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Sample records for americium 245

  1. Preparation of americium amalgam

    International Nuclear Information System (INIS)

    The authors describe a method for the electrochemical preparation of an americium amalgam from americium dioxide and americium 241 and 243 for use in determining the physicochemical properties of the alloy. Moessbauer spectra were made using neptunium dioxide, in the neptunium 237 form, as an absorber. Results show that electrolysis produces a homogeneous amalgam that gives an unoxidized product on vacuum distillation at 200 degrees C

  2. Preparation of americium amalgam

    International Nuclear Information System (INIS)

    Using the method of NGR-spectroscopy with the aid of 241Am isotope chemical state of transuranium elements in the volume and on the surface of amalgams is studied. Amalgam preparation was realized in a simplified electrolytic cell. It is shown that in the process of amalgam preparation the first order of reaction as to actinide is observed; americium is distributed gradually over the volume and it is partially sorbed by the surface of glass capillary. NGR spectrum of dry residue after mercury distillation at 200 deg C points to the presence of americium-mercury intermetal compounds

  3. 1976 Hanford americium accident

    Energy Technology Data Exchange (ETDEWEB)

    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 ..mu..Ci 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.

  4. 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)

  5. The Biokinetic Model of Americium

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    To improve in vivo measurements for detecting internal exposure from transuranium radio nuclides, such as neptunium, plutonium, americium, the bioknetic model was studied. According to ICRP report (1993, 1995, 1997) and other research, the

  6. SCI 245 Courses /Snaptutorial

    OpenAIRE

    Lucyfier

    2015-01-01

    For more classes visit www.snaptutorial.com   SCI 245 Week 1CheckPoint Study of Earth SCI 245 Week 1 Assignment Minerals SCI 245 Week 2 CheckPoint Fossils and the Geologic Column SCI 245 Week 2 DQ 1 and DQ 2 SCI 245 Week 3 CheckPoint Plate Tectonic Theory SCI 245 Week 3 Assignment Earthquakes SCI 245 Week 4 CheckPoint Igneous Rocks SCI 245 Week 4 DQ 1 and DQ 2 SCI 245 Week 5 CheckPoint Weathering and Erosion SCI 245 Week 5 Assignment Sedime...

  7. Americium product solidification and disposal

    International Nuclear Information System (INIS)

    The americium product from the TRUEX processing plant needs to be converted into a form suitable for ultimate disposal. An evaluation of the disposal based on safety, number of process steps, demonstrated operability of the processes, production of low-level alpha waste streams, and simplicity of maintenance with low radiation exposures to personnel during maintenance, has been made. The best process is to load the americium on a cation exchange resin followed by calcination or oxidation of the resin after loading

  8. MGT 245 uop Courses/ uophelp

    OpenAIRE

    Uophelp

    2015-01-01

    For more course tutorials visit www.uophelp.com   MGT 245 Assignment: Organizational Culture MGT 245 Capstone Discussion Question MGT 245 Assignment: Effective Teams MGT 245 CheckPoint: Employee Profile MGT 245 CheckPoint 1: Organizational Structure MGT 245 CheckPoint: Conflict Analysis MGT 245 CheckPoint 2: Peer Review MGT 245 CheckPoint: Employee Programs MGT 245 CheckPoint: Performance Evaluation MGT 245 CheckPoint: Change Management ...

  9. MGT 245 Courses/Indigohelp

    OpenAIRE

    charles

    2015-01-01

    For more classes visits www.indigohelp.com   MGT 245 Assignment: Organizational Culture MGT 245 Capstone Discussion Question MGT 245 Assignment: Effective Teams MGT 245 CheckPoint: Employee Profile MGT 245 CheckPoint 1: Organizational Structure MGT 245 CheckPoint: Conflict Analysis MGT 245 CheckPoint 2: Peer Review MGT 245 CheckPoint: Employee Programs MGT 245 CheckPoint: Performance Evaluation MGT 245 CheckPoint: Change Management ...

  10. SCI 245 Course Tutorial / indigohelp

    OpenAIRE

    roman8034

    2015-01-01

    SCI 245 Entire Course  For more classes visit www.indigohelp.com   SCI 245 Week 1CheckPoint Study of Earth SCI 245 Week 1 Assignment Minerals SCI 245 Week 2 CheckPoint Fossils and the Geologic Column SCI 245 Week 2 DQ 1 and DQ 2 SCI 245 Week 3 CheckPoint Plate Tectonic Theory SCI 245 Week 3 Assignment Earthquakes SCI 245 Week 4 CheckPoint Igneous Rocks SCI 245 Week 4 DQ 1 and DQ 2 SCI 245 Week 5 CheckPoint Weathering and Erosion SC...

  11. MGT 245 Course Tutorial/snaptutorial

    OpenAIRE

    roman8034

    2015-01-01

    MGT 245 Entire Course For more classes visit www.snaptutorial.com   MGT 245 Assignment: Organizational Culture MGT 245 Capstone Discussion Question MGT 245 Assignment: Effective Teams MGT 245 CheckPoint: Employee Profile MGT 245 CheckPoint 1: Organizational Structure MGT 245 CheckPoint: Conflict Analysis MGT 245 CheckPoint 2: Peer Review MGT 245 CheckPoint: Employee Programs MGT 245 CheckPoint: Performance Evaluation MGT 245 CheckPo...

  12. Spectrochemical analysis of curium and americium samples

    International Nuclear Information System (INIS)

    Spectrochemical procedures have been developed to determine impurities in americium and curium samples. The simultaneous separation of many impurity elements from the base material (americium and curium) is carried out with extraction and extraction-chromatographic methods using di-2-ethylhexylphosphoric acid. It is shown that part of the elements are separated with extraction or sorption of americium and curium; the other part with the Talspeak process. Two fractions in the extraction chromatography and three fractions in the extraction separation of americium and curium, containing impurities, are analyzed separately by a.c. or d.c. arc spectrography. To increase the sensitivity of the spectrographic analysis and accelerate the burn-up of impurities from the crater of the carbon electrode bismuth fluoride and sodium chloride were used as chemically active substances. The extraction of impurities from weighed quantities of americium and curium samples of 5 to 10 mg permits the lower limit of determined impurity concentrations to be extended to 1 x 10-4 to 5 x 10-3% m/m. (author)

  13. Pyrochemical technology of plutonium and americium preparation and purification

    International Nuclear Information System (INIS)

    Pyrochemical tecnology of metallic plutonium and americium preparation and purification is considered. Investigations into plutonium dioxide reduction up to metal; plutonium electrolytic refining in molten salts; plutonium extraction from the molten salts and preparation of americium dioxide and metallic americium from its tetrafluoride are described

  14. 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.

  15. MGT 245 UOP Course Tutorial / Tutorialoutlet

    OpenAIRE

    karthi

    2015-01-01

    For more course tutorials visit www.tutorialoutlet.com MGT 245 Assignment: Organizational Culture MGT 245 Capstone Discussion Question MGT 245 Assignment: Effective Teams MGT 245 CheckPoint: Employee Profile MGT 245 CheckPoint 1: Organizational Structure MGT 245 CheckPoint: Conflict Analysis MGT 245 CheckPoint 2: Peer Review MGT 245 CheckPoint: Employee Programs MGT 245 CheckPoint: Performance Evaluation MGT 245 CheckPoint: Change Management MGT...

  16. 1976 Hanford americium exposure incident: psychological aspects

    International Nuclear Information System (INIS)

    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

  17. Incentives for transmutation of americium in thermal reactors

    International Nuclear Information System (INIS)

    This report describes possible benefits when americium is irradiated in a thermal reactor. If all plutonium is partitioned from spent fuel, americium is the main contributor to the radiotoxicity of spent fuel upto several thousands of years of storage. It is shown that americium can be transmuted to other nuclides upon irradiation in a thermal reactor, leading to a 50% reduction of the radiotoxicity of neptunium, which can be an important contributor to the dose due to leakage of nuclides after one million years of storage. The radiotoxicity of americium can be reduced considerably after irradiation for 3 to 6 years in a thermal reactor with thermal neutron flux of 1014 cm-2s-1. The strongly α and neutron emitting transmutation products can most probably not be recycled again, so a transmutation process is suggested in which americium is irradiated for 3 to 6 years and then put to final storage. It is shown that the radiotoxicity of the transmuation products after a storage time of about one hundred years can be considerably reduced compared to the radiotoxicity of the initial americium. The same holds for the α activity and heat emission of the transmutation products. Because plutonium in spent fuel contributes for about 80% to the radiotoxicity upto 105 years of storage, recycling and transmutation of plutonium has first priority. Transmutation of americium is only meaningful when the radiotoxicity of plutonium is reduced far below the radiotoxicity of americium. (orig.)

  18. 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.

  19. ShCG 245

    Directory of Open Access Journals (Sweden)

    Hrant M. Tovmassian

    2007-01-01

    Full Text Available Los grupos compactos de galaxias Shakhbazian son las configuraciones más densas que se conocen. Hace algunos años iniciamos un estudio fotométrico y espectroscópico de estos grupos. En este artículo presentamos los resultados de la investigación en los grupos ShCG 104, ShCG 120, ShCG 243 y ShCG 245. Presentamos los corrimientos al rojo de las galaxias miembro, los resultados de la fotometría R, las curvas de brillo superficial-radio efectivo, las masas estimadas, las luminosidades y las razones masa-luminosidad de los grupos, además de algunos parámetros dinámicos como la dispersión de velocidad radial y el tiempo de cruce. Los ShCGs estudiados consisten principalmente de galaxias elípticas y lenticulares. Se muestra que algunas galaxias en estos grupos están en proceso de interacción.

  20. 48 CFR 245.607 - Scrap.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Scrap. 245.607 Section 245.607 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF... Inventory 245.607 Scrap....

  1. 48 CFR 245.603 - Disposal methods.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Disposal methods. 245.603 Section 245.603 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... Contractor Inventory 245.603 Disposal methods....

  2. Electrochemical oxidation of americium in nitric medium: study of reaction mechanisms; Oxydation de l'americium par voie electrochimique: etude des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Picart, S.; Chartier, D.; Donnet, L.; Adnet, J.M. [CEA Valrho, (DCC/DRRV/SPHA), 30 - Marcoule (France)

    2000-07-01

    One alternative selected by the CEA for partitioning minor actinides from aqueous solutions containing fission products is the selective extraction of oxidized americium. This is the SESAME process (Selective Extraction and Separation of Americium by Means of Electrolysis) aimed to convert americium to oxidation state (VI) and then extract it with a specific extractant of high valences. This paper presents the study of the electrochemical oxidation of americium in nitric medium which represents an important stage of the process. The reaction can be divided into two main steps: oxidation of americium (III) to americium (IV), and then of americium (IV) to americium (VI). For the first oxidation step, a ligand L is needed to stabilize the intermediate species americium (IV) which disproportionates in its free form into americium (III) and (V). Phospho-tungstate or silico-tungstate are appropriate ligands because they are stable in concentrated nitric acid and show a great affinity for metallic cations at oxidation state (IV) (Table 1 lists the stability constants of americium (IV) complexes). The presence of the lacunary poly-anion lowers the potential of the americium (IV) / americium (Ill) redox pair (see Figure 5 for the diagram of the apparent formal potential of americium versus ligand concentration). This makes it thermodynamically possible to oxidize americium (III) into americium (IV) at the anode of an electrolyzer in nitric acid. For the second oxidation step, a strong oxidant redox mediator, like silver (II), is needed to convert complexed americium at oxidation state (IV) to oxidation state (V). The AmVL complex is then hydrolyzed to yield americyle (V) aqua ion. A spectroscopic Raman study with {sup 18}O labeled species showed that the oxygen atoms of the americyle moiety came from water. This indicates that water hydrolyzes the americium (V) complex to produce americyle (V) aqua ion, AmO{sub 2}{sup +}. This cation reacts with silver (Il) to give

  3. 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

  4. 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.

  5. Mixed chelation therapy for removal of plutonium and americium

    International Nuclear Information System (INIS)

    Iron-binding compounds, 2,3-dihydroxybenzoic acid (DHBA), 2-hydroxybenzoic acid (HBA), and 2-(acetyloxy)benzoic acid (ABA), were tested for their ability to remove americium and plutonium from rats following intraperitioneal injection of the radionuclides as citrates (pH 5). Treatments, 2 mmol/kg, were given on days 3, 6, 10, 12 and 14 following the actinide injection. DHBA and HBA caused about a 20% decrease in liver retention of americium compared to the control value, and DHB caused a similar effect for plutonium. The above agents, co-administered with 0.5 mmol polyaminopolycarboxylic acid (PAPCA)-type chelons, did not change tissue retention of americium and plutonium from that due to the PAPCAs alone. Administration of americium and plutonium to the same rats is useful for studying removal agents since the two actinides behave independently in their biological disposition and response to removal

  6. Gamma-sources on the basis of metallic americium-241

    International Nuclear Information System (INIS)

    A batch of gamma-radiation sources has been manufactured from metallic americium-241 of isotopic purity, its activity varying from 0.08 to 0.93 GBq. The cores of the sources are high-purity americium metal condensate on a tantalum or stainless steel substrate prepared by thermal decomposition of 241Pu-241Am alloy in a high vacuum. 7 refs., 1 tab

  7. 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.

  8. Pyrochemical investigations into recovering plutonium from americium extraction salt residues

    International Nuclear Information System (INIS)

    Progress into developing a pyrochemical technique for separating and recovering plutonium from spent americium extraction waste salts has concentrated on selective chemical reduction with lanthanum metal and calcium metal and on the solvent extraction of americium with calcium metal. Both techniques are effective for recovering plutonium from the waste salt, although neither appears suitable as a separation technique for recycling a plutonium stream back to mainline purification processes. 17 refs., 13 figs., 2 tabs

  9. Electrochemical oxidation of americium in nitric medium: study of reaction mechanisms

    International Nuclear Information System (INIS)

    One alternative selected by the CEA for partitioning minor actinides from aqueous solutions containing fission products is the selective extraction of oxidized americium. This is the SESAME process (Selective Extraction and Separation of Americium by Means of Electrolysis) aimed to convert americium to oxidation state (VI) and then extract it with a specific extractant of high valences. This paper presents the study of the electrochemical oxidation of americium in nitric medium which represents an important stage of the process. The reaction can be divided into two main steps: oxidation of americium (III) to americium (IV), and then of americium (IV) to americium (VI). For the first oxidation step, a ligand L is needed to stabilize the intermediate species americium (IV) which disproportionates in its free form into americium (III) and (V). Phospho-tungstate or silico-tungstate are appropriate ligands because they are stable in concentrated nitric acid and show a great affinity for metallic cations at oxidation state (IV) (Table 1 lists the stability constants of americium (IV) complexes). The presence of the lacunary poly-anion lowers the potential of the americium (IV) / americium (Ill) redox pair (see Figure 5 for the diagram of the apparent formal potential of americium versus ligand concentration). This makes it thermodynamically possible to oxidize americium (III) into americium (IV) at the anode of an electrolyzer in nitric acid. For the second oxidation step, a strong oxidant redox mediator, like silver (II), is needed to convert complexed americium at oxidation state (IV) to oxidation state (V). The AmVL complex is then hydrolyzed to yield americyle (V) aqua ion. A spectroscopic Raman study with 18O labeled species showed that the oxygen atoms of the americyle moiety came from water. This indicates that water hydrolyzes the americium (V) complex to produce americyle (V) aqua ion, AmO2+. This cation reacts with silver (Il) to give americyle (VI) ion. Figure

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

    International Nuclear Information System (INIS)

    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 HNO3, 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 HNO3 at 25 C, which corresponds to approximately 1.7 mg-241Am/g-adsorbent(dried). The prospect of applying the adsorbent to the treatment of aqueous waste contaminated with americium appears promising. (orig.)

  11. Salvage of plutonium-and americium-contaminated metals

    International Nuclear Information System (INIS)

    Melt-slagging techniques were evaluated as a decontamination and consolidation step for metals contaminated with oxides of plutonium and americium. Experiments were performed in which mild steel, stainless steel, and nickel metals contaminated with oxides of plutonium and americium were melted in the presence of silicate slags of various compositions. The metal products were low in contamination, with the plutonium and americium strongly fractionated to the slags. Partition coefficients (plutonium in slag/plutonium in steel) of 7*10/sup 6/ with borosilicate slag and 3*10/sup 6/ for calcium, magnesium silicate slag were measured. Decontamination of metals containing as much as 14,000 p.p.m. plutonium appears to be as efficient as that of metals with plutonium levels of 400 p.p.m. Staged extraction, that is, a remelting of processed metal with clean slag, results in further decontamination of the metal. 10 refs

  12. 8 CFR 245.4 - Documentary requirements.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Documentary requirements. 245.4 Section 245... STATUS TO THAT OF PERSON ADMITTED FOR PERMANENT RESIDENCE § 245.4 Documentary requirements. The provisions of part 211 of this chapter relating to the documentary requirements for immigrants shall...

  13. 32 CFR 245.5 - Terms.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Terms. 245.5 Section 245.5 National Defense... EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT) Explanation of Terms, Acronyms and Abbreviations § 245.5 Terms. For the purpose of this part, the words “will” and “shall” denote mandatory action by...

  14. 32 CFR 245.3 - Responsibilities.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Responsibilities. 245.3 Section 245.3 National... PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT) General § 245.3 Responsibilities. The Assistant Secretary of Defense for Networks and Information Integration will ensure the responsibilities...

  15. 32 CFR 245.13 - Responsibilities.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Responsibilities. 245.13 Section 245.13 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS PLAN FOR THE EMERGENCY SECURITY CONTROL OF AIR TRAFFIC (ESCAT) The ESCAT Plan § 245.13...

  16. 33 CFR 117.245 - Smyrna River.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Smyrna River. 117.245 Section 117.245 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Delaware § 117.245 Smyrna River. The draw of the...

  17. 48 CFR 245.7101 - Forms.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Forms. 245.7101 Section 245.7101 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Plant Clearance Forms 245.7101 Forms. Use the forms...

  18. 8 CFR 245a.32 - Ineligible aliens.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Ineligible aliens. 245a.32 Section 245a.32 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO... IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.32 Ineligible aliens....

  19. 14 CFR 121.245 - Fire walls.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire walls. 121.245 Section 121.245 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS..., FLAG, AND SUPPLEMENTAL OPERATIONS Special Airworthiness Requirements § 121.245 Fire walls. Each...

  20. 24 CFR 245.120 - Meeting space.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Meeting space. 245.120 Section 245... PARTICIPATION IN MULTIFAMILY HOUSING PROJECTS Tenant Organizations § 245.120 Meeting space. (a) Owners of... of any community room or other available space appropriate for meetings that is part of...

  1. 1976 Hanford americium exposure incident: overview and perspective

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. Synthesis and characterization of uranium-americium mixed oxides

    International Nuclear Information System (INIS)

    Americium isotopes represent a significant part of high-level and long-lived nuclear waste in spent fuels. Among the envisaged reprocessing scenarios, their transmutation in fast neutron reactors using uranium-americium mixed-oxide pellets (U1-xAmxO2±δ) is a promising option which would help decrease the ecological footprint of ultimate waste repository sites. In this context, this thesis is dedicated to the study of such compounds over a wide range of americium contents (7.5 at.% ≤ Am/(U+Am) ≤ 70 at.%), with an emphasis on their fabrication from single-oxide precursors and the assessment of their structural and thermodynamic stabilities, also taking self-irradiation effects into account. Results highlight the main influence of americium reduction to Am(+III), not only on the mechanisms of solid-state formation of the U1-xAmxO2±δ solid solution, but also on the stabilization of oxidized uranium cations and the formation of defects in the oxygen sublattice such as vacancies and cub-octahedral clusters. In addition, the data acquired concerning the stability of U1-xAmxO2±δ compounds (existence of a miscibility gap, vaporization behavior) were compared to calculations based on new thermodynamic modelling of the U-Am-O ternary system. Finally, α-self-irradiation-induced structural effects on U1-xAmxO2±δ compounds were analyzed using XRD, XAS and TEM, allowing the influence of americium content on the structural swelling to be studied as well as the description of the evolution of radiation-induced structural defects. (author)

  4. 8 CFR 245a.6 - Treatment of denied application under part 245a, Subpart B.

    Science.gov (United States)

    2010-01-01

    ... Act of 1986 (IRCA) Legalization Provisions § 245a.6 Treatment of denied application under part 245a... to temporary resident status, the LIFE Legalization application shall be deemed converted to...

  5. Neptunium and americium control for international non-proliferation regime

    International Nuclear Information System (INIS)

    It was decided in the IAEA Board of Governors Meeting held in Sept. 1999 that Neptunium and Americium could be diverted for manufacturing nuclear weapon or explosives, so that appropriate measures should be taken for the prevention of proliferation of these materials. It is expected to take relatively long time for settling down the aligned system dealing with the above materials because the present regulatory statement was prepared on the basis of voluntary offers from the States concerned. The necessity of preventive measures is being convinced among Member States, but it would not be easy to take voluntary participation in detail because of their respective interests. It is expected that this paper could contribute to the effective response as to the international commitments as well as for protecting the domestic nuclear industry and R and D area through analysis on the IAEA's approach on Neptunium and Americium

  6. Thermophysical properties of americium-containing barium plutonate

    International Nuclear Information System (INIS)

    Polycrystalline specimens of americium-containing barium plutonate have been prepared by mixing the appropriate amounts of (Pu0.91Am0.09)O2 and BaCO3 powders followed by reacting and sintering at 1600 K under the flowing gas atmosphere of dry-air. The sintered specimens had a single phase of orthorhombic perovskite structure and were crack-free. Elastic moduli were determined from longitudinal and shear sound velocities. Debye temperature was also determined from sound velocities and lattice parameter measurements. Thermal conductivity was calculated from measured density at room temperature, literature values of heat capacity and thermal diffusivity measured by laser flash method in vacuum. Thermal conductivity of americium-containing barium plutonate was roughly independent of temperature and registered almost the same magnitude as that of BaPuO3 and BaUO3. (author)

  7. 1976 Hanford americium-exposure incident: decontamination and treatment facility

    International Nuclear Information System (INIS)

    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

  8. 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.

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

    Science.gov (United States)

    FitzPatrick, John R.; Dunn, Jerry G.; Avens, Larry R.

    1987-01-01

    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, 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.

  10. Gut uptake factors for plutonium, americium and curium

    International Nuclear Information System (INIS)

    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)

  11. 24 CFR 245.5 - Purpose.

    Science.gov (United States)

    2010-04-01

    ... such projects, including their good physical condition, proper maintenance, security, energy efficiency... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Purpose. 245.5 Section 245.5 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE...

  12. 48 CFR 245.606-3 - Acceptance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Acceptance. 245.606-3..., DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Reporting, Redistribution, and Disposal of Contractor Inventory 245.606-3 Acceptance. (a) If the schedules are acceptable, the plant clearance...

  13. 40 CFR 86.245-94 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 18 2010-07-01 2010-07-01 false 86.245-94 Section 86.245-94 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... Year Gasoline-Fueled New Light-Duty Vehicles, New Light-Duty Trucks and New Medium-Duty...

  14. 43 CFR 24.5 - International agreements.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false International agreements. 24.5 Section 24... WILDLIFE POLICY: STATE-FEDERAL RELATIONSHIPS § 24.5 International agreements. (a) International conventions... shall be to recommend that the United States negotiate and accede to only those international...

  15. 40 CFR 1033.245 - Deterioration factors.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Deterioration factors. 1033.245... CONTROLS CONTROL OF EMISSIONS FROM LOCOMOTIVES Certifying Engine Families § 1033.245 Deterioration factors. Establish deterioration factors for each pollutant to determine, as described in § 1033.240, whether...

  16. 40 CFR 1042.245 - Deterioration factors.

    Science.gov (United States)

    2010-07-01

    ... as described in § 1042.125 and 40 CFR part 1065, subpart E. (d) Include the following information in... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Deterioration factors. 1042.245... Certifying Engine Families § 1042.245 Deterioration factors. This section describes how to...

  17. 20 CFR 627.245 - Work experience.

    Science.gov (United States)

    2010-04-01

    ... PROGRAMS UNDER TITLES I, II, AND III OF THE ACT Program Requirements § 627.245 Work experience. (a) Definition. Work experience means a short-term or part-time training assignment with a public or private... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Work experience. 627.245 Section...

  18. 33 CFR 104.245 - Communications.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Communications. 104.245 Section... MARITIME SECURITY: VESSELS Vessel Security Requirements § 104.245 Communications. (a) The Vessel Security... board the vessel. (b) Communications systems and procedures must allow effective and...

  19. 42 CFR 24.5 - Peer review.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Peer review. 24.5 Section 24.5 Public Health PUBLIC....5 Peer review. An individual may not be considered for appointment into the SBRS unless his/her qualifications have been reviewed by a PHS peer review committee and the committee has recommended appointment...

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

    International Nuclear Information System (INIS)

    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

  1. 10 CFR 31.8 - Americium-241 and radium-226 in the form of calibration or reference sources.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Americium-241 and radium-226 in the form of calibration or... BYPRODUCT MATERIAL § 31.8 Americium-241 and radium-226 in the form of calibration or reference sources. (a..., americium-241 or radium-226 in the form of calibration or reference sources: (1) Any person in a...

  2. 48 CFR 245.7309-7 - Default.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Sale of Surplus Contractor Inventory 245.7309-7... otherwise dispose of any or all such property and to charge losses and incidental expenses to the...

  3. 8 CFR 245a.21 - Confidentiality.

    Science.gov (United States)

    2010-01-01

    ... IMMIGRATION AND NATIONALITY ACT Legal Immigration Family Equity (LIFE) Act Legalization Provisions § 245a.21... individual employed under contract by the Service to work in connection with the LIFE Legalization...

  4. 8 CFR 245a.19 - Interviews.

    Science.gov (United States)

    2010-01-01

    ... IMMIGRATION AND NATIONALITY ACT Legal Immigration Family Equity (LIFE) Act Legalization Provisions § 245a.19... application shall be denied for lack of prosecution. Applications for LIFE Legalization adjustment may...

  5. Uncertainty analysis of doses from ingestion of plutonium and americium.

    Science.gov (United States)

    Puncher, M; Harrison, J D

    2012-02-01

    Uncertainty analyses have been performed on the biokinetic model for americium currently used by the International Commission on Radiological Protection (ICRP), and the model for plutonium recently derived by Leggett, considering acute intakes by ingestion by adult members of the public. The analyses calculated distributions of doses per unit intake. Those parameters having the greatest impact on prospective doses were identified by sensitivity analysis; the most important were the fraction absorbed from the alimentary tract, f(1), and rates of uptake from blood to bone surfaces. Probability distributions were selected based on the observed distribution of plutonium and americium in human subjects where possible; the distributions for f(1) reflected uncertainty on the average value of this parameter for non-specified plutonium and americium compounds ingested by adult members of the public. The calculated distributions of effective doses for ingested (239)Pu and (241)Am were well described by log-normal distributions, with doses varying by around a factor of 3 above and below the central values; the distributions contain the current ICRP Publication 67 dose coefficients for ingestion of (239)Pu and (241)Am by adult members of the public. Uncertainty on f(1) values had the greatest impact on doses, particularly effective dose. It is concluded that: (1) more precise data on f(1) values would have a greater effect in reducing uncertainties on doses from ingested (239)Pu and (241)Am, than reducing uncertainty on other model parameter values and (2) the results support the dose coefficients (Sv Bq(-1) intake) derived by ICRP for ingestion of (239)Pu and (241)Am by adult members of the public.

  6. Recovery of americium-241 from aged plutonium metal

    International Nuclear Information System (INIS)

    After separation and purification, both actinides were precipitated as oxalates and calcined. A large-scale process was developed using dissolution, separation, purification, precipitation, and calcination. Efforts were made to control corrosion, to avoid product contamination, to keep the volume of process and waste solutions manageable, and to denitrate solutions with formic acid. The Multipurpose Processing Facility (MPPF), designed for recovery of transplutonium isotopes, was used for the first time for the precipitation and calcination of americium. Also, for the first time,, large-scale formic acid denitration was performed in a canyon vessel at SRP

  7. Effect of 241-americium on bone marrow stroma

    International Nuclear Information System (INIS)

    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)

  8. Preferential decorporation of americium by pulmonary administration of DTPA dry powder after inhalation of aged PuO2 containing americium in rats

    International Nuclear Information System (INIS)

    After inhalation of plutonium oxides containing various percentages of americium in rats, we identified an acellular transient pulmonary compartment, the epithelial lining fluid (ELF), in which a fraction of actinide oxides dissolve prior to absorption and subsequent extrapulmonary deposit. Chelation therapy is usually considered to be poorly efficient after inhalation of actinide oxides. However, in the present study, prompt pulmonary administration of diethylenetriaminepentaacetic acid (DTPA) as a dry powder led to a decrease in actinide content in ELF together with a limitation of bone and liver deposits. Because americium is more soluble than plutonium, higher amounts of americium were found in ELF, extrapulmonary tissues and urine. Our results also demonstrated that the higher efficacy of DTPA on americium compared to plutonium in ELF induced a preferential inhibition of extrapulmonary deposit and a greater urinary excretion of americium compared to plutonium. All together, our data justify the use of an early and local DTPA treatment after inhalation of plutonium oxide aerosols in which americium can be in high proportion such as in aged compounds. (authors)

  9. Kilogram-scale purification of americium by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Wheelwright, E. J.

    1979-01-01

    Sequential anion and cation exchange processes have been used for the final purification of /sup 241/Am recovered during the reprocessing of aged plutonium metallurgical scrap. Plutonium was removed by absorption of Dowex 1, X-3.5 (30 to 50 mesh) anion exchange resin from 6.5 to 7.5 M HNO/sub 3/ feed solution. Following a water dilution to 0.75 to 1.0 M HNO/sub 3/, americium was absorbed on Dowex 50W, X-8 (50 to 100 mesh) cation exchange resion. Final purification was accomplished by elution of the absorbed band down 3 to 4 successive beds of the same resin, preloaded with Zn/sup 2 +/, with an NH/sub 4/OH buffered chelating agent. The recovery of mixed /sup 241/Am-/sup 243/Am from power reactor reprocessing waste has been demonstrated. Solvent extraction was used to recover a HNO/sub 3/ solution of mixed lanthanides and actinides from waste generated by the reprocessng of 13.5 tons of Shippingport Power Reactor blanket fuel. Sequential cation exchange band-displacement processes were then used to separate americium and curium from the lanthanides and then to separate approx. 60 g of /sup 244/Cm from 1000 g of mixed /sup 241/Am-/sup 243/Am.

  10. Analytical performance of radiochemical method for americium determination in urine

    International Nuclear Information System (INIS)

    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 243Am 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-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)

  11. Development of separation techniques of americium from reprocessing solution

    International Nuclear Information System (INIS)

    Americium(Am) and neptunium(Np) finally transfer to the waste stream in the current PUREX reprocessing process. As an option, some methods have been developed to recover Am and Np from the waste stream to decrease long-term toxicity of the high level waste. The most stable valence state of Am is III, but TBP (tri-n-butyl phosphate) which is an extractant used in the PUREX reprocessing does not extract Am(III). Therefore, some special extractants have been developed to recover Am(III). However, they also extract rare-earth elements(REs), which necessitates the separation process for Am from REs. We have been developing a separation process which consists of valence control of Am to the VI state and its extraction with TBP. This process allows Am recovery from reprocessing solution and Am separation from REs simultaneously. Americium(III) is oxidized to Am(VI) by electrochemical oxidation and chemical oxidation using peroxodisulfate ammonium and silver nitrate. The latter was adopted here because the chemical oxidation reaction proceeds faster than the electrochemical method. Reaction mechanisms of oxidation and extraction were investigated. Based on the mechanisms, we found that extraction efficiency could be improved and waste generation could be minimized. (author)

  12. Selective leaching studies of deep-sea sediments loaded with americium, neptunium and plutonium

    International Nuclear Information System (INIS)

    A series of selective leaching experiments were undertaken to investigate the solid phase speciation and distribution of americium, neptunium and plutonium which had been experimentally loaded onto different marine sediment types. The chemical leaches employed showed rather poor selectivity but certain trends were evident. Adsorption was not by ion exchange. Americium showed a preferential affinity for carbonate and plutonium for organic matter. Neptunium appeared to have no preferential affinities. Americium was sorbed by acetic acid residues (CaCO3 removed) and by unleached carbonate-rich sediments with equal efficiency. This indicates that it is able to diversify its solid phase affinity/distribution depending upon which solid phases are available. (author)

  13. Pretreatment of americium/curium solutions for vitrification

    International Nuclear Information System (INIS)

    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

  14. Plutonium and americium in sediments of Lithuanian lakes

    International Nuclear Information System (INIS)

    The assessment of contribution of the global and the Chernobyl NPP (Nuclear Power Plant) accident plutonium and americium to plutonium pollution in sediments of Lithuanian lakes is presented. Theoretical evaluation of activity ratios of 238Pu/239+240Pu and 241Pu/239+240Pu in the reactor of unit 4 of the Chernobyl NPP before the accident was performed by means of the ORIGEN-ARP code from the SCALE 4.4A program package. Non-uniform distribution of radionuclides in depositions on the Lithuanian territory after nuclear weapon tests and the Chernobyl NPP accident is experimentally observed by measuring the lake sediment pollution with actinides. The activity concentration of sediments polluted with plutonium ranges from 2.0 ± 0.5 Bq/kg d.w. (dry weight) in Lake Asavelis to 14 ± 2 Bq/kg d.w. in Lake Juodis. The ratio of activity concentrations of plutonium isotopes 238Pu/239+240Pu measured by α-spectrometry in the 10-cm-thick upper layer of bottom sediment varies from 0.03 in Lake Juodis to 0.3 in Lake Zuvintas. The analysis of the ratio values shows that the deposition of the Chernobyl origin plutonium is prevailing in southern and south-western regions of Lithuania. Plutonium of nuclear weapon tests origin in sediments of lakes is observed on the whole territory of Lithuania, and it is especially distinct in central Lithuania. The americium activity due to 241Pu decay after the Chernobyl NPP accident and global depositions in bottom sediments of Lithuanian lakes has been evaluated to be from 0.9 to 5.7 Bq/kg. (author)

  15. Kinetic parameters of transformation of americium and plutonium physicochemical forms in podsol soils

    International Nuclear Information System (INIS)

    Kinetic parameters of transformation of americium and plutonium physicochemical forms have been estimated and the prognosis of fixing and remobilization of these nuclides in podsol soils have been made on that basis in the work. (authors)

  16. Calibration procedures for in vivo sodium iodide spectrometry of plutonium and americium in the human lung

    International Nuclear Information System (INIS)

    This paper describes the calibration techniques and associated error analysis for the in vivo measurement by NaI spectrometry of heavy elements in the lung, specifically plutonium and americium. A very brief description of the instrumentation system is included

  17. Relativistic density functional theory modeling of plutonium and americium higher oxide molecules

    Science.gov (United States)

    Zaitsevskii, Andréi; Mosyagin, Nikolai S.; Titov, Anatoly V.; Kiselev, Yuri M.

    2013-07-01

    The results of electronic structure modeling of plutonium and americium higher oxide molecules (actinide oxidation states VI through VIII) by two-component relativistic density functional theory are presented. Ground-state equilibrium molecular structures, main features of charge distributions, and energetics of AnO3, AnO4, An2On (An=Pu, Am), and PuAmOn, n = 6-8, are determined. In all cases, molecular geometries of americium and mixed plutonium-americium oxides are similar to those of the corresponding plutonium compounds, though chemical bonding in americium oxides is markedly weaker. Relatively high stability of the mixed heptoxide PuAmO7 is noticed; the Pu(VIII) and especially Am(VIII) oxides are expected to be unstable.

  18. 48 CFR 245.7310-1 - Demilitarization.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT GOVERNMENT PROPERTY Sale of Surplus Contractor Inventory 245.7310-1..., and charge the defaulting Purchaser will all excess costs incurred by the Contractor. The Contractor..., to the Purchaser. In the event the excess costs exceed the purchase price, the defaulting...

  19. 8 CFR 245a.10 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... IMMIGRATION AND NATIONALITY ACT Legal Immigration Family Equity (LIFE) Act Legalization Provisions § 245a.10... or she attempted to file or was discouraged from filing an application for legalization during the... LIFE Act Amendments of 2000. LIFE Legalization means the provisions of section 1104 of the LIFE Act...

  20. 8 CFR 245a.17 - Citizenship skills.

    Science.gov (United States)

    2010-01-01

    ... IMMIGRATION AND NATIONALITY ACT Legal Immigration Family Equity (LIFE) Act Legalization Provisions § 245a.17 Citizenship skills. (a) Requirements. Applicants for adjustment under LIFE Legalization must meet the... exception under paragraph (c) of this section applies to the applicant, LIFE Legalization applicants...

  1. 8 CFR 245.1 - Eligibility.

    Science.gov (United States)

    2010-01-01

    ... adjustment application. The motion to reopen must be made in accordance with the provisions of 8 CFR 103.5... applying for adjustment of status listed in § 245.1(c), is eligible to receive an immigrant visa, and has an immigrant visa immediately available at the time of filing the application for adjustment...

  2. 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)

  3. Dicty_cDB: VHD245 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available VH (Link to library) VHD245 (Link to dictyBase) - - - Contig-U16363-1 - (Link to Original site) - - VHD2...45Z 549 - - - - Show VHD245 Library VH (Link to library) Clone ID VHD245 (Link to dicty...iol.tsukuba.ac.jp/CSM/VH/VHD2-B/VHD245Q.Seq.d/ Representative seq. ID - (Link to ...Original site) Representative DNA sequence >VHD245 (VHD245Q) /CSM/VH/VHD2-B/VHD245Q.Seq.d/ XXXXXXXXXXGTTTAGC...ctyostelium discoideum dcd2A mRNA for ceramidase, complete cds. 1066 0.0 1 BU801815 |BU801815.1 SJF2DTD01 SJ

  4. 28 CFR 2.45 - Same; youth offenders.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Same; youth offenders. 2.45 Section 2.45..., YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.45 Same; youth... Commission or a member thereof, when of the opinion that a youth offender will be benefited by...

  5. 46 CFR 170.245 - Foam flotation material.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material. (a... by reference; see 46 CFR 170.015), including the requirements for fire resistance. (3) A...

  6. 48 CFR 245.608-2 - Standard screening.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Standard screening. 245.608-2 Section 245.608-2 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... Contractor Inventory 245.608-2 Standard screening. (b)(1) For the first 30 days, property screening will...

  7. 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.

  8. 10 CFR 32.57 - Calibration or reference sources containing americium-241 or radium-226: Requirements for license...

    Science.gov (United States)

    2010-01-01

    ... or radium-226: Requirements for license to manufacture or initially transfer. 32.57 Section 32.57... americium-241 or radium-226: Requirements for license to manufacture or initially transfer. An application... containing americium-241 or radium-226, for distribution to persons generally licensed under § 31.8 of...

  9. Separation and determination of americium in low-level alkaline waste of NPP origin

    Science.gov (United States)

    Todorov, B.; Djingova, R.; Nikiforova, A.

    2006-01-01

    The aim of this work is to develop a short and cost-saving procedure for the determination of 241Am in sludge sample of the alkaline low-level radioactive waste (LL LRAW) collected from Nuclear Power Plant “Kozloduy”. The determination of americium was a part of a complex analytical approach, where group actinide separation was achieved. An anion exchange was used for separation of americium from uranium, plutonium and iron. For the separation of americium extraction with diethylhexyl phosphoric acid (DEHPA) was studied. The final radioactive samples were prepared by micro co-precipitation with NdF3, counted by alpha and gamma spectrometry. The procedure takes 2 hours. The recovery yield of the procedure amounts to (95 ± 1.5)% and the detection limit is 53 mBq/kg 241Am (t=150 000 s). The analytical procedure was applied for actual liquid wastes and results were compared to standard procedure.

  10. Isotopic and elemental composition of plutonium/americium oxides influence pulmonary and extra-pulmonary distribution after inhalation in rats

    International Nuclear Information System (INIS)

    The biodistribution of plutonium and americium has been studied in a rat model after inhalation of two PuO2 powders in lungs and extra-pulmonary organs from 3 d to 3 mo. The main difference between the two powders was the content of americium (approximately 46% and 4.5% of total alpha activity). The PuO2 with a higher proportion of americium shows an accelerated transfer of activity from lungs to blood as compared to PuO2 with the lower americium content, illustrated by increased urinary excretion and higher bone and liver actinide retention. The total alpha activity measured reflects mostly the americium biological behavior. The activity contained in epithelial lining fluid, recovered in the acellular phase of broncho-alveolar lavages, mainly contains americium, whereas plutonium remains trapped in macrophages. Epithelial lining fluid could represent a transitional pulmonary compartment prior to translocation of actinides to the blood and subsequent deposition in extra-pulmonary retention organs. In addition, differential behaviors of plutonium and americium are also observed between the PuO2 powders with a higher dissolution rate for both plutonium and americium being obtained for the PuO2 with the highest americium content. Our results indicate that the biological behavior of plutonium and americium after translocation into blood differ two-fold: (1) for the two actinides for the same PuO2 aerosol, and (2) for the same actinide from the two different aerosols. These results highlight the importance of considering the specific behavior of each contaminant after accidental pulmonary intake when assessing extra-pulmonary deposits from the level of activity excreted in urine or for therapeutic strategy decisions. (authors)

  11. Isotopic and elemental composition of plutonium/americium oxides influence pulmonary and extra-pulmonary distribution after inhalation in rats.

    Science.gov (United States)

    Van der Meeren, A; Grémy, O

    2010-09-01

    The biodistribution of plutonium and americium has been studied in a rat model after inhalation of two PuO(2) powders in lungs and extra-pulmonary organs from 3 d to 3 mo. The main difference between the two powders was the content of americium (approximately 46% and 4.5% of total alpha activity). The PuO(2) with a higher proportion of americium shows an accelerated transfer of activity from lungs to blood as compared to PuO(2) with the lower americium content, illustrated by increased urinary excretion and higher bone and liver actinide retention. The total alpha activity measured reflects mostly the americium biological behavior. The activity contained in epithelial lining fluid, recovered in the acellular phase of broncho-alveolar lavages, mainly contains americium, whereas plutonium remains trapped in macrophages. Epithelial lining fluid could represent a transitional pulmonary compartment prior to translocation of actinides to the blood and subsequent deposition in extra-pulmonary retention organs. In addition, differential behaviors of plutonium and americium are also observed between the PuO(2) powders with a higher dissolution rate for both plutonium and americium being obtained for the PuO(2) with the highest americium content. Our results indicate that the biological behavior of plutonium and americium after translocation into blood differ two-fold: (1) for the two actinides for the same PuO(2) aerosol, and (2) for the same actinide from the two different aerosols. These results highlight the importance of considering the specific behavior of each contaminant after accidental pulmonary intake when assessing extra-pulmonary deposits from the level of activity excreted in urine or for therapeutic strategy decisions.

  12. 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)

    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 237Pu 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)

  13. Cesium-137 and americium-241 distribution by granulometric fractions of soil at Azgir test site grounds

    International Nuclear Information System (INIS)

    In measurements of radionuclide specific content in surface soil layer of contaminated territories it is important to determine in what agglomerations of soil particles there is the highest radionuclide concentration. For this purpose granulometric composition of soil at Azgir test site was studied and cesium-137 and americium-241 distribution by soil fractions was researched. (author)

  14. Apparatus for fabrication of americium- beryllium neutron sources prevents capsule contamination

    Science.gov (United States)

    Mohr, W. C.; Van Loom, J. A.

    1967-01-01

    Modified gloved enclosure is used to fill a capsule with a mixture of americium and beryllium radioactive powders to seal weld the opening, and to test it for leaks. It contains a horizontal partition, vortex mixer, mounting press, welder, test vessel, and radiation shielding to prevent surface contamination.

  15. 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...

  16. 24 CFR 245.100 - Right of tenants to organize.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Right of tenants to organize. 245... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER AUTHORITIES TENANT PARTICIPATION IN MULTIFAMILY HOUSING PROJECTS Tenant Organizations § 245.100 Right...

  17. 48 CFR 245.607-70 - Scrap warranty.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Scrap warranty. 245.607-70... Contractor Inventory 245.607-70 Scrap warranty. (a) If the contractor sells its inventory as scrap to anyone... 1639, Scrap Warranty. (b) The contracting officer may release the contractor from the terms of...

  18. 48 CFR 1852.245-75 - Title to equipment.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Title to equipment. 1852.245-75 Section 1852.245-75 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND SPACE... description, manufacturer and model number, date acquired, cost, and condition information, and shall...

  19. Effect of bone-status on retention and distribution of americium-241 in bones of small rodents

    International Nuclear Information System (INIS)

    Forced physical exercise before and after application of americium-241 resulted in only small changes in bone-structure and behaviour of the radionuclide in bone. Feeding of a low phosphorus or low calcium diet resulted in an increased excretion of americium from bone, whereby Zn-DTPA as chelating agent removed an additional fraction of the radionuclide from bone. Low calcium diet and simultaneous continuous infusion of pharmacological doses of vitamin D-hormones didn't increase the excretion of americium more than the low calcium diet alone. (orig.)

  20. 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

  1. SKIN DOSIMETRY IN CONDITIONS OF ITS CONSTANT SURFACE CONTAMINATION WITH SOLUTIONS OF PLUTONIUM-239 AND AMERICIUM-241

    Directory of Open Access Journals (Sweden)

    E. B. Ershov

    2012-01-01

    Full Text Available The article considers, on the basis of experimental data, the issue of assessing dose burdens to the skin basal layer in conditions of its permanent contamination with solutions of plutonium-239 and americium-241 and subsequent decontamination.

  2. Influence of biofilms on migration of uranium, americium and europium in the environment; Einfluss von Biofilmen auf das Migrationsverhalten von Uran, Americium und Europium in der Umwelt

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Nils; Zirnstein, Isabel; Arnold, Thuro

    2015-07-01

    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).

  3. Liquid-liquid extraction separation and sequential determination of plutonium and americium in environmental samples by alpha-spectrometry

    International Nuclear Information System (INIS)

    A procedure is described by which plutonium and americium can be determined in environmental samples. The sample is leached with nitric acid and hydrogen peroxide, and the two elements are co-precipitated with ferric hydroxide and calcium oxalate. The calcium oxalate is incinerated at 4500 and the ash is dissolved in nitric acid. Plutonium is extracted with tri-n-octylamine solution in xylene from 4M nitric acid and stripped with ammonium iodide/hydrochloric acid. Americium is extracted with thenoyltrifluoroacetone solution in xylene at pH 4 together with rare-earth elements and stripped with 1M nitric acid. Americium and the rare-earth elements thus separated are sorbed on Dowex 1 x 4 resin from 1M nitric acid in 93% methanol, the rare-earth elements are eluted with 0.1M hydrochloric acid/0.5M ammonium thiocyanate/80% methanol and the americium is finally eluted with 1.5M hydrochloric acid in 86% methanol. Plutonium and americium in each fraction are electro-deposited and determined by alpha-spectrometry. Overall average recoveries are 81% for plutonium and 59% for americium. (author)

  4. Influence of environmental factors on the gastrointestinal absorption of plutonium and americium

    International Nuclear Information System (INIS)

    The absorption of plutonium and americium from the gastrointestinal tract was studied, using adult hamsters and rabbits. Both actinides were administered as inorganic compounds, as organic complexes with naturally occurring chelating agents, and in a biologically incorporated form in liver tissues. The absorption of the tetravalent and hexavalent forms of plutonium were compared and the effect of protracted administration at very low concentrations was investigated. In addition, plutonium uptake from contaminated sediments and grass, collected near a nuclear-fuel reprocessing plant, was measured. The results of these studies suggest that chronic exposure of man to plutonium and americium in food and water will not lead to any substantial increase in their gastrointestinal absorption above the values currently recommended by the International Commission on Radiological Protection to define the occupational exposure of workers

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

    International Nuclear Information System (INIS)

    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 AmO2 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-AmCl3 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)

  6. Analysis of americium-beryllium neutron source composition using the FRAM code

    Energy Technology Data Exchange (ETDEWEB)

    Hypes, P. A. (Philip A.); Bracken, D. S. (David S.); Sampson, Thomas E.; Taylor, W. A. (Wayne A.)

    2002-01-01

    The FRAM code was originally developed to analyze high-resolution gamma spectra from plutonium items. Its capabilities have since been expanded to include analysis of uranium spectra. The flexibility of the software also enables a capable spectroscopist to use FRAM to analyze spectra in which neither plutonium nor uranium is present in significant amounts. This paper documents the use of FRAM to determine the {sup 239}Pu/{sup 241}Am, {sup 243}Am/{sup 241}Am, {sup 237}Np/{sup 241}Am, and {sup 239}Np/{sup 241}Am ratios in americium-beryllium neutron sources. The effective specific power of each neutron source was calculated from the ratios determined by FRAM in order to determine the americium mass of each of these neutron sources using calorimetric assay. We will also discuss the use of FRAM for the general case of isotopic analysis of nonplutonium, nonuranium items.

  7. Experimental Insight into the Radiation Resistance of Zirconia-Based Americium Ceramics

    International Nuclear Information System (INIS)

    Our works shows that the americium pyrochlore 241Am2Zr2O7 undergoes a phase transition to a defect-fluorite structure along with an unusual volume contraction when subjected to internal radiation from α-emitting actinides. Disorder relaxation proceeds through the simultaneous formation of cation anti sites and oxygen Frenkel pairs. X-ray absorption spectroscopy at the Am-LII and the Zr-K edges reveals that Am-O polyhedra show an increasing disorder with increasing exposure. In contrast, the Zr-O polyhedral units remain highly ordered, while rotating along edges and corners, thereby reducing the structural strain imposed by the growing disorder around americium. We believe it is this particular property of the compound that provides the remarkable resistance to radiation (≥9.4 * 1018) α-decay events g-1 or 0.80 dpa). (authors)

  8. Standard test method for quantitative determination of americium 241 in plutonium by Gamma-Ray spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1994-01-01

    1.1 This test method covers the quantitative determination of americium 241 by gamma-ray spectrometry in plutonium nitrate solution samples that do not contain significant amounts of radioactive fission products or other high specific activity gamma-ray emitters. 1.2 This test method can be used to determine the americium 241 in samples of plutonium metal, oxide and other solid forms, when the solid is appropriately sampled and dissolved. 1.3 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.

  9. Calcium and zinc DTPA administration for internal contamination with plutonium-238 and americium-241.

    Science.gov (United States)

    Kazzi, Ziad N; Heyl, Alexander; Ruprecht, Johann

    2012-08-01

    The accidental or intentional release of plutonium or americium can cause acute and long term adverse health effects if they enter the human body by ingestion, inhalation, or injection. These effects can be prevented by rapid removal of these radionuclides by chelators such as calcium or zinc diethylenetriaminepentaacetate (calcium or zinc DTPA). These compounds have been shown to be efficacious in enhancing the elimination of members of the actinide family particularly plutonium and americium when administered intravenously or by nebulizer. The efficacy and adverse effects profile depend on several factors that include the route of internalization of the actinide, the type, and route time of administration of the chelator, and whether the calcium or zinc salt of DTPA is used. Current and future research efforts should be directed at overcoming limitations associated with the use of these complex drugs by using innovative methods that can enhance their structural and therapeutic properties.

  10. 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.

