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Sample records for americium 246

  1. Actinide Oxidation State and O/M Ratio in Hypostoichiometric Uranium-Plutonium-Americium U0.750Pu0.246Am0.004O2-x Mixed Oxides.

    Science.gov (United States)

    Vauchy, Romain; Belin, Renaud C; Robisson, Anne-Charlotte; Lebreton, Florent; Aufore, Laurence; Scheinost, Andreas C; Martin, Philippe M

    2016-03-07

    Innovative americium-bearing uranium-plutonium mixed oxides U1-yPuyO2-x are envisioned as nuclear fuel for sodium-cooled fast neutron reactors (SFRs). The oxygen-to-metal (O/M) ratio, directly related to the oxidation state of cations, affects many of the fuel properties. Thus, a thorough knowledge of its variation with the sintering conditions is essential. The aim of this work is to follow the oxidation state of uranium, plutonium, and americium, and so the O/M ratio, in U0.750Pu0.246Am0.004O2-x samples sintered for 4 h at 2023 K in various Ar + 5% H2 + z vpm H2O (z = ∼ 15, ∼ 90, and ∼ 200) gas mixtures. The O/M ratios were determined by gravimetry, XAS, and XRD and evidenced a partial oxidation of the samples at room temperature. Finally, by comparing XANES and EXAFS results to that of a previous study, we demonstrate that the presence of uranium does not influence the interactions between americium and plutonium and that the differences in the O/M ratio between the investigated conditions is controlled by the reduction of plutonium. We also discuss the role of the homogeneity of cation distribution, as determined by EPMA, on the mechanisms involved in the reduction process.

  2. 1976 Hanford americium accident

    International Nuclear Information System (INIS)

    Heid, K.R.; Breitenstein, B.D.; Palmer, H.E.; McMurray, B.J.; Wald, N.

    1979-01-01

    This report presents the 2.5-year medical course of a 64-year-old Hanford nuclear chemical operator who was involved in an accident in an americium recovery facility in August 1976. He was heavily externally contaminated with americium, sustained a substantial internal deposition of this isotope, and was burned with concentrated nitric acid and injured by flying debris about the face and neck. The medical care given the patient, including the decontamination efforts and clinical laboratory studies, are discussed. In-vivo measurements were used to estimate the dose rates and the accumulated doses to body organs. Urinary and fecal excreta were collected and analyzed for americium content. Interpretation of these data was complicated by the fact that the intake resulted both from inhalation and from solubilization of the americium embedded in facial tissues. A total of 1100 μCi was excreted in urine and feces during the first 2 years following the accident. The long-term use of diethylenetriaminepentate (DTPA), used principally as the zinc salt, is discussed including the method, route of administration, and effectiveness. To date, the patient has apparently experienced no complications attributable to this extensive course of therapy, even though he has been given approximately 560 grams of DTPA. 4 figures, 1 table

  3. Chemistry of americium

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1976-01-01

    Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

  4. Americium in water and sediments

    International Nuclear Information System (INIS)

    Coughtrey, P.J.; Jackson, D.; Jones, C.H.; Thorne, M.C.

    1984-01-01

    Data for americium 241 in aquatic environments are presented derived from areas contaminated solely by global fallout, and also from areas contaminated by radioactive waste discharges. For several water bodies, in particular the Mediterranean, comprehensive data are given characterising the inputs, distribution, geochemical behaviour and biological availability of americium. Many data are also reported for concentrations of americium in North European coastal waters (e.g. English Channel, North Sea, Irish Sea, Baltic Sea, Barents Sea and the Eastern Atlantic). Much of the discussion in this section is in terms of the behaviour of americium relative to plutonium. (Auth.)

  5. Recycling of americium

    International Nuclear Information System (INIS)

    Hagstroem, Ingela

    1999-12-01

    Separation of actinides from spent nuclear fuel is a part of the process of recycling fissile material. Extracting agents for partitioning the high level liquid waste (HLLW) from conventional PUREX reprocessing is studied. The CTH-process is based on three consecutive extraction cycles. In the first cycle protactinium, uranium, neptunium and plutonium are removed by extraction with di-2-ethylhexyl-phosphoric acid (HDEHP) from a 6 M nitric acid HLLW solution. Distribution ratios for actinides, fission products and corrosion products between HLLW and 1 M HDEHP in an aliphatic diluent have been investigated. To avoid addition of chemicals the acidity is reduced by a tributylphosphate (TBP) extraction cycle. The distribution ratios of elements present in HLLW have been measured between 50 % TBP in an aliphatic diluent and synthetic HLLW in range 0.1-6 M nitric acid. In the third extraction cycle americium and curium are extracted. To separate trivalent actinides from lanthanides a method based on selective stripping of the actinides from 1 M HDEHP is proposed. The aqueous phase containing ammonia, diethylenetriaminepentaacetic acid (DTPA) and lactic acid is recycled in a closed loop after reextraction of the actinides into a second organic phase also containing 1 M HDEHP. Distribution ratios for americium and neodymium have been measured at varying DTPA and lactic acid concentrations and at varying pH. Nitrogen-donor reagents have been shown to have a potential to separate trivalent actinides from lanthanides. 2,2':6,2''-terpyridine as extractant follows the CHON-principle and can in synergy with 2-bromodecanoic acid separate americium from europium. Distribution ratios for americium and europium, in the range of 0.02-0.12 M nitric acid, between nitric acid and 0.02 M terpyridine with 1 M 2-bromodecanoic acid in tert-butylbenzene (TBB) was investigated. Comparison with other nitrogen-donor reagents show that increasing lipophilicity of the molecule, by substitution of

  6. Americium-241 - ED 4308

    International Nuclear Information System (INIS)

    Ammerich, M.; Frot, P.; Gambini, D.; Gauron, C.; Moureaux, P.; Herbelet, G.; Lahaye, T.; Le Guen, B.; Pihet, P.; Rannou, A.; Vidal, E.

    2012-12-01

    This sheet presents the characteristics of Americium-241, its origin, and its radio-physical and biological properties. It briefly describes its use in nuclear medicine. It indicates its dosimetric parameters for external exposure, cutaneous contamination, and internal exposure due to acute contamination or to chronic contamination. It indicates and comments the various exposure control techniques: ambient dose rate measurement, surface contamination measurement, atmosphere contamination. It addresses the means of protection: premise design, protection against external exposure and against internal exposure. It describes how areas are delimited and controlled within the premises: regulatory areas, controls to be performed. It addresses the personnel classification, training and medical survey. It addresses the issue of wastes and effluents. It briefly recalls the administrative procedures related to the authorization and declaration of possession and use of sealed and unsealed sources. It indicates regulatory aspects related to the road transport of Americium-241, describes what is to be done in case of incident or accident (for the different types of contamination or exposure)

  7. Plutonium and americium separation from salts

    International Nuclear Information System (INIS)

    Hagan, P.G.; Miner, F.J.

    1976-01-01

    Salts or materials containing plutonium and americium are dissolved in hydrochloric acid, heated, and contacted with an alkali metal carbonate solution to precipitate plutonium and americium carbonates which are thereafter readily separable from the solution

  8. Transmutation of Americium in Fast Neutron Facilities

    OpenAIRE

    Zhang, Youpeng

    2011-01-01

    In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on c...

  9. Metabolism of americium-241 in dairy animals

    International Nuclear Information System (INIS)

    Sutton, W.W.; Patzer, R.G.; Mullen, A.A.; Hahn, P.B.; Potter, G.D.

    1978-10-01

    Groups of lactating cows and goats were used to examine americium-241 metabolism in dairy animals. Following either single oral or intravenous nuclide doses, samples of milk, urine, blood, and feces were taken over a 168-hr collection period and the americium concentrations were determined by gamma counting. Gastrointestinal uptake of americium by both cows and goats was estimated to be 0.014% of the respective oral doses. The cumulative percentage of oral dose transported to milk and urine was 4.4 x 10 -4 and 1.1 x 10 -3 respectively for cows and 4.4 x 10 -3 and 1.2 x 10 -3 respectively for goats. The relatively high americium concentrations noted in caprine milk following the oral doses are discussed. Plasma concentrations of americium decreased rapidly following all intravenous injections. The average percentage of injected americium transferred to milk, urine, and feces was 3, 6, and 2% respectively for cows and 2, 4, and 2% respectively for goats. In both intravenously dosed groups, approximately 30% of all americium released from the body was found in the urine during the first 24 hrs after injection. All animals were sacrificed 8 to 9 days after dosing. Bovine bone retained the greatest fraction of the administered dose followed by the liver. However, liver retained the greatest amount of americium in the goats following both oral and intravenous doses. Comparisons are presented between americium-241 and plutonium-238 transport in dairy cows

  10. Production of americium isotopes in France

    International Nuclear Information System (INIS)

    Koehly, G.; Bourges, J.; Madic, C.; Nguyen, T.H.; Lecomte, M.

    1984-12-01

    The program of productions of americium 241 and 243 isotopes is based respectively on the retreatment of aged plutonium alloys or plutonium dioxide and on the treatment of plutonium targets irradiated either in CELESTIN reactors for Pu-Al alloys or OSIRIS reactor for plutonium 242 dioxide. All the operations, including americium final purifications, are carried out in hot cells equipped with remote manipulators. The chemical processes are based on the use of extraction chromatography with hydrophobic SiO 2 impregnated with extracting agents. Plutonium targets and aged plutonium alloys are dissolved in nitric acid using conventional techniques while plutonium dioxide dissolutions are performed routine at 300 grams scale with electrogenerated silver II in 4M HNO 3 at room temperature. The separation between plutonium and americium is performed by extraction of Pu(IV) either on TBP/SiO 2 or TOAHNO 3 /SiO 2 column. Americium recovery from waste streams rid of plutonium is realized by chromatographic extraction of Am(III) using mainly TBP and episodically DHDECMP as extractant. The final purification of both americium isotopes uses the selective extraction of Am(VI) on HDDiBMP/SiO 2 column at 60 grams scale. Using the overall process a total amount of 1000 grams of americium 241 and 100 grams of americium 243 has been produced nowadays and the AmO 2 final product indicates a purity better than 98.5%

  11. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-06-22

    Acqueous Chloride mission is to recover plutonium and americium from pyrochemical residues (undesirable form for utilization and storage) and generate plutonium oxide and americium oxide. Plutonium oxide is recycled into Pu metal production flowsheet. It is suitable for storage. Americium oxide is a valuable product, sold through the DOE-OS isotope sales program.

  12. Formation of americium and europium humate complexes

    International Nuclear Information System (INIS)

    Minai, Y.; Tominaga, T.; Meguro, Y.

    1991-01-01

    Binding constants of americium and europium with a humic acid were determined to study if complex formation of trivalent actinide-humates affects dissolved species of the actinides in hydrosphere. The purified humic acid was characterized by means of UV-vis, IR, and pH titration, indicating high carboxylate capacity and low aromaticity. Binding constants of americium and europium humates were determined at pH 4.6 and 6.0 by solvent extraction using 241 Am or 152 Eu as a tracer. The binding constants for americium-humate obtained preliminarily suggest that complexes with humic acid are not negligible in speciation of trivalent actinides in hydrosphere. The obtained binding constants were nearly identical with those determined previously by the same procedures, but with humic acids of different origin and compositions. (author)

  13. Biosorption of americium by alginate beads

    International Nuclear Information System (INIS)

    Borba, Tania Regina de; Marumo, Julio Takehiro; Goes, Marcos Maciel de; Ferreira, Rafael Vicente de Padua; Sakata, Solange Kazumi

    2009-01-01

    The use of biotechnology to remove heavy metals from wastes plays great potential in treatment of radioactive wastes and therefore the aim of this study was to evaluate the biosorption of americium by alginate beads. Biosorption has been defined as the property of certain biomolecules to bind and remove selected ions or other molecules from aqueous solutions. The calcium alginate beads as biosorbent were prepared and analyzed for americium uptaking. The experiments were performed in different solution activity concentrations, pH and exposure time. The results suggest that biosorption process is more efficient at pH 4 and for 75, 150, 300 Bq/mL and 120 minutes were necessary to remove almost 100% of the americium-241 from the solution. (author)

  14. New Fecal Method for Plutonium and Americium

    International Nuclear Information System (INIS)

    Maxwell, S.L. III

    2000-01-01

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin (Eichrom Industries), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin, which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Industries). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as thorium-228

  15. New fecal method for plutonium and americium

    International Nuclear Information System (INIS)

    Maxwell, S.L.; Fauth, D.J.; Nichols, S.T.

    2001-01-01

    A new fecal analysis method that dissolves plutonium oxide was developed at the Westinghouse Savannah River Site. Diphonix Resin R (Eichrom Technologies), is used to pre-concentrate the actinides from digested fecal samples. A rapid microwave digestion technique is used to remove the actinides from the Diphonix Resin R , which effectively extracts plutonium and americium from acidic solutions containing hydrofluoric acid. After resin digestion, the plutonium and americium are recovered in a small volume of nitric acid that is loaded onto small extraction chromatography columns, TEVA Resin and TRU Resin (Eichrom Technologies). The method enables complete dissolution of plutonium oxide and provides high recovery of plutonium and americium with good removal of thorium isotopes such as 228 Th. (author)

  16. Transmutation of Americium in Fast Neutron Facilities

    International Nuclear Information System (INIS)

    Zhang, Youpeng

    2011-01-01

    In this thesis, the feasibility to use a medium sized sodium cooled fast reactor fully loaded with MOX fuel for efficient transmutation of americium is investigated by simulating the safety performance of a BN600-type fast reactor loaded with different fractions of americium in the fuel, using the safety parameters obtained with the SERPENT Monte Carlo code. The focus is on americium mainly due to its long-term contribution to the radiotoxicity of spent nuclear fuel and its deterioration on core's safety parameters. Applying the SAS4A/SASSYS transient analysis code, it is demonstrated that the power rating needs to be reduced by 6% for each percent additional americium introduction into the reference MOX fuel, maintaining 100 K margin to fuel melting, which is the most limiting failure mechanism. Safety analysis of a new Accelerator Driven System design with a smaller pin pitch-to-diameter ratio comparing to the reference EFIT-400 design, aiming at improving neutron source efficiency, was also performed by simulating performance for unprotected loss of flow, unprotected transient overpower, and protected loss-of-heat-sink transients, using neutronic parameters obtained from MCNP calculations. Thanks to the introduction of the austenitic 15/15Ti stainless steel with enhanced creep rupture resistance and acceptable irradiation swelling rate, the suggested ADS design loaded with nitride fuel and cooled by lead-bismuth eutectic could survive the full set of transients, preserving a margin of 130 K to cladding rupture during the most limiting transient. The thesis concludes that efficient transmutation of americium in a medium sized sodium cooled fast reactor loaded with MOX fuel is possible but leads to a severe power penalty. Instead, preserving transmutation rates of minor actinides up to 42 kg/TWh th , the suggested ADS design with enhanced proton source efficiency appears like a better option for americium transmutation

  17. Preparation of americium source for smoke detector

    International Nuclear Information System (INIS)

    Ramaswami, A.; Singh, R.J.; Manohar, S.B.

    1994-01-01

    This report describes the method developed for the preparation of 241 Am source for smoke detector. Americium was electrodeposited from iso-propyl alcohol medium on silver backing. Thin layer of gold (few hundred micro gram thick) was plated on the americium source to make it safe for handling. The thickness of plated gold was such that the alpha radiations from the 241 Am source could escape out of the gold layer and cause ionisation in the surrounding air. The performance of the prepared sources were checked in a smoke detector and was found to be satisfactory and comparable to the imported sources. (author). 1 refs., 2 figs., 1 tab

  18. Redox chemistry of americium in nitric acid media

    International Nuclear Information System (INIS)

    Picart, S.; Jobelin, I.; Armengol, G.; Adnet, JM.

    2004-01-01

    The redox properties of the actinides are very important parameters for speciation studies and spent nuclear fuel reprocessing based on liquid-liquid extraction of actinides at different oxidation states (as in the Purex or Sesame process). They are also very useful for developing analytical tools including coulometry and redox titration. This study addressed the americium(IV)/americium(III) and americium(VI)/americium(V) redox couples, focusing on exhaustive acquisition of the thermodynamic and kinetic parameters of americium oxidation at an electrode in a complexing nitric acid medium. (authors)

  19. 1976 Hanford americium exposure incident: psychological aspects

    International Nuclear Information System (INIS)

    Brown, W.R.

    1982-01-01

    Accidents involving exposure to radiation or radioactive materials may involve an unusual degree of emotional trauma. Methods that may be employed in dealing with such trauma are discussed in relation to a specific accident in which a radiation worker was injured and seriously contaminated with americium-241

  20. Americium migration in basalt and implications to repository risk analysis

    International Nuclear Information System (INIS)

    Rickert, P.G.

    1980-01-01

    Experiments were performed with americium as a minor component in groundwater. Batch adsorption, migration through column, and filtration experiments were performed. It was determined in batch experiments that americium is strongly adsorbed from solution. It was determined with filtration experiments that large percentages of the americium concentrations suspended by the contact solutions in batch experiments and suspended by the infiltrating groundwater in migration experiments were associated with particulate. Filtration was determined to be the primary mode of removal of americium from infiltrating groundwater in a column of granulated basalt (20 to 50 mesh) and an intact core of permeable basalt. Fractionally, 0.46 and 0.22 of the americium component in the infiltrating groundwater was transported through the column and core respectively. In view of these filtration and migration experiment results, the concept of K/sub d/ in the chromatographic sense is meaningless for predicting americium migration in bedrock by groundwater transport at near neutral pH

  1. Procedure for the analysis of americium in complex matrices

    International Nuclear Information System (INIS)

    Knab, D.

    1978-02-01

    A radioanalytical procedure for the analysis of americium in complex matrices has been developed. Clean separations of americium can be obtained from up to 100 g of sample ash, regardless of the starting material. The ability to analyze large masses of material provides the increased sensitivity necessary to detect americium in many environmental samples. The procedure adequately decontaminates from rare earth elements and natural radioactive nuclides that interfere with the alpha spectrometric measurements

  2. The relative physiological and toxicological properties of americium and plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Carter, R.E.; Busch, E.; Johnson, O. [and others

    1951-11-15

    The relative physiological and toxicological properties of americium and plutonium have been studied following their intravenous administration to rats. The urinary and fecal excretion of americium was similar to that of plutonium administered as Pu(N0{sub 3}){sub 4}. The deposition of americium the tissues and organs of the rat was also similar to that observed for plutonium. The liver and the skeleton were the major sites of deposition. Zirconium citrate administered 15 minutes after injection of americium increased the urinary excretion of americium and decreased the amount found in the liver and the skeleton at 4 and 16 days. LD{sub 30}{sup 50} studies showed americium was slightly less toxic when given in the acute toxic range than was plutonium. The difference was, however, too slight to be important in establishing a larger tolerance does for americium. Survival studies, hematological observations, bone marrow observations, comparison of tumor incidence and the incidence of skeletal abnormalities indicated that americium and plutonium have essentially the same chronic toxicity when given on an equal {mu}c. basis. These studies support the conclusion that the tolerance values for americium should be essentially the same as those for Plutonium.

  3. Investigation of americium-241 metal alloys for target applications

    International Nuclear Information System (INIS)

    Conner, W.V.; Rockwell International Corp., Golden, CO

    1982-01-01

    Several 241 Am metal alloys have been investigated for possible use in the Lawrence Livermore National Laboratory Radiochemical Diagnostic Tracer Program. Several properties were desired for an alloy to be useful for tracer program applications. A suitable alloy would have a fairly high density, be ductile, homogeneous and easy to prepare. Alloys investigated have included uranium-americium, aluminium-americium, and cerium-americium. Uranium-americium alloys with the desired properties proved to be difficult to prepare, and work with this alloy was discontinued. Aluminium-americium alloys were much easier to prepare, but the alloy consisted of an aluminium-americium intermetallic compound (AmAl 4 ) in an aluminum matrix. This alloy could be cast and formed into shapes, but the low density of aluminum, and other problems, made the alloy unsuitable for the intended application. Americium metal was found to have a high solid solubility in cerium and alloys prepared from these two elements exhibited all of the properties desired for the tracer program application. Cerium-americium alloys containing up to 34 wt% americium have been prepared using both co-melting and co-reduction techniques. The latter technique involves co-reduction of cerium tetrafluoride and americium tetrafluoride with calcium metal in a sealed reduction vessel. Casting techniques have been developed for preparing up to eight 2.2 cm (0.87 in) diameter disks in a single casting, and cerium-americium metal alloy disks containing from 10 to 25 wt% 241 Am have been prepared using these techniques. (orig.)

  4. Surface complexation modeling of americium sorption onto volcanic tuff.

    Science.gov (United States)

    Ding, M; Kelkar, S; Meijer, A

    2014-10-01

    Results of a surface complexation model (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The model was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be modeled with two surface reactions involving an americium sulfate and an americium carbonate complex. It was assumed in applying the model to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface complexation constants, derived in this study, allow prediction of sorption of americium in a natural complex system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways. Published by Elsevier Ltd.

  5. Self-irradiation and oxidation effects on americium sesquioxide and Raman spectroscopy studies of americium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Horlait, Denis [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France); Caraballo, Richard [CEA, DEN, DTCD/SECM/LMPA, F-30207 Bagnols-sur-Cèze Cedex (France); Lebreton, Florent [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France); Jégou, Christophe [CEA, DEN, DTCD/SECM/LMPA, F-30207 Bagnols-sur-Cèze Cedex (France); Roussel, Pascal [Unité de Catalyse et Chimie du Solide, UMR 8012 CNRS, Ecole Nationale Supérieure de Chimie de Lille BP 90108, 59652 Villeneuve d’Ascq Cedex (France); Delahaye, Thibaud, E-mail: thibaud.delahaye@cea.fr [CEA, DEN, DTEC/SDTC/LEMA, F-30207 Bagnols-sur-Cèze Cedex (France)

    2014-09-15

    Americium oxides samples were characterized by X-ray diffraction (XRD) and Raman spectroscopy, with an emphasis on their structural behavior under oxidation and self-irradiation. Raman spectra of americium dioxide (AmO{sub 2}) and sesquioxide (Am{sub 2}O{sub 3}) were obtained for the first time. With the help of literature data on isostructural oxides, Raman signatures of Ia-3 C-type Am{sub 2}O{sub 3} and P-3m1 A-type Am{sub 2}O{sub 3} are identified. For AmO{sub 2,} a clear band is noted at 390 cm{sup −1}. Its nature is compared to that of the other actinide dioxides. Am{sub 2}O{sub 3} evolution under ambient conditions and against {sup 241}Am α self-irradiation was monitored by powder XRD. The sample, initially composed of A-type Am{sub 2}O{sub 3} as major phase as well as C2/m B-type and C-type structures as minor phases, progressively oxidizes to Fm-3m AmO{sub 2−δ} over a few months. On the basis of diffractogram refinements, evolutions of unit cell volumes caused by self-irradiation are also determined and discussed. - Graphical abstract: The evolution of americium oxide under ambient conditions was monitored using XRD (X-ray diffraction) and Raman spectroscopy. After a thermal treatment under reducing conditions, a polyphasic sample mainly composed of A- and C-type americium sesquioxides is evidenced by XRD and Raman spectroscopy. The sample then evolves through two processes: oxidation and self-irradiation. The first one provokes the progressive appearance of F-type americium dioxide while the initial phases disappear, whereas the main effect of the second is a structural swelling with time. - Highlights: • The first Raman spectroscopy measurements on americium oxides were performed. • Observed Am{sub 2}O{sub 3} Raman bands were identified thanks to data on analogue compounds. • AmO{sub 2} assumed T{sub 2g} band presents a shift compared to the actinide dioxide series. • Am{sub 2}O{sub 3} evolution under self-irradiation and oxidation was also

  6. Higher Americium Oxidation State Research Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Mincher, Bruce J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Law, Jack D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Goff, George S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shehee, Thomas C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hobbs, David T. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-12-18

    The partitioning of hexavalent Am from dissolved nuclear fuel requires the ability to efficiently oxidize Am(III) to Am(VI) and to maintain that oxidation state for a length of time sufficient to perform the separation. Several oxidants have been, or are being developed. Chemical oxidants include Ag-catalyzed ozone, Ag-catalyzed peroxydisulfate, Cu(III) periodate, and sodium bismuthate. Hexavalent americium has also now successfully been prepared by electrolysis, using functionalized electrodes. So-called auto-reduction rates of Am(VI) are sufficiently slow to allow for separations. However, for separations based on solvent extraction or ion exchange using organic resins, the high valence state must be maintained under the reducing conditions of the organic phase contact, and a holding oxidant is probably necessary. Until now, only Cu(III) periodate and sodium bismuthate oxidation have been successfully combined with solvent extraction separations. Bismuthate oxidation provided the higher DAm, since it acts as its own holding oxidant, and a successful hot test using centrifugal contactors was performed. For the other oxidants, Ag-catalyzed peroxydisulfate will not oxidize americium in nitric acid concentrations above 0.3 M, and it is not being further investigated. Peroxydisulfate in the absence of Ag catalysis is being used to prepare Am(V) in ion exchange work, discussed below. Preliminary work with Ag-catalyzed ozone has been unsuccessful for extractions of Am(VI) from 6.5 M HNO3, and only one attempt at extraction, also from 6.5 M HNO3, using the electrolytic oxidation has been attempted. However, this high acid concentration was based on the highest Am extraction efficiency using the bismuthate oxidant; which is only sparingly soluble, and thus the oxidation yield is based on bismuthate solubility. Lower acid concentrations may be sufficient with alternative oxidants and work with Ag-ozone, Cu(III) and electrolysis is on-going. Two non

  7. Feasibility of the fabrication of americium targets

    International Nuclear Information System (INIS)

    Haas, D.; Somers, J.

    1999-01-01

    The paper compares the processes used at ITU for the fabrication of americium targets for transmutation: powder mixing process, sol-gel method and the infiltration by an active solution of inactive pellets. The advantages of the latter process, related mainly to the lower level of dust formation, are stressed. Moreover, the radiological constraints on the fabrication as a function of Am content and of selected fabrication process are evaluated. As conclusion, the feasibility of Am target fabrication has been demonstrated on a laboratory scale, based on experimental results evaluation. The penalties due to radiological constraints in a semi-industrial process are acceptable. The future developments consist in the construction of a laboratory fully dedicated to minor actinides fuel pins or targets fabrication. (author)

  8. Americium/Curium Disposition Life Cycle Planning Study

    International Nuclear Information System (INIS)

    Jackson, W.N.; Krupa, J.; Stutts, P.; Nester, S.; Raimesch, R.

    1998-01-01

    At the request of the Department of Energy Savannah River Office (DOE- SR), Westinghouse Savannah River Company (WSRC) evaluated concepts to complete disposition of Americium and Curium (Am/Cm) bearing materials currently located at the Savannah River Site (SRS)

  9. Plutonium and Americium Geochemistry at Hanford: A Site Wide Review

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Felmy, Andrew R.

    2012-08-23

    This report was produced to provide a systematic review of the state-of-knowledge of plutonium and americium geochemistry at the Hanford Site. The report integrates existing knowledge of the subsurface migration behavior of plutonium and americium at the Hanford Site with available information in the scientific literature regarding the geochemistry of plutonium and americium in systems that are environmentally relevant to the Hanford Site. As a part of the report, key research needs are identified and prioritized, with the ultimate goal of developing a science-based capability to quantitatively assess risk at sites contaminated with plutonium and americium at the Hanford Site and the impact of remediation technologies and closure strategies.

  10. Americium/Curium Disposition Life Cycle Planning Study

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, W.N. [Westinghouse Savannah River Company, AIKEN, SC (United States); Krupa, J.; Stutts, P.; Nester, S.; Raimesch, R.

    1998-04-30

    At the request of the Department of Energy Savannah River Office (DOE- SR), Westinghouse Savannah River Company (WSRC) evaluated concepts to complete disposition of Americium and Curium (Am/Cm) bearing materials currently located at the Savannah River Site (SRS).

  11. PROCESS FOR SEPARATING AMERICIUM AND CURIUM FROM RARE EARTH ELEMENTS

    Science.gov (United States)

    Baybarz, R.D.; Lloyd, M.H.

    1963-02-26

    This invention relates to methods of separating americium and curium values from rare earth values. In accordance with the invention americium, curium, and rare earth values are sorbed on an anion exchange resin. A major portion of the rare earth values are selectively stripped from the resin with a concentrated aqueous solution of lithium chloride, and americium, curium, and a minor portion of rare earth values are then stripped from the resin with a dilute aqueous solution of lithium chloride. The americium and curium values are further purified by increasing the concentration of lithium chloride in the solution to at least 8 molar and selectively extracting rare earth values from the resulting solution with a monoalkylphosphoric acid. (AEC)

  12. Aqueous Chloride Operations Overview: Plutonium and Americium Purification/Recovery

    Energy Technology Data Exchange (ETDEWEB)

    Gardner, Kyle Shelton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kimball, David Bryan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Skidmore, Bradley Evan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-28

    These are a set of slides intended for an information session as part of recruiting activities at Brigham Young University. It gives an overview of aqueous chloride operations, specifically on plutonium and americium purification/recovery. This presentation details the steps taken perform these processes, from plutonium size reduction, dissolution, solvent extraction, oxalate precipitation, to calcination. For americium recovery, it details the CLEAR (chloride extraction and actinide recovery) Line, oxalate precipitation and calcination.

  13. 1976 Hanford americium-exposure incident: external decontamination procedures

    International Nuclear Information System (INIS)

    Jech, J.J.; Berry, J.R.; Breitenstein, B.D.

    1982-01-01

    An accident resulted in the deposition on an injured workman's skin surfaces, in acid-burned areas and in lacerations, of something in excess of 6 mCi americium-241. The external decontamination procedures used, the change in americium content of the skin during the course of treatment, and some of the unusual problems encountered from the extrusion of foreign material and flaking of skin and scar tissue are described

  14. Preparation of americium metal of high purity and determination of the heat of formation of the hydrated trivalent americium ion

    International Nuclear Information System (INIS)

    Spirlet, J.C.

    1975-10-01

    In order to redetermine some physical and chemical properties of americium metal, several grams of Am-241 have been prepared by two independent methods: lanthanum reduction of the oxide and thermal dissociation of the intermetallic compound Pt 5 Am. After its separation from excess lanthanum or alloy constituent by evaporation, americium metal was further purified by sublimation at 1100 deg C and 10 -6 Torr. Irrespective of the method of preparation, the americium samples displayed the same d.h.c.p. crystal structure. As determined by vacuum hot extraction, the oxygen, nitrogen and hydrogen contents are equal to or smaller than 250, 50 and 20 ppm, respectively. The heats of solution of americium metal (d.c.h.p. structure) in aqueous hydrochloric acid solutions have been measured at 298.15+-0.05K. The standard enthalpy of formation of Am 3+ (aq) is obtained as -616.7+-1.2 kJ mol -1 [fr

  15. Citric complexes, neodymium citrate and americium citrate

    International Nuclear Information System (INIS)

    Bouhlassa, Saidati.

    1981-06-01

    The behaviour of neodymium and americium has been studied in citric aqueous medium by two methods: solvent extraction of elements at tracer scale as chelates and by potentiometry. So range of pH and concentrations of elements and citric acid never reached before have been explored: 10 -7 -1 M, 10 -10 -3 , Csub(H3 Cit) -1 M, 1 2 O; AmCit, xH 2 O; NdCit 2 Co(NH 3 ) 6 , 8H 2 O; AmCit 2 Co(NH 3 ) 6 , xH 2 O and Nd 3 (OH) 4 (Cit) 4 NH 4 (Co(NH 3 ) 6 ) 2 , 18H 2 O. Their spectroscopic and crystallographic characteristics have been listed and studied. The nephelauxetic effect has been estimated from citric complexes as well as from citrates of these elements. The structure of the complexes in solution has been discussed on the basis of analysis of hypersensitive transition in different complexes [fr

  16. Applicability of insoluble tannin to treatment of waste containing americium

    International Nuclear Information System (INIS)

    Matsumura, T.; Usuda, S.

    1998-01-01

    The applicability of insoluble tannin adsorbent to the treatment of aqueous waste contaminated with americium has been investigated. Insoluble tannin is considered highly applicable because it consists of only carbon, hydrogen and oxygen and so its volume can be easily reduced by incineration. This report describes measurements of the americium distribution coefficient in low concentration nitric acid. The americium distribution coefficients were found to decrease with increasing concentration of nitric acid and sodium nitrate, and with increasing temperature. At 25 C in 2.0 x 10 -3 M HNO 3 , the distribution coefficient was found to be 2000 ml g -1 . The adsorption capacity was determined by column experiments using europium as a simulant of americium, and found to be 7 x 10 -3 mmol g -1 -dried tannin in 0.01 M HNO 3 at 25 C, which corresponds to approximately 1.7 mg- 241 Am/g-adsorbent(dried). The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (orig.)

  17. A process for the recovery of americium from analytical wastes

    International Nuclear Information System (INIS)

    Brossard, P.; Kwinta, J.; Schwander, Y.

    1984-12-01

    The object of the present work is to define a procedure for the extraction of americium contained in hundreds of liters of liquid analytical wastes. The main objective is to produce wastes for which the americium concentration is lower than 0,5 mg/l, the operations being carried out in glove boxes. Dihexyl N, N-diethylcarbamylmethylene phosphonate (DHDECMP) is used for the extraction of americium. Experimental laboratory results and procedure design are described. Distribution coefficient, DHDECMP concentration, addition of TBP, influence of PH and temperature are studied. A bank of mixer-settlers appears to be the most appropriate laboratory equipment to handle large volume of solution with a good efficiency

  18. The selective extraction of americium from high level liquid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Adnet, J.M.; Donnet, L.; Brossard, P.; Bourges, J.

    1996-12-31

    One of the possible ways selected by CEA for the partitioning of minor actinides from solutions containing fission products is the selective extraction of the oxidized species. This papers deals with the latest developments in the electrochemical oxidation of americium in nitric media to the oxidation states (IV) and (VI). Oxidized americium is generated and stabilized through the use of poly anionic ligands such as the phospho tungstate. With in view the use of such ligands in the treatment of real liquid wastes, the complexation of several metallic ions has been investigated A first experiment done with a real liquid waste to prove the possibility to selectively extract the oxidized americium is presented. (authors). 8 refs.

  19. Synergistic extraction behaviour of americium from simulated acidic waste solutions

    International Nuclear Information System (INIS)

    Pathak, P.N.; Veeraraghavan, R.; Mohapatra, P.K.; Manchanda, V.K.

    1998-01-01

    The extraction behaviour of americium has been investigated with mixtures of 3-phenyl-4-benzoyl-5-isoxazolone (PBI) and oxodonors viz. tri-n-butyl phosphate (TBP), tri-n-octyl phosphine oxide (TOPO) and di-n-butyl octanamide (DBOA) using dodecane as the diluent from 1-6 M HNO 3 media. It is observed that D Am remains unaltered with PBI concentration (in the range 0.06-0.1 M) at 1.47 M TBP in the entire range of HNO 3 concentration. PBI and TBP in combination appears more promising compared to other synergistic systems. The possibility of using this mixture for americium removal from high level liquid waste solution has been explored. Extraction studies indicated that prior removal of uranium by 20% TBP in dodecane is helpful in the quantitative recovery of americium in three contacts. Effect of lanthanides on D Am is found to be marginal. (orig.)

  20. Covalency in Americium(III) Hexachloride.

    Science.gov (United States)

    Cross, Justin N; Su, Jing; Batista, Enrique R; Cary, Samantha K; Evans, William J; Kozimor, Stosh A; Mocko, Veronika; Scott, Brian L; Stein, Benjamin W; Windorff, Cory J; Yang, Ping

    2017-06-28

    Developing a better understanding of covalency (or orbital mixing) is of fundamental importance. Covalency occupies a central role in directing chemical and physical properties for almost any given compound or material. Hence, the concept of covalency has potential to generate broad and substantial scientific advances, ranging from biological applications to condensed matter physics. Given the importance of orbital mixing combined with the difficultly in measuring covalency, estimating or inferring covalency often leads to fiery debate. Consider the 60-year controversy sparked by Seaborg and co-workers ( Diamond, R. M.; Street, K., Jr.; Seaborg, G. T. J. Am. Chem. Soc. 1954 , 76 , 1461 ) when it was proposed that covalency from 5f-orbitals contributed to the unique behavior of americium in chloride matrixes. Herein, we describe the use of ligand K-edge X-ray absorption spectroscopy (XAS) and electronic structure calculations to quantify the extent of covalent bonding in-arguably-one of the most difficult systems to study, the Am-Cl interaction within AmCl 6 3- . We observed both 5f- and 6d-orbital mixing with the Cl-3p orbitals; however, contributions from the 6d-orbitals were more substantial. Comparisons with the isoelectronic EuCl 6 3- indicated that the amount of Cl 3p-mixing with Eu III 5d-orbitals was similar to that observed with the Am III 6d-orbitals. Meanwhile, the results confirmed Seaborg's 1954 hypothesis that Am III 5f-orbital covalency was more substantial than 4f-orbital mixing for Eu III .

  1. The ingestion of plutonium and americium by range cattle

    International Nuclear Information System (INIS)

    Blincoe, C.; Bohman, V.R.; Smith, D.D.

    1981-01-01

    The intake of plutonium and americium in the diet of cattle grazing on plutonium contaminated desert range was determined. Daily feed intake of the grazing animals was also determined so that the amount of nuclides ingested daily could be ascertained. Soil ingested by range cattle constituted the principal and possibly only source of ingested plutonium and americium and resulted in a daily intake of 3600-6600 pCi 238 Pu, 85,000-400,000 pCi 239 Pu, and 11,000-31,000 pCi 241 Am daily. Determining transuranic intake by direct measurement and from the composition and contamination of the diet gave identical results. (author)

  2. 1976 Hanford americium exposure incident: overview and perspective

    International Nuclear Information System (INIS)

    Thompson, R.C.

    1982-01-01

    Salient features of the 1976 Hanford americium exposure incident are discussed. Comparisons are made with previous human and animal exposure data, and conclusions drawn relative to the injured workman, to health physics practices, and to the adequacy of current exposure limits

  3. Determination of plutonium, americium and curium in the marine environment

    International Nuclear Information System (INIS)

    Grenaut, CLaude; Germain, Pierre; Miramand, Pierre.

    1982-01-01

    The method used in the Laboratory for plutonium, americium and curium determination in marine samples (water, sediments, animals, plants) is presented. It is a modification of a procedure based on adsorption on ion exchange resins developed by other authors. The preliminary preparation of the samples, the radiochemical procedures and electrodeposition are described so as to be used as a practical handbook [fr

  4. Reduction Rates for Higher Americium Oxidation States in Nitric Acid

    Energy Technology Data Exchange (ETDEWEB)

    Grimes, Travis Shane [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mincher, Bruce Jay [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schmitt, Nicholas C [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-30

    The stability of hexavalent americium was measured using multiple americium concentrations and nitric acid concentrations after contact with the strong oxidant sodium bismuthate. Contrary to our hypotheses Am(VI) was not reduced faster at higher americium concentrations, and the reduction was only zero-order at short time scales. Attempts to model the reduction kinetics using zero order kinetic models showed Am(VI) reduction in nitric acid is more complex than the autoreduction processes reported by others in perchloric acid. The classical zero-order reduction of Am(VI) was found here only for short times on the order of a few hours. We did show that the rate of Am(V) production was less than the rate of Am(VI) reduction, indicating that some Am(VI) undergoes two electron-reduction to Am(IV). We also monitored the Am(VI) reduction in contact with the organic diluent dodecane. A direct comparison of these results with those in the absence of the organic diluent showed the reduction rates for Am(VI) were not statistically different for both systems. Additional americium oxidations conducted in the presence of Ce(IV)/Ce(III) ions showed that Am(VI) is reduced without the typical growth of Am(V) observed in the systems sans Ce ion. This was an interesting result which suggests a potential new reduction/oxidation pathway for Am in the presence of Ce; however, these results were very preliminary, and will require additional experiments to understand the mechanism by which this occurs. Overall, these studies have shown that hexavalent americium is fundamentally stable enough in nitric acid to run a separations process. However, the complicated nature of the reduction pathways based on the system components is far from being rigorously understood.

  5. Kinetics and mechanism of oxidation of americium(III) to americium(VI) in dilute phosphoric acid solutions

    International Nuclear Information System (INIS)

    Milyukova, M.S.; Litvina, M.N.; Myasoedov, B.F.

    1980-01-01

    The reaction between trivalent americium and a mixture of silver with ammonium persulfate in 0.1-3M H 3 PO 4 solutions was studied. Hexavalent americium was found to be the product of interaction under these conditions. Americium oxidation is described with a first order equation with rate constants k=18.7 hr -1 and k=8.74 hr -1 for 0.1-0.5M and 1M H 3 PO 4 , respectively. The activation energy calculated from the temperature dependence of the rate of americium oxidation by a mixture of Ag 3 PO 4 with (NH 4 ) 2 S 2 O 8 is 9.1 kcal/mole. The stability of Am(VI) in 0.1-1M H 3 PO 4 was studied. No reduction of Am(VI) over a period of 30-40 hrs was observed; after that the reduction of Am(VI) follows a zero order law with the apparent rate constant k=0.0036 hr -1 . The mechanism of Am(III) oxidation with a mixture of silver and ammonium persulfate is discussed. (author)

  6. 24 CFR 246.21 - Rental charges.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Rental charges. 246.21 Section 246.21 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... CONTROL Subsidized Insured Projects § 246.21 Rental charges. The Department finds that it is necessary and...

  7. 24 CFR 246.30 - Rental charges.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Rental charges. 246.30 Section 246.30 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued... CONTROL HUD-Owned Projects § 246.30 Rental charges. The Department has exclusive jurisdiction over the...

  8. 24 CFR 246.5 - Rental charges.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Rental charges. 246.5 Section 246.5 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF... Unsubsidized Insured Projects § 246.5 Rental charges. The Department will generally not interfere in the...

  9. 48 CFR 2453.246 - Quality Assurance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Quality Assurance. 2453.246 Section 2453.246 Federal Acquisition Regulations System DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT CLAUSES AND FORMS FORMS Prescription of Forms 2453.246 Quality Assurance. ...

  10. 48 CFR 246.701 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Definitions. 246.701 Section 246.701 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Warranties 246.701 Definitions. Acceptance, as...

  11. 7 CFR 246.11 - Nutrition education.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Nutrition education. 246.11 Section 246.11 Agriculture... Participant Benefits § 246.11 Nutrition education. (a) General. (1) Nutrition education shall be considered a benefit of the Program, and shall be made available at no cost to the participant. Nutrition education...

  12. Americium extraction by alkylpyrocatechin from alkaline salt solutions

    International Nuclear Information System (INIS)

    Karalova, Z.K.; Rodionova, L.M.; Myasoedov, B.F.

    1984-01-01

    Effect of iron, aluminium, calcium, and sodium nitrates on americium extraction by 0.1 mol/l DOP solution [4-(α-α dioctylethyl) pyrocatechin] in toluene from a mixture of 2 mol/l NaOH with 0.1 mol/l EDTA has been investigated. It has been shown that americium extraction does not change essen-- tially in the presence of salts that permits to use DOP for Am extraction from alkaline solutions in the presence of outside salts. Verification of the above method of extraction of radioactive isotopes has been carried out. According to the data obtained double extraction provides a preparation of alkaline solutions practically free from radioactive isotopes. DOP application for Am extraction from alkaline salt solutions allows one to carry out repeated Am concentration and separation from accompanying elements. Conditions, under which Fe(3)-Am(3) pair separation coefficient achieves nx10 2 -10 4 , have been found out

  13. Contribution to the study of higher valency states of americium

    International Nuclear Information System (INIS)

    Langlet, Jean.

    1976-01-01

    Study of the chemistry of the higher valencies of americium in aqueous solutions and especially the autoreduction phenomenon. First a purification method of americium solutions is studied by precipitation, solvent extraction and ion exchange chromatography. Studies of higher valency states chemical properties are disturbed by the autoreduction phenomenon changing Am VI and Am V in Am III more stable. Stabilization of higher valency states, characterized by a steady concentration of Am VI in solution, can be done by complexation of Am VI and Am V ions or by a protecting effect of foreign ions. The original medium used has a complexing effect by SO 4 2- ions and a protecting effect by the system S 2 O 8 2- -Ag + consuming H 2 O 2 main reducing agent produced by water radiolysis. These effects are shown by the study of Am VI in acid and basic solutions. A mechanism of the stabilization effect is given [fr

  14. Method for removal of plutonium impurity from americium oxides and fluorides

    Science.gov (United States)

    FitzPatrick, J.R.; Dunn, J.G.; Avens, L.R.

    1987-02-13

    Method for removal of plutonium impurity from americium oxides and fluorides. AmF/sub 4/ is not further oxidized to AmF/sub 6/ by the application of O/sub 2/F at room temperature thereto, while plutonium compounds present in the americium sample are fluorinated to volatile PuF/sub 6/, which can readily be separated therefrom, leaving the purified americium oxides and/or fluorides as the solid tetrafluoride thereof.

  15. Research program on development of advanced treatment technology for americium-containing aqueous waste in NUCEF

    International Nuclear Information System (INIS)

    Mineo, Hideaki; Matsumura, Tatsuro; Tsubata, Yasuhiro

    1996-10-01

    A research program was prepared on the development of an advanced treatment process for the americium-containing concentrated aqueous waste in NUCEF, than allows americium recovery for the reuse and the reduction of TRU waste generation. A preliminary analysis was conducted on the separation requirements based on the components estimated for the waste. An R and D strategy was proposed from the view to reduce TRU waste generated in the processing that the highest priority is given on the control of TRU leakage such as americium into the effluent stream after americium recovery and the minimization of salt used in the separation over the decontamination of impurities from americium. The extraction chromatographic method was selected as a candidate technology for americium separation under the principle to use reagents that are functional in acidic conditions such as bidentate extractants of DHEDECMP, CMPO or diamides, considering the larger flexibilities in process modification and possible multi-component separation with compact equipment and the past achievements on the recovery of kg quantities of americium. Major R and D items extracted are screening and evaluation of extractants for americium and plutonium, optimization of separation conditions, selection of denitration method, equipment developments and development of solidification methods of discarded americium after reuse and of various kinds of separation residues. In order to cope these items, four steps of R and D program were proposed, i.e., fundamental experiment in beaker-scale on screening and evaluation of extractants, flowsheet study in bench-scale using simulated and small amount of americium aqueous waste solution to evaluate candidate process, americium recovery test in iron-shielded cell to be installed in NUCEF. It is objected to make recovery of 100g orders of americium used for research on fundamental TRU fuel properties. (J.P.N.)

  16. Ingestion Pathway Transfer Factors for Plutonium and Americium

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, A.

    1999-07-28

    Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site.

  17. 1976 Hanford americium-exposure incident: decontamination and treatment facility

    International Nuclear Information System (INIS)

    Berry, J.R.; McMurray, B.J.; Jech, J.J.; Breitenstein, B.D.; Quigley, E.J.

    1982-01-01

    An injured worker, contaminated with over 6 mCi of americium-241, required special treatment and housing for 4 months. This paper is a description of the design and management of the facility in which most of the treatment and housing occurred. The problems associated with contamination control, waste handling, supplies, and radiological concerns during the two-stage transfer of the patient from a controlled situation to his normal living environment are discussed in detail

  18. Americium-241: the most useful isotope of the actinide elements

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1984-01-01

    Used extensively in nuclear gauges and in many other areas, this man-made element (Atomic Number 95) was first isolated in weighable amounts during World War II. Americium is now a very useful by-product of the nuclear industry and is produced in kilogram amounts by appropriate recovery, separation and purification processes. A review will be presented of its discovery, nuclear and chemical properties, and uses, with emphasis on its production process and separations chemistry

  19. Extraction separation of americium and curium. A review

    International Nuclear Information System (INIS)

    Petrzilova, H.

    1976-11-01

    A survey is given of extraction systems suitable for transplutonium element separation and preparation as well as for the practical application of their nuclear properties. Methods are discussed in detail of separating the actinide and the lanthanide fractions from fission and corrosion products and of separating americium from curium. The description is completed with flowsheets showing the separation of transplutonium elements from irradiated targets and waste solutions after spent fuel reprocessing. (L.K.)

  20. Ingestion Pathway Transfer Factors for Plutonium and Americium

    International Nuclear Information System (INIS)

    Blanchard, A.

    1999-01-01

    Overall transfer factors for major ingestion pathways are derived for plutonium and americium. These transfer factors relate the radionuclide concentration in a given foodstuff to deposition on the soil. Equations describing basic relationships consistent with Regulatory Guide 1.109 are followed. Updated values and coefficients from IAEA Technical Reports Series No. 364 are used when a available. Preference is given to using factors specific to the Savannah River Site

  1. On the structure of thorium and americium adenosine triphosphate complexes

    International Nuclear Information System (INIS)

    Mostapha, Sarah; Berton, Laurence; Boubals, Nathalie; Zorz, Nicole; Charbonnel, Marie-Christine; Fontaine-Vive, Fabien; Den Auwer, Christophe; Solari, Pier Lorenzo

    2014-01-01

    The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electro-spray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes. (authors)

  2. On the structure of thorium and americium adenosine triphosphate complexes.

    Science.gov (United States)

    Mostapha, Sarah; Fontaine-Vive, Fabien; Berthon, Laurence; Boubals, Nathalie; Zorz, Nicole; Solari, Pier Lorenzo; Charbonnel, Marie Christine; Den Auwer, Christophe

    2014-11-01

    The actinides are chemical poisons and radiological hazards. One challenge to better appraise their toxicity and develop countermeasures in case of exposure of living organisms is to better assess pathways of contamination. Because of the high chemical affinity of those actinide elements for phosphate groups and the ubiquity of such chemical functions in biochemistry, nucleotides and in particular adenosine triphosphate nucleotide (ATP) may be considered critical target building blocks for actinides. Combinations of spectroscopic techniques (Fourier transformed Infra Red [FTIR], Electrospray Ionization Mass Spectrometry [ESI-MS], and Extended X-ray Absorption Fine Structure [EXAFS]) with quantum chemical calculations have been implemented in order to assess the actinides coordination arrangement with ATP. We describe and compare herein the interaction of ATP with thorium and americium; thorium(IV) as a representative of actinide(IV) like plutonium(IV) and americium(III) as a representative of all heavier actinides. In the case of thorium, an insoluble complex is readily formed. In the case of americium, a behavior identical to that described previously for lutetium has been observed with insoluble and soluble complexes. The comparative study of ATP complexation with Th(IV) and Am(III) shows their ability to form insoluble complexes for which a structural model has been proposed by analogy with previously described Lu(III) complexes.

  3. The EFTTRA-T4 experiment on americium transmutation

    CERN Document Server

    Konings, R J M; Dassel, G; Pijlgroms, B J; Somers, J; Toscano, E

    2000-01-01

    In the EFTTRA-T4 experiment the irradiation behaviour of a target containing americium dispersed in MgAl sub 2 O sub 4 was studied. Pellets containing 10-12 wt% sup 2 sup 4 sup 1 Am were fabricated by the infiltration method. However, it was found that the americium, intended to be present as AmO sub 2 sub - sub x , formed a compound, probably AmAlO sub 3 , during sintering. The T4 target was irradiated in the High Flux Reactor (HFR) Petten from August 1996 to January 1998 (358.4 fpd's). Post-test burn-up calculations indicated that the sup 2 sup 4 sup 1 Am concentration is reduced to 4% of the initial value at the end of the irradiation. The fraction of the initial americium atoms that were fissioned is 28%. Non-destructive and destructive examinations of the target indicated that swelling of the target pellets occurred. This is attributed to accumulation of helium, produced by alpha decay of sup 2 sup 4 sup 2 Cm that occurs in the transmutation scheme of sup 2 sup 4 sup 1 Am.

  4. Gut uptake factors for plutonium, americium and curium

    International Nuclear Information System (INIS)

    Harrison, J.D.

    1982-01-01

    Data on estimates of the absorption of plutonium, americium and curium from the human gut based on measurements of uptake in other mammalian species are reviewed. It is proposed that for all adult members of the public ingesting low concentrations of plutonium in food and water, 0.05% would be an appropriate value of absorption except when the conditions of exposure are known and a lower value can be justified. For dietary intakes of americium and curium, the available data do not warrant a change from the ICRP value of 0.05%. For newborn children ingesting americium, curium and soluble forms of plutonium, a value of 1% absorption is proposed for the first 3 months of life during which the infant is maintained on a milk diet. It is proposed that a value of 0.5% should be used for the first year of life to take account of the gradual maturation of the gut. In considering the ingestion of insoluble oxides of plutonium by infants, it is proposed that absorption is taken as 0.1% for the first 3 months and 0.05% for the first year. (author)

  5. Extraction of pentavalent americium by di(2-ethylhexyl)phosphoric acid

    International Nuclear Information System (INIS)

    Molochnikova, N.P.; Myasoedov, B.F.; Frenkel, V.Ya.

    1983-01-01

    Conditions have been found for the extraction of americium(V) by HDEHP in octane from acetate buffer solutions at pH 4.5-5.0 in the presence of ammonium persulphate which was necessary to stabilize oxidized americium under these conditions. The effect of the nature of a solvent on the extraction coefficient of americium(V) was studied. Macroamounts of americium(V) were extracted by 0.5M HDEHP in octane. The absorption spectrum of americium(V) in the extract has been recorded. The stability of americium(V) in the organic phase was evaluated. The absence of interfering influence of the anions of phosphotungstic acids on the extraction of americium(V) by 0.5M HDEHP in octane makes it possible to separate americium(V) from trivalent actinides during one extraction from acetate solutions at pH 4.5-5.0 in the presence of 10 -3 M potassium phosphotungstate; the separation factor is about 10 3 . (author)

  6. Airborne plutonium-239 and americium-241 concentrations measured from the 125-meter Hanford Meteorological Tower

    International Nuclear Information System (INIS)

    Sehmel, G.A.

    1978-01-01

    Airborne plutonium-239 and americium-241 concentrations and fluxes were measured at six heights from 1.9 to 122 m on the Hanford meteorological tower. The data show that plutonium-239 was transported on nonrespirable and small particles at all heights. Airborne americium-241 concentrations on small particles were maximum at the 91 m height

  7. Robotic sample preparation for radiochemical plutonium and americium analyses

    International Nuclear Information System (INIS)

    Stalnaker, N.; Beugelsdijk, T.; Thurston, A.; Quintana, J.

    1985-01-01

    A Zymate robotic system has been assembled and programmed to prepare samples for plutonium and americium analyses by radioactivity counting. The system performs two procedures: a simple dilution procedure and a TTA (xylene) extraction of plutonium. To perform the procedures, the robotic system executes 11 unit operations such as weighing, pipetting, mixing, etc. Approximately 150 programs, which require 64 kilobytes of memory, control the system. The system is now being tested with high-purity plutonium metal and plutonium oxide samples. Our studies indicate that the system can give results that agree within 5% at the 95% confidence level with determinations performed manually. 1 ref., 1 fig., 1 tab

  8. Implications of plutonium and americium recycling on MOX fuel fabrication

    International Nuclear Information System (INIS)

    Renard, A.; Pilate, S.; Maldague, Th.; La Fuente, A.; Evrard, G.

    1995-01-01

    The impact of the multiple recycling of plutonium in power reactors on the radiation dose rates is analyzed for the most critical stage in a MOX fuel fabrication plant. The limitation of the number of Pu recycling in light water reactors would rather stem from reactor core physics features. The case of recovering americium with plutonium is also considered and the necessary additions of shielding are evaluated. A comparison between the recycling of Pu in fast reactors and in light water reactors is presented. (author)

  9. Effect of 241-americium on bone marrow stroma

    International Nuclear Information System (INIS)

    Heuvel, R. van den

    1990-01-01

    The regulation of haemopoiesis occurs via complex interactions between the stroma and the haemopoietic cells. An attempt to further clarifying the mechanisms and the exact role of the stroma in the regulation was made in a study. Results revealed that the murine bone marrow stromal cells are highly radiosensitive after injection with 241-americium and can thus be considered as a target population after internal contamination. In addition, observations are made which may be important for risk estimation for the developing animal and during pregnancy. Contamination in utero and by lactation shows persistent damage up to 1 year after contamination at an average annual dose of 5 cGy. (author)

  10. Solubility of americium-241 in in vitro bovine ruminal-gastrointestinal fluids and predicted tissue retention and milk secretion of field-ingested americium-241

    International Nuclear Information System (INIS)

    Barth, J.

    1978-01-01

    The alimentary solubility and behavior of americium-241 were studied in an artificial rumen and simulated bovine gastrointestinal fluids. Rumen juice was augmented with americium-241 nitrate solution and incubated for 24 hours. This juice was successively converted by the addition of bile and enzymes and adjustment of the pH to simulate the digestive stages of the abomasum, duodenum, jejunum, and lower small intestine. Fluid samples were collected from each of these digestive stages and radioanalyzed for soluble americium-241. Shortly after the addition of americium-241 to rumen juice, an average of 15.3% remained soluble while 7.2% remained soluble following the incubation period. The solubility decreased to 5.3% following the abomasal period and increased to 11.6% and 20.0% when maintained at pH 4.0 and 5.0, respectively, in the duodenal phase. The solubility increased to 52% during the jejunal incubation period and was reduced to 44.8% during the lower intestinal incubation period. The sharp rise in americium-241 solubility during the jejunal incubation perid was found to be due mainly to the action of bile. Predictions of tissue retention and milk secretion of americium-241 ingested by grazing cattle at Area 13 of the Nevada Test Site are included

  11. Analysis of americium, plutonium and technetium solubility in groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Seiji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-08-01

    Safety assessments for geologic disposal of radioactive waste generally use solubilities of radioactive elements as the parameter restricting the dissolution of the elements from a waste matrix. This study evaluated americium, plutonium and technetium solubilities under a variety of geochemical conditions using the geochemical model EQ3/6. Thermodynamic data of elements used in the analysis were provided in the JAERI-data base. Chemical properties of both natural groundwater and interstitial water in buffer materials (bentonite and concrete) were investigated to determine the variations in Eh, pH and ligand concentrations (CO{sub 3}{sup 2-}, F{sup -}, PO{sub 4}{sup 3-}, SO{sub 4}{sup 2-}, NO{sub 3}{sup -} and NH{sub 4}{sup +}). These properties can play an important role in the complexation of radioactive elements. Effect of the groundwater chemical properties on the solubility and formation of chemical species for americium, plutonium and technetium was predicted based on the solubility analyses under a variety of geochemical conditions. The solubility and speciation of the radioactive elements were estimated, taking into account the possible range of chemical compositions determined from the groundwater investigation. (author)

  12. Plutonium and americium in the foodchain lichen-reindeer-man

    International Nuclear Information System (INIS)

    Jaakkola, T.; Hakanen, M.; Keinonen, M.; Mussalo, H.; Miettinen, J.K.

    1977-01-01

    The atmospheric nuclear tests have produced a worldwide fallout of transuranium elements. In addition to plutonium measurable concentrations of americium are to be found in terrestrial and aquatic environments. The metabolism of plutonium in reindeer was investigated by analyzing plutonium in liver, bone, and lung collected during 1963-1976. To determine the distribution of plutonium in reindeer all tissues of four animals of different ages were analyzed. To estimate the uptake of plutonium from the gastrointestinal tract in reindeer, the tissue samples of elk were also analyzed. Elk which is of the same genus as reindeer does not feed on lichen but mainly on deciduous plants, buds, young twigs, and leaves of trees and bushes. The composition of its feed corresponds fairly well to that of reindeer during the summer. Studies on behaviour of americium along the foodchain lichen-reindeer-man were started by determining the Am-241 concentrations in lichen and reindeer liver. The Am-241 results were compared with those of Pu-239,240. The plutonium contents of the southern Finns, whose diet does not contain reindeer tissues, were determined by analyzing autopsy tissue samples (liver, lung, and bone). The southern Finns form a control group to the Lapps consuming reindeer tissues. Plutonium analyses of the placenta, blood, and tooth samples of the Lapps were performed

  13. Uptake and recovery of americium and uranium by Anacystis biomass

    International Nuclear Information System (INIS)

    Liu, H.H.; Jiunntzong Wu

    1993-01-01

    The optimum conditions for the uptake of americium and uranium from wastewater solutions by Anacystis nidulans cells, and the recovery of these radionuclides were studied. The optimum pH range for both actinides was in the acidic region between 3.0 and 5.0. In a pH 3.5 solution with an algal biomass of 70 μg/mL, up to 95% of the Am and U were taken up by the cells. However, the uptake levels were lowered considerably when ethylene dinitrilotetraacetic acid (EDTA) or iron or calcium ions were present in the solutions. Most of the radionuclides taken up by the cells could also be desorbed by washing with salt solutions. Of nine salt solutions tested, ammonium carbonate was the most effective. Our experiments using algal biomass to remove radionuclides from wastewater showed that about 92% of americium and 85% of uranium in wastewater could be taken up by algal biomass, from which about 46% of the Am and 82% of the U originally present in the wastewater could be recovered by elution with a salt solution. 17 refs., 7 figs., 2 tabs

  14. Extraction of americium of different oxidation states in two-phase aqueous system based on polyethylene glycol

    International Nuclear Information System (INIS)

    Molochnikova, N.P.; Frenkel', V.Ya.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-01-01

    Americium extraction in different oxidation states in two-phase aqueous system based on polyethylene glycol is investigated. Conditions for quantitative extraction of americium (3) and americium (5) from ammonium sulfate solutions within pH=3-5 interval in the presence of arsenazo 3 are found. Composition of the produced americium complexes with reagent is determined; americium (3) interacts with arsenazo 3 in ammonium sulfate solutions with the formation of MeR and Me 2 R composition complexes. Absorption spectrum characteristics of americium (3) and- (5) complexes with arsenazo 3 in ammonium sulfate solutions and extracts based polyethylene glycol aqueous solutions are given. Molar extinction coefficients of americium complexes with arsenazo (3) in these solutions are determined

  15. Rare earth elements during diagenesis of abyssal sediments: analogies with a transuranic element americium

    International Nuclear Information System (INIS)

    Boust, D.

    1987-03-01

    One of the possibilities for the storage of high-level radioactive wastes consists in burying them into abyssal sediments, the sediments being supposed to barrier out radionuclides migration. The objective of the work was to estimate the efficiency of sediment barrier with respect to americium. As there is no americium in abyssal sediments, an indirect approach was used: the behaviour of the rare earth elements, the best natural analogs of americium. They were analysed in a 15 m long core, from the Cap Verde abyssal plateau. The terrigenous phase derived from the African continent was modified by short-term processes (1-1000 years); the intermediate rare earth elements were dissolved. Mineral coatings, enriched in rare earth appeared. After burial, the evolution continued at a much slower rate (10 5 - 10 6 years). The rare elements of the mineral coatings derived from the dissolution of the terrigenous phase and from an additional source, deeper in the sediment column. The fluxes of rare earth elements from sediment to water column were estimated. In suboxic sediments, the dissolved particulate equilibrium was related to redox conditions. The short-term reactivity of americium was studied in laboratory experiments. Simple americium migration models showed that the sediments barrier was totally efficient with respect to americium. In the conditions, neptunium 237 a daughter product of americium 241 could induce fluxes of 10 16 atoms per year per ton of stored waste (10 -8 Ci y-1), during millions years, towards the water column [fr

  16. 32 CFR 246.5 - Responsibilities.

    Science.gov (United States)

    2010-07-01

    ... , and readership focus groups to gather information. 6 See footnote 1 to § 246.4(c). (f) The Other... APF accounting and reporting procedures required by DoD Instruction 7000.12 5 , in coordination with...

  17. Analysis of biological samples for americium and curium

    International Nuclear Information System (INIS)

    Miglio, J.J.

