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Sample records for fraktsionnogo sostava srii

  1. The adsorption of Sr(II) and Cs(I) ions by irradiated Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Yiming Tan; Jundong Feng; Liang Qiu; Zhentian Zhao; Xiaohong Zhang; Haiqian Zhang

    2017-01-01

    Adsorption behavior and mechanism of Sr(II) and Cs(I) in single and binary solutions using irradiated Saccharomyces cerevisiae was investigated. The effects of several environmental factors on Sr(II) and Cs(I) adsorption to irradiated Saccharomyces cerevisiae was determined. The equilibrium experimental data were simulated by different kinetic models and isotherm models. The combined effect of Sr(II) and Cs(I) on Saccharomyces cerevisiae is generally antagonistic. SEM and EDS analyses indicate that crystals formed on the cell surface are precipitate of Sr(II) and Cs(I), respectively. (author)

  2. Investigation of the strontium (Sr(II)) adsorption of an alginate microsphere as a low-cost adsorbent for removal and recovery from seawater.

    Science.gov (United States)

    Hong, Hye-Jin; Ryu, Jungho; Park, In-Su; Ryu, Taegong; Chung, Kang-Sup; Kim, Byuong-Gyu

    2016-01-01

    In this paper, we investigated alginate microspheres as a low-cost adsorbent for strontium (Sr(II)) removal and recovery from seawater. Alginate microspheres have demonstrated a superior adsorption capacity for Sr(II) ions (≈110 mg/g). A Freundlich isotherm model fits well with the Sr(II) adsorption of an alginate microsphere. The mechanism of Sr(II) adsorption is inferred as an ion exchange reaction with Ca(II) ions. The effects of the solution pH and co-existing ions in seawater are also investigated. Except for a pH of 1-2, Sr(II) adsorption capacity is not affected by pH. However, increasing the seawater concentration of metal cations seriously decreases Sr(II) uptake. In particular, highly concentrated (15,000 mg/L) Na(I) ions significantly interfere with Sr(II) adsorption. Sr(II) desorption was performed using 0.1 M HCl and CaCl2. Both regenerants show an excellent desorption efficiency, but the FTIR spectrum reveals that the chemical structure of the microsphere is destroyed after repeated use of HCl. Conversely, CaCl2 successfully desorbed Sr(II) without damage, and the Sr(II) adsorption capacity does not decrease after three repeated uses. The alginate microsphere was also applied to the adsorption of Sr(II) in a real seawater medium. Because of inhibition by co-existing ions, the Sr(II) adsorption capacity was decreased and the adsorption rate was retarded compared with D.I. water. Although the Sr(II) adsorption capacity was decreased, the alginate microsphere still exhibited 17.8 mg/g of Sr(II) uptake in the seawater medium. Considering its excellent Sr(II) uptake in seawater and its reusability, an alginate microsphere is an appropriate cost-effective adsorbent for the removal and recovery of Sr(II) from seawater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Biosorption of Sr(II) from aqueous solutions using aerobic granules. Equilibrium and mechanisms

    International Nuclear Information System (INIS)

    Li Wang; Xiang Liu; Xiao-feng Chen; Duu-Jong Lee; Joo-Hwa Tay; Yi Zhang; Chun-li Wan

    2015-01-01

    Aqueous strontium biosorption using aerobic granules was investigated. Parameters affecting the biosorption were optimized, including initial pH, biomass dosage, temperature, and rotation speed. The equilibrium data were fitted using Langmuir and Freundlich models, and both could well describe the process (R 2 = 0.987 and 0.989, respectively). Ion exchange and water-desorption experiments were conducted, and ion exchange together with physical adsorption were found to be the main mechanisms. The aerobic granules were characterized with methods including scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The results showed that surface complexation could also be involved in the Sr(II) biosorption. (author)

  4. Adsorption of Sr(II) and Eu(III) on Na-rectorite. Effect of pH, ionic strength, concentration and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J.; Wang, X.K. [School of Nuclear Science and Engineering, North China Electric Power Univ., BJ (China); Key Lab. of Novel Thin Film Solar Cells, Inst. of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Chen, C.L.; Sheng, G.D.; Li, J.X. [Key Lab. of Novel Thin Film Solar Cells, Inst. of Plasma Physics, Chinese Academy of Sciences, Hefei (China); Chen, Y.X. [School of Nuclear Science and Engineering, North China Electric Power Univ., BJ (China)

    2010-07-01

    The surface charge characteristics of Na-rectorite (NaAl{sub 4}[Si,Al]{sub 8}O{sub 20}(OH){sub 4}.nH{sub 2}O;) were studied by potentiometric acid-base titrations. Sr(II) and Eu(III) adsorptions on Na-rectorite as a function of pH, ionic strength, and Sr(II)/Eu(III) concentrations were carried out to investigate the surface interactions between Sr(II)/Eu(III) with Na-rectorite. The results indicated that the adsorptions of Sr(II) and Eu(III) on Na-rectorite increased with increasing pH and decreased with increasing ionic strength and initial Sr(II)/Eu(III) concentrations, and that the affinity of Na-rectorite for Eu(III) was much higher than for Sr(II). The experimental data of Sr(II)/Eu(III) adsorption were simulated by the diffuse-layer model (DLM) well with the aid of FITEQL 3.2. Simultaneous adsorptions of Sr(II) and Eu(III) on Na-rectorite were also modeled using the DLM. The adsorption mechanisms of Sr(II) and Eu(III) on Na-rectorite may be dominated by ion exchange interaction at low pH or moderate pH, and by surface complexation interaction at high pH. (orig.)

  5. Adsorption behavior of multiwall carbon nanotube/iron oxide magnetic composites for Ni(II) and Sr(II)

    International Nuclear Information System (INIS)

    Chen Changlun; Hu Jun; Shao Dadong; Li Jiaxing; Wang Xiangke

    2009-01-01

    Multiwall carbon nanotube (MWCNT)/iron oxide magnetic composites were prepared, and were characterized by scan electron microscopy using a field emission scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. The adsorptions of Ni(II) and Sr(II) onto MWCNT/iron oxide magnetic composites were studied as a function of pH and ionic strength. The results show that the adsorptions of Ni(II) and Sr(II) on the magnetic composites is strongly dependent on pH and ionic strength. The adsorption capacity of the magnetic composites is much higher than that of MWCNTs and iron oxides. The solid magnetic composites can be separated from the solution by a magnetic process. The Langmuir model fits the adsorption isotherm data of Ni(II) better than the Freundlich model. Results of desorption study shows that Ni(II) adsorbed onto the magnetic composites can be easily desorbed at pH < 2.0. MWCNT/iron oxide magnetic composites may be a promising candidate for pre-concentration and solidification of heavy metal ions and radionuclides from large volumes of aqueous solution, as required for remediation purposes.

  6. Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay.

    Science.gov (United States)

    Kasar, Sharayu; Kumar, Sumit; Bajpai, R K; Tomar, B S

    2016-01-01

    Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay, proposed as a backfill material in the Indian geological repository, was studied using the out-diffusion method. Radiotracers (22)Na, (137)Cs, (85)Sr and (154)Eu were used; the first three are carrier-free enabling experimental work at sub-micromolar metal ion concentration, and Eu(III) tracer (154)Eu was used at sub millimolar concentration. An out-diffusion methodology, wherein a thin planar source of radioactivity placed between two clay columns diffuses out, was used to obtain the apparent diffusion coefficient (Da) values. This methodology enabled determination of diffusion coefficient even for strongly sorbing (154)Eu. Da values for (22)Na, (137)Cs, (85)Sr and (154)Eu were 2.35 (±0.14) × 10(-11), 2.65 (±0.09) × 10(-12), 3.32 (±0.15) × 10(-11) and 1.23 (±0.15) × 10(-13) m(2) s(-1), respectively. Da values were found to be in fair agreement with literature data reported for similar mineralogical sediments. Sorption of radionuclides on the clay was also determined in the present study and differences in Da values were rationalized on the basis of sorption data. Distribution ratios (Kd) for Cs(I) and Eu(III) were higher than that for Sr(II), which in turn was higher than that for Na(I). Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Adsorption of Sr(II) on clay minerals: effects of salt concentration, loading and pH

    International Nuclear Information System (INIS)

    Rafferty, P.; Shiao, S.Y.; Binz, C.M.; Meyer, R.E.

    1981-01-01

    The adsorption of Sr(II) on a number of clay minerals has been investigated by means of a batch technique in solutions of sodium salts. Generally the results can be approximated by ideal ion exchange equations. Distribution coefficients at trace loading follow the linear relation log D = s log [Na(I)sub(aq)] + b where b is a constant and s had values of from about - 1.5 to - 2.0, which are fairly close to the ideal valve of - 2. Adsorption isotherms at constant pH and salt concentration are linear in the low loading region. Distribution coefficients for montmorillonite are almost independent of pH in the intermediate pH region 5 to 7 but for illite and kaolinite, increases in the distribution coefficient with pH are observed. Comparison of these results with literature values, insofar as it is possible, shows that distribution coefficients are usually within a factor of two or three for the same mineral with similar capacities under the same conditions even if techniques of preparation and measurement are different, but values may vary considerably more if the capacities of the different mineral samples are greatly different. Values of the distribution coefficient at very high salt concentration are very low, considerably less than unity at 4 M NaCl. Thus migration rates of Sr(II), relative to water flow, through geologic formations whose adsorption behavior is dominated by these clay minerals are likely to be high at high salt concentrations. (author)

  8. Spectroscopic and thermal degradation behavior of Mg(II, Ca(II, Ba(II and Sr(II complexes with paracetamol drug

    Directory of Open Access Journals (Sweden)

    Moamen S. Refat

    2017-05-01

    Full Text Available Complexes of Mg(II, Ca(II, Ba(II and Sr(II with paracetamol drug were synthesized and characterized by elemental analysis, conductivity, UV–Vis, IR, and 1H NMR spectroscopy and thermal analysis, as well as screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as paracetamol behaves as a neutral bidentate ligand coordinated to the metal ions via the lone pair of electrons of nitrogen and carbonyl-O atoms of the amide group. From the microanalytical data, the stoichiometry of the complexes reacts with Mg(II, Ca(II, Ba(II and Sr(II by molar ratios (2:1 (paracetamol:metal ion. The thermal behavior (TG/DTG of the complexes was studied. The ligand and their metal complexes were screened against both of antibacterial and fungicidal activities.

  9. Spectroscopic and thermal degradation behavior of Mg(II), Ca(II), Ba(II) and Sr(II) complexes with paracetamol drug

    OpenAIRE

    Moamen S. Refat; Gehad G. Mohamed; Mohamed Y. El-Sayed; Hamada M.A. Killa; Hammad Fetooh

    2017-01-01

    Complexes of Mg(II), Ca(II), Ba(II) and Sr(II) with paracetamol drug were synthesized and characterized by elemental analysis, conductivity, UV–Vis, IR, and 1H NMR spectroscopy and thermal analysis, as well as screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as paracetamol behaves as a neutral bidentate ligand coordinated to the metal ions via the lone pair of electrons of nitrogen and carbonyl-O atoms of the amide group. From the microanalytical dat...

  10. Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al2O3

    International Nuclear Information System (INIS)

    Shiao, S.Y.; Egozy, Y.; Meyer, R.E.

    1981-01-01

    Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al 2 O 3 was carried out over a wide range of NaCl concentration and solution pH. In the medium pH region (pH 5 to 9), adsorption depends strongly on pH and less on salt concentration. However, in the high pH region (pH above 9), the salt dependence of the distribution coefficient becomes important. (author)

  11. Parametric study of the sorption of Cs(I) and Sr(II) on mixture of bentonite and magnetite using SCM + IEXM

    International Nuclear Information System (INIS)

    Filipska, H.; Stamberg, K.

    2005-01-01

    Full text of publication follows: The behaviour and subsequent fate of released radionuclides in bentonite barrier surrounding the degraded canister is influenced mainly by sorption. We studied sorption processes in such system experimentally and we modelled and simulated them using surface-complexation (SCM) and ion exchange (IExM) models. Our experimental system consisted of: (1) synthetic granitic water with a given ionic strength (0.1 or 0.01 NaNO 3 ), (2) radionuclides studied (10 -6 mol/l CsCl or SrCl 2 .6H 2 O spiked with 137 Cs or 85 Sr), (3) bentonite pre-treated with the aim to remove carbonates, and magnetite as a representative of corrosion products of steel canister. The alkali-metric and acidimetric titrations under exclusion of CO 2 and the percentage of sorption as a function of pH under oxic conditions at room temperature for bentonite, magnetite and their mixtures under different conditions were determined. The resulting data were modelled and appropriate mathematical description was found: SCM non-electrostatic so called Chemical Model (CEM) for the description of sorption on edge sites and ion exchange model (IExM) for sorption on layer sites. Component Additivity Approach (CA) composed of weighted combination of models describing sorption on bentonite and magnetite was verified. In the course of evaluation procedures, the protonation constants, total concentrations of edge sites and layer sites, cation exchange constants and sorption constants for present Cs and Sr forms were obtained by fitting corresponding experimental data. Consequently, CEM+IExM models and the calculated model parameters were used for predictive (simulation) calculations and parametric study of the sorption of Cs(I) and Sr(II) on bentonite, magnetite and their mixtures. The parametric study covered the influence of pH, solid to liquid ratio, bentonite to magnetite ratio, initial concentrations of Cs and Sr, pCO 2 and ionic strength on the values of selectivity coefficients

  12. Synthesis and characterization of ultrasound assisted “graphene oxide–magnetite” hybrid, and investigation of its adsorption properties for Sr(II) and Co(II) ions

    Energy Technology Data Exchange (ETDEWEB)

    Tayyebi, Ahmad; Outokesh, Mohammad, E-mail: Outokesh@sharif.edu; Moradi, Shahab; Doram, Amir

    2015-10-30

    Graphical abstract: - Highlights: • Narrow size magnetite NPs were synthesized by ultrasound assisted coprecipitaion method. • A formation mechanism for deposition of magnetite NPs on graphene oxide is proposed. • The formation mechanism supported using X-ray photoelectron spectroscopy analysis. • The modified Langevin equation was used for size estimation of magnetite NPs on M–GO. • Adsorption properties of M–GO for Co(II) and Sr(II) were investigated. - Abstract: Magnetite nanoparticles with a size distribution of 15–21 nm were synthesized and decorated onto surface of graphene oxide by ultrasound assisted precipitation. Size and size distribution of the obtained M–GO hybrid were appreciably finer than the hybrids prepared by stirring method. M–GO is a superparamagnetic material with saturation magnetization of 31 emu g{sup −1}. The Langevin equation was successfully applied for estimation of size of Fe{sub 3}O{sub 4} nanoparticles in M–GO hybrid, with maximum error of 17.5%. The study put forward a formation mechanism for M–GO, based on instrumental analyses. Adsorption isotherms of Sr{sup 2+} and Co{sup 2+} ions, which were fitted by Langmuir monolayer model, displayed two-fold higher capacity for Co{sup 2+} ions, presumably due to its similarity to Fe{sup 2+} (of Fe{sub 3}O{sub 4} component). Uptake of both Co{sup 2+} and Sr{sup 2+} ions were endothermic, and spontaneous, however the former proceeded through inner-shell complex formation, while the latter took place via ion exchange mechanism. Rate of adsorption of Co{sup 2+} was faster, but for both ions, chemical reaction was the rate determining step. Sorption of Sr{sup 2+} and Co{sup 2+} ions greatly increased at pHs above 5, where (1) surface zeta potential changed its sign, and (2) deprotonating reactions at the surface became complete.

  13. Mixed ligand complexes of alkaline earth metals: Part XII. Mg(II, Ca(II, Sr(II and Ba(II complexes with 5-chlorosalicylaldehyde and salicylaldehyde or hydroxyaromatic ketones

    Directory of Open Access Journals (Sweden)

    MITHLESH AGRAWAL

    2002-04-01

    Full Text Available The reactions of alkaline earth metal chlorides with 5-chlorosalicylaldehyde and salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been carried out in 1 : 1 : 1 mole ratio and the mixed ligand complexes of the type MLL’(H2O2 (where M = Mg(II, Ca(II, Sr(II and Ba(II, HL = 5-chlorosalicylaldehyde and HL’ = salicylaldehyde, 2-hydroxyacetophenone or 2-hydroxypropiophenone have been isolated. These complexes were characterized by TLC, conductance measurements, IR and 1H-NMR spectra.

  14. Zn(II, Mn(II and Sr(II Behavior in a Natural Carbonate Reservoir System. Part I: Impact of Salinity, Initial pH and Initial Zn(II Concentration in Atmospheric Conditions

    Directory of Open Access Journals (Sweden)

    Auffray B.

    2016-07-01

    Full Text Available The sorption of inorganic elements on carbonate minerals is well known in strictly controlled conditions which limit the impact of other phenomena such as dissolution and/or precipitation. In this study, we evidence the behavior of Zn(II (initially in solution and two trace elements, Mn(II and Sr(II (released by carbonate dissolution in the context of a leakage from a CO2 storage site. The initial pH chosen are either equal to the pH of the water-CO2 equilibrium (~ 2.98 or equal to the pH of the water-CO2-calcite system (~ 4.8 in CO2 storage conditions. From this initial influx of liquid, saturated or not with respect to calcite, the batch experiments evolve freely to their equilibrium, as it would occur in a natural context after a perturbation. The batch experiments are carried out on two natural carbonates (from Lavoux and St-Emilion with PCO2 = 10−3.5 bar, with different initial conditions ([Zn(II]i from 10−4 to 10−6 M, either with pure water or 100 g/L NaCl brine. The equilibrium regarding calcite dissolution is confirmed in all experiments, while the zinc sorption evidenced does not always correspond to the two-step mechanism described in the literature. A preferential sorption of about 10% of the concentration is evidenced for Mn(II in aqueous experiments, while Sr(II is more sorbed in saline conditions. This study also shows that this preferential sorption, depending on the salinity, is independent of the natural carbonate considered. Then, the simulations carried out with PHREEQC show that experiments and simulations match well concerning the equilibrium of dissolution and the sole zinc sorption, with log KZn(II ~ 2 in pure water and close to 4 in high salinity conditions. When the simulations were possible, the log K values for Mn(II and Sr(II were much different from those in the literature obtained by sorption in controlled conditions. It is shown that a new conceptual model regarding multiple Trace Elements (TE sorption is

  15. Spectroscopic, Elemental and Thermal Analysis, and Positron Annihilation Studies on Ca(II), Sr(II), Ba(II), Pb(II), and Fe(III) Penicillin G Potassium Complexes

    Science.gov (United States)

    Refat, M. S.; Sharshara, T.

    2015-11-01

    The [Pb(Pin)2] · 3H2O, [M(Pin)(H2O)2(Cl)] · nH2O (M = SrII, CaII or BaII; n = 0-1), and [Fe(Pin)2(Cl)(H2O)] · H2O penicillin G potassium (Pin) complexes were synthesized and characterized using elemental analyses, molar conductivity, thermal analysis and electronic spectroscopy techniques. The positron annihilation lifetime (PAL) and Doppler broadening (DB) techniques have been employed to probe the defects and structural changes of Pin ligand and its complexes. The PAL and DB line-shape parameters were discussed in terms of the structure, molecular weight, ligand-metal molar ratio, and other properties of the Pin complexes.

  16. Physicochemical impact studies of gamma rays on "aspirin" analgesics drug and its metal complexes in solid form: Synthesis, spectroscopic and biological assessment of Ca(II), Mg(II), Sr(II) and Ba(II) aspirinate complexes

    Science.gov (United States)

    Refat, Moamen S.; Sharshar, T.; Elsabawy, Khaled M.; Heiba, Zein K.

    2013-09-01

    Metal aspirinate complexes, M2(Asp)4, where M is Mg(II), Ca(II), Sr(II) or Ba(II) are formed by refluxed of aspirin (Asp) with divalent non-transition metal ions of group (II) and characterized by elemental analysis and spectroscopic measurements (infrared, electronic, 1H NMR, Raman, X-ray powder diffraction and scanning electron microscopy). Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal:ligand). Infrared spectra of the complexes agree with the coordination to the central metal atom through three donation sites of two oxygen atoms of bridge bidentate carboxylate group and oxygen atom of sbnd Cdbnd O of acetyl group. Infrared spectra coupled with the results of elemental analyzes suggested a distorted octahedral structure for the M(II) aspirinate complexes. Gamma irradiation was tested as a method for stabilization of aspirin as well as their complexes. The effect of gamma irradiation, with dose of 80 Gy, on the properties of aspirinate complexes was studied. The aspirinate chelates have been screened for their in vitro antibacterial activity against four bacteria, gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial activity than the free aspirin chelate.

  17. Studies on the separation of {sup 89}Sr(II) from irradiated yttria target using 4, 4{sup '}(5{sup '}) di-tert-butyl-cyclohexano-18-crown-6 (DtBuCH18C6) by solvent extraction technique

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Debasish; Vithya, Jayagopal; Kumar, Ramalingam; Venkata Subramani, Canchipuram Ramamoorthy; Vasudeva Rao, Polur Ranga [Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam (India). Chemistry Group

    2016-07-01

    The radioisotope {sup 89}Sr as {sup 89}SrCl{sub 2} is medically useful for bone pain palliation and is produced in fast reactors using the {sup 89}Y(n, p){sup 89}Sr reaction. A procedure for isolation of the radionuclide {sup 89}Sr by chemical processing of the irradiated Y{sub 2}O{sub 3} target has been standardised and trial runs have been carried out at the Fast Breeder Test Reactor (FBTR), Kalpakkam. The chemical processing of the irradiated Y{sub 2}O{sub 3} target involves (i) the removal of target Y(III) by TBP extraction and (ii) further purification of the separated {sup 89}Sr fraction by cationic exchange chromatography. However a selective isolation of {sup 89}Sr by the Sr-specific crown ether makes the above chemical processing faster and relatively simple. This work presents a study on the selective removal of Sr from the irradiated target dissolver solution using the Sr-specific crown ether 4,4{sup '}(5{sup '}) di-tert-butyl-cyclohexano-18-crown-6 (DtBuCH18C6) in octanol medium. The separation behaviour of the other impurities such as Ce(IV), Y(III), Tb(III), Eu(III), Zn(II), Mn(II) and Rb(I) present along with Sr(II) in the irradiated sample was also investigated. The method of separation by using the crown ether DtBuCH18C6 is proved to be a potential tool for the purification of {sup 89}Sr(II) source produced from yttria target in fast reactors.

  18. Effect of the plutonium isotopic composition on the performance of fast reactors; Effet de la composition isotopique du plutonium sur le rendement de reacteurs a neutrons rapides; Vliyanie izotopnogo sostava plutoniya na rabotu reaktorov na bystrykh nejtronakh; Efectos de la composicion isotopica del plutonio sobre el funcionamiento de los reactores rapidos

    Energy Technology Data Exchange (ETDEWEB)

    Yiftah, S [Israel Atomic Energy Commission (Israel)

    1962-03-15

    fisionables por neutrones termicos ({sup 239}Pu y {sup 241}Pu), cuanto mas impuro sea el plutonio, tanto menor sera la masa critica y mayor la razon de reproduccion. Tomando como ejemplo el reactor de 1500 l, se comprobo ademas que al eliminar un 40 por ciento del sodio inicialmente presente en el cuerpo, la variacion de reactividad tiende a ser negativa a medida que aumenta la proporcion de isotopos superiores contenidos en el combustible de plutonio (en forma de metal, oxido o carburo). (author) [Russian] Izotopnyj sostav plutoniya, kotoryj dolzhen ispol'zovat'sya v kachestve goryuchego dlya reaktorov na bystrykh nejtronakh, budet zaviset' ot istochnika polucheniya plutoniya. V printsipe vozmozhny tri razlichnykh istochnika: a) proizvodyashchie reaktory; b) teplovye ehnergeticheskie reaktory (ispol'zuyushchie v kachestve topliva estestvennyj ili obogashchennyj uran); c) zony vosproizvodstv a reaktora na bystrykh nejtronakh. V osnovnom istochnik (a) i v nekotorom otnoshenii istochnik (s) budut davat' sravnitel'no 'chistyj' plutonij, t.e. glavnym obrazom plutonij-239, togda kak plutonij iz istochnika (b) budet 'gryaznym', t.e. plutoniem, bogatym izotopami plutoniya-240, plutoniya-241 i plutoniya-242. Stepen' 'zagryazneniya' budet zaviset' ot tipa reaktora, velichiny vygoraniya i voobshche ot istorii oblucheniya topliva. V takom sluchae voznikaet vopros, mozhno li ispol'zovat' v kachestve goryuchego dlya reaktorov na bystrykh nejtronakh lyubye vidy plutoniya. Dlya izucheniya vliyaniya razlichnogo izotopnogo sostava plutonievogo topliva v metallicheskom, oksidnom i karbidnom vide na rabotu reaktorov na bystrykh nejtronakh byli osushchestvleny ogranichennye serii podschetov po 16-gruppovoj diffuzionnoj teorii sfericheskoj geometrii s pomoshch'yu 16-gruppovogo komplekta poperechnykh sechenij, razrabotannogo nedavno Iftakhom, Okrentom i Mol'dauerom s ispol'zovaniem trekh razlichnykh vidov plutoniya, nachinaya s chistogo plutoniya-239 i povyshaya kolichestvo bolee vysokikh izotopov

  19. Composition and Vacancy Flux Effects in Tracer Diffusion in Silver-Gold Alloys; Effets de la Composition et du Flux de Lacunes sur la Diffusion des Indicateurs dans les Alliages d'Or et d'Argent; Vliyanie sostava i potoka vakansij pri diffuzii indikatorov v splavakh serebra i zolota; Efectos de la Composicion y del Flujo de Huecos Sobre la Difusion de Indicadores en Aleaciones Plata-Oro

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, R. O.; Slifkin, L. [University of North Carolina, Chapel Hill, NC (United States)

    1966-02-15

    desplazamiento del centro de masas correspondiente a la distribucion del indicador oro, la cual no sufre deformacion alguna puesto que D es practicamente independiente de la posicion. El indicador inerte, de particulas finas, permite localizar la interfase original con precision de algunos micrones. Los resultados obtenidos hasta febrero de 1965 senalan que el centro correspondiente a la distribucion del indicador oro se desplaza unos 20 {mu}m hacia el extremo rico en plata. (author) [Russian] Izuchenie samodiffuzii v splavah serebra s zolotom pokazy- vaet, chto jenergii aktivacii monotonno umen'shajutsja s uvelicheniem koncentracii zolota. Rezul'taty jetih issledovanij nel'zja ob{sup j}asnit' ishodja iz teorij, osnovannyh na sootvetst- vujushhih sostojanijah, vlijanii razmera ili teplote rastvorenija; odnako razvitaja Leklerom jelektrostatisticheskaja teorija Lazara pozvoljaet poluchit' polukolichestvennoe soglasie. Umen'shenie predjeksponencial'nyh faktorov s uvelicheniem koncentracii zolota ukazyvaet na to, chto jentropija vakansij dlja migracii linejno umen'shaetsja s izmeneniem sosta- va na 1,5 ROT chistogo serebra do chistogo zolota. V otnoshenii kazhdogo indikatora pri postojannoj temperature kojefficient diffuzii DE zavisimosti ot sostava pokazyvaet shirokij minimum. S pomoshh'ju jetih dannyh, ispol'zuemyh dlja proverki teorij vzaimodejst- vija mezhdu vakansiej i primes'ju, ustanavlivaetsja, chto tol'ko dannye Manninga i Lidiarda dajut udovletvoritel'nye i neprotivorechivye rezul'taty. Pribavlenie bolee podvizhnogo serebra k menee podvizhnomu zolotu fakticheski umen'shaet Bdlja oboih indikatorov; analiz pokazyvaet, chto prisutstvie atoma serebra, smezhnogo s vakansiej, i atoma zolota umen'- shaet chastotu skachka atoma zolota priblizitel'no na velichinzg 0,4. Nalichie shirokogo minimuma na grafike zavisimosti DOT sostava pozvoljaet issledo- vat' vlijanie potoka vakansii na diffuziju indikatora. Para Kirkendalla prigotovljaetsja iz sostavov, simmetrichno smeshhennyh

  20. Pedogennyje i litogennyje osobennosti mineralogičeskogo sostava černozema na krasnocvetnych porodach

    Czech Academy of Sciences Publication Activity Database

    Lesovaja, S. N.; Kapička, Aleš; Petrovský, Eduard; Aparin, B. F.

    2003-01-01

    Roč. 36, č. 12 (2003), s. 1482-1490 ISSN 0032-180X Grant - others:RFFI(RU) 01-04-48815 Institutional research plan: CEZ:AV0Z3012916 Keywords : mineralogical composition * chernozem * magnetic minerals Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  1. Conversion of borate ions in liquid phase. Izmenenie sostava borationov v zhidkoj faze

    Energy Technology Data Exchange (ETDEWEB)

    Gode, G K; Bernare, A A [Latvijskij Gosudarstvennyj Univ., Riga (USSR)

    1989-01-01

    Isomolar series of aquepus solutions of magnesium chloride and potassium tetraborate at 25 deg C are investigated by the refractometry method. It is established that inderite containing triborate-ion is crystalized from solutions of rather high concentration. In 0.1 M solution reagents form supersaturated solutions with the decreased refractive index against the calculated one. It is supposed that this deviation is caused by partial transformation of tetraborate-ion to triborate-ion under the magnesium ion effect.

  2. Influence of smectite mineralogical composition on the adsorption properties of Sr(II); Vplyv mineralogickeho zlozenia smektitov na adsorpcne vlastnosti Sr(II)

    Energy Technology Data Exchange (ETDEWEB)

    Krajnak, A; Rosskopfova, O; Galambos, M [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra jadrovej chemie, 84215 Bratislava (Slovakia)

    2012-04-25

    Bentonite with suitable mineralogical, erosion and rheological properties as well as with favorable adsorption and retardation behaviour to the ionic forms of radionuclides are useful in multi-barrier system of deep geological repository for high level radioactive wastes and spent nuclear fuel. Central European significant bentonite deposit Jelsovy potok from Kremnicka site, which is located in Slovakia, has a great potential for use just as a bentonite barrier in this repository. The aim of this work was to study the effect of the mineralogical composition of bentonite Jelsovy potok and on the adsorption behaviour of strontium cations by montmorillonite standards BET-1 and STx-1. The strontium-90 isotope, which is found in spent nuclear fuel is a biological analogue of calcium, and has every malignant effect on the body. From this point of view, it is important to study and monitor the migration of strontium in the biosphere.