  11. Bidentate organophosphorus extraction of americium and plutonium from Hanford Plutonium Reclamation Facility waste

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1974-09-01

    Applicability of bidentate organiphosphorus reagents to recovery of americium and plutonium from Hanford's Plutonium Reclamation Facility acid (approx. 2M HNO/sub 3/) waste stream (CAW solution) was studied. A solvent extraction process which employs a 30% DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate)-CCl/sub 4/ extractant was devised and successfully tested in mixer-settler runs with actual CAW solution. Substitution of DHDECMP for DBBP eliminates the need to perform careful neutralization of unbuffered CAW soluton and increases overall americium recovery from the present 60 to 80% level to greater than or equal to 90%. Disadvantages to such substitution include the high cost (approx. $50/liter) of DHDECMP and the need to purify it (by acid (6M HCl) hydrolysis and alkaline washing) from small amounts of an unidentified impurity which prevents stripping of americium with dilute HNO/sub 3/. Distribution data obtained in this study confirm Siddall's earlier contention that bidentate organophosphorus regents can be used to remove actinides from concentrated high-level Purex process acid waste; a conceptual flowsheet for such an extraction process is given.

  12. 8 CFR 245.23 - Adjustment of aliens in T nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... pursuant to 8 CFR 214.11(s); (2) The alien is described in sections 212(a)(3), 212(a)(10)(C), or 212(a)(10...-entered using an advance parole document issued under 8 CFR 245.2(a)(4)(ii)(B), the date that the alien...) Inapplicability of 8 CFR 245.1 and 245.2. Sections 245.1 and 245.2 of this chapter do not apply to aliens...

  13. Americium(3) coordination chemistry: An unexplored diversity of structure and bonding

    Energy Technology Data Exchange (ETDEWEB)

    Fedosseev, A.M.; Grigoriev, M.S.; Budantseva, N.A. [A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Moscow (Russian Federation); Guillaumont, D.; Den Auwer, Ch.; Moisy, Ph. [CEA Marcoule, Nuclear Energy Division, RadioChemistry and Processes Department, 30 (France); Le Naour, C.; Simoni, E. [CNRS, University Paris-11 Orsay, IPN, 91 - Orsay (France)

    2010-06-15

    The comparison of the physicochemical behavior of the actinides with that of the lanthanides can be justified by the analogy of their electronic structure, as each of the series is made up of elements corresponding to the filling of a given (n)f atomic shell. However relatively few points of comparison are available, given the lack of available structure for trans-plutonium(III) elements and the additional difficulty of stabilizing coordination complexes of uranium(III) to plutonium(III). This contribution is a focal point of trans-plutonium(III) chemistry and, more specifically, of some americium compounds that have been recently synthesized, all related with hard acid oxygen donor ligands that may be involved in the reprocessing chain of nuclear fuel. After a brief review of the solid hydrates and aquo species for the lanthanide and actinide families, we discuss two types of ligands that have in common three carboxylic groups, namely the amino-tri-acetic acid and the citric acid anions. The additional roles of the nitrogen atom for the first one and of the hydroxy function for the second one are discussed. Accordingly, five new complexes with either americium or lanthanides elements are described: [Co(NH{sub 3}){sub 6}][M(NTA){sub 2}(H{sub 2}O)].8H{sub 2}O with M Nd, Yb and Am, and [Co(NH{sub 3}){sub 6}]{sub 2}K[M{sub 3}(Cit){sub 4}(H{sub 2}O){sub 3}].18H{sub 2}O with Nd and Am cations. In all cases the americium complexes are isostructural with their lanthanide equivalents. (authors)

  14. Americium(3) coordination chemistry: An unexplored diversity of structure and bonding

    International Nuclear Information System (INIS)

    The comparison of the physicochemical behavior of the actinides with that of the lanthanides can be justified by the analogy of their electronic structure, as each of the series is made up of elements corresponding to the filling of a given (n)f atomic shell. However relatively few points of comparison are available, given the lack of available structure for trans-plutonium(III) elements and the additional difficulty of stabilizing coordination complexes of uranium(III) to plutonium(III). This contribution is a focal point of trans-plutonium(III) chemistry and, more specifically, of some americium compounds that have been recently synthesized, all related with hard acid oxygen donor ligands that may be involved in the reprocessing chain of nuclear fuel. After a brief review of the solid hydrates and aquo species for the lanthanide and actinide families, we discuss two types of ligands that have in common three carboxylic groups, namely the amino-tri-acetic acid and the citric acid anions. The additional roles of the nitrogen atom for the first one and of the hydroxy function for the second one are discussed. Accordingly, five new complexes with either americium or lanthanides elements are described: [Co(NH3)6][M(NTA)2(H2O)].8H2O with M Nd, Yb and Am, and [Co(NH3)6]2K[M3(Cit)4(H2O)3].18H2O with Nd and Am cations. In all cases the americium complexes are isostructural with their lanthanide equivalents. (authors)

  15. MARIOS: Irradiation of UO{sub 2} containing 15% americium at well defined temperature

    Energy Technology Data Exchange (ETDEWEB)

    D' Agata, E., E-mail: elio.dagata@ec.europa.eu [European Commission, Joint Research Centre, Institute for Energy - P.O. Box 2, 1755 ZG Petten (Netherlands); Hania, P.R. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Bejaoui, S. [Commissariat a l' Energie Atomique, DEC CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France); Sciolla, C.; Wyatt, T.; Hannink, M.H.C. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Herlet, N.; Jankowiak, A. [Commissariat a l' Energie Atomique DTEC CEA Marcoule, 30207 Bagnols sur Ceze Cedex (France); Klaassen, F.C. [Nuclear Research and Consultancy Group, P.O. Box 25, 1755 ZG Petten (Netherlands); Bonnerot, J.-M. [Commissariat a l' Energie Atomique, DEC CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer MARIOS is designed to check the behaviour of Minor Actinide Blanket Module concept. Black-Right-Pointing-Pointer Main requirement of the experiment is an accurate control of the temperature. Black-Right-Pointing-Pointer The swelling and the helium release will be the main output of the experiment. Black-Right-Pointing-Pointer A complementary experiment (DIAMINO), will be performed in the next future. - Abstract: Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. The MARIOS irradiation experiment is the latest of a series of experiments on americium transmutation (e.g. EFTTRA-T4, EFTTRA-T4bis, HELIOS). MARIOS experiment is carried out in the framework of the 4-year project FAIRFUELS of the EURATOM 7th Framework Programme (FP7). During the past years of experimental work in the field of transmutation and tests of innovative nuclear fuel containing americium, the release or trapping of helium as well as swelling has shown to be the key issue for the design of such kinds of target. Therefore, the main objective of the MARIOS experiment is to study the in-pile behaviour of UO{sub 2} containing minor actinides (MAs) in order to gain knowledge on the role of the microstructure and of the temperature on the gas release and on fuel swelling. The MARIOS experiment will be conducted in the HFR (high flux reactor) in Petten (The Netherlands) and will start in the beginning of 2011. It has been planned that the experiment will last 11 cycles, corresponding to 11 months. This paper covers the description of the objective of the experiment, as well as a general description of the design of the experiment.

  16. 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

  17. 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

  18. Americium characterization by X-ray fluorescence and absorption spectroscopy in plutonium uranium mixed oxide

    International Nuclear Information System (INIS)

    Plutonium uranium mixed oxide (MOX) fuels are currently used in nuclear reactors. The actinides in these fuels need to be analyzed after irradiation for assessing their behaviour with regard to their environment and the coolant. In this work the study of the atomic structure and next-neighbour environment of Am in the (Pu,U)O2 lattice in an irradiated (60 MW d kg−1) MOX sample was performed employing micro-X-ray fluorescence (µ-XRF) and micro-X-ray absorption fine structure (µ-XAFS) spectroscopy. The chemical bonds, valences and stoichiometry of Am (∼0.66 wt%) are determined from the experimental data gained for the irradiated fuel material examined in its peripheral zone (rim) of the fuel. In the irradiated sample Am builds up as Am3+ species within an [AmO8]13− coordination environment (e.g. >90%) and no (III XAFS spectra recorded for the irradiated MOX sub-sample in the rim zone for a 300 μm×300 μm beam size area investigated over six scans of 4 h. The records remain constant during multi-scan. The analysis of the XAFS signal shows that Am is found as trivalent in the UO2 matrix. This analytical work shall open the door of very challenging analysis (speciation of fission product and actinides) in irradiated nuclear fuels. - Highlights: • Americium was characterized by microX-ray absorption spectroscopy in irradiated MOX fuel. • The americium redox state as determined from XAS data of irradiated fuel material was Am(III). • In the sample, the Am3+ face an AmO813− coordination environment in the (Pu,U)O2 matrix. • The americium dioxide is reduced by the uranium dioxide matrix

  19. 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.

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

    International Nuclear Information System (INIS)

    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).

  1. 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

    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...... plutonium from the latter to Spitsbergen waters. Fallout plutonium in Arctic waters has a residence time of the order of several years, while for Pu from Sellafield we estimate mean residence times of 11–15 months in Scottish waters and, tentatively, 1·5-3 y during transport from the North Channel (north...

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

    International Nuclear Information System (INIS)

    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

  3. Purification of used scintillation liquids containing the alpha emitters americium and plutonium

    International Nuclear Information System (INIS)

    In Sweden, alpha radioactive waste liquids with an activity over some kBq per waste container cannot be sent for final storage. Therefore, in this work, a method for a purification of alpha active scintillation cocktails was developed. Until today (March, 2013) more than 20 L of scintillation liquids have successfully been purified from americium and plutonium. The products of the process are a solid fraction that can be sent to final storage and a practically non-radioactive liquid fraction that can be sent to municipal incineration. (author)

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

    International Nuclear Information System (INIS)

    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

  5. 33 CFR 245.20 - Determination of hazard to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Determination of hazard to..., DEPARTMENT OF DEFENSE REMOVAL OF WRECKS AND OTHER OBSTRUCTIONS § 245.20 Determination of hazard to navigation... Coast Guard district to jointly determine whether the obstruction poses a hazard to navigation....

  6. 48 CFR 245.607-2 - Recovering precious metals.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Recovering precious metals... Disposal of Contractor Inventory 245.607-2 Recovering precious metals. (b) Precious metals are silver, gold... office with disposition instructions for certain categories of precious metals-bearing...

  7. 48 CFR 3053.245-70 - Report of Government property.

    Science.gov (United States)

    2010-10-01

    ... 3053.245-70 Report of Government property. The following form is prescribed for use by contractors to report Government property, as specified in (HSAR) 48 CFR 3045.505-14: DHS Form 0700-05, Contractor's... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Report of...

  8. 48 CFR 245.7310-7 - Scrap warranty.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Scrap warranty. 245.7310-7... Scrap warranty. The following condition shall be used whenever property, other than production scrap, is offered for sale as scrap: Scrap Warranty The Purchaser represents and warrants that the property will...

  9. 8 CFR 245a.13 - During pendency of application.

    Science.gov (United States)

    2010-01-01

    ... 245A OF THE IMMIGRATION AND NATIONALITY ACT Legal Immigration Family Equity (LIFE) Act Legalization... States submits a prima facie application for adjustment of status under LIFE Legalization during the...) of this section. Any domestic LIFE Legalization applicant who departs the United States while his...

  10. 8 CFR 245a.2 - Application for temporary residence.

    Science.gov (United States)

    2010-01-01

    ...) Legalization Provisions § 245a.2 Application for temporary residence. (a) Application period for temporary... apply for legalization, may file for adjustment to temporary residence status: (1) An alien (other than... legalization and who was present in the United States in an unlawful status prior to January 1, 1982,...

  11. 48 CFR 245.608-5 - Special items screening.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Special items screening... Disposal of Contractor Inventory 245.608-5 Special items screening. (a) Special test equipment with... screening of the composite STE unit. (A) If the contracting department/agency and the requiring...

  12. 40 CFR 180.245 - Streptomycin; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Streptomycin; tolerances for residues...) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.245 Streptomycin; tolerances for residues. (a) General. (1) Tolerances are established...

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

    International Nuclear Information System (INIS)

    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 (CO3)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-CO3 complexes are not needed). No evidence of Am(CO3)45- 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 PuO2(CO3) is measured in bicarbonate media at high ionic strength, to obtain the solubility product and formation constants of the PuO2(CO3)i2-2i complexes

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

    International Nuclear Information System (INIS)

    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.)

  15. EURADOS intercomparison on measurements and Monte Carlo modelling for the assessment of Americium in a USTUR leg phantom

    International Nuclear Information System (INIS)

    A collaboration of the EURADOS working group on 'Internal Dosimetry' and the United States Transuranium and Uranium Registries (USTUR) has taken place to carry out an intercomparison on measurements and Monte Carlo modelling determining americium deposited in the bone of a USTUR leg phantom. Preliminary results and conclusions of this intercomparison exercise are presented here. (authors)

  16. Anomalous aryl strengthening of americium and europium complexes during extraction by alkylenediphosphine dioxides from perchloric acid media

    International Nuclear Information System (INIS)

    Extraction of americium and europium from perchlorate environments by solutions of three types of methylenediphosphine dioxides, namely (C6H5)P(O)(CH2)sub(n)(O)P(C6H5)2, (C6H5)2P(O)CH2(O)P(C8H17)2 and (C8H17)2P(O)(CH2)sub(n)(O)P(C8H17)2 has been studied (n is 1 or 2 ) The diluents used have been dichlorethane and chloroform. In perchlorate environments the distribuiton coefficients of americium and europium have proved to be by about 3 orders of magnitude higher than in nitric acid environments, i.e. in perchlorate media the complexes are far more stable. Separation coefficients of americium and REE in perchloric acid soutions are much higher than in nitrate environments. The average value of Am/Eu separation coeffecient at 1-5 M acidity was about 6 (with dichlorethane as diluent) or about 7 (with chloroform as diluent). The complexes essentially exist as trisolvated. Americium complexes display anomalous stability increase upon being diluted: by about 2 orders of magnitude with dichlorethane and by up to 3 orders of magnitude with chloroform used as diluent

  17. Investigations of neutron characteristics for salt blanket models; integral fission cross section measurements of neptunium, plutonium, americium and curium isotopes

    International Nuclear Information System (INIS)

    Neutron characteristics of salt blanket micromodels containing eutectic mixtures of sodium, zirconium, and uranium fluorides were measured on FKBN-2M, BIGR and MAKET facilities. The effective fission cross sections of neptunium, plutonium, americium, and curium isotopes were measured on the neutron spectra formed by micromodels. (author)

  18. 8 CFR 245a.11 - Eligibility to adjust to LPR status.

    Science.gov (United States)

    2010-01-01

    ... Legalization Provisions § 245a.11 Eligibility to adjust to LPR status. An eligible alien, as defined in § 245a.10, may adjust status to LPR status under LIFE Legalization if: (a) He or she properly files,...

  19. Purification of scintillation cocktails containing the alpha emitters americium and plutonium

    International Nuclear Information System (INIS)

    One efficient way of measuring alpha emitters is by the usage of liquid scintillation counting (LSC). A liquid sample is placed in a vial containing a scintillation cocktail. The alpha particles excite electrons in the surrounding liquid, and when they are de-excited photons are emitted. The photons are detected and the activity can be quantified. LSC has a high efficiency for alpha radiation and is therefore a fast and easy way for measuring alpha emitting samples. One drawback is that it does not differentiate very well between alpha energies; measurements of for example curium and plutonium simultaneously are impossible and demand other techniques. Another drawback is the production of a liquid alpha active waste. In Sweden alpha radioactive waste liquids with an activity over some kBq per waste container cannot be sent for final storage. If, however, the activity of the liquids could be reduced by precipitation of the actinides, it would be possible to send away the liquid samples to municipal incineration. In this work a method for a purification of alpha active scintillation cocktails was developed. The method was first tried on a lab scale, and then scaled up. Until today (March, 2013) more than 20 liters of scintillation liquids have successfully been purified from americium and plutonium at Chalmers University of Technology in Sweden. The four scintillation cocktails used were Emulsifier Safe®, Hionic-Fluor®, Ultima Gold AB® and Ultima Gold XR®. The scintillation cocktails could all be purified from americium with higher yield than 95%. The yield was kept when the liquids were mixed. Also plutonium could be precipitated with a yield over 95% in all cocktails except in Hionic-Fluor® (>55%). However, that liquid in particular could be purified (>95%) by mixing it with the three other cocktails. Up-scaling was performed to a batch size of 6-8 L of scintillation cocktail. In neither the americium nor the plutonium system, adverse effects of increasing the

  20. 14 CFR 125.245 - Organization required to perform maintenance, preventive maintenance, and alteration.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Organization required to perform maintenance, preventive maintenance, and alteration. 125.245 Section 125.245 Aeronautics and Space FEDERAL... GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Maintenance § 125.245 Organization required to perform...

  1. 48 CFR 245.7101-4 - DD Form 1640, Request for Plant Clearance.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1640, Request for Plant Clearance. 245.7101-4 Section 245.7101-4 Federal Acquisition Regulations System DEFENSE... Forms 245.7101-4 DD Form 1640, Request for Plant Clearance. Use to request plant clearance assistance...

  2. 48 CFR 245.7101-2 - DD Form 1149, Requisition and Invoice Shipping Document.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1149, Requisition and Invoice Shipping Document. 245.7101-2 Section 245.7101-2 Federal Acquisition Regulations System... Plant Clearance Forms 245.7101-2 DD Form 1149, Requisition and Invoice Shipping Document. Use...

  3. 27 CFR 24.245 - Use of carbon dioxide in still wine.

    Science.gov (United States)

    2010-04-01

    ... still wine. 24.245 Section 24.245 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Storage, Treatment and Finishing of Wine § 24.245 Use of carbon dioxide in still wine. The addition of carbon dioxide to (and retention in) still...

  4. 48 CFR 252.245-7000 - Government-furnished mapping, charting, and geodesy property.

    Science.gov (United States)

    2010-10-01

    ... mapping, charting, and geodesy property. 252.245-7000 Section 252.245-7000 Federal Acquisition Regulations..., charting, and geodesy property. As prescribed in 245.107-70, use the following clause: Government-Furnished Mapping, Charting, and Geodesy Property (DEC 1991) (a) Definition—Mapping, charting, and geodesy...

  5. Miniature microwave plasma antenna at 2.45 GHz

    Science.gov (United States)

    Vachkov, Vasil; Kiss'ovski, Zhivko

    2015-12-01

    New unique miniature plasma antenna driven by a one microwave signal at frequency of 2.45 GHz is constructed and tested. The length of the antenna (l = 16 mm) is much shorter than the free space wavelength of the signal. The parameters of the plasma column (n = 2.6±0.4×1018 m-3, Te = 3.1±0.2 eV) are obtained from argon emission spectrum by applying the line ratio method. The simulations of this monopole antenna reveal that in the standing wave regime the plasma antenna is effective transmitter at a frequency of 2.45 GHz. The results we obtained show that the shape of the radiation pattern of the plasma antenna depends on the plasma density, the exciter and the distance above the grounded plane.

  6. HCC-240fa氟化合成HFC-245fa技术进展%Progress on Synthesizing HFC -245fa by Fluorinating HCC -240fa

    Institute of Scientific and Technical Information of China (English)

    张国利; 杨会娥; 张文庆; 赵新堂

    2009-01-01

    HFC-245fa作为ODS发泡剂HCHC-141b和CFC-11的良好替代品,具有很好工业前景.全面综述了以HCC-240fa为原料合成HFC-245fa的各种工艺,并对HFC-245fa粗品的提纯进行详细的讨论.

  7. Network Analysis of Plasmidomes: The Azospirillum brasilense Sp245 Case

    Directory of Open Access Journals (Sweden)

    Valerio Orlandini

    2014-01-01

    Full Text Available Azospirillum brasilense is a nitrogen-fixing bacterium living in association with plant roots. The genome of the strain Sp245, isolated in Brazil from wheat roots, consists of one chromosome and six plasmids. In this work, the A. brasilense Sp245 plasmids were analyzed in order to shed some light on the evolutionary pathways they followed over time. To this purpose, a similarity network approach was applied in order to identify the evolutionary relationships among all the A. brasilense plasmids encoded proteins; in this context a computational pipeline specifically devoted to the analysis and the visualization of the network-like evolutionary relationships among different plasmids molecules was developed. This information was supplemented with a detailed (in silico functional characterization of both the connected (i.e., sharing homology with other sequences in the dataset and the unconnected (i.e., not sharing homology components of the network. Furthermore, the most likely source organism for each of the genes encoded by A. brasilense plasmids was checked, allowing the identification of possible trends of gene loss/gain in this microorganism. Data obtained provided a detailed description of the evolutionary landscape of the plasmids of A. brasilense Sp245, suggesting some of the molecular mechanisms responsible for the present-day structure of these molecules.

  8. Network Analysis of Plasmidomes: The Azospirillum brasilense Sp245 Case.

    Science.gov (United States)

    Orlandini, Valerio; Emiliani, Giovanni; Fondi, Marco; Maida, Isabel; Perrin, Elena; Fani, Renato

    2014-01-01

    Azospirillum brasilense is a nitrogen-fixing bacterium living in association with plant roots. The genome of the strain Sp245, isolated in Brazil from wheat roots, consists of one chromosome and six plasmids. In this work, the A. brasilense Sp245 plasmids were analyzed in order to shed some light on the evolutionary pathways they followed over time. To this purpose, a similarity network approach was applied in order to identify the evolutionary relationships among all the A. brasilense plasmids encoded proteins; in this context a computational pipeline specifically devoted to the analysis and the visualization of the network-like evolutionary relationships among different plasmids molecules was developed. This information was supplemented with a detailed (in silico) functional characterization of both the connected (i.e., sharing homology with other sequences in the dataset) and the unconnected (i.e., not sharing homology) components of the network. Furthermore, the most likely source organism for each of the genes encoded by A. brasilense plasmids was checked, allowing the identification of possible trends of gene loss/gain in this microorganism. Data obtained provided a detailed description of the evolutionary landscape of the plasmids of A. brasilense Sp245, suggesting some of the molecular mechanisms responsible for the present-day structure of these molecules.

  9. A thermodynamic study of actinide oxide targets/fuels for americium transmutation

    International Nuclear Information System (INIS)

    A thermodynamic study was performed on the systems Am-O, AmOx-MgO, AmOx-MgAl2O4, Pu-Mg-O and U-Mg-O. Both experimental work (X-ray analyses, oxygen potential measurements etc.) and calculations on the phase diagrams involved were made. The reaction between americium oxide and spinel is expected to form the compound AmAlO3. Isothermal sections have been calculated for AmOx-(MgO, Al2O3), Pu-Mg-O and U-Mg-O at 2000 K using the software package ''Thermo-Calc''. Thermodynamic equilibrium data were used to predict the behaviour of actinide oxides in a reactor. The implication of the results for the technological application is discussed, with emphasis on the effects of the high oxygen potential of AmO2 as compared to the conventional fuel, i.e. UO2. (author)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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 NaClO4, 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 β110 = 2.56 ± 0.08 and log β120 = 3.93 ± 0.19. (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. Transportability Class of Americium in K Basin Sludge under Ambient and Hydrothermal Processing Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Delegard, Calvin H.; Schmitt, Bruce E.; Schmidt, Andrew J.

    2006-08-01

    This report establishes the technical bases for using a ''slow uptake'' instead of a ''moderate uptake'' transportability class for americium-241 (241Am) for the K Basin Sludge Treatment Project (STP) dose consequence analysis. Slow uptake classes are used for most uranium and plutonium oxides. A moderate uptake class has been used in prior STP analyses for 241Am based on the properties of separated 241Am and its associated oxide. However, when 241Am exists as an ingrown progeny (and as a small mass fraction) within plutonium mixtures, it is appropriate to assign transportability factors of the predominant plutonium mixtures (typically slow) to the Am241. It is argued that the transportability factor for 241Am in sludge likewise should be slow because it exists as a small mass fraction as the ingrown progeny within the uranium oxide in sludge. In this report, the transportability class assignment for 241Am is underpinned with radiochemical characterization data on K Basin sludge and with studies conducted with other irradiated fuel exposed to elevated temperatures and conditions similar to the STP. Key findings and conclusions from evaluation of the characterization data and published literature are summarized here. Plutonium and 241Am make up very small fractions of the uranium within the K Basin sludge matrix. Plutonium is present at about 1 atom per 500 atoms of uranium and 241Am at about 1 atom per 19000 of uranium. Plutonium and americium are found to remain with uranium in the solid phase in all of the {approx}60 samples taken and analyzed from various sources of K Basin sludge. The uranium-specific concentrations of plutonium and americium also remain approximately constant over a uranium concentration range (in the dry sludge solids) from 0.2 to 94 wt%, a factor of {approx}460. This invariability demonstrates that 241Am does not partition from the uranium or plutonium fraction for any characterized sludge matrix. Most

  14. The behaviour under irradiation of molybdenum matrix for inert matrix fuel containing americium oxide (CerMet concept)

    Science.gov (United States)

    D'Agata, E.; Knol, S.; Fedorov, A. V.; Fernandez, A.; Somers, J.; Klaassen, F.

    2015-10-01

    Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors or Accelerator Driven System (ADS, subcritical reactors dedicated to transmutation) of long-lived nuclides like 241Am is therefore an option for the reduction of radiotoxicity of waste packages to be stored in a repository. In order to safely burn americium in a fast reactor or ADS, it must be incorporated in a matrix that could be metallic (CerMet target) or ceramic (CerCer target). One of the most promising matrix to incorporate Am is molybdenum. In order to address the issues (swelling, stability under irradiation, gas retention and release) of using Mo as matrix to transmute Am, two irradiation experiments have been conducted recently at the High Flux Reactor (HFR) in Petten (The Netherland) namely HELIOS and BODEX. The BODEX experiment is a separate effect test, where the molybdenum behaviour is studied without the presence of fission products using 10B to "produce" helium, the HELIOS experiment included a more representative fuel target with the presence of Am and fission product. This paper covers the results of Post Irradiation Examination (PIE) of the two irradiation experiments mentioned above where molybdenum behaviour has been deeply investigated as possible matrix to transmute americium (CerMet fuel target). The behaviour of molybdenum looks satisfying at operating temperature but at high temperature (above 1000 °C) more investigation should be performed.

  15. Consideration of the effect of lymph-node deposition upon the measurement of plutonium and americium in the lungs

    International Nuclear Information System (INIS)

    Measurement of an inhaled radionuclide by external photon counting includes quantities which may be contained in lymph nodes, as well as quantities in the lungs. An overestimate of the lung burden can result, if a portion of the radionuclide were present in the lymph nodes. This problem is analyzed with respect to the measurement of inhaled plutonium containing plutonium-241 and americium-241, when americium-241 has been used as a tracer for the plutonium. Equations are derived which yield the amounts of americium and of plutonium in the lungs and in the lymph nodes as a function of time after exposure and for various translocation and retention parameters. Count histories (count profiles) of actual exposure cases are compared with calculated count profiles in order to gain insight into possible values of the translocation and retention parameters. Comparison is also made with calculated count profiles using values of translocation and retention parameters recommended by the International Commission on Radiological Protection (ICRP) for use with the Task Group Lung Model. The magnitude of the possible overestimate (error factor) was calculated for combinations o

  16. HELIOS: the new design of the irradiation of U-free fuels for americium transmutation

    Energy Technology Data Exchange (ETDEWEB)

    D' Agata, E. [European Commission, Joint Research Centre, Institute for Energy, P.O. Box 2, 1755 ZG Petten (Netherlands); Klaassen, F.; Sciolla, C. [Nuclear Research and Consultancy Group, Dept. Life Cycle and Innovations, P.O. Box 25 1755 ZG Petten (Netherlands); Fernandez-Carretero, A. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Bonnerot, J.M. [Commissariat a l' Energie Atomique, DEC/SESC/LC2I CEA-Cadarache, 13108 St. Paul lez Durance Cedex (France)

    2009-06-15

    Americium is one of the radioactive elements that mostly contribute to the radiotoxicity of the nuclear spent fuel. Transmutation of long-lived nuclides like Americium is an option for the reduction of the mass, the radiotoxicity and the decay heat of nuclear waste. The HELIOS irradiation experiment is the last evolution in a series of experiments on americium transmutation. The previous experiments, EFTTRA-T4 and T4bis, have shown that the release or trapping of helium is the key issue for the design of such kind of target. In fact, the production of helium, which is characteristic of {sup 241}Am transmutation, is quite significant. The experiment is carried out in the framework of the 4-year project EUROTRANS of the EURATOM 6. Framework Programme (FP6). Therefore, the main objective of the HELIOS experiment is to study the in-pile behaviour of U-free fuels such as CerCer (Pu, Am, Zr)O{sub 2} and Am{sub 2}Zr{sub 2}O{sub 7}+MgO or CerMet (Pu, Am)O{sub 2}+Mo in order to gain knowledge on the role of the fuel microstructure and of the temperature on the gas release and on the fuel swelling. The experiment was planned to be conducted in the HFR (High Flux Reactor) in Petten (The Netherlands) starting the first quarter of 2007. Because of the innovative aspects of the fuel, the fabrication has had some delays as well as the final safety analyses of the original design showed some unexpected deviation. Besides, the HFR reactor has been unavailable since August 2008. Due to the reasons described above, the experiment has been postponed. HELIOS should start in the first quarter of 2009 and will last 300 full power days. The paper will cover the description of the new design of the irradiation experiment HELIOS. The experiment has been split in two parts (HELIOS1 and HELIOS2) which will be irradiated together. Moreover, due to the high temperature achieved in cladding and to the high amount of helium produced during transmutation the experiment previously designed for a

  17. Anomalous aryl strengthening of complexes at americium and europium extraction with alkylenediphospine dioxide from perchloric media

    International Nuclear Information System (INIS)

    Studied was the extraction of americium(3) and europium(3) from perchlorate solutions(0.001 M) with dioxides of alkylenediphosphines of three types: aryl Ph2P(O)CH2(O)PPh2(briefly 4P), and Ph2P(O)(CH2)2(O)PPh2, mixed Ph2P(O)CH2(O)P(C8H17)2 (or 2Ph2Oct) and alkyl (C8H17)2P(O)CH2(O)P(C8H17)2 (or 4 Oct). Trisolvates of MeS3x(ClO4)3 are predominantly formed but americium disolvates are also present upon dilution with dichloroethane. For 4Ph,2Ph2Oct and 4 Oct the concentration is, respectively, 1015, 2x1014, and 1013; for disolvates by 4 orders of magnitude lower which is, nevertheless, by 2 orders of magnitude higher than for nitric acid solutions. The separation coefficient of β Am/Eu for 4Ph attains 6-8. As in the case of nitrate solutions, an anomalous aryl strengthening of the complexes is observed: an increase in the distribution coefficients and extraction constants in the series of 4 Oct - 2Ph 2 Oct - 4Ph, in spite of the introduction of electronegative aryl substituents into the dioxide molecule, which reduce electron density on oxygen atoms and basicity of dioxides. In contrast to nitric acid solutions, observed is a nonlinear effect of a change in basicity on extraction properties upon dilution with dichloroethane (dioxide of 2Ph2 Oct does not occupy an intermediate position but is close to 4Ph). Upon dilution with chloroform the dependence is linear and anomalous effect rises due to a different nature of interactions of dioxides with chloroform. When the bridge increases up to ethylene, an anomalous strengthening of the complexes disappears. However, the distribution coefficients upon extraction with alkyl dioxide are considerably lower, which can be explained by a stronger extraction of perchloric acid

  18. [Biofilm Formation by the Nonflagellated flhB1 Mutant of Azospirillum brasilense Sp245].

    Science.gov (United States)

    Shelud'ko, A V; Filip'echeva, Yu A; Shumiliva, E M; Khlebtsov, B N; Burov, A M; Petrova, L P; Katsy, E I

    2015-01-01

    Azospirillum brasilense Sp245 with mixed flagellation are able to form biofilms on various surfaces. A nonflagellated mutant of this strain with inactivated chromosomal copy of the flhB gene (flhB1) was shown to exhibit specific traits at the later stages of biofilm formation on a hydrophilic (glass) surface. Mature biofilms of the flhB1::Omegon-Km mutant Sp245.1063 were considerably thinner than those of the parent strain Sp245. The biofilms of the mutant were more susceptible to the forces of hydrodynamic shear. A. brasilense Sp245 cells in biofilms were not found to possess lateral flagella. Cells with polar flagella were, however, revealed by atomic force microscopy of mature native biofilms of strain Sp245. Preservation of a polar flagellum (probably nonmotile) on the cells of A. brasilense Sp245 may enhance the biofilm stability.

  19. Comparing R1233zd And R245fa For Low Temperature ORC Applications

    OpenAIRE

    Datla, Bala V.; Brasz, Joost J.

    2014-01-01

    The majority of recently introduced ORC systems use R245fa as working fluid. The lower saturation pressures of R245fa versus R134a allowed the use of existing HVAC electric motors, compressors, evaporators and condensers after minor modifications as ORC electric generators, turbines/expanders, boilers and condensers. At elevated saturation temperatures R245fa turbine/expander equipment matches the power density of R134a HVAC compressors equipment. Refrigerants with still lower saturation pres...

  20. Americium-based oxides: Dense pellet fabrication from co-converted oxalates

    Energy Technology Data Exchange (ETDEWEB)

    Horlait, Denis; Lebreton, Florent [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France); Gauthé, Aurélie [CEA, DEN, DRCP/SERA/LCAR, 30207 Bagnols-sur-Cèze (France); Caisso, Marie [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France); Arab-Chapelet, Bénédicte; Picart, Sébastien [CEA, DEN, DRCP/SERA/LCAR, 30207 Bagnols-sur-Cèze (France); Delahaye, Thibaud, E-mail: thibaud.delahaye@cea.fr [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze (France)

    2014-01-15

    Mixed oxides are used as nuclear fuels and are notably envisaged for future fuel cycles including plutonium and minor actinide recycling. In this context, processes are being developed for the fabrication of uranium–americium mixed-oxide compounds for transmutation. The purpose of these processes is not only the compliance with fuel specifications in terms of density and homogeneity, but also the simplification of the process for its industrialization as well as lowering dust generation. In this paper, the use of a U{sub 0.85}Am{sub 0.15}O{sub 2±δ} powder synthesized by oxalate co-conversion as a precursor for dense fuel fabrications is assessed. This study notably focuses on sintering, which yielded pellets up to 96% of the theoretical density, taking advantage of the high reactivity and homogeneity of the powder. As-obtained pellets were further characterized to be compared to those obtained via processes based on the UMACS (Uranium Minor Actinide Conventional Sintering) process. This comparison highlights several advantages of co-converted powder as a precursor for simplified processes that generate little dust.

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

    International Nuclear Information System (INIS)

    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)

  2. Mutual separation of americium(III) and europium(III) using glycolamic acid and thioglycolamic acid

    Energy Technology Data Exchange (ETDEWEB)

    Suneesh, A.S.; Venkatesan, K.A.; Syamala, K.V.; Antony, M.P.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2012-07-01

    The extractants, bis(2-ethylhexyl)diglycolamicacid (HDEHDGA) and bis(2-ethylhexy)thiodiglycolamic acid (HDEHSDGA) were synthesized and characterized by {sup 1}H and {sup 13}C NMR, mass and IR spectroscopy. The extraction behaviour of {sup (152+154})Eu(III) and {sup 241}Am(III) from nitric acid medium by a solution of HDEHDGA (or HDEHSDGA) in n-dodecane (n-DD) was studied for the mutual separation of actinides and lanthanides. The effect of various parameters such as the pH, concentrations of HDEHDGA, HDEHSDGA, sodium nitrate, N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and diethylenetriaminepentaacetic acid (DTPA) on the separation factor (SF) of americium(III) over europium(III) and vice versa was studied, and the conditions needed for the preferential separation were optimised. The results show that HDEHDGA exhibits higher extraction for {sup (152+154)}Eu(III) and HDEHSDGA shows the superior selectivity for {sup 241}Am(III). (orig.)

  3. Determination of plutonium americium and curium in soil samples by solvent extraction with trioctylphosphine oxide

    International Nuclear Information System (INIS)

    A method of Pu, Am and Cm determination in soil samples, which was developed for analyzing samples from territories subjected to radioactive contamination as a result of the Chernobyl accident is described. After preliminary treatment the samples were leached by solution of 7 mol/l HNO23+0.3 mol/l KBrO3 during heating. Pu was isolated by extraction with 0.05 mol TOPO from 7 mol/l HNO3. 144Ce and partially remaining in water phase isotopes of Zr, U and Th were isolated in an extraction-chromatographic column with TOPO and PbO2. Then Am and Cm were extracted by 0.2 mol/l TOPO from solution 1 mol/l HLact+0.07 mol/l DTPA+1 mol/l Al(NO3)3. Alpha-activity of both extracted products was determined in liquid scintillation counter. Chemical yield of plutonium counted to 85±10%, that of americium and curium -75±10%. 17 refs

  4. 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.

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

    International Nuclear Information System (INIS)

    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 241Am in the freshwater environment aim to establish a relation between the behavior of 241Am 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 241Am with humic acids and competition with trivalent cations such as A1 and Fe, were proven to be significant on the speciation of 241Am. Based on the registration of the 241Am uptake by a large number of freshwater organisms, the crayfish Astacus leptodactylus Eschscholtz was chosen to study the whole-body uptake of 241Am, 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 241Am in the hemolymph and the hepatopancreas, and its subcellular distribution in the digestive gland. Finally, by comparing the physiology of 241Am with some other metals (240Pu, 64Cu, 198Au) with analogous or contradictional properties, we tried to find out whether the behavior of 241Am in organisms can be explained from its chemical characteristics

  6. Solution speciation of plutonium and Americium at an Australian legacy radioactive waste disposal site.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Harrison, Jennifer J; Thiruvoth, Sangeeth; Wilsher, Kerry; Wong, Henri K Y; Johansen, Mathew P; Waite, T David; Payne, Timothy E

    2014-09-01

    During the 1960s, radioactive waste containing small amounts of plutonium (Pu) and americium (Am) was disposed in shallow trenches at the Little Forest Burial Ground (LFBG), located near the southern suburbs of Sydney, Australia. Because of periodic saturation and overflowing of the former disposal trenches, Pu and Am have been transferred from the buried wastes into the surrounding surface soils. The presence of readily detected amounts of Pu and Am in the trench waters provides a unique opportunity to study their aqueous speciation under environmentally relevant conditions. This study aims to comprehensively investigate the chemical speciation of Pu and Am in the trench water by combining fluoride coprecipitation, solvent extraction, particle size fractionation, and thermochemical modeling. The predominant oxidation states of dissolved Pu and Am species were found to be Pu(IV) and Am(III), and large proportions of both actinides (Pu, 97.7%; Am, 86.8%) were associated with mobile colloids in the submicron size range. On the basis of this information, possible management options are assessed. PMID:25126837

  7. Solution speciation of plutonium and Americium at an Australian legacy radioactive waste disposal site.

    Science.gov (United States)

    Ikeda-Ohno, Atsushi; Harrison, Jennifer J; Thiruvoth, Sangeeth; Wilsher, Kerry; Wong, Henri K Y; Johansen, Mathew P; Waite, T David; Payne, Timothy E

    2014-09-01

    During the 1960s, radioactive waste containing small amounts of plutonium (Pu) and americium (Am) was disposed in shallow trenches at the Little Forest Burial Ground (LFBG), located near the southern suburbs of Sydney, Australia. Because of periodic saturation and overflowing of the former disposal trenches, Pu and Am have been transferred from the buried wastes into the surrounding surface soils. The presence of readily detected amounts of Pu and Am in the trench waters provides a unique opportunity to study their aqueous speciation under environmentally relevant conditions. This study aims to comprehensively investigate the chemical speciation of Pu and Am in the trench water by combining fluoride coprecipitation, solvent extraction, particle size fractionation, and thermochemical modeling. The predominant oxidation states of dissolved Pu and Am species were found to be Pu(IV) and Am(III), and large proportions of both actinides (Pu, 97.7%; Am, 86.8%) were associated with mobile colloids in the submicron size range. On the basis of this information, possible management options are assessed.

  8. 8 CFR 245a.37 - Termination of Family Unity Program benefits.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Termination of Family Unity Program... UNDER SECTION 245A OF THE IMMIGRATION AND NATIONALITY ACT LIFE Act Amendments Family Unity Provisions § 245a.37 Termination of Family Unity Program benefits. (a) Grounds for termination. The Service...

  9. 48 CFR 245.603-71 - Disposal of contractor inventory for NATO cooperative projects.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Disposal of contractor inventory for NATO cooperative projects. 245.603-71 Section 245.603-71 Federal Acquisition Regulations... inventory for NATO cooperative projects. (a) North Atlantic Treaty Organization (NATO) cooperative...

  10. Assessing the 24/5 Library: A Case Study in Data and Perspectives

    Science.gov (United States)

    Johnson, Ken; McCallister, Kelly

    2015-01-01

    The 24-hour/5-days-per-week (24/5) model at Belk Library & Information Commons has experienced multiple changes since first implemented in 2006. First the library started small, then expanded, then reduced, and finally expanded again. This article tells the story of a library's 24/5 evolution within the assessment cycle framework, describes…

  11. 48 CFR 245.302 - Contracts with foreign governments or international organizations.

    Science.gov (United States)

    2010-10-01

    ... governments or international organizations. 245.302 Section 245.302 Federal Acquisition Regulations System... international organizations. (1) General. (i) Approval. A contractor may use Government property on work for foreign governments and international organizations only when approved in writing by the...

  12. A study of plutonium and americium concentrations in seaspray on the southern Scottish coast

    International Nuclear Information System (INIS)

    Seaspray and seawater have been collected from the southern Scottish coast and, for comparison, Cumbria in northwest England during 1989 and 1991. The occurrence of sea-to-land transfer of the actinides plutonium and americium in seaspray was observed on these coasts using muslin screens (a semi-quantitative technique most efficient for collecting large spray droplets) and high volume conventional air samplers. The actinides and fine particulate in the spray were present in relatively higher concentrations than measured in the adjacent seawater, i.e. the spray was enriched in particulate actinides. The net efficiency of the muslim screens in collecting airborne plutonium isotopes and 241Am generally appeared to be about 20%. A review of earlier published concentrations of 239+240Pu and 241Am measured in aerosol and deposition for over a year several tens of metres inland was carried out. This suggested that airborne activities are up to a factor of 5 times higher in Cumbria than southern Scotland. However, neither the new data collected in 1989 and 1991 nor this older data suggests any enhancement of seaspray actinide enrichment in southern Scotland compared to Cumbria. This finding contrasts with earlier, more limited, comparisons that have been carried out which suggested such a difference. There is clear evidence of considerable localised spatial and temporal variability in aerosol actinide enrichment over the beaches in both areas. Enrichments varies between 20 and 500 relative to the adjacent surf zone waters. However, the average enrichment in spray based on the continuous measurements made further inland is likely to be at the lower end of this range. (author)

  13. Biosorption of Americium-242 by saccharomyces cerevisiae: preliminary evaluation and mechanism

    International Nuclear Information System (INIS)

    As an important radioisotope in nuclear industry and other fields, americium-241 is one of the most serious contamination concerns duo to its high radiation toxicity and long half-life. In this experiment, the biosorption of 241Am from solution by a fungus, Saccharomyces cerevisiae (S. cerevisiae), and the effects of various experimental conditions on the biosorption and the mechanism were explored. The preliminary results showed that S. cerevisiae is a very efficient biosorbent. An average of more than 99% of the total 241Am could be removed by S. cerevisiae of 2.1g/L (dry weight) from 241Am solutions of 2.22MBq/L -555 MBq/L (Co). The adsorption equilibrium was achieved within 1 hour and the optimum pH ranged 1-3. The culture times of more than 16 hours were suitable and the efficient adsorption of 241Am by the S. cerevisiae could be noted. The biosorption of 241Am by the decomposed cell wall, protoplasm or cell membrane of S. cerevisiae was same efficient as by the intact fungus, but the some components of S. cerevisiae, such as protein and acylation group had obvious effect on adsorption. When the concentrations of coexistent Eu3+, Nd3+ were 100 times more than that of 241Am, the adsorption rates would drop to 65%. However, most of the investigated acidic ions have no significant influence on the 241Am adsorption but minute change of pH value, while the saturated EDTA can strong inhibit the biosorption of 241Am.. (authors)

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

    International Nuclear Information System (INIS)

    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.)

  15. The treatment of liquid radioactive waste containing Americium by using a cation exchange method

    International Nuclear Information System (INIS)

    A research in the treatment of a liquid radioactive waste containing americium has been done. The liquid radioactive waste used in this research was standard solution of U dan Ce with the initial activity of 100 ppm. The experimental investigation is aimed at a study of the effects of the waste pH, the column dimension of IR-120 cation exchanger which is expressed as L/D, the flow rate of a liquid waste and the influence of thiocyanate as a complex agent against the efficiency of a decontamination for uranium and cerium element. The experiment was done by passing downward the feed of uranium and cerium solution into an IR-120 type of cation exchanger with the L/D of 11.37. From the experimental parameters done in this research where the influence of waste pH was varied from 3 - 8, the geometric column (L/D) 11.37, the liquid flow rate was from 2.5 - 10 ml/m and the thiocyanate concentration was between 100 ppm-500 ppm can be concluded that the optimum operational condition for the ion exchange achieved were the waste pH for uranium = 4 and the waste pH for cerium = 6, the flow rate = 2.5 ml/men. From the given maximum value of DF for uranium = 24 (DE = 95.83%) and of DF for cerium = 40 (DE = 97.5%), it can also be concluded that this investigation is to be continued in order that the greater value of DF/DE can be achieved

  16. 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)

    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 239Np and 241Am 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)

  17. [Raoultella planticola, a new strain degrading 2,4,5-trichlorophenoxyacetic acid].

    Science.gov (United States)

    Zharikova, N V; Markusheva, T V; Galkin, E G; Korobov, V V; Zhurenko, E Iu; Sitdikova, L R; Kolganova, T V; Kuznetsov, B B; Turova, T P

    2006-01-01

    A new strain that degrades the herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was isolated from soil, which was exposed to factors related to the petrochemical industry. According to its physiological, biochemical, cultural, and morphological traits, together with the sequence of the 16S rRNA gene, the strain was identified as Raoultella planticola 33-4ch. The strain could consume 2,4,5-T as a sole source of carbon and energy. The amount of 2,4,5-T in the culture medium decreased by 51% after five days of incubation. Raoultella planticola 33-4ch consumes 2,4,5-T to produce 4-chlorophenoxyacetic, phenoxyacetic, and 3-methyl-2,6-dioxo-4-hexenoic acids.

  18. CLONING AND CHARACTERIZATION OF A CHROMOSOMAL DNA REGION REQUIRED FOR GROWTH ON 2,4,5-T BY PSEUDOMONAS CEPACIA AC1100

    Science.gov (United States)

    A series of spontaneous 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) nonmetabolizing mutants of Pseudomonas cepacia AC1100 were characterized to be defective in either 2,4,5-T uptake or conversion of this compound to 2,4,5-trichlorophenol (2,4,5-TCP). Two of these mutants, RHC22 a...

  19. Effect of a long-term release of plutonium and americium into an estuarine and coastal sea ecosystem

    International Nuclear Information System (INIS)

    This paper discusses the general problem of speciation of plutonium and americium in aquatic ecosystems and the implications relative to their fate in those systems. The following conclusions were reached: several oxidation states of plutonium coexist in the natural environment; the effect of environmental changes such as pH and Esub(h) values and complexes are probably the cause of these various oxidation states; a clearer definition of the 'concentration factor' should be given in view of the important role the sediments play in supplying plutonium for transfer through the food web. (author)

  20. EFFECT OF COMPOSITION OF SELECTED GROUNDWATERS FROM THE BASIN AND RANGE PROVINCE ON PLUTONIUM, NEPTUNIUM, AND AMERICIUM SPECIATION.

    Science.gov (United States)

    Rees, Terry F.; Cleveland, Jess M.; Nash, Kenneth L.

    1984-01-01

    The speciation of plutonium, neptunium, and americium was determined in groundwaters from four sources in the Basin and Range Province: the lower carbonate aquifer, Nevada Test Site (NTS) (Crystal Pool); alluvial fill, Frenchman Flat, NTS (well 5C); Hualapai Valley, Arizona (Red Lake south well); and Tularosa Basin, New Mexico (Rentfrow well). The results were interpreted to indicate that plutonium and, to a lesser extent, neptunium are least soluble in reducing groundwaters containing a large concentration of sulfate ion and a small concentration of strongly complexing anions. The results further emphasize the desirability of including studies such as this among the other site-selection criteria for nuclear waste repositories.

  1. Microstructure and elemental distribution of americium-containing MOX fuel under the short-term irradiation tests

    International Nuclear Information System (INIS)

    In order to investigate the effect of americium addition to MOX fuels on the irradiation behavior, the 'Am-1' program is being conducted in JAEA. The Am-1 program consists of two short-term irradiation tests of 10-minute and 24-hour irradiations and a steady-state irradiation test. The short-term irradiation tests were successfully completed and the post irradiation examinations (PIEs) are in progress. The PIEs for Am-containing MOX fuels focused on the microstructural evolution and redistribution behavior of Am at the initial stage of irradiation and the results to date are reported. (author)

  2. Development of a methodology for the determination of americium and thorium by ICP-AES and their inter-element effect

    International Nuclear Information System (INIS)

    Due to the scarcity of good quality uranium resources, the growth of nuclear technology in India is dependent on the utilization of the vast thorium resources. Therefore, Advance Heavy Water Reactor is going to acquire significant role in the scenario of Indian nuclear technology, where (Th, Pu)O2 will be utilized as fuel in the outermost ring of the reactor core. This will lead to a complex matrix containing thorium as well as americium, which is formed due to β-decay of plutonium. The amount of americium is dependent on the burn up and the storage time of the Pu based fuels. In the present case, attempt was made to develop a method for the determination of americium as well as thorium by ICP-AES. Two emission lines of americium were identified and calibration curves were established for determination of americium. Though the detection limit of 283.236 nm line (5 ng mL-1) of americium was found to be better than that of 408.930 nm (11 ng mL-1), the former line is significantly interfered by large amount of thorium. Three analytical lines (i.e. 283.242, 283.730 and 401.913 nm) of thorium were identified and calibration curves were established along with their detection limits. It was observed that 283.242 and 401.913 nm line are having similar detection limits (18 and 13 ng mL-1, respectively) which are better than that of 283.730 nm (60 ng mL-1). This can be attributed to the high background of 283.273 nm channel of thorium. The spectral interference study revealed that even small amount of americium has significant contribution on 283.242 nm channel of thorium while the other two channels remain practically unaffected. Considering both these facts, spectral interference and analytical performance (detection limits and sensitivity), it was concluded that 401.913 nm line is the best analytical line out of the three lines for determination of thorium in presence of americium. (author)

  3. Effect of radiolysis on leachability of plutonium and americium from 76-101 glass. [Glass containing 2 mole % plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L.; Fried, S.; Friedman, A.M.; Susak, N.; Rickert, P.; Sullivan, J.C.; Karim, D.P.; Lam, D.J.

    1982-01-01

    One aspect of the leachability of actinide-bearing glass which has not been adequately addressed is the effect of radiolysis of the system (glass-water) on the amount of actinides liberated from the glass. In the present study, we have investigated the leaching of plutonium and americium from 76-101 glass samples (containing 2 mole % plutonium) in the presence of a one megaRad/hour gamma-radiation field. The presence of the radiation field was found to increase the leaching rate of both plutonium and americium by a factor of five. Speciation studies of the plutonium in the leachate indicate that the plutonium is present predominantly in the higher oxidation states, Pu(V) and Pu(VI) and that it is significantly associated with colloidal particles. Examination of the glass surfaces with x-ray photoemission spectroscopy, XPS, both before and after leaching was carried out; these studies showed lower surface concentrations of plutonium in the samples of glass leached in the radiation field. 1 figure, 3 tables.