    1976-01-01

    A method of analyzing biological materials by liquid scintillation counting for americium and curium which greatly reduces the contribution from 40 K is described. The method employs an extractant liquid scintillation cocktail using N,N,N-trioctyl-N-methyl-ammonium chloride as the extractant. Instrument as well as tissue backgrounds are reduced. The lowered backgrounds allow picocurie level samples to be analyzed by liquid scintillation counting instead of alpha pulse height analysis. The samples are reduced to a carbon-free ash and then dissolved in 8M LiNo 3 which is also 10 -2 M in HNO 3 . An aliquot is placed in a liquid scintillation vial along with the extractant-scintillator, shaken and counted

  18. Pretreatment of americium/curium solutions for vitrification

    International Nuclear Information System (INIS)

    Rudisill, T.S.

    1996-01-01

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to the heavy isotope programs at Oak Ridge National Laboratory. Prior to vitrification, an in-tank oxalate precipitation and a series of oxalic/nitric acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Pretreatment development experiments were performed to understand the behavior of the lanthanides and the metal impurities during the oxalate precipitation and properties of the precipitate slurry. The results of these experiments will be used to refine the target glass composition allowing optimization of the primary processing parameters and design of the solution transfer equipment

  19. Determination of the oxygen-metal-ratio of uranium-americium mixed oxides

    International Nuclear Information System (INIS)

    Bartscher, W.

    1982-01-01

    During the dissolution of uranium-americium mixed oxides in phosphoric acid under nitrogen tetravalent uranium is oxidized by tetravalent americium. The obtained hexavalent uranium is determined by constant potential coulometry. The coulombs measured are equivalent to the oxygen in excess of the minimum composition of UO 2 x AmO 1 . 5 . The total uranium content of the sample is determined in a subsequent coulometric titration. The oxygen-metal ratio of the sample can be calculated for a given uranium-americium ratio. An excess of uranium dioxide is necessary in order to suppress the oxidation of water by tetravalent americium. The standard deviation of the method is 0.0017 O/M units. (orig.) [de

  20. In-line measurement of plutonium and americium in mixed solutions

    International Nuclear Information System (INIS)

    Li, T.K.

    1981-01-01

    A solution assay instrument (SAI) has been developed at the Los Alamos National Laboratory and installed in the plutonium purification and americium recovery process area in the Los Alamos Plutonium Processing Facility. The instrument is designed for accurate, timely, and simultaneous nondestructive analysis of plutonium and americium in process solutions that have a wide range of concentrations and Am/Pu ratios. For a 25-mL sample, the assay precision is 5 g/L within a 2000-s count time

  1. Biochemical fractionation and cellular distribution of americium and plutonium in the biomass of freshwater macrophytes

    International Nuclear Information System (INIS)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.Ya.

    2011-01-01

    Accumulation of americium ( 241 Am) and plutonium ( 238,242 Pu) and their distribution in cell compartments and biochemical components of the biomass of freshwater aquatic plants Elodea canadensis, Ceratophyllum demersum and Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory experiments. Americium and plutonium taken up from water by Elodea canadensis apical shoots were mainly absorbed by structural components of plant cells (90% for 241 Am; 89% for 238 Pu and 82-87% for 242 Pu). About 10-18% of isotope activity was recorded in the cytosol fraction. The major concentration (76-92%) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-24% of americium activity was registered in the fraction of proteins and carbohydrates, and just a minor concentration (<1%) in the lipid fraction. The distribution of plutonium in the biomass fractions of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides of cell walls of freshwater submerged macrophytes. (author)

  2. Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

    International Nuclear Information System (INIS)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA.

    2010-01-01

    Accumulation of uranium ( 238 U), americium ( 241 Am) and plutonium ( 242 Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

  3. Distribution of uranium, americium and plutonium in the biomass of freshwater macrophytes

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Kalacheva, G.S.; Bolsunovsky, A.YA. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2010-07-01

    Accumulation of uranium ({sup 238}U), americium ({sup 241}Am) and plutonium ({sup 242}Pu) and their distribution in cell compartments and biochemical components of the biomass of aquatic plants Elodea canadensis, Ceratophyllum demersum, Myrioplyllum spicatum and aquatic moss Fontinalis antipyretica have been investigated in laboratory batch experiments. Isotopes of uranium, americium and plutonium taken up from the water by Elodea canadensis apical shoots were mainly absorbed by cell walls, plasmalemma and organelles. A small portion of isotopes (about 6-13 %) could be dissolved in cytoplasm. The major portion (76-92 %) of americium was bound to cell wall cellulose-like polysaccharides of Elodea canadensis, Myriophyllum spicatum, Ceratophyllum demersum and Fontinalis antipyretica, 8-23 % of americium activity was registered in the fraction of proteins and carbohydrates, and just a small portion (< 1%) in lipid fraction. The distribution of plutonium in the biomass fraction of Elodea was similar to that of americium. Hence, americium and plutonium had the highest affinity to cellulose-like polysaccharides in Elodea biomass. Distribution of uranium in the biomass of Elodea differed essentially from that of transuranium elements: a considerable portion of uranium was recorded in the fraction of protein and carbohydrates (51 %). From our data we can assume that uranium has higher affinity to carbohydrates than proteins. (authors)

  4. Selective dissolution of americium by ferricyanide ions in basic aqueous solutions

    International Nuclear Information System (INIS)

    Meyer, D.; Fouchard, S.; Simoni, E.

    2000-01-01

    Americium exhibits a soluble form in aqueous alkaline media under oxidizing conditions which is not the case for the other Transplutonium Elements (TPE). This property can be exploited for High Level Liquid Waste (HLLW) treatment to extract Am, one of the main radionuclides responsible for the long term radiotoxicity of nuclear waste. The Soluble Am compound can be obtained by adding a concentrated basic solution of ferricyanide ions (Fe(CN) 6 3- ) to a trivalent americium hydroxide precipitate. The method allows complete and rapid extraction of americium via its soluble form in alkaline solutions. Under these conditions, other TPE and lanthanides remain in the solid state as precipitates of highly insoluble trivalent hydroxides. In the case of dissolution involving large amounts of americium, the formation of the soluble americium species is followed by the appearance of a reddish precipitate in the basic solution. Dissolution of the reddish solid in NaOH or NaOH/Fe(CN) 6 3- media demonstrated the existence of a media dependent solubility of the precipitate, and therefore the existence of at least two forms of soluble Am. Spectroscopic studies (UV-visible, EXAFS-XANES) of this reddish solid led to the determination of an Am oxidation state (pentavalent americium) and its possible formula (Na 2 AmVO 2 (OH) 3 .nH 2 O). Electrochemical studies show that the only possible oxidation reaction of trivalent americium in the working media yields the pentavalent form, and that the hexavalent state is unattainable. Stoichiometric and spectroscopic studies show that not all the ferricyanide ions required for complete dissolution of Am remain in the free Fe(CN) 6 3- form. This observation supports the view that this dissolution of Am(III) solid compound is much more complex than a simple oxidation by the ferricyanide ions. The existence of a molecular interaction between Am(V)O 2 + and ferricyanide ions is highly probable. This work demonstrates that the selective dissolution

  5. Effect of americium-241 on luminous bacteria. Role of peroxides

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrova, M., E-mail: maka-alexandrova@rambler.r [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Rozhko, T. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Vydryakova, G. [Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation); Kudryasheva, N. [Siberian Federal University, Svobodny 79, 660041 Krasnoyarsk (Russian Federation); Institute of Biophysics SB RAS, Akademgorodok 50, 660036 Krasnoyarsk (Russian Federation)

    2011-04-15

    The effect of americium-241 ({sup 241}Am), an alpha-emitting radionuclide of high specific activity, on luminous bacteria Photobacterium phosphoreum was studied. Traces of {sup 241}Am in nutrient media (0.16-6.67 kBq/L) suppressed the growth of bacteria, but enhanced luminescence intensity and quantum yield at room temperature. Lower temperature (4 {sup o}C) increased the time of bacterial luminescence and revealed a stage of bioluminescence inhibition after 150 h of bioluminescence registration start. The role of conditions of exposure the bacterial cells to the {sup 241}Am is discussed. The effect of {sup 241}Am on luminous bacteria was attributed to peroxide compounds generated in water solutions as secondary products of radioactive decay. Increase of peroxide concentration in {sup 241}Am solutions was demonstrated; and the similarity of {sup 241}Am and hydrogen peroxide effects on bacterial luminescence was revealed. The study provides a scientific basis for elaboration of bioluminescence-based assay to monitor radiotoxicity of alpha-emitting radionuclides in aquatic solutions. - Highlights: {yields} Am-241 in water solutions (A = 0.16-6.7 kBq/L) suppresses bacterial growth.{yields} Am-241 (A = 0.16-6.7 kBq/L) stimulate bacterial luminescence. {yields} Peroxides, secondary radiolysis products, cause increase of bacterial luminescence.

  6. Americium/Curium Melter 2A Pilot Tests

    International Nuclear Information System (INIS)

    Smith, M.E.; Fellinger, A.P.; Jones, T.M.; Miller, C.B.; Miller, D.H.; Snyder, T.K.; Stone, M.E.; Witt, D.C.

    1998-05-01

    Isotopes of americium (Am) and curium (Cm) were produced in the past at the Savannah River Site (SRS) for research, medical, and radiological applications. These highly radioactive and valuable isotopes have been stored in an SRS reprocessing facility for a number of years. Vitrification of this solution will allow the material to be more safely stored until it is transported to the DOE Oak Ridge Reservation for use in research and medical applications. To this end, the Am/Cm Melter 2A pilot system, a full-scale non- radioactive pilot plant of the system to be installed at the reprocessing facility, was designed, constructed and tested. The full- scale pilot system has a frit and aqueous feed delivery system, a dual zone bushing melter, and an off-gas treatment system. The main items which were tested included the dual zone bushing melter, the drain tube with dual heating and cooling zones, glass compositions, and the off-gas system which used for the first time a film cooler/lower melter plenum. Most of the process and equipment were proven to function properly, but several problems were found which will need further work. A system description and a discussion of test results will be given

  7. Density of simulated americium/curium melter feed solution

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.S.

    1997-09-22

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70{degrees} C. The measured density decreased linearly at a rate of 0.0007 g/cm3/{degree} C from an average value of 1.2326 g/cm{sup 3} at 20{degrees} C to an average value of 1.1973g/cm{sup 3} at 70{degrees} C.

  8. Density of simulated americium/curium melter feed solution

    International Nuclear Information System (INIS)

    Rudisill, T.S.

    1997-01-01

    Vitrification will be used to stabilize an americium/curium (Am/Cm) solution presently stored in F-Canyon for eventual transport to Oak Ridge National Laboratory and use in heavy isotope production programs. Prior to vitrification, a series of in-tank oxalate precipitation and nitric/oxalic acid washes will be used to separate these elements and lanthanide fission products from the bulk of the uranium and metal impurities present in the solution. Following nitric acid dissolution and oxalate destruction, the solution will be denitrated and evaporated to a dissolved solids concentration of approximately 100 g/l (on an oxide basis). During the Am/Cm vitrification, an airlift will be used to supply the concentrated feed solution to a constant head tank which drains through a filter and an in-line orifice to the melter. Since the delivery system is sensitive to the physical properties of the feed, a simulated solution was prepared and used to measure the density as a function of temperature between 20 to 70 degrees C. The measured density decreased linearly at a rate of 0.0007 g/cm3/degree C from an average value of 1.2326 g/cm 3 at 20 degrees C to an average value of 1.1973g/cm 3 at 70 degrees C

  9. Americium adsorption on the surface of macrophytic algae

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, F.P.; Fowler, S.W.

    1985-01-01

    Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring ..cap alpha..-emitter /sup 210/Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author).

  10. Americium adsorption on the surface of macrophytic algae

    International Nuclear Information System (INIS)

    Carvalho, F.P.; Fowler, S.W.

    1985-01-01

    Data are presented on the rates at which americium (Am) deposits upon blade surfaces of three benthic algal species (Ulva rigida, Fucus vesiculosus and Gigartina stellata) following short-term exposures (1-6 h). Am is taken up in direct proportion to the ambient radionuclide concentration in sea water. Uptake by the green alga was 3 to 5 times greater than that for the brown and red species. Experimental evidence indicated that Am accumulation is a passive process and that adsorption takes place mainly on the thin outer organic coating of the seaweed. The Am transport coefficients are quite similar to that previously found for the naturally occurring α-emitter 210 Po, but are an order of magnitude lower than a plutonium transport coefficient reported in the literature. Release of labelled extracellular products associated with the algal surface coating is considered to be responsible for the rapid loss of Am observed previously in macroalgae and may in fact serve as a mechanism for transferring Am to filter feeding zooplankton. (author)

  11. 48 CFR 246.408-70 - Subsistence.

    Science.gov (United States)

    2010-10-01

    ... quality in food, to perform quality assurance for subsistence contract items. The designation may— (1..., DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Government Contract Quality Assurance 246.408-70...; (2) Technical requirements; and (3) Inspection procedures needed to assure wholesomeness of foods. (b...

  12. 40 CFR 246.200 - High-grade paper recovery.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-grade paper recovery. 246.200 Section 246.200 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES SOURCE... paper recovery. ...

  13. The rapid determination of americium curium, and uranium in urine by ultrafiltration

    International Nuclear Information System (INIS)

    Stradling, G.N.; Popplewell, D.S.; Ham, G.J.; Griffin, R.

    1975-01-01

    The rapid ultrafiltration method developed for the assay of plutonium has been extended to the determination of americium, curium and uranium in urine. The limits of detection for americium and curium, and uranium are 0.09 and 0.12 dm -1 l -1 respectively, and the analysis time excluding counting less than 2 hours. The method can therefor be effectively used as a rapid screening procedure. When the reference level for plutonium is exceeded, the α activity may require to be characterised. The single ultrafiltration technique must be modified for turbid urine samples. The method is inappropriate, except for uranium, when the urine contains DTPA. (author)

  14. 7 CFR 246.13 - Financial management system.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Financial management system. 246.13 Section 246.13... State Agency Provisions § 246.13 Financial management system. (a) Disclosure of expenditures. The State agency shall maintain a financial management system which provides accurate, current and complete...

  15. 48 CFR 552.246-71 - Source Inspection by Government.

    Science.gov (United States)

    2010-10-01

    ... Government. 552.246-71 Section 552.246-71 Federal Acquisition Regulations System GENERAL SERVICES....246-71 Source Inspection by Government. As prescribed in 546.302-71, insert the following clause: Source Inspection by Government (JUNE 1, 2009) (a) Inspection by Government personnel. (1) Supplies to be...

  16. 7 CFR 246.1 - General purpose and scope.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false General purpose and scope. 246.1 Section 246.1... General § 246.1 General purpose and scope. This part announces regulations under which the Secretary of... health by reason of inadequate nutrition or health care, or both. The purpose of the Program is to...

  17. 48 CFR 246.504 - Certificate of conformance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Certificate of conformance. 246.504 Section 246.504 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Acceptance 246.504 Certificate of conformance...

  18. 48 CFR 246.371 - Notification of potential safety issues.

    Science.gov (United States)

    2010-10-01

    ... safety issues. 246.371 Section 246.371 Federal Acquisition Regulations System DEFENSE ACQUISITION... Notification of potential safety issues. (a) Use the clause at 252.246-7003, Notification of Potential Safety Issues, in solicitations and contracts for the acquisition of— (1) Repairable or consumable parts...

  19. 48 CFR 246.202 - Types of contract quality requirements.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Types of contract quality requirements. 246.202 Section 246.202 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Quality Requirements 246.202...

  20. 7 CFR 246.5 - Selection of local agencies.

    Science.gov (United States)

    2010-01-01

    ... a notice in the local media (unless it has received an application from a local public or nonprofit... 7 Agriculture 4 2010-01-01 2010-01-01 false Selection of local agencies. 246.5 Section 246.5... State and Local Agency Eligibility § 246.5 Selection of local agencies. (a) General. This section sets...

  1. Medical management after contamination and incorporation of americium in occupational exposure. Medizinische Massnahmen nach Kontamination und Inkorporation von Americium bei beruflicher Strahlenexposition

    Energy Technology Data Exchange (ETDEWEB)

    Gensicke, F.; Stopp, G.; Scheler, R.; Klucke, H.; Czarwinski, R.; Naumann, M.; Hoelzer, F.; Ott, R.; Schmidt, I. (Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (Germany, F.R.). Abt. Strahlenschutzmedizin)

    1990-10-01

    In handling with an ampule of {sup 241}Am-nitrate solution one person received an contamination of the body surface, especially the face and the hairs, and an internal contamination of americium. The paper presents the results obtained in medical management to reduced the contamination of the skin and of the incorporated radionuclide. The radioactivity of the body surface could be reduced up to small local areas. After treatment with DTPA (Ditripentat) the internal exposure decrease about 83%. (orig.).

  2. Adsorption-desorption characteristics of plutonium and americium with sediment particles in the estuarine environment: studies using plutonium-237 and americium-241

    International Nuclear Information System (INIS)

    Murray, C.N.; Fukai, R.

    1975-01-01

    The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45 μm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

  3. Total and Compound Formation Cross Sections for Americium Nuclei: Recommendations for Coupled-Channels Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-11

    Calculations for total cross sections and compound-nucleus (CN) formation cross sections for americium isotopes are described, for use in the 2017 NA-22 evaluation effort. The code ECIS 2006 was used in conjunction with Frank Dietrich's wrapper `runtemplate'.

  4. Evaluation of the readsorption of plutonium and americium in dynamic fractionations of environmental solid samples

    DEFF Research Database (Denmark)

    Petersen, Roongrat; Hou, Xiaolin; Hansen, Elo Harald

    2008-01-01

    extractions. The degree of readsorption in dynamic and conventional batch extraction systems are compared and evaluated by using a double-spiking technique. A high degree of readsorption of plutonium and americium (>75%) was observed in both systems, and they also exhibited similar distribution patterns...

  5. Migration ability of plutonium and americium in the soils of Polessie State Radiation-Ecological Reserve

    International Nuclear Information System (INIS)

    Svetlana Ovsiannikova; Maryna Papenia; Katsiaryna Voinikava; Galina Sokolik; Sergey Svirschevsky; Justin Brown; Lindys Skipperud

    2010-01-01

    The physicochemical forms of radionuclides in soils determine the processes of their entry into the soil solutions, redistribution in the soil profile, soil-plant and soil-ground or surface waters transfer as well as spreading outside the contaminated area. The vertical distribution of plutonium and americium and their physicochemical forms in soils of Polessie State Radiation-Ecological Reserve (PSRER) were studied with the aim of establishing the potential for radionuclide migration. Samples of alluvial soddy-podzolic and peaty soils with a low (1-3%) and relatively high (∼80% of dry sample mass) content of organic matter have been selected for investigation. A method employing sequential selective extraction has been used for analysis of radionuclide physicochemical forms in the soils. Activity concentrations of 238 Pu, 239,240 Pu and 241 Am in the samples were determined via radiochemical analysis with alpha-spectrometric identification of radionuclides. The results indicate that the main proportion of plutonium and americium remains in the 0-20 cm soil layer. The inventories of mobile and biologically available forms of plutonium and americium, expressed as a percentage of the total radionuclide content in soil, lie in the ranges of 1.1-9.4 and 2.7-29% respectively. Greater proportions of mobile and biologically available forms of radionuclides appear to be associated with mineral soil as compared to organic soil. In both mineral and organic soils, the portion of mobile americium is higher than plutonium. The inventories of mobile forms of plutonium and americium increase with the depth of soils. (author)

  6. Interaction and diffusion transport of americium in soils

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez-Guinart, Oriol; Rigol, Anna; Vidal, Miquel [Analytical Chemistry department, Faculty of Chemistry, University of Barcelona, Marti i Franques 1-11, 08028, Barcelona (Spain)

    2014-07-01

    The final disposal of High Level Radioactive Wastes (HLRW) is based on its long-term storage in underground facilities located in geological stable sites with a multi-barrier system, the so called Deep Geological Repositories (DGR), that will keep HLRW confined for >10.000 years. After this period of time, leachates rich in long-live radioisotopes might escape from DGR and start to transport towards the biosphere. There is still a lack of information concerning the interaction and transport in soils of some radionuclides present in HLRW, especially for radionuclides that present a high sorption, such as americium (Am). Having reliable information about the mobility of radionuclides in soils is crucial in order to develop risk assessment models and to take proper decisions in case of soil contamination. The aim of the present work was, by means of laboratory scale experiments, to study the interaction and, for first time, to evaluate the diffusion transport of {sup 241}Am in soils. The {sup 241}Am interaction in soils was assessed by applying sorption batch assays to 20 soil samples with contrasted edaphic properties which allowed us to quantify the solid-liquid distribution coefficient (K{sub d}) and desorption percentage. K{sub d} (Am) values ranged from 10{sup 3} to 10{sup 5} L kg{sup -1} and desorption percentages were always less than 2% which denoted a high capacity of the soil to incorporate the Am and a low reversibility of the sorption process. The influence of soil properties in {sup 241}Am interaction was studied by means of multiple linear and multivariate regressions. Although a single correlation between K{sub d} (Am) values and a soil property was not found, the main properties affecting {sup 241}Am interaction in soils were soil pH, carbonate and organic matter contents in the soil. Finally, additional batch assays at different controlled pH were done to study Am sorption as a function of the contact solution pH. A variation of the Am sorption

  7. Structural characterisations and mechanistic investigations of the selective dissolution of americium by the ferricyanide ions in alkaline media. Application for the partitioning americium curium

    International Nuclear Information System (INIS)

    Fouchard, Sebastien

    2000-01-01

    Americium exhibits a high solubility form in basic media under oxidant conditions, unlike the other Transplutonium elements (TPE). This property can be used in the frame of High Level Liquid Waste (HLLW) treatment in order to extract preferentially the americium element, the main responsible of the long term radiotoxicity of the nuclear waste. This soluble compound can be obtained by addition of a concentrated basic solution of Fe(CN) 6 3- ions on Am(OH) 3 precipitates. This technique enables a rapid extraction of Am by the synthesis of this soluble form in alkaline solutions. Under these conditions, the other TPE remain in the solid state as trivalent hydroxide solids, strongly insoluble. In the case of dissolutions involving large amounts of Am(OH) 3 , the formation of the soluble complex is concomitant with the appearance of a reddish precipitate in the basic solution. Dissolution experiments which were carried out on this solid in NaOH/Fe(CN) 6 3- have demonstrated the dependency of the solubility equilibria with the media. Spectroscopic studies (UV Visible, XAS) on the precipitate have enabled the determination of the chemical structure and the oxidation state of the americium in the solid: Na 2 Am(V)O 2 (OH) 3 ,nH 2 O. Electrochemical studies on the americium solution have confirmed that the oxidation of Am(OH) 3 by the Fe(CN) 6 3- ions in basic media could only lead to the pentavalent form. A stoichiometric study carries out between a AmO 2 + ion and one Fe(CN) 6 3- ion and the spectroscopic characterisation of this reaction have demonstrated that the Fe(CN) 6 3- ion didn't remain as an un-complexed form in solution after the alkaline mixing. These results tend to prove that this dissolution of Am(OH) 3 is much more complex than a simple oxidation by the Fe(CN) 6 3- ions. The existence of molecular interactions between AmO 2 + and Fe(CN) 6 3- has been postulated and a mechanistic scheme has been proposed in order to explain the appearance of the soluble

  8. Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

    DEFF Research Database (Denmark)

    Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

    1986-01-01

    of the Irish Sea) to Spitsbergen. 241Am found in Arctic waters probably originates from the decay of fallout 241Pu and, like Pu, tentatively has a residence time of the order of several years. Americium from Sellafield has an estimated mean residence time of 4–6 months in Scottish waters.......Plutonium and americium have been measured in surface waters of the Greenland and Barents Seas and in the northern North Sea from 1980 through 1984. Measurements in water and biota, Fucus, Mytilus and Patella, were carried out in North-English and Scottish waters in 1982 and Fucus samples were...... collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of latitude 65°N, while for 238Pu a substantial fraction originates from European nuclear fuel reprocessing facilities. The 238Pu/239+240Pu isotope ratio provides clear evidence of the transport of effluent...

  9. Biochemical behaviour of plutonium and americium and geochemical modelling of the soil solution

    International Nuclear Information System (INIS)

    Bryan, N.D.; Livens, F.R.; Horrill, A.D.

    1994-01-01

    Field observations suggest that plutonium and americium in the environment are present in very different chemical forms in the interstitial waters of an intertidal sediment. Thermodynamic modelling using the PHREEQE code predicts that plutonium is present entirely in oxidation state (V) as the PuO 2 CO 3 - ion, whereas americium is present entirely in oxidation state (III), largely as the uncharged Am(OH)CO 3 species, but with significant concentrations of the Am 3+ and the AmSO 4 + ions. There are, however, differences between these predictions and others published for a very similar system which apparently arise from uncertainties in the thermodynamic data. Field data cannot resolve these differences unambiguously. (author) 29 refs.; 3 tabs

  10. High-purity germanium detection system for the in vivo measurement of americium and plutonium

    International Nuclear Information System (INIS)

    Tyree, W.H.; Falk, R.B.; Wood, C.B.; Liskey, R.W.

    1976-01-01

    A high-purity germanium (HPGe) array, photon-counting system has been developed for the Rocky Flats Plant Body-Counter Medical Facility. The newly improved system provides exceptional resolutions of low-energy X-ray and gamma-ray spectra associated with the in vivo deposition of plutonium and americium. Described are the operational parameters of the system and some qualitative results illustrating detector performance for the photon emissions produced from the decay of plutonium and americium between energy ranges from 10 to 100 kiloelectron volts. Since large amounts of data are easily generated with the system, data storage, analysis, and computer software developments continue to be an essential ingredient for processing spectral data obtained from the detectors. Absence of quantitative data is intentional. The primary concern of the study was to evaluate the effects of the various physical and electronic operational parameters before adding those related entirely to a human subject

  11. Electrodeposition of americium on a liquid cadmium cathode from a molten salt bath

    International Nuclear Information System (INIS)

    Laplace, A.; Lacquement, J.; Maillard, C.; Donner, L.

    2004-01-01

    A high-activity experiment involving the electrode position of americium on a liquid cadmium cathode from a LiCl-KCl eutectic with about 3 g of AmO 2 was conducted in a shielded cell in the ATALANTE complex. After describing the electrolyzer and the experimental conditions, the authors discuss the preparation of the LiCl-KCl-AmCl 3 solution and briefly review its electrochemical properties. It was clearly confirmed that Am(III) reduction on an inert solid cathode occurs in two steps forming Am(II) before Am(0), whereas only one reduction step was observed on liquid cadmium. The main results of this study concern americium electrode position on the liquid cadmium cathode (recovery yields, current densities, problems encountered). The solvent properties of cadmium for actinide/lanthanide separation are discussed. (authors)

  12. Determination of americium and plutonium in autopsy tissue: methods and problems

    International Nuclear Information System (INIS)

    Boyd, H.A.; Eutsler, B.C.; McInroy, J.F.

    1979-01-01

    The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average 242 Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average 242 Am tracer yield is 85 +- 7% for 40 determinations

  13. Final Radiological Assessment of External Exposure for CLEAR-Line Americium Recovery Operations

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Adam C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Belooussova, Olga N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hetrick, Lucas Duane [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-12

    Los Alamos National Laboratory is currently planning to implement an americium recovery program. The americium, ordinarily isotopically pure 241Am, would be extracted from existing Pu materials, converted to an oxide and shipped to support fabrication of americium oxide-beryllium neutron sources. These operations would occur in the currently proposed Chloride Extraction and Actinide Recovery (CLEAR) line of glove boxes. This glove box line would be collocated with the currently-operational Experimental Chloride Extraction Line (EXCEL). The focus of this document is to provide an in-depth assessment of the currently planned radiation protection measures and to determine whether or not further design work is required to satisfy design-goal and ALARA requirements. Further, this document presents a history of americium recovery operations in the Department of Energy and high-level descriptions of the CLEAR line operations to provide a basis of comparison. Under the working assumptions adopted by this study, it was found that the evaluated design appears to mitigate doses to a level that satisfies the ALARA-in-design requirements of 10 CFR 835 as implemented by the Los Alamos National Laboratory procedure P121. The analyses indicate that extremity doses would also meet design requirements. Dose-rate calculations were performed using the radiation transport code MCNP5 and doses were estimated using a time-motion study developed in consort with the subject matter expert. A copy of this report and all supporting documentation are located on the Radiological Engineering server at Y:\\Rad Engineering\\2013 PROJECTS\\TA-55 Clear Line.

  14. Quantitative determination of americium and curium in solutions using potassium tungstophosphate

    International Nuclear Information System (INIS)

    Chistyakov, V.M.; Baranov, A.A.; Erin, E.A.; Timoaeev, G.A.

    1990-01-01

    Two methods of americium (4) and curium (4) titration-replacement and redox ones - have been considered. According to the replacement method thorium nitrate solution was used as a titrant and the final point of titration was determined spectophotometrically. Using the method developed, on the basis of experimental data, the composition of thorium (4) complex with potassium tungstophosphate was determined. In case of the redox titration sodium nitrite was used, and the final titration point was indicated either spectrophotometrically or potentiometrically

  15. Medical management after contamination and incorporation of americium in occupational exposure

    International Nuclear Information System (INIS)

    Gensicke, F.; Stopp, G.; Scheler, R.; Klucke, H.; Czarwinski, R.; Naumann, M.; Hoelzer, F.; Ott, R.; Schmidt, I.

    1990-01-01

    In handling with an ampule of 241 Am-nitrate solution one person received an contamination of the body surface, especially the face and the hairs, and an internal contamination of americium. The paper presents the results obtained in medical management to reduced the contamination of the skin and of the incorporated radionuclide. The radioactivity of the body surface could be reduced up to small local areas. After treatment with DTPA (Ditripentat) the internal exposure decrease about 83%. (orig.) [de

  16. Experimental studies to validate model calculations and maximum solubility limits for Plutonium and Americium

    International Nuclear Information System (INIS)

    2017-01-01

    This report focuses on studies of KIT-INE to derive a significantly improved description of the chemical behaviour of Americium and Plutonium in saline NaCl, MgCl 2 and CaCl 2 brine systems. The studies are based on new experimental data and aim at deriving reliable Am and Pu solubility limits for the investigated systems as well as deriving comprehensive thermodynamic model descriptions. Both aspects are of high relevance in the context of potential source term estimations for Americium and Plutonium in aqueous brine systems and related scenarios. Americium and Plutonium are long-lived alpha emitting radionuclides which due to their high radiotoxicity need to be accounted for in a reliable and traceable way. The hydrolysis of trivalent actinides and the effect of highly alkaline pH conditions on the solubility of trivalent actinides in calcium chloride rich brine solutions were investigated and a thermodynamic model derived. The solubility of Plutonium in saline brine systems was studied under reducing and non-reducing conditions and is described within a new thermodynamic model. The influence of dissolved carbonate on Americium and Plutonium solubility in MgCl 2 solutions was investigated and quantitative information on Am and Pu solubility limits in these systems derived. Thermodynamic constants and model parameter derived in this work are implemented in the Thermodynamic Reference Database THEREDA owned by BfS. According to the quality assurance approach in THEREDA, is was necessary to publish parts of this work in peer-reviewed scientific journals. The publications are focused on solubility experiments, spectroscopy of aquatic and solid species and thermodynamic data. (Neck et al., Pure Appl. Chem., Vol. 81, (2009), pp. 1555-1568., Altmaier et al., Radiochimica Acta, 97, (2009), pp. 187-192., Altmaier et al., Actinide Research Quarterly, No 2., (2011), pp. 29-32.).

  17. Adsorption-Desorption Characteristics of Plutonium and Americium with Sediment Particles in the Estuarine Environment

    International Nuclear Information System (INIS)

    Murray, C.N.; Fukai, R.

    1976-01-01

    The particle formation of plutonium and americium, their adsorption onto fresh water sediments and the desorption from the sediments in sea water were studied in the Laboratory under simulated river-estuary conditions, using γ-emitting plutonium-237 and americium-241. The results of the experiments show that the particle formation of plutonium depends on its valence states, on pH and on the salinity of the medium. For river water at pH4, some 25%, 20% and 30% of the added 237 Pu was in particulate form, larger than 0.45pm, for Pu (III), Pu (IV) and Pu (VI), respectively, while 65%, 90% and 50% of the respective valence states was associated with particles at pH 8. In sea water the general pattern remains similar, although Pu (VI) is more soluble in sea water owing to higher ligand concentrations for carbonate and bicarbonate complexes. The pH-dependency of particle formation of Am (III) is more steep than that of plutonium and seems to be influenced by colloidal substances occurring in the experimental media. The adsorption-desorption characteristics of plutonium and americium with the sediment in river water as well as sea water reflect the characteristics of their particle formation, being dependent upon such properties as valence states, the pH and salinity of the medium. A sewage effluent added to the media has small but measurable effects on the adsorption-desorption processes of plutonium. (author)

  18. Bis(2-ethylhexyl)sulfoxide as an extractant for americium(III) from aqueous nitrate media

    International Nuclear Information System (INIS)

    Shukla, J.P.; Kedari, C.S.

    1992-01-01

    Solvent extraction separation of Am(III) from dilute aqueous nitrate media into n-dodecane by bis(2-ethylhexyl)sulfoxide (BESO) has been investigated over a wide range of experimental conditions. Very poor extractability of Am(III) necessitated the use of calcium nitrate as the salting-out agent. Effects of certain variables such as acidity, extractant concentration, salting-out agent concentration, organic diluents on the metal extraction by BESO have been examined in detail. By increasing the concentration of BESO in organic phase or calcium nitrate in aqueous phase, nearly quantitative extraction of americium even from moderate acidity is accomplished. Slope analyses applied to Am(III) distribution experiments from acidic nitrate solutions indicate predominant formation of the trisolvated organic phase complex, Am(NO 3 ) 3 *3BESO for which equilibrium constant is found to be, log K x = 1.99. Extraction behavior of Am(III) has also been evaluated in the presence of several water-miscible polar organic solvents to study their possible synergistic effects on its extraction. Extractability of americium increased 5 to 10-fold with increasing concentration of some of these additives, with maximum enhancement being observed in the presence of acetone or acetonitrile. Recovery of BESO from loaded americium is easily obtained using dilute nitric acid as the strippant. (author) 30 refs.; 2 figs.; 5 tabs

  19. Fabrication of uranium-americium mixed oxide pellet from microsphere precursors: Application of CRMP process

    Science.gov (United States)

    Remy, E.; Picart, S.; Delahaye, T.; Jobelin, I.; Lebreton, F.; Horlait, D.; Bisel, I.; Blanchart, P.; Ayral, A.

    2014-10-01

    Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Recently, several processes have been developed in order to validate fabrication flowchart in terms of material specifications such as density and homogeneity but also to suggest simplifications for lowering industrial costs and hazards linked to dust generation of highly contaminating and irradiating compounds. This study deals with the application of an innovative route using mixed oxide microspheres obtained from metal loaded resin bead calcination, called Calcined Resin Microsphere Pelletization (CRMP). The synthesis of mixed oxide microsphere precursor of U0.9Am0.1O2±δ is described as well as its characterisation. The use of this free-flowing precursor allows the pressing and sintering of one pellet of U0.9Am0.1O2±δ. The ceramic obtained was characterised and results showed that its microstructure is dense and homogeneous and its density attains 95% of the theoretical density. This study validates the scientific feasibility of the CRMP process applied to the fabrication of uranium and americium-containing materials.

  20. Influence of dissolved organic substances in groundwater on sorption behavior of americium and neptunium

    International Nuclear Information System (INIS)

    Boggs, S. Jr.; Seitz, M.G.

    1984-01-01

    Groundwaters typically contain dissolved organic carbon consisting largely of high molecular weight compounds of humic and fulvic acids. To evaluate whether these dissolved organic substances can enhance the tranport of radionuclides through the groundwater system, experiments were conducted to examine the sorption of americium and neptunium onto crushed basalt in the presence of dissolved humic- and fulvic-acid organic carbon introduced into synthetic groundwater. The partitioning experiments with synthetic groundwater show that increasing the concentration of either humic or fulvic acid in the water has a significant inhibiting effect on sorption of both americium and neptunium. At 22 0 C, adsorption of these radionuclides, as measured by distribution ratios (the ratio of nuclide sorbed onto the solid to nuclide in solution at the end of the experiment), decreased by 25% to 50% by addition of as little as 1 mg/L dissolved organic carbon and by one to two orders of magnitude by addition of 100 to 200 mg/L dissolved organic carbon. Distribution ratios measured in solutions reacted at 90 0 C similarly decreased with the addition of dissolved organic carbon but generally ranged from one to two orders of magnitude higher than those determined in the 22 0 C experiment. These results suggest that organic carbon dissolved in deep groundwaters may significantly enhance the mobility of radionuclides of americium and neptunium. 23 references, 5 figures, 11 tables

  1. 48 CFR 852.246-72 - Frozen processed foods.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Frozen processed foods. 852.246-72 Section 852.246-72 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS... Frozen processed foods. As prescribed in 846.302-72, insert the following clause: Frozen Processed Foods...

  2. 48 CFR 246.470-2 - Quality evaluation data.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Quality evaluation data... 246.470-2 Quality evaluation data. The contract administration office shall establish a system for the collection, evaluation, and use of the types of quality evaluation data specified in PGI 246.470-2. [71 FR...

  3. Physics of plutonium and americium recycling in PWR using advanced fuel concepts

    International Nuclear Information System (INIS)

    Hourcade, E.

    2004-01-01

    PWR waste inventory management is considered in many countries including Frances as one of the main current issues. Pu and Am are the 2 main contents both in term of volume and long term radio-toxicity. Waiting for the Generation IV systems implementation (2035-2050), one of the mid-term solutions for their transmutation involves the use of advanced fuels in Pressurized Water Reactors (PWR). These have to require as little modification as possible of the core internals, the cooling system and fuel cycle facilities (fabrication and reprocessing). The first part of this paper deals with some neutronic characteristics of Pu and/or Am recycling. In a second part, 2 technical solutions MOX-HMR and APA-DUPLEX-84 are presented and the third part is devoted to the study of a few global strategies. The main neutronic parameters to be considered for Pu and Am recycling in PWR are void coefficient, Doppler coefficient, fraction of delayed neutrons and power distribution (especially for heterogeneous configurations). The modification of the moderation ratio, the opportunity to use inert matrices (targets), the optimisation of Uranium, Plutonium and Americium contents are the key parameters to play with. One of the solutions (APA-DUPLEX-84) presented here is a heterogeneous assembly with regular moderation ratio composed with both target fuel rods (Pu and Am embedded in an inert matrix) and standard UO 2 fuel rods. An EPR (European Pressurised Reactor) type reactor, loaded only with assemblies containing 84 peripheral targets, can reach an Americium consumption rate of (4.4; 23 kg/TWh) depending on the assembly concept. For Pu and Am inventories stabilisation, the theoretical fraction of reactors loaded with Pu + Am or Pu assemblies is about 60%. For Americium inventory stabilisation, the fraction decreases down to 16%, but Pu is produced at a rate of 18.5 Kg/TWh (-25% compared to one through UOX cycle)

  4. Accumulation of americium-241 in the biomass of aquatic plants of the Yenisei river: experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Zotina, T.A.; Bolsunovsky, A.Y.A.; Bondareva, L.G. [Institute of Biophysics SB RAS, Akademgorodok, Krasnoyarsk (Russian Federation)

    2004-07-01

    Due to the operation of the Mining-and-Chemical Combine (Krasnoyarsk-26), which has been manufacturing weapons-grade plutonium for several decades, the Yenisei River is contaminated with transuranic elements (including {sup 241}Am). {sup 241}Am was found in the riverside soil, sediment and in the biomass of aquatic plants (Bolsunovsky et al., 1999, 2002). Aquatic plants are an important link in the migration of radionuclides in an aquatic ecosystem. In laboratory experiments, we investigated accumulation of {sup 241}Am by the submerged macrophyte from the Yenisei River: the pond weed (Elodea canadensis) and the aquatic moss (Fontinalis antipyretica), and release of {sup 241}Am from the biomass. The content of {sup 241}Am was measured on a Canberra (USA) gamma-spectrometer. The experiments showed that specific accumulation and concentration factors of {sup 241}Am in the plants were in inverse proportion to their biomass. We obtained new data on release of {sup 241}Am from the biomass of macrophyte. Americium-241 was more firmly fixed in the biomass of the aquatic moss. In 12 months, the biomass of the aquatic moss released about 30% of the initial americium activity into the water. To compare, the biomass of the pond weed released into the water medium up to 64% of the initial {sup 241}Am activity in 1.5 4 months. The release rate was dependent on the decomposition rate of the plant biomass. The experiments showed that submerged macrophyte of the Yenisei River can accumulate considerable activities of {sup 241}Am and retain americium for long periods of time in biomass. (author)

  5. Speciation of americium in seawater and accumulation in the marine sponge Aplysina cavernicola.

    Science.gov (United States)

    Maloubier, Melody; Michel, Hervé; Solari, Pier Lorenzo; Moisy, Philippe; Tribalat, Marie-Aude; Oberhaensli, François R; Dechraoui Bottein, Marie Yasmine; Thomas, Olivier P; Monfort, Marguerite; Moulin, Christophe; Den Auwer, Christophe

    2015-12-21

    The fate of radionuclides in the environment is a cause of great concern for modern society, seen especially in 2011 after the Fukushima accident. Among the environmental compartments, seawater covers most of the earth's surface and may be directly or indirectly impacted. The interaction between radionuclides and the marine compartment is therefore essential for better understanding the transfer mechanisms from the hydrosphere to the biosphere. This information allows for the evaluation of the impact on humans via our interaction with the biotope that has been largely undocumented up to now. In this report, we attempt to make a link between the speciation of heavy elements in natural seawater and their uptake by a model marine organism. More specifically, because the interaction of actinides with marine invertebrates has been poorly studied, the accumulation in a representative member of the Mediterranean coralligenous habitat, the sponge Aplysina cavernicola, was investigated and its uptake curve exposed to a radiotracer (241)Am was estimated using a high-purity Ge gamma spectrometer. But in order to go beyond the phenomenological accumulation rate, the speciation of americium(III) in seawater must be assessed. The speciation of (241)Am (and natural europium as its chemically stable surrogate) in seawater was determined using a combination of different techniques: Time-Resolved Laser-Induced Fluorescence (TRLIF), Extended X-ray Absorption Fine Structure (EXAFS) at the LIII edge, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy (SEM) and the resulting data were compared with the speciation modeling. In seawater, the americium(III) complex (as well as the corresponding europium complex, although with conformational differences) was identified as a ternary sodium biscarbonato complex, whose formula can be tentatively written as NaAm(CO3)2·nH2O. It is therefore this chemical form of americium that is

  6. Uptake of plutonium and americium by barley from two contaminated Nevada Test Site soils

    International Nuclear Information System (INIS)

    Schulz, R.K.; Tompkins, G.A.; Leventhal, L.; Babcock, K.L.

    1976-01-01

    Barley (Hordeum vulgare, Var. Atlas 68) plant uptake of Pu 239 , Pu 240 , and Am 241 was studied using two soil samples collected from widely separated areas of the Nevada Test Site. Each area had been previously contaminated with plutonium and americium as a result of a separate high explosive (nonnuclear) detonation of a device containing plutonium. The plants were grown on 3-kg soil samples in a controlled environment chamber. The plutonium concentration ratio (plutonium concentration in dry plant tissue/plutonium concentration in dry soil) was in the order of 10 -5 for plant vegetative material. The plutonium concentration ratio for the grain was 20 to 100 times lower than that in the vegetative material. Concentration ratios for americium were in the order of 10 -4 for vegetative growth and 25 to 75 times lower for the grain. These results imply that americium is more available to plants than plutonium. Plutonium-bearing particles were identified in a soil sample using an autoradiographic technique and then separated from the soil samples. The Pu 239 oxide equivalent diameters of plutonium-bearing particles could be described by a log-normal distribution function in the range of 0.2 to 0.7 μm. The actual diameters of the particles were 2 to 3 times the PuO 2 equivalent diameter. Microprobe analyses of the surface region of particles greater than 2 μm showed the following order of abundance: U, Pu is greater than O is greater than Al is greater than Si is greater than Fe is greater than Mg. Photographs obtained with a scanning electron microscope revealed that some of the particles are quite irregular and have large specific surface areas which might enhance solubility and plant uptake

  7. Fabrication of uranium–americium mixed oxide pellet from microsphere precursors: Application of CRMP process

    Energy Technology Data Exchange (ETDEWEB)

    Remy, E. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Picart, S., E-mail: sebastien.picart@cea.fr [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Delahaye, T. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Jobelin, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Lebreton, F.; Horlait, D. [Fuel Cycle Technology Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Bisel, I. [Radiochemistry and Processes Department, CEA, Nuclear Energy Division, F-30207 Bagnols-sur-Cèze (France); Blanchart, P. [Heterogeneous Materials Research Group, Centre Européen de la Céramique, F-87068 Limoges (France); Ayral, A. [Institut Européen des Membranes, CNRS-ENSCM-UM2, CC47, University Montpellier 2, F-34095 Montpellier cedex 5 (France)

    2014-10-15

    Highlights: • Dust free process for (U,Am)O{sub 2} transmutation target fabrication. • Synthesis of U{sub 0.9}Am{sub 0.1}O{sub 2} mixed oxide microspheres from ion exchange resin. • Fabrication of dense U{sub 0.9}Am{sub 0.1}O{sub 2} pellet with 95% TD from mixed oxide microspheres. - Abstract: Mixed uranium–americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Recently, several processes have been developed in order to validate fabrication flowchart in terms of material specifications such as density and homogeneity but also to suggest simplifications for lowering industrial costs and hazards linked to dust generation of highly contaminating and irradiating compounds. This study deals with the application of an innovative route using mixed oxide microspheres obtained from metal loaded resin bead calcination, called Calcined Resin Microsphere Pelletization (CRMP). The synthesis of mixed oxide microsphere precursor of U{sub 0.9}Am{sub 0.1}O{sub 2±δ} is described as well as its characterisation. The use of this free-flowing precursor allows the pressing and sintering of one pellet of U{sub 0.9}Am{sub 0.1}O{sub 2±δ}. The ceramic obtained was characterised and results showed that its microstructure is dense and homogeneous and its density attains 95% of the theoretical density. This study validates the scientific feasibility of the CRMP process applied to the fabrication of uranium and americium-containing materials.

  8. 7 CFR 246.19 - Management evaluation and monitoring reviews.

    Science.gov (United States)

    2010-01-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND CHILDREN Monitoring and Review § 246.19 Management evaluation and monitoring reviews... education, participant services, civil rights compliance, accountability, financial management systems, and...

  9. 48 CFR 246.370 - Material inspection and receiving report.

    Science.gov (United States)

    2010-10-01

    ... REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Clauses 246.370... deliverable is a scientific or technical report; (5) Research and development contracts not requiring the...

  10. Recovery of Americium-241 from lightning rod by the method of chemical treatment

    International Nuclear Information System (INIS)

    Cruz, W.H.

    2013-01-01

    About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ( 241 Am), fewer and Radium 226 ( 226 Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of 241 Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The 241 Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel 241 Am technique was used electrodeposition. (author)

  11. Comparison of acid leachate and fusion methods to determine plutonium and americium in environmental samples

    International Nuclear Information System (INIS)

    Smith, L.L.; Markun, F.; TenKate, T.

    1992-06-01

    The Analytical Chemistry Laboratory at Argonne National Laboratory performs radiochemical analyses for a wide variety of sites within the Department of Energy complex. Since the chemical history of the samples may vary drastically from site to site, the effectiveness of any analytical technique may also vary. This study compares a potassium fluoride-pyrosulfate fusion technique with an acid leachate method. Both normal and high-fired soils and vegetation samples were analyzed for both americium and plutonium. Results show both methods work well, except for plutonium in high-fired soils. Here the fusion method provides higher accuracy

  12. Influence of biofilms on migration of uranium, americium and europium in the environment

    International Nuclear Information System (INIS)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-01-01

    The report on the influence of biofilms on migration of uranium, americium and europium in the environment deals with the contamination problems of uranium mines such as SDAG WISMUT in Saxonia and Thuringia. In mine waters microorganisms form a complex microbiological biocoenosis in spite of low pH values and high heavy metal concentrations including high uranium concentrations. The analyses used microbiological methods like confocal laser scanning microscopy and molecular-biological techniques. The interactions of microorganism with fluorescent radioactive heavy metal ions were performed with TRLFS (time resolved laser-induced fluorescence spectroscopy).

  13. Rad Calc III: Radioanalysis calculation program for plutonium and americium determination

    International Nuclear Information System (INIS)

    Blackadar, J.M.; Wong, A.S.; Stalnaker, N.D.; Willerton, J.R.

    2000-01-01

    The radiochemistry team of the Analytical Chemistry Group has supported nuclear materials production and management programs at Los Alamos National Laboratory since the 1940s. Routinely, plutonium and americium contents in various matrices (such as metals, oxides, process solutions, and waste streams) are determined by direct alpha and gamma analyses. Over the years, analysts have written a number of computer programs to calculate analytical results. In 1999, the program was enhanced and upgraded to produce Rad Calc III. The new program, written in Visual Basic 4.0, corrects limitations of previous versions, offers enhanced features, and incorporates user suggestions to customize the program and make it more user friendly

  14. Recovery of americium from slag and crucible wastes and its purification

    International Nuclear Information System (INIS)

    Michael, K.M.; Dabholkar, G.M.; Vijayan, K.; Ramamoorthy, N.; Narayanan, C.V.; Jambunathan, U.; Kapoor, S.C.

    1990-01-01

    A method of recovery and purification of americium-241 from slag waste streams is described. Extraction of Am from slag solution of 0.16 M HNO 3 was carried out by tri-n-butyl phosphate. After stripping with acetic acid, Am was precipitated at pH 1. This was followed by metathesis to remove Ca. Final separation of Pu from Am solution was achieved by anion exchange method using Dowex 1x4 anion exchange resin. Details of large scale recovery of Am from slag are also described. (author). 12 refs., 11 tabs., 1 fig

  15. Distribution coefficients for plutonium and americium on particulates in aquatic environments

    International Nuclear Information System (INIS)

    Sanchez, A.L.; Schell, W.R.; Sibley, T.H.

    1982-01-01

    The distribution coefficients of two transuranic elements, plutonium and americium, were measured experimentally in laboratory systems of selected freshwater, estuarine, and marine environments. Gamma-ray emitting isotopes of these radionuclides, 237 Pu and 241 Am, were significantly greater than the sorption Ksub(d) values, suggesting some irreversibility in the sorption of these radionuclides onto sediments. The effects of pH and of sediment concentration on the distribution coefficients were also investigated. There were significant changes in the Ksub(d) values as these parameters were varied. Experiments using sterilized and nonsterilized samples for some of the sediment/water systems indicate possible bacterial effects on Ksub(d) values. (author)

  16. Plutonium and americium in arctic waters, the North Sea and Scottish and Irish coastal zones

    DEFF Research Database (Denmark)

    Hallstadius, L.; Aarkrog, Asker; Dahlgaard, Henning

    1986-01-01

    collected from the Irish coast in 1983. Fallout is found to dominate as a source of 239+240Pu north of latitude 65°N, while for 238Pu a substantial fraction originates from European nuclear fuel reprocessing facilities. The 238Pu/239+240Pu isotope ratio provides clear evidence of the transport of effluent...... of the Irish Sea) to Spitsbergen. 241Am found in Arctic waters probably originates from the decay of fallout 241Pu and, like Pu, tentatively has a residence time of the order of several years. Americium from Sellafield has an estimated mean residence time of 4–6 months in Scottish waters....

  17. Laboratory investigation of the role of desorption kinetics on americium transport associated with bentonite colloids.

    Science.gov (United States)

    Dittrich, Timothy Mark; Boukhalfa, Hakim; Ware, Stuart Douglas; Reimus, Paul William

    2015-10-01

    Understanding the parameters that control colloid-mediated transport of radionuclides is important for the safe disposal of used nuclear fuel. We report an experimental and reactive transport modeling examination of americium transport in a groundwater-bentonite-fracture fill material system. A series of batch sorption and column transport experiments were conducted to determine the role of desorption kinetics from bentonite colloids in the transport of americium through fracture materials. We used fracture fill material from a shear zone in altered granodiorite collected from the Grimsel Test Site (GTS) in Switzerland and colloidal suspensions generated from FEBEX bentonite, a potential repository backfill material. The colloidal suspension (100 mg L(-1)) was prepared in synthetic groundwater that matched the natural water chemistry at GTS and was spiked with 5.5 × 10(-10) M (241)Am. Batch characterizations indicated that 97% of the americium in the stock suspension was adsorbed to the colloids. Breakthrough experiments conducted by injecting the americium colloidal suspension through three identical columns in series, each with mean residence times of 6 h, show that more than 95% of the bentonite colloids were transported through each of the columns, with modeled colloid filtration rates (k(f)) of 0.01-0.02 h(-1). Am recoveries in each column were 55-60%, and Am desorption rate constants from the colloids, determined from 1-D transport modeling, were 0.96, 0.98, and 0.91 h(-1) in the three columns, respectively. The consistency in Am recoveries and desorption rate constants in each column indicates that the Am was not associated with binding sites of widely-varying strengths on the colloids, as one binding site with fast kinetics represented the system accurately for all three sequential columns. Our data suggest that colloid-mediated transport of Am in a bentonite-fracture fill material system is unlikely to result in transport over long distance scales because

  18. Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

    International Nuclear Information System (INIS)

    Guillou, P.

    1990-12-01

    The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

  19. Transmutation of americium and curium incorporated in zirconia-based host materials

    Energy Technology Data Exchange (ETDEWEB)

    Raison, P.E. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d' Etudes des Combustibles; Haire, R.G. [Oak Ridge National Lab., TN (United States)

    2001-07-01

    Presented are studies involving the incorporation of americium and curium in zirconia-based materials. First explored was the pseudo ternary system AmO{sub 2}-ZrO{sub 2}-Y{sub 2}O{sub 3}. It was determined that selected Y-CSZ materials can incorporate significant quantities of americium oxide and remain cubic single-phase. The cell parameters of these fluorite-type products were established to be linear with the AmO{sub 2} content. The Cm{sub 2}O{sub 3}-ZrO{sub 2} system was also investigated. It was found that at 25 mol% of CmO{sub 1.5}, the Cm(III) stabilized zirconia in its cubic form (a = 5.21 {+-}0.01 Angstrom). At higher and lower concentrations, diphasic materials were encountered. At 50 mol% of CmO{sub 1.5}, a pyrochlore oxide - Cm{sub 2}Zr{sub 2}O{sub 7} - is formed (a = 10.63 {+-}0.02 Angstrom). (author)

  20. Fuel cycle covariance of plutonium and americium separations to repository capacity using information theoretic measures

    International Nuclear Information System (INIS)

    Scopatz, Anthony; Schneider, Erich; Li, Jun; Yim, Man-Sung

    2011-01-01

    A light water reactor, fast reactor symbiotic fuel cycle scenario was modeled and parameterized based on thirty independent inputs. Simultaneously and stochastically choosing different values for each of these inputs and performing the associated fuel cycle mass-balance calculation, the fuel cycle itself underwent Monte Carlo simulation. A novel information theoretic metric is postulated as a measure of system-wide covariance. This metric is the coefficient of variation of the set of uncertainty coefficients generated from 2D slices of a 3D contingency table. It is then applied to the fuel cycle, taking fast reactor used fuel plutonium and americium separations as independent variables and the capacity of a fully-loaded tuff repository as the response. This set of parameters is known from prior studies to have a strong covariance. When measured with all 435 other input parameters possible, the fast reactor plutonium and americium separations pair was found to be ranked the second most covariant. This verifies that the coefficient of variation metric captures the desired sensitivity of sensitivity effects in the nuclear fuel cycle. (author)

  1. Contribution to the prediction of americium, plutonium and neptunium behaviour in the geosphere: chemical data

    International Nuclear Information System (INIS)

    Robouch, P.

    1989-01-01

    An exhaustive bibliographic review on hydrolysis of americium gives the stability constants, at zero ionic strength. No evidence of Am(OH) 4 - formation was found by solubility studies up to pH 2 (CO 3 ) 3 characterised by its X-ray diffraction pattern is studied at a high ionic strength. All the published results on Am in carbonate media are reinterpreted using these stability constants (Am-OH-CO 3 complexes are not needed). No evidence of Am(CO 3 ) 4 5- formation was found by spectrophotometry up to 3M. Literature results are used to determine the formal redox potentials at pH = 9.4 and to calculate the formation constants, at zero ionic strength. The formation of complexes between americium and humic materials (purified fulvic and humic acids) has been studied by a spectrophotometric technique. The results are interpreted by the formation of a 1:1 complexe. Solubility of the solid PuO 2 (CO 3 ) is measured in bicarbonate media at high ionic strength, to obtain the solubility product and formation constants of the PuO 2 (CO 3 ) i 2-2i complexes [fr

  2. Production of a square geometry Americium standard source for use with photodiodes

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Priscila; Geraldo, Bianca; Raele, Marcus P.; Marumo, Júlio T.; Vicente, Roberto; Zahn, Guilherme S.; Genezini, Frederico A., E-mail: priscila3.costa@usp.br, E-mail: fredzini@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    In the development of a thermal neutron detector using a square photodiode and a thin boron film, a radioactive calibration source with the same geometry was needed. An americium-243 standard source was produced by electrodeposition aiming at the calibration of a PIN-type silicon photodiode with a detection area of 10 x 10 mm{sup 2}. To produce the samples two tests were performed. In the first test, a square stainless steel plate (10 x 10 mm{sup 2}) was fixed on the surface of the conventional plate, which was removed after deposition. To reduce the loss of activity of the source, in the second test nail polish was applied on the silver plate leaving only an area of 10 x 10 mm{sup 2} without varnish coating. Once the electrodeposition process was completed, the activity concentration measurement was performed by alpha particle spectrometry. The first method presented a lower activity when compared to the total activity of Am-243 added initially. For the second method, the total activity was concentrate in the exposed square region (without nail polish). The results showed that it is possible to obtain a square geometry source; furthermore, the surrounding nail polish was not contaminated by {sup 243}Am. The comparison of these two approaches indicated that the second method was more efficient as it was possible to concentrate all the americium activity in the delimited square area. (author)

  3. Comparison of Americium-Beryllium neutron spectrum obtained using activation foil detectors and NE-213 spectrometer

    International Nuclear Information System (INIS)

    Sunny, Sunil; Subbaiah, K.V.; Selvakumaran, T.S.

    1999-01-01

    Neutron spectrum of Americium - Beryllium (α,n) source is measured with two different spectrometers vis-a-vis activation foils (foil detectors) and NE-213 organic scintillator. Activity induced in the foils is measured with 4π-β-γ sodium iodide detector by integrating counts under photo peak and the saturation activity is found by correcting to elapsed time before counting. The data on calculated activity is fed into the unfolding code, SAND-II to obtain neutron spectrum. In the case of organic scintillator, the pulse height spectrum is obtained using MCA and this is processed with unfolding code DUST in order to get neutron spectrum. The Americium - Beryllium (α,n) neutron spectrum thus obtained by two different methods is compared. It is inferred that the NE-213 scintillator spectrum is in excellent agreement with the values beyond 1MeV. Neutron spectrum obtained by activation foils depends on initial guess spectrum and is found to be in reasonable agreement with NE-213 spectrum. (author)

  4. 48 CFR 252.246-7003 - Notification of Potential Safety Issues.

    Science.gov (United States)

    2010-10-01

    ... Safety Issues. 252.246-7003 Section 252.246-7003 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.246-7003 Notification of Potential Safety Issues. As prescribed in 246.371(a), use the following clause: Notification of Potential Safety Issues (JAN 2007) (a...

  5. The distribution of plutonium-239 and americium-241 in the Syrian hamster following its intravenous administration as citrate

    International Nuclear Information System (INIS)

    Rodwell, P.; Stather, J.W.

    1978-01-01

    Actinide distribution in various tissues and the skeleton of hamsters by liquid scintillation counting or isotope dilution. For plutonium 57% of activity was concentrated in the skeleton and more than 90% in the liver and skeleton after seven days. For americium the liver retained more than 50% of total activity and 25% was excreted in urine within seven days. (U.K.)

  6. Worldwide bioassay data resources for plutonium/americium internal dosimetry studies

    International Nuclear Information System (INIS)

    Miller, G.; Bertelli, L.; Little, T.; Guilmette, R.; Riddell, T.; Filipy, R.

    2005-01-01

    Full text: Biokinetic models are the scientific underpinning of internal dosimetry. These models describe how materials of interest taken into the body by various routes (for example inhalation) are transported through the body, allowing the modelling of bioassay measurements and the estimation of radiation dose. The International Commission on Radiation Protection (ICRP) publishes biokinetic models for use in internal dosimetry. These models represent the consensus judgement of a committee of experts, based on human and animal data. Nonetheless, it is important to validate biokinetic models using directly applicable data, in a scientifically transparent manner, especially for internal dosimetry research purposes (as opposed to radiation protection), as in epidemiology studies. Two major goals would be to determine individual variations of model parameters for the purpose of assessing this source of uncertainty in internal dose calculations, and to determine values of workplace specific parameters (such as particle solubility in lung fluids) for different representative workplaces. Furthermore, data on the observed frequency of intakes under various conditions can be used in the interpretation of bioassay data. All of the above may be couched in the terminology of Bayesian statistical analysis and amount to the determination of the Bayesian prior probability distributions needed in a Bayesian interpretation of bioassay data. The authors have direct knowledge of several significant databases of plutonium/americium bioassay data (including autopsy data). The purpose of this paper is to acquaint the worldwide community with these resources and to invite others who may know of other such databases to participate with us in a publication that would document the content, form, and the procedures for seeking access to these databases. These databases represent a tremendous scientific resource in this field. Examples of databases known to the authors include: the

  7. Complex formation of trivalent americium with salicylic acid at very low concentrations

    International Nuclear Information System (INIS)

    Melanie Mueller; Margret Acker; Steffen Taut; Gert Bernhard; Forschungszentrum Dresden-Rossendorf, Dresden

    2010-01-01

    For the first time, the complexation of americium(III) with salicylic acid was studied at trace metal concentrations using a 2.0 m Long Path Flow Cell for UV-vis spectroscopy. The detection limit of Am(III) in aqueous solution at pH 3.0 was found to be 5 x 10 -9 M. Two Am(III)-salicylate complexes were formed at pH 5.0 in 0.1 M NaClO 4 , indicated by a clear red shift of the absorption maximum. The absorption spectra obtained from spectrophotometric titration were analyzed by means of factor analysis and complex stabilities were calculated to be log β 110 = 2.56 ± 0.08 and log β 120 = 3.93 ± 0.19. (author)

  8. Plutonium and americium concentrations and vertical profiles in some Italian mosses used as bioindicators

    International Nuclear Information System (INIS)

    Testa, C.; Desideri, D.; Meli, M.A.; Guerra, F.; Degetto, S.; Jia, G.; Gerdol, R.

    1998-01-01

    We have examined the uptake of actinide elements Am and Pu by different species of lichen and moss collected in two locations (Urbino, Central Italy; Alps region, North-east Italy). Plutonium and americium were separated and determined by extraction chromatography, electrodeposition and alpha-spectrometry. This paper summarizes our results with a special emphasis on the vertical profiles of these actinides in two different species of mosses. Several 1-2 cm depth sections were obtained and dated by 210 Pb method. A typical peak for 239,240 Pu and 241 Am was found in the very old moss species ('Sphagnum Compactum') at a depth corresponding to the period 1960-1970 which was the period characterized by the maximum nuclear weapon tests. In a younger moss species ('Neckeria Crispa') no peak was observed and the regression curves showed that Am is more mobile than 239,240 Pu and 238 Pu. (author)

  9. The uptake of plutonium-239, 240, americium-241, strontium-90 into plants

    International Nuclear Information System (INIS)

    Popplewell, D.S.; Ham, G.J.; Johnson, T.E.