  3. Synthesis, structure and fluorescence properties of a novel 3D Sr(II) coordination polymer

    Science.gov (United States)

    Tan, Yu-Hui; Xu, Qing; Gu, Zhi-Feng; Gao, Ji-Xing; Wang, Bin; Liu, Yi; Yang, Chang-Shan; Tang, Yun-Zhi

    2016-09-01

    Solvothermal reaction of 2,2‧-bipyridine-5,5‧-dicarboxylic acid (H2bpdc) and SrCl2 affords a novel coordination polymer [Sr(Hbpdc)2]n1. X-ray structure determination shows that 1 exhibits a novel three-dimensional network. The unique Sr II cation sits on a two-fold axis and coordinated by four O-atom donors from four Hbptc- ligands and four N-atom donors from two Hbptc- ligands in distorted dodecahedral geometry. In 1 each Sr II cation connects to six different Hbptc- ligands and each Hbptc- ligand bridges three different Sr II cations which results in the formation of a three-dimensional polymeric structure. Corresponding to the free ligand, the fluorescent emission of complex 1 display remarkable "Einstain" shifts, which may be attributed to the coordination interaction of Sr atoms, thus reduce the rigidity of pyridyl rings.

  4. Sorption of Sr(II) onto nanocomposites of graphene oxide-polymeric matrix

    Czech Academy of Sciences Publication Activity Database

    Bubeníková, M.; Ecorchard, Petra; Szatmáry, L.; Mrózek, Ondřej; Salačová, P.; Tolasz, Jakub

    2018-01-01

    Roč. 315, č. 2 (2018), s. 263-272 ISSN 0236-5731 R&D Projects: GA TA ČR(CZ) TA04020222 Institutional support: RVO:61388980 Keywords : Graphene oxide * Nanocomposite * PA66 * Polystyrene * Radiostrontium removal Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 1.282, year: 2016

  5. Synthesis of the phase with T sub c =110 K in Bi(Pb)-Sr-Ca-Cu-O superconducting ceramics. Sintez fazy T sub c =110 K sverkhprovodyashchej keramiki sostava Bi(Pb)-Sr-Ca-Cu-O

    Energy Technology Data Exchange (ETDEWEB)

    Dubovitskij, A V; Makarov, E F; Makova, M K; Merzhanov, V A; Topnikov, V N [AN SSSR, Moscow (USSR). Inst. Khimicheskoj Fiziki

    1991-05-01

    Synthesis of 110 K single-phase bismuth ceramics (BiPb){sub 2}Sr{sub 2}Ca{sub n-1}Cu{sub n}O{sub x} was conducted in narrow temperature and time range. Diffusion of bismuth ions is proposed to be the decisive factor of synthesis of bismuth ceramics. The diffusion depends on prehistory of basic burden preparation and on its dispersivity and homogeneity in particluar. Optimal time of synthesis for lead doped ceramics of 2223 composition, synthesized from initial nitrate components, is equal to 65 h at 850 deg C. The role of Pb{sup 2+} ions is probably reduced to decrease of diffusion mobility of Bi{sup 3+} ions over the bismuth sublattice. Ceramics doping with CdO and CdCl{sub 2} compounds instead of lead stabilizes superconductivity in bismuth ceramics, but with worth superconducting parameters.

  6. The Relationship between Blood Injury and Absorbed Dose in Criticality Accidents; Relations entre la Deterioration du Sang et la Dose Absorbee lors d'Accidents Dus a la Formation d'un Etat Critique; Svyaz' mezhdu velichinoj pogloshchennoj dozy pri avariyakh na reaktorakh, dostigshikh kritichnosti, i narusheniem sostava krovi; Relacion entre las Hemolesiones y la Dosis Absorbida en los Accidentes de Criticidad

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, J. A. [Health Physics and Medical Division, Atomic Energy Research Establishment, Harwell (United Kingdom)

    1964-03-15

    The neutron and gamma doses to individuals exposed in criticality accidents have been recalculated to yield the surface-absorbed dose to the trunk of the body. The relationship is examined between this dose estimate and blood-count profile scores that are based on the scoring system of N. Wald and G. E. Thoma for deviations from the normal of the lymphocyte, neutrophil and platelet-peripheral blood counts. It is shown that a quantity based on the surface-absorbed gamma dose and the Na{sup 24} activity in the blood shows a better correlation with the blood-count profile score and is a better prognostic guide for the degree of radiation injury than any of the conventional dose estimates. The R. B. E's of the heavy-particle recoil doses deduced from these observations are consistent in general with values obtained from experiments on dogs. (author) [French] L'auteur a fait un nouveau calcul des doses de neutrons et de rayons gamma delivrees aux personnes exposees lors d'accidents due a la formation d'un etat critique, pour obtenir la dose en surface absorbee par le tronc. Il a etudie la relation entre cette estimation de la dose et la 'courbe resultante de numeration globulaire' de N. Wald et G. E. Thoma du point de vue des anomalies en lymphocytes, polynucleaires neutrophiles et plaquettes. Il montre qu'une quantite fondee sur la dose absorbee en surface de rayons gamma et l'activite de {sup 24}Na dans le sang accuse une meilleure correlation avec la courbe resultante de numeration globulaire et permet de mieux prevoir le degre de radiolesion que toute autre estimation classique de la dose. Les EBR des doses dues aux particules lourdes de recul, deduites de ces observations, concordent dans l'ensemble avec les valeurs obtenues au cours d'experiences sur des chiens. (author) [Spanish] El autor reviso sus calculos sobre las dosis de neutrones y rayos gamma en los sujetos expuestos a consecuencia de accidentes de criticidad, a fin de determinar las dosis superficiales absorbidas por el tronco humano. Examina la relacion entre estas estimaciones de dosis y los valores del diagrama del recuento sanguineo basado en el sistema de valoracion propuesto por N. Wald y G. E. Thoma para las desviaciones con respecto a los indices normales de linfocitos, neutrofilos y plaquetas en la sangre periferica. Demuestra que un parametro basado en la dosis gamma absorbida superficialmente y en la actividad del {sup 24}Na en la sangre concuerda mas satisfactoriamente con el diagrama mencionado y se presta mejor para pronosticar la gravedad de una radiolesion que cualquiera de las estimaciones dosimetricas corrientes. En general, la EBR de las dosis de particulas pesadas de retroceso deducida de estas observaciones armoniza con los valores obtenidos en experimentos realizados con perros. (author) [Russian] Dlja opredelenija dozy, pogloshhennoj poverhnost'ju tela cheloveka,vychisljalis' dozy nejtronnogo i gamma-obluchenij dlja lic, podvergshihsja oblucheniju pri avarijah na reaktorah, dostigshih kritichnosti. Izuchalas' svjaz' mezhdu jetimi dozami i ''profil'nym sostavom krovi'' po metodu M. Uolda i Dzh. Toma dlja otklonenij ot normy limfocitov, nejtrofil'nyh lejkocitov i trombocitov. Pokazano, chto velichina dozy, poluchennaja pri podschete poverhnostnoj pogloshhennoj dozy gamma- obluchenija i urovnja aktivnosti natrija-24 v krovi, v bol'shej stepeni soglasuetsja s profil'nym sostavom krovi i javljaetsja bolee nadezhnym prognosticheskim priznakom pri ocenke ste peni luch ev o go porazhenija, chem standartnye metody ocenki doz obluchenija. Otnositel'naja biologicheskaja jeffektivnost' doz tjazhelyh chastic otdachi, poluchennyh pri jetih nabljudenijah, v obshhem so glasuetsja s velichinami, poluchennymi v rezul'tate jeksperimentov na sobakah. (author)

  7. Poly[μ2-aqua-aqua-μ5-naphthalene-2,7-disulfonato-strontium

    Directory of Open Access Journals (Sweden)

    Shan Gao

    2011-12-01

    Full Text Available In the crystal structure of the polymeric title compound, [Sr(C10H6O6S2(H2O2]n, the naphthalene-2,7-disulfonate dianion uses one –SO3 unit to bind to two SrII cations and the other –SO3 unit to bind to three SrII cations; of the two coordinated water molecules, one is monodentate to one SrII cation, whereas the other bridges two SrII cations. The μ5-bridging mode of the dianon and the μ2-bridging mode of the water molecule generate a polymeric three-dimensional network which is consolidated by O—H...O hydrogen bonds. The SrII cation exists in an undefined eight-coordinate environment.

  8. Photo-induced bleaching of sensory rhodopsin II (phoborhodopsin) from Halobacterium salinarum by hydroxylamine: identification of the responsible intermediates.

    Science.gov (United States)

    Tamogami, Jun; Kikukawa, Takashi; Ikeda, Yoichi; Demura, Makoto; Nara, Toshifumi; Kamo, Naoki

    2012-01-05

    Sensory rhodopsin II from Halobacterium salinarum (HsSRII) is a retinal protein in which retinal binds to a specific lysine residue through a Schiff base. Here, we investigated the photobleaching of HsSRII in the presence of hydroxylamine. For identification of intermediate(s) attacked by hydroxylamine, we employed the flash-induced bleaching method. In order to change the concentration of intermediates, such as M- and O-intermediates, experiments were performed under varying flashlight intensities and concentrations of azide that accelerated only the M-decay. We found the proportional relationship between the bleaching rate and area under the concentration-time curve of M, indicating a preferential attack of hydroxylamine on M. Since hydroxylamine is a water-soluble reagent, we hypothesize that for M, hydrophilicity or water-accessibility increases specifically in the moiety of Schiff base. Thus, hydroxylamine bleaching rates may be an indication of conformational changes near the Schiff base. We also considered the possibility that azide may induce a small conformational change around the Schiff base. We compared the hydroxylamine susceptibility between HsSRII and NpSRII (SRII from Natronomonas pharaonis) and found that the M of HsSRII is about three times more susceptible than that of the stable NpSRII. In addition, long illumination to HsSRII easily produced M-like photoproduct, P370. We thus infer that the instability of HsSRII under illumination may be related to this increase of hydrophilicity at M and P370. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Synthesis and characterization of 2,3,13,14-tetramethyl (ethyl or p-tolyl-1,4,12,15-tetraazacyclodocosa-1,3,12,14-tetraene complexes of Mg(II, Ca(II, Sr(II and Ba(II

    Directory of Open Access Journals (Sweden)

    SEEMA GUPTA

    2002-07-01

    Full Text Available 2+2 Cyclocondensation of 1,7-diaminoheptane with a-diketones, viz. 2,3-butanedione, 3,4-hexanedione or 4,4’-dimethylbenzil, in the presence of Mg2+, Ca2+, Sr2+ and Ba2+ ions as templates yields a series of complexes of the type [ML(X2] (where L = N4 macrocycle having a 22-membered ring and X = Cl or NCS. The resulting complexes were characterized by elemental analysis, conductance measurements and IR and 1H-NMR spectral studies.

  10. Poly[[tetraaqua(μ3-naphthalene-1,6-disulfonato-κ4O1:O6,O6′:O6′′strontium(II] monohydrate

    Directory of Open Access Journals (Sweden)

    Shan Gao

    2011-12-01

    Full Text Available In the crystal structure of the polymeric title compound, {[Sr(C10H6O6S2(H2O4]·H2O}n, the naphthalene-1,6-disulfonate dianion uses one –SO3 unit to O,O′-chelate to an SrII cation and its third O atom to bind to another SrII cation. The other –SO3 unit binds to yet another SrII atom. The four coordinated water molecules are monodentate but one is disordered over two positions in a 1:1 ratio. The μ3-bonding mode of the dianion generates a polymeric three-dimensional network; the network is consolidated by O—H...O hydrogen bonds. The SrII cation exists in an undefined eight-coordinate environment.

  11. Anchoring of CoHFC nanoparticles on clinoptilolite for remedy of nuclear wastes

    Directory of Open Access Journals (Sweden)

    Yousefi Taher

    2017-01-01

    Full Text Available To improve the mechanical properties, the cobalt ferrocyanide precipitation was carried out on clinoptilolite as an inorganic polymer. In this work the combination of two important factors, stability (zeolite and high adsorption capacity (cobalt ferrocyanide were considered to improve the ions uptake ability of adsorbent. The modification was approved by X-ray diffraction, Scanning electronic microscopy and Fourier transform infrared spectroscopy. The modified zeolite was applied to remove Sr(II and Cs(I ions from aqueous solution in a batch system. The adsorption capacities of modified zeolite for Cs(I and Sr(II improved to 90 and 130 mgg-1, respectively. The Sr(II and Cs(I removal were investigated as a function of shaking time, pH, Sr(II, and Cs(I initial concentration and temperature. The experimental data were fitted well to Langmuir isotherm model for two sorbet metal ions. The time dependence sorption data showed that the uptakes of Cs(I and Sr(II were very rapid and apparent sorption equilibriums were achieved within 100 min of contact time. The kinetic experimental data were fitted to the pseudo-first order, pseudo-second order, the double exponential, Elovich and intraparticle diffusion models. The sorption rates and capacities as well as rate constants were evaluated.

  12. catena-Poly[[[diaqua(2-fluorobenzoato-κ2O,O′strontium]-μ3-2-fluorobenzoato-κ5O:O,O′:O′,F] monohydrate

    Directory of Open Access Journals (Sweden)

    Zhu-Nian Jin

    2011-04-01

    Full Text Available In the title compound, {[Sr(C7H4FO22(H2O2]·H2O}n, the SrII atom is coordinated by six O atoms and one F atom from four 2-fluorobenzoate ligands and two water molecules, resulting in an irregular SrFO8 coordination environment. The μ3-2-fluorobenzoate ligand bridges three symmetry-related SrII atoms, giving rise to a chain structure extending along [010]. The polymeric chains are connected via O—H...O hydrogen bonds into a two-dimensional supramolecular structure parallel to (100.

  13. Poly[[aqua(μ5-3,4,5,6-tetracarboxycyclohexane-1,2-dicarboxylatostrontium] monohydrate

    Directory of Open Access Journals (Sweden)

    Pei-Chi Cheng

    2011-12-01

    Full Text Available In the title compound, {[Sr(C12H10O12(H2O]·H2O}n, the SrII ion is coordinated by six O atoms of five symmetry-related 3,4,5,6-tetracarboxycyclohexane-1,2-dicarboxylate ligands and one water molecule in a slightly distorted monocapped trigonal–prismatic environment. The ligands bridge the SrII ions, forming a two-dimensional structure. In the crystal, O—H...O hydrogen bonds further connect the structure into a three-dimensional network. The H atoms of two of the carboxyl groups were refined as half-occupancy.

  14. Potassium iron(III)hexacyanoferrate(II) supported on polymethylmethacrylate ion-exchanger for removal of strontium(II)

    International Nuclear Information System (INIS)

    Taj, S.; Ashraf Chaudhry, M.; Mazhar, M.

    2009-01-01

    Potassium iron(III)hexacyanoferrate(II) supported on poly metylmethacrylate has been synthesized and investigated for the strontium(II) removal from HNO 3 and HCl solutions. The ion exchange material characterized by different techniques and found to be stable in 1.0-4.0 M HNO 3 solutions, has been used to elaborate different parameters related to ion exchange and sorption processes involved. The data collected suggested its use to undertake removal of Sr(II) from more acidic active waste solutions. Thus the material synthesized had been adjudged to present better chances of application for Sr(II) removal as compared to other such materials. (author)

  15. (II) metal ions using phosphonate-functionalized polymer

    Indian Academy of Sciences (India)

    The metal binding was examined by the energy dispersive spectroscopy and scanning electron microscopy for the adsorbed Sr(II). Batch adsorption studies were performed by varying three parameters, namely initial pH, adsorbentdose and the contact time. The reaction kinetics was determined by the Langmuir, Freundlich, ...

  16. Study on the acid-base surface property of the magnetite graphene oxide and its usage for the removal of radiostrontium from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Chen, H.; Li, J.X.; Zhang, S.W.; Ren, X.M.; Sun, Y.B.; Wen, T.; Wang, X.K. [Chinese Academy of Sciences, Hefei (China). Key Laboratory of Novel Thin Film Solar Cells

    2013-07-01

    Acid-base titrations of magnetite/graphene oxide (M/GO) and Sr(II) adsorption onto M/GO were operated to investigate surface properties of M/GO and surface complexation bonding interactions between Sr(II) and M/GO. Experimental results showed that Sr(II) adsorption onto M/GO was facilitated by a high pH value and a low ionic strength. Modeling results exhaustively explained the changes of adsorption morphological at different pH and ionic strengths. Thermodynamic parameters ({Delta}H , {Delta}S , and {Delta}G ) calculated from the adsorption isotherms showed the adsorption of Sr(II) onto M/GO composite was an endothermic and spontaneous process. M/GO could be separated by magnetic separation from aqueous solution in large scale. The adsorption performance suggests M/GO could be a promising adsorbent material for the preconcentration and separation of radiostrontium from aqueous solution in radionuclide pollution cleanup. (orig.)

  17. Synergistic interface behavior of strontium adsorption using mixed microorganisms.

    Science.gov (United States)

    Hu, Wenyuan; Dong, Faqin; Yang, Guangmin; Peng, Xin; Huang, Xiaojun; Liu, Mingxue; Zhang, Jing

    2017-08-10

    The proper handling of low-level radioactive waste is crucial to promote the sustainable development of nuclear power. Research into the mechanism for interactions between bacterium and radionuclides is the starting point for achieving successful remediation of radionuclides with microorganisms. Using Sr(II) as a simulation radionuclide and the mixed microorganisms of Saccharomyces cerevisiae and Bacillus subtilis as the biological adsorbent, this study investigates behavior at the interface between Sr(II) and the microorganisms as well as the mechanisms governing that behavior. The results show that the optimal ratio of mixed microorganisms is S. cerevisiae 2.0 g L -1 to B. subtilis 0.05 g L -1 , and the optimal pH is about 6.3. Sr(II) biosorption onto the mixed microorganisms is spontaneous and endothermic in nature. The kinetics and the equilibrium isotherm data of the biosorption process can be described with pseudo-second-order equation and the Langmuir isotherm equation, respectively. The key interaction between the biological adsorbent and Sr(II) involves shared electronic pairs arising from chemical reactions via bond complexation or electronic exchange, and spectral and energy spectrum analysis show that functional groups (e.g., hydroxyl, carboxyl, amino, amide) at the interface between the radionuclide and the mixed microorganisms are the main active sites of the interface reactions.

  18. Effect of adsorbents and chemical treatments on the removal of strontium from aqueous solutions

    International Nuclear Information System (INIS)

    Ahmadpour, A.; Zabihi, M.; Tahmasbi, M.; Bastami, T. Rohani

    2010-01-01

    In the present investigation, three different solid wastes namely almond green hull, eggplant hull, and moss were initially treated and used as adsorbents for the adsorption of strontium ion from aqueous solutions. Adsorbent types and chemical treatments are proved to have effective roles on the adsorption of Sr(II) ion. Among the three adsorbents, almond green hull demonstrated strong affinity toward strontium ion in different solutions. The effectiveness of this new adsorbent was studied in batch adsorption mode under a variety of experimental conditions such as: different chemical treatments, various amounts of adsorbent, and initial metal-ion concentration. The optimum doses of adsorbent for the maximum Sr(II) adsorption were found to be 0.2 and 0.3 g for 45 and 102 mg L -1 solutions, respectively. High Sr(II) adsorption efficiencies were achieved only in the first 3 min of adsorbent's contact time. The kinetics of Sr(II) adsorption on almond green hull was also examined and it was observed that it follows the pseudo second-order behavior. Both Langmuir and Freundlich models well predicted the experimental adsorption isotherm data. The maximum adsorption capacity on almond green hull was found to be 116.3 mg g -1 . The present study also confirmed that these low cost agriculture byproducts could be used as efficient adsorbents for the removal of strontium from wastewater streams.

  19. Recent progress of partitioning process in JAERI: development of amide-based artist process

    International Nuclear Information System (INIS)

    Shoichi, Tachimori; Yuji, Sasaki; Yasuji, Morita; Shin-ichi, Suzuki

    2003-01-01

    A branched-alkyl monoamide which extracts An(VI) exclusively by the steric effect and tridentate diglycol-amide; TODGA, which recovers all actinides and Sr(II) from highly acidic waste solutions, were developed. Then, a new chemical process, ARTIST process, is proposed for the treatment of nuclear spent fuel consolidating plutonium management and the partitioning concept. (author)

  20. Adsorption of some radionuclides on kaolinite mineral surface

    International Nuclear Information System (INIS)

    Hafez, M.B.; Said, F.I.A.

    1986-01-01

    Fixation of 187 Cs(I), 144 Ce(III), 90 Sr(II), 233 U(VI), 239 Pu(IV) and 211 Am(III) from aqueous and phosphate media on kaolinite was studied. The fixation of the nuclides on the mineral was found to depend on the pH and the hydrolytic behaviour of the elements

  1. Poly[[diaqua-μ4-pyrazine-2,3-dicarboxylato-κ6N,O2:O2′:O3,O3′:O3-strontium(II] monohydrate

    Directory of Open Access Journals (Sweden)

    Vahid Amani

    2008-07-01

    Full Text Available In the title compound, {[Sr(C6H2N2O4(H2O2]·H2O}n, the SrII ions are bridged by the pyrazine-2,3-dicarboxylate ligands with the formation of two-dimensional polymeric layers parallel to the ac plane. Each SrII ion is eight-coordinated by one N and five O atoms from the four ligands and two water molecules. The coordination polyhedron is derived from a pentagonal bipyramid with an O atom at the apex on one side of the equatorial plane and two O atoms sharing the apical site on the other side. The coordinated and uncoordinated water molecules are involved in O—H...O and O—H...N hydrogen bonds, which consolidate the crystal structure.

  2. Separation of americium (III) and strontium (II) using TEHDGA and 18-crown-6

    Energy Technology Data Exchange (ETDEWEB)

    Sinharoy, Prithwish; Khan, Pasupati Nath; Nair, Deepika; Jagasia, Poonam; Dhami, P.S.; Kaushik, C.P.; Banerjee, Kalyan [Bhabha Atomic Research Centre, Mumbai (India). Nuclear Recycle Group; Anitha, M. [Bhabha Atomic Research Centre, Mumbai (India). Rare Earth Development Section; Sharma, J.N. [Bhabha Atomic Research Centre, Mumbai (India). Process Development Div.

    2017-06-01

    This work describes extraction of Am(III) and Sr(II) together with tetra(2-ethylhexyl) diglycolamide (TEHDGA) and selective back-extraction of strontium with a strontium complexant, 18-crown-6, leading to their separation from each other. 0.3 M TEHDGA+5% isodecyl alcohol/n-dodecane was used to extract Am(III) and Sr(II) from 4 M nitric acid into organic phase with very high D (D{sub Am}=1000, D{sub Sr}=22) and 0.1 M 18-crown-6 dissolved in 4 M nitric acid is used for selective stripping of Sr(II) from loaded extract phase. Am(III) left in the extract phase was then stripped with 0.01 M nitric acid. Stripping of Sr(II) was found to increase with increase in 18-crown-6 concentration, at 0.1 M 18-crown-6 dissolved in 4 M nitric acid, 83% of the loaded strontium (D{sub Sr}=0.20) was back-extracted in a single contact while loss of Am(III) was 0.8% (D{sub Am}=122.45). Stoichiometry limit of 1:1 was observed between strontium and 18-crown-6. Strontium was precipitated and separated from the complexant by Na{sub 2}SO{sub 4} or Na{sub 2}CO{sub 3}. This process was tested with simulated solution of high level waste and found suitable for quantitative recovery of strontium with high purity.

  3. Determination of Conditional Stability Constants for Metal Ions with Humic Acid using Chemically Immobilised Humic Acid on Silica Gel

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, G.; Guszi, J. [Frederic Joliot-Curie' National Research Inst. for Rad iobiology and Radiohygiene, Budapest, H-1775 (Hungary)]. e-mail: szabogy@hp.osski.hu; Miyajima, T. [Dept. of Chemistry, Faculty of Science and Engineering, Saga Univ ., 1-Honjo, Saga (Japan); Geckeis, H. [Forschungszentrum Karlsruhe, Inst. fuer Nuk leare Entsorgung, 76021 Karlsruhe (Germany); Reiller, P. [Commissariat a l' Energie A tomique, CE Saclay, Laboratoire de Speciation des Radionucleides et des Molecule s, F-91191 Gif-sur-Yvette (France); Bulman, R.A. [Radiation Protection Div., Health Protection Agency, Chilton, Didcot (United Kingdom)

    2007-06-15

    Limitations on aqueous solution chemistries of humic acid, and also hydrolysis of some cationic species, restrict measurement of conditional stability constants of 4f- and 5f-series elements as humate complexes. Reported log {beta} values are determined by using non-linear regression binding isotherms, of Am(III) and Th(IV), and also Ag(I) and Sr(II), bound by a humic acid composite.

  4. Macrocyclic receptors immobilized to monodisperse porous polymer particles by chemical grafting and physical impregnation for strontium capture: A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yang [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Du, Yi [Department of Chemical Engineering, Laboratory for Advanced Materials, Tsinghua University, Beijing (China); Lv, Dachao [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Ye, Gang, E-mail: yegang@tsinghua.edu.cn [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China); Wang, Jianchen [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing (China)

    2014-06-01

    Graphical abstract: Macrocyclic receptors grafted to monodisperse porous polymer particles for Sr(II) capture. - Highlights: • Synthesis of novel selective Sr adsorbent grafted with macrocyclic receptors. • New monodisperse porous polymer particles used to promote Sr adsorption. • Comparative study and discussion on adsorption behaviour and mechanism. • A chromatographic process proposed for Sr separation in simulated HLLW. - Abstract: Separation of strontium is of great significance for radioactive waste treatment and environmental remediation after nuclear accidents. In this work, a novel class of adsorbent (Crown-g-MPPPs) was synthesized by chemical grafting a macrocyclic ether receptor to monodisperse porous polymer particles (MPPPs) for strontium adsorption. Meanwhile, a counterpart material (Crown@MPPPs) with the receptor molecules immobilized to the MPPPs substrate by physical impregnation was prepared. To investigate how the immobilization manner and distribution of the receptors influence the adsorption ability, a comparative study on the adsorption behaviour of the two materials towards Sr(II) in HNO{sub 3} media was accomplished. Due to the shorter diffusion path and covalently-bonded structure, Crown-g-MPPPs showed faster adsorption kinetics and better stability for cycle use. While Crown@MPPPs had the advantages of facile synthesis and higher adsorption capacity, owing to the absence of conformational constraint to form complexation with Sr(II). Kinetic functions (Lagergren pseudo-first-order/pseudo-second-order functions) and adsorption isotherm models (Langmuir/Freundlich models) were used to fit the experimental data and examine the adsorption mechanism. On this basis, a chromatographic process was proposed by using Crown@MPPPs for an effective separation of Sr(II) (91%) in simulated high level liquid waste (HLLW)

  5. Application of proton induced x-ray emission (PIXE) in estimation of trace metals entrapped in silica matrix

    International Nuclear Information System (INIS)

    Jal, P.K.; Patel, Sabita; Mishra, B.K.; Sudarshan, M.; Saha, A.

    2005-01-01

    Proton induced x-ray emission technique is used for multielemental analysis of metal ions adsorbed on nanosilica surface. At pH 3.5, silica traps uranium selectively from a mixture of solutions of 13 different metal ions viz., K(I), Ca(II), Fe(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Sr(II), Cd(II). Ba(II), Hg(II) and UO 2 (VI). (author)

  6. Bentonite as a backfill material for shallow land repositories

    International Nuclear Information System (INIS)

    Yalmali, V.S.; Deshingkar, D.S.

    2001-01-01

    Two commercially available indigenous bentonite samples were evaluated for their cesium and strontium sorption properties in distilled water and surface water. By converting them into sodium form, the distribution coefficients for both cesium (I) and strontium (II) increased. Sodium bentonite was recommended because of high sorption capacity for Cs(I), Mg(II) and Sr(II) for use as backfill material in shallow land repositories where cement waste form containing Cs, Sr and Be wastes are disposed. (author)

  7. Crystal structure of poly[[hexaqua-1κ4O,2κ2O-bis(μ3-pyridine-2,4-dicarboxylato-1κO2:2κ2N,O2′;1′κO4cobalt(IIstrontium(II] dihydrate

    Directory of Open Access Journals (Sweden)

    Zhaojun Yu

    2015-09-01

    Full Text Available In the title polymeric complex, {[CoSr(C7H3NO42(H2O6]·2H2O}n, the CoII ion, which is situated on a crystallographic centre of inversion, is six-coordinated by two O atoms and two N atoms from two pyridine-2,4-dicarboxylate (pydc2− ligands and two terminal water molecules in a slightly distorted octahedral geometry, to form a trans-[Co(pydc2(H2O2]2− unit. The SrII ion, situated on a C2 axis, is coordinated by four O atoms from four pydc2− ligands and four water molecules. The coordination geometry of the SrII atom can be best described as a distorted dodecahedron. Each SrII ion bridges four [Co(pydc2(H2O2]2− units by four COO− groups of four pydc2− ligands to form a three-dimensional network structure. Two additional solvent water molecules are observed in the crystal structure and are connected to the three-dimensional coordination polymer by O—H...O hydrogen bonds. Further intra- and intermolecular O—H...O hydrogen bonds consolidate the overall structure.

  8. Biosorptive behavior of some dead biomasses in the removal of Sr(85+89) from aqueous solutions

    International Nuclear Information System (INIS)

    Mishra, S.P.; Tiwari, D.