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

    International Nuclear Information System (INIS)

    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

  5. Experimental Study on Behavior of Americium in Pyrochemical Process of Nitride Fuel Cycle

    International Nuclear Information System (INIS)

    R and D on the transmutation of long-lived minor actinides (MA) by the accelerator-driven system (ADS) using nitride fuels is underway at JAEA. In regard to reprocessing technology, pyrochemical process has several advantages in case of treating spent fuel with large decay heat and fast neutron emission, and recovering highly enriched N-15. In the pyrochemical reprocessing, plutonium and MA are dissolved in LiCl-KCl eutectic melts and selectively recovered into liquid cadmium (Cd) cathode by molten salt electrorefining. The electrochemical behavior in LiCl-KCl eutectic melts and the subsequent nitride formation behavior of plutonium and MA recovered in liquid Cd cathode are investigated. In this paper, recent results on electrochemical study of americium (Am) on electrolyses of AmN in LiCl-KCl eutectic melts and nitride formation of Am recovered in the liquid Cd cathode are presented. Electrochemical behavior of Am on anodic dissolution of AmN and recovery of Am into a liquid Cd cathode by electrolyses in LiCl-KCl eutectic melts was investigated by transient electrochemical techniques. The formal standard potential of Am(III)/Am(0) obtained with the liquid Cd electrode is more positive than that calculated for the solid metal electrode. The potential shift is considered to be attributed to the lowering of the activity of Am by the formation of the intermetallic compound with Cd. Potentiostatic electrolyses of AmN in LiCl-KCl eutectic melts containing AmCl3 at 773 K were carried out. Nitrogen gas generated by the anodic dissolution of AmN was observed, and the current efficiency was obtained from the ratio of the amount of released nitrogen gas and the passed electric charge to be 20 - 28 %. Am was recovered as Am-Cd alloy in the liquid Cd cathode, in which AmCd6 type phase was identified besides Cd phase. The recovered Am was converted to AmN by the nitridation-distillation combined method, in which the Am-Cd alloy was heated in nitrogen gas stream at 973 K. These

  6. Biodegradation of 2,4,5-trichlorophenoxyacetic acid by a pure culture of Pseudomonas cepacia.

    OpenAIRE

    Kilbane, J J; Chatterjee, D K; Karns, J S; Kellogg, S T; Chakrabarty, A M

    1982-01-01

    A pure culture of Pseudomonas cepacia, designated AC1100, that can utilize 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as its sole source of carbon and energy was isolated. An actively growing culture of AC1100 was able to degrade more than 97% of 2,4,5-T, present at 1 mg/ml, within 6 days as determined by chloride release, gas chromatographic, and spectrophotometric analyses. The ability of AC1100 to oxidize a variety of chlorophenols and related compounds is also reported.

  7. LIBS Spectral Data for a Mixed Actinide Fuel Pellet Containing Uranium, Plutonium, Neptunium and Americium

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Los Alamos National Laboratory; Berg, John M. [Los Alamos National Laboratory; Le, Loan A. [Los Alamos National Laboratory; Lopez, Leon N. [Los Alamos National Laboratory; Barefield, James E. [Los Alamos National Laboratory

    2012-06-18

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze a mixed actinide fuel pellet containing 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2}. The preliminary data shown here is the first report of LIBS analysis of a mixed actinide fuel pellet, to the authors knowledge. The LIBS spectral data was acquired in a plutonium facility at Los Alamos National Laboratory where the sample was contained within a glove box. The initial installation of the glove box was not intended for complete ultraviolet (UV), visible (VIS) and near infrared (NIR) transmission, therefore the LIBS spectrum is truncated in the UV and NIR regions due to the optical transmission of the window port and filters that were installed. The optical collection of the emission from the LIBS plasma will be optimized in the future. However, the preliminary LIBS data acquired is worth reporting due to the uniqueness of the sample and spectral data. The analysis of several actinides in the presence of each other is an important feature of this analysis since traditional methods must chemically separate uranium, plutonium, neptunium, and americium prior to analysis. Due to the historic nature of the sample fuel pellet analyzed, the provided sample composition of 75% UO{sub 2}/20% PuO{sub 2}/3% AmO{sub 2}/2% NpO{sub 2} cannot be confirm without further analytical processing. Uranium, plutonium, and americium emission lines were abundant and easily assigned while neptunium was more difficult to identify. There may be several reasons for this observation, other than knowing the exact sample composition of the fuel pellet. First, the atomic emission wavelength resources for neptunium are limited and such techniques as hollow cathode discharge lamp have different dynamics than the plasma used in LIBS which results in different emission spectra. Secondly, due to the complex sample of four actinide elements, which all have very dense electronic energy levels, there may be reactions and

  8. Preconcentration of low levels of americium and plutonium from waste waters by synthetic water-soluble metal-binding polymers with ultrafiltration

    International Nuclear Information System (INIS)

    A preconcentration approach to assist in the measurement of low levels of americium and plutonium in waste waters has been developed based on the concept of using water-soluble metal-binding polymers in combination with ultrafiltration. The method has been optimized to give over 90% recovery and accountability from actual waste water. (author)

  9. Theoretical investigation of pressure-induced structural transitions in americium using GGA+U and hybrid density functional theory methods

    DEFF Research Database (Denmark)

    Verma, Ashok K.; Modak, P.; Sharma, Surinder M.;

    2013-01-01

    First-principles calculations have been performed for americium (Am) metal using the generalized gradient approximation + orbital-dependent onsite Coulomb repulsion via Hubbard interaction (GGA+U) and hybrid density functional theory (HYB-DFT) methods to investigate various ground state propertie...

  10. 8 CFR 245a.14 - Application for class membership in the CSS, LULAC, or Zambrano lawsuit.

    Science.gov (United States)

    2010-01-01

    ... Equity (LIFE) Act Legalization Provisions § 245a.14 Application for class membership in the CSS, LULAC... alien must provide with the application for LIFE Legalization evidence establishing that, before...

  11. Antibacterial activity of synthesized 2,4,5-trisubstituted imidazole derivatives

    Digital Repository Service at National Institute of Oceanography (India)

    Khan, M.S.; Siddiqui, S.A.; Siddiqui, M.S.R.A.; Goswami, U.; Srinivasan, K.V.; Khan, M.I.

    ornidazole, secnidazole and tinidazole are anti- bacterial and antiprotozoal drugs (20). Metronidazole is active only against anaerobic organisms. It is activated when reduced through electron donation from ferredoxin or flavodoxin (21). Activated MTZ... concentration The disk diffusion method (23) was used for the preliminary anti- bacterial evaluation of 2,4,5-trisubstitued imidazoles. The minimun inhibitory concentrations (MIC) (Table 1) of 2,4,5-trisubstitued imi- dazoles, showing inhibition...

  12. Stability of penta- and hexavalent americium in the solutions of sodium peroxydisulfate and sodium bromate at intensive internal α-irradiation

    International Nuclear Information System (INIS)

    The spectrometric method has been used for studying the dependence of the rates of radiolytic reduction of Am(5) and (6) on the initial concentration of sodium persulfate and bromate, Am(5) and (6), acidity, and the dose rate of inner alpha-irradiation of the solutions. The high dose rates of inner alpha-irradiation of solutions (up to 3.25x1021 eV/lxmin-250Ci/l) have been attained with the aid of curium isotopes. The stability of americium (6) ions towards the action of ionizing radiation in solutions of sodium persulfate and bromate has been shown to be considerable lower than that of americium (5). The chemical difference has been shown in radiolytic behaviour between Am(5) and Am(6) ions in solutions of sodium persulfate and bromate. The equations have been derived showing the dependence of the rates of Am(6) and Am(5) reduction of different variables

  13. Comparative XRPD and XAS study of the impact of the synthesis process on the electronic and structural environments of uranium-americium mixed oxides

    Science.gov (United States)

    Prieur, D.; Lebreton, F.; Martin, P. M.; Caisso, M.; Butzbach, R.; Somers, J.; Delahaye, T.

    2015-10-01

    Uranium-americium mixed oxides are potential compounds to reduce americium inventory in nuclear waste via a partitioning and transmutation strategy. A thorough assessment of the oxygen-to-metal ratio is paramount in such materials as it determines the important underlying electronic structure and phase relations, affecting both thermal conductivity of the material and its interaction with the cladding and coolant. In 2011, various XAS experiments on U1-xAmxO2±δ samples prepared by different synthesis methods have reported contradictory results on the charge distribution of U and Am. This work alleviates this discrepancy. The XAS results confirm that, independently of the synthesis process, the reductive sintering of U1-xAmxO2±δ leads to the formation of similar fluorite solid solution indicating the presence of Am+III and U+V in equimolar proportions.

  14. THE FIRST ISOLATION OF AMERICIUM IN THE FORM OF PURE COMPOUNDS - THE SPECIFIC ALPHA-ACTIVITY AND HALF-LIFE OF Am241

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, B.B.; Asprey, L.B.

    1950-07-20

    The microgram scale isolation and preparation of pure compounds of americium is described. Data are presented to show that the alpha-half-life of the isotope Am{sup 241} is 490 {+-} 14 years. The absorption spectrum of Am(III) in 1M nitric acid in the range 3500-8000 mu is given. The wave lengths of 10 of the most prominent lines in the copper spark emission spectrum of americium are given to the nearest 0.01 {angstrom}. Evidence is presented to show that the potential for the Am(III)-Am(IV) couple in acid solution is more negative than -2v and that the potential for the Am(II)-Am(III) couple is more positive than +0.9v.

  15. First results of the 2.45 GHz Oshima electron cyclotron resonance ion source

    Energy Technology Data Exchange (ETDEWEB)

    Asaji, T., E-mail: asaji@nc-toyama.ac.jp [National Institute of Technology, Toyama College, 13 Hongo, Toyama 939-8630 (Japan); Nakamura, T.; Furuse, M. [National Institute of Technology, Oshima College, 1091-1 Komatsu, Suouoshima, Oshima, Yamaguchi 742-2193 (Japan); Hitobo, T. [Tateyama Machine Co., Ltd., 30 Shimonoban, Toyama 930-1305 (Japan); Uchida, T. [Graduate School of Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585 (Japan); Muramatsu, M. [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kato, Y. [Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan)

    2016-02-15

    A new electron cyclotron resonance ion source has been constructed at Oshima College with a 2.45 GHz magnetron microwave source and permanent magnets employed as the main components. In addition, a solid-state power amplifier with a frequency range of 2.5–6.0 GHz was installed to study two-frequency plasma heating. Three solenoid coils were set up for adjusting the axial magnetic fields. Argon plasma generation and ion beam production have been conducted during the first year of operation. Ion current densities in the ECR plasma were measured using a biased disk. For 2.45 and 4.65 GHz two-frequency plasma heating, the ion density was approximately 1.5 times higher than that of 2.45 GHz single-frequency heating.

  16. A Density Functional Study of Atomic Hydrogen and Oxygen Chemisorption on the Relaxed (0001) Surface of Double Hexagonal Close Packed Americium

    OpenAIRE

    Dholabhai, P. P.; Atta-Fynn, R.; A.K. Ray

    2009-01-01

    Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the adlayer str...

  17. 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)

    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

  18. Microwave ablation at 915 MHz vs 2.45 GHz: A theoretical and experimental investigation

    Energy Technology Data Exchange (ETDEWEB)

    Curto, Sergio; Taj-Eldin, Mohammed; Fairchild, Dillon; Prakash, Punit, E-mail: prakashp@ksu.edu [Department of Electrical and Computer Engineering, Kansas State University, Manhattan, Kansas 66506 (United States)

    2015-11-15

    Purpose: The relationship between microwave ablation system operating frequency and ablation performance is not currently well understood. The objective of this study was to comparatively assess the differences in microwave ablation at 915 MHz and 2.45 GHz. Methods: Analytical expressions for electromagnetic radiation from point sources were used to compare power deposition at the two frequencies of interest. A 3D electromagnetic-thermal bioheat transfer solver was implemented with the finite element method to characterize power deposition and thermal ablation with asymmetrical insulated dipole antennas (single-antenna and dual-antenna synchronous arrays). Simulation results were validated against experiments in ex vivo tissue. Results: Theoretical, computational, and experimental results indicated greater power deposition and larger diameter ablation zones when using a single insulated microwave antenna at 2.45 GHz; experimentally, 32 ± 4.1 mm and 36.3 ± 1.0 mm for 5 and 10 min, respectively, at 2.45 GHz, compared to 24 ± 1.7 mm and 29.5 ± 0.6 mm at 915 MHz, with 30 W forward power at the antenna input port. In experiments, faster heating was observed at locations 5 mm (0.91 vs 0.49 °C/s) and 10 mm (0.28 vs 0.15 °C/s) from the antenna operating at 2.45 GHz. Larger ablation zones were observed with dual-antenna arrays at 2.45 GHz; however, the differences were less pronounced than for single antennas. Conclusions: Single- and dual-antenna arrays systems operating at 2.45 GHz yield larger ablation zone due to greater power deposition in proximity to the antenna, as well as greater role of thermal conduction.

  19. Microwave ablation at 915 MHz vs 2.45 GHz: A theoretical and experimental investigation

    International Nuclear Information System (INIS)

    Purpose: The relationship between microwave ablation system operating frequency and ablation performance is not currently well understood. The objective of this study was to comparatively assess the differences in microwave ablation at 915 MHz and 2.45 GHz. Methods: Analytical expressions for electromagnetic radiation from point sources were used to compare power deposition at the two frequencies of interest. A 3D electromagnetic-thermal bioheat transfer solver was implemented with the finite element method to characterize power deposition and thermal ablation with asymmetrical insulated dipole antennas (single-antenna and dual-antenna synchronous arrays). Simulation results were validated against experiments in ex vivo tissue. Results: Theoretical, computational, and experimental results indicated greater power deposition and larger diameter ablation zones when using a single insulated microwave antenna at 2.45 GHz; experimentally, 32 ± 4.1 mm and 36.3 ± 1.0 mm for 5 and 10 min, respectively, at 2.45 GHz, compared to 24 ± 1.7 mm and 29.5 ± 0.6 mm at 915 MHz, with 30 W forward power at the antenna input port. In experiments, faster heating was observed at locations 5 mm (0.91 vs 0.49 °C/s) and 10 mm (0.28 vs 0.15 °C/s) from the antenna operating at 2.45 GHz. Larger ablation zones were observed with dual-antenna arrays at 2.45 GHz; however, the differences were less pronounced than for single antennas. Conclusions: Single- and dual-antenna arrays systems operating at 2.45 GHz yield larger ablation zone due to greater power deposition in proximity to the antenna, as well as greater role of thermal conduction

  20. A new method for the determination of plutonium and americium using high pressure microwave digestion and alpha-spectrometry or ICP-SMS

    International Nuclear Information System (INIS)

    Plutonium and americium are radionuclides particularly difficult to measure in environmental samples because they are a-emitters and therefore necessitate a careful separation before any measurement, either using radiometric methods or ICP-SMS. Recent developments in extraction chromatography resins such as EichromR TRU and TEVA have resolved many of the analytical problems but drawbacks such as low recovery and spectral interferences still occasionally occur. Here, we report on the use of the new EichromR DGA resin in association with TEVA resin and high pressure microwave acid leaching for the sequential determination of plutonium and americium in environmental samples. The method results in average recoveries of 83 ± 15% for plutonium and 73 ± 22% for americium (n = 60), and a less than 10% deviation from reference values of four IAEA reference materials and three samples from intercomparisons exercises. The method is also suitable for measuring 239Pu in water samples at the μBq/l level, if ICP-SMS is used for the measurement. (author)

  1. 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)

    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

  2. Comparative XRPD and XAS study of the impact of the synthesis process on the electronic and structural environments of uranium–americium mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Prieur, D., E-mail: dam.prieur@gmail.com [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Lebreton, F. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France); Martin, P.M. [CEA, DEN, DEC/SESC/LLCC, 13108 Saint-Paul-Lez-Durance cedex (France); Caisso, M. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France); Butzbach, R. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Radiochemistry, P.O. Box 10119, 01314 Dresden (Germany); Somers, J. [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, D-76125 Karlsruhe (Germany); Delahaye, T. [CEA, DEN, DTEC/SDTC/LEMA, 30207 Bagnols-sur-Cèze cedex (France)

    2015-10-15

    Uranium–americium mixed oxides are potential compounds to reduce americium inventory in nuclear waste via a partitioning and transmutation strategy. A thorough assessment of the oxygen-to-metal ratio is paramount in such materials as it determines the important underlying electronic structure and phase relations, affecting both thermal conductivity of the material and its interaction with the cladding and coolant. In 2011, various XAS experiments on U{sub 1−x}Am{sub x}O{sub 2±δ} samples prepared by different synthesis methods have reported contradictory results on the charge distribution of U and Am. This work alleviates this discrepancy. The XAS results confirm that, independently of the synthesis process, the reductive sintering of U{sub 1−x}Am{sub x}O{sub 2±δ} leads to the formation of similar fluorite solid solution indicating the presence of Am{sup +III} and U{sup +V} in equimolar proportions. - Graphical abstract: Formation of (U{sup IV/V},Am{sup III})O{sup 2} solid solution by sol–gel and by powder metallurgy. - Highlights: • Uranium–americium mixed oxides were synthesized by sol–gel and powder metallurgy. • Fluorite solid solutions with similar local environment have been obtained. • U{sup V} and Am{sup III} are formed in equimolar proportions.

  3. R245fa传热特性的实验研究%Experimental Study on Evaporating Heat Transfer Characteristics of HFC-245fa

    Institute of Scientific and Technical Information of China (English)

    黄晓艳; 王华; 王辉涛

    2011-01-01

    对R245fa水平光滑管管内流动沸腾换热特性进行了实验研究,主要包括加热水质量流速、工质质量流速、蒸发温度以及干度对局部换热系数的影响,结果表明在相同蒸发温度及加热水质量流速下,随着工质质量流速增大,管内流动沸腾换热系数迅速升高;在相同工质质量流速及蒸发温度下,随着加热水质量流速的增大,管内流动沸腾换热系数升高;在相同工质质量流速及加熟水质量流速下,随着蒸发温度的升高,管内流动沸腾换热系数降低.分别采用Chen公式、Liu-Winterton公式、Shah公式计算了与本实验相同工况下R245fa的管内流动沸腾换热系数,其结果表明:3个预测公式的计算结果与实验值之间的平均误差分别为31.6%、6.3%、37.4%.采用Liu-Winterton公式计算R245fa的流动沸腾换热系数满足工程实际的要求.%Convective boiling heat transfer characteristics of R245fa inside horizontal tube are investigated at various mass flow rates of hot water, working fluids and at various evaporation temperatures. The investigation results show that convective boiling heat transfer coefficients goes up with the increase of hot water and working fluid mass flow rate, but it is contrary to evaporation temperature. By comparisons of the experimental local heat transfer coefficients with that predicted by Chen correlation, Liu-Winterton correlation and Shah correlation, it is concluded that deviations of these three correlations are 31.6 %、 6.3 %、37.4 % respectively. Liu-Winterton correlation is more precise to predict convective boiling heat transfer coefficients of R245fa than Chen correlation and Shah correlation.

  4. 7 CFR 2.45 - Deputy Under Secretary for Rural Economic and Community Development.

    Science.gov (United States)

    2010-01-01

    ... the Under Secretary for Rural Development § 2.45 Deputy Under Secretary for Rural Economic and... Under Secretary for Rural Economic and Community Development, to be exercised only during the absence or... may hereafter be delegated to the Under Secretary for Rural Economic and Community Development....

  5. 40 CFR 1065.245 - Sample flow meter for batch sampling.

    Science.gov (United States)

    2010-07-01

    ... POLLUTION CONTROLS ENGINE-TESTING PROCEDURES Measurement Instruments Flow-Related Measurements § 1065.245... laminar flow element, an ultrasonic flow meter, a subsonic venturi, a critical-flow venturi or multiple... diluted exhaust and sample-flow measurements and their upstream pressures and temperatures remain...

  6. 8 CFR 245.11 - Adjustment of aliens in S nonimmigrant classification.

    Science.gov (United States)

    2010-01-01

    ... supporting documents specified in the instructions to Form I-485 and described in 8 CFR 245.2. Secondary... in 8 CFR 103.2(b)(2). The S nonimmigrant applying to adjust must complete Part 2 of Form I-485 by... unavailable, affidavits may be submitted as provided in 8 CFR 103.2(b)(2). (e) Priority date. The...

  7. 48 CFR 245.7206 - Transmitting DD Form 1342, DoD Property Record.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Transmitting DD Form 1342... Instructions 245.7206 Transmitting DD Form 1342, DoD Property Record. As a minimum, the plant clearance officer will provide the following information in a letter forwarding DD Forms 1342 to DSCR— (a) Number of...

  8. 8 CFR 245a.3 - Application for adjustment from temporary to permanent resident status.

    Science.gov (United States)

    2010-01-01

    ...) Evidence of recognition under 8 CFR 245a.3(b)(5)(i)(A), (B), or (C) (e.g., certification from a qualified... grams or less of marijuana; (iv) Paragraphs (27) (prejudicial to the public interest), (28) (communists... Processing Facility may issue a new decision that will grant the benefit which has been requested....

  9. Tannic acid Catalyzed an Efficient Synthesis of 2,4,5-Triaryl-1H-Imidazole

    Directory of Open Access Journals (Sweden)

    Shitole Nana Vikram

    2013-05-01

    Full Text Available Tannic acid (C76H52O46 has been found to be an efficient catalyst for one-pot synthesis of 2,4,5-triaryl substituted imidazoles by the reaction of an arylaldehyde, benzyl/benzoin and an ammonium acetate. The short reaction time and excellent yields making this protocol practical and economically attractive.

  10. 48 CFR 1852.245-73 - Financial reporting of NASA property in the custody of contractors.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Financial reporting of NASA... CONTRACT CLAUSES Texts of Provisions and Clauses 1852.245-73 Financial reporting of NASA property in the custody of contractors. As prescribed in 1845.106-70(d), insert the following clause: Financial...

  11. 8 CFR 245a.18 - Ineligibility and applicability of grounds of inadmissibility.

    Science.gov (United States)

    2010-01-01

    ... (LIFE) Act Legalization Provisions § 245a.18 Ineligibility and applicability of grounds of... for waiver of inadmissibility grounds for LIFE Legalization applicants under sections 212(a)(9)(A) and 212(a)(9)(C) of the Act. An applicant for adjustment of status under LIFE Legalization who...

  12. 5 CFR 531.245 - Computing locality rates and special rates for GM employees.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Computing locality rates and special... Gm Employees § 531.245 Computing locality rates and special rates for GM employees. Locality rates and special rates are computed for GM employees in the same manner as locality rates and special...

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

    International Nuclear Information System (INIS)

    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)

  14. Intramolecular sensitization of americium luminescence in solution: shining light on short-lived forbidden 5f transitions.

    Science.gov (United States)

    Sturzbecher-Hoehne, M; Yang, P; D'Aléo, A; Abergel, R J

    2016-06-14

    The photophysical properties and solution thermodynamics of water soluble trivalent americium (Am(III)) complexes formed with multidentate chromophore-bearing ligands, 3,4,3-LI(1,2-HOPO), Enterobactin, and 5-LIO(Me-3,2-HOPO), were investigated. The three chelators were shown to act as antenna chromophores for Am(III), generating sensitized luminescence emission from the metal upon complexation, with very short lifetimes ranging from 33 to 42 ns and low luminescence quantum yields (10(-3) to 10(-2)%), characteristic of Near Infra-Red emitters in similar systems. The specific emission peak of Am(III) assigned to the (5)D1 → (7)F1 f-f transition was exploited to characterize the high proton-independent stability of the complex formed with the most efficient sensitizer 3,4,3-LI(1,2-HOPO), with a log β110 = 20.4 ± 0.2 value. In addition, the optical and solution thermodynamic features of these Am(III) complexes, combined with density functional theory calculations, were used to probe the influence of electronic structure on coordination properties across the f-element series and to gain insight into ligand field effects.

  15. Nano-cerium vanadate: a novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste.

    Science.gov (United States)

    Banerjee, Chayan; Dudwadkar, Nilesh; Tripathi, Subhash Chandra; Gandhi, Pritam Maniklal; Grover, Vinita; Kaushik, Chetan Prakash; Tyagi, Avesh Kumar

    2014-09-15

    Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides (233)U (4.82 MeV α) and (241)Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr(2+), Ru(3+), Fe(3+), etc., in the uptake process indicated CeVO4 nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions.

  16. Distribution of plutonium, americium, and several rare earth fission product elements between liquid cadmium and LiCl-KCl eutectic

    International Nuclear Information System (INIS)

    Separation factors were measured that describe the partition between molten cadmium and molten LiCl-KCl eutectic of plutonium, americium, praseodymium, neodymium, cerium, lanthanum, gadolinium, dysprosium, and yttrium. The temperature range was 753-788 K, and the range of concentrations was that allowed by the sensitivity of the chemical analysis methods. Mean separation factors were derived for Am-Pu, Nd-Am, Nd-Pu, Nd-Pr, Gd-La, Dy-La, La-Ce, La-Nd, Y-La, and Y-Nd. Where previously published data were available, agreement was good. For convenience, the following series of separation factors relative to plutonium was derived by combining the measured separation factors: Pu, 1.00 (basis); Am, 1.54; Pr, 22.0; Nd, 23.4; Ce, 26; La, 70; Gd, 77; Dy, 270; Y, 3000. These data are used in calculating the distribution of the actinide and rare earth elements in the prochemical reprocessing of spent fuel from the Integral Fast Reactor. (orig.)

  17. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    International Nuclear Information System (INIS)

    Routine counting methods and ICP-MS are unable to directly measure the new US Department of Energy (DOE) regulatory level for discharge waters containing alpha-emitting radionuclides of 30 pCi/L total alpha or the 0.05 pCi/L regulatory level for Pu or Am activity required for surface waters at the Rocky Flats site by the State of Colorado. This inability indicates the need to develop rapid, reliable, and robust analytical techniques for measuring actinide metal ions, particularly americium and plutonium. Selective separation or preconcentration techniques would aid in this effort. Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for 241Am(III) and 238Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4

  18. Characteristics of plutonium and americium contamination at the former U.K. atomic weapons test ranges at Maralinga and Emu

    International Nuclear Information System (INIS)

    Physico-chemical studies on environmental plutonium are described, which provide data integral to an assessment of dose for the inhalation of artificial actinides by Australian Aborigines living a semi-traditional lifestyle at Maralinga and Emu, sites of U.K. atomic weapons tests between 1953 and 1963. The most significant area, from a radiological perspective, is the area contaminated by plutonium in a series of ''one point'' safety trials in which large quantities of plutonium were dispersed explosively at a location known as Taranaki. The activity distribution of plutonium and americium with particle size is quite different from the mass distribution, as a considerably higher proportion of the activity is contained in the finer (inhalable) fraction than of the mass. Except in areas which were disturbed through ploughing during a cleanup in 1967, most the activity remains in the top 1 cm of the surface. Much of the activity is in particulate form, even at distances > 20 km from the firing sites, and discrete particles have been located even at distances beyond 100 km. Data are presented which permit the assessment of annual committed doses through the inhalation pathway, for Aborigines living a semi-traditional lifestyle in the areas affected by the Taranaki firings in particular. (author)

  19. 48 CFR 245.606-70 - Instructions for completing DD Form 1342, DoD Property Record.

    Science.gov (United States)

    2010-10-01

    ... completing DD Form 1342, DoD Property Record. 245.606-70 Section 245.606-70 Federal Acquisition Regulations... completing DD Form 1342, DoD Property Record. (a) The contractor shall list excess industrial plant equipment (IPE) on DD Form 1342, DoD Property Record, and submit it to the Government property administrator...

  20. 8 CFR 245.12 - What are the procedures for certain Polish and Hungarian parolees who are adjusting status to...

    Science.gov (United States)

    2010-01-01

    ... adjusting status to that of permanent resident under the Illegal Immigration Reform and Immigrant... and Hungarian parolees who are adjusting status to that of permanent resident under the Illegal Immigration Reform and Immigrant Responsibility Act of 1996? 245.12 Section 245.12 Aliens and...

  1. High-Frequency Wireless Communications System: 2.45-GHz Front-End Circuit and System Integration

    Science.gov (United States)

    Chen, M.-H.; Huang, M.-C.; Ting, Y.-C.; Chen, H.-H.; Li, T.-L.

    2010-01-01

    In this article, a course on high-frequency wireless communications systems is presented. With the 145-MHz baseband subsystem available from a prerequisite course, the present course emphasizes the design and implementation of the 2.45-GHz front-end subsystem as well as system integration issues. In this curriculum, the 2.45-GHz front-end…

  2. Clinic analysis on 245 cases with fever of unknown origin%245例发热待查病例临床分析

    Institute of Scientific and Technical Information of China (English)

    周青; 谭德明; 谢玉桃; 李聪智; 徐旭雯; 欧阳奕; 易钊泉; 鲁猛厚

    2012-01-01

    目的 探讨245例不明原因发热(fever of unknown origin,FUO)患者的病因构成、临床特点及诊疗体会.方法 回顾性分析2009年1月-2011年4月在中南大学湘雅医院感染病科住院且符合FUO诊断标准的245例患者的病历资料.结果 245例FUO患者中,最终明确诊断220例,确诊率为89.80%;出院时仍未明确诊断25例(10.20%).220例确诊病例的病因分别为:感染性疾病158例(64.49%),其中细菌/真菌感染所占比率最高,达63.92%(101/158),结核病居第2位,占23.42%(37/158);结缔组织疾病33例(13.47%),成人斯蒂尔病所占比率最高,达60.61%(20/33);肿瘤性疾病22例(8.98%),其中淋巴瘤占59.09%(13/22);其他疾病7例(2.86%).结论 FUO的病因诊断主要是感染性疾病,细菌/真菌感染是其中最主要病因;结缔组织疾病和肿瘤性疾病在FUO病因中也占重要地位.大多数FUO经仔细地体格检查和清晰的临床分析以及必要的实验室检查是可以得到确诊的.%Objective To evaluate the causes and clinical features of 245 fever of unknown origin (FUO) cases. Methods Clinical data of 245 hospitalized FUO patients from January,2009 to April, 2011 in a hospital were analyzed retrospectively. Results Of 245 patients with FUO, 220 cases (89. 80%) were diagnosed definitely,25 cases (10. 20%) were still not diagnosed definitely when they discharged from hospital. The overall etiology distribution were as follows: 158 (64. 49%) were infectiou diseases, 63. 92%(101/158) of which were caused by bacteria/fungi, 23.42% (37/158) were tuberculosis; 33( 13. 47%) were connective tissue disease(CTD), 60.16% (20/33) of which were adult-onset Still' s disease; 22 (8. 98%) were tumor, 59. 09% (13/22) of which were lymphoma; 7(2. 86%) were other diseases. Conclusion The main causes in FUO are infectious diseases, bacteria/fungi infection is the most common cause; In addition, the percentage of the CTD and tumor are also relatively high. Most FUO

  3. The role of natural organic matter in the migration behaviour of americium in the Boom Clay - Part 1: migration experiments

    International Nuclear Information System (INIS)

    Full text of publication follows: In demonstrating the suitability of Boom Clay as reference site for studying the disposal of radioactive waste, the role of the relatively high amount of Natural Organic Matter (NOM) present in the Boom Clay on the mobility of critical radionuclides needs to be investigated thoroughly. It is generally accepted that trivalent actinides and lanthanides form strong complexes with humic substances. Complexation of these trivalent radionuclides with NOM present in the Boom Clay may therefore have two opposite effects. If complexed by the aqueous phase NOM (the mobile NOM), the radionuclide transport will be governed by the mobility of these dissolved radionuclide- NOM species. If complexed by the solid phase NOM (the immobile NOM) the migration will be retarded. One of the aims of the EC projects TRANCOM-Clay and TRANCOM-II was to investigate the role of mobile NOM as radionuclide carrier in order to develop a conceptual model for inclusion in a performance assessment (PA) model. The migration behaviour of Americium (used as an analogue for the critical radionuclide Pu) was investigated by complexing 241Am with radiolabelled (14C-labelled) NOM before passing through undisturbed Boom Clay cores contained in columns. The use of two different radionuclides, allows the migration behaviour of both the NOM and the Am to be followed. The results of the migration experiments showed that the Am-NOM complexes dissociated when they came into contact with Boom Clay and that the bulk of Am became immobilised (either as Am complexed to immobile NOM or sorbed to the mineral phase). Only a small percentage of the complex persisted as 'stabilised' Am-OM complex which exhibited slow dissociation kinetics upon moving through the Boom Clay. When the applied radionuclide source also contains Am in the form of an inorganic solid phase (when Am is applied above the solubility limit), a continuous source of Am exists to form 'temporarily stabilised' Am

  4. Experimental study of Americium-241 biokinetics in Homarus Gammarus lobster. Analysis of the accumulation and detoxication mechanisms at the sub-cellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

    Energy Technology Data Exchange (ETDEWEB)

    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. Nano-cerium vanadate: A novel inorganic ion exchanger for removal of americium and uranium from simulated aqueous nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Chayan; Dudwadkar, Nilesh [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tripathi, Subhash Chandra, E-mail: sctri001@gmail.com [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Gandhi, Pritam Maniklal [Fuel Reprocessing Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Grover, Vinita [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kaushik, Chetan Prakash [Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Tyagi, Avesh Kumar, E-mail: aktyagi@barc.gov.in [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2014-09-15

    Highlights: • Template free, low temperature synthesis of CeVO{sub 4} nanopowders. • Thermodynamically and kinetically favourable uptake of Am(III) and U(VI) exhibited. • K{sub d} and ΔG° values for Am(III) and U(VI) uptake in pH 1–6 are reported. • Interdiffusion coefficients and zeta potential values in pH 1–6 are reported. • Possible application in low level aqueous nuclear waste remediation. - Abstract: Cerium vanadate nanopowders were synthesized by a facile low temperature co-precipitation method. The product was characterized by X-ray diffraction and transmission electron microscopy and found to consist of ∼25 nm spherical nanoparticles. The efficiency of these nanopowders for uptake of alpha-emitting radionuclides {sup 233}U (4.82 MeV α) and {sup 241}Am (5.49 MeV α, 60 keV γ) has been investigated. Thermodynamically and kinetically favorable uptake of these radionuclides resulted in their complete removal within 3 h from aqueous acidic feed solutions. The uptake capacity was observed to increase with increase in pH as the zeta potential value decreased with the increase in pH but effect of ionic strength was insignificant. Little influence of the ions like Sr{sup 2+}, Ru{sup 3+}, Fe{sup 3+}, etc., in the uptake process indicated CeVO{sub 4} nanopowders to be amenable for practical applications. The isotherms indicated predominant uptake of the radioactive metal ions in the solid phase of the exchanger at lower feed concentrations and linear Kielland plots with positive slopes indicated favorable exchange of the metal ions with the nanopowder. Performance comparison with the other sorbents reported indicated excellent potential of nano-cerium vanadate for removing americium and uranium from large volumes of aqueous acidic solutions.

  6. Plutonium, americium and radiocaesium in the marine environment close to the Vandellos I nuclear power plant before decommissioning

    International Nuclear Information System (INIS)

    The Vandellos nuclear power plant (NPP), releasing low-level radioactive liquid waste to the Mediterranean Sea, is the first to be decommissioned in Spain, after an incident which occurred in 1989. The presence, distribution and uptake of various artificial radionuclides (radiocaesium, plutonium and americium) in the environment close to the plant were studied in seawater, bottom sediments and biota, including Posidonia oceanica, fish, crustaceans and molluscs. Seawater, sediments and Posidonia oceanica showed enhanced levels in the close vicinity of the NPP, although the effect was restricted to its near environment. Maximum concentrations in seawater were 11.6±0.5 Bq m-3 and 16.9±1.2 mBq m-3 for 137Cs and 239,240Pu, respectively. When sediment concentrations were normalized to excess 210Pb, they showed both the short-distance transport of artificial radionuclides from the Vandellos plant and the long-distance transport of 137Cs from the Asco NPP. Posidonia oceanica showed the presence of various gamma-emitters attributed to the impact of the Chernobyl accident, on which the effect of the NPP was superimposed. Seawater, sediment and Posidonia oceanica collected near the plant also showed an enhancement of the plutonium isotopic ratio above the fallout value. The uptake of these radionuclides by marine organisms was detectable but limited. Pelagic fish showed relatively higher 137Cs concentrations and only in the case of demersal fish was the plutonium isotopic ratio increased. The reported levels constitute a set of baseline values against which the impact of the decommissioning operations of the Vandellos I NPP can be studied

  7. Effect of genomic rearrangement on heavy metal tolerance in the plant-growth-promoting rhizobacterium Azospirillum brasilense Sp245.

    Science.gov (United States)

    Shelud'ko, Andrei V; Varshalomidze, Olga E; Petrova, Lilia P; Katsy, Elena I

    2012-01-01

    A derivative of Azospirillum brasilense Sp245, Sp245.5, which spontaneously lost 85 and 120 MDa replicons upon the formation of a new megaplasmid, has been shown to produce a novel lipopolysaccharide and to lose Calcofluor-binding polysaccharides. As compared to Sp245, the derivative displays notably increased heavy metal tolerance. The phenotypes of Sp245 and Sp245.5 are characterized by the following minimal inhibitory concentrations (MICs) of heavy metals: 0.5 and 0.9 μmol l(-1) of Ag(+), 0.4 and 0.7 mmol l(-1) of Co(2+), 0.9 and 4.7 mmol l(-1) of Cu(2+), and 3.1 and 11.5 mmol l(-1) of Zn(2+), respectively. In Sp245, in the presence of a nonlethal concentration (0.625 μmol l(-1)) of the efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP), the MIC of cobalt, copper, and zinc drop 1.3- to 1.6-fold, but the low tolerance to silver is unaffected. In Sp245.5, CCCP does not affect cobalt tolerance, suppresses tolerance to copper and silver to the wild-type levels, and causes a 1.4-fold decrease in resistance to zinc. Therefore, significant elevation of heavy metal tolerance in Sp245.5 seems caused by the induction/overexpression of the proton-dependent efflux of certain metal ions. The novel cell surface and other unknown factors could also be responsible for the increased tolerance of A. brasilense Sp245.5 to heavy metals.

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

    International Nuclear Information System (INIS)

    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 CaCl2 endash 26 mole percent KCl or pure CaCl2. 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

  9. 8 CFR 245.13 - Adjustment of status of certain nationals of Nicaragua and Cuba under Public Law 105-100.

    Science.gov (United States)

    2010-01-01

    ... Immigration Court in accordance with 8 CFR 240.11(f). If a request for a fee waiver is denied, the applicaion... of Nicaragua and Cuba under Public Law 105-100. 245.13 Section 245.13 Aliens and Nationality... PERMANENT RESIDENCE § 245.13 Adjustment of status of certain nationals of Nicaragua and Cuba under...

  10. 48 CFR 245.7101-3 - DD Form 1348-1, DoD Single Line Item Release/Receipt Document.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false DD Form 1348-1, DoD Single Line Item Release/Receipt Document. 245.7101-3 Section 245.7101-3 Federal Acquisition Regulations... PROPERTY Plant Clearance Forms 245.7101-3 DD Form 1348-1, DoD Single Line Item Release/Receipt...

  11. 49 CFR 40.245 - What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD?

    Science.gov (United States)

    2010-10-01

    ... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... Alcohol Screening Tests § 40.245 What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the...

  12. CHARACTERIZATION AND NUCLEOTIDE SEQUENCE DETERMINATION OF A REPEAT ELEMENT ISOLATED FROM A 2,4,5,-T DEGRADING STRAIN OF PSEUDOMONAS CEPACIA

    Science.gov (United States)

    Pseudomonas cepacia strain AC1100, capable of growth on 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), was mutated to the 2,4,5-T− strain PT88 by a ColE1 :: Tn5 chromosomal insertion. Using cloned DNA from the region flanking the insertion, a 1477-bp sequence (designated RS1100) wa...

  13. Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea.

    Science.gov (United States)

    Hunt, G J

    1998-06-01

    Our previous studies have indicated lower values of the gut transfer factor ('f1 values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Carastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 h samples of urine and faeces. Urine samples indicated f1 values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7 x 10(-4) with an arithmetic mean in the range (2-3) x 10(-4), and for americium up to 2.6 x 10(-4) with an arithmetic mean of 1.2 x 10(-4). Limited data based on volunteers eating cockles from the Solway suggest that f1 values for americium may be greater at distance from Sellafield. The measured values compare with 5 x 10(-4) used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f1 value in the region of 0.2, twice the value currently used by ICRP. For 137Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f1 = 1.0. Technetium-99 gave f1 values up to about 0.6, in reasonable conformity with the ICRP value of 0.5.

  14. Transfer across the human gut of environmental plutonium, americium, cobalt, caesium and technetium: studies with cockles (Cerastoderma edule) from the Irish Sea

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, G.J. [CEFAS Laboratory, Lowestoft, Suffolk NR33 0HT (United Kingdom)

    1998-06-01

    Our previous studies have indicated lower values of the gut transfer factor ('f{sub L} values') for plutonium and americium in winkles (Littorina littorea) than adopted by ICRP. The present study was undertaken primarily to investigate whether this observation extends to other species. Samples of cockles (Cerastoderma edule) from Ravenglass, Cumbria were eaten by volunteers who provided 24 samples of urine and faeces. Urine samples indicated f{sub L} values for cockles which were higher than for winkles; for plutonium these ranged overall up to 7x10{sup -4} with an arithmetic mean in the range (2-3)x10{sup -4}, and for americium up to 2.6x10{sup -4} with an arithmetic mean of 1.2x10{sup -4}. Limited data based on volunteers eating cockles from the Solway suggest that f{sub L} values for americium may be greater at distance from Sellafield. The measured values compare with 5x10{sup -4} used by the ICRP for environmental forms of both elements, which would appear to provide adequate protection when calculating doses from Cumbrian cockles. Data for other nuclides were obtained by analysing faecal samples from the volunteers who ate the Ravenglass cockles. Cobalt-60 showed an f{sub L} value in the region of 0.2, twice the value currently used by ICRP. For {sup 137}Cs, variabilities were indicated in the range 0.08 to 0.43, within the ICRP value of f{sub L}=1.0. Technetium-99 gave f{sub L} values up to about 0.6, in reasonable conformity with the ICRP value of 0.5. (author)

  15. Determination by gamma-ray spectrometry of the plutonium and americium content of the Pu/Am separation scraps. Application to molten salts; Determination par spectrometrie gamma de la teneur en plutonium et en americium de produits issus de separation Pu/Am. Application aux bains de sels

    Energy Technology Data Exchange (ETDEWEB)

    Godot, A. [CEA Valduc, Dept. de Traitement des Materiaux Nucleaires, 21 - Is-sur-Tille (France); Perot, B. [CEA Cadarache, Dept. de Technologie Nucleaire, Service de Modelisation des Transferts et Mesures Nucleaires, 13 - Saint-Paul-lez-Durance (France)

    2005-07-01

    Within the framework of plutonium recycling operations in CEA Valduc (France), americium is extracted from molten plutonium metal into a molten salt during an electrolysis process. The scraps (spent salt, cathode, and crucible) contain extracted americium and a part of plutonium. Nuclear material management requires a very accurate determination of the plutonium content. Gamma-ray spectroscopy is performed on Molten Salt Extraction (MSE) scraps located inside the glove box, in order to assess the plutonium and americium contents. The measurement accuracy is influenced by the device geometry, nuclear instrumentation, screens located between the sample and the detector, counting statistics and matrix attenuation, self-absorption within the spent salt being very important. The purpose of this study is to validate the 'infinite energy extrapolation' method employed to correct for self-attenuation, and to detect any potential bias. We present a numerical study performed with the MCNP computer code to identify the most influential parameters and some suggestions to improve the measurement accuracy. A final uncertainty of approximately 40% is achieved on the plutonium mass. (authors)

  16. An experimental study of americium-241 biokinetics in the Lobster Homarus Gammarus. Analysis of the accumulation/storage and detoxification processes at the subcellular level; Etude experimentale des biocinetiques de l`americium-241 chez le homard homarus gammarus. Analyse des mecanismes d`accumulation et de detoxication au niveau subcellulaire

    Energy Technology Data Exchange (ETDEWEB)

    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 {sup 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.

  17. Preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens and their use for bacterial detection.

    Science.gov (United States)

    Dykman, Lev A; Staroverov, Sergei A; Guliy, Olga I; Ignatov, Oleg V; Fomin, Alexander S; Vidyasheva, Irina V; Karavaeva, Olga A; Bunin, Viktor D; Burygin, Gennady L

    2012-01-01

    This article reports the first preparation of miniantibodies to Azospirillum brasilense Sp245 surface antigens by using a combinatorial phage library of sheep antibodies. The prepared phage antibodies were used for the first time for lipopolysaccharide and flagellin detection by dot assay, electro-optical analysis of cell suspensions, and transmission electron microscopy. Interaction of A. brasilense Sp245 with antilipopolysaccharide and antiflagellin phage-displayed miniantibodies caused the magnitude of the electro-optical signal to change considerably. The electro-optical results were in good agreement with the electron microscopic data. This is the first reported possibility of employing phage-displayed miniantibodies in bacterial detection aided by electro-optical analysis of cell suspensions.

  18. Which neuro-physiologic effects at low level 2.45 GHz RF exposure?

    International Nuclear Information System (INIS)

    The LS electromagnetic band (1-4 GHz) is widely used both in domestic and industrial domains. Several studies suggested that the biological systems would exhibit a specific sensitivity to the 2.45 GHz microwaves (water resonance frequency). Potential human health hazards and especially a disruption of the cholinergic system have been reported, due to exposure to microwaves even at low power density. This work presents a multi-parametric study of freely moving rat where neuro-physiology was investigated during 70 hours using neurochemical (micro-dialysis technique), electrophysiological, behavioral (vigilance stages quantification) and thermo-physiological approaches. The rats were exposed 24 hours to a 2.45 GHz pulsed electromagnetic field at low power density. In this exposure conditions, no significant effect have been reported. (authors)

  19. Dissertation on the computer-based exploitation of a coincidence multi parametric recording. Application to the study of the disintegration scheme of Americium 241

    International Nuclear Information System (INIS)

    After having presented the meaning of disintegration scheme (alpha and gamma emissions, internal conversion, mean lifetime), the author highlights the benefits of the use of multi-parametric chain for the recording of correlated parameters, and of the use of a computer for the analysis of bi-parametric information based on contour lines. Using the example of Americium 241, the author shows how these information are obtained (alpha and gamma spectrometry, time measurement), how they are chosen, coded, analysed and stored, and then processed by contour lines

  20. Cell investigations simultaneously with exposure to 2.45 GHz microwaves.

    Science.gov (United States)

    Martin, Diana; Cinca, Sabin; Margaritescu, Irina; Neagu, Monica; Iacob, Nicusor; Ighigeanu, Daniel; Matei, Constantin; Craciun, Gabriela; Manaila, Elena; Chirita, Doru Aurel; Moisescu, Mihaela

    2009-01-01

    The paper presents two microwave (MW) exposure systems (MWESs) that permit observations and measurements on cell cultures during their exposure to MW of 2.45 GHz: MWES-1 and MWES-2. MWES-1 is designed for the measurement of the cell membrane fluorescence anisotropies (MFA) simultaneously with MW exposure. MWES-2 is designed for the cells culture exploration under an inverted microscope before, during and after MW exposure. MWES-1 consists mainly of a 2.45 GHz microwave generator (MWG-2.45 GHz-SAIREM) of 0-25 W, equipped with forward power and reflected power displaying, and an adjustable coaxial antenna immersed directly into the cuvette with the cells-suspension of a Spex type spectrofluorometer. The MW effect on membrane fluidity of B16F10 malignant melanoma (B16F10-MM) cells in suspension were investigated with MWES-1, by MFA measurements. We observed a MW induced transition temperature (ITT) rising strongly during the MW exposure as compared with ITT obtained by classical heating (CH). The MWES-2 consists of the MWG-2.45 GHz-SAIREM generator and a rectangular waveguide applicator with traveling wave placed between the condenser and the objective of a Zeiss Axiovert 200 microscope, equipped with a fluorescence device and image acquisition. The MW effects on shape and apoptosis of the B16F10-MM cells were investigate with MWES-2. The B16F10-MM cells exhibited visible shape changes during MW exposure up to 37 degrees C. The MW exposure induced cells apoptosis/necrosis in several seconds after that MW are applied, beginning with SAR = 1.5 W/sample, compared to CH controls exposed at the same temperature dynamics. PMID:21384706

  1. Complex dielectric constants for selected near-millimeter-wave materials at 245 GHz

    Science.gov (United States)

    Dutta, J. M.; Jones, C. R.; Dave, H.

    1986-01-01

    A double-beam instrument developed in this laboratory has been used to measure the complex dielectric constant of selected materials at 245 GHz. It is reported here the results for crystalline quartz, fused silica (Spectrosil WF and Dynasil 4000), beryllia (iso-pressed), boron nitride (hot-pressed), and a nickel ferrite (Trans-Tech 2-111). Results are compared with the data obtained by other researchers.

  2. 8 CFR 245.24 - Adjustment of aliens in U nonimmigrant status.

    Science.gov (United States)

    2010-01-01

    ... section if the alien's U nonimmigrant status has been revoked pursuant to 8 CFR 214.14(h). (d) Application... member or the principal U-1 alien, would suffer extreme hardship as described in 8 CFR 245.24(g) (to the... either a U-1, U-2, U-3, U-4 or U-5 nonimmigrant, as defined in 8 CFR 214.1(a)(2), and (ii) Continues...

  3. Electrophysical characteristics of Azospirillum brasilense Sp245 during interaction with antibodies to various cell surface epitopes.

    Science.gov (United States)

    Guliy, Olga I; Matora, Larisa Y; Burygin, Gennady L; Dykman, Lev A; Ostudin, Nikolai A; Bunin, Viktor D; Ignatov, Vladimir V; Ignatov, Oleg V

    2007-11-15

    This work was undertaken to examine the electrooptical characteristics of cells of Azospirillum brasilense Sp245 during their interaction with antibodies developed to various cell surface epitopes. We used the dependences of the cell suspension optical density changes induced by electroorientation on the orienting field frequency (740, 1000, 1450, 2000, and 2800kHz). Cell interactions with homologous strain-specific antibodies to the A. brasilense Sp245 O antigen and with homologous antibodies to whole bacterial cells brought about considerable changes in the electrooptical properties of the bacterial suspension. When genus-specific antibodies to the flagellin of the Azospirillum sheathed flagellum and antibodies to the serologically distinct O antigen of A. brasilense Sp7 were included in the A. brasilense Sp245 suspension, the changes caused in the electrooptical signal were slight and had values close to those for the above changes. These findings agree well with the immunochemical characteristics of the Azospirillum O antigens and with the data on the topographical distribution of the Azospirillum major cell surface antigens. The obtained results can serve as a basis for the development of a rapid test for the intraspecies detection of microorganisms.

  4. 1,3-Substituted Imidazolidine-2,4,5-triones: Synthesis and Inhibition of Cholinergic Enzymes

    Directory of Open Access Journals (Sweden)

    Josef Jampilek

    2011-09-01

    Full Text Available A series of novel and highly active acetylcholinesterase and butyrylcholinesterase inhibitors derived from substituted benzothiazoles containing an imidazolidine-2,4,5-trione moiety were synthesized and characterized. The molecular structure of 1-(2,6-diisopropyl-phenyl-3-[(1R-1-(6-fluoro-1,3-benzothiazol-2-ylethyl]-imidazolidine-2,4,5-trione (3g was determined by single-crystal X-ray diffraction. Both optical isomers are present as two independent molecules in the triclinic crystal system. The lipophilicity of the compounds was determined as the partition coefficient log Kow using the traditional shake-flask method. The in vitro inhibitory activity on acetylcholinesterase from electric eel and butyrylcholinesterase isolated from equine serum was determined. The inhibitory activity on acetylcholinesterase was significantly higher than that of the standard drug rivastigmine. The discussed compounds are also promising inhibitors of butyrylcholinesterase, as some of the prepared compounds inhibit butyrylcholinesterase better than the internal standards rivastigmine and galanthamine. The highest inhibitory activity (IC50 = 1.66 μmol/L corresponds to the compound 1-(4-isopropylphenyl-3-[(R-1-(6-fluorobenzo[d]thiazol-2-ylethyl]imidazolidine-2,4,5-trione (3d. For all the studied compounds, the relationships between the lipophilicity and the chemical structure as well as their structure-activity relationships are discussed.