    1984-01-01

    This report describes the results of measurements on the uptake of plutonium, americium, strontium-90 and caesium-137 into peas, beet, oats, sweet corn, tomatoes and vegetable marrow grown in tubs containing radioactively-contaminated silts. The silts had been taken from an area of West Cumbria commonly referred to as the Ravenglass estuary. The experiments are categorised as being carried out under non-standard conditions because of the manner in which the radioactivity came to be incorporated into the growth medium. The growth medium was representative of conditions which could arise when the estuarine silt moves inland under the influence of wind and tide and mixes with the adjacent farm land. The silt had been contaminated by radioactive effluents from the nuclear fuels reprocessing plant at Sellafield and this contamination had been brought about by natural means. (Auth.)

  10. Separation of trivalent americium and europium by purified Cyanex 301 immobilized in macro porous polymer

    International Nuclear Information System (INIS)

    Jing Chen; Veltkamp, A.C.; Booij, A.S.

    2002-01-01

    High separation ability of purified Cyanex 301 towards trivalent americium over europium in liquid-liquid extraction is confirmed. Solvent 2-nitrophenyl octyl ether (NPOE) lowered the partitioning of Am 3+ but remained the separation ability over europium. Solvent toluene and 3-octanone lowered the separation factor to ∼ 1000. It is feasible to separate Am 3+ from Eu 3+ by Cyanex 301 which was immobilized in the macro porous polymer (MPP). 3-Octanone is a suitable solvent for dissolving NH 4 OH-saponified Cyanex 301 and MPP is a suitable solid supported material for column operation. A five-step column experiment demonstrated the feasibility to separate Am 3+ from Eu 3+ in column which was packed with Cyanex 301-impregnated MPP. (author)

  11. Spectral properties of americium(III) in silicate matrices. Concentration-dependent up-conversion emission

    International Nuclear Information System (INIS)

    Assefa, Zerihun; Haire, R.G.; Stump, N.

    2002-01-01

    We have been pursuing the spectroscopic properties of actinide ions in silicate matrices. One facet of these studies involves the behavior of Stokes and anti-Stokes emissions exhibited by Am 3+ in these hosts. Several attributes have been found to influence the spectral profile, which include excitation wavelength, laser power, and dopant-concentration. Excitation with the 514.5 nm (19435 cm -1 ) line of argon laser provides anti-Stokes emissions at 21100 and ∼19920 cm -1 in the borosilicate matrices. This up-conversion was found to proceed through a multi-photon scheme, and the efficiency increases with increased dopant concentration. Based on our concentration-dependent studies, the up-conversion is suggested to involve a cross-relaxation process [( 5 D 1' , 7 F 0' ) ( 7 F 6' , 7 F 2' )] between neighboring americium ions. (author)

  12. Standard practice for The separation of americium from plutonium by ion exchange

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This practice describes the use of an ion exchange technique to separate plutonium from solutions containing low concentrations of americium prior to measurement of the 241Am by gamma counting. 1.2 This practice covers the removal of plutonium, but not all the other radioactive isotopes that may interfere in the determination of 241Am. 1.3 This practice can be used when 241Am is to be determined in samples in which the plutonium is in the form of metal, oxide, or other solid provided that the solid is appropriately sampled and dissolved (See Test Methods C758, C759, and C1168). 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  13. Magnesium ionophore II as an extraction agent for trivalent europium and americium

    Energy Technology Data Exchange (ETDEWEB)

    Makrlik, Emanuel [Czech Univ. of Life Sciences, Prague (Czech Republic). Faculty of Environmental Sciences; Vanura, Petr [Univ. of Chemistry and Technology, Prague (Czech Republic). Dept. of Analytical Chemistry

    2016-11-01

    Solvent extraction of microamounts of trivalent europium and americium into nitrobenzene by using a mixture of hydrogen dicarbollylcobaltate (H{sup +}B{sup -}) and magnesium ionophore II (L) was studied. The equilibrium data were explained assuming that the species HL{sup +}, HL{sup +}{sub 2}, ML{sup 3+}{sub 2}, and ML{sup 3+}{sub 3} (M{sup 3+} = Eu{sup 3+}, Am{sup 3+}; L=magnesium, ionophore II) are extracted into the nitrobenzene phase. Extraction and stability constants of the cationic complex species in nitrobenzene saturated with water were determined and discussed. From the experimental results it is evident that this effective magnesium ionophore II receptor for the Eu{sup 3+} and Am{sup 3+} cations could be considered as a potential extraction agent for nuclear waste treatment.

  14. 40 CFR 246.202-3 - Recommended procedures: Market study.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Market study... § 246.202-3 Recommended procedures: Market study. An investigation of markets should be made by the...: (a) Identifying potential purchasers of the recovered corrugated through standard market research...

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  20. 40 CFR 86.246-94 - Intermediate temperature testing.

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  1. Separation of oxidized americium from lanthanides by use of pillared metal(IV) phosphate-phosphonate hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Burns, J.D.; Clearfield, A. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Borkowski, M.; Reed, D.T. [Los Alamos National Laboratory, Carlsbad, NM (United States). Earth and Environmental Sciences Div.

    2012-07-01

    Closing the nuclear fuel cycle in the US poses many challenges, one of which is found in the waste streams, which contain both trivalent lanthanides and actinides. The separation of americium from the raffinate will dramatically reduce the long-term radiotoxicity of the waste. The sorption of americium in both the tri- and pentavalent oxidation states was observed for four M(IV) phosphate-phosphonate ion exchange materials in nitric acid at pH 2. High selectivity was observed for reduced Am(III) with K{sub d} values ca. 6 x 10{sup 5} mL/g, while the K{sub d} values for Am(V) were much lower. A new method of synthesizing and stabilizing AmO{sub 2}{sup +} to yield a lifetime of at least 24 h in acidic media using a combination of sodium persulfate and calcium hypochlorite will be described.

  2. Separation of oxidized americium from lanthanides by use of pillared metal(IV) phosphate-phosphonate hybrid materials

    International Nuclear Information System (INIS)

    Burns, J.D.; Clearfield, A.; Borkowski, M.; Reed, D.T.

    2012-01-01

    Closing the nuclear fuel cycle in the US poses many challenges, one of which is found in the waste streams, which contain both trivalent lanthanides and actinides. The separation of americium from the raffinate will dramatically reduce the long-term radiotoxicity of the waste. The sorption of americium in both the tri- and pentavalent oxidation states was observed for four M(IV) phosphate-phosphonate ion exchange materials in nitric acid at pH 2. High selectivity was observed for reduced Am(III) with K d values ca. 6 x 10 5 mL/g, while the K d values for Am(V) were much lower. A new method of synthesizing and stabilizing AmO 2 + to yield a lifetime of at least 24 h in acidic media using a combination of sodium persulfate and calcium hypochlorite will be described.

  3. Upper limits to americium concentration in large sized sodium-cooled fast reactors loaded with metallic fuel

    International Nuclear Information System (INIS)

    Zhang, Youpeng; Wallenius, Janne

    2014-01-01

    Highlights: • The americium transmutation capability of Integral Fast Reactor was investigated. • The impact from americium introduction was parameterized by applying SERPENT Monte Carlo calculations. • Higher americium content in metallic fuel leads to a power penalty, preserving consistent safety margins. - Abstract: Transient analysis of a large sized sodium-cooled reactor loaded with metallic fuel modified by different fractions of americium have been performed. Unprotected loss-of-offsite power, unprotected loss-of-flow and unprotected transient-over-power accidents were simulated with the SAS4A/SASSYS code based on the geometrical model of an IFR with power rating of 2500 MW th , using safety parameters obtained with the SERPENT Monte Carlo code. The Ti-modified austenitic D9 steel, having higher creep rupture strength, was considered as the cladding and structural material apart from the ferritic/martensitic HT9 steel. For the reference case of U–12Pu–1Am–10Zr fuel at EOEC, the margin to fuel melt during a design basis condition UTOP is about 50 K for a maximum linear rating of 30 kW/m. In order to maintain a margin of 50 K to fuel failure, the linear power rating has to be reduced by ∼3% and 6% for 2 wt.% and 3 wt.% Am introduction into the fuel respectively. Hence, an Am concentration of 2–3 wt.% in the fuel would lead to a power penalty of 3–6%, permitting a consumption rate of 3.0–5.1 kg Am/TW h th . This consumption rate is significantly higher than the one previously obtained for oxide fuelled SFRs

  4. Uptake of americium-241 by plants from contaminated Chernobyl exclusive zone test site soils

    International Nuclear Information System (INIS)

    Rashydov, N.M.

    2002-01-01

    Americium-241 was found to accumulate in soils and biological objects of the environment. Its concentration has increased many times after the Chernobyl disaster and can be expected to increase about 40 times in the future. This research concentrated on the contaminated exclusive Chernobyl zone polluted by trace radionuclides, their behavior and accumulation by various plant species. Special attention is devoted to the bioavailability of 241 Am to the plants Galium rivale, G. tinctorium, G. aparine, G. intermedium, Berteroa incana, Artemisia absinthium, A. vulgaris, Centaurea borysthenica, C. arenaria, Cirsium arvense, Succissa pratensis, Solidago virgaurea, Linaria vulgaris, Lepidium ruderale, Stenactis annua, Veronica maxima, Verbascum lychnitis, Euphorbia cyparissias, Genista tinctoria, Erigeron canadensis, Oenothera biennis, Betula pendula and Quercus robur, which were collected from the Chernobyl, Kopachi, and Yanov districts. The plant samples of Oenothera biennis, Betula pendula and Quercus robur were collected from the Yanov district, where the soil contamination by 241 Am and 137 Cs was at the level of 660 and 27 MBq/m 2 , respectively. Gamma spectroscopy and radiochemical methods were used to estimate the activity concentration of 137 Cs, 90 Sr, 238 Pu, 239+240 Pu, 241 Am. The radionuclides were measured in the dry green mass of the plant samples and in the dry soils. The contamination of the Oenothera biennis, Betula pendula and Quercus robur samples by 137 Cs was (5.8±1,5)x10 6 , (7.4±1.1)x10 5 , and (2.6±0.2)x10 6 Bq/kg dry mass, respectively, and contamination by 241 Am was 47±5, 45±3 and 3.2±0.2 Bq/kg, respectively. The soil-to-plant transfer ratio for 137 Cs ranged lay within the interval of 0.2 to 0.03 Bq/kg : Bq/m 2 , the the transfer ratio for 241 Am did not exceed 7x10 -5 Bq/kg : Bq/m 2 . The coefficient of the relative contents of the 241 Am/ 239+240 Pu radionuclides in the various plant samples varied from 3.2 to 8.3, while for soil from

  5. 48 CFR 52.246-9 - Inspection of Research and Development (Short Form).

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    2010-10-01

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  6. 40 CFR 246.201-6 - Recommended procedures: Transportation to market.

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    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Recommended procedures: Transportation to market. 246.201-6 Section 246.201-6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Procedures § 246.201-6 Recommended procedures: Transportation to market. Transportation to market may be...

  7. 48 CFR 552.246-77 - Additional Contract Warranty Provisions for Supplies of a Noncomplex Nature.

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    ... Warranty Provisions for Supplies of a Noncomplex Nature. 552.246-77 Section 552.246-77 Federal Acquisition... a Noncomplex Nature. As prescribed in 546.710(a), insert the following clause in solicitations and contracts that include FAR 52.246-17, Warranty of Supplies of a Noncomplex Nature. Additional Contract...

  8. 48 CFR 246.402 - Government contract quality assurance at source.

    Science.gov (United States)

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  9. Contrasts between the marine and freshwater biological interactions of plutonium and americium

    International Nuclear Information System (INIS)

    Livingston, H.D.; Bowen, V.T.

    1975-01-01

    Whether in lakes or the oceans the transuranic elements plutonium and americium are taken up by marine organisms, with concentration factors that would class them as nice, typical heavy metals. There is no evidence for strong, widespread discrimination against the transuranics by either plant or animal absorptive surfaces. In both freshwater and marine situations the major reservoir of Pu and Am soon becomes the sediments, and organisms are more exposed to uptake of these nuclides the closer is their ecological involvement with the sediments. Although there is little evidence that this can be an ionic strength effect, it does appear that Pu may be somewhat more available, biologically, in marine environments, and Am, conversely, in fresh water. We incline to the belief that details of these behaviors are usually controlled by local availability of organic complexers. No compelling evidence exists of increase in Pu concentration at higher levels of food chains; in marine situations this appears true of Am as well, but a few data suggest that in fresh water fish there is a progressive increase, in higher trophic levels, in the ratio Am to Pu. Although marine and fresh water biogeochemistries of transuranics are much more similar than we had expected, it will generally be dangerous to extrapolate from one to the other. In both systems there appears to us no question that we are observing real element biogeochemistry, not the redistribution of inert, labelled, fallout fragments

  10. Multicompartment kinetic models for the metabolism of americium, plutonium and uranium in rats

    International Nuclear Information System (INIS)

    Sontag, W.

    1986-01-01

    To examine the kinetic behaviour of americium, plutonium and uranium in male and female rats, an extended mammillary model has been developed, composed of 10 compartments connected with 17 linear transfer coefficients. The 10 compartments describe the behaviour of the three nuclides in the blood, skeleton, liver and kidney; the remaining activity is assigned to one residual organ. Each organ is divided into two compartments, short- and long-term. In the skeleton the short-term compartment has been assumed to be the bone surface and marrow, and the long-term compartment the deep bone; in the liver, evidence suggests that the short-term compartment is physiologically associated with lysosomes and the long-term compartment identical with telolysosomes. Influence of age, sex and different nuclides on the transfer coefficients and the absorbed radiation dose are discussed. By using the transfer coefficients calculated for intravenous injection, the behaviour of the nuclides in skeleton and liver during continuous intake has been calculated. The behaviour of the three nuclides in skeleton and liver after intravenous injection has also been calculated with the additional assumption that from the fifth day the animals were treated continuously with a chelating agent. (UK)

  11. Development and Testing of an Americium/Lanthanide Separation Flowsheet Using Sodium Bismuthate

    Energy Technology Data Exchange (ETDEWEB)

    Jack Law; Bruce Mincher; Troy Garn; Mitchell Greenhalgh; Nicholas Schmitt; Veronica Rutledge

    2014-04-01

    The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. A separation process amenable to process scale-up remains elusive. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series this separation is challenging ; however, higher oxidation states of americium can be prepared using sodium bismuthate and separated via solvent extraction using diamylamylphosphonate (DAAP) extraction. Among the other trivalent metals only Ce is also oxidized and extracted. Due to the long-term instability of Am(VI) , the loaded organic phase is readily selectively stripped to partition the actinide to a new acidic aqueous phase. Batch extraction distribution ratio measurements were used to design a flowsheet to accomplish this separation. Additionally, crossflow filtration was investigated as a method to filter the bismuthate solids from the feed solution prior to extraction. Results of the filtration studies, flowsheet development work and flowsheet performance testing using a centrifugal contactor are detailed.

  12. Speciation and bioavailability of Americium-241 in the fresh water environment

    International Nuclear Information System (INIS)

    Bierkens, J.

    1986-01-01

    Due to its anthropogenic origin, the transuranic americium 241 confronts physiologists with the intriguing question, which mechanisms are involved in the incorporation or elimination of such artificial elements in biological cycles. The investigations on the speciation and bioavailability of 241 Am in the freshwater environment aim to establish a relation between the behavior of 241 Am in freshwater ecosystems and its availability for biota. In the limnic environment, most often characterized by a high organic load and a low conductivity, the effect of complexation of 241 Am with humic acids and competition with trivalent cations such as A1 and Fe, were proven to be significant on the speciation of 241 Am. Based on the registration of the 241 Am uptake by a large number of freshwater organisms, the crayfish Astacus leptodactylus Eschscholtz was chosen to study the whole-body uptake of 241 Am, its corresponding organ distribution and its retention in the animal. The share of external fixation and ingestion in the global uptake, and the effect of speciation on it, were studied more carefully. Other aspects in this physiological part were: the kinetics of 241 Am in the hemolymph and the hepatopancreas, and its subcellular distribution in the digestive gland. Finally, by comparing the physiology of 241 Am with some other metals ( 240 Pu, 64 Cu, 198 Au) with analogous or contradictional properties, we tried to find out whether the behavior of 241 Am in organisms can be explained from its chemical characteristics

  13. Americium and plutonium in water, biota, and sediment from the central Oregon coast

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Reinald Dreas [Oregon State Univ., Corvallis, OR (United States)

    1982-06-01

    Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels.

  14. Americium and plutonium in water, biota, and sediment from the central Oregon coast

    International Nuclear Information System (INIS)

    Nielsen, R.D.

    1982-06-01

    Plutonium-239, 240 and americium-241 were measured in the mussel Mytilus californianus from the region of Coos Bay, OR. The flesh of this species has a plutonium concentration of about 90 fCi/kg, and an Am-241/Pu-239, 240 ratio that is high relative to mixed fallout, ranging between two and three. Transuranic concentrations in sediment, unfiltered water, and filterable particulates were also measured; none of these materials has an Am/Pu ratio as greatly elevated as the mussels, and there is no apparent difference in the Am/Pu ratio of terrestrial runoff and coastal water. Sediment core profiles do not allow accumulation rates or depositional histories to be identified, but it does not appear that material characterized by a high Am/Pu ratio has ever been introduced to this estuary. Other bivalves (Tresus capax and Macoma nasuta) and a polychaete (Abarenicola sp.) do not have an elevated Am/Pu ratio, although the absolute activity of plutonium in the infaunal bivalves is roughly four times that in the mussels

  15. In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    William F. Bauer; Brian K. Schuetz; Gary M. Huestis; Thomas B. Lints; Brian K. Harris; R. Duane Ball; Gracy Elias

    2012-09-01

    Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dose estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.

  16. Removal of plutonium and Americium from hydrochloric acid waste streams using extraction chromatography

    International Nuclear Information System (INIS)

    Schulte, L.D.; FitzPatrick, J.R.; Salazar, R.R.; Schake, B.S.; Martinez, B.T.

    1995-01-01

    Extraction chromatography is under development as a method to lower actinide activity levels in hydrochloric acid (HCl) effluent streams. Successful application of this technique for radioactive liquid waste treatment would provide a low activity feedstream for HCl recycle, reduce the loss of radioactivity to the environment in aqueous effluents, and lower the quantity and improve the form of solid waste generated. The extraction of plutonium and americium from HCl solutions was examined for several commercial and laboratory-produced sorbed resin materials. Polymer beads were coated with n-octyl(phenyl)-N,N-diisobutylcarbamoyl- methylphosphine oxide (CMPO) and either tributyl phosphate (TBP), or diamyl amylphosphonate (DAAP). Distribution coefficients for Pu and Am were measured by contact studies in 1-10 M HCl, while varying REDOX conditions, actinide loading levels, and resin formulations. Flow experiments were run to evaluate actinide loading and elution under varied conditions. Significant differences in the actinide distribution coefficients in contact experiments, and in actinide retention in flow experiments were observed as a function of resin formulation

  17. Cleanex process: a versatile solvent extraction process for recovery and purification of lanthanides, americium, and curium

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Collins, E.D.; King, L.J.

    1979-01-01

    At a concentration of 1 M in straight-chain hydrocarbon diluent, HDEHP will extract americium, curium, and other trivalent actinide and lanthanide elements from dilute acid or salt solutions. The solute is back-extracted with more concentrated acid, either nitric or hydrochloric. The process has been used in the continuous, countercurrent mode, but its greatest advantage arises in batch extractions where the excess acid can be titrated with NaOH to produce a final acidity of about 0.03 M. Under these conditions, 99% recovery can be achieved, usually in one stage. Cleanex was used on the 50-liter scale at the Transuranium Processing Plant at Oak Ridge for 12 years to provide a broad spectrum cleanup to transuranium elements before applying more sophisticated techniques for separating individual products. The process is also used routinely to recover excessive losses of curium and/or californium from plant waste streams. The solvent system is relatively resistant to radiation damage, being usable up to 200 W-h/liter

  18. Assessment of radiation doses from residential smoke detectors that contain americium-241

    International Nuclear Information System (INIS)

    O'Donnell, F.R.; Etnier, E.L.; Holton, G.A.; Travis, C.C.

    1981-10-01

    External dose equivalents and internal dose commitments were estimated for individuals and populations from annual distribution, use, and disposal of 10 million ionization chamber smoke detectors that contain 110 kBq (3 μCi) americium-241 each. Under exposure scenarios developed for normal distribution, use, and disposal using the best available information, annual external dose equivalents to average individuals were estimated to range from 4 fSv (0.4 prem) to 20 nSv (2 μrem) for total body and from 7 fSv to 40 nSv for bone. Internal dose commitments to individuals under post disposal scenarios were estimated to range from 0.006 to 80 μSv (0.0006 to 8 mrem) to total body and from 0.06 to 800 μSv to bone. The total collective dose (the sum of external dose equivalents and 50-year internal dose commitments) for all individuals involved with distribution, use, or disposal of 10 million smoke detectors was estimated

  19. Study of biosorbents application on the treatment of radioactive liquid wastes with americium-241

    International Nuclear Information System (INIS)

    Borba, Tania Regina de

    2010-01-01

    The use of nuclear energy for many different purposes has been intensified and highlighted by the benefits that it provides. Medical diagnosis and therapy, agriculture, industry and electricity generation are examples of its application. However, nuclear energy generates radioactive wastes that require suitable treatment ensuring life and environmental safety. Biosorption and bioaccumulation represent an emergent alternative for the treatment of radioactive liquid wastes, providing volume reduction and physical state change. This work aimed to study biosorbents for the treatment of radioactive liquid wastes contaminated with americium-241 in order to reduce the volume and change the physical state from liquid to solid. The biosorbents evaluated were Saccharomyces cerevisiae immobilized in calcium alginate beads, inactivated and free cells of Saccharomyces cerevisiae, calcium alginate beads, Bacillus subtilis, Cupriavidus metallidurans and Ochrobactrum anthropi. The results were quite satisfactory, achieving 100% in some cases. The technique presented in this work may be useful and viable for implementing at the Waste Management Laboratory of IPEN - CNEN/SP in short term, since it is an easy and low cost method. (author)

  20. Separation of neptunium, plutonium, americium and curium from uranium with di-(2-ethylhexyl)-phosphoric acid (HDEHP) for radiometric and ICP-MS analysis

    International Nuclear Information System (INIS)

    Ramebaeck, H.; Skaalberg, M.

    1998-01-01

    The possibility of using di-(2-ethylhexyl)-phosphoric acid (HDEHP) in solvent extraction for the separation of neptunium, plutonium, americium and curium from large amounts of uranium was studied. Neptunium, plutonium, americium and curium (as well as uranium) were extracted from HNO 3 , whereafter americium and curium were back-extracted with 5M HNO 3 . Thereafter was neptunium back-extracted in 1M HNO 3 containing hydroxylamine hydronitrate. Finally, plutonium was back-extracted in 3M HCl containing Ti(III). The method separates 238 Pu from 241 Am for α-spectroscopy. For ICP-MS analysis, the interferences from 238 U are eliminated: tailing from 238 U, for analysis of 237 Np, and the interference of 238 UH + for analysis of 239 Pu. The method has been used for the analysis of actinides in samples from a spent nuclear fuel leaching and radionuclide transport experiment. (author)

  1. Use of radioisotopes in the study of tetracycline analytical application. Extraction of compounds formed between tetracycline and neptunium and americium elements

    International Nuclear Information System (INIS)

    Saiki, M.; Lima, F.W. de

    1986-01-01

    The behavior of tetracycline as complexing agent, in solvent extraction studies of neptunium and americium, using benzyl alcohol as the organic phase, is presented. By using radioactive tracers of 239 Np and 2 4 1 Am the extraction percent of these elements were determined as a function of pH in the absence and in the presence of several masking agents. The influence of shaking time and the use of different types of supporting eletrolytes upon the extraction behavior was also studied. The extraction curves obtained using EDTA as masking agent show that tetracycline can be used for neptunium and americium separation. In this condition neptunium is extracted into the organic phase and americium remains in the aqueous phase. (Author) [pt

  2. Transport of plutonium, americium, and curium from soils into plants by roots

    International Nuclear Information System (INIS)

    Pimpl, M.; Schuettelkopf, H.

    1979-12-01

    For assessing the dose from radionuclides in agricultural products by ingestion it is necessary to know the soil to plant transfer factors. The literature was entirely investigated, in order to judge the size of the soil to plant transfer factors. In total, 92 publications - from 1948 to 1978 -have been evaluated. As result, transfer factors from 10 -9 to 10 -3 have been found for Plutonium, and from 10 -6 to 1 for Americium. For Curium only few data are available in literature. The considerable variation of the measured transfer factors is based on the dependence of these transfer factors from the ion exchange capacity of soils, from the amount of organic materials, from the pH-value, and from the mode of contamination. There are, in any case, contradictory data, although there has been detected a dependence of the transfer factors from these parameters. Chelating agenst increase the transfer factors to approximately 1300. As well, fertilizers have an influence on the size of the transfer factors - however, the relationships have been scarcely investigated. The distribution of actinides within the individual parts of plants has been investigated. The highest concentrations are in the roots; in the plant parts above ground the concentration of actinides decreases considerably. The most inferior transfer factors were measured for the respective seed or fruits. The soil to plant transfer factors of actinides are more dependend on the age of the plants within one growing period. At the beginning of the period, the transfer factor is considerably higher than at the end of this period. With respect to plants with a growing period of several years, correlations are unknown. (orig.) [de

  3. Experiments comparing the uptake of americium from chloride media using extraction chromatography

    International Nuclear Information System (INIS)

    FitzPatrick, J.R.; Schake, B.S.; Schulte, L.D.; Martinez, B.T.; Salazar, R.R.

    1995-01-01

    Clean-up of actinide effluent waste steams is of increasing importance at the Los Alamos Plutonium Facility, TA-55, and removing the actinide elements to very low levels allows less radioactivity to go the Los Alamos National Laboratory Water Treatment Facility, TA-50, thus reducing the number of drums of TRU waste. Americium (Am) is a difficult element to remove from chloride media because the +3 state is difficult to oxidize and chelating resins work better with elements such as plutonium which are more readily oxidized to the +4 and/or +6 state. Currently in hydrochloric acid (HC1) media, the acidic liquid waste is neutralized with potassium hydroxide to precipitate the metal hydroxides, before disposal to TA-50. This process is not very efficient. The removal of Am from chloride media was compared using a series of resins, some commercial and some made in our laboratory, using different percentages by weight of octyl(phenyl)-N,N-diiso- butylcarbamoyl-methylphosphine oxide (CMPO ) along with diamyl amylphosphonate (DAAP) or tributyl phosphate (TBP) as diluents. Resins were also made with no added diluent. Early comparisons using small-scale contact studies with 0.5 grams of resin in 0.1M-12M HC1, and subsequent small-scale flow experiments show a trend in which Am uptake is proportional to the amount of CMPO on the resins and the diluent plays a minor role in the uptake of Am from these solutions. Redox chemistry effects were also investigated. From these studies, it is possible to determine the best conditions for the removal of Am from HC1 media thus reducing the gross alpha content of the waste stream by a factor of 10-100 which reduces the number of barrels of waste produced at the Water Treatment Facility

  4. Concentration and vertical distribution of plutonium and americium in Italian mosses and lichens

    International Nuclear Information System (INIS)

    Jia, G.; Desideri, D.; Guerra, F.; Meli, M.A.; Testa, C.

    1997-01-01

    The plutonium and americium concentration and vertical distribution in some Italian mosses and lichens have been determined. The 239,240 Pu, 238 Pu and 241 Am concentration ranges in tree trunk lichens 0.83-1.87, 0.052-0.154 and 0.180-0.770 Bq/kg, respectively. The corresponding values in tree mosses are higher and more scattered ranging from 0.321 to 4.96, from 0.029 to 0.171 and from 0.200 to 1.93 Bq/kg. The mean 238 Pu/ 239,240 Pu and 241 Am/ 239,240 Pu ratios are 0.088±0.037 and 0.38 ± 0.13 in lichens and 0.091±0.072 and 0.54±0.16 in tree mosses. The Pu and Am concentrations are relatively low in terrestrial mosses. The 239,240 Pu, 238 Pu and 241 Am vertical distributions in a terrestrial moss core (Neckera Crispa) collected near Urbino (central Italy) show an exponential decrease with the height. On the contrary the 241 Am vertical distribution in another terrestrial moss core (Sphagnum Compactum) collected in the Alps (northern Italy) shows an interesting peak at 16 cm which corresponds to the deposition of fallout from the nuclear weapon tests in 1960's. The 241 Am movement upward and downward in the moss core is also studied. The results show once again that both mosses and lichens are very effective accumulators of Pu and Am and that they can be used as good biological indicators of the radionuclide airborne pollution from nuclear facilities and nuclear weapon tests. They can play a very important role in cycling naturally or artificially enhanced radionuclides in the atmosphere over long time scales. (author)

  5. Americium/Lanthanide Separations in Alkaline Solutions for Advanced Nuclear Fuel Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Goff, George S. [Los Alamos National Laboratory; Long, Kristy Marie [Los Alamos National Laboratory; Reilly, Sean D. [Los Alamos National Laboratory; Jarvinen, Gordon D. [Los Alamos National Laboratory; Runde, Wolfgang H. [Los Alamos National Laboratory

    2012-06-11

    Project goals: Can used nuclear fuel be partitioned by dissolution in alkaline aqueous solution to give a solution of uranium, neptunium, plutonium, americium and curium and a filterable solid containing nearly all of the lanthanide fission products and certain other fission products? What is the chemistry of Am/Cm/Ln in oxidative carbonate solutions? Can higher oxidation states of Am be stabilized and exploited? Conclusions: Am(VI) is kinetically stable in 0.5-2.0 M carbonate solutions for hours. Aliquat 336 in toluene has been successfully shown to extract U(VI) and Pu(VI) from carbonate solutions. (Stepanov et al 2011). Higher carbonate concentration gives lower D, SF{sub U/Eu} for = 4 in 1 M K{sub 2}CO{sub 3}. Experiments with Am(VI) were unsuccessful due to reduction by the organics. Multiple sources of reducing organics...more optimization. Reduction experiments of Am(VI) in dodecane/octanol/Aliquat 336 show that after 5 minutes of contact, only 30-40% of the Am(VI) has been reduced. Long enough to perform an extraction. Shorter contact times, lower T, and lower Aliquat 336 concentration still did not result in any significant extraction of Am. Anion exchange experiments using a strong base anion exchanger show uptake of U(VI) with minimal uptake of Nd(III). Experiments with Am(VI) indicate Am sorption with a Kd of 9 (10 minute contact) but sorption mechanism is not yet understood. SF{sub U/Nd} for = 7 and SF{sub U/Eu} for = 19 after 24 hours in 1 M K{sub 2}CO{sub 3}.

  6. Determination of americium and curium using ion-exchange in the nitric-acid-methanol medium for environmental analysis

    International Nuclear Information System (INIS)

    Holm, E.; Fukai, R.

    1976-01-01

    While transplutonic elements are only slightly sorbed to anion exchangers from hydrochloric or nitric acid media, the presence of alcohol enhances the anionic exchange of these elements, especially in nitric and sulfuric solutions. In the present work a method has been developed for determining americium and curium in environmental samples, on the basis of the difference between the sorption characteristics to anion exchangers in the acid-methanol system of these transplutonic elements and those of plutonium, polonium and thorium. The method also permits us to perform sequential determination of plutonium, when necessary

  7. Temperature and concentration dependences of the electrical resistivity for alloys of plutonium with americium under normal conditions

    Science.gov (United States)

    Tsiovkin, Yu. Yu.; Povzner, A. A.; Tsiovkina, L. Yu.; Dremov, V. V.; Kabirova, L. R.; Dyachenko, A. A.; Bystrushkin, V. B.; Ryabukhina, M. V.; Lukoyanov, A. V.; Shorikov, A. O.

    2010-01-01

    The temperature and concentration dependences of the electrical resistivity for alloys of americium with plutonium are analyzed in terms of the multiband conductivity model for binary disordered substitution-type alloys. For the case of high temperatures ( T > ΘD, ΘD is the Debye temperature), a system of self-consistent equations of the coherent potential approximation has been derived for the scattering of conduction electrons by impurities and phonons without any constraints on the interaction intensity. The definitions of the shift and broadening operator for a single-electron level are used to show qualitatively and quantitatively that the pattern of the temperature dependence of the electrical resistivity for alloys is determined by the balance between the coherent and incoherent contributions to the electron-phonon scattering and that the interference conduction electron scattering mechanism can be the main cause of the negative temperature coefficient of resistivity observed in some alloys involving actinides. It is shown that the great values of the observed resistivity may be attributable to interband transitions of charge carriers and renormalization of their effective mass through strong s-d band hybridization. The concentration and temperature dependences of the resistivity for alloys of plutonium and americium calculated in terms of the derived conductivity model are compared with the available experimental data.

  8. Osteosarcoma induction by plutonium-239, americium-241 and neptunium-237 : the problem of deriving risk estimates for man

    International Nuclear Information System (INIS)

    Taylor, D.M.

    1988-01-01

    Spontaneous bone cancer (osteosarcoma) represents only about 0.3% of all human cancers, but is well known to be inducible in humans by internal contamination with radium-226 and radium-224. plutonium-239, americium-241 and neptunium-237 form, or will form, the principal long-lived alpha particle emitting components of high activity waste and burnt-up nuclear fuel elements. These three nuclides deposit extensively in human bone and although, fortunately, no case of a human osteosarcoma induced by any of these nuclides is known, evidence from animal studies suggests that all three are more effective than radium-226 in inducing osteosarcoma. The assumption that the ratio of the risk factors, the number of osteosarcoma expected per 10000 person/animal Gy, for radium-226 and any other bone-seeking alpha-emitter will be independent of animal species has formed the basis of all the important studies of the radiotoxicity of actinide nuclides in experimental animals. The aim of this communication is to review the risk factors which may be calculated from the various animal studies carried out over the last thirty years with plutonium-237, americium-241 and neptunium-237 and to consider the problems which may arise in extrapolating these risk factors to homo sapiens

  9. The photoluminescence of crystallophosphors on the base of NaBi(WO4)2 activated by americium, plutonium and neptunium

    International Nuclear Information System (INIS)

    Gliva, V.R.; Novikov, Yu.P.; Myasoedov, B.F.

    1989-01-01

    The luminescence properties of crystallophosphors based on NaBi(WO 4 ) 2 activated by americium, plutonium and neptunium were studied. The synthesis of crystallophosphors is described. Crystallophosphors luminesce in the near infrared region. The excitation and luminescence spectra of crystallophosphors are considered. The dependence of luminescence yield is linear in the wide interval of activator concentration. (author) 3 refs.; 4 figs

  10. Peculiar Behavior of (U,Am)O(2-δ) Compounds for High Americium Contents Evidenced by XRD, XAS, and Raman Spectroscopy.

    Science.gov (United States)

    Lebreton, Florent; Horlait, Denis; Caraballo, Richard; Martin, Philippe M; Scheinost, Andreas C; Rossberg, Andre; Jégou, Christophe; Delahaye, Thibaud

    2015-10-19

    In U(1-x)Am(x)O(2±δ) compounds with low americium content (x ≤ 20 atom %) and oxygen-to-metal (O/M) ratios close to 2.0, Am(III+) cations are charge-balanced by an equivalent amount of U(V+) cations while the fluorite structure of pure U(IV+)O2 is maintained. Up to now, it is unknown whether this observation also holds for higher americium contents. In this study, we combined X-ray diffraction with Raman and X-ray absorption spectroscopies to investigate a U(0.5)Am(0.5)O(2±δ) compound. Our results indicate that americium is again only present as Am(III+), while U(V+) remains below the amount required for charge balance. Unlike lower americium contents, this leads to an overall oxygen hypostoichiometry with an average O/M ratio of 1.92(2). The cationic sublattice is only slightly affected by the coexistence of large amounts of reduced (Am(III+)) and oxidized (U(V+)) cations, whereas significant deviations from the fluorite structure are evidenced by both extended X-ray absorption fine structure and Raman spectroscopies in the oxygen sublattice, with the observation of both vacancies and interstitials, the latter being apparently consistent with the insertion of U6O12 cuboctahedral-type clusters (as observed in the U4O9 or U3O7 phases). These results thus highlight the specificities of uranium-americium mixed oxides, which behave more like trivalent lanthanide-doped UO2 than U(1-x)Pu(x)O(2±δ) MOX fuels.

  11. 40 CFR 52.246 - Control of dry cleaning solvent vapor losses.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control of dry cleaning solvent vapor losses. 52.246 Section 52.246 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... cleaning solvent vapor losses. (a) For the purpose of this section, “dry cleaning operation” means that...

  12. 48 CFR 246.202-4 - Higher-level contract quality requirements.

    Science.gov (United States)

    2010-10-01

    ... quality requirements. 246.202-4 Section 246.202-4 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Quality... requirements, including nongovernment quality system standards adopted to meet DoD needs, are listed in the DoD...

  13. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and Management...

  14. Chemical behaviour of trivalent and pentavalent americium in saline NaCl-solutions. Studies of transferability of laboratory data to natural conditions. Interim report. Reported period: 1.2.1993-31.12.1993; Chemisches Verhalten von drei- und fuenfwertigem Americium in Salinen NaCl-Loesungen. Untersuchung der Uebertragbarkeit von Labordaten auf natuerliche Verhaeltnisse. Zwischenbericht. Berichtszeitraum 1.2.1993-31.12.1993

    Energy Technology Data Exchange (ETDEWEB)

    Runde, W.; Kim, J.I.

    1994-09-15

    In order to clarify the chemical behaviour of Americium in saline aqueous systems relevant for final storage this study deals with the chemical reactions of trivalent and pentavalent Americium in NaCl-solutions under the influence of radiolysis from its own alpha radiation. The focus of the study was on investigating the geologically relevant reactions, such as hydrolysis or carbonate- and chloride complexing in solid-liquid equilibriums. Comprehensive measurements on solubility and spectroscopic studies in NaCl-solutions were carried out in a CO{sub 2}-free atmosphere and 10{sup -2} atm CO{sub 2} partial pressure. Identification and characterisation of the AM (III) and AM(V) solid phases were supplemented by structural research with the chemically analogue EU (III) and Np(V) compounds. The alpha-radiation induced radiolysis in saline NaCl solutions and the redox behaviour of Americium which was influenced thereby were spectroscopically quantified. (orig.) [Deutsch] Zur Klaerung des chemischen Verhaltens von Americium in endlagerrelevanten salinen aquatischen Systemen befasst sich die vorliegende Arbeit mit den chemischen Reaktionen des drei- und fuenfwertigen Americiums in NaCl-Loesungen unter dem Einfluss der Radiolyse durch die eigene {alpha}-Strahlung. Der Schwerpunkt dieser Arbeit lag auf der Untersuchung der geologisch relevanten Reaktionen, wie Hydrolyse sowie Carbonat- und Chloridkomplexierung in fest-fluessig Gleichgewichtssystemen. Hierzu wurden umfassende Loeslichkeitsmessungen und spektroskopische Untersuchungen in NaCl-Loesungen, sowohl unter CO{sub 2}-freier Atmosphaere als auch unter 10{sup -2} atm CO{sub 2}-Partialdruck, durchgefuehrt. Die Identifizierung und Charakterisierung der Am(III)- und Am(V)-Festphasen wurde ergaenzt durch strukturelle Untersuchungen mit den chemisch analogen Eu(III)- und Np(V)-Verbindungen. Die von der {alpha}-Strahlung induzierte Radiolyse in salinen NaCl-Loesungen und das dadurch beeinflusste Redoxverhalten von Americium

  15. Sequential separation method for the determination of Plutonium and Americium in fecal samples

    International Nuclear Information System (INIS)

    Raveendran, Nanda; Rao, D.D.; Yadav, J.R.; Baburajan, A.

    2014-01-01

    The estimation of internal contamination due to Plutonium and Americium of radiation workers of Advanced Fuel Fabrication Facility (AFFF) at Tarapur was carried out by the bioassay (Fecal sample) of the workers. Conventionally the separation of 'Pu' and 'Am' was carried out by alkali fusion followed by the anion exchange separation for Pu and cation exchange separation for Am. This paper deals with an alternative method in which initially the entire ash of the sample added with 236 Pu tracer (3-11 mBq) and 243 Am tracer (2.8-14.5 mBq) was acid leached and Pu was separated by anion exchange as per standard analytical procedure and Am by using TRU resin. In this work the extraction chromatography method using TRU resin procured from Eichrom,U.K. which contains N-N-di isobutyl carbanoyl methyl phosphine oxide (CMPO) as extractant, tri-n-butyl phosphate (TBP) as diluent absorbed on inert polymeric support has been used for the separation of Am from fecal sample. The 8N HNO 3 effluent from Pu separation step was dried and the residue was dissolved in 10 ml 1M Al(NO 3 ) 3 in 3M HNO 3 and pinch of Ascorbic acid was added and loaded on a TRU resin column (dia ∼ 4 mm and height 60 mm) preconditioned with 30 ml 1M Al(NO 3 ) 3 in 3 MHNO 3 . The column was washed with 5 ml 3M HNO 3 and 5 ml 2M HNO 3 . The nitrate concentration was lowered using addition of 10 ml 0.05 M HNO 3 . Am was eluted with 3 ml 9M HCl and 20 ml 2M HCl. The elute was dried and electrodeposited on a SS planchet in NH 4 (SO 4 ) 2 solution at pH 2.2 for two hours. Pu and Am activity estimated by counting in passivated ion implanted planner Silicon detector (PIPS) coupled to 8K channel alpha spectrometer. The sample was counted for duration of 3-4 lacs of seconds. In this study the numbers of samples analyzed are 25. The paper gives detail of analytical recoveries of Pu tracer varies from 55-90 % with a mean of 70% and std. deviation 9.9%. The Am tracer recovery was in the range of 20-89.3% with a mean of

  16. Crystallographic and Spectroscopic Characterization of Americium Complexes Containing the Bis[(phosphino)methyl]pyridine-1-oxide (NOPOPO) Ligand Platform

    Energy Technology Data Exchange (ETDEWEB)

    Corbey, Jordan F. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Rapko, Brian M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Wang, Zheming [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; McNamara, Bruce K. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Surbella, Robert G. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Pellegrini, Kristi L. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States; Schwantes, Jon M. [Pacific Northwest National Laboratory, Richland, Washington 99354, United States

    2018-02-06

    Abstract The crystal structures of americium species containing a common multi-functional phosphine oxide ligand, reported for its ability to extract f elements from acidic solutions, namely 2,6-[Ph2P(O)CH2]2C5H3-NO, L, have finally been determined after over three decades of separations studies involving these species and their surrogates. The molecular compounds Am(L)(NO3)3, Am 1:1, and [Am(L)2(NO3)][NO3]2, Am 2:1, along with their neodymium and europium analogs were synthesized and characterized using single-crystal X-ray crystallography, attenuated total reflectance Fourier transform infrared (ATR) spectroscopy and luminescence spectroscopy to provide a comprehensive comparison with new and known analogous complexes.

  17. Structural study of 2,4,6-triisopropylbenzenesulfonyl chloride

    International Nuclear Information System (INIS)

    Laba, V. I.; Sviridova, A. V.; Nesterov, V. N.

    2009-01-01

    The structure of 2,4,6-triisopropylbenzenesulfonyl chloride (TPSCl) (I) was studied by X-ray diffraction. Compound I is a highly selective condensing agent first suggested by Khorana for the formation of the C3'-C5' interribonucleotide linkage in the oligo- and polyribonucleotide synthesis. I crystals are orthorhombic. At -120 deg. C, the unit-cell parameters are a = 14.184(4) A, b = 11.344(5) A, c = 19.883(6) A, V = 3199(2) A 3 , d calc = 1.257 g/cm 3 , Z = 8, sp. gr. Pbca. Molecule I adopts a strongly flattened boat conformation with the carbon atoms C-SO 2 Cl (C 1 ) and C-i-Pr (C4) of the benzene ring deviating from the bottom of the boat by 0.065(1) and 0.032(1) A, respectively. Molecule I is sterically overcrowded, resulting in an increase in the bond lengths and bond-angle distortions in the fragment containing the SO 2 Cl group and two ortho-i-Pr groups. Nonbonded contacts that are present in the molecule can be considered weak intramolecular hydrogen bonds (for example, the (CH 3 ) 2 C-H-O=S bond). There is no rotation of the SO 2 Cl, ortho-i-Pr, and CH 3 groups. The above-mentioned facts are, apparently, responsible for the specific selectivity of TPSCl. New readily available sterically hindered arenesulfonyl chlorides were designed.

  18. Moessbauer spectroscopy of 237Np created by α-decay of 241Am in some compounds of americium

    International Nuclear Information System (INIS)

    Rebizant, Jean.

    1977-01-01

    The Moessbauer emission spectra of 237 Np impurities fed by α decay of 241 Am were measured in the following compounds: Am metal, AmPtsub(x) (x=1, 3, 5), AmAs, AmBi, Am 2 O 3 , AmO 2 , Lisub(x)AmOsub(x+1) (x=1, 2, 3, 4) and Li 6 AmO 6 . The studies concerned the consequences of the recoil and ionization effects, associated with the α-decay of 241 Am in the solid phase; these are analysed in situ and on a time scale of about 100 ns after the α emission; the dependence of these effects on the physico-chemical nature of the host and on the temperature; information about the electronic, magnetic and structural properties and, also, about the vibrational properties of the Np impurity in the investigated solid matrice as far as the previous effects do not hamper such conclusions. The existence itself of the Moessbauer effect shows that the Np ions are stabilized in well-defined lattice locations at the time of emission of the 59.5keV γ quanta (approximately 100ns), once this level is reached after the 241 Am decay. In Am metal and AmPtsub(x) alloys, the observation of a single charge state for neptunium indicates that the electronic effects associated with the α-decay are recovered in less than 100ns. In the americium oxide compounds and the monopnictides AmAs and AmBi, several charge states of neptunium recoil ions are observed; this shows unambiguously the importance of the ionization effects caused by the α-decay. Some informations about magnetic and electronic properties of the americium host matrices were obtained. The vibration modes of 237 Np impurities in the lattice of Am metal are described by means of the Debye model with a characteristic temperature thetasub(D)=115K [fr

  19. Separation of americium by liquid-liquid extraction using diglycol-amides water-soluble complexing agents

    Energy Technology Data Exchange (ETDEWEB)

    Chapron, S.; Marie, C.; Pacary, V.; Duchesne, M.T.; Miguirditchian, M. [CEA, Centre de Marcoule, Nuclear Energy Division, RadioChemistry and Processses Departement, 30207 Bagnols-sur-Ceze (France); Arrachart, G.; Pellet-Rostaing, S. [Institut de Chimie Separative de Marcoule, LTSM, Bat 426, F-30207 Bagnols-sur- Ceze (France)

    2016-07-01

    Recycling americium (Am) alone from spent nuclear fuels is an important option studied for the future nuclear cycle (Generation IV systems) since Am belongs to the main contributors of the long-term radiotoxicity and heat power of final waste. Since 2008, a liquid-liquid extraction process called EXAm has been developed by the CEA to allow the recovery of Am alone from a PUREX raffinate (a dissolution solution already cleared from U, Np and Pu). A mixture of DMDOHEMA (N,N'-dimethyl-N,N'-dioctyl-2-(2-(hexyloxy)ethyl)-malonamide) and HDEHP (di-2-ethylhexylphosphoric acid) in TPH is used as the solvent and the Am/Cm selectivity is improved using TEDGA (N,N,N',N'-tetraethyl-diglycolamide) as a selective complexing agent to maintain Cm and heavier lanthanides in the acidic aqueous phase (5 M HNO{sub 3}). Americium is then stripped selectively from light lanthanides at low acidity (pH=3) with a poly-aminocarboxylic acid. The feasibility of sole Am recovery was already demonstrated during hot tests in ATALANTE facility and the EXAm process was adapted to a concentrated raffinate to optimize the process compactness. The speciation of TEDGA complexes formed in the aqueous phase with Am, Cm and lanthanides was studied to better understand and model the behavior of TEDGA in the process. Some Ln-TEDGA species are extracted into the organic phase and this specific chemistry might play a role in the Am/Cm selectivity improvement. Hence the hydrophilicity-lipophilicity balance of the complexing agent is an important parameter. In this comprehensive study, new analogues of TEDGA were synthesized and tested in the EXAm process conditions to understand the relationship between their structure and selectivity. New derivatives of TEDGA with different N-alkyl chain lengths and ramifications were synthesized. The impact of lipophilicity on ligand partitioning and Am/Cm selectivity was investigated. (authors)

  20. Inspection report of unauthorized possession and use of unsealed americium-241 and subsequent confiscation, J.C. Haynes Company, Newark, Ohio

    International Nuclear Information System (INIS)

    1985-11-01

    This US Nuclear Regulatory Commission report documents the circumstances surrounding the March 26, 1985, confiscation and subsequent decontamination activities related to the use of unauthorized quantities of americium-241 at the John C. Haynes Company (licensee) of Newark, Ohio. It focuses on the period from early February to July 26, 1985. The incident started when NRC Region III recieved information that John C. Haynes possessed unauthorized quantities of americium-241 and was conducting unauthorized activities (diamond irradiation). By July 26, 1985, the decontamination activities at the licensee's laboratory were concluded. The licensee's actions with diamond irradiation resulted in contamination in restricted and unrestricted areas of the facility. The confiscation and decontamination activities required the combined efforts of NRC, Federal Bureau of Investigation, US Department of Energy, Oak Ridge Associated Universities, the State of Ohio, and the US Environmental Protection Agency. The report describes the factual information and significant findings associated with the confiscation and decontamination activities

  1. Evaluation of neutron cross sections for 244Cm, 246Cm, and 248Cm

    International Nuclear Information System (INIS)

    Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.

    1977-01-01

    An evaluation of neutron cross sections for 244 246 248 Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience

  2. Role of UV photolysis in accelerating the biodegradation of 2,4,6-TCP.

    Science.gov (United States)

    Wang, Wenbing; Kirumba, George; Zhang, Yongming; Wu, Yanqing; Rittmann, Bruce E

    2015-09-18

    2,4,6-TCP, a kind of chlorinated aromatic and aliphatic compound, is difficult to be biodegraded by ordinary microorganisms. UV photolysis and biodegradation of 2,4,6-TCP by Bacillus amyloliquefaciens intimate coupling is a potential means to accelerate its biotransformation. The initial steps of 2,4,6-TCP biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. It was demonstrated that B. amyloliquefaciens has the 2,4,6-TCP monooxygenase gene tcpA which could encode 2,4,6-TCP monooxygenase (TCP-MO). TCP-MO would catalytically decompose 2,4,6-TCP into 2,6-DCHQ. We employed an internal loop photolytic biofilm reactor for 2,4,6-TCP degradation. Sequentially coupled photolysis and biodegradation experimental results suggested that 2,4,6-TCP removal rate in P + B (TCP(UV) + phenol) protocol was higher by 77 and 103 % when compared to B (TCP + phenol) and B (TCP-only) protocols respectively. The corresponding loss rate coefficient (k) values were 0.069, 0.039, 0.034 mg/L·min -1 respectively. This is because UV photolysis converted 2,4,6-TCP into its intermediates: 2,4-dichlorophenol (2,4-DCP), 4-monochlorophenol (4-MCP), phenol, 2,6-dichloro-p-hydroquinone (2,6-DCHQ), with all displaying less inhibition to bacterial action. In addition, phenol was the crucial UV-photolysis product from 2,4,6-TCP, its catabolic oxidation generating internal electron carriers that may accelerate the initial steps of 2,4,6-TCP biodegradation. Intimately coupled photolysis and biodegradation experimental results suggested that 2,4,6-TCP removal rate in P&B (TCP + phenol) protocol was higher by 166 and 681 % when compared to P&B (TCP-only) and P + B protocols respectively. The corresponding loss rate coefficient (k) values were 0.539, 0.203, 0.069 mg/L·min -1 respectively. It provided sufficient evidence to demonstrate that intimately coupled photolysis and biodegradation accelerated 2,4,6-TCP removal

  3. Evaluation of neutron cross sections for /sup 244/Cm, /sup 246/Cm, and /sup 248/Cm

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.

    1977-01-01

    An evaluation of neutron cross sections for /sup 244/ /sup 246/ /sup 248/Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience. (SDF)

  4. Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1991-12-01

    The Americium 241 radioelement accumulation and elimination rate and mechanisms in the lobster organism have been experimentally studied; incorporation and detoxification capacities of each organ are evaluated. The existence of various biological compartments is shown; the major role of the digestive gland in accumulation of the radioelement, its distribution towards the various organs, and its resorption is comprehensively described, with an analysis at the subcellular and molecular levels. 401 p., 65 fig., 43 tab., 428 ref

  5. An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level

    International Nuclear Information System (INIS)

    Paquet, F.

    1993-01-01

    An experimental study of americium-241 kinetics has been conducted in the lobster Homarus gammmarus. The investigations were conducted at all the levels from the whole body to the subcellular and molecular levels. The animals were contaminated by a single or chronic ingestion of 241 Am labelled mussels. Assessments of accumulation, elimination and distribution of the radionuclide were established on organisms kept in the laboratory; they made it possible to demonstrate the importance of the digestive gland in the radionuclide transfer pathways. The preliminary results led to structural then ultrastructural investigations of the digestive gland in association with radioautographic studies and cellular extractions methods. Four cellular types were demonstrated, only two of them being implied in the radionuclide retention, the former being responsible for americium intake and the latter for its long-term retention. By means of biochemical techniques, subcellular accumulation was studied and the organelles implied in the nuclide retention were specified. Finally, a method of cellular nuclei dissociation was developed; it made it possible to analyse the molecular nature of americium ligands and to demonstrate the function of the protein nuclear matrix in the nuclide retention

  6. Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously by TiO2 nanotubes/graphene composite

    Science.gov (United States)

    Slamet, Raudina

    2017-11-01

    Industrial waters in coal pyrolysis process, synthetic chemicals and oil and gas process contain phenol derivatives that are dangerous to the environment and needs to be removed, one of them is 2,4,6-Trichlorophenol. Degradation of 2,4,6-Trichlorophenol and hydrogen production simultaneously have been investigated using TiNT/Graphene composite at various graphene loading and initial concentration of 2,4,6-Trichlorophenol. Optimal graphene loading of 0.6 wt% was obtained in the simultaneous system with 89% elimination of 2,4,6-Trichlorophenol and 986 µmol of hydrogen production. Test results showed that addition of 2,4,6-Trichlorophenol would subsequently increased 2,4,6-Trichlorophenol conversion and enhanced hydrogen production linearly. 2.7 times greater hydrogen production was found in addition of 50 ppm 2,4,6-Trichlorophenol.

  7. The potential of ion mobility spectrometry (IMS) for detection of 2,4,6-trichloroanisole (2,4,6-TCA) in wine.

    Science.gov (United States)

    Karpas, Zeev; Guamán, Ana V; Calvo, Daniel; Pardo, Antonio; Marco, Santiago

    2012-05-15

    The off-flavor of "tainted wine" is attributed mainly to the presence of 2,4,6-trichloroanisole (2,4,6-TCA) in the wine. In the present study the atmospheric pressure gas-phase ion chemistry, pertaining to ion mobility spectrometry, of 2,4,6-trichloroanisole was investigated. In positive ion mode the dominant species is a monomer ion with a lower intensity dimer species with reduced mobility values (K(0)) of 1.58 and 1.20 cm(2)V(-1) s(-1), respectively. In negative mode the ion with K(0) =1.64 cm(2)V(-1)s(-1) is ascribed to a trichlorophenoxide species while the ions with K(0) =1.48 and 1.13 cm(2)V(-1)s(-1) are attributed to chloride attachment adducts of a TCA monomer and dimer, respectively. The limit of detection of the system for 2,4,6-TCA dissolved in dichloromethane deposited on a filter paper was 2.1 μg and 1.7 ppm in the gas phase. In ethanol and in wine the limit of detection is higher implying that pre-concentration and pre-separation are required before IMS can be used to monitor the level of TCA in wine. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Preliminary results from uranium/americium affinity studies under experimental conditions for cesium removal from NPP ''Kozloduy'' simulated wastes solutions

    International Nuclear Information System (INIS)

    Nikiforova, A.; Kinova, L.; Peneva, C.; Taskaeva, I.; Petrova, P.

    2005-01-01

    We use the approach described by Westinghouse Savannah River Company using ammonium molybdophosphate (AMP) to remove elevated concentrations of radioactive cesium to facilitate handling waste samples from NPP K ozloduy . Preliminary series of tests were carried out to determine the exact conditions for sufficient cesium removal from five simulated waste solutions with concentrations of compounds, whose complexing power complicates any subsequent processing. Simulated wastes solutions contain high concentrations of nitrates, borates, H 2 C 2 O 4 , ethylenediaminetetraacetate (EDTA) and Citric acid, according to the composition of the real waste from the NPP. On this basis a laboratory treatment protocol was created. This experiment is a preparation for the analysis of real waste samples. In this sense the results are preliminary. Unwanted removal of non-cesium radioactive species from simulated waste solutions was studied with gamma spectrometry with the aim to find a compromise between on the one hand the AMP effectiveness and on the other hand unwanted affinity to AMP of Uranium and Americium. Success for the treatment protocol is defined by proving minimal uptake of U and Am, while at the same time demonstrating good removal effectiveness through the use of AMP. Uptake of U and Am were determined as influenced by oxidizing agents at nitric acid concentrations, proposed by Savannah River National laboratory. It was found that AMP does not significantly remove U and Am when concentration of oxidizing agents is more than 0.1M for simulated waste solutions and for contact times inherent in laboratory treatment protocol. Uranium and Americium affinity under experimental conditions for cesium removal were evaluated from gamma spectrometric data. Results are given for the model experiment and an approach for the real waste analysis is chosen. Under our experimental conditions simulated wastes solutions showed minimal affinity to AMP when U and Am are most probably in

  9. Analytical utility of the M series x-ray emission lines applied to uranium, neptunium, plutonium, and americium

    International Nuclear Information System (INIS)

    Miller, A.G.

    1976-01-01

    Secondary emission x-ray analysis for actinide elements has usually meant utilizing the L series x-ray lines. The major disadvantage of these x-ray lines is that they fall in the region of high level Bremsstrahlung radiation, producing a high background and, subsequently, larger error and high detection limits. The utilization of the M series x-ray lines of actinide elements with wavelength dispersive x-ray spectrometers greatly minimizes these problems. Calibration curves for uranium, neptunium, plutonium, and americium were prepared by the ''coprex'' method, and the analytical characteristics of the L and M series compared. The Mα and β x-ray lines, under optimum conditions, are several times more sensitive than their L series counterparts. With the greater sensitivity in addition to the lower background, peak to background ratios for M lines up to 40 times greater than those for L lines were obtained. Detection limits can be lowered from about 0.7 μg using the Lα 1 line to 0.05 μg when M x-ray lines are used. The relative advantages and disadvantages of utilizing the L and M series x-ray lines for secondary emission x-ray analysis are discussed

  10. Use of radioanalytical methods for determination of uranium, neptunium, plutonium, americium and curium isotopes in radioactive wastes

    International Nuclear Information System (INIS)

    Geraldo, Bianca

    2012-01-01

    Activated charcoal is a common type of radioactive waste that contains high concentrations of fission and activation products. The management of this waste includes its characterization aiming the determination and quantification of the specific radionuclides including those known as Difficult-to-Measure Radionuclides (RDM). The analysis of the RDM's generally involves complex radiochemical analysis for purification and separation of the radionuclides, which are expensive and time-consuming. The objective of this work was to define a methodology for sequential analysis of the isotopes of uranium, neptunium, plutonium, americium and curium present in a type of radioactive waste, evaluating chemical yield, analysis of time spent, amount of secondary waste generated and cost. Three methodologies were compared and validated that employ ion exchange (TI + EC), extraction chromatography (EC) and extraction with polymers (ECP). The waste chosen was the activated charcoal from the purification system of primary circuit water cooling the reactor IEA-R1. The charcoal samples were dissolved by acid digestion followed by purification and separation of isotopes with ion exchange resins, extraction and chromatographic extraction polymers. Isotopes were analyzed on an alpha spectrometer, equipped with surface barrier detectors. The chemical yields were satisfactory for the methods TI + EC and EC. ECP method was comparable with those methods only for uranium. Statistical analysis as well the analysis of time spent, amount of secondary waste generated and cost revealed that EC method is the most effective for identifying and quantifying U, Np, Pu, Am and Cm present in charcoal. (author)

  11. Vertical transport of particulate-associated plutonium and americium in the upper water column of the Northeast Pacific

    International Nuclear Information System (INIS)

    Fowler, S.W.; Ballestra, S.; La Rosa, J.; Fukai, R.

    1983-01-01

    Concentrations of plutonium (Pu) and americium (Am) were determined in seawater, suspended particulate matter, sediment trap samples, and biogenic material collected at the VERTEX I site in the North Pacific off central California. From a vertical profile taken over the upper 1500 m, the presence of sub-surface maxima of sup(239+240)Pu and 241 Am were identified between 100 to 750 m and 250 to 750 m, respectively. A large fraction (32%) of the filterable sup(239+240)Pu in surface waters was associated with cells during a phytoplankton bloom; Pu:Am activity ratios in surface water and the suspended particles indicated that Pu was concentrated by the cells to a greater degree than Am. However, similar measurements beneath the surface layer showed an overall enrichment of Am over Pu on fine suspended particles with depth. Freshly produced zooplankton fecal pellets and large, fast sinking particles collected in PITS contained relatively high concentrations of Pu and Am. Both transuranic concentrations in trapped particles and transuranic flux tended to increase with depth down to 750 m, suggesting that their scavenging is in the upper water column. Am appeared to be scavenged by sinking biogenic particles to a greater extent than Pu. The results are discussed. (author)

  12. Functions of Flavin Reductase and Quinone Reductase in 2,4,6-Trichlorophenol Degradation by Cupriavidus necator JMP134▿

    OpenAIRE

    Belchik, Sara Mae; Xun, Luying

    2007-01-01

    The tcpRXABCYD operon of Cupriavidus necator JMP134 is involved in the degradation of 2,4,6-trichlorophenol (2,4,6-TCP), a toxic pollutant. TcpA is a reduced flavin adenine dinucleotide (FADH2)-dependent monooxygenase that converts 2,4,6-TCP to 6-chlorohydroxyquinone. It has been implied via genetic analysis that TcpX acts as an FAD reductase to supply TcpA with FADH2, whereas the function of TcpB in 2,4,6-TCP degradation is still unclear. In order to provide direct biochemical evidence for t...

  13. Molten salt extraction (MSE) of americium from plutonium metal in CaCl2-KCl-PuCl3 and CaCl2-PuCl3 salt systems

    International Nuclear Information System (INIS)

    Dodson, K.E.

    1992-01-01

    Molten salt extraction (MSE) of americium-241 from reactor-grade plutonium has been developed using plutonium trichloride salt in stationary furnaces. Batch runs with oxidized and oxide-free metal have been conducted at temperature ranges between 750 and 945C, and plutonium trichloride concentrations from one to one hundred mole percent. Salt-to-metal ratios of 0.10, 0.15, and 0 30 were examined. The solvent salt was either eutectic 74 mole percent CaCl 2 endash 26 mole percent KCl or pure CaCl 2 . Evidence of trivalent product americium, and effects of temperature, salt-to-metal ratio, and oxide contamination on the americium extraction efficiency are given. 24 refs, 20 figs, 13 tabs

  14. Observations on the redistribution of plutonium and americium in the Irish Sea sediments, 1978 to 1996: concentrations and inventories

    International Nuclear Information System (INIS)

    Kershaw, P.J.; Denoon, D.C.; Woodhead, D.S.