    2002-01-01

    Biosorptive behavior of some dead biomasses (viz., bark of Azadirachta indica and Mangifera indica and rice hulls) was assessed for the removal of an important fission fragment, Sr(II) ions from aqueous solutions using radiotracer technique. Single batch experiments revealed that the increase in sorptive concentration (1.0 x 10 -8 to 1.0 x 10 -2 mol x dm -3 ), temperature (298 to 328 K) and solution pH (3.0 to 10.5) greatly enhanced the removal of Sr(II) ions and the 'ion-exchange' along with surface complexation type uptake of Sr(II) followed the Freundlich adsorption isotherm for the entire concentration range (1.0 x 10 -2 to 1.0 x 10 -8 mol x dm -3 ). Desorption experiments suggest that the uptake is irreversible and the irradiation of these materials enhanced their applicability as showed greater stability towards ionizing radiations from a 300 mCi (Ra-Be) neutron source. (author)

  9. Macrocyclic receptors immobilized to monodisperse porous polymer particles by chemical grafting and physical impregnation for strontium capture: a comparative study.

    Science.gov (United States)

    Song, Yang; Du, Yi; Lv, Dachao; Ye, Gang; Wang, Jianchen

    2014-06-15

    Separation of strontium is of great significance for radioactive waste treatment and environmental remediation after nuclear accidents. In this work, a novel class of adsorbent (Crown-g-MPPPs) was synthesized by chemical grafting a macrocyclic ether receptor to monodisperse porous polymer particles (MPPPs) for strontium adsorption. Meanwhile, a counterpart material (Crown@MPPPs) with the receptor molecules immobilized to the MPPPs substrate by physical impregnation was prepared. To investigate how the immobilization manner and distribution of the receptors influence the adsorption ability, a comparative study on the adsorption behaviour of the two materials towards Sr(II) in HNO3 media was accomplished. Due to the shorter diffusion path and covalently-bonded structure, Crown-g-MPPPs showed faster adsorption kinetics and better stability for cycle use. While Crown@MPPPs had the advantages of facile synthesis and higher adsorption capacity, owing to the absence of conformational constraint to form complexation with Sr(II). Kinetic functions (Lagergren pseudo-first-order/pseudo-second-order functions) and adsorption isotherm models (Langmuir/Freundlich models) were used to fit the experimental data and examine the adsorption mechanism. On this basis, a chromatographic process was proposed by using Crown@MPPPs for an effective separation of Sr(II) (91%) in simulated high level liquid waste (HLLW). Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Sorption of cesium, strontium, and technetium onto organic-extracted shales

    International Nuclear Information System (INIS)

    Ho, P.C.

    1992-01-01

    The sorption of Cs(I), Sr(II), and Tc(VII) onto organic-extracted shales from synthetic brine groundwaters and from 0.03-M NaHCO 3 solution under oxid conditions at room temperature has been studied. The shale samples used in this study were Pumpkin Valley, Upper Dowelltown, Pierre and Green River Formation Shales. The organic content of these shales ranges from less than 2 wt% to 13 wt%. Soxhlet extraction with chloroform and a mixture of chloroform and methanol removed 0.07 to 5.9 wt% of the total organic matter from these shales. In comparison with the results of sorption of these three metal ions onto the corresponding untreated shales, it was observed that there were moderate to significant sorption decreases of Cs(I) and Sr(II) on all four organic-extracted shale samples and moderate sorption decrease of Tc(VII) on the organic-extracted Pumpkin Valley, Pierre, and Green River Shale samples, but only moderate sorption increases of Tc(VII) on the organic-extracted Upper Dowelltown Shale samples from the brine groundwaters. Nevertheless, sorption of Cs(I), Sr(II), and Tc(VII) on all four organic-extracted shale samples from the bicarbonate solution in most cases did not show a consistent pattern. (orig.)

  11. Development of the chromatographic partitioning of cesium and strontium utilizing two macroporous silica-based calix[4]arene-crown and amide impregnated polymeric composites: PREC partitioning process.

    Science.gov (United States)

    Zhang, Anyun; Kuraoka, Etsushu; Kumagai, Mikio

    2007-07-20

    To partition effectively Cs(I) and Sr(II), two harmful heat emitting nuclides, from a highly active liquid waste by extraction chromatography, two kinds of macroporous silica-based polymeric materials, Calix[4]arene-R14/SiO(2)-P and TODGA/SiO(2)-P, were synthesized. Two chelating agents, 1,3-[(2,4-diethyl-heptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14), an excellent supramolecular compound having molecular recognition ability for Cs(I), and N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) were impregnated and immobilized into the pores of SiO(2)-P particles support by a vacuum sucking technique. The loading and elution of 11 typical simulated fission and non-fission products from 4.0M or 2.0M HNO(3) were performed at 298K. It was found that in the first column packed with the Calix[4]arene-R14/SiO(2)-P, all of the simulated elements were separated effectively into two groups: (1) Na(I), K(I), Sr(II), Fe(III), Ba(II), Ru(III), Pd(II), Zr(IV), and Mo(VI) (noted as Sr-group); (2) Cs(I)-Rb(I) (Cs-group) by eluting with 4.0M HNO(3) and distilled water, respectively. The harmful element Cs(I) flowed into the second group along with Rb(I) because of their close sorption and elution properties towards Calix[4]arene-R14/SiO(2)-P, while Sr(II) showed no sorption and flowed into Sr-containing group. In the second column packed with TODGA/SiO(2)-P, the Sr-group was separated into (1) Ba(II), Ru(III), Na(I), K(I), Fe(III), and Mo(VI) (non-sorption group); (2) Sr(II); (3) Pd(II); and (4) Zr(IV) by eluting with 2.0M HNO(3), 0.01M HNO(3), 0.05M DTPA-pH 2.5, and 0.5M H(2)C(2)O(4), respectively. Sr(II) adsorbed towards TODGA/SiO(2)-P flowed into the second group and showed the excellent separation efficiency from others. Based on the elution behavior of the tested elements, an advanced PREC (Partitioning and Recovery of two heat generators from an acidic HLW (high activity liquid waste) by Extraction Chromatography) process was proposed.

  12. Macrocyclic receptor showing extremely high Sr(II)/Ca(II) and Pb(II)/Ca(II) selectivities with potential application in chelation treatment of metal intoxication.

    Science.gov (United States)

    Ferreirós-Martínez, Raquel; Esteban-Gómez, David; Tóth, Éva; de Blas, Andrés; Platas-Iglesias, Carlos; Rodríguez-Blas, Teresa

    2011-04-18

    Herein we report a detailed investigation of the complexation properties of the macrocyclic decadentate receptor N,N'-Bis[(6-carboxy-2-pyridil)methyl]-4,13-diaza-18-crown-6 (H(2)bp18c6) toward different divalent metal ions [Zn(II), Cd(II), Pb(II), Sr(II), and Ca(II)] in aqueous solution. We have found that this ligand is especially suited for the complexation of large metal ions such as Sr(II) and Pb(II), which results in very high Pb(II)/Ca(II) and Pb(II)/Zn(II) selectivities (in fact, higher than those found for ligands widely used for the treatment of lead poisoning such as ethylenediaminetetraacetic acid (edta)), as well as in the highest Sr(II)/Ca(II) selectivity reported so far. These results have been rationalized on the basis of the structure of the complexes. X-ray crystal diffraction, (1)H and (13)C NMR spectroscopy, as well as theoretical calculations at the density functional theory (B3LYP) level have been performed. Our results indicate that for large metal ions such as Pb(II) and Sr(II) the most stable conformation is Δ(δλδ)(δλδ), while for Ca(II) our calculations predict the Δ(λδλ)(λδλ) form being the most stable one. The selectivity that bp18c6(2-) shows for Sr(II) over Ca(II) can be attributed to a better fit between the large Sr(II) ions and the relatively large crown fragment of the ligand. The X-ray crystal structure of the Pb(II) complex shows that the Δ(δλδ)(δλδ) conformation observed in solution is also maintained in the solid state. The Pb(II) ion is endocyclically coordinated, being directly bound to the 10 donor atoms of the ligand. The bond distances to the donor atoms of the pendant arms (2.55-2.60 Å) are substantially shorter than those between the metal ion and the donor atoms of the crown moiety (2.92-3.04 Å). This is a typical situation observed for the so-called hemidirected compounds, in which the Pb(II) lone pair is stereochemically active. The X-ray structures of the Zn(II) and Cd(II) complexes show that

  13. Sensory rhodopsins I and II modulate a methylation/demethylation system in Halobacterium halobium phototaxis

    International Nuclear Information System (INIS)

    Spudich, E.N.; Takahashi, T.; Spudich, J.L.

    1989-01-01

    This work demonstrates that phototaxis stimuli in the archaebacterium Halobacterium halobium control a methylation/demethylation system in vivo through photoactivation of sensory rhodopsin I (SR-I) in either its attractant or repellent signaling form as well as through the repellent receptor sensory rhodopsin II (SR-II, also called phoborhodopsin). The effects of positive stimuli that suppress swimming reversals (i.e., an increase in attractant or decrease in repellent light) and negative stimuli that induce swimming reversals (i.e., a decrease in attractant or increase in repellent light) through each photoreceptor were monitored by assaying release of volatile [3H]methyl groups. This assay has been used to measure [3H]methanol produced during the process of adaptation to chemotactic stimuli in eubacteria. In H. halobium positive photostimuli produce a transient increase in the rate of demethylation followed by a decrease below the unstimulated value, whereas negative photostimuli cause an increase followed by a rate similar to that of the unstimulated value. Photoactivation of the SR-I attractant and simultaneous photoactivation of the SR-II repellent receptors cancel in their effects on demethylation, demonstrating the methylation system is regulated by an integrated signal. Analysis of mutants indicates that the source for the volatile methyl groups is intrinsic membrane proteins distinct from the chromoproteins that share the membrane. A methyl-accepting protein (94 kDa) previously correlated in amount with the SR-I chromoprotein (25 kDa) is shown here to be missing in a recently isolated SR-I-SR-II+ mutant (Flx3b), thus confirming the association of this protein with SR-I. Photoactivated SR-II in mutant Flx3b controls demethylation, predicting the existence of a photomodulated methyl-accepting component distinct from the 94-kDa protein of SR-I

  14. Sorption of cesium and strontium from concentrated brines by backfill barrier materials

    International Nuclear Information System (INIS)

    Winslow, C.D.

    1981-03-01

    The sorption of radionuclides from potentially intruding groundwater at a nuclear waste repository is a major chemical function of backfill barriers. In this study, various materials (including clays, zeolites and an inorganic ion exchanger) were screened for the sorption of the fission products cesium and strontium in concentrated brines. Representative brines A and B for the Waste Isolation Pilot Plant (WIPP), a proposed radioactive waste repository and test facility in bedded salt were used. Sorption properties were quantified using empirical distribution coefficients, k/sub d/. Of the materials examined, sodium titanate had the highest k/sub d/ for the sorption of Sr(II) in both brine A (k/sub d/ = 125 ml/g) and brine B(k/sub d/ = 500 to 600 ml/g). A mordenite-type zeolite was the most effective getter for Cs(I) in brine A (k/sub d = 27 ml/g), while illite yielded the highest k/sub d/ for Cs(I) in brine B (k/sub d/ = 115 ml/g). The relative merit of these k/sub d/ values is evaluated in terms of calculated estimates of breakthrough times for a backfill barrier containing the getter. Results show that a backfill mixture containing these getters is potentially an effective barrier to the migration of Sr(II) and Cs(I), although further study (especially for the sorption of cesium from brine A) is recommended. Initial mechanistic studies revealed competing ion effects which would support an ion exchange mechanism. K/sub d/'s were constant over a Sr(II) concentration range of 10 -11 to 10 -5 M and a Cs(I) concentration range of 10 -8 to 10 -5 M, supporting the choice of a linear sorption isotherm as a model for the results. Constant batch composition was shown to be attained within one week

  15. Role of diluent on the separation of {sup 90}Y from {sup 90}Sr by solvent extraction and supported liquid membrane using T2EHDGA as the extractant

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, S. [Planning and Coordination Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India); Raut, D.R. [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India); Mohapatra, P.K., E-mail: mpatra@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085 (India)

    2012-04-15

    The separation behaviour of {sup 90}Y from {sup 90}Sr was investigated by diluent variation using solvent extraction and supported liquid membrane techniques employing N,N,N Prime ,N Prime -tetra-2-ethylhexyldiglycolamide (T2EHDGA) as the extractant. Both D{sub Y} (distribution ratio of Y(III)) and S.F. (separation factor) were found to be high in the solvent extraction studies when chloroform was used as the diluent. Subsequent supported liquid membrane (SLM) studies using PTFE flat sheet membranes containing 0.2 M T2EHDGA in various diluents indicated the trend of Y transport as xylene>hexone>chloroform>carbon tetrachloride>n-dodecane+30% iso-decanol mixture. However, the Sr(II) transport rates were also high with xylene, hexone, and carbon tetrachloride as the diluents which led us to carry out subsequent studies using chloroform and n-dodecane+30% iso-decanol mixture. Acid variation studies in chloroform system indicated an interesting phenomena of increasing Y(III) transport and decreasing Sr(II) transport with increasing acid concentration. Separation of {sup 90}Y from a mixture of {sup 90}Sr and {sup 90}Y was also attempted. - Highlights: Black-Right-Pointing-Pointer SLM studies using PTFE flat sheet membranes containing T2EHDGA as carrier was carried out for Y-90 separation from Sr-90. Black-Right-Pointing-Pointer The trend of Y transport as xylene>hexone>chloroform>carbon tetrachloride>n-dodecane+30% iso-decanol mixture. Black-Right-Pointing-Pointer Acid variation studies in chloroform system indicated an interesting phenomena of increasing Y(III) transport and decreasing Sr(II) transport with increasing acid concentration. Black-Right-Pointing-Pointer The present studies suggested that T2EHDGA-SLM show limited promise if coupled to another separation method such as extraction chromatography.

  16. Multiplex Real-Time qPCR Assay for Simultaneous and Sensitive Detection of Phytoplasmas in Sesame Plants and Insect Vectors.

    Science.gov (United States)

    Ikten, Cengiz; Ustun, Rustem; Catal, Mursel; Yol, Engin; Uzun, Bulent

    2016-01-01

    Phyllody, a destructive and economically important disease worldwide caused by phytoplasma infections, is characterized by the abnormal development of floral structures into stunted leafy parts and contributes to serious losses in crop plants, including sesame (Sesamum indicum L.). Accurate identification, differentiation, and quantification of phyllody-causing phytoplasmas are essential for effective management of this plant disease and for selection of resistant sesame varieties. In this study, a diagnostic multiplex qPCR assay was developed using TaqMan® chemistry based on detection of the 16S ribosomal RNA gene of phytoplasmas and the 18S ribosomal gene of sesame. Phytoplasma and sesame specific primers and probes labeled with different fluorescent dyes were used for simultaneous amplification of 16SrII and 16SrIX phytoplasmas in a single tube. The multiplex real-time qPCR assay allowed accurate detection, differentiation, and quantification of 16SrII and 16SrIX groups in 109 sesame plant and 92 insect vector samples tested. The assay was found to have a detection sensitivity of 1.8 x 102 and 1.6 x 102 DNA copies for absolute quantification of 16SrII and 16SrIX group phytoplasmas, respectively. Relative quantification was effective and reliable for determination of phyllody phytoplasma DNA amounts normalized to sesame DNA in infected plant tissues. The development of this qPCR assay provides a method for the rapid measurement of infection loads to identify resistance levels of sesame genotypes against phyllody phytoplasma disease.

  17. Multiplex Real-Time qPCR Assay for Simultaneous and Sensitive Detection of Phytoplasmas in Sesame Plants and Insect Vectors.

    Directory of Open Access Journals (Sweden)

    Cengiz Ikten

    Full Text Available Phyllody, a destructive and economically important disease worldwide caused by phytoplasma infections, is characterized by the abnormal development of floral structures into stunted leafy parts and contributes to serious losses in crop plants, including sesame (Sesamum indicum L.. Accurate identification, differentiation, and quantification of phyllody-causing phytoplasmas are essential for effective management of this plant disease and for selection of resistant sesame varieties. In this study, a diagnostic multiplex qPCR assay was developed using TaqMan® chemistry based on detection of the 16S ribosomal RNA gene of phytoplasmas and the 18S ribosomal gene of sesame. Phytoplasma and sesame specific primers and probes labeled with different fluorescent dyes were used for simultaneous amplification of 16SrII and 16SrIX phytoplasmas in a single tube. The multiplex real-time qPCR assay allowed accurate detection, differentiation, and quantification of 16SrII and 16SrIX groups in 109 sesame plant and 92 insect vector samples tested. The assay was found to have a detection sensitivity of 1.8 x 102 and 1.6 x 102 DNA copies for absolute quantification of 16SrII and 16SrIX group phytoplasmas, respectively. Relative quantification was effective and reliable for determination of phyllody phytoplasma DNA amounts normalized to sesame DNA in infected plant tissues. The development of this qPCR assay provides a method for the rapid measurement of infection loads to identify resistance levels of sesame genotypes against phyllody phytoplasma disease.

  18. Poly[diaqua(μ5-pyridine-3,5-dicarboxylatostrontium

    Directory of Open Access Journals (Sweden)

    Dan Li

    2012-06-01

    Full Text Available In the structure of the title compound, [Sr(C7H3NO4(H2O2]n, the SrII cation is eight-coordinated in form of a distorted dodecahedron by two water O atoms and by five O atoms and one N atom from five pyridine-3,5-dicarboxylate anions. The bridging mode of the anions leads to the formation of a layered network parallel to (100. O—H...O hydrogen bonding between the coordinating water molecules and the carboxylate groups of adjacent layers consolidates the crystal packing. Weak C—H...O interactions are also observed.

  19. Poly[μ-aqua-μ4-terephthalato-strontium

    Directory of Open Access Journals (Sweden)

    Lei Yang

    2011-02-01

    Full Text Available In the title compound, [Sr(C8H4O4(H2O]n, the SrII atom exhibits coordination number eight, with six O atoms from four carboxylate groups (two bidentate and two monodentate of terephthalate ligands and two water O atoms. The SrO8 polyhedra are linked into inorganic chains by sharing three coplanar O atoms. These inorganic chains are extended along the b axis to form layers in the ab plane by O—C—O linking. Parallel layers are connected by terephthalic groups, forming a three-dimensional framework. O—H...O hydrogen-bonding interactions are observed.

  20. Retention behavior of actinides and long lived fission products on Smectite rich clays

    International Nuclear Information System (INIS)

    Tomar, B.S.

    2014-01-01

    In the present work, sorption of Am(llI), Cs(I) and Sr(ll) by the Smectite rich clay from western India has been studied in detail under the varying experimental conditions, viz., pH, ionic strength, and metal ion concentration. The experimental data on sorption have been modeled using the surface complexation model. Am(llI) sorption by smectite rich clay was found to increase with the pH of the suspension. At lower pH values, the sorption decreased with increasing ionic strength of the suspension, but remained constant at higher pH values. This is reminiscent of the ion exchange mechanism at lower pH and predominantly inner sphere complexation at higher pH. Surface complexation modeling using FITEQL could successfully explain these two mechanisms operating in the different pH values. Sorption of Cs(I) and Sr(II) by the smectite rich clay was studied under the varying experimental conditions. Though the sorption of both the metal ions increased with pH, it decreased with the increasing ionic strength, at all pH values, suggesting ion exchange as the predominant mechanism at all pH values. Further, the ionic strength dependence was different in the case of Cs(I) and Sr(II) depending upon the metal ion concentration. At same metal ion concentration of Cs(I) and Sr(II) (10 -5 M) the extent of decrease with ionic strength was same in both cases, while at 10 -9 M, Cs(I), the decrease was much smaller than that at 10 -5 M. This indicates the existence of ion exchange sites having different affinities. These studies have shown high retention capacity of the clay for actinides and long lived fission products with the sorption following ion exchange mechanism in the case of Cs(I) and Sr(II) and a combination of ion exchange and surface complexation in the case of Am(III) depending upon the pH. The sorption data could be successfully explained within the framework of FITEQL, taking into account both the types of binding sites

  1. Separation of cesium from simulated active waste using zinc hexacyanoferrate supported composite

    International Nuclear Information System (INIS)

    Somida, H.H.; El Zahhar, A.A.; Shehata, M.K.; El Naggar, H.A.

    2003-01-01

    Potassium zinc hexacyanoferrate (KZnHCF) was prepared and supported on polyacrylonitrile (PAN) binding polymer. This composite was characterized and used to study the elimination of cesium from acidic radioactive waste containing Sr(II), Eu(II), Am(II), Zr(IV), Hf(IV) and Nb(V) using batch and column techniques. The sorption capacity of this composite for cesium was found to be 1.14 meq/g for column technique. The effect of presence of NH 4 SCN, NaNo 3 and other complexing agents in the aqueous solutions was studied

  2. Poly[tetraaqua-μ3-pyridine-3,5-dicarboxylato-strontium(II

    Directory of Open Access Journals (Sweden)

    Shirin Daneshvar

    2008-02-01

    Full Text Available The reaction of strontium(II nitrate with the proton-transfer compound (pdaH2(py-3,5-dc·H2O (where pda = propane-1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid leads to the formation of the title polymeric compound, [Sr(C7H3NO4(H2O4]n. The propane-1,3-diaminium cation is not incorporated in this crystal structure. The SrII atom lies on an inversion centre and is eight-coordinated by four O atoms from three py-3,5-dc ligands and four O atoms from four coordinated water molecules. The coordination polyhedron of the SrII atom is a distorted dodecahedron. These binuclear units are connected via the carboxylate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant interactions consisting of hydrogen bonds (X—H...O, with X = O and C and π–π stacking interactions [3.4604 (19 Å] connect the various components to form a supramolecular structure.

  3. Biosorption study of radiotoxic nuclide and toxic heavy metals using green adsorbent

    International Nuclear Information System (INIS)

    Bagla, Hemlata K.

    2014-01-01

    Our research scientifically illuminates the pioneering and successful application of the ancient Indian epitome of energy, Dry Cow Dung Powder, DCP, a combo humiresin, in its naive 'as it is form' for the bioremediation of toxic pollutants. The potential of DCP to sequester toxic heavy metal ions such as Cr(III), Cr(VI). Cd(II), Hg(II) and radionuclide 90 Sr(II) has been successfully demonstrated, employing tracer technique. The Batch equilibration method and all the important parameters such as pH, dose of sorbent, metal ion concentration, contact time, agitation speed, temperature and interference of different salts have been studied and optimized. The study on thermodynamic, kinetic and isotherm modeling of biosorption indicates that it is feasible, eco-friendly and efficient process to employ DCP for the removal of metal ions from aqueous medium. Spectroscopic analysis by FTIR and EDAX effectively explain the mechanism involved in the biosorption by DCP. The adsorption capacity and the pseudo-second order rate constant were also obtained by regression analysis. Thus DCP proves to be Eco-friendly resin for the removal of these toxic pollutants such as Cr(III), Cr(VI), Cd(II), Hg(II) and 90 Sr(II) from aqueous medium. (author)

  4. Synthesis and Characterization of Novel Magnetic Nano-Materials and Studying Their Potential Application in Recovery of Metal Ions

    International Nuclear Information System (INIS)

    Moussa, S.I.M.

    2013-01-01

    The release of hazardous pollutants and their dispersion in the environment can cause adverse impacts on both environment and public health. These pollutants are more easily controlled when they are generated than after they are dispersed. Therefore, it is necessity of prime to design treatment processes can remove the contaminants at their source. Recently, many industrial and nuclear activities produce large amounts of wastewaters that contains a variety of contaminants. These contaminants may include toxic metals or radioactive isotopes. The efforts in this work are firstly directed to prepare some materials to be used as sorbents for removal of Sr(II), Cd(II) and Eu(III) radionuclide from waste solutions. The study concerned with the characterization of the prepared sorbents using surface area (BET), FTIR, X-Ray, TG/DTA, SEM and magnetic properties to throw light on its sense when practically used as a decontaminating material in aqueous systems. Also, the work involves the sorption of Sr(II), Cd(II) and Eu(III) ions from aqueous solutions under different experimental conditions to clarify the affinity of these sorbents and to assess main factors affecting the sorption behavior of these species. This is to evaluate the efficiency of these sorbents to be used as decontaminating materials for treatment of hazard wastes and finally to judge the criteria of sorbents selectivity towards the studies solutes.

  5. Signaling and Adaptation Modulate the Dynamics of the Photosensoric Complex of Natronomonas pharaonis.

    Directory of Open Access Journals (Sweden)

    Philipp S Orekhov

    2015-10-01

    Full Text Available Motile bacteria and archaea respond to chemical and physical stimuli seeking optimal conditions for survival. To this end transmembrane chemo- and photoreceptors organized in large arrays initiate signaling cascades and ultimately regulate the rotation of flagellar motors. To unravel the molecular mechanism of signaling in an archaeal phototaxis complex we performed coarse-grained molecular dynamics simulations of a trimer of receptor/transducer dimers, namely NpSRII/NpHtrII from Natronomonas pharaonis. Signaling is regulated by a reversible methylation mechanism called adaptation, which also influences the level of basal receptor activation. Mimicking two extreme methylation states in our simulations we found conformational changes for the transmembrane region of NpSRII/NpHtrII which resemble experimentally observed light-induced changes. Further downstream in the cytoplasmic domain of the transducer the signal propagates via distinct changes in the dynamics of HAMP1, HAMP2, the adaptation domain and the binding region for the kinase CheA, where conformational rearrangements were found to be subtle. Overall these observations suggest a signaling mechanism based on dynamic allostery resembling models previously proposed for E. coli chemoreceptors, indicating similar properties of signal transduction for archaeal photoreceptors and bacterial chemoreceptors.

  6. Novel fungus-Fe{sub 3}O{sub 4} bio-nanocomposites as high performance adsorbents for the removal of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Congcong [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); University of Science and Technology of China, Hefei 230000 (China); Cheng, Wencai [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); Sun, Yubing, E-mail: sunyb@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Wang, Xiangke, E-mail: xkwang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-09-15

    Highlights: • Fungus was used as a template for the assembly of nano-Fe{sub 3}O{sub 4}. • Fungal template directed the nano-Fe{sub 3}O{sub 4} structure from the micro-scale level. • Fungal template enhanced the dispersity and stability of nano-Fe{sub 3}O{sub 4}. • Fungus-Fe{sub 3}O{sub 4} exhibited high sorption capacity for Sr(II), Th(IV) and U(VI). • Fungus-Fe{sub 3}O{sub 4} possessed satisfactory regeneration performance and reusability. - Abstract: The bio-nanocomposites of fungus-Fe{sub 3}O{sub 4} were successfully synthesized using a low-cost self-assembly technique. SEM images showed uniform decoration of nano-Fe{sub 3}O{sub 4} particles on fungus surface. The FTIR analysis indicated that nano-Fe{sub 3}O{sub 4} was combined to the fungus surface by chemical bonds. The sorption ability of fungus-Fe{sub 3}O{sub 4} toward Sr(II), Th(IV) and U(VI) was evaluated by batch techniques. Radionuclide sorption on fungus-Fe{sub 3}O{sub 4} was independent of ionic strength, indicating that inner-sphere surface complexion dominated their sorption. XPS analysis indicated that the inner-sphere radionuclide complexes were formed by mainly bonding with oxygen-containing functional groups (i.e., alcohol, acetal and carboxyl) of fungus-Fe{sub 3}O{sub 4}. The maximum sorption capacities of fungus-Fe{sub 3}O{sub 4} calculated from Langmuir isotherm model were 100.9, 223.9 and 280.8 mg/g for Sr(II) and U(VI) at pH 5.0, and Th(IV) at pH 3.0, respectively, at 303 K. Fungus-Fe{sub 3}O{sub 4} also exhibited excellent regeneration performance for the preconcentration of radionuclides. The calculated thermodynamic parameters showed that the sorption of radionuclides on fungus-Fe{sub 3}O{sub 4} was a spontaneous and endothermic process. The findings herein highlight the novel synthesis method of fungus-Fe{sub 3}O{sub 4} and its high sorption ability for radionuclides.

  7. Poly[μ2-aqua-aqua-μ4-pyridine-2,4-dicarboxylato-strontium

    Directory of Open Access Journals (Sweden)

    Zohreh Derikvand

    2009-08-01

    Full Text Available In the title polymeric complex, [Sr(C7H3NO4(H2O2]n, the SrII atom is eight-coordinated by four O atoms and one N atom of four pyridine-2,4-dicarboxylate (py-2,4-dc ligands and three O atoms of three coordinated water molecules in a dodecahedral geometry. These units are connected via the carboxylate O atoms and water molecules, building polymeric layers parallel to (100. In the crystal structure, non-covalent interactions consisting of O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.862 (17 and 3.749 (17 Å] connect the various components, forming a three-dimensional structure.

  8. Crystal structure of poly[[μ2-diaqua-diaqua-μ2-l-proline-κ2O:O′-strontium] dibromide

    Directory of Open Access Journals (Sweden)

    Selladurai Sathiskumar

    2015-10-01

    Full Text Available In the title coordination polymer, {[Sr(C5H9NO2(H2O4]Br2}n, the proline molecule exists in a zwitterionic form with one of the ring C atoms disordered over two sites [site-occupancy factors = 0.57 (6:0.43 (6]. The SrII ion is nine-coordinated by six water O atoms, two monodentate and two μ2-bridging, and three carboxylate O atoms of the proline ligands, with two bridging [Sr—O range = 2.524 (4–2.800 (5 Å]. In the crystal, there is no direct interaction between the proline molecules. However, the proline and water molecules associate with the bromide counter-anions through a number of intermolecular O—H...Br and N—H...Br hydrogen-bonding interactions, giving a three-dimensional supramolecular structure.