  5. 2.45 GHz Class E Power Amplifier for a Transmitter Combining LINC and EER

    Directory of Open Access Journals (Sweden)

    M. Dirix

    2009-01-01

    Full Text Available A 10 W class-E RF power amplifier (PA is designed and fabricated using a Cree GaN HEMT. The proposed PA uses an innovative input circuit to optimize band with. At 2.45 GHz the PA achieves a PAE of 60 % at an outputpower of 40 dBm. The resulting amplifier is simulated and constructed using a transmissionline topology. Two of these amplifiers are fabricated on a single board for outphasing application. Their suitability for outphasing application and supply modulation is investigated. 

  6. [Isolation and purification of Mn-peroxidase from Azospirillum brasilense Sp245].

    Science.gov (United States)

    Kupriashina, M A; Selivanov, N Iu; Nikitina, V E

    2012-01-01

    Homogenous Mn-peroxidase of a 26-fold purity grade was isolated from a culture of Azospirillum brasilense Sp245 cultivated on a medium containing 0.1 mM pyrocatechol. The molecular weight of the enzyme is 43 kD as revealed by electrophoresis in SDS-PAAG. It was shown that the use of pyrocatechol and 2,2'-azino-bis(3-ethylbenzotiazoline-6-sulfonate) at concentrations of 0.1 and I mM as inductors increased the Mn-peroxidase activity by a factor of 3.

  7. Yeast Interacting Proteins Database: YLR291C, YLR245C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available YLR291C GCD7 Beta subunit of the translation initiation factor eIF2B, the guanine-n... as a negative regulator of GCN4 expression Rows with this bait as bait (8) Rows with this bait as prey (0) YLR...ows with this prey as prey (4) Rows with this prey as bait (1) 17 5 3 5 0 0 0 0 0 - - - - - 0 0 15 - Show YLR291C Bait ORF YLR...h this bait as prey (0) Prey ORF YLR245C Prey gene name CDD1 Prey description Cytidine deaminase; catalyzes

  8. Structure, magnetic order and excitations in the 245 family of Fe-based superconductors.

    Science.gov (United States)

    Bao, Wei

    2015-01-21

    Elastic neutron scattering simultaneously probes both the crystal structure and magnetic order in a material. Inelastic neutron scattering measures phonons and magnetic excitations. Here, we review the average composition, crystal structure and magnetic order in the 245 family of Fe-based superconductors and in related insulating compounds from neutron diffraction works. A three-dimensional phase-diagram summarizes various structural, magnetic and electronic properties as a function of the sample composition. A high pressure phase diagram for the superconductor is also provided. Magnetic excitations and the theoretic Heisenberg Hamiltonian are provided for the superconductor. Issues for future works are discussed. PMID:25427222

  9. Resolved 24.5 micron emission from massive young stellar objects

    Science.gov (United States)

    de Wit, W. J.; Hoare, M. G.; Fujiyoshi, T.; Oudmaijer, R. D.; Honda, M.; Kataza, H.; Miyata, T.; Okamoto, Y. K.; Onaka, T.; Sako, S.; Yamashita, T.

    2009-01-01

    Context: Massive young stellar objects (MYSO) are surrounded by massive dusty envelopes, whose physical structure and geometry are determined by the star formation process. Aims: Our principal aim is to establish the density structure of MYSO envelopes on scales of ~1000 AU. This constitutes an increase of a factor ~10 in angular resolution compared to similar studies performed in the (sub)mm. Methods: We have obtained diffraction-limited (0.6´´) 24.5 μm images (field of view of 40 arcsec×30 arcsec) of 14 well-known massive star formation regions with the COMICS instrument mounted on the 8.2 m Subaru telescope. We construct azimuthally averaged intensity profiles of the resolved MYSO envelopes and build spectral energy distributions (SEDs) from archival data and the COMICS 24.5 μm flux density. The SEDs range from near-infrared to millimeter wavelengths. Self-consistent 1-D radiative transfer models described by a density dependence of the form n(r) ∝ r-p are used to simultaneously compare the intensity profiles and SEDs to model predictions. Results: The images reveal the presence of discrete MYSO sources which are resolved on arcsecond scales, and, to first-order, the observed emission is circular on the sky. For many sources, the spherical models are capable of satisfactorily reproducing the 24.5 μm intensity profile, the 24.5 μm flux density, the 9.7 μm silicate absorption feature, and the submm emission. They are described by density distributions with p =1.0±0.25. Such distributions are shallower than those found on larger scales probed with single-dish (sub)mm studies. Other sources have density laws that are shallower/steeper than p=1.0 and there is evidence that these are viewed near edge-on or near face-on respectively. In these cases spherical models fail to provide good fits to the data. The images also reveal a diffuse component tracing somewhat larger scale structures, particularly visible in the regions S 140, AFGL 2136, IRAS 20126

  10. Inhaled americium dioxide

    International Nuclear Information System (INIS)

    This project includes experiments to determine the effects of Zn-DTPA therapy on the retention, translocation and biological effects of inhaled 241AmO2. Beagle dogs that received inhalation exposure to 241AmO2 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 241Am. Another group of dogs that received inhalation exposure to 241AmO2 and were treated daily with Zn-DTPA had initial pulmonary deposition of 19 to 26 μCi 241Am. These dogs did not develop respiratory insufficiency, and hematologic and clinical chemistry changes were less severe than in the non-DTPA-treated dogs

  11. Evaluation of isopentane, R-245fa and their mixtures as working fluids for organic Rankine cycles

    International Nuclear Information System (INIS)

    Low grade thermal energy from sources such as solar, geothermal and industrial waste heat in the temperature range of 380–425 K can be converted to electrical energy with reasonable efficiency using isopentane and R-245fa. While the former is flammable and the latter has considerable global warming potential, their mixture in 0.7/0.3 mole fraction is shown to obviate these disadvantages and yet retain dominant merits of each fluid. A realistic thermodynamic analysis is carried out wherein the possible sources of irreversibilities such as isentropic efficiencies of the expander and the pump and entropy generation in the regenerator, boiler and condenser are accounted for. The performance of the system in the chosen range of heat source temperatures is evaluated. A technique of identifying the required source temperature for a given output of the plant and the maximum operating temperature of the working fluid is developed. This is based on the pinch point occurrence in the boiler and entropy generation in the boiling and superheating regions of the boiler. It is shown that cycle efficiencies of 10–13% can be obtained in the range investigated at an optimal expansion ratio of 7–10. -- Highlights: ► Non-water based working fluids and their mixtures for power generation. ► Results for isopentane, R-245fa and their mixtures. ► Appropriation of irreversibilities in cycle components. ► Entropy generation based identification of heat source temperature

  12. Adsorption and photodegradation kinetics of herbicide 2,4,5-trichlorophenoxyacetic acid with MgFeTi layered double hydroxides.

    Science.gov (United States)

    Nguyen, Thi Kim Phuong; Beak, Min-wook; Huy, Bui The; Lee, Yong-Ill

    2016-03-01

    The calcined layered double hydroxides (cLDHs) Ti-doped and undoped MgFe for this study were prepared by co-precipitation method followed by calcination at 500 °C. The as-prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer Emmett Teller (BET) and UV-Vis diffuse reflectance spectrum (DRS) techniques and tested for adsorption and photodegradation (including photocatalytic and photo-Fenton-like) of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in aqueous solutions under visible light irradiation. In the range of studied operating conditions, the as-prepared samples exhibited excellent photo-Fenton-like activity, leading to more than 80-95% degradation of 2,4,5-T at initial concentration of 100 mg L(-1) with 4 g calcined LDHs per liter, was accomplished in 360 min, while 2,4,5-T half-life time was as short as 99-182 min. The kinetics of adsorption and photodegradation of 2,4,5-T were also discussed. These results offered a green, low cost and high efficiency photocatalyst for environmental remediation. PMID:26706931

  13. 2,4,5-三硝基咪唑铵盐新法合成及性能%Synthesis and Performance of Ammonium 2,4,5-Trinitroimidazole

    Institute of Scientific and Technical Information of China (English)

    侯可辉; 刘祖亮; 张华燕; 成健

    2013-01-01

    设计了2,4,5-三硝基咪唑铵盐新的合成方法,以4-硝基咪唑为原料,经碘代、硝化得到2,4,5-三硝基咪唑,再与氨水成盐合成了目标化合物,总收率33.3%,并采用质谱、红外光谱等进行了结构表征.利用DSC和TG研究了2,4,5-三硝基咪唑铵盐的热性能,其熔解温度为254.52℃,分解温度为308.31℃,热重变化范围为203.6 ~399.9℃,总共失重94%.2,4,5-三硝基咪唑铵盐摩擦感度2%,撞击感度为18%,是一种低感炸药.%Ammonium 2,4,5-trinitroimidazole was synthesized by a new methodising 4-nitroimidazole as primary materials,followed by iodinaton,nitralysis and salifying with ammonia in yield of 33.3%. The structure was confirmed by MS and IR. Thermal behavior of ammonium 2,4,5-trinitroimidazole was studied by DSC and TG,melting and decomposition temperatures are 254.52℃ and 308.31 ℃, and the mass loss due to overall reaction (203.6 -399.9 ℃) is 94%. Friction and impact sensitivities are 2% and 18% .respectively,and it was a low sensitivity energetic materials.

  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. Partitioning studies in China and the separation of americium and fission product rare earths with dialkyl phosphinic acid and its thio-substituted derivatives

    International Nuclear Information System (INIS)

    Studies on the TRPO extractions process for recovering actinides from highly active waste (HAW) and its application to the pretreatment of Chinese HAW are described. The removal of Sr by di-cyclohexyl 18 crown 6 and the removal of Cs by spherical titanium ferrous hexa-cyanate from acidic waste are also described. Results of the extraction of trivalent americium and fission product rare earths (FPREs) by dialkyl-phosphinic, dialkyl-mono-thio-phosphinic and dialkyl-di-thio-phosphinic acids are reported. Dialkyl-thio-phosphinic acid (commercial product Cyanex 301, alkyl =2, 4, 4-methyl-pentyl) shows very high selectivity towards Am. Using 1M Cyanex 301 -kerosene as extractant, 99.9 % Am can be separated from 0.5M(Pr+Nd)(NO3)3 solution with 3-4 extraction stages and 3-4 scrubbing stages. (authors)

  16. Theoretical and experimental study of the bio-geochemical behaviour of americium 241 in simplified rhizosphere conditions. Application to a calcareous agricultural soil

    International Nuclear Information System (INIS)

    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 241Am 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. 241Am remobilization has been studied at the laboratory using leaching experiments performed in controlled conditions on reworked calcareous soils artificially contaminated with 241Am. 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, Fetot, organic acids, 241Am) and its bacterial biomass content too. The overall results indicate that 241Am 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 (10-4 M) re-mobilizes only a very small part of the americium fixed on the solid phase. The desorption of 241Am corresponds to a solid/liquid coefficient of partition (Kd) of about 105 L.kg-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 241Am remobilization. On the other hand, the presence of strong citrate concentrations (≥ 10-2 M) allows 300 to 10000 time greater re-mobilizations by the complexing of 241Am released after the dissolution of the carrying phases. Finally, the colloidal transport of 241Am has been systematically observed in a limited but significant extend and

  17. 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)

    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 239Pu containing 8-12% 240Pu (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 241Am 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 241Am, 243Am and 244Cm. 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 241Am 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)

  18. Magnetocaloric Effect of Ni56Mn18.8Ga24.5Gd0.7 Alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    With the addition of Gd, the Ni56Mn18.8Ga24.5Gd0.7 alloy exhibits non-modulated martensite phase at room temperature. From the illustration of Gd microstructure, it can be found that Gd exists along the subgrain boundaries. Hence,he crystalline size decreases and the mechanical properties improve. Ac-susceptibility results show that Ni56Mn18.8Ga24.5Gd0.7 alloy still undergoes simultaneous structural and magnetic transitions and transforms from ferromagnetic martensitic phase to paramagnetic austenitic phase with increasing temperature. The maximum magnetic entropy change is 13.4 J· (kg· K) - 1 under 1.9 T field at 338 K. The giant magnetocaloric effect found in Ni56Mn18.8Ga24.5Gd0.7 alloy is attributed to the concurrently occurring first-order structural- and magnetic-phase transitions.

  19. Formation of a Tidal Dwarf Galaxy in the Interacting System Arp 245 (NGC 2992/93)

    Science.gov (United States)

    Duc, P.-A.; Brinks, E.; Springel, V.; Pichardo, B.; Weilbacher, P.; Mirabel, I. F.

    2000-09-01

    Among the various phenomena observed in interacting galaxies is the ejection due to tidal forces of stellar and gaseous material into the intergalactic medium and its subsequent rearranging which can lead to the formation of self-gravitating tidal dwarf galaxies (TDGs). We investigate this process with a detailed multiwavelength study of the interacting system Arp 245 and a numerical model of the collision computed with a Tree-SPH code. Our observations consist of optical/near-infrared broadband imaging, Hα imaging, optical spectroscopy, H I VLA cartography and CO line mapping. The system, composed of the two spiral galaxies NGC 2992 and NGC 2993, is observed at an early stage of the interaction, about 100 Myr after perigalacticon, though at a time when tidal tails have already developed. The VLA observations disclose a third partner to the interaction: an edge-on, flat galaxy, FGC 0938, which looks strikingly undisturbed and might just be falling toward the NGC 2992/93 system. Our H I map shows prominent counterparts to the optical tails. Whereas the stellar and gaseous components of the plume that originates from NGC 2992 match, the stellar and H I tails emanating from NGC 2993 have a different morphology. In particular, the H I forms a ring, a feature that has been successfully reproduced by our numerical simulations. The H I emission in the system as a whole peaks at the tip of the NGC 2992 tail where a gas reservoir of about 109 Msolar, about 60% of the H I toward NGC 2992, coincides with a star-forming optical condensation, A245N. The latter tidal object exhibits properties ranging between those of dwarf irregular galaxies (structural parameters, gas content, star formation rate) and those of spiral disks (metallicity, star formation efficiency, stellar population). Although it is likely, based on our analysis of the H I and model data cube, that A245N might become an independent dwarf galaxy, the dynamical evidence is still open to debate. Prompted by the

  20. Assessment of americium and curium transmutation in magnesia based targets in different spectral zones of an experimental accelerator driven system

    Science.gov (United States)

    Haeck, W.; Malambu, E.; Sobolev, V. P.; Aït Abderrahim, H.

    2006-06-01

    The potential to incinerate minor actinides (MA) in a sub-critical accelerator-driven system (ADS) is a subject of study in several countries where nuclear power plants are present. The performance of the MYRRHA experimental ADS, as to the transmutation of Am and Cm in the inert matrix fuel (IMF) samples consisting of 40 vol.% (Cm0.1Am0.5Pu0.4)O1.88 fuel and 60 vol.% MgO matrix with a density of 6.077 g cm-3 in three various spectrum regions, were analysed at the belgian nuclear research centre SCK · CEN. The irradiation period of 810 effective full power days (EFPD) followed by a storage period of 2 years was considered. The ALEPH code system currently under development at SCK · CEN was used to carry out this study. The total amount of MA is shown to decrease in all three considered cases. For Am, the decrease is the largest in the reflector (89% decrease) but at the cost of a net Cm production (92% increase). In the two other positions (inside the core region), 20-30% of Am has disappeared but with a lower production of Cm (between 7% and 11%). In the reflector, a significant build-up of long-lived 245Cm, 246Cm, 247Cm and 248Cm was also observed while the production of these isotopes is 10-1000 times smaller in the core. The reduction of the Pu content is also the highest in the reflector position (41%). In the other positions the incinerated amount of Pu is much smaller: 1-5%.

  1. A 0.35μm CMOS Mixer for 2.45-GHz RFID Application

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A RF mixer with both low noise and high linearity is designed,operating at 2.45-GHz ISM band for RFID application.The designed mixer uses an optimal input matching network and the carefully chosen sizes of transistors,also with the appropriate bias point,to improve the noise figure(NF).Also,with a resonant LC loop as the current source and a parallel PMOS-resistor as the load,the mixer has a high linearity.The post simulation results show that the single side- band noise figure of 8.57 dB,conversion gain of 10.02 dB,input 1-dB compression point(P-1dB)of-8.33 dBm,and input third-order intercept point(IIP3)of 5.35 dBm.

  2. Local atomic structure in equilibrium and supercooled liquid Zr(75.5)Pd(24.5).

    Science.gov (United States)

    Mauro, N A; Fu, W; Bendert, J C; Cheng, Y Q; Ma, E; Kelton, K F

    2012-07-28

    Atomic structures were obtained in equilibrium and supercooled eutectic Zr(75.5)Pd(24.5) liquids by in situ high-energy synchrotron diffraction measurements using the beamline electrostatic levitation (BESL) technique, which provides a high-vacuum, containerless, environment. Reverse Monte Carlo fits to the x-ray static structure factors, constrained using partial pair correlation functions obtained from ab initio molecular dynamics simulations, indicate the presence of medium-range order (MRO) in the form of a strong tendency for Pd-Pd (solute-solute) avoidance. This order persists over the entire temperature range studied, from 170 °C above the equilibrium liquidus temperature to 263 °C below it. Further, a quantitative analysis of the atomic structures obtained indicates a modest degree of icosahedral-like local order around Pd atoms, with the clusters showing an increased tendency for face-sharing to form more extended structures with decreasing temperature. PMID:22852625

  3. VUV irradiance measurement of a 2.45 GHz microwave-driven hydrogen discharge

    CERN Document Server

    Komppula, J; Kalvas, T; Koivisto, H; Kronholm, R; Laulainen, J; Myllyperkiö, P

    2015-01-01

    Absolute values of VUV-emission of a 2.45 GHz microwave-driven hydrogen discharge are reported. The measurements were performed with a robust and straightforward method based on a photodiode and optical filters. It was found that the volumetric photon emission rate in the VUV-range (80-250 nm) is $10^{16}$-$10^{17}$ 1/cm$^3$s, which corresponds to approximately 8% dissipation of injected microwave power by VUV photon emission. The volumetric emission of characteristic emission bands was utilized to diagnostics of molecular plasma processes including volumetric rates of ionization, dissociation and excitation to high vibrational levels and metastable states. The estimated reaction rates imply that each injected molecule experiences several inelastic electron impact collisions. The upper limit for the total density of metastable neutrals ($2S$ atoms and $c^3\\Pi_u$ molecules) was estimated to be approximately 0.5% of the neutral gas density.

  4. VUV irradiance measurement of a 2.45 GHz microwave-driven hydrogen discharge

    Science.gov (United States)

    Komppula, J.; Tarvainen, O.; Kalvas, T.; Koivisto, H.; Kronholm, R.; Laulainen, J.; Myllyperkiö, P.

    2015-09-01

    Absolute values of VUV-emission of a 2.45 GHz microwave-driven hydrogen discharge are reported. The measurements were performed with a robust and straightforward method based on a photodiode and optical filters. It was found that the volumetric photon emission rate in the VUV-range (80-250 nm) is 1016-1017 cm-3 s-1, which corresponds to approximately 8% dissipation of injected microwave power by VUV photon emission. The volumetric emission of characteristic emission bands was utilized to diagnostics of molecular plasma processes including volumetric rates of ionization, dissociation and excitation to high vibrational levels and metastable states. The estimated reaction rates imply that each injected molecule experiences several inelastic electron impact collisions. The upper limit for the total density of metastable neutrals (2S atoms and {{c}3}{{\\Pi}u} molecules) was estimated to be approximately 0.5% of the neutral gas density.

  5. Yeast Interacting Proteins Database: YNL189W, YLR245C [Yeast Interacting Proteins Database

    Lifescience Database Archive (English)

    Full Text Available may also play a role in regulation of protein degradation Rows with this bait as bait (55) Rows with this bait as prey... and cytoplasm Rows with this prey as prey (4) Rows with this prey as bait (1) 67 5 4 8 0 0 0 0 0 - - - - - ...ein degradation Rows with this bait as bait Rows with this bait as bait (55) Rows with this bait as prey... Rows with this bait as prey (0) Prey ORF YLR245C Prey gene name CDD1 Prey descriptio...ave not been identified, localizes to both the nucleus and cytoplasm Rows with this prey as prey Rows with this prey as prey

  6. The Formation of Tidal Dwarf Galaxies in Interacting Systems: the Case of Arp 245 (NGC 2992/93)

    Science.gov (United States)

    Brinks, Elias; Duc, Pierre-Alain; Springel, Volker; Pichardo, Barbara; Weilbacher, Peter; Mirabel, Felix

    We present some highlights of our multi-wavelength study, which involves optical broad- and narrow-band imaging, long-slit spectroscopy, high-resolution HI and CO observations, of the interacting system Arp 245. This object consists of the galaxies NGC 2992 and NGC 2993. Based on a numerical model of the collision, which was computed with a Tree-SPH code, we derive that Arp 245 is observed at an early stage of the interaction, about 100 Myr after perigalacticon, though at a time when tidal tails have already developed. At the tip of the NGC 2992 tail we find a gas reservoir of about 10^9M_odot, or about 60% of the HI which is seen towards NGC 2992, which coincides with what appears to be a star-forming tidal dwarf galaxy, A245N. The TDG A245N exhibits properties ranging between those of dwarf irregular galaxies (structural parameters, gas content, star formation rate) and those of spiral disks (metallicity, star formation efficiency, stellar population). We speculate what the required conditions are to form a TDG, and how they can be distinguished from field dwarf irregulars.

  7. 12 CFR 24.5 - Public welfare investment after-the-fact notice and prior approval procedures.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Public welfare investment after-the-fact notice... OTHER PUBLIC WELFARE INVESTMENTS § 24.5 Public welfare investment after-the-fact notice and prior... outstanding public welfare investments and commitments, including the investment that is the subject of...

  8. 24 CFR 245.417 - Initial submission of materials to HUD: Conversion of residential units to a nonresidential use...

    Science.gov (United States)

    2010-04-01

    ... HUD: Conversion of residential units to a nonresidential use, or to cooperative housing or... Covered Action § 245.417 Initial submission of materials to HUD: Conversion of residential units to a nonresidential use, or to cooperative housing or condominiums. In the case of a conversion of residential...

  9. 8 CFR 245a.4 - Adjustment to lawful resident status of certain nationals of countries for which extended...

    Science.gov (United States)

    2010-01-01

    ...) Legalization Provisions § 245a.4 Adjustment to lawful resident status of certain nationals of countries for..., provided they meet the continuous residence requirements, and are otherwise eligible for legalization. (7... legalization status. (12) Through the passage of time means through the expiration date of the...

  10. 30 CFR 250.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

    Science.gov (United States)

    2010-07-01

    ... analysis must be consistent with the EPA's risk management plan methodologies outlined in 40 CFR part 68. ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What hydrogen sulfide (H2S) information must... Documents (docd) § 250.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?...

  11. 8 CFR 245.7 - Adjustment of status of certain Soviet and Indochinese parolees under the Foreign Operations...

    Science.gov (United States)

    2010-01-01

    ... adjustment is filed, (3) Is admissible to the United States as an immigrant, except as provided in paragraph... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of status of certain Soviet and... ADJUSTMENT OF STATUS TO THAT OF PERSON ADMITTED FOR PERMANENT RESIDENCE § 245.7 Adjustment of status...

  12. Spontaneous Super-Swarming Derivatives of Azospirillum brasilense Sp245 have Different DNA Profiles and Behavior in the Presence of Various Nitrogen Sources.

    Science.gov (United States)

    Varshalomidze, Olga E; Petrova, Lilia P; Shelud'ko, Andrei V; Katsy, Elena I

    2012-12-01

    Azospirillum brasilense swims in liquid environments and swarms in semisolid media. Five variants of A. brasilense Sp245, Sp245.P1-Sp245.P5, which swarmed faster than Sp245 in a semisolid malate-salt medium, have been isolated. In Sp245.P1-Sp245.P4, a new megaplasmid was revealed instead of an indigenous 85-MDa plasmid (p85). By polymerase chain reactions (PCR) with primers to the segments of p85 important for proper bacterial motility/flagellation and for dissimilatory nitrite and NO reduction, that DNA of p85 was found retained by all the variants. In ERIC- and RAPD-PCR, microdiversity between the total DNAs of Sp245 and its variants was detected. Interstrain differences in growth characteristics in liquid peptone-succinate-salt medium with KNO3 or KNO2 and in KNO2 production/consumption were revealed. Although all the variants swam and swarmed faster than Sp245 in the medium supplemented with NH4Cl or KNO3, not all of them could do so in MPSS with KNO2.

  13. USP2-45 Is a Circadian Clock Output Effector Regulating Calcium Absorption at the Post-Translational Level.

    Directory of Open Access Journals (Sweden)

    Daniel Pouly

    Full Text Available The mammalian circadian clock influences most aspects of physiology and behavior through the transcriptional control of a wide variety of genes, mostly in a tissue-specific manner. About 20 clock-controlled genes (CCGs oscillate in virtually all mammalian tissues and are generally considered as core clock components. One of them is Ubiquitin-Specific Protease 2 (Usp2, whose status remains controversial, as it may be a cogwheel regulating the stability or activity of core cogwheels or an output effector. We report here that Usp2 is a clock output effector related to bodily Ca2+ homeostasis, a feature that is conserved across evolution. Drosophila with a whole-body knockdown of the orthologue of Usp2, CG14619 (dUsp2-kd, predominantly die during pupation but are rescued by dietary Ca2+ supplementation. Usp2-KO mice show hyperabsorption of dietary Ca2+ in small intestine, likely due to strong overexpression of the membrane scaffold protein NHERF4, a regulator of the Ca2+ channel TRPV6 mediating dietary Ca2+ uptake. In this tissue, USP2-45 is found in membrane fractions and negatively regulates NHERF4 protein abundance in a rhythmic manner at the protein level. In clock mutant animals (Cry1/Cry2-dKO, rhythmic USP2-45 expression is lost, as well as the one of NHERF4, confirming the inverse relationship between USP2-45 and NHERF4 protein levels. Finally, USP2-45 interacts in vitro with NHERF4 and endogenous Clathrin Heavy Chain. Taken together these data prompt us to define USP2-45 as the first clock output effector acting at the post-translational level at cell membranes and possibly regulating membrane permeability of Ca2+.

  14. 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

    2016-03-01

    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. PMID:26907589

  15. Plasma studies and beam emittance measurements of 2.45 GHz microwave ion source at VECC

    International Nuclear Information System (INIS)

    A 2.45 GHz microwave ion source operating at VECC is able to produce a total beam current of ∼ 12 mA at a beam energy of 75 KeV with a microwave power of 400 W as described in. In order to optimize the performance of the ion source, we have conducted systematic studies with the variation of ion source gas flow rate, magnetic field, extraction voltage, suppressor voltage, microwave power etc. The total extracted beam current was recorded as a function of each of the earlier mentioned parameters. Moreover, we have studied the effect on extracted beam current and its transmission in the beam transport line due to dielectric and water introduction into the plasma chamber. In the best setting, we have found a total extracted beam current of 12.5 mA with a beam transmission of 70 %. Furthermore, we have also studied the extracted beam current and its transmission in the beam transport line using aluminum plasma chamber of different diameters. Finally, we have estimated the beam emittance by solenoid scan technique of a neutralized 75 KeV, 5 mA proton beam by measuring beam profile using a non-interceptive residual gas fluorescence monitor. The measured normalized rms emittance of the neutralized beam is 0.05 mm-mrad, which seems to be quite reasonable. (author)

  16. Flexible indium-gallium-zinc-oxide Schottky diode operating beyond 2.45 GHz.

    Science.gov (United States)

    Zhang, Jiawei; Li, Yunpeng; Zhang, Binglei; Wang, Hanbin; Xin, Qian; Song, Aimin

    2015-01-01

    Mechanically flexible mobile phones have been long anticipated due to the rapid development of thin-film electronics in the last couple of decades. However, to date, no such phone has been developed, largely due to a lack of flexible electronic components that are fast enough for the required wireless communications, in particular the speed-demanding front-end rectifiers. Here Schottky diodes based on amorphous indium-gallium-zinc-oxide (IGZO) are fabricated on flexible plastic substrates. Using suitable radio-frequency mesa structures, a range of IGZO thicknesses and diode sizes have been studied. The results have revealed an unexpected dependence of the diode speed on the IGZO thickness. The findings enable the best optimized flexible diodes to reach 6.3 GHz at zero bias, which is beyond the critical benchmark speed of 2.45 GHz to satisfy the principal frequency bands of smart phones such as those for cellular communication, Bluetooth, Wi-Fi and global satellite positioning. PMID:26138510

  17. 管束效应对HFC245fa与HCFC123膜状凝结换热影响%Effect of Inundation on Film Condensation of HFC245fa and HCFC123 on Horizontal Tubes

    Institute of Scientific and Technical Information of China (English)

    马志先; 张吉礼; 孙德兴

    2012-01-01

    建立试验系统、改进试验方法,试验研究HFC245fa与HCFC123在光管与3种强化换热管(2D-A,3D-A与3D-B)管束外冷凝换热特性.试验管束由4列排深为5排的列管构成,换热管公称外径为19.05 mm、有效换热长度为500 mm.试验中,利用改进的Wilson图解法获得水侧对流传热系数,通过轮转试验方法消除管束试验中各试验管换热本构差异等因素对管束效应测试分析的影响.试验结果表明,Kern模型预测值与HFC245fa与HCFC123光管管束外凝结换热结果偏差随试验热通量升高而增大;管束效应对光管与三维表面强化管(3D-B)凝结换热影响比其对二维表面低肋管(2D-A)影响显著;管束效应对HFC245fa在3D-B管外凝结换热影响在n>3后超过Nusselt管束模型预测值;HFC245fa在3D-B管束外凝结换热性能随管排深度的变化规律与其在光管管束外的变化规律及Nusselt模型显示规律明显不同.%A test facility was constructed to perform shell-side condensation testing, and test results are presented for HFC245fa and HCFC123 using horizontal tube bundles (4 lines×5 rows) consist of smooth tubes and 2D-A, 3D-A and 3D-B enhanced tubes. Effect of inundation on the condensation heat transfer coefficient (CHTC) is considered in the study. The nominal diameter of test tubes is 19.05 mm and the active length of the test section is 500 mm. In the experiment, water-side convection heat transfer coefficient of enhanced tube was gained by modified Wilson plot method and the tube row effect is studied by a designed method with high precision. The results show that the deviation between CHTC of HCFC123 and HFC245fa on smooth tube bundle and that predicted by Kern's model increased with the increase of heat flow rate; Inundation effect significantly affects CHTC of smooth and 3D-B tubes, but lightly affects that of 2D-A tubes; Inundation effect of HFC245fa on 3D-B tubes is more severity than that predicted by Nusselt model for

  18. 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).

  19. The recycling of the actinides neptunium, americium and curium in a fast power reactor to reduce the long term activity in a final store

    International Nuclear Information System (INIS)

    The starting point for the considerations and calculations given in this dissertation is the inevitable production of radioactive materials in the use of nuclear energy, which creates a considerable potential danger in a final store for a very long period. As one possibility of alleviating this problem, a concept for recycling the waste actinides neptunium, americium and curium was proposed. The waste actinides are separated in the reprocessing of burnt-up fuel elements and reach a further irradiation circuit. There they pass through the stages 'manufacture of irradiation elements', 'use in a fast power reactor' and reprocessing of irradiation elements' several times. In each irradiation and subsequent storage, about 17% of the waste actinides are removed by fission or by conversion into nuclides which can be reused as fuel, so that during the life of 40 years of the fast recycling reacor, the waste actinides can be reduced in mass by one half. In order to determine this mass reduction effect, a model calculation was developed, which includes the representation of the neutron physics and thermal properties of the reactor core and the storage and reprocessing of the irradiation elements. (orig./RB)

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

    International Nuclear Information System (INIS)

    The paper presents a new sampling method for studying in-body radioactive contamination by bone-seeking radionuclides such as 90Sr, 239+240Pu, 238Pu, 241Am 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 238Pu 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 90Sr 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).

  1. The estimation of reactions of hematopoietic systems of organisms to the effect, caused by americium and plutonium, of nuclear industry workers

    Energy Technology Data Exchange (ETDEWEB)

    Gasteva, G. N.; Ivanova, T. A.; Gordeeva, A. A.; Suvorova, L. A.; Molokanov, A. A.; Badine, I.

    2004-07-01

    Object of research are the workers having in an organism radioactive substance (Am-241 and Pu-239). The purpose of work was the estimation of reaction hemopoietic systems of an organism on influence of americium and plutonium at workers of the nuclear industry. At the surveyed contingent of persons the determined effects caused by total influence Am-241 and Pu-239 are ascertained; chronic radiation disease with development, besides diffusive a pneumoscleoris and a chronic toxic-chemical radiating bronchitis, reactions of system of blood, jet hepatopathy which frequency accrued with increase doses loadings and essentially did not depend on age. In peripheral blood on the foreground jet changes act: hyperglobulia, the tendency to neutrophilus leukocytosis, monocytosis, increase ESR, decrease (reduction ?/G of factor reflecting weight and processing of defeat bronchus and pulmonary of system. Stable downstroke in number thrombocytes and reticulocytes in peripheral blood, their direct dependence on a doze of an irradiation, reflect hypoplastic a background hemogenesis, caused by long influence incorporatedin a bone and a bone brain of radioactive substances. At cytologic research punctate a bone brain jet changes which are expressed in increase of functional activity erythro-and myelopoiesiscome to light and provide compensatory reaction of peripheral blood. At histologic research of a bone brain and a bone fabric attributes of development atrophic process which is expressed in reduction of volume parenchyma a bone brain (a fatty atrophy) and dysplasia to a bone fabric are observed.

  2. A novel polymeric catalyst for the one-pot synthesis of 2,4,5-triaryl-1H-imidazoles

    Indian Academy of Sciences (India)

    Ali Mohammadi; Hossein Keshvari; Reza Sandaroos; Hamed Rouhi; Zeinalabedin Sepehr

    2012-05-01

    An efficient synthesis of 2,4,5-trisubstituted imidazoles is achieved by three component cyclocondensation of benzil or benzoin, aldehyde and ammonium acetate by using novel polymeric catalyst [poly(AMPS-co-AA)] under solvent-free conditions. The key advantages of this process are high yields, shorter reaction times, easy work-up, purification of products by non-chromatographic method and the reusability of the catalyst.

  3. Experimental evidence of E × B plasma rotation in a 2.45 GHz hydrogen discharge

    Energy Technology Data Exchange (ETDEWEB)

    Cortázar, O. D., E-mail: daniel.cortazar@uclm.es [Institute for Energy Research-INEI, University of Castilla-La Mancha, C.J. Cela s/n, 13170 Ciudad Real (Spain); Megía-Macías, A. [CERN, BE-ABP-HSL Department, CH1211 Geneva (Switzerland); E.S.S. Bilbao, Polígono Ugaldeguren III, A-7B, 48170 Zamudio (Spain); Tarvainen, O.; Koivisto, H. [Department of Physics, Accelerator Laboratory, University of Jyväskylä, PO Box 35 (YFL), 40500 Jyväskylä (Finland)

    2015-12-15

    An experimental observation of a rotating plasma structure in a 2.45 GHz microwave-driven hydrogen discharge is reported. The rotation is presumably produced by E × B drift. The formation of the rotating plasma structure is sensitive to the strength of the off-resonance static magnetic field. The rotation frequency is on the order of 10 kHz and is affected by the neutral gas pressure and applied microwave power.

  4. Polarization of Unbalanced Antennas for Ear-to-Ear On-Body Communications at 2.45 GHz

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2011-01-01

    The impact of antenna polarization on the earto- ear transmission channel at 2.45 GHz is investigated. Two antenna configurations have been considered for monopole antennas operated on small ground planes that are placed next to the human head. The two setups provide different current distributions...... on the ground planes, which has a drastic impact on the antenna polarization. Their performances are compared in terms of maximum path gain (|S21|) and obtainable bandwidth of the antenna structures....

  5. Bit error rate analysis of Wi-Fi and bluetooth under the interference of 2.45 GHz RFID

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    IEEE 802.11b WLAN (Wi-Fi) and IEEE 802.15.1 WPAN (bluetooth) are prevalent nowadays, and radio frequency identification (RFID) is an emerging technology which has wider applications. 802.11b occupies unlicensed industrial, scientific and medical (ISM) band (2.4-2.483 5 GHz) and uses direct sequence spread spectrum (DSSS) to alleviate the narrow band interference and fading. Bluetooth is also one user of ISM band and adopts frequency hopping spread spectrum (FHSS) to avoid the mutual interference. RFID can operate on multiple frequency bands, such as 135 KHz, 13.56 MHz and 2.45 GHz. When 2.45 GHz RFID device, which uses FHSS, collocates with 802.11b or bluetooth, the mutual interference is inevitable. Although DSSS and FHSS are applied to mitigate the interference, their performance degradation may be very significant. Therefore, in this article, the impact of 2.45 GHz RFID on 802.11b and bluetooth is investigated. Bit error rate (BER) of 802.11b and bluetooth are analyzed by establishing a mathematical model, and the simula-tion results are compared with the theoretical analysis to justify this mathematical model.

  6. Purification and characterization of β-Fructosidase with inulinase activity from Aspergillus niger - 245

    Directory of Open Access Journals (Sweden)

    Vinícius D'Arcadia Cruz

    1998-01-01

    Full Text Available Aspergillus niger - 245, a strain isolated from soil samples showed good β-fructosidase activity when inoculated in medium formulated with dahlia extract tubers. The enzyme was purified by precipitation in ammonium sulphate and percolated in DEAE-Sephadex A-50 and CM-cellulose columns, witch showed a single peack in all the purification steps, maintaining the I/S ratio between 0.32 to, 0.39. Optimum pH for inulinase activity (I was between 4.0 - 4.5 and for invertase activity (S between 2.5 and 5.0. The optimum temperature was 60O.C for both activities and no loss in activity was observed when it was maintained at this temperature for 30 min. The Km value was 1.44 and 5.0, respectively, for I and S and Vm value 10.48 and 30.55, respectively. The I activity was strongly inhibited by Hg2+ and Ag+ and 2 x 10-3 M of glucose, but not by fructose at the same concentration. The enzyme showed an exo-action mechanism, acting on the inulin of different origins. In assay conditions total hydrolysis of all the frutans was obtained, although it has shown larger activity on the chicory inulin than that one from artichoke Jerusalem and dahlia, in the first 30 min. The obtained results suggested that the enzyme presented good potential for industrial application in the preparing the fructose syrupsAspergillus niger - 245, isolado do solo mostrou boa atividade de b-frutosidase meio formulado com extrato de tubérculos de dahlia. A enzima foi purificada por precipitação em sulfato de amônia e percolada em colunas de DEAE-Sephadex A-50 e CM-celulose, produzindo um único pico em todas as fases de purificação e mantendo a relação I/S entre 0,32 a 0,39. O pH ótimo para a atividade de inulinase (I foi encontrado entre 4,0 - 4.5 e para a atividade de invertase (S em 2,5 e 5,0. A temperatura ótima foi de 60O.C para ambas as atividades e nenhuma perda foi observada quando mantida nesta temperatura por 30 min. Os valores de Km foram de 1,44 e 5

  7. Review of Australian health economic evaluation – 245 interventions: what can we say about cost effectiveness?

    Directory of Open Access Journals (Sweden)

    Mortimer Duncan

    2008-05-01

    Full Text Available Abstract Background There is an increasing body of published cost-utility analyses of health interventions which we sought to draw together to inform research and policy. Methods To achieve consistency in costing base and policy context, study scope was limited to Australian-based cost-effectiveness analyses. Through a comprehensive literature review we identified 245 health care interventions that met our study criteria. Results The median cost-effectiveness ratio was A$18,100 (~US$13,000 per QALY/DALY/LY (quality adjusted life year gained or, disability adjusted life year averted or life year gained. Some modalities tended to perform worse, such as vaccinations and diagnostics (median cost/QALY $58,000 and $68,000 respectively, than others such as allied health, lifestyle, in-patient interventions (median cost/QALY/DALY/LY all at ~A$9,000~US$6,500. Interventions addressing some diseases such as diabetes and impaired glucose tolerance or alcohol and drug dependence tended to perform well (median cost/QALY/DALY/LY 25 years (median cost/QALY/DALY/LY Conclusion For any given condition, modality or setting there are likely to be examples of interventions that are cost effective and cost ineffective. It will be important for decision makers to make decisions based on the individual merits of an intervention rather than rely on broad generalisations. Further evaluation is warranted to address gaps in the literature and to ensure that evaluations are performed in areas with greatest potential benefit.

  8. 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.)

  9. Composites of surface imprinting polymer capped Mn-doped ZnS quantum dots for room-temperature phosphorescence probing of 2,4,5-trichlorophenol

    International Nuclear Information System (INIS)

    In this paper, a simple procedure for the determination of 2,4,5-trichlorophenol (2,4,5-TCP) is reported. Mn-doped ZnS quantum dots (QDs) capped by molecularly imprinted polymers (MIPs) were prepared. MIPs were characterized by spectrofluorometer, UV–vis spectrophotometer, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM) and scanning electron microscope (SEM). Meanwhile, spectrofluorometer was used to the evaluation of optical stability, the effect of pH, and the selective and sensitive determination of 2,4,5-TCP. Under optical conditions, MIPs-capped Mn-doped ZnS QDs were successfully applied to the detection of 2,4,5-TCP in water selectively and sensitively, and a linear relationship was obtained to cover the concentration range of 5.0–50 μmol L−1 with a correlation coefficient of 0.9913. Moreover, 2,4,5-TCP could quench the room temperature phosphorescence of MIPs-capped Mn-doped ZnS QDs in a concentration-dependent manner, which was best described by a Stern–Volmer-type equation. - Highlights: • Molecularly imprinted polymers (MIPs)-capped Mn-doped ZnS quantum dots (QDs) were prepared. • The composite materials integrated the advantages of the high selectivity of the molecular imprinting and strong RTP property of the QDs. • The composite materials was successfully applied to selectively and sensitively detect 2,4,5-TCP in water

  10. 6,6 '-bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo 1,2,4 triazine-3-yl) 2,2 ' bipyridine, an effective extracting agent for the separation of americium(III) and curium(III) from the lanthanides

    International Nuclear Information System (INIS)

    The extraction of americium(III), curium(III), and the lanthanides(III) from nitric acid by 6,6'- bis (5,5,8,8-tetramethyl-5,6,7,8-tetra-hydro-benzo[1,2,4]triazine-3-yl)-[2,2'] bipyridine (CyMe4-BTBP) has been studied. Since the extraction kinetics were slow, N,N'-dimethyl-N,N'-di-octyl-2-(2-hexyl-oxy-ethyl)malonamide (DMDOHEMA) was added as a phase transfer reagent. With a mixture of 0.01 M CyMe4-BTBP + 0.25 M DMDOHEMA in n -octanol, extraction equilibrium was reached within 5 min of mixing. At a nitric acid concentration of 1 M, an americium(III) distribution ratio of approx. 10 was achieved. Americium(III)/lanthanide(III) separation factors between 50 (dysprosium) and 1500 (lanthanum) were obtained. Whereas americium(III) and curium(III) were extracted as di-solvates, the stoichiometries of the lanthanide(III) complexes were not identified unambiguously, owing to the presence of DMDOHEMA. In the absence of DMDOHEMA, both americium(III) and europium(III) were extracted as di-solvates. Back-extraction with 0.1 M nitric acid was thermodynamically possible but rather slow. Using a buffered glycolate solution of pH=4, an americium(III) distribution ratio of 0.01 was obtained within 5 min of mixing. There was no evidence of degradation of the extractant, for example, the extraction performance of CyMe4-BTBP during hydrolysis with 1 M nitric acid did not change over a two month contact. (authors)

  11. Mixed Signal Generation System Based on C8051F206 and FT245R USB%基于C8051F206和FT245R USB的混合信号生成系统

    Institute of Scientific and Technical Information of China (English)

    虞文胜; 温倩

    2014-01-01

    In order to generate self-check signal and speed instruction of radar antenna system test signals, design a kind of mixed signal generation system based on C8051F206 and FT245R.The system uses FT245R USB chip to realize the communication of upper machine, and rely on C8051F206 high SPC and C language to response the instructions of upper machine in a reliable way and send real-time measured parts required for the self-check instruction ,speed instruction,etc.This paper introduces the principle of hardware design and software design of mixed signal systems. Practical application shows that the system can accurately generate radar antenna system self-check signal, speed signal and real-time feedback test results.%为了产生雷达天线系统测试时所需的自检信号、速度指令等信号,设计了一种基于基于 C8051F206和FT245R的混合信号生成系统。该系统利用FT245R USB接口芯片实现与上位机通信,并依靠C8051F206高程控性和C语言的高灵活性,可靠地响应上位机指令并实时发送被测件所需的自检信号、速度指令等信号源。介绍了混合信号生成系统硬件设计和软件设计的原理。实际应用表明,该系统能准确地生成被测件雷达天线系统所需的自检信号、速度指令信号,并实时地反馈测试结果。

  12. Curium-245 and curium-247 neutron cross sections between 10 keV and 10 MeV

    International Nuclear Information System (INIS)

    The optical model code 2PLUS and the statistical model codes COMNUC and CASCADE were used to compute neutron cross sections for Cm-245 and Cm-247 between 10 keV and 10 MeV. Cross sections for elastic and inelastic scattering, radiative capture, fission, and the (n,2n) reactions were computed. The parameters for the fission model were selected to yield agreement with the cross sections from the Physics-8 bomb shot. Pu-239 cross sections were calculated and compared with existing cross section evaluations to demonstrate the validity of the calculational methods

  13. Genetic Variants Of Cytochrome b-245, Alpha Polypeptide Gene And Premature Acute Myocardial Infarction Risk In An Iranian Population

    Directory of Open Access Journals (Sweden)

    Amin Fatemeh

    2015-10-01

    Full Text Available Background: Oxidative stress induced by superoxide anion plays critical roles in the pathogenesis of coronary artery disease (CAD and hence acute myocardial infarction (AMI. The major source of superoxide production in vascular smooth muscle and endothelial cells is the NADPH oxidase complex. An essential component of this complex is p22phox, that is encoded by the cytochrome b-245, alpha polypeptide (CYBA gene. The aim of this study was to investigate the association of CYBA variants (rs1049255 and rs4673 and premature acute myocardial infarction risk in an Iranian population.

  14. Solvent-free and catalyst-free method for the synthesis of 2,4,5-triarylimidazoles under microwave irradiation

    Institute of Scientific and Technical Information of China (English)

    Jian Feng Zhou; Gui Xia Gong; Hui Qin Zhu; Feng Xia Zhu

    2009-01-01

    A facile procedure for the synthesis of 2,4,5-triarylimidazoles is being reported starting from benzil, aromatic aldehyde and ammonium acetate. The reactions were carried out with catalyst-free, solvent-free and under microwave irradiation conditions in high yield (80-99%) with short time (3-5 min) and environmental benign, as well as convenient operation. The structures of the compounds have been confirmed on the basis of their IR, ~1H NMR, and/or ~(13)C NMR, MS, and elemental analyzer.

  15. Design of JGD24-5 Solid State Time-Limited Protection Relay%JGD24-5型固体式限时保护继电器的设计

    Institute of Scientific and Technical Information of China (English)

    刘凯; 赵辉

    2013-01-01

    The paper provides basic technical properties for the JGD 24-5 solid state time-limited protection relay.And design method is described for such relays .The focus is on design of input circuit , delay filter circuit, time-limited protection circuit, isolation circuit, driver circuit and series output circuit .Additionally, calculation methods are shown for some significant parameters .%  文章给出了JGD24-5型固体式限时保护继电器的主要技术指标,介绍了该类产品的设计方法,重点介绍了输入电路、延时滤波电路、限时保护电路、隔离电路、驱动电路和串联输出电路的设计,并给出了一些重要参数的计算方法。

  16. 固溶处理对304/Q245R焊接接头组织及性能的影响%Effect of solution treatment on microstructure and properties of 304/Q245R welded joint

    Institute of Scientific and Technical Information of China (English)

    刘培茹; 路平; 徐志欣

    2016-01-01

    为研究固溶处理对304奥氏体不锈钢和Q245R碳钢异种金属焊接接头显微组织及性能的影响,采用E309-16奥氏体不锈钢焊丝对6 mm厚的304/Q245R板材进行手工电弧焊,焊后使用箱式电阻炉对焊接接头进行固溶处理,对焊接接头进行显微组织观察和力学性能测试.结果表明:相对于固溶处理前,固溶处理后的接头焊缝组织为灰色奥氏体和黑色铁素体,枝晶偏析程度明显降低,Cr、Ni等合金元素分布较为均匀;焊缝和碳钢侧热影响区硬度值均有所提高,最高硬度值为304.59 HV,出现在焊缝位置;接头抗拉强度较高,达570 MPa,拉伸断裂发生在母材Q245R碳钢部位.另外,对焊缝进行XRD测定,未检测到不利于接头性能的相,这表明固溶处理后的异种金属接头性能良好,能够满足工程中的实际需求.%In order to investigate the effect of solution treatment on microstructures and mechanical properties of welded joint made of two dissimilar metals 304 austenitic stainless steel and Q245R carbon steel, the 304 and Q245R metal plates with thickness of 6 mm were welded together by the manual arc welding method with E309-16 austenitic stainless welding wire. After welding, the welded joint was solution⁃treated in the box resistance furnace. The microstructures and mechanical properties of the welded joint were analyzed and investigated by means of microstructure observation and mechanical property testing. The results show that compared to the welded joint without solution treatment, the microstructures of weld are gray austenite and black ferrites, dendritic segregation alleviated, and the alloy elements especially Cr and Ni are uniformly distributed. The micro⁃hardness are increases for the welding seam and welding heat affected zone of carbon steel, and the highest micro⁃hardness ia about 304.59 HV in the welding seam. The ultimate tensile strength of the welded joint

  17. Impact of the cation distribution homogeneity on the americium oxidation state in the U0.54Pu0.45Am0.01O2-x mixed oxide

    Science.gov (United States)

    Vauchy, Romain; Robisson, Anne-Charlotte; Martin, Philippe M.; Belin, Renaud C.; Aufore, Laurence; Scheinost, Andreas C.; Hodaj, Fiqiri

    2015-01-01

    The impact of the cation distribution homogeneity of the U0.54Pu0.45Am0.01O2-x mixed oxide on the americium oxidation state was studied by coupling X-ray diffraction (XRD), electron probe micro analysis (EPMA) and X-ray absorption spectroscopy (XAS). Oxygen-hypostoichiometric Am-bearing uranium-plutonium mixed oxide pellets were fabricated by two different co-milling based processes in order to obtain different cation distribution homogeneities. The americium was generated from β- decay of 241Pu. The XRD analysis of the obtained compounds did not reveal any structural difference between the samples. EPMA, however, revealed a high homogeneity in the cation distribution for one sample, and substantial heterogeneity of the U-Pu (so Am) distribution for the other. The difference in cation distribution was linked to a difference in Am chemistry as investigated by XAS, with Am being present at mixed +III/+IV oxidation state in the heterogeneous compound, whereas only Am(IV) was observed in the homogeneous compound. Previously reported discrepancies on Am oxidation states can hence be explained by cation distribution homogeneity effects.