    1999-01-01

    The distribution of plutonium and americium in the sub-tidal sediments of the Irish Sea is described following major surveys in 1978, 1983, 1988 and 1995. Concentrations in surface sediments have declined near the source at Sellafield since 1988. Time-series of inter-tidal surface sediment concentrations are presented from 1977 onwards, revealing the importance of sediment reworking and transport in controlling the evolution of the environmental signal. The surface and near-surface sediments, in the eastern Irish Sea 'mud-patch', are generally well mixed with respect to Pu (α) and 241 Am distributions but show increasing variability with depth - up to 4 orders of magnitude in concentration. The inventories of 239,240 Pu and 241 Am in the sub-tidal sediments have been estimated and compared with the reported decay-corrected discharges. These amounted to 360 and 545 TBq respectively, in 1995, about 60% of the total decay-corrected discharge. Part of the unaccounted fraction may be due to unrepresentative sampling of the seabed. It is speculated that some tens of TBq of plutonium and 241 Am reside undetected in the large volumes of coarse-grained, sub-tidal and inter-tidal sediment which characterise much of the Irish Sea. This has been due to the inability of the available corers to penetrate to the base of contamination in these mobile sediments. Further observations are needed to verify and quantify the missing amount. A budget of plutonium-α and 241 Am has been estimated based on published observations in the three main compartments: water column, sub-tidal and inter-tidal sediments. This amounts to 460-540 TBq and 575-586 TBq respectively, or 64-75% and 60-61%, of the decay-corrected reported discharge. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Picomolar traces of americium(III) introduce drastic changes in the structural chemistry of terbium(III). A break in the ''gadolinium break''

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Jan M. [TU Wien, Atominstitut, Vienna (Austria); Mueller, Danny; Knoll, Christian; Wilkovitsch, Martin; Weinberger, Peter [TU Wien, Institute of Applied Synthetic Chemistry, Vienna (Austria); Giester, Gerald [University of Vienna, Institute of Mineralogy and Crystallography, Vienna (Austria); Ofner, Johannes; Lendl, Bernhard [TU Wien, Institute of Chemical Technologies and Analytics, Vienna (Austria); Steinhauser, Georg [Leibniz Universitaet Hannover, Institute of Radioecology and Radiation Protection (Germany)

    2017-10-16

    The crystallization of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] (ZT) in the presence of trace amounts (ca. 50 Bq, ca. 1.6 pmol) of americium results in 1) the accumulation of the americium tracer in the crystalline solid and 2) a material that adopts a different crystal structure to that formed in the absence of americium. Americium-doped [Tb(Am)(H{sub 2}O){sub 7}ZT]{sub 2} ZT.10 H{sub 2}O is isostructural to light lanthanide (Ce-Gd) 5,5{sup '}-azobis[1H-tetrazol-1-ide] compounds, rather than to the heavy lanthanide (Tb-Lu) 5,5{sup '}-azobis[1H-tetrazol-1-ide] (e.g., [Tb(H{sub 2}O){sub 8}]{sub 2}ZT{sub 3}.6 H{sub 2}O) derivatives. Traces of Am seem to force the Tb compound into a structure normally preferred by the lighter lanthanides, despite a 10{sup 8}-fold Tb excess. The americium-doped material was studied by single-crystal X-ray diffraction, vibrational spectroscopy, radiochemical neutron activation analysis, and scanning electron microscopy. In addition, the inclusion properties of terbium 5,5{sup '}-azobis[1H-tetrazol-1-ide] towards americium were quantified, and a model for the crystallization process is proposed. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  16. Measurement of total alpha activity of neptunium, plutonium, and americium in highly radioactive Hanford waste by iron hydroxide precipitation and 2-heptanone solvent extraction

    International Nuclear Information System (INIS)

    Maiti, T.C.; Kaye, J.H.

    1992-06-01

    An improved method has been developed to concentrate the major alpha-emitting actinide elements neptunium, plutonium, and americium from samples with high salt content such as those resulting from efforts to characterize Hanford storage tank waste. Actinide elements are concentrated by coprecipitation of their hydroxides using iron carrier. The iron is removed by extraction from 8M HCI with 2-heptanone. The actinide elements remain in the aqueous phase free from salts, iron, and long-lived fission products. Recoveries averaged 98 percent

  17. 8 CFR 246.4 - Immigration judge's authority; withdrawal and substitution.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Immigration judge's authority; withdrawal... IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 246.4 Immigration judge's authority; withdrawal and substitution. In any proceeding conducted under this part, the immigration judge shall have...

  18. 7 CFR 58.246 - Cleaning of dryers, collectors, conveyors, ducts, sifters and storage bins.

    Science.gov (United States)

    2010-01-01

    ... (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG... Inspection and Grading Service 1 Operations and Operating Procedures § 58.246 Cleaning of dryers, collectors...

  19. 48 CFR 1852.246-70 - Mission Critical Space System Personnel Reliability Program.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Mission Critical Space... CONTRACT CLAUSES Texts of Provisions and Clauses 1852.246-70 Mission Critical Space System Personnel Reliability Program. As prescribed in 1846.370(a), insert the following clause: Mission Critical Space System...

  20. 12 CFR 24.6 - Examples of qualifying public welfare investments.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Examples of qualifying public welfare... INVESTMENTS § 24.6 Examples of qualifying public welfare investments. Investments that primarily support the following types of activities are examples of investments that meet the requirements of § 24.3: (a...

  1. SAGE ANALYSIS OF TRANSCRIPTOME RESPONSES IN ARABIDOPSIS ROOTS EXPOSED TO 2,4,6-TRINITROTOLUENE

    Science.gov (United States)

    Serial Analysis of Gene Expression (SAGE) was used to profile transcript levels in Arabidopsis thaliana roots and assess their responses to 2,4,6-trinitrotoluene (TNT) exposure. SAGE libraries representing control and TNT-exposed seedling root transcripts were constructed, and ea...

  2. 1,3,5-Triazine-2,4,6-triyltrisulfamic acid (TTSA)

    Indian Academy of Sciences (India)

    Melamine reacted with chlorosufonic acid (ClSO3H) to form a new sulfamic-type acid, 1,3,5-triazine-2,4,6-triyltrisulfamic acid (TTSA). Both nitrosation of secondary amines and oxidation of urazoles were accomplished by using TTSA/NaNO2 system under mild and heterogeneous conditions with good to excellent yields.

  3. 25 CFR 1000.246 - Must an AFA that contains a construction project or activity incorporate provisions of Federal...

    Science.gov (United States)

    2010-04-01

    ... as possible in the construction process. If Tribal construction standards are consistent with or... 25 Indians 2 2010-04-01 2010-04-01 false Must an AFA that contains a construction project or activity incorporate provisions of Federal construction standards? 1000.246 Section 1000.246 Indians OFFICE...

  4. Pilot investigation on formation of 2,4,6-trichloroanisole via microbial O-methylation of 2,4,6-trichlorophenol in drinking water distribution system: An insight into microbial mechanism.

    Science.gov (United States)

    Zhang, Kejia; Cao, Cong; Zhou, Xinyan; Zheng, Feifei; Sun, Youmin; Cai, Zhengqing; Fu, Jie

    2017-12-11

    Taste & odor (T&O) problems in drinking water are always complained by customers. Recent studies have indicated biofilms in drinking water distribution system (DWDS) are always ignored as potential sources of T&O compounds. In this paper, the formation of 2,4,6-trichloroanisole (2,4,6-TCA), one of the dominant T&O compounds, was investigated in a pilot-scale DWDS. The addition of precursor 2,4,6-trichlorophenol (2,4,6-TCP) of 0.2 mg/L induced the formation of 2,4,6-TCA with a maximum yield of ∼400 ng/L, and the formation kinetics can be described by a pseudo-first-order kinetic model. Effects of water distribution factors such as pipe material, temperature, flow velocity, and residual chlorine on the formation of 2,4,6-TCA were evaluated, and the pipe material was found to have the most remarkable effect. Ductile iron and stainless steel pipes produced much more 2,4,6-TCA than polyethylene (PE) pipe. The biofilm microbial communities on the three types of pipe walls were then comprehensively analyzed by heterotrophic plate count and 16S rRNA/ITS1 genes high throughput sequencing. The links between the 2,4,6-TCA formation potential and the microbial activity in genus and enzymatic levels in DWDS have been revealed for the first time. According to the characteristics of microbial assemblages of producing 2,4,6-TCA, quorum-sensing (QS) bacterial signaling system and extracellular DNA (eDNA) may be two promising targets for biofilm treatment and 2,4,6-TCA control in DWDS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Synthesis of zirconia sol stabilized by trivalent cations (yttrium and neodymium or americium): a precursor for Am-bearing cubic stabilized zirconia.

    Science.gov (United States)

    Lemonnier, Stephane; Grandjean, Stephane; Robisson, Anne-Charlotte; Jolivet, Jean-Pierre

    2010-03-07

    Recent concepts for nuclear fuel and targets for transmuting long-lived radionuclides (minor actinides) and for the development of innovative Gen-IV nuclear fuel cycles imply fabricating host phases for actinide or mixed actinide compounds. Cubic stabilized zirconia (Zr, Y, Am)O(2-x) is one of the mixed phases tested in transmutation experiments. Wet chemical routes as an alternative to the powder metallurgy are being investigated to obtain the required phases while minimizing the handling of contaminating radioactive powder. Hydrolysis of zirconium, neodymium (a typical surrogate for americium) and yttrium in aqueous media in the presence of acetylacetone was firstly investigated. Progressive hydrolysis of zirconium acetylacetonate and sorption of trivalent cations and acacH on the zirconia particles led to a stable dispersion of nanoparticles (5-7 nm) in the 6-7 pH range. This sol gels with time or with temperature. The application to americium-containing solutions was then successfully tested: a stable sol was synthesized, characterized and used to prepare cubic stabilized zirconia (Zr, Y, Am)O(2-x).

  6. Determining the americium transmutation rate and fission rate by post-irradiation examination within the scope of the ECRIX-H experiment

    Energy Technology Data Exchange (ETDEWEB)

    Lamontagne, J., E-mail: jerome.lamontagne@cea.fr [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Pontillon, Y. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Esbelin, E. [CEA, DEN, DRCP, Marcoule, F-30207 Bagnols-sur-Cèze (France); Béjaoui, S.; Pasquet, B. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Bourdot, P. [CEA, DEN, DER, Cadarache, F-13108 St. Paul Lez Durance (France); Bonnerot, J.M. [Commissariat à l’énergie atomique et aux énergies alternatives (CEA), DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France)

    2013-09-15

    The ECRIX-H experiment aims to assess the feasibility of transmuting americium micro-dispersed in an inert magnesia matrix under a locally moderated neutron flux in the Phénix reactor. A first set of examinations demonstrated that pellet behaviour was satisfactory with moderate swelling at the end of the irradiation. Additional post-irradiation examinations needed to be conducted to confirm the high transmutation rate so as to definitively conclude on the success of the ECRIX-H experiment. This article presents and discusses the results of these new examinations. They confirm the satisfactory behaviour of the MgO matrix not only during the basic irradiation but also during post-irradiation thermal transients. These examinations also provide additional information on the behaviour of fission products both in the americium-based particles and in the MgO matrix. These results particularly validate the transmutation rate predicted by the calculation codes using several different analytical techniques. The fission rate is also determined.

  7. Analytical performance of radiochemical method for americium determination in urine; Desempenho analitico do metodo radioquimico para determinacao de americio em urina

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Juliana Ferreira; Carneiro, Janete C.G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: ju_barreto@terra.com.br

    2005-07-01

    This paper presents an analytical method developed and adapted for separation and analysis of Plutonium (Pu) isotopes and Americium (Am) in urine samples. The proposed method will attend the demand of internal exposure monitoring program for workers involved mainly with dismantling rods and radioactive smoke detectors. In this experimental procedure four steps are involved as preparation of samples, sequential radiochemical separation, preparation of the source for electroplating and quantification by alpha spectrometry. In the first stage of radiochemical separation, plutonium is conventionally isolated employing the anion exchange technique. Americium isolation is achieved sequentially by chromatographic extraction (Tru.spec column) from the load and rinse solutions coming from the anion exchange column. The {sup 243}Am tracer is added into the sample as chemical yield monitors and to correct the results improving the precision and accuracy. The mean recovery obtained is 60%, and the detection limit for 24h urine sample is 1.0 mBq L{sup -1} in accordance with the literature. Based in the preliminary results, the method is appropriate to be used in monitoring programme of workers with a potential risk of internal contamination. (author)

  8. Levan-type fructooligosaccharide production using Bacillus licheniformis RN-01 levansucrase Y246S immobilized on chitosan beads

    Directory of Open Access Journals (Sweden)

    Surawut Sangmanee

    2016-06-01

    Full Text Available Bacillus licheniformis RN-01 levansucrase Y246S (LsRN-Y246S was immobilized by covalently linking onto chitosan, Sepabead EC-EP, and Sepabead EC-HFA, beads. The stability of immobilized LsRN-Y246S was found to be the highest with chitosan beads, retaining more than 70% activity after 13 weeks storage at 4 oC, and 68% activity after 12 hours incubation at 40°C. LsRN-Y246S immobilized on chitosan beads withstands sucrose concentrations up to 70% (w/v, retaining over 85% of its activity, significantly better than LsRN-Y246S immobilized on others supporting matrices. LsRN-Y246S immobilized on chitosan showed a 2.4 fold increase in activity in the presence of Mn2+, and gave slight protection against deactivation by of Cu2+, Zn2+, Fe3+, SDS and EDTA. A maximum of 8.36 g and an average of 7.35 g LFOS yield at least up to DP 11 can be produced from 25 g of sucrose, during five production cycles. We have demonstrated that LFOS can be effectively produced by chitosan immobilized LsRN-Y246S and purified.

  9. Biosensor-Based Approaches for Detecting Ochratoxin A and 2,4,6-Trichloroanisole in Beverages

    Directory of Open Access Journals (Sweden)

    Sophia Mavrikou

    2018-03-01

    Full Text Available Mycotoxins and haloanisoles are secondary metabolites produced under special conditions of temperature and humidity by fungi colonizing a variety of commodities from preharvest up to consumer use. Ochratoxin A and 2,4,6-trichloanisole are produced mainly by species of the genus Aspergillus and Penicillium. Ochratoxin A exhibits nephrotic effects and can, potentially, be associated with human carcinogenesis, whereas 2,4,6-trichloanisole is primarily responsible for cork taint in wines. This review provides an overview of recent advances in biosensor technology for the determination of the aforementioned compounds in wine, beer and other beverages, as well as cork stoppers, which help in establishing and carrying out proper product quality-management strategies. Such a detailed investigation of biosensor-based detection methods of these toxic compounds in beverages could lead to the provision of safe-to-consume products, and allow the prioritization of future research efforts.

  10. Microbial Transformation of 2,4,6-Trinitrotoluene in Aerobic Soil Columns

    OpenAIRE

    Bruns-Nagel, D.; Breitung, J.; von Low, E.; Steinbach, K.; Gorontzy, T.; Kahl, M.; Blotevogel, K.; Gemsa, D.

    1996-01-01

    2,4,6-Trinitrotoluene (TNT)-contaminated soil material of a former TNT production plant was percolated aerobically in soil columns. Nineteen days of percolation with a potassium phosphate buffer supplemented with glucose or glucose plus ammonium sulfate caused an over 90% decline in the amount of extractable nitroaromatics in soils containing 70 to 2,100 mg of TNT per kg (dry weight). In the percolation solution, a complete elimination of TNT was achieved. Mutagenicity and soil toxicity were ...

  11. The in vitro metabolites of 2,4,6-trichlorophenol and their DNA strand breaking properties.

    Science.gov (United States)

    Juhl, U; Blum, K; Witte, I

    1989-01-01

    The carcinogenic compound 2,4,6-trichlorophenol (2,4,6-TCP) was incubated with rat liver S-9 fraction. Three metabolites were identified: 2,6-dichloro-1,4-hydroquinone (DHQ), and two isomers of hydroxypentachlorodiphenyl ether (OH-Cl5-DPE). The latter are probably products of microsomal .OH radical attack on the trichlorophenol molecule forming phenoxy free radicals. These would undergo dimerizations with other molecules present in solution. The 2,6-dichloro-1,4-semiquinone free radical was identified by ESR spectroscopy. It is formed at physiological conditions in phosphate buffer at pH 7.2 and 7.8, with a more intensive signal at the more alkaline pH. The formation is probably due to the autoxidation of the corresponding hydroquinone. Incubation of a mixture of metabolites with PM2 DNA at pH 7.2 resulted in single strand breaks. Addition of catalase and dimethylsulfoxide (DMSO) inhibited the DNA strand scission. It was concluded that reactive oxygen species (ROS), produced during the formation of the semiquinone radical, were responsible for the observed DNA damage. The significance of the ROS and the semiquinone free radical is discussed in view of the reported tumorgenicity of 2,4,6-TCP in rats and mice.

  12. Inhaled americium dioxide

    International Nuclear Information System (INIS)

    Park, J.F.

    1982-01-01

    This project includes experiments to determine the effects of Zn-DTPA therapy on the retention, translocation and biological effects of inhaled 241 AmO 2 . Beagle dogs that received inhalation exposure to 241 AmO 2 developed leukopenia, clincial chemistry changes associated with hepatocellular damage, and were euthanized due to respiratory insufficiency caused by radiation pneumonitis 120 to 131 days after pulmonary deposition of 22 to 65 μCi 241 Am. Another group of dogs that received inhalation exposure to 241 AmO 2 and were treated daily with Zn-DTPA had initial pulmonary deposition of 19 to 26 μCi 241 Am. These dogs did not develop respiratory insufficiency, and hematologic and clinical chemistry changes were less severe than in the non-DTPA-treated dogs

  13. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    International Nuclear Information System (INIS)

    Groettheim, Siri

    2000-01-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m 3 , and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m 3 . In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m 3 , and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  14. Recovery of Americium-241 from lightning rod by the method of chemical treatment; Recuperacion del Americio-241 provenientes de los pararrayos por el metodo de tratamiento quimico

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, W.H., E-mail: wcruz@ipen.gob.pe [Instituto Peruano de Energia Nuclear (GRRA/IPEN), Lima (Peru). Division de Gestion de Residuos Radiactivos

    2013-07-01

    About 95% of the lightning rods installed in the Peruvian territory have set in their structures, pose small amounts of radioactive sources such as Americium-241 ({sup 241}Am), fewer and Radium 226 ({sup 226}Ra) these are alpha emitters and have a half life of 432 years and 1600 years respectively. In this paper describes the recovery of radioactive sources of {sup 241}Am radioactive lightning rods using the conventional chemical treatment method using agents and acids to break down the slides. The {sup 241}Am recovered was as excitation source and alpha particle generator for analysing samples by X Ray Fluorescence, for fixing the stainless steel {sup 241}Am technique was used electrodeposition. (author)

  15. Artificial radionuclides in the Northern European Marine Environment. Distribution of radiocaesium, plutonium and americium in sea water and sediments in 1995

    Energy Technology Data Exchange (ETDEWEB)

    Groettheim, Siri

    2000-07-01

    This study considers the distribution of radiocaesium, plutonium and americium in the northern marine environment. The highest radiocaesium activity in sea water was observed in Skagerrak, 26 Bq/m{sub 3}, and in surface sediments in the Norwegian Sea, 60 Bq/kg. These enhanced levels were related to Chernobyl. The highest 239,240Pu activity in surface water was measured in the western North Sea, 66 mBq/m{sub 3}. In sea water, sub-surface maxima were observed at several locations with an 239,240Pu activity up to 160 mBq/m{sub 3}, and were related to Sellafield. With the exception to the North Sea, surface sediments reflected Pu from global fallout from weapons tests only. (author)

  16. Contribution of filamentous fungi to the musty odorant 2,4,6-trichloroanisole in water supply reservoirs and associated drinking water treatment plants.

    Science.gov (United States)

    Bai, Xiuzhi; Zhang, Ting; Qu, Zhipeng; Li, Haipu; Yang, Zhaoguang

    2017-09-01

    In this study, the distribution of 2,4,6-trichloroanisole (2,4,6-TCA) in two water supply reservoirs and four associated drinking water treatment plants (DWTPs) were investigated. The 2,4,6-TCA concentrations were in the range of 1.53-2.36 ng L -1 in water supply reservoirs and 0.76-6.58 ng L -1 at DWTPs. To determine the contribution of filamentous fungi to 2,4,6-TCA in a full-scale treatment process, the concentrations of 2,4,6-TCA in raw water, settled water, post-filtration water, and finished water were measured. The results showed that 2,4,6-TCA levels continuously increased until chlorination, suggesting that 2,4,6-TCA could form without a chlorination reaction and fungi might be the major contributor to the 2,4,6-TCA formation. Meanwhile, twenty-nine fungal strains were isolated and identified by morphological and molecular biological methods. Of the seventeen isolated fungal species, eleven showed the capability to convert 2,4,6-trichlorophenol (2,4,6-TCP) to 2,4,6-TCA. The highest level of 2,4,6-TCA formation was carried out by Aspergillus versicolor voucher BJ1-3: 40.5% of the original 2,4,6-TCP was converted to 2,4,6-TCA. There was a significant variation in the capability of different species to generate 2,4,6-TCA. The results from the proportions of cell-free, cell-attached, and cell-bound 2,4,6-TCA suggested that 2,4,6-TCA generated by fungi was mainly distributed in their extracellular environment. In addition to 2,4,6-TCA, five putative volatile by-products were also identified by gas chromatography and mass spectrometry. These findings increase our understanding on the mechanisms involved in the formation of 2,4,6-TCA and provide insights into managing and controlling 2,4,6-TCA-related problems in drinking water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Evaluation of Orally Delivered ST-246 as Postexposure Prophylactic and Antiviral Therapeutic in an Aerosolized Rabbitpox Rabbit Model

    National Research Council Canada - National Science Library

    Nalca, Aysegul; Hatkin, Josh M; Garza, Nicole L; Nichols, Donald K; Norris, Sarah W; Hruby, Dennis E; Jordan, Robert

    2008-01-01

    ...) to treat smallpox or monkeypox infection. In this study, we showed that administration of the antiviral compound ST-246 to rabbits by oral gavage, once daily for 14 days beginning 1h postexposure (p.e.), resulted in 100...

  18. Safe handling of kilogram amounts of fuel-grade plutonium and of gram amounts of plutonium-238, americium-241 and curium-244

    International Nuclear Information System (INIS)

    Louwrier, K.P.; Richter, K.

    1976-01-01

    During the past 10 years about 600 glove-boxes have been installed at the Institute for Transuranium Elements at Karlsruhe. About 80% of these glove-boxes have been designed and equipped for handling 100-g to 1-kg amounts of 239 Pu containing 8-12% 240 Pu (low-exposure plutonium). A small proportion of the glove-boxes is equipped with additional shielding in the form of lead sheet or lead glass for work with recycled plutonium. In these glove-boxes gram-amounts of 241 Am have also been handled for preparation of Al-Am targets using tongs and additional shielding inside the glove-boxes themselves. Water- and lead-shielded glove-boxes equipped with telemanipulators have been installed for routine work with gram-amounts of 241 Am, 243 Am and 244 Cm. A prediction of the expected radiation dose for the personnel is difficult and only valid for a preparation procedure with well-defined preparation steps, owing to the fact that gamma dose-rates depend strongly upon proximity and source seize. Gamma radiation dose measurements during non-routine work for 241 Am target preparation showed that handling of gram amounts leads to a rather high irradiation dose for the personnel, despite lead or steel glove-box shielding and shielding within the glove-boxes. A direct glove-hand to americium contact must be avoided. For all glove-handling of materials with gamma radiation an irradiation control of the forearms of the personnel by, for example, thermoluminescence dosimeters is necessary. Routine handling of americium and curium should be executed with master-slave equipment behind neutron and gamma shielding. (author)

  19. Preliminary application of 241-Americium calcaneus bone mineral density measurement in osteoporosis. Comparison with double X-ray densitometry of the lumber spine

    International Nuclear Information System (INIS)

    Guan Liang; Zhu Chengmo; Li Peiyong; Wang Hui; Pu Mingfang; Qiu Jigao

    2001-01-01

    Bone mineral density (BMD) of calcaneus in 54 normals, 45 Osteoporosis, 25 suspected osteoporosis and 16 other non-osteoporosis patients, a total of 140 cases were measured by HUAKE (HK-1) 241-Americium BMD absorpmetry, among them 43 were compared with that of lumber spine (L2 - L4) measured by Lunar Corporation's Expert-XL absorpmeter. BMD of normal group of calcaneus was (409.8 +- 79.4) mg/cm 2 . The BMD were decreased slowly with the increasing age. The BMD of osteoporosis, suspected osteoporosis and non-osteoporosis group were 230.3 +- 62.3, 395.7 +- 57.4 and 363.3 +- 51.9 mg/cm 2 respectively. The BMD of osteoporosis group was much lower than that of normal group, and also lower than that of the other two groups, among 26 patients (57.78%) had bone fracture, all was in accordance with the clinical diagnosis of osteoporosis. The BMD of suspected osteoporosis and non-osteoporosis had no significant difference with normal group. The coefficient variation (CV) of BMD in repeated measurement in calcaneus of 4 participants was less than 1.2%. The correlative coefficient (r) between BMD of calcaneus and lumber spine (L2 - L4) group was 0.6824. The correlative coefficient of normal young adult-matched percentage and T value in 2 groups were 0.6863 and 0.6755 respectively, whereas aged-matched percentage, Z value were 0.4614 and 0.5009 respectively. In conclusion 241-Americium calcaneus BMD absorpmetry has the advantage of low price, easy to operate, reliable and valuable in diagnosis osteoporosis. The correlations of calcaneus and lumber spine BMD, normal young adult-matched percentage and T value were rather good

  20. Correction factor K calculation for Americium-Beryllium neutron sources measured in a manganese sulfate bath; Calculo do fator de correcao K para fontes de neutrons de Americio-Berilio medida no banho de sulfato de manganes do LNMRI/IRD

    Energy Technology Data Exchange (ETDEWEB)

    Leite, Sandro P.; Fonseca, Evaldo S. da; Patrao, Karla C.S.; Goncalves, Marcello G. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Neutrons; Pereira, Walsan W. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. Nacional de Metrologia das Radiacoes Ionizantes (LNMRI)

    2005-03-15

    This paper simulates a manganese sulfate bath at the Ionizing Radiation Metrology National Laboratory for the calculation of K correction factor for the neutro emission ratio in some Americium-Beryllium sources.

  1. Transformation of 2,4,6-trichlorophenol by the white rot fungi Panus tigrinus and Coriolus versicolor.

    Science.gov (United States)

    Leontievsky, A A; Myasoedova, N M; Baskunov, B P; Evans, C S; Golovleva, L A

    2000-01-01

    The toxicity of thirteen isomers of mono-, di-, tri- and pentachlorophenols was tested in potato-dextrose agar cultures of the white rot fungi Panus tigrinus and Coriolus versicolor. 2,4,6-Trichlorophenol (2,4,6-TCP) was chosen for further study of its toxicity and transformation in liquid cultures of these fungi. Two schemes of 2,4,6-TCP addition were tested to minimize its toxic effect to fungal cultures: stepwise addition from the moment of inoculation and single addition after five days of growth. In both cases the ligninolytic enzyme systems of both fungi were found to be responsible for 2,4,6-TCP transformation. 2,6-Dichloro-1,4-hydroquinol and 2,6-dichloro-1,4-benzoquinone were found as products of primary oxidation of 2,4,6-TCP by intact fungal cultures and purified ligninolytic enzymes, Mn-peroxidases and laccases of both fungi. However, primary attack of 2,4,6-TCP in P. tigrinus culture was conducted mainly by Mn-peroxidase, while in C. versicolor it was catalyzed predominantly by laccase, suggesting a different mode of regulation of these enzymes in the two fungi.

  2. Monoklonale Antikörper zum Nachweis von 2,4,6-Trichloranisol in Kork

    OpenAIRE

    Lausterer, Ralph

    2005-01-01

    Die Verbindung 2,4,6-Trichloranisol (TCA) kann in Kork und Wein vorkommen. TCA entsteht durch mikrobielle Umsetzung von Chlorphenolen. In den betroffenen Industrien führt TCA zu jährlichen Verlusten von mehr als einer Milliarde €. Zur Bestimmung von TCA sollten enzymkoppelte Immunabsorptionstest (ELISAs) mit monoklonalen Antikörpern (mAk) entwickelt werden. Es wurden drei TCA-spezifische mAk-produzierende Zelllinien gewonnen. Mit diesen mAk wurden hochsensitive ELISAs hergstellt, die eine Nac...

  3. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan.

    Science.gov (United States)

    León Vintró, L; Mitchell, P I; Omarova, A; Burkitbayev, M; Jiménez Nápoles, H; Priest, N D

    2009-04-01

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that (241)Am, (239,240)Pu and (238)U concentrations in well waters within the study area are in the range 0.04-87mBq dm(-3), 0.7-99mBq dm(-3), and 74-213mBq dm(-3), respectively, and for (241)Am and (239,240)Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01mBq dm(-3), 0.08mBq dm(-3) and 0.32mBq dm(-3) for (241)Am, (239,240)Pu and (238)U, respectively. The (235)U/(238)U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42microSv (mean 21microSv). Presently, the ground water feeding these wells would not appear to be contaminated with

  4. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan

    Energy Technology Data Exchange (ETDEWEB)

    Leon Vintro, L. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland)], E-mail: luis.leon@ucd.ie; Mitchell, P.I.; Omarova, A. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Burkitbayev, M. [Department of Inorganic Chemistry, Al-Faraby Kazakh National University, Almaty (Kazakhstan); Jimenez Napoles, H. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Priest, N.D. [School of Health and Social Sciences, Middlesex University, Enfield, EN3 4SA (United Kingdom)

    2009-04-15

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that {sup 241}Am, {sup 239,240}Pu and {sup 238}U concentrations in well waters within the study area are in the range 0.04-87 mBq dm{sup -3}, 0.7-99 mBq dm{sup -3}, and 74-213 mBq dm{sup -3}, respectively, and for {sup 241}Am and {sup 239,240}Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01 mBq dm{sup -3}, 0.08 mBq dm{sup -3} and 0.32 mBq dm{sup -3} for {sup 241}Am, {sup 239,240}Pu and {sup 238}U, respectively. The {sup 235}U/{sup 238}U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42 {mu}Sv (mean 21 {mu

  5. Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil; Etude theorique et experimentale du comportement biogeochimique de l'americium-241 en conditions rhizospheriques simplifiees. Application dans un sol agricole calcaire

    Energy Technology Data Exchange (ETDEWEB)

    Perrier, T

    2004-06-01

    Americium 241, is one of the most radio-toxic contaminant produced during the nuclear fuel cycle. It can be found in all environmental compartments, in particular the soils. The main goals of this study are to identify, quantify and model the effect of the main factors controlling the mobility of {sup 241}Am in the rhizosphere and the agricultural soils. The physico-chemical parameters of the soil and of the soil solution, the potential role of microorganisms on the sorption-desorption processes, and the speciation of americium in solution have been more particularly studied. {sup 241}Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with {sup 241}Am. The soil samples have been washed out in different hydrodynamic conditions by solutions with various compositions. The eluted solution has been analyzed (pH, conductivity, ionic composition, Fe{sub tot}, organic acids, {sup 241}Am) and its bacterial biomass content too. The overall results indicate that {sup 241}Am remobilization is contrasted and strongly linked with the condition under study (pH, ionic strength, glucose and/or citrate concentration). Therefore, a solution in equilibrium with the soil or containing small exudate concentrations (10{sup -4} M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of {sup 241}Am corresponds to a solid/liquid coefficient of partition (K{sub d}) of about 10{sup 5} L.kg{sup -1}. A significant addition of glucose induces an important dissolution of soil carbonates by the indirect action of microorganisms, but does not significantly favor the {sup 241}Am remobilization. On the other hand, the presence of strong citrate concentrations ({>=} 10{sup -2} M) allows 300 to 10000 time greater re-mobilizations by the complexing of {sup 241}Am released after the dissolution of the carrying phases. Finally, the colloidal

  6. Progressive Vaccinia: Case Description and Laboratory-Guided Therapy With Vaccinia Immune Globulin, ST-246, and CMX001

    Science.gov (United States)

    Lederman, Edith R.; Davidson, Whitni; Groff, Harold L.; Smith, Scott K.; Warkentien, Tyler; Li, Yu; Wilkins, Kimberly A.; Karem, Kevin L.; Akondy, Rama S.; Ahmed, Rafi; Frace, Michael; Shieh, Wun-Ju; Zaki, Sherif; Hruby, Dennis E.; Painter, Wendy P.; Bergman, Kimberly L.; Cohen, Jeffrey I.; Damon, Inger K.

    2012-01-01

    Progressive vaccinia (PV) is a rare but potentially lethal complication that develops in smallpox vaccine recipients with severely impaired cellular immunity. We describe a patient with PV who required treatment with vaccinia immune globulin and who received 2 investigational agents, ST-246 and CMX001. We describe the various molecular, pharmacokinetic, and immunologic studies that provided guidance to escalate and then successfully discontinue therapy. Despite development of resistance to ST-246 during treatment, the patient had resolution of PV. This case demonstrates the need for continued development of novel anti-orthopoxvirus pharmaceuticals and the importance of both intensive and timely clinical and laboratory support in management of PV. PMID:22904336

  7. 2,4,6-trinitrophenol (TNP): An organic material for nonlinear optical (NLO) applications

    Science.gov (United States)

    Srinivasan, P.; Gunasekaran, M.; Kanagasekaran, T.; Gopalakrishnan, R.; Ramasamy, P.

    2006-04-01

    The bulk single crystals of 2,4,6-trinitrophenol (TNP) have been grown by slow cooling solution growth technique using acetone and ethanol as solvents. Good-quality crystals were obtained from ethanol as solvent. The solubility in acetone and ethanol was studied. The X-ray diffraction and mass spectrum studies were performed for material confirmation. FT-IR and FT-Raman measurements were carried out for spectral analyses. The factor group analysis was carried out for TNP which predicts that there are 453 vibrational optical modes. Relative second harmonic generation (SHG) efficiency of TNP was compared with that of urea and KDP. TNP exhibit SHG efficiency over 1.4 order of magnitude higher than that of urea and 13.4 order of magnitude higher than that of KDP. The melting point, hardness and UV-Vis spectral studies were carried for the grown crystals.

  8. Synthesis and biological activity of substituted 2,4,6-s-triazines.

    Science.gov (United States)

    Pandey, Vinod Kumar; Tusi, Sarah; Tusi, Zehra; Joshi, Madhawanand; Bajpai, Shashikala

    2004-03-01

    Reaction of 7-hydroxy-4-methyl coumarin with amido/ imido alcohols in ethanol containing concentrated hydrochloric acid afforded 8-aralkyl amido/imido-alkyl-7-hydroxy-4-methyl-coumarins (1a-f). Interaction of 1a-f with hydrazine hydrate in pyridine resulted in 1-amino-8-aralkyl amido/imido-alkyl-7-hydroxy-4-methyl-2-oxo-quinolines (2a-f). Treatment of 2 with formaldehyde in ethanol resulted in 1,3,5-tris-(8-aralkyl amido/imido-alkyl-7-hydroxy-4-methyl-2-oxo-quinolinyl)-2,4,6-hexahydro-s-triazines (3a-c). Antiviral activity of compounds 2a-d and 3a, 3b upon Japanese encephalitis virus (JEV) and Herpes simplex virus-1 (HSV-1) was evaluated on vero cells in vitro. 3a-c were also screened for their antihypertensive activity.

  9. Poly[[triaqua(μ3-pyridine-2,4,6-tricarboxylatoterbium(III] monohydrate

    Directory of Open Access Journals (Sweden)

    Hong-lin Zhu

    2012-07-01

    Full Text Available The asymmetric unit of the title compound, {[Tb(C8H2NO6(H2O3]·H2O}n, contains one TbIII ion, one pyridine-2,4,6-tricarboxylate (ptc anion, three aqua ligands and one lattice water molecule. The TbIII ion is nine coordinated by one N and five O atoms from three ptc ligands and by three O atoms from the three aqua ligands in a distorted bicapped trigonal–prismatic geometry. The ptc ligands bridge the TbIII ions into a two-dimensional polymeric framework parallel to (100. An extensive O—H...O hydrogen-bonding network consolidates the crystal packing.

  10. Adsorption of 2,4,6-trinitrotoluene on carboxylated porous polystyrene microspheres

    International Nuclear Information System (INIS)

    Ye Zhengfang; Meng Qingqiang; Lu Shengtao

    2012-01-01

    Large-pore-size (150 nm) polystyrene (PSt) microspheres were carboxylated with phthalic anhydride (PA) through Friedel-Crafts acetylation to study the adsorption of 2,4,6-trinitrotoluene (TNT) on this material from aqueous solution. The scanning electron microscope (SEM) images and mercury porosimetry measurements (MPM) of the microspheres showed that the pore structure was unchanged during the reaction. High adsorption capacity (11.2 mg g -1 of suction-dried adsorbent) and adsorption rate (33.9 mg g -1 h -1 ) for TNT were observed during the study. As shown by the adsorption isotherm, the adsorption of TNT on PA-PSt can be described by the Freundlich adsorption equation, indicating heterogeneous adsorption process. On-column adsorption of TNT on PA-PSt and elution indicated that TNT can be completely removed from aqueous solution and condensed into acetone.

  11. Reliability of optical fibres and components final report of COST 246

    CERN Document Server

    Griffioen, Willem; Gadonna, Michel; Limberger, Hans; Heens, Bernard; Knuuttila, Hanna; Kurkjian, Charles; Mirza, Shehzad; Opacic, Aleksandar; Regio, Paola; Semjonov, Sergei

    1999-01-01

    Reliability of Optical Fibres and Components reports the findings of COST 246 (1993-1998) - European research initiative in the field of optical telecommunications. Experts in the materials and reliability field of optical fibres and components have contributed to this unique study programme. The results, conclusions and achievements of their work have been obtained through joint experimentation and discussion with representatives from manufacturing and research groups. Topics covered include: Lifetime estimation; Failure mechanisms; Ageing test methods; Field data and service environments for components. For the first time the reader can explore the reliability of products and examine the results and conclusions in published form. This comprehensive volume is intended to provide a deeper understanding of the reliability of optical fibres and components. The book will be extremely useful to all scientists and practitioners involved in the industry.

  12. Towards the island of superheavy stability - Prompt spectroscopy of 246Fm and 256Rf nuclei

    International Nuclear Information System (INIS)

    Piot, J.

    2010-10-01

    The region of trans-fermium nuclei (Z = 100 to 104) is the last region of the nuclides chart to be accessible to spectroscopic measurements. It therefore provides the ultimate anchor points for nuclear models. This region also lies on the path of the alpha-decay chains of the super-heavy elements. This region represents the limit of today's spectroscopic capabilities. It therefore requires technological developments in order to overcome these limits. My thesis focuses on various aspects of the spectroscopy of trans-fermium nuclei. I took part in the development of the TNT2D digital acquisition cards for germanium detectors. I validated their use on the gamma-ray spectrometer JUROGAM during an in-beam experiment and demonstrated the gain compared to an analogue acquisition system. These tests were part of the developments needed to secure a study of the prompt spectroscopy of 256 Rf. The preparation of this experiment also lead me to work on the development of a 50 Ti beam. For that purpose, I studied and tested the use of titanium organo-metallic compounds compatible with the MIVOC technique. In parallel, I studied the use of metallic and oxide titanium pellets with an inductive oven newly developed at the University of Jyvaeskylae. In addition to these developments, I had the opportunity to study the in-beam prompt spectroscopy of 246 Fm at the University of Jyvaeskylae. The measurements yielded a rotational band built on the ground state of 246 Fm. This band has been observed up to the level 16 + and shows a behaviour quite similar to the neighbouring even-even isotopes, except for the top of the band for which a wider statistics is necessary in order to conclude. (author)

  13. Study of biosorbents application on the treatment of radioactive liquid wastes with americium-241; Estudo da aplicacao de biossorventes no tratamento de rejeitos radioativos liquidos contendo americio-241

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Tania Regina de

    2010-07-01

    The use of nuclear energy for many different purposes has been intensified and highlighted by the benefits that it provides. Medical diagnosis and therapy, agriculture, industry and electricity generation are examples of its application. However, nuclear energy generates radioactive wastes that require suitable treatment ensuring life and environmental safety. Biosorption and bioaccumulation represent an emergent alternative for the treatment of radioactive liquid wastes, providing volume reduction and physical state change. This work aimed to study biosorbents for the treatment of radioactive liquid wastes contaminated with americium-241 in order to reduce the volume and change the physical state from liquid to solid. The biosorbents evaluated were Saccharomyces cerevisiae immobilized in calcium alginate beads, inactivated and free cells of Saccharomyces cerevisiae, calcium alginate beads, Bacillus subtilis, Cupriavidus metallidurans and Ochrobactrum anthropi. The results were quite satisfactory, achieving 100% in some cases. The technique presented in this work may be useful and viable for implementing at the Waste Management Laboratory of IPEN - CNEN/SP in short term, since it is an easy and low cost method. (author)

  14. Diluent and extractant effects on the enthalpy of extraction of uranium(VI) and americium(III) nitrates by trialkyl phosphates

    International Nuclear Information System (INIS)

    Srinivasan, T.G.; Vasudeva Rao, P.R.; Sood, D.D.

    1998-01-01

    The effect of various diluents such as n-hexane, n-heptane n-octane, isooctane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-hexadecane, cyclohexane, benzene, toluene, p-xylene, mesitylene and o-dichlorobenzene on the enthalpy of extraction of uranyl nitrate by tri-n-amyl phosphate (TAP) over the temperature range 283 K--333 K has been studied. The results indicate that the enthalpy of extraction does not vary significantly with the diluents studied. Also enthalpies of extraction of uranyl nitrate and americium(III) nitrate by neutral organo phosphorous extractants such as tri-n-butyl phosphate (TBP), tri-n-amyl phosphate (TAP), tri-sec-butyl phosphate (TsBP), tri-isoamyl phosphate (TiAP) and tri-n-hexyl phosphate (THP) have been studied. An attempt has been made to explain the trends, on the basis of the nature of the solvate formed and the different terms which contribute to the overall enthalpy change

  15. Human bones obtained from routine joint replacement surgery as a tool for studies of plutonium, americium and {sup 90}Sr body-burden in general public

    Energy Technology Data Exchange (ETDEWEB)

    Mietelski, Jerzy W., E-mail: jerzy.mietelski@ifj.edu.pl [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland); Golec, Edward B. [Traumatology and Orthopaedic Clinic, 5th Military Clinical Hospital and Polyclinic, Independent Public Healthcare Facility, Wroclawska 1-3, 30-901 Cracow (Poland); Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Department of Physical Therapy Basics, Faculty of Physical Therapy, Administration College, Bielsko-Biala (Poland); Tomankiewicz, Ewa [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland); Golec, Joanna [Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Physical Therapy Department, Institute of Physical Therapy, Faculty of Heath Science, Jagiellonian University, Medical College, Cracow (Poland); Nowak, Sebastian [Traumatology and Orthopaedic Clinic, 5th Military Clinical Hospital and Polyclinic, Independent Public Healthcare Facility, Wroclawska 1-3, 30-901 Cracow (Poland); Orthopaedic Rehabilitation Department, Chair of Clinical Rehabilitation, Faculty of Motor of the Bronislaw Czech' s Academy of Physical Education, Cracow (Poland); Szczygiel, Elzbieta [Physical Therapy Department, Institute of Physical Therapy, Faculty of Heath Science, Jagiellonian University, Medical College, Cracow (Poland); Brudecki, Kamil [Henryk Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Radzikowskiego 152, 31-342 Cracow (Poland)

    2011-06-15

    The paper presents a new sampling method for studying in-body radioactive contamination by bone-seeking radionuclides such as {sup 90}Sr, {sup 239+240}Pu, {sup 238}Pu, {sup 241}Am and selected gamma-emitters, in human bones. The presented results were obtained for samples retrieved from routine surgeries, namely knee or hip joints replacements with implants, performed on individuals from Southern Poland. This allowed to collect representative sets of general public samples. The applied analytical radiochemical procedure for bone matrix is described in details. Due to low concentrations of {sup 238}Pu the ratio of Pu isotopes which might be used for Pu source identification is obtained only as upper limits other then global fallout (for example Chernobyl) origin of Pu. Calculated concentrations of radioisotopes are comparable to the existing data from post-mortem studies on human bones retrieved from autopsy or exhumations. Human bones removed during knee or hip joint surgery provide a simple and ethical way for obtaining samples for plutonium, americium and {sup 90}Sr in-body contamination studies in general public. - Highlights: > Surgery for joint replacement as novel sampling method for studying in-body radioactive contamination. > Proposed way of sampling is not causing ethic doubts. > It is a convenient way of collecting human bone samples from global population. > The applied analytical radiochemical procedure for bone matrix is described in details. > The opposite patient age correlations trends were found for 90Sr (negative) and Pu, Am (positive).

  16. Americium-241 integral radiative capture cross section in over-moderated neutron spectrum from pile oscillator measurements in the Minerve reactor

    Directory of Open Access Journals (Sweden)

    Geslot Benoit

    2017-01-01

    Full Text Available An experimental program, called AMSTRAMGRAM, was recently conducted in the Minerve low power reactor operated by CEA Cadarache within the frame of the CHANDA initiative (Solving CHAllenges in Nuclear Data. Its aim was to measure the integral capture cross section of 241Am in the thermal domain. Motivation of this work is driven by large differences in this actinide thermal point reported by major nuclear data libraries. The AMSTRAMGRAM experiment, that made use of well characterized EC-JRC americium samples, was based on the oscillation technique commonly implemented in the Minerve reactor. First results are presented and discussed in this article. A preliminary calculation scheme was used to compare measured and calculated results. It is shown that this work confirms a bias previously observed with JEFF-3.1.1 (C/E-1 = −10.5 ± 2%. On the opposite, the experiment is in close agreement with 241Am thermal point reported in JEFF-3.2 (C/E-1 = 0.5 ± 2%.

  17. Preparation and characterization of molecularly-imprinted magnetic microspheres for adsorption of 2,4,6-trichlorophenol from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ping; Pan, Jianming; Yan, Yongsheng [Jiangsu University, Zhenjiang (China); Sun, Qilong; Li, Jianfeng; Tan, Zhenjiang [Jilin Normal University, Siping (China)

    2015-04-15

    Magnetic molecularly imprinted microspheres (MMIS) were successfully prepared by suspension polymerization, and then as-prepared MMIS were used as adsorbents for selective recognition of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. The results composites were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results demonstrated that MMIS possesses porous spherical morphology, and exhibits good thermal stability and magnetic property (Ms=10.14 emu g{sup -1}). Then batch mode of binding experiments was used to determine the equilibrium, kinetics and selectivity recognition. The Langmuir isotherm model fitted the equilibrium data better than did the Freundlich model, and the maximum adsorption capacity on MMIS was about 1.7 times higher than that of MNIS. Kinetics behaviors of MMIS were well described by the pseudo-second-order model. MMIS possessed outstanding selectivity recognition for 2,4,6-TCP in the presence of other competitive phenols (such as sesamol, 3-CP, thymol, 2,4-DCP). Furthermore, the reusability performance of MMIS showed about 17.53% loss after five repeated cycles. Finally, the MMIS were successfully applied to the selective extraction of 2,4,6-TCP from the vegetable samples.

  18. Radiolysis of aqueous solutions of sodium salt of adipic acid bis-(2,4,6-triiodo-3-carboxyanilide). [Gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Kharlamov, V.T.; Pikaev, A.K.; Shubnyakova, L.P.; Sysoeva, K.S.

    1975-07-01

    The ..gamma.. radiolysis of aqueous solutions of the sodium salt of adipic acid bis-(2,4,6-triiodo-3-carboxyanilide) was studied. The radiation-chemical decomposition yields of this compound and the formation of iodide ions under various conditions were measured. (auth)

  19. 78 FR 19413 - Listing of Color Additives Exempt From Certification; Reactive Blue 246 and Reactive Blue 247...

    Science.gov (United States)

    2013-04-01

    ... the dockets to read background documents or objections received, go to http://www.regulations.gov and insert the docket numbers, found in brackets in the heading of this document, into the ``Search'' box and... petitioner. This study demonstrated that there was no detectable migration of C.I. Reactive Blue 246 at the...

  20. 40 CFR 721.5356 - Ethanol, 2,2′2″-nitrilotris-, compound with alpha-2,4,6-tris (1-phenylethyl)phenyl]-omega...

    Science.gov (United States)

    2010-07-01

    ...-, compound with alpha-2,4,6-tris (1-phenylethyl)phenyl]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate. 721...]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate. (a) Chemical substance and significant new uses... alpha-[2,4,6-tris(1-phenylethyl)phenyl]-omega-hydroxypoly (oxy-1,2-ethanediyl) phosphate (PMN P-98-185...

  1. Practical ruthenium-catalyzed cyclocarbonylation of allenyl alcohols in 2,4,6-collidine leading to alpha,beta-unsaturated lactones: concise stereoselective synthesis of (+)-isomintlactone.

    Science.gov (United States)

    Tsubuki, Masayoshi; Takahashi, Kazunori; Honda, Toshio

    2009-02-06

    We have found that ruthenium-catalyzed cyclocarbonylation of allenyl alcohols in 2,4,6-collidine under atmospheric pressure of carbon monoxide smoothly proceeds to afford alpha,beta-unsaturated five- and six-membered lactones in moderate to good yields. Furthermore, we have completed a highly stereoselective synthesis of (+)-isomintlactone by the cyclocarbonylation of allenyl alcohol using 2,4,6-collidine.

  2. Separation of americium(III) and europium(III) from nitrate medium using a binary mixture of Cyanex-301 with neutral donor ligands

    International Nuclear Information System (INIS)

    Bhattacharyya, A.; Mohapatra, P.K.; Manchanda, V.K.

    2005-01-01

    Separation behaviour of Am 3+ and Eu 3+ was investigated from aqueous nitrate medium using a binary mixture of Cyanex-301 (bis(2,4,4- trimethylpentyl) dithiophosphinic acid) and several N, O or S donor ligands such as 1,10-phenanthroline (phen), TPTZ (2,4,6- tri(2-pyridyl)- 1,3,5- triazine), 2,2'-bipyridyl(bipy), hexa thia 18 crown 6 (S 6 18C6), TBP (tri-n-butyl phosphate), TBTP (tri-n-butyl thiophosphate) in toluene. The S.F. values of >40,000 obtained with bipy and phen are the highest reported to date. (author)

  3. Visual detection of 2,4,6-trinitrotolune by molecularly imprinted colloidal array photonic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Asher, Sanford A., E-mail: asher@pitt.edu [Department of Chemistry, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Meng, Zihui, E-mail: m_zihui@yahoo.com [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yan, Zequn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Xue, Min, E-mail: minxue@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Qiu, Lili, E-mail: qiulili@bit.edu.cn [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China); Yi, Da [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing, 100081 (China)

    2016-10-05

    Graphical abstract: Molecularly imprinted colloidal array (MICA) was explored for the selective visual detection of TNT with color changing from green to red. And molecularly imprinted colloidal particles (MICs) were evaluated for the adsorption capacity and the imprinting efficiency. The MICA had excellent flexibility, reversibility and stability. It promised high potential for the visual semi-quantitative detection of other explosives. - Highlights: • Molecularly imprinted colloidal array (MICA) was used to visually detect TNT. • The relationship of particle size, diffracted wavelength and color was discussed. • The adsorption capacity and imprinting efficiency of MICs were calculated. • MICA had short response time, high selectivity, good reversibility and stability. • MICA had high potential to be used in other customed visual explosive detection. - Abstract: We developed a photonic crystal (PhC) sensor for the quantification of 2,4,6-trinitrotoluene (TNT) in solution. Monodisperse (210 nm in diameter) molecularly imprinted colloidal particles (MICs) for TNT were prepared by the emulsion polymerization of methyl methacrylate and acrylamide in the presence of TNT as a template. The MICs were then self-assembled into close-packed opal PhC films. The adsorption capacity of the MICs for TNT was 64 mg TNT/g. The diffraction from the PhC depended on the TNT concentration in a methanol/water (3/2, v/v) potassium dihydrogen phosphate buffer solution (pH = 7.0, 30 mM). The limit of detection (LOD) of the sensor was 1.03 μg. The color of the molecularly imprinted colloidal array (MICA) changed from green to red with an 84 nm diffraction red shift when the TNT concentration increased to 20 mM. The sensor response time was 3 min. The PhC sensor was selective for TNT compared to similar compounds such as 2,4,6-trinitrophenol, 2,4-dinitrotoluene, 2,6-dinitrotoluene, 2-nitromesitylene, 4-nitrotoluene, 2-nitrotoluene, 1,3-dinitrobenzene, methylbenzene, 4-nitrophenol

  4. Solubility of plutonium and americium-241 from rumen contents of cattle grazing on plutonium-contaminated desert vegetation in in vitro bovine gastrointestinal fluids - August 1975 to January 1977

    International Nuclear Information System (INIS)

    Barth, J.; Giles, K.R.; Brown, K.W.

    1985-01-01

    The alimentary solubility of plutonium and americium-241 ingested by cattle grazing at Area 13 of the Nevada Test Site and the Clean Slate II site on the Tonopah Test Range in Nevada was studied in a series of experiments. For each experiment, or trial, rumen contents collected from a fistulated steer or a normal animals at the time of sacrifice were incubated in simulated bovine gastrointestinal fluids, and the solubility of plutonium and americium was analyzed following the abomasal, duodenal, jejunal, and lower intestinal digestive states. For Area 13, the peak plutonium-238 solubilities ranged from 1.09 to 9.60 percent for animals grazing in the inner enclosure that surrounds ground zero (GZ); for animals grazing in the outer enclosure, the peaks ranged from 1.86 to 18.46%. The peak plutonium-239 solubilities ranged from 0.71 to 4.81% for animals from the inner enclosure and from 0.71 to 3.61% for animals from the outer enclosure. Plutonium-238 was generally more soluble than plutonium-239. Plutonium ingested by cattle grazing in the outer enclosure was usually more soluble than plutonium ingested by cattle grazing in the inner enclosure. The highest concentrations of plutonium in the rumen contents of cattle grazing in the inner enclosure were found in trials conducted during August and November 1975 and January 1976. These concentrations decreased during the February, May, and July 1976 trials. The decrease was followed by an increase in plutonium concentration during the November 1976 trial. The concentration of americium-241 followed the same trend. 13 references, 13 tables

  5. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    International Nuclear Information System (INIS)

    Ketelaer, Jens

    2010-01-01

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N ∝ 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of 241 Am could be measured directly for the first time. (orig.)

  6. The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium

    Energy Technology Data Exchange (ETDEWEB)

    Ketelaer, Jens

    2010-06-14

    The construction of TRIGA-TRAP and direct high-precision Penning trap mass measurements on rare-earth elements and americium: Nuclear masses are an important quantity to study nuclear structure since they reflect the sum of all nucleonic interactions. Many experimental possibilities exist to precisely measure masses, out of which the Penning trap is the tool to reach the highest precision. Moreover, absolute mass measurements can be performed using carbon, the atomic-mass standard, as a reference. The new double-Penning trap mass spectrometer TRIGA-TRAP has been installed and commissioned within this thesis work, which is the very first experimental setup of this kind located at a nuclear reactor. New technical developments have been carried out such as a reliable non-resonant laser ablation ion source for the production of carbon cluster ions and are still continued, like a non-destructive ion detection technique for single-ion measurements. Neutron-rich fission products will be available by the reactor that are important for nuclear astrophysics, especially the r-process. Prior to the on-line coupling to the reactor, TRIGA-TRAP already performed off-line mass measurements on stable and long-lived isotopes and will continue this program. The main focus within this thesis was on certain rare-earth nuclides in the well-established region of deformation around N {proportional_to} 90. Another field of interest are mass measurements on actinoids to test mass models and to provide direct links to the mass standard. Within this thesis, the mass of {sup 241}Am could be measured directly for the first time. (orig.)

  7. High uptake of 2,4,6-trinitrotoluene by vetiver grass - Potential for phytoremediation?

    International Nuclear Information System (INIS)

    Makris, Konstantinos C.; Shakya, Kabindra M.; Datta, Rupali; Sarkar, Dibyendu; Pachanoor, Devanand

    2007-01-01

    2,4,6-Trinitrotoluene (TNT) is a potent mutagen, and a Group C human carcinogen that has been widely used to produce munitions and explosives. Vast areas that have been previously used as ranges, munition burning, and open detonation sites are heavily contaminated with TNT. Conventional remediation activities in such sites are expensive and damaging to the ecosystem. Phytoremediation offers a cost-effective, environment-friendly solution, utilizing plants to extract TNT from contaminated soil. We investigated the potential use of vetiver grass (Vetiveria zizanioides) to effectively remove TNT from contaminated solutions. Vetiver grass plants were grown in hydroponic systems containing 40 mg TNT L -1 for 8 d. Aqueous concentrations of TNT reached the method detection limit (∼1 μg L -1 ) within the 8-d period, demonstrating high affinity of vetiver for TNT, without any visible toxic effects. Results from this preliminary hydroponic study are encouraging, but in need of verification using TNT-contaminated soils. - Vetiver grass demonstrates ability to absorb TNT in aqueous media

  8. Phototransformation of 2,4,6-trinitrotoluene: Sensitized by riboflavin under different irradiation spectral range

    International Nuclear Information System (INIS)

    Yang Xin; Zhao Xueheng; Hwang, H.-M.

    2007-01-01

    Riboflavin-sensitized phototransformation of 2,4,6-trinitrotoluene (TNT) under natural sunlight was investigated with reverse-phase high performance liquid chromatography/mass spectrometry (HPLC/MS) and gas chromatography/mass spectrometry (GC/MS). The effect of different spectral region of sunlight on TNT phototransformation in the absence or presence of riboflavin was also investigated by using optical filters with cut-off at 400 or 455 nm. The concentration of riboflavin in the phototransformation of TNT was optimized. Concentration of riboflavin and TNT was 1.0 and 50 μM, respectively. The rates of phototransformation of TNT under natural sunlight in the presence or absence of riboflavin were conformed to initial pseudo-first-order rate equation. The photolysis half life of TNT in the presence of riboflavin was 21.87 min, compared to 39 min in the absence of riboflavin under natural sunlight. Two major phototransformation products of TNT, 3,5-dinitroaniline (3,5-DNA) and 1,3,5-trinitrobenzene (1,3,5-TNB), were detected in the samples in the presence of riboflavin receiving irradiation at full wavelength or wavelength >400 nm. The results indicate that riboflavin mediates TNT sensitized-phototransfomation under natural sunlight or near-UV-vis light

  9. Evaluation of the cardiovascular system by digital subtraction angiography in 246 patients

    Energy Technology Data Exchange (ETDEWEB)

    Higuma, Kikuhiko; Ohta, Takashi; Hiroto, Seiji

    1987-07-01

    Usefulness of intravenous digital subtraction angiography (DSA) was examined in 246 patients with cardiovascular disorders. This examination was done by centrally intravenous DSA (CIVDSA) in all patients to reduce the risks and discomforts by peripheral intravenous DSA. 1) CIVDSA could be done safely in patients aged 18 to 81 years. 2) The good diagnostic quality by CIVDSA was obtained in 81.3% of patients. These images were classified into 7 groups according to the cardiovascular system, that is, the jugular arteries, the upper extremity arteries, the thoracic aorta, the left ventricle, the abnominal aorta, the renal arteries, and the lower extremity arteries, whose rate of good diagnostic quality were 100%, 70%, 67.7%, 79.5%, 84.8%, 87%, and 71.4% respectively. 3) The poor diagnostic quality was obtained in 18.7%. 4) The severe complications were not found in any case during this examination. Our results indicate that DSA is the safe, simple and useful method to obtain the diagnostic quality image of the cardiovascular system, especially, of the occulsive arterial disease, the aortic aneurisma, the renovascular stenosis and the cardiac function of postmyocardial infarction, even in aged patients.

  10. Sonochemical synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kien-Yin

    1996-05-01

    The synthesis of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) from trichlorotrinitrobenzene (TCTNB) in toluene and ammonium hydroxide solution under the influence of ultrasonic waves was investigated. When the two-phase reaction mixture was irradiated with high intensity ultrasound at ambient temperature, fine-particle TATB (FP-TATB) was produced. This sonochemically produced TATB powder is lemon color in appearance and was analyzed to have the same explosive properties as reported in the literature. That is, it is insensitive to impact stimuli, and thermally stable. The median particle diameter of FP-TATB was calculated to be around 14 {mu}m, and the powder can be pressed to a density of 1.82 g/cm{sup 3} without a binder. The amination process is simple and requires neither the monitoring of the ammonia gas pressure nor the controlling of the reaction temperature during amination reaction, and we anticipate no problem in large scale production of FP-TATB.

  11. Soil decontamination of 2,4,6- trinitrotoluene by alfalfa (Medicago sativa).

    Science.gov (United States)

    Fallahi, S; Habibi-Rezaei, M; Khayami, M; Heydari, R

    2007-12-15

    Present study investigate the toxicity effect of 2,4,6-trinitrotoluene (TNT) on a terrestrial plant, alfalfa (Medicago sativa) in artificial soils. In this study, TNT toxicity assessment was performed on spiked silica with this nitroaromatic compound by determination of the percent of emergence and shoots and roots biomasses at the concentration range of 3.2-10000 mg kg(-1) Dry Weight (DW). The emergence was reduced by 22-32% after 5 days of exposure at TNT concentrations up to 100 mg kg(-1) DW; shoot and root biomasses were reduced by 48-50 and 63-74%, respectively after 30 days exposure at TNT concentrations root and shoot were measured by High-Performance Liquid Chromatography (HPLC). Analyses of TNT spiked soil extracts reveal hat during alfalfa cultivation for 30 days, TNT was partially transformed at the extent of 15-27%. This transformation decreased at higher TNT soil concentrations. TNT is taken up and metabolized by plants to its downstream derivatives.

  12. Study on the colorimetric properties of 2,4,6-triarylpyridine derivative compound for imaging Formaldehyde

    Science.gov (United States)

    Ovianto, D.; Ma’ruf, F. A. R.; Fadilah, N. N.; Sugiharta, I. B. A. R.; Purwono, B.

    2017-11-01

    The derivative compound of 2,4,6-triarylpyridine was synthesized in two steps. The target compound was tested as colorimetric chemosensor against formaldehyde and the limit of detection was also determined using spectrophotometer UV-vis. The first step of the synthesis was the formation of 4-phenyl-2,6-bis(4-nitrophenyl)pyridine compound (1) from 4-nitroacetophenon and benzaldehyde. The second step of the synthesis was the formation of 4-phenyl-2,6-bis-(4-aminophenyl)pyridine (2) from reduction of the nitro group in compound 1 by HCl 37% solution and Sn metal. Compound 1 and 2 were characterized by spectrometers FTIR, 1H NMR and direct inlet-mass spectrometry. The results showed that compound 1 was synthesized with a yield of 78.3% and compound 2 with a yield of 68.9%. Compound 2 as chemosensor showed color transition from colorless to yellow in chemosensor test against formaldehyde in ethanol solvent. The limit of detection of formaldehyde was measured as 4.7×10-3 M using spectrophotometer UV-vis.

