radiation effect was more remarkable with increasing radiation dosage. Three kinds of the immunofluorescence positive cells percentages were analysed with weighted linear regression method. The relational coefficients (r) of Th, Ts and B lymphocytes were 0.8131, 0.8832 and 0.9086. The significant tests of regression coefficient showed that the radiosensitivities of Ts and B lymphocytes were higher than that of Th lymphocytes

  7. The transfer of 137Cs and 60Co from feed to pork

    The transfer of 137Cs and 60Co from fodder to meat and other organs was studied in growing pigs. The influence of two different feeding methods (potato and grain) commonly used in Germany was investigated. The radionuclides were transferred into plants by root uptake and these were fed once a day, all at once, to young pigs until they reached maturity. In this manner, the radioactivity was administered to the pigs in a similar chemical form as would occur after radioactive contamination of soil. It is demonstrated that the two feeding practices have only a minor influence on transfer coefficients, which were determined to be ≤0.002 days/kg for 60Co in meat and in the ranges 0.18-0.26 (potato-feeding) and 0.17-0.33 days/kg (grain-feeding), respectively, for 137Cs in different components of the meat; the transfer coefficients for 137Cs into different organs range from 0.06 to 0.24 days/kg after potato-feeding and from 0.12 to 0.29 after grain-feeding. (author)

  8. Scattering factor evaluation and study of medical intervention following intake of 60Co

    Guidelines for the assessment of internal doses from monitoring suggest default measurement of uncertainties (i.e. lognormal scattering factor, SF) to be used for different types of monitoring data. In this paper, SF values have been evaluated for internal contamination due to 60Co in two cases using whole body counting data. SF values of 1.04 and 1.03 were obtained for case I and II, respectively while SF value of 1.03 was obtained using bioassay data for case I. SF evaluated is in good agreement with the default values given by IDEAS guidelines. The present study also presents the follow up study of a case I of 60Co internal contamination using whole body counting and bioassay analysis. The effect of medical intervention applied on the subject is studied. Medical intervention of d-Penicillamine (250 mg x 4 daily) was orally administered from 13th day of initial exposure for about a fortnight, which showed reduction of activity present by 33.4% through urine. (author)

  9. Grafting of HEMA onto dopamine coated stainless steel by 60Co-γ irradiation method

    A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Co-γ irradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay. - Highlights: • Poly-HEMA was grafted onto the surface of SS by 60Co-γ-ray irradiation. • Pristine SS was coated by dopamine to form a dense poly-dopamine film before radiation grafting. • The biocompatibility and hydrophility of SS were improved after the grafting of HEMA

  10. Effects of 60Co γ-rays irradiation on seed growth of ground-cover chrysanthemum

    The seeds of ground-cover chrysanthemum were used to study the effects of different doses of 60Co γ-rays irradiation(10-50 Gy) on seed germination and physiological characteristics. The results showed that the rate of seed germination and seedling survival decreased significantly with the irradiation doses. With the increase of irradiation dose to above 20 Gy, the content of malondialdehyde (MDA) and activity of peroxidase (POD) in seedlings significantly increased. The similar trends were found in the activities of superoxide dismutase (SOD) and glutathione reductase (GR). Catalase (CAT) activity increased at doses lower than 20 Gy, and then decreased at the higher doses, whereas ascorbate peroxidase (APX) activity did not alter except for 40 Gy. It is concluded that the suitable irradiation dose of mutation breeding is 20 Gy for the seeds of ground-cover chrysanthemum. Although 60Co γ-rays irradiation resulted in damage of membrane lipid peroxidation in the survival seedlings, the increased activity of CAT and POD could protect them against the damage. (authors)