  18. 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)

    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)

  19. Sorption and diffusion of cobalt, nickel, strontium, iodine, cesium and americium in natural fissure surfaces and drill core cups studied by autoradiography, 3

    International Nuclear Information System (INIS)

    This report summarizes the studies on sorption and diffusion of Cs, Sr, Co, Ni, Am and I in common rocks in Finnish bedrock carried out in laboratory experiments. Samples used in these studies were sections of drill cores containing filled and unfilled natural fracture surfaces and drill cores with a diamond drilled longitudinal cavity in the middle of the sample (drill core cups). Samples originated from the two nuclear power plant sites in Finland: tonalite and mica gneiss from Olkiluoto in Eurajoki and rapakivi granite from Haestholmen in Loviisa. The water used in the experiments was synthetic groundwater spiked at a time with one of the radionuclides: Cs-134, Sr-90, Co-60, Ni-63, Am-241 and I-125. Contact times from one week to one year were used to evaluate time dependence of diffusion. An autoradiographic method was used for determination of the penetration depths and diffusion pathways of elements. For determination of diffusion coefficients a quantitative computerized autoradiographic method was used to get the concentration profiles of the radionuclides in the drill cores. Sorption on natural fracture surfaces was more effective than on freshly drilled core samples. Filling materials on natural fracture surfaces, except calcite, increased sorption. The distribution coefficients for drill core cups were about the same as those for unfilled natural fracture surfaces after a contact time of one week and the sorption tendency of radionuclides was: Ka(Cs) > Ka(Co) > Ka(Am) > Ka(Ni) > Ka(Sr) > Ka(I). Radionuclides were observed to penetrate into fissures of the rock matrix and high-capacity minerals. Strontium was found as far as 35 mm in a filled natural fracture surface sample of rapakivi granite after a contact time of one year. The corresponding values were 3.0 mm for cesium, 2.1 mm for cobalt and 2.6 mm for nickel. For americium no diffusion could be observed (a-values for strontium was 6.6 x 10-16-1.1 x 10-13 m2/s, for cesium 4.7 x 10-16-7.2 x 10-15 m2/s

  20. Separation by sequential chromatography of americium, plutonium and neptunium elements: application to the study of trans-uranian elements migration in a European lacustrine system

    International Nuclear Information System (INIS)

    The nuclear tests carried out in the atmosphere in the Sixties, the accidents and in particular that to the power station of Chernobyl in 1986, were at the origin of the dispersion of a significant quantity of transuranic elements and fission products. The study of a lake system, such that of the Blelham Tarn in Great Britain, presented in this memory, can bring interesting answers to the problems of management of the environment. The determination of the radionuclides in sediment cores made it possible not only to establish the history of the depositions and consequently the origin of the radionuclides, but also to evaluate the various transfers which took place according to the parameters of the site and the properties of the elements. The studied transuranic elements are plutonium 238, 239-240, americium 241 and neptunium 237. Alpha emitting radionuclides, their determination requires complex radiochemical separations. A method was worked out to successively separate the three radioelements by using a same chromatographic column. Cesium 137 is the studied fission product, its determination is done by direct Gamma spectrometry. Lead 210, natural radionuclide, whose atmospheric flow can be supposed constant. makes it possible to obtain a chronology of the various events. The detailed vertical study of sediment cores showed that the accumulation mode of the studied elements is the same one and that the methods of dating converge. The cesium, more mobile than transuranic elements in the atmosphere, was detected in the 1963 and 1986 fallout whereas an activity out of transuranic elements appears only for the 1963 fallout. The activity of the 1963 cesium fallout is of the same order of magnitude as that of 1986. The calculation of the diffusion coefficients of the elements in the sediments shows an increased migration of cesium compared to transuranic elements. An inventory on the whole of the lake made it possible to note that the atmospheric fallout constitute the

  1. A 915 MHz/2.45 GHz ECR plasma source for large area ion beam and plasma processing

    International Nuclear Information System (INIS)

    The technology for producing uniform, high density (1011--1012/cm3) microwave discharges over cross sections of 50 cm2 is well established. The present challenge is to extend the high density, and electrodeless benefits of microwave discharges to produce uniform densities over an area of 300--700 cm2. Such discharges have important applications for 6 to 8-in. single wafer processing and as large surface, broad beam, high current density ion sources. The design principles for scaling the 18 cm diam MPDR ECR cavity applicator technology to 38--47 cm diam are reviewed. Microwave discharges with diameters of 20--30 cm can be created when these applicators are excited with either 2.45 GHz or 915 MHz. The design and construction of a prototype cavity applicator with a 20 cm diam discharge is described. The discharge is enclosed with a 12-pole multicusp static magnetic field produced by 2-in. by 2-in. by 1-in. rare-earth magnets. Each magnet has a pole face field strength of 3 kG. The experimental test of this plasma source in argon gas excited with 2.45 GHz energy is reviewed

  2. The influence of p53 gene 245 site mutation to human lung adenocarcinoma cell line H1299%p53基因245位点突变对非小细胞肺癌细胞H1299的影响

    Institute of Scientific and Technical Information of China (English)

    王蕊; 宫兆华; 姜立新; 孙等军; 矫爱红; 陈剑; 张良明

    2011-01-01

    Background and purpose: The mutation of thc p53 gene could bca common molccular biological event during the process of lung adenocarcinoma because 245 site was a hot site for p53 gene mutation.A study of 245 site's mutation of p53 may provide the basic theories for the diagnosis and treatment for lung adenocarcinoma.This study aimed to investigate the influence of p53 245 site's mutation on p53-deficient human lung cancer H1299 cell line in vitro.Methods: H1299 cells were transiently transfected with wide type p53 and G245V p53 plasmid.Flow cytometry was performed for cell apoptosis analysis.H1299 cells were also stably transfected with wide type p53 and G245V p53 plasmid.The G418-selected cells were assayed for colony-forming efficiency, and the transfected cells were examined using MTT for the purpose of drawing the growth curve and evaluazing cell growth.Results: In the experimental study of cell apoptosis, we could see that the apoptosis rate of H1299 cells transfected with G245V-p53 gene appeared significantly less than in cells transfected with wide type p53 gene (P<0.001), similar happened to those transfected with pcmv plasmid.The colony-forming efficiency showed that there were more cells transfected with G245V-p53 gene than those transfected with wide type p53 gene(P<0.05).Thc growth curve indicates that cells transfectcd with G245V-p53 gene grew faster than those transfected with wide type p53 gene.Conclusion: Wild type p53 gene loses all function when mutation happens to the site 245.%背景与目的:p53基因突变是肺腺癌发生中的常见的分子生物学事件,第245位点突变为其突变热点之一,因此研究p53基因第245位点突变可能为肺腺痛的诊断、治疗提供一定的理论基础.本研究旨在研究肺癌常见的245位点突变对p53缺失的人肺腺癌细胞系H1299的影响.方法:应用流式细胞术观察脂质体瞬时转染p53基因第245突变体(G245V)对细胞凋亡的影响,同时用稳定转染观察

  3. Photosynthetic 14C fixation in leaves and isolated chloroplasts of some scrub species under the influence of paraquat and 2,4,5-T

    International Nuclear Information System (INIS)

    The diurnal course of carbon dioxide uptake in the leaves of six nonsucculent semiarid scrub species was investigated. Five nonsucculent scrub species, Carissa spinarum, Maba buxifolia, Flacourtia sepiaria, Gymnosporia emerginata and Dodonaea viscosa exhibited nocturnal carbon assimilation while day time CO2 uptake was predominant in Chomelia asiatica. Foliar application of paraquat (100 mg 1sup(-1)) or 2,4,5-T (2000 mg 1sup(-1)) caused a marked inhibition in the dark uptake of CO2. On the other hand, carbon uptake during day was slightly reduced. Studies on the carbon assimilation of isolated chloroplasts under the influence of paraquat or 2,4,5-T revealed that paraquat is more effective than 2,4,5-T in the suppression of carbon assimilation of in vivo and in vitro chloroplasts. The data suggested that the process of nocturnal carbon assimilation is far more sensitive to paraquat than the light dependent carbon fixation during day. (author)

  4. Residues in blackcurrants, fodder peas, spinach and potatoes treated with sublethal doses of 2,4,5-T to simulate wind drift damage

    DEFF Research Database (Denmark)

    Løkke, Hans; Odgaard, Peder

    1981-01-01

    .1 kg ha-1 on potato plants, the disappearance of 2,4,5-T was rapid during the first month, but residues were translocated into the tubers and reached a constant level of 0.02 mg kg-1 after 1 month until harvest at 108 days after treatment. In all crops, visible effects were observed after treatment...... concentrations declined in the same period due to growth dilution. In spinach leaves from old plants, treated with 0.1 kg ha-1, 0.05 mg of 2,4,5-T kg-1 was found 14 days after treatment. Fodder peas showed no residues (<0.002 mg kg-1) at harvest 62 days after treatment with 2,4,5-T esters. After application of 0...

  5. [The structure of the O-specific polysaccharide from a mutant of nitrogen-fixing rhizobacterium Azospirillum brasilense Sp245 with an altered plasmid content].

    Science.gov (United States)

    Fedonenko, Iu P; Katsy, E I; Petrova, L P; Boĭko, A S; Zdorovenko, E L; Kachala, V V; Shashkov, A S; Knirel', Iu A

    2010-01-01

    The rhizobacteria Azospirillum brasilense Sp245 produce antigenically different lipopolysaccharides LPSI and LPSII, both containing identical pentasaccharides built from D-rhamnose residues as the repeated chains of O-specific oligosaccharides (OPS). In this study, we report the structure of the OPS from A. brasilense LPSI(-)LPSII(-)-mutant Sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-MDa megaplasmid after the long-term storage of the bacteria in a rich medium. The repeating unit of the A. brasilense mutant Sp245.5 appeared to be a disaccharide consisting of residues of N-acetyl-D-galactosamine and N-acetyl-D-mannosaminuronic acid: [Formula: see text].

  6. 欧盟照明电器生态设计执行措施245/2009/EC法规解读(上)%Discussion on Commission Regulation (EC) No 245/2009 Implementing Ecodesign Requirements for Lighting Product (Ⅰ)

    Institute of Scientific and Technical Information of China (English)

    蒋建平; 朱培武; 余子英

    2009-01-01

    欧盟有关荧光灯、高强度气体放电灯等照明电器生态设计执行措施245/2009/EC法规已经正式发布,于2009年4月13日开始生效.本文从主要内容和技术指标解读该法规,重点研究各类电光源产品的最低能效要求及与我国国家标准的差异,提出应对该法规的思路和建议.

  7. Retroperitoneal laparoscopic resection and reconstructive surgeries in urology (report of 245 cases)%后腹腔镜下泌尿外科手术245例报告

    Institute of Scientific and Technical Information of China (English)

    王元林; 孙兆林; 朱建国; 杨秀书; 刘军; 徐述雄; 李凯

    2008-01-01

    Objective To evaluate the safety and efficacy of retroperitoneal laparoscopic resec-tion and reconstructive surgeries in urology. Methods Retroperitoneal laparoseopic resection and re-constructive surgeries were performed on 245 patients including 17 cases of adrenalectomies, 32 cases of radical nephrectomies, 12 cases of partial nephrectomies, 53 cases of nephrectomies, 5 cases of nephroureterectomies, 6 cases of unroofing of peripelvie renal cysts, 46 cases of unroofing of renal cysts, 4 cases of unroofing of polyeystic kidneys, 12 cases of pyeloplasties, 58 cases of ureterolithoto-roles. Results All 245 surgeries were successfully completed. The mean operation time was 59 (20-250) min and the estimated blood loss was 5-300 ml with no transfusion. There was no serious complication during perioperative period. Conclusion Retroperitoneal laparoscopic resection and re-conatruetive surgery in urology is safe and effective with the advantages of minimal invasion, quick re-covery and few complications.%目的 总结后腹腔镜技术在泌尿外科切除与成形手术中应用的临床经验. 方法泌尿系疾病患者245例,均采用腹腔镜技术经腹膜后途经完成手术,包括肾上腺切除术17例、根治性肾切除术32例、肾部分切除术12例、肾结核肾切除术15例、巨大肾积水肾切除术5例、无功能肾切除术32例、马蹄肾单侧无功能肾切除术1例、肾盂癌根治术5例、肾盂旁囊肿去顶减压术6例、肾囊肿去顶减压术46例、多囊肾去顶减压术4例(6侧)、肾盂成形术12例、输尿管切开取石术58例(62侧). 结果 245例(251侧)均一次成功,手术时间20~250 min,平均59 min.术中出血量约5~300 ml.手术并发症有腹膜损伤4例,立即缝合;皮下气肿9例、皮下瘀血2例,术后自行吸收;切口漏尿3例,经过半卧位引流和保留导尿4~7 d后停止.恢复顺利,术后1~7 d下床活动. 结论 后腹腔镜手术具有刨伤小、术后恢复快、并发症少

  8. The Asp245-->Asn mutant of Coprinus cinereus peroxidase. Characterization by 1H-NMR spectroscopy and comparison with the wild-type enzyme.

    Science.gov (United States)

    Veitch, N C; Gao, Y; Welinder, K G

    1996-11-12

    The resting, fluoride-ligated and cyanide-ligated states of the Asp245-->Asn mutant of Coprinus cinereus peroxidase (D245N CIP) have been characterized using 1H-NMR spectroscopy in conjunction with parallel studies of the wild-type enzyme. Analysis of the spectra of resting state D245N CIP over the pH range 5-10 has uncovered the existence of three high-spin species in dynamic equilibrium with each other. The predominant species at neutral pH is six-coordinate high-spin (6-c HS), with a distal water molecule as the sixth ligand. This species is in slow exchange on the NMR time scale with a second six-coordinate high-spin species (6-c HS*) and a five-coordinate high-spin species (5-c HS**), toward acidic and alkaline pH values, respectively. The 6-c HS* species appears to be unique and is proposed to differ from the 6-c HS species by protonation of the proximal His residue, whereas the 5-c HS** species lacks the proximal His ligand and is coordinated by a hydroxyl group. In sharp contrast, wild-type CIP is a five-coordinate high-spin (5-c HS) species over the same pH range. The D245N CIP mutant also exhibits a greater affinity for fluoride than wild-type CIP. The 1H-NMR spectrum of cyanide-ligated D245N CIP, assigned using two-dimensional methods, differs significantly from that of the wild-type enzyme. Perturbations to heme and heme-linked proton resonances are rationalised in terms of the loss or significant weakening of the hydrogen bond between His183 N delta 1H and the side-chain of residue 245 when Asp is replaced by Asn. This subtle interaction directly affects the heme pocket structure of CIP both proximal and distal to the heme plane.

  9. 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.

  10. Design and Measurement of a 2.45 Ghz On-Body Antenna Optimized for Hearing Instrument Applications

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Jakobsen, Kaj Bjarne; Thaysen, Jesper

    2012-01-01

    structure can be made conformal to the outer surface of a hearing instrument, such that the bandwidth of the antenna is optimized given the available volume. The radiation patterns, ear-to-ear path gain and available bandwidth is measured and compared to the simulated results. It is found that the antenna......A balanced PIFA-inspired antenna design is presented for use with the 2:45 GHz ear-to-ear radio channel. The antenna is designed such that the radiated electric fields are primarily polarized normal to the surface of the head, in order to obtain a high on-body path gain (jS21 j). The antenna...

  11. Design of a 2.45 GHz ECR Ion Source for Production of Medium Charge States Ions

    International Nuclear Information System (INIS)

    At Lawrence Berkeley National Laboratory we are constructing an ECR ion source test facility for nuclear science experiments. For this purpose a single-stage 2.45 GHz electron cyclotron resonance ion source has been designed and fabricated. It features an axial magnetic field with a mirror ratio of up to 5.5 and a hexapole field produced by a novel Nd-Fe-B permanent magnet assembly. In order to enhance the ion confinement time the source plasma volume has been enlarged as much as possible while still maintaining a high mirror ratio. This paper describes the design of the source. Ion optics simulation of the extraction system currently under design will also be presented

  12. Mössbauer spectroscopic study of 57Fe metabolic transformations in the rhizobacterium Azospirillum brasilense Sp245

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Kovács, Krisztina; Biró, Borbála; Homonnay, Zoltán; Kuzmann, Ernő

    2014-04-01

    Preliminary 57Fe transmission Mössbauer spectroscopic data were obtained for the first time for live cells of the plant-growth-promoting rhizobacterium Azospirillum brasilense (wild-type strain Sp245) grown aerobically with 57FeIII-nitrilotriacetate (NTA) complex as a sole source of iron. The results obtained have shown that live cells actively reduce part of the assimilated iron(III) to iron(II), the latter amounting up to 33 % of total cellular iron after 18 h of growth, and 48 % after additional 3 days of storage of the dense wet cell suspension in nutrient-free saline solution in air at room temperature (measured at 80 K). The cellular iron(II) was found to be represented by two quadrupole doublets of different high-spin forms, while the parameters of the cellular iron(III) were close to those typical for bacterioferritins.

  13. Development of a Novel Switched-Mode 2.45 GHz Microwave Multiapplicator Ablation System

    Directory of Open Access Journals (Sweden)

    Guido Biffi Gentili

    2014-01-01

    Full Text Available The development of a novel switched-mode 2.45 GHz microwave (MW multiapplicator system intended for laparoscopic and open surgical thermoablative treatments is presented. The system differs from the other synchronous and asynchronous commercially available equipments because it employs a fast sequential switching (FSS technique for feeding an array of up to four high efficiency MW applicators. FSS technology, if properly engineered, allows improving system compactness, modularity, overall efficiency, and operational flexibility. Full-wave electromagnetic (EM and thermal (TH simulations have been made to confirm the expected performances of the FSS technology. Here we provide an overview of technical details and early ex-vivo experiments carried out with a full functional β-prototype of the system.

  14. Theoretical study on the structural and antioxidant properties of some recently synthesised 2,4,5-trimethoxy chalcones.

    Science.gov (United States)

    Wang, Guirong; Xue, Yunsheng; An, Lin; Zheng, Youguang; Dou, Yunyan; Zhang, Ling; Liu, Yi

    2015-03-15

    The free radical scavenging activity of a series of 2,4,5-trimethoxy chalcones has been computationally explored using the density functional theory (DFT) method. Three potential working mechanisms, hydrogen atom transfer (HAT), stepwise electron transfer proton transfer (SET-PT) and sequential proton loss electron transfer (SPLET) have been investigated. The physiochemical parameters including O-H bond dissociation enthalpy (BDE), ionisation potential (IP), proton dissociation enthalpy (PDE), proton affinity (PA) and electron transfer enthalpy (ETE) have been calculated in gas phase and solvents. The order of antioxidant efficiencies predicted theoretically in this work is in good agreement with that reported by experimental results. The results obtained demonstrate that HAT would be the most favourable mechanism in the gas and benzene phases, whereas the SPLET mechanism is the thermodynamically preferred pathway in polar media. In addition, the importance of the A-ring on the radical scavenging capabilities of chalcones was also confirmed.

  15. Novel synthesis, structural analysis, photophysical properties and theoretical study of 2,4,5-tris(2-pyridyl)imidazole

    Science.gov (United States)

    Báez-Castro, Alberto; Baldenebro-López, Jesús; Glossman-Mitnik, Daniel; Höpfl, Herbert; Cruz-Enríquez, Adriana; Miranda-Soto, Valentín; Parra-Hake, Miguel; Campos-Gaxiola, José J.

    2015-11-01

    2,4,5-Tris(2-pyridyl)imidazole has been successfully synthetized by a novel synthetic route and fully characterized by FT-IR,UV-Vis and fluorescence spectroscopy, one- and two-dimensional NMR spectroscopy (1H, 13C{1H} ATP, 1H-1H COSY, NOESY 1H-13C HSQC and HMBC) high-resolution, mass spectrometry (HR-FAB+), and single-crystal X-ray diffraction analysis. Additionally, the molecular geometry, vibrational frequencies and infrared intensities were calculated by density functional theory using the M06/6-31G(d) level of theory, showing good agreement with the experimental results. The title compound showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV-Vis and fluorescence spectroscopy, and theoretically using TD-DFT calculations. Natural and Mulliken atomic charges and the molecular electrostatic potential (MEP) have been mapped.

  16. 桌面的3D诱惑——Acer Aspire GD245HQ显示器

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    3D当前被炒得如火如萘,3D电影、3D电视机、3D投影机、3D相机、3D蓝光机,当然还有3D显示器,可以说3D已经在我们的周围无处不在,现在你可以轻轻松松地随时随地体验3D世界。坐在显示器前,戴上眼镜,让Acer GD245HQ 3D显示器为你带来身临其境的真切画面吧。

  17. Possibility of 2,4,5-triamino-6-hydroxypyrimidine as an intermediate in the pathway of riboflavin biosynthesis.

    Science.gov (United States)

    Nakajima, K; Yamada, Y; Mitsuda, H

    1985-01-01

    It was studied with resting cells of a high flavinogenic mold, Eremothecium ashbyii, whether or not 2,4,5-triamino-6-hydroxypyrimidine (THP) is an intermediate in the early pathway of riboflavin biosynthesis. A small amounts of THP strongly inhibited riboflavin formation in the resting cells, but the inhibition was effectively reversed by the added purines, except for adenine. Radioactive tracer experiments showed that the incorporation of the radioactivity from [2-14C]THP into riboflavin was negligible. The results obtained strongly suggest that THP is not an intermediate but a rigid inhibitor for riboflavin formation, and thus there is non salvage pathway of THP for the pathway of riboflavin biosynthesis in resting cells of E. ashbyii. PMID:4041122

  18. 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)

  19. 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)

    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)

  20. [Mutants of bacterium Azospirillum brasilense Sp245 with Omegon insertion in mmsB or fabG genes of lipid metabolism are defective in motility and flagellation].

    Science.gov (United States)

    Kovtunov, E A; Shelud'ko, A V; Chernyshova, M P; Petrova, L P; Katsy, E I

    2013-11-01

    Bacteria Azospirillum brasilense have mixed flagellation: in addition to the polar flagellum, numerous lateral flagella are formed in their cells on medium with increased density. Flagella determine the active swimming and swarming capacities of azospirilla. Using A. brasilense Sp245 as an example, we showed that the Omegon-Km artificial transposon insertion into the chromosomal gene for 3-hydroxyisobutyrate dehydrogenase (mmsB) was concurrent with the appearance of significant defects in the formation of polar flagella and with the paralysis of lateral flagella. The Sp245 mutant with the Omegon insertion into the plasmid AZOBR_p1-borne gene for 3-oxoacyl-[acyl-carrier protein]-reductase (fabG) showed the complete loss of flagella and the swarming capacity, as well as significant defects in polar flagellar assembly (though some cells are still motile in liquid medium). The viability of the A. brasilense Sp245 mutants with the Omegon insertion into the mmsB or fabG gene was not reduced. No considerable differences in the fatty acid composition of whole cell lipid extracts were found for the A. brasilense Sp245 strain and its mmsB and fabG mutants.

  1. Ceric ammonium nitrate catalysed three component one-pot efficient synthesis of 2,4,5-triaryl-1H-imidazoles

    Indian Academy of Sciences (India)

    Jaiprakash N Sangshetti; Nagnnath D Kokare; Sandeep A Kotharkara; Devanand B Shinde

    2008-09-01

    Ceric ammonium nitrate (CAN) is used as an efficient catalyst for the synthesis of 2,4,5-triaryl-1H-imidazoles via condensation of benzoin/benzil, ammonium acetate, and aromatic aldehydes. The easy work-up, higher yields and shorter reaction time are the advantages of the method presented here.

  2. Amberlyst A-15: Reusable catalyst for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted-1-imidazoles under MW irradiation

    Indian Academy of Sciences (India)

    Shivaji S Pandit; Swapnil K Bhalerao; Uddhav S Aher; Gorakshanath L Adhav; Vikram U Pandit

    2011-07-01

    One-pot multi-component condensation of benzyl, aldehydes, ammonium acetate and primary amines were used for synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted-1-imidazole derivatives underMWradiation using amberlyst A-15 as a catalysts. This catalyst has several advantages (simple work-up, low cost and reusability).

  3. 8 CFR 245.9 - Adjustment of status of certain nationals of the People's Republic of China under Public Law 102...

    Science.gov (United States)

    2010-01-01

    ... district directors in 8 CFR part 245 to accept and adjudicate an application for adjustment of status under..., 1990, and October 9, 1992; (5) Is admissible to the United States as an immigrant, unless the basis for... period begins on July 1, 1993. To benefit from the provisions of Public Law 102-404 (the Chinese...

  4. 8 CFR 245a.15 - Continuous residence in an unlawful status since prior to January 1, 1982, through May 4, 1988.

    Science.gov (United States)

    2010-01-01

    ... Legal Immigration Family Equity (LIFE) Act Legalization Provisions § 245a.15 Continuous residence in an... must provide with the application for LIFE Legalization evidence establishing that he or she entered... aliens, who are otherwise eligible to adjust to LPR status pursuant to LIFE Legalization, may file...

  5. 8 CFR 245.18 - How can physicians (with approved Forms I-140) that are serving in medically underserved areas or...

    Science.gov (United States)

    2010-01-01

    ... physicians submitting adjustment applications upon approval of an immigrant petition are required to follow... he or she has completed the service required under 8 CFR 204.12(a), USCIS shall serve the alien... ADJUSTMENT OF STATUS TO THAT OF PERSON ADMITTED FOR PERMANENT RESIDENCE § 245.18 How can physicians...

  6. Time-Domain Measurement of the Ear-to-Ear On-Body Path Gain at 2.45 GHz in a Radio Anechoic Environment

    DEFF Research Database (Denmark)

    Kvist, Søren Helstrup; Thaysen, Jesper; Jakobsen, Kaj Bjarne

    2012-01-01

    The ear-to-ear on-body path gain (jS21j) at 2:45 GHz is measured in the time domain. The measurements were conducted in a radio anechoic environment to study the effects of the on-body paths only. Two different monopole antenna configurations that are polarized normal and tangential to the surface...

  7. 2,4,5-TRICHLOROPHENOXYACETIC ACID INFLUENCE ON 2,6-DINITROTOLUENE-INDUCED URINE GENOTOXICITY IN FISCHER 344 RATS: EFFECT ON G.I. MICROFLORA AND ENZYME ACTIVITY

    Science.gov (United States)

    2,4,5-Trichlorophenoxyacetic acid and 2,6-dinitrotoluene are hazardous chemicals that have potential harmful effects 2,6-DNT is recognized as a hepatoxicant while 2,4,5-T, a component in Agent Orange, is also suspect. ,6-DNT requires both oxidative and reductive metabolism to eli...

  8. The effect of 245 amblyopial cases with comprehensive treatment in children%综合疗法治疗儿童弱视245例疗效分析

    Institute of Scientific and Technical Information of China (English)

    哈文静; 胡怡芳

    2001-01-01

    Objectives Study the result of comprehensive treatment method in amblyopia children.Methods The results of comprehensive treatment method in 245 cases (440 eyes)of amblyopia children were reported.Results The total recovery rate was 61.36%,while the minimal degree of amblyopia was 83.87%,ametropic amblyopia 71.47%,anisometropic amblyopia 50.00%,strabismic amblyopia 26.00%,form vision deprivation and congenital amblyopia 0.Conclusions There is a strong correlation with age,degree,fixation character and type of amblyopia.The ametropic amblyopia was the best in response to treatment.The central Fixation was better than anisometropic.%目的探讨综合疗法治疗儿童弱视的疗效。方法选用综合疗法治疗儿童弱视245例,440眼。结果治愈率:轻度83.87%,中度59.08%,重度29.55%;中心注视型78.26%,非中心注视型42.86%;屈光不正性71.47%,屈光参差性50.00%,斜视性26.00%,形觉剥夺性及先天性弱视治愈率 0。总治愈率61.14%。结论弱视的疗效与弱视的程度、类型、注视性质及年龄有关。弱视程度越轻效果越好,尤以屈光不正性疗效最好。中心注视型者优于非中心注视型者。在弱视治疗的同时应重视对较小患儿家长的宣教工作。

  9. Spectroscopic (FT-IR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of organic 2,4,5-trichloroaniline

    Science.gov (United States)

    Govindarajan, M.; Karabacak, M.; Periandy, S.; Tanuja, D.

    2012-11-01

    In this work, the experimental and theoretical study on the molecular structure and vibrational spectra of 2,4,5-trichloroaniline (C6H4NCl3, abbreviated as 2,4,5-TClA) were studied. The FT-IR and FT-Raman spectra were recorded. The molecular geometry and vibrational frequencies in the ground state were calculated by using the Hartree-Fock (HF) and density functional theory (DFT) methods (B3LYP) with 6-311++G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of 2,4,5-TClA with calculated results by HF and DFT indicates that B3LYP is superior to HF method for molecular vibrational problems. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and the first hyperpolarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4,5-TClA molecule may have microscopic nonlinear optical (NLO) behavior with non-zero values. Mulliken atomic charges of 2,4,5-TClA was calculated and compared with aniline and chlorobenzene molecules. The 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results.

  10. Crystal structure of triaqua(1,10-phenanthroline-κ2N,N′(2,4,5-trifluoro-3-methoxybenzoato-κO1cobalt(II 2,4,5-trifluoro-3-methoxybenzoate

    Directory of Open Access Journals (Sweden)

    Junshan Sun

    2014-11-01

    Full Text Available The title salt, [Co(C8H4F3O3(C12H8N2(H2O3](C8H4F3O3, was obtained under solvothermal conditions by the reaction of 2,4,5-trifluoro-3-methoxybenzoic acid with CoCl2 in the presence of 1,10-phenanthroline (phen. The CoII ion is octahedrally coordinated by two N atoms [Co—N = 2.165 (2 and 2.129 (2 Å] from the phen ligand, by one carboxylate O atom [Co—O = 2.107 (1 Å] and by three O atoms from water molecules [Co—O = 2.093 (1, 2.102 (1 and 2.114 (1 Å]. The equatorial positions of the slightly distorted octahedron are occupied by the N atoms, the carboxylate O and one water O atom. An intra- and intermolecular O—H...O hydrogen-bonding network between the water-containing complex cation and the organic anion leads to the formation of ribbons parallel to [010].

  11. Effects of olive leave extract on metabolic disorders and oxidative stress induced by 2.45 GHz WIFI signals.

    Science.gov (United States)

    Salah, Myriam Ben; Abdelmelek, Hafedh; Abderraba, Manef

    2013-11-01

    We investigated the effect of olive leaves extract administration on glucose metabolism and oxidative response in liver and kidneys of rats exposed to radio frequency (RF). The exposure of rats to RF (2.45 GHz, 1h/day during 21 consecutive days) induced a diabetes-like status. Moreover, RF decreased the activities of glutathione peroxidase (GPx, -33.33% and -49.40%) catalase (CAT, -43.39% and -39.62%) and the superoxide dismutase (SOD, -59.29% and -68.53%) and groups thiol amount (-62.68% and -34.85%), respectively in liver and kidneys. Indeed, exposure to RF increased the malondialdehyde (MDA, 29.69% and 51.35%) concentration respectively in liver and kidneys. Olive leaves extract administration (100 mg/kg, ip) in RF-exposed rats prevented glucose metabolism disruption and restored the activities of GPx, CAT and SOD and thiol group amount in liver and kidneys. Moreover, olive leave extract administration was able to bring down the elevated levels of MDA in liver but not in kidneys. Our investigations suggested that RF exposure induced a diabetes-like status through alteration of oxidative response. Olive leaves extract was able to correct glucose metabolism disorder by minimizing oxidative stress induced by RF in rat tissues. PMID:23994945

  12. Effects of acute exposure to WIFI signals (2.45GHz) on heart variability and blood pressure in Albinos rabbit.

    Science.gov (United States)

    Saili, Linda; Hanini, Amel; Smirani, Chiraz; Azzouz, Ines; Azzouz, Amina; Sakly, Mohsen; Abdelmelek, Hafedh; Bouslama, Zihad

    2015-09-01

    Electrocardiogram and arterial pressure measurements were studied under acute exposures to WIFI (2.45GHz) during one hour in adult male rabbits. Antennas of WIFI were placed at 25cm at the right side near the heart. Acute exposure of rabbits to WIFI increased heart frequency (+22%) and arterial blood pressure (+14%). Moreover, analysis of ECG revealed that WIFI induced a combined increase of PR and QT intervals. By contrast, the same exposure failed to alter maximum amplitude and P waves. After intravenously injection of dopamine (0.50ml/kg) and epinephrine (0.50ml/kg) under acute exposure to RF we found that, WIFI alter catecholamines (dopamine, epinephrine) action on heart variability and blood pressure compared to control. These results suggest for the first time, as far as we know, that exposure to WIFI affect heart rhythm, blood pressure, and catecholamines efficacy on cardiovascular system; indicating that radiofrequency can act directly and/or indirectly on cardiovascular system. PMID:26356390

  13. Experimental results of superimposing 9.9 GHz extraordinary mode microwaves on 2.45 GHz ECRIS plasma

    International Nuclear Information System (INIS)

    Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection are investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF

  14. Experimental results of superimposing 9.9 GHz extraordinary mode microwaves on 2.45 GHz ECRIS plasma

    Energy Technology Data Exchange (ETDEWEB)

    Nishiokada, Takuya, E-mail: nishiokada@nf.eie.eng.osaka-u.ac.jp; Nagaya, Tomoki; Hagino, Shogo; Otsuka, Takuro; Sato, Fuminobu; Kato, Yushi [Division of Electrical, Electronic, and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871 (Japan); Muramatsu, Masayuki; Kitagawa, Atsushi [National Institute of Radiological Sciences (NIRS), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-855 (Japan)

    2016-02-15

    Efficient production of multicharged ions has been investigated on the tandem-type ECRIS in Osaka University. According to the consideration of the accessibility conditions of microwaves to resonance and cutoff regions, it was suggested that the upper hybrid resonance (UHR) heating contributed to enhancement of ion beam intensity. In order to enhance multicharged ion beams efficiently, injecting higher frequency microwave with extraordinary (X-mode) toward UHR region has been tried. In this study, 2.45 GHz frequency microwaves are used for conventional ECR discharge, and 9.9 GHz frequency microwaves with X-mode are superimposed for UHR heating. The effects of additive microwave injection are investigated experimentally in terms of plasma parameters and electron energy distribution function (EEDF) measured by Langmuir probe and ion beam current. As the results show, it is confirmed that the electrons in the high energy region are affected by 9.9 GHz X-mode microwave injection from the detailed analysis of EEDF.

  15. Synthesis of the isotopes of elements 118 and 116 in the 249Cf and 245Cm+48Ca fusion reactions

    Energy Technology Data Exchange (ETDEWEB)

    Oganessian, Y T; Utyonkov, V K; Lobanov, Y V; Abdullin, F S; Polyakov, A N; Sagaidak, R N; Shirokovsky, I V; Tsyganov, Y S; Voinov, A A; Gulbekian, G G; Bogomolov, S L; Gikal, B N; Mezentsev, A N; Iliev, S; Subbotin, V G; Sukhov, A M; Subotic, K; Zagrebaev, V I; Vostokin, G K; Itkis, M G; Moody, K J; . Patin, J B; Shaughnessy, D A; Stoyer, M A; Stoyer, N J; Wilk, P A; Kenneally, J M; Landrum, J H; Wild, J F; Lougheed, R W

    2006-01-31

    The decay properties of {sup 290}116 and {sup 291}116, and the dependence of their production cross sections on the excitation energies of the compound nucleus, {sup 293}116, have been measured in the {sup 245}Cm({sup 48}Ca,xn){sup 293-x}116 reaction. These isotopes of element 116 are the decay daughters of element 118 isotopes, which are produced via the {sup 249}Cf+{sup 48}Ca reaction. They performed the element 118 experiment at two projectile energies, corresponding to {sup 297}118 compound nucleus excitation energies of E* = 29.2 {+-} 2.5 and 34.4 {+-} 2.3 MeV. During an irradiation with a total beam dose of 4.1 x 10{sup 19} {sup 48}Ca projectiles, three similar decay chains consisting of two or three consecutive {alpha} decays and terminated by a spontaneous fission (SF) with high total kinetic energy of about 230 MeV were observed. The three decay chains originated from the even-even isotope {sup 294}118 (E{sub {alpha}} = 11.65 {+-} 0.06 MeV, T{sub {alpha}} = 0.89{sub -0.31}{sup +1.07} ms) produced in the 3n-evaporation channel of the {sup 249}Cf+{sup 48}Ca reaction with a maximum cross section of 0.5{sub -0.3}{sup +1.6} pb.

  16. Measurement of enhanced heat transfer coefficient with perforated twisted tape inserts during condensation of R-245fa

    Science.gov (United States)

    Khatua, A. K.; Kumar, P.; Singh, H. N.; Kumar, R.

    2016-04-01

    The experimental conductive heat transfer results for flow through inserted perforated twisted tapes in a horizontal tube during condensation of pure R-245fa vapor. The test section consisting of two separate coaxial double pipes assembled in series, acted like a counter flow heat exchanger, where the refrigerant condensed inside the inner tube by rejecting heat to the cooling water flowing inside the outer tube in reversed direction. Data for three perforated twisted tapes having constant twist ratio of 7.1 mm and pitch of perforation as 12.5, 25.0 and 37.5 mm, inserted one by one in full length of test condenser by varying refrigerant mass flux from 100 to 200 kg/m2 s in steps of 50 kg/m2 s for the range of vapor quality from 0.1 to 0.9, were collected together with flow and without insert (plain tube). It has been found that the perforated twisted tape insert having pitch of perforation equal to in order of 12.5 mm gives the highest value of average heat transfer coefficient and is of the order of 37.5 % more than that of the plain one and the correlation predicts the experimental data within an error band of ±15 %.

  17. Effects of Wi-Fi (2.45 GH z Exposure on Apoptosis, Sperm Parameters and Testicular Histomorphometry in Rats: A Time Course Study

    Directory of Open Access Journals (Sweden)

    Saeed Shokri

    2015-07-01

    Full Text Available Objective: In today’s world, 2.45-GHz radio-frequency radiation (RFR from industrial, scientific, medical, military and domestic applications is the main part of indoor-outdoor electromagnetic field exposure. Long-term effects of 2.45-GHz Wi-Fi radiation on male reproductive system was not known completely. Therefore, this study aimed to investigate the major cause of male infertility during short- and long-term exposure of Wi-Fi radiation. Materials and Methods: This is an animal experimental study, which was conducted in the Department of Anatomical Sciences, Faculty of Medicine, Zanjan University of Medical Sciences, Zanjan, IRAN, from June to August 2014. Three-month-old male Wistar rats (n=27 were exposed to the 2.45 GHz radiation in a chamber with two Wi-Fi antennas on opposite walls. Animals were divided into the three following groups: I. control group (n=9 including healthy animals without any exposure to the antenna, II. 1-hour group (n=9 exposed to the 2.45 GHz Wi-Fi radiation for 1 hour per day during two months and III.7-hour group (n=9 exposed to the 2.45 GHz Wi-Fi radiation for 7 hours per day during 2 months. Sperm parameters, caspase-3 concentrations, histomorphometric changes of testis in addition to the apoptotic indexes were evaluated in the exposed and control animals. Results: Both 1-hour and 7-hour groups showed a decrease in sperm parameters in a time dependent pattern. In parallel, the number of apoptosis-positive cells and caspase-3 activity increased in the seminiferous tubules of exposed rats. The seminal vesicle weight reduced significantly in both1-hour or 7-hour groups in comparison to the control group. Conclusion: Regarding to the progressive privilege of 2.45 GHz wireless networks in our environment, we concluded that there should be a major concern regarding the timedependent exposure of whole-body to the higher frequencies of Wi-Fi networks existing in the vicinity of our living places.

  18. Study of the rhizobacterium Azospirillum brasilense Sp245 using Mössbauer spectroscopy with a high velocity resolution: Implication for the analysis of ferritin-like iron cores

    Science.gov (United States)

    Alenkina, I. V.; Oshtrakh, M. I.; Tugarova, A. V.; Biró, B.; Semionkin, V. A.; Kamnev, A. A.

    2014-09-01

    The results of a comparative study of two samples of the rhizobacterium Azospirillum brasilense (strain Sp245) prepared in different conditions and of human liver ferritin using Mössbauer spectroscopy with a high velocity resolution demonstrated the presence of ferritin-like iron (i.e. iron similar to that found in ferritin-like proteins) in the bacterium. Mössbauer spectra of these samples were fitted in two ways: as a rough approximation using a one quadrupole doublet fit (the homogeneous iron core model) and using a superposition of quadrupole doublets (the heterogeneous iron core model). Both results demonstrated differences in the Mössbauer parameters for mammalian ferritin and for bacterial ferritin-like iron. Moreover, some differences in the Mössbauer parameters were observed between the two samples of A. brasilense Sp245 related to the differences in their preparation conditions.

  19. Improvement in the Shape Memory Response of Ti50.5Ni24.5Pd25 High-Temperature Shape Memory Alloy with Scandium Microalloying

    Science.gov (United States)

    Atli, K. C.; Karaman, I; Noebe, R. D.; Garg, A.; Chumlyakov, Y. I.; Kireeva, I. V.

    2010-01-01

    A Ti(50.5)Ni(24.5)Pd25 high-temperature shape memory alloy (HTSMA) is microalloyed with 0.5 at. pct scandium (Sc) to enhance its shape-memory characteristics, in particular, dimensional stability under repeated thermomechanical cycles. For both Ti(50.5)Ni(24.5)Pd25 and the Sc-alloyed material, differential scanning calorimetry is conducted for multiple cycles to characterize cyclic stability of the transformation temperatures. The microstructure is evaluated using electron microscopy, X-ray diffractometry, and wavelength dispersive spectroscopy. Isobaric thermal cycling experiments are used to determine transformation temperatures, dimensional stability, and work output as a function of stress. The Sc-doped alloy displays more stable shape memory response with smaller irrecoverable strain and narrower thermal hysteresis than the baseline ternary alloy. This improvement in performance is attributed to the solid solution hardening effect of Sc.

  20. A comparison of the toxicity and metabolism of phenol and chlorinated phenols by Lemna gibba, with special reference to 2,4,5-trichlorophenol

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, H.A.; Barber, J.T.; Ensley, H.E.; Polito, M.A. [Tulane Univ., New Orleans, LA (United States)

    1997-02-01

    The toxicity of a series of chlorinated phenols, from phenol to pentachlorophenol, was determined using frond reproduction in aseptically grown Lemna gibba. The toxicities of the phenols tended to increase as the number of chlorine substituents on the phenol ring increased. The plants metabolized each of the phenols in the same manner producing metabolites that were more polar than their parent compounds. The metabolite for 2,4,5-trichlorophenol was isolated and identified by nuclear magnetic resonance spectroscopy and chemical ionization mass spectroscopy. The structural identity was confirmed by comparison with synthetic material as 2,4,5-trichlorophenyl-{beta}-D-glucopyranoside. These results, together with previously published results, suggest that conjugation with D-glucose is a stereotypic response of duckweed to challenge by phenol and chlorinated phenols.

  1. Design and analysis of an implantable CPW-fed X-monopole antenna for 2.45-GHz ISM band applications.

    Science.gov (United States)

    Ashok Kumar, Srinivasan; Shanmuganantham, Thangavelu

    2014-03-01

    A novel antenna design that effectively covers the industrial, scientific, and medical (ISM) band at 2.45 GHz using an X-shaped structure with a coplanar waveguide (CPW) feed is described. The antenna has a compact size of 67.6 mm(3). The proposed design is effective for ISM band biotelemetry with a wakeup controller (2.45 GHz). An experimental prototype of the compact implantable CPW-fed X-shaped monopole antenna was fabricated on a biocompatible alumina Al2O3 ceramic substrate. The optimal antenna was fabricated and tested in minced tissue from the front leg of a pig and on a human body phantom liquid. The simulated and measured bandwidths are 180 MHz and 210 MHz in the ISM band, respectively. PMID:24404821

  2. Nano copper and cobalt ferrites as heterogeneous catalysts for the one-pot synthesis of 2,4,5-tri substituted imidazoles

    Indian Academy of Sciences (India)

    Paul Douglas Sanasi; D Santhipriya; Y Ramesh; M Ravi Kumar; B Swathi; K Jaya Rao

    2014-11-01

    A simple one-pot synthesis has been developed for the synthesis of 2,4,5-trisubstituted imidazoles using magnetic recyclable spinel nano copper and cobalt ferrites by the condensation of benzil, aromatic aldehyde and ammonium acetate in ethanol as solvent. The reaction, with these catalysts was carried out under mild reaction conditions with very good yields of substituted imidazoles. These catalysts can be recycled very easily and reused, which makes this methodology environmentally benign.

  3. A novel and an efficient catalyst for one-pot synthesis of 2,4,5-trisubstituted imidazoles by using microwave irradiation under solvent-free conditions

    Indian Academy of Sciences (India)

    Javad Safari; Shiva Dehghan Khalili; Sayed Hossein Banitaba

    2010-05-01

    (NH4)6Mo7O24.4H2O has been used as an efficient catalyst for an improved and rapid synthesis of 2,4,5-trisubstituted imidazoles by a three-component, one-pot condensation of benzil, aryl aldehydes and ammonium acetate in good yields under solvent-free conditions using microwave irradiation. The reactions in conventional heating conditions were compared with the microwave-assisted reactions.

  4. Protective effects of β-glucan against oxidative injury induced by 2.45-GHz electromagnetic radiation in the skin tissue of rats.

    Science.gov (United States)

    Ceyhan, Ali Murat; Akkaya, Vahide Baysal; Güleçol, Şeyma Celik; Ceyhan, Betül Mermi; Özgüner, Fehmi; Chen, WenChieh

    2012-09-01

    In recent times, there is widespread use of 2.45-GHz irradiation-emitting devices in industrial, medical, military and domestic application. The aim of the present study was to investigate the effect of 2.45-GHz electromagnetic radiation (EMR) on the oxidant and antioxidant status of skin and to examine the possible protective effects of β-glucans against the oxidative injury. Thirty-two male Wistar albino rats were randomly divided into four equal groups: control; sham exposed; EMR; and EMR + β-glucan. A 2.45-GHz EMR emitted device from the experimental exposure was applied to the EMR group and EMR + β-glucan group for 60 min daily, respectively, for 4 weeks. β-glucan was administered via gavage at a dose of 50 mg/kg/day before each exposure to radiation in the treatment group. The activities of antioxidant enzymes, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT), as well as the concentration of malondialdehyde (MDA) were measured in tissue homogenates of the skin. Exposure to 2.45-GHz EMR caused a significant increase in MDA levels and CAT activity, while the activities of SOD and GSH-Px decreased in skin tissues. Systemic β-glucan significantly reversed the elevation of MDA levels and the reduction of SOD activities. β-glucan treatment also slightly enhanced the activity of CAT and prevented the depletion of GSH-Px activity caused by EMR, but not statistically significantly. The present study demonstrated the role of oxidative mechanisms in EMR-induced skin tissue damages and that β-glucan could ameliorate oxidative skin injury via its antioxidant properties.

  5. Measurement of neutron induced fission of {sup 235}U, {sup 233}U and {sup 245}Cm with the FIC detector at the CERN n-TOF facility

    Energy Technology Data Exchange (ETDEWEB)

    Calviani, M.; Karadimos, D.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Cano-Ott, D.; Capote, R.; Carrapic, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kappeler, F.; Kadi, Y.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    A series of measurements of neutron induced fission cross section of various transuranic isotopes have been performed at the CERN n-TOF spallation neutron facility, in the energy range from thermal to nearly 250 MeV. The experimental apparatus consists in a fast ionization chamber (FIC), used as a fission fragment detector with a high efficiency. Good discrimination between alphas and fission fragments can be obtained with a simple amplitude threshold. In order to allow the monitoring of the neutron beam and to extract the n-TOF neutron flux, the well known cross section of the {sup 235}U(n,f) reaction, considered as a fission standard, has been used. Preliminary results for the cross section are shown for some selected isotopes such as {sup 235}U, {sup 233}U and {sup 245}Cm in the energy range from 0.050 eV to about 2 MeV. These results for {sup 235}U, {sup 233}U and {sup 245}Cm show results consistent with databases in the resonance region, with no normalization required for {sup 233}U. In the case of {sup 245}Cm, for the energy range between thermal and 20 eV, we obtained the first experimental data ever published, while showing a good agreement with previous data in the region above that value.

  6. Electromagnetic fields at 2.45 GHz trigger changes in heat shock proteins 90 and 70 without altering apoptotic activity in rat thyroid gland

    Directory of Open Access Journals (Sweden)

    María José Misa Agustiño

    2012-07-01

    Non-ionizing radiation at 2.45 GHz may modify the expression of genes that codify heat shock proteins (HSP in the thyroid gland. Using the enzyme-linked immunosorbent assay (ELISA technique, we studied levels of HSP-90 and HSP-70. We also used hematoxilin eosin to look for evidence of lesions in the gland and applied the DAPI technique of fluorescence to search for evidence of chromatin condensation and nuclear fragmentation in the thyroid cells of adult female Sprague-Dawley rats. Fifty-four rats were individually exposed for 30 min to 2.45 GHz radiation in a Gigahertz transverse electromagnetic (GTEM cell at different levels of non-thermal specific absorption rate (SAR, which was calculated using the finite difference time domain (FDTD technique. Ninety minutes after radiation, HSP-90 and HSP-70 had decreased significantly (P<0.01 after applying a SAR of 0.046±1.10 W/Kg or 0.104±5.10−3 W/Kg. Twenty-four hours after radiation, HSP-90 had partially recovered and HSP-70 had recovered completely. There were few indications of lesions in the glandular structure and signs of apoptosis were negative in all radiated animals. The results suggest that acute sub-thermal radiation at 2.45 GHz may alter levels of cellular stress in rat thyroid gland without initially altering their anti-apoptotic capacity.

  7. Quantum chemical and direct dynamic study on homogeneous gas-phase formation of PBDD/Fs from 2,4,5-tribromophenol and 3,4-dibromophenol.

    Science.gov (United States)

    Yu, Wanni; Li, Pengfei; Xu, Fei; Hu, Jingtian; Zhang, Qingzhu; Wang, Wenxing

    2013-09-01

    2,4,5-Tribromophenol (2,4,5-TBP) and 3,4-dibromophenol (3,4-DBP) have the minimum number of Br atoms needed to form 2,3,7,8-PBDD/Fs, which are the most toxic among all 210 PBDD/F isomers. A mechanistic understanding of the formation of PBDD/Fs is a prerequisite for minimizing their emissions. In this paper, the homogeneous gas-phase formation of PBDD/Fs from 2,4,5-TBP and 3,4-DBP as precursors was investigated theoretically by using the density functional theory (DFT) method. The mathematical model to predict the formation of PBDD/Fs places a high demand on accurate kinetic parameters. So, the rate constants of key elementary steps involved in the formation of PBDD/Fs were calculated by using canonical variational transition-state (CVT) theory with small curvature tunneling (SCT) contribution over a wide temperature range of 600-1200K. The pre-exponential factors and the activation energies are also reported. This might be the first to investigate the formation of 2,3,7,8-PBDD/Fs. The present study shows that the formation of PBDDs dominates over the formation of PBDFs. The meta bromine facilitates the dimerization of bromophenoxy radicals (BPRs), whereas the para and ortho bromines suppress the dimerization of BPRs.