  13. Evaluation of the cardiovascular system by digital subtraction angiography in 246 patients

    International Nuclear Information System (INIS)

    Higuma, Kikuhiko; Ohta, Takashi; Hiroto, Seiji

    1987-01-01

    Usefulness of intravenous digital subtraction angiography (DSA) was examined in 246 patients with cardiovascular disorders. This examination was done by centrally intravenous DSA (CIVDSA) in all patients to reduce the risks and discomforts by peripheral intravenous DSA. 1) CIVDSA could be done safely in patients aged 18 to 81 years. 2) The good diagnostic quality by CIVDSA was obtained in 81.3 % of patients. These images were classified into 7 groups according to the cardiovascular system, that is, the jugular arteries, the upper extremity arteries, the thoracic aorta, the left ventricle, the abnominal aorta, the renal arteries, and the lower extremity arteries, whose rate of good diagnostic quality were 100 %, 70 %, 67.7 %, 79.5 %, 84.8 %, 87 %, and 71.4 % respectively. 3) The poor diagnostic quality was obtained in 18.7 %. 4) The severe complications were not found in any case during this examination. Our results indicate that DSA is the safe, simple and useful method to obtain the diagnostic quality image of the cardiovascular system, especially, of the occulsive arterial disease, the aortic aneurisma, the renovascular stenosis and the cardiac function of postmyocardial infarction, even in aged patients. (author)

  14. Degradation of 2,4,6-trichlorophenol with peroxymonosulfate catalyzed by soluble and supported iron porphyrins.

    Science.gov (United States)

    Günay, Tuğçe; Çimen, Yasemin

    2017-12-01

    Degradation of 2,4,6-trichloropenol (TCP) with peroxymonosulfate (PMS) catalyzed by iron porphyrin tetrasulfonate ([FePTS)] was investigated in an 8-to-1 (v/v) CH 3 OH-H 2 O mixture. Typical reaction medium contained a 4.00 mL methanol solution of TCP (0.100 mmol), a 0.50 mL aqueous solution of catalyst (5.0 × 10 -4  mmol), and 0.100 mmol PMS (as 0.031 g of Oxone). The reaction was performed at ambient temperature. The conversion of TCP was 74% in 30 min and 80% in 6 h when the catalyst was [FePTS]. Amberlite IRA-900 supported [FePTS] catalyst was also prepared. In the recycling experiments the homogeneous [FePTS] lost its activity after the first cycle, while [FePTS]-Amberlite IRA 900 maintained its activity for the first 2 cycles. After the second cycle, the conversion of TCP dropped to degradation of TCP with PMS was also attempted using cobalt, copper, nickel and palladium porphyrin tetrasulfonate catalysts, however, no catalytic activity was observed with these structures. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Degradation of 2,4,6-trinitrotoluene by P. aeruginosa and characterization of some metabolites

    Directory of Open Access Journals (Sweden)

    Hatice Aysun Mercimek

    2015-03-01

    Full Text Available Degradation of 2,4,6-trinitrotoluene (TNT, a nitroaromatic explosive found in the soil and ground water, was investigated using Pseudomonas aeruginosa in in vitroexperiments. Biodegradable abilitiy of this bacteria was performed with 50 and 75 mg L−1 TNT concentrations in a defined liquid medium for 96 h time period. Treatment of TNT in supernatant samples taken at 0, 6, 12, 24, 48, 72 and 96 h from agitated vessels was followed by reverse-phase high-performance liquid chromatography (HPLC. In cultures supplemented with 50 and 75 mgL−1 TNT, after 96 h of incubation 46% and 59% reduction were detected respectively. Two metabolites as degradation intermediates with nitrite release into the medium, 2,4-dinitrotoluene (2,4-DNT and 4-aminodinitrotoluene (4-ADNT, were elucidated by thin layer chromatography (TLC and gas chromatography-mass spectrometry (GC-MS. These findings clearly indicate that Pseudomonas aeruginosa can be used in bioremediation of TNT contaminated sites.

  16. Chemically catalyzed uptake of 2,4,6-trinitrotoluene by Vetiveria zizanioides

    International Nuclear Information System (INIS)

    Makris, Konstantinos C.; Shakya, Kabindra M.; Datta, Rupali; Sarkar, Dibyendu; Pachanoor, Devanand

    2007-01-01

    The efficiency of vetiver grass (Vetiveria zizanioides) in removing 2,4,6-trinitrotoluene (TNT) from aqueous media was explored in the presence of a common agrochemical, urea, used as a chaotropic agent. Chaotropic agents disrupt water structure, increasing solubilization of hydrophobic compounds (TNT), thus, enhancing plant TNT uptake. The primary objectives of this study were to: (i) characterize TNT absorption by vetiver in hydroponic media, and (ii) determine the effect of urea on chemically catalyzing TNT uptake by vetiver grass in hydroponic media. Results showed that vetiver exhibited a high TNT uptake capacity (1.026 mg g -1 ), but kinetics were slow. Uptake was considerably enhanced in the presence of urea, which significantly (p<0.001) increased the 2nd-order reaction rate constant over that of the untreated (no urea) control. Three major TNT metabolites were detected in the roots, but not in the shoot, namely 1,3,5-trinitrobenzene, 4-amino 2,6-dinitrotoluene, and 2-amino 4,6-dinitrotoluene, indicating TNT degradation by vetiver grass. - A common agrochemical, urea catalyzes TNT removal by vetiver grass in aqueous media

  17. Chemically catalyzed uptake of 2,4,6-trinitrotoluene by Vetiveria zizanioides

    Energy Technology Data Exchange (ETDEWEB)

    Makris, Konstantinos C. [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Shakya, Kabindra M. [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Datta, Rupali [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Sarkar, Dibyendu [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States)]. E-mail: dibyendu.sarkar@utsa.edu; Pachanoor, Devanand [Environmental Geochemistry Laboratory, Department of Earth and Environmental Science, College of Sciences, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States)

    2007-07-15

    The efficiency of vetiver grass (Vetiveria zizanioides) in removing 2,4,6-trinitrotoluene (TNT) from aqueous media was explored in the presence of a common agrochemical, urea, used as a chaotropic agent. Chaotropic agents disrupt water structure, increasing solubilization of hydrophobic compounds (TNT), thus, enhancing plant TNT uptake. The primary objectives of this study were to: (i) characterize TNT absorption by vetiver in hydroponic media, and (ii) determine the effect of urea on chemically catalyzing TNT uptake by vetiver grass in hydroponic media. Results showed that vetiver exhibited a high TNT uptake capacity (1.026 mg g{sup -1}), but kinetics were slow. Uptake was considerably enhanced in the presence of urea, which significantly (p<0.001) increased the 2nd-order reaction rate constant over that of the untreated (no urea) control. Three major TNT metabolites were detected in the roots, but not in the shoot, namely 1,3,5-trinitrobenzene, 4-amino 2,6-dinitrotoluene, and 2-amino 4,6-dinitrotoluene, indicating TNT degradation by vetiver grass. - A common agrochemical, urea catalyzes TNT removal by vetiver grass in aqueous media.

  18. PBCDD/F formation from radical/radical cross-condensation of 2-Chlorophenoxy with 2-Bromophenoxy, 2,4-Dichlorophenoxy with 2,4-Dibromophenoxy, and 2,4,6-Trichlorophenoxy with 2,4,6-Tribromophenoxy

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Xiangli [Environment Research Institute, Shandong University, Jinan 250100 (China); Yu, Wanni [Environment Research Institute, Shandong University, Jinan 250100 (China); College of Resources and Environment, Linyi University, Linyi 276000 (China); Xu, Fei [Environment Research Institute, Shandong University, Jinan 250100 (China); Zhang, Qingzhu, E-mail: zqz@sdu.edu.cn [Environment Research Institute, Shandong University, Jinan 250100 (China); Hu, Jingtian; Wang, Wenxing [Environment Research Institute, Shandong University, Jinan 250100 (China)

    2015-09-15

    Highlights: • We studied the formation of PBCDD/Fs from the reaction of three CPRs with BPRs. • The substitution pattern of halogenated phenols determines those of PBCDD/Fs. • The substitution of halogenated phenols influence the coupling of phenoxy radicals. • The rate constants of the crucial elementary steps were evaluated. - Abstract: Quantum chemical calculations were carried out to investigate the homogeneous gas-phase formation of mixed polybrominated/chlorinated dibenzo-p-dioxins/benzofurans (PBCDD/Fs) from the cross-condensation of 2-chlorophenoxy radical (2-CPR) with 2-bromophenoxy radical (2-BPR), 2,4-dichlorophenoxy radical (2,4-DCPR) with 2,4-dibromophenoxy radical (2,4-DBPR), and 2,4,6-trichlorophenoxy radical (2,4,6-TCPR) with 2,4,6-tribromophenoxy radical (2,4,6-TBPR). The geometrical parameters and vibrational frequencies were calculated at the MPWB1K/6-31+G(d,p) level, and single-point energy calculations were performed at the MPWB1K/6-311+G(3df,2p) level of theory. The rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT) theory with the small curvature tunneling (SCT) correction over a wide temperature range of 600–1200 K. Studies show that the substitution pattern of halogenated phenols not only determines the substitution pattern of the resulting PBCDD/Fs, but also has a significant influence on the formation mechanism of PBCDD/Fs, especially on the coupling of the halogenated phenoxy radicals.

  19. Single-pulse Raman and photoacoustic spectroscopy studies of triaminotrinitrobenzene (TATB) and related compounds. [Trinitrobenzene (TNB), 1-amino-2,4,6-trinitrobenzene(MATB), 1,3-diamino-2,4,6-trinitrobenzene (DATB)

    Energy Technology Data Exchange (ETDEWEB)

    Trott, W.M.; Renlund, A.M.; Jungst, R.G.

    1985-01-01

    Pulsed-laser-excited Raman scattering methods and photoacoustic spectroscopy have been applied to the study of porous, granular samples (i.e., pressed pellets) of 1,3,5-trinitrobenzene (TNB), 1-amino-2,4,6-trinitrobenzene (MATB), 1,3-diamino-2,4,6-trinitrobenzene (DATB) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). Single-pulse spontaneous Raman spectra have been obtained for all four materials. Using 532-nm excitation, the intensity of the background emission observed with the Raman scattered light varies as TNB > MATB > DATB > TATB. This trend is compared to information on the long-wavelength absorption edge of MATB, DATB and TATB as determined by the photoacoustic spectra of these materials. Stimulated Raman scattering has been observed for three of the compounds with conversion efficiency as follows: DATB > TATB > MATB. In the case of TATB, this process may be limited by photo-induced chemical reactions. The relatively efficient formation of one or more stable photolysis products in TATB is evident on the basis of its photoacoustic spectrum. Preliminary single-pulse Raman scattering measurements on shocked TATB are also described. 16 references, 13 figures, 2 tables.

  20. The statistical model calculation of prompt neutron spectra from spontaneous fission of {sup 244}Cm and {sup 246}Cm

    Energy Technology Data Exchange (ETDEWEB)

    Gerasimenko, B.F. [V.G. Khlopin Radium Inst., Saint Peterburg (Russian Federation)

    1997-03-01

    The calculations of integral spectra of prompt neutrons of spontaneous fission of {sup 244}Cm and {sup 246}Cm were carried out. The calculations were done by the Statistical Computer Code Complex SCOFIN applying the Hauser-Feschbach method as applied to the description of the de-excitation of excited fission fragments by means of neutron emission. The emission of dipole gamma-quanta from these fragments was considered as a competing process. The average excitation energy of a fragment was calculated by two-spheroidal model of tangent fragments. The density of levels in an excited fragment was calculated by the Fermi-gas model. The quite satisfactory agreement was reached between theoretical and experimental results obtained in frames of Project measurements. The calculated values of average multiplicities of neutron number were 2,746 for {sup 244}Cm and 2,927 for {sup 246}Cm that was in a good accordance with published experimental figures. (author)

  1. Source separation for materials recovery guidelines. Part 246. [High-grade paper, corrugated container, and residential materials recovery

    Energy Technology Data Exchange (ETDEWEB)

    1976-04-23

    These guidelines are issued under the Authority of Section 209(a) of the Solid Waste Disposal Act of 1965 (PL 89-272), as amended by the Resource Recovery Act of 1970 (PL 91-512). Chapter I of Title 40 of the Code of Federal Regulations is amended effective May 24, 1976 by adding a new Part 246. The guidelines are applicable to the source separation of residential, commercial, and institutional solid wastes. Explicitly excluded are mining, agricultural, and industrial solid wastes; hazardous wastes; sludges; construction and demolition wastes; infectious wastes; classified waste. Specific requirements and recommended procedures for high-grade paper recovery, residential materials recovery, and corrugated container recovery are included in Part 246. (MCW)

  2. The Oxidation of 2,4,6-Trinitrotoluene with an Ozone-Oxygen Mixture: A Simple Method for Preparation of 1,3,5-Trinitrobenzene

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Zarei

    2013-01-01

    Full Text Available The oxidation of 2,4,6-trinitrotoluene (TNT to 1,3,5-trinitrobenzene (TNB in one step, 2,4,6-trinitrobenzoic acid (TNBA, and 2,4,6-trinitrobenzaldehyde (TNBAl with an ozone-oxygen mixture in different solvents, catalysts, and temperatures has been investigated. Reducing the number of steps in the oxidation of TNT to TNB is the major advantage of this procedure with respect to conventional processes such as chromic acid and potassium permanganate. The oxidation of TNT to TNB was completed in one step as compared to two steps in the conventional approach. The products were obtained with relatively good yield.

  3. Hemin immobilized into metal-organic frameworks as an electrochemical biosensor for 2,4,6-trichlorophenol

    Science.gov (United States)

    Zhang, Ting; Wang, Lu; Gao, Congwei; Zhao, Chaoyue; Wang, Yang; Wang, Jianmin

    2018-02-01

    Hemin immobilized into copper-based metal-organic frameworks was successfully prepared and used as a new electrode material for sensitive electrochemical biosensing. X-ray diffraction patterns, Fourier transform infrared spectra, scanning electron microscopy, UV-vis absorption spectroscopy, and cyclic voltammetry were used to characterize the resultant composites. Due to the interaction between the copper atom groups and hemin, the constrained environment in Cu-MOF-74 acts as a matrix to avoid the dimerization of enzyme molecules and retain its biological activity. The hemin/Cu-MOF composites demonstrated enhanced electrocatalytical activity and high stability towards the oxidation of 2,4,6-trichlorophenol. Under optimum experimental conditions, the sensor showed a wide linear relationship over the range of 0.01-9 μmol L-1 with a detection limit (3σ) of 0.005 μmol L-1. The relative standard deviations were 4.6% and 3.5% for five repeated measurements of 0.5 and 5 μmol L-1 2,4,6-trichlorophenol, respectively. The detection platforms for 2,4,6-trichlorophenol developed here not only indicate that hemin/Cu-MOF-74 possesses intrinsic biological reactivity, but also enable further work to be conducted towards the application of enzyme-containing metal-organic frameworks in electrochemical biosensors.

  4. Development of a cellular biosensor for the detection of 2,4,6-trichloroanisole (TCA).

    Science.gov (United States)

    Varelas, Vassileios; Sanvicens, Nuria; M-Pilar-Marco; Kintzios, Spiridon

    2011-05-15

    2,4,6-trichloroanisole (TCA) is a microbial metabolite formed from chlorophenols through the activity of several natural fungal strains present on the cork oak bark. TCA is the primary compound responsible for the mousty/mould off-odour known as "cork taint" present in cork stoppers, wine, water and alcoholic beverages. Chromatographic and electrochemical methods are currently used for the determination of TCA, however its detection at low concentrations remains a technical challenge. The aim of this study was the development of a rapid novel biosensor system based on the Bioelectric Recognition Assay (BERA). The sensor measured the electric response of cultured membrane-engineered fibroblast cells suspended in an alginate gel matrix due to the change of their membrane potential in the presence of the analyte. Membrane-engineered cells were prepared by osmotic insertion of 0.5 μg/l of specific TCA antibodies into the membrane of the cells. The BERA-based sensor was able to detect TCA in a few minutes (3-5 min) at extremely low concentrations (10(-1)ppt), thus demonstrating higher sensitivity than the human sensory threshold. In addition, the assay was quite selective against other haloanisoles and halophenols structurally related to or co-occurring with TCA. Finally the sensor was tested against real white wine samples from cork soaks. At this real test, the BERA sensor was able to detect TCA from cork soaks rapidly (3-5 min) at very low concentrations (1.02-12 ng/l), covering the whole range for the detection threshold for wines (1.4-10 ng/l). Therefore, this novel biosensor offers new perspectives for ultra-rapid, ultra-sensitive and low-cost monitoring of TCA presence in cork and wine and possibly also other food commodities. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Epithelial-Myoepithelial Carcinoma of the Salivary Glands: An Analysis of 246 Cases.

    Science.gov (United States)

    Vázquez, Alejandro; Patel, Tapan D; D'Aguillo, Christine M; Abdou, Rami Y; Farver, William; Baredes, Soly; Eloy, Jean Anderson; Park, Richard Chan W

    2015-10-01

    Epithelial-myoepithelial carcinoma (EMC) is a rare neoplasm of the salivary glands. In this study, we aim to examine the demographic, clinicopathologic, and survival features of EMC using a population-based approach. Retrospective cohort study. The Surveillance, Epidemiology, and End Result (SEER) database (1973-2010) was queried for EMC of the major salivary glands. Data were analyzed with respect to various demographic and clinicopathologic factors. Survival was analyzed using the Kaplan-Meier and Cox proportional hazards models. In total, 246 cases were available for frequency analysis and 207 for survival analysis. Mean ± SD age at diagnosis was 63.8 ± 15.4 years. EMC affected females more frequently (57.3%). Distant metastases were present at diagnosis in only 4.5% of cases. Overall disease-specific survival (DSS) at 60, 120, and 180 months was 91.3%, 90.2%, and 80.7%, respectively. Patients with low-grade histology had significantly better survival at 180 months relative to those with high-grade tumors (90.6% vs 0.0%, P = .0246). When stratified by tumor size, patients with lesions >4 cm had the worst survival at 180 months (58.8%, P = .0003). All but 9 of the 207 cases available for survival analysis underwent surgery. A total of 85 patients (41.1%) received radiotherapy in addition to surgery. No survival benefit was noted for patients who received radiotherapy compared with those who did not (P = .4832). This report represents the largest series of EMC to date. Despite being regarded as a low-grade, indolent tumor, a significant fraction of our cohort underwent radiotherapy in addition to surgery, with no apparent added survival benefit. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

  6. Dual role of endogenous serotonin in 2,4,6-trinitrobenzene sulfonic acid-induced colitis

    Directory of Open Access Journals (Sweden)

    Alberto eRapalli

    2016-03-01

    Full Text Available Background and Aims: Changes in gut serotonin content have been described in Inflammatory Bowel Disease and in different experimental models of colitis: the critical role of this monoamine in the pathogenesis of chronic gastrointestinal inflammation is gradually emerging. Aim of the present study was to evaluate the contribution of endogenous serotonin through the activation of its specific receptor subtypes to the local and systemic inflammatory responses in an experimental model of Inflammatory Bowel Disease. Methods: Colitis was induced by intrarectal 2,4,6-TriNitroBenzene Sulfonic acid in mice subacutely treated with selective antagonists of 5-HT1A (WAY100135, 5-HT2A (Ketanserin, 5-HT3 (Ondansetron, 5-HT4 (GR125487, 5-HT7 (SB269970 receptors and with 5-HT1A agonist 8-Hydroxy-2-(di-n-propylaminotetralin. Results: Blockade of 5-HT1A receptors worsened TNBS-induced local and systemic neutrophil recruitment while 5-HT1A agonist delayed and mitigated the severity of colitis, counteracting the increase in colonic 5-HT content. On the contrary, blockade of 5-HT2A receptors improved global health conditions, reduced colonic morphological alterations, down-regulated neutrophil recruitment, inflammatory cytokines levels and colonic apoptosis. Antagonism of 5-HT3, 5-HT4 and 5-HT7 receptor sites did not remarkably affect the progression and outcome of the pathology or only slightly improved it.Conclusions: The prevailing deleterious contribution given by endogenous serotonin to inflammation in TNBS-induced colitis is seemingly mediated by 5-HT2A and, to a lesser extent, by 5-HT4 receptors and coexists with the weak beneficial effect elicited by 5-HT1A stimulation. These findings suggest how only a selective interference with 5-HT pro-inflammatory actions may represent an additional potential therapeutic option for intestinal inflammatory disorders.

  7. Biodegradation of TNT (2,4,6-Trinitrotoluene) by Phanerochaete chrysosporium

    International Nuclear Information System (INIS)

    Fernando, T.; Bumpus, J.A.; Aust, S.D.

    1990-01-01

    Extensive biodegradation of TNT (2,4,6-trinitrotoluene) by the white rot fungus Phanerochaete chrysosporium was observed. At an initial concentration of 1.3 mg/liter, 35.4 ± 3.6% of the [ 14 C]TNT was degraded to 14 CO 2 in 18 days. The addition of glucose 12 days after the addition of TNT did not stimulate mineralization, and, after 18 days of incubation with TNT only, about 3.3% of the initial TNT could be recovered. Mineralization of [ 14 C]TNT absorbed on soil was also examined. Ground corncobs served as the nutrient for slow but sustained degradation of [ 14 C]TNT to 14 CO 2 such that 6.3 ± 0.6% of the [ 14 C]TNT initially present was converted to 14 CO 2 during the 30-day incubation period. Mass balance analysis of liquid cultures and of soil-corncob cultures revealed that polar [ 14 C]TNT metabolites are formed in both systems, and high-performance liquid chromatography analyses revealed that less then 5% of the radioactivity remained as undegraded [ 14 C]TNT following incubation with the fungus in soil and liquid cultures. When the concentration of TNT in cultures (both liquid and soil) was adjusted to contamination levels that might be found in the environment, i.e., 10,000 mg/kg in soil and 100 mg/liter in water, mineralization studies showed that 18.4 ± 2.9% and 19.6 ± 3.5% of the initial TNT was converted to 14 CO 2 in 90 days in soil and liquid cultures, respectively. In both cases (90 days in water at 100 mg/liter and in soil at 10,000 mg/kg) approximately 85% of the TNT was degraded. These results suggest that this fungus may be useful for the decontamination of sites in the environment contaminated with TNT

  8. Update of JAEA-TDB. Additional selection of thermodynamic data for solid and gaseous phases on nickel, selenium, zirconium, technetium, thorium, uranium, neptunium plutonium and americium, update of thermodynamic data on iodine, and some modifications

    International Nuclear Information System (INIS)

    Kitamura, Akira; Fujiwara, Kenso; Doi, Reisuke; Yoshida, Yasushi

    2012-07-01

    We additionally selected thermodynamic data for solid and gaseous phases of nickel, selenium, zirconium, technetium, thorium, uranium, neptunium, plutonium and americium to our thermodynamic database JAEA-TDB for geological disposal of radioactive waste of high-level and TRU wastes. We thermodynamically obtained equilibrium constant from addition and subtraction of Gibbs free energy of formation on nickel, selenium, zirconium, technetium, thorium, uranium, neptunium plutonium and americium, which were selected in the Thermochemical Database Project by the Nuclear Energy Agency in the Organisation for Economic Co-operation and Development. Furthermore, we collected and updated thermodynamic data on iodine, changed master species of technetium(IV), and added thermodynamic data on selenium due to improving reliability of the thermodynamic database. We prepared text files of the updated thermodynamic database (JAEA-TDB) for geochemical calculation programs of PHREEQC, EQ3/6 and Geochemist's Workbench. These text files are contained in the attached CD-ROM and will be available on our Website (http://migrationdb.jaea.go.jp/). (author)

  9. Determining the americium transmutation rate and fission rate by post-irradiation examination within the scope of the ECRIX-H experiment

    Science.gov (United States)

    Lamontagne, J.; Pontillon, Y.; Esbelin, E.; Béjaoui, S.; Pasquet, B.; Bourdot, P.; Bonnerot, J. M.

    2013-09-01

    The ECRIX-H experiment aims to assess the feasibility of transmuting americium micro-dispersed in an inert magnesia matrix under a locally moderated neutron flux in the Phénix reactor. A first set of examinations demonstrated that pellet behaviour was satisfactory with moderate swelling at the end of the irradiation. Additional post-irradiation examinations needed to be conducted to confirm the high transmutation rate so as to definitively conclude on the success of the ECRIX-H experiment. This article presents and discusses the results of these new examinations. They confirm the satisfactory behaviour of the MgO matrix not only during the basic irradiation but also during post-irradiation thermal transients. These examinations also provide additional information on the behaviour of fission products both in the americium-based particles and in the MgO matrix. These results particularly validate the transmutation rate predicted by the calculation codes using several different analytical techniques. The fission rate is also determined. Moderate pellet swelling under irradiation (6.7 vol.%), while only 23% of the produced He and 4% of the fission gases were released from the fuel. No interaction between the pellets and the cladding. Formation of bubbles due to the precipitation of fission gases and He mainly in bubbles located inside the americium-based particles. These bubbles are the main cause of macroscopic swelling in the pellets. Well-crystallised structure of the MgO matrix which shows no amorphisation after irradiation despite the presence of fission products. The absence of any reaction of MgO with the americium-based phase, Formation of a PuO2-type crystalline phase from AmO1.62 particles following the Am transmutation process. A shielded electron probe micro-analyser (EPMA) 'CAMECA' Camebax equipped to collect and exploit the measurements using the 'SAMx' system. A Philips XL30 scanning electron microscope (SEM). Field acquisitions were performed thanks to

  10. Fabrication of targets for transmutation of americium : synthesis of inertial matrix by sol-gel method. Procedure study on the infiltration of a radioactive solutions

    International Nuclear Information System (INIS)

    Fernandez Carretero, A.

    2002-01-01

    addition a new and unexpected phase formed by the reaction of americium with spinel during the high temperature synthesis process has been identified. This new phase could provide a unique menas to stabilise Am in one particular oxidation state. (Author)

  11. Neutron-Induced Fission Cross Section of Uranium, Americium and Curium Isotopes. Progress report - Research Contract 14485, Coordinated Research Project on Minor Actinide Neutron Reaction Data (MANREAD)

    International Nuclear Information System (INIS)

    Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.

    2009-12-01

    This report contains brief description of the Lead Slowing Down Spectrometer and results of measurements of neutron-induced fission cross sections for 236 U, 242m Am, 243 Cm, 244 Cm, 245 Cm and 246 Cm done at this spectrometer. The work was partially supported through the IAEA research contract RC-14485-RD in the framework of the IAEA Coordinated Research Project 'Minor Actinide Neutron Reaction Data (MANREAD)'. The detailed description of the experimental set up, measurements procedure and data treatment can be found in the JIA-1182 (2007) and JIA-1212 (2009) reports from the Institute of Nuclear Research of the Russian Academy of Science published in Russian. Part 1 contains the first year report of the research contract and part 2 the second year report. (author)

  12. Americium behaviour in plastic vessels

    Energy Technology Data Exchange (ETDEWEB)

    Legarda, F.; Herranz, M. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Idoeta, R., E-mail: raquel.idoeta@ehu.e [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain); Abelairas, A. [Departamento de Ingenieria Nuclear y Mecanica de Fluidos, Escuela Tecnica Superior de Ingenieria de Bilbao, Universidad del Pais Vasco (UPV/EHU), Alameda de Urquijo s/n, 48013 Bilbao (Spain)

    2010-07-15

    The adsorption of {sup 241}Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of {sup 241}Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of {sup 241}Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  13. Americium behaviour in plastic vessels

    International Nuclear Information System (INIS)

    Legarda, F.; Herranz, M.; Idoeta, R.; Abelairas, A.

    2010-01-01

    The adsorption of 241 Am dissolved in water in different plastic storage vessels was determined. Three different plastics were investigated with natural and distilled waters and the retention of 241 Am by these plastics was studied. The same was done by varying vessel agitation time, vessel agitation speed, surface/volume ratio of water in the vessels and water pH. Adsorptions were measured to be between 0% and 70%. The adsorption of 241 Am is minimized with no water agitation, with PET or PVC plastics, and by water acidification.

  14. EURADOS action for determination of americium in skull measures in vivo and Monte Carlo simulation; Accion EURADOS para la determinacion de americio en craneo mediante medidas in-vivo y simulacion Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Ponte, M. A.; Navarro Amaro, J. F.; Perez Lopez, B.; Navarro Bravo, T.; Nogueira, P.; Vrba, T.

    2013-07-01

    From the Group of WG7 internal dosimetry of the EURADOS Organization (European Radiation Dosimetry group, e.V.) which It coordinates CIEMAT, international action for the vivo measurement of americium has been conducted in three mannequins type skull with detectors of Germanium by gamma spectrometry and simulation by Monte Carlo methods. Such action has been raised as two separate exercises, with the participation of institutions in Europe, America and Asia. Other actions similar precede this vivo intercomparison of measurement and modeling Monte Carlo1. The preliminary results and associated findings are presented in this work. The laboratory of the body radioactivity (CRC) of service counter of dosimetry staff internal (DPI) of the CIEMAT, it has been one of the participants in vivo measures exercise. On the other hand part, the Group of numerical dosimetry of CIEMAT is participant of the Monte Carlo2 simulation exercise. (Author)

  15. Critical and shielding parametric studies with the Monte Carlo code TRIPOLI to identify the key points to take into account during the transportation of blanket assemblies with high ratio of americium

    International Nuclear Information System (INIS)

    Gosmain, Cecile-Aline

    2011-01-01

    In the framework of French research program on Generation IV sodium cooled fast reactor, one possible option consists in burning minor actinides in this kind of Advanced Sodium Technological Reactor. Two types of transmutation mode are studied in the world : the homogeneous mode of transmutation where actinides are scattered with very low enrichment ratio in fissile assemblies and the heterogeneous mode where fissile core is surrounded by blanket assemblies filled with minor actinides with ratio of incorporated actinides up to 20%. Depending on which element is considered to be burnt and on its content, these minor actinides contents imply constraints on assemblies' transportation between Nuclear Power Plants and fuel cycle facilities. In this study, we present some academic studies in order to identify some key constraints linked to the residual power and neutron/gamma load of such kind of blanket assemblies. To simplify the approach, we considered a modeling of a 'model cask' dedicated to the transportation of a unique irradiated blanket assembly loaded with 20% of Americium and basically inspired from an existent cask designed initially for the damaged fissile Superphenix assembly transport. Thermal calculations performed with EDF-SYRTHES code have shown that due to thermal limitations on cladding temperature, the decay time to be considered before transportation is 20 years. This study is based on explicit 3D representations of the cask and the contained blanket assembly with the Monte Carlo code TRIPOLI/JEFF3.1.1 library and concludes that after such a decay time, the transportation of a unique Americium radial blanket is feasible only if the design of our model cask is modified in order to comply with the dose limitation criterion. (author)

  16. High-spin intermediates of the photolysis of 2,4,6-triazido-3-chloro-5-fluoropyridine

    Directory of Open Access Journals (Sweden)

    Sergei V. Chapyshev

    2013-04-01

    Full Text Available In contrast to theoretical expectations, the photolysis of 2,4,6-triazido-3-chloro-5-fluoropyridine in argon at 5 K gives rise to EPR peaks of just two triplet mononitrenes, two quintet dinitrenes, and a septet trinitrene. EPR spectral simulations in combination with DFT calculations show that observable nitrenes can be assigned to triplet 2,4-diazido-3-chloro-5-fluoropyridyl-6-nitrene (DT = 1.026 cm−1, ET = 0, triplet 2,6-diazido-3-chloro-5-fluoropyridyl-4-nitrene (DT = 1.122 cm−1, ET = 0.0018 cm−1, quintet 4-azido-3-chloro-5-fluoropyridyl-2,6-dinitrene (DQ = 0.215 cm−1, EQ = 0.0545 cm−1, quintet 2-azido-3-chloro-5-fluoropyridyl-4,6-dinitrene (DQ = 0.209 cm−1, EQ = 0.039 cm−1 and septet 3-chloro-5-fluoropyridyl-2,4,6-trinitrene (DS = −0.1021 cm−1, ES = −0.0034 cm−1. Preferential photodissociation of the azido groups located in ortho-positions to the fluorine atom of pyridines is associated with strong π-conjugation of these groups with the pyridine ring. On photoexcitation, such azido groups are more efficiently involved in reorganization of the molecular electronic system and more easily adopt geometries of the locally excited predissociation states.

  17. Adsorptive removal of 2,4,6-trichlorophenol in aqueous solution using calcined kaolinite-biomass composites.

    Science.gov (United States)

    Olu-Owolabi, Bamidele I; Alabi, Alimoh H; Diagboya, Paul N; Unuabonah, Emmanuel I; Düring, Rolf-Alexander

    2017-05-01

    Synergistically combined low-cost composites may be effective for the potential treatment of effluents containing organic pollutants. Hence, preparation of Carica-papaya-modified-kaolinite (CPK) and pine-cone-modified-kaolinite (PCK) composites via calcination of pure kaolinite (KAC), Carica-papaya and pine-cone seeds is demonstrated. The composites' specific surface areas were reduced by more than 57% but no structural modification in KAC lattice d-spacing, indicating impregnation of calcined biomass on clay surfaces and pores. However, composites' cation exchange capacities were enhanced over 4-fold, indicating higher potential for adsorption. Adsorption of 2,4,6-trichlorophenol on composites and KAC showed that CPK and PCK attained equilibrium relatively faster (30 min) compared to KAC (60 min). Modeling studies showed that 2,4,6-trichlorophenol removal mechanisms involved electrostatic interactions on sites of similar energy. Modification enhanced adsorption by 52 and 250% in PCK and CPK, respectively, and adsorption increased with temperature. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Electrochemical destruction of dinitrotoluene isomers and 2,4,6-trinitrotoluene in spent acid from toluene nitration process.

    Science.gov (United States)

    Chen, Wen-Shing; Liang, Jing-Song

    2009-01-30

    Mineralization of dinitrotoluene (DNT) isomers and 2,4,6-trinitrotoluene (TNT) in spent acid was conducted by in situ electrogenerated hydrogen peroxide. The electrolytic experiments were carried out to elucidate the influence of various operating parameters on the performance of mineralization of total organic compounds (TOC) in spent acid, including electrode potential, reaction temperature, oxygen dosage and concentration of sulfuric acid. It is worth noting that organic compounds could be completely mineralized by hydrogen peroxide obtained from cathodic reduction of oxygen, which was mainly supplied by anodic oxidation of water. Based on the spectra identified by gas chromatograph/mass spectrometer (GC/MS), it is proposed that oxidative degradation of 2,4-DNT and/or 2,6-DNT, 2,4,6-TNT results in o-mononitrotoluene (MNT) and 1,3,5-trinitrobenzene, respectively. Due to the removal of TOC and some amount of water, the electrolytic method established is promising for industrial application to regeneration of spent acid from toluene nitration process.

  19. Synthesis of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide – a tailor-made photoinitiator for dental adhesives

    Directory of Open Access Journals (Sweden)

    Norbert Moszner

    2010-03-01

    Full Text Available Because of the poor solubility of the commercially available bisacylphosphine oxides in dental acidic aqueous primer formulations, bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine oxide (WBAPO was synthesized starting from 3-(chloromethyl-2,4,6-trimethylbenzoic acid by the dichlorophosphine route. The substituent was introduced by etherification with 2-(allyloxyethanol. In the second step, 3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoic acid was chlorinated. The formed acid chloride showed an unexpected low thermal stability. Its thermal rearrangement at 180 °C resulted in a fast formation of 3-(chloromethyl-2,4,6-trimethylbenzoic acid 2-(allyloxyethyl ester. In the third step, the acid chloride was reacted with phenylphosphine dilithium with the formation of bis(3-{[2-(allyloxyethoxy]methyl}-2,4,6-trimethylbenzoyl(phenylphosphine, which was oxidized to WBAPO. The structure of WBAPO was confirmed by 1H NMR, 13C NMR, 31P NMR, and IR spectroscopy, as well as elemental analysis. WBAPO, a yellow liquid, possesses improved solubility in polar solvents and shows UV–vis absorption, and a high photoreactivity comparable with the commercially available bisacylphosphine oxides. A sufficient storage stability was found in dental acidic aqueous primer formulations.

  20. Structural studies of the polysaccharides from the lipopolysaccharides of Azospirillum brasilense Sp246 and SpBr14.

    Science.gov (United States)

    Sigida, Elena N; Fedonenko, Yuliya P; Shashkov, Alexander S; Grinev, Vyacheslav S; Zdorovenko, Evelina L; Konnova, Svetlana A; Ignatov, Vladimir V; Knirel, Yuriy A

    2014-10-29

    Lipopolysaccharides from closely related Azospirillum brasilense strains, Sp246 and SpBr14, were obtained by phenol-water extraction. Mild acid hydrolysis of the lipopolysaccharides followed by GPC on Sephadex G-50 resulted in polysaccharide mixtures. On the basis of sugar and methylation analyses, Smith degradation and (1)H and (13)C NMR spectroscopy data, it was concluded that both bacteria possess the same two distinct polysaccharides having structures 1 and 2: [structure: see text]. Structure 1 has been reported earlier for a polysaccharide of A. brasilense 54 [Fedonenko et al., 2011] whereas to our knowledge structure 2 has not been hitherto found in bacterial polysaccharides. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Ecotoxicological evaluation of in situ bioremediation of soils contaminated by the explosive 2,4,6-trinitrotoluene (TNT)

    International Nuclear Information System (INIS)

    Frische, Tobias

    2003-01-01

    The luminescent bacteria assay, using soil leachates, was the most sensitive toxicity indicator. - To evaluate the environmental relevance of in situ bioremediation of contaminated soils, effective and reliable monitoring approaches are of special importance. The presented study was conducted as part of a research project investigating in situ bioremediation of topsoils contaminated by the explosive 2,4,6-trinitrotoluene (TNT). Changes in soil toxicity within different experimental fields at a former ordnance factory were evaluated using a battery of five bioassays (plant growth, Collembola reproduction, soil respiration, luminescent bacteria acute toxicity and mutagenicity test) in combination to chemical contaminant analysis. Resulting data reveal clear differences in sensitivities between methods with the luminescent bacteria assay performed with soil leachates as most sensitive toxicity indicator. Complete test battery results are presented in so-called soil toxicity profiles to visualise and facilitate the interpretation of data. Both biological and chemical monitoring results indicate a reduction of soil toxicity within 17 months of remediation

  2. Facile and Green Approach to the Synthesis of Boron Nitride Quantum Dots for 2,4,6-Trinitrophenol Sensing.

    Science.gov (United States)

    Peng, Dong; Zhang, Li; Li, Fang-Fang; Cui, Wei-Rong; Liang, Ru-Ping; Qiu, Jian-Ding

    2018-02-28

    A facile and green approach has been developed for synthesis of boron nitride quantum dots (BNQDs). The obtained BNQDs exhibit strong fluorescence and excellent stabilities, including high thermostability, good salt tolerance stability, pH-independence ability, and excellent antiphotobleaching capability. The strong inner filter effect between 2,4,6-trinitrophenol (TNP) and BNQDs resulted in fluorescence quenching of BNQDs. Thus, TNP can be selectively and sensitively detected in the concentration range of 0.25-200 μM, with a limit detection of 0.14 μM. The BNQD-based turn-off sensor shows potential prospects for rapidly and selectively detecting TNP in natural water samples without tedious sample pretreatment processes.

  3. N-(2-{[5-Bromo-2-(piperidin-1-ylpyrimidin-4-yl]sulfanyl}-4-methoxyphenyl-2,4,6-trimethylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Mohan Kumar

    2012-09-01

    Full Text Available In the title compound, C25H29BrN4O3S2, the benzene rings bridged by the sulfonamide group are tilted relative to each other by 63.9 (1° and the dihedral angle between the sulfur-bridged pyrimidine and benzene rings is 64.9 (1°. The molecular conformation is stabilized by a weak intramolecular π–π stacking interaction between the pyrimidine and the 2,4,6-trimethylbenzene rings [centroid–centroid distance = 3.766 (2 Å]. The piperidine ring adopts a chair conformation. In the crystal, molecules are linked into inversion dimers by pairs of N—H...O hydrogen bonds and these dimers are further linked by C—H...O hydrogen bonds into chains propagating along [010].

  4. 1,3,5-Trialkyl-2,4,6-triiodobenzenes: novel X-ray contrast agents for gastrointestinal imaging.

    Science.gov (United States)

    Estep, K G; Josef, K A; Bacon, E R; Illig, C R; Toner, J L; Mishra, D; Blazak, W F; Miller, D M; Johnson, D K; Allen, J M; Spencer, A; Wilson, S A

    2000-05-18

    Examination of the gastrointestinal (GI) tract has been performed for decades using barium sulfate. Although this agent has many recognized limitations including extreme radiopacity, poor intrinsic affinity for the GI mucosa, and very high density, no alternative contrast agents have emerged which produce comparable or better contrast visualization. In fact, the various techniques of the GI radiologic examination (i.e., single contrast, double contrast, biphasic) were developed to compensate for its limitations. Each of these techniques requires complex patient manipulation to achieve adequate mucosal coating or compression to overcome the marked radiopacity of barium sulfate in order to obtain a diagnostically useful examination. A series of novel radiopaque oils, the 1,3, 5-trialkyl-2,4,6-triiodobenzenes, was designed to improve the efficacy, stability, and safety of barium formulations. These substances were prepared in two steps from 1,3,5-trichlorobenzene. Compound 17 (1,3,5-tri-n-hexyl-2,4,6-triiodobenzene), formulated as an oil-in-water emulsion, was found to be well-tolerated in rodents (mice, hamsters, rats) following acute oral and/or intraperitoneal administrations at 4 times the anticipated human clinical dose. No metabolism of 17 was detected in rat, hamster, dog, monkey, or human hepatic microsomes, suggesting the lack of oral toxicity was a consequence of poor absorption. In imaging experiments in dogs, emulsions of 17 have demonstrated excellent mucosal coating and improved radiodensity relative to barium sulfate suspensions. On the basis of the preliminary imaging and toxicity data, compound 17 was selected as a potential development candidate.

  5. Three-phase packed bed reactor with an evaporating solvent—I. Experimental: the hydrogenation of 2,4,6-trinitrotoluene in methanol

    NARCIS (Netherlands)

    van Gelder, K.B.; Damhof, J.K.; Kroijenga, P.J.; Westerterp, K.R.

    1990-01-01

    In this paper we present experimental data on the three-phase hydrogenation of 2,4,6-trinitrotoluene (TNT) to triaminotoluene. The experiments are performed in a cocurrent upflow packed bed reactor. Methanol is used as an evaporating solvent. The influence of the main operating parameters, the

  6. Highly Sensitive Determination of 2,4,6-Trinitrotoluene and Related Byproducts Using a Diol Functionalized Column for High Performance Liquid Chromatography

    NARCIS (Netherlands)

    Gümüscü, B.; Erdogan, Zeynep; Guler, Mustafa O.; Tekinay, Turgay

    2016-01-01

    In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT); 2,4-dinitrotoluene (2,4-DNT); 2,6-dinitrotoluene (2,6-DNT); 2-aminodinitrotoluene (2-ADNT) and 4-aminodinitrotoluene (4-ADNT) molecules in high-performance liquid-chromatography (HPLC) with UV sensor has

  7. APR-246 (PRIMA-1(MET)) strongly synergizes with AZD2281 (olaparib) induced PARP inhibition to induce apoptosis in non-small cell lung cancer cell lines.

    Science.gov (United States)

    Deben, Christophe; Lardon, Filip; Wouters, An; Op de Beeck, Ken; Van den Bossche, Jolien; Jacobs, Julie; Van Der Steen, Nele; Peeters, Marc; Rolfo, Christian; Deschoolmeester, Vanessa; Pauwels, Patrick

    2016-06-01

    APR-246 (PRIMA-1(Met)) is able to bind mutant p53 and restore its normal conformation and function. The compound has also been shown to increase intracellular ROS levels. Importantly, the poly-[ADP-ribose] polymerase-1 (PARP-1) enzyme plays an important role in the repair of ROS-induced DNA damage. We hypothesize that by blocking this repair with the PARP-inhibitor AZD2281 (olaparib), DNA damage would accumulate in the cell leading to massive apoptosis. We observed that APR-246 synergistically enhanced the cytotoxic response of olaparib in TP53 mutant non-small cell lung cancer cell lines, resulting in a strong apoptotic response. In the presence of wild type p53 a G2/M cell cycle block was predominantly observed. NOXA expression levels were significantly increased in a TP53 mutant background, and remained unchanged in the wild type cell line. The combined treatment of APR-246 and olaparib induced cell death that was associated with increased ROS production, accumulation of DNA damage and translocation of p53 to the mitochondria. Out data suggest a promising targeted combination strategy in which the response to olaparib is synergistically enhanced by the addition of APR-246, especially in a TP53 mutant background. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. Selectivity of bis-triazinyl bipyridine ligands for americium(III) in Am/Eu separation by solvent extraction. Part 1. Quantum mechanical study on the structures of BTBP complexes and on the energy of the separation.

    Science.gov (United States)

    Narbutt, Jerzy; Oziminski, Wojciech P

    2012-12-21

    Theoretical studies were carried out on two pairs of americium and europium complexes formed by tetra-N-dentate lipophilic BTBP ligands, neutral [ML(NO(3))(3)] and cationic [ML(2)](3+) where M = Am(III) or Eu(III), and L = 6,6'-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (C2-BTBP). Molecular structures of the complexes have been optimized at the B3LYP/6-31G(d) level and total energies of the complexes in various media were estimated using single point calculations performed at the B3LYP/6-311G(d,p) and MP2/6-311G(d,p) levels of theory. In the calculations americium and europium ions were treated using pseudo-relativistic Stuttgart-Dresden effective core potentials and the accompanying basis sets. Selectivity in solvent extraction separation of two metal ions is a co-operative function of contributions from all extractable metal complexes, which depend on physico-chemical properties of each individual complex and on its relative amount in the system. Semi-quantitative analysis of BTBP selectivity in the Am/Eu separation process, based on the contributions from the two pairs of Am(III) and Eu(III) complexes, has been carried out. To calculate the energy of Am/Eu separation, a model of the extraction process was used, consisting of complex formation in water and transfer of the formed complex to the organic phase. Under the assumptions discussed in the paper, this simple two-step model results in reliable values of the calculated differences in the energy changes for each pair of the Am/Eu complexes in both steps of the process. The greater thermodynamic stability (in water) of the Am-BTBP complexes, as compared with the analogous Eu species, caused by greater covalency of the Am-N than Eu-N bonds, is most likely the main reason for BTBP selectivity in the separation of the two metal ions. The other potential reason, i.e. differences in lipophilic properties of the analogous complexes of Am and Eu, is less important with regard to this selectivity.

  9. 3D Visualization of Developmental Toxicity of 2,4,6-Trinitrotoluene in Zebrafish Embryogenesis Using Light-Sheet Microscopy

    Directory of Open Access Journals (Sweden)

    Juneyong Eum

    2016-11-01

    Full Text Available Environmental contamination by trinitrotoluene is of global concern due to its widespread use in military ordnance and commercial explosives. Despite known long-term persistence in groundwater and soil, the toxicological profile of trinitrotoluene and other explosive wastes have not been systematically measured using in vivo biological assays. Zebrafish embryos are ideal model vertebrates for high-throughput toxicity screening and live in vivo imaging due to their small size and transparency during embryogenesis. Here, we used Single Plane Illumination Microscopy (SPIM/light sheet microscopy to assess the developmental toxicity of explosive-contaminated water in zebrafish embryos and report 2,4,6-trinitrotoluene-associated developmental abnormalities, including defects in heart formation and circulation, in 3D. Levels of apoptotic cell death were higher in the actively developing tissues of trinitrotoluene-treated embryos than controls. Live 3D imaging of heart tube development at cellular resolution by light-sheet microscopy revealed trinitrotoluene-associated cardiac toxicity, including hypoplastic heart chamber formation and cardiac looping defects, while the real time PCR (polymerase chain reaction quantitatively measured the molecular changes in the heart and blood development supporting the developmental defects at the molecular level. Identification of cellular toxicity in zebrafish using the state-of-the-art 3D imaging system could form the basis of a sensitive biosensor for environmental contaminants and be further valued by combining it with molecular analysis.

  10. Extraction-less, rapid assay for the direct detection of 2,4,6-trichloroanisole (TCA) in cork samples.

    Science.gov (United States)

    Apostolou, Theofylaktos; Pascual, Nuria; Marco, M-Pilar; Moschos, Anastassios; Petropoulos, Anastassios; Kaltsas, Grigoris; Kintzios, Spyridon

    2014-07-01

    2,4,6-trichloroanisole (TCA), the cork taint molecule, has been the target of several analytical approaches over the few past years. In spite of the development of highly efficient and sensitive tools for its detection, ranging from advanced chromatography to biosensor-based techniques, a practical breakthrough for routine cork screening purposes has not yet been realized, in part due to the requirement of a lengthy extraction of TCA in organic solvents, mostly 12% ethanol and the high detectability required. In the present report, we present a modification of a previously reported biosensor system based on the measurement of the electric response of cultured fibroblast cells membrane-engineered with the pAb78 TCA-specific antibody. Samples were prepared by macerating cork tissue and mixing it directly with the cellular biorecognition elements, without any intervening extraction process. By using this novel approach, we were able to detect TCA in just five minutes at extremely low concentrations (down to 0.2 ppt). The novel biosensor offers a number of practical benefits, including a very considerable reduction in the total assay time by one day, and a full portability, enabling its direct employment for on-site, high throughput screening of cork in the field and production facilities, without requiring any type of supporting infrastructure. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Laccase-polyacrylonitrile nanofibrous membrane: highly immobilized, stable, reusable, and efficacious for 2,4,6-trichlorophenol removal.

    Science.gov (United States)

    Xu, Ran; Chi, Chenglong; Li, Fengting; Zhang, Bingru

    2013-12-11

    Increasing attention has been given to nanobiocatalysis for commercial applications. In this study, laccase was immobilized on polyacrylonitrile (PAN) nanofibrous membranes through ethanol/HCl method of amidination reaction and successfully applied for removal of 2,4,6-trichlorophenol (TCP) from water. PAN membranes with fiber diameters from 200 nm to 300 nm were fabricated via electrospinning and provided a large surface area for enzyme immobilization and catalytic reactions. Images of scanning electron microscope demonstrated the enzyme molecules were aggregated on the nanofiber surface. The immobilized laccase exhibited 72% of the free enzyme activity and kept 60% of its initial activity after 10 operation cycles. Moreover, the storage stability of the immobilized laccase was considered excellent because they maintained more than 92% of the initial activity after 18 days of storage, whereas the free laccase retained only 20%. The laccase-PAN nanofibrous membranes exhibited high removal efficiency of TCP under the combined actions of biodegradation and adsorption. More than 85% of the TCP was removed under optimum conditions. Effects of various factors on TCP removal efficiency of the immobilized laccase were analyzed. Results suggest that laccase-PAN nanofibrous membranes can be used in removing TCP from aqueous sources and have potential for use in other commercial applications.

  12. Effectiveness of urea in enhancing the extractability of 2,4,6-trinitrotoluene from chemically variant soils.

    Science.gov (United States)

    Das, Padmini; Sarkar, Dibyendu; Makris, Konstantinos C; Punamiya, Pravin; Datta, Rupali

    2013-11-01

    One of the major challenges in developing an effective phytoremediation technology for 2,4,6-trinitrotoluene (TNT) contaminated soils is limited plant uptake resulting from low solubility of TNT. The effectiveness of urea as a solubilizing agent in increasing plant uptake of TNT in hydroponic systems has been documented. Our preliminary greenhouse experiments using urea were also very promising, but further characterization of the performance of urea in highly-complex soil-solution was necessary. The present study investigated the natural retention capacity of four chemically variant soils and optimized the factors influencing the effectiveness of urea in enhancing TNT solubility in the soil solutions. Results show that the extent of TNT sorption and desorption varies with the soil properties, and is mainly dependent on soil organic matter (SOM) content. Hysteretic desorption of TNT in all tested soils suggests irreversible sorption of TNT and indicates the need of using an extractant to increase the release of TNT in soil solutions. Urea significantly (pcrops. The data obtained from this batch study will facilitate the optimization of a chemically-catalyzed phytoremediation model for cleaning up TNT-contaminated soils. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Curcumin inhibits epigen and amphiregulin upregulated by 2,4,6-trinitrochlorobenzene associated with attenuation of skin swelling.

    Science.gov (United States)

    Sakai, Hiroyasu; Sato, Ken; Sato, Fumiaki; Kai, Yuki; Mandokoro, Kazutaka; Matsumoto, Kenjiro; Kato, Shinichi; Yumoto, Tetsuro; Narita, Minoru; Chiba, Yoshihiko

    2017-08-01

    Contact dermatitis model involving repeated application of hapten is used as a tool to assess dermatitis, as characterized by thickening. Involvement of cell proliferation, elicited by repeated hapten-stimulation, in this swelling has been unclear. Curcumin is reported to reduce inflammation. We examined involvement of cell proliferation and the role of extracellular regulated kinase (ERK) in 2,4,6-trinitrochlorobenzene (TNCB) challenge-induced ear swelling. We also examined the effects of curcumin in this model. Mice were sensitized with TNCB to the abdominal skin. Then, they were challenged with TNCB to the ear three times. The ERK activation inhibitor U0126 or curcumin was applied 30 min before each TNCB challenge. TNCB challenge-induced increased epidermal cell number and dermal thickening. Gene expressions of epithelial mitogen (EPGN), amphiregulin (AREG) and heparin-binding-epidermal growth factor (HB-EGF) were increased in the ears after the last TNCB challenge. Ki-67 immunoreactivity was increased in the dermis in TNCB-challenged ears. TNCB-induced swelling was inhibited by U0126 and curcumin. Curcumin also attenuated TNCB-induced ERK phosphorylation and expression of EPGN and AREG genes. Ear swelling induced by TNCB challenge might be mediated, in part, by the EPGN- and AREG-ERK proliferation pathway and was inhibited by curcumin.

  14. Synthesis and Docking Studies of 2,4,6-Trihydroxy-3-Geranylacetophenone Analogs as Potential Lipoxygenase Inhibitor

    Directory of Open Access Journals (Sweden)

    Chean Hui Ng

    2014-08-01

    Full Text Available The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs and aromatic groups could significantly affect the enzymatic activity.

  15. The renaissance of 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT) coordination chemistry.

    Science.gov (United States)

    Safin, Damir A; Frost, Jamie M; Murugesu, Muralee

    2015-12-21

    In this perspective we report on recently accumulated data on the synthesis and coordination chemistry of 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine (TPymT). Although a highly attractive ligand, owing to the presence of three fused terpyridine-like coordination pockets, the coordination chemistry of TPymT has something of a chequered past. This can principally be attributed to the hydrolysis of the ligand, which readily occurs under mild conditions. Thus, after first being synthesised in 1959 it had only been used a handful of times to synthesise coordination compounds until we began reinvestigating its chemistry in early 2013. Despite the significant challenges associated with its use, our work over the past two years has demonstrated that coordination chemistry with TPymT is indeed possible. Herein, we describe an overview of this body of work as it stands, and discuss its potential impact in a variety of areas including porous materials, catalysis and crystal engineering.

  16. Reduction of the explosive 2,4,6-trinitrophenylmethylnitramine (tetryl) catalyzed by oxygen sensitive nitro reductase enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Shah, M.M.; Spain, J.C. [Tyndall Air Force Base, FL (United States)

    1995-12-01

    Reduction of nitroaromatic compounds by nitroreductase enzymes generally leads to the formation of the corresponding amines. However, we recently found that the incubation of the explosive 2,4,6-trinitrophenylmethylnitramine (tetryl) with ferredoxin-NADP oxidoreductase, an oxygen sensitive nitroreductase from spinach in the presence of NADPH led to the elimination of the nitramine nitro group from tetryl and the formation of N-methylpicramide (NMP). Other oxygen sensitive nitroreductase enzymes including glutathione reductase, xanthine oxidase, and cytochrome c reductase were also able to release nitrite from tetryl. Nitrite was not eliminated from tetryl by an oxygen insensitive nitrobenzene reductase. For every mole of tetryl reduced, one mole each of nitrite and NMP were produced. The rate of nitrite elimination was inhibited under aerobic conditions. Subsequent oxygen uptake studies suggested that under aerobic conditions, molecular oxygen was reduced by FNR and tetryl served as the redox mediator. Our results suggest that under aerobic conditions; tetryl is reduced to the nitroanion radical by the enzyme and this radical is involved in the reduction of molecular oxygen.

  17. Pyrolusite (beta-MnO2)-mediated, near dry-phase oxidation of 2,4,6-trichlorophenol.

    Science.gov (United States)

    Smith, Brant A; Siems, William E; Teel, Amy L; Watts, Richard J

    2006-06-01

    The pyrolusite (beta-MnO2)-mediated oxidation of 2,4,6-trichlorophenol (TCP) under nonaqueous conditions was investigated to assess the potential for abiotic transformations of chlorophenols and their transformation pathways when they are released to soils and the vadose zone. Lower rates of TCP oxidation were found at lower relative humidities, but the rates were still relatively high under near-dry conditions, with 86% of the TCP transformed within 24 h at less than 2% relative humidity. The rates of TCP transformation and soluble manganese formation at less than 2% relative humidity were not affected by atmospheric oxygen content. The manganese oxide-mediated oxidation of TCP resulted in the formation of 2,6-dichloro-1,4-benzoquinone and dimers, including polychlorinated phenoxyphenols and at least one tetrachlorodibenzo-p-dioxin. The products are consistent with the proposed mechanism in which some of the TCP is transformed into trichlorophenoxy radicals that attack TCP and its transformation products. The present results demonstrate that naturally occurring manganese oxides have the potential to oxidize industrial compounds such as TCP; however, the transformation products may be more toxic and persistent than the parent compound.

  18. Synthesis, molecular structure, spectroscopic properties and stability of (Z)-N-methyl-C-2,4,6-trimethylphenylnitrone

    Science.gov (United States)

    Lasri, Jamal; Ismail, Ali I.; Haukka, Matti; Soliman, Saied M.

    2015-02-01

    New N-methyl-C-2,4,6-trimethylphenylnitrone 1 has been synthesized starting from N-methylhydroxylamine and mesitaldehyde. The product was fully characterized using different spectroscopic techniques; FTIR, NMR, UV-Vis, high resolution mass spectrometry and X-ray diffraction. The relative stability and percent of population of its two possible isomers (E and Z) were calculated using the B3LYP/6-311++G(d,p) method in gas phase and in solution. In agreement with the X-ray results, it was found that Z-isomer is the most stable one in both gas phase and solution. The molecular geometry, vibrational frequencies, gauge-including atomic orbital (GIAO), and chemical shift values were also calculated using the same level of theory. The TD-DFT results of the studied nitrone predicted a π-π∗ transition band at 285.1 nm (fosc = 0.3543) in the gas phase. The rest of the spectral bands undergo either hyperchromic or hypsochromic shifts in the presence of solvent. Polarizability and HOMO-LUMO gap values were used to predict the nonlinear optical properties (NLO) of the studied compound. NBO analysis has been used to determine the most accurate Lewis structure of the studied molecule.

  19. Highly selective detection of 2,4,6-trinitrophenol by using newly developed terbium-doped blue carbon dots.

    Science.gov (United States)

    Chen, Bin Bin; Liu, Ze Xi; Zou, Hong Yan; Huang, Cheng Zhi

    2016-04-25

    The detection of nitroaromatic explosives is of great importance owing to their strong explosive power and harmfulness in terms of the environment, homeland security and public safety. Herein, rare earth-doped carbon dots with multifunctional features were firstly prepared by simply keeping the mixture of terbium(iii) nitrate pentahydrate and citric acid at 190 °C for 30 min. The as-prepared terbium doped carbon dots (Tb-CDs), through a rapid and simple direct carbonization route, have a size of about 3 nm, and exhibit excitation wavelength dependent emission of blue fluorescence, are stable, and can be applied for the selective and colorimetric detection of 2,4,6-trinitrophenol (TNP) in the range of 500 nM-100 μM with a limit of detection of 200 nM based on the inner filtering effect (IFE) of the excitation and emission bands of Tb-CDs by TNP and the electron transfer (ET) from Tb-CDs to TNP, giving a precise and highly reproducible result for detecting complex water samples.

  20. Theoretical determination of anisotropic thermal conductivity for crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB).

    Science.gov (United States)

    Kroonblawd, Matthew P; Sewell, Thomas D

    2013-08-21

    Bond stretching and three-center angle bending potentials have been developed to extend an existing rigid-bond 1,3,5-triamino-2,4,6-trinitrobenzene molecular dynamics force field [D. Bedrov, O. Borodin, G. D. Smith, T. D. Sewell, D. M. Dattelbaum, and L. L. Stevens, J. Chem. Phys. 131, 224703 (2009)] for simulations requiring fully flexible molecules. The potentials were fit to experimental vibrational spectra and electronic structure predictions of vibrational normal modes using a combination of zero kelvin eigenmode analysis for the isolated molecule and power spectra for the isolated molecule and crystal. A reverse non-equilibrium molecular dynamics method [F. Müller-Plathe, J. Chem. Phys. 106, 6082 (1997)] was used to obtain the room temperature, atmospheric pressure thermal conductivity along three directions in a well-defined, non-orthogonal basis. The thermal conductivity was found to be significantly anisotropic with values 1.13 ± 0.07, 1.07 ± 0.07, and 0.65 ± 0.03 W m(-1) K(-1) for directions nominally parallel to the a, b, and c lattice vectors, respectively.

  1. A combination of p53-activating APR-246 and phosphatidylserine-targeting antibody potently inhibits tumor development in hormone-dependent mutant p53-expressing breast cancer xenografts

    Directory of Open Access Journals (Sweden)

    Liang Y

    2018-03-01

    Full Text Available Yayun Liang,1 Benford Mafuvadze,1 Cynthia Besch-Williford,2 Salman M Hyder1 1Deparment of Biomedical Sciences and Dalton Cardiovascular Research Center, Columbia, MO, USA; 2IDEXX BioResearch, Columbia, MO, USA Background: Between 30 and 40% of human breast cancers express a defective tumor suppressor p53 gene. Wild-type p53 tumor suppressor protein promotes cell-cycle arrest and apoptosis and inhibits vascular endothelial growth factor–dependent angiogenesis, whereas mutant p53 protein (mtp53 lacks these functions, resulting in tumor cell survival and metastasis. Restoration of p53 function is therefore a promising drug-targeted strategy for combating mtp53-expressing breast cancer. Methods: In this study, we sought to determine whether administration of APR-246, a small-molecule drug that restores p53 function, in combination with 2aG4, an antibody that targets phosphatidylserine residues on tumor blood vessels and disrupts tumor vasculature, effectively inhibits advanced hormone-dependent breast cancer tumor growth. Results: APR-246 reduced cell viability in mtp53-expressing BT-474 and T47-D human breast cancer cells in vitro, and significantly induced apoptosis in a dose-dependent manner. However, APR-246 did not reduce cell viability in MCF-7 breast cancer cells, which express wild-type p53. We next examined APR-246’s anti-tumor effects in vivo using BT-474 and T47-D tumor xenografts established in female nude mice. Tumor-bearing mice were treated with APR-246 and/or 2aG4 and tumor volume followed over time. Tumor growth was more effectively suppressed by combination treatment than by either agent alone, and combination therapy completely eradicated some tumors. Immunohistochemistry analysis of tumor tissue sections demonstrated that combination therapy more effectively induced apoptosis and reduced cell proliferation in tumor xenografts than either agent alone. Importantly, combination therapy dramatically reduced the density of blood

  2. 2-(4,6-dimetil-2-pirimidiniltio) alkanų rūgščių hidrazidų sąveika su karboniliniais junginiais

    OpenAIRE

    Kuršys, Marius

    2005-01-01

    In this work the alkylation of 4,6-dimethylpyrimidin-2(1H)-thione with ethyl bromoalkanoates was described. It was found the reactions in the present of potassium carbonate in boiling acetonitrile gave rise to corresponding S-alkylated derivatives. Under treatment of ethyl 2-(4,6-dimethyl-2-pirimidinylthio)alkanoates with excess of hydrazine hydrate the corresponding hydrazides were prepared. Further refluxing with aromatic monocarbonylic compounds led to formation of corresponding hydrazones...

  3. 1,1´,1´´-(2,4,6-Trihydroxybenzene-1,3,5-triyl)triethanone tautomerism revisited

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Kamounah, Fadhil S.; Zhiryakova, Diana

    2014-01-01

    It has recently been suggested that 1,1′,1′′-(2,4,6-trihydroxybenzene-1,3,5-triyl)triethanone may be tautomeric. Using 13C NMR chemical shifts and deuterium isotope effects on 13C chemical shifts, it is demonstrated that this is not the case. This compound occurs as a strongly hydrogen bonded ben....... In addition, conventional UV–vis spectroscopy data suggest not tautomeric, but aggregation behaviour of the molecule in methanol and acetonitrile....