  9. Propyl phthalimide-modified thiacalixphenyl[4]arene as a “turn on” chemosensor for Hg(II) ions

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Krunal; Panchal, Urvi; Mehta, Viren; Panchal, Manthan; Kongor, Anita; Jain, V.K., E-mail: drvkjain@hotmail.com

    2016-11-15

    Thiacalixphenyl[4]arene tetra N-(3-propyl) phthalimide (TPTN3PPh), a novel thiacalixarene bearing a N-(3-bromopropyl) phthalimide group, was synthesized and characterized by Electrospray Ionization Mass Spectrometry (ESI-MS) and NMR. The ability of TPTN3PPh to recognize the cations Fe(III), Cu(II), Cd(II), Zn(II), Cr(II), Ca(II), Co(II), Mg(II), Ag(I), Pb(II), Sr(II), Hg (II), Th(II), Ba(II), Bi(II), K(I), and Na(I) was evaluated. Only Hg(II) was selectively and sensitively detected using a spectrofluorimetric method, with a detection limit as low as 3.10×10{sup −9} M. Analysis of the binding behavior of TPTN3PPh with Hg(II) revealed 1:2 complex formation. Real sample analysis detected nano levels of mercury ions in a waste water samples.

  10. The application of experimental design methodology for the investigation of liquid radioactive waste treatment

    Directory of Open Access Journals (Sweden)

    Šljivić-Ivanović Marija Z.

    2017-01-01

    Full Text Available The sorption properties of waste facade, brick, and asphalt sample towards Sr(II, Co(II, and Ni(II ions from single and multicomponent solutions were investigated. The highest sorption capacity was found for Ni(II ions, while the most effective sorbent was facade. Simplex Centroid Mixture Design was used in order to investigate the sorption processes of ions from solutions with different composition as well as the competition between the cations. Based on the statistical analysis results, the equations for data modeling were proposed. According to the observations, the investigated solid matrices can be effectively used for the liquid radioactive waste treatment. Furthermore, the applied methodology turned out to be an easy and operational way for the investigations of multicomponent sorption processes. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. III 43009 and Grant no. OI 171007

  11. Ion exchange kinetics of alkaline earths on Zr(IV) arsenosilicate cation exchanger

    International Nuclear Information System (INIS)

    Varshney, K.G.; Agrawal, S.; Varshney, K.

    1984-01-01

    A new approach based on the Nernst-Planck equations was applied to study the ion exchange kinetics for the exchange reactions of Mg(II), Ca(II), Sr(II) and Ba(II) with H + -ions at various temperatures on the zirconium(IV) arsenosilicate phase. Under the conditions of particle diffusion, the rate of exchange was found to be independent of the metal ion concentration at and above 0.1 M in aqueous medium. Energy and entropy of activation were determined and found to vary linearly with the ionic radii and mobilities of alkaline earths, a unique feature observed for an inorganic ion exchanger. The results are useful for predicting the ion exchange processes occurring on the surface of an inorganic material of the type studied. (author)

  12. The behaviour of trace elements and radionuclides in must of grapes during fermentation and usual wine technology

    International Nuclear Information System (INIS)

    Hellmuth, K.H.; Fischer, E.

    1985-01-01

    The elements Co(II), Sr(II), Cs(I), Tl(I) and Am(III) were added as their radionuclides to the must of white grapes of one vintage and from that wine was prepared using usual wine technology. The elimination of the elements during the fermentation and as a consequence of the subsequent treatments has been determined. The decrease of the metal contents with time follows approximately an exponential function in the cases of Co, Cs, Tl and Am, whereas the Sr-content remains nearly constant. In the total balance, the following residual values were found in the final wine: Co 8.6+-0.6%, Sr 41+-4%, Cs 0.13+-0.07 resp. 0.031+-0.008%, Tl 1.3+-0.2% and Am 1.0+-0.2% of the initial value. (orig./PW) [de

  13. Ablation of biological tissues by radiation of strontium vapor laser

    Energy Technology Data Exchange (ETDEWEB)

    Soldatov, A. N., E-mail: general@tic.tsu.ru; Vasilieva, A. V., E-mail: anita-tomsk@mail.ru [National Research Tomsk State University, Lenin ave., 36, 634050, Tomsk (Russian Federation)

    2015-11-17

    A two-stage laser system consisting of a master oscillator and a power amplifier based on sources of self- contained transitions in pairs SrI and SrII has been developed. The radiation spectrum contains 8 laser lines generating in the range of 1 – 6.45 μm, with a generation pulse length of 50 – 150 ns, and pulse energy of ∼ 2.5 mJ. The divergence of the output beam was close to the diffraction and did not exceed 0.5 mrad. The control range of the laser pulse repetition rate varied from 10 to 15 000 Hz. The given laser system has allowed to perform ablation of bone tissue samples without visible thermal damage.

  14. Controlled in meso phase crystallization--a method for the structural investigation of membrane proteins.

    Directory of Open Access Journals (Sweden)

    Jan Kubicek

    Full Text Available We investigated in meso crystallization of membrane proteins to develop a fast screening technology which combines features of the well established classical vapor diffusion experiment with the batch meso phase crystallization, but without premixing of protein and monoolein. It inherits the advantages of both methods, namely (i the stabilization of membrane proteins in the meso phase, (ii the control of hydration level and additive concentration by vapor diffusion. The new technology (iii significantly simplifies in meso crystallization experiments and allows the use of standard liquid handling robots suitable for 96 well formats. CIMP crystallization furthermore allows (iv direct monitoring of phase transformation and crystallization events. Bacteriorhodopsin (BR crystals of high quality and diffraction up to 1.3 Å resolution have been obtained in this approach. CIMP and the developed consumables and protocols have been successfully applied to obtain crystals of sensory rhodopsin II (SRII from Halobacterium salinarum for the first time.

  15. Synthesis, Structural, and Adsorption Properties and Thermal Stability of Nanohydroxyapatite/Polysaccharide Composites.

    Science.gov (United States)

    Skwarek, Ewa; Goncharuk, Olena; Sternik, Dariusz; Janusz, Wladyslaw; Gdula, Karolina; Gun'ko, Vladimir M

    2017-12-01

    A series of composites based on nanohydroxyapatite (nHAp) and natural polysaccharides (PS) (nHAp/agar, nHAp/chitosan, nHAp/pectin FB300, nHAp/pectin APA103, nHAp/sodium alginate) was synthesized by liquid-phase two-step method and characterized using nitrogen adsorption-desorption, DSC, TG, FTIR spectroscopy, and SEM. The analysis of nitrogen adsorption-desorption data shows that composites with a nHAp: PS ratio of 4:1 exhibit a sufficiently high specific surface area from 49 to 82 m 2 /g. The incremental pore size distributions indicate mainly mesoporosity. The composites with the component ratio 1:1 preferably form a film-like structure, and the value of S BET varies from 0.3 to 43 m 2 /g depending on the nature of a polysaccharide. Adsorption of Sr(II) on the composites from the aqueous solutions has been studied. The thermal properties of polysaccharides alone and in nHAp/PS show the influence of nHAp, since there is a shift of characteristic DSC and DTG peaks. FTIR spectroscopy data confirm the presence of functional groups typical for nHAp as well as polysaccharides in composites. Structure and morphological characteristics of the composites are strongly dependent on the ratio of components, since nHAp/PS at 4:1 have relatively large S BET values and a good ability to adsorb metal ions. The comparison of the adsorption capacity with respect to Sr(II) of nHAp, polysaccharides, and composites shows that it of the latter is higher than that of nHAp (per 1 m 2 of surface).

  16. Molecular Characterization of the 16S rRNA Gene of Phytoplasmas Detected in Two Leafhopper Species Associated with Alfalfa Plants Infected with Witches' Broom in Oman

    Directory of Open Access Journals (Sweden)

    A.J. Khan

    2003-12-01

    Full Text Available Two leafhopper species, Austroagallia avicula and Empoasca sp., were consistently found in alfalfa fields infected with witches’ broom phytoplasma (OmanAlfWB in the Al-Batinah, Dakhliya, North and South Sharqiya, Muscat, and Al-Bureimi regions of the Sultanate of Oman. Phytoplasmas from both leafhoppers were detected by specific polymerase chain reaction (PCR amplification of the 16S rRNA gene and the spacer region in direct PCR using P1/P7 primer pairs. Comparative RFLP profiles of the amplified rRNA gene and the spacer region from leafhopper phytoplasmas and from 20 phytoplasma controls yielded patterns referable to phytoplasmas belonging to the peanut witches’ broom group (16SrII group. In particular, extensive RFLP analyses with the endonucleases HpaII, Tru9I, Tsp509I, and RsaI indicated that the phytoplasmas in A. avicula and Empoasca sp. were identical but showed some differences from OmanAlfWB; however, RFLP patterns obtained with TaqI showed the OmanAlfWB and the phytoplasmas from the two leafhoppers to be identical. Direct PCR products amplified from phytoplasma leafhopper DNA using the P1/P7 primer pair were cloned and sequenced yielding 1758 bp and 1755 bp products from A. avicula and Empoasca sp. respectively; the homology of these sequences with OmanAlfWB and papaya yellow crinkle phytoplasmas was more than 98%. A phylogenetic tree based on the 16S rRNA gene and spacer region sequences from 44 phytoplasmas revealed that the phytoplasmas from the leafhoppers clustered with OmanAlfWB, papaya yellow crinkle, and gerbera phyllody phytoplasmas, all belonging to 16SrII group, but were distinct from lime witches’ broom phytoplasma, the most commonly found phytoplasma in the Sultanate of Oman.

  17. Immobilisation of strontium, nickel and iodide by a sulphate-resisting Portland cement

    International Nuclear Information System (INIS)

    Wieland, E.; Tits, J.; Spieler, P.; Dobler, J.-P.

    1998-01-01

    The interaction of Sr(II), Ni(II) and I(-I) with sulphate-resisting Portland cement was investigated under highly alkaline conditions. Batch-sorption studies were performed by contacting HTS cement (haute teneur en silice, sulphate-resisting Portland cement, Lafarge, France) with artificial cement pore water (ACW). The composition of ACW was 0.18 M KOH, 0.114 M NaOH and 1.2 mM Ca(OH) 2 . 85 Sr, 63 Ni and 125 I were used as tracers. In the experiments with Sr(II) and Ni(II), isosaccharinic acid (ISA) was added to ACW at 10 -5 M to 10 -2 M in order to study the effect of complexing ligands on radionuclide retention. The stability of the tracer solutions and the cement suspensions were first assessed. Moreover, the inventory of the stable elements were determined in cement and cement pore water. We then studied the kinetics of the radionuclide-cement interaction process and measured the dependence of the distribution ratio (R d ) on the concentration of ISA and on the concentration of cement particles (S:L ratio). In the case of 63 Ni and 125 I a strong decrease in the distribution ratio (R d ) with increasing S:L ratio was observed. There is strong indication that the inventory of the stable fraction of an element present in cement pore water accounts for the retention of the radioisotope fraction. The results further indicate that phase transformations may occur in non-pre-equilibrated cement systems (non-equilibrium conditions) which affect 63 Ni uptake by HTS cement. The distribution ratios measured on HTS cement were compared with values obtained from measurements on important cement components (portlandite, CSH/C(A)SH-phases)

  18. Experimental Investigation of the Effect of the Excess Fuel Coefficient on the Electrical Conductivity of Potassium-Seeded Hydrocarbon Fuel Combustion Products; 042d 041a 0421 041f 0414

    Energy Technology Data Exchange (ETDEWEB)

    Gol' denberg, S. A.; Zimin, Je. P.; Levlev, V. N.; Popov, V. A. [Energeticheskij Institut Im. G.M.Krzhizhanovskogo, Moskva, USSR (Russian Federation)

    1968-11-15

    zavisimosti mezhdu ionizaciej dobavki kalija i sostavom produktov sgoranija dvuh uglevodorodnyh topliv: benzina i metana. Variacija sostava produktov sgoranija obespechivalas' izmeneniem kojefficienta izbytka topliva v gorjuchej smesi. Izmerenija provodilis' pri neskol'kihfiksirovannyh znachenijah temperatury v diapazone ot 1850 do 3000 Degree-Sign K (polnoe davlenie - 1 at). Temperatura podderzhivalas' postojannoj (putem razbavlenija produktov sgoranija azotom). Poluchennye jeksperimental'nye dannye po provodimosti sootvetstvujut parcial'nomu davleniju dobavki kalija (1%). V oblasti vysokih temperatur (pri ispol'zovanii benzina v kachestve topliva) izmerenija provodilis' neposredstvenno pri dobavke 1%, togda kak v oblasti nizkih temperatur (pri ispol'zovanii metana v kachestve topliva) izmerenija provodilis' pri dobavke 3 x 10{sup -2}% a zatem rezul'taty byli pereschitany na dobavku 1%. Dlja izmerenija provodimosti ispol'zovalis' metod rezonansnogo kontura i metod zatuhanija radiovoln ({lambda} = 0,8 sm). Temperatura produktov sgoranija izmerjalas' po obrashheniju D-linii natrija. Izmerenija pokazali, chto jelektroprovodnost' produktov sgoranija s dobavkoj kalija umen'shaetsja pri umen'shenii kojefficienta izbytka topliva. Pri dostatochno bol'shih kojefficientah izbytka topliva jeto snizhenie projavljaetsja slabo. Rezkoe snizhenie jelektroprovodnosti (v neskol'ko raz) sosredotocheno v oblasti znachenij kojefficienta izbytka topliva, priblizitel'no ot 1 do 1,7. Dlja interpretacii jeksperimental'nyh dannyh ispol'zovalis'-rezul'taty teoreticheskogo rascheta vlijanija gidroksila ON na process ionizacii dobavki kalija cherez obrazovanie gidrookisi KON i zahvat chasti svobodnyh jelektronov s obrazovaniem otricatel'nogo iona ON{sup -}. Takoe sravnenie prodemonstrirovalo horoshee kachestvennoe soglasovanie jeksperimental'nyh i raschetnyh dannyh, chto podtverzhdaet pravil'nost' rassmatrivaemogo mehanizma vlijanija opredelennogo sostava produktov sgoranija na ionizaciju dobavki

  19. Adsorption of heavy metal ions on molybdenum and molybdenum trioxide from dilute aqueous solution

    International Nuclear Information System (INIS)

    Utsunomiya, Taizo; Hoshino, Yoshio; Sakabe, Ken-ichi

    1984-01-01

    The adsorption of heavy metal ions such as Co(II), Cu(II) and Pb(II) on molybdenum powder has been investigated by the batch technique as a function of soaking time, concentration of heavy metal ions and coexisting salts, pH etc. Molybdenum trioxide was also used as an adsorbent for a comparison to discuss the adsorption mechanism. The amount of these heavy metal ions adsorbed was highly pH and coexisting salts dependent. These adsorbents have features of selective adsorption for Pb(II) and large adsorption rate. The adsorption of heavy metal ions on these adsorbents proceeds independently or concurrently by following complex mechanism; (1) cation exchange reaction by hydroxyl radical on the surface of Mo and MoO 3 is predominant for most of heavy metal ions except Pb(II) [Co(II), Mn(II), Fe(III), Ni(II), Zn(II), Cd(II) and Sr(II)], (2) reduction (electron exchange reaction) to low ionic or metallic state after cation exchange reaction [Cu(II) and Ag(I) on Mo] and (3) formation of a compound [Pb(II) on both Mo and MoO 3 ]. (author)

  20. Organic geochemistry: Effects of organic components of shales on adsorption: Progress report

    International Nuclear Information System (INIS)

    Ho, P.C.

    1988-11-01

    The Sedimentary Rock Program at the Oak Ridge National Laboratory is investigating shale to determine its potential suitability as a host rock for the disposal of high-level radioactive wastes (HLW). The selected shales are Upper Dowelltown, Pierre, Green River Formation, and two Conasauga (Nolichucky and Pumpkin Valley) Shales, which represent mineralogical and compositional extremes of shales in the United States. According to mineralogical studies, the first three shales contain 5 to 13 wt % of organic matter, and the two Conasauga Shales only contain trace amounts (2 wt %) of organic matter. Soxhlet extraction with chloroform and a mixture of chloroform and methanol can remove 0.07 to 5.9 wt % of the total organic matter from these shales. Preliminary analysis if these organic extracts reveals the existence of organic carboxylic acids and hydrocarbons in these samples. Adsorption of elements such as Cs(I), Sr(II) and Tc(VII) on the organic-extracted Upper Dowelltown, Pierre, green River Formation and Pumpkin Valley Shales in synthetic groundwaters (simulating groundwaters in the Conasauga Shales) and in 0.03-M NaHCO 3 solution indicates interaction between each of the three elements and the organic-extractable bitumen. 28 refs., 8 figs., 10 tabs

  1. 90Y and 90Sr separation from hydrochloric acid solutions using TODGA as the extractant by solvent extraction and SLM methods

    International Nuclear Information System (INIS)

    Dutta, S.; Raut, D.R.; Mohapatra, P.K.; Manchanda, V.K.

    2010-01-01

    Yttrium-90 is an important radionuclide known for its therapeutic application in nuclear medicine. It is a pure β-emitter with no associated gamma rays and decays to stable daughter 90 Zr. Suitability of this isotope is because of its short half-life (t 1/2 = 64.2 hrs) and high β emissions (E max = 2.28 MeV. An important source of 90 Y is through the decay of 90 Sr, which produces carrier free isotope. 90 Sr (t 1/2 28 yrs) attains secular equilibrium with 90 Y in a short period and can serve as a long term source for the latter isotope because of relatively long half-life of the parent isotope. Solvent extraction studies with N,N,N',N'-tetra-octyldiglycolamide (TODGA) has shown that Y(III) is well extracted in 6 M HCI while at the same time, extraction of Sr(II) is very low leading to a separation factor (D Y /D Sr = 60,000). This property of TODGA can be exploited for the separation of Y from Sr. In the present work, Supported Liquid Membrane (SLM) based separation of Y and Sr has been explored using TODGA as the carrier

  2. Effects of various metals on survival, growth, reproduction, and metabolism of Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Biesinger, K E; Christensen, G M

    1972-01-01

    The toxicities of various metals to Daphnia magna were evaluated on the basis of a 48-hr 50% lethal concentration (lc50) 3-week 16% reproductive impairment concentrations (In micrograms per liter) for the metal ions tested were: Na(I), 680,000; Ca(II), 116,000; Mg(II), 82,000; K(I), 53,000; Sr(II), 42,000; Ba(II), 5,800; Fe(III), 4,380; Mn(II), 4,100; As(V), 520; Sn(II), 350; Cr(III), 330; Al(III), 320; Zn(II), 70; Au(III), 60; Ni(II), 30; Pb(II), 30; Cu(II), 22; Pt(IV), 14; Co(II), 10; Hg(II), 3.4; and Cd(II), 0.17. At mental concentrations permitting survival but impairing reproduction, daphnids weighed less than control animals. Amounts of total protein and glutamic oxalacetic transaminase activity varied with the different metals. The negative logarithm of the solubility product constant 8 pksp of the metal sulfides, electronegativity, and the logarithm of the equilibrium constant (log keg) of the metal-ATP complex were positively correlated with toxicity to D. magna. Other physicochemical properties were considered, but no additional correlations were found.

  3. Recovery of molybdenum using alumina microspheres and precipitation with selective organic reagents

    International Nuclear Information System (INIS)

    Carvalho, Fatima Maria Sequeira de; Abrao, Alcidio

    1998-01-01

    In this paper is presented a study for the optimization of dissolution of the UAL x plates used for irradiation and production of radiomolybdenum. The alloy is dissolved in nitric acid with mercury as catalyst. The separation and concentration of the molybdenum was achieved using a chromatographic grade alumina microspheres column. the purified eluted molybdenum is finally precipitated using one of the selective reagents: alizarine blue, α,α'- bipyridine and 1,10-phenanthroline. Any one of the obtained precipitate can be fired to the molybdenum trioxide. The interference of the following elements was studied: Re(VII), U(VI), Cr(VI), W(VI), V(V), Te(IV), Ti(IV), Zr(IV), Th(IV), Fe(III), Au(III), Ru(III), Al(III), Bi(III), Sb(III), Ce(IV), Pr(III), Sc(III), Y(III), Sm(III), Ba(II), Sr(II), Ni(II), Co(II), Cs(I). The molybdenum precipitates were characterized by gravimetric, CHN, TG, DTG, IR and X-ray diffraction analyses. (author)

  4. Removal of uranium(VI) from aqueous solutions by new phosphorus-containing carbon spheres synthesized via one-step hydrothermal carbonization of glucose in the presence of phosphoric acid

    International Nuclear Information System (INIS)

    Zhi-bin Zhang; East China Institute of Technology, Fuzhou; China University of Geosciences, Wuhan; Zhi-wei Zhou; Xiao-hong Cao; Yun-hai Liu; Guo-xuan Xiong; East China Institute of Technology, Fuzhou; Ping Liang; East China Institute of Technology, Fuzhou; China University of Geosciences, Wuhan

    2014-01-01

    The novel phosphorus-rich hydrothermal carbon spheres (HCSs-PO 4 ) have been synthesized via one-step hydrothermal carbonization of glucose in the presence of phosphoric acid. The textural and surface chemistry properties were characterized using Boehm titrations, scanning electron microscopy and Fourier transform infrared spectrometer. The content of oxygen-containing functional groups on the surface of HCSs increased from 0.053 to 1.009 mmol g -1 by phosphate group modification. The adsorption ability of HCSsPO 4 has been explored for the removal of uranium from aqueous solutions. The adsorption kinetic data were best described by the pseudo-second-order equation. Adsorption process could be well defined by the Langmuir isotherm, the adsorption capacity of HCSs increased from 80.00 to 285.70 mg g -1 after phosphate group modification. And thermodynamic parameters indicated the adsorption process was feasible,endothermic and spontaneous. Selective adsorption studies showed that the HCSs-PO 4 could selectively remove U(VI), and the selectivity coefficients had been improved in the presence of co-existing ions, Na(I), Ni(II), Sr(II), Mn(II), Mg(II) and Zn(II). Complete removal (99.9 %) of U(VI) from 1.0 L industry wastewater containing 15.0 mg U(VI) ions was possible with 12.0 g HCSs-PO 4 . (author)

  5. Strontium PVC-membrane sensor based on 2-[(2-mercaptophenylimino)methyl]phenol

    Energy Technology Data Exchange (ETDEWEB)

    Zamani, Hassan Ali [Young Researchers Club, Quchan branch, Islamic Azad University, Quchan (Iran, Islamic Republic of)], E-mail: haszamani@yahoo.com; Ganjali, Mohammad Reza; Norouzi, Parviz [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of); Endocrine and Metabolism Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Adib, Mahdi [Center of Excellence in Electrochemistry, Faculty of Chemistry, University of Tehran, Tehran (Iran, Islamic Republic of)

    2008-01-10

    The 2-[(2-mercaptophenylimino)methyl]phenol (MPMP) was used as an excellent ionophore in the construction of a Sr{sup 2+} PVC-based membrane sensor. The best performance was obtained with a membrane composition of 30% poly(vinyl chloride), 62% nitrobenzen (NB), 5.5% MPMP and 2.5% sodium tetraphenyl borate (NaTBP). This sensor demonstrates a good selectivity and sensitivity towards the strontium ion for many cations, including alkali, alkaline earth, transition and heavy metal ions. The sensor revealed a great enhancement in selectivity coefficients for strontium ions in comparison with the previously reported strontium sensors. The proposed sensor exhibits a Nernstian behavior (with a slope of 29.6 {+-} 0.3 mV per decade) for the concentration range of (1.0 x 10{sup -6}-1.0 x 10{sup -1} M) with a detection limit of 5.5 x 10{sup -7} M (48.2 ng/mL). It illustrates a relatively fast response time in the whole concentration range (< 10 s) and it can be used for at least 10 weeks in a pH range of 2.8-9.6. The developed sensor was successfully used as an indicator electrode in the Sr(II) titration with EDTA and the Sr{sup 2+} ion recovery from binary mixtures.

  6. DNA Bar-Coding for Phytoplasma Identification

    DEFF Research Database (Denmark)

    Makarova, Olga; Contaldo, Nicoletta; Paltrinieri, Samanta

    2013-01-01

    Phytoplasma identi fi cation has proved dif fi cult due to their inability to be maintained in vitro. DNA barcoding is an identi fi cation method based on comparison of a short DNA sequence with known sequences from a database. A DNA barcoding tool has been developed for phytoplasma identi fi cat...... genes, can be used to identify the following phytoplasma groups: 16SrI, 16SrII, 16SrIII, 16SrIV, 16SrV, 16SrVI, 16SrVII, 16SrIX, 16SrX, 16SrXI, 16SrXII, 16SrXV, 16SrXX, 16SrXXI....... cation. While other sequencebased methods may be well adapted to identification of particular strains of phytoplasmas, often they cannot be used for the simultaneous identification of phytoplasmas from different groups. The phytoplasma DNA barcoding protocol in this chapter, based on the tuf and 16SrRNA......Phytoplasma identi fi cation has proved dif fi cult due to their inability to be maintained in vitro. DNA barcoding is an identi fi cation method based on comparison of a short DNA sequence with known sequences from a database. A DNA barcoding tool has been developed for phytoplasma identi fi...

  7. Integral membrane protein structure determination using pseudocontact shifts

    Energy Technology Data Exchange (ETDEWEB)

    Crick, Duncan J.; Wang, Jue X. [University of Cambridge, Department of Biochemistry (United Kingdom); Graham, Bim; Swarbrick, James D. [Monash University, Monash Institute of Pharmaceutical Sciences (Australia); Mott, Helen R.; Nietlispach, Daniel, E-mail: dn206@cam.ac.uk [University of Cambridge, Department of Biochemistry (United Kingdom)

    2015-04-15

    Obtaining enough experimental restraints can be a limiting factor in the NMR structure determination of larger proteins. This is particularly the case for large assemblies such as membrane proteins that have been solubilized in a membrane-mimicking environment. Whilst in such cases extensive deuteration strategies are regularly utilised with the aim to improve the spectral quality, these schemes often limit the number of NOEs obtainable, making complementary strategies highly beneficial for successful structure elucidation. Recently, lanthanide-induced pseudocontact shifts (PCSs) have been established as a structural tool for globular proteins. Here, we demonstrate that a PCS-based approach can be successfully applied for the structure determination of integral membrane proteins. Using the 7TM α-helical microbial receptor pSRII, we show that PCS-derived restraints from lanthanide binding tags attached to four different positions of the protein facilitate the backbone structure determination when combined with a limited set of NOEs. In contrast, the same set of NOEs fails to determine the correct 3D fold. The latter situation is frequently encountered in polytopical α-helical membrane proteins and a PCS approach is thus suitable even for this particularly challenging class of membrane proteins. The ease of measuring PCSs makes this an attractive route for structure determination of large membrane proteins in general.

  8. Evaluation of a novel and efficient solvent system containing chlorinated cobalt dicarbollide for radio-cesium recovery from acidic wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kandwal, Pankaj; Mohapatra, Prasanta Kumar [Bhabha Atomic Research Centre, Mumbai (India). Radiochemistry Div.

    2014-11-01

    A novel solvent system containing chlorinated cobalt dicarbollide (CCD) in a diluent mixture containing 2-nitrophenyloctyl ether (NPOE) and n-dodecane was found to be highly efficient for the extraction of radio-cesium from acidic feed conditions. When PEG-400 (polyethylene glycol with average molecular weight of 400) was added to the solvent system, it was found to extract radio-strontium as well similar to that reported with the UNEX (Universal Extractant) solvent. The solvent system was found to be superior as compared to analogous solvent systems reported previously using CCD in either nitrobenzene or PTMS (phenyltrifluoromethyl sulphone, a fluorinated diluent). The present work deals with less toxic solvent formulation which can be used as an alternative to these hazardous/toxic chemicals for simultaneous recovery of Cs(I) and Sr(II) from acidic solutions. Batch co-current extraction data are also presented for the simultaneous recovery of Cs and Sr which indicated near quantitative extraction (>99.5%) of the metal ions in 4 and 3 stages, respectively. The reusability and radiolytic stability studies were also carried out which suggested highly encouraging results.

  9. Luminescence enhancement of (Sr1-x Mx )2 SiO4 :Eu2+ phosphors with M (Ca2+ /Zn2+ ) partial substitution for white light-emitting diodes.

    Science.gov (United States)

    Wang, Yulong; Zhang, Wentao; Gao, Yang; Long, Jianping; Li, Junfeng

    2017-02-01

    Eu 2 + -doped Sr 2 SiO 4 phosphor with Ca 2 + /Zn 2 + substitution, (Sr 1-x M x ) 2 SiO 4 :Eu 2 + (M = Ca, Zn), was prepared using a high-temperature solid-state reaction method. The structure and luminescence properties of Ca 2 + /Zn 2 + partially substituted Sr 2 SiO 4 :Eu 2 + phosphors were investigated in detail. With Ca 2 + or Zn 2 + added to the silicate host, the crystal phase could be transformed between the α-form and the β-form of the Sr 2 SiO 4 structure. Under UV excitation at 367 nm, all samples exhibit a broad band emission from 420 to 680 nm due to the 4f 6 5d 1  → 4f 7 transition of Eu 2 + ions. The broad emission band consists of two peaks at 482 and 547 nm, which correspond to Eu 2 + ions occupying the ten-fold oxygen-coordinated Sr.(I) site and the nine-fold oxygen-coordinated Sr.(II) site, respectively. The luminescence properties, including the intensity and lifetime of Sr 2 SiO 4 :Eu 2 + phosphors, improved remarkably on Ca 2 + /Zn 2 + addition, and promote its application in white light-emitting diodes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Horizontal transfer of potential mobile units in phytoplasmas.

    Science.gov (United States)

    Ku, Chuan; Lo, Wen-Sui; Kuo, Chih-Horng

    2013-09-01

    Phytoplasmas are uncultivated phytopathogenic bacteria that cause diseases in a wide range of economically important plants. Through secretion of effector proteins, they are able to manipulate their plant hosts to facilitate their multiplication and dispersal by insect vectors. The genome sequences of several phytoplasmas have been characterized to date and a group of putative composite transposons called potential mobile units (PMUs) are found in these highly reduced genomes. Recently, our team reported the genome sequence and comparative analysis of a peanut witches' broom (PnWB) phytoplasma, the first representative of the phytoplasma 16SrII group. Comparisons between the species phylogeny and the phylogenies of the PMU genes revealed that the PnWB PMU is likely to have been transferred from the 16SrI group. This indicates that PMUs are not only the DNA unit for transposition within a genome, but also for horizontal transfer among divergent phytoplasma lineages. Given the association of PMUs with effector genes, the mobility of PMUs across genomes has important implications for phytoplasma ecology and evolution.