  8. Abatement of fluorinated compounds using a 2.45 GHz microwave plasma torch with a reverse vortex plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H.; Cho, C.H.; Shin, D.H. [Plasma Technology Research Center, National Fusion Research Institute, 814-2 Oxikdo-dong, Gunsan-city, Jeollabuk-do (Korea, Republic of); Hong, Y.C., E-mail: ychong@nfri.re.kr [Plasma Technology Research Center, National Fusion Research Institute, 814-2 Oxikdo-dong, Gunsan-city, Jeollabuk-do (Korea, Republic of); Shin, Y.W. [Plasma Technology Research Center, National Fusion Research Institute, 814-2 Oxikdo-dong, Gunsan-city, Jeollabuk-do (Korea, Republic of); School of Advanced Green Energy and Environments, Handong Global University, Heunghae-eup, Buk-gu, Pohang-city, Gyeongbuk (Korea, Republic of)

    2015-08-30

    Highlights: • We developed a microwave plasma torch with reverse vortex reactor (RVR). • We calculated a volume fraction and temperature distribution of discharge gas and waste. • The performance of reverse vortex reactor increased from 29% to 43% than conventional vortex reactor. - Abstract: Abatement of fluorinated compounds (FCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. We have developed a 2.45 GHz microwave plasma torch with reverse vortex reactor (RVR). In order to design a reverse vortex plasma reactor, we calculated a volume fraction and temperature distribution of discharge gas and waste gas in RVR by ANSYS CFX of computational fluid dynamics (CFD) simulation code. Abatement experiments have been performed with respect to SF{sub 6}, NF{sub 3} by varying plasma power and N{sub 2} flow rates, and FCs concentration. Detailed experiments were conducted on the abatement of NF{sub 3} and SF{sub 6} in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). The DRE of 99.9% for NF{sub 3} was achieved without an additive gas at the N{sub 2} flow rate of 150 liter per minute (L/min) by applying a microwave power of 6 kW with RVR. Also, a DRE of SF{sub 6} was 99.99% at the N{sub 2} flow rate of 60 L/min using an applied microwave power of 6 kW. The performance of reverse vortex reactor increased about 43% of NF{sub 3} and 29% of SF{sub 6} abatements results definition by decomposition energy per liter more than conventional vortex reactor.

  9. Abatement of fluorinated compounds using a 2.45 GHz microwave plasma torch with a reverse vortex plasma reactor

    International Nuclear Information System (INIS)

    Highlights: • We developed a microwave plasma torch with reverse vortex reactor (RVR). • We calculated a volume fraction and temperature distribution of discharge gas and waste. • The performance of reverse vortex reactor increased from 29% to 43% than conventional vortex reactor. - Abstract: Abatement of fluorinated compounds (FCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. We have developed a 2.45 GHz microwave plasma torch with reverse vortex reactor (RVR). In order to design a reverse vortex plasma reactor, we calculated a volume fraction and temperature distribution of discharge gas and waste gas in RVR by ANSYS CFX of computational fluid dynamics (CFD) simulation code. Abatement experiments have been performed with respect to SF6, NF3 by varying plasma power and N2 flow rates, and FCs concentration. Detailed experiments were conducted on the abatement of NF3 and SF6 in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). The DRE of 99.9% for NF3 was achieved without an additive gas at the N2 flow rate of 150 liter per minute (L/min) by applying a microwave power of 6 kW with RVR. Also, a DRE of SF6 was 99.99% at the N2 flow rate of 60 L/min using an applied microwave power of 6 kW. The performance of reverse vortex reactor increased about 43% of NF3 and 29% of SF6 abatements results definition by decomposition energy per liter more than conventional vortex reactor

  10. [Changes in Cell Surface Properties and Biofilm Formation Efficiency in Azospirillum brasilense Sp245 Mutants in the Putative Genes of Lipid Metabolism mmsB1 and fabG1].

    Science.gov (United States)

    Shumilova, E; Shelud'ko, A V; Filip'echeva, Yu A; Evstigneeva, S S; Ponomareva, E G; Petrova, L P; Katsy, E I

    2016-01-01

    The previously obtained insertion mutants ofAzospirillum brasilense Sp245 in the genes mmsBl and fabG1 (strains SK039 and Sp245.1610, respectively) were characterized by impaired flagellation and motility. The putative products of expression of these genes are 3-hydroxyisobutyrate dehydrogenase and 3-oxoacyl-[acyl-carrier protein] reductase, respectively. In the present work, A. brasilense- Sp245 strains SK039 and Sp245.1610 were found to have differences in the content of 3-hydroxyhexadecanoic, hexadecanoic, 3-hydroxytetradecanoic, hexadecenoic, octadecenoic, and nonadecanoic acids in their lipopolysaccharide prepa- rations, as well as in cell hydrophobicity and hemagglutination activity and dynamics of cell aggregation, in biomass amount, and in the relative content of lipopolysaccharide antigens in mature biofilms formed on hydrophilic or hydrophobic surfaces.

  11. [Changes in Cell Surface Properties and Biofilm Formation Efficiency in Azospirillum brasilense Sp245 Mutants in the Putative Genes of Lipid Metabolism mmsB1 and fabG1].

    Science.gov (United States)

    Shumilova, E; Shelud'ko, A V; Filip'echeva, Yu A; Evstigneeva, S S; Ponomareva, E G; Petrova, L P; Katsy, E I

    2016-01-01

    The previously obtained insertion mutants ofAzospirillum brasilense Sp245 in the genes mmsBl and fabG1 (strains SK039 and Sp245.1610, respectively) were characterized by impaired flagellation and motility. The putative products of expression of these genes are 3-hydroxyisobutyrate dehydrogenase and 3-oxoacyl-[acyl-carrier protein] reductase, respectively. In the present work, A. brasilense- Sp245 strains SK039 and Sp245.1610 were found to have differences in the content of 3-hydroxyhexadecanoic, hexadecanoic, 3-hydroxytetradecanoic, hexadecenoic, octadecenoic, and nonadecanoic acids in their lipopolysaccharide prepa- rations, as well as in cell hydrophobicity and hemagglutination activity and dynamics of cell aggregation, in biomass amount, and in the relative content of lipopolysaccharide antigens in mature biofilms formed on hydrophilic or hydrophobic surfaces. PMID:27476204

  12. Use of radioactive methods for determination of uranium, neptunium, plutonium, americium and curium isotopes in waste radioactive; Utilizacao de metodos radioanaliticos para determinacao de isotopos de uranio, netunio, plutonio, americio e curio em rejeitos radioativos

    Energy Technology Data Exchange (ETDEWEB)

    Geraldo, Bianca

    2012-07-01

    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)

  13. Effects of V-type ducts on condensation heat transfer of HFC245fa on horizontal tube bundles%V型导液槽对HFC245fa水平管束外冷凝换热影响

    Institute of Scientific and Technical Information of China (English)

    马志先; 张吉礼; 孙德兴

    2011-01-01

    试验研究了HFC245fa在水平光管与强化管管束外的冷凝换热特性,提出在管束中加装V型导液槽来消除管束效应的方法,并通过试验研究了V型导液槽对管束冷凝换热特性的影响.试验管束由4列排深为5排的列管构成,带导液槽管束的前4排管下方加装了两段长度为450 mm的导液槽;试验换热管公称外径为19.05 mm、换热长度为1000 mm.试验中,以Wilson描点法获得强化换热管水侧对流传热系数,以对比试验方法研究了V型导液槽对水平管束外冷凝换热性能的影响.结果表明:传统的管束效应模型仅在较小的热通量范围适用;凝液在管间的迁移形态与流态随管上作用凝液量的系列变化是导致管束效应变化的主要因素;加装导液槽可有效控制凝液在管间的迁移,控制管束效应;加装导液槽使光管单管冷凝传热能力下降10%左右,使光管管束总体换热能力提升4.5%~9.5%;加装导液槽对强化管单管冷凝换热性能的影响比对光管影响强近4倍.本文研究成果对引入导液槽开发新型高效卧式冷凝管束具有指导意义.%In a horizontal condensation tube-bundle, the inundation effect, resulted from local condensation film and falling condensate from upper tube rows, may reduce the condensation heat transfer coefficient (CHTC) considerably. This paper presents an experimental study on condensation heat transfer characteristic of HFC245fa on horizontal tube bundles. A scheme was proposed to reduce the tube row effect resulted from falling condensate with V-type ducts, and the effect of the duct on CHTC of the tube bundles was investigated experimentally. The tube bundle consisted of 4 columns, each with 5 tubes, with smooth tubes and enhanced tubes, separately. Two columns out of the four were equipped with the duct. The equivalent outside diameter and effective length for heat transfer of tubes were 19.05 mm and 1000 mm respectively. In the experiment, water

  14. 肘关节功能障碍245例疗效及病因分析%Outcomes and etiology of elbow joint dysfunction: an analysis of 245 cases

    Institute of Scientific and Technical Information of China (English)

    夏震; 刘珅; 范存义

    2016-01-01

    Objective To evaluate the clinical outcomes of open arthrolysis combined with hinged external fixator for treatment of elbow stiffness,and investigate the common etiologies in patients with elbow joint dysfunction to provide guidance for prevention and treatment.Methods A retrospective review was conducted of 245 cases of elbow joint dysfunction that were treated in our hospital between January 2010 and December 2013.Range of motion of the elbow before and after the surgery was compared.The etiologic features and distribution were analyzed.Results Elbow joint range of motion improved from an average of (37 ± 20)°preoperatively to (121 ± 12)°postoperatively.The Mayo Elbow Performance Index (MEPI) increased from an average of 57 ± 10 to 93 ± 7.The differences were statistically significant (P < 0.01).The most common cause of dysfunction of the elbow was trauma which accounted for 90.61%.The five leading etiologies of posttraumatic elbow joint dysfunction were fractures of the distal humerus (34.29%),periarticular fracture dislocations (19.18%),olecranon fractures (17.14%),simple dislocation of the elbow joint (10.61%),and fractures of the radial head (9.39%).Heterotopic bone formation was found in 161 patients (65.71%).Predisposition factors for developing heterotopic ossification included duration of immobilization after the trauma or operation,early rehabilitation,and accompanying traumatic brain injury or burn.Elbow dysfunction caused by simple dislocation of the elbow joint was seen more in female patients than in male patients (P < 0.01).Proliferative synovitis was the most common etiology of non-traumatic elbow joint dysfunction.Conclusion Combination of open arthrolysis and hinged external fixator can increase range of motion of the elbow joint and lead to good outcomes.Trauma to the elbow and subsequent heterotopic ossification are the direct causes for elbow joint dysfunction.Fracture of the distal humerus is the most common primary

  15. A Novel Substitution of The Heme-binding Residue Histidine-245 by Histidine-249 in Heme Oxygenase HugZ%血红素氧合酶HugZ组氨酸-249对组氨酸-245侧链缺失补偿的结构基础

    Institute of Scientific and Technical Information of China (English)

    沈溪辉; 胡永林; 王大成

    2012-01-01

    The heme oxygenase HugZ from Helicobacter pylori plays essential roles in the colonization of the bacteria in human hosts and is required for the utilization of heme as the sole iron source. Residue His245, which is highly conserved, coordinates the heme iron through its sidechain imidazole group. Surprisingly, this residue was not required for the enzymatic activities of HugZ. To investigate the roles played by His245 in heme binding and enzymatic mechanisms of HugZ, we have solved the crystal structure of HugZ mutant H245A at 2.55 (A) resolution and found that a nearby histidine residue, His249, coordinates the heme iron. This substitution is made possible by the fact that both residues 245 and 249 are located in a flexible loop region ranged from Gly239 to the C-terminus. Similar structural features have not been observed in other heme oxygenases so far. We have also performed spectroscopic studies on the heme-binding properties of HugZ and relevant mutants and our results suggest that the flexible C-terminal loop region of HugZ and the presence of multiple histidine residues in this region may play important roles in heme recruiting and in the catalytic mechanisms of HugZ.%血红素氧合酶HugZ是幽门螺旋杆菌(Helicobacter pylori)利用宿主血红素作为铁源的关键蛋白.HugZ的His245残基侧链咪唑基与血红素中心铁配位结合,是酶活中心的重要组成部分.用定点突变的方法构建HugZ突变体H245A、H249A和H245A/H249A基因,并将突变体蛋白表达纯化.通过X射线晶体学途径解析了突变体H245A与血红素复合物的2.55(A)分辨率晶体结构.结构解析表明,HugZ的His249残基侧链咪唑基团与血红素的铁原子结合,从而补偿了His245侧链缺失.这种结构特征在已知血红素氧合酶中未曾发现.Va1238ψ平面的可翻转和Gly239的柔性是His249能与血红素配位结合的关键原因,二者的共同作用改变了C端肽链的走向,使Va1238与His249之间的柔性

  16. The relationship between visible light emission and species fraction of the hydrogen ion beams extracted from 2.45 GHz microwave discharge

    CERN Document Server

    Cortázar, O D; Tarvainen, O; Kalvas, T; Koivisto, H

    2015-01-01

    The relationship between Balmer-α and Fulcher-band emissions with extracted H +, H+2 , and H+3 ions is demonstrated for a 2.45 GHz microwave discharge. Ion mass spectra and optical measurements of Balmer-α and Fulcher-band emissions have been obtained with a Wien Filter having an optical view-port on the plasma chamber axis. The beam of approximately 1 mA is analyzed for different plasma conditions simultaneously with the measurement of light emissions both with temporal resolution. The use of visible light emissions as a valuable diagnostic tool for monitoring the species fraction of the extracted beams is proposed.

  17. High Concentration InGaN/GaN Multi-Quantum Well Solar Cells with a Peak Open-Circuit Voltage of 2.45 V

    International Nuclear Information System (INIS)

    We report InGaN/GaN multi-quantum well (MQW) solar cells with a comparatively high open-circuit voltage and good concentration properties. The open circuit voltage (Voc) keeps increasing logarithmically with concentration ratio until 60 suns. The peak Voc of InGaN/GaN MQW solar cells, which has a predominant peak wavelength of 456 nm from electroluminescence measurements, is found to be 2.45 V when the concentration ratio reaches 333×. Furthermore, the dependence of conversion efficiency and fill factor on concentration ratio are analyzed. (cross-disciplinary physics and related areas of science and technology)

  18. Mono 1000: A simple and efficient 2.45 GHz electron cyclotron resonance ion source using a new magnetic structure concept

    Science.gov (United States)

    Jardin, P.; Barue, C.; Canet, C.; Dupuis, M.; Flambard, J. L.; Gaubert, G.; Lecesne, N.; Lehérissier, P.; Lemagnen, F.; Leroy, R.; Pacquet, J.-Y.; Pellemoine, F.; Rataud, J.-P.; Laurent, M. G. Saint; Villari, A. C. C.

    2002-02-01

    The production of singly charged atomic and molecular ions with a new 2.45 GHz electron cyclotron resonance ion source has been studied. The ion source Mono 1000 uses a new magnetic confinement structure. The elements Ne, Ar, and Kr are ionized with efficiencies close to 100%, while 45% has been achieved for He. In the case of the molecules SO2 and SF6, more than 90% overall efficiency has been observed with more than 40% of sulfur atoms leaving the source under the form S+. A total extracted yield of 4×1012 singly charged fulleren (C60) ions per second has also been observed.

  19. Photometric and spectroscopic study of Shakhbazian compact galaxy groups ShCG 104, ShCG 120, ShCG 223, and ShCG 245

    OpenAIRE

    Tovmassian, Hrant M.; H. Tiersch; Tovmassian, Gaghik H.; V. H. Chavushyan; Neizvestny, S.; Pramskij, A. G.; J. P. Torres-Papaqui; M Rozas

    2007-01-01

    Los grupos compactos de galaxias Shakhbazian son las configuraciones más densas que se conocen. Hace algunos años iniciamos un estudio fotométrico y espectroscópico de estos grupos. En este artículo presentamos los resultados de la investigación en los grupos ShCG 104, ShCG 120, ShCG 243 y ShCG 245. Presentamos los corrimientos al rojo de las galaxias miembro, los resultados de la fotometría R, las curvas de brillo superficial-radio efectivo, las masas estimadas, las luminosida...

  20. Fate of the herbicides 2,4,5-T, atrazine, and DNOC in a shallow, anaerobic aquifer investigated by in situ passive diffusive emitters and laboratory batch experiments

    DEFF Research Database (Denmark)

    Arildskov, N.P.; Pedersen, Philip Grinder; Albrechtsen, Hans-Jørgen

    2001-01-01

    simultaneously with tritiated water (HTO) as tracer in the depth interval 3 to 4 rubs (meters below surface) by use of passive diffusive emitters. Atrazine and 2,4,5-T were persistent during the approximately 18 days residence time in the aquifer. In contrast, DNOC was rapidly removed from the water phase...... first-order kinetics, and when normalized to the sediment/water-ratio, the field and laboratory derived rate constants compared well. The DNOC degradation in the methanogenic incubations (8 to 9 rubs) was up to 50 times faster than in the sediments from 3 to 4 rubs, likely due to the low redox potential....

  1. Report on the low-RF-power and data-acquisition-systems of the 2.45 GHz Lower-Hybrid Transmitter at the ASDEX tokamak

    International Nuclear Information System (INIS)

    This report relates to the low-power section of the 2.45 GHz transmitter used for current drive experiments at the ASDEX tokamak. The high-RF-power section is dealt with elsewhere. Data acquisition and evaluation of quantities pertaining to the Lower Hybrid experiment are also treated here. As in the previous report on the 1.3 GHz system (M. Zouhar: 'Beschreibung des Niederleistungsteils des HF-Systems fuer die LH-Experimente in ASDEX.', IPP-report 4/218, February 1984), most space is spent in commenting upon the amplitude (power)- and phase-feedback control loops. (orig.)

  2. Solubility and speciation studies of waste radionuclides pertinent to geologic disposal at Yucca Mountain: Results on neptunium, plutonium and americium in J-13 groundwater; Letter report (R707): Reporting period, October 1, 1985--September 30, 1987

    Energy Technology Data Exchange (ETDEWEB)

    Nitsche, H.; Standifer, E.M.; Lee, S.C.; Gatti, R.C.; Tucker, D.B.

    1988-01-01

    We have studied the solubilities of neptunium, plutonium, and americium in J-13 groundwater from Yucca Mountain (Nevada) at three temperatures and hydrogen ion concentrations. They are 25{degree}, 60{degree}C, and 90{degree}C and pH 5.9, 7.0, and 8.5. The results for 25{degree}C are from a study which we did during FY 1984. We included these previous results in the tables to give more information on the solubility temperature dependence; they were, however, done at only one pH (7.0). The solubilities were studied from oversaturation. The nuclides were added at the beginning of each experiment as NpO{sub 2}{sup +}, Pu{sup 4+}, and Am{sup 3+}. The neptunium solubility decreased with increasing temperature and with increasing pH. The soluble neptunium did not change oxidation state at steady state. The pentavalent neptunium was increasingly complexed by carbonate with increasing pH. All solids were crystalline and contained carbonate, except the solid formed at 90{degree}C and pH 5.9. We identified this solid as crystalline Np{sub 2}P{sub 5}. The 25{degree}C, pH 7 solid was Na{sub 3}NpO{sub 2}(CO{sub 3}){sub 2} {center_dot} nH{sub 2}O. Plutonium concentrations decreased with increasing temperature and showed no trend with pH. Pu(V) and Pu(VI) were the dominant oxidation states in the supernatant solution; as the amount of Pu(V) increased with pH, Pu(VI) decreed. The steady-state solids were mostly amorphous, although some contained a crystalline component. They contained Pu(IV) polymer and unknown carbonates.

  3. Comparative analysis of CO2-based transcritical Rankine cycle and HFC245fa-based subcritical organic Rankine cycle using low-temperature geothermal source

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A detailed thermodynamic and techno-economic comparison is presented for a CO2-based transcritical Rankine cycle and a subcritical organic Rankine cycle (ORC) using HFC245fa (1,1,1,3,3-pentafluoro-propane) as the working fluid driven by the low-temperature geothermal source,in order to determine the configuration that presents the maximum net power output with a minimum investment.The evaluations of both Rankine cycles have been performed based on equal thermodynamic mean heat rejection temperature by varying certain system operating parameters to achieve each Rankine cycle’s optimum design at various geothermal source temperature levels ranging from 80oC to 120oC.The results obtained show that the optimum ther-modynamic mean heat injection temperatures of both Rankine cycles are distributed in the scope of 55% to 65% of a given geothermal source temperature level,and that the CO2-based transcritical Rankine cycle presents 3% to 7% higher net power output,84% reduction of turbine inlet volume flow rate,47% reduction of expansion ratio and 1.68 times higher total heat transfer capacity compared with the HFC245fa-based subcritical ORC.It is also indicated that using the CO2-based transcritical system can reduce the dimension of turbine design.However,it requires larger heat transfer areas with higher strength heat exchanger materials because of the higher system pressure.

  4. Shadow of a Colossus: A z=2.45 Galaxy Protocluster Detected in 3D Ly-a Forest Tomographic Mapping of the COSMOS Field

    CERN Document Server

    Lee, Khee-Gan; White, Martin; Prochaska, J Xavier; Font-Ribera, Andreu; Schlegel, David J; Rich, R Michael; Suzuki, Nao; Stark, Casey W; Fevre, Olivier Le; Nugent, Peter E; Salvato, Mara; Zamorani, Gianni

    2015-01-01

    Using moderate-resolution optical spectra from 58 background Lyman-break galaxies and quasars at $z\\sim 2.3-3$ within a $11.5'\\times13.5'$ area of the COSMOS field ($\\sim 1200\\,\\mathrm{deg}^2$ projected area density or $\\sim 2.4\\,h^{-1}\\,\\mathrm{Mpc}$ mean transverse separation), we reconstruct a 3D tomographic map of the foreground Ly$\\alpha$ forest absorption at $2.22.45$ associated with a recently-discovered galaxy protocluster at the same redshift. Based on simulations matched to our data, we estimate the enclosed dark matter mass within this IGM overdensity to be $M_{\\rm dm} (z=2.45) = (9\\pm4)\\times 10^{13}\\,h^{-1}\\,\\mathrm{M_\\o...

  5. Assessing the efficacy of co-inoculation of wheat seedlings with the associative bacteria Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245.

    Science.gov (United States)

    Yegorenkova, Irina V; Tregubova, Kristina V; Burygin, Gennady L; Matora, Larisa Y; Ignatov, Vladimir V

    2016-03-01

    Co-inoculation of associative bacteria, which have high nitrogen-fixing activity, tolerance for environmental conditions, and the ability to compete with the natural microflora, is used widely to enhance the growth and yields of agricultural plants. We evaluated the ability of 2 co-inoculated plant-growth-promoting rhizobacteria, Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245, to colonize roots of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings, and we assessed the morphometric parameters of wheat early in its development. Analysis by ELISA with polyclonal antibodies raised against the exopolysaccharide of P. polymyxa 1465 and the lipopolysaccharide of A. brasilense Sp245 demonstrated that the root-colonizing activity of A. brasilense was higher when the bacterium was co-inoculated with P. polymyxa than when it was inoculated singly. Immunofluorescence microscopy with Alexa Fluor 532-labeled antibodies revealed sites of attachment of co-inoculated P. polymyxa and A. brasilense and showed that the 2 bacteria colonized similar regions of the roots. Co-inoculation exerted a negative effect on wheat seedling development, inhibiting root length by 17.6%, total root weight by 11%, and total shoot weight by 12%. Under certain conditions, dual inoculation of wheat may prove ineffective, apparently owing to the competition between the rhizobacteria for colonization sites on the plant roots. The findings from this study may aid in developing techniques for mixed bacterial inoculation of cultivated plants. PMID:26863134

  6. Assessing the efficacy of co-inoculation of wheat seedlings with the associative bacteria Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245.

    Science.gov (United States)

    Yegorenkova, Irina V; Tregubova, Kristina V; Burygin, Gennady L; Matora, Larisa Y; Ignatov, Vladimir V

    2016-03-01

    Co-inoculation of associative bacteria, which have high nitrogen-fixing activity, tolerance for environmental conditions, and the ability to compete with the natural microflora, is used widely to enhance the growth and yields of agricultural plants. We evaluated the ability of 2 co-inoculated plant-growth-promoting rhizobacteria, Paenibacillus polymyxa 1465 and Azospirillum brasilense Sp245, to colonize roots of wheat (Triticum aestivum L. 'Saratovskaya 29') seedlings, and we assessed the morphometric parameters of wheat early in its development. Analysis by ELISA with polyclonal antibodies raised against the exopolysaccharide of P. polymyxa 1465 and the lipopolysaccharide of A. brasilense Sp245 demonstrated that the root-colonizing activity of A. brasilense was higher when the bacterium was co-inoculated with P. polymyxa than when it was inoculated singly. Immunofluorescence microscopy with Alexa Fluor 532-labeled antibodies revealed sites of attachment of co-inoculated P. polymyxa and A. brasilense and showed that the 2 bacteria colonized similar regions of the roots. Co-inoculation exerted a negative effect on wheat seedling development, inhibiting root length by 17.6%, total root weight by 11%, and total shoot weight by 12%. Under certain conditions, dual inoculation of wheat may prove ineffective, apparently owing to the competition between the rhizobacteria for colonization sites on the plant roots. The findings from this study may aid in developing techniques for mixed bacterial inoculation of cultivated plants.

  7. Porovnání sběracích lisů CLAAS ROLLANT 46 SILAGE a LELY WELGER RP 245 při sklizni píce a slámy.

    OpenAIRE

    KOCÁBEK, Jan

    2012-01-01

    This thesis is focused on a comparison of round balers from two different producers. The compared balers were Claas Rollant 46 Silage and Lely Welger RP 245. The compared parametrs were the quality of the cutting, compressibility and the quality of forage, The thesis is supplemented by an analysis of performance indicators and exploitation , the cost of pressing and the cost per 1 ton of harvested materiál. For the baler Lely Welger RP 245 the better quality of haylage , more effective compre...

  8. Repetitive generation of 2.45 MeV nuclear fusion neutron from deuterated nano-sized particles irradiated by 20 TW all-solid-state laser

    International Nuclear Information System (INIS)

    We propose a novel neutron source technique using ultra-high intensity laser based on the cluster fusion scheme. We have developed the high-repetition rate 20 TW ultra-short pulse laser system MATSU-1 pumped by the efficient diode-pumped high energy solid-state laser KURE-1. Irradiating the ultra-high intensity of >2x1018 W/cm2 in 60 fs laser pulse, high-energy deuterons were generated from the Coulomb explosion of deuterated polystyrene solid nanoparticles, and 2.45 MeV neutrons were observed by deuteron-deuteron fusion reaction. The yield of 104-105 neutrons per shot was stably observed during a hundred shots at 0.1-1 Hz operation. (author)

  9. Catalytic transfer hydrogenation of azobenzene by low-valent nickel complexes: a route to 1,2-disubstituted benzimidazoles and 2,4,5-trisubstituted imidazolines.

    Science.gov (United States)

    Zurita, Daniel A; Flores-Alamo, Marcos; García, Juventino J

    2016-06-21

    The one-pot synthesis of 1,2-disubstituted benzimidazoles by the transfer hydrogenation of azobenzene, using benzylamine as a hydrogen donor, sequential rearrangement of hydrazobenzene to semidine and further condensation with N-benzylideneamine is reported, catalyzed by 2 mol% of [Ni(COD)2] : dippe. The N2 substitution on benzimidazole can be controlled by the selection of different azobenzenes and C2 substitution will only depend on the chosen benzylamine. The current methodology avoids the addition of external oxidants, which are needed in the classical benzimidazole synthesis. In addition, the byproduct, N-benzylideneamine, obtained from dehydrogenation of benzylamine produced 2,4,5-trisubstituted imidazolines by cyclization and C-H functionalization, and this route was optimized with the use of 2 mol% of [Ni(COD)2] : 2PPh3. PMID:27254530

  10. FTIR and Raman spectra, DFT and normal coordinate computations of 2,4,5- and 2,4,6-tri-fluoroanilines

    Science.gov (United States)

    Mukherjee, V.; Singh, N. P.; Yadav, R. A.

    2009-07-01

    FTIR and Raman spectra of the 2,4,5- and 2,4,6-tri-fluoroaniline molecules have been reported. Density functional method has been employed to calculate the optimized geometrical parameters, atomic charges and vibrational frequencies. In addition, SQM force field method has also been employed to calculate potential energy distribution matrix. The observed and calculated IR and Raman spectra have been simulated. Each normal mode has been assigned using observed and calculated vibrational frequencies, IR and Raman intensities, depolarization ratios for the Raman lines, vector displacements and potential energy distributions. Optimized geometrical parameters, atomic charges and vibrational frequencies have been compared for the title molecules. The influences of presence of fluorine atoms to the geometries and normal modes of the aniline molecule have also been discussed.

  11. Strategic Petroleum Reserve (SPR) oil storage cavern sulphur mines 2-4-5 certification tests and analysis. Part I: 1981 testing. Part II: 1982 testing

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, R.R.

    1982-12-01

    Well leak tests and a cavern pressure were conducted in June through December 1981, and are described in Part I. The tests did not indicate conclusively that there was no leakage from the cavern, but the data indicate that cavern structural failure during oil storage is unlikely. The test results indicated that retesting and well workover were desirable prior to making a decision on the cavern use. Well leak tests were conducted in March through May 1982, and are described in Part II. The tests indicated that there was no significant leakage from wells 2 and 4 but that the leakage from wells 2A and 5 exceeded the DOE criterion. Because of the proximity of cavern 2-4-5 to the edge of the salt, this cavern should be considered for only one fill/withdrawal cycle prior to extensive reevaluation. 57 figures, 17 tables.

  12. Fission Cross-section Measurements of (233)U, (245)Cm and (241,243)Am at CERN n_TOF Facility

    CERN Document Server

    Calviani, M; Andriamonje, S; Chiaveri, E; Vlachoudis, V; Colonna, N; Meaze, M H; Marrone, S; Tagliente, G; Terlizzi, R; Belloni, F; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C; Aerts, G; Berthoumieux, E; Dridi, W; Gunsing, F; Pancin, J; Perrot, L; Plukis, A; Alvarez, H; Duran, I; Paradela, C; Alvarez-Velarde, F; Cano-Ott, D; Gonzalez-Romero, E; Guerrero, C; Martinez, T; Villamarin, D; Vicente, M C; Andrzejewski, J; Marganiec, J; Assimakopoulos, P; Karadimos, D; Karamanis, D; Papachristodoulou, C; Patronis, N; Audouin, L; David, S; Ferrant, L; Isaev, S; Stephan, C; Tassan-Got, L; Badurek, G; Jericha, E; Leeb, H; Oberhummer, H; Pigni, M T; Baumann, P; Kerveno, M; Lukic, S; Rudolf, G; Becvar, F; Krticka, M; Calvino, F; Capote, R; Carrillo De Albornoz, A; Marques, L; Salgado, J; Tavora, L; Vaz, P; Cennini, P; Dahlfors, M; Ferrari, A; Gramegna, F; Herrera-Martinez, A; Kadi, Y; Mastinu, P; Praena, J; Sarchiapone, L; Wendler, H; Chepel, V; Ferreira-Marques, R; Goncalves, I; Lindote, A; Lopes, I; Neves, F; Cortes, G; Poch, A; Pretel, C; Couture, A; Cox, J; O'brien, S; Wiescher, M; Dillman, I; Heil, M; Kappeler, F; Mosconi, M; Plag, R; Voss, F; Walter, S; Wisshak, K; Dolfini, R; Rubbia, C; Domingo-Pardo, C; Tain, J L; Eleftheriadis, C; Savvidis, I; Frais-Koelbl, H; Griesmayer, E; Furman, W; Konovalov, V; Goverdovski, A; Ketlerov, V; Haas, B; Haight, R; Reifarth, R; Igashira, M; Koehler, P; Kossionides, E; Lampoudis, C; Lozano, M; Quesada, J; Massimi, C; Vannini, G; Mengoni, A; Oshima, M; Papadopoulos, C; Vlastou, R; Pavlik, A; Pavlopoulos, P; Plompen, A; Rullhusen, P; Rauscher, T; Rosetti, M; Ventura, A

    2011-01-01

    Neutron-induced fission cross-sections of minor actinides have been measured using the n_TOF white neutron source at CERN, Geneva, as part of a large experimental program aiming at collecting new data relevant for nuclear astrophysics and for the design of advanced reactor systems. The measurements at n_TOF take advantage of the innovative features of the n_TOF facility, namely the wide energy range, high instantaneous neutron flux and good energy resolution. Final results on the fission cross-section of 233U, 245Cm and 243Am from thermal to 20 MeV are here reported, together with preliminary results for 241Am. The measurement have been performed with a dedicated Fast Ionization Chamber (FIC), a fission fragment detector with a very high efficiency, relative to the very well known cross-section of 235U, measured simultaneously with the same detector.

  13. PRODUCTION OF S = 0, -1 RESONANT STATES IN K- p INTERACTIONS AT 2.45 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Ronald R.; Friedman, Jerome H.; Siegel, Daniel M.; Flatte, Stanley; Alvarez, Luis W.; Barbaro-Galtieri, Angela; Button-Shafer, Janice; Dahl, Orin I.; Eberhard, Philippe; Humphrey, William E.; Kalbfleisch, George R.; Lindsey, James S.; Merrill, Deane W.; Murray, Joseph J.; Rittenberg, Alan; Shively, Frank T.; Smith, Gerald A.; Tripp, Robert D.

    1964-07-07

    About 70,000 pictures of 2.45-GeV/c K{sup -}-p interactions have been obtained in the present 72-inch hydrogen bubble-chamber experiment. Approximately 24,000 events of all topologies except 1-, 2-, and 3-prong events have been measured, and 50% have been remeasured. They report here on a study of the production of known resonances in the reactions: (1) K{sup -} + p {yields} {Lambda} + {pi}{sup +} + {pi}{sup -}; (2) K{sup -} + p {yields} {Lambda} + {pi}{sup +} + {pi}{sup 0} + {pi}{sup -}. The cross section for production and number of events in reactions (1) and (2) are given in Table I.

  14. Dosimetry of a set-up for the exposure of newborn mice to 2.45-GHz WiFi frequencies

    International Nuclear Information System (INIS)

    This work describes the dosimetry of a two waveguide cell system designed to expose newborn mice to electromagnetic fields associated with wireless fidelity signals in the frequency band of 2.45 GHz. The dosimetric characterisation of the exposure system was performed both numerically and experimentally. Specific measures were adopted with regard to the increase in both weight and size of the biological target during the exposure period. The specific absorption rate (SAR, W kg-1) for 1 W of input power vs. weight curve was assessed. The curve evidenced an SAR pattern varying from -1 to > 6 W kg-1 during the first 5 weeks of the life of mice, with a peak resonance phenomenon at a weight around 5 g. This curve was used to set the appropriate level of input power during experimental sessions to expose the growing mice to a defined and constant dose. (authors)

  15. Dielectric and magnetic properties of NiFe{sub 2}O{sub 4} at 2.45 GHz and heating capacity for potential uses under microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Polaert, Isabelle, E-mail: isabelle.polaert@insa-rouen.fr [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Bastien, Samuel [Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada); Legras, Benoit [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada); Estel, Lionel [LSPC (Laboratoire de Sécurité des Procédés Chimiques). Institut National des Sciences Appliquées INSA Rouen (France); Braidy, Nadi [Département de génie chimique et de génie biotechnologique, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1 (Canada)

    2015-01-15

    This paper presents the dielectric and magnetic properties, measured at 2.45 GHz, of a new nickel ferrite, NiFe{sub 2}O{sub 4}, synthetized by plasma technology. These properties were measured by the small perturbation method in a resonant cavity, from 293 to 513 K. Using these values, the adiabatic heating of nanoparticles of NiFe{sub 2}O{sub 4} under microwave irradiation was also modeled. The wave propagation equation (Maxwell's equation) coupled to the heat transfer in the solid was numerically solved. The influence of parameters such as the bed volume, its porosity, the microwave incident power or the microwave system geometry is discussed. This study demonstrates that NiFe{sub 2}O{sub 4} nanoparticles can be rapidly heated up to at least 513 K under microwaves and can probably achieve higher temperatures according to the thermal insulation. The magnetic contribution to heating overcomes the dielectric one in the explored temperature range. Very efficient energy yield (>90%) can then be achieved when the magnetic field position is centered over the bed. - Highlights: • A new nickel ferrite, NiFe{sub 2}O{sub 4}, was synthetized by plasma technology. • Its dielectric and magnetic properties were measured at 2.45 GHz. • The adiabatic heating of nanoparticles of NiFe{sub 2}O{sub 4} under microwave was modeled. • NiFe{sub 2}O{sub 4} nanoparticles can be rapidly heated up to at least 513 K. • The magnetic contribution to heating overcomes the dielectric one from 293 K to 513 K.

  16. Dielectric and magnetic properties of NiFe2O4 at 2.45 GHz and heating capacity for potential uses under microwaves

    International Nuclear Information System (INIS)

    This paper presents the dielectric and magnetic properties, measured at 2.45 GHz, of a new nickel ferrite, NiFe2O4, synthetized by plasma technology. These properties were measured by the small perturbation method in a resonant cavity, from 293 to 513 K. Using these values, the adiabatic heating of nanoparticles of NiFe2O4 under microwave irradiation was also modeled. The wave propagation equation (Maxwell's equation) coupled to the heat transfer in the solid was numerically solved. The influence of parameters such as the bed volume, its porosity, the microwave incident power or the microwave system geometry is discussed. This study demonstrates that NiFe2O4 nanoparticles can be rapidly heated up to at least 513 K under microwaves and can probably achieve higher temperatures according to the thermal insulation. The magnetic contribution to heating overcomes the dielectric one in the explored temperature range. Very efficient energy yield (>90%) can then be achieved when the magnetic field position is centered over the bed. - Highlights: • A new nickel ferrite, NiFe2O4, was synthetized by plasma technology. • Its dielectric and magnetic properties were measured at 2.45 GHz. • The adiabatic heating of nanoparticles of NiFe2O4 under microwave was modeled. • NiFe2O4 nanoparticles can be rapidly heated up to at least 513 K. • The magnetic contribution to heating overcomes the dielectric one from 293 K to 513 K

  17. In vitro and in vivo inhibitory activity of 6-amino-2,4,5-trimethylpyridin-3-ols against inflammatory bowel disease.

    Science.gov (United States)

    Banskota, Suhrid; Kang, Han-Eol; Kim, Dong-Guk; Park, Sang Won; Jang, Hyeonjin; Karmacharya, Ujjwala; Jeong, Byeong-Seon; Kim, Jung-Ae; Nam, Tae-Gyu

    2016-10-01

    Although the pathogenesis of inflammatory bowel disease (IBD) is complex, attachment and infiltration of leukocytes to gut epithelium induced by pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α) represents the initial step of inflammation in IBD. Previously, we have reported that some 6-amino-2,4,5-trimethylpyridin-3-ols have significant levels of antiangiogenic activity via PI3K inhibition. Based on the reports that angiogenesis is involved in the aggravation of IBD and that PI3K is a potential target for IBD therapy, we investigated whether the scaffold has inhibitory activity against in vitro and in vivo models of colitis. Many analogues showed >80% inhibition against TNF-α-induced monocyte adhesion to colon epithelial cells at 1μM. Compound 8m showed IC50=0.19μM, which is about five orders of magnitude better than that of 5-aminosalicylic acid (5-ASA, IC50=18.1mM), a positive control. In a rat model of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis, orally administered 8m dramatically ameliorated TNBS-induced colon inflammation. It was demonstrated by a high level of suppression in myeloperoxidase (MPO), a surrogate marker of colitis, as well as almost perfect recovery of colon and body weights in a dose-dependent manner. Compared to sulfasalazine, a prodrug of 5-ASA, compound 8m showed >300-fold better efficacy in those parameters. Taken together, 6-amino-2,4,5-trimethylpyridin-3-ols can provide a novel platform for anti-IBD drug discovery. PMID:27597248

  18. 245例脑外伤所致精神障碍者家属抑郁状况及相关因素分析%Depression Status of the Family Member and Its Influencing Factors in the Patient with Mental Disorder Caused by Cerebral Trauma: 245 Cases Analysis

    Institute of Scientific and Technical Information of China (English)

    杨成龙; 庞艳霞; 谢岩平; 许海峰

    2013-01-01

    目的 了解脑外伤所致精神障碍者家属抑郁状况及其影响因素. 方法 应用自行设计的一般资料调查问卷和抑郁自评量表(self-rating depression scale,SDS),对245名被鉴定人家属进行抑郁状况调查,并依据SDS评分指数分为抑郁组和非抑郁组,进行单因素以及多元逐步回归分析.结果 245名被鉴定人家属中117名家属存在不同程度的抑郁症状,其中轻度68例、中度42例、重度7例.在多元逐步回归分析中,亲缘关系、家属性格特征、付费方式为被鉴定人家属抑郁状况的主要影响因素. 结论 脑外伤所致精神障碍者家属抑郁状况应引起足够重视,给予针对性的心理干预.%Objective To determine the family member's depression status and its influencing factors in the patient with mental disorder caused by cerebral trauma.Methods The self-designed information questionnaire and self-rating depression scale (SDS) were used to investigate 245 family members' depression conditions.On the basis of SDS score index,all cases were divided into depression group and non-depression group.The data were analyzed by the tmivariate analysis and multiple factors regression analysis.Results In the 245 family members,117 family members had different degrees of depressive symptoms including 68 with mild depression,42 with moderate depression,and 7 with severe depression.In the multiple factors regression analysis,genetic relationship,personality characteristics and payment method were the main influencing factors of the depression status.Conclusion Much attention should be paid to the family member's depression condition of the patient with mental disorder caused by cerebral trauma through specific psychological intervention.

  19. [Insertional mutation in the AZOBR_p60120 gene is accompanied by defects in the synthesis of lipopolysaccharide and calcofluor-binding polysaccharides in the bacterium Azospirillum brasilense Sp245].

    Science.gov (United States)

    Katsy, E I; Prilipov, A G

    2015-03-01

    In the bacterium Azospirillum brasilense Sp245, extracellular calcofluor-binding polysaccharides (Cal+ phenotype) and two types of lipopolysaccharides, LPSI and LPSII, were previously identified. These lipopolysaccharides share the same repeating O-polysaccharide unit but have different antigenic structures and different charges of their O-polysaccharides and/or core oligosaccharides. Several dozens of predicted genes involved in the biosynthesis of polysaccharides have been localized in the AZOBR_p6 plasmid of strain Sp245 (GenBank accession no. HE577333). In the present work, it was demonstrated that an artificial transposon Omegon-Km had inserted into the central region of the AZOBR_p60120 gene in the A. brasilense Sp245 LPSI- Cal- KM252 mutant. In A. brasilense strain Sp245, this plasmid gene encodes a putative glycosyltransferase containing conserved domains characteristic of the enzymes participating in the synthesis of O-polysaccharides and capsular polysaccharides (accession no. YP004987664). In mutant KM252, a respective predicted protein is expected to be completely inactivated. As a result of the analysis of the EcoRI fragment of the AZOBR_p6 plasmid, encompassing the AZOBR_p60120 gene and a number of other loci, novel data on the structure of AZOBR_p6 were obtained: an approximately 5-kb gap (GenBank accession no. KM189439) was closed in the nucleotide sequence of this plasmid.

  20. PEG-400 as an efficient reaction medium for the synthesis of 2,4,5-triaryl-1H-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles

    Institute of Scientific and Technical Information of China (English)

    Xi Cun Wang; Hai Peng Gong; Zheng Jun Quan; Lei Li; He Lin Ye

    2009-01-01

    An efficient protocol for the one-pot multicomponent synthesis of various 2,4,5-triaryl- IH-imidazoles and 1,2,4,5-tetraaryl-1H-imidazoles using PEG-400 as reaction medium is described. This method has the advantages of good yields, less pollution and simple reaction conditions.

  1. The proliferation potential of neptunium and americium

    Energy Technology Data Exchange (ETDEWEB)

    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)

  2. Delocalization and new phase in Americium: theory

    Energy Technology Data Exchange (ETDEWEB)

    Soderlind, P

    1999-04-23

    Density-functional electronic structure calculations have been used to investigate the high pressure behavior of Am. At about 80 kbar (8 GPa) calculations reveal a monoclinic phase similar to the ground state structure of plutonium ({alpha}-Pu). The experimentally suggested {alpha}-U structure is found to be substantially higher in energy. The phase transition from fcc to the low symmetry structure is shown to originate from a drastic change in the nature of the electronic structure induced by the elevated pressure. A calculated volume collapse of about 25% is associated with the transition. For the low density phase, an orbital polarization correction to the local spin density (LSD) theory was applied. Gradient terms of the electron density were included in the calculation of the exchange/correlation energy and potential, according to the generalized gradient approximation (GGA). The results are consistent with a Mott transition; the 5f electrons are delocalized and bonding on the high density side of the transition and chemically inert and non-bonding (localized) on the other. Theory compares rather well with recent experimental data which implies that electron correlation effects are reasonably modeled in our orbital polarization scheme.

  3. 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.

  4. Observation of 2.45 MeV neutrons correlated with natural atmospheric lightning discharges by Lead-Free Gulmarg Neutron Monitor

    Science.gov (United States)

    Ishtiaq, P. M.; Mufti, S.; Darzi, M. A.; Mir, T. A.; Shah, G. N.

    2016-01-01

    The first experimental evidence of detecting the neutrons correlated with the natural atmospheric lightning discharges (NALD) was obtained with Lead-Free Gulmarg Neutron Monitor (LFGNM) operating at High Altitude Research Laboratory, Gulmarg, Kashmir, India, and was reported in the year 1985. The neutron observations still continue with LFGNM. However, the current configuration of LFGNM is the upgraded version of the system used earlier to record neutron bursts (in the recording period of 320 μs in four successive electronic gates of 80 μs each) supposedly originating from an NALD. In the current system the neutron recording time period/interval has been extended to 1260 μs with 63 successive gates of 20 μs each. The system also simultaneously records the differential times—maximum up to 14—between the consecutive strokes of a multistroke lightning flash. The distance between an NALD channel and LFGNM setup is determined empirically by making use of the time delay (td)/time of flight (TOF) measurement of the first detected neutron subsequent to the sensing of the electrostatic field variation caused by the initiation of an NALD in the ambient atmosphere of the LFGNM setup. Assuming a priori incident energy as 2.45 MeV of the detected neutrons supposedly generated due to the fusion of deuterium ions in the lightning discharge channel leads to quantifying the neutron emission flux if the NALD channel distance with respect to the LFGNM setup is established. In this paper we discuss the experiment and the time profiles of several of a large number of the major neutron burst events recorded with LFGNM in association with NALDs. Moreover, a rare and an extraordinary neutron burst event, in terms of its associated "td/TOF" of first detected neutron after triggering, recorded by this system is specifically discussed. In this event, the recorded TOF of 14 μs of the escaping neutron detected by the system immediately after getting triggered by the NALD that struck a

  5. Granular activated carbon adsorption and microwave regeneration for the treatment of 2,4,5-trichlorobiphenyl in simulated soil-washing solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu Xitao [Persistent Organic Pollutants Research Centre, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Yu Gang [Persistent Organic Pollutants Research Centre, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)]. E-mail: yg-den@tsinghua.edu.cn; Han Wenya [Persistent Organic Pollutants Research Centre, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2007-08-25

    The treatment of 2,4,5-trichlorobiphenyl (PCB29) in simulated soil-washing solution by granular activated carbon (GAC) adsorption and microwave (MW) regeneration was investigated in this study. The PCB29 adsorption process was carried out in a continuous flow adsorption column. After adsorption, the PCB29-loaded GAC was dried at 103 deg. C, and regenerated in a quartz reactor by 2450 MHz MW irradiation at 700 W for 5 min. The efficacy of this procedure was analyzed by determining the rates and amounts of PCB29 adsorbed in successive adsorption/MW regeneration cycles. Effects of the regeneration on the textural properties and the PCB29 adsorption capacity of GAC were examined. It was found that after several adsorption/MW regeneration cycles, the adsorption rate of GAC increased, whereas, the adsorption capacity decreased, which could be explained according to the change of textural properties. Most of the PCB29 adsorbed on GAC was degraded within 3 min under MW irradiation, and the analysis of degradation products by GC-MS demonstrated that PCB29 experienced dechlorination during this treatment.

  6. Comparative behavioral effects between synthetic 2,4,5-trimethylthiazoline (TMT) and the odor of natural fox (Vulpes vulpes) feces in mice.

    Science.gov (United States)

    Buron, Gaelle; Hacquemand, Romain; Pourie, Gregory; Lucarz, Annie; Jacquot, Laurence; Brand, Gerard

    2007-10-01

    Synthetic 2,4,5-trimethylthiazoline (TMT)--a component of red fox (Vulpes vulpes) feces--is frequently used to induce unconditioned fear in rodents. Surprisingly, direct comparison between TMT and natural fox feces odor is almost nonexistent. In this study, Experiment 1 compared the avoidance in relation to TMT concentration, natural fox feces, and gender of fox and mice. Results show that the avoidance is (a) higher with either pure or 50% TMT as compared to natural fox feces, whereas the difference is slight with 10% TMT, and (b) significantly higher for the female mouse group compared to the male mouse group with TMT as well as natural fox feces. In addition, no clear difference in effect was observed between male and female fox feces. Experiment 2 compared behavioral parameters recorded as an index of fear and anxiety, general activity, and avoidance in elevated plus-maze and open-field chamber between 10% TMT and natural fox feces in relation to the estrus cycle of the mice. Results show no cycle period effect--except for the avoidance parameter "distance to odorant"--and no different effects between 10% TMT and natural fox feces except for freezing.

  7. Banana peel: a potential substrate for laccase production by Aspergillus fumigatus VkJ2.4.5 in solid-state fermentation.

    Science.gov (United States)

    Vivekanand, V; Dwivedi, Pallavi; Pareek, Nidhi; Singh, Rajesh P

    2011-09-01

    In solid-state fermentation, among various solid supports evaluated, banana peel was found to be an ideal support and resulted into higher levels of laccase (6281.4 ± 63.60 U l(-1)) along with notable levels of manganese peroxidase production (1339.0 ± 131.23 U l(-1)) by Aspergillus fumigatus VkJ2.4.5. Maximum levels of laccase was achieved under derived conditions consisting of 80% of moisture level, 6 days of incubation period, 6% inoculum level, and an aeration level of 2.5 l min(-1). A column-tray bioreactor was designed to scale up and economize the enzyme production in three successive cycles of fermentation using the same fungal biomass. Thermal and pH stability profiles revealed that enzyme was stable up to 50°C and at varying pH range from 5-9 for up to 2 h. The apparent molecular weight of laccase was found to be 34 ± 1 kDa. MALDI-TOF/TOF analysis of the protein showed significant homology with maximum identity of 67% to other laccases reported in database.

  8. Synthesis, crystal structure investigation, DFT studies and DPPH radical scavenging activity of 1-(furan-2-ylmethyl)-2,4,5-triphenyl-1H-imidazole derivatives

    Science.gov (United States)

    Rajaraman, D.; Sundararajan, G.; Rajkumar, R.; Bharanidharan, S.; Krishnasamy, K.

    2016-03-01

    A new series of 1-(furan-2ylmethyl)-2,4,5-triphenyl-1H-imidazole derivatives are conveniently synthesized and characterized by IR, 1H NMR and 13C NMR spectral techniques. The compound 5a also characterized by HSQC correlation spectra. All the newly synthesized compounds were evaluated for their antioxidant activities with DPPH radical scavenging activity. The structure of 5e was also confirmed by single crystal XRD analysis and optimized bond parameters are calculated by density functional theory (DFT) method at B3LYP/6-31G (d, p) level of theory. The optimized geometrical parameters obtained by DFT calculation are in good agreement with single crystal XRD data. The experimentally observed FT-IR and FT-Raman bands were assigned to different normal modes of the molecule. The stability and charge delocalization of the molecule were also studied by natural bond orbital (NBO) analysis. The HOMO-LUMO energies describe the charge transfer takes place within the molecule. Molecular electrostatic potential has been analyzed. The reported 5e molecule used as a potential NLO material since it has high μβ0 value.