  4. Biodegradation of 2,4,6-TCA by the white-rot fungus Phlebia radiata is initiated by a phase I (O-demethylation)-phase II (O-conjugation) reactions system: implications for the chlorine cycle.

    Science.gov (United States)

    Campoy, Sonia; Alvarez-Rodríguez, María Luisa; Recio, Eliseo; Rumbero, Angel; Coque, Juan-José R

    2009-01-01

    Thirteen species of white-rot fungi tested have been shown to efficiently biodegrade 1 mM 2,4,6-trichloroanisole (2,4,6-TCA) in liquid cultures. The maximum biodegradation rate (94.5% in 10-day incubations) was exhibited by a Phlebia radiata strain. The enzymes of the ligninolytic complex, laccase, lignin peroxidase (LiP), manganese peroxidase (MnP) and versatile peroxidase (VP) were not able to transform 2,4,6-TCA in in vitro reactions, indicating that the ligninolytic complex was not involved in the initial attack to 2,4,6-TCA. Instead, the first biodegradative steps were carried out by a phase I and phase II reactions system. Phase I reaction consisted on a O-demethylation catalysed by a microsomal cytochrome P-450 monooxygenase to produce 2,4,6-trichlorophenol (2,4,6-TCP). Later, in a phase II reaction catalysed by a microsomal UDP-glucosyltransferase, 2,4,6-TCP was detoxified by O-conjugation with D-glucose to produce 2,4,6-TCP-1-O-d-glucoside (TCPG). This compound accumulated in culture supernatants, reaching its maximum concentration between 48 and 72 h of growth. TCPG levels decreased constantly by the end of fermentation, indicating that it was subsequently metabolized. A catalase activity was able to break in vitro the glycosidic link to produce 2,4,6-TCP, whereas ligninolytic enzymes did not have a significant effect on the biotransformation of that compound. Once formed, 2,4,6-TCP was further degraded as detected by a concomitant release of 2.6 mol of chloride ions by 1 mol of initial 2,4,6-TCA, indicating that this compound underwent almost a complete dehalogenation and biodegradation. It was concluded that P. radiata combines two different degradative mechanisms in order to biodegrade 2,4,6-TCA. The significance of the capability of white-rot fungi to O-demethylate chloroanisoles for the global chlorine cycle is discussed.

  5. Thermal stability of the anionic sigma complexes of 2,4,6-trinitroanisole with the methylates of the alkaline-earth metals

    Energy Technology Data Exchange (ETDEWEB)

    Glaz, A.I.; Soldatova, T.A.; Golopolosova, T.V.; Gitis, S.S.

    1987-09-10

    The study of the stability of the 1,1-dimethoxy-2,4,6-trinitrocyclohexadienates of the alkali metals when they are heated in air showed that their temperature of decomposition and the heat effect of the process are dependent on the nature of the cation. Our study centered on the thermal decomposition of the products resulting from the addition of the methylates of calcium, strontium, and barium to 2,4,6-trinitroanisole. For a quantitative assessment of the process we used the combined methods of differential-thermal analysis and differential thermogravimetry. The anionic sigma-complexes of 2,4,6-trinitroanisole with the methylates of the alkaline-earth metals decompose on heating into the corresponding picrates; at the same time, when one passes from the calcium slat to the strontium and barium salts the decomposition temperature and the heat effect of the process show a drop which is linked to the structure both of the complexes and of the picrates forming therefrom.

  6. Prevalence and significance of early repolarisation in a black African population: data of 246 individuals with cardiovascular morbidity.

    Science.gov (United States)

    Bonny, Aime; Noah, Dominique Noah; Amougou, Sylvie Ndongo; Saka, Cecile

    2013-08-01

    Early repolarisation (ER) is commonly seen on electrocardiograms (ECG). Recent reports have described the relationship between ER and sudden cardiac death (SCD). The prevalence and significance of ER have not been studied in black Africans. We matched clinical and ECG records of subjects over 18 years of age who consulted a cardiac unit in two medical centres of Douala, Cameroon. A questionnaire focusing on past history of syncope or family history of sudden unexplained death (SUD) was filled in by each subject. A 12-lead ECG was recorded by a trained nurse and analysed by two independent physicians. Of the 752 ECGs recorded, we studied 246 index cases. The mean age of subjects was 45 ± 16 years and 53% were female. Almost 57% had hypertension, 41% had palpitations and 18% reported a history of syncope. ER pattern was found in 20% [slurring in three (3%), notching in 13% and both in three (7%)]. ER subjects were younger than those without (41 ± 16 vs 49 ± 16 years, p = 0.0048). Lead localisation was predominantly the laterals for the slurring pattern, whereas the inferior and lateral leads were equally involved for the notching pattern. Negative T waves in the infero-lateral leads were associated with ER (p = 0.00025). Among the subjects with syncope, 41% displayed ER and 13% did not have ER (p = 0.00014). The notching pattern seemed to be associated with syncope (p = 0.00011). Early repolarisation is frequent in black Africans, especially in the setting of cardiovascular morbidity. Early repolarisation may be associated with a past history of syncope, especially the notched pattern.

  7. Transplacental transport and fetal localization of bispehnol A, tetrabromobisphenol A and 2,4,6-tribromophenol in mice

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, A.; Brunstroem, B.; Brandt, I. [Uppsala Univ. (Sweden). Dept. of Environmental Toxicology; Cantillana, T.; Bergman, Aa. [Stockholm Univ. (Sweden). Dept. of Environmental Chemistry

    2004-09-15

    Bisphenol A (BPA) is an intermediate in the production of epoxy resins, while its brominated derivative tetrabromobishenol A (TBBPA) and its photolysis degradation product 2,4,6-tribromophenol (TBP) are widely used flame retardants. These brominated compounds have been identified in human blood. TBBPA, TBP and a number of 4-hydroxy-PCBs (e.g. 4-OH-CB107) are high affinity ligands for the thyroxin (T4) transporter transthyretin (TTR) in rodents and other species. Displacement of T4 from the TTR binding site has been proposed as an important mechanism of endocrine disruption by certain halogenated phenolic environmental pollutants. BPA is a fairly potent environmental estrogen receptor agonist that can induce an array of estrogenic effects in several species including mammals, birds and fish. Although the estrogenic activity of TBBPA is less obvious, this brominated BPA analog has been reported to interact with the estrogen receptor and induce estrogenic effects in some in vitro test systems. While the reproductive and developmental toxicity of BPA is well documented, there is evidence that also halogenated phenolic compounds can pass the placental barrier and induce such toxicity. Within the objectives of the COMPARE EU project we study the fetal and maternal kinetics and transplacental transport of phenolic environmental pollutants in pregnant mice. To explore the role of TTR in the placental and blood-brain barrier transport, we employ TTR-deficient mice. For comparative reasons, we also explore the transfer to bird embryos following injection into the yolk or administration to the egg-laying bird. In the present communication, we report on the disposition of BPA, TBBPA and TBP in the fetoplacental unit in pregnant wild-type mice.

  8. Fate and stability of 14C-labeled 2,4,6-trinitrotoluene in contaminated soil following microbial bioremediation processes.

    Science.gov (United States)

    Weiss, Martin; Geyer, Roland; Günther, Thomas; Kaestner, Matthias

    2004-09-01

    Biological treatment of 2,4,6-trinitrotoluene (TNT) in soil rarely results in complete mineralization of the parent compound. More often, the largest proportion of the TNT carbon is incorporated into the soil organic matrix. Therefore, we evaluated the stability of nonextractable residues from various bioremediation processes of 14C-TNT in soils. The extractable amounts of the residual radioactivity varied between 7 and 33% and thus the nonextractable amount between 93 and 67% (3-15% in fulvic acids, 26-46% in humic acids, and 27-44% in the humin fraction). The residue-containing soils were analyzed for the release of radioactivity after treatment by physical (freeze and thaw, grinding of soil, and steam extraction), chemical (acid rain and addition of metal complexing agent), and biological methods (addition of compost, white rot fungi, radical-generating enzymes, and germination of plants). Freeze and thaw treatment and grinding of the soil did not alter the partitioning of the label significantly. Steam extraction and acid rain extraction increased the water extractability to 11 to 29% and to 51.6% in the native TNT-contaminated soil. The addition of ethylenediamine-tetraacetate (EDTA) increased the extractability from 7 to 12%. After biological treatment, only slightly increased extractability (<10%) was observed. No increase of extractable TNT or known metabolites was observed with any of the treatments. Thus, under the treatment conditions applied in this study, the residues formed during microbial transformation of TNT may be biogenic residues with low mobilization potential and low hazardous impact.

  9. Effects of humanin on experimental colitis induced by 2,4,6-trinitrobenzene sulphonic acid in rats.

    Science.gov (United States)

    Gultekin, Fatma A; Emre, Ali U; Celik, Sevim K; Barut, Figen; Tali, Ufuk; Sumer, Demet; Turkcu, Ummuhani O

    2017-01-01

    The excessive apoptosis of intestinal epithelial cells (IECs) partly accounts for the development of colonic inflammation and eventually results in ulcerative colitis (UC). Humanin, an endogenous anti-apoptotic peptide, has previously been shown to protect against Alzheimer's disease and a variety of cellular insults. The present study aimed to investigate the effects of glysin variant of humanin (HNG) on 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced colitis in rats. Rats were divided into four groups as follows: Group 1 (n = 8): control; isotonic saline solution 0.1 ml/rat rectally, Group 2 (n = 8): TNBS colitis; 0.1 ml of a 2.5% (w/v) TNBS solution in 50% ethanol rectally, Group 3 (n = 8): 10 μM HNG, and Group 4 (n = 8): 20 μM HNG intraperitoneal (ip) on day 2 and 6 after rectal TNBS administration. Rats were sacrificed 7 days after the induction of colitis. Blood and tissue samples were harvested for biochemical and histopathological analysis. HNG treatment significantly ameliorated weight loss and macroscopic and microscopic scores. TNBS-induced colitis significantly increased the colonic mRNA expression of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and caspase-3 activities in group II in comparison to the group I. HNG treatment was associated with an inhibition of mRNA expression of TNF-α and IL-1β, and a decrease in caspase-3 activities in colon tissues in group III and IV when compared to group II. The results of this study indicate that HNG treatment may exert beneficial effects in UC by decreasing inflammatory reactions and apoptosis.

  10. Uptake of 2,4,6-Trinitrotoluene (TNT) by Vetiver grass (Vetiviera ziznoides L.) -- Preliminary results from a hydroponic study

    Science.gov (United States)

    Shakya, K. M.; Sarkar, D.; Datta, R.; Makris, K.; Pachanoor, D.

    2006-05-01

    2,4,6-Trinitrotoluene(TNT) is a potent mutagen and a Group C human carcinogen that has been widely used to produce munitions and explosives. As a result, vast areas that have been previously used as military ranges, munition burning and open detonation sites have been heavily contaminated with TNT. Conventional remedial activities in such contaminated sites commonly rely on methods such as incineration, land filling and soil composting. Phytoremediation offers a cost-effective solution, utilizing plants to phytoextract TNT from the contaminated soil. We propose the use of vetiver grass (Vetiveria zizanoides) to remove TNT from such contaminated soils. Vetiver is a fast-growing and adaptive grass, enabling its use in TNT-contaminated sites in a wide variety of soil types and climate. We also hypothesized that TNT removal by vetiver grass will be enhanced by utilizing a chaotropic agent (urea) to alter rhizosphere/root hair chemical environment. The objectives of this preliminary hydroponic study were: i) to investigate the effectiveness of vetiver grass in removing TNT from solution, and ii) to evaluate the use of a common agrochemical (urea) in enhancing TNT removal by vetiver grass. Vetiver plants were grown in a hydroponic system with five different TNT concentrations (0, 5, 10, 25, and 50 mg TNT L-1) and three urea concentrations (0, 0.01 and 0.1%). A plant density of 10 g L-1 and three replicate vessels per treatment were used. Aliquots were collected at several time intervals up to 192 hour, and were analyzed for TNT with HPLC. Results showed that vetiver was able to remove TNT from hydroponic solutions. The overall magnitude and kinetics of TNT removal by vetiver grass was enhanced in the presence of urea. TNT removal kinetics depended on TNT and urea initial concentrations, suggestive of second-order kinetic reactions. Preliminary results are encouraging, but in need for verification using more detailed studies involving TNT-contaminated soils. Ongoing

  11. Biomonitoring of 2,4,6-trinitrotoluene and degradation products in the marine environment with transplanted blue mussels (M. edulis).

    Science.gov (United States)

    Strehse, Jennifer S; Appel, Daniel; Geist, Catharina; Martin, Hans-Jörg; Maser, Edmund

    2017-09-01

    Since World War I considerable amounts of warfare material have been dumped at sea worldwide, but little is known about the fate of the explosive components in the marine environment. Sea dumped munitions are able to contaminate the surroundings because of the release of explosive chemicals due to corrosion and breaching or by detonation after blast-operations. This implies the risk of accumulation of toxic compounds in human and wildlife food chains. With the help of divers, we performed an active biomonitoring study with transplanted blue mussels (M. edulis) in a burdened area (Kolberger Heide, Germany) with explosive compounds near blast craters over an exposure time of 93days. With this biomonitoring system, we could show that blue mussels accumulate 2,4,6-trinitrotoluene (TNT) and its metabolites 2-amino-4,6-dinitrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT) in their tissues. In all mussels deployed at the ground, we found a body burden with 2-ADNT of 103.75±12.77ng/g wet weight and with 4-ADNT of 131.31±9.53ng/g wet weight. TNT itself has been found in six mussels with an average concentration of 31.04±3.26ng/g mussel wet weight. In the mussels positioned at one meter above the ground no TNT nor 2-ADNT could be detected, but 4-ADNT was found in all samples with an average concentration of 8.71±2.88ng/g mussel wet weight. To the best of our knowledge, this is the first study using blue mussels M. edulis as an active biomonitoring system for TNT and its metabolites 2-ADNT and 4-ADNT in a free field experiment in a burdened area. Moreover, with this system, we unequivocally proved that these toxic explosives accumulate in the marine biota resp. in the marine food chain, thereby posing a possible risk to the marine ecosphere and human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Visceral hypersensitivity is provoked by 2,4,6-trinitrobenzene sulfonic acid-induced ileitis in rats

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Shah

    2016-07-01

    Full Text Available Background and Aims: Crohn’s Disease (CD, a chronic Inflammatory Bowel Disease, can occur in any part of the gastrointestinal tract, but most frequently in the ileum. Visceral hypersensitivity contributes for development of chronic abdominal pain in this disease. Currently, the understanding of the mechanism underlying hypersensitivity of Crohn’s ileitis has been hindered by a lack of specific animal model. The present study is undertaken to investigate the visceral hypersensitivity provoked by 2,4,6-trinitrobenzene sulfonic (TNBS-induced ileitis rats.Methods: Male Sprague-Dawley rats were anaesthetized and laparotomized for intraileal injection of TNBS (0.6 ml, 80 mg/kg body weight in 30% ethanol, n = 48, an equal volume of 30% Ethanol (n = 24 and Saline (n = 24, respectively. Visceral hypersensitivity was assessed by visceromotor responses (VMR to 20, 40, 60, 80 and 100 mmHg colorectal distension pressure (CRD at day 1, 3, 7, 14, 21 and 28. Immediately after CRD test, the rats were euthanized for collecting the terminal ileal segment for histopathological examinations and ELISA of myleoperoxidase and cytokines (TNF-α, IL-1β, IL-6, and dorsal root ganglia (T11 for determination of calcitonin gene-related peptide by immunohistochemistry, respectively. Results: Among all groups, TNBS-treatment showed transmural inflammation initially at 3 days, reached maximum at 7 days and persisted up to 21 days. The rats with ileitis exhibited (P < 0.05 VMR to CRD at day 7 to day 21. The calcitonin gene-related peptide-immunoreactive positive cells increased (P < 0.05 in dorsal root ganglia at day 7 to 21, which was persistently consistent with visceral hypersensitivity in TNBS-treated rats.Conclusions: TNBS injection into the ileum induced transmural ileitis including granuloma and visceral hypersensitivity. As this model mimics clinical manifestations of CD, it may provide a road map to probe the pathogenesis of gut inflammation and visceral

  13. 10 CFR 110.23 - General license for the export of byproduct material.

    Science.gov (United States)

    2010-01-01

    ...) Actinium-225 and -227, americium-241 and -242m, californium-248, -249, -250, -251, -252, -253, and -254, curium-240, -241, -242, -243, -244, -245, -246 and -247, einsteinium-252, -253, -254 and -255, fermium...

  14. Convergent Total Synthesis of Paecilomycin B and 6'-epi-Paecilomycin B by a Barbier-Type Reaction Using 2,4,6-Triisopropylphenyllithium.

    Science.gov (United States)

    Ohba, Kiyomi; Nakata, Masaya

    2018-02-15

    The convergent total synthesis of the natural product paecilomycin B and its 6'-epimer was investigated. The aryl-C-glycoside skeleton was constructed by an intramolecular Barbier-type reaction using 2,4,6-triisopropylphenyllithium and subsequent deoxygenation of the resulting anomeric hydroxy group. Starting from aryl iodide 24, the addition reaction afforded the thermodynamically stable C-β macrocyclic adduct 41a in 29% yield and the C-α adduct 41b in 1% yield. Meanwhile, aryl iodide 43 (6'-epimer of 24) gave only the C-α adduct 44 in 76% yield. The stereoselectivities of these nucleophilic addition reactions are also discussed.

  15. PRIMA-1Met/APR-246 induces apoptosis and tumor growth delay in small cell lung cancer expressing mutant p53

    DEFF Research Database (Denmark)

    Zandi, Roza; Selivanova, Galina; Christensen, Camilla Laulund

    2011-01-01

    Small cell lung cancer (SCLC) is a highly malignant disease with poor prognosis, necessitating the need to develop new and efficient treatment modalities. PRIMA-1(Met) (p53-dependent reactivation of massive apoptosis), also known as APR-246, is a small molecule, which restores tumor suppressor...... function to mutant p53 and induces cancer cell death in various cancer types. Since p53 is mutated in more than 90% of SCLC, we investigated the ability of PRIMA-1(Met) to induce apoptosis and inhibit tumor growth in SCLC with different p53 mutations....

  16. Vanillin Analogues o-Vanillin and 2,4,6-Trihydroxybenzaldehyde Inhibit NFĸB Activation and Suppress Growth of A375 Human Melanoma.

    Science.gov (United States)

    Marton, Annamária; Kúsz, Erzsébet; Kolozsi, Csongor; Tubak, Vilmos; Zagotto, Giuseppe; Buzás, Krisztina; Quintieri, Luigi; Vizler, Csaba

    2016-11-01

    Constitutive activation of nuclear factor kappa-B (NFĸB) is a hallmark of various cancer types, including melanoma. Chemotherapy may further increase tumour NFĸB activity, a phenomenon that, in turn, exacerbates drug resistance. This study aimed at preliminary screening of a panel of aromatic aldehydes, including vanillin, for cytotoxicity and suppression of tumour cell NFĸB activity. The cytotoxic and NFĸB-inhibitory effects of 10 aromatic aldehydes, including vanillin, were investigated in cultured A375 human melanoma cells. Each compound was assayed alone and in combination with the model NFĸB-activating drug doxorubicin. The most promising analogues were then tested alone and in combination with 4-hydroperoxycyclophosphamide in vitro, and with cyclophosphamide in mice bearing A375 xenografts. The vanillin analogues o-vanillin and 2,4,6-trihydroxybenzaldehyde exhibited cytotoxicity against cultured A375 cells, and inhibited doxorubicin- and 4-hydroperoxycyclophosphamide-induced NFĸB activation. They also suppressed A375 cell growth in mice. o-vanillin and 2,4,6-trihydroxybenzaldehyde deserve further evaluation as potential anticancer drugs. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  17. Thiocyanate cadmium(II) complexes of 2,4,6-tri(2-pyridyl)-1,3,5-triazine – Synthesis, structure and luminescence properties

    Energy Technology Data Exchange (ETDEWEB)

    Nawrot, I. [Department of Crystallography, Institute of Chemistry, University of Silesia, ul. Szkolna 9, 40-006 Katowice (Poland); Machura, B., E-mail: basia@ich.us.edu.pl [Department of Crystallography, Institute of Chemistry, University of Silesia, ul. Szkolna 9, 40-006 Katowice (Poland); Kruszynski, R., E-mail: rafal.kruszynski@p.lodz.pl [Department of X-ray Crystallography and Crystal Chemistry, Institute of General and Ecological Chemistry, Lodz University of Technology, ul. Żeromskiego 116, 90-924 Łódź (Poland)

    2014-12-15

    Two new thiocyanate cadmium(II) complexes of 2,4,6-tri(2-pyridyl)-1,3,5-triazine were synthesized and characterized. The resulted complexes [Cd(SCN)(NO{sub 3})(tptz)(H{sub 2}O)] (1) and [Cd(SCN){sub 2}(tptz)(MeOH)] (2) were studied by IR, UV–vis spectroscopy and single crystal X-ray analysis. The luminescent properties of 1 and 2 were studied in solution and solid state and compared with the free ligand. To get detailed insight into the electronic structure and spectroscopic properties of [Cd(SCN)(NO{sub 3})(tptz)(H{sub 2}O)] and [Cd(SCN){sub 2}(tptz)(MeOH)], the density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed. - Highlights: • Two novel thiocyanate cadmium(II) compounds of 2,4,6-tri(2-pyridyl)-1,3,5-triazine were synthesized. • The compounds were identified by IR, UV–vis spectroscopy and X-ray analysis. • The fluorescence properties of the complexes were examined and compared with the free ligand. • The electronic spectra were investigated at the TD-DFT level employing B3LYP/LANL2DZ.

  18. Hexaaquabis[3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanido-κ2N3,O4]barium tetrahydrate

    Directory of Open Access Journals (Sweden)

    Nguyen Dinh Do

    2013-11-01

    Full Text Available In the title compound, [Ba(C7H5N2O52(H2O6]·4H2O, the Ba2+ cation lies on a twofold rotation axis and is ten-coordinated by two 3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanide oxo O atoms [Ba—O = 2.8715 (17 Å], two hydroxyimino N atoms [Ba—N = 3.036 (2 Å], and six water molecules [Ba—O = 2.847 (2, 2.848 (2, and 2.880 (2 Å]. The 3,5-bis(hydroxyimino-1-methyl-2,4,6-trioxocyclohexanide monoanions act in a bidentate chelating manner, coordinating through an N atom of the non-deprotonated hydroxyimino group and an O atom of the neighboring oxo group. Two lattice water molecules are located in the cavities of the framework and are involved in hydrogen bonding to O atoms of one of the coordinating water molecules and the O atom of a keto group of the ligand. As a result, a three-dimensional network is formed.

  19. The first detection of ionized helium in the local ISM - EUVE and IUE spectroscopy of the hot DA white dwarf GD 246

    Science.gov (United States)

    Vennes, Stephane; Dupuis, Jean; Rumph, Todd; Drake, Jeremy; Bowyer, Stuart; Chayer, Pierre; Fontaine, Gilles

    1993-01-01

    We report observations of the extreme ultraviolet spectrum of the hot degenerate star GD 246 obtained with the EUVE. Our initial attempt at modeling the photospheric emission from the white dwarf reveals a relatively uncontaminated pure H spectrum in the range above 200 A, allowing a study of interstellar continuum absorption features in the line of sight of GD 246. Modeling of the He I autoionization transition discussed by Rumph et al. (1993), and the EUV continuum using the white dwarf as a source of background radiation provides measurements of both neutral and, for the first time, singly ionized He column densities in the local ISM (LISM). We estimate the He ionization fraction He II/(He I + He II) at roughly 25 percent with a total He column of 1.40-1.65 x 10 exp 18/sq cm. We have measured and compared H I column densities from the saturated Ly-alpha ISM absorption in IUE high-dispersion spectroscopy and from EUV continuum absorption: the two measurements are in good agreement with a total H column of 1.2-1.6 x 10 exp 19/sq cm. We discuss some implications for the nature of the LISM, particularly in the context of current models of the EUV radiation field.

  20. Decomposition of dinitrotoluene isomers and 2,4,6-trinitrotoluene in spent acid from toluene nitration process by ozonation and photo-ozonation

    International Nuclear Information System (INIS)

    Chen, W.-S.; Juan, C.-N.; Wei, K.-M.

    2007-01-01

    Ozone and UV/O 3 were employed to mineralize dinitrotoluene (DNT) isomers and 2,4,6-trinitrotoluene (TNT) in spent acid from toluene nitration process. The oxidative degradation tests were carried out to elucidate the influence of various operating variables on the performance of mineralization of total organic compounds (TOC) in spent acid, including reaction temperature, intensity of UV (254 nm) irradiation, dosage of ozone and concentration of sulfuric acid. It is remarkable that the nearly complete mineralization of organic compounds can be achieved by ozonation combined with UV irradiation. Nevertheless, the hydroxyl radicals (·OH) would not be generated by either ozone decomposition or photolysis of ozone under the experimental condition of this study. According to the spectra identified by gas chromatograph/mass spectrometer (GC/MS) and further confirmed by gas chromatograph/flame ionization detector (GC/FID), the multiple oxidation pathways of DNT isomers are given, which include o-, m-, p-mononitrotoluene (MNT) and 1,3-dinitrobenzene, respectively. In addition, oxidative degradation of 2,4,6-TNT leads to a 1,3,5-trinitrobenzene intermediate

  1. Decomposition of dinitrotoluene isomers and 2,4,6-trinitrotoluene in spent acid from toluene nitration process by ozonation and photo-ozonation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, W.-S. [Department of Chemical Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan (China)]. E-mail: chenwen@yuntech.edu.tw; Juan, C.-N. [Department of Chemical Engineering, National Yunlin University of Science and Technology, Yunlin 640, Taiwan (China); Wei, K.-M. [Refining and Manufacturing Research Center, Chinese Petroleum Corporation, Chia-Yi 600, Taiwan (China)

    2007-08-17

    Ozone and UV/O{sub 3} were employed to mineralize dinitrotoluene (DNT) isomers and 2,4,6-trinitrotoluene (TNT) in spent acid from toluene nitration process. The oxidative degradation tests were carried out to elucidate the influence of various operating variables on the performance of mineralization of total organic compounds (TOC) in spent acid, including reaction temperature, intensity of UV (254 nm) irradiation, dosage of ozone and concentration of sulfuric acid. It is remarkable that the nearly complete mineralization of organic compounds can be achieved by ozonation combined with UV irradiation. Nevertheless, the hydroxyl radicals ({center_dot}OH) would not be generated by either ozone decomposition or photolysis of ozone under the experimental condition of this study. According to the spectra identified by gas chromatograph/mass spectrometer (GC/MS) and further confirmed by gas chromatograph/flame ionization detector (GC/FID), the multiple oxidation pathways of DNT isomers are given, which include o-, m-, p-mononitrotoluene (MNT) and 1,3-dinitrobenzene, respectively. In addition, oxidative degradation of 2,4,6-TNT leads to a 1,3,5-trinitrobenzene intermediate.

  2. Decomposition of dinitrotoluene isomers and 2,4,6-trinitrotoluene in spent acid from toluene nitration process by ozonation and photo-ozonation.

    Science.gov (United States)

    Chen, Wen-Shing; Juan, Chien-Neng; Wei, Kuo-Ming

    2007-08-17

    Ozone and UV/O3 were employed to mineralize dinitrotoluene (DNT) isomers and 2,4,6-trinitrotoluene (TNT) in spent acid from toluene nitration process. The oxidative degradation tests were carried out to elucidate the influence of various operating variables on the performance of mineralization of total organic compounds (TOC) in spent acid, including reaction temperature, intensity of UV (254 nm) irradiation, dosage of ozone and concentration of sulfuric acid. It is remarkable that the nearly complete mineralization of organic compounds can be achieved by ozonation combined with UV irradiation. Nevertheless, the hydroxyl radicals (*OH) would not be generated by either ozone decomposition or photolysis of ozone under the experimental condition of this study. According to the spectra identified by gas chromatograph/mass spectrometer (GC/MS) and further confirmed by gas chromatograph/flame ionization detector (GC/FID), the multiple oxidation pathways of DNT isomers are given, which include o-, m-, p-mononitrotoluene (MNT) and 1,3-dinitrobenzene, respectively. In addition, oxidative degradation of 2,4,6-TNT leads to a 1,3,5-trinitrobenzene intermediate.

  3. ANALISIS SIFAT TARIK DAN IMPAK KOMPOSIT SERAT RAMI DENGAN PERLAKUAN ALKALI DALAM WAKTU 2,4,6 DAN 8 JAM BERMATRIK POLIESTER

    Directory of Open Access Journals (Sweden)

    Pramuko Ilmu Purboputro

    2017-10-01

    Full Text Available Ikatan interfacal bonding pada komposit serat alam sangat tergantung dari kekasaran permukaan serat. Permukaan serat dapat ditingkatkan daya ikatan permukaannya dengan cara mencelupkan pada larutan alkali. Pencelupan ini akan mengurangi lapisan lignin yang mengurangi kekuatan ikat pada permukaan serat. Pada penelitian ini proses yang digunakan adalah perlakuan alkali terhadap permukaan serat dengan  cara merendam serat rami selama 2,4,6, dan 8 jam. Larutah alkali yang digunakan adalah larutan NaOH dengan konsentrasi 10% pada pelarut air. Serat rami   Boehmeria nivea (L Goud direndam pada larutan NaOH selama 2,4,6, dan 8 jam perendaman, untuk menghilangkan zat ligninnya agar kekuatan ikatan permukaan bisa diperbaiki.  Pengujian yang dilakukan adalah pengujian tarik dan pengujian impak. Hasil yang didapat adalah kekuatan tarik terbesar didapat pada perendaman 8 jam yaitu sebesar 41,9 MPa. Modulus young terbesar didapat pada perendaman 2 jam, yaitu 2743,15 Mpa, dan kekuatan impak terbesar adalah 0,0725 Joule/mm2 terjadi pada perendaman 4 jam   Kata kunci : komposit serat, kekuatan tarik, kekuatan impak, perendaman alkali

  4. Evaluation of neutron data for americium-241

    Energy Technology Data Exchange (ETDEWEB)

    Maslov, V.M.; Sukhovitskij, E.Sh.; Porodzinskij, Yu.V.; Klepatskij, A.B.; Morogovskij, G.B. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    The evaluation of neutron data for {sup 241}Am is made in the energy region from 10{sup -5} eV up to 20 MeV. The results of the evaluation are compiled in the ENDF/B-VI format. This work is performed under the Project Agreement CIS-03-95 with the International Science and Technology Center (Moscow). The Financing Party for the Project is Japan. The evaluation was requested by Y. Kikuchi (JAERI). (author). 60 refs.

  5. The proliferation potential of neptunium and americium

    International Nuclear Information System (INIS)

    An, J. S.; Shin, J. S.; Kim, J. S.; Kwack, E. H.; Kim, B. K.

    2000-05-01

    It is recognized that some trans-uranic elements other than plutonium, in particular Np and Am, if will be available in sufficient quantities, could be used for nuclear explosive devices. The spent fuel has been accumulating in number of nuclear power plant and operation of large scale commercial reprocessing plants. However, these materials are not covered by the definition of special fissionable material in the Agency Statute. At the time when the Statute was adopted, the availability of meaningful quantities of separated Np and Am was remote and they were not included in the definition of special fissionable material. Then, IAEA Board decided a measure for control of Np and Am on September 1999. This report contains the control method and the characteristic of Np and Am for using domestic nuclear industries, and it can be useful for understanding how to report and account of Np and Am. (author)

  6. Analysis procedure for americium in environmental samples

    International Nuclear Information System (INIS)

    Holloway, R.W.; Hayes, D.W.

    1982-01-01

    Several methods for the analysis of 241 Am in environmental samples were evaluated and a preferred method was selected. This method was modified and used to determine the 241 Am content in sediments, biota, and water. The advantages and limitations of the method are discussed. The method is also suitable for 244 Cm analysis

  7. Experiments of pyrochemical process with americium

    International Nuclear Information System (INIS)

    Hayashi, Hirokazu; Minato, Kazuo

    2004-01-01

    Experiments of pyrochemical process of minor actinide nitrides are scheduled. Experimental procedures of electrochemical study of the molten salts containing minor actinides (10-100mg) were established. Preliminary study with a rare earth element used as a surrogate was carried out in the hot cells using master-slave manipulators. (author)

  8. 1976 Hanford Americium exposure incident: hematologic effects

    International Nuclear Information System (INIS)

    Ragan, H.A.; Mahaffey, J.A.; Breitenstein, B.D.

    1982-05-01

    Hematologic evaluation of an individual with an initial systemic body burden of approx. 200 μCi 241 Am revealed a significant (P < 0.01) reduction of total leukocytes, neutrophils, and lymphocytes. This effect on total leukocytes and neutrophils was evident approx. 30 days after exposure, appeared to stabilize at about 3 months after exposure, and remained at this lower level thorugh a 52-months observation period. The effect on lymphocytes was apparent by 3 days after exposure, stabilizing at approx. 50% of pre-exposure values for about 7 months, with a return to pre-exposure levels in the following 4 y. There was a progressive and significant (P < 0.001) decline in platelet counts during the 52-months postexposure period. The pattern of response in erythrocyte parameters was complex. Immediately after the accident, these values were less than the pre-exposure mean level; they gradually increased (P < 0.001) for approx. 2 y and then began a progressive decline (P < 0.001)

  9. Fluorescence-based Sensing of 2,4,6-Trinitrotoluene (TNT Using a Multi-channeled Poly(methyl methacrylate (PMMA Microimmunosensor

    Directory of Open Access Journals (Sweden)

    Anne W. Kusterbeck

    2010-01-01

    Full Text Available Fluorescence immunoassays employing monoclonal antibodies directed against the explosive 2,4,6-trinitrotoluene (TNT were conducted in a multi-channel microimmunosensor. The multi-channel microimmunosensor was prepared in poly (methyl methacrylate (PMMA via hot embossing from a brass molding tool. The multi-channeled microfluidic device was sol-gel coated to generate a siloxane surface that provided a scaffold for antibody immobilization. AlexaFluor-cadaverine-trinitrobenzene (AlexaFluor-Cad-TNB was used as the reporter molecule in a displacement immunoassay. The limit of detection was 1-10 ng/mL (ppb with a linear dynamic range that covered three orders of magnitude. In addition, antibody crossreactivity was investigated using hexahydro-1,3,5-triazine (RDX, HMX, 2,4-dinitrotoluene (DNT, 4-nitrotoluene (4-NT and 2-amino-4,6-DNT.

  10. Synthesis of novel tripodal-benzimidazole from 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine: Structural, electrochemical and antimicrobial studies

    International Nuclear Information System (INIS)

    Koc, Ziya Erdem; Bingol, Haluk; Saf, Ahmet O.; Torlak, Emrah; Coskun, Ahmet

    2010-01-01

    Four new tripodal-benzimidazole derivatives were synthesized by Schiff base reaction between 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine (TRIPOD) and different diamine derivatives. The structures of the obtained compounds were identified by FT-IR, 1 H NMR, 13 C NMR and UV-vis spectral data, thermal analysis and elemental analysis. Electrochemical behaviors of the compounds were studied by cyclic voltammetry in DMF including 0.1 M [NBu 4 ] [PF 6 ]. The voltammograms showed peaks having similar characteristics except tripodal-benzimidazole including -NO 2 derivative. In addition, their antimicrobial activities were evaluated by using the standard disk diffusion method in dimethylformamide media. The activities were determined against 4 bacteria cultures by comparing to those of gentamycin.

  11. Graphene-based electrochemical sensor for detection of 2,4,6-trinitrotoluene (TNT) in seawater: the comparison of single-, few-, and multilayer graphene nanoribbons and graphite microparticles.

    Science.gov (United States)

    Goh, Madeline Shuhua; Pumera, Martin

    2011-01-01

    The detection of explosives in seawater is of great interest. We compared response single-, few-, and multilayer graphene nanoribbons and graphite microparticle-based electrodes toward the electrochemical reduction of 2,4,6-trinitrotoluene (TNT). We optimized parameters such as accumulation time, accumulation potential, and pH. We found that few-layer graphene exhibits about 20% enhanced signal for TNT after accumulation when compared to multilayer graphene nanoribbons. However, graphite microparticle-modified electrode provides higher sensitivity, and there was no significant difference in the performance of single-, few-, and multilayer graphene nanoribbons and graphite microparticles for the electrochemical detection of TNT. We established the limit of detection of TNT in untreated seawater at 1 μg/mL.

  12. Fabrication of surface plasmon resonance sensor surface with control of the nonspecific adsorption and affinity for the detection of 2,4,6-trinitrotoluene using an antifouling copolymer

    Directory of Open Access Journals (Sweden)

    Rui eYatabe

    2014-04-01

    Full Text Available We fabricated a surface plasmon resonance (SPR sensor using a hydrophilic polymer for the highly sensitive detection of 2,4,6-trinitrotoluene (TNT. The hydrophilic polymer was made from mono-2-(methacryloyloxyethylsuccinate (MES and 2-hydroxyethylmethacrylate (HEMA by surface-initiated atom transfer radical polymerization (SI-ATRP. The detection of TNT was carried out by displacement assay with the SPR measurement. In displacement assay, the affinity between anti-TNT antibody and the sensor surface, affects to the sensitivity. In the SPR measurement, nonspecific adsorption should be controlled because SPR sensor cannot discriminate between specific and nonspecific adsorption. Therefore, the affinity and nonspecific adsorption were controlled by changing the ratio of HEMA to MES. A detection limit of 0.4 ng/ml (ppb for TNT was achieved using a sensor surface with the lowest affinity without nonspecific adsorption.

  13. Organic salts formed by 2,4,6-triaminopyrimidine and selected carboxylic acids via a variety of hydrogen bonds: Synthons cooperation, and crystal structures

    Science.gov (United States)

    Xing, Peiqi; Li, Qingyun; Li, Yingying; Wang, Kunpeng; Zhang, Qi; Wang, Lei

    2017-05-01

    By using solvent evaporation method, 2,4,6-triaminopyrimidine (TAPI) is employed to crystallize with a variety of acids, including 3,5-dihydroxybenzoic acid (HDHBA), 3-nitrophthalic acid (H2NPA), 5-amino-2,4,6-triiodoisophthalic acid (H2ATIPIA), 2,5-dibromoterephthalic acid (H2DBTPA), 1,5-naphthalenedisulfonic acid (H2NDSA), sebacic acid (H2SA), 1,2,4-benzenetricarboxylic acid (H3BTA), and biphenyl-2,2‧,5,5'-tetracarboxylic acid (H4BPTA). In all eight complexes, protons are completely exchanged from O atom of acid to nitrogen of TAPI in 1, 3, 4, and, 5, partly transferred in 2, 6, 7, and 8. The crystal structure of all eight complexes exhibit that classical robust hydrogen bonds X-H⋯X (X = O/N) direct the molecular crystals to bind together in a stacking modes. Classical hydrogen bond Nsbnd H⋯O is participated in forming all eight organic salts, while hydrogen bonding Osbnd H⋯O are found in constructing the diversity structures in salts 1, 2, 3, 4, 6, and 7. The analysis shows that some classical supramolecular synthons, such as I R22(8), V R24(12), and VI S(6), are observed again in the construction of hydrogen-bonding networks. In the formation of layered and reticular structure, strong hydrogen bonds between water molecules and ligands having well-refined hydrogen atoms have been considered. Water molecules play an important role in building supramolecular structures of 1, 2, 3, 4, 7, and 8. Moreover, salts 1-8 are further characterized and analyzed by element analysis, infrared radiation, thermogravimetric analysis, proton nuclear magnetic resonance spectra, and mass spectra.

  14. Novel photo-catalysts containing 2,4,6-tri-phenyl-thiapyrylium encapsulated within zeolites. Enhanced photo-catalytic activity as compared to the pyrylium analogues

    Energy Technology Data Exchange (ETDEWEB)

    Alvaro, M.; Carbonell, E.; Fornes, V.; Hermenegildo, Garcia [Universidad Politecnica de Valencia, Instituto Tecnologia Quimica and Departamento de Quimica, Valencia (Spain)

    2004-07-01

    A series of solid photo-catalysts containing either 2,4.6-triplienyl-pyrylium (TP{sup +}) or 2,4,6-tri-phenyl-thiapyrylium (TPTP{sup +}) encapsulated within zeolite Y or Beta, or deposited on amorphous silica or MCM-41, have been prepared. These photo-catalysts have been tested for the degradation of aqueous solutions of phenol (40 ppm) or aniline (40 or 80 ppm, initial pH 3) as model reactions. TPTP{sup +} photo-catalysts were found to be more active and stable than those containing TP{sup +}, the initial efficiency order being: TPTP/MCM-41 {approx} TPTP/SiO{sub 2} > TPTPaBeta > TPTPaY > TiO{sub 2}. In the case of TPTP/SiO{sub 2} and TPTP/MCM-41 the photo-catalysts are largely decomposed during the photo-catalytic reaction, as compared to TPTP+ encapsulated within zeolites Y and Beta; in the latter, although the initial activity is considerably lower the dye persists after the irradiation and can be reused. In this way the final productivity of TPTPaBeta is at least four times higher than when the dye is supported on SiO{sub 2} or MCM-41. Addition of an initial concentration of H{sub 2}O{sub 2} (10{sup -3} M) accelerates the photo-degradation of phenol by a factor of 6 but it does not have much influence in the case of aniline. (authors)

  15. Identification of lysine 74 in the pyruvate binding site of alanine dehydrogenase from Bacillus subtilis - Chemical modification with 2,4,6-trinitrobenzenesulfonic acid, N-succinimidyl 3-(2-pyridyldithio)propionate, and 5'-(P-(fluorosulfonyl)benzoyl)adenosine

    NARCIS (Netherlands)

    Delforge, D; Devreese, B; Dieu, M; Delaive, E; VanBeeumen, J; Remacle, J

    1997-01-01

    L-Alanine dehydrogenase hom Bacillus subtilis was inactivated with two different lysine-directed chemical reagents, i.e. 2,4,6-trinitrobenzenesulfonic acid and N-succinimidyl 3-(2-pyridyldithio)propionate. In both cases, the inactivation followed pseudo first-order kinetics, with a 1:1

  16. Impact of long-term partial aeration on the removal of 2,4,6-trichlorophenol in an initially methanogenic fluidized bed bioreactor.

    Science.gov (United States)

    Garibay-Orijel, Claudio; Hoyo-Vadillo, Carlos; Ponce-Noyola, Teresa; García-Mena, Jaime; Poggi-Varaldo, Héctor Mario

    2006-08-05

    A fluidized bed bioreactor (FBBR) was operated for more than 1000 days under two regimes, Methanogenic (M) and Methanogenic-Aerobic (M-A), to remove 2,4,6-trichlorophenol (TCP) and phenol (Phe) from a synthetic wastewater, containing different amounts of TCP and Phe, using different aeration flow-rates (0, 2.13, and 1.06 NL O(2)/L.day). M conditions (80:20 mg/L of TCP:Phe, 0 NL O(2)/L.day) showed similar TCP and Phe removal (>95%). Nevertheless accumulation of 4-chlorophenol (4CP) up to 16 mg/L and Phe up to 4 mg/L was observed, while in M-A conditions (80:20 mg/L of TCP:Phe, 2.13 NL O(2)/L.day) TCP and Phe removal achieved 99.9(+)% and after 70 days no accumulation of intermediates were detected. The increase of TCP and Phe in the influent under M-A conditions from 80:20 to 120:30 mg/L of TCP:Phe did not negatively affect the removal of TCP, intermediates and Phe; in fact, they were similar to those in previous M-A conditions. The decrease in the oxygen flow rate from 2.13 to 1.06 NL O(2)/L.day had no negative effect on pollutant removals, which were as high as in previous two M-A conditions. The specific methanogenic activity of bioparticles of the fluidized bed decreased with long-term partial aeration, starting from 1.097 mmol CH(4)/h.g(TKN) in the M regime (day 60) to TCP and less chlorinated intermediates could be achieved in an initially methanogenic FBBR under conditions of partial aeration, although long-term operation seemed to negatively affect the methanogenic activity of biomass. It is also likely that after extended aeration the microbial community was finally enriched with strains with the ability to attack 2,4,6-TCP under aerobic conditions. This report represents the first evidence of a long exposure to oxygen of an anaerobic microbial consortium that efficiently remove TCP. (c) 2006 Wiley Periodicals, Inc.

  17. Mechanistic and Kinetic Studies on the Homogeneous Gas-Phase Formation of PCTA/DTs from 2,4-Dichlorothiophenol and 2,4,6-Trichlorothiophenol

    Directory of Open Access Journals (Sweden)

    Fei Xu

    2015-08-01

    Full Text Available Polychlorinated thianthrene/dibenzothiophenes (PCTA/DTs are sulfur analogues compounds to polychlorinated dibenzo-p-dioxin/dibenzofurans (PCDD/Fs. Chlorothiophenols (CTPs are key precursors to form PCTA/DTs. 2,4-DCTP has the minimum number of Cl atoms to form 2,4,6,8-tetrachlorinated dibenzothiophenes (2,4,6,8-TeCDT, which is the most important and widely detected of the PCDTs. In this paper, quantum chemical calculations were carried out to investigate the homogeneous gas-phase formation of PCTA/DTs from 2,4-DCTP and 2,4,6-TCTP precursors at the MPWB1K/6-311+G(3df,2p//MPWB1K/6-31+G(d,p level. Several energetically feasible pathways were revealed to compare the formation potential of PCTA/DT products. The rate constants of the crucial elementary reactions were evaluated by the canonical variational transition-state (CVT theory with the small curvature tunneling (SCT correction over a wide temperature range of 600–1200 K. This study shows that pathways that ended with elimination of Cl step were dominant over pathways ended with elimination of the H step. The water molecule has a negative catalytic effect on the H-shift step and hinders the formation of PCDTs from 2,4-DCTP. This study, together with works already published from our group, clearly illustrates an increased propensity for the dioxin formation from CTPs over the analogous CPs.

  18. 2,4,6-Tribromophenol Interferes with the Thyroid Hormone System by Regulating Thyroid Hormones and the Responsible Genes in Mice.

    Science.gov (United States)

    Lee, Dongoh; Ahn, Changhwan; Hong, Eui-Ju; An, Beum-Soo; Hyun, Sang-Hwan; Choi, Kyung-Chul; Jeung, Eui-Bae

    2016-07-12

    2,4,6-Tribromophenol (TBP) is a brominated flame retardant (BFR). Based on its affinity for transthyretin, TBP could compete with endogenous thyroid hormone. In this study, the effects of TBP on the thyroid hormone system were assessed in mice. Briefly, animals were exposed to 40 and 250 mg/kg TBP. Thyroid hormones were also administered with or without TBP. When mice were treated with TBP, deiodinase 1 (Dio1) and thyroid hormone receptor β isoform 2 (Thrβ2) decreased in the pituitary gland. The levels of deiodinase 2 (Dio2) and growth hormone (Gh) mRNA increased in response to 250 mg/kg of TBP, and the relative mRNA level of thyroid stimulating hormone β (Tshβ) increased in the pituitary gland. Dio1 and Thrβ1 expression in the liver were not altered, while Dio1 decreased in response to co-treatment with thyroid hormones. The thyroid gland activity decreased in response to TBP, as did the levels of free triiodothyronine and free thyroxine in serum. Taken together, these findings indicate that TBP can disrupt thyroid hormone homeostasis and the presence of TBP influenced thyroid actions as regulators of gene expression. These data suggest that TBP interferes with thyroid hormone systems.

  19. catena-Poly[[[aquatripyridinecobalt(II]-μ-5-amino-2,4,6-triiodoisophthalato-κ2O1:O3] pyridine solvate

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2008-11-01

    Full Text Available The reaction of cobalt(II nitrate with 5-amino-2,4,6-triiodoisophthalic acid (ATPA in pyridine solution leads to the formation of the title compound, {[Co(C8H2I3NO4(C5H5N3(H2O]·C5H5N}n. The Co2+ ion is six-coordinated by three N atoms, one water O atom and two O atoms from two ATPA ligands to form a distorted octahedral geometry. The two carboxylate groups of ATPA act as bridging ligands connecting the CoII metal centers to form one-dimensional zigzag chains along the c axis, with Co—O distances in the range 2.104 (4–2.135 (4 Å. The average Co—N distance is 2.171 Å. A classical O—H...N hydrogen bond is formed by the coordinating water molecule and the pyridine solvent molecule. The structure was refined from a racemically twinned crystal with a twin ratio of approximately 8:1.

  20. Facile Synthesis, Characterization, and In Vitro Antimicrobial Screening of a New Series of 2,4,6-Trisubstituted-s-triazine Based Compounds

    Directory of Open Access Journals (Sweden)

    Ravi Bhushan Singh

    2015-01-01

    Full Text Available A series of new 2,4,6-trisubstituted-s-triazine was synthesized, assessed for antimicrobial activity, and characterized by FTIR, 1HNMR, 13CNMR, and elemental analysis. The tested compounds, 4d, 4g, 4h, 4k, and 4n, have shown considerable in vitro antibacterial efficacy with reference to the standard drug ciprofloxacin (MIC 3.125 μgmL−1 against B. subtilis, E. coli, and K. pneumoniae. It was observed that compounds 4d and 4h displayed equipotent antibacterial efficacy against B. subtilis (MIC 3.125 μgmL−1 and S. aureus (MIC 6.25 μgmL−1. The studies demonstrated that the para-fluorophenylpiperazine substituted s-triazine (4n was potent and exhibited broad spectrum antibacterial activity against S. epidermidis, K. pneumoniae, and P. aeruginosa with MIC of 6.25 μgmL−1 and for E. coli, it showed an MIC of 3.125 μgmL−1 equipotent with reference to the standard drug. Among all the compounds under investigation, compound 4g also demonstrated significant antifungal activity (3.125 μgmL−1 against C. albicans.

  1. Recommendations for developing the optimum method for da installations to comply with 40 CFR 246-source separation for materials recovery guidelines. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Donahue, B.A.; Gershman, H.W.; Gardner, W.P.; Price, J.D.

    1977-05-01

    This report is the end-product of a study which involved both an examination of source separation techniques for materials recovery and an evaluation of current Department of the Army (DA) operations, especially those related to solid waste management. The purpose of the study was to arrive at the optimum method or methods by which DA installations could integrate source separation procedures into their current solid waste management activities, as required by the U.S. Environmental Protection Agency's 40 CFR 246 -- Source Separation for Materials Recovery Guidelines. The report was written with the goal of providing assistance -- both background information and specific instructions for procedures -- to the managing activities faced with compliance with the guidelines at the installation level. The procedures recommended in the report are those which can most easily be included in current operations while still producing significant resource recovery results. It is considered advisable for DA to institute only the 'Required' procedures from the guidelines, acting on the 'Recommended' procedures only where they can be handled with existing equipment, personnel, and funds. Procedural changes at the installation level must be preceded by DA and Department of Defense policy and guidance alterations, for which Recommendations are also provided.

  2. 2,4,6-Tribromophenol Interferes with the Thyroid Hormone System by Regulating Thyroid Hormones and the Responsible Genes in Mice

    Directory of Open Access Journals (Sweden)

    Dongoh Lee

    2016-07-01

    Full Text Available 2,4,6-Tribromophenol (TBP is a brominated flame retardant (BFR. Based on its affinity for transthyretin, TBP could compete with endogenous thyroid hormone. In this study, the effects of TBP on the thyroid hormone system were assessed in mice. Briefly, animals were exposed to 40 and 250 mg/kg TBP. Thyroid hormones were also administered with or without TBP. When mice were treated with TBP, deiodinase 1 (Dio1 and thyroid hormone receptor β isoform 2 (Thrβ2 decreased in the pituitary gland. The levels of deiodinase 2 (Dio2 and growth hormone (Gh mRNA increased in response to 250 mg/kg of TBP, and the relative mRNA level of thyroid stimulating hormone β (Tshβ increased in the pituitary gland. Dio1 and Thrβ1 expression in the liver were not altered, while Dio1 decreased in response to co-treatment with thyroid hormones. The thyroid gland activity decreased in response to TBP, as did the levels of free triiodothyronine and free thyroxine in serum. Taken together, these findings indicate that TBP can disrupt thyroid hormone homeostasis and the presence of TBP influenced thyroid actions as regulators of gene expression. These data suggest that TBP interferes with thyroid hormone systems

  3. A CHANDRA OBSERVATION OF 3C 288-REHEATING THE COOL CORE OF A 3 keV CLUSTER FROM A NUCLEAR OUTBURST at z = 0.246

    International Nuclear Information System (INIS)

    Lal, D. V.; Kraft, R. P.; Forman, W. R.; Jones, C.; Nulsen, P. E. J.; Evans, D. A.; Lee, J. C.; Hardcastle, M. J.; Croston, J. H.

    2010-01-01

    We present results from a 42 ks Chandra/ACIS-S observation of the transitional FR I/FR II radio galaxy 3C 288 at z = 0.246. We detect ∼3 keV gas extending to a radius of ∼0.5 Mpc with a 0.5-2.0 keV luminosity of 6.6 x 10 43 erg s -1 , implying that 3C 288 lies at the center of a poor cluster. We find multiple surface brightness discontinuities in the gas indicative of either a shock driven by the inflation of the radio lobes or a recent merger event. The temperature across the discontinuities is roughly constant with no signature of a cool core, thus disfavoring either the merger cold front or sloshing scenarios. We argue therefore that the discontinuities are shocks due to the supersonic inflation of the radio lobes. If they are shocks, the energy of the outburst is ∼10 60 erg, or roughly 30% of the thermal energy of the gas within the radius of the shock, assuming that the shocks are part of a front produced by a single outburst. The cooling time of the gas is ∼10 8 yr, so that the energy deposited by the nuclear outburst could have reheated and efficiently disrupted a cool core.

  4. Spectrophotometric analysis of vitamin E using Cu(I)-Bathocuproine or/and Fe(II)-2,4,6-tris-(2'-pyridyl)-s-triazine complexes

    International Nuclear Information System (INIS)

    Devi, I.; Memon, S. A.; Khuhawar, M.Y.

    2004-01-01

    Vitamin E (tocopherols and tocotrienols) antioxidants are determined by reducing Cu(II) to Cu(I) or Fe(III) to Fe(II) in presence of vitamin E and subsequent complexation of Cu(I) with bathocuproine and/or Fe(II) with 2,4,6-tris-(2'-pyridyl)-s-triazine (TPTZ). Both the reactions are monitored separately, Cu(I)-bathocuproine at 479 nm where as, Fe(II)-(TPTZ) at 595 nm spectrophotometrically. Linear calibration curves are achieved for both complexes between I to 5mu g ml-1 for vitamin E. The methods were applied for the determination of vitamin E in pharmaceutical preparations and edible oils. Vitamin E, from edible oils, was solvent extracted into n-hexane prior to saponification. Furthermore, a single lined flow was also examined. A larger excess of Cu(II) or Fe =(II) with different concentrations of vitamin E in buffer pH 4 was run on the line and constant amounts of reagent bathocuproine or TPTZ in each case was injected through the injector. The peak height shows a linear relationship for vitamin E between 0.5 to 2.5 mu g ml-1 for both complexes. (author)

  5. Modeling and investigation of new explosive materials based on N-(3,5-dimethyl-2,4,6-trinitrophenyl)-1H-1,2,4-triazol-3-amine.

    Science.gov (United States)

    Tamuliene, Jelena; Sarlauskas, Jonas; Bekesiene, Svajone

    2017-08-01

    This study presents an investigation of the effects of adding extra nitro group substituents to N-(3,5-dimethyl-2,4,6-trinitrophenyl)-1H-1,2,4-triazol-3-amine (HEM-II) on its thermal and chemical stability as well as its explosive performance. An analysis of the thermal stabilities of HEM-II and HEM-II-based molecules based on an investigation of the binding energy per atom for each molecule was performed. The values of the gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) as well as those of the chemical hardness and softness for HEM-II and the HEM-II-based molecules were studied to determine the chemical stabilities of these molecules. The detonation velocity and oxygen balance of each HEM-II-based molecule were investigated to elucidate its explosive properties. The results of our investigation show that the presence of additional nitro groups suppresses the tendency of the new HEM-II-based explosive material to react with other materials, improves its explosive properties (strength), decreases the likelihood that it will degrade, and enhances its toxicity and thermal stability. We also found that zero-point correction does not need to be performed when molecules with different substituents are investigated and compared.

  6. Tracing the cycling and fate of the explosive 2,4,6-trinitrotoluene in coastal marine systems with a stable isotopic tracer, 15N-[TNT

    Science.gov (United States)

    Smith, Richard W.; Vlahos, Penny; Böhlke, John Karl; Ariyarathna, Thivanka; Ballentine, Mark; Cooper, Christopher; Fallis, Stephen; Groshens, Thomas J.; Tobias, Craig

    2015-01-01

    2,4,6-Trinitrotoluene (TNT) has been used as a military explosive for over a hundred years. Contamination concerns have arisen as a result of manufacturing and use on a large scale; however, despite decades of work addressing TNT contamination in the environment, its fate in marine ecosystems is not fully resolved. Here we examine the cycling and fate of TNT in the coastal marine systems by spiking a marine mesocosm containing seawater, sediments, and macrobiota with isotopically labeled TNT (15N-[TNT]), simultaneously monitoring removal, transformation, mineralization, sorption, and biological uptake over a period of 16 days. TNT degradation was rapid, and we observed accumulation of reduced transformation products dissolved in the water column and in pore waters, sorbed to sediments and suspended particulate matter (SPM), and in the tissues of macrobiota. Bulk δ15N analysis of sediments, SPM, and tissues revealed large quantities of 15N beyond that accounted for in identifiable derivatives. TNT-derived N was also found in the dissolved inorganic N (DIN) pool. Using multivariate statistical analysis and a 15N mass balance approach, we identify the major transformation pathways of TNT, including the deamination of reduced TNT derivatives, potentially promoted by sorption to SPM and oxic surface sediments.

  7. Experimental and quantum chemical studies of a new organic proton transfer compound, 1H-imidazole-3-ium-3-hydroxy-2,4,6-trinitrophenolate

    Science.gov (United States)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M.

    2018-02-01

    A new proton transfer compound, 1H-imidazole-3-ium-3-hydroxy-2,4,6-trinitrophenolate (IMHTP), was crystallized by slow evaporation-solution growth technique. 1H and 13C NMR spectral studies confirm the molecular structure of the grown crystal. Single crystal X-ray diffraction study confirms that IMHTP crystallizes in monoclinic system with space group P21/c. Thermal curves (TG/DTA) show that the material is thermally stable up to 198 °C. The crystal emits fluorescence at 510 nm, proving its utility in making green light emitting materials in optical applications. The stable molecular structure was optimized by Gaussian 09 program with B3LYP/6-311++G(d,p) level of basis set. The frontier molecular orbital study shows that the charge transfer interaction occurs within the complex. The calculated first-order hyperpolarizability value of IMHTP is 44 times higher than that the reference material, urea. The electrostatic potential map was used to probe into electrophilic and nucleophilic reactive sites present in the molecule.

  8. Preconcentration of Co, Ni, Cd and Zn on naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent and flame atomic absorption determination

    Directory of Open Access Journals (Sweden)

    TAYYEBEH MADRAKIAN

    2010-05-01

    Full Text Available A preconcentration method was developed for the determination of trace amounts of Co, Ni, Cd and Zn by atomic absorption spectrometry. The method is based on the retention of the metal cations by naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent in a column. The adsorbed metals were then eluted from the column with hydrochloric acid and the Co, Ni, Cd and Zn were determined by flame atomic absorption spectrometry. The optimal extraction and elution conditions were studied. The effects of diverse ions on the preconcentration were also investigated. A preconcentration factor of 250 for Co(II, Ni(II and Zn(II, and 400 for Cd(II can easily be achieved. Calibration graphs were obtained and the detection limits of the method for Co(II, Ni(II, Cd(II and Zn(II were 0.51, 0.49, 0.17 and 0.10 ng mL-1, respectively. The relative standard deviations (RSD of 0.37–2.31 % for Co, 0.37–3.73 % for Ni, 2.20–2.40 % for Cd and 1.50–2.56 % for Zn were obtained. The method was also used for the simultaneous preconcentration of these elements and the method was successfully applied to their preconcentration and determination. The method was applied to the determination of Co, Ni, Cd and Zn in several real samples.

  9. Adsorption characteristics of green 5-arylaminomethylene pyrimidine-2,4,6-triones on mild steel surface in acidic medium: Experimental and computational approach

    Science.gov (United States)

    Verma, Chandrabhan; Olasunkanmi, Lukman O.; Ebenso, Eno E.; Quraishi, M. A.

    2018-03-01

    The effect of electron withdrawing nitro (-NO2) and electron releasing hydroxyl (-OH) groups on corrosion inhibition potentials of 5-arylaminomethylenepyrimidine-2,4,6-trione (AMP) had been studied. Four AMPs tagged AMP-1, AMP-2, AMP-3 and AMP-4 were studied for their ability to inhibit mild steel corrosion in 1 M HCl using experimental and theoretical methods. Gravimetric results showed that inhibition efficiency of the studied inhibitors increases with increasing concentration. The results further revealed that that electron withdrawing nitro (-NO2) group decreases the inhibition efficiency of AMP, while electron donating hydroxyl (-OH) group increases the inhibition efficiency of AMP. SEM and AFM studies showed that the studied compounds inhibit mild steel corrosion by adsorbing at the metal/electrolyte interface and their adsorption obeyed the Temkin adsorption isotherm. Potentiodynamic polarization study revealed that studied inhibitors act as mixed type inhibitors with predominant effect on cathodic reaction. The inhibitive strength of the compounds might have direct relationship electron donating ability of the molecules as revealed by quantum chemical parameters. The order of interaction energies derived from Monte Carlo simulations is AMP-4 > AMP-3 > AMP-2 > AMP-1, which is in agreement with the order of inhibition efficiencies obtained from experimental measurements.

  10. 2,4,6-Tribromophenol Interferes with the Thyroid Hormone System by Regulating Thyroid Hormones and the Responsible Genes in Mice

    Science.gov (United States)

    Lee, Dongoh; Ahn, Changhwan; Hong, Eui-Ju; An, Beum-Soo; Hyun, Sang-Hwan; Choi, Kyung-Chul; Jeung, Eui-Bae

    2016-01-01

    2,4,6-Tribromophenol (TBP) is a brominated flame retardant (BFR). Based on its affinity for transthyretin, TBP could compete with endogenous thyroid hormone. In this study, the effects of TBP on the thyroid hormone system were assessed in mice. Briefly, animals were exposed to 40 and 250 mg/kg TBP. Thyroid hormones were also administered with or without TBP. When mice were treated with TBP, deiodinase 1 (Dio1) and thyroid hormone receptor β isoform 2 (Thrβ2) decreased in the pituitary gland. The levels of deiodinase 2 (Dio2) and growth hormone (Gh) mRNA increased in response to 250 mg/kg of TBP, and the relative mRNA level of thyroid stimulating hormone β (Tshβ) increased in the pituitary gland. Dio1 and Thrβ1 expression in the liver were not altered, while Dio1 decreased in response to co-treatment with thyroid hormones. The thyroid gland activity decreased in response to TBP, as did the levels of free triiodothyronine and free thyroxine in serum. Taken together, these findings indicate that TBP can disrupt thyroid hormone homeostasis and the presence of TBP influenced thyroid actions as regulators of gene expression. These data suggest that TBP interferes with thyroid hormone systems PMID:27420076

  11. Systems Biology Approach to Bioremediation of Nitroaromatics: Constraint-Based Analysis of 2,4,6-Trinitrotoluene Biotransformation by Escherichia coli.