  11. Crystal growth, characterization and theoretical studies of alkaline earth metal-doped tetrakis(thiourea)nickel(II) chloride.

    Science.gov (United States)

    Agilandeshwari, R; Muthu, K; Meenatchi, V; Meena, K; Rajasekar, M; Aditya Prasad, A; Meenakshisundaram, S P

    2015-02-25

    The influence of Sr(II)-doping on the properties of tetrakis(thiourea)nickel(II) chloride (TTNC) has been described. The reduction in the intensity observed in powder X-ray diffraction of doped specimen and slight shifts in vibrational frequencies of doped specimens confirm the lattice stress as a result of doping. Surface morphological changes due to doping of the Sr(II) are observed by scanning electron microscopy. The incorporation of metal into the host crystal lattice was confirmed by energy dispersive X-ray spectroscopy. Lattice parameters are determined by single crystal XRD analysis. The thermogravimetric and differential thermal analysis studies reveal the purity of the materials and no decomposition is observed up to the melting point. The nonlinear optical properties of the doped and undoped specimens were studied. Theoretical calculations were performed using the Density functional theory (DFT) method with B3LYP/LANL2DZ as the basis set. The molecular geometry and vibrational frequencies of TTNC in the ground state were calculated and the observed structural parameters of TTNC are compared with parameters obtained from single crystal X-ray studies. The atomic charge distributions are obtained by Mulliken charge population analysis. The first-order molecular hyperpolarizability, polarizability and dipole moment were derived. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Diglycolamide based dendrimers for sequestration of trivalent actinides: solvent extraction and liquid membrane studies

    International Nuclear Information System (INIS)

    Ansari, S.A.; Mohapatra, P.K.; Leoncini, A.; Verboom, W.

    2017-01-01

    Three diglycolamide-functionalized (poly(propylene imine)) diaminobutane dendrimers, viz. zero generation (L_I), first generation (L_I_I), and second generation (L_I_I_I), were synthesized and evaluated for their extraction ability towards trivalent actinides. The distribution ratio (D) of Am"3"+ with 1.0 mmol/L ligand at 3 M HNO_3 followed the order: 0.1 (L_I) < 42 (L_I_I) < 110 (L_I_I_I). The D values of Am(_I_I_I) at lower acidity (0.01 M HNO_3) were significantly low, giving good stripping option with the dilute acid solution. Extraction of other metal ions from 3 M HNO_3 indicated good selectivity of Am(III) over U(VI), Sr(II) and Cs(I). Supported liquid membrane (SLM) studies were explored for the transport of Am(III) from acidic feed solution, where ligand inventory is extremely low. (author)

  13. Evaluation of selectivity and radiolysis behavior of some promising isonicotinamids and dipicolinamides as extractants

    Energy Technology Data Exchange (ETDEWEB)

    Mowafy, E.A. [Atomic Energy Authority, Cairo (Egypt). Hot Labs. Center

    2007-07-01

    A series of long chain isonicotinamides (pyridine-4-carboxamides) and dipicolinamides (pyridine-2,6-dicarboxamides) have been prepared with different substituting groups and the extracting ability for Fe(III), Am(III), Eu(III), Sr(II), Co(II) and Cs(I) from nitric acid solutions has been studied. Distribution ratios of Fe(III) as function of nitric acid concentration, extractants concentration and salting-out agent have been measured by using N,N'-dioctylisonicotinamide (DOINA) and N,N,N',N'-tetraoctyldipicolinamide (TODPA) which were chosen for further studies. Irradiation of DOINA and TOBPA by different gamma doses showed a different extraction behavior for Fe(III). The radiolytic degradation of the investigated amides has been estimated by quantitive IR spectroscopy. The results indicated that the radiolytic stability is influenced by the structure of the investigated amides. Symmetrical isonicotinamides or dipicolinamide seems to be less affected by radiation compared with unsymmetrical isonicotiniamides or dipicolinamides. The extraction of iron from aqueous solutions with the investigated extractants is fast. Separation of iron(III) based on kinetic basis was carried out. (orig.)

  14. A Preliminary Study of Two Different Clays for Separation of Some Artificial Radionuclides in Stimulated Waste

    International Nuclear Information System (INIS)

    Lasheen, Y.F.; Seliman, A.F.; Shehata, F.A.; Youssef, M.A.; Abo-Aly, M.

    2016-01-01

    The removal of long lived radionuclides, such as 134 Cs(I), 133 Ba(II), 90 Sr(II) and 152 Eu(III) by bentonite (W-Bent) and kaolin (S-Kaol) was studied as a function of different parameters using a batch technique. The results showed that the optimum ph was selected to be 6. Kinetically in case of W-Bent, the adsorption is heterogeneous for 134 Cs, 133 Ba and homogenous for 90 Sr and 152 Eu. The distribution coefficient values follow the order of 1 '5 2 Eu> 134 Cs> 90 Sr> 133 Ba. Langmuir, Freundlish, Dubinin-Raduskevich (D-R) and Temkin isotherm models were applied. According to the D-R model, W-Bent showed a high affinity to 152 Eu with a maximum capacity (q m = 0.43 mol/Kg) in comparison with S-Kaol (q m =0.023 mol/Kg). Also according to D-R model the adsorption energy (E> 8.0 KJ mol -1 ) that means the adsorption reaction is expected to be chemisorption. Finally both clays are cost-effective sorbent materials with an excellent adsorption capacity, but some surface modification for S-Kaol is recommended to be more effective than its natural form

  15. Band gaps and photocurrent responses of two novel alkaline earth metal(II) complexes based on 4,5-di(4′-carboxylphenyl)benzene

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Jiang Ping; Yan, Zhi Shuo; Long, Ji Ying [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Gong, Yun, E-mail: gongyun7211@cqu.edu.cn [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Lin, Jian Hua, E-mail: jhlin@pku.edu.cn [Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2017-01-15

    By using a rigid dicarboxylate ligand, 4,5-di(4′-carboxylphenyl)benzene (H{sub 2}L), two complexes formulated as SrL(DMF)(H{sub 2}O)·(CH{sub 3}CN) (DMF=N,N′-dimethylformamide) (1) and BaL(H{sub 2}O){sub 2} (2) were solvothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complexes 1 and 2 display two-dimensional (2D) layer structures. The two complexes exhibit different electrochemical and photoelectrochemical properties. Their thermal stabilities, cyclic voltammograms, UV–vis absorption and diffuse reflectance spectra and photoluminescence properties have been investigated. The band structures, the total density of states (TDOS) and partial density of states (PDOS) of the two complexes were calculated by CASTEP program. Complex 2 exhibits much higher photocurrent density than complex 1. The Mott–Schottky plots reveal that complexes 1 and 2 both are p-type semiconductors, which are in agreement with their band structure calculations. - Graphical abstract: Two alkaline earth metal(II) complexes with 2D layer structures are p-type semiconductors, they possess different band structures and density of states. And the Ba(II) complex 2 exhibits much higher photocurrent density than the Sr(II) complex 1.

  16. Identifikasi Molekuler Fitoplasma yang Berasosiasi dengan Tanaman Kaktus Hias Opuntia sp.

    Directory of Open Access Journals (Sweden)

    Ariny Prasetya

    2017-11-01

    Full Text Available Cactus species (Opuntia sp. is a popular ornamental succulent plant. Some ornamental cactus species in Indonesia showing proliferation and green mosaic pattern symptoms have been reported to be associated with phytoplasma infection. However, further molecular identification for accurate classification of the causal phytoplasma has not been done.  This study aimed to diagnose phytoplasma associated with Opuntia sp. based on molecular methods involving PCR standard combined with nested-PCR, cloning and DNA sequencing. Standard PCR was carried out using P1/P7 primers followed by nested-PCR using R16F2n/R16R2 or fU5/rU3 primer pairs which amplify the 16S rRNA gene targets of 1.2 kb and 880 bp, respectively. Amplified fragment of nested-PCR using R16F2n/R16R2 primers was chosen to be cloned and sequenced for further identification and classification of phytoplasma.  BLASTn analysis showed that the phytoplasma from Opuntia sp. was closely related to 16SrII group. Phylogenetic analysis and in silico RFLP indicated that phytoplasma strain infecting Opuntia sp. was a member of subgroup 16SrII-C (cactus witches’ broom phytoplasma. This is a newly report of cactus witches’ broom phytoplasma on Opuntia sp. in Indonesia.   

  17. Physico-chemical characterisation data and sorption measurements of Cs, Ni, Eu, Th, U, Cl, I and Se on MX-80 bentonite

    International Nuclear Information System (INIS)

    Bradbury, M. H.; Baeyens, B.

    2011-12-01

    This report describes the work carried out in the Laboratory for Waste Management of the Nuclear Energy and Safety Research Department at the Paul Scherrer Institut on MX-80 bentonite in support of Swiss radioactive waste performance assessment studies. With particular regard to Stage 2 of the Sectoral Plan for Deep Geological Disposal, it was considered to be important to bring together in one document the information and results that have accrued over the years from both 'in house' studies and associated relevant literature data. The report gives a brief overview of the physicochemical characteristics and porewater chemistry determined for MX-80 bentonite followed by the results of an extensive experimental sorption programme on the uptake of Cs(I), Ni(II), Eu(III), Th(IV), U(VI), Cl(-I), I(-I) and Se(IV) on the same material. Sorption values are also given for K(I), Ca(II) and Sr(II) which were deduced from porewater chemistry modelling studies. (authors)

  18. Deteksi dan Identifikasi Fitoplasma yang Berasosiasi dengan Penyakit Layu Kelapa Di Pulau Derawan, Kalimantan Timur

    Directory of Open Access Journals (Sweden)

    Agus Eko Prasetyo

    2017-09-01

    Full Text Available Coconut is a major commodity in Derawan island as source of additional income for the farmers. Research was conducted to detect and identify phytoplasmas associated with coconut wilt disease in Derawan island. Coconut wilt disease was indicated by the typical symptoms, i.e.  leaf yellowing, shorten of coconut sheaths and leaves, necrosis and collapse of old leaves, and also nut fall.  The presence of phytoplasmas in phloem tissues of coconut stem was observed using fluorescence and electron microscope.  Identification of phytoplasmas was carried out by nested-PCR and sequencing of the 16S rRNA gene.  DNA fragment of phytoplasma with the size of 1.25 kbp was successfully amplified using primer pairs P1/P7, followed by primer pairs R16F2n/R16R2.  Sequence analysis of the amplified fragments showed that phytoplasma associated with coconut wilt disease in Derawan island belongs to 16SrII (witches broom phytoplasma and 16SrXI (ca. Phytoplasma oryzae groups.

  19. Identification of 16SrIX-C phytoplasmas in Argyranthemum frutescens in Italy

    Directory of Open Access Journals (Sweden)

    Luca FERRETTI

    2015-04-01

    Full Text Available Phytoplasmas are cell wall-less microorganisms associated with plant diseases worldwide. Many important food, vegetable and fruits crops as well as ornamental plants can be severely affected by these pathogens, with significant economic impacts. Phytoplasma diseases of ornamentals have been described worldwide in a wide range of plant genera, and 11 different 16Sr groups have been identified. In Italy, many ornamental plant species belonging to several botanical families have been found to be infected by phytoplasmas, classified into the ribosomal groups 16SrI, 16SrII, 16SrV and 16SrXII. During a survey carried out in commercial gardens in Rome, some marguerite daisy (Argyranthemum frutescens plants showing symptoms of phytoplasma-like disease, were collected and submitted to molecular analyses. Cloning and sequencing of the portion of the 16S rRNA gene followed by BLAST analysis, real and virtual restriction fragment length polymorphism anlaysis with AluI and RsaI, allowed assignment of the detected phytoplasma to the 16SrIX-C group (Picris echioides yellows, PEY.

  20. New Phase in the System Uranium-Molybdenum-Silicon; Nouvelle phase dans le systeme uranium-molybdene-silicium; Novaya faza v sisteme uran-molibden'-kremnij; Una fase nueva en el sistema uranio-molibdeno-silicio

    Energy Technology Data Exchange (ETDEWEB)

    Sikirica, M.; Ban, Z. [Rudjer Bokovic Institute, Zagreb, Yugoslavia (Croatia)

    1963-11-15

    During the investigation of the ternary system uranium-molybdenum-silicon, a new phase with the composition U{sub 4}Mo{sub 5}-Si{sub 3} was formed. Structure determination exclusively based on the powder data showed that the particular phase belongs to the hexagonal system. Space group P6/mmc or one of the sub-groups is indicated. Unit cell dimensions were found to be a = 5.37{sub 0}A, c = 8 . 58{sub 2}A. A comparison of calculated and observed intensities shows close resemblance to the structure of the Laves phases of the C14-type. (author) [French] Au cours de recherches sur le systeme ternaire uranium-molybdene-silicium, on a constate la formation d'une nouvelle phase, de composition U{sub 4}Mo{sub 5}Si{sub 3}. Une determination de la structure, exclusivement fondee sur des donnees relatives a la poudre, a revele que cette phase particuliere appartenait au systeme hexagonal. Les auteurs indiquent un groupe spatial P6/mmc ou un des sous-groupes. Les dimensions d'une maille individuelle sont donnees par a = 5,37{sub 0}A, c = 8,58{sub 2}A. La comparaison entre l'intensite calculee et Tintensite observee montre une ressemblance etroite avec la structure des phases de Laves du type C-14. (author) [Spanish] En-el curso del estudio del sistema temario uranio-molibdeno-silicio, los autores observaron la formacion de una fase cuya composicion responde a la formula U{sub 4}Mo{sub 5}Si{sub 3}. La determinacion de la estructura, basada exclusivamente en los datos referentes al material en polvo, demuestra que esa fase pertenece al sistema hexagonal. Se senalo la existencia de un grupo especial P6/mmc y se comprobo que las dimensiones de la celda elemental son a = 5,37{sub 0}A, c = 8,58{sub 2}A. La comparacion de las intensidades calculadas con las observadas indica que existe una analogia estrecha con la estructura de la fase de Laves del tipo C 14. (author) [Russian] Pri izuchenii trojnoj sistemy uran - molibden - kremnij obrazovalas' novaya faza sostava U{sub 4}Mo{sub 5

  1. Copolymerization of Ethylene Induced by Cobalt-60 Gamma Radiation; Copolymerisation de l'ethylene induite par des rayons gamma du cobalt-60; Sopolimerizatsiya ehtilena pod dejstviem gamma-izlucheniya ot istochnika ks'yali-60; Copolimerizacion del etileno inducida por las radiaciones gamma del cobalto-60

    Energy Technology Data Exchange (ETDEWEB)

    Steinberg, M.; Colombo, P. [Brookhaven National Laboratory, Long Island, NY (United States)

    1963-11-15

    fraccionada. La identificacion se efectuo por espectroscopia infrarroja y la composicion se determino por analisis elemental. Para algunos de los productos de reaccion, los autores indican los puntos de fusion cristalinos, las densidades, las caracteristicas de solubilidad y los pesos moleculares. Obtuvieron pruebas de la copolimerizacion del etileno con cada uno de los siguientes monomeros: estireno, metacrilato de metilo, acetato de vinilo, acrilonitrilo, acetato de alilo, isobuteno, clorotrifluoretileno, trans 2-buteno, acrilato de metilo, isopreno, propeno, cloruro de vinilo, 1-buteno, cis 2-buteno, oxido de carbono, vinilpirrolidona, metilvinilcetona y divinilbenceno. Comprobaron que los datos experimentales obtenidos en el estudio del sistema etileno-oxido de carbono responden a una forma lineal de la ecuacion de composicion del copolimero. Encontraron el valor 22,0 para la razon ({alpha}) de las constantes de velocidad especificas correspondientes al oxido de carbono y al etileno, respectivamente, lo que indica que en calidad de monomero el oxido de carbono se activa en tal medida que se fija al extremo de una cadena de radical etilenico libre con una velocidad 22 veces mayor que un monomero etilenico. (author) [Russian] Byla izuchen vyzvannaya gamma-izlucheniem sopolimerizatsiya ehtilena s ryadom razlichnykh monomerov pri temperature 20{sup o}C i pri nachal'nykh davleniyakh do 680 atm. Ehksperimenty provodilis' staticheski v dvukhfaznykh sistemakh, za isklyucheniem sistemy ehtilen-okis' ugleroda. Razdelenie sopolimerov proizvodilos' metodami ehkstraktsii rastvoritelem i fraktsionirovannogo osazhdeniya. Dlya identifikatsii ispol'zovali infrakrasnuyu spektroskopiyu, a dlya opredeleniya sostava - ehlementarnyj analiz. Privedeny kharakte- ristiki nekotorykh produktov reaktsii, vklyuchayushchie ikh temperaturu plavleniya, plotnost', rastvorimost' i molekulyarnyj ves. Ustanovlena sopolimerizatsiya ehtilena s kazhdym iz sleduyushchikh monomerov: stirolom, metilmetakrilatom

  2. Blue photoluminescence and long lasting phosphorescence properties of a novel chloride phosphate phosphor: Sr5(PO4)3Cl:Eu2+

    International Nuclear Information System (INIS)

    Wu, Chuanqiang; Zhang, Jiachi; Feng, Pengfei; Duan, Yiming; Zhang, Zhiya; Wang, Yuhua

    2014-01-01

    A novel blue emitting long lasting phosphorescence phosphor Sr 5 (PO 4 ) 3 Cl:Eu 2+ is synthesized by solid state method at 1223 K in reducing atmosphere. The afterglow emission spectrum shows one broad band centered at 441 nm due to the 5d–4f transition of Eu 2+ at six coordinated Sr(II) sites and the color coordinates are calculated to be (0.149, 0.095) which is close to the light blue region. The excitation band is in 240–430 nm and partly overlaps the solar irradiation on Earth's surface. The long lasting phosphorescence of the optimal sample doping by 0.1 mol%Eu 2+ can be recorded for about 1040 s (0.32 mcd/m 2 ). Thermoluminescence shows that there are at least three types of traps corresponding to peaks at 340 K, 382 K, 500 K, respectively. The filling and fading experiments reveal that the traps in Sr 5 (PO 4 ) 3 Cl:Eu 2+ are independent. The shallow traps (340 K) essentially contribute to the visible long lasting phosphorescence, while the deep traps (382 K and 500 K) are proved to be very stable. Thus, the Sr 5 (PO 4 ) 3 Cl:Eu 2+ material shows potential applications as not only a long lasting phosphorescence phosphor, but also an optical storage material. -- Highlights: • The blue long lasting phosphorescence of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is first reported. • Filling and fading experiments are carried out for revealing natures of traps. • The afterglow mechanism for independent traps of Sr 5 (PO 4 ) 3 Cl:Eu 2+ is proposed

  3. Ultraviolet spectroscopy and metal ions detection

    International Nuclear Information System (INIS)

    Chaudry, M.A.

    1995-01-01

    The spectrochemical analysis is based on the interaction of radiation with the chemical species and depends on their nature, having pi, sigma or electrons, or d and f electrons, UV. Visible spectrophotometry has been used extensively in the detection and determination of both organics and inorganics. In UV detection the sensitivity is proportional to the bath length and the excitation coefficient of the given sample. It may be insensitive to many species unless these are converted to UV, absorbing derivatives. The technique has been applied for the monitoring of the effluents from HPLC, as chlorides or other complexes of various elements in this article the utility of HCl as reagent for the spectrophotometric determination of the metal ions like Al(III), As(III,IV), Ba(II), Cd(II), Ca(II) Ce(III), Cs(i), Cr(III,VI), Co(II), Cu(II), Dy(III), Eu(III), Gd(III), Au(III), Hf(IV), Ho(III), In(III), Fe(III), La(III), Pb(II), Lu (III), Mg(II), Mn(II), Hg(II), Mo(VI), Ni(II), Pd(II), Pt(IV), K(I), Pr(III), Re(VII), Ru(IV), Sm(III), Sc(III), Ag(I), Sr(II) Te(III), Th(IV), Sn(II,IV), Ti(III,IV), W(VI), U(VI), V(IV,V), Yb(III), Zn(II) AND Zr(IV) Ions i.e. for meta ions from d of the most of these metal ions has been found sufficient permit their detection in HPLC. Their molar absorptive have also been reported. Reference has also been provided to post column derivatization of some metal ions from d and f block elements for their detection in HPLC. (author) 12 figs.; 6 tabs.; 27 refs

  4. Studies on supercritical hydrothermal syntheses of uranium and lanthanide oxide particles and their reaction mechanisms

    Science.gov (United States)

    Hwang, DongKi; Tsukahara, Takehiko; Tanaka, Kosuke; Osaka, Masahiko; Ikeda, Yasuhisa

    2015-11-01

    In order to develop preparation method of raw metal oxide particles for low decontaminated MOX fuels by supercritical hydrothermal (SH) treatments, we have investigated behavior of aqueous solutions dissolving U(VI), Ln(III) (Ln: lanthanide = Ce, Pr, Nd, Sm, Tb), Cs(I), and Sr(II) nitrate or chloride compounds under SH conditions (temperature = 400-500 °C, pressure = 30-40 MPa). As a result, it was found that Ln(NO3)3 (Ln = Ce, Pr, Tb) compounds produce LnO2, that Ln(NO3)3 (Ln = Nd, Sm) compounds are hardly converted to their oxides, and that LnCl3 (Ln = Ce, Pr, Nd, Sm, Tb), CsNO3, and Sr(NO3)2 do not form their oxide compounds. Furthermore, HNO2 species were detected in the liquid phase obtained after treating HNO3 aqueous solutions containing Ln(NO3)3 (Ln = Ce, Pr, Tb) under SH conditions, and also NO2 and NO compounds were found to be produced by decomposition of HNO3. From these results, it was proposed that the Ln oxide (LnO2) particles are directly formed with oxidation of Ln(III) to Ln(IV) by HNO3 and HNO2 species in the SH systems. Moreover, the uranyl ions were found to form U3O8 and UO3 depending on the concentration of HNO3. From these results, it is expected that the raw metal oxide particles for low decontaminated MOX fuels are efficiently prepared by the SH method.

  5. Optical and Microcantilever-Based Sensors for Real-Time In Situ Characterization of High-Level Waste

    International Nuclear Information System (INIS)

    Braun, Gilbert M.; Bryan, Samuel

    2002-01-01

    Fundamental research is being conducted to develop sensors for strontium that can be used in real-time to characterize high-level waste (HLW) process streams. Two fundamentally different approaches are being pursued, which have in common the dependence on highly selective molecular recognition agents. In one approach, an array of chemically selective sensors with sensitive fluorescent probes to signal the presence of the constituent of interest are coupled to fiber optics for remote analytical applications. The second approach employs sensitive microcantilever sensors that have been demonstrated to have unprecedented sensitivity in solution for Cs+ and CrO4 -. Selectivity in microcantilever-based sensors is achieved by modifying the surface of a gold-coated cantilever with a monolayer coating of an alkanethiol derivative of the molecular recognition agent. The approaches are complementary since fiber optic sensors can be deployed in the highly alkaline environment of HLW, bu t a method of immobilizing a fluorescent molecular recognition agents in a polymer film or bead on the surface of the optical fiber has yet to be demonstrated. The microcantilever-based sensors function by converting molecular complexation into surface stress, and they have been demonstrated to have the requisite sensitivity. However, we will investigate method of protecting Si or SiN microcantilever sensors in the highly alkaline environment of HLW while maintaining high selectivity. One objective of this project is to develop Sr(II) molecular recognition agents with rapidly established equilibria needed for real-time analysis, and initial research will focus on calixarene-crown ethers as a platform. Sensors for alkali metal ions, hydroxide, and temperature will be part of the array of sensor elements that will be demonstrated in this program for both the cantilever and fiber optic sensor approaches

  6. Evaluation of several novel diamide based ligands for selective extraction of tetravalent plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishna, Mallampalli; Nayak, Shashikant K. [Heavy Water Board, V.S. Bhavan, Mumbai (India); Raut, Dhaval R.; Mohapatra, Prasanta K. [Bhabha Atomic Research Center, Mumbai (India). Radiochemistry Division; Nayak, Sandip K. [Bhabha Atomic Research Center, Mumbai (India). Bioorganic Division

    2017-06-01

    The present paper describes the selective extraction of tetravalent plutonium employing several diamide ligands containing aromatic spacer groups. The ligands containing two amide functional groups attached to a 2,4,6-tri-phenyl pyridine moiety with different substituents viz.; L{sub I} (iso-butyl), L{sub II}(n-butyl), L{sub III}(n-octyl), L{sub IV} (2-ethylhexyl) at the amidic nitrogen atom were evaluated for the extraction of Pu(IV) using their nitrobenzene solutions. The distribution ratio values of Pu(IV) with the diamide ligands followed the order: L{sub II}>L{sub I}>L{sub III}>L{sub IV} and were significantly higher than those of metal ions such as Cs(I), Sr(II), Am(III) and Eu(III). The distribution ratio values of U(VI) were about 2-3 orders magnitude lower than those of Pu(IV). The extraction and stripping kinetics were found to be moderately fast and it took less than 30 min (less than 5 min for L{sub I} and L{sub IV}) to obtain equilibrium D values. The extraction was found to be increasing with the aqueous phase nitric acid concentration conforming to a solvation mechanism of extraction. The extracted species contained two ligand molecules for L{sub I} and L{sub II} while monosolvates were observed for the other two extractants. The ligands showed good radiation stability up to an absorbed dose of 630 kGy.

  7. Phytoplasma phylogenetics based on analysis of secA and 23S rRNA gene sequences for improved resolution of candidate species of 'Candidatus Phytoplasma'.

    Science.gov (United States)

    Hodgetts, Jennifer; Boonham, Neil; Mumford, Rick; Harrison, Nigel; Dickinson, Matthew

    2008-08-01

    Phytoplasma phylogenetics has focused primarily on sequences of the non-coding 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (16-23S ISR), and primers that enable amplification of these regions from all phytoplasmas by PCR are well established. In this study, primers based on the secA gene have been developed into a semi-nested PCR assay that results in a sequence of the expected size (about 480 bp) from all 34 phytoplasmas examined, including strains representative of 12 16Sr groups. Phylogenetic analysis of secA gene sequences showed similar clustering of phytoplasmas when compared with clusters resolved by similar sequence analyses of a 16-23S ISR-23S rRNA gene contig or of the 16S rRNA gene alone. The main differences between trees were in the branch lengths, which were elongated in the 16-23S ISR-23S rRNA gene tree when compared with the 16S rRNA gene tree and elongated still further in the secA gene tree, despite this being a shorter sequence. The improved resolution in the secA gene-derived phylogenetic tree resulted in the 16SrII group splitting into two distinct clusters, while phytoplasmas associated with coconut lethal yellowing-type diseases split into three distinct groups, thereby supporting past proposals that they represent different candidate species within 'Candidatus Phytoplasma'. The ability to differentiate 16Sr groups and subgroups by virtual RFLP analysis of secA gene sequences suggests that this gene may provide an informative alternative molecular marker for pathogen identification and diagnosis of phytoplasma diseases.

  8. On the real performance of cation exchange resins in wastewater treatment under conditions of cation competition: the case of heavy metal pollution.

    Science.gov (United States)

    Prelot, Benedicte; Ayed, Imen; Marchandeau, Franck; Zajac, Jerzy

    2014-01-01

    Sorption performance of cation-exchange resins Amberlite® IRN77 and Amberlite™ IRN9652 toward Cs(I) and Sr(II) has been tested in single-component aqueous solutions and simulated waste effluents containing other monovalent (Effluent 1) or divalent (Effluent 2) metal cations, as well as nitrate, borate, or carbonate anions. The individual sorption isotherms of each main component were measured by the solution depletion method. The differential molar enthalpy changes accompanying the ion-exchange between Cs+ or Sr2+ ions and protons at the resin surface from single-component nitrate solutions were measured by isothermal titration calorimetry and they showed a higher specificity of the two resins toward cesium. Compared to the retention limits of both resins under such idealized conditions, an important depression in the maximum adsorption capacity toward each main component was observed in multication systems. The overall effect of ion exchange process appeared to be an unpredictable outcome of the individual sorption capacities of the two resins toward various cations as a function of the cation charge, size, and concentration. The cesium retention capacity of the resins was diminished to about 25% of the "ideal" value in Effluent 1 and 50% in Effluent 2; a further decrease to about 15% was observed upon concomitant strontium addition. The uptake of strontium by the resins was found to be less sensitive to the addition of other metal components: the greatest decrease in the amount adsorbed was 60% of the ideal value in the two effluents for Amberlite® IRN77 and 75% for Amberlite™ IRN9652. It was therefore demonstrated that any performance tests carried out under idealized conditions should be exploited with much caution to predict the real performance of cation exchange resins under conditions of cation competition.

  9. Identification of efficient chelating acids responsible for Cesium, Strontium and Barium complexes solubilization in mixed wastes

    International Nuclear Information System (INIS)

    Borai, E.H.