  9. Bioremediation of soils co-contaminated with heavy metals and 2,4,5-trichlorophenol by fruiting body of Clitocybe maxima.

    Science.gov (United States)

    Liu, Hongying; Guo, Shanshan; Jiao, Kai; Hou, Junjun; Xie, Han; Xu, Heng

    2015-08-30

    Pot experiments were performed to investigate the single effect of 2,4,5-trichlorophenol (TCP) or heavy metals (Cu, Cd, Cu+Cd) and the combined effects of metals-TCP on the growth of Clitocybe maxima together with the accumulation of heavy metals as well as dissipation of TCP. Results showed a negative effect of contaminations on fruiting time and biomass of the mushroom. TCP decreased significantly in soils accounting for 70.66-96.24% of the initial extractable concentration in planted soil and 66.47-91.42% in unplanted soil, which showed that the dissipation of TCP was enhanced with mushroom planting. Higher biological activities (bacterial counts, soil respiration and laccase activity) were detected in planted soils relative to unplanted controls, and the enhanced dissipation of TCP in planted soils might be derived from the increased biological activities. The metals accumulation in mushroom increased with the augment of metal load, and the proportion of acetic acid (HOAc) extractable metal in soils with C. maxima was larger than that in unplanted soils, which may be an explanation of metal uptake by C. maxima. These results suggested that the presence of C. maxima was effective in promoting the bioremediation of soil contaminated with heavy metals and TCP.

  10. FDTD analysis of temperature elevation in the lens of human and rabbit models due to near-field and far-field exposures at 2.45 GHz.

    Science.gov (United States)

    Oizumi, Takuya; Laakso, Ilkka; Hirata, Akimasa; Fujiwara, Osamu; Watanabe, Soichi; Taki, Masao; Kojima, Masami; Sasaki, Hiroshi; Sasaki, Kazuyuki

    2013-07-01

    The eye is said to be one of the most sensitive organs to microwave heating. According to previous studies, the possibility of microwave-induced cataract formation has been experimentally investigated in rabbit and monkey eyes, but not for the human eye due to ethical reasons. In the present study, the temperature elevation in the lens, the skin around the eye and the core temperature of numerical human and rabbit models for far-field and near-field exposures at 2.45 GHz are investigated. The temperature elevations in the human and rabbit models were compared with the threshold temperatures for inducing cataracts, thermal pain in the skin and reversible health effects such as heat exhaustion or heat stroke. For plane-wave exposure, the core temperature elevation is shown to be essential both in the human and in the rabbit models as suggested in the international guidelines and standards. For localised exposure of the human eye, the temperature elevation of the skin was essential, and the lens temperature did not reach its threshold for thermal pain. On the other hand, the lens temperature elevation was found to be dominant for the rabbit eye. PMID:23390146

  11. Recoil-range studies of heavy products of multinucleon transfer from /sup 18/O to /sup 245/Cm and /sup 249/Cf

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, R.M.

    1982-09-01

    Recoil range distributions were measured for alpha and spontaneous fission activities made in the bombardment of /sup 245/Cm and /sup 249/Cf with /sup 18/O from 6.20 MeV/nucleon down to the interaction barrier. The shape of the distributions indicates tht transfers of up to four protons take place via a combination of quasi-elastic (QET) and deep inelastic (DIT) mechanisms, rather than complete fusion-de-excitation (CF) or massive transfer (MT). Angular distributions constructed from recoil range distributions, assuming QET/DIT, indicate that the QET component contributes more significantly to the heavy product residue cross section than the DIT, even though primary cross sections are expected to be higher for DIT than for QET. This may be explained qualitatively as a result of the high excitation energies associated with DIT; the very negative Q/sub gg/ of projectile stripping for these systems combined with the lower expected optimal Q/sub rxn/ of QET compared to DIT can give QET products comparatively low excitation.

  12. Oxidative stress of brain and liver is increased by Wi-Fi (2.45GHz) exposure of rats during pregnancy and the development of newborns.

    Science.gov (United States)

    Çelik, Ömer; Kahya, Mehmet Cemal; Nazıroğlu, Mustafa

    2016-09-01

    An excessive production of reactive oxygen substances (ROS) and reduced antioxidant defence systems resulting from electromagnetic radiation (EMR) exposure may lead to oxidative brain and liver damage and degradation of membranes during pregnancy and development of rat pups. We aimed to investigate the effects of Wi-Fi-induced EMR on the brain and liver antioxidant redox systems in the rat during pregnancy and development. Sixteen pregnant rats and their 48 newborns were equally divided into control and EMR groups. The EMR groups were exposed to 2.45GHz EMR (1h/day for 5 days/week) from pregnancy to 3 weeks of age. Brain cortex and liver samples were taken from the newborns between the first and third weeks. In the EMR groups, lipid peroxidation levels in the brain and liver were increased following EMR exposure; however, the glutathione peroxidase (GSH-Px) activity, and vitamin A, vitamin E and β-carotene concentrations were decreased in the brain and liver. Glutathione (GSH) and vitamin C concentrations in the brain were also lower in the EMR groups than in the controls; however, their concentrations did not change in the liver. In conclusion, Wi-Fi-induced oxidative stress in the brain and liver of developing rats was the result of reduced GSH-Px, GSH and antioxidant vitamin concentrations. Moreover, the brain seemed to be more sensitive to oxidative injury compared to the liver in the development of newborns.

  13. The therapeutic effect of a pulsed electromagnetic field on the reproductive patterns of male Wistar rats exposed to a 2.45-GHz microwave field

    Directory of Open Access Journals (Sweden)

    Sanjay Kumar

    2011-01-01

    Full Text Available INTRODUCTION: Environmental exposure to man-made electromagnetic fields has been steadily increasing with the growing demand for electronic items that are operational at various frequencies. Testicular function is particularly susceptible to radiation emitted by electromagnetic fields. OBJECTIVES: This study aimed to examine the therapeutic effects of a pulsed electromagnetic field (100 Hz on the reproductive systems of male Wistar rats (70 days old. METHODS: The experiments were divided into five groups: microwave sham, microwave exposure (2.45 GHz, pulsed electromagnetic field sham, pulsed electromagnetic field (100 Hz exposure, and microwave/pulsed electromagnetic field exposure. The animals were exposed for 2 hours/day for 60 days. After exposure, the animals were sacrificed, their sperm was used for creatine and caspase assays, and their serum was used for melatonin and testosterone assays. RESULTS: The results showed significant increases in caspase and creatine kinase and significant decreases in testosterone and melatonin in the exposed groups. This finding emphasizes that reactive oxygen species (a potential inducer of cancer are the primary cause of DNA damage. However, pulsed electromagnetic field exposure relieves the effect of microwave exposure by inducing Faraday currents. CONCLUSIONS: Electromagnetic fields are recognized as hazards that affect testicular function by generating reactive oxygen species and reduce the bioavailability of androgen to maturing spermatozoa. Thus, microwave exposure adversely affects male fertility, whereas pulsed electromagnetic field therapy is a non-invasive, simple technique that can be used as a scavenger agent to combat oxidative stress.

  14. Effects of long-term pre- and post-natal exposure to 2.45 GHz wireless devices on developing male rat kidney.

    Science.gov (United States)

    Kuybulu, Ayça Esra; Öktem, Faruk; Çiriş, İbrahim Metin; Sutcu, Recep; Örmeci, Ahmet Rıfat; Çömlekçi, Selçuk; Uz, Efkan

    2016-05-01

    Purpose The aim of the present study was to investigate oxidative stress and apoptosis in kidney tissues of male Wistar rats that pre- and postnatally exposed to wireless electromagnetic field (EMF) with an internet frequency of 2.45 GHz for a long time. Methods The study was conducted in three groups of rats which were pre-natal, post-natal. and sham exposed groups. Oxidative stress markers and histological evaluation of kidney tissues were studied. Results Renal tissue malondialdehyde (MDA) and total oxidant (TOS) levels of pre-natal group were high and total antioxidant (TAS) and superoxide dismutase (SOD) levels were low. Spot urine NAG/creatinine ratio was significantly higher in pre- and post-natal groups (p Bcl-2 in cortical and medullar areas of pre-natal group (p values, 0.000, 0.002, 0.000, respectively) when compared with sham group. Bcl2/Bax staining intensity ratios of medullar and cortical area was higher in pre-natal group than sham group (p = 0.018, p = 0.011). Conclusion Based on this study, it is thought that chronic pre- and post-natal period exposure to wireless internet frequency of EMF may cause chronic kidney damages; staying away from EMF source in especially pregnancy and early childhood period may reduce negative effects of exposure on kidney. PMID:26905323

  15. Inter-beat intervals of cardiac-cell aggregates during exposure to 2.45 GHz CW, pulsed, and square-wave-modulated microwaves.

    Science.gov (United States)

    Seaman, R L; DeHaan, R L

    1993-01-01

    Inter-beat intervals of aggregated cardiac cells from chicken embryos were studied during 190 s exposures to 2.45 GHz microwaves in an open-ended coaxial device. Averaged specific-absorption rates (SARs) and modulation conditions were 1.2-86.9 W/kg continuous-wave (CW), 1.2-12.2 W/kg pulse modulation (PW, duty cycle approximately 11%), and 12.0-43.5 W/kg square-wave modulation (duty cycle = 50%). The inter-beat interval decreased during microwave exposures at 42.0 W/kg and higher when CW or square-wave modulation was used, which is consistent with established effects of elevated temperatures. However, increases in the inter-beat interval during CW exposures at 1.2-12.2 W/kg, and decreases in the inter-beat interval after PW exposures at 8.4-12.2 W/kg, are not consistent with simple thermal effects. Analysis of variance indicated that SAR, modulation, and the modulation-SAR interaction were all significant factors in altering the inter-beat interval. The latter two factors indicated that the cardiac cells were affected by athermal as well as thermal effects of microwave exposure.

  16. Dynamic simulation on thermal processes of flat-plate solar collector based on high temperature refrigerants R245fa%基于高温工质R245fa的太阳能平板集热器集热过程动态模拟

    Institute of Scientific and Technical Information of China (English)

    白景辉; 马良栋; 张吉礼

    2009-01-01

    提出了一种以R245fa为循环工质的气液分离双级太阳能集热系统.对第一级集热系统的集热过程进行了动态数值模拟.结果表明,系统的集热过程受太阳辐射强度的影响最大,受系统肩动温度的影响较小.当系统从环境温度启动达到工质蒸发状态时.减少循环工质的质量或增大集热面积均能有效地减少系统的运行时间,而增大系统集热面积是较佳方案.

  17. Erratum to "Solar Sources and Geospace Consequences of Interplanetary Magnetic Clouds Observed During Solar Cycle 23-Paper 1" [J. Atmos. Sol.-Terr. Phys. 70(2-4) (2008) 245-253

    Science.gov (United States)

    Gopalswamy, N.; Akiyama, S.; Yashiro, S.; Michalek, G.; Lepping, R. P.

    2009-01-01

    One of the figures (Fig. 4) in "Solar sources and geospace consequences of interplanetary magnetic Clouds observed during solar cycle 23 -- Paper 1" by Gopalswamy et al. (2008, JASTP, Vol. 70, Issues 2-4, February 2008, pp. 245-253) is incorrect because of a software error in t he routine that was used to make the plot. The source positions of various magnetic cloud (MC) types are therefore not plotted correctly.

  18. Alkyl hydroperoxide reductase has a role in oxidative stress resistance and in modulating changes in cell-surface properties in Azospirillum brasilense Sp245.

    Science.gov (United States)

    Wasim, Mariam; Bible, Amber N; Xie, Zhihong; Alexandre, Gladys

    2009-04-01

    An ahpC mutant derivative of Azospirillum brasilense Sp245 (strain SK586) that encodes an alkyl hydroperoxide reductase was found to be more sensitive to oxidative stress caused by organic hydroperoxides compared with the wild-type. In addition, the ahpC mutant strain had multiple defects in a large array of cellular functions that were consistent with alteration of cell-surface properties, such as cell morphology in stationary phase, Calcofluor White-, Congo Red- and lectin-binding abilities, as well as cell-to-cell aggregation and flocculation. All phenotypes of the ahpC mutant were complemented by in trans expression of AhpC, and overexpression of AhpC in the wild-type strain was found to affect the same set of phenotypes, suggesting that the pleiotropic effects were caused by the ahpC mutation. SK586 was also found to be fully motile, but it lost motility at a higher rate than the wild-type during growth, such that most SK586 cells were non-motile in stationary phase. Despite these defects, the mutant did not differ from the wild-type in short-term colonization of sterile wheat roots when inoculated alone, and in competition with the wild-type strain; this implied that AhpC activity may not endow the cells with a competitive advantage in colonization under these conditions. Although the exact function of AhpC in affecting these phenotypes remains to be determined, changes in cell morphology, surface properties, cell-to-cell aggregation and flocculation are common adaptive responses to various stresses in bacteria, and the data obtained here suggest that AhpC contributes to modulating such stress responses in A. brasilense.

  19. U-Pb Geochronology, Geochemistry and Kinematic Analyses of Subduction-Related Late Triassic Basins in Northern Chile (24.5º-26ºS).

    Science.gov (United States)

    Espinoza, M. E.

    2015-12-01

    In northern Chile (24.5°-26°S) two Pre-Andean depocenters crop out: the Cifuncho basin in the Coastal Cordillera and the Profeta basin in the Precordillera. These basins have been classically interpreted as a continental rifting unrelated to subduction during the period prior to the Andean orogenic cycle. However, recent petrographic and geochemical data suggest the development of these basins in an active subduction system. In order to test this hypothesis and to establish the geologic evolution of the basins and the strain field during the rifting process, we present preliminary U-Pb geochronological and geochemical data together with structural analyses of synrift structures. The geochronological data along the Cifuncho and Profeta basins, show a main continental sedimentary deposition during the Norian to Raethian. Volcanosedimentary rocks show a main detrital supply of Early Permian age (~297-283 Ma). This input can be associated with the volcanic La Tabla Formation and/or the exhumation of Permian granitoids. A minor supply close to ~478 Ma is related to a source from the Lower Ordovician arc (~480 Ma), suggesting the tectonic exhumation of this source to the east of the Profeta basin during the Late Triassic. On the other hand, structural analysis was carried in third and four order extensional faults (<10 m of slip) along the Profeta basin. Most of the faults show a clear synrift character with the development of fault controlled growing strata. The kinematic analyses evidence a variability in the orientation of the maximum strain axes from a main northwest to a subordinate northeast direction of extension. Thus, the intimate relation between the continental sedimentary deposition and a proximal volcanism of intermediate composition and calk-alkaline affinity, suggests the development of these basins in a supra-subduction setting during the Late Triassic. Structural data probably reflect local variation in the strain field across the basins.

  20. μ-ICC2.45在线微波浓度测量仪服务于沼气加工和污水污泥的处理%The Application of μ-ICC 2.45 On-line Microwave Concentration Measurement in the Processing of Biogas and Sewage Sludge

    Institute of Scientific and Technical Information of China (English)

    赵剑峰; K.-H.Theisen; M.Deutsch

    2012-01-01

    This article describes that the process of biogas and treatment of sewage,sludge was detected by the instrument of proMtec on-line microware concentration measurement.With its novel measurement means and unique structural design,the instrument was used to measure the on-line TS-content of materials which entering and discharging from the fermentation tank,this method could achieve the suitable material balance and maximal methane profits.The method also plays an important monitoring role in the whole process and would save energy and reduce emission.For comparison with the conventional measurement,μ-ICC 2.45 measuring system has more advantages,which will not be affected on the coating and storage,and the transmitter can be installed directly on the large pipeline or tank.%本文介绍proMtec在线实时微波浓度测量仪在沼气生产中对填料的浓度、污水污泥处理过程中对污泥浓度密度进行测量的应用。以其新颖的测量手段和独特的结构设计,对进入发酵罐物料和其卸料的在线TS-含量进行监控,以达到最理想的物料平衡,提高细菌的活性,使沼气收益最大化。在线式实时监控,有利于对生产过程的即时掌控,帮助实现节能减排。相比较传统测量方法,μ-ICC 2.45测量设备探头不受结垢、堵塞的影响,可直接安装于大口径的管路或是箱体上。

  1. CW/Pulsed H{sup −} ion beam generation with PKU Cs-free 2.45 GHz microwave driven ion source

    Energy Technology Data Exchange (ETDEWEB)

    Peng, S. X., E-mail: sxpeng@pku.edu.cn; Ren, H. T.; Xu, Y.; Zhang, T.; Zhang, J. F.; Zhao, J.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, People' s Republic of China (China); Zhang, A. L. [University of Chinese Academy of Sciences, Beijing 100049, People' s Republic of China (China); Chen, J. E. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871, People' s Republic of China (China); University of Chinese Academy of Sciences, Beijing 100049, People' s Republic of China (China)

    2015-04-08

    Circular accelerators used for positron emission tomography (PET, i.e. accelerator used for make radio isotopes) need several mA of CW H- ion beam for their routine operation. Other facilities, like Space Radio-Environment Simulate Assembly (SPRESA), require less than 10 mA pulsed mode H{sup −} beam. Caesium free negative hydrogen ion source is a good choice for those facilities because of its compact structure, easy operation and low cost. Up to now, there is no H{sup −} source able to produce very intense H{sup −} beams with important variation of the duty factor{sup [1]}. Recently, a new version of 2.45 GHz microwave H{sup −} ion source was designed at PKU, based on lessons learnt from the previous one. This non cesiated source is very compact thanks to its permanent magnet configuration. Special attention was paid on the design of the discharge chamber structure, electron dumping and extraction system. Source test to produce H{sup −} ion beams in pulsed and CW mode was carried out on PKU ion source test bench. In CW mode, a 10.8 mA/30keV H{sup −} beam with rms emittance about 0.16 π·mm·mrad has been obtained with only 500 W rf power. The power efficiency reaches 21 mA/kW. In pulsed mode with duty factor of 10% (100Hz/1ms), this compact source can easily deliver 20 mA H{sup −} ion beam at 35 keV with rms emittance about 0.2 π·mm·mrad when RF power is set at 2.2 kW (peak power). Several hour successive running operation in both modes and totaling more than 200 hours proves its high quality. The outside dimension of this new H{sup −} source body is ϕ116 mm × 124 mm, and the entire H{sup −} source infrastructure, including rf matching section, plasma chamber and extraction system, is ϕ310 × 180 mm. The high voltage region is limited with in a ϕ310 mm × 230 mm diagram. Details are given in this paper.

  2. Stable Isotope Geochemistry of Extremely Well-Preserved 2.45-Billion-Year-Old Hydrothermal Systems in the Vetreny Belt, Baltic Shield: Insights into Paleohydrosphere

    Science.gov (United States)

    Zakharov, D. O.; Bindeman, I. N.

    2015-12-01

    The early Paleoproterozoic was an eventful period in the Earth's history. The first portions of free oxygen emerged in the atmosphere, Snowball Earth glaciations happened several times and the first supercontinent broke up due to extensive rifting. These events should have affected the stable isotopic composition of the hydrosphere. In this study, we use rocks that were altered in underwater hydrothermal systems to investigate the stable isotopic composition of the hydrosphere 2.39-2.45 billion years ago (hereinafter, Ga). Extremely low-δ18O (down to -27.5‰ SMOW) rocks from 2.39 Ga metamorphosed subglacial hydrothermal systems of the Belomorian belt, Baltic Shield formed at near-equatorial latitudes suggesting a Snowball (or Slushball) Earth glaciation. These results motivated us to look at temporally and geographically close hydrothermal systems from the unmetamorhposed 2.45 Ga Vetreny Belt rift. The length of the rift is 250 km and it is composed of high-Mg basalts, mafic-ultramafic intrusions and sedimentary successions. We examined several localities of high-Mg basalt flows that include astonishingly fresh pillow lavas, often with preserved volcanic glass, eruptive breccias, and hydrothermal alteration zones. Collected samples serve a great textural evidence of water-rock interaction that occurred in situ while basalts were cooling. The preliminary results from coexisting quartz and epidote (T, D18O=311°C), and from coexisting calcite and quartz (T, D18O=190°C) yield values of δ18O of involved water between -1.6 and -0.9 ‰. The values of δ13C in calcites vary between -4.0 and -2.3 ‰. It is likely that hydrothermal fluids operated in the Vetreny Belt rift were derived from seawater that is no different from modern oceanic water in terms of δ18O. Apparently, the rift was a Paleoproterozoic analog of the modern Red Sea, filled with oceanic water. The result is important because the Vetreny Belt rift predates the onset of Snowball Earth glaciation at 2

  3. Magnetic-field-induced Strain and Energy Consumption of win-boundary Motion in Ni52Mn24.5Ga23.5 Single Crystal%Ni52Mn24.5Ga23.5单晶的磁感生应变及孪晶界移动的能量损耗

    Institute of Scientific and Technical Information of China (English)

    张健; 吴振兴; 李济林; 刘海定; 崔玉亭

    2010-01-01

    测量了不同温度下Ni52Mn24.5Ga23.5 单晶的磁感生应变.温度在280 K(略低于马氏体相变完成温度)时,测量得到的磁感生应变量高达-1.2%;随着温度的降低,磁感生应变量会迅速减小;在250 K的温度下,磁感生应变量仅为-0.37%,结果说明:铁磁形状记忆合金NiMnGa材料的磁感生应变具有明显的温度依赖性.此外,根据热力学理论,计算了在不同温度下,1个循环(升、降磁场)磁感生应变过程中孪晶界移动的能量损耗,结果表明:同种样品、不同温度下的磁感生应变量可定性地反映一个循环过程中孪晶界移动的能量损耗的大小.

  4. Bis(tetra­methyl­amonium) bis­(2,4,5-carboxy­benzoate)–benzene-1,2,4,5-tetra­carboxylic acid (1/1)

    OpenAIRE

    Girginova, Penka I.; Tito Trindade; João Rocha; Jacek Klinowski; Almeida Paz, Filipe A.; Luís Cunha-Silva

    2007-01-01

    The asymmetric unit of the title compound, 2C4H12N+·2C10H5O8−·C10H6O8, consists of a tetramethylamonium cation, an anion derived from the singly deprotonated pyromellitic acid anion, 2,4,5-carboxybenzoate (H3bta−), and one-half of a benzene-1,2,4,5-tetracarboxylic acid (H4bta) molecule, which has the centroid of the aromatic ring positioned at a crystallographic centre of inversion. The H4bta and H3bta− residues are involved in an extensive intermolecular O—H...

  5. ZrOC12·8H2O catalyzed one-pot synthesis of 2,4,5-triaryl-1H-imidazoles and substituted 1,4-di(4,5-diphenylimidazolyl)benzene

    Institute of Scientific and Technical Information of China (English)

    Jaiprakash N.Sangshetti; Nagnnath D.Kokare; Sandeep A.Kotharkar; Devanand B.Shinde

    2008-01-01

    A simple one-pot synthetic method for the preparation of 2,4,5-triaryl-lH-imidazoles from benzoin or benzil,ammonium acetate,aromatic aldehydes,and ZrOCl 2·8H 2O catalyst is described.The ZrOCl2-8H2O catalyst was found to be equally effective for aromatic and heteroaromatic aldehydes and also for the preparation of substituted 1,4-di(4,5-diphenylimidazol-yl) benzene.

  6. Measurement of the Neutron Capture Cross Sections of $^{233}$U, $^{237}$Np, $^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm with a Total Absorption Calorimeter at n_TOF

    CERN Multimedia

    Beer, H; Wiescher, M; Cox, J; Rapp, W; Embid, M; Dababneh, S

    2002-01-01

    Accurate and reliable neutron capture cross section data for actinides are necessary for the poper design, safety regulation and precise performance assessment of transmutation devices such as Fast Critical Reactors or Accelerator Driven Systems (ADS). The goal of this proposal is the measurement of the neutron capture cross sections of $^{233}$U, $^{237}$Np, $^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm at n_TOF with an accuracy of 5~\\%. $^{233}$U plays an essential role in the Th fuel cycle, which has been proposed as a safer and cleaner alternative to the U fuel cycle. The capture cross sections of $^{237}$Np,$^{240,242}$Pu, $^{241,243}$Am and $^{245}$Cm play a key role in the design and optimization of a strategy for the Nuclear Waste Transmutation. A high accuracy can be achieved at n_TOF in such measurements due to a combination of features unique in the world: high instantaneous neutron fluence and excellent energy resolution of the facility, innovative Data Acquisition System based on flash ADCs and t...

  7. Effect of herbicide concentration and organic and inorganic nutrient amendment on the mineralization of mecoprop, 2,4-D and 2,4,5-T in soil and aquifer samples

    International Nuclear Information System (INIS)

    The impact of the herbicide concentration (0.10-10 000 μg kg-1) and addition of organic and inorganic nutrients on mecoprop, 2,4-D and 2,4,5-T mineralization in aquifer and soil samples was studied in laboratory experiments. Generally, 2,4-D was most rapidly mineralized followed by mecoprop and 2,4,5-T. A shift from non-growth to growth-linked mineralization kinetics was observed in aquifer sediment with 2,4-D concentrations >0.10 μg kg-1 and mecoprop concentrations >10.0 μg kg-1. The shift was apparent at higher herbicide concentrations in soil coinciding with a lower bioavailable fraction and a higher herbicide sorption to soil. Herbicide addition did not affect the bacterial density, although 2,4-D and mecoprop applied at 10 000 μg kg-1 stimulated growth of specific degraders. Generally, nutrient amendments did not stimulate mineralization at the lowest herbicide concentrations. In contrast, the mineralization rate of higher herbicide concentrations was significantly stimulated by the amendment of inorganic nutrients. - Natural attenuation and biostimulation potential of a wide concentration range of three phenoxyalkanoic acid herbicides were evaluated in agricultural soil and aquifer sediment

  8. Low Noise Amplifier for 2.45 GHz Frequency Band at 0.18 μm CMOS Technology for IEEE Standard 802.11 b/g WLAN

    Directory of Open Access Journals (Sweden)

    Viranjay M. Srivastava

    2012-08-01

    Full Text Available This paper presents the design of low noise amplifier (LNA at 2.45 GHz and integrated at 0.18 µm RF CMOS process technology. This type of LNA at 2.45 GHz is use in the Bluetooth receiver. The proposed method is useful to optimize noise performance and power gain while maintaining good input and output matching. The amplifier is designed to be used as first stage of a receiver for wireless communication. The main aim of designer is to achieve low noise figure with improved gain with the help of CMOS technology by using single stage n-MOS amplifier. The simulation results show a forward gain of 14.0 dB, a noise-figure of 0.5 dB and stability factor is approximate unity, in which the circuit operates at 14.2 mA drain current with supply voltage of 3.5 V and biasing voltage of 1.5 V.

  9. Versatility of heme coordination demonstrated in a fungal peroxidase. Absorption and resonance Raman studies of Coprinus cinereus peroxidase and the Asp245-->Asn mutant at various pH values.

    Science.gov (United States)

    Smulevich, G; Neri, F; Marzocchi, M P; Welinder, K G

    1996-08-13

    The pH dependence of the electronic absorption and resonance Raman (RR) spectra of FeIII and FeII forms of Coprinus cinereus peroxidase (CIP) and its Asp245-->Asn (D245N) mutant has been examined in detail. The spectral data were obtained in the pH range 3.8-12.0. These spectra were used to assess the spin and ligation states of the heme via the porphyrin marker band frequencies and the wavelengths of the absorption maxima, especially that of the band (CT1) due to the charge transfer from the porphyrin to the heme iron via the a' 2u(pi)-->eg (d pi) electronic transition. The RR spectra were obtained by using different excitation wavelengths and polarized light. The data obtained for ferric CIP show that two pH-induced structural transitions exist. At acid pH the Soret and the CT1 absorption maxima occur at 394 and 652 nm, respectively, compared with the values of 403 and 649 nm observed at neutral pH. The electronic data indicate that at acid pH the proximal Fe-Im bond might be weakened or ruptured, and the RR spectra show a new species (5-c HS) different from the normal neutral 5-coordinate high-spin (5-c HS) heme. At pH 12.0, the protein converts to a 6-coordinate low-spin (6-c LS) heme with a hydroxyl ligand coordinated in the sixth position of the heme iron and strongly hydrogen-bonded with the positively charged guanidinium group of the distal Arg51 residue. Replacement of the aspartate carboxylate group of Asp245, which acts as hydrogen-bond acceptor to the proximal His183 ligand of the heme Fe, with a carboxamide group of an asparagine residue has a profound influence on the heme coordination. The RR spectra of the Fe(II) form of this mutant at both neutral and alkaline pH values show a band at 204 cm-1 assigned to the Fe-His stretch associated with a fairly weak or non-hydrogen-bonded imidazole. The ferric form of the mutant shows a great variability in coordination and spin states upon pH titration. Between pH 8.8 and 3.8 the spectra are mainly

  10. Estudo das malformações congênitas do aparelho urinário: análise de 6.245 necropsias pediátricas Study of urinary tract congenital malformations: analysis of 6,245 pediatric autopsies

    Directory of Open Access Journals (Sweden)

    Lucia de Noronha

    2003-09-01

    Full Text Available O presente estudo tece investigações sobre os aspectos epidemiológicos de malformações do aparelho urinário de uma população de natimortos, neomortos, lactentes, pré-escolares e escolares de uma amostra representativa da população de Curitiba e região metropolitana - análise de 40 anos de necropsias na Unidade de Patologia Pediátrica e Perinatal (UPPP do Serviço de Anatomia Patológica do Hospital de Clínicas de Curitiba da Universidade Federal do Paraná (UFPR. Variáveis como sexo, idade, faixa etária e causas de morte são correlacionadas, estratificando a amostra em grupos específicos de indivíduos, apontando anormalidades epidemiológicas, doenças raras e a relação das doenças com o processo de morte. Foram encontrados 182 casos com malformações do aparelho urinário, correspondendo a 2,9% do número de necropsias avaliadas. Não foram observadas diferenças entre os sexos, e houve maior prevalência de recém-natos com tais anormalidades. A classe mais prevalente foi a de malformações renais e de trato urinário superior, com 150 casos.The presented study investigates epidemiologic aspects regarding congenital malformations of the urinary tract in a representative sample of stillborns, newborns, infants and children from Curitiba, analising autopsies from the Pediatric and Perinatal Pathology Unit (Service of the Clinical Hospital - Curitiba, Paraná in a 40-year period. Sex, age groups and death causes are correlated, dividing the cases in specific groups of study, revealing epidemiologic abnormalities, rare diseases and diseases related to the death process. Out of 6,245 autopsies, 182 cases (2.9% presented urinary tract congenital malformations. There was no difference between sex, and the group of newborns was the most prevalent. The group of malformations of the kidney and upper urinary tract contributed with 150 abnormalities.

  11. The effect of Fe addition on the transformation temperatures, lattice parameter and magnetization saturation of Ni{sub 52.5-X}Mn{sub 23}Ga{sub 24.5}Fe{sub X} ferromagnetic shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Parra, D.E.; Alvarado-Hernandez, F.; Ayala, O.; Ochoa-Gamboa, R.A. [Centro de Investigacion en Materiales Avanzados S.C. Miguel de Cervantes 120, Complejo industrial Chihuahua, 31109 Chihuahua (Mexico); Flores-Zuniga, H. [Centro de Investigacion en Materiales Avanzados S.C. Miguel de Cervantes 120, Complejo industrial Chihuahua, 31109 Chihuahua (Mexico)], E-mail: horacio.flores@cimav.edu.mx; Rios-Jara, D. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, Col. Lomas 4a seccion, 78216 San Luis Potosi, S.L.P. (Mexico)

    2008-09-22

    The effect of Fe addition on martensitic transformation temperatures, Curie temperature (T{sub C}), lattice parameters and magnetization saturation was studied in Ni{sub 52.5-X}Mn{sub 23}Ga{sub 24.5}Fe{sub X} alloys fabricated by arc-melting furnace. The characterizations were performed by DSC, X-ray diffraction and magnetometry. Fe replacing Ni sites leads to an increment on lattice parameter and on the magnetization saturation of the austenitic phase at room temperature. Also, T{sub C} increases from 370 K up to 400 K and remains constant for X {>=} 3.1 at.% Fe. In contrast, martensitic transformation temperatures decrease with Fe substituting Ni.

  12. Analysis of the antibiotics susceptibility on 254 strains of Escherichia coli isolated from clinic%245例大肠埃希菌临床分离株药敏分析

    Institute of Scientific and Technical Information of China (English)

    胡景玉; 杜红丽; 乔艳梅; 郭连峰; 赵二强

    2012-01-01

    OBJECTIVE To understand the resistance characteristics of E. Coli in Hengshui, and to provide the basis for clinical treatment. METHODS Total 245 strains of E. Coli were collected from microbiology laboratory of Harrison International Peace Hospital (torn December, 2008 to June, 2011. Minimum inhibitory concentrations ( MICs) to 20 antibiotics of the isolates were determined by broth dilution method, and the values of MIC50 and MIC90 were calculated. RESULTS Imipenem, piperaciUin/tazobactam and cefoperazone/sulbactam showed a good antibacterial activity, and its MIC50 was 0.5μg/ml, 1μg/ ml, 0.5μg/ml, MIC90 was 2μg/ml, other drugs showed different degrees of resistance and E. Coli producing ESBLs in a higher detection rate. CONCLUSION E. Coli isolated in our hospital is multi-resistance but sensitive to imipenem, piperacillin/ tazobactam and cefoperazone/sulbactam.%目的 了解衡水地区大肠埃希菌的药敏情况,以更好的为临床用药提供依据.方法 收集了哈励逊国际和平医院微生物实验室2008年12月~2011年6月间所有送检大肠埃希菌株245例进行检测分析,采用肉汤稀释法测18种抗菌药物最低抑菌浓度(MIC)并计算其MIC50和MIC90.结果 亚胺培南、哌拉西林/他唑巴坦和头孢哌酮/舒巴坦显示良好的抗菌作用,其MIC50分别为0.5 μg/ml、1μg/ml、0.5 μg/ml; MIC90均为2 μg/ml,其他药物显示不同程度的耐药,且大肠埃希菌产ESBLs的检出率较高.结论 检出的大肠埃希菌存在多重耐药,仅对亚胺培南、哌拉西林/他唑巴坦和头孢哌酮/舒巴坦普遍敏感.

  13. 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)

  14. 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)

  15. Electric vehicle propulsion batteries: design and cost study for nickel/zinc battery manufacture. Task A. [25 kWh, 700 pounds, 245 Ah at 100+ V, 4. 77 ft/sup 3/

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    For satisfying the 25-kWh energy requirement necessary for vehicle propulsion, a 700-pound nickel--zinc battery was configured. Containing 64 individual cells, the unit was selected for minimum weight from computed packaging possibilities. Unit volume was projected to be 4.77 cubic feet. Capacity of the cells delivering 100+ volts was set at 245 ampere-hours. Selection was made primarily because of the compatibility with expressed vehicle requirements of a lower-current system. Manufacturing costs were computed for a unit using sintered positive electrodes at $86/kWh, pilot plant rate, and $78/kWh, production plant rate. Based on a lower than anticipated cost differential between sintered and nonsintered positive electrodes and certain other performance differences, the sintered electrode was chosen for the battery design. Capital expenditures for a production rate of 10,000 batteries per year are estimated to be $2,316,500. Capital expenditure for demonstrating production rates in a pilot plant facility is approximately $280,000, with the use of some shared available equipment. 29 figures, 9 tables.

  16. Analysis and comparison of microstrip antenna for 2.45GHz RFID applications%面向RFID应用的几种2.45GHz微带天线的分析比较

    Institute of Scientific and Technical Information of China (English)

    夏文祥; 胡永忠

    2011-01-01

    With the wide use of RFID, microstrip antenna has become the indispensable part in RFID, common microstrip antennas have single dipole and double dipole antennas. Based on the current application of RFID, some on-board antennas based on 2.45 GHz are put forward. The structures are analyzed combining with the the basic theory of antenna. This paper discusses the advantages and disadvantages of various microstrip antennas through the analysis of the simulation results which generated by using simulation software HFSS. It provides suggest for the application of RFID.%随着RFID的广泛应用,微带天线已经成为RFID中不可缺少的一部分,常见的微带天线有单偶极子和双偶极子天线。根据目前RFID的应用,提出了几种基于2.45GHz的板载天线,同时结合天线的基本理论对这几种结构进行了分析,并通过HFSS软件进行仿真比较。通过对仿真结果的分析,讨论了各种微带天线的优缺点,为RFID的应用提供了参考。

  17. Chinese Frost multidimensional perfectionism scale: a survey of perfectionism under different background in undergraduates%中文Frost多维完美主义量表对1 245名大学生测试结果分析

    Institute of Scientific and Technical Information of China (English)

    马珺; 冯泽永; 杨小丽

    2008-01-01

    目的 研究大学生在不同背景下完美主义心理的差别.方法 用中文Frost多维完美主义量表(Chinese Frost multidimensional perfectionism scale, CFMPS)对1 245 名大学生进行测试.结果 CFMPS的得分在是否独生子女(P=0.009)、成绩等级(P=0.008)和母亲文化程度(P=0.001)上有显著的统计学差异,在性别、年级、生源、家庭经济情况、是否担任学生干部等几个方面没有统计学差异(P>0 05).结论 完美主义既是一种稳定的人格特质,也因个体背景不同(如是否独生子女、成绩等级、母亲文化程度)而有所差异.

  18. Charged pion form factor between $Q^2$=0.60 and 2.45 GeV$^2$. I. Measurements of the cross section for the ${^1}$H($e,e'\\pi^+$)$n$ reaction.

    Energy Technology Data Exchange (ETDEWEB)

    Blok, Henk; Horn, Tanja; Huber, Garth; Beise, Elizabeth; Gaskell, David; Mack, David; Tadevosyan, Vardan; Volmer, Jochen; Abbott, David; Aniol, Konrad; Anklin, Heinz; Armstrong, Christopher; Arrington, John; Assamagan, Ketevi; Avery, Steven; Baker, O; Barrett, Robert; Bochna, Christopher; Boeglin, Werner; Brash, Edward; Breuer, Herbert; Chang, C; Chang, C C; Chant, Nicholas; Christy, Michael; Dunne, James; Eden, Thomas; Ent, Rolf; Fenker, Howard; Gibson, Edward; Gilman, Ronald; Gustafsson, Kenneth; Hinton, Wendy; Holt, Roy; Jackson, Harold; uk Jin, Seong; Jones, Mark; Keppel, Cynthia; Kim, pyunghun; Kim, Wooyoung; King, Paul; Klein, Andreas; Koltenuk, Douglas; Kovaltchouk, Vitali; Liang, Meihua; Liu, Jinghua; Lolos, George; Lung, Allison; Margaziotis, Demetrius; Markowitz, Pete; Matsumura, Akihiko; McKee, David; Meekins, David; Mitchell, Joseph; Miyoshi, Toshinobu; Mkrtchyan, Hamlet; Mueller, Robert; Niculescu, Gabriel; Niculescu, Maria-Ioana; Okayasu, Yuichi; Pentchev, Lubomir; Perdrisat, Charles; Pitz, David; Potterveld, David; Punjabi, Vina; Qin, Liming; Reimer, Paul; Reinhold, Joerg; Roche, Julie; Roos, Philip; Sarty, Adam; Shin, Ilkyoung; Smith, Gregory; Stepanyan, Stepan; Tang, Liguang; Tvaskis, Vladas; van der Meer, Rob; Vansyoc, Kelley; Van Westrum, Derek; Vidakovic, Sandra; Vulcan, William; Warren, Glen; Wood, Stephen; Xu, C; Yan, Chen; Zhao, Wenxia; Zheng, Xiaochao; Zihlmann, Benedikt

    2008-10-01

    DOI: http://dx.doi.org/10.1103/PhysRevC.78.045202
    Cross sections for the reaction 1H(e,e'pi+)n were measured in Hall C at Thomas Jefferson National Accelerator Facility (JLab) using the high-intensity Continuous Electron Beam Accelerator Facility (CEBAF) to determine the charged pion form factor. Data were taken for central four-momentum transfers ranging from Q2=0.60 to 2.45 GeV2 at an invariant mass of the virtual photon-nucleon system of W=1.95 and 2.22 GeV. The measured cross sections were separated into the four structure functions sigmaL,sigmaT,sigmaLT, and sigmaTT. The various parts of the experimental setup and the analysis steps are described in detail, including the calibrations and systematic studies, which were needed to obtain high-precision results. The different types of systematic uncertainties are also discussed. The results for the separated cross sections as a function of the Mandelstam variable t at the different values of Q2 are presented. Some global featu

  19. (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl and (enH2)MnAs(III)As(V)S6: two thioarsenates(III, V) with mixed-valent optical properties.

    Science.gov (United States)

    Du, Ke-Zhao; Feng, Mei-Ling; Qi, Xing-Hui; Ma, Zu-Ju; Li, Long-Hua; Li, Jian-Rong; Du, Cheng-Feng; Zou, Guo-Dong; Huang, Xiao-Ying

    2014-02-21

    Two mixed-valent thioarsenates, namely (enH2)(4.5)[In(As(V)S4)3][As2(III)(μ-S2)S3]Cl (1) and (enH2)MnAs(III)As(V)S6 (2) (en = ethylenediamine), have been solvothermally synthesized and characterized. Thermal stability, magnetic and mixed-valent optical properties, as well as theoretical band structures and DOSs, of 1 and 2 have also been studied.

  20. Preparation of americium targets for nuclear chemistry experiments at DANCE

    International Nuclear Information System (INIS)

    Using 1 gram of 241Am from LANL stocks, the purification steps required to obtain a solution of 241Am from the original material are described. Part of the purified solution was submitted for purity analysis by mass spectrometry, radiochemistry and trace metals analysis. The impurities were expected to be 239Pu and 237Np. A second fraction of this material was used for electroplating three samples onto titanium disks that were suitable for insertion into an instrument package to be placed into the DANCE detector. The purification methods used, the electroplating setup and the solutions to various problems that were encountered in making these targets are discussed. The analytical results are discussed as well as the yields from the electrodeposition process. Comparison of these yields with those from similar experiments utilizing 235U and 243Am are also discussed. (author)

  1. Americium separation from nuclear fuel dissolution using higher oxidation states.

    Energy Technology Data Exchange (ETDEWEB)

    Bruce J. Mincher

    2009-09-01

    Much of the complexity in current AFCI proposals is driven by the need to separate the minor actinides from the lanthanides. Partitioning and recycling Am, but not Cm, would allow for significant simplification because Am has redox chemistry that may be exploited while Cm does not. Here, we have explored methods based on higher oxidation states of Am (AmV and AmVI) to partition Am from the lanthanides. In a separate but related approach we have also initiated an investigation of the utility of TRUEX Am extraction from thiocyanate solution. The stripping of loaded TRUEX by Am oxidation or SCN- has not yet proved successful; however, the partitioning of inextractable AmV by TRUEX shows promise.

  2. Recovery of neptunium, plutonium, and americium from highly active waste

    International Nuclear Information System (INIS)

    Trialkylphosphine oxides (TRPO) (alkyl is 6c-C8) were chosen as the extractant for the recovery of Np, Pu, and Am from highly active waste (HAW) because of its extraction ability, excellent solvent behavior, high radiolytic stability, and low cost. Process chemistry based on 30 vol % TRPO-kerosene as solvent is presented. Extraction of Am in the presence of macro amounts of neodymium, adjustment of Np valence by electrolytic reduction, selective stripping of actinides from loaded organic phase, and loading capacity of the solvent are included. Process parameters of multistage countercurrent extraction and stripping and the results of experimental verification are given. From HAW with ∼1 M nitric acid concentration, recovery of actinides is higher than 99.9%. The actinides extracted can be stripped out separately into Am, Np-Pu, and U fractions. The behavior of nonactinide HAW constituents, including Tc, is discussed

  3. Property Data for Simulated Americium/Curium Glasses

    International Nuclear Information System (INIS)

    The authors studied the properties of mixed lanthanide-alumino-borosilicate glasses. Fifty-five glasses were designed to augment a previous, Phase I, study by systematically varying the composition of Ln2O3 and the concentrations of Ln2O3, SiO2, B2O3, Al2O3, and SrO in glass. These glasses were designed and fabricated at the Savannah River Technology Center and tested at the Pacific Northwest National Laboratory. The properties measured include the high-temperature viscosity (η) as a function of temperature (T) and the liquidus temperature (TL) of Phase II test glasses

  4. The vapour pressure of americium(III) chloride

    International Nuclear Information System (INIS)

    Based on the method described by Fischer, an ultramicro-size appratus was developed for static determination of the saturation vapour pressure of highly radioactive materials. The apparatus was tested with MgCl2, MnCl2, HoCl3 and ScF3. The vapour pressure curves of MgCl2 and MnCl2 were in good agreement with other publications and thus proved the efficiency of the apparatus in spite of its difficulties of handling. The values measured for HoCl3 and ScF3 differed from those of earlier publications. However, these deviations have been observed before and may be the result of the different measuring principles of static and dynamic methods. For AmCl3, the following vapour pressure equation was established: log psub(Torr)=-(11826/T)+10.7. The thermodynamic parameters of the evaporation process were calculated on this basis, and the values for AmBr3 and PnCl3 were determined by extrapolation. (orig.)

  5. 1976 Hanford americium-exposure incident: accident description

    International Nuclear Information System (INIS)

    An accident is described, involving the explosion of an ion-exchange column containing about 100 g of 241Am. A chemical operator was injured in this accident, receiving acid burns and superficial cuts on the upper part of his body. From 1 to 5 curies of 241Am is estimated to have been deposited on the injured worker and on his clothing

  6. 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...

  7. 50 CFR 665.245 - Gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... operating VMS unit certified by NMFS may enter Crustacean Permit Area 1 with lobster traps on board on or after June 25, but must remain outside the Crustacean Permit Area 1 VMS Subarea until the NWHI lobster... and has on board an operational VMS unit certified by NMFS may transit Crustacean Permit Area...

  8. 8 CFR 245a.1 - Definitions.

    Science.gov (United States)

    2010-01-01

    ... English language competency, and attainment of these skills is measured either by successful completion of... enroll foreign students under § 214.3 which establishes that the said school forwarded to the Service a..., services to pregnant women or children under 18 years of age, or treatment in the interest of public...

  9. A 24.5-Year Global Dataset of Direct Normal Irradiance: Result from the Application of a Global-to-Beam Model to the NASA GEWEX SRB Global Horizontal Irradiance

    Science.gov (United States)

    Zhang, T.; Stackhouse, P. W.; Chandler, W.; Hoell, J. M., Jr.; Westberg, D. J.

    2015-12-01

    The DIRINDEX model has previously been applied to the NASA GEWEX SRB Release 3.0 global horizontal irradiances (GHIs) to derive 3-hourly, daily and monthly mean direct normal irradiances (DNIs) for the period from 2000 to 2005 (http://dx.doi.org/10.1016/j.solener.2014.09.006), though the model was originally designed to estimate hourly DNIs from hourly GHIs. Input to the DIRINDEX model comprised 1.) the 3-hourly all-sky and clear-sky GHIs from the GEWEX SRB dataset; 2.) the surface pressure and the atmospheric column water vapor from the GEOS4 dataset; and 3.) daily mean aerosol optical depth at 700 nm derived from the daily mean aerosol data from the Model of Atmospheric Transport and CHemistry (MATCH). The GEWEX SRB data is spatially available on a quasi-equal-area global grid system consisting of 44016 boxes ranging from 1 degree latitude by 1 degree longitude around the Equator to 1 degree latitude by 120 degree longitude next to the poles. The derived DNIs were on the same grid system. Due to the limited availability of the MATCH aerosol data, the model was applied to the years from 2000 to 2005 only. The results were compared with ground-based measurements from 39 sites of the Baseline Surface Radiation Network (BSRN). The comparison statistics show that the results were in better agreement with their BSRN counterparts than the current Surface meteorology and Solar Energy (SSE) Release 6.0 data (https://eosweb.larc.nasa.gov/sse/). In this paper, we present results from the model over the entire time span of the GEWEX SRB Release 3.0 data (July 1983 to December2007) in which the MERRA atmospheric data were substituted for the GEOS4 data, and the Max-Planck Aerosol Climatology Version 1 (MAC-v1) data for the MATCH data. As a consequence, we derived a 24.5-year DNI dataset of global coverage continuous from July 1983 to December 2007. Comparisons with the BSRN data show that the results are comparable in quality with that from the earlier application.

  10. 欧盟荧光灯、高强度气体放电灯及配套镇流器与灯具生态设计要求法规解析%Interpretation & Analysis to EU Commission Regulation (EC) No 245/2009 on Ecodesign Requirements for Fluorescent Lamps without Integrated Ballast, for High Intensity Discharge Lamps,and for Ballasts and Luminaires Able to Operate Such Lamps

    Institute of Scientific and Technical Information of China (English)

    张俊斌

    2009-01-01

    欧盟为贯彻用能产品生态设计指令(EuP指令),已出台两个针对照明电器的法规.本文介绍了编号为(EC)No 245/2009法规的要求,解析了这些要求的用意.最后对两个法规的异同进行了小结和点评.

  11. 1-Methyl-2-[(E-2,4,5-trimethoxystyryl]pyridinium iodideThis paper is dedicated to the late His Majesty King Chulalongkorn (King Rama V of Thailand for his numerous reforms to modernize the country on the occasion of Chulalongkorn Day (Piyamaharaj Day which fell on the 23rd October.

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-12-01

    Full Text Available In the title compound, C17H20NO3+·I−, the cation exists in the E configuration. The pyridinium and benzene rings are close to coplanar, with a dihedral angle of 7.43 (12° between them. The three methoxy groups of 2,4,5-trimethoxyphenyl are essentially coplanar with the benzene plane, with C—O—C—C torsion angles of 1.0 (3, −1.9 (3 and 3.6 (3°. A weak intramolecular C—H...O interaction generates an S(6 ring motif. In the crystal, the cations are stacked in columns in an antiparallel manner along the a axis through π–π interactions, with a centroid–centroid distance of 3.7714 (16 Å. The iodide anion is situated between the columns and linked to the cation by a weak C—H...I interaction.