    Science.gov (United States)

    Iman, Maryam; Sobati, Tabassom; Panahi, Yunes; Mobasheri, Meysam

    2017-08-14

    Microbial remediation of nitroaromatic compounds (NACs) is a promising environmentally friendly and cost-effective approach to the removal of these life-threating agents. Escherichia coli ( E. coli ) has shown remarkable capability for the biotransformation of 2,4,6-trinitro-toluene (TNT). Efforts to develop E. coli as an efficient TNT degrading biocatalyst will benefit from holistic flux-level description of interactions between multiple TNT transforming pathways operating in the strain. To gain such an insight, we extended the genome-scale constraint-based model of E. coli to account for a curated version of major TNT transformation pathways known or evidently hypothesized to be active in E. coli in present of TNT. Using constraint-based analysis (CBA) methods, we then performed several series of in silico experiments to elucidate the contribution of these pathways individually or in combination to the E. coli TNT transformation capacity. Results of our analyses were validated by replicating several experimentally observed TNT degradation phenotypes in E. coli cultures. We further used the extended model to explore the influence of process parameters, including aeration regime, TNT concentration, cell density, and carbon source on TNT degradation efficiency. We also conducted an in silico metabolic engineering study to design a series of E. coli mutants capable of degrading TNT at higher yield compared with the wild-type strain. Our study, therefore, extends the application of CBA to bioremediation of nitroaromatics and demonstrates the usefulness of this approach to inform bioremediation research.

  12. A New Indirect Spectrofluorimetric Method for Determination of Ascorbic Acid with 2,4,6-Tripyridyl-S-Triazine in Pharmaceutical Samples

    Directory of Open Access Journals (Sweden)

    Lejla Klepo

    2016-01-01

    Full Text Available Ascorbic acid (AA is a water-soluble vitamin which shows no fluorescence. However, in reaction with iron(III, AA is oxidised to dehydroascorbic acid and iron(III is reduced to iron(II which forms a complex with 2,4,6-tripyridyl-S-triazine (TPTZ in buffered medium. The relative fluorescence intensity of the resulting Fe(TPTZ22+ complex can be measured at excitation and emission wavelengths of 393 and 790 nm, respectively. Based on this data, a new indirect spectrofluorimetric method for the determination of AA in pharmaceutical samples was proposed. Influence of the reaction conditions, such as acidity of acetic buffer, concentration of TPTZ and iron(III, reaction time and instrumental parameters were investigated in detail. The linear range was from 5.4 × 10−4 to 5.4 × 10−6 mol·L−1 (R = 0.9971. The LOD was 7.7 × 10−7 mol·L−1 and LOQ was 2.3 × 10−4 mol·L−1. Fourteen pharmaceutical samples containing various amounts of AA were analysed. Influences of potential interfering substances were also examined. Analysis of commercial pharmaceutical formulations showed good correlation with the nominal values given by the manufacturers and with the results obtained by a titration method. The proposed method can be applied in routine quality control in the pharmaceutical industry due to its sensitivity, simplicity, selectivity and low cost.

  13. Copolymerization with 2,4,6-triaminopyrimidine for the rolling-up the layer structure, tunable electronic properties, and photocatalysis of g-C3N4.

    Science.gov (United States)

    Ho, Wingkei; Zhang, Zizhong; Lin, Wei; Huang, Shuping; Zhang, Xianwen; Wang, Xuxu; Huang, Yu

    2015-03-11

    Copolymerization with 2,4,6-triaminopyrimidine (TAP) is developed for precise substitution of one nitrogen with carbon atom in the triazine ring of polymeric g-C3N4. Direct incorporation of C4N2 ring from TAP into the network retains the structural features of g-C3N4, but induces the rolling-up of g-C3N4 sheets into tubular configuration. The band gap energy is narrowed from 2.7 to 2.4 eV by a negative shift of valence band of the g-C3N4 photocatalyst, which enhances charge-carrier migration and separation, leading to higher photocatalytic activity for NO gas pollutant removal. It is attributed to the decrease of the π-deficiency and the generation of imbalanced electron density in π-electron conjugated units of g-C3N4 by TAP incorporation. This work provides a significant technique for precise control of heteroatom in the framework of g-C3N4 to finely adjust its intrinsic electronic properties and its photocatalytic properties.

  14. Preparation of N-(3-BROMO-2,4,6-trimethylacetanilide) iminodiacetic acid and its 99MTc-complex for hepatobiliary imaging

    International Nuclear Information System (INIS)

    Choi, Ok Ja; Hong, Young Don; Gwon, Hui Jeong; Choi, Sang Mu; Choi, Sun Ju

    2005-01-01

    N-(3-bromo-2,4,6-trimethylacetanilide) iminodiacetic acid (BrTIDA) was synthesized using nitrilotriacetic anhydride prepared in situ, and lyophilized vials were prepared which contained 20 mg of BrTIDA and 0.4 mg of SnCl 2 . To evaluate the clinical efficacy of the in-house prepared lyophilized kit, a technetium-99m complex of BrTIDA was prepared; its in vivo pharmacokinetic behavior was evaluated via animal studies to assess the hepatocytic function and the functional status of the cystic duct and the gallbladder. Serial static image scans of rabbits and the biodistribution in mice injected with 99m Tc-BrTIDA revealed that none of the tissues except for the hepatobiliary system showed radioactivity concentrations, and a rapid clearance from the organs was observed. In conclusion, a lyophilized kit and its prepared 99m Tc-BrTIDA can be applied as a hepatobiliary imaging agent for the evaluation of the functional status of the hepatocytes and the patency of the biliary duct

  15. Adsorption isotherms, kinetics, thermodynamics and desorption studies of 2,4,6-trichlorophenol on oil palm empty fruit bunch-based activated carbon

    International Nuclear Information System (INIS)

    Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H.

    2009-01-01

    The adsorption characteristics of 2,4,6-trichlorophenol (TCP) on activated carbon prepared from oil palm empty fruit bunch (EFB) were evaluated. The effects of TCP initial concentration, agitation time, solution pH and temperature on TCP adsorption were investigated. TCP adsorption uptake was found to increase with increase in initial concentration, agitation time and solution temperature whereas adsorption of TCP was more favourable at acidic pH. The adsorption equilibrium data were best represented by the Freundlich and Redlich-Peterson isotherms. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. Boyd plot revealed that the adsorption of TCP on the activated carbon was mainly governed by particle diffusion. Thermodynamic parameters such as standard enthalpy (ΔH o ), standard entropy (ΔS o ), standard free energy (ΔG o ) and activation energy were determined. The regeneration efficiency of the spent activated carbon was high, with TCP desorption of 99.6%.

  16. Systems Biology Approach to Bioremediation of Nitroaromatics: Constraint-Based Analysis of 2,4,6-Trinitrotoluene Biotransformation by Escherichia coli

    Directory of Open Access Journals (Sweden)

    Maryam Iman

    2017-08-01

    Full Text Available Microbial remediation of nitroaromatic compounds (NACs is a promising environmentally friendly and cost-effective approach to the removal of these life-threating agents. Escherichia coli (E. coli has shown remarkable capability for the biotransformation of 2,4,6-trinitro-toluene (TNT. Efforts to develop E. coli as an efficient TNT degrading biocatalyst will benefit from holistic flux-level description of interactions between multiple TNT transforming pathways operating in the strain. To gain such an insight, we extended the genome-scale constraint-based model of E. coli to account for a curated version of major TNT transformation pathways known or evidently hypothesized to be active in E. coli in present of TNT. Using constraint-based analysis (CBA methods, we then performed several series of in silico experiments to elucidate the contribution of these pathways individually or in combination to the E. coli TNT transformation capacity. Results of our analyses were validated by replicating several experimentally observed TNT degradation phenotypes in E. coli cultures. We further used the extended model to explore the influence of process parameters, including aeration regime, TNT concentration, cell density, and carbon source on TNT degradation efficiency. We also conducted an in silico metabolic engineering study to design a series of E. coli mutants capable of degrading TNT at higher yield compared with the wild-type strain. Our study, therefore, extends the application of CBA to bioremediation of nitroaromatics and demonstrates the usefulness of this approach to inform bioremediation research.

  17. Stand-off imaging Raman spectroscopy for forensic analysis of post-blast scenes: trace detection of ammonium nitrate and 2,4,6-trinitrotoluene

    Science.gov (United States)

    Ceco, Ema; Önnerud, Hans; Menning, Dennis; Gilljam, John L.; Bââth, Petra; Östmark, Henric

    2014-05-01

    The following paper presents a realistic forensic capability test of an imaging Raman spectroscopy based demonstrator system, developed at FOI, the Swedish Defence Research Agency. The system uses a 532 nm laser to irradiate a surface of 25×25mm. The backscattered radiation from the surface is collected by an 8" telescope with subsequent optical system, and is finally imaged onto an ICCD camera. We present here an explosives trace analysis study of samples collected from a realistic scenario after a detonation. A left-behind 5 kg IED, based on ammonium nitrate with a TNT (2,4,6-trinitrotoluene) booster, was detonated in a plastic garbage bin. Aluminum sample plates were mounted vertically on a holder approximately 6 m from the point of detonation. Minutes after the detonation, the samples were analyzed with stand-off imaging Raman spectroscopy from a distance of 10 m. Trace amounts could be detected from the secondary explosive (ammonium nitrate with an analysis time of 1 min. Measurement results also indicated detection of residues from the booster (TNT). The sample plates were subsequently swabbed and analyzed with HPLC and GC-MS analyses to confirm the results from the stand-off imaging Raman system. The presented findings indicate that it is possible to determine the type of explosive used in an IED from a distance, within minutes after the attack, and without tampering with physical evidence at the crime scene.

  18. Fabrication of an SPR Sensor Surface with Antifouling Properties for Highly Sensitive Detection of 2,4,6-Trinitrotoluene Using Surface-Initiated Atom Transfer Polymerization

    Directory of Open Access Journals (Sweden)

    Kiyoshi Toko

    2013-07-01

    Full Text Available In this study, we modified a surface plasmon resonance immunosensor chip with a polymer using surface-initiated atom transfer polymerization (SI-ATRP for the highly sensitive detection of 2,4,6-trinitrotoluene (TNT. To immobilize a TNT analogue on the polymer, mono-2-(methacryloyloxyethylsuccinate (MES, which has a carboxyl group, was used in this study. However, the anti-TNT antibody may adsorb non-specifically on the polymer surface by an electrostatic interaction because MES is negatively charged. Therefore, a mixed monomer with MES and diethylaminoethylmethacrylate (DEAEM, which has a tertiary amino group and is positively charged, was prepared to obtain electroneutrality for suppressing the nonspecific adsorption. The detection of TNT was performed by inhibition assay using the polymer surface. To ensure high sensitivity to TNT, the affinity between the surface and the antibody was optimized by controlling the density of the initiator for ATRP by mixing two types of self-assembled monolayer reagents. As a result, a limit of detection of 5.7 pg/mL (ppt for TNT was achieved using the optimized surface.

  19. DECHLORINATION OF 2,4,6-TRICHLOROPHENOL BY FREE AND IMMOBILIZED LACCASE FROM TRAMETES VERSICOLOR IN A LAB SCALE BIOREACTOR Arzu ÜNAL, Ahmet ÇABUK, Nazif KOLONKAYA

    Directory of Open Access Journals (Sweden)

    Nazif KOLANKAYA

    2011-08-01

    Full Text Available Detoxification of a chlorinated phenolic compound, 2,4,6- trichlorophenol through treatment with laccase enzyme produced by a white rot fungus, Trametes versicolor was investigated. Enzymaticdechlorination experiments by using free and immobilized laccase have been performed in a lab scale bioreactor. Chlorine ion and dissolved oxygen electrodes mounted to the bioreactor were used continuouslyto detect the profiles of chlorine ions and oxygen consumption, respectively, in reaction medium. The maximum dechlorination activity of laccase for free and immobilized form was determined as 160 μM of substrate concentration at pH 5.0, 25 °C, and 30 min of incubation time. Also, GC/MS analyses of enzymatic degradation products indicated that chlorine removal was a result of degradation of 2,4,6- trichlorophenol by the laccase under the determined optimum conditions.

  20. Americium-curium separation by means of selective extraction of hexavalent americium using a centrifugal contactor

    International Nuclear Information System (INIS)

    Musikas, C.; Germain, M.; Bathellier, A.

    1979-01-01

    This paper deals with Am (VI) - Cm (III) separation in nitrate media. The kinetics of oxidation of Am (III) by sodium persulfate in the presence of Ag + ions were reinvestigated by studying the effect of additions of small amounts of reagents which do not drastically change the distribution coefficients of Am (VI) or Cm (III) ions. Organo phosphorus solvents were selected because they are radiation resistant, possess weak reductant properties and that their affinity for hexavalent ion is high. The operating procedure was selected by consideration of the results of the two previous investigations. This can be done by using a centrifugal contactor enabling in to set organic-aqueous phase contact time in accordance with the kinetics of extraction of Am (VI), oxidation of Am (III) in aqueous phase, and reduction of Am (VI) in organic phase

  1. Self-assembly of novel supramolecular silver(I) compound based on mixed ligands bipy/TST3- H3TST=2,4,6-tris (4-sulfophenylamino)-1,3,5-triazine

    NARCIS (Netherlands)

    Yu, Yunfang; Wei, Yongqin; Broer, Ria; Wu, Kechen

    2007-01-01

    The novel supramolecular silver(I) compound with formula [Ag-6(TST)(2)(bipy)(6)(H2O)(2)](n) center dot 3nH(2)O (1) based on assembly of Ag(I) and mixed ligand bipy/TST3-, bipy = 2,2'-bipyridine, H3TST = 2,4,6-tris(4-sulfophenylamino)-1,3,5-triazine, has been prepared by hydrothermal method. In the

  2. Spectral, thermal, structural and quantum chemical calculations of 3,5-dimethyl-1H-pyrazol-2-ium-3-hydroxy-2,4,6-trinitrophenolate - A new organic proton transfer crystal

    Science.gov (United States)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M.

    2017-12-01

    Single crystals of a new proton transfer optical material, 3,5-dimethyl-1H-pyrazol-2-ium-3-hydroxy-2,4,6-trinitrophenolate (DPHTP), were obtained using slow evaporation of methanolic solution containing 1:1 M quantities of 3,5 dimethyl-1H-pyrazole and 3-hydroxy 2,4,6-trinitro phenol (styphnic acid). Asymmetric unit of DPHTP contains a univalent 3,5- dimethylpyrazolium cation with a univalent 3-hydroxy-2,4,6-trinitrophenolate anion. The various types of carbon atoms and protons in the compound were established using 1H and 13C NMR spectral studies. Thermal stability and decomposition pattern of DPHTP were studied by TG/DTA. The optical nonlinearities of DPHTP have been investigated by Z-scan technique with He-Ne laser radiation of wavelength 632.8 nm. The equilibrium optimized geometry, the first order hyperpolarizability calculations, molecular electrostatic interactions, frontier molecular orbital analysis, Mulliken population analysis have been calculated by density functional theoretical (DFT) method with (B3LYP)/6-311++G(d,p) level of basis set. First order hyperpolarizability (β) of DPHTP is 22 times greater than that of urea.

  3. Total glucosides of peony attenuates 2,4,6-trinitrobenzene sulfonic acid/ethanol-induced colitis in rats through adjustment of TH1/TH2 cytokines polarization.

    Science.gov (United States)

    Zhang, Yabing; Zhou, Rui; Zhou, Feng; Cheng, Hong; Xia, Bing

    2014-01-01

    The present study is to investigate effects of total glucosides of peony (TGP) on 2,4,6-trinitrobenzene sulfonic acid (TNBS)/ethanol-induced colitis in rats and to explore potential clinical use of TGP for treatment of inflammatory bowel disease. Sixty Sprague-Dawley rats were randomly grouped into normal controls, model controls, sulfasalazine (SASP) controls (100 mg/kg/day), and low, medium, and high-dose TGP groups (25, 50, and 100 mg/kg/day, respectively). 24 h following colonic instillation of TNBS, TGP, and SASP were given by gastric gavage three times a day for 7 days. Disease activity index (DAI), colon macroscopic damage index (CMDI), histopathological score (HPS), and myeloperoxidase (MPO) activity were evaluated. Levels of serum TNF-α, IL-1β, and IL-10 were measured by ELISA, and expression of TNF-α, IL-1β, and IL-10 mRNA and protein in colonic tissues was detected by RT-PCR and western blot, respectively. Compared with rats in the model controls, TGP (50 or 100 mg/kg/day)-treated rats with TNBS/ethanol-induced colitis showed significant improvements of DAI, CMDI, HPS, and MPO activity. Moreover, administration of TGP (50 or 100 mg/kg/day) decreased the up-regulated levels of serum TNF-α and IL-1β, and expression of TNF-α and IL-1β mRNA and protein in colonic tissues, and increased the serum IL-10 and colonic IL-10 mRNA and protein level. And there was no significant difference compared with administration of SASP (P > 0.05). TGP attenuates TNBS/ethanol-induced colitis in rats and its efficacy is similar to SASP, the potential mechanism might be related to the adjustment of Th1/Th2 cytokines polarization by decreasing pro-inflammatory cytokine TNF-α and IL-1β, and increasing anti-inflammatory cytokine IL-10.

  4. Contribution of thermal energy to initial ion production in matrix-assisted laser desorption/ionization observed with 2,4,6-trihydroxyacetophenone.

    Science.gov (United States)

    Lai, Yin-Hung; Chen, Bo-Gaun; Lee, Yuan Tseh; Wang, Yi-Sheng; Lin, Sheng Hsien

    2014-08-15

    Although several reaction models have been proposed in the literature to explain matrix-assisted laser desorption/ionization (MALDI), further study is still necessary to explore the important ionization pathways that occur under the high-temperature environment of MALDI. 2,4,6-Trihydroxyacetophenone (THAP) is an ideal compound for evaluating the contribution of thermal energy to an initial reaction with minimum side reactions. Desorbed neutral THAP and ions were measured using a crossed-molecular beam machine and commercial MALDI-TOF instrument, respectively. A quantitative model incorporating an Arrhenius-type desorption rate derived from transition state theory was proposed. Reaction enthalpy was calculated using GAUSSIAN 03 software with dielectric effect. Additional evidence of thermal-induced proton disproportionation was given by the indirect ionization of THAP embedded in excess fullerene molecules excited by a 450 nm laser. The quantitative model predicted that proton disproportionation of THAP would be achieved by thermal energy converted from a commonly used single UV laser photon. The dielectric effect reduced the reaction Gibbs free energy considerably even when the dielectric constant was reduced under high-temperature MALDI conditions. With minimum fitting parameters, observations of pure THAP and THAP mixed with fullerene both agreed with predictions. Proton disproportionation of solid THAP was energetically favorable with a single UV laser photon. The quantitative model revealed an important initial ionization pathway induced by the abrupt heating of matrix crystals. In the matrix crystals, the dielectric effect reduced reaction Gibbs free energy under typical MALDI conditions. The result suggested that thermal energy plays an important role in the initial ionization reaction of THAP. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Development of a microwave assisted extraction method for the analysis of 2,4,6-trichloroanisole in cork stoppers by SIDA-SBSE-GC-MS

    International Nuclear Information System (INIS)

    Vestner, Jochen; Fritsch, Stefanie; Rauhut, Doris

    2010-01-01

    The aim of this research work was focused on the replacement of the time-consuming soaking of cork stoppers which is mainly used as screening method for cork lots in connection with sensory analysis and/or analytical methods to detect releasable 2,4,6-trichloroanisole (TCA) of natural cork stoppers. Releasable TCA from whole cork stoppers was analysed with the application of a microwave assisted extraction method (MAE) in combination with stir bar sorptive extraction (SBSE). The soaking of corks (SOAK) was used as a reference method to optimise MAE parameters. Cork lots of different quality and TCA contamination levels were used to adapt MAE. Pre-tests indicated that an MAE at 40 deg. C for 120 min with 90 min of cooling time are suitable conditions to avoid an over-extraction of TCA of low and medium tainted cork stoppers in comparison to SOAK. These MAE parameters allow the measuring of almost the same amounts of releasable TCA as with the application of the soaking procedure in the relevant range ( -1 releasable TCA from one cork) to evaluate the TCA level of cork stoppers. Stable isotope dilution assay (SIDA) was applied to optimise quantification of the released TCA with deuterium-labelled TCA (TCA-d 5 ) using a time-saving GC-MS technique in single ion monitoring (SIM) mode. The developed MAE method allows the measuring of releasable TCA from the whole cork stopper under improved conditions and in connection with a low use of solvent and a higher sample throughput.

  6. Purifying, cloning and characterizing a novel dehalogenase from Bacillus sp. GZT to enhance the biodegradation of 2,4,6-tribromophenol in water.

    Science.gov (United States)

    Liang, Zhishu; Li, Guiying; An, Taicheng

    2017-06-01

    2,4,6-Tribromophenol (TBP), an intermediate of brominated flame retardants, can easily release to environment and recalcitrant to degradation. Previously, Bacillus sp. GZT, a pure aerobic strain capable of simultaneously debrominating and mineralizing TBP, was successfully isolated by us. To further obtain a practical application and dig up its TBP degradation mechanism, a total of 46.7-fold purification of a novel dehalogenase with a final specific activity of 18.9 U mg -1 and a molecular mass of 63.4 kDa was achieved. Under optimal conditions (35 °C and 200 rpm), up to 80% degradation efficiencies were achieved within 120 min. Adding H 2 O 2 , NADPH, Mn 2+ and Mg 2+ promoted enzyme reaction effectively; while EDTA, methyl viologen, Ni 2+ , Cu 2+ , Ca 2+ and Fe 2+ strongly inhibited reaction activities. The debromination of TBP was catalyzed by the enzyme at a Km of 78 μM and a Vmax of 0.65 min -1  mg protein -1 , which indicated that this dehalogenase could specifically eliminate TBP with a high efficiency and stability. Based on MALDI-TOF/TOF analysis, the dehalogenase shared 98% identity with peptide ABC transporter substrate-binding protein. One open reading frame (ORF) encoding this peptide was found in Strain GZT genome, subjected to clone and expressed in Escherichia coli (E. coli) to characterize the encoding gene. Result showed that this recombinant strain could also remove as similar amount of TBP as Bacillus sp. GZT under the identical condition. Based on these results, we suggest that this newly-isolated TBP dehalogenase highlights a new approach for remediating TBP pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Computational investigation and hydrogen/deuterium exchange of the fixed charge derivative tris(2,4,6-trimethoxyphenyl) phosphonium: implications for the aspartic acid cleavage mechanism.

    Science.gov (United States)

    Herrmann, Kristin A; Wysocki, Vicki H; Vorpagel, Erich R

    2005-07-01

    Aspartic acid (Asp)-containing peptides with the fixed charge derivative tris(2,4,6trimethoxyphenyl) phosphonium (tTMP-P+) were explored computationally and experimentally by hydrogen/deuterium (H/D) exchange and by fragmentation studies to probe the phenomenon of selective cleavage C-terminal to Asp in the absence of a "mobile" proton. Ab initio modeling of the tTMP-P+ electrostatic potential shows that the positive charge is distributed on the phosphonium group and therefore is not initiating or directing fragmentation as would a "mobile" proton. Geometry optimizations and vibrational analyses of different Asp conformations show that the Asp structure with a hydrogen bond between the side-chain hydroxy and backbone carbonyl lies 2.8 kcal/mol above the lowest energy conformer. In reactions with D2O, the phosphonium-derived doubly charged peptide (H+)P+LDIFSDF rapidly exchanges all 12 of its exchangeable hydrogens for deuterium and also displays a nonexchanging population. With no added proton, P+LDIFSDF exchanges a maximum of 4 of 11 exchangeable hydrogens for deuterium. No exchange is observed when all acidic groups are converted to the corresponding methyl esters. Together, these H/D exchange results indicate that the acidic hydrogens are "mobile locally" because they are able to participate in exchange even in the absence of an added proton. Fragmentation of two distinct (H+)P+LDIFSDF ion populations shows that the nonexchanging population displays selective cleavage, whereas the exchanging population fragments more evenly across the peptide backbone. This result indicates that H/D exchange can sometimes distinguish between and provide a means of separation of different protonation motifs and that these protonation motifs can have an effect on the fragmentation.

  8. Highly sensitive determination of 2,4,6-trinitrotoluene and related byproducts using a diol functionalized column for high performance liquid chromatography.

    Directory of Open Access Journals (Sweden)

    Burcu Gumuscu

    Full Text Available In this work, a new detection method for complete separation of 2,4,6-trinitrotoluene (TNT; 2,4-dinitrotoluene (2,4-DNT; 2,6-dinitrotoluene (2,6-DNT; 2-aminodinitrotoluene (2-ADNT and 4-aminodinitrotoluene (4-ADNT molecules in high-performance liquid-chromatography (HPLC with UV sensor has been developed using diol column. This approach improves on cost, time, and sensitivity over the existing methods, providing a simple and effective alternative. Total analysis time was less than 13 minutes including column re-equilibration between runs, in which water and acetonitrile were used as gradient elution solvents. Under optimized conditions, the minimum resolution between 2,4-DNT and 2,6-DNT peaks was 2.06. The recovery rates for spiked environmental samples were between 95-98%. The detection limits for diol column ranged from 0.78 to 1.17 µg/L for TNT and its byproducts. While the solvent consumption was 26.4 mL/min for two-phase EPA and 30 mL/min for EPA 8330 methods, it was only 8.8 mL/min for diol column. The resolution was improved up to 49% respect to two-phase EPA and EPA 8330 methods. When compared to C-18 and phenyl-3 columns, solvent usage was reduced up to 64% using diol column and resolution was enhanced approximately two-fold. The sensitivity of diol column was afforded by the hydroxyl groups on polyol layer, joining the formation of charge-transfer complexes with nitroaromatic compounds according to acceptor-donor interactions. Having compliance with current requirements, the proposed method demonstrates sensitive and robust separation.

  9. Development of a microwave assisted extraction method for the analysis of 2,4,6-trichloroanisole in cork stoppers by SIDA-SBSE-GC-MS

    Energy Technology Data Exchange (ETDEWEB)

    Vestner, Jochen [Forschungsanstalt Geisenheim, Fachgebiet Mikrobiologie und Biochemie, Von-Lade-Strasse 1, D-65366 Geisenheim (Germany); Hochschule RheinMain, Fachbereich Geisenheim, Von-Lade-Strasse 1, D-65366 Geisenheim (Germany); Fritsch, Stefanie [Forschungsanstalt Geisenheim, Fachgebiet Mikrobiologie und Biochemie, Von-Lade-Strasse 1, D-65366 Geisenheim (Germany); Rauhut, Doris, E-mail: doris.rauhut@fa-gm.de [Forschungsanstalt Geisenheim, Fachgebiet Mikrobiologie und Biochemie, Von-Lade-Strasse 1, D-65366 Geisenheim (Germany)

    2010-02-15

    The aim of this research work was focused on the replacement of the time-consuming soaking of cork stoppers which is mainly used as screening method for cork lots in connection with sensory analysis and/or analytical methods to detect releasable 2,4,6-trichloroanisole (TCA) of natural cork stoppers. Releasable TCA from whole cork stoppers was analysed with the application of a microwave assisted extraction method (MAE) in combination with stir bar sorptive extraction (SBSE). The soaking of corks (SOAK) was used as a reference method to optimise MAE parameters. Cork lots of different quality and TCA contamination levels were used to adapt MAE. Pre-tests indicated that an MAE at 40 deg. C for 120 min with 90 min of cooling time are suitable conditions to avoid an over-extraction of TCA of low and medium tainted cork stoppers in comparison to SOAK. These MAE parameters allow the measuring of almost the same amounts of releasable TCA as with the application of the soaking procedure in the relevant range (<25 ng L{sup -1} releasable TCA from one cork) to evaluate the TCA level of cork stoppers. Stable isotope dilution assay (SIDA) was applied to optimise quantification of the released TCA with deuterium-labelled TCA (TCA-d{sub 5}) using a time-saving GC-MS technique in single ion monitoring (SIM) mode. The developed MAE method allows the measuring of releasable TCA from the whole cork stopper under improved conditions and in connection with a low use of solvent and a higher sample throughput.

  10. Effects of sinomenine on the expression of microRNA-155 in 2,4,6-trinitrobenzenesulfonic acid-induced colitis in mice.

    Directory of Open Access Journals (Sweden)

    Qiao Yu

    Full Text Available Sinomenine, a pure alkaloid isolated in Chinese medicine from the root of Sinomenium acutum, has been demonstrated to have anti-inflammatory and immunosuppressive effects. MicroRNAs (miRNAs are gradually being recognized as critical mediators of disease pathogenesis via coordinated regulation of molecular effector pathways.After colitis was induced in mice by instillation of 5% (w/v 2,4,6-trinitrobenzenesulfonic acid (TNBS, sinomenine at a dose of 100 or 200 mg/kg was orally administered once daily for 7 days. We evaluated body weight, survival rate, diarrhea score, histological score and myeloperoxidase (MPO activity. The mRNA and protein expression levels of miR-155, c-Maf, TNF-α and IFN-γ were determined by quantitative RT-PCR and immunohistochemistry, respectively. Sinomenine (100 or 200 mg/kg-treated mice with TNBS-induced colitis were significantly improved in terms of body weight, survival rate, diarrhea score, histological score and MPO activity compared with untreated mice. Both dosages of sinomenine significantly decreased the mRNA and protein expression levels of c-Maf, TNF-α and IFN-γ, which elevated in TNBS-induced colitis. Furthermore, sinomenine at a dose of 200 mg/kg significantly decreased the level of miR-155 expression by 71% (p = 0.025 compared with untreated TNBS-induced colitis in mice.Our study evaluated the effects and potential mechanisms of sinomenine in the anti-inflammatory response via miRNA-155 in mice with TNBS-induced colitis. Our findings suggest that sinomenine has anti-inflammatory effects on TNBS-induced colitis by down-regulating the levels of miR-155 and several related inflammatory cytokines.

  11. Development of a chemiluminescence-based quantitative lateral flow immunoassay for on-field detection of 2,4,6-trinitrotoluene.

    Science.gov (United States)

    Mirasoli, Mara; Buragina, Angela; Dolci, Luisa Stella; Guardigli, Massimo; Simoni, Patrizia; Montoya, Angel; Maiolini, Elisabetta; Girotti, Stefano; Roda, Aldo

    2012-04-06

    Simple, rapid and highly sensitive assays, possibly allowing on-site analysis, are required in the security and forensic fields or to obtain early signs of environmental pollution. Several bioanalytical methods and biosensors based on portable devices have been developed for this purpose. Among them, Lateral Flow ImmunoAssays (LFIAs) offer the advantages of rapidity and ease of use and, thanks to the high specificity of antigen-antibody binding, allow greatly simplifying and reducing sample pre-analytical treatments. However, LFIAs usually employ colloidal gold or latex beads as labels and they rely on the formation of colored bands visible by the naked eye. With this assay format, only qualitative or semi-quantitative information can be obtained and low sensitivity is achieved. Recently, the use of enzyme-catalyzed chemiluminescence detection in LFIA has been proposed to overcome these problems. In this work, we describe the development of a quantitative CL-LFIA assay for the detection of 2,4,6-trinitrotoluene (TNT) in real samples. Thanks to the use of a portable imaging device for CL signal measurement based on a thermoelectrically cooled CCD camera, the analysis could be performed directly on-field. A limit of detection of 0.2 μg mL(-1) TNT was obtained, which is five times lower than that obtained with a previously described colloidal gold-based LFIA developed employing the same immunoreagents. The dynamic range of the assay extended up to 5 μg mL(-1) TNT and recoveries ranging from 97% to 111% were obtained in the analysis of real samples (post blast residues obtained from controlled explosion). Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Introduction (PSW-GTR-246)

    Science.gov (United States)

    James Halperin; David. Ganz

    2013-01-01

    Globally, approximately two-thirds of the world's forests are considered degraded, but practical, cost-effective tools for monitoring forest quality remain elusive. Techniques for monitoring deforestation and changes to forest carbon stocks are widespread and well published. However, techniques for monitoring forest degradation are relatively untested in...

  13. Kinetic studies of the BrO + ClO cross-reaction over the range T = 246-314 K.

    Science.gov (United States)

    Ferracci, Valerio; Rowley, David M

    2014-01-21

    The kinetics of the atmospherically important gas phase radical reaction between BrO and ClO have been studied over the temperature range T = 246-314 K by means of laser flash photolysis coupled with UV absorption spectroscopy. Charge-coupled-device (CCD) detection allowed simultaneous monitoring of both free radicals and the OClO product using 'differential' spectroscopy, which minimised interference from underlying UV absorbing species. In this way, the total rate coefficient for BrO + ClO → products (1) was measured, along with that for the OClO producing channel of this process BrO + ClO → OClO + Br (1c). These reaction rate coefficients are described by the Arrhenius expressions: k1/cm(3) molecule(-1) s(-1) = (2.5 ± 2.2) × 10(-12) exp[(630 ± 240)/T] and k(1c)/cm(3) molecule(-1) s(-1) = (4.6 ± 3.0) × 10(-12) exp[(280 ± 180)/T], where errors are 2σ, statistical only. An extensive sensitivity analysis was performed to quantify the potential additional systematic uncertainties in this work arising from uncertainties in secondary chemistry, absorption cross-sections and precursor concentrations. This analysis identified the reactions of initial and secondarily generated bromine atoms (specifically Br + O3 and Br + Cl2O) as particularly important, along with the reversible combination of ClO with OClO forming Cl2O3. Potential uncertainty in this latter process was used to define the lowest temperature of the present study. Results from this work indicate larger absolute values for k1 and k(1c) than those reported in previous studies, but a weaker negative temperature dependence for k(1c) than previously observed, resulting in a branching ratio for with a positive temperature dependence, in disagreement with previous studies. is the principal source of OClO in the polar stratosphere and is commonly used in atmospheric models as an indicator of stratospheric bromine chemistry. Thus these measurements might lead to a reinterpretation of modelled

  14. Association between Exposure to Benzodiazepines and Related Drugs and Survivorship of Total Hip Replacement in Arthritis: A Population-Based Cohort Study of 246,940 Patients.

    Directory of Open Access Journals (Sweden)

    Dan Beziz

    Full Text Available Total hip replacement (THR is successful in treating hip arthritis. Prosthetic survivorship may depend on the medications taken by the patient; particularly, the role of benzodiazepines and related drugs (Z-drugs with THR revision has been poorly investigated. Our objective was to compare THR short-term survivorship according to level of exposure to benzodiazepine and Z-drugs.All French patients aged 40 years or older, having undergone primary THR from January 1, 2009, through December 31, 2012, for arthritis according to French national health insurance databases were included in the cohort. Outcome of interest was THR revision, including any surgical procedure in which the implant or any component was changed or removed. Follow-up started the day the primary THR was performed. Observations were right-censored on December 31, 2014, if neither revision nor death had yet occurred. Exposure of interest was the cumulative defined daily doses per day (cDDD/day of benzodiazepines and Z-drugs dispensed within 6 months before or after inclusion. We defined four exposure groups; cDDD/d = 0: unexposed; 0.38: high exposure. THR survivorship was assessed according to level of exposure to benzodiazepines and Z-drugs in univariate and multivariate Cox models adjusted for patient, THR and implanting center characteristics.The study cohort comprised 246,940 individuals: mean age at baseline, 69.9 years; women, 57.9%; unexposed: 51.7%; low exposure: 16.7%; medium exposure: 15.9%; and high exposure: 15.7%. During the median 45-month follow-up, 9043 individuals underwent prosthetic revision. Adjusted hazard ratios in low, medium and high exposed groups were 1.18 (95%CI, 1.12-1.26; P<0.001, 1.32 (95%CI, 1.24-1.40; P<0.001 and 1.37 (95%CI, 1.29-1.45; P<0.001, respectively, compared to unexposed.Exposure to benzodiazepines and Z-drugs is associated with an increased risk of THR revision, with a dose-response relationship. Cautious prescribing might be needed as well

  15. The novel isotopically coded short-range photo-reactive crosslinker 2,4,6-triazido-1,3,5-triazine (TATA) for studying protein structures.

    Science.gov (United States)

    Brodie, Nicholas I; Petrotchenko, Evgeniy V; Borchers, Christoph H

    2016-10-21

    Short-distance molecular-modeling constraints are advantageous for elucidating the structures of individual proteins and protein conformational changes. Commonly used amine-reactive crosslinks are relatively long (14Å), partly due to the length of the lysine side-chain, and are sparsely distributed throughout a protein. Short-distance non-specific crosslinkers can provide a larger number of tighter molecular-modeling constraints. Here we describe the use of a short-range homo-trifunctional isotopically-coded non-specific photo-reactive crosslinking reagent, 2,4,6-triazido-1,3,5-triazine (TATA)- 12 C 3 / 13 C 3 , for MS-based protein crosslinking studies. Upon activation by 254nm UV light, TATA- 12 C 3 / 13 C 3 generates up to three nitrene radicals capable of non-selective crosslinking at ~5Å. This reagent was validated using cyclohexane, several test peptides, and myoglobin, and was found to react with a large number of amino acids, forming multiple crosslinked products. The myoglobin crosslinks detected by MS agreed with the known structure of myoglobin; arranging the protein's secondary-structure motifs into their correct fold was possible based solely on the constraints imposed by the crosslinks. Finally, TATA was used to crosslink the α-synuclein monomer. The 10 short-distance constraints provided by TATA crosslinking led to an initial model of the molten-globule form of the native α-synuclein monomer; this provides a suggested structure for the precursor of the misfolded α-synuclein proteoforms involved in synucleopathies. The isotopically labeled short-range non-specific crosslinker TATA- 12 C 3 / 13 C 3 was characterized for use in crosslinking-based protein structural studies. The crosslinking products of TATA can provide a distance constraint of merely 5Ǻ between crosslinked residues. TATA- 12 C 3 / 13 C 3 had broad reactivity, crosslinking a wide variety of amino acids, including lysine, glutamic and aspartic acid, asparagine, glutamine, glycine

  16. (E-N-[2-(9-Fluorenylidene-3a,5,7-trimethyl-3,3a-dihydro-2H-indol-3-ylidene]-2,4,6-trimethylaniline

    Directory of Open Access Journals (Sweden)

    Norihiro Tokitoh

    2008-02-01

    Full Text Available The title compound, C33H30N2, has an E configuration at the imine double bond. The angle between the least-squares planes of the imine C=N—C group and the benzene ring of the 2,4,6-trimethylphenyl substituent is 85.38 (11°. The crystal structure is sustained mainly by intermolecular π–π interactions (3.510 Å between the two fluorene rings and some C—H...π interactions.

  17. Synthesis and the crystal and molecular structures of (H3L . Cl)[CoCl4] and H2L[CuBr4] (L is 2,4,6-Tri(N,N-dimethylamino)methylphenol)

    International Nuclear Information System (INIS)

    Kovalchukova, O. V.; Stash, A. I.; Strashnova, S. B.; Romashkina, E. P.; Zaitsev, B. E.

    2010-01-01

    The complex compounds (H 3 L . Cl)[CoCl 4 ] (I) and H 2 L[CuBr 4 ] (II), where L is 2,4,6-tri(N,N-dimethylamino)methylphenol, were isolated in the crystalline state and studied by X-ray diffraction. The organic cations were found to be outer-sphere ligands. All three nitrogen atoms of the tertiary amino groups are protonated. In compound I, the H 3 L 3+ cation exists as the cis tautomer. In compound II, the H 2 L 2+ dication exists as the trans isomer. In the crystal structure, the dications are arranged in layers via hydrogen bonds.

  18. Beyaz Çürükçül Mantar Trametes versicolor’dan Elde Edilen Lakkaz Enzimi İle 2,4,6-Triklorofenol’ün Enzimatik Deklorinasyonunun Kinetik Modellemesi

    Directory of Open Access Journals (Sweden)

    Arzu Ünal

    2016-03-01

    Full Text Available Bu çalışmada beyaz çürükçül mantar suşu Trametes versicolor’dan elde edilen lakkaz enzimi ile toksik klorlu fenolik bir bileşik olan 2,4,6-triklorofenol’ün deklorinasyonuna bağlı detoksifikasyonunun kinetik modellemesi araştırıldı. Substrat olarak kullanılan 2,4,6-triklorofenol’ün deklorinasyonuna bağlı detoksifikasyon kinetiğinin değerlendirilmesinde bir istatistik programı olan Systat 10 paket programı, deklorinasyonun kinetik davranışlarının açıklanması için iki substratlı çözüm ortamı olarak kullanıldı. Deneyler ve istatistiksel analizler sonucunda, Moser eşitliğinin en uygun kinetik model olduğu gözlendi. Elde edilen istatistiksel verilerden ve grafikten, çift-substratlı modelin deney verileri ile iyi bir uyum içinde olduğu görüldü. Enzimatik deklorinasyon kinetiğini tanımlayan model için elde edilen biyokinetik parametre değerleri Vmax =9,341 ppmO2/dk, Ks =38,254 g/L, Ko =20,747 ppm, R = 1,895 ve N = 1,233 olarak hesaplandı. Literatürde 2,4,6-trikolorofenol’ün degradasyonuna ilişkin herhangi bir kinetik modelleme çalışmasına rastlanmamış olup, bu araştırma ile ilk kez tarafımızdan 2,4,6-trikolorofenol’ün enzimatik deklorinasyonuna bağlı degradasyonunun kinetik modellemesi gerçekleştirildi. GC/MS Analiz sonuçları, lakkaz enzimi ile gerçekleştirilen enzimatik deklorinasyon boyunca kullanılan klorofenolik bileşiğin, %80-%100 oranında parçalandığını gösterdi. GC/MS analiz sonuçlarına bağlı olarak deklorinasyondan sorumlu olan enzimin lakkaz olduğu sonucunun literatür bulgularını da desteklediği görüldü.

  19. Immunization with the SDPM1 peptide lowers amyloid plaque burden and improves cognitive function in the APPswePSEN1(A246E) transgenic mouse model of Alzheimer's disease.

    Science.gov (United States)

    Wang, Chiou-Miin; Devries, Sarah; Camboni, Marybeth; Glass, Matthew; Martin, Paul T

    2010-09-01

    Vaccination has become an important therapeutic approach to the treatment of Alzheimer's disease (AD), however, immunization with Abeta amyloid can have unwanted, potentially lethal, side effects. Here we demonstrate an alternative peptide-mimotope vaccine strategy using the SDPM1 peptide. SDPM1 is a 20 amino acid peptide bounded by cysteines that binds tetramer forms of Abeta(1-40)- and Abeta(1-42)-amyloids and blocks subsequent Abeta amyloid aggregation. Immunization of mice with SDPM1 induced peptide-mimotope antibodies with the same biological activity as the SDPM1 peptide. When done prior to the onset of amyloid plaque formation, SDPM1 vaccination of APPswePSEN1(A246E) transgenic mice reduced amyloid plaque burden and Abeta(1-40) and Abeta(1-42) levels in the brain, improved cognitive performance in Morris water maze tests, and resulted in no increased T cell responses to immunogenic or Abeta peptides or brain inflammation. When done after plaque burden was already significant, SDPM1 immunization still significantly reduced amyloid plaque burden and Abeta(1-40/1-42) peptide levels in APPswePSEN1(A246E) brain without inducing encephalitogenic T cell responses or brain inflammation, but treatment at this stage did not improve cognitive function. These experiments demonstrate the efficacy of a novel vaccine approach for Alzheimer's disease where immunization with an Abeta(1-40/1-42) amyloid-specific binding and blocking peptide is used to inhibit the development of neuropathology and cognitive dysfunction.

  20. Diacetato-κO;κ2O,O′-aqua(2,4,6-tri-2-pyridyl-1,3,5-triazine-κ3N2,N1,N6manganese(II monohydrate

    Directory of Open Access Journals (Sweden)

    Kwang Ha

    2011-09-01

    Full Text Available The MnII ion in the title compound, [Mn(CH3CO22(C18H12N6(H2O]·H2O, is seven-coordinated in an approximately pentagonal–bipyramidal geometry by three N atoms of the tridentate 2,4,6-tri-2-pyridyl-1,3,5-triazine ligand and four O atoms from two distinct anionic acetato ligands and a water molecule. One acetate anion chelates the Mn atom via two O atoms occupying equatorial positions, and the other anion coordinates the Mn atom as a monodentate ligand via one O atom. The complex and solvent water molecules are linked by inter- and intramolecular O—H...O, O—H...N and C—H...O hydrogen bonds into a three-dimensional network.

  1. Group separation of transplutonium and rare earth elements by liquid chromatography with free stationary phase using 2,4,6-tris[ditolylphosphoryl] - 1,3,5 - triazine as extractant

    International Nuclear Information System (INIS)

    Chmutova, M.K.; Ivanova, L.A.; Bodrin, G.B.; Polikarpov, Yu.M.; Myasoedov, B.F.

    1994-01-01

    Methods of group separation of trace amounts of transplutonium elements (TPE) and weight amounts of rare earth elements (REE) in the systems on the basis of bifunctional neutral organophosphoric compounds by the method of liquid chromatography with a free stationary phase have been developed. When solution of 2,4,6 - tris[ditolylphosphoryl] - 1,3,5 - triazine in chloroform was used as stationary phase, REE were the first to be washed out by 0.5 mol/l NH 4 SCN-1 mol/l HCl solution, then TPE - by 0.025 mol/l of oxyethylidenediphosphonic acid in water. the fractions contained about 100% of one of the groups without impurity of the other. 7 refs.; 6 figs

  2. Bis[1,3-bis(2,4,6-trimethylphenyl-2,3-dihydro-1H-imidazol-2-ylidene]dinitrosyl(tetrahydroborato-κ2H,H′tungsten(0

    Directory of Open Access Journals (Sweden)

    Heinz Berke

    2011-01-01

    Full Text Available In the title paramagnetic 19-electron neutral complex, [W(BH4(C21H24N22(NO2], the W(0 atom is coordinated by two 1,3-bis(2,4,6-trimethylphenylimidazol-2-ylidene (IMes carbene ligands, two NO groups and two H atoms of an η2-tetrahydroborate ligand. Depending on the number of coordination sites (n assigned to the BH4− ligand, the coordination geometry of the W atom may either be described as approximately trigonal–bipyramidal (n = 1 or as very distorted octahedral with the bridging H atoms filling two coordination positions (n = 2. In the latter case, the coplanar NO groups and bridging H atoms (r.m.s. deviation = 0.032 Å form one octahedral plane, with mutually trans-oriented carbene ligands. In the crystal, molecules are connected via C—H...O interactions.

  3. Fabrication of targets for transmutation of americium : synthesis of inertial matrix by sol-gel method. Procedure study on the infiltration of a radioactive solutions; Fabricacion de blancos para la transmutacion de americio: sintesis de matrices inertes por el metodo sol-gel. Estudio del procedimiento de infiltracion de disoluciones radiactivas

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Carretero, A. [Universidad Complutense de Madrid (Spain)

    2002-07-01

    made. In addition a new and unexpected phase formed by the reaction of americium with spinel during the high temperature synthesis process has been identified. This new phase could provide a unique menas to stabilise Am in one particular oxidation state. (Author)

  4. Study of the electrochemical oxidation of Am with lacunary heteropolyanions and silver nitrate; Etude de l'oxydation electrochimique de l'americium en presence d'heteropolyanions lacunaires et de nitrate d'argent en milieu aqueux acide

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D

    1999-07-01

    Electrochemical oxidation of Am(III) with certain lacunary heteropolyanions (LHPA {alpha}{sub 2}-P{sub 2}W{sub 17}O{sub 61}{sup 10-} or {alpha}SiW{sub 11}O{sub 39}{sup 8-}) and silver nitrate is an efficient way to prepare Am(VI). This document presents bibliographic data and an experimental study of the process. Thus, it has been established that Am(IV) is an intermediate species in the reaction and occurs in 1:1 (Amt{sup IV}LHPA) or 1:2 (Am {sup IV}(LHAP){sub 2}) complexes with the relevant LHPA. These 1:1 complexes of Am(IV) have been identified and isolated in this work whereas 1:2 complexes were known from previous studies. The reactivity of these complexes in oxidation shows that 1:1 complexes of Am(IV) are oxidised much more quickly than 1:2 complexes. Apparent stability constants of Am(III) and Am(IV) complexes with the relevant LHPA have been measured for a 1 M nitric acid medium. Thermodynamic data of the reaction are then assessed: redox potentials of Am pairs are computed for a 1 M nitric acid medium containing various amount of LHPA ligands. Those results show that the role of LHPA is to stabilize the intermediate species Am(IV) by lowering the Am(IV)/Am(III) pair potential of about 1 Volt. Nevertheless, if this stabilisation is too strong (i.e. of tungsto-silicate), the oxidation of Am(IV) requires high anodic potential (more than 2 V/ENH). Then, the faradic yield of the oxidation of americium is poor because of water oxidation. This study has also shown that the main role of silver is to catalyze the electrochemical oxidation of Am{sup IV}(LHPA){sub X} complexes. Indeed, these oxidations without silver are extremely slow. An oxygen tracer experiment has been performed during the oxidation of Am(III) in Am(VI). It has been shown that the oxygen atoms of Am(VI) (AMO{sub 2}{sup 2+}) come from water molecules of the solvent and not from the complexing oxygen atoms of the ligands. (author)

  5. Plutonium and americium behavior in coral atoll environments

    International Nuclear Information System (INIS)

    Noshkin, V.E.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Eagle, R.J.

    1984-01-01

    Inventories of 239+240 Pu and 241 Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of 239+240 Pu and lesser amounts of 241 Am are continuously mobilizing from these sedimentary reservoirs. The amount of 239+240 Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized 239+240 Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of 239+240 Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of 241 Am to 239+240 Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of 239+240 Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables

  6. Gastrointestinal absorption of americium in rats: effect of citrate concentration

    International Nuclear Information System (INIS)

    Inaba, J.; Ishigure, N.; Oghiso, Y.; Sato, H.

    1994-01-01

    The gastrointestinal absorption of 241 Am was studied in relation to the amount of sodium citrate administered with it. Fasted Wistar strain female rats received 241 Am orally in sodium citrate solution of various concentrations and 5 days after administration animals were sacrificed and the retention and distribution of 241 Am was studied. The results indicated that the f 1 value was very high at about 10% of administered activity when 241 Am was given to fasted rats with a large amount of sodium citrate. (author)

  7. Further Studies of Plutonium and Americium at Thule, Greenland

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Dahlgaard, Henning; Nilsson, Karen Kristina

    1984-01-01

    further away from the impact point and at some locations the vertical distribution indicated a downward displacement of Pu in the sediment column since 1974. Seawater and seaplants showed no evidence of the presence of Pu from sources other than fallout; but Pu in benthos varied nearly proportionally...

  8. Uptake of plutonium and americium by plants from soils

    International Nuclear Information System (INIS)

    Schulz, R.K.; Tompkins, G.A.; Babcock, K.L.

    1975-01-01

    Plant uptake of 239 , 240 Pu and 241 Am was studied on two soil samples collected on the Nevada Test Site. These soils had each been previously contaminated with the radionuclides by high explosive detonation of devices containing plutonium. The 239 PuO 2 equivalent diameters of plutonium bearing particles present in the soil samples were determined and found to be log-normal in the range of 0.2 to 0.7 μm. Particles were examined by electronmicroscopy and found to be 2 to 3 times larger than the 239 PuO 2 equivalent diameter. Electron microprobe analysis showed that these particles consisted primarily of Pu, U, and O, with Al, Si, Fe and Mg present in much smaller amounts. The plutonium distribution ratio (D. R. = nuclide concentration in plant/nuclide concentration in soil) was in the order of 10 -5 for barley plant vegetation and was 20 to 100 times lower for barley grain. The D. R. for 241 Am was in the order of 10 -4 for vegetative growth and 25-75 times lower for the grain. In other uptake experiments three different soils were utilized: slightly acid forest soil, neutral valley soil, and calcareous alkaline soil. The 239 240 Pu and 241 Am were added to the soil as nitrate or chloride solution to facilitate the addition of Pu to soil in different oxidation states. Where Pu in the higher oxidation states (nitrate) was added to the alkaline calcareous soil, the highest plant uptake was observed. In uptake experiments with wheat the plutonium distribution ratio of the grain ranged from about 4 x 10 -8 to 4 x 10 -6 . The 241 Am D. R.'s ranged from 3 x 10 -7 to 3 x 10 -5 . (U.S.)

  9. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    International Nuclear Information System (INIS)

    Liao Jiali; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

    2004-01-01

    Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove 241 Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting 241 Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb 241 Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of 241 Am was removed from 241 Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of 241 Am. At this time, the total adsorption of 241 Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed 241 Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO 3

  10. Further Studies of Plutonium and Americium at Thule, Greenland

    DEFF Research Database (Denmark)

    Aarkrog, Asker; Dahlgaard, Henning; Nilsson, Karen Kristina

    1984-01-01

    Eleven years after the accidental loss of nuclear weapons in 1968, the fourth scientific expedition to Thule occurred. The estimated inventory of 1 TBq 239,240Pu in the marine sediments was unchanged when compared with the estimate based on the 1974 data. Plutonium from the accident had moved...

  11. Europium (III) and americium (III) stability constants with humic acid

    International Nuclear Information System (INIS)

    Torres, R.A.; Choppin, G.R.

    1984-01-01

    The stability constants for tracer concentrations of Eu(III) and Am(III) complexes with a humic acid extracted from a lake-bottom sediment were measured using a solvent extraction system. The organic extractant was di(2-ethylhexyl)-phosphoric acid in toluene while the humate aqueous phase had a constant ionic strength of 0.1 M (NaClO 4 ). Aqueous humic acid concentrations were monitored by measuring uv-visible absorbances at approx.= 380 nm. The total carboxylate capacity of the humic acid was determined by direct potentiometric titration to be 3.86 +- 0.03 meq/g. The humic acid displayed typical characteristics of a polyelectrolyte - the apparent pKsub(a), as well as the calculated metal ion stability constants increased as the degree of ionization (α) increased. The binding data required a fit of two stability constants, β 1 and β 2 , such that for Eu, log β 1 = 8.86 α + 4.39, log β 2 = 3.55 α + 11.06 while for Am, log β 1 = 10.58 α + 3.84, log β 2 = 5.32 α + 10.42. With hydroxide, carbonate, and humate as competing ligands, the humate complex associated with the β 1 constant is calculated to be the dominant species for the trivalent actinides and lanthanides under conditions present in natural waters. (orig.)

  12. Ecological behavior of plutonium and americium in a freshwater pond

    International Nuclear Information System (INIS)

    Emery, R.M.; Klopfer, D.C.; Garland, T.R.; Weimer, W.C.

    1975-03-01

    A Pu processing waste pond on the Hanford Reservation has been studied since mid-1973 to characterize the pond's limnology and determine the ecological behavior in this ecosystem. About 8.1 kg of Pu was reported to have been discharged into waste trenches leading to the pond. Mean ratios of isotopes in the sediments are 0.85 for 238 Pu to 239 240 Pu, 0.61 for 241 Am to 238 Pu, and 0.49 for 241 Am to 239 240 Pu. Levels of Pu and Am in the interstitial water range from 0.5 to 13 pCi/g (dry wt. of sediment). For 238 Pu in pond water the mean concentration is 0.007 pCi/l, for 239 240 Pu it is 0.002 pCi/l, and for 241 Am it is 1.08 pCi/l. The remaining biota had Pu and Am levels which were generally well below those of the sediments. (U.S.)

  13. A bioassay method for americium and curium in feces

    International Nuclear Information System (INIS)

    Alexandre Gagne; Dominic Lariviere; Joel Surette; Sheila Kramer-Tremblay; Xiongxin Dai; Candice Didychuk

    2013-01-01

    Fecal radiobioassay is an essential and sensitive tool to estimate the internal intake of actinides after a radiological incident. A new fecal analysis method, based on lithium metaborate fusion of fecal ash for complete sample dissolution followed by sequential column chromatography separation of actinides, has been developed for the determination of low-level Am and Cm in a large size sample. Spiked synthetic fecal samples were analyzed to evaluate method performance against the acceptance criteria for radiobioassay as defined by ANSI N13.30; both satisfactory accuracy and repeatability were achieved. This method is a promising candidate for reliable dose assessment of low level actinide exposure to meet the regulatory requirements of routine radiobioassay for nuclear workers and the public. (author)

  14. Biosorption of americium-241 by immobilized Rhizopus arrihizus

    Energy Technology Data Exchange (ETDEWEB)

    Liao Jiali E-mail: liaojiali@163.com; Yang Yuanyou; Luo Shunzhong; Liu Ning; Jin Jiannan; Zhang Taiming; Zhao Pengji

    2004-01-01

    Rhizopus arrihizus (R. arrihizus), a fungus, which in previous experiments had shown encouraging ability to remove {sup 241}Am from solutions, was immobilized by calcium alginate and other reagents. The various factors affecting {sup 241}Am biosorption by the immobilized R. arrihizus were investigated. The results showed that not only can immobilized R. arrihizus adsorb {sup 241}Am as efficiently as free R. arrihizus, but that also can be used repeatedly or continuously. The biosorption equilibrium was achieved within 2 h, and more than 94% of {sup 241}Am was removed from {sup 241}Am solutions of 1.08 MBq/l by immobilized R. arrihizu in the pH range 1-7. Temperature did not affect the adsorption on immobilized R. arrihizus in the range 15-45 deg. C. After repeated adsorption for 8 times, the immobilized R. arrihizus still adsorbed more than 97% of {sup 241}Am. At this time, the total adsorption of {sup 241}Am was more than 88.6 KBq/g, and had not yet reached saturation. Ninety-five percent of the adsorbed {sup 241}Am was desorbed by saturated EDTA solution and 98% by 2 mol/l HNO{sub 3}.

  15. High-Resolution Measurements of Neutron Energy Spectra from Americium-Beryllium and Americium-Boron Neutron Sources

    Science.gov (United States)

    Marsh, James W.

    Available from UMI in association with The British Library. A Helium-3 sandwich spectrometer incorporating two semiconductor detectors was designed and constructed to enable the measurement of high resolution neutron energy spectra in the energy range from 100 keV to 15 MeV. The instrument is novel in respect of the inclusion of an anode wire which enables the gas chamber to function as a gas proportional counter. Few similar instruments have been constructed and no similar instrument is known to be currently (1990) in use in the UK. The efficiency of the spectrometer was determined experimentally, using a Californium-252 spontaneous fission source, in the low-scatter facility of the National physical Laboratory. A Monte Carlo code has been written to determine the absolute efficiency over an energy range from 81 keV to 20 MeV. The calculated values were used to extrapolate the measured efficiency to higher energies. Furthermore the Monte Carlo code was used to determine certain operating parameters to optimise the efficiency of the spectrometer. The neutron energy spectra from two different size standard Am-Be neutron sources and a standard Am-B neutron source available at NPL were measured. Although these types of neutron sources have been subject to energy spectra measurements elsewhere, the present work improves considerably on the previous poorer energy resolution and energy range. The new data indicates for the three neutron sources studied that the ambient dose equivalent, H*(10) per unit fluence, for each, were identical, being within 2% of 3.70 E-10 Sv cm^2.

  16. Rhodium(III)-catalyzed regioselective C2-amidation of indoles with N-(2,4,6-trichlorobenzoyloxy)amides and its synthetic application to the development of a novel potential PPARγ modulator.

    Science.gov (United States)

    Shi, Jingjing; Zhao, Guanguan; Wang, Xiaowei; Xu, H Eric; Yi, Wei

    2014-09-21

    A new and efficient method for the direct regioselective C2-amidation of various functionalized indoles with several N-(2,4,6-trichlorobenzoyloxy)amides via Rh(iii)-catalyzed C-H activation/N-O cleavage/C-N formation using the pyrimidyl group as a readily installable and removable directing group has been developed. With this method, a variety of valuable 2-amido indoles can be easily prepared under mild conditions with broad functional group tolerance and excellent region-/site-specificities. Application of this strategy to the synthesis of target compound as a novel PPARγ modulator was also demonstrated. The results from biological evaluation showed that compound had a partial PPARγ agonistic activity and a strong PPARγ binding affinity with an IC50 value of 120.0 nM, along with a less pronounced adipocyte differentiation ability compared to the currently marketed anti-diabetic drug rosiglitazone, suggesting that further development of such a compound might be of great interest.

  17. Physico-chemical characterization, density functional theory (DFT) studies and Hirshfeld surface analysis of a new organic optical material: 1H-benzo[d]imidazol-3-ium-2,4,6-trinitrobenzene-1,3 bis(olate)

    Science.gov (United States)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M.

    2017-10-01

    A novel organic crystal, 1H-benzo[d]imidazol-3-ium-2,4,6-trinitrobenzene-1,3 bis(olate) (BITB), was synthesized. Single crystals of BITB were harvested by solution growth-slow evaporation technique. 1H and 13C NMR spectroscopic techniques were utilized to confirm the presence of various types of carbons and protons in BITB. Single crystal XRD confirms that BITB crystallizes in monoclinic system with a space group of P21/n. The suitability of this material for optical applications was assessed by optical absorption, transmittance, reflectance and refractive index spectroscopic techniques. Gaussian 09 program at B3LYP/6-311++G(d,p) level of basis set as used for the optimization of molecular structure of BITB. Greater first order hyperpolarizability value of BITB is due to intensive hydrogen bond network in the crystal. The value is 15 times greater than that of Urea, a reference standard. Computation of frontier molecular orbitals and electrostatic potential surface helped to understand the electron density and reactive sites in BITB. The material was thermally stable up to 220 °C. Hirshfeld surface analysis was performed to quantify the covalent and non covalent interactions.

  18. Field-Induced Single-Ion Magnet Behaviour in Two New Cobalt(II Coordination Polymers with 2,4,6-Tris(4-pyridyl-1,3,5-triazine

    Directory of Open Access Journals (Sweden)

    Dong Shao

    2017-12-01

    Full Text Available We herein reported the syntheses, crystal structures, and magnetic properties of a two-dimensional coordination polymer {[CoII(TPT2/3(H2O4][CH3COO]2·(H2O4}n (1 and a chain compound {[CoII(TPT2(CHOO2(H2O2]}n (2 based on the 2,4,6-Tris(4-pyridyl-1,3,5-triazine (TPT ligand. Structure analyses showed that complex 1 had a cationic hexagonal framework structure, while 2 was a neutral zig-zag chain structure with different distorted octahedral coordination environments. Magnetic measurements revealed that both complexes exhibit large easy-plane magnetic anisotropy with the zero-field splitting parameter D = 47.7 and 62.1 cm−1 for 1 and 2, respectively. This magnetic anisotropy leads to the field-induced slow magnetic relaxation behaviour. However, their magnetic dynamics are quite different; while complex 1 experienced a dominating thermally activated Orbach relaxation at the whole measured temperature region, 2 exhibited multiple relaxation pathways involving direct, Raman, and quantum tunneling (QTM processes at low temperatures and Orbach relaxation at high temperatures. The present complexes enlarge the family of framework-based single-ion magnets (SIMs and highlight the significance of the structural dimensionality to the final magnetic properties.

  19. Constitutive ω-3 fatty acid production in fat-1 transgenic mice and docosahexaenoic acid administration to wild type mice protect against 2,4,6-trinitrobenzene sulfonic acid-induced colitis.

    Science.gov (United States)

    Yum, Hye-Won; Kang, Jing X; Hahm, Ki Baik; Surh, Young-Joon

    2017-06-10

    Omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) are known to have strong anti-inflammatory effects. In the present study, we investigated the protective effects of ω-3 PUFAs on experimentally induced murine colitis. Intrarectal administration of 2.5% 2,4,6-trinitrobenzene sulfonic acid (TNBS) caused inflammation in the colon of wild type mice, but this was less severe in fat-1 transgenic mice that constitutively produce ω-3 PUFAs from ω-6 PUFAs. The intraperitoneal administration of docosahexaenoic acid (DHA), a representative ω-3 PUFA, was also protective against TNBS-induced murine colitis. In addition, endogenously formed and exogenously introduced ω-3 PUFAs attenuated the production of malondialdehyde and 4-hydroxynonenal in the colon of TNBS-treated mice. The effective protection against inflammatory and oxidative colonic tissue damages in fat-1 and DHA-treated mice was associated with suppression of NF-κB activation and cyclooxygenase-2 expression and with elevated activation of Nrf2 and upregulation of its target gene, heme oxygenase-1. Taken together, these results provide mechanistic basis of protective action of ω-3 fatty PUFAs against experimental colitis. Copyright © 2017. Published by Elsevier Inc.

  20. Hydroxonium hydrate tris(2,4,6-triamino-1,3,5-triazin-1-ium bis[bis(pyridine-2,6-dicarboxylatocuprate(II] pyridine-2,6-dicarboxylic acid hexahydrate

    Directory of Open Access Journals (Sweden)

    Shabnam Hooshmand

    2009-02-01

    Full Text Available The reaction of copper(II nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2 and 2,4,6-triamino-1,3,5-triazine (melamine in aqueous solution in a 1:2:2 molar ratio gave the title compound, (H5O2(C3H7N63[Cu(C7H3NO42]2·C7H5NO4·6H2O. The hydroxonium hydrate (H5O2+, also known as the Zundel cation, resides on a twofold rotation axis. The O—H distance is 1.274 (14 Å, the O...O distance is 2.518 (5 Å, and the O—H—O angle is 162 (8°. One of the melamine H+ cations, the uncoordinated pydcH2, and two water molecules also reside on crystallographic twofold axes. The CuII atom has a tetragonally distorted octahedral coordination environment. The structure features extensive hydrogen bonding, with 21 distinct interactions. There is also a centrosymmetric C=O...π interaction with an O...centroid distance of 3.288 (3 Å. The structure is similar to a mixed-valence manganese(II/III structure but shows interesting differences in the metal-atom coordination. One of the water molecules is equally disordered with respect to a twofold axis.

  1. Solvent-Induced Change of Electronic Spectra and Magnetic Susceptibility of Co(II) Coordination Polymer with 2,4,6-Tris(4-pyridyl)-1,3,5-triazine.

    Science.gov (United States)

    Polunin, Ruslan A; Burkovskaya, Nataliya P; Satska, Juliya A; Kolotilov, Sergey V; Kiskin, Mikhail A; Aleksandrov, Grigory G; Cador, Olivier; Ouahab, Lahcène; Eremenko, Igor L; Pavlishchuk, Vitaly V

    2015-06-01

    One-dimensional coordination polymer [Co(Piv)2(4-ptz)(C2H5OH)2]n (compound 1, Piv(-) = pivalate, 4-ptz = 2,4,6-tris(4-pyridyl)-1,3,5-triazine) was synthesized by interaction of Co(II) pivalate with 4-ptz. Desolvation of 1 led to formation of [Co(Piv)2(4-ptz)]n (compound 2), which adsorbed N2 and H2 at 78 K as a typical microporous sorbent. In contrast, absorption of methanol and ethanol by 2 at 295 K led to structural transformation probably connected with coordination of these alcohols to Co(II). Formation of 2 from 1 was accompanied by change of color of sample from orange to brown and more than 2-fold decrease of molar magnetic susceptibility (χM) in the temperature range from 2 to 300 K. Resolvation of 2 by ethanol or water resulted in restoration of spectral characteristics and χM values almost to the level of that of 1. χMT versus T curves for 1 and samples, obtained by resolvation of 2 by H2O or C2H5OH, were fitted using a model for Co(II) complex with zero-field splitting of this ion.

  2. Studies on synthesis, structural, luminescent and thermal properties of a new non-linear optical crystal: 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate

    Energy Technology Data Exchange (ETDEWEB)

    Dhamodharan, P.; Sathya, K.; Dhandapani, M., E-mail: chemistrydhandapani@gmail.com

    2017-03-01

    A new organic proton transfer complex having NLO activity, 4-amino-4H-1,2,4-triazol-1-ium-3-hydroxy-2,4,6-trinitrophenolate (ATHTP), was crystallized to investigate the factors which stabilize the structure of the crystal. The compound crystallizes in triclinic system with space group P-1. Elemental analysis, thermal analysis, UV–Vis–NIR, FT-IR and NMR spectral analyses were carried out to characterize the crystal. Optical, spectral and thermal properties of the title crystal were analyzed to recommend the material for optical applications. Z-scan was used to measure the effective third-order nonlinear optical susceptibility and nonlinear refractive index. The crystal structure was determined using single crystal XRD method and the structure was optimized using Gaussian 09 program at B3LYP/6-311++G(d,p) level of basis set. This hydrogen bond interactions led to the increase in first-order hyperpolarizability of ATHTP and was 30 times greater than that of urea. Hirshfeld analyses surface analysis was carried out to explore intermolecular interactions in the crystalline state. - Highlights: • Single crystals were grown by slow evaporation solution growth technique. • N-H…O, O-H…O and C-H…O type of interactions lead to stable network. • The thermal stability of the compound was investigated by TG/DTA analyses. • The third-order nonlinear optical susceptibility is found to be 2.1×10{sup −7} esu. • Hirshfeld analyses explore covalent and non covalent interactions.

  3. Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene.

    Science.gov (United States)

    Naumenko, Ekaterina Anatolevna; Ahlemeyer, Barbara; Baumgart-Vogt, Eveline

    2017-03-01

    2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC 50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. © 2016 Wiley Periodicals, Inc.

  4. Characteristics of energy exchange between inter- and intramolecular degrees of freedom in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with implications for coarse-grained simulations of shock waves in polyatomic molecular crystals

    International Nuclear Information System (INIS)

    Kroonblawd, Matthew P.; Sewell, Thomas D.; Maillet, Jean-Bernard

    2016-01-01

    In this report, we characterize the kinetics and dynamics of energy exchange between intramolecular and intermolecular degrees of freedom (DoF) in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). All-atom molecular dynamics (MD) simulations are used to obtain predictions for relaxation from certain limiting initial distributions of energy between the intra- and intermolecular DoF. The results are used to parameterize a coarse-grained Dissipative Particle Dynamics at constant Energy (DPDE) model for TATB. Each TATB molecule in the DPDE model is represented as an all-atom, rigid-molecule mesoparticle, with explicit external (molecular translational and rotational) DoF and coarse-grained implicit internal (vibrational) DoF. In addition to conserving linear and angular momentum, the DPDE equations of motion conserve the total system energy provided that particles can exchange energy between their external and internal DoF. The internal temperature of a TATB molecule is calculated using an internal equation of state, which we develop here, and the temperatures of the external and internal DoF are coupled using a fluctuation-dissipation relation. The DPDE force expression requires specification of the input parameter σ that determines the rate at which energy is exchanged between external and internal DoF. We adjusted σ based on the predictions for relaxation processes obtained from MD simulations. The parameterized DPDE model was employed in large-scale simulations of shock compression of TATB. We show that the rate of energy exchange governed by σ can significantly influence the transient behavior of the system behind the shock

  5. Characteristics of energy exchange between inter- and intramolecular degrees of freedom in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) with implications for coarse-grained simulations of shock waves in polyatomic molecular crystals

    Science.gov (United States)

    Kroonblawd, Matthew P.; Sewell, Thomas D.; Maillet, Jean-Bernard

    2016-02-01

    In this report, we characterize the kinetics and dynamics of energy exchange between intramolecular and intermolecular degrees of freedom (DoF) in crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). All-atom molecular dynamics (MD) simulations are used to obtain predictions for relaxation from certain limiting initial distributions of energy between the intra- and intermolecular DoF. The results are used to parameterize a coarse-grained Dissipative Particle Dynamics at constant Energy (DPDE) model for TATB. Each TATB molecule in the DPDE model is represented as an all-atom, rigid-molecule mesoparticle, with explicit external (molecular translational and rotational) DoF and coarse-grained implicit internal (vibrational) DoF. In addition to conserving linear and angular momentum, the DPDE equations of motion conserve the total system energy provided that particles can exchange energy between their external and internal DoF. The internal temperature of a TATB molecule is calculated using an internal equation of state, which we develop here, and the temperatures of the external and internal DoF are coupled using a fluctuation-dissipation relation. The DPDE force expression requires specification of the input parameter σ that determines the rate at which energy is exchanged between external and internal DoF. We adjusted σ based on the predictions for relaxation processes obtained from MD simulations. The parameterized DPDE model was employed in large-scale simulations of shock compression of TATB. We show that the rate of energy exchange governed by σ can significantly influence the transient behavior of the system behind the shock.

  6. Rapid determination of silver in cultivated Japanese and South Korean oysters and Japanese rock oysters using the 24.6-s neutron activation product 110Ag and estimation of its average daily intake

    International Nuclear Information System (INIS)

    Fukushima, M.; Chatt, A.

    2013-01-01

    Soft tissues of cultivated Japanese (Miyagi Prefecture) and South Korean (Koje-do and Kosong) oysters and Japanese rock oysters (Honshu Island) were analyzed to measure silver levels. The soft tissues, namely hepatopancreas, gill, muscle, and mantle were separated, freeze-dried, pulverized, and analyzed by an instrumental neutron activation analysis method in conjunction with Compton suppression spectrometry (INAA-CSS). The method consisted of the irradiation of samples in a neutron flux of 5 x 10 11 cm -2 s -1 using the rapid transfer system in an inner pneumatic irradiation site of the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility for 12-15 s, decay for 20 s, and counting for 60 s. The 657.8-keV gamma-ray of the 24.6-s nuclide 110 Ag was used for assaying silver. The method was validated using NIST, NRC and NIES certified reference materials. An absolute detection limit of 0.05 μg silver using NIST SRM 1566b Oyster Tissue was achieved. About 10-50 times higher levels of silver were found in cultivated Japanese oysters compared to the South Korean ones. The silver concentrations in cultivated oysters in Miyagi Prefecture showed the following trend: gill > mantle > hepatopancreas > muscle as well as on the age. Rock oysters generally had higher silver content compared to cultivated oysters. A very preliminary value of about 0.466 μg silver average intake per person per day was estimated from the consumption of oysters by the people living in the Sendai city of Miyagi Prefecture. (author)

  7. A study comparing the efficacy of antimicrobial agents versus enzyme (P-gp) inducers in the treatment of 2,4,6 trinitrobenzenesulfonic acid-induced colitis in rats.

    Science.gov (United States)

    Toklu, H Z; Kabasakal, L; Imeryuz, N; Kan, B; Celikel, C; Cetinel, S; Orun, O; Yuksel, M; Dulger, G A

    2013-08-01

    The intestinal microflora is an important cofactor in the pathogenesis of intestinal inflammation; and the epithelial cell barrier function is critical in providing protection against the stimulation of mucosal immune system by the microflora. In the present study, therapeutic role of the antibacterial drugs rifampicin and ciprofloxacine were investigated in comparison to spironolactone, an enzyme inducer, in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis of the rats. Drugs were administered for 14 days following induction of colitis. All drug treatments ameliorated the clinical hallmarks of colitis as determined by body weight loss and assessment of diarrhea, colon length, and histology. Oxidative damage and neutrophil infiltration as well as nuclear factor κB (NF-κB) and tumor necrosis factor α (TNF-α) expressions that were increased during colitis, were decreased significantly. Rifampicin and ciprofloxacin were probably effective due to their antibacterial and immunomodulating properties. The multidrug resistence gene (MDR1) and its product p-glycoprotein (P-gp) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). In the present study, findings of the P-gp expression were inconclusive but regarding previous studies, it can be suggested that the beneficial effects of rifampicin and spironolactone may be partly due to their action as a P-gp ligand. Spironolactone has been reported to supress the transcription of proinflamatory cytokines that are considered to be of importance in immunoinflammatory diseases. It is also a powerful pregnane X receptor (PXR) inducer; thus, inhibition of the expression of NF-κB and TNF-α, and amelioration of inflammation by spironolactone suggest that this may have been through the activation of PXR. However, our findings regarding PXR expression were inconclusive. Activation of PXR by spironolactone probably also contributed to the induction of P-gp, resulting in extrusion of noxious substances

  8. 7 CFR 246.4 - State plan.

    Science.gov (United States)

    2010-01-01

    .... Participants will include homeless individuals. (iii) Instructions concerning all food delivery operations... under the Program. (14) A description of the food delivery system as it operates at the State agency level, including— (i) Type of system. All food delivery systems in use within the State agency's...

  9. 7 CFR 246.14 - Program costs.

    Science.gov (United States)

    2010-01-01

    ... delivery contractor, or supplier in a direct distribution food delivery system. In addition, food costs may... delivery system, including the cost of transporting food. (5) The cost of translators for materials and... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE...

  10. 40 CFR 246.101 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... packing wastes generated at industrial facilities. (h) Construction and demolition waste means the waste building materials, packaging, and rubble resulting from construction, remodeling, repair, and demolition... facilities for the purpose of these guidelines. (m) Food waste means the organic residues generated by the...

  11. Publications | Page 246 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC works with developing-country researchers and institutions to build local capacity through funding, knowledge sharing, and training. Through books, articles, research publications, and studies, we aim to widen the impact of our investment and advance development research. We share the results of our funded ...

  12. 7 CFR 246.3 - Administration.

    Science.gov (United States)

    2010-01-01

    ... part 3017); governing restrictions on lobbying (7 CFR part 3018); and governing the drug-free workplace... Nutritionist; and (vi) Have at least one of the following: Program development skills, education background and..., counseling skills or experience in participant advocacy. (4) A designated breastfeeding promotion coordinator...

  13. 7 CFR 246.26 - Other provisions.

    Science.gov (United States)

    2010-01-01

    ... taxation, welfare and public assistance programs. (b) Statistical information. FNS reserves the right to... by Federal, State, or local law or policy or unless the information supports a State or local agency... State agency to participate in the program for each of Federal fiscal years 2006 through 2009, including...

  14. 40 CFR 246.100 - Scope.

    Science.gov (United States)

    2010-07-01

    ... mining, agricultural, and industrial solid wastes; hazardous wastes; sludges; construction and demolition... separation. Pursuant to section 211 of the Solid Waste Disposal Act, as amended, and Executive Order 11752... technical assistance in the form of sample cost analysis formats, sample bid specifications, implementation...

  15. Melaminium 2,4,6-trihydroxybenzoate dihydrate

    Directory of Open Access Journals (Sweden)

    Timothy J Prior

    2009-09-01

    Full Text Available In the title compound, C3H7N6+·C7H5O5−·2H2O, the melaminium and benzoate ions are approximately planar (r.m.s. deviation of the non-hydrogen atoms is 0.093 Å and there is a strong C22(8 hydrogen-bonding embrace between them. The centre of symmetry generates a second acid–base pair which is bound to the first by a C22(8 (N—H...N embrace common between melamine molecules in similar compounds. Further extensive hydrogen bonding assembles the components into a three-dimensional hydrogen-bonded network.

  16. 32 CFR 246.4 - Policy.

    Science.gov (United States)

    2010-07-01

    ... without news management or censorship. The calculated withholding of unfavorable news is prohibited. (c... through newspaper sales, resale of commercial publications, authorized advertising, job printing, and...

  17. Publications | Page 246 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Women who work in South Korea and Taiwan had access to NGOs and government services when facing difficulties while women in the Gulf region have nowhere to turn. Transnational marriage migration largely occurs outside the planning and control of the State. In both lines of domestic work, brokers... Sustaining water ...

  18. 43 CFR 24.6 - Cooperative agreements.

    Science.gov (United States)

    2010-10-01

    ... Congressional policy (e.g., Fish and Wildlife Coordination Act of 1956) of State-Federal cooperation and coordination in the area of fish and wildlife conservation, State and Federal agencies have implemented...: (1) Protection, maintenance, and development of fish and wildlife habitat; (2) Fish and wildlife...

  19. 32 CFR 246.3 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... population, currency fluctuations, inflation, armed conflict, national contingency deployment, and others. (b... (Force Management and Personnel) [OASD (FM&P)] that address S&S personnel and business policies. The S&S...

  20. 7 CFR 246.2 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... service. A supervised publicly or privately operated shelter (including a welfare hotel or congregate... nighttime residence is: (1) A supervised publicly or privately operated shelter (including a welfare hotel... must ensure the reliability and integrity of the technology used and the security and confidentiality...

  1. 7 CFR 246.10 - Supplemental foods.

    Science.gov (United States)

    2010-01-01

    ... order to meet religious eating patterns; and (ii) The State agency has the discretion to require medical... for: (A) Infants whose only condition is: (1) A diagnosed formula intolerance or food allergy to...; or (2) A non-specific formula or food intolerance. (B) Women and children who have a food intolerance...

  2. Differential sensitivity of aerobic gram-positive and gram-negative microorganisms to 2,4,6-trinitrotoluene (TNT) leads to dissimilar growth and TNT transformation: Results of soil and pure culture studies

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, M.E.; Manning, J.F. Jr.

    1996-07-30

    The effects of 2,4,6-trinitrotoluene (TNT) on indigenous soil populations and pure bacterial cultures were examined. The number of colony-forming units (CFU) appearing when TNT-contaminated soil was spread on 0.3% molasses plates decreased by 50% when the agar was amended with 67 {mu}g TNT mL{sup -1}, whereas a 99% reduction was observed when uncontaminated soil was plated. Furthermore, TNT-contaminated soil harbored a greater number of organisms able to grow on plates amended with greater than 10 {mu}g TNT mL{sup -1}. The percentage of gram-positive isolates was markedly less in TNT-contaminated soil (7%; 2 of 30) than in uncontaminated soil (61%; 20 of 33). Pseudomonas aeruginosa, Pseudomonas corrugate, Pseudomonasfluorescens and Alcaligenes xylosoxidans made up the majority of the gram-negative isolates from TNT-contaminated soil. Gram-positive isolates from both soils demonstrated marked growth inhibition when greater than 8-16 {mu}g TNT mL{sup -1} was present in the culture media. Most pure cultures of known aerobic gram-negative organisms readily degraded TNT and evidenced net consumption of reduced metabolites. However, pure cultures of aerobic gram-positive bacteria were sensitive to relatively low concentrations of TNT as indicated by the 50% reduction in growth and TNT transformation which was observed at approximately 10 {mu}g TNT mL{sup -1}. Most non-sporeforming gram-positive organisms incubated in molasses media amended with 80 {mu}g TNT mL{sup -1} or greater became unculturable, whereas all strains tested remained culturable when incubated in mineral media amended with 98 {mu}g TNT mL{sup -1}, indicating that TNT sensitivity is likely linked to cell growth. These results indicate that gram-negative organisms are most likely responsible for any TNT transformation in contaminated soil, due to their relative insensitivity to high TNT concentrations and their ability to transform TNT.

  3. Monomer-to-polymer conversion and micro-tensile bond strength to dentine of experimental and commercial adhesives containing diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide or a camphorquinone/amine photo-initiator system.

    Science.gov (United States)

    Miletic, Vesna; Pongprueksa, Pong; De Munck, Jan; Brooks, Neil R; Van Meerbeek, Bart

    2013-10-01

    To compare the degree of conversion (DC) of adhesives initiated by diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) or a camphorquinone/tertiary amine system (CQ/Amine) as well as their 'immediate' micro-tensile bond strength (μTBS) to bur-cut dentine. DC of Scotchbond Universal ('SBU'; 3M ESPE), its experimental counterpart containing TPO as photo-initiator system, an experimental G-aenial Bond ('Ga-B'; GC) adhesive formulation, and an experimental LUB-102 adhesive formulation ('LUB', Kuraray Noritake), containing as photo-initiatior system either 2wt% CQ along with 2wt% tertiary amine ('SBU_CQ/Amine'; 'Ga-B_CQ/Amine'; 'LUB_CQ/Amine'), or 2wt% TPO ('SBU_TPO'; 'Ga-B_TPO'; 'LUB_TPO'), was determined using Fourier-transform infrared spectroscopy (FTIR), after being cured with a dual-wavelength light-curing unit (bluephase 20i, Ivoclar Vivadent). The same adhesive formulations were applied to bur-cut mid-coronal dentine of intact human molars, and subjected to a μTBS test after 1-week water storage. Besides being applied following a self-etch (SE) application mode, the adhesive formulations SBU_CQ/Amine and SBU_TPO were also applied following an etch-and-rinse (E&R) mode, this both for DS and μTBS measurement. No significant difference in DC was found for any of the adhesive formulations, except for SBU_CQ/Amine_SE and SBU_TPO_SE. For both SBU formulations, a significantly higher DC was reached for the E&R than the SE approach. Regarding μTBS, no significant differences were recorded, except for the significantly higher μTBS measured for SBU_CQ/Amine_E&R and SBU_TPO_E&R. In self-etch adhesives, the photo-initiator TPO may be used instead of CQ/Amine. The curing and 'immediate' bonding efficiency depended on the application protocol (E&R versus SE), but not on the photo-initiator system. The photo-initiator TPO may be used in self-etch adhesives instead of CQ/Amine with similar curing and 'immediate' bonding efficiency. Copyright © 2013 Elsevier Ltd. All

  4. Investigation of the retention and distribution of americium-241 in the baboon and the enhanced removal of americium-241 from the body by diethylenetriaminepentaacetic acid (DTPA)

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Cohen, N.; Wrenn, M.E.

    1975-01-01

    Experiments were performed to study the metabolism and distribution of intravenously administered 241 Am in the adult and juvenile baboon; in addition, decorporation therapy using Na 3 -CaDTPA was performed on selected baboons to assess the efficacy of this drug in removing systemic burdens of 241 Am from this primate species. Determination of the kinetics of 241 Am was accomplished principally by in vivo methodologies and by radiochemical analysis of 241 Am activity of biological material. The use of Na 3 -CaDTPA as a therapeutic agent for the removal of 241 Am from the body proved to be an effective form of treatment in the case of early administration. (U.S.)

  5. Bromido(2,4,6-trimethylphenylmercury(II

    Directory of Open Access Journals (Sweden)

    Frank Meyer-Wegner

    2012-04-01

    Full Text Available Molecules of the title compound, [HgBr(C9H11], are located on a crystallographic twofold rotation axis. Due to the molecular symmetry, the HgII atom is linearly coordinated by the ipso-C of the mesityl group and the Br atom. In the crystal, molecules lie in planes parallel to (001.

  6. 7 CFR 246.16a - Infant formula cost containment.

    Science.gov (United States)

    2010-01-01

    ... with home delivery or direct distribution food delivery systems; (2) Indian State agencies with 1,000... anticipated costs for modifying its automated data processing system or components of its food delivery system... agencies with retail food delivery systems based on the following guidelines: (1) FNS will solicit bids and...

  7. 7 CFR 246.25 - Records and reports.

    Science.gov (United States)

    2010-01-01

    ..., information pertaining to financial operations, food delivery systems, food instrument issuance and redemption... Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE... participation; (B) Actual and projected food funds expenditures; (C) A listing by source year of food and NSA...

  8. Dicty_cDB: SSJ246 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ifihf*kkkkkkkkkkkkkkkk Translated Amino Acid sequence (All Frames) Frame A: kl*nviqiitinhkc*lnpkesnffnfsrkhtik**cstlrccstccnsrfid...nfsrkhtik**cstlrccstccnsrfidccrccsy lnlqriln*liihilipweifenlivylinn*LYLLIFKKKKKKK...AAAAAAAAAAAAAAAAAAAAAAAA sequence update 1998.12.21 Translated Amino Acid sequence kl*nviqiitinhkc*lnpkesnff

  9. All projects related to | Page 246 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Region: North and Central America, South America, Argentina, Bolivia, Brazil, Chile, Colombia, Mexico, Peru. Program: Food, Environment, and Health. Total Funding: CA$ 123,600.00. Nouveau Programme de Troisième Cycle Interuniversitaire : Phase 2. Project. Social sciences in sub-Saharan Africa are severely ...

  10. 48 CFR 252.246-7001 - Warranty of data.

    Science.gov (United States)

    2010-10-01

    ... and acceptance by the Government of technical data furnished under this contract, and notwithstanding any provision of this contract concerning the conclusiveness of acceptance, the Contractor warrants... Contractor by written notice that the Government elects a price or fee adjustment instead of correction or...

  11. 7 CFR 246.9 - Fair hearing procedures for participants.

    Science.gov (United States)

    2010-01-01

    ... defined as any clear expression by the individual, the individual's parent, caretaker, or other... or local agency shall not limit or interfere with the individual's freedom to request a hearing. (e...

  12. Decree number 1.246 of September 16, 1994

    International Nuclear Information System (INIS)

    1994-01-01

    Promulgates the Treaty for Proscription of Nuclear Weapon in Latin America and Caribbean - Tlatelolco Treaty, held in Mexico City in February 14, 1967 an the Resolutions numbers 267(E-V), of July 3, 1990, 268 (XII), of May 10, 1991 and 290 (VII), of August 26, 1992, all of them adopted by the General Conference of the Organism for the Proscription of Nuclear Weapon in Latin America and Caribbean (OPANAL) in Mexico City

  13. 7 CFR 246.12 - Food delivery systems.

    Science.gov (United States)

    2010-01-01

    ... percentage of anticipated food sales by type of payment, i.e., cash, Supplemental Nutrition Assistance... calculate average payments per food instrument type for groups of vendors that meet the above-50-percent... instruments and cash-value vouchers. (2) Design. The State agency must design all food delivery systems to be...

  14. 246 ADMINISTRATION OF JUSTICE IN NIGERIA: A CASE FOR ...

    African Journals Online (AJOL)

    Fr. Ikenga

    administration of justice in Nigeria even though Judges, like Caesar's wife, are expected to be above board. It is also the ... 4Dame Roma Mitchell, 'The Appointment of judges and their Return to the Bar', Address to the second Biennial ..... impinge upon, or be seen to impinge upon, how they decide cases and treat certain.

  15. 7 CFR 246.16 - Distribution of funds.

    Science.gov (United States)

    2010-01-01

    ... technical assistance and research evaluation projects for the WIC Farmers' Market Nutrition Program. (b... management information system, including an electronic benefit transfer system. (B) Funds spent forward will... government purchases, as published by the Bureau of Economic Analysis of the Department of Commerce, for the...

  16. 42 CFR 24.6 - Pay and compensation.

    Science.gov (United States)

    2010-10-01

    ...) Salary surveys of similar skills in pertinent labor markets; and (7) Other relevant factors. (e) Annual... of an institution of higher education immediately prior to his appointment as a member of the Service... Executive Schedule unless a higher rate of pay is expressly approved on an individual basis by the President...

  17. Page | 246 CONCEPT OF CRIME IN THE ADMINISTRATION OF ...

    African Journals Online (AJOL)

    Fr. Ikenga

    view of the libertarians, also called the utilitarian view, dominated western jurisprudence while the positivist views pervade modern thinking in both the domestic and international arena. It was finally discovered that the uniqueness of the different views is that crimes must attract punishment for its breach. It is submitted that ...

  18. preparation and nucleophilic substitution of the 2,4,6

    African Journals Online (AJOL)

    Mgina

    pyridinium salt 3 during preparation or could be the consequence of the nucleophilic substitution reaction. In case of the first presumption, racemization of 3 might have happened via acid mediated tautomerization of the vinylogous compound 5 , an intermediate formed during preparation of the triphenylpyridinium salt ...

  19. 2,4,6-Tri-p-tolylpyridine

    Directory of Open Access Journals (Sweden)

    Si-Ping Tang

    2009-06-01

    Full Text Available In the title compound, C26H23N, the complete molecule is generated by crystallographic mirror symmetry, with the N atom and four C atoms lying on the reflection plane. The dihedral angles between the pyridine ring and pendant benzene rings are 2.9 (1, 14.1 (1 and 14.1 (1°. Neighbouring molecules are stabilized through intermolecular π–π interactions along the c axis [centroid-to-centroid distance = 3.804 (2 Å], forming one-dimensional chains.

  20. Preparation and nucleophilic substitution of the 2,4,6 ...

    African Journals Online (AJOL)

    Three methods for preparation of D-amino acids by nucleophilic substitution on derivatives of their L-antipodes have been attempted. Nucleophilic substitution on optically active phenylalanine ethyl ester triphenylpyridinium salt yielded partial inverted azide products. The N,N-disulfonylimide intermediate of the same ester ...

  1. 48 CFR 2452.246-70 - Inspection and acceptance.

    Science.gov (United States)

    2010-10-01

    ... solicitations and contracts: Inspection and Acceptance (FEB 2006) Inspection and acceptance of all work required... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Inspection and acceptance... DEVELOPMENT CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses...

  2. Page | 246 CONCEPT OF CRIME IN THE ADMINISTRATION OF ...

    African Journals Online (AJOL)

    Fr. Ikenga

    Abstract. There are various definitions of crime from the perspectives of moralists, libertarians, positivists, etc. This research covers Criminal Code, Penal Code as well as Shariah Penal Code. The doctrinal method of research was adopted to analytically study the concept of crime. It was found that the moralist sees.

  3. 40 CFR 98.246 - Data reporting requirements.

    Science.gov (United States)

    2010-07-01

    ... process unit. (1) The petrochemical process unit ID number or other appropriate descriptor. (2) The type... that burned both process off-gas and supplemental fuel. (9) If you comply with the alternative to... the mass balance calculation. (b) If you use CEMS to measure CO2 emissions in accordance with § 98.243...

  4. 7 CFR 246.6 - Agreements with local agencies.

    Science.gov (United States)

    2010-01-01

    ... approved by FNS; (8) Maintains complete, accurate, documented and current accounting of all Program funds... criteria used for certification, including information on the area served, income standards used, and... submits reports as required to permit effective enforcement of the nondiscrimination laws. (c) Indian...

  5. Water Quality Criteria for 2,4,6-Trinitrotoluene (TNT)

    Science.gov (United States)

    1987-08-01

    Bureau of Standards, May, 1976. [As cited in Liu et al. 1983]. Letavet, A. A. 1964. Professionalnyje bolezni. Izdanije 2-e. Moskva, Medicina , 758. [As...military explosives on hands. J. Forensic Scl.29:284-290. ABSTRACT. Urbanski, T. 1983a. Chemistry and Technology of Explosives, Vol. 2, Pergammon Press, New

  6. An Assessment of surgical outcome amongst 246 cataract ...

    African Journals Online (AJOL)

    Windows2G

    Poor outcome was associated with pre-existing ocular disease in. 10.8% of the eyes operated and were due to pre-existing glaucoma, macular degeneration, optic atrophy and diabetic retinopathy. Conclusion: Best functional visual results are obtained by modern techniques of ECCE with IOL, which ensures that the patient ...

  7. 48 CFR 1652.246-70 - FEHB Inspection.

    Science.gov (United States)

    2010-10-01

    ... and in a manner that will not unreasonably delay the work. (b) The Contractor shall maintain and the... examine and audit all books and records relating to the contract for purposes of the Contracting officer's... and audit for the record retention period specified in the Federal Employees Health Benefits...

  8. Degradation of 2,4,6-trinitrotoluene by selected helophytes

    Czech Academy of Sciences Publication Activity Database

    Nepovím, Aleš; Hebner, A.; Soudek, Petr; Gerth, A.; Thomas, H.; Smrček, S.; Vaněk, Tomáš

    2005-01-01

    Roč. 60, - (2005), s. 1454-1461 ISSN 0045-6535 R&D Projects: GA ČR(CZ) GP206/02/P065; GA MŠk(CZ) 1P05OC042 Institutional research plan: CEZ:AV0Z40550506 Keywords : TNT * biodegradation * emergent plant Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.297, year: 2005

  9. 48 CFR 252.246-7002 - Warranty of construction (Germany).

    Science.gov (United States)

    2010-10-01

    ... workmanship performed. (d) The Contractor shall restore any work damaged in fulfilling the terms and... damage at the Contractor's expense. (g) With respect to all warranties, express or implied, from... all warranties to be executed in writing, for the benefit of the Government, if directed by the...

  10. 48 CFR 52.246-21 - Warranty of Construction.

    Science.gov (United States)

    2010-10-01

    ... restore any work damaged in fulfilling the terms and conditions of this clause. The Contractor's warranty.... (g) With respect to all warranties, express or implied, from subcontractors, manufacturers, or... executed, in writing, for the benefit of the Government, if directed by the Contracting Officer; and (3...

  11. 40 CFR 408.246 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... pollutant property Pretreatment standard BOD5 No limitation. TSS Do. pH Do. Oil and grease Do. [40 FR 55791... subpart that introduces process wastewater pollutants into a publicly owned treatment works must comply...

  12. 48 CFR 52.246-15 - Certificate of Conformance.

    Science.gov (United States)

    2010-10-01

    ... Conformance (APR 1984) (a) When authorized in writing by the cognizant Contract Administration Office (CAO... under this contract until use of the Certificate of Conformance has been authorized in writing by the... office or attached to the CAO copy when contract administration (Block 10 of the DD Form 250) is...

  13. 32 CFR Appendix D to Part 246 - Editorial Operations

    Science.gov (United States)

    2010-07-01

    ... major purpose of the Stars and Stripes is to provide news and information from varied sources. This aids... its subordinate commands. All reporting necessarily requires some investigation and, as with... journalists. While the Stars and Stripes staff cannot conduct independent investigations that fall under the...

  14. Dicty_cDB: CFF246 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available Frames) Frame A: y**igncikr*t*ire**k*ww****f*kik***n*w***ckynkrws*fsftinknnks n*kyik***w*ck*yky*wy*wwck*yky...ky**wyrttsttnl*rtkctkrsimeg*rcy f*w**yc***fr*n*frisyfsrkyynnnnnynnnynk*tkny*t*i**kfnnf*kfirn tlkfh**frvrin*-

  15. 32 CFR Appendix A to Part 246 - Mission

    Science.gov (United States)

    2010-07-01

    ...-sponsored regional and local media pools. ... readers, the Stars and Stripes shall pay special attention to news of local, host-country conditions relevant to their audiences. They shall provide, through their reporters and bureaus, news of local...

  16. 7 CFR 246.7 - Certification of participants.

    Science.gov (United States)

    2010-01-01

    ... constant or unlimited access. (D) Payments or benefits provided under certain Federal programs or acts are...(c)); (11) Payments under the Low-income Home Energy Assistance Act, as amended (Pub. L. 99-125, sec...

  17. 40 CFR Appendix to Part 246 - Recommended Bibliography

    Science.gov (United States)

    2010-07-01

    ... economics of separate refuse collection. SCS Engineers, Inc. report. Long Beach, California, April 1974. 22....S. Environmental Protection Agency, 1974. 70 p. (Distributed by National Technical Information... distributed by National Technical Information Service, Springfield, Virginia.) SCS Engineers, Inc. Analysis of...

  18. Rapid selective separation of americium/curium from simulated nuclear forensic matrices using triazine ligands

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, Matthew A.; Livens, Francis R.; Heath, Sarah L. [Manchester Univ. (United Kingdom). Centre for Radiochemistry Research; Thompson, Paul; Marsden, Olivia J. [AWE, Aldermaston, Reading (United Kingdom); Harwood, Laurence M.; Hudson, Michael J. [Reading Univ. (United Kingdom). Dept. of Chemistry; Lewis, Frank W. [Reading Univ. (United Kingdom). Dept. of Chemistry; Northumbria Univ., Newcastle upon Tyne (United Kingdom). Dept. of Chemical and Forensic Sciences

    2015-07-01

    In analysis of complex nuclear forensic samples containing lanthanides, actinides and matrix elements, rapid selective extraction of Am/Cm for quantification is challenging, in particular due the difficult separation of Am/Cm from lanthanides. Here we present a separation process for Am/Cm(III) which is achieved using a combination of AG1-X8 chromatography followed by Am/Cm extraction with a triazine ligand. The ligands tested in our process were CyMe{sub 4}-BTPhen, CyMe{sub 4}-BTBP, CA-BTP and CA-BTPhen. Our process allows for purification and quantification of Am and Cm (recoveries 80% - 100%) and other major actinides in < 2 d without the use of multiple columns or thiocyanate. The process is unaffected by high level Ca(II)/Fe(III)/Al(III) (10 mg mL{sup -1}) and thus requires little pre-treatment of samples.

  19. Criteria Considered in Selecting Feed Items for Americium-241 Oxide Production Operations

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Louis D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-01-30

    The analysis in this document serves the purpose of defining a number of attributes in selection of feed items to be utilized in recovery/recycle of Pu and also production operations of 241AmO2 material intended to meet specification requirements. This document was written in response to a specific request on the part of the 2014 annual program review which took place over the dates of October 28-29, 2014. A number of feed attributes are noted including: (1) Non-interference with existing Pu recovery operations; (2) Content of sufficient 241Am to allow process efficiency in recovery operations; (3) Absence of indications that 243Am might be mixed in with the Pu/241Am material; (4) Absence of indications that Cm might be mixed in with the Pu/241Am material; (5) Absence of indications of other chemical elements that would present difficulty in chemical separation from 241Am; (6) Feed material not expected to present difficulty in dissolution; (7) Dose issues; (8) Process efficiency; (9) Size; (10) Hazard associated with items and package configuration in the vault; (11) Within existing NEPA documentation. The analysis in this document provides a baseline of attributes considered for feed materials, but does not presume to replace the need for technical expertise and judgment on the part of individuals responsible for selecting the material feed to be processed. This document is not comprehensive as regards all attributes that could prove to be important. The value of placing a formal QA hold point on accepting feed items versus more informal management of feed items is discussed in the summation of this analysis. The existing planned QA hold points on 241AmO2 products produced and packaged may be adequate as the entire project is based on QA of the product rather than QA of the process. The probability of introduction of items that would inherently cause the241AmO2 products produced to be outside of specification requirements appears to be rather small.

  20. Role of americium interference in analysis of samples containing rare earths

    International Nuclear Information System (INIS)

    Mohapatra, P.K.; Adya, V.C.; Thulasidas, S.K.; Bhattacharyya, A.; Kumar, Mithlesh; Godbole, S.V.; Manchanda, V.K.

    2007-01-01

    Quality control of nuclear fuel samples requires precise estimation of rare earths which have high neutron absorption cross sections and act as neutron poisons. Am is generated by nuclear decay where as lanthanides may be present as impurities picked up during reprocessing/fuel fabrication. Precise estimation of the rare earths by ICP-AES method in presence of 241 Am is a challenging task due to the likelihood of spectral interference of the latter. Rare earths impurities in the purified Am sample were estimated by ICP-AES method. Known amounts of the rare earths viz. Sm, Eu, Dy and Gd were used as synthetic sample and the interference due to Am was investigated. (author)

  1. Extraction of Americium and Europium by Diphosphine Dioxides and Their Mixtures with Chlorinated Cobalt Dicarbollide

    International Nuclear Information System (INIS)

    R. Scott Herbst; Dean R. Peterman; Terry A. Todd

    2005-01-01

    Extraction of Am and Eu using mixtures of diphosphine dioxides (DPDO, e.g., (R1)2P(O)(CH2)nP(O)(R2)2 where R1, R2 = Ph, Bu; n = 1,2), with and without chlorinated cobalt dicarbollide (CCD) in the polar diluents 1,2-dichloroethane (DCE), meta-nitrobenzotrifluoride (F-3), bis-tetrafluoropropyl ether of diethylene glycol (F-8) and phenyltrifluoromethyl sulfone (FS-13) from HNO3, HClO4, LiNO3 and LiClO4 solutions has been investigated. The anomalous aryl strengthening (AAS) effect, i.e. the anomalous increase of extraction ability of methylene bridged diphosphine dioxides due to substitution of aromatic (i.e., phenyl) for alkyl (e.g., butyl or octyl) moieties (DAm increases by three to four orders of magnitude), is only observed during the extraction of Am and Eu from acidic media. In salt media the AAS effect is weakly observed, and is practically absent in such diluents as F-3 and FS-13. The extraction isotherm in the case of DPDO with an observed AAS effect indicates the distribution coefficients of Eu decrease by a factor of two to three, even at the concentration ratio of DPDO:Eu = 50:1; however, these values decrease only by 10% for the DPDO that do not indicate an observed AAS effect. It is proposed that the presence of water in the diluent is necessary for manifestation of the AAS effect. The synergistic effects of adding chlorinated cobalt dicarbollide (CCD) with the DPDO that has been reported for other systems was also found to prevail in several of the systems investigated in this study. On addition of CCD with the DPDO, a considerable synergistic effect is observed (DAm increases by three to four orders of magnitude) during Am and Eu extraction from nitrate media. In perchlorate media the synergistic effect is absent. The most probable reason for synergism in the presence of CCD is the higher hydrophobicity of the CCD anion as compared to the nitrate anion. The results of this work will be of utility in understanding existing and developing new extraction systems designed for the simultaneous removal of multiple radionuclides from acidic streams

  2. Multi-recycling of plutonium and incineration of americium, curium, and technetium in PWRs

    International Nuclear Information System (INIS)

    Golfier, H.; Bergeron, J.; Puill, A.; Rohart, M.

    2000-01-01

    The future of nuclear power requires a clear strategy for radwaste and Plutonium management. Pressurized water reactors (PWR) and the associated fuel cycle installations represent the largest part of the French power plants (and are partly paid off). The reactors in service produce an annual 10 tons of Pu, 1.4 tons of minor actinides (MA), and 3.8 tons of long-lived fission products (LLFP). The spent fuel is reprocessed in La Hague plant to recover the energetic elements U and Pu. The latter was initially dedicated to power Fast Breeder Reactors that converted the depleted and reprocessed, thus ensuring a significant part of the French national energy resources. The shut-down of Super-Phenix, the postponement of building of Fast Breeder Reactors (FBR) and the relaxed need for stretching natural U resources raise the issue of Pu management. In fact, the Pu mono-recycling practiced in France since 1987 (St Laurent B1) only slows down the Pu accumulation in spent nuclear fuel, yet it is unable to stabilize the Pu inventory. Beyond the cooperation with its industrial partners, CEA investigates solutions for short and medium term Pu management thus contributing to research required for keeping nuclear power as an energy option. The range of these investigations shall cover both adaptations for light water reactors to facilitate Pu recycling and more innovative solutions concerning reactors, fuel and fuel cycle. The aim of using Pu more efficiently in PWR has led, not only for economic and non-proliferation reasons, but also for considerations related to the optimization of Pu and MA management. The mastery of Pu inventory is a requirement for all long-lived radwaste management methods. In this context, the potential of innovative PWRs has been investigated to control the Pu fluxes and to make them a milestone on the way to clean nuclear power. This paper presents the most recent results related to Pu utilization and MA and LLFP incineration like (Am+Cm) and Tc. To determine the influence of the Pu fluxes, a 1450 MWe PWR with one standard and one innovative concept (code named APA for Advanced Plutonium fuel Assembly) have been performed. A multi-recycling scenario is simulated with a 400 TWhe power plant park. (authors)

  3. Fundamental chemistry and materials science of americium in selected immobilization glasses

    Energy Technology Data Exchange (ETDEWEB)

    Haire, R.G. [Oak Ridge National Lab., TN (United States); Stump, N.A. [Winston-Salem State Univ., NC (United States). Dept. of Physical Sciences

    1996-12-01

    We have pursued some of the fundamental chemistry and materials science of Am in 3 glass matrices, two being high-temperature (850 and 1400 C mp) silicate-based glasses and the third a sol-gel glass. Optical spectroscopy was the principal tool. One aspect of this work was to determine the oxidation state exhibited by Am in these matrices, as well as factors that control or may alter this state. A correlation was noted between the oxidation state of the f-elements in the two high-temperature glasses with their high-temperature oxide chemistries. One exception was Am: although AmO{sub 2} is the stable oxide encountered in air, when this dioxide was incorporated into the high-temperature glasses, only trivalent Am was found in the products. When Am(III) was used to prepare the sol-gel glasses at ambient temperature, and after these products were heated in air to 800 C, only Am(III) was observed. Potential explanations for the unexpected Am behavior is offered in the context of its basic chemistry. Experimental spectra, spectroscopic assignments, etc. are discussed.

  4. Plutonium, americium and 90Sr in bones of the some wild animals living in Poland

    International Nuclear Information System (INIS)

    Mietelski, J.W.; Kitowski, I.; Tomankiewicz, E.; Gaca, P.; Blazej, S.

    2006-01-01

    Bones of the wild foxes (Vulpes vulpes), roe deer (Capreolus capreolus), deer (Cervus elaphus), wild boars (Sus scorf), mooses (Alces alces), as well as of certain kinds of rodents and insectivorous animals were ashed and milled prior to the radioactivity measurement in the γ-spectrometer. 238 Pu, 239,240 Pu, 241 Am and 90 Sr contents were determined. The results are presented in terms of the kind and origin of the animals. North-east, central-east and south-est parts of Poland were taken into an account

  5. Kinetics of the oxidation-reduction reactions of uranium, neptunium, plutonium, and americium in aqueous solutions

    International Nuclear Information System (INIS)

    Newton, T.W.

    1975-01-01

    This is a review with about 250 references. Data for 240 reactions are cataloged and quantitative activation parameters are tabulated for 79 of these. Some empirical correlations are given. Twelve typical reactions are discussed in detail, along with the effects of self-irradiation and ionic strength. (U.S.)

  6. Treatment of selected primary gynecologic and pelvic malignancies with 241Americium

    International Nuclear Information System (INIS)

    Chung, Joyce Y.; Peschel, Richard E.; Kacinski, Barry; Nath, Ravinder; Pourang, Rauman; Roberts, Kenneth; Fischer, Diana; Chambers, Joseph; Schwartz, Peter E.; Wilson, Lynn

    1995-01-01

    Purpose: To evaluate the efficacy of encapsulated 241 Am in the treatment of primary gynecological malignancies and in previously irradiated patients with recurrent disease in the pelvis. Materials and Methods: Encapsulated 241 Am primarily emits 60keV photons which are effectively shielded by thin layers of high atomic number materials. Dose distributions in water are similar to those produced by Cs-137 photons but with a half-value layer that is considerably less. Cases of 28 patients (12-primary, 16-recurrent) who have been treated with 241 Am at the Yale University School of Medicine since 1986 were retrospectively reviewed. Data concerning dosimetry, disease site, prior treatment, recurrence, disease-free survival, overall survival, and complications were evaluated. Results: Median follow up for the 12 patients with primary gynecological tumors was 19 months (7mo-51mo). There were 6 vulvar, 3 vaginal, 2 cervical and 1 endometrial carcinomas. Median surface dose of 241 Am was 42.2 Gy (23.3Gy-106.6Gy). As part of their initial therapy 11 received pelvic external beam radiation therapy, 6 underwent surgery and 2 received other forms of intracavitary brachytherapy. Of these 12 patients, 11 achieved a complete response (CR) with the duration of CR ranging from 7 to 51 months. Actuarial disease-free survival at 3 years was 66% (S.E.=.16) and actuarial overall survival at 3 years was 91% (S.E.=.08). Median follow up for the 16 patients with recurrent pelvic malignancies was 72 months (20mo-99mo). There were 9 cases of endometrial, 3 vulvar, 3 colorectal, and 1 cervical carinomas. Fifteen of 16 received some form of surgery and radiotherapy prior to their treatment with 241 Am. Median surface dose of 241 Am was 40.3 (17.6Gy-141.7Gy). Of these 16 patients, 10 achieved a CR with the duration of CR ranging from 3 to 88 months. Actuarial disease-free survival at 5 years was 51% (S.E.=.16) and actuarial overall survival at 5 years was 43% (S.E.=.14). Complications were observed in 1 primarily treated patient (soft tissue necrosis) and in 3 patients with recurrent disease (colonic obstruction, rectal fissure, and GI bleed, respectively). Conclusion: The unique dosimetric characteristics of 241 Am allow effective and safe treatment of selected primary gynecological malignancies and in previously irradiated patients with recurrent pelvic malignancies

  7. Fabrication of uranium-americium mixed oxide fuels: thermodynamical modeling and materials properties

    International Nuclear Information System (INIS)

    Prieur, D.

    2011-01-01

    Fuel irradiation in pressurized water reactors lead to the formation of fission products and minor actinides (Np, Am, Cm) which can be transmuted in fast neutrons reactors. In this context, the aim of this work was to study the fabrication conditions of the U 1-y Am y O 2+x fuels which exhibit particular thermodynamical properties requiring an accurate monitoring of the oxygen potential during the sintering step. For this reason, a thermodynamical model was developed to assess the optimum sintering conditions for these materials. From these calculations, U 1-y Am y O 2+x (y=0.10; 0.15; 0.20; 0.30) were sintered in two range of atmosphere. In hyper-stoichiometric conditions at low temperature, porous and multiphasic compounds are obtained whereas in reducing conditions at high temperature materials are dense and monophasic. XAFS analyses were performed in order to obtain additional experimental data for the thermodynamical modeling refinement. These characterizations also showed the reduction of Am(+IV) to Am(+III) and the partial oxidation of U(+IV) to U(+V) due to a charge compensation mechanism occurring during the sintering. Finally, taking into account the high - activity of Am, self-irradiation effects were studied for two types of microstructures and two Am contents (10 and 15%). For each composition, a lattice parameter increase was observed without structural change coupled with a macroscopic swelling of the pellet diameter up to 1.2% for the dense compounds and 0.6% for the tailored porosity materials. (author) [fr

  8. Thermochemistry of selected trivalent lanthanide and americium compounds: orthorhombic and hexagonal hydroxycarbonates

    International Nuclear Information System (INIS)

    Rorif, F.; Fuger, J.; Desreux, J.F.

    2005-01-01

    The molar enthalpies of dissolution of a number of well-characterized hexagonal hydroxycarbonates Ln(OH)CO 3 (hex) (Ln = La, Nd, Sm, Eu) in 6.00 mol dm -3 HCl were measured at 298.15K. A new sealed solution micro-calorimeter was developed for this purpose. It was made of an 18-carat gold alloy in order to improve the performances of a calorimeter previously built in our laboratory. The following standard molar enthalpies of formation, Δ f H m [Ln(OH)CO 3 , hex], in kJ mol -1 , were calculated: -(1627.8±1.6), -(1614.8±1.9), -(1613.4±1.6), and -(1523.0±3.0), for the La, Nd, Sm, and Eu compounds, respectively. These results allowed an extrapolation to Δ f H m [Eu(OH)CO 3 .0.5H 2 O, orth] = -(1653.4±3.6) kJ mol -1 and to Δ f H m [Am(OH)CO 3 , hex] = -(1552.5±3.3) kJ mol -1 . Using auxiliary data and estimated entropies, the solubility products of the hexagonal hydroxycarbonates were calculated. They are compared here with values deduced from solubility and calorimetric measurements for the corresponding orthorhombic hydroxycarbonates. Our approach generally leads to values similar to those deduced from solubility studies. The orthorhombic form is found to be metastable with respect to the hexagonal form. (orig.)

  9. Distribution of plutonium and americium in whole bodies donated to the United States Transuranium Registry

    International Nuclear Information System (INIS)

    McInroy, J.F.; Kathren, R.L.; Swint, M.J.

    1989-01-01

    Radiochemical analysis of whole body donations from six former nuclear industry workers 30 or more years post-exposure revealed about 45% of the total body deposition of 239 Pu and 35% of the 241 Am in the respiratory tract of the four cases with inhalation exposure. These proportions are greater than predicted by the current ICRP lung model. Exclusive of the respiratory tract, the mean fractional systemic deposition of 239 Pu in the tissues of five whole bodies was: liver 35.4% ± 12.5%; skeleton 53.7% ± 12.5%; striated muscle 6.5% ± 1.8% and all other organs and tissues 4.4% ± 1.7%. For 241 Am, the comparable values in four cases were liver 6.5% ± 4.8%; skeleton 73.5% ± 12.4%; muscle 14.3% ± 7.6%; and all other tissues and organs 6.65% ± 4.2%. The systemic distribution of 239 Pu was generally consistent with ICRP Publication 30. A significant fraction of both nuclides was retained in the muscle and other soft tissues which serve as long-term storage depots. Initial fractionation of 241 Am between skeleton and liver is consistent with the 50:30 ratio proposed in ICRP Publication 48 assuming an effective clearance half-time from the liver of about 2 y. Estimates of 239 Pu deposition made on the basis of urinalysis results in vivo were typically greater than the observed deposition measured in the tissues of the whole body after death. (author)

  10. Controlling Hexavalent Americium – A Centerpiece to a Compact Nuclear Fuel Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Shafer/Braley, Jenifer; Nash, Kenneth L; Lumetta, Gregg; McCann, Kevin; Sinkov, Sergey I

    2014-10-01

    Closing the nuclear fuel cycle could be simplified by recovering the actinides U through Am as a group. This could be achieved by converting U, Np, Pu and Am to the hexavalent state. Uranium, Np and Pu are readily oxidized to the hexavalent state. Generation of hexavalent Am in acidic solutions is more difficult, as the standard reduction potential of the Am(VI) /Am(III) couple (+1.68 V in 1 M HClO4) is well outside of the electrochemical stability window of water. While the oxidation and separation of Am has been demonstrated under laboratory conditions, several issues could plague scale up and implementation of this separation with used fuel. Two primary concerns are considered. The first issue concerns the stability of the oxidized Am. The second involves the undesirable co-extraction of tetravalent f-elements with the hexavalent actinides. To address the first concern regarding Am redox instability, Am reduction will be monitored under a variety of different conditions to establish the means of improving the stability of Am(VI) in the organic phase. Identifying the components contributing most significantly to its reduction will allow thoughtful modification of the process. To address the second concern, we propose to apply branched chain extractants to separate hexavalent actinides from tetravalent f-elements. Both branched monoamide and organophosphorus extractants have demonstrated significant selectivity for UO22+ versus Th4+, with separation factors generally on the order of 100. The efforts of this two-pronged research program should represent a significant step forward in the development of aqueous separations approaches designed to recover the U-Am actinides based on the availability of the hexavalent oxidation state. For the purposes of this proposal, separations based on this approach will be called SAn(VI) separations, indicating the Separation of An(VI).

  11. Separation of americium from lanthanides in nitric acid medium by DPTP in octanol-dodecane

    International Nuclear Information System (INIS)

    Tang Hongbin; Ye Guoan; Cheng Qifu; Ye Yuxing; Jiang Dexiang; Zhu Wenbin; Chen Hui; Zhang Hu; He Hui; Li Gaoliang

    2008-01-01

    Considering the good solubility of 2,6-bis(5,6-di-n-propyl-1,2,4-triazin-3-yl)- pyridine (DPTP) and avoiding the third phase formation, octanol-dodecane (ODOD) with a volume fraction of 30% was selected as the diluent. The distribution ratios of Am(III) and Eu(III) were studied as a function of a number of parameters such as con- tact time, nitrate ion and the nitric acid concentration in aqueous phase, the concentration of DPTP in the organic phase. A counter-current cascade (10 mL glass tube with plug) extraction experiment was carried out with 0.04 mol/L DPTP/ODOD. In the experiments, the flow rate ratios are as following: F:X:S=1:0.63:0.25, BF:BX=1:1; the feed solution, Eu(III) + Am(III) in 1.0 mol/L HNO 3 solution; scrubbing solution, 1.0 mol/L HNO 3 solution; stripping reagent, 0.01 mol/L HNO 3 . The results show that the recovery of Am is 98.42%, only containing Am/Eu is 45, SF Eu/Am is more than 10 3 . (authors)

  12. A consistent set of thermodynamic constants for americium (III) species with hydroxyl and carbonate

    International Nuclear Information System (INIS)

    Kerrisk, J.F.; Silva, R.J.

    1986-01-01

    A consistent set of thermodynamic constants for aqueous species, and compounds of Am(III) with hydroxyl and carbonate ligands has been developed. The procedure used to develop these constants involved establishing a value for one formation constant at a time in a sequential order, starting with the hydrolysis products and hydroxide solids, and then proceeding to carbonate species. The EQ3NR chemical-equilibrium model was used to test the constants developed. These constants are consistent with most of the experimental data that form their basis; however, considerable uncertainty still exists in some aspects of the Am(III) data

  13. Optimization of TRPO process parameters for americium extraction from high level waste

    International Nuclear Information System (INIS)

    Chen Jing; Wang Jianchen; Song Chongli

    2001-01-01

    The numerical calculations for Am multistage fractional extraction by trialkyl phosphine oxide (TRPO) were verified by a hot test. 1750L/t-U high level waste (HLW) was used as the feed to the TRPO process. The analysis used the simple objective function to minimize the total waste content in the TRPO process streams. Some process parameters were optimized after other parameters were selected. The optimal process parameters for Am extraction by TRPO are: 10 stages for extraction and 2 stages for scrubbing; a flow rate ratio of 0.931 for extraction and 4.42 for scrubbing; nitric acid concentration of 1.35 mol/L for the feed and 0.5 mol/L for the scrubbing solution. Finally, the nitric acid and Am concentration profiles in the optimal TRPO extraction process are given

  14. 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.

  15. Fundamental chemistry and materials science of americium in selected immobilization glasses

    International Nuclear Information System (INIS)

    Haire, R.G.; Stump, N.A.

    1996-01-01

    We have pursued some of the fundamental chemistry and materials science of Am in 3 glass matrices, two being high-temperature (850 and 1400 C mp) silicate-based glasses and the third a sol-gel glass. Optical spectroscopy was the principal tool. One aspect of this work was to determine the oxidation state exhibited by Am in these matrices, as well as factors that control or may alter this state. A correlation was noted between the oxidation state of the f-elements in the two high-temperature glasses with their high-temperature oxide chemistries. One exception was Am: although AmO 2 is the stable oxide encountered in air, when this dioxide was incorporated into the high-temperature glasses, only trivalent Am was found in the products. When Am(III) was used to prepare the sol-gel glasses at ambient temperature, and after these products were heated in air to 800 C, only Am(III) was observed. Potential explanations for the unexpected Am behavior is offered in the context of its basic chemistry. Experimental spectra, spectroscopic assignments, etc. are discussed

  16. Standard test method for the radiochemical determination of americium-241 in soil by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This method covers the determination of americium–241 in soil by means of chemical separations and alpha spectrometry. It is designed to analyze up to ten grams of soil or other sample matrices that contain up to 30 mg of combined rare earths. This method allows the determination of americium–241 concentrations from ambient levels to applicable standards. The values stated in SI units are to be regarded as standard. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precaution statements, see Section 10.

  17. Photochemical oxidation of americium(3) in bicarbonate-carbonate solutions saturated with N2O

    International Nuclear Information System (INIS)

    Shilov, V.P.; Yusov, A.B.

    1993-01-01

    The influence of UV radiation on 1.1x10 -4 mol/l Am(3) in bicarbonate-carbonate solutions of sodium and potassium saturated with N 2 O was studied by spectrographic method. In all the cases Am(4) was formed as a primary product. Initial rate of Am(4) accumulation remains stable in solutions up to HCO 3 - or HCO 3 - +CO 3 2- concentration of approximately 1.5 mol/l, but it decreases in case of their higher concentration. In solutions with pH 8.4-10 Am(4) disproportionates at a slow rate and the method suggested permits attaining practically 100% yield of it

  18. Sorption of carbon, cobalt, nickel, strontium, iodine, cesium, americium and neptumium in rocks and minerals

    International Nuclear Information System (INIS)

    Pinnoja, S.; Jaakkola, T.; Kaemaeraeinen, E.L.; Koskinen, A.; Lindberg, A.

    1984-09-01

    Sorption of the radionuclides C-14, Co-58, Ni-63, I-125, Sr-85, Cs-134, Am-241 and Np-237, which are important in nuclear waste, were studied in rock by autoradiographic method. Samples were selected to represent common rocks and minerals in Finnish bedrock: rapakivi granite, tonalite, mica gneiss, granodiorite, biotite, quartz, plagioclase, K feldspar and hornblende. Polished thin sections were used to determine the contributions of different minerals to the sorption of the radionuclides. Sawn rock pieces (1.2 x 1.2 x 1.6 cm) were used to determine the Ksub(a)-values for rough rock surfaces where penetration into the rock matrix was found. The sorption order of the elements determined with the rock pieces was Ksub(a)sup(Cs)>Ksub(a)sup(Ni)>Ksub(a)sup(Co)>Ksub(a)sup(Sr)>Ksub(a)sup(C)>Ksub(a)sup(I). The same order of sorption was determined with thin sections for all nuclides except carbon, which was not sorbed on thin sections. Wide differences in the Ksub(a)-values for different minerals were found for Cs and Sr. The sorption mechanism for these elements is presumed to be ion exchange. The Ksub(a)-values of Cs varied between 0.1 x 10 -4 and 600 x 10 -4 m 3 /m 2 and those for Sr between 0.01 x 10 -4 and 10 x 10 -4 m 3 /m 2 . The lowest values were determined for quartz and the highest for biotite. Radionuclides having a tendency to form pseudocolloids and hydroxide precipitates (Am, Np, Ni) were sorbed on thin sections with only small variation in Ksub(a)-values: all values were between 1 x 10 -4 and 10 x 10 -4 and 100 x 10 -4 m 3 /m 2 . A very good agreement was found between experimental and calculated Ksub(a)-values for rock thin sections. Ksub(a)-values were calculated by multiplying the percentages of individual minerals in the rock by the Ksub(a)-values of the corresponding pure minerals and summing the results. Calculated Ksub(a)-values were occasionally up to 50% smaller than the experimental ones, owing to the low contents of some high adsorbing minerals not included in the calculations

  19. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    International Nuclear Information System (INIS)

    Albrecht-Schmitt, Thomas Edward

    2013-01-01

    The past three years of support by the Heavy Elements Chemistry Program have been highly productive in terms of advanced degrees awarded, currently supported graduate students, peer-reviewed publications, and presentations made at universities, national laboratories, and at international conferences. Ph.D. degrees were granted to Shuao Wang and Juan Diwu, who both went on to post-doctoral appointments at the Glenn T. Seaborg Center at Lawrence Berkeley National Laboratory with Jeff Long and Ken Raymond, respectively. Pius Adelani completed his Ph.D. with me and is now a post-doc with Peter C. Burns. Andrea Alsobrook finished her Ph.D. and is now a post-doc at Savannah River with Dave Hobbs. Anna Nelson completed her Ph.D. and is now a post-doc with Rod Ewing at the University of Michigan. As can be gleaned from this list, students supported by the Heavy Elements Chemistry grant have remained interested in actinide science after leaving my program. This follows in line with previous graduates in this program such as Richard E. Sykora, who did his post-doctoral work at Oak Ridge National Laboratory with R. G. Haire, and Amanda C. Bean, who is a staff scientist at Los Alamos National Laboratory, and Philip M. Almond and Thomas C. Shehee, who are both staff scientists at Savannah River National Laboratory, Gengbang Jin who is a staff scientist at Argonne National Lab, and Travis Bray who has been a post-doc at both LBNL and ANL. Clearly this program is serving as a pipe-line for students to enter into careers in the national laboratories. About half of my students depart the DOE complex for academia or industry. My undergraduate researchers also remain active in actinide chemistry after leaving my group. Dan Wells was a productive undergraduate of mine, and went on to pursue a Ph.D. on uranium and neptunium chalcogenides with Jim Ibers at Northwestern. After earning his Ph.D., he went directly into the nuclear industry

  20. A Study of the Translocation of Plutonium and Americium from Wounds

    Energy Technology Data Exchange (ETDEWEB)

    Watters, R. L. [Colorado State Univ., Fort Collins, CO (United States); Lebel, Jacques L. [Colorado State Univ., Fort Collins, CO (United States); Johnson, LaMar J. [Colorado State Univ., Fort Collins, CO (United States); Bull, Emory H. [Colorado State Univ., Fort Collins, CO (United States)

    1968-12-15

    The technological feasibility and economic advantages of the use of plutonium in power reactors and in other plutoniumfueled systems have been widely explored and demonstrated (1). As the use of plutonium and other transuranic nuclides has increased, the chance of their deposition within the human body has increased. A relatively complete review of the literature regarding the modes of entry, distribution, excretion, and means of evaluating plutonium within living systems has been recently published (2, 3).