    2007-01-01

    The present paper is focused to characterize the available multi dentate ligand species and their metal ion complexes of cesium (Cs), strontium (Sr) and barium (Ba) formed with the parent chelators, complexing agents and its fragment products in mixed waste filtrate. The developed separation programs of different ligands by different mobile phases were based on the decrease of the effective charge of the anionic species in a differentiated way hence, the retention times on the stationary phases (AS-4A and AS-12A) are changed. Ion chromatographic (IC) analysis of the metal complexes showed that the carboxylic acids that are responsible for solubilizing Cs, Sr and Ba in the waste filtrate are NTA, Citrate and PDCA, respectively. Therefore, the predominant metal complexes in the filtrate at high ph are Cs (I)-NTA, Sr (IT)-Citrate and Ba (IT)-PDCA. Identification of the metal ion complexes responsible for solubilizing Cs, Sr and Ba was applied on the fresh and aged waste filtrates, to monitor their chemical behavior, which leads to increased control of the waste treatment process. Although, concentration measurements of both fresh and aged filtrates confirmed that the degradation process has occurred mainly due to a harsh chemical environment, the concentration of Cs(I), Sr(II) and Ba(II) increased slightly in the aged filterate compared with the fresh filtrate. This is due to the decomposition and/or degradation of their metal complexes and hence leads to free metal ion species in the filtrate. These observations indicate that the organic content of mixed waste filtrate is dynamic and need continuous analytical monitoring

  10. Comparative study of amrutbhallataka and glucosamine sulphate in osteoarthritis: Six months open label randomized controlled clinical trial

    Directory of Open Access Journals (Sweden)

    Ashwinikumar Raut

    2013-01-01

    Full Text Available Background: AmrutBhallatak (ABFN02, a ′rasayana′ drug from Ayurveda is indicated in degenerative diseases and arthritis. Objective: To evaluate safety and efficacy of ABFN02 in osteoarthritis (OA and compare it with Glucosamine sulphate (GS Materials and Methods: This was a r andomized open comparative study. Ambulant OPD patients of OA knees (n = 112 were enrolled for 24 weeks. Tablets (750mg each of GS and ABFN02 were matched. Three groups of patients: (A GS, one tablet × twice/day × 24 weeks. (B ABFN02, incremental pulse dosage (one tablet x twice/day × two weeks, two tablets × twice/day × two weeks, three tablets × twice/day × two weeks, two such cycles of drug and non-drug phases alternately for six weeks each (C ABFN02 continuous dosage akin to GS. Pain visual analogue score (Pain-VAS and Western Ontario and Mc-Master University Osteoarthritis Index (WOMAC were the primary outcome measures. Secondary outcome measures were Health assessment questionnaire (HAQ, paracetamol consumption, 50 feet walking, physician and patient global assessment, knee stiffness, knee status, urinary CTX II, serum TNFa-SRI, SRII and MRI knee in randomly selected patients. Results: ABFNO2 and GS demonstrated, adherence to treatment 87.75% and 74.3%, reduction in Pain-VAS at rest 61.05% and 57.1%, reduction in pain-VAS on activity 57.4% and 59.8%, WOMAC score drop 62.8% and 59.1% respectively. Secondary outcome measures were comparable in all groups. Safety measures were also comparable. No serious adverse events reported. However, asymptomatic reversible rise in liver enzymes was noted in the ABFNO2 group. Conclusions: ABFN02 has significant activity in OA; the formulation needs further investigation.

  11. Structural and chemical reactivity modifications of a cobalt perovskite induced by Sr-substitution. An in situ XAS study

    International Nuclear Information System (INIS)

    Hueso, Jose L.; Holgado, Juan P.; Pereñíguez, Rosa; Gonzalez-DelaCruz, V.M.; Caballero, Alfonso

    2015-01-01

    LaCoO 3 and La 0.5 Sr 0.5 CoO 3−δ perovskites have been studied by in situ Co K-edge XAS. Although the partial substitution of La(III) by Sr(II) species induces an important increase in the catalytic oxidation activity and modifies the electronic state of the perovskite, no changes could be detected in the oxidation state of cobalt atoms. So, maintaining the electroneutrality of the perovskite requires the generation of oxygen vacancies in the network. The presence of these vacancies explains that the substituted perovskite is now much more reducible than the original LaCoO 3 perovskite. As detected by in situ XAS, after a consecutive reduction and oxidation treatment, the original crystalline structure of the LaCoO 3 perovskite is maintained, although in a more disordered state, which is not the case for the Sr doped perovskite. So, the La 0.5 Sr 0.5 CoO 3−δ perovskite submitted to the same hydrogen reduction treatment produces metallic cobalt, while as determined by in situ XAS spectroscopy the subsequent oxidation treatment yields a Co(III) oxide phase with spinel structure. Surprisingly, no Co(II) species are detected in this new spinel phase. - Highlights: • A Sr-substituted lanthanum cobalt perovskite has been prepared by spray pyrolysis. • It has been established that Co(III) cations are present in both perovskites. • LaCoO 3 is a less reducible phase than the substituted La 0.5 Sr 0.5 CoO 3−δ . • After reoxidation of reduced La 0.5 Sr 0.5 CoO 3−δ , a 100% Co(III) spinel is obtained

  12. Mechanisms for Reduction of Natural Waters Technogenic Pollution by Metals due to Complexions with Humus Substances (Zoning: Western Siberia and the European Territory of Russia)

    Science.gov (United States)

    Dinu, M. I.

    2017-11-01

    The article described the complexation of metal ions with humus substances in natural waters (small lakes). Humus substances as the major biochemical components of natural water have a significant impact on the forms and migration of metals and the toxicity of natural objects. This article presents the results of large-scale chemical experiments: the study of the structural features (zonal aspects) of humus substances extracted from soil and water natural climatic zones (more than 300 objects) in Russia (European Russia and West Siberia); the influence of structural features on the physic-chemical parameters of humus acids and, in particular, on their complexing ability. The functional specifics of humus matter extracted from soils is estimated using spectrometric techniques. The conditional stability constants for Fe(III), Cu(II), Pb(II), Cd(II), Zn(II), Ni(II), Co(II), Mn(II), Cr(III), Ca(II), Mg(II), Sr(II), and Al(III) are experimentally determined with the electrochemical, spectroscopic analysis methods. The activities of metals are classified according to their affinity to humus compounds in soils and water. The determined conditional stability constants of the complexes are tested by model experiments, and it is demonstrated that Fe and Al ions have higher conditional stability constants than the ions of alkali earth metals, Pb, Cu, and Zn. Furthermore, the influence of aluminium ions and iron on the complexation of copper and lead as well as the influence of lead and copper on complexation of cobalt and nickel have been identified. The metal forms in a large number of lakes are calculated basing on the experiments’ results. The main chemical mechanisms of the distribution of metals by forms in the water of the lakes in European Russia and West Siberia are described.

  13. Bleeding evaluation of the stationary phase from a few novel macroporous silica-substrate polymeric materials used for radionuclide partitioning from HLLW in MAREC process

    International Nuclear Information System (INIS)

    Zhang, A.; Wei, Y.; Kumagai, M.

    2005-01-01

    To separate minor actinides from HLLW by extraction chromatography, a few novel silica-based di(2-ethylhexyl)phosphoric acid (HDEHP), 4,4',(5')-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6), octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO), and N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) polymeric adsorption materials (HDEHP/SiO 2 -P, DtBuCH18C6/SiO 2 -P, CMPO/SiO 2 -P, and TODGA/SiO 2 -P) were synthesized by impregnating HDEHP, DtBuCH18C6, CMPO, and TODGA into the pores of porous SiO 2 -P particles, which were the new kind of inorganic/organic composites consisted of macroporous SiO 2 and copolymer. The bleeding behavior of these composites was investigated by examining the effect of contact time and HNO 3 concentration. It was found that in the tested HNO 3 concentration range, a noticeable quantity of DtBuCH18C6, at least 600 ppm, leaked out from DtBuCH18C6/SiO 2 -P because of the protonation of DtBuCH18C6 with hydrogen ion, while the others were lower and basically equivalent to the solubility of HDEHP, CMPO, or TODGA in corresponding acidities solutions. Based on the batch experiment, the bleeding of CMPO/SiO 2 -P and TODGA/SiO 2 -P, the main adsorbents used in MAREC process for HLLW partitioning, was evaluated by column operation in 0.01M HNO 3 and 3M HNO 3 . The quantity of CMPO leaked was ∼48 ppm in 0.01M HNO 3 and ∼37 ppm in 3.0M HNO 3 . The bleeding of TODGA decreased from 23.2 ppm to 7.27 ppm at the initial stage and then basically kept constant. An actual bleeding of TODGA was evaluated by the separation of Sr(II) from a 2.0M HNO 3 solution containing 5.0 x 10 -3 M of 6 typically simulated elements. (author)

  14. Hazardous Waste Water Remediation by Ecoresin-Dry Cow Dung Powder

    Science.gov (United States)

    Bagla, Hemlata; Barot, Nisha

    2013-04-01

    Water, the matter, matrix, medium and the mother of our life, is indeed one of the drivers of Nature. Through water cycle only the intra and inter equilibrium is maintained constantly between entire 'green' and 'blue'. Unfortunately, with each successive epoch of industrialization and urbanization, human societies have produced non-biodegradable waste hulk with far beyond handling capacities of mankind. At this juncture the very need is to appreciate and move towards the cost as well as time effective scientific alternatives for the removal of aqueous heavy metal pollutants. Green chemistry advocates the utilization of naturally available bio-resins which are environmentally benign alternative to current synthetic materials and technologies employed for waste water treatment. This explicit investigation aims to explore Dry Cow dung powder, DCP, a natural biosorbent as a green and clean alternative for the aqueous waste water treatment. It is naturally available bio-organic, complex, polymorphic humified fecal matter of cow and is enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as 'Humic acid'(HA). The HA has been successfully extracted by authors from DCP and this piece of work has been published in the International Journal [1]. We have developed simple, efficient and eco-friendly method for the removal of aqueous heavy metal pollutant such as Cr(VI) [2], Cd(II), Cr(III) [3] and Hg(II) as well radiotoxic 90Sr(II) [4], employing DCP. DCP is employed without any pre or post treatment. Being freely and easily available DCP has an edge over processed natural adsorbent considering their cost, time and energy efficiency. In nutshell we have to remember that prevention is better than the cure. If we fail to meet this, the situation will surely augment which will drain our water, our life, to slaughters knife..! Reference: 1. H.K.Bagla, N.S.Barot, Soil Amendement by Green Supplement: Dry Cowdung powder, EGUGA - 11

  15. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    Bradburry, M.; Baeyens, B.

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P CO 2 . In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab→Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some appreciation of the uncertainties

  16. Adsorption of uranium composites onto saltrock oxides - experimental and theoretical study.

    Science.gov (United States)

    Ivanova, Bojidarka; Spiteller, Michael

    2014-09-01

    The study encompassed experimental mass spectrometric and theoretical quantum chemical studies on adsorption of uranium species in different oxidation states of the metal ion, and oxides of UxOy(n+) type, where x = 1 or 3, y = 2 or 8, and n = 0, 1 or 2 onto nanosize-particles of saltrock oxides MO (M = Mg(II), Ca(II), Ni(II), Co(II), Sr(II) or Ba(II)), M2Oy (M = Au(III) or Ag(I), y = 3 or 1) silicates 3Al2O3.2SiO2, natural kaolinite (Al2O2·2SiO2·2H2O), illite (K0.78Ca0.02Na0.02(Mg0.34Al1.69Fe(III)0.02)[Si3.35Al0.65]O10(OH)2·nH2O), CaSiO3, 3MgO·4SiO2,H2O, and M(1)M(2)(SiO4)X2 (M(1) = M(2) = Al or M(1) = K, M(2) = Al, X = F or Cl), respectively. The UV-MALDI-Orbitrap mass spectrometry was utilized in solid-state and semi-liquid colloidal state, involving the laser ablation at λex = 337.2 nm. The theoretical modeling and experimental design was based on chemical-, physico-chemical, physical and biological processes involving uranium species under environmental conditions. Therefore, the results reported are crucial for quality control and monitoring programs for assessment of radionuclide migration. They impact significantly the methodology for evaluation of human health risk from radioactive contamination. The study has importance for understanding the coordination and red-ox chemistry of uranium compounds as well. Due to the double nature of uranium between rare element and superconductivity like materials as well as variety of oxidation states ∈ (+1)-(+6), the there remain challenging areas for theoretical and experimental research, which are of significant importance for management of nuclear fuel cycles and waste storage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Cementitious Near-Field Sorption Data Base for Performance Assessment of an ILW Repository in Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E.; Van Loon, L. R

    2003-08-01

    The present report describes a cement sorption database (SDB) for the safety-relevant radionuclides to be disposed of in the planned Swiss repository for long-lived intermediate-level radioactive wastes (ILW). This report is an update on earlier SDBs, which were compiled for the cementitious near field of a repository for low- and intermediate-level radioactive wastes (L/ILW) by BRADBURY + SAROTT (1995) and BRADBURY + VAN LOON (1998). The radionuclide inventories are determined by the waste streams to be disposed of in the ILW repository. A list of the safety-relevant radionuclides was provided based on the currently available information on ILW inventories. The compositions of the cement porewaters in the near fields of the L/ILW and ILW repositories, which had been calculated using well-established codes for modelling cement degradation, were compared to identify any differences in the near-field conditions and to assess their influence on radionuclide sorption. Sorption values were selected based on the previously reported SDBs for the near field of the L/ILW repository. Sorption values were revised if new information and/or data were available which allowed changes to or re-appraisals of the data to be made. The sorption values recommended in this report were either selected on the basis of data from in-house experimental studies or from literature data. For some key radioelements, i.e., Cs(l), Sr(II), Ni(II), Eu(lll), Th(IV) and Sn(IV), new data were available from in-house measurements. These elements had been selected for experimental studies due to their relevance to safety assessment and/or their importance as appropriate chemical analogues. Degradation products of bitumen and cellulose, concrete admixtures and cement-derived near-field colloids were taken into account as the main potential perturbations, which could reduce radionuclide sorption in the near field. Possible impacts of the perturbing factors on radionuclide mobility were considered and

  18. Experimental And Modelling Investigations on Na-Illite: Acid-Base Behaviour And the Sorption Of Strontium, Nickel, Europium And Uranyl

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Baeyens, B.

    2005-06-01

    In an extensive study the physico-chemical, protolysis and sorption characteristics of Sr(II), Ni(II), Eu(III) and U(VI) have been measured on illite and modeled over a wide range of pH, sorbate and NaCI0 4 concentrations. SampIes of Illite du Puy, collected in the region of Le Puy-en- Velay, France, were carefully conditioned to the Na-form and physico-chemically characterised. Potentiometric titrations on suspensions of the Na-illite were carried out using a batch back titration technique in 0.01, 0.1 and 0.5 M NaCI0 4 background electrolytes from pH 2 to 12 in an inert atmosphere glove box. The supernatant solutions from each titration experiment in each series were analysed for K, Mg, Ca, Sr, Si, Al, Fe and Mn. The titration data were modeled in terms of the protolysis of two amphoteric edge sites (=S W1 0H and =S W2 0H) without an electrostatic term. The protonation/deprotonation constants and site capacities obtained from the titration measurements were then fixed. The sorption edge and isotherm data were modeled with strong (=S S OH) and weak (=S W1 0H) surface complexation sites, assumed to have the same protolysis constants, again without electrostatic terms. Uptake by cation exchange was included in all of the calculations. This sorption model, the 2 site protolysis non electrostatic surface complexation and cation exchange model, had been developed previously for montmorillonite and was successful in describing the sorption characteristics of Sr, Ni, Eu and U on Na-illite over a wide range of conditions. Cation exchange capacity, strong and weak site capacities and protolysis constants for Na-illite are given, together with surface complexation constants and selectivity coefficients for Sr, Ni, Eu and U. At 0.01 M NaCI0 4 and pH below 8 the sorption of Sr, Ni, Eu and U was dominated by a cation exchange mechanism. The strong dependency of sorption on pH observed under these conditions arose from the competitive effects of Ca and Al on the uptake of the

  19. Experimental And Modelling Investigations on Na-Illite: Acid-Base Behaviour And the Sorption Of Strontium, Nickel, Europium And Uranyl

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.H.; Baeyens, B

    2005-06-01

    In an extensive study the physico-chemical, protolysis and sorption characteristics of Sr(II), Ni(II), Eu(III) and U(VI) have been measured on illite and modeled over a wide range of pH, sorbate and NaCI0{sub 4} concentrations. SampIes of Illite du Puy, collected in the region of Le Puy-en- Velay, France, were carefully conditioned to the Na-form and physico-chemically characterised. Potentiometric titrations on suspensions of the Na-illite were carried out using a batch back titration technique in 0.01, 0.1 and 0.5 M NaCI0{sub 4} background electrolytes from pH 2 to 12 in an inert atmosphere glove box. The supernatant solutions from each titration experiment in each series were analysed for K, Mg, Ca, Sr, Si, Al, Fe and Mn. The titration data were modeled in terms of the protolysis of two amphoteric edge sites (=S{sup W1}0H and =S{sup W2}0H) without an electrostatic term. The protonation/deprotonation constants and site capacities obtained from the titration measurements were then fixed. The sorption edge and isotherm data were modeled with strong (=S{sup S}OH) and weak (=S{sup W1}0H) surface complexation sites, assumed to have the same protolysis constants, again without electrostatic terms. Uptake by cation exchange was included in all of the calculations. This sorption model, the 2 site protolysis non electrostatic surface complexation and cation exchange model, had been developed previously for montmorillonite and was successful in describing the sorption characteristics of Sr, Ni, Eu and U on Na-illite over a wide range of conditions. Cation exchange capacity, strong and weak site capacities and protolysis constants for Na-illite are given, together with surface complexation constants and selectivity coefficients for Sr, Ni, Eu and U. At 0.01 M NaCI0{sub 4} and pH below 8 the sorption of Sr, Ni, Eu and U was dominated by a cation exchange mechanism. The strong dependency of sorption on pH observed under these conditions arose from the competitive effects of

  20. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradburry, M.; Baeyens, B

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P{sub CO{sub 2}}. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab{yields}Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some

  1. Major accident analyses for experimental zero-power fast reactor assemblies; Analyse des accidents graves pouvant survenir dans les reacteurs experimentaux a neutrons rapides de puissance zero; Analiz krupnoj avarii dlya ehksperimental'ny kh reaktornykh ustanovok nulevoj moshchnosti na bystrykh nejtronakh; Analisis de los accidentes graves que pueden producirse en los reactores experimentales rapidos de potencia cero

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, G.; Barts, E. W.; Kapil, S.; Tomabechi, K. [Argonne National Laboratory, Argonne, IL (United States)

    1962-03-15

    'shogo reaktora s aktivnoj zonoj obychnogo sostava. Byla issledovana men'shaya aktivnaya zona s vysokim pustotnym koehffitsientom, kak potentsial'no bolee opasnaya sistema. U ehtikh dvukh sistem obnaruzhen ochen' razlichnyj vremennoj rezhim. V sluchayakh ser'eznykh avarij na ustanovkakh nulevoj moshchnosti atomy U{sup 235}, kotorye raspredeleny v plastinakh obogashchennogo urana, ochen' bystro nagrevayutsya, togda kak ostal'naya chast' aktivnoj zony po sushchestvu ostaetsya kholodnoj, i takim obrazom gazoobraznyj U{sup 235} sozdaet raspredelennoe davlenie. V doklade budet dano opisanie primeneniya k gazu Van der Vaalsa koda AX-I nejtronnoj fiziki i gidrodinamiki. Drugim vazhnym izmeneniem uravneniya sostoyaniya, ispol'zovannogo v kode, yavlyaetsya primenenie uravneniya Mie-Grinejzena, vyvedennoe iz teorii tverdogo sostoyaniya. EHto izmenenie daet vozmozhnost' bolee udovletvoritel'n o vyrazit' chlen davleniya dlya aktivnykh zon razlichnogo sostava. Vvidu togo, chto plastiny U{sup 235} s vysokim obogashcheniem v ustanovke nulevoj moshchnosti nagrevayutsya gorazdo bystree, chem obednennye uranovye plastiny, vozmozhnost' polucheniya rezul'tiruyushcheg o polozhitel'nogo ehffekta Dopplera namnogo bol'she v ehksperimental'noj ustanovke, chem v reaktore-razmnozhitel e ehkvivalentnoj moshchnosti. EHtot risk byl issledovan v otnoshenii ryada vozmozhnykh ustanovok. Ehti raschety ukazyvayut na to, chto koehffitsient Dopplera ustanovki nulevoj moshchnosti ne priobretaet opasnogo znacheniya, poka ne budut sozdany sistemy krupnykh ehnergeticheskikh reaktorov-razmnozhitelej na oksidnom toplive s ochen' myagkimi spektrami ehnergii nejtronov. (author)

  2. On the Behaviour of Radioisotopes Incorporated in Glass Blocks; Le Comportement des Radioisotopes Vitrifies; O Povedenii Radioaktivnyh Izotopov, Lokalizovannyh v Steklovidnyh Blokah; Comportamiento de los Radioisotopos Vitrificados

    Energy Technology Data Exchange (ETDEWEB)

    Zimakov, P. V.; Kulichenko, V. V.; Duhovich, F. S.; Salamatmn, B. A.

    1963-02-15

    mismos y, por consiguiente, en su capacidad de fijacion de los isotopos. Esas alteraciones son mas pronunciadas en la superficie, debido al contacto con los agentes externos (aire, agua). El riesgo-de lixiviacion aumenta, como es logico, con la irradiacion de los bloques. Los experimentos realizados por los autores demuestran que los radioisotopos de las capas superficiales acusan una fuerte tendencia a pasar al estado gaseoso. Teniendo en cuenta el efecto combinado de los factores que actuan sobre los bloques vitreos diurante un almacenamiento prolongado, es preciso, mediante una eleccion adecuada de su composicion quimica (tundente) y de. las condiciones de elaboracion, asegurar la fijacion deseada de los isotopos radiactivos en los bloques enterrados. Ofrece gran interes, en ese sentido, el empleo de compuestos de titanio para la preparacion del fundente. (author) [Russian] V svjazi s tem, chto nekotorye izotopy imejut bol'shie periody poluraspada, neobhodimo obespechit' ih nadezhnuju lokalizaciju ka dlitel'noe vremja, a jeto trebuet izuchenija povedenija takih izotopov v steklovidnyh blokah pod vlijaniem uslovij, kotorye sozdajutsja pri dlitel'nom hranenii: samorazogrev, samoobluchenie, vlijanie okruzhajushhej sredy. Stremlenie ogranichit ob'em blokov d. ja zahoronenija i letuchest' izotopov pri ih prigotovlenii (temperatura - ne vyshe 1200 Degree-Sign C) privodit k neodnorodnoj'strukture takih blokov- Oni javljajutsja ne istinnym steklom, a ''steklovidnymi'' soedinenijami. Svojstva takih blokov i prochnost' lokalizacii v nih oskolochnyh izotopov sil'no zavisjat ot ih himicheskogo sostava (kolichestvo i priroda fljusa), uslovij prigotovlenija i posledujushhego hranenija. Povyshennaja temperatura, razvivajushhajasja v rezul'tate teplovydelenija vysokoradioaktivnyh blokov v mogil'nike, vyzyvaet himicheskie i fizicheskie processy v ih strukturah i sil'no vlijaet na prochnost' lokalizacii v nih oskolkov, osobenno s poverhnosti blokov. Vyshhelachivaemoet' izotopov iz

  3. Materials Control in the Fabrication of Enriched Uranium Fuels; Controle des Matieres au Cours de la Fabrication des Combustibles a Base d'Uranium Enrichi; Uchet materialov pri izgotovlenii topliva na obogashchennom urane; Control de Materiales en la Elaboracion de Combustibles de Uranio Enriquecido

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, Jr., R. G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1966-02-15

    rashozhdenij; 3) svedenie maksimal'nogo chisla proverok v minimal'noe chislo zapjsej vo izbezhanie povtorenij i 4) vvedenie v sistemu dostatochnogo chisla perekrestnyh proverok dlja obespechenija nadezhnosti. V kazhdoj programme izgotovlenija uspeh obespechivalo vvedenie edinoobraznoj procedury na sledujushhih stadijah: 1) ishodnye materialy v tom vide, kak oni poluchajutsja; 2) izgotovlenie komponentov; 3) obrabotka komponentov i 4) obrashhenie s lomom. Svedenie dannyh ucheta v obshhuju glavnuju svodku okazalos' poleznym dlja podtverzhdenija pravil'nosti material'noj inventarizacii, dlja ocenki tehnologicheskih processov izgotovlenija i dlja sostavlenija otchetov dlja rukovodstva. Vyrabotka metodov vyborki prob i izuchenie rezul'tatov pokazali, chto dlja dostizhenija pravil'nogo sostava topliva neobhodimo proizvodit' mnogokratnyj kontrol'. V sluchajah, kogda samym vazhnym predstavljaetsja sostav topliva v vide splava, uspeshno primenjali mehanicheskoe gruppirovanie i izmerenie plotnosti. Obrashhenie s lomom igraet bol'shuju rol' v ustanovlenii material'nogo balansa, kotoryj pozvoljaet podtverdit' pravil'nost' sostava topliva i obespechivaet horoshee vedenie otchetnosti. Zapisi i instrukcii po obrashheniju s materialami, vkljuchaja metody sostavlenija partij i fizicheskoj markirovki, formulirovalis' takim obrazom, chtoby oni mogli byt' poleznymi dlja izgotovitelja pri kontrole nad kritichnost'ju. (author)

  4. The Problem of Storing Fission Products Arising from the Processing of Irradiated Uranium-Molybdenum Alloys; Probleme du Stockage des Produits de Fission en Provenance du Traitement des Alliages Uranium-Molybdene Irradies; 041f 0420 041e 0411 041b 0415 041c 0410 0425 0420 0410 041d 0415 041d 0418 042f 041e 0422 0425 041e 0414 041e 0412 041f 041e 0421 041b 0415 041f 0415 0420 0415 0420 0410 0411 041e 0422 041a 0418 041e 0411 041b 0423 0427 0415 041d 041d 041e 0413 041e 0421 041f 041b 0410 0412 0410 0423 0420 0410 041d - 041c 041e 041b 0418 0411 0414 0415 041d ; El Problema del Almacenamiento de los Productos de Fision Procedentes del Tratamiento de las Aleaciones Uranio-Molibdeno Irradiadas

    Energy Technology Data Exchange (ETDEWEB)

    Faugeras, P.; Kikindai, T. [Commissariat a l' Energie Atomique, Paris (France)

    1963-02-15

    el reactor, pero presentan serios inconvenientes en lo que respecta al almacenamiento de los productos de fision resultantes de su tratamiento. La insolubilidad del molibdeno impide concentrar por evaporacion las soluciones de los productos de fision. Por tal motivo, los autores han estudiado la posibilidad de solubilizar el molibdeno agregandole reactivos tales como el hierro o los iones fosforicos. De este modo, es posible obtener soluciones finales de 60 g/l Mo con hierro, 100 g/l Mo con PO{sub 4}H{sub 3}. Los volumenes que es preciso almacenar siguen siendo importantes (sobre todo con el hierro) y por eso se ha estudiado la calcinacion de los nitratos en un lecho fluidizado. La reaccion tiene lugar a los 400 Degree-Sign C aproximadamente. El comportamiento del rutenio y la friabilidad del solido calcinado (importante formacion de particulas menudas) ha inducido a los autores a reemplazar este procedimiento por el de preparacion de vidrios fosfAtados. (author) [Russian] Povedenie splavov uran-molibden v reaktore predstavljaet prakticheskij interes. Odnako voznikaet problema hranenija produktov delenija, kotorye poluchajutsja v rezul'tate ih pererabotki. V tom sluchae, kogda molibden nahoditsja v nerastvorennom sostojanii, ljuboe koncentrirovanie produktov delenija putem isparenija rastvora prakticheski nevozmozhno. Vot pochemu my orientirovalis' na izuchenie rastvorenija mo'libdena pribavleniem takih reagentov, kak zhelezo idi fosfat-iony. Mozhno poluchit' rastvor sostava: 60 g/l Mo s Re ili. 100 g/l Mo sPO{sub 4}H{sub 3} V jetom sluchae ob'edy, prednaznachennye dlja hranenija, uvelichivajutsja (osobenno pri dobavlenii Fe). Bylo izucheno prokalivanie nitratov v dvizhushhemsja sdoe. Reakcija prohodit pri temperature okolo 400 Degree-Sign C. Letuchest' rutenija i hrupkost' tverdogo prokalennogo veshhestva (vsledstvie obrazovanija znachitel'nogo kolichestva uglja) zastavila'nas otkazat'sja ot'jetogo processa i'perejti k izgotovleniju fosfatnyh stekol. (author)

  5. Measurement of the wear rate of cast grinding balls using radioactive tracers; Evaluation de l'usure des boulets pour concasseurs, au moyen des indicateurs radioactifs; Izmerenie skorosti iznosa litykh drobil'nykh sharov pri pomoshchi mechenykh atomov; Medicion de la velocidad de desgaste de bolas trituradoras de acero colado con ayuda de indicadores radiactivos

    Energy Technology Data Exchange (ETDEWEB)

    Keys, J D; Eichholz, G G [Department of Mines and Technical Surveys, Ottawa, ON (Canada)

    1962-01-15

    'nykh sharov v razlichnykh rabochikh usloviyakh i dlya sopostavleniya rezul'tatov, poluchaemykh s sharami raznykh tipov ili raznogo sostava, byli uspeshno ispol'zovany mechenye atomy. Na protyazhenii neskol'kikh nedel' bylo provedeno nablyudenie za partiej mechenykh stal'nykh sharov v drobil'noj rabote i byli sobrany statisticheskie dannye otnositel'no iznosa i poteri vesa. V khode opytnykh tsiklov do otlivki sharov k rasplavlennomu metallu byl dobavlen kobal't-60 i posle ehtogo bylo provedeno nablyudenie nad litymi sharami v ikh rabote na razrabotkakh zheleznoj rudy. Partiya mechenykh radioizotopami sharov byla dobavlena k drobil'nym sharam drobilki s normal'noj emkost'yu zagruzki priblizitel'no v 75 tonn, H cherez kazhduyu nedelyu iz drobilki vybiralis' obraztsy zagruzki dlya iz{sup y}atiya mechenykh sharov. EHti shary proveryalis' i vzveshivalis' i podschityvalas' skorost' ikh iznosa. EHtot metod okazalsya praktichnym sposobom issledovaniya svojstv iznosa v rabochikh usloviyakh na ustanovke. (author)

  6. A Contribution to the Study of the Oxidation of Uranium Monocarbide in Carbonic Anhydride at High Temperatures; Contribution a l'etude de l'oxydation du monocarbure d'uranium dans l'anhydride carbonique aux temperatures elevees; Vklad v izuchenie voprosa okisleniya monokarbida urana v ugol'nom angidride pri povyshennykh temperaturakh; Contribucion al estudio de la oxidacion del monocarburo de uranio en anhidrido carbonico a temperaturas elevadas

    Energy Technology Data Exchange (ETDEWEB)

    Desrues, R; Paidassi, J.; Darras, R. [Centre d' Etudes Nucleaires, Saclay (France)

    1963-11-15

    monocarburo, sea que provengan del uranio o bien del dicarburo, disminuye la resistencia de este compuesto a la oxidacion; ello puede atribuirse sobre todo al hecho de que aquellas sufren una oxidacion muy seria, especialmente a raiz de las tensiones mecanicas que causa. 3. En todos los casos, el proceso de oxidacion puede caracterizarse por una energia de activacion igual a 29 000 cal/M, valor muy proximo al correspondiente a la oxidacion del uranio metalico en el mismo gas y a la difusion del oxigeno en el oxido de uranio (UO{sub 2}) que se forma. (author) [Russian] Obraztsy monokarbida urana, poluchennogo dvumya razlichnymi metodami, i obraztsy ker- meta sostava 96,7 ves% U-3,3 ves% S podvergalis' dejstviyu ugol'nogo angidrida, tshchatel'no ochishchennogo ot kisloroda i vodyanykh parov, v intervalakh 350 - 600 deg. C, i nablyudalos' ikh okislenie odnovremenno mikrograficheskim i gravimetricheskim sposobami pri pomoshchi termovesov Ehjro. Bylo otmecheno sleduyushchee: 1) Krivye vyrazhayut uvelichenie vesa kak funktsiyu vremeni i vnachale nosyat yarko vyrazhennyj linejnyj kharakter, zatem bystro vozrastayut, chto ob{sup y}asnyaetsya, v osnovnom,progressivnym razlozheniem obraztsov. Vprochem, poluchennye dannye uvelicheniya vesa yavlyayutsya bolee nizkimi chem te, kotorye byli opublikovany do nastoyashchego vremeni, chto sleduet, ochevidno, pripisat' bolee vysokoj chistote upotreblennogo ugol'nogo angitrida i ochen' neznachitel'noj poristosti ispol'zovannogo monokarbida urana. 2) Nalichie vklyuchenij v monokarbid, kotorye sootvetstvuyut uranu ili dikarbidu, umen'shaet stojkost' ehtogo materiala k okisleniyu, chto sleduet pripisat', glavnym obrazom,katastroficheskomu okisleniyu samikh vklyuchenij iz-za mekhanicheskikh svyazej. 3) Vo vsekh sluchayakh protsess okisleniya mozhet byt' okharakterizovan ehnergiej aktivatsii, ravnoj 29 000 kal/mol', velichinoj, ochen' blizkoj k toj, kotoraya sootvetstvuet okisleniyu metallicheskogo urana v tom zhe gaze i diffuzii kisloroda v okisi

  7. Dispersion-Type Absorbing Materials for the Control Organs of Thermal Reactors; Absorbants du Type a Dispersion pour les Organes de Commande des Reacteurs a Neutrons Thermiques; Pogloshchayushchie materialy dispersionnogo tipa dlya organov regulirovaniya teplovykh reaktorov; Absorbentes de Tipo Dispersion para los Organos de Mando de los Reactores Termicos

    Energy Technology Data Exchange (ETDEWEB)

    Nosov, V. I.; Ponomarjov-Stepnoj, H. H.; Portnoj, K. I.; Savel' ev, E. G.

    1964-06-15

    'nyh jelementov (gadolinija, samarija, evropija it d.). Rassmatrivajutsja voprosy izmenenija pogloshhajushhej sposobnosti ot sostava materiala, mehanicheskie i teplofizicheskie svojstva pogloshhajushhih materialov v zavisimosti ot koncentracii vvodimogo v splav poglotitelja i, nakonec, rezul'taty izuchenija vlijanija obluchenija na svojstva ukazannyh materialov. Pokazano, chto pogloshhajushhie splavy s okislami redkozemel'nyh jelementov, dispergirovannymi v metallicheskuju matricu, obladajut znachitel'noj pogloshhajushhej sposobnost'ju pri sravnitel'no nebol'shom soderzhanii poglotitelja v splave - (5 - 10). Splavy tipa nimonik s dobavkami okislov redkozemel'nyh jelementov imejut sravnitel'no vysokie znachenija prochnostnyh i teplofizicheskih harakteristik (o{sub B}, E, {lambda}) pri povyshennyh temperaturah v oblasti koncentracij poglotitelja Tilde-Operator do (10% Dispersionnye materialy podobnogo tipa obladajut udovletvoritel'noj radiacionnoj stojkost'ju v pole obluchenija ( Tilde-Operator 3 x 10{sup 20} n/cm{sup 2}) v uslovijah vysokih temperatur. (author)

  8. The Determination of Sub-Microgram Quantities, of Amino Acids with H{sup 3}- and C{sup 1}4-Labelled 1-Fluoro-2.4 Dinitrobenzene; Determination d'acides amines en quantites inferieures au microgramme a l'aide de 1-fluoro-2,4-dinitrobenzen e marque au {sup 3}H et au {sup 14}C; Podschet submikrogrammnykh kolichestv aminokislot pri pomoshchi 2 : 4 dinitroftor'enzola, mechennogo H{sup 3} i C{sup 14}; Determinacion de cantidades de aminoacidos inferiores al microgramo por medio de 1-fluoro-2,4-dinitrobenceno marcado con {sup 3}H y {sup 14}C

    Energy Technology Data Exchange (ETDEWEB)

    Beale, D; Whitehead, J K [Middlesex Hospital Medical School, London (United Kingdom)

    1962-01-15

    satisfactoriament con los valores que suministra el analisis por derivacion empleando anhidrido acetico marcado con {sup 3}H y con {sup 14}C, y con los que se obtienen mediante cromatografia de intercambio ionico. (author) [Russian] Opisyvaetsya metod izotopnogo derivatsionnogo analiza dlya opredeleniya aminokislot pri nizkom urovne v 10{sup -5} mikro-mol' v gidrolizatakh proteina. 2:4 djnitroftorbenzola-H{sup 3} (G) byl sintezirovan iz ' brombenzola-H{sup 3}(G) i 2 : 4 dinitroftorbenzola-C{sup 14}(G), kotoryj byl poluchen iz khlorbenzola-C{sup 14}(G). Metod analiza vklyuchaet obrabotku smesi amino-kislot tritirovannym reaktivom (udel'naya aktivnost' 12.8 mikro kyuri/mikro ehkvijalent) v shchelochnoj rastvore, k kotoromu prisoedinyaetsya primes' s izvestnoj aktivnost' (6000 raspadov v minutu) proizvodnykh 2 : 4 dinitrofenila , mechennogo S14. Posle rastvoryayushchej ehkstraktsii smeshannaya reaktsiya vydelyaet iz svoego sostava proizvodnye dinitrofinila dvumya putyami khromatografii na bumage i soderzhanie H''3 i C''1''4 kazhdoj kapli opredelyaetsya szhiganiem i gazovym podschetom. Podschet H''3 daet kolichestvo, ravnoe proizvodnoj DNK iz aminokisloty, otdelennoj ot osnovnoj smesi, a schet C''1''4 ukazyvaet na velichinu poter', poluchivshikhsya vo vremya analiza. Itogi, poluchennye v rezul'tate analiza 1 mikrogramma gidrolizovannogo insulina polnost'yu soglasuyutsya s velichinami, poluchennymi v rezul'tate derivatsionnogo analiza s ispol'zovaniem uksusnogo angidrida, mechennogo H{sup 3} i C{sup 14} i s pomoshch'yu khromotografii ionnogo obmena smol. (author)

  9. Characterization of 200-UP-1 Aquifer Sediments and Results of Sorption-Desorption Tests Using Spiked Uncontaminated Groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Um, Wooyong; Serne, R JEFFREY.; Bjornstad, Bruce N.; Schaef, Herbert T.; Brown, Christopher F.; Legore, Virginia L.; Geiszler, Keith N.; Baum, Steven R.; Valenta, Michelle M.; Kutnyakov, Igor V.; Vickerman, Tanya S.; Lindberg, Michael J.

    2005-11-16

    Core characterization showed only 4 out of 13 core liner samples were intact samples and that the others were slough material. The intact samples showed typical Ringold Unit E characteristics such as being dominated by gravel and sand. Moderately reducing conditions are inferred in some core from borehole C4299. This reducing condition was caused by the hard tool process used to drill the wells. One core showed significant presence of ferric iron oxide/clay coatings on the gravels. There were no highly contaminated sediments found in the cores from the three new boreholes in UP-1 operable unit, especially for uranium. The presence of slough and ''flour'' caused by hard tooling is a serious challenge to obtaining field relevant sediments for use in geochemical experiments to determine the adsorption-desorption tendencies of redox sensitive elements such as uranium. The adsorption of COCs on intact Ringold Formation sediments and Fe/clay coatings showed that most of the anionic contaminants [Tc(VII), Se(VI), U(VI), Cr(VI), and I(-I)] did not adsorbed very well compared to cationic [Np(V), Sr(II), and Cs(I)] radionuclides. The high hydrous iron oxide content in Fe/clay coatings caused the highest Kd values for U and Np, suggesting these hydrous oxides are the key solid adsorbent in the sediments. Enhanced adsorption behavior for Tc, and Cr and perhaps Se on the sediments was considered an ?artifact? result caused by the induced reducing conditions from the hard tool drilling. Additional U(VI) adsorption Kd studies were performed on Ringold Formation sediments to develop more robust Kd data base for U. The <2 mm size separates of three UP-1 sediments showed a linear U(VI) adsorption isotherm up 1 ppm of total U(VI) concentration in solution. The additional U(VI) Kds obtained from varying carbonate concentration indicated that U(VI) adsorption was strongly influenced by the concentration of carbonate in solution. U(VI) adsorption decreased with

  10. Kinetics of biosorption of hazardous metals by green soil supplement

    Science.gov (United States)

    Bagla, Hemlata; Khilnani, Roshan

    2016-04-01

    The process of metal retention by soil may include ion exchange, adsorption and precipitation. These reaction mechanisms have been defined through fitting the data into different equilibrium and kinetic models. The natural organic matter in soil consists of various fractions like macro-organic material, plant residues, soil biomass and stable humus. Most of the organic matter is dominated with large amount of humic substances. Humic fractions in soil are known to have indirect and direct effects on plant growth and crop production. Humic substances increase the cation exchange capacity, providing a strong buffer capacity to resist sudden drastic chemical changes in soil which enhance soil fertility and environmental quality. The cation-humic interactions exert control on the reactivity of the cation, influencing its bioavailability in the soil system. The investigation of metal concentrations adsorbed with time can be useful to estimate the metal bioavailability in soil. Understanding how metals interact and compete for adsorption sites is of great interest to those involved in environmental remediation. Cow Dung is bio-organic, complex, polymorphic fecal matter of the bovine species, enriched with 'Humic acid' (HA), 'Fulvic Acid', etc. The HA in Cow Dung has been successfully extracted using neutralization reaction and its presence was confirmed by comparison with FTIR spectra of standard HA (IHSS). Since, dry Cow dung powder (DCP) is being added as a soil supplement to enhance the quality of soil, it is important to understand the kinetics associated with it. This work reports kinetic studies of various toxic and hazardous elements such as Cr(III), Cr(VI), Sr(II), Cd(II), Hg(II) and Co(II) adsorption by dry Cow dung powder. Kinetic experiments demonstrated rapid metal uptake. The Kinetic biosorption data were obtained by Batch experiments to explore the rate of biosorption by DCP at optimum parameters and varying the time of reaction from 1-30 min. The dynamics

  11. Effects of Incorporated Radioactivity and External Radiation on Heterogeneous Catalysis; Effets de la radioactivite incorporee et des rayonnements externes sur la catalyse heterogene; Vliyanie vvedennoj radioaktivnosti i vneshnego oblucheniya na geterogennyj kataliz; Efectos de la radiactividad incorporada y de la irradiacion externa sobre la catalisis heterogenea

    Energy Technology Data Exchange (ETDEWEB)

    Krohn, N. A.; Wymer, R. G. [Oak Ridge National Laboratory, Oak Ridge and University of Tennessee, Knoxville, Tennessee (United States)

    1963-11-15

    aktivirovannykh alyumokhromovykh katalizatorakh. Izucheny ehffekty vvedeniya v katalizator radioaktivnykh izotopov i predvaritel'nogo gamma-oblucheniya ot istochnika Co''6''0. Sud'fatmagnievyj katalizator i katalizator smeshannogo tipa sul'fat magniya + sul'fat natriya, soderzhashchie do 45,5 mkkyuri (S''3''5)/r, pri raschete na edinitsu poverkhnosti menee aktivny, chem katalizatory togo zhe sostava, no ne soderzhashchie radioaktivnykh izotopov. Oslablenie kataliticheskoj aktivnosti sokhranyalos' dazhe posle togo, kak radioaktivnost' sushchestvenno pala, dalee, pri obluchenii rentgenovskimi luchami, kotoroe provodilos' v protsesse reaktsii, nikakikh izmenenij v kataliticheskoj aktivnosti ne nablyudalos'. Na osnovanii ehtikh dannykh sdelan vyvod, chto ehmissiya beta-chastits iz katalizatora v protsesse ego ispol'zovaniya ne okazyvaet nikakogo vliyaniya. Soobshcheniya ob usilenii kataliticheskoj aktivnosti sleduet otnesti za schet togo, chto pri prigotovlenii katalizatorov u tekh iz nikh, kotorye soderzhali radioaktivnye izotopy, vozmozhno poluchalas' bol'shaya ploshchad' poverkh- nosti, chem u tekh, kotorye ne soderzhali radioaktivnykh izotopov. Ehto obstoyatel'stvo ne bylo prinyato vo vnimanie. Predvaritel'noe gamma-obluchenie ot istochnika Co''6''0 dozoj 10''1''1 erg/g ne okazalo vliyaniya na kataliticheskuyu aktivnost'. S drugoj storony, predvaritel'noe obluchenie gamma-luchami ot istochnika Co{sup 60} alyumokhromovykh katalizatorov dozoj 4,2 x 10{sup 11} erg/g usililo kataliticheskuyu aktivnost' pochti na 34%, pri 485{sup o}C. V to zhe vremya vvedenie v katalizator do 148 mkkyuri (Pm{sup 147} )/g katalizatora ne okazyvalo pochti nikakogo vozdejstviya. V ehtom sluchae ne nablyudalos' skol'ko-nibud' zametnogo vliyaniya izlucheniya na ploshchad' poverkhnosti ili na kazhushchuyusya ehnergiyu aktivatsii. (author)

  12. Recent Advances in Low-Level Scintillation Counting of Tritium; Progres recents dans le comptage a scintillations de faibles teneurs en tritium; Poslednie dostizheniya v oblasti stsintillyatsionnogo scheta tritiya nizkogo urovnya; Progresos recientes en el recuento por centelleo de bajas concentraciones de tritio

    Energy Technology Data Exchange (ETDEWEB)

    Kaufman, W J; Nir, A; Parks, G; Hours, R M [University of California, Berkeley, CA (United States)

    1962-01-15

    . Con este sistema se ha logrado una sensibilidad de deteccion correspondiente a una concentracion de tritio de 0,55 x 10{sup -12} c/ml con un rendimiento de 6,9% y un fondo de 52 imp/min. Se utilizo una muestra de agua de 31,6 ml y un centelleador de 170 mi de volumen total. Se ha podido comprobar que una fuente interna de 57Co constituye un medio adecuado para controlar el rendimiento de recuento del tritio en el intervalo comprendido entre 2 y 7%, con una desviacion standard de 0,1%. Respecto de los metodos anteriores, posee la ventaja de que permite una rapida valoracion del rendimiento sin necesidad de modificar la muestra. Se efectuaron estudios sobre la reduccion del fondo con miras a evaluar la influencia de la interaccion luminosa y de las radiaciones cosmicas. En el estudio se empleo un blindaje de anticoincidencia con una envoltura de material plastico. Se determinaron los efectos a largo plazo ejercidos sobre la estabilidad del sistema por la deterioracion de las muestras y las desviaciones en el equipo de recuento. (author) [Russian] Bylo provedeno issledovanie zhidkostnoj stsintillyatsionnoj schetnoj sistemy s tsel'yu optimizirovat ' chuvstvitel'nost ' registratsii, vyrazhaemuyu funktsiej velichiny obraztsa, ehffektivnosti i fona. Issledovanie vklyuchalo peresmotr sostava sentillyatora. Naibolee udovletvoritel'nym byl najden sostav v sisteme dioksana-naftalinavody s soderzhaniem vody v 18,6%. Dal'- nejshee izuchenie geometrii schetnogo sosuda i ob{sup e}ma stsintillyatora privelo k ispol'zovaniyu tsilindricheskogo kontejnera iz teflona s fotoumnozhitelyami s vysokousilennoj kvartsevoj poverkhnost'yu v neposredstvennom kontakte s rastvorom. EHta sistema pokazala chuvstvitel'nost' registratsii tritiya, sootvetstvuyushchuyu kontsentratsii 0,55 x 10{sup -12} kyuri/millilitr pri ehffektivnosti v 6,9% i fone v 52 otscheta v minutu. Byl ispol'zovan obrazets s ob{sup e}mom vody v 31,6 millilitra pri obshchem ob{sup e}me stsintillyatora v 170 millilitrov. Bylo

  13. The Origin and Nature of Radioactive Wastes in the United States Atomic Energy Programme; Origine et Nature des Dechets Radioactifs de l'Execution des Programmes d'Energie Atomique aux Etats-Unis; 041f 0420 041e 0418 0421 0425 041e 0416 0414 ; Origen y Naturaleza de los Desechos Radiactivos en el Programa de Energia Atomica de los Estados Unidos

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, F. R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1960-07-01

    clases de desechos: desechos de actividad media, que resultan de la disolucion quimica, y contienen el 0,1 per ciento, aproximadamente, del total de los productos de fision, y desechos de actividad elevada, que contienen el resto de los productos de fision en una solucion diluida de acido nitrico. El volumen de los desechos evaporados varia entre 0,8 1 per kilogramo de uranio, para los combustibles poco enriquecidos y 500 1 por kilogramo de uranio, para los muy enriquecidos, se prove que la industria nuecleoelectrica de los Estados Unidos producira como termino medio unos 5 1 de desechos de actividad elevada y media por kilogramo de uranio utilizado. En los Estados Unidos se calcula que para 1970 esta industria habra producido unos 3 x 10{sup 9} curies disueltos en un volumen de 2,7 x 10{sup 7} l y 6 x 10{sup 10} curies en 1,1 x 10{sup 9} l de solucion para el ano 2000. Los desechos procedentes de los reactores generadores plantean, por razon de su composicion, nuevos problemas de almacenamiento y evacuacion. (author) [Russian] Sostav othodov, obrazuemyh pri jekspluatacii reaktorov, zavisit, vo-pervyh, ot obrabotki, kotoraja primenjaetsja pri vosproizvodstve toplivnyh jelementov, i, vo-vtoryh, ot pervonachal'nogo sostava toplivnyh jelementov. Pri obrabotki s primeneniem jekstrakcii vodnyh rastvorov vysokaja, srednjaja i nizkaja aktivnost' othodov voznikaet v priblizitel'nom ob'emnom sootnoshenii, ravnom odnomu, pjati i 100 sootvetstvenno. Othody, voznikajushhie v rezul'tate vosproizvodstva vysokoobogashhennyh toplivnyh jelementov, byvajut bol'shimi po ob{sup e}mu, tak kak oni soderzhat toplivnyj razbavitel'. Nizkoobogashhennye toplivnye jelementy obychno sostojat iz uranovoj serdceviny, pokrytoj aljuminiem, cirkoniem ili nerzhavejushhej stal'ju ; jeti jelementy dajut dva vida othodov. Pervye othody srednej stepeni aktivnosti, soderzhashhie okolo 0,1% produktov raspada, voznikajut v rezul'tate himicheskogo rastvorenija. Vtoroj vid othodov s vysokoj stepen'ju aktivnosti

  14. The Permanent Disposal of Highly Radioactive Wastes by Incorporation into Glass; Elimination Permanente de Dechets Hautement Radioactifs par Incorporation dans le Verre; 041e 041a 041e 041d 0427 0414 ; La Evacuacion Permanente de Desechos de Elevada Radiactividad Incorporandolos en Vidrio

    Energy Technology Data Exchange (ETDEWEB)

    Watson, L. C.; Aikin, A. M.; Bancroft, A. I. [Atomic Energy of Canada Ltd. (Canada)

    1960-07-01

    . Jetot process byl prodemonstrirovan proizvodstvom stekla, soderzhashhego do 50 kjuri smeshannyh rasshhepljajushhihsja produktov pjati-shestiletnej davnosti na kilogramm. Operacija provodilas' po ciklam po norme 4 kilogramma na cikl. Jeti operacii pokazali, chto rasshhepljajushhiesja produkty mogut byt' zakljucheny v steklo bezopasno i udobno. Rassmotrenie mnogih problem, svjazannyh s postojannym hraneniem ili okonchatel'nym udaleniem vysokoradioaktivnogo stekla privelo k vyvodu, chto ego sleduet zahoronjat' v zemlju ili hranit' v iskusstvennyh pogrebah, V takih uslovijah othody v sluchae neobhodimosti vsegda mogut byt' podvergnuty dopolnitel'nomu kontrolju. Esli othody pomeshhajutsja neposredstvenno v grunt, to osnovnym metodom, s pomoshh'ju kotorogo rasshhepljajushhiesja produkty mogut byt' vypushheny vo vneshnjuju sredu, javljaetsja vyshhelachivanie iz stekla v vodu. V svjazi s jetim schitajut vazhnym znat' skorost', pri kotoroj rasshhepljajushhiesja produkty budut rasseivat'sja jetim metodom. V laboratorii polucheno znachitel'noe kolichestvo dannyh o vyshhelachivanii s pomoshh'ju vody. Bylo najdeno, chto skorost' vyshhelachivanija zavisit ot sostava stekla. Izmerenija, provedennye pri ispytanii vseh sostavov stekla, pokazali, chto skorost' vyshhelachivanija rasshhepljajushhihsja produktov iz stekla so vremenem umen'shaetsja. Posle neskol'kih mesjacev prebyvanija v vode skorost' vysvobozhdenija iz stekla s razlichnym sostavom byla ravna primerno 10{sup -4} procenta v god ot dvuhkilogrammovoj stekljannoj polusfery. Poluchennye dannye byli ispol'zovany dlja opredelenija vysvobozhdenija rasshhepljajushhihsja produktov iz stekla, soderzhashhego bol'shie kolichestva rasshhepljajushhihsja produktov, kotorye budut akkumulirovat'sja v rezul'tate raboty jenergeticheskih reaktorov. (author)

  15. Sorption Regularities in Behaviour of Fission-Product Elements during Filtration of their Solutions through Ground; Lois de l'Absorption des Elements Radioactifs Lors du Filtrage des Solutions a Travers les Terrains; 0417 0410 041a 041e 041d 0414 ; Leyes de la Absorcion de los Elementos Radiactivos Cuando se Filtran Soluciones a Traves de las Formaciones Geologicas

    Energy Technology Data Exchange (ETDEWEB)

    Spitsyn, V. I.; Balukova, V. D.; Gromov, V. V.; Zakharov, S. I.; Zhagin, B. P.; Spiridonov, F. M.

    1960-07-01

    menee 10 metrov s dvumja rezkimi granicami umen'shenija radioaktivnosti grunta: v poverhnostnoj chasti i na glubine fronta fil'tracii rastvora. Krome togo, otdel'no izuchalos' pogloshhenie radiostroncija prirodnymi sorbentami, preimushhestvenno chistymi mineralami, shiroko rasprostranennymi v pochvah i gruntah. Prisutstvie dazhe nebol'shih kolichestv ionov kal'cija rezko snizhaet stepen' sorbcii radiostroncija. Odnako v zavisimosti ot sostava sorbenta stroncij, pri prochih ravnyh uslovijah, mozhet pogloshhat'sja v bol'shej stepeni, chem kal'cij. Polevaja proverka sorbcii i migracii radiostroncija pokazala, chto pri fil'tracii radioaktivnyh rastvorov sleduet rassmatrivat' dva vozmozhnyh varianta. Pervyj - rastvory sbrasyvajutsja v grunty, ne podvergajushhiesja vozdejstviju vodnogo potoka. Pri jetom radiostroncij zaderzhivaetsja gruntami. Vtoroj - radiojelementy popadajut neposredstvenno v vodonesushhij gorizont. V jetom sluchae proishodit migracija radiostroncija s potokom gruntovoj vody, a takzhe ego migracija po gruntam s nalozheniem processov sorbcii i desorbcii. (author)

  16. Physico-chemical characterisation data and sorption measurements of Cs, Ni, Eu, Th, U, Cl, I and Se on MX-80 bentonite

    International Nuclear Information System (INIS)

    Bradbury, M. H.; Baeyens, B.

    2011-12-01

    The Laboratory for Waste Management of the Nuclear Energy and Safety Research Department at the Paul Scherrer Institute is performing work to develop and test models as well as to acquire specific data relevant to performance assessments of Swiss radioactive waste repositories. These investigations are undertaken in close co-operation with, and with the financial support of, the National Cooperative for the Disposal of Radioactive Waste (Nagra). The present report describes the work carried out on MX-80 bentonite in support of Swiss radioactive waste performance assessment studies. With particular regard to Stage 2 of the Sectoral Plan for deep geological disposal, it was considered to be important to bring together in one document the information and results that have accrued over the years from both 'in house' studies and associated relevant literature data. The report gives a brief overview of the physico-chemical characteristics and porewater chemistry determined for MX-80 bentonite followed by the results of an extensive experimental sorption programme on the uptake of Cs(I), Ni(II), Eu(III), Th(IV), U(VI), CI(-I), I(-I) and Se(IV) on the same material. Sorption values are also given for K(I), Ca(II) and Sr(II) which were deduced from porewater chemistry modelling studies. The main aim of this work is to provide a compilation of experimental data on sorption isotherms for key radionuclides on MX-80 bentonite in the frame of the Swiss radioactive waste disposal programme. However, they also provide basic data sets to test the predictive capacity of mechanistic sorption models. In the first part of this work the mineralogy and physico-chemical characteristics of the MX-80 bentonite used in this work are presented: mineralogy, surface areas, sulphate and chloride inventories, CEC, cation occupancies, selectivity coefficients for K-Na, Mg-Na and Ca-Na exchange equilibria, amphoteric edge site capacities and protolysis constants and whole rock analyses (trace

  17. In Vivo and Air Dosimetry of Fission-Spectrum Neutrons; Dosimetrie In Vivo et dans l'Air du Spectre des Neutrons de Fission; Dozimetriya v vozdukhe i dozimetriya In Vivo nejtronov spektra deleniya; Dosimetria In Vivo y en el Aire de Neutrones de un Espectro de Fision

    Energy Technology Data Exchange (ETDEWEB)

    Mobley, T. S.; Engel, R. E.; Godden, W. R. [Kirtland Airforce Base, New Mexico (United States); Penikas, V. T. [AFIT, Wright-Patterson Air Force Base, Ohio, with Duty Station at University of Rochester, School of Medicine and Dentistry, Rochester, NY (United States)

    1964-03-15

    bornogo sharika, soderzhashhego kadmij i pokrytogo fol'goj poroga delenija (Pu, Np, U), sernoj tabletki i treh tipov dozimetrov, primenjavshihsja v podkozhnom detektore. Dozimetricheskij pribor pomeshali v brjushnoj polosti podopytnyh zhivotnyh za vosemnadcat' chasov do obluchenija, prikrepljaja e go k perednej storone rubcevogo otdela zheludka. Opisyvaetsja metod rassechenija rubcevogo otdela zheludka. Doza nejtronov izmerjalas' s pomoshh'ju porogovyh izmerenij fol'gi. Zoloto i zoloto, pokrytoe kadmiem, ispol'zovalis' dlja opredelenija integrirovannogo potoka teplovyh nejtronov; plutonij-239, neptunij-237, uran-238 i sera-32 - dlja opredelenija integrirovannyh potokov bystryh nejtronov; radiofotoljuminiscentnye stekljannye sterzhni - dlja opredelenija dozy gamma-luchej. Ovcu podvergali oblucheniju sboku na rasstojanii (po srednej linii) 200 cm, ili 175 sm ot centra kriticheskoj sborki. Doza nejtronov v radah, izmerennaja v vozduhe na rasstojanii 200 sm sostavljala 161 {+-}5,5 rada; na rasstojanii 175 sm - 242 {+-} 16,6 rada. Doza gamma-luchej na sootvetstvujushhih rasstojanijah so stavljala 3 3 {+-}2 ,4 i 4 2 {+-}2 ,5 rentgena. Dozy na vhode i vyhode, a takzhe doza vo vnutrennem detektore kolebalas' v svjazi s vnezapnym pod{sup e}mom temperatury, uvelicheniem rasstojanija ot reaktora, polozheniem fol'gi v otnoshenii reaktora i zavisela ot tolshhiny i sostava oslabljajushhih dozu tkanej. (author)

  18. Injection of Plasma Blobs into A Mirror Trap With Adiabatic Plasma Compression: ''ASPA'' Device; Injection d'Amas de Plasma dans un Piege a Miroirs avec Compression Adiaba Tique - Machine 'ASPA'; Inzhektsiya plazmennykh sgustkov v probochnuyu lovushku s adiabaticheskim szhatiem plazmy. Ustanovka ''ASPA''; Inyeccion de Plasmoides en una Trampa de Espejos con Compresion Adiabatica. La Instalacion 'ASPA'

    Energy Technology Data Exchange (ETDEWEB)

    Babichev, A. P.; Burjak, E. M.; Gorbunova, E. F.; Karchevskij, A. I.; Muromkin, Ju. A. [Institut Atomnoj Ehnergii, Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1966-04-15

    kotorymi 20 sm (probochnoe otnoshenie 1:2). Maksimal'naja naprjazhennost' impul'snogo magnitnogo polja v probkah sostavljaet 40 kje, vremja narastanija magnitnogo polja Tilde-Operator 40 mksek, a vremja spada polja 350 mksek. Provodilis' mass-spektrometricheskie issledovanija sostava i jenergeticheskih raspredelenij ionnoj komponenty plazmy v titanovom i koaksial'nom inzhektorah. S pomoshh'ju mikrovolnovogo interferometra izmerjalas' plotnost' plazmennogo sgustka pri ego dvizhenii ot inzhektora k rabochej oblasti szhatija. Issledovalos', takzhe, prohozhdenie plazmennogo sgustka cherez magnitnuju probku s naprjazhennost'ju polja do 20 kje. V odnih opytah pole probki bylo parallel'no vedushhemu magnitnomu polju, a v drugih - antiparallel'no, t.e. sozdavalos'' pole divertornogo tipa s dvumja oblastjami nulevoj naprjazhennosti polja. Pokazano, chto inzhektiruemyj plazmennyj sgustok (kak dlja titanovogo, tak i dlja koaksial'nogo inzhektorov) otnositel'no svobodno pronikaet cherez magnitnuju probku, kogda pole probki sovpadaet po napravleniju s vedushhim magnitnym polem; i prakticheski ne prohodit v sluchae polja divertornogo tipa. Na osnovanii jetih opytov pokazana vozmozhnost' otsechki tjazhelyh primesej inzhektiruemoj plazmy s pomoshh'ju impul'snogo magnitnogo zatvora, sozdajushhego oblasti s nulevoj naprjazhennost'ju magnitnogo polja i vyhodom magnitnyh silovyh linij na stenki kamery. V predvaritel'nyh jeksperimentah po adiabaticheskomu szhatiju plazmy v lovushke probochnoj konfiguracii zaregistrirovano zhestkoe rentgenovskoe izluchenie (jenergija 30 kjev) i issledovano vlijanie nachal'nogo magnitnogo polja i parametrov plazmennogo sgustka na intensivnost' i zhestkost' jetogo izluchenija. (author)

  19. Design and characteristics of beta-excited X-ray sources; Caracteristiques des sources de rayons X excitees par des particules beta; Konstruktsiya i kharakteristiki beta-vozbuzhdennykh istochnikov rentgenovskikh luchej; Diseno y caracteristicas de las fuentes de rayos X excitadas por particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Filosofo, I; Reiffel, L; Stone, C A; Voyvodic, L [Physics Division, Armour Research Foundation, Chicago, IL (United States)

    1962-01-15

    'zovaniya istochnika vysokogo urovnya, v kotorom sam prometij-147 yavlyaetsya glavnoj mishen'yu rentgenovskikh luchej. Detektirovanie rentgenovskikh luchej proizvodilos' pri pomoshchi stsintillyatsionnykh i proportsional'nykh schetchikov sovmestno s 256-kanal'nym amplitudnym analizatorom impul'sov. Dlya istolkovaniya ehksperimental'nykh dannykh bylo vyrabotano i opisano analiticheskoe vyrazhenie protsessov obrazovaniya rentgenovskikh luchej beta-chastitsami. Esli uchest' tormoznoe izluchenie, obolochechnuyu K-ionizatsiyu i flyuorestsiruyushchee vozbuzhdenie rentgenovskikh luchej, to mozhno vyvesti podkhodyashchuyu matematicheskuyu formulu dlya opredeleniya spektra i vykhoda fotonov v funktsii ot maksimal'noj beta-ehnergii, tolshchiny misheni i konfiguratsii istochnika. Poluchaetsya otlichnoe sovpadenie raschetnykh rezul'tatov s ehksperimental'no poluchennymi vykhodami, chto podtverzhadaet tsennost' ehtogo sposoba analiza. Takim obrazom otkryvaetsya vozmozhnost' dlya optimizatsii konstruktsii izotopnykh istochnikov rentgenovskikh luchej v otnoshenii tekh ili inykh primenenij. Byli skonstruirovany prototipnye istochniki kriptona-85 i prometiya-147 i obsuzhdayutsya poluchennye s nimi rezul'taty izmerenij tolshchiny i analiza sostava. Byl takzhe skonstruirovan istochnik prometiya-147 vysokogo urovnya dlya promyshlennoj radiografii i obsuzhdayutsya rezul'taty ispol'zovaniya ehtogo istochnika, a takzhe tselesoobraznost' primeneniya usilitelej izobrazheniya, chto dolzhno eshche bol'she rasshirit' oblast' primeneniya ehtogo metoda. Nakonets, daetsya obshchij obzor vozmozhnostej, preimushchestv i ogranichenij izotopnykh istochnikov rentgenovskikh luchej. (author)

  20. Chemical State of Radiobromine Formed by the Rb{sup 85}(n, {alpha}) Br{sup 82} Reaction; Etat Chimique Du Ra Diobrome Forme Par La Reaction {sup 85}Rb (n, {alpha}) {sup 82}Br; 0425 0418 041c 0418 0427 0415 0421 041a 041e 0415 0421 041e 0421 0422 041e 042f 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 041e 0413 041e 0411 0420 041e 041c 0410 , 041e 0411 0420 0410 0417 041e 0412 0410 041d 041d 041e 0413 041e 041f 0420 0418 0420 0415 0410 041a 0426 0418 0418 Rb{sup 85}(n, {alpha}) Br{sup 82}; Estado Quimico Del Radiobromo Formado Por La Reaccion {sup 85}Rb (n, {alpha}) {sup 82}Br

    Energy Technology Data Exchange (ETDEWEB)

    Vlatkovic, M.; Kauiic, S. [' ' Ruder Boskovic' ' Institute, Zagreb, Yugoslavia (Croatia)

    1965-04-15

    avtory podcherkivajut znachenie himicheskogo sostava veshhestva misheni i neijeotopnosti sredy, skazyvajushheesja na raspredelenii vysokojenergeticheskih atomov broma-82 i ih nesposobnosti otzhigat'sja v issleduemyh soedinenijah rubidija. (author)

  1. The Technology and Applications of Large Fission Product Beta Sources; Technologie et applications des grandes sources beta de fission; Tekhnologiya i primenenie krupnykh istochnikov beta-izluchenij, ispuskaemykh produktami deleniya; Tecnologia y utilizacion de los productos de fision como fuentes de irradiacion beta de elevada intensidad

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, Joseph [Radiation Applications Incorporated (United States)

    1960-07-15

    poverkhnostnykh sloev plastmassy i tekstilya. 2. Massivnye, prochnye, inertnye, bezopasnye i nedorogie istochniki beta-izluchenij mogut stroit'sya putem nadlezhashchego rasshireniya sushchestvuyushchikh tekhnicheskikh ustanovok. Osobenno mnogoobeshchayushchimi predstavlyayutsya zaklyuchayushchie v sebe istochniki steklyannye ampuly. 3. Podschety pogloshcheniya beta-izluchenij pokazyvayut, chto predstavlyaetsya vozmozhnym skonstruirovat netochechnye istochniki s dostatochno vysokim kpd ispol'zovani ya moshchnosti, dokhodyashchim do 20%. Byli vyvedeny uravneniya i sostavleny krivye dayushchie dozirovku i kpd ispol'zovani ya beta-izluchenij v zavisimosti ot konfiguratsii izluchatelya, sostava veshchestv i materialov, vkhodyashchikh v konstruktsiyu istochnika i misheni. Dlya proverki pravil'nosti ehtikh podschetov v nastoyashchee vremya provoditsya ehksperimental'na ya programma. 4. Izuchenie proizvodstvennoj sebestoimosti ukazyvat, chto beta-izlucheniya, ispuskaemye produktami deleniya, mogut konkurirovat' s drugimi istochnikami izluchenij. (author)

  2. Radiation-pulse transmission via a long cable without a preamplifier and/or a pulse transformer; Transmission d'impulsions de rayonnement par cable long sans l'adjonction d'un preamplificateur ou d'un transformateur d'impulsions; Peredacha impul'snykh izluchenij no kabelyu na dal'nie rasstoyaniya bez predvaritel'nogo usileniya i/ili bez preobrazovaniya impul'sov; Transmision de impulsos por cables de gran longitud sin preamplificador y/o transformador de impulsos

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, H; Tohyama, T [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)

    1962-04-15

    kompleksnoe soprotivlenie usilitelya No. 2 budet sootvetstvovat' kharakteristike kabelya pri pomoshchi vklyuchennogo kompleksnogo i menyayushchegosya soprotivleniya. Takim obrazom, ustrojstvo vida No. 2 bylo v shirokoj mere prisposobleno k nashemu yadernomu pribornomu oborudovaniyu, kak naprimer k nejtronnomu izmeritelyu vlazhnosti pochvy (schetchik BF{sub 3}) analizatoru sostava pochvy (stsintillyatsionnyj spektrometr), tolshchinomeru snega (schetchik Gejgera-Myullera) i distantsionnym kontrol'nym dozimetricheskim priboram. Otsutstvie predvaritel'nykh usilitelej i preobrazovatelej impul'sov delaet vozmozhnym primenenie ehtikh detektorov na mestnosti v osobykh usloviyakh, kak naprimer, pri vysokikh ili nizkikh temperaturakh, bystrom potoke nejtronov (gamma-izluchenij) i t.d. Nalichie tol'ko odnogo koaksial'nogo kabelya uproshchaet rabotu detektorov na dal'nem rasstoyanii. Peredacha impul'sov po kabelyu na dal'nie rasstoyaniya svyshe 500 metrov ne povliyala na stsintillyatsionnuyu spektroskopiyu gamma-izluchenij. (author)

  3. Radiation Polymerization in the Solid Phase; Polymerisation radiochimique en phase solide; Radiatsionnaya polimerizatsiya v tverdoj faze; Radiopolimerizacion en fase solida

    Energy Technology Data Exchange (ETDEWEB)

    Barkalov, I. M.; Gol' danskij, V. I.; Enikolopov, N. S.; Terekhova, S. F.; Trofimova, G. M.

    1963-11-15

    energfa de activacion, a diferencia de la postpolimerizacion lenta, que exige la misma energia de activacion que el proceso en fase liquida. (author) [Russian] Radiatsionnoj polimerizatsii tverdykh i zamorozhennykh monomerov za poslednee vremya udelyaetsya bol'shoe vnimanie. EHtot vopros predstavlyaet bol'shoj interes kak s prakticheskoj tochki zreniya, tak i s tochki zreniya novykh teorij khimicheskoj kinetikich radiatsionnoj khimii. Kak izvestno, strogaya prostranstvennaya uporyadochennost' monomernykh edinits v polimere obuslavlivaet rezkoe uluchshenie fiziko-mekhanicheskikh svojstv bez izmeneniya khimicheskogo sostava. Dlya sinteza stereoregulyarnykh polimerov ispol'zuetsya printsip matritsy, t.e. monomernaya edinitsa strogo orientiruetsya v prostranstve putem obrazovaniya kompleksa s katalizatorom ili kakim-libo drugim veshchestvom. Naprimer, pri radiatsionnoj polimerizatsii ryada monomerov, orientirovannykh v klatratnykh kompleksakh mocheviny i tiomocheviny, polucheny kristallicheskie stereopegulyarnye polimery. Odnako naibolee prostym variantom yavlyaetsya orientatsiya monomera v sobstvennoj kristallicheskoj reshetke. Khotya mnogie teoreticheskie voprosy v ehtoj oblasti ostayutsya neyasnymi, prakticheskoe ispol'zovanie ehtogo sposoba ves'ma zamanchivo. Tak, pri radiatsionnoj polimerizatsii kristallicheskogo trioksana uzhe poluchen vysokokristallicheskij polioksimetilen. Trebuetsya, odnako, dal'nejshaya teoreticheskaya razrabotka ehtogo metoda. Neobkhodimo dlya kazhdogo otdel'nogo monomera vyyasnit' vklad razlichnykh vidov reaktsij, proiskhodyashchikh pri obluchenii i posleduptsem plavlenii tverdykh monomerov (spetsificheskaya radiatsionnaya reaktsiya, postpolimerizatsiya i polimerizatsiya v tochkakh fazovykh perekhodov) v obshchuyu kartinu protsessa. Vypolnennoe v poslednee vremya v Institute khimicheskoj fiziki podrobnoe issledovanie kinetiki radiatsionnoj tverdofaznoj polimerizatsii ryada monomerov s primeneniem kalorimetricheskogo metoda i s nablyudeniem signala

  4. Rapid Estimation of Fast-Neutron Doses following Radiation Exposure in Criticality Accidents: The S{sup 32}(n, p)P{sup 32} Reaction in Body Hair; Prompte Evaluation des Doses de Neutrons Rapides apres une Exposition au Rayonnement a la Suite d'Accidents de Criticite: Reaction {sup 32}S(n, p){sup 32}P dans le Systeme Pileux; 0411 042b 0421 0414 ; Evaluacion Acelerada de Dosis de Neutrones Rapidos Despues de una Irradiacion Consecutiva a un Accidente de Criticidad: La Reaccion {sup 32}S(n, p){sup 32}P en el Pelo

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, D. F. [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1965-06-15

    han deducido para cada caso, concordaban satisfactoriamente con las determinaciones independientes de las fisiones totales efectuadas por procedimientos analiticos clasicos. Para obtener rapidamente la dosis aproximada de neutrones rapidos, basta multiplicar por 0,49 la actividad del {sup 32}P, expresada en des/min. g de pelo a T = 0 y medida con cualquier sistema de recuento de rendimiento conocido, para obtener la dosis neutronica en rad correspondiente al 'nivel azufre'. (author) [Russian] Sochetanie unikal'nogo himicheskogo sostava, opredelennogo anatomicheskogo stroenija i dostupnosti, delaet chelovecheskij volos poleznym materialom dlja bystroj ocenki doz bystryh nejtronov, poluchaemyh personalom, svjazannym s rabotoj v avarijnyh uslovijah v kriticheskom sostojanii. V chelovecheskom volose otmechaetsja odno i to zhe soderzhanie sery, nezavisimo ot pola, cveta ili raspredelenija. Velichina 0,048 {+-} 0,005g sery na 1 g volosa ukazyvaet, chto 5 % mogut byt' ispol'zovany v kachestve standartnoj cifry dlja harakteristiki soderzhanija sery pri predvaritel'nyh ocenkah dozy bez vnesenija popravok na analiz soderzhanija sery v volosah otdel'nyh lic. Pri otsutstvii legko udaljaemogo vneshnego zagrjaznenija v volosah soderzhitsja menee 0,025 procentov fosfora. Poskol'ku poperechnye sechenija aktivacii fosfora i sery odinakovy, fakticheskoe otsutstvie fosfora daet vozmozhnost' ispol'zovat' volos v kachestve porogovogo detektora dlja biologicheskoj sery pri izmerenii potoka nejtronov s jenergiej svyshe 2,5 Mjev s pomoshh'ju reakcii S{sup 32}(n, p)P{sup 32}. Razrabotany metody dlja bystrogo vydelenija radiohimicheski chistogo R{sup 32} s cel'ju obespechenija klinicheski poleznyh ocenok obluchenija bystrymi nejtronami postradavshih vo vremja avarij v kriticheskom sostojanii. Pri otsutstvii bol'shogo zagrjaznenija produktami delenija predvaritel'nye ocenki mozhno provesti v techenie dvuh chasov. Dlja osushhestvlenija bolee shirokoj procedury po udaleniju produktov delenija

  5. Food Irradiation Research and Pilot Facilities in Operation or Planned in India; Recherches sur l'irradiation des Denrees Alimentaires et Installations Pilotes en Service ou a l'Etude en Inde; Izuchenie oblucheniya pishchevykh produktov' i dejstvuyushchie'i zaplanirovannye opytnye ustanovki v Indii; Irradiacion de Alimentos en la India: Investigaciones y Plantas Piloto en Servicio o en Proyecto

    Energy Technology Data Exchange (ETDEWEB)

    Kumta, U. S.; Sreenivasan, A. [Atomic Energy Establishment Trombay, Bombay (India)

    1966-11-15

    (40% vlazhnosti) pri komnatnoj temperature (25 - 28 Degree-Sign S) bolee chem do 150 dnej. Jetot process byl issledovan s tochki zrenija dopustimoj dozy obluchenija, sinergichnogo jeffekta sarbinovoj kisloty, uluchshenija kachestva v rezul'tate drugih vidov fizicheskoj i himicheskoj obrabotki i vida upakovochnogo materiala. Pojavlenie pleseni i nezhelatel'nyh zapahov okislenija u syra mozhet byt' zaderzhano primerno na 20 dnej pri komnatnoj temperature v rezul'tate obluchenija slabymi dozami (0,1 i 0,2 Mrad) i primenenija obertki, pokrytoj sarbinovoj kislotoj. Radiacionnoe povrezhdenie belkov ryby bylo izucheno s tochki zrenija stepeni ih rasshheplenija, skoplenija, jeffekta raskrytija i jelektroforeznoj podvizhnosti. Obnadezhivajushhie rezul'taty byli polucheny pri primenenii radiacii dlja dezinfesta- cii zerna i prodlenija sroka hranenija indijskogo hleba. Prodolzhaetsja izuchenie izmenenij sostava i pitatel'nosti obluchennoj pshenicy. Opisany sushhestvujushhie i zaplanirovannye ustanovki dlja obluchenija. Laboratorija obluchenija i obrabotki pishhevyh produktov, kotoraja budet gotova v skorom vremeni, budet imet' sbornyj obluchatel' s kobal'tom-60 (100 000 kjuri), portativnyj obluchatel' dlja zerna s kobal'tom-60 (28000 kjuri) i drugie ustanovki dlja obluchenija pishhevyh produktov, a takzhe analiticheskie i issledovatel'skie laboratorii. Predusmotrennaja proizvoditel'nost' sbornogo obluchatelja sostavljaet 100 funtov/chas pri doze. 0,5 Mrad, a portativnogo obluchatelja - 500 funtov/chas zerna pri doze 15 krad. (author)

  6. Method of obtaining concentrated preparations of Cl{sup 36} and Br{sup 82} by recoil nuclei under exposure to high-density neutron fields; Preparation de composes du chlore-36 et du brome-82 de haute activite specifique, par exposition de noyaux de recul a des champs neutroniques intenses; Poluchenie kontsentrirovannykh preparatov Cl{sup 36} i Br{sup 82} metodom yader otdachi pri obluchenii v nejtronnykh polyakh vysokoj plotnosti; Obtencion de compuestos de cloro-36 y de bromo-82 de alta actividad especifica por retroceso de nucleos en campos neutronicos intensos

    Energy Technology Data Exchange (ETDEWEB)

    Kurchatova, L N; Kurchatov, B V

    1962-01-15

    resultado de la superposicion de toda una serie de procesos : formacion de atomos de cloro radiactivo, separacion radiolitica del haluro, difusion de los productos obtenidos en la red cristalina del carbono, su sorcion en la superficie y su recombinacion en distintos centros. La extraordinaria variedad de condiciones en que se forman e interaccionan los productos de irradiacion con el esqueleto carbonico y su superficie depende de un gran numero de factores, a saber : la estructura ultramicroscopica, la naturaleza de los nuevos compuestos, que estan relacionados con el tipo de compuestos superficiales, la existencia en la superficie del carbono de centros con un espectro continuo de energia de sorcion, la probable formacion de diversos centros estacionarios de recombinacion por irradiacion del carbono, etc. Por ello, las tecnicas utilizadas ofrecen la posibilidad de realizar una gran variedad de experimentos a fin de establecer las condiciones optimas de enriquecimiento. (author) [Russian] Klassicheskij metod polucheniya kontsentrirovannykh radioaktivnykh preparatov Stsilarda-CHalmersa obychno rassmatrivaetsya kak malo ehffektivnyj pri ispol'zovanii bol'shikh integral'nykh potokov nejtronov iz-za znachitel'nogo razlozheniya obluchaemogo soedineniya pod dejstviem radiatsii. Avtorami najdeny soedineniya broma i khlora s uglerodom, pozvolyayushchie poluchat' sushchestvennoe obogashchenie radioaktivnymi izotopami khlora i broma metodom yader otdachi pri obluchenii v nejtronnykh potokakh poryadka 10{sup 13} nejtr./sek-cm{sup 2}. EHti soedineniya otvechayut formule C{sub n}X, gde X-Cl ili Br, N = 10 + 20 dlya soedineniya khlora i 25 + 70 -dlya soedinenij broma. Oni dostatochno ustojchivy termicheski i khimicheski. Soedinenie sostava C{sub 30}Br vyderzhivaet nagrevanie do 300{sup o}C v atmosfere argona bez otshchepleniya broma; ono razlagaetsya polnost'yu pri temperature 600{sup o}C. Ukazannoe soedinenie broma s uglerodom prakticheski ustojchivo k vozdejstviyu vodnykh rastvorov

  7. Irradiation of Tropical Fruits and Vegetables; Irradiation de Fruits et Legumes Tropicaux; Obluchenie tropicheskikh fruktov i ovoshchej; Irradiacion de Frutas y Verduras Tropicales

    Energy Technology Data Exchange (ETDEWEB)

    Dharkar, S. D.; Sreenivasan, A. [Atomic Energy Establishment Trombay, Bombay (India)

    1966-11-15

    issledovannymi fruktami byli plody guava, sapota (sapo-, dillas) ; i tomaty; dlja vseh ih mogla byt' dostignuta zaderzhka v sozrevanii primerno v 5 dnej pri ispol'zovanii dozy v 20 - 25 kilorad. Struchkovyj perec, banany i apel'siny ne pokazali kakoj-libo zaderzhki v sozrevanii posle obluchenija; chto kasaetsja apel'sinov, to imelo mesto neskol'ko uskorennoe sozrevanie. Poluvysushennye banany (40% vlagi) posle obluchenija dozoj v 0,5 megarad horosho sohranjajutsja po krajnej mere v techenie treh mesjacev, togda kak obezvozhennye banany (10% vlagi) ne tol'ko ochen' chuvstvitel'ny k infekcii pleseni, no i obladajut plohimi kachestvami s tochki zrenija cveta, vkusa, sohranenija pitatel'nyh veshhestv i vosstanovlenija sostava. Podhodjashhee sochetanie teplovoj obrabotki i obluchenija uspeshno primenjalos' dlja sterilizacii plodov mango, guava, sapota i jablok, prichem obychno konservirovannye produkty s luchshej strukturoj, vkusom i sohraneniem pitatel'nyh kachestv mogli byt' polucheny s pomoshh'ju obrabotki pri 70 Degree-Sign v techenie 10 minut i 400 kilorad. Analogichnym obrazom konservirovannyj goroh otlichnogo kachestva mozhno poluchit' putem kombinirovannogo ispol'zovanija oblucheniem v 800 kilorad pri temperature 100 Degree-Sign v techenie 5 minut. Radiosterilizovannyj apel'sinovyj cqk mozhno takzhe poluchit' putem sochetanija obluchenija dozoj v 400 kilorad s posledujushhej slaboj teplovoj obrabotkoj pri 50 Degree-Sign S v techenie 15 minut. Pri dozah v 10 kilorad dlja kartofelja i 6 kilorad dlja luka mozhet byt' zaderzhano prorastanie, chto vedet k uvelicheniju sroka hranenija do 32 i 24 nedel' sootvetstvenno po sravneniju s vos'minedel'nym periodom dlja neobluchennyh kontrol'nyh produktov. Osnovnye issledovanija, otnosjashhiesja k predohraneniju fruktov i ovoshhej ot porchi s pomoshh'ju radiacii, vkljuchajut v sebja issledovanija a) chuvstvitel'nosti mikroorganizmov, vyzyvajushhih porchu produktov (Micrococcus radiodurans, Streptococcus faecalis), k radiacii s predvaritel

  8. The Formation of Polymeric Products in Reactions of Polyvalent Recoil Atoms; Formation de Polymeres lors de Reactions Provoquees par des Atomes de Recul Polyvalents; Obrazovanie polimernykh produktov pri reaktsiyakh polivalentnykh atomov otdachi; Formacion de Polimeros en las Reacciones de Atomos de Retroceso Polivalentes

    Energy Technology Data Exchange (ETDEWEB)

    Dzantiev, B. G.; Stukan, R. A.; Shvedchikov, A. P.; Shishkov, A. V. [Institut Himicheskoj Fiziki AN SSSR, Moskva, SSSR (Russian Federation)

    1965-04-15

    mechenyh polimernyh produktov v processe himicheskoj stabilizacii atomov otdachi sery-35 i ugleroda-14, poluchajushhihsja po jadernym reakcijam Cl{sup 35} /n, p/S{sup 35} i N{sup 14}/n, p/C{sup 14} v gazovoj i zhidkoj fazah. Mozhno predpolozhit', chto v processe stabilizacii gorjachie atomy ugleroda obrazujut metilenovye biradikaly, kotorye po svoej sposobnosti vstupat' v reakciju vo mnogom napominajut povedenie atomarnoj sery. Issledovanija provodilis' kak dlja parafinovyh (CH{sub 4}, C{sub 2}H{sub 6}), tak i dlja ciklicheskih (ciklogeksan, ciklogeksen, benzol) uglevodorod. Oblucheniju podvergalis' binarnye sistemy uglevodorod-datchik gorjachih atomov S{sup 35} i C{sup 14}. V kachestve poslednego ispol'zovalis' soedinenija CCI{sub 4}, HCl i ammiak. Obluchenie provodilos' na reaktore tipa IRT-1000 pri potoke teplovyh nejtronov 10{sup 11} - 10{sup 12} neJtron/cm{sup 2}sek. Pokazano, chto dlja razlichnyh soedinenij v zhidkoj faze do 60-90% sery-35 stabilizuetsja v forme polimera, vyhod kotorogo jekstremal'no zavisit ot sostava, prohodja cherez maksimum pri sootnoshenii komponentov, blizkom k jekvimolekuljarnomu. V gazovoj faze vyhod polimera sostavljaet 30 - 40% ot obshhej aktivnosti. Metodom radiohromatografii na bumage ustanovleno, chto mechenye polimernye produkty imejut slozhnyj sostav i predstavljajut soboj smes' dvuh kachestvenno otlichnyh tipov soedinenij, vyhod kotoryh po-raznomu menjaetsja v zavisimosti ot sootnoshenija komponentov. Uvelichenie vremeni obluchenija privodit k rostu vyhoda mechenogo polimera. V sluchae zhidkofaznoj sistemy C{sub 6}H{sub 12}-CCl{sub 4} molekuljarnyj ves S{sup 35}-soderzhashhego polimera, opredeljalsja metodom diffuzii iz kapilljara i okazalsja ravnym 5000 dlja polimera odnogo tipa i 500 - 1000 dlja drugogo. Obrazovanie vysokokipjashhego mechenogo produkta nabljudalos' takzhe pri obluchenii chistogo CCI{sub 4}. Analogichnye opyty provodilis' v sisteme jetilen -ammiak v gazovoj faze pri vysokom davlenii. Pokazano, chto v jetom sluchae

  9. Thermodynamic Behaviour of Hypostoichiometric UO{sub 2}; Comportement Thermodynamique de UO{sub 2} HypostoeChiometrique; Termodinamicheskoe povedenie gipostekhiometricheskoj UO{sub 2}; Comportamiento Termodinamico del UO{sub 2} Subestequiometrico

    Energy Technology Data Exchange (ETDEWEB)

    Aitken, E. A.; Brassfield, H. C.; Fryxell, R. E. [General Electric Company, Nuclear Materials and Propulsion Operation, Cincinnati, OH (United States)

    1966-02-15

    nagrevajutsja do temperatury svyshe 1 700 Degree-Sign S, otnoshenie o/i tab- letki menjaetsja i dostigaet ravnovesija, opredeljaemogo aktivnost'ju kisloroda atmosfery, okruzhajushhej obolochku. UO{sub 2} ne reagiruet s tantalom, noiz-zavysokoj rastvorimosti kislo- roda v tantale poslednij igraet rol' membrany. Ispol'zuja dannye kongrujentnogo vypari- vanija i opytov s tantalovoj obolochkoj, provedennyh v razlichnyh smesjah argon - vodorod, byla opredelena aktivnost' kisloroda v okisi urana kak funkcija stehiometrii. Chastichnaja moljarnaja svobodnaja jenergija kisloroda G(O{sub 2}) vozrastaet pochti linejno pri nedostatke kislo- roda s vozrastaniem otnoshenija kislorod-uran. Kogda sostav priblizhaetsja k stehiometri- cheskomu, velichina G(O{sub 2}) rastet ochen' rezko. Ispol'zuja jeti rezul'taty vmeste s ocenochny- mi velichinami G(O{sub 2}) pri izbytke kisloroda, vzjatymi iz literatury, pokazano, chto dannye pri opredelennoj temperature soglasujutsja so staticheskoj model'ju. Jeta model' dopuskaet, chto otklonenie ot stehiometricheskogo sostava proishodit i z-zaizbytka atomov kisloroda, zanimajushhih mezhdouzlija, ili i z - z a nedostatka kisloroda na kislorodnoj podreshetke. Razu- porjadochenie proishodit s vnutrennimi atomami kisloroda i s kislorodnymi vakansijami. Jenergiju kisloroda po Frenkelju sostavljaet 60 kkal/gramm-atom, chto horosho soglasuetsja s ocenkami, poluchennymi iz dannyh kislorodnoj samodiffuzii. Rassmatrivaetsja svjaz' mezhdu G(O{sub 2}) I chastichnym davleniem gazoobraznyh okisej, UO i UO{sub 2} i v obshhem plane kommentirujut- sja rezul'taty opytov s drugimi soedinenijami, takimi kak ThO{sub 2} provedennyh s ispol'zova- niem teh zhe jeksperimental'nyh metodov. (author)