  12. A comparison of the biodistribution and biokinetics of {sup 99m}Tc-anti-CD66 mAb BW 250/183 and {sup 99m}Tc-anti-CD45 mAb YTH 24.5 with regard to suitability for myeloablative radioimmunotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Buchmann, Inga [Department of Nuclear Medicine, University Hospital, Ulm (Germany); Klinik und Poliklinik fuer Nuklearmedizin, Gebaeude 210, Johannes-Gutenberg-Universitaet Mainz, 55101, Mainz (Germany); Kull, Thomas; Glatting, Gerhard; Kotzerke, Jorg; Rattat, Dirk; Reske, Sven N. [Department of Nuclear Medicine, University Hospital, Ulm (Germany); Bunjes, Donald; Dohner, Hartmut [Department of Hematology, University Hospital, Ulm (Germany); Hale, Geoffrey [Sir William Dunn School of Pathology, Oxford (United Kingdom)

    2003-05-01

    Radioimmunotherapy (RIT) with radiolabelled monoclonal antibodies (mAbs) is an effective method of achieving myeloablation in leukaemia patients prior to stem cell transplantation (SCT). We wished to compare the approaches of specific binding to leukaemic blasts and non-specific binding to benign red marrow cells, which results in a myeloablative ''cross-fire'' effect. Therefore, we prospectively evaluated the biodistribution and biokinetics of the anti-CD45 mAb YTH 24.5 and the anti-CD66 mAb BW 250/183 with regard to their suitability for myeloablative RIT. The red marrow selective anti-CD66 mAb BW 250/183 (IgG1) binds to normal granulopoietic cells. In contrast, the anti-CD45 mAb YTH 24.5 (IgG2b) binds to 85-90% of acute leukaemic blasts and almost all haematopoietic white cells. Patients with leukaemic blast infiltration of the marrow <25% and assigned for RIT and SCT were included. Twelve patients (eight male, four female; median age 46{+-}7 years) with AML (5), CML (5) or ALL (2) were examined. Both mAbs were labelled with technetium-99m. Within 48 h, 906{+-}209 MBq {sup 99m}Tc-anti-CD66 mAb and 760{+-}331 MBq {sup 99m}Tc-anti-CD45 mAb were injected consecutively. Scintigraphic and urinary measurements were performed 1, 2, 4 and 24 h after injection. Serum activities were evaluated 2, 5, 10, 15, 30 and 60 min and 2, 4 and 24 h after injection. Compared with the anti-CD45 mAb, the anti-CD66 mAb showed an approximately fourfold higher accumulation in the red marrow, a 2.5-fold lower accumulation in the liver and similar accumulation in the kidneys. The serum activity (% of the injected dose) initially decreased faster for the anti-CD45 mAb but was similar for the two mAbs 24 h after injection: 3.3%{+-}1.2% (anti-CD66 mAb) and 2.4%{+-}1.1% (anti-CD45 mAb). The cumulated urinary excretion was 17%{+-}6.6% (anti-CD66 mAb) and 27.3%{+-}7.9% (anti-CD45 mAb) 24 h after application. In these patients with low tumour load, the anti-CD66 mAb BW 250

  13. 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)

    Experiments were performed to study the metabolism and distribution of intravenously administered 241Am in the adult and juvenile baboon; in addition, decorporation therapy using Na3-CaDTPA was performed on selected baboons to assess the efficacy of this drug in removing systemic burdens of 241Am from this primate species. Determination of the kinetics of 241Am was accomplished principally by in vivo methodologies and by radiochemical analysis of 241Am activity of biological material. The use of Na3-CaDTPA as a therapeutic agent for the removal of 241Am from the body proved to be an effective form of treatment in the case of early administration. (U.S.)

  14. 24 CFR 990.245 - Types of appeals.

    Science.gov (United States)

    2010-04-01

    ... taken aggressive marketing and outreach measures to rent these units. For example, a PHA could appeal if... may appeal its PEL if it can produce actual project cost data derived from actual asset management, as... specific local conditions. This appeal would be based on demonstrations that the model's predictions...

  15. 7 CFR 245.3 - Eligibility standards and criteria.

    Science.gov (United States)

    2010-01-01

    ... under the jurisdiction of the local educational agency, specify the uniform family-size income criteria... the National School Lunch or School Breakfast Programs and in commodity-only schools, and for determining eligibility for free milk when the School Food Authority has chosen to serve free milk in...

  16. 48 CFR 52.245-1 - Government Property.

    Science.gov (United States)

    2010-10-01

    ... otherwise, or the contract requires electronic submission of inventory disposal schedules, the Contractor... Contractor. Property records means the records created and maintained by the contractor in support of its... Management Regulation 102-71.20 (41 CFR 102-71.20). Sensitive property means property potentially...

  17. 48 CFR 1253.245-70 - Report of Government property.

    Science.gov (United States)

    2010-10-01

    ... following form is prescribed for use by contractors to report Government property, as specified in (TAR) 48 CFR 1245.505-1470: Form DOT F 4220.43, Contractor Report of Government Property. See 1245.505-1470... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Report of...

  18. 1935 15' Quad #245 Aerial Photo Mosaic Index

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Aerial Photo Reference Mosaics contain aerial photographs that are retrievable on a frame by frame basis. The inventory contains imagery from various sources that...

  19. 24 CFR 245.420 - Rights of tenants to participate.

    Science.gov (United States)

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT MORTGAGE AND LOAN INSURANCE PROGRAMS UNDER NATIONAL HOUSING ACT AND OTHER... representatives acting for tenants individually or as a group) must have the right to inspect and copy the... business hours. (b) The tenants have the right during this period to submit written comments on...

  20. Lophine (2,4,5-triphenyl-1H-imidazole

    Directory of Open Access Journals (Sweden)

    Diana Yanover

    2009-04-01

    Full Text Available The title compound, C21H16N2, has been known since 1877. Although the crystal structure of 36 derivatives of lophine are known, the structure of parent compound has remained unknown until now. The three phenyl rings bonded to the imidazole core are not coplanar with the latter, with dihedral angles of 21.4 (3, 24.7 (3, and 39.0 (3°, respectively, between the phenyl ring planes in the 2-, 4- and 5-positions of the imidazole ring. The molecules are packed in layers running perpendicular to the b axis. Although there are acceptor and donor atoms for hydrogen bonds, no such interactions are detected in the crystal in contrast to other lophine derivatives.

  1. 19 CFR 24.5 - Filing identification number.

    Science.gov (United States)

    2010-04-01

    ..., the Social Security number. (2) If neither an Internal Revenue Service employer identification number nor a Social Security number has been assigned, the word “None” shall be written on the line provided... Service employer identification number or a Social Security number, an importer identification...

  2. 32 CFR 245.21 - ESCAT air traffic priority list.

    Science.gov (United States)

    2010-07-01

    ... homeland security. (e) Priority Five. (1) Air transport of military commanders, their representatives, DoD...-3). (3) Military retaliatory aircraft, including direct tanker support aircraft, executing strategic.... military offensive and defensive operations including the use of activated Civil Reserve Air Fleet...

  3. 50 CFR 216.245 - Requirements for monitoring and reporting.

    Science.gov (United States)

    2010-10-01

    ... to categorize in any way, the observed behavior of the animals (such as animal closing to bow ride... explosive detonations. The Navy shall provide NMFS with species or description of the animal(s), the condition of the animal(s) (including carcass condition if the animal is dead), location, time of...

  4. 48 CFR 1552.245-70 - Government property.

    Science.gov (United States)

    2010-10-01

    ... Government. f. Lease versus purchase analysis shall be furnished with the request to acquire property on... classification listed on the EPA Property Report form, with the exception of material, the contractor shall provide the total acquisition cost and total quantity. If there are zero items in a classification, or...

  5. 8 CFR 245.10 - Adjustment of status upon payment of additional sum under section 245(i).

    Science.gov (United States)

    2010-01-01

    ... to the regulations of the Secretary of Labor, 20 CFR 656.21. (3) Approvable when filed means that, as... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Adjustment of status upon payment of... SECURITY IMMIGRATION REGULATIONS ADJUSTMENT OF STATUS TO THAT OF PERSON ADMITTED FOR PERMANENT...

  6. Americium-Curium Stabilization - 5'' Cylindrical Induction Melter System Design Basis

    Energy Technology Data Exchange (ETDEWEB)

    Witt, D.C.

    1999-11-08

    Approximately 11,000 liters (3,600) gallons of solution containing isotopes of Am and Cm are currently stored in F-Canyon Tank 17.1. These isotopes were recovered during plutonium-242 production campaigns in the mid- and late-1970s. Experimental work for the project began in 1995 by the Savannah River Technology Center (SRTC). Details of the process are given in the various sections of this document.

  7. Biosorption of radionuclide Americium-241 by A. niger spore and hyphae

    International Nuclear Information System (INIS)

    The biosorption of radionuclide 241Am from solution was studied by a. niger spore and hyphae, and the effects of the operational conditions on the treatment were investigated. The results showed the treatment by A. niger spore and hyphae were very efficient. An average of 96% of the total 241Am was removed from 241Am solutions of 5.6-111 MBq/L (C0), with adsorption capacities (W) of 7.2-142.4 MBq/g biomass, 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 h and the optimum pH value ranged 3-0.1 mol/L HNO3 and 3-2 for spore and hyphae of A. niger, respectively. No significant effects on 241Am biosorption were observed at 15 degree C-45 degree C, or challenged with containing Au3+ or Ag+, even 2000 times above 241Am amount. the index relationship between concentrations and adsorption capacities of 241Am indicated that the 241Am biosorption by A. niger spore and hyphae obey to Freundlich adsorption equation. The adsorption behavior of A. niger spore and hyphae were basically coincident

  8. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    Science.gov (United States)

    Sato, I.; Suto, M.; Miwa, S.; Hirosawa, T.; Koyama, S.

    2013-06-01

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10-4 min-1 and 1.60 × 10-4 min-1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure.

  9. Fabrication of uranium-americium mixed oxide fuels: thermodynamical modeling and materials properties

    International Nuclear Information System (INIS)

    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 U1-yAmyO2+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, U1-yAmyO2+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)

  10. Chemical behaviour of americium in natural aquatic solutions: Hydrolysis, radiolysis and redox reactions

    International Nuclear Information System (INIS)

    Hydrolysis and redox reactions of the Am(III) and Am(V) ions have been investigated in NaClO4 and NaCl solutions as well as in natural saline groundwaters. The hydrolysis constants of Am(OH)n3-n species and the solubility product of Am(OH)3(s) have been determined in 0.1 M NaClO4, 0.1 M NaCl and 0.6 M NaCl solutions. As observed in concentrated NaCl solutions (> 3 M), the α-radiation induces the radiolytic oxidation of the Cl--ion to produce Cl2, HClO, ClO- and other oxidized species, which result in a strongly oxidizing medium. Consequently Am(III) is oxidized to Am(V). Under these conditions the hydrolysis constants of AmO2(OH)n1-n species and the solubility product are also determined. The α-radiation induced radiolysis reactions in NaCl solution and the subsequent oxidation reaction of Am(III) have been systematically investigated by varying pH, NaCl concentration and specific α-activity. Also included in the investigation are a few selected groundwaters of relatively high salinity from the Gorleben aquifer systems. (orig.)

  11. Effect of solvent on in vitro dissolution: Summary of results for uranium, americium, and cobalt aerosols

    International Nuclear Information System (INIS)

    The revised 10 CFR Part 20 has adopted the ICRP Publication 30 method for calculating the committed effective dose equivalent from intakes of radionuclides. This dosimetry scheme requires knowledge or assumptions about the chemical form of the radionuclide, its particle size, and its known or assumed solubility. The solubility is classified as being either D (relatively soluble), W, or Y (relatively insoluble), depending on whether the material dissolves over periods of days, weeks, or years. Although Nuclear Regulatory Commission licensees may wish to take advantage of material-specific knowledge in order to adjust annual limits on intake and derived air concentrations, relatively few radioactive materials to which workers and the general population may be exposed have been adequately characterized either in terms of physicochemical form or solubility. Experimental measurement of solubility using some type of in vitro dissolution measurement system is therefore needed. However, there is currently no clear consensus regarding the appropriate design of in vitro dissolution systems, particularly when considering the range of different radionuclides to be studied, and the complexity of the biological mechanisms involved in the retention and clearance of inhaled deposited radioactive particles. The purpose of this study was to evaluate the effect of the several solvents on the dissolution of four test aerosols (57Co3O4, 241AmO2, ammonium diuranate [ADU], and U3O8) selected to encompass a variety of chemical and biochemical properties in vivo. The results of this study provide some guidance on the usefulness of in vitro dissolution tests for estimating the solubility of unknown radionuclide particles within the context of a simple model such as the class D, W, and Y formulation of ICRP 30

  12. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kazi, Zakir H. [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Cornett, Jack R., E-mail: jack.cornett@uottawa.ca [Department of Earth Science, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada); Zhao, Xaiolei; Kieser, Liam [Department of Physics, University of Ottawa, 140 Louis Pasteur Avenue, Ottawa K1N 6N5 (Canada)

    2014-06-01

    Highlights: • Am and Pu were adsorbed and separated using a single extraction chromatography DGA column. • Pu was eluted from the column completely using on-column reduction of Pu(IV) to Pu(III). • ²⁴¹Am and 239,240Pu measurements by accelerator mass spectrometry (AMS) agree with the certified values in two SRMs. Abstract: A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8 M HNO₃ with 0.05 M NaNO₂ before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO₃, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl₃ facilitated the complete desorption of Pu. Interferences (e.g. Ca²⁺, Fe³⁺) were washed off from the resin bed with excess HNO₃. Using NdF₃, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7 ± 5.3% and 95.5 ± 4.6% for ²⁴¹Am and ²⁴²Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1 ± 6.0 and 96.8 ± 5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1–100 Bq kg⁻¹. The single column separation of Pu and Am saves reagents, separation time, and cost.

  13. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht-Schmitt, Thomas Edward

    2013-09-14

    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.

  14. Separation of Americium from Fission Product Lanthanides Using Cyanex 301 Extraction

    Institute of Scientific and Technical Information of China (English)

    ZHU Yongjun; CHEN Jing

    2001-01-01

    The extraction behavior of bis (2,4,4-trimethylpentyl)dithiophosphinic acid (HBTMPDTP),purified from Cyanex 301,was studied for extracting Am3+ and trivalent lanthanides (Lns).HBTMPDTP shows very high selectivity for Am.Separation factor(SF)of Am and Eu,SF Am/Eu,(trace amount)reaches a high value of 5.9×103 and SF Am/(Pr+Nd) (macro amount)is about 2×103.The mathematical model for the distribution ratios and process parameters calculated for HBTMPDTP extraction was established and the calculated results were verified experimentally.In a five-stage countercurrent process,the extraction rates of Am and Lns were >99.999% and 0.14%,respectively,to fulfill the separation requirements.The efficiency of this process was also verified in a cross-flow extraction experiment using a genuine Am-FPLns fraction.In the presence of TBP,the extraction of Am and Eu is enhanced,but their separation is reduced to some extent.A fairly good separation was achieved in a fractional extraction process using a mixture of HBTMPDTP and TBP in kerosene at low pH.

  15. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    Science.gov (United States)

    Jandel, M.; Bredeweg, T. A.; Stoyer, M. A.; Wu, C. Y.; Fowler, M. M.; Becker, J. A.; Bond, E. M.; Couture, A.; Haight, R. C.; Haslett, R. J.; Henderson, R. A.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2009-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for 241Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for 243Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on 242mAm will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,γ) events from (n,f) events. The first direct observation of neutron capture on 242mAm in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  16. Plutonium and americium in air on the coasts of the Irish Sea

    International Nuclear Information System (INIS)

    Measurements of artificial radionuclides in air, deposition and seawater were carried out at coastal and inland locations in Cumbria, south-west Scotland, Northern Ireland and North Wales. The measurements were undertaken to determine the distribution of artificial radionuclides in the coastal environment attributable to discharges from Sellafield and to investigate the mechanisms responsible for the increased radionuclide concentration in the marine aerosol and their subsequent transfer to land. A number of different sampling methods were used and the contribution each method could make to the understanding of the marine aerosol was assessed. Measurements of the size distribution of the marine aerosol was also undertaken. The measurements demonstrated that the actinide concentrations measured in the air and deposition at coastal locations could be related to near shore sea water concentrations, but that no direct proportionality existed. It was also determined that a significant proportion of the material transferred from sea to land was associated with larger particulate present in the marine aerosol during conditions of above average onshore winds. (author)

  17. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Jandel, Marian [Los Alamos National Laboratory

    2008-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  18. Concordant plutonium-241-americium-241 dating of environmental samples: results from forest fire ash

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, Steven J [Los Alamos National Laboratory; Oldham, Warren J [Los Alamos National Laboratory; Murrell, Michael T [Los Alamos National Laboratory; Katzman, Danny [Los Alamos National Laboratory

    2010-12-07

    We have measured the Pu, {sup 237}Np, {sup 241}Am, and {sup 151}Sm isotopic systematics for a set of forest fire ash samples from various locations in the western U.S. including Montana, Wyoming, Idaho, and New Mexico. The goal of this study is to develop a concordant {sup 241}Pu (t{sub 1/2} = 14.4 y)-{sup 241}Am dating method for environmental collections. Environmental samples often contain mixtures of components including global fallout. There are a number of approaches for subtracting the global fallout component for such samples. One approach is to use {sup 242}/{sup 239}Pu as a normalizing isotope ratio in a three-isotope plot, where this ratio for the nonglobal fallout component can be estimated or assumed to be small. This study investigates a new, complementary method of normalization using the long-lived fission product, {sup 151}Sm (t{sub 1/2} = 90 y). We find that forest fire ash concentrates actinides and fission products with {approx}1E10 atoms {sup 239}Pu/g and {approx}1E8 atoms {sup 151}Sm/g, allowing us to measure these nuclides by mass spectrometric (MIC-TIMS) and radiometric (liquid scintillation counting) methods. The forest fire ash samples are characterized by a western U.S. regional isotopic signature representing varying mixtures of global fallout with a local component from atmospheric testing of nuclear weapons at the Nevada Test Site (NTS). Our results also show that {sup 151}Sm is well correlated with the Pu nuclides in the forest fire ash, suggesting that these nuclides have similar geochemical behavior in the environment. Results of this correlation indicate that the {sup 151}Sm/{sup 239}Pu atom ratio for global fallout is {approx}0.164, in agreement with an independent estimate of 0.165 based on {sup 137}Cs fission yields for atmospheric weapons tests at the NTS. {sup 241}Pu-{sup 241}Am dating of the non-global fallout component in the forest fire ash samples yield ages in the late 1950's-early 1960's, consistent with a peak in NTS weapons testing at that time. The age results for this component are in agreement using both {sup 242}Pu and {sup 151}Sm normalizations, although the errors for the {sup 151}Sm correction are currently larger due to the greater uncertainty of their measurements. Additional efforts to develop a concordant {sup 241}Pu-{sup 241}Am dating method for environmental collections are underway with emphasis on soil cores.

  19. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    International Nuclear Information System (INIS)

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for 241Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for 243Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on 242mAm will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,γ) from (n,f) events. The first evidence of neutron capture on 242mAm in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  20. Mean squared slowing-down distance and age of americium-beryllium neutrons in perspex

    International Nuclear Information System (INIS)

    THe mean squared slowing-down distance 2>, and the age to thermal capture (Migration Area), M2, are direct measures of the slowing.down, and the spreading out, processes of neutrons in a medium. They also enter directly into reactor calculations. These parameters have been determined experimentally for Am-Be neutrons (mean energy 4.46 MeV), in a block of perspex, using the activities induced in thin indium foils from the 115In(n,γ)116In reactions. (author) 13 refs.; 5 figs.; 2 tabs

  1. Americium-Curium Stabilization - 5'' Cylindrical Induction Melter System Design Basis

    International Nuclear Information System (INIS)

    Approximately 11,000 liters (3,600) gallons of solution containing isotopes of Am and Cm are currently stored in F-Canyon Tank 17.1. These isotopes were recovered during plutonium-242 production campaigns in the mid- and late-1970s. Experimental work for the project began in 1995 by the Savannah River Technology Center (SRTC). Details of the process are given in the various sections of this document

  2. Effect of solvent on in vitro dissolution: Summary of results for uranium, americium, and cobalt aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Hoover, M.D.

    1995-12-01

    The revised 10 CFR Part 20 has adopted the ICRP Publication 30 method for calculating the committed effective dose equivalent from intakes of radionuclides. This dosimetry scheme requires knowledge or assumptions about the chemical form of the radionuclide, its particle size, and its known or assumed solubility. The solubility is classified as being either D (relatively soluble), W, or Y (relatively insoluble), depending on whether the material dissolves over periods of days, weeks, or years. Although Nuclear Regulatory Commission licensees may wish to take advantage of material-specific knowledge in order to adjust annual limits on intake and derived air concentrations, relatively few radioactive materials to which workers and the general population may be exposed have been adequately characterized either in terms of physicochemical form or solubility. Experimental measurement of solubility using some type of in vitro dissolution measurement system is therefore needed. However, there is currently no clear consensus regarding the appropriate design of in vitro dissolution systems, particularly when considering the range of different radionuclides to be studied, and the complexity of the biological mechanisms involved in the retention and clearance of inhaled deposited radioactive particles. The purpose of this study was to evaluate the effect of the several solvents on the dissolution of four test aerosols ({sup 57}Co{sub 3}O{sub 4}, {sup 241}AmO{sub 2}, ammonium diuranate [ADU], and U{sub 3}O{sub 8}) selected to encompass a variety of chemical and biochemical properties in vivo. The results of this study provide some guidance on the usefulness of in vitro dissolution tests for estimating the solubility of unknown radionuclide particles within the context of a simple model such as the class D, W, and Y formulation of ICRP 30.

  3. Distribution of plutonium and americium in human and animal tissues after chronic exposures

    International Nuclear Information System (INIS)

    The distribution of plutonium in the tissues of a group of southern Finns was determined. Their Pu intake had been solely from fallout via inhalation. A group of northern Finns was also studied. They obtain most of the Pu from inhalation, but also some from their diet which is rich in reindeer liver. Reindeer obtain large amounts of transuranium elements in their natural winter diet, which mainly consists of lichen. Pu-239, 240 and Am-241 were also analyzed in elk because it is closely related to reindeer but does not feed on lichen. It was found that much of the Am-241 in reindeer tissues is due to ingrowth from Pu-241 in the animal. The aim of this study to establish whether this situation is also true for the human bone. (H.K.)

  4. Separation of americium(III) from lanthanides(III) by nanofiltration-complexation in aqueous medium

    International Nuclear Information System (INIS)

    The separation of Am(III) from a mixture of lanthanides(III) was performed in aqueous medium by nanofiltration combined with a complexation step using a DTPA derivative as selective complexing agent. (author)

  5. Optimization of TRPO Process Parameters for Americium Extraction from High Level Waste

    Institute of Scientific and Technical Information of China (English)

    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.1750 L/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.

  6. Functional sorbents for selective capture of plutonium, americium, uranium, and thorium in blood.

    Science.gov (United States)

    Yantasee, Wassana; Sangvanich, Thanapon; Creim, Jeffery A; Pattamakomsan, Kanda; Wiacek, Robert J; Fryxell, Glen E; Addleman, R Shane; Timchalk, Charles

    2010-09-01

    Self-assembled monolayer on mesoporous supports (SAMMS) are hybrid materials created from attachment of organic moieties onto very high surface area mesoporous silica. SAMMS with surface chemistries including three isomers of hydroxypyridinone, diphosphonic acid, acetamide phosphonic acid, glycinyl urea, and diethylenetriamine pentaacetate (DTPA) analog were evaluated for chelation of actinides ((239)Pu, (241)Am, uranium, thorium) from blood. Direct blood decorporation using sorbents does not have the toxicity or renal challenges associated with traditional chelation therapy and may have potential applications for critical exposure cases, reduction of nonspecific dose during actinide radiotherapy, and for sorbent hemoperfusion in renal insufficient patients, whose kidneys clear radionuclides at a very slow rate. Sorption affinity (K(d)), sorption rate, selectivity, and stability of SAMMS were measured in batch contact experiments. An isomer of hydroxypyridinone (3,4-HOPO) on SAMMS demonstrated the highest affinity for all four actinides from blood and plasma and greatly outperformed the DTPA analog on SAMMS and commercial resins. In batch contact, a fifty percent reduction of actinides in blood was achieved within minutes, and there was no evidence of protein fouling or material leaching in blood after 24 h. The engineered form of SAMMS (bead format) was further evaluated in a 100-fold scaled-down hemoperfusion device and showed no blood clotting after 2 h. A 0.2 g quantity of SAMMS could reduce 50 wt.% of 100 ppb uranium in 50 mL of plasma in 18 min and that of 500 dpm mL(-1) in 24 min. 3,4-HOPO-SAMMS has a long shelf-life in air and at room temperature for at least 8 y, indicating its feasibility for stockpiling in preparedness for an emergency. The excellent efficacy and stability of SAMMS materials in complex biological matrices suggest that SAMMS can also be used as orally administered drugs and for wound decontamination. By changing the organic groups of SAMMS, they can be used not only for actinides but also for other radionuclides. By using the mixture of these SAMMS materials, broad spectrum decorporation of radionuclides is very feasible.

  7. Sorption of americium in tuff and pure minerals using synthetic and natural groundwaters

    International Nuclear Information System (INIS)

    The distribution of Am between selected solid and liquid phases has been studied using initial 241Am solutions with a molarity smaller than 1 x 10-11. The synthetic and natural groundwaters used have pH values in the 7--8 range and a total alkalinity of approximately 1 mN which is mainly due to bicarbonate. Mass spectrometric isotope dilution was utilized to determine the amount of Am in the solution phase initially and after equilibrium was attained. Using this sensitive technique, 7 x 108 atoms of 241Am were accurately measured. Our results indicate that the percent of Am lost to the walls of the container in the absence of geologic material varies from 35 to 84. The Am sorption coefficient determined is on the order of 103 ml/g for clinoptilolite, 104 ml/g for tuff consisting mainly of alkali feldspar and cristobalite, and 105 ml/g for romanechite. 12 refs

  8. Americium-241 and plutonium-237 turnover in mussels ( Mytilus galloprovincialis) living in field enclosures

    Science.gov (United States)

    Guary, J. C.; Fowler, S. W.

    1981-02-01

    Loss of 241Am and 237Pu from contaminated mussels ( Mytilus galloprovincialis) living in situ in the Mediterranean Sea is described as the sum of three exponential functions. In the case of 241Am, two short-lived compartments representing a total of 80% of the incorporated radionuclide turned over rapidly with biological half-lives of 2 and 3 weeks. The remaining fraction of 241Am, associated with a long-lived compartment, was lost at an extremely slow rate ( Tb1/2=1·3 years). Plutonium-237 turnover in the two short-lived compartments (containing 70% of the Pu) was more rapid ( Tb1/2=1-2 days and 2 weeks) than that of 241Am; however, there was some indication that subsequent loss rates of the two radionuclides in long-lived compartments may be similar if determined over comparable periods of time. Loss rates of 241Am differed for the various tissues, with the most rapid rates occurring in gill, viscera and shell. Abrupt changes in loss observed in muscle and mantle suggested a translocation of 241Am to muscle and mantle during depuration. Whole shell contained by far the largest fraction (˜90%) of both 241Am and 237Pu taken up; in addition, these radionuclides are not irreversibly bound to mussel shell but readily leach into the water. These observations suggest that mollusc shell may influence the biogeochemistry of transuranic elements in littoral zones.

  9. New Synthetic Methods and Structure-Property Relationships in Neptunium, Plutonium, and Americium Borates. Final report

    International Nuclear Information System (INIS)

    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

  10. Combined procedure using radiochemical separation of plutonium, americium and uranium radionuclides for alpha-spectrometry

    International Nuclear Information System (INIS)

    Radiochemical separation of Pu, Am and U was tested from synthetic solutions and evaporator concentrate samples from nuclear power plants for isolation of each of them for alpha-spectrometry analysis. The separation was performed by anion-exchange chromatography, extraction chromatography, using TRU resin, and precipitation techniques. The aim of the study was to develop a sensitive analytical procedure for the sequential determination of 242Pu, 238Pu, 239+240Pu, 241Am and 235,238U in radioactive wastes. 238Pu, 242Pu, 243Am and 232U were used as tracers. The measurements of α emitting radionuclides were performed by semiconductor detector that is used especially when spectrometric information is needed. For synthetic solutions the chemical recovery was based on associated iron concentration and was about 93%. (author)

  11. Study on the uptake of Americium using PC88A - impregnated macroporous polymeric beads

    International Nuclear Information System (INIS)

    The prime objective of radioactive waste treatment in nuclear industry is to minimize the waste volume by efficient process without generating secondary radioactive waste for its final disposal. Among the currently available technologies, for separation and recovery of metal ions, solvent extraction, ion-exchange, membrane based technologies and solid sorbent materials are more popular means. Though, all these technologies play major role in all the bulk separation processes, their marked limitations force the separation scientists to think of advance, more efficient and technically feasible alternatives. The extractant impregnated polymeric beads (EIMPBs), impregnated with metal-specific extractants, exhibit reliable separation performances under column operation, and hence bridge the gap between solvent extraction and ion exchange techniques. In the present work, PC88A impregnated PES beads are prepared and the sorption of Am (III) from aqueous waste solutions is investigated. The synthesized EIMPBs were characterized by FTIR, TGA and SEM techniques. The physiochemical strength of the beads was found to be excellent. The sorption study of Am (III), using these beads, was carried out by batch equilibration method and the effect of various parameters, like pH, equilibration time, Am (III) concentration, etc., on the sorption process, was investigated. The synthesized polymeric beads presented fairly higher sorption capacity for Am (III) at pH 3. The kinetics of extraction is very fast. The saturation of sorption is achieved in about 60 minutes of equilibration. The sorption kinetics data fits well in the pseudo second-order model, indicating that the sorption is dominated by chemisorptions. The sorption of Am (III) is observed to follow Langmuir isotherm and the monolayer capacity was calculated as 2.498 mg/g. The quantitative stripping of the extracted Am (III) can be achieved by using 0.1M oxalic acid. The blank polymeric beads, without PC88A,have shown negligible sorption of Am (III) under the similar experimental conditions

  12. Americium and plutonium release behavior from irradiated mixed oxide fuel during heating

    International Nuclear Information System (INIS)

    The release behavior of Pu and Am was investigated under the reducing atmosphere expected in sodium cooled fast reactor severe accidents. Irradiated Pu and U mixed oxide fuels were heated at maximum temperatures of 2773 K and 3273 K. EPMA, γ-ray spectrometry and α-ray spectrometry for released and residual materials revealed that Pu and Am can be released more easily than U under the reducing atmosphere. The respective release rate coefficients for Pu and Am were obtained as 3.11 × 10−4 min−1 and 1.60 × 10−4 min−1 at 2773 K under the reducing atmosphere with oxygen partial pressure less than 0.02 Pa. Results of thermochemical calculations indicated that the main released chemical forms would likely be PuO for Pu and Am for Am under quite low oxygen partial pressure

  13. Kinetics of the oxidation-reduction reactions of uranium, neptunium, plutonium, and americium in aqueous solutions

    International Nuclear Information System (INIS)

    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.)

  14. Americium and plutonium separation by extraction chromatography for determination by accelerator mass spectrometry.

    Science.gov (United States)

    Kazi, Zakir H; Cornett, Jack R; Zhao, Xaiolei; Kieser, Liam

    2014-06-01

    A simple method was developed to separate Pu and Am using single column extraction chromatography employing N,N,N',N'-tetra-n-octyldiglycolamide (DGA) resin. Isotope dilution measurements of Am and Pu were performed using accelerator mass spectrometry (AMS) and alpha spectrometry. For maximum adsorption Pu was stabilized in the tetra valent oxidation state in 8M HNO3 with 0.05 M NaNO2 before loading the sample onto the resin. Am(III) was adsorbed also onto the resin from concentrated HNO3, and desorbed with 0.1 M HCl while keeping the Pu adsorbed. The on-column reduction of Pu(IV) to Pu(III) with 0.02 M TiCl3 facilitated the complete desorption of Pu. Interferences (e.g. Ca(2+), Fe(3+)) were washed off from the resin bed with excess HNO3. Using NdF3, micro-precipitates of the separated isotopes were prepared for analysis by both AMS and alpha spectrometry. The recovery was 97.7±5.3% and 95.5±4.6% for (241)Am and (242)Pu respectively in reagents without a matrix. The recoveries of the same isotopes were 99.1±6.0 and 96.8±5.3% respectively in garden soil. The robustness of the method was validated using certified reference materials (IAEA 384 and IAEA 385). The measurements agree with the certified values over a range of about 1-100 Bq kg(-1). The single column separation of Pu and Am saves reagents, separation time, and cost. PMID:24856406

  15. Rapid selective separation of americium/curium from simulated nuclear forensic matrices using triazine ligands

    International Nuclear Information System (INIS)

    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 CyMe4-BTPhen, CyMe4-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-1) and thus requires little pre-treatment of samples.

  16. 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.

  17. Subsurface Behavior of Plutonium and Americium at Non-Hanford Sites and Relevance to Hanford

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Riley, Robert G.

    2008-02-01

    Seven sites where Pu release to the environment has raised significant environmental concerns have been reviewed. A summary of the most significant hydrologic and geochemical features, contaminant release events and transport processes relevant to Pu migration at the seven sites is presented.

  18. Radiocaesium, plutonium and americium partitioning and solid speciation in sized, inter-tidal sediments from Strangford Lough

    International Nuclear Information System (INIS)

    Fine-grained surface (0-2 cm) sediment was collected at an inter-tidal site (Mahee Island) in Strangford Lough, on the NE coast of Ireland in September 1997. The sediment was wet-sieved into standard sized fractions using Endecott test sieves and the fractions assayed for 137Cs, 239,240Pu and 241Am content. Sub-samples of each fraction were measured with a Malvern 2600 laser diffraction analyser, which confirmed that >90% of the particles in each fraction was in the defined size range

  19. Speciation of plutonium and americium in the soils affected by Kraton-3 accidental underground nuclear explosion in Yakutia (Russia)

    International Nuclear Information System (INIS)

    In calcareous soils from Yakutia only 0.1 % or less 239Pu and 241Am exist in water-soluble form, i.e., the mobility of these radionuclides is relatively low. In the top humus-containing layer (0-4 cm) 239Pu and 241Am are distributed uniformly between organic and inorganic soil components. In the bottom soil layer (20-30 cm) the radionuclides are present mainly in inorganic soil components. The estimation of the radionuclide mobility demonstrates that 241Am is potentially a more mobile element than 239Pu. In the considered calcareous soils collected from the top layer 239Pu and 241Am exist both in humic and fulvic acids (FA). 241Am is much stronger bound to the group of mobile FA than 239Pu. In the bottom soil layer 239Pu and 241Am have been found mainly in FA. (author)

  20. LITERATURE REVIEW ON THE SORPTION OF PLUTONIUM, URANIUM, NEPTUNIUM, AMERICIUM AND TECHNETIUM TO CORROSION PRODUCTS ON WASTE TANK LINERS

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Kaplan, D.

    2012-02-29

    The Savannah River Site (SRS) has conducted performance assessment (PA) calculations to determine the risk associated with closing liquid waste tanks. The PA estimates the risk associated with a number of scenarios, making various assumptions. Throughout all of these scenarios, it is assumed that the carbon-steel tank liners holding the liquid waste do not sorb the radionuclides. Tank liners have been shown to form corrosion products, such as Fe-oxyhydroxides (Wiersma and Subramanian 2002). Many corrosion products, including Fe-oxyhydroxides, at the high pH values of tank effluent, take on a very strong negative charge. Given that many radionuclides may have net positive charges, either as free ions or complexed species, it is expected that many radionuclides will sorb to corrosion products associated with tank liners. The objective of this report was to conduct a literature review to investigate whether Pu, U, Np, Am and Tc would sorb to corrosion products on tank liners after they were filled with reducing grout (cementitious material containing slag to promote reducing conditions). The approach was to evaluate radionuclides sorption literature with iron oxyhydroxide phases, such as hematite ({alpha}-Fe{sub 2}O{sub 3}), magnetite (Fe{sub 3}O{sub 4}), goethite ({alpha}-FeOOH) and ferrihydrite (Fe{sub 2}O{sub 3} {center_dot} 0.5H{sub 2}O). The primary interest was the sorption behavior under tank closure conditions where the tanks will be filled with reducing cementitious materials. Because there were no laboratory studies conducted using site specific experimental conditions, (e.g., high pH and HLW tank aqueous and solid phase chemical conditions), it was necessary to extend the literature review to lower pH studies and noncementitious conditions. Consequently, this report relied on existing lower pH trends, existing geochemical modeling, and experimental spectroscopic evidence conducted at lower pH levels. The scope did not include evaluating the appropriateness of K{sub d} values for the Fe-oxyhydroxides, but instead to evaluate whether it is a conservative assumption to exclude this sorption process of radionuclides onto tank liner corrosion products in the PA model. This may identify another source for PA conservatism since the modeling did not consider any sorption by the tank liner.

  1. A Review of Subsurface Behavior of Plutonium and Americium at the 200-PW-1/3/6 Operable Units

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J.; Riley, Robert G.

    2008-01-31

    This report begins with a brief summary of the history and current status of 200-PW-1/3/6 OUs in section 2.0. This is followed by a description of our concentual model of Pu/Am migration at the 200-PW-1/3/6 OUs, during both past artificial recharge conditions and current natural recharge condictions (section 3.0). Section 4.0 discusses data gaps and information needs. The final section (section 5.0) provides recommendations for futher work to address the data gaps and information needs identified in section 4.0.

  2. Study of plutonium and americium contamination in agricultural area, radiological impact caused by consumption of vegetables of this area

    International Nuclear Information System (INIS)

    The transuranide concentration has been studied for 30 years in vegetable production, crops in wide extensions and in private-owned farms, all of them situated within the Pu-contaminated area of Palomares due to an air accident in 1966. Based on these studies, a preliminary estimation of the radiological risk caused by the consumption of these products by the inhabitants was possible. The results show that most of the fruits present a surface contamination, which disappears or is significantly reduced when they are washed. The contamination present in edible parts of the vegetables, as well as the contamination of other products included in the diet, has facilitated the estimation of the effective dose for ingestion and the committed effective dose for 50 years for the inhabitants. The main conclusions are: those plants, whose cultivation period is less than a year, present a low level of contamination; the green parts of the plants have a higher contamination than the fruits; the Pu soil to plant transfer factor is very low. In general, those plants that have remained in the contaminated land for several years present a high contamination level; the ingestion of products from Palomares does not represent an important risk for the population, even in the case that the products were totally consumed by a critical group.( author)

  3. The determination of alpha-emitting nuclides of plutonium, americium and curium in environmental materials: Pt. 1

    International Nuclear Information System (INIS)

    Within the Aquatic Environment Protection Division of the Directorate of Fisheries Research (DFR), the Radioanalytical Group routinely analyses a wide range of environmental materials for a substantial number of radionuclides. A wide variety of radiochemical procedures have been developed at different laboratories but there are no 'standard' methods because the methods are continually developing. Nevertheless, it is useful, as in this present series, periodically to draw together the methods which are in routine use at a laboratory and to discuss their development and application. (author)

  4. Studies on the binding and transport processes of americium-241 hydroxide polymers in rat lung and bovine alveolar macrophages

    International Nuclear Information System (INIS)

    The binding of Am-241 hydroxide polymers to the cell components of rat lung was investigated using differential centrifugation, density gradient centrifugation with different media, gel chromatography, free flow electrophoresis and electron microscopic autoradiography with Pu-241. The bovine alveolar macrophage cultures were introduced as an in vitro test system for Am-241 uptake. Form the biochemical and electron microscopic studies it can be concluded that Am-241 is taken up by pulmonary macrophages, where its first storage site is probably the lysosome. Then the Am-241 seems to be solubilized in the lysosomes and to be bound to the cytosolic ferritin of macrophages. Am-241 might be released from the cells and crosses the alveolar membranes as bound to transferrin or as low molecular weight form. (orig.)

  5. Oxidation-reduction properties of americium, curium, berkelium, californium, einsteinium and fermium, and thermodynamic consequences for the 5f series

    International Nuclear Information System (INIS)

    The amalgamation of 5f elements from Am to Fm has been studied by using 241Am, 244Cm, 249Bk, 249Cf, 252Cf, 253Es, 254Es, 252Fm and 255Fm with two electrochemical methods, radiocoulometry and radiopolarography, perfectly adapted to investigate extremely diluted solutions when the concentration of electroactive species is as low as 10-16M. The theory of radiocoulometry has been developed in the general cases of reversible and irreversible electrode process. It has been used to interpret the experimental data on the kinetic curves of amalgamation, and to estimate the standard rate constant of the electrode process in complexing medium (citric). On the other hand the radiopolarographic method has been applied to study the mechanism of reduction at the dropping mercury electrode of cations M3+ in aqueous medium to the metal M with formation of amalgam. The results are exploited into two directions: 1- Acquisition of some data concerning the oxidation-reduction properties of elements from Am to Fm. Therefore the standard electrode E0 [M(III-0)] potentials for Bk, Cf and Es, and the standard electrode E0 [M(II-0)] potential for Fm are estimated and the relative stability of each oxidation state (from II to VII) of 5f elements is discussed; 2- Acquisition of unknown thermodynamic data on transcalifornium elements. Correlations between 4f and 5f elements are precised and some divergences appear for the second half of 4f and 5f series (i.e. for 65<=Z<=71 and 97<=Z<=103)

  6. Effects of americium-241 and humic substances on Photobacterium phosphoreum: Bioluminescence and diffuse reflectance FTIR spectroscopic studies

    Science.gov (United States)

    Kamnev, Alexander A.; Tugarova, Anna V.; Selivanova, Maria A.; Tarantilis, Petros A.; Polissiou, Moschos G.; Kudryasheva, Nadezhda S.

    The integral bioluminescence (BL) intensity of live Photobacterium phosphoreum cells (strain 1883 IBSO), sampled at the stationary growth stage (20 h), was monitored for further 300 h in the absence (control) and presence of 241Am (an α-emitting radionuclide of a high specific activity) in the growth medium. The activity concentration of 241Am was 2 kBq l-1; [241Am] = 6.5 × 10-11 M. Parallel experiments were also performed with water-soluble humic substances (HS, 2.5 mg l-1; containing over 70% potassium humate) added to the culture medium as a possible detoxifying agent. The BL spectra of all the bacterial samples were very similar (λmax = 481 ± 3 nm; FWHM = 83 ± 3 nm) showing that 241Am (also with HS) influenced the bacterial BL system at stages prior to the formation of electronically excited states. The HS added per se virtually did not influence the integral BL intensity. In the presence of 241Am, BL was initially activated but inhibited after 180 h, while the system 241Am + HS showed an effective activation of BL up to 300 h which slowly decreased with time. Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, applied to dry cell biomass sampled at the stationary growth phase, was used to control possible metabolic responses of the bacteria to the α-radioactivity stress (observed earlier for other bacteria under other stresses). The DRIFT spectra were all very similar showing a low content of intracellular poly-3-hydroxybutyrate (at the level of a few percent of dry biomass) and no or negligible spectroscopic changes in the presence of 241Am and/or HS. This assumes the α-radioactivity effect to be transmitted by live cells mainly to the bacterial BL enzyme system, with negligible structural or compositional changes in cellular macrocomponents at the stationary growth phase.

  7. UNDERSTANDING VARIATION IN PARTITION COEFFICIENT KD, VALUES, VOLUME III: AMERICIUM, ARSENIC, CURIUM, IODINE, NEPTUNIUM, RADIUM, AND TECHNETIUM

    Science.gov (United States)

    This report describes the conceptualization, measurement, and use of the partition (or distribution) coefficient, Kd, parameter, and the geochemical aqueous solution and sorbent properties that are most important in controlling adsorption/retardation behavior of selected contamin...

  8. Evaluation of synthetic water-soluble metal-binding polymers with ultrafiltration for selective concentration of americium and plutonium

    International Nuclear Information System (INIS)

    Water-soluble metal-binding polymers in combination with ultrafiltration are shown to be an effective method for selectively removing dilute actinide ions from acidic solutions of high ionic strength. The actinide-binding properties of commercially available water-soluble polymers and several polymers which have been reported in the literature were evaluated. The functional groups incorporated in the polymers were pyrrolidone, amine, oxime, and carboxylic, phosphonic, or sulfonic acid. The polymer containing phosphonic acid groups gave the best results with high distribution coefficients and concentration factors for 241Am(III) and 238Pu(III)/(IV) at pH 4 to 6 and ionic strengths of 0.1 to 4. (author)

  9. Salicylic acid failed to increase the efficacy of Ca-DTPA in the decorporation of plutonium and americium

    International Nuclear Information System (INIS)

    Male and female C57BL/Do mice were each given a single i.p. injection of 237+239Pu + 241Am as the citrate complex at 45 days of age. Twice weekly i.p. injecctions of either 500 μmol/kg Ca-DTPA or 500 μmol/kg Ca-DTPA, mixed just before injection with 2000 μmol/kg salicylic acid (SA), were begun 3 days after nuclide administration and continued for 5 weeks. Control mice were injected each time with isotonic saline. Nuclide retention was determined by in vivo counting using NaI(T1) spectrometry. At the end of treatment, total-body retention of Pu or Am in the mice given Ca-DTPA was significantly lower (P < 0.001) than in the control animals. Mice treated with Ca-DTPA + SA were statistically indistinguishable from mice treated with Ca-DTPA

  10. Salicylic acid failed to increase the efficacy of Ca-DTPA in the decorporation of plutonium and americium

    International Nuclear Information System (INIS)

    Male and female C57BL/Do mice were each given a single ip injection of /sup 237 + 239/Pu + 241Am as the citrate complex at 45 days of age. Twice-weekly ip injections of either 500 μmole/kg Ca-DTPA or 500 μmole/kg Ca-DTPA mixed just before injection with 2000 μmole/kg salicylic acid (SA) were begun 3 days after nuclide administration and continued for 5 weeks. Control mice were injected each time with isotonic saline. Nuclide retention was determined by in vivo γ-ray counting using a NaI(Tl) crystal spectrometer. At the end of treatment, total-body retention of Pu or Am in the mice given Ca-DTPA was significantly lower (P < 0.001) than that in the control animals. Mice treated with Ca-DTPA plus SA were statistically indistinguishable from mice treated with Ca-DTPA alone

  11. Handling of a glove box accident. Surgical treatment of a wound contaminated by a mixture of plutonium-239 and americium

    International Nuclear Information System (INIS)

    An employee of the Valduc Centre (France) suffered an injury to his right thumb when working in a glove-box on a pipeline which had contained a solution of 239Pu and Am. The lesion was slight but attempts at decontamination were fruitless. The contamination was deep-seated (activity of not less than 18nCi). DTPA was injected intravenously, and it was decided to excise the lesion surgically. Thanks to the quality of its physical facilities and the professional quality of its radiation medicine and surgery team, the Valduc Centre was able to carry out the operation successfully. The result was excellent, and the contamination was eliminated to the satisfaction of both the patient and the physician. (author)

  12. Effects of Hanford high-level waste components on the solubility and sorption of cobalt, strontium, neptunium, plutonium, and americium

    International Nuclear Information System (INIS)

    High-level radioactive defense waste solutions, originating from plutonium recovery and waste processing operations at the U.S. Department of Energy's Hanford Site, currently are stored in mild steel-lined concrete tanks located in thick sedimentary beds of sand and gravel. Statistically designed experiments were used to identify the effects of 12 major chemical components of Hanford waste solution on radionuclide solubility and sorption. The chemical components with the most effect on radioelement solubility and sorption were NaOH, NaAl0/sub 2/, EDTA, and HEDTA. The EDTA and HEDTA increased Co, Sr, and Am solubility and decreased sorption for almost all radioelements studied. Sodium hydroxide and NaAlO/sub 2/ increased Pu solubility and decreased Np and Pu sorption. Sodium nitride decreased Np solubility, while Na/sub 2/CO/sub 3/ and HEDTA increased it. These observations give evidence for the formation of radioelement complexes which are soluble and are not strongly sorbed by the sediments near the waste tanks

  13. Metal chloride hydrates as Lewis acid catalysts in multicomponent synthesis of 2,4,5-triarylimidazoles or 2,4,5-triaryloxazoles

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Marcelo V. [Departamento de Engenharia de Processos, Fundacao de Ciencia e Tecnologia, Cachoeirinha, RS (Brazil); Russowsky, Dennis, E-mail: dennis@iq.ufrgs.br [Laboratorio de Sinteses Organicas, Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Porto Alegre-RS (Brazil); Ruthner, Marcelo M.; Fontoura, Luiz A.M. [Curso de Quimica, Universidade Luterana do Brasil, Canoas, RS (Brazil)

    2012-07-01

    A series of nine metal chloride hydrates (ZnCl{sub 2}.2H{sub 2}O, SnCl{sub 2}.2H{sub 2}O, CdCl{sub 2}.2H{sub 2}O, MnCl{sub 2}.4H{sub 2}O, CoCl{sub 2}.6H{sub 2}O, SrCl{sub 2}.6H{sub 2}O, NiCl{sub 2}.6H{sub 2}O, CrCl{sub 3}.6H{sub 2}O and CeCl{sub 3}.7H{sub 2}O) was investigated as mild and inexpensive Lewis acid catalysts to promote the multicomponent synthesis of triarylimidazoles. Reactions starting from benzil showed the best results when SnCl{sub 2}.2H{sub 2}O was used, while for benzoin as the starting material, CeCl{sub 3}.7H{sub 2}O was more efficient. All reactions were performed in EtOH as solvent. These catalysts were also successfully employed in the synthesis of triaryloxazoles. (author)

  14. 47 CFR 24.245 - Reimbursement under the Cost-Sharing Plan.

    Science.gov (United States)

    2010-10-01

    ... SERVICES PERSONAL COMMUNICATIONS SERVICES Broadband PCS Policies Governing Microwave Relocation from the... reimbursement cap as defined in § 24.243(b). Such reimbursement will not be subject to depreciation under...

  15. 25 CFR 700.245 - Time limits on processing of initial requests.

    Science.gov (United States)

    2010-04-01

    ... public holidays) after receipt of a request. This determination shall be communicated immediately to the..., but in no case may the time limit be extended for more than ten (10) working days: (1) The need to... of the running of the twenty (20) working-day appeal period set out in § 700.247. If a...

  16. Flow boiling of R245fa in vertical small metallic tubes

    OpenAIRE

    Pike-Wilson, Emily Alexandra

    2014-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University London The research presented is part of a larger study, dedicated to investigating flow boiling in small to microchannels. The test facility, originally designed by Huo (2005) and since used by Chen (2006) and Mahmoud (2011), has been used to investigate flow boiling of R134a across a range of channel diameters and both seamless cold drawn and welded channels. These previous studies concluded...

  17. Multicellular algae from lower Proterozoic (2.45 Ga) weathering crusts of the Kola Peninsula

    Science.gov (United States)

    Astafieva, Marina M.; Rozanov, Alexei Y.; Hoover, Richard B.

    2011-10-01

    Microbiological analysis of several cold-preserved tissue samples from the Siberian baby mammoth known as Lyuba revealed a number of culturable bacterial strains that were grown on anaerobic media at 3 oC. Lactic acid produced by LAB (lactic acid bacteria) group, usually by members of the genera Carnobacterium and Lactosphera, appears to be a wonderful preservative that keeps other bacteria from colonizing a system. Permafrost and lactic acid preserved the body of this one month-old baby mammoth and kept it in exceptionally good condition, resulting in this mammoth being the most complete sample of the species ever recovered. The diversity of novel psychrophilic anaerobic isolates was expressed on morphological, physiological and phylogenetic levels. Here, we discuss the specifics of the isolation of new psychrophilic strains, differentiation from trivial contamination, and preliminary results for characterization of the cultures

  18. 17 CFR 245.102 - Exceptions to definition of blackout period.

    Science.gov (United States)

    2010-04-01

    ... corporate merger, acquisition, divestiture or similar transaction involving the plan or plan sponsor, the... able to participate in the same class of equity securities after the merger, acquisition,...

  19. 17 CFR 245.101 - Prohibition of insider trading during pension fund blackout periods.

    Science.gov (United States)

    2010-04-01

    ... equity securities in connection with a merger, acquisition, divestiture or similar transaction occurring... from section 306(a)(1) of the Sarbanes-Oxley Act of 2002: (1) Any acquisition of equity securities... acquisition is made pursuant to a plan providing for the regular reinvestment of dividends or interest and...

  20. 7 CFR 245.5 - Public announcement of the eligibility criteria.

    Science.gov (United States)

    2010-01-01

    ...), or a school which includes food service fees in its tuition, where all attending children are provided the same meals or milk. Such announcements shall be made at the beginning of each school year or...), a letter or notice and application distributed on or about the beginning of each school year